* [PATCH v2 0/4] Introduce the Counter character device interface
@ 2020-05-16 19:19 ` William Breathitt Gray
0 siblings, 0 replies; 38+ messages in thread
From: William Breathitt Gray @ 2020-05-16 19:19 UTC (permalink / raw)
To: jic23
Cc: kamel.bouhara, gwendal, alexandre.belloni, david, linux-iio,
linux-kernel, linux-stm32, linux-arm-kernel, syednwaris,
patrick.havelange, fabrice.gasnier, mcoquelin.stm32,
alexandre.torgue, William Breathitt Gray
Changes in v2:
- Use fixed-width data types to represent Counter data types
- Use union of function prototypes to store read/write callbacks
- Eliminate the counter-strings and counter-sysfs-callback files by
inlining relevant code
- Reimplement chrdev code to handle read/write calls instead of ioctl
- Remove struct counter_enum (I'm postponing this development until I
get the core functionality solid)
- Remove devm_counter_unregister as unnecessary
Over the past couple years we have noticed some shortcomings with the
Counter sysfs interface. Although useful in the majority of situations,
there are certain use-cases where interacting through sysfs attributes
can become cumbersome and inefficient. A desire to support more advanced
functionality such as timestamps, multi-axis positioning tables, and
other such latency-sensitive applications, has motivated a reevaluation
of the Counter subsystem. I believe a character device interface will be
helpful for this more niche area of counter device use.
To quell any concerns from the offset: this patchset makes no changes to
the existing Counter sysfs userspace interface -- existing userspace
applications will continue to work with no modifications necessary. I
request that driver maintainers please test their applications to verify
that this is true, and report any discrepancies if they arise.
However, this patchset does contain a major reimplementation of the
Counter subsystem core and driver API. A reimplementation was necessary
in order to separate the sysfs code from the counter device drivers and
internalize it as a dedicated component of the core Counter subsystem
module. A minor benefit from all of this is that the sysfs interface is
now ensured a certain amount of consistency because the translation is
performed outside of individual counter device drivers.
Essentially, the reimplementation has enabled counter device drivers to
pass and handle data as native C datatypes now rather than the sysfs
strings from before. A high-level view of how a count value is passed
down from a counter device driver can be exemplified by the following:
----------------------
/ Counter device \
+----------------------+
| Count register: 0x28 |
+----------------------+
|
-----------------
/ raw count data /
-----------------
|
V
+----------------------------+
| Counter device driver |----------+
+----------------------------+ |
| Processes data from device | -------------------
|----------------------------| / driver callbacks /
| Type: u64 | -------------------
| Value: 42 | |
+----------------------------+ |
| |
---------- |
/ u64 / |
---------- |
| |
| V
| +----------------------+
| | Counter core |
| +----------------------+
| | Routes device driver |
| | callbacks to the |
| | userspace interfaces |
| +----------------------+
| |
| -------------------
| / driver callbacks /
| -------------------
| |
+-------+---------------+ |
| | |
| +-------|-------+
| | |
V | V
+--------------------+ | +---------------------+
| Counter sysfs |<-+->| Counter chrdev |
+--------------------+ +---------------------+
| Translates to the | | Translates to the |
| standard Counter | | standard Counter |
| sysfs output | | character device |
|--------------------| |---------------------+
| Type: const char * | | Type: u64 |
| Value: "42" | | Value: 42 |
+--------------------+ +---------------------+
| |
--------------- ----------
/ const char * / / u64 /
--------------- ----------
| |
| V
| +-----------+
| | read |
| +-----------+
| \ Count: 42 /
| -----------
|
V
+--------------------------------------------------+
| `/sys/bus/counter/devices/counterX/countY/count` |
+--------------------------------------------------+
\ Count: "42" /
--------------------------------------------------
I am aware that an in-kernel API can simplify the data transfer between
counter device drivers and the userspace interfaces, but I want to
postpone that development until after the new Counter character device
interface is solidified. A userspace ABI is effectively immutable so I
want to make sure we get that right before working on an in-kernel API
that is more flexible to change. However, when we do develop an
in-kernel API, it will likely be housed as part of the Counter core
component, through which the userspace interfaces will then communicate.
Interaction with Counter character devices occurs via standard character
device read/write operations. This allows userspace applications to
access and set counter data using native C datatypes rather than working
through string translations.
The following are some questions I have about this patchset:
1. Should the data format of the character device be configured via a
sysfs attribute?
In this patchset, the first 196095 bytes of the character device are
dedicated as a selection area to choose which Counter components or
extensions should be exposed; the subsequent bytes are the actual
data for the Counter components and extensions that were selected.
Moving this selection to a sysfs attribute and dedicating the
character device to just data transfer might be a better design. If
such a design is chosen, should the selection attribute be
human-readable or binary?
2. How much space should allotted for strings?
Each Counter component and extension has a respective size allotted
for its data (u8 data is allotted 1 byte, u64 data is allotted 8
bytes, etc.); I have arbitrarily chosen to allot 64 bytes for
strings. Is this an apt size, or should string data be allotted more
or less space?
3. Should the owning component of an extension be handled by the device
driver or Counter subsystem?
The Counter subsystem figures out the owner (enum counter_owner_type)
for each component/extension in the counter-sysfs and counter-chrdev
code. When a callback must be executed, there are various switch
statements throughout the code to check whether the respective
Device, Signal, or Count version of the callback should be executed;
similarly, the appropriate owner type must match for the struct
counter_data macros such as COUNTER_DATA_DEVICE_U64,
COUNTER_DATA_SIGNAL_U64, COUNTER_DATA_COUNT_U64, etc.
All this complexity in the Counter subsystem code can be eliminated
if a single callback type with a `void *owner` parameter is defined
for use with all three owner types (Device, Signal, and Count). The
device driver would then be responsible for casting the callback
argument to the appropriate owner type; but in theory, this should
not be much of a problem since the device driver is responsible for
assigning the callbacks to the owning component anyway.
William Breathitt Gray (4):
counter: Internalize sysfs interface code
docs: counter: Update to reflect sysfs internalization
counter: Add character device interface
docs: counter: Document character device interface
Documentation/driver-api/generic-counter.rst | 275 +++-
MAINTAINERS | 3 +-
drivers/counter/104-quad-8.c | 547 +++----
drivers/counter/Makefile | 1 +
drivers/counter/counter-chrdev.c | 656 ++++++++
drivers/counter/counter-chrdev.h | 16 +
drivers/counter/counter-core.c | 187 +++
drivers/counter/counter-sysfs.c | 881 +++++++++++
drivers/counter/counter-sysfs.h | 14 +
drivers/counter/counter.c | 1496 ------------------
drivers/counter/ftm-quaddec.c | 89 +-
drivers/counter/stm32-lptimer-cnt.c | 161 +-
drivers/counter/stm32-timer-cnt.c | 139 +-
drivers/counter/ti-eqep.c | 211 +--
include/linux/counter.h | 626 ++++----
include/linux/counter_enum.h | 45 -
include/uapi/linux/counter-types.h | 45 +
17 files changed, 2826 insertions(+), 2566 deletions(-)
create mode 100644 drivers/counter/counter-chrdev.c
create mode 100644 drivers/counter/counter-chrdev.h
create mode 100644 drivers/counter/counter-core.c
create mode 100644 drivers/counter/counter-sysfs.c
create mode 100644 drivers/counter/counter-sysfs.h
delete mode 100644 drivers/counter/counter.c
delete mode 100644 include/linux/counter_enum.h
create mode 100644 include/uapi/linux/counter-types.h
--
2.26.2
^ permalink raw reply [flat|nested] 38+ messages in thread
* [PATCH v2 0/4] Introduce the Counter character device interface
@ 2020-05-16 19:19 ` William Breathitt Gray
0 siblings, 0 replies; 38+ messages in thread
From: William Breathitt Gray @ 2020-05-16 19:19 UTC (permalink / raw)
To: jic23
Cc: kamel.bouhara, gwendal, david, linux-iio, patrick.havelange,
alexandre.belloni, linux-kernel, mcoquelin.stm32,
William Breathitt Gray, fabrice.gasnier, syednwaris, linux-stm32,
linux-arm-kernel, alexandre.torgue
Changes in v2:
- Use fixed-width data types to represent Counter data types
- Use union of function prototypes to store read/write callbacks
- Eliminate the counter-strings and counter-sysfs-callback files by
inlining relevant code
- Reimplement chrdev code to handle read/write calls instead of ioctl
- Remove struct counter_enum (I'm postponing this development until I
get the core functionality solid)
- Remove devm_counter_unregister as unnecessary
Over the past couple years we have noticed some shortcomings with the
Counter sysfs interface. Although useful in the majority of situations,
there are certain use-cases where interacting through sysfs attributes
can become cumbersome and inefficient. A desire to support more advanced
functionality such as timestamps, multi-axis positioning tables, and
other such latency-sensitive applications, has motivated a reevaluation
of the Counter subsystem. I believe a character device interface will be
helpful for this more niche area of counter device use.
To quell any concerns from the offset: this patchset makes no changes to
the existing Counter sysfs userspace interface -- existing userspace
applications will continue to work with no modifications necessary. I
request that driver maintainers please test their applications to verify
that this is true, and report any discrepancies if they arise.
However, this patchset does contain a major reimplementation of the
Counter subsystem core and driver API. A reimplementation was necessary
in order to separate the sysfs code from the counter device drivers and
internalize it as a dedicated component of the core Counter subsystem
module. A minor benefit from all of this is that the sysfs interface is
now ensured a certain amount of consistency because the translation is
performed outside of individual counter device drivers.
Essentially, the reimplementation has enabled counter device drivers to
pass and handle data as native C datatypes now rather than the sysfs
strings from before. A high-level view of how a count value is passed
down from a counter device driver can be exemplified by the following:
----------------------
/ Counter device \
+----------------------+
| Count register: 0x28 |
+----------------------+
|
-----------------
/ raw count data /
-----------------
|
V
+----------------------------+
| Counter device driver |----------+
+----------------------------+ |
| Processes data from device | -------------------
|----------------------------| / driver callbacks /
| Type: u64 | -------------------
| Value: 42 | |
+----------------------------+ |
| |
---------- |
/ u64 / |
---------- |
| |
| V
| +----------------------+
| | Counter core |
| +----------------------+
| | Routes device driver |
| | callbacks to the |
| | userspace interfaces |
| +----------------------+
| |
| -------------------
| / driver callbacks /
| -------------------
| |
+-------+---------------+ |
| | |
| +-------|-------+
| | |
V | V
+--------------------+ | +---------------------+
| Counter sysfs |<-+->| Counter chrdev |
+--------------------+ +---------------------+
| Translates to the | | Translates to the |
| standard Counter | | standard Counter |
| sysfs output | | character device |
|--------------------| |---------------------+
| Type: const char * | | Type: u64 |
| Value: "42" | | Value: 42 |
+--------------------+ +---------------------+
| |
--------------- ----------
/ const char * / / u64 /
--------------- ----------
| |
| V
| +-----------+
| | read |
| +-----------+
| \ Count: 42 /
| -----------
|
V
+--------------------------------------------------+
| `/sys/bus/counter/devices/counterX/countY/count` |
+--------------------------------------------------+
\ Count: "42" /
--------------------------------------------------
I am aware that an in-kernel API can simplify the data transfer between
counter device drivers and the userspace interfaces, but I want to
postpone that development until after the new Counter character device
interface is solidified. A userspace ABI is effectively immutable so I
want to make sure we get that right before working on an in-kernel API
that is more flexible to change. However, when we do develop an
in-kernel API, it will likely be housed as part of the Counter core
component, through which the userspace interfaces will then communicate.
Interaction with Counter character devices occurs via standard character
device read/write operations. This allows userspace applications to
access and set counter data using native C datatypes rather than working
through string translations.
The following are some questions I have about this patchset:
1. Should the data format of the character device be configured via a
sysfs attribute?
In this patchset, the first 196095 bytes of the character device are
dedicated as a selection area to choose which Counter components or
extensions should be exposed; the subsequent bytes are the actual
data for the Counter components and extensions that were selected.
Moving this selection to a sysfs attribute and dedicating the
character device to just data transfer might be a better design. If
such a design is chosen, should the selection attribute be
human-readable or binary?
2. How much space should allotted for strings?
Each Counter component and extension has a respective size allotted
for its data (u8 data is allotted 1 byte, u64 data is allotted 8
bytes, etc.); I have arbitrarily chosen to allot 64 bytes for
strings. Is this an apt size, or should string data be allotted more
or less space?
3. Should the owning component of an extension be handled by the device
driver or Counter subsystem?
The Counter subsystem figures out the owner (enum counter_owner_type)
for each component/extension in the counter-sysfs and counter-chrdev
code. When a callback must be executed, there are various switch
statements throughout the code to check whether the respective
Device, Signal, or Count version of the callback should be executed;
similarly, the appropriate owner type must match for the struct
counter_data macros such as COUNTER_DATA_DEVICE_U64,
COUNTER_DATA_SIGNAL_U64, COUNTER_DATA_COUNT_U64, etc.
All this complexity in the Counter subsystem code can be eliminated
if a single callback type with a `void *owner` parameter is defined
for use with all three owner types (Device, Signal, and Count). The
device driver would then be responsible for casting the callback
argument to the appropriate owner type; but in theory, this should
not be much of a problem since the device driver is responsible for
assigning the callbacks to the owning component anyway.
William Breathitt Gray (4):
counter: Internalize sysfs interface code
docs: counter: Update to reflect sysfs internalization
counter: Add character device interface
docs: counter: Document character device interface
Documentation/driver-api/generic-counter.rst | 275 +++-
MAINTAINERS | 3 +-
drivers/counter/104-quad-8.c | 547 +++----
drivers/counter/Makefile | 1 +
drivers/counter/counter-chrdev.c | 656 ++++++++
drivers/counter/counter-chrdev.h | 16 +
drivers/counter/counter-core.c | 187 +++
drivers/counter/counter-sysfs.c | 881 +++++++++++
drivers/counter/counter-sysfs.h | 14 +
drivers/counter/counter.c | 1496 ------------------
drivers/counter/ftm-quaddec.c | 89 +-
drivers/counter/stm32-lptimer-cnt.c | 161 +-
drivers/counter/stm32-timer-cnt.c | 139 +-
drivers/counter/ti-eqep.c | 211 +--
include/linux/counter.h | 626 ++++----
include/linux/counter_enum.h | 45 -
include/uapi/linux/counter-types.h | 45 +
17 files changed, 2826 insertions(+), 2566 deletions(-)
create mode 100644 drivers/counter/counter-chrdev.c
create mode 100644 drivers/counter/counter-chrdev.h
create mode 100644 drivers/counter/counter-core.c
create mode 100644 drivers/counter/counter-sysfs.c
create mode 100644 drivers/counter/counter-sysfs.h
delete mode 100644 drivers/counter/counter.c
delete mode 100644 include/linux/counter_enum.h
create mode 100644 include/uapi/linux/counter-types.h
--
2.26.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 38+ messages in thread
* [PATCH v2 1/4] counter: Internalize sysfs interface code
2020-05-16 19:19 ` William Breathitt Gray
(?)
@ 2020-05-16 19:19 ` William Breathitt Gray
2020-05-20 13:10 ` kbuild test robot
2020-05-24 16:08 ` Jonathan Cameron
-1 siblings, 2 replies; 38+ messages in thread
From: William Breathitt Gray @ 2020-05-16 19:19 UTC (permalink / raw)
To: jic23
Cc: kamel.bouhara, gwendal, alexandre.belloni, david, linux-iio,
linux-kernel, linux-stm32, linux-arm-kernel, syednwaris,
patrick.havelange, fabrice.gasnier, mcoquelin.stm32,
alexandre.torgue, William Breathitt Gray
This is a reimplementation of the Generic Counter driver interface.
There are no modifications to the Counter subsystem userspace interface,
so existing userspace applications should continue to run seamlessly.
Overview
========
The purpose of this patch is to internalize the sysfs interface code
among the various counter drivers into a shared module. Counter drivers
pass and take data natively (i.e. u8, u64, char *, etc.) and the shared
counter module handles the translation between the sysfs interface. This
gurantees a standard userspace interface for all counter drivers, and
helps generalize the Generic Counter driver ABI in order to support the
Generic Counter chrdev interface (introduced in a subsequent patch)
without significant changes to the existing counter drivers.
A high-level view of how a count value is passed down from a counter
driver can be exemplified by the following:
----------------------
/ Counter device \
+----------------------+
| Count register: 0x28 |
+----------------------+
|
-----------------
/ raw count data /
-----------------
|
V
+----------------------------+
| Counter device driver |----------+
+----------------------------+ |
| Processes data from device | -------------------
|----------------------------| / driver callbacks /
| Type: unsigned long | -------------------
| Value: 42 | |
+----------------------------+ |
| |
---------------- |
/ unsigned long / |
---------------- |
| |
| V
| +----------------------+
| | Counter core |
| +----------------------+
| | Routes device driver |
| | callbacks to the |
| | userspace interfaces |
| +----------------------+
| |
| -------------------
| / driver callbacks /
| -------------------
| |
+-------+ |
| |
| +---------------+
| |
V |
+--------------------+ |
| Counter sysfs |<-+
+--------------------+
| Translates to the |
| standard Counter |
| sysfs output |
|--------------------|
| Type: const char * |
| Value: "42" |
+--------------------+
|
---------------
/ const char * /
---------------
|
V
+--------------------------------------------------+
| `/sys/bus/counter/devices/counterX/countY/count` |
+--------------------------------------------------+
\ Count: "42" /
--------------------------------------------------
There are three primary components involved:
Counter device driver
---------------------
Communicates with the hardware device to read/write data; e.g.
counter drivers for 104-quad-8, stm32-timer, etc.
Counter core
------------
Registers the counter device driver to the system so that the
respective callbacks are called during userspace interaction
Counter sysfs
-------------
Translates counter data to the standard Counter sysfs interface
format and vice versa
Driver ABI
==========
This reimplementation entails several changes to the driver ABI. In
particular, the device driver callbacks are now expected to handle
standard C datatypes rather than translating the sysfs I/O directly.
To that end, the struct counter_data structure is introduced to
establish counter extensions for Signals, Synapses, and Counts.
The "type" member specifies the type of high-level data (e.g. BOOL,
COUNT_DIRECTION, etc.) handled by this extension. The "*_read" and
"*_write" members can then be set by the counter device driver with
callbacks to handle that data using native C data types (i.e. u8, u64,
char *, etc.).
Convenience macros such as COUNTER_DATA_COUNT_U64 are provided for use
by driver authors. In particular, driver authors are expected to use
the provided macros for standard Counter subsystem attributes in order
to maintain a consistent interface for userspace. For example, a counter
device driver may define several standard attributes like so:
struct counter_data count_ext[] = {
COUNTER_DATA_DIRECTION(count_direction_read),
COUNTER_DATA_ENABLE(count_enable_read, count_enable_write),
COUNTER_DATA_CEILING(count_ceiling_read, count_ceiling_write),
};
This makes it intuitive to see, add, and modify the attributes that are
supported by this driver ("direction", "enable", and "ceiling") and to
maintain this code without getting lost in a web of struct braces.
Callbacks must match the function type expected for the respective
component or extension. These function types are defined in the struct
counter_data structure as the "*_read" and "*_write" union members.
The corresponding callback prototypes for the extensions above would be:
int count_direction_read(struct counter_device *counter,
struct counter_count *count, u8 *direction);
int count_enable_read(struct counter_device *counter,
struct counter_count *count, u8 *enable);
int count_enable_write(struct counter_device *counter,
struct counter_count *count, u8 enable);
int count_ceiling_read(struct counter_device *counter,
struct counter_count *count, u64 *ceiling);
int count_ceiling_write(struct counter_device *counter,
struct counter_count *count, u64 ceiling);
In this way, driver authors no longer need to mess with sysfs strings
and are instead able to focus on what they actually care about doing --
getting data to/from the devices -- while the Generic Counter interface
handles the translation of that data for them between the various
userspace interfaces (e.g. sysfs and chardev).
Architecture
============
Counter device registration is the same as before: drivers populate a
struct counter_device with components and callbacks, then pass the
structure to the devm_counter_register function. However, what's
different now is how the Counter subsystem code handles this
registration internally.
Whereas before callbacks would interact directly with sysfs data, this
interaction is now abstracted and instead callbacks interact with native
C data types. The counter_data structure forms the basis for Counter
extentions.
The counter-sysfs.c file contains the code to parse through the
counter_device structure and register the requested components and
extensions. Attributes are created and populated based on type, with
respective translation functions to handle the mapping between sysfs and
the counter driver callbacks.
The translation performed for each attribute is straightforward: the
attribute type and data is parsed from the counter_attribute structure,
the respective counter driver read/write callback is called, and sysfs
I/O is handled before or after the driver read/write function is called.
Cc: Syed Nayyar Waris <syednwaris@gmail.com>
Cc: Patrick Havelange <patrick.havelange@essensium.com>
Cc: Fabrice Gasnier <fabrice.gasnier@st.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: David Lechner <david@lechnology.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
MAINTAINERS | 2 +-
drivers/counter/104-quad-8.c | 547 +++++-----
drivers/counter/Makefile | 1 +
drivers/counter/counter-core.c | 157 +++
drivers/counter/counter-sysfs.c | 881 ++++++++++++++++
drivers/counter/counter-sysfs.h | 14 +
drivers/counter/counter.c | 1496 ---------------------------
drivers/counter/ftm-quaddec.c | 89 +-
drivers/counter/stm32-lptimer-cnt.c | 161 +--
drivers/counter/stm32-timer-cnt.c | 139 +--
drivers/counter/ti-eqep.c | 211 ++--
include/linux/counter.h | 610 +++++------
include/linux/counter_enum.h | 45 -
include/uapi/linux/counter-types.h | 45 +
14 files changed, 1908 insertions(+), 2490 deletions(-)
create mode 100644 drivers/counter/counter-core.c
create mode 100644 drivers/counter/counter-sysfs.c
create mode 100644 drivers/counter/counter-sysfs.h
delete mode 100644 drivers/counter/counter.c
delete mode 100644 include/linux/counter_enum.h
create mode 100644 include/uapi/linux/counter-types.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 60ed2963efaa..ef72b5755793 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4365,7 +4365,7 @@ F: Documentation/ABI/testing/sysfs-bus-counter*
F: Documentation/driver-api/generic-counter.rst
F: drivers/counter/
F: include/linux/counter.h
-F: include/linux/counter_enum.h
+F: include/uapi/linux/counter-types.h
CPMAC ETHERNET DRIVER
M: Florian Fainelli <f.fainelli@gmail.com>
diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c
index aa13708c2bc3..ff1c8f8d1417 100644
--- a/drivers/counter/104-quad-8.c
+++ b/drivers/counter/104-quad-8.c
@@ -17,6 +17,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
+#include <linux/string.h>
#include <linux/types.h>
#define QUAD8_EXTENT 32
@@ -621,7 +622,7 @@ static const struct iio_chan_spec quad8_channels[] = {
};
static int quad8_signal_read(struct counter_device *counter,
- struct counter_signal *signal, enum counter_signal_value *val)
+ struct counter_signal *signal, u8 *val)
{
const struct quad8_iio *const priv = counter->priv;
unsigned int state;
@@ -639,7 +640,7 @@ static int quad8_signal_read(struct counter_device *counter,
}
static int quad8_count_read(struct counter_device *counter,
- struct counter_count *count, unsigned long *val)
+ struct counter_count *count, u64 *val)
{
struct quad8_iio *const priv = counter->priv;
const int base_offset = priv->base + 2 * count->id;
@@ -670,7 +671,7 @@ static int quad8_count_read(struct counter_device *counter,
}
static int quad8_count_write(struct counter_device *counter,
- struct counter_count *count, unsigned long val)
+ struct counter_count *count, u64 val)
{
struct quad8_iio *const priv = counter->priv;
const int base_offset = priv->base + 2 * count->id;
@@ -710,22 +711,16 @@ static int quad8_count_write(struct counter_device *counter,
return 0;
}
-enum quad8_count_function {
- QUAD8_COUNT_FUNCTION_PULSE_DIRECTION = 0,
- QUAD8_COUNT_FUNCTION_QUADRATURE_X1,
- QUAD8_COUNT_FUNCTION_QUADRATURE_X2,
- QUAD8_COUNT_FUNCTION_QUADRATURE_X4
-};
-static enum counter_count_function quad8_count_functions_list[] = {
- [QUAD8_COUNT_FUNCTION_PULSE_DIRECTION] = COUNTER_COUNT_FUNCTION_PULSE_DIRECTION,
- [QUAD8_COUNT_FUNCTION_QUADRATURE_X1] = COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A,
- [QUAD8_COUNT_FUNCTION_QUADRATURE_X2] = COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A,
- [QUAD8_COUNT_FUNCTION_QUADRATURE_X4] = COUNTER_COUNT_FUNCTION_QUADRATURE_X4
+static const u8 quad8_count_functions_list[] = {
+ COUNTER_COUNT_FUNCTION_PULSE_DIRECTION,
+ COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A,
+ COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A,
+ COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
};
-static int quad8_function_get(struct counter_device *counter,
- struct counter_count *count, size_t *function)
+static int quad8_function_read(struct counter_device *counter,
+ struct counter_count *count, u8 *function)
{
struct quad8_iio *const priv = counter->priv;
const int id = count->id;
@@ -735,25 +730,25 @@ static int quad8_function_get(struct counter_device *counter,
if (priv->quadrature_mode[id])
switch (priv->quadrature_scale[id]) {
case 0:
- *function = QUAD8_COUNT_FUNCTION_QUADRATURE_X1;
+ *function = COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A;
break;
case 1:
- *function = QUAD8_COUNT_FUNCTION_QUADRATURE_X2;
+ *function = COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A;
break;
case 2:
- *function = QUAD8_COUNT_FUNCTION_QUADRATURE_X4;
+ *function = COUNTER_COUNT_FUNCTION_QUADRATURE_X4;
break;
}
else
- *function = QUAD8_COUNT_FUNCTION_PULSE_DIRECTION;
+ *function = COUNTER_COUNT_FUNCTION_PULSE_DIRECTION;
mutex_unlock(&priv->lock);
return 0;
}
-static int quad8_function_set(struct counter_device *counter,
- struct counter_count *count, size_t function)
+static int quad8_function_write(struct counter_device *counter,
+ struct counter_count *count, u8 function)
{
struct quad8_iio *const priv = counter->priv;
const int id = count->id;
@@ -769,7 +764,7 @@ static int quad8_function_set(struct counter_device *counter,
mode_cfg = priv->count_mode[id] << 1;
idr_cfg = priv->index_polarity[id] << 1;
- if (function == QUAD8_COUNT_FUNCTION_PULSE_DIRECTION) {
+ if (function == COUNTER_COUNT_FUNCTION_PULSE_DIRECTION) {
*quadrature_mode = 0;
/* Quadrature scaling only available in quadrature mode */
@@ -785,15 +780,15 @@ static int quad8_function_set(struct counter_device *counter,
*quadrature_mode = 1;
switch (function) {
- case QUAD8_COUNT_FUNCTION_QUADRATURE_X1:
+ case COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A:
*scale = 0;
mode_cfg |= QUAD8_CMR_QUADRATURE_X1;
break;
- case QUAD8_COUNT_FUNCTION_QUADRATURE_X2:
+ case COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A:
*scale = 1;
mode_cfg |= QUAD8_CMR_QUADRATURE_X2;
break;
- case QUAD8_COUNT_FUNCTION_QUADRATURE_X4:
+ case COUNTER_COUNT_FUNCTION_QUADRATURE_X4:
*scale = 2;
mode_cfg |= QUAD8_CMR_QUADRATURE_X4;
break;
@@ -808,8 +803,8 @@ static int quad8_function_set(struct counter_device *counter,
return 0;
}
-static void quad8_direction_get(struct counter_device *counter,
- struct counter_count *count, enum counter_count_direction *direction)
+static int quad8_direction_read(struct counter_device *counter,
+ struct counter_count *count, u8 *direction)
{
const struct quad8_iio *const priv = counter->priv;
unsigned int ud_flag;
@@ -820,153 +815,155 @@ static void quad8_direction_get(struct counter_device *counter,
*direction = (ud_flag) ? COUNTER_COUNT_DIRECTION_FORWARD :
COUNTER_COUNT_DIRECTION_BACKWARD;
-}
-enum quad8_synapse_action {
- QUAD8_SYNAPSE_ACTION_NONE = 0,
- QUAD8_SYNAPSE_ACTION_RISING_EDGE,
- QUAD8_SYNAPSE_ACTION_FALLING_EDGE,
- QUAD8_SYNAPSE_ACTION_BOTH_EDGES
-};
+ return 0;
+}
-static enum counter_synapse_action quad8_index_actions_list[] = {
- [QUAD8_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,
- [QUAD8_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE
+static const u8 quad8_index_actions_list[] = {
+ COUNTER_SYNAPSE_ACTION_NONE,
+ COUNTER_SYNAPSE_ACTION_RISING_EDGE,
};
-static enum counter_synapse_action quad8_synapse_actions_list[] = {
- [QUAD8_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,
- [QUAD8_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE,
- [QUAD8_SYNAPSE_ACTION_FALLING_EDGE] = COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
- [QUAD8_SYNAPSE_ACTION_BOTH_EDGES] = COUNTER_SYNAPSE_ACTION_BOTH_EDGES
+static const u8 quad8_synapse_actions_list[] = {
+ COUNTER_SYNAPSE_ACTION_NONE,
+ COUNTER_SYNAPSE_ACTION_RISING_EDGE,
+ COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
+ COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
};
-static int quad8_action_get(struct counter_device *counter,
- struct counter_count *count, struct counter_synapse *synapse,
- size_t *action)
+static int quad8_action_read(struct counter_device *counter,
+ struct counter_count *count,
+ struct counter_synapse *synapse, u8 *action)
{
struct quad8_iio *const priv = counter->priv;
int err;
- size_t function = 0;
+ u8 function;
const size_t signal_a_id = count->synapses[0].signal->id;
- enum counter_count_direction direction;
+ u8 direction;
/* Handle Index signals */
if (synapse->signal->id >= 16) {
if (priv->preset_enable[count->id])
- *action = QUAD8_SYNAPSE_ACTION_RISING_EDGE;
+ *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
else
- *action = QUAD8_SYNAPSE_ACTION_NONE;
+ *action = COUNTER_SYNAPSE_ACTION_NONE;
return 0;
}
- err = quad8_function_get(counter, count, &function);
+ err = quad8_function_read(counter, count, &function);
if (err)
return err;
/* Default action mode */
- *action = QUAD8_SYNAPSE_ACTION_NONE;
+ *action = COUNTER_SYNAPSE_ACTION_NONE;
/* Determine action mode based on current count function mode */
switch (function) {
- case QUAD8_COUNT_FUNCTION_PULSE_DIRECTION:
+ case COUNTER_COUNT_FUNCTION_PULSE_DIRECTION:
if (synapse->signal->id == signal_a_id)
- *action = QUAD8_SYNAPSE_ACTION_RISING_EDGE;
+ *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
break;
- case QUAD8_COUNT_FUNCTION_QUADRATURE_X1:
+ case COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A:
if (synapse->signal->id == signal_a_id) {
- quad8_direction_get(counter, count, &direction);
+ err = quad8_direction_read(counter, count, &direction);
+ if (err)
+ return err;
if (direction == COUNTER_COUNT_DIRECTION_FORWARD)
- *action = QUAD8_SYNAPSE_ACTION_RISING_EDGE;
+ *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
else
- *action = QUAD8_SYNAPSE_ACTION_FALLING_EDGE;
+ *action = COUNTER_SYNAPSE_ACTION_FALLING_EDGE;
}
break;
- case QUAD8_COUNT_FUNCTION_QUADRATURE_X2:
+ case COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A:
if (synapse->signal->id == signal_a_id)
- *action = QUAD8_SYNAPSE_ACTION_BOTH_EDGES;
+ *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
break;
- case QUAD8_COUNT_FUNCTION_QUADRATURE_X4:
- *action = QUAD8_SYNAPSE_ACTION_BOTH_EDGES;
+ case COUNTER_COUNT_FUNCTION_QUADRATURE_X4:
+ *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
break;
}
return 0;
}
-static const struct counter_ops quad8_ops = {
- .signal_read = quad8_signal_read,
- .count_read = quad8_count_read,
- .count_write = quad8_count_write,
- .function_get = quad8_function_get,
- .function_set = quad8_function_set,
- .action_get = quad8_action_get
-};
-
-static int quad8_index_polarity_get(struct counter_device *counter,
- struct counter_signal *signal, size_t *index_polarity)
+static ssize_t quad8_index_polarity_read(struct counter_device *counter,
+ struct counter_signal *signal,
+ char *buf, size_t size)
{
const struct quad8_iio *const priv = counter->priv;
- const size_t channel_id = signal->id - 16;
-
- *index_polarity = priv->index_polarity[channel_id];
+ const size_t index = priv->index_polarity[signal->id - 16];
- return 0;
+ return snprintf(buf, size, "%s\n", quad8_index_polarity_modes[index]);
}
-static int quad8_index_polarity_set(struct counter_device *counter,
- struct counter_signal *signal, size_t index_polarity)
+static ssize_t quad8_index_polarity_write(struct counter_device *counter,
+ struct counter_signal *signal,
+ const char *buf, size_t size)
{
struct quad8_iio *const priv = counter->priv;
const size_t channel_id = signal->id - 16;
const int base_offset = priv->base + 2 * channel_id + 1;
- unsigned int idr_cfg = index_polarity << 1;
+ int index_polarity;
+ unsigned int idr_cfg;
- mutex_lock(&priv->lock);
+ index_polarity = sysfs_match_string(quad8_index_polarity_modes, buf);
+ if (index_polarity < 0)
+ return index_polarity;
- idr_cfg |= priv->synchronous_mode[channel_id];
+ mutex_lock(&priv->lock);
priv->index_polarity[channel_id] = index_polarity;
/* Load Index Control configuration to Index Control Register */
+ idr_cfg = priv->synchronous_mode[channel_id] | index_polarity << 1;
outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
mutex_unlock(&priv->lock);
- return 0;
+ return size;
}
-static struct counter_signal_enum_ext quad8_index_pol_enum = {
- .items = quad8_index_polarity_modes,
- .num_items = ARRAY_SIZE(quad8_index_polarity_modes),
- .get = quad8_index_polarity_get,
- .set = quad8_index_polarity_set
-};
+static ssize_t quad8_index_polarity_available_read(
+ struct counter_device *counter, struct counter_signal *signal,
+ char *buf, size_t size)
+{
+ size_t i;
+ size_t len = 0;
-static int quad8_synchronous_mode_get(struct counter_device *counter,
- struct counter_signal *signal, size_t *synchronous_mode)
+ for (i = 0; i < ARRAY_SIZE(quad8_index_polarity_modes) && size > 1; i++)
+ len += scnprintf(buf + len, size - len, "%s\n",
+ quad8_index_polarity_modes[i]);
+
+ return len;
+}
+
+static ssize_t quad8_synchronous_mode_read(struct counter_device *counter,
+ struct counter_signal *signal,
+ char *buf, size_t size)
{
const struct quad8_iio *const priv = counter->priv;
- const size_t channel_id = signal->id - 16;
-
- *synchronous_mode = priv->synchronous_mode[channel_id];
+ const size_t index = priv->synchronous_mode[signal->id - 16];
- return 0;
+ return snprintf(buf, size, "%s\n", quad8_synchronous_modes[index]);
}
-static int quad8_synchronous_mode_set(struct counter_device *counter,
- struct counter_signal *signal, size_t synchronous_mode)
+static ssize_t quad8_synchronous_mode_write(struct counter_device *counter,
+ struct counter_signal *signal,
+ const char *buf, size_t size)
{
struct quad8_iio *const priv = counter->priv;
const size_t channel_id = signal->id - 16;
const int base_offset = priv->base + 2 * channel_id + 1;
- unsigned int idr_cfg = synchronous_mode;
+ int synchronous_mode;
+ unsigned int idr_cfg;
- mutex_lock(&priv->lock);
+ synchronous_mode = sysfs_match_string(quad8_synchronous_modes, buf);
+ if (synchronous_mode < 0)
+ return synchronous_mode;
- idr_cfg |= priv->index_polarity[channel_id] << 1;
+ mutex_lock(&priv->lock);
/* Index function must be non-synchronous in non-quadrature mode */
if (synchronous_mode && !priv->quadrature_mode[channel_id]) {
@@ -977,29 +974,39 @@ static int quad8_synchronous_mode_set(struct counter_device *counter,
priv->synchronous_mode[channel_id] = synchronous_mode;
/* Load Index Control configuration to Index Control Register */
+ idr_cfg = synchronous_mode | priv->index_polarity[channel_id] << 1;
outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
mutex_unlock(&priv->lock);
- return 0;
+ return size;
}
-static struct counter_signal_enum_ext quad8_syn_mode_enum = {
- .items = quad8_synchronous_modes,
- .num_items = ARRAY_SIZE(quad8_synchronous_modes),
- .get = quad8_synchronous_mode_get,
- .set = quad8_synchronous_mode_set
-};
+static ssize_t quad8_synchronous_mode_available_read(
+ struct counter_device *counter, struct counter_signal *signal,
+ char *buf, size_t size)
+{
+ size_t i;
+ size_t len = 0;
-static ssize_t quad8_count_floor_read(struct counter_device *counter,
- struct counter_count *count, void *private, char *buf)
+ for (i = 0; i < ARRAY_SIZE(quad8_synchronous_modes) && size > 1; i++)
+ len += scnprintf(buf + len, size - len, "%s\n",
+ quad8_synchronous_modes[i]);
+
+ return len;
+}
+
+static int quad8_count_floor_read(struct counter_device *counter,
+ struct counter_count *count, u64 *floor)
{
/* Only a floor of 0 is supported */
- return sprintf(buf, "0\n");
+ *floor = 0;
+
+ return 0;
}
-static int quad8_count_mode_get(struct counter_device *counter,
- struct counter_count *count, size_t *cnt_mode)
+static int quad8_count_mode_read(struct counter_device *counter,
+ struct counter_count *count, u8 *cnt_mode)
{
const struct quad8_iio *const priv = counter->priv;
@@ -1022,35 +1029,36 @@ static int quad8_count_mode_get(struct counter_device *counter,
return 0;
}
-static int quad8_count_mode_set(struct counter_device *counter,
- struct counter_count *count, size_t cnt_mode)
+static int quad8_count_mode_write(struct counter_device *counter,
+ struct counter_count *count, u8 cnt_mode)
{
struct quad8_iio *const priv = counter->priv;
+ unsigned int count_mode;
unsigned int mode_cfg;
const int base_offset = priv->base + 2 * count->id + 1;
/* Map Generic Counter count mode to 104-QUAD-8 count mode */
switch (cnt_mode) {
case COUNTER_COUNT_MODE_NORMAL:
- cnt_mode = 0;
+ count_mode = 0;
break;
case COUNTER_COUNT_MODE_RANGE_LIMIT:
- cnt_mode = 1;
+ count_mode = 1;
break;
case COUNTER_COUNT_MODE_NON_RECYCLE:
- cnt_mode = 2;
+ count_mode = 2;
break;
case COUNTER_COUNT_MODE_MODULO_N:
- cnt_mode = 3;
+ count_mode = 3;
break;
}
mutex_lock(&priv->lock);
- priv->count_mode[count->id] = cnt_mode;
+ priv->count_mode[count->id] = count_mode;
/* Set count mode configuration value */
- mode_cfg = cnt_mode << 1;
+ mode_cfg = count_mode << 1;
/* Add quadrature mode configuration */
if (priv->quadrature_mode[count->id])
@@ -1064,85 +1072,86 @@ static int quad8_count_mode_set(struct counter_device *counter,
return 0;
}
-static struct counter_count_enum_ext quad8_cnt_mode_enum = {
- .items = counter_count_mode_str,
- .num_items = ARRAY_SIZE(counter_count_mode_str),
- .get = quad8_count_mode_get,
- .set = quad8_count_mode_set
+static const u8 quad8_cnt_modes[] = {
+ COUNTER_COUNT_MODE_NORMAL,
+ COUNTER_COUNT_MODE_RANGE_LIMIT,
+ COUNTER_COUNT_MODE_NON_RECYCLE,
+ COUNTER_COUNT_MODE_MODULO_N,
};
-static ssize_t quad8_count_direction_read(struct counter_device *counter,
- struct counter_count *count, void *priv, char *buf)
-{
- enum counter_count_direction dir;
-
- quad8_direction_get(counter, count, &dir);
-
- return sprintf(buf, "%s\n", counter_count_direction_str[dir]);
-}
+static DEFINE_COUNTER_AVAILABLE(quad8_count_mode_available, quad8_cnt_modes);
-static ssize_t quad8_count_enable_read(struct counter_device *counter,
- struct counter_count *count, void *private, char *buf)
+static int quad8_count_enable_read(struct counter_device *counter,
+ struct counter_count *count, u8 *enable)
{
const struct quad8_iio *const priv = counter->priv;
- return sprintf(buf, "%u\n", priv->ab_enable[count->id]);
+ *enable = priv->ab_enable[count->id];
+
+ return 0;
}
-static ssize_t quad8_count_enable_write(struct counter_device *counter,
- struct counter_count *count, void *private, const char *buf, size_t len)
+static int quad8_count_enable_write(struct counter_device *counter,
+ struct counter_count *count, u8 enable)
{
struct quad8_iio *const priv = counter->priv;
const int base_offset = priv->base + 2 * count->id;
- int err;
- bool ab_enable;
unsigned int ior_cfg;
- err = kstrtobool(buf, &ab_enable);
- if (err)
- return err;
-
mutex_lock(&priv->lock);
- priv->ab_enable[count->id] = ab_enable;
+ priv->ab_enable[count->id] = enable;
- ior_cfg = ab_enable | priv->preset_enable[count->id] << 1;
+ ior_cfg = enable | priv->preset_enable[count->id] << 1;
/* Load I/O control configuration */
outb(QUAD8_CTR_IOR | ior_cfg, base_offset + 1);
mutex_unlock(&priv->lock);
- return len;
+ return 0;
}
-static int quad8_error_noise_get(struct counter_device *counter,
- struct counter_count *count, size_t *noise_error)
+static ssize_t quad8_error_noise_read(struct counter_device *counter,
+ struct counter_count *count, char *buf,
+ size_t size)
{
const struct quad8_iio *const priv = counter->priv;
const int base_offset = priv->base + 2 * count->id + 1;
+ size_t noise_error;
- *noise_error = !!(inb(base_offset) & QUAD8_FLAG_E);
+ noise_error = !!(inb(base_offset) & QUAD8_FLAG_E);
- return 0;
+ return snprintf(buf, size, "%s\n",
+ quad8_noise_error_states[noise_error]);
}
-static struct counter_count_enum_ext quad8_error_noise_enum = {
- .items = quad8_noise_error_states,
- .num_items = ARRAY_SIZE(quad8_noise_error_states),
- .get = quad8_error_noise_get
-};
+static ssize_t quad8_error_noise_available_read(struct counter_device *counter,
+ struct counter_count *count,
+ char *buf, size_t size)
+{
+ size_t i;
+ size_t len = 0;
+
+ for (i = 0; i < ARRAY_SIZE(quad8_noise_error_states) && size > 1; i++)
+ len += scnprintf(buf + len, size - len, "%s\n",
+ quad8_noise_error_states[i]);
+
+ return len;
+}
-static ssize_t quad8_count_preset_read(struct counter_device *counter,
- struct counter_count *count, void *private, char *buf)
+static int quad8_count_preset_read(struct counter_device *counter,
+ struct counter_count *count, u64 *preset)
{
const struct quad8_iio *const priv = counter->priv;
- return sprintf(buf, "%u\n", priv->preset[count->id]);
+ *preset = priv->preset[count->id];
+
+ return 0;
}
-static void quad8_preset_register_set(struct quad8_iio *quad8iio, int id,
- unsigned int preset)
+static void quad8_preset_register_set(struct quad8_iio *const quad8iio,
+ const int id, const u64 preset)
{
const unsigned int base_offset = quad8iio->base + 2 * id;
int i;
@@ -1157,16 +1166,10 @@ static void quad8_preset_register_set(struct quad8_iio *quad8iio, int id,
outb(preset >> (8 * i), base_offset);
}
-static ssize_t quad8_count_preset_write(struct counter_device *counter,
- struct counter_count *count, void *private, const char *buf, size_t len)
+static int quad8_count_preset_write(struct counter_device *counter,
+ struct counter_count *count, u64 preset)
{
struct quad8_iio *const priv = counter->priv;
- unsigned int preset;
- int ret;
-
- ret = kstrtouint(buf, 0, &preset);
- if (ret)
- return ret;
/* Only 24-bit values are supported */
if (preset > 0xFFFFFF)
@@ -1178,11 +1181,11 @@ static ssize_t quad8_count_preset_write(struct counter_device *counter,
mutex_unlock(&priv->lock);
- return len;
+ return 0;
}
-static ssize_t quad8_count_ceiling_read(struct counter_device *counter,
- struct counter_count *count, void *private, char *buf)
+static int quad8_count_ceiling_read(struct counter_device *counter,
+ struct counter_count *count, u64 *ceiling)
{
struct quad8_iio *const priv = counter->priv;
@@ -1193,25 +1196,21 @@ static ssize_t quad8_count_ceiling_read(struct counter_device *counter,
case 1:
case 3:
mutex_unlock(&priv->lock);
- return sprintf(buf, "%u\n", priv->preset[count->id]);
+ return quad8_count_preset_read(counter, count, ceiling);
}
mutex_unlock(&priv->lock);
/* By default 0x1FFFFFF (25 bits unsigned) is maximum count */
- return sprintf(buf, "33554431\n");
+ *ceiling = 0x1FFFFFF;
+
+ return 0;
}
-static ssize_t quad8_count_ceiling_write(struct counter_device *counter,
- struct counter_count *count, void *private, const char *buf, size_t len)
+static int quad8_count_ceiling_write(struct counter_device *counter,
+ struct counter_count *count, u64 ceiling)
{
struct quad8_iio *const priv = counter->priv;
- unsigned int ceiling;
- int ret;
-
- ret = kstrtouint(buf, 0, &ceiling);
- if (ret)
- return ret;
/* Only 24-bit values are supported */
if (ceiling > 0xFFFFFF)
@@ -1223,36 +1222,33 @@ static ssize_t quad8_count_ceiling_write(struct counter_device *counter,
switch (priv->count_mode[count->id]) {
case 1:
case 3:
- quad8_preset_register_set(priv, count->id, ceiling);
- break;
+ return quad8_count_preset_write(counter, count, ceiling);
}
mutex_unlock(&priv->lock);
- return len;
+ return -EINVAL;
}
-static ssize_t quad8_count_preset_enable_read(struct counter_device *counter,
- struct counter_count *count, void *private, char *buf)
+static int quad8_count_preset_enable_read(struct counter_device *counter,
+ struct counter_count *count,
+ u8 *preset_enable)
{
const struct quad8_iio *const priv = counter->priv;
- return sprintf(buf, "%u\n", !priv->preset_enable[count->id]);
+ *preset_enable = !priv->preset_enable[count->id];
+
+ return 0;
}
-static ssize_t quad8_count_preset_enable_write(struct counter_device *counter,
- struct counter_count *count, void *private, const char *buf, size_t len)
+static int quad8_count_preset_enable_write(struct counter_device *counter,
+ struct counter_count *count,
+ u8 preset_enable)
{
struct quad8_iio *const priv = counter->priv;
const int base_offset = priv->base + 2 * count->id + 1;
- bool preset_enable;
- int ret;
unsigned int ior_cfg;
- ret = kstrtobool(buf, &preset_enable);
- if (ret)
- return ret;
-
/* Preset enable is active low in Input/Output Control register */
preset_enable = !preset_enable;
@@ -1260,25 +1256,24 @@ static ssize_t quad8_count_preset_enable_write(struct counter_device *counter,
priv->preset_enable[count->id] = preset_enable;
- ior_cfg = priv->ab_enable[count->id] | (unsigned int)preset_enable << 1;
+ ior_cfg = priv->ab_enable[count->id] | preset_enable << 1;
/* Load I/O control configuration to Input / Output Control Register */
outb(QUAD8_CTR_IOR | ior_cfg, base_offset);
mutex_unlock(&priv->lock);
- return len;
+ return 0;
}
-static ssize_t quad8_signal_cable_fault_read(struct counter_device *counter,
- struct counter_signal *signal,
- void *private, char *buf)
+static int quad8_signal_cable_fault_read(struct counter_device *counter,
+ struct counter_signal *signal,
+ u8 *cable_fault)
{
const struct quad8_iio *const priv = counter->priv;
const size_t channel_id = signal->id / 2;
const bool disabled = !(priv->cable_fault_enable & BIT(channel_id));
unsigned int status;
- unsigned int fault;
if (disabled)
return -EINVAL;
@@ -1287,36 +1282,31 @@ static ssize_t quad8_signal_cable_fault_read(struct counter_device *counter,
status = inb(priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS);
/* Mask respective channel and invert logic */
- fault = !(status & BIT(channel_id));
+ *cable_fault = !(status & BIT(channel_id));
- return sprintf(buf, "%u\n", fault);
+ return 0;
}
-static ssize_t quad8_signal_cable_fault_enable_read(
- struct counter_device *counter, struct counter_signal *signal,
- void *private, char *buf)
+static int quad8_signal_cable_fault_enable_read(struct counter_device *counter,
+ struct counter_signal *signal,
+ u8 *enable)
{
const struct quad8_iio *const priv = counter->priv;
const size_t channel_id = signal->id / 2;
- const unsigned int enb = !!(priv->cable_fault_enable & BIT(channel_id));
- return sprintf(buf, "%u\n", enb);
+ *enable = !!(priv->cable_fault_enable & BIT(channel_id));
+
+ return 0;
}
-static ssize_t quad8_signal_cable_fault_enable_write(
- struct counter_device *counter, struct counter_signal *signal,
- void *private, const char *buf, size_t len)
+static int quad8_signal_cable_fault_enable_write(struct counter_device *counter,
+ struct counter_signal *signal,
+ u8 enable)
{
struct quad8_iio *const priv = counter->priv;
const size_t channel_id = signal->id / 2;
- bool enable;
- int ret;
unsigned int cable_fault_enable;
- ret = kstrtobool(buf, &enable);
- if (ret)
- return ret;
-
if (enable)
priv->cable_fault_enable |= BIT(channel_id);
else
@@ -1327,31 +1317,27 @@ static ssize_t quad8_signal_cable_fault_enable_write(
outb(cable_fault_enable, priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS);
- return len;
+ return 0;
}
-static ssize_t quad8_signal_fck_prescaler_read(struct counter_device *counter,
- struct counter_signal *signal, void *private, char *buf)
+static int quad8_signal_fck_prescaler_read(struct counter_device *counter,
+ struct counter_signal *signal,
+ u8 *prescaler)
{
const struct quad8_iio *const priv = counter->priv;
- const size_t channel_id = signal->id / 2;
- return sprintf(buf, "%u\n", priv->fck_prescaler[channel_id]);
+ *prescaler = priv->fck_prescaler[signal->id / 2];
+
+ return 0;
}
-static ssize_t quad8_signal_fck_prescaler_write(struct counter_device *counter,
- struct counter_signal *signal, void *private, const char *buf,
- size_t len)
+static int quad8_signal_fck_prescaler_write(struct counter_device *counter,
+ struct counter_signal *signal,
+ u8 prescaler)
{
struct quad8_iio *const priv = counter->priv;
const size_t channel_id = signal->id / 2;
const int base_offset = priv->base + 2 * channel_id;
- u8 prescaler;
- int ret;
-
- ret = kstrtou8(buf, 0, &prescaler);
- if (ret)
- return ret;
priv->fck_prescaler[channel_id] = prescaler;
@@ -1363,31 +1349,30 @@ static ssize_t quad8_signal_fck_prescaler_write(struct counter_device *counter,
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_PRESET_PSC,
base_offset + 1);
- return len;
+ return 0;
}
-static const struct counter_signal_ext quad8_signal_ext[] = {
- {
- .name = "cable_fault",
- .read = quad8_signal_cable_fault_read
- },
- {
- .name = "cable_fault_enable",
- .read = quad8_signal_cable_fault_enable_read,
- .write = quad8_signal_cable_fault_enable_write
- },
- {
- .name = "filter_clock_prescaler",
- .read = quad8_signal_fck_prescaler_read,
- .write = quad8_signal_fck_prescaler_write
- }
+static struct counter_data quad8_signal_ext[] = {
+ COUNTER_DATA_SIGNAL_BOOL("cable_fault", quad8_signal_cable_fault_read,
+ NULL),
+ COUNTER_DATA_SIGNAL_BOOL("cable_fault_enable",
+ quad8_signal_cable_fault_enable_read,
+ quad8_signal_cable_fault_enable_write),
+ COUNTER_DATA_SIGNAL_U8("filter_clock_prescaler",
+ quad8_signal_fck_prescaler_read,
+ quad8_signal_fck_prescaler_write)
};
-static const struct counter_signal_ext quad8_index_ext[] = {
- COUNTER_SIGNAL_ENUM("index_polarity", &quad8_index_pol_enum),
- COUNTER_SIGNAL_ENUM_AVAILABLE("index_polarity", &quad8_index_pol_enum),
- COUNTER_SIGNAL_ENUM("synchronous_mode", &quad8_syn_mode_enum),
- COUNTER_SIGNAL_ENUM_AVAILABLE("synchronous_mode", &quad8_syn_mode_enum)
+static struct counter_data quad8_index_ext[] = {
+ COUNTER_DATA_SIGNAL_STRING("index_polarity", quad8_index_polarity_read,
+ quad8_index_polarity_write),
+ COUNTER_DATA_SIGNAL_STRING("index_polarity_available",
+ quad8_index_polarity_available_read, NULL),
+ COUNTER_DATA_SIGNAL_STRING("synchronous_mode",
+ quad8_synchronous_mode_read,
+ quad8_synchronous_mode_write),
+ COUNTER_DATA_SIGNAL_STRING("synchronous_mode_available",
+ quad8_synchronous_mode_available_read, NULL),
};
#define QUAD8_QUAD_SIGNAL(_id, _name) { \
@@ -1456,39 +1441,20 @@ static struct counter_synapse quad8_count_synapses[][3] = {
QUAD8_COUNT_SYNAPSES(6), QUAD8_COUNT_SYNAPSES(7)
};
-static const struct counter_count_ext quad8_count_ext[] = {
- {
- .name = "ceiling",
- .read = quad8_count_ceiling_read,
- .write = quad8_count_ceiling_write
- },
- {
- .name = "floor",
- .read = quad8_count_floor_read
- },
- COUNTER_COUNT_ENUM("count_mode", &quad8_cnt_mode_enum),
- COUNTER_COUNT_ENUM_AVAILABLE("count_mode", &quad8_cnt_mode_enum),
- {
- .name = "direction",
- .read = quad8_count_direction_read
- },
- {
- .name = "enable",
- .read = quad8_count_enable_read,
- .write = quad8_count_enable_write
- },
- COUNTER_COUNT_ENUM("error_noise", &quad8_error_noise_enum),
- COUNTER_COUNT_ENUM_AVAILABLE("error_noise", &quad8_error_noise_enum),
- {
- .name = "preset",
- .read = quad8_count_preset_read,
- .write = quad8_count_preset_write
- },
- {
- .name = "preset_enable",
- .read = quad8_count_preset_enable_read,
- .write = quad8_count_preset_enable_write
- }
+static struct counter_data quad8_count_ext[] = {
+ COUNTER_DATA_CEILING(quad8_count_ceiling_read,
+ quad8_count_ceiling_write),
+ COUNTER_DATA_FLOOR(quad8_count_floor_read, NULL),
+ COUNTER_DATA_COUNT_MODE(quad8_count_mode_read, quad8_count_mode_write,
+ quad8_count_mode_available),
+ COUNTER_DATA_DIRECTION(quad8_direction_read),
+ COUNTER_DATA_ENABLE(quad8_count_enable_read, quad8_count_enable_write),
+ COUNTER_DATA_COUNT_STRING("error_noise", quad8_error_noise_read, NULL),
+ COUNTER_DATA_COUNT_STRING("error_noise_available",
+ quad8_error_noise_available_read, NULL),
+ COUNTER_DATA_PRESET(quad8_count_preset_read, quad8_count_preset_write),
+ COUNTER_DATA_PRESET_ENABLE(quad8_count_preset_enable_read,
+ quad8_count_preset_enable_write),
};
#define QUAD8_COUNT(_id, _cntname) { \
@@ -1544,7 +1510,12 @@ static int quad8_probe(struct device *dev, unsigned int id)
quad8iio = iio_priv(indio_dev);
quad8iio->counter.name = dev_name(dev);
quad8iio->counter.parent = dev;
- quad8iio->counter.ops = &quad8_ops;
+ quad8iio->counter.signal_read = quad8_signal_read;
+ quad8iio->counter.count_read = quad8_count_read;
+ quad8iio->counter.count_write = quad8_count_write;
+ quad8iio->counter.function_read = quad8_function_read;
+ quad8iio->counter.function_write = quad8_function_write;
+ quad8iio->counter.action_read = quad8_action_read;
quad8iio->counter.counts = quad8_counts;
quad8iio->counter.num_counts = ARRAY_SIZE(quad8_counts);
quad8iio->counter.signals = quad8_signals;
diff --git a/drivers/counter/Makefile b/drivers/counter/Makefile
index 55142d1f4c43..f48e337cbd85 100644
--- a/drivers/counter/Makefile
+++ b/drivers/counter/Makefile
@@ -4,6 +4,7 @@
#
obj-$(CONFIG_COUNTER) += counter.o
+counter-y := counter-core.o counter-sysfs.o
obj-$(CONFIG_104_QUAD_8) += 104-quad-8.o
obj-$(CONFIG_STM32_TIMER_CNT) += stm32-timer-cnt.o
diff --git a/drivers/counter/counter-core.c b/drivers/counter/counter-core.c
new file mode 100644
index 000000000000..499664809c75
--- /dev/null
+++ b/drivers/counter/counter-core.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic Counter interface
+ * Copyright (C) 2020 William Breathitt Gray
+ */
+#include <linux/counter.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/gfp.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/module.h>
+
+#include "counter-sysfs.h"
+
+/* Provides a unique ID for each counter device */
+static DEFINE_IDA(counter_ida);
+
+static void counter_device_release(struct device *dev)
+{
+ struct counter_device *const counter = dev_get_drvdata(dev);
+
+ counter_sysfs_free(counter);
+ ida_simple_remove(&counter_ida, counter->id);
+}
+
+static struct device_type counter_device_type = {
+ .name = "counter_device",
+ .release = counter_device_release
+};
+
+static struct bus_type counter_bus_type = {
+ .name = "counter"
+};
+
+/**
+ * counter_register - register Counter to the system
+ * @counter: pointer to Counter to register
+ *
+ * This function registers a Counter to the system. A sysfs "counter" directory
+ * will be created and populated with sysfs attributes correlating with the
+ * Counter Signals, Synapses, and Counts respectively.
+ */
+int counter_register(struct counter_device *const counter)
+{
+ struct device *const dev = &counter->dev;
+ int err;
+
+ /* Acquire unique ID */
+ counter->id = ida_simple_get(&counter_ida, 0, 0, GFP_KERNEL);
+ if (counter->id < 0)
+ return counter->id;
+
+ /* Configure device structure for Counter */
+ dev->type = &counter_device_type;
+ dev->bus = &counter_bus_type;
+ if (counter->parent) {
+ dev->parent = counter->parent;
+ dev->of_node = counter->parent->of_node;
+ }
+ dev_set_name(dev, "counter%d", counter->id);
+ device_initialize(dev);
+ dev_set_drvdata(dev, counter);
+
+ /* Add Counter sysfs attributes */
+ err = counter_sysfs_add(counter);
+ if (err)
+ goto err_free_id;
+
+ /* Add device to system */
+ err = device_add(dev);
+ if (err)
+ goto err_free_sysfs;
+
+ return 0;
+
+err_free_sysfs:
+ counter_sysfs_free(counter);
+err_free_id:
+ ida_simple_remove(&counter_ida, counter->id);
+ return err;
+}
+EXPORT_SYMBOL_GPL(counter_register);
+
+/**
+ * counter_unregister - unregister Counter from the system
+ * @counter: pointer to Counter to unregister
+ *
+ * The Counter is unregistered from the system; all allocated memory is freed.
+ */
+void counter_unregister(struct counter_device *const counter)
+{
+ if (counter) {
+ device_del(&counter->dev);
+ counter_sysfs_free(counter);
+ }
+}
+EXPORT_SYMBOL_GPL(counter_unregister);
+
+static void devm_counter_unreg(struct device *dev, void *res)
+{
+ counter_unregister(*(struct counter_device **)res);
+}
+
+/**
+ * devm_counter_register - Resource-managed counter_register
+ * @dev: device to allocate counter_device for
+ * @counter: pointer to Counter to register
+ *
+ * Managed counter_register. The Counter registered with this function is
+ * automatically unregistered on driver detach. This function calls
+ * counter_register internally. Refer to that function for more information.
+ *
+ * If an Counter registered with this function needs to be unregistered
+ * separately, devm_counter_unregister must be used.
+ *
+ * RETURNS:
+ * 0 on success, negative error number on failure.
+ */
+int devm_counter_register(struct device *dev,
+ struct counter_device *const counter)
+{
+ struct counter_device **ptr;
+ int ret;
+
+ ptr = devres_alloc(devm_counter_unreg, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return -ENOMEM;
+
+ ret = counter_register(counter);
+ if (!ret) {
+ *ptr = counter;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(devm_counter_register);
+
+static int __init counter_init(void)
+{
+ return bus_register(&counter_bus_type);
+}
+
+static void __exit counter_exit(void)
+{
+ bus_unregister(&counter_bus_type);
+}
+
+subsys_initcall(counter_init);
+module_exit(counter_exit);
+
+MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
+MODULE_DESCRIPTION("Generic Counter interface");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/counter/counter-sysfs.c b/drivers/counter/counter-sysfs.c
new file mode 100644
index 000000000000..d30a3239eb41
--- /dev/null
+++ b/drivers/counter/counter-sysfs.c
@@ -0,0 +1,881 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic Counter sysfs interface
+ * Copyright (C) 2020 William Breathitt Gray
+ */
+#include <linux/counter.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gfp.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+
+enum counter_owner_type {
+ COUNTER_OWNER_TYPE_DEVICE,
+ COUNTER_OWNER_TYPE_SIGNAL,
+ COUNTER_OWNER_TYPE_COUNT,
+};
+
+struct counter_attribute {
+ struct device_attribute dev_attr;
+ struct list_head l;
+
+ struct counter_data data;
+ enum counter_owner_type type;
+ void *owner;
+};
+
+#define to_counter_attribute(_dev_attr) \
+ container_of(_dev_attr, struct counter_attribute, dev_attr)
+
+static const char *const counter_count_function_str[] = {
+ [COUNTER_COUNT_FUNCTION_INCREASE] = "increase",
+ [COUNTER_COUNT_FUNCTION_DECREASE] = "decrease",
+ [COUNTER_COUNT_FUNCTION_PULSE_DIRECTION] = "pulse-direction",
+ [COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A] = "quadrature x1 a",
+ [COUNTER_COUNT_FUNCTION_QUADRATURE_X1_B] = "quadrature x1 b",
+ [COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A] = "quadrature x2 a",
+ [COUNTER_COUNT_FUNCTION_QUADRATURE_X2_B] = "quadrature x2 b",
+ [COUNTER_COUNT_FUNCTION_QUADRATURE_X4] = "quadrature x4"
+};
+
+static const char *const counter_signal_value_str[] = {
+ [COUNTER_SIGNAL_LOW] = "low",
+ [COUNTER_SIGNAL_HIGH] = "high"
+};
+
+static const char *const counter_synapse_action_str[] = {
+ [COUNTER_SYNAPSE_ACTION_NONE] = "none",
+ [COUNTER_SYNAPSE_ACTION_RISING_EDGE] = "rising edge",
+ [COUNTER_SYNAPSE_ACTION_FALLING_EDGE] = "falling edge",
+ [COUNTER_SYNAPSE_ACTION_BOTH_EDGES] = "both edges"
+};
+
+static const char *const counter_count_direction_str[] = {
+ [COUNTER_COUNT_DIRECTION_FORWARD] = "forward",
+ [COUNTER_COUNT_DIRECTION_BACKWARD] = "backward"
+};
+
+static const char *const counter_count_mode_str[] = {
+ [COUNTER_COUNT_MODE_NORMAL] = "normal",
+ [COUNTER_COUNT_MODE_RANGE_LIMIT] = "range limit",
+ [COUNTER_COUNT_MODE_NON_RECYCLE] = "non-recycle",
+ [COUNTER_COUNT_MODE_MODULO_N] = "modulo-n"
+};
+
+static ssize_t counter_data_u8_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ const struct counter_attribute *const a = to_counter_attribute(attr);
+ struct counter_device *const counter = dev_get_drvdata(dev);
+ int err;
+ u8 data;
+
+ switch (a->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ err = a->data.device_u8_read(counter, &data);
+ break;
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ err = a->data.signal_u8_read(counter, a->owner, &data);
+ break;
+ case COUNTER_OWNER_TYPE_COUNT:
+ if (a->data.type == COUNTER_DATA_TYPE_SYNAPSE_ACTION)
+ err = a->data.action_read(counter, a->owner,
+ a->data.priv, &data);
+ else
+ err = a->data.count_u8_read(counter, a->owner, &data);
+ break;
+ default: return -EINVAL;
+ }
+ if (err)
+ return err;
+
+ switch (a->data.type) {
+ case COUNTER_DATA_TYPE_BOOL:
+ return sprintf(buf, "%u\n", (unsigned int)!!data);
+ case COUNTER_DATA_TYPE_COUNT_FUNCTION:
+ return sprintf(buf, "%s\n", counter_count_function_str[data]);
+ case COUNTER_DATA_TYPE_SIGNAL:
+ return sprintf(buf, "%s\n", counter_signal_value_str[data]);
+ case COUNTER_DATA_TYPE_SYNAPSE_ACTION:
+ return sprintf(buf, "%s\n", counter_synapse_action_str[data]);
+ case COUNTER_DATA_TYPE_COUNT_DIRECTION:
+ return sprintf(buf, "%s\n", counter_count_direction_str[data]);
+ case COUNTER_DATA_TYPE_COUNT_MODE:
+ return sprintf(buf, "%s\n", counter_count_mode_str[data]);
+ }
+
+ return sprintf(buf, "%u\n", (unsigned int)data);
+}
+
+static int find_in_string_array(u8 *const item, const u8 *const items,
+ const size_t num_items, const char *const buf,
+ const char *const string_array[])
+{
+ size_t index;
+
+ for (index = 0; index < num_items; index++) {
+ *item = items[index];
+ if (sysfs_streq(buf, string_array[*item]))
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static ssize_t counter_data_u8_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ const struct counter_attribute *const a = to_counter_attribute(attr);
+ struct counter_device *const counter = dev_get_drvdata(dev);
+ struct counter_count *const count = a->owner;
+ struct counter_synapse *const synapse = a->data.priv;
+ const struct counter_available *const available = a->data.priv;
+ int err;
+ bool bool_data;
+ u8 data;
+
+ switch (a->data.type) {
+ case COUNTER_DATA_TYPE_BOOL:
+ err = kstrtobool(buf, &bool_data);
+ data = bool_data;
+ break;
+ case COUNTER_DATA_TYPE_COUNT_FUNCTION:
+ err = find_in_string_array(&data, count->functions_list,
+ count->num_functions, buf,
+ counter_count_function_str);
+ break;
+ case COUNTER_DATA_TYPE_SYNAPSE_ACTION:
+ err = find_in_string_array(&data, synapse->actions_list,
+ synapse->num_actions, buf,
+ counter_synapse_action_str);
+ break;
+ case COUNTER_DATA_TYPE_COUNT_MODE:
+ err = find_in_string_array(&data, available->items,
+ available->num_items, buf,
+ counter_count_mode_str);
+ break;
+ default:
+ err = kstrtou8(buf, 0, &data);
+ break;
+ }
+ if (err)
+ return err;
+
+ switch (a->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ err = a->data.device_u8_write(counter, data);
+ break;
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ err = a->data.signal_u8_write(counter, a->owner, data);
+ break;
+ case COUNTER_OWNER_TYPE_COUNT:
+ if (a->data.type == COUNTER_DATA_TYPE_SYNAPSE_ACTION)
+ err = a->data.action_write(counter, count, synapse,
+ data);
+ else
+ err = a->data.count_u8_write(counter, count, data);
+ break;
+ }
+ if (err)
+ return err;
+
+ return len;
+}
+
+static ssize_t counter_data_u64_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ const struct counter_attribute *const a = to_counter_attribute(attr);
+ struct counter_device *const counter = dev_get_drvdata(dev);
+ int err;
+ u64 data;
+
+ switch (a->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ err = a->data.device_u64_read(counter, &data);
+ break;
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ err = a->data.signal_u64_read(counter, a->owner, &data);
+ break;
+ case COUNTER_OWNER_TYPE_COUNT:
+ err = a->data.count_u64_read(counter, a->owner, &data);
+ break;
+ default: return -EINVAL;
+ }
+ if (err)
+ return err;
+
+ return sprintf(buf, "%llu\n", (unsigned long long)data);
+}
+
+static ssize_t counter_data_u64_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ const struct counter_attribute *const a = to_counter_attribute(attr);
+ struct counter_device *const counter = dev_get_drvdata(dev);
+ int err;
+ u64 data;
+
+ err = kstrtou64(buf, 0, &data);
+ if (err)
+ return err;
+
+ switch (a->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ err = a->data.device_u64_write(counter, data);
+ break;
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ err = a->data.signal_u64_write(counter, a->owner, data);
+ break;
+ case COUNTER_OWNER_TYPE_COUNT:
+ err = a->data.count_u64_write(counter, a->owner, data);
+ break;
+ }
+ if (err)
+ return err;
+
+ return len;
+}
+
+static ssize_t counter_data_string_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ const struct counter_attribute *const a = to_counter_attribute(attr);
+ struct counter_device *const counter = dev_get_drvdata(dev);
+
+ switch (a->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ return a->data.device_string_read(counter, buf, PAGE_SIZE);
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ return a->data.signal_string_read(counter, a->owner, buf,
+ PAGE_SIZE);
+ case COUNTER_OWNER_TYPE_COUNT:
+ return a->data.count_string_read(counter, a->owner, buf,
+ PAGE_SIZE);
+ }
+
+ return -EINVAL;
+}
+
+static ssize_t counter_data_string_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ const struct counter_attribute *const a = to_counter_attribute(attr);
+ struct counter_device *const counter = dev_get_drvdata(dev);
+
+ switch (a->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ return a->data.device_string_write(counter, buf, len);
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ return a->data.signal_string_write(counter, a->owner, buf, len);
+ case COUNTER_OWNER_TYPE_COUNT:
+ return a->data.count_string_write(counter, a->owner, buf, len);
+ }
+
+ return -EINVAL;
+}
+
+static ssize_t items_available_show(const u8 *const items,
+ const size_t num_items,
+ const char *const string_array[], char *buf)
+{
+ size_t len = 0;
+ size_t index;
+
+ for (index = 0; index < num_items; index++)
+ len += sprintf(buf + len, "%s\n", string_array[items[index]]);
+
+ return len;
+}
+
+static ssize_t counter_data_available_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ const struct counter_attribute *const a = to_counter_attribute(attr);
+ const struct counter_count *const count = a->owner;
+ const struct counter_synapse *const synapse = a->data.priv;
+ const struct counter_available *const available = a->data.priv;
+
+ switch (a->data.type) {
+ case COUNTER_DATA_TYPE_COUNT_FUNCTION:
+ return items_available_show(count->functions_list,
+ count->num_functions,
+ counter_count_function_str, buf);
+ case COUNTER_DATA_TYPE_SYNAPSE_ACTION:
+ return items_available_show(synapse->actions_list,
+ synapse->num_actions,
+ counter_synapse_action_str, buf);
+ case COUNTER_DATA_TYPE_COUNT_MODE:
+ return items_available_show(available->items,
+ available->num_items,
+ counter_count_mode_str, buf);
+ }
+
+ return -EINVAL;
+}
+
+struct counter_dynamic_name {
+ struct list_head l;
+ const char *name;
+};
+
+static int counter_available_attribute_create(
+ struct counter_attribute_group *const group,
+ struct list_head *const names, const struct counter_data *const data,
+ void *const owner)
+{
+ struct counter_attribute *counter_attr;
+ struct device_attribute *dev_attr;
+ struct counter_dynamic_name *dyn_name;
+
+ /* Allocate Counter attribute */
+ counter_attr = kzalloc(sizeof(*counter_attr), GFP_KERNEL);
+ if (!counter_attr)
+ return -ENOMEM;
+ list_add(&counter_attr->l, &group->attr_list);
+ group->num_attr++;
+
+ /* Configure Counter attribute */
+ counter_attr->data = *data;
+ counter_attr->owner = owner;
+
+ /* Initialize sysfs attribute */
+ dev_attr = &counter_attr->dev_attr;
+ sysfs_attr_init(&dev_attr->attr);
+
+ /* Generate dynamic name list item */
+ dyn_name = kmalloc(sizeof(*dyn_name), GFP_KERNEL);
+ if (!dyn_name)
+ return -ENOMEM;
+ list_add(&dyn_name->l, names);
+
+ /* Generate available attribute name */
+ dyn_name->name = kasprintf(GFP_KERNEL, "%s_available", data->name);
+ if (!dyn_name->name)
+ return -ENOMEM;
+
+ /* Configure device attribute */
+ dev_attr->attr.name = dyn_name->name;
+ dev_attr->attr.mode = 0444;
+ dev_attr->show = counter_data_available_show;
+
+ return 0;
+}
+
+static int counter_attribute_create(struct counter_attribute_group *const group,
+ struct list_head *const names,
+ const struct counter_data *const data,
+ const enum counter_owner_type type,
+ void *const owner)
+{
+ struct counter_attribute *counter_attr;
+ struct device_attribute *dev_attr;
+
+ /* Allocate Counter attribute */
+ counter_attr = kzalloc(sizeof(*counter_attr), GFP_KERNEL);
+ if (!counter_attr)
+ return -ENOMEM;
+ list_add(&counter_attr->l, &group->attr_list);
+ group->num_attr++;
+
+ /* Configure Counter attribute */
+ counter_attr->data = *data;
+ counter_attr->type = type;
+ counter_attr->owner = owner;
+
+ /* Configure device attribute */
+ dev_attr = &counter_attr->dev_attr;
+ sysfs_attr_init(&dev_attr->attr);
+ dev_attr->attr.name = data->name;
+ switch (data->type) {
+ case COUNTER_DATA_TYPE_U8:
+ case COUNTER_DATA_TYPE_BOOL:
+ case COUNTER_DATA_TYPE_SIGNAL:
+ case COUNTER_DATA_TYPE_COUNT_FUNCTION:
+ case COUNTER_DATA_TYPE_SYNAPSE_ACTION:
+ case COUNTER_DATA_TYPE_COUNT_DIRECTION:
+ case COUNTER_DATA_TYPE_COUNT_MODE:
+ if (data->device_u8_read) {
+ dev_attr->attr.mode |= 0444;
+ dev_attr->show = counter_data_u8_show;
+ }
+ if (data->device_u8_write) {
+ dev_attr->attr.mode |= 0200;
+ dev_attr->store = counter_data_u8_store;
+ }
+ break;
+ case COUNTER_DATA_TYPE_U64:
+ if (data->device_u64_read) {
+ dev_attr->attr.mode |= 0444;
+ dev_attr->show = counter_data_u64_show;
+ }
+ if (data->device_u64_write) {
+ dev_attr->attr.mode |= 0200;
+ dev_attr->store = counter_data_u64_store;
+ }
+ break;
+ case COUNTER_DATA_TYPE_STRING:
+ if (data->device_string_read) {
+ dev_attr->attr.mode |= 0444;
+ dev_attr->show = counter_data_string_show;
+ }
+ if (data->device_string_write) {
+ dev_attr->attr.mode |= 0200;
+ dev_attr->store = counter_data_string_store;
+ }
+ break;
+ }
+
+ switch (data->type) {
+ case COUNTER_DATA_TYPE_COUNT_FUNCTION:
+ case COUNTER_DATA_TYPE_SYNAPSE_ACTION:
+ case COUNTER_DATA_TYPE_COUNT_MODE:
+ return counter_available_attribute_create(group, names, data,
+ owner);
+ }
+
+ return 0;
+}
+
+static struct counter_data counter_signal_data = {
+ .type = COUNTER_DATA_TYPE_SIGNAL,
+ .name = "signal",
+};
+
+static struct counter_data counter_name_data =
+ COUNTER_DATA_DEVICE_STRING("name", NULL, NULL);
+
+static ssize_t counter_signal_name_read(struct counter_device *counter,
+ struct counter_signal *signal,
+ char *buf, size_t size)
+{
+ return snprintf(buf, size, "%s\n", signal->name);
+}
+
+static int counter_signal_attributes_create(
+ struct counter_attribute_group *const group,
+ struct counter_device *const counter,
+ struct counter_signal *const signal)
+{
+ struct list_head *const names = &counter->dynamic_names_list;
+ const enum counter_owner_type type = COUNTER_OWNER_TYPE_SIGNAL;
+ int err;
+ struct counter_data data;
+ size_t i;
+ const struct counter_data *ext;
+
+ /* Create main Signal attribute */
+ data = counter_signal_data;
+ data.signal_u8_read = counter->signal_read;
+ err = counter_attribute_create(group, names, &data, type, signal);
+ if (err)
+ return err;
+
+ /* Create Signal name attribute */
+ data = counter_name_data;
+ data.signal_string_read = counter_signal_name_read;
+ err = counter_attribute_create(group, names, &data, type, signal);
+ if (err)
+ return err;
+
+ /* Create an attribute for each extension */
+ for (i = 0; i < signal->num_ext; i++) {
+ ext = signal->ext + i;
+ err = counter_attribute_create(group, names, ext, type, signal);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+static int counter_signals_register(
+ struct counter_attribute_group *const groups_list,
+ struct counter_device *const counter)
+{
+ size_t i;
+ struct counter_signal *signal;
+ const char *name;
+ int err;
+
+ /* Register each Signal */
+ for (i = 0; i < counter->num_signals; i++) {
+ signal = counter->signals + i;
+
+ /* Generate Signal attribute directory name */
+ name = kasprintf(GFP_KERNEL, "signal%d", signal->id);
+ if (!name)
+ return -ENOMEM;
+ groups_list[i].attr_group.name = name;
+
+ /* Create all attributes associated with Signal */
+ err = counter_signal_attributes_create(groups_list + i, counter,
+ signal);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+static int counter_synapses_register(
+ struct counter_attribute_group *const group,
+ struct counter_device *const counter, struct counter_count *const count)
+{
+ struct list_head *const names = &counter->dynamic_names_list;
+ const enum counter_owner_type type = COUNTER_OWNER_TYPE_COUNT;
+ size_t i;
+ struct counter_synapse *synapse;
+ int id;
+ struct counter_dynamic_name *dyn_name;
+ struct counter_data data;
+ int err;
+
+ /* Register each Synapse */
+ for (i = 0; i < count->num_synapses; i++) {
+ synapse = count->synapses + i;
+ id = synapse->signal->id;
+
+ /* Generate dynamic name list item */
+ dyn_name = kmalloc(sizeof(*dyn_name), GFP_KERNEL);
+ if (!dyn_name)
+ return -ENOMEM;
+ list_add(&dyn_name->l, names);
+
+ /* Generate Synapse action name */
+ dyn_name->name = kasprintf(GFP_KERNEL, "signal%d_action", id);
+ if (!dyn_name->name)
+ return -ENOMEM;
+
+ /* Create action attribute */
+ data.type = COUNTER_DATA_TYPE_SYNAPSE_ACTION;
+ data.name = dyn_name->name;
+ data.action_read = counter->action_read;
+ data.action_write = counter->action_write;
+ data.priv = synapse;
+ err = counter_attribute_create(group, names, &data, type,
+ count);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+static struct counter_data counter_count_data =
+ COUNTER_DATA_COUNT_U64("count", NULL, NULL);
+
+static ssize_t counter_count_name_read(struct counter_device *counter,
+ struct counter_count *count, char *buf,
+ size_t size)
+{
+ return snprintf(buf, size, "%s\n", count->name);
+}
+
+static struct counter_data counter_count_function_data = {
+ .type = COUNTER_DATA_TYPE_COUNT_FUNCTION,
+ .name = "function",
+};
+
+static int counter_count_attributes_create(
+ struct counter_attribute_group *const group,
+ struct counter_device *const counter,
+ struct counter_count *const count)
+{
+ struct list_head *const names = &counter->dynamic_names_list;
+ const enum counter_owner_type type = COUNTER_OWNER_TYPE_COUNT;
+ int err;
+ struct counter_data data;
+ size_t i;
+ const struct counter_data *ext;
+
+ /* Create main Count attribute */
+ data = counter_count_data;
+ data.count_u64_read = counter->count_read;
+ data.count_u64_write = counter->count_write;
+ err = counter_attribute_create(group, names, &data, type, count);
+ if (err)
+ return err;
+
+ /* Create Count name attribute */
+ data = counter_name_data;
+ data.count_string_read = counter_count_name_read;
+ err = counter_attribute_create(group, names, &data, type, count);
+ if (err)
+ return err;
+
+ /* Create Count function attribute */
+ data = counter_count_function_data;
+ data.count_u8_read = counter->function_read;
+ data.count_u8_write = counter->function_write;
+ err = counter_attribute_create(group, names, &data, type, count);
+ if (err)
+ return err;
+
+ /* Create an attribute for each extension */
+ for (i = 0; i < count->num_ext; i++) {
+ ext = count->ext + i;
+ err = counter_attribute_create(group, names, ext, type, count);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+static int counter_counts_register(
+ struct counter_attribute_group *const groups_list,
+ struct counter_device *const counter)
+{
+ size_t i;
+ struct counter_count *count;
+ const char *name;
+ int err;
+
+ /* Register each Count */
+ for (i = 0; i < counter->num_counts; i++) {
+ count = counter->counts + i;
+
+ /* Generate Count attribute directory name */
+ name = kasprintf(GFP_KERNEL, "count%d", count->id);
+ if (!name)
+ return -ENOMEM;
+ groups_list[i].attr_group.name = name;
+
+ /* Register the Synapses associated with each Count */
+ err = counter_synapses_register(groups_list + i, counter,
+ count);
+ if (err)
+ return err;
+
+ /* Create all attributes associated with Count */
+ err = counter_count_attributes_create(groups_list + i, counter,
+ count);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+static ssize_t counter_name_read(struct counter_device *counter, char *buf,
+ size_t size)
+{
+ return snprintf(buf, size, "%s\n", counter->name);
+}
+
+static int counter_num_signals_read(struct counter_device *counter, u8 *val)
+{
+ *val = counter->num_signals;
+ return 0;
+}
+
+static int counter_num_counts_read(struct counter_device *counter, u8 *val)
+{
+ *val = counter->num_counts;
+ return 0;
+}
+
+static struct counter_data counter_num_signals_data =
+ COUNTER_DATA_DEVICE_U8("num_signals", counter_num_signals_read, NULL);
+
+static struct counter_data counter_num_counts_data =
+ COUNTER_DATA_DEVICE_U8("num_counts", counter_num_counts_read, NULL);
+
+static void counter_groups_list_free(struct counter_device *const counter)
+{
+ struct counter_attribute_group *group;
+ struct counter_attribute *p, *n;
+
+ /* Loop through all attribute groups (signals, counts, device, etc.) */
+ while (counter->num_groups--) {
+ group = counter->groups_list + counter->num_groups;
+
+ /* Free all attribute group and associated attributes memory */
+ kfree(group->attr_group.name);
+ kfree(group->attr_group.attrs);
+
+ /* Free attribute list */
+ list_for_each_entry_safe(p, n, &group->attr_list, l)
+ kfree(p);
+ }
+
+ kfree(counter->groups_list);
+}
+
+static int counter_device_register(struct counter_attribute_group *group,
+ struct counter_device *const counter)
+{
+ struct list_head *const names = &counter->dynamic_names_list;
+ const enum counter_owner_type type = COUNTER_OWNER_TYPE_DEVICE;
+ struct counter_data data;
+ int err;
+ size_t i;
+ const struct counter_data *ext;
+
+ /* Register Signals */
+ err = counter_signals_register(group, counter);
+ if (err)
+ goto err_free_groups_list;
+ group += counter->num_signals;
+
+ /* Register Counts and respective Synapses */
+ err = counter_counts_register(group, counter);
+ if (err)
+ goto err_free_groups_list;
+ group += counter->num_counts;
+
+ /* Create name attribute */
+ data = counter_name_data;
+ data.device_string_read = counter_name_read;
+ err = counter_attribute_create(group, names, &data, type, NULL);
+ if (err)
+ goto err_free_groups_list;
+
+ /* Create num_signals attribute */
+ data = counter_num_signals_data;
+ err = counter_attribute_create(group, names, &data, type, NULL);
+ if (err)
+ goto err_free_groups_list;
+
+ /* Create num_counts attribute */
+ data = counter_num_counts_data;
+ err = counter_attribute_create(group, names, &data, type, NULL);
+ if (err)
+ goto err_free_groups_list;
+
+ /* Create an attribute for each extension */
+ for (i = 0; i < counter->num_ext; i++) {
+ ext = counter->ext + i;
+ err = counter_attribute_create(group, names, ext, type, NULL);
+ if (err)
+ goto err_free_groups_list;
+ }
+
+ return 0;
+
+err_free_groups_list:
+ counter_groups_list_free(counter);
+ return err;
+}
+
+static int counter_groups_list_prepare(struct counter_device *const counter)
+{
+ const size_t num_grps = counter->num_signals + counter->num_counts + 1;
+ struct counter_attribute_group *groups_list;
+ size_t i;
+
+ /* Allocate space for attribute groups (signals, counts, and ext) */
+ groups_list = kcalloc(num_grps, sizeof(*groups_list), GFP_KERNEL);
+ if (!groups_list)
+ return -ENOMEM;
+
+ /* Store groups_list in counter structure */
+ counter->groups_list = groups_list;
+ counter->num_groups = num_grps;
+
+ /* Initialize attribute lists */
+ for (i = 0; i < num_grps; i++)
+ INIT_LIST_HEAD(&groups_list[i].attr_list);
+
+ /* Register Counter device attributes */
+ return counter_device_register(groups_list, counter);
+}
+
+static int counter_groups_prepare(struct counter_device *const counter)
+{
+ size_t i, j;
+ struct counter_attribute_group *group;
+ struct attribute **attrs;
+ int err;
+ struct counter_attribute *p;
+
+ /* Allocate attribute groups for association with device */
+ counter->groups = kcalloc(counter->num_groups + 1,
+ sizeof(*counter->groups), GFP_KERNEL);
+ if (!counter->groups)
+ return -ENOMEM;
+
+ /* Prepare each group of attributes for association */
+ for (i = 0; i < counter->num_groups; i++) {
+ group = counter->groups_list + i;
+
+ /* Allocate space for attribute pointers */
+ attrs = kcalloc(group->num_attr + 1, sizeof(*attrs),
+ GFP_KERNEL);
+ if (!attrs) {
+ err = -ENOMEM;
+ goto err_free_groups;
+ }
+ group->attr_group.attrs = attrs;
+
+ /* Add attribute pointers to attribute group */
+ j = 0;
+ list_for_each_entry(p, &group->attr_list, l)
+ attrs[j++] = &p->dev_attr.attr;
+
+ /* Group attributes in attribute group */
+ counter->groups[i] = &group->attr_group;
+ }
+ /* Associate attributes with device */
+ counter->dev.groups = counter->groups;
+
+ return 0;
+
+err_free_groups:
+ kfree(counter->groups);
+ return err;
+}
+
+static void counter_dynamic_names_free(struct list_head *const names)
+{
+ struct counter_dynamic_name *p, *n;
+
+ list_for_each_entry_safe(p, n, names, l) {
+ kfree(p->name);
+ kfree(p);
+ }
+}
+
+int counter_sysfs_add(struct counter_device *const counter)
+{
+ int err;
+
+ /* Initialize Synapse names list */
+ INIT_LIST_HEAD(&counter->dynamic_names_list);
+
+ /* Prepare device attributes */
+ err = counter_groups_list_prepare(counter);
+ if (err)
+ goto err_free_names;
+
+ /* Organize device attributes to groups and match to device */
+ err = counter_groups_prepare(counter);
+ if (err)
+ goto err_free_groups_list;
+
+ return 0;
+
+err_free_groups_list:
+ counter_groups_list_free(counter);
+err_free_names:
+ counter_dynamic_names_free(&counter->dynamic_names_list);
+ return err;
+}
+
+void counter_sysfs_free(struct counter_device *const counter)
+{
+ kfree(counter->groups);
+ counter_groups_list_free(counter);
+ counter_dynamic_names_free(&counter->dynamic_names_list);
+}
diff --git a/drivers/counter/counter-sysfs.h b/drivers/counter/counter-sysfs.h
new file mode 100644
index 000000000000..00e7cd6ea083
--- /dev/null
+++ b/drivers/counter/counter-sysfs.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Counter sysfs interface
+ * Copyright (C) 2020 William Breathitt Gray
+ */
+#ifndef _COUNTER_SYSFS_H_
+#define _COUNTER_SYSFS_H_
+
+#include <linux/counter.h>
+
+int counter_sysfs_add(struct counter_device *const counter);
+void counter_sysfs_free(struct counter_device *const counter);
+
+#endif /* _COUNTER_SYSFS_H_ */
diff --git a/drivers/counter/counter.c b/drivers/counter/counter.c
deleted file mode 100644
index 6a683d086008..000000000000
--- a/drivers/counter/counter.c
+++ /dev/null
@@ -1,1496 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Generic Counter interface
- * Copyright (C) 2018 William Breathitt Gray
- */
-#include <linux/counter.h>
-#include <linux/device.h>
-#include <linux/err.h>
-#include <linux/export.h>
-#include <linux/fs.h>
-#include <linux/gfp.h>
-#include <linux/idr.h>
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/list.h>
-#include <linux/module.h>
-#include <linux/printk.h>
-#include <linux/slab.h>
-#include <linux/string.h>
-#include <linux/sysfs.h>
-#include <linux/types.h>
-
-const char *const counter_count_direction_str[2] = {
- [COUNTER_COUNT_DIRECTION_FORWARD] = "forward",
- [COUNTER_COUNT_DIRECTION_BACKWARD] = "backward"
-};
-EXPORT_SYMBOL_GPL(counter_count_direction_str);
-
-const char *const counter_count_mode_str[4] = {
- [COUNTER_COUNT_MODE_NORMAL] = "normal",
- [COUNTER_COUNT_MODE_RANGE_LIMIT] = "range limit",
- [COUNTER_COUNT_MODE_NON_RECYCLE] = "non-recycle",
- [COUNTER_COUNT_MODE_MODULO_N] = "modulo-n"
-};
-EXPORT_SYMBOL_GPL(counter_count_mode_str);
-
-ssize_t counter_signal_enum_read(struct counter_device *counter,
- struct counter_signal *signal, void *priv,
- char *buf)
-{
- const struct counter_signal_enum_ext *const e = priv;
- int err;
- size_t index;
-
- if (!e->get)
- return -EINVAL;
-
- err = e->get(counter, signal, &index);
- if (err)
- return err;
-
- if (index >= e->num_items)
- return -EINVAL;
-
- return sprintf(buf, "%s\n", e->items[index]);
-}
-EXPORT_SYMBOL_GPL(counter_signal_enum_read);
-
-ssize_t counter_signal_enum_write(struct counter_device *counter,
- struct counter_signal *signal, void *priv,
- const char *buf, size_t len)
-{
- const struct counter_signal_enum_ext *const e = priv;
- ssize_t index;
- int err;
-
- if (!e->set)
- return -EINVAL;
-
- index = __sysfs_match_string(e->items, e->num_items, buf);
- if (index < 0)
- return index;
-
- err = e->set(counter, signal, index);
- if (err)
- return err;
-
- return len;
-}
-EXPORT_SYMBOL_GPL(counter_signal_enum_write);
-
-ssize_t counter_signal_enum_available_read(struct counter_device *counter,
- struct counter_signal *signal,
- void *priv, char *buf)
-{
- const struct counter_signal_enum_ext *const e = priv;
- size_t i;
- size_t len = 0;
-
- if (!e->num_items)
- return 0;
-
- for (i = 0; i < e->num_items; i++)
- len += sprintf(buf + len, "%s\n", e->items[i]);
-
- return len;
-}
-EXPORT_SYMBOL_GPL(counter_signal_enum_available_read);
-
-ssize_t counter_count_enum_read(struct counter_device *counter,
- struct counter_count *count, void *priv,
- char *buf)
-{
- const struct counter_count_enum_ext *const e = priv;
- int err;
- size_t index;
-
- if (!e->get)
- return -EINVAL;
-
- err = e->get(counter, count, &index);
- if (err)
- return err;
-
- if (index >= e->num_items)
- return -EINVAL;
-
- return sprintf(buf, "%s\n", e->items[index]);
-}
-EXPORT_SYMBOL_GPL(counter_count_enum_read);
-
-ssize_t counter_count_enum_write(struct counter_device *counter,
- struct counter_count *count, void *priv,
- const char *buf, size_t len)
-{
- const struct counter_count_enum_ext *const e = priv;
- ssize_t index;
- int err;
-
- if (!e->set)
- return -EINVAL;
-
- index = __sysfs_match_string(e->items, e->num_items, buf);
- if (index < 0)
- return index;
-
- err = e->set(counter, count, index);
- if (err)
- return err;
-
- return len;
-}
-EXPORT_SYMBOL_GPL(counter_count_enum_write);
-
-ssize_t counter_count_enum_available_read(struct counter_device *counter,
- struct counter_count *count,
- void *priv, char *buf)
-{
- const struct counter_count_enum_ext *const e = priv;
- size_t i;
- size_t len = 0;
-
- if (!e->num_items)
- return 0;
-
- for (i = 0; i < e->num_items; i++)
- len += sprintf(buf + len, "%s\n", e->items[i]);
-
- return len;
-}
-EXPORT_SYMBOL_GPL(counter_count_enum_available_read);
-
-ssize_t counter_device_enum_read(struct counter_device *counter, void *priv,
- char *buf)
-{
- const struct counter_device_enum_ext *const e = priv;
- int err;
- size_t index;
-
- if (!e->get)
- return -EINVAL;
-
- err = e->get(counter, &index);
- if (err)
- return err;
-
- if (index >= e->num_items)
- return -EINVAL;
-
- return sprintf(buf, "%s\n", e->items[index]);
-}
-EXPORT_SYMBOL_GPL(counter_device_enum_read);
-
-ssize_t counter_device_enum_write(struct counter_device *counter, void *priv,
- const char *buf, size_t len)
-{
- const struct counter_device_enum_ext *const e = priv;
- ssize_t index;
- int err;
-
- if (!e->set)
- return -EINVAL;
-
- index = __sysfs_match_string(e->items, e->num_items, buf);
- if (index < 0)
- return index;
-
- err = e->set(counter, index);
- if (err)
- return err;
-
- return len;
-}
-EXPORT_SYMBOL_GPL(counter_device_enum_write);
-
-ssize_t counter_device_enum_available_read(struct counter_device *counter,
- void *priv, char *buf)
-{
- const struct counter_device_enum_ext *const e = priv;
- size_t i;
- size_t len = 0;
-
- if (!e->num_items)
- return 0;
-
- for (i = 0; i < e->num_items; i++)
- len += sprintf(buf + len, "%s\n", e->items[i]);
-
- return len;
-}
-EXPORT_SYMBOL_GPL(counter_device_enum_available_read);
-
-struct counter_attr_parm {
- struct counter_device_attr_group *group;
- const char *prefix;
- const char *name;
- ssize_t (*show)(struct device *dev, struct device_attribute *attr,
- char *buf);
- ssize_t (*store)(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t len);
- void *component;
-};
-
-struct counter_device_attr {
- struct device_attribute dev_attr;
- struct list_head l;
- void *component;
-};
-
-static int counter_attribute_create(const struct counter_attr_parm *const parm)
-{
- struct counter_device_attr *counter_attr;
- struct device_attribute *dev_attr;
- int err;
- struct list_head *const attr_list = &parm->group->attr_list;
-
- /* Allocate a Counter device attribute */
- counter_attr = kzalloc(sizeof(*counter_attr), GFP_KERNEL);
- if (!counter_attr)
- return -ENOMEM;
- dev_attr = &counter_attr->dev_attr;
-
- sysfs_attr_init(&dev_attr->attr);
-
- /* Configure device attribute */
- dev_attr->attr.name = kasprintf(GFP_KERNEL, "%s%s", parm->prefix,
- parm->name);
- if (!dev_attr->attr.name) {
- err = -ENOMEM;
- goto err_free_counter_attr;
- }
- if (parm->show) {
- dev_attr->attr.mode |= 0444;
- dev_attr->show = parm->show;
- }
- if (parm->store) {
- dev_attr->attr.mode |= 0200;
- dev_attr->store = parm->store;
- }
-
- /* Store associated Counter component with attribute */
- counter_attr->component = parm->component;
-
- /* Keep track of the attribute for later cleanup */
- list_add(&counter_attr->l, attr_list);
- parm->group->num_attr++;
-
- return 0;
-
-err_free_counter_attr:
- kfree(counter_attr);
- return err;
-}
-
-#define to_counter_attr(_dev_attr) \
- container_of(_dev_attr, struct counter_device_attr, dev_attr)
-
-struct counter_signal_unit {
- struct counter_signal *signal;
-};
-
-static const char *const counter_signal_value_str[] = {
- [COUNTER_SIGNAL_LOW] = "low",
- [COUNTER_SIGNAL_HIGH] = "high"
-};
-
-static ssize_t counter_signal_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct counter_device *const counter = dev_get_drvdata(dev);
- const struct counter_device_attr *const devattr = to_counter_attr(attr);
- const struct counter_signal_unit *const component = devattr->component;
- struct counter_signal *const signal = component->signal;
- int err;
- enum counter_signal_value val;
-
- err = counter->ops->signal_read(counter, signal, &val);
- if (err)
- return err;
-
- return sprintf(buf, "%s\n", counter_signal_value_str[val]);
-}
-
-struct counter_name_unit {
- const char *name;
-};
-
-static ssize_t counter_device_attr_name_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- const struct counter_name_unit *const comp = to_counter_attr(attr)->component;
-
- return sprintf(buf, "%s\n", comp->name);
-}
-
-static int counter_name_attribute_create(
- struct counter_device_attr_group *const group,
- const char *const name)
-{
- struct counter_name_unit *name_comp;
- struct counter_attr_parm parm;
- int err;
-
- /* Skip if no name */
- if (!name)
- return 0;
-
- /* Allocate name attribute component */
- name_comp = kmalloc(sizeof(*name_comp), GFP_KERNEL);
- if (!name_comp)
- return -ENOMEM;
- name_comp->name = name;
-
- /* Allocate Signal name attribute */
- parm.group = group;
- parm.prefix = "";
- parm.name = "name";
- parm.show = counter_device_attr_name_show;
- parm.store = NULL;
- parm.component = name_comp;
- err = counter_attribute_create(&parm);
- if (err)
- goto err_free_name_comp;
-
- return 0;
-
-err_free_name_comp:
- kfree(name_comp);
- return err;
-}
-
-struct counter_signal_ext_unit {
- struct counter_signal *signal;
- const struct counter_signal_ext *ext;
-};
-
-static ssize_t counter_signal_ext_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- const struct counter_device_attr *const devattr = to_counter_attr(attr);
- const struct counter_signal_ext_unit *const comp = devattr->component;
- const struct counter_signal_ext *const ext = comp->ext;
-
- return ext->read(dev_get_drvdata(dev), comp->signal, ext->priv, buf);
-}
-
-static ssize_t counter_signal_ext_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t len)
-{
- const struct counter_device_attr *const devattr = to_counter_attr(attr);
- const struct counter_signal_ext_unit *const comp = devattr->component;
- const struct counter_signal_ext *const ext = comp->ext;
-
- return ext->write(dev_get_drvdata(dev), comp->signal, ext->priv, buf,
- len);
-}
-
-static void counter_device_attr_list_free(struct list_head *attr_list)
-{
- struct counter_device_attr *p, *n;
-
- list_for_each_entry_safe(p, n, attr_list, l) {
- /* free attribute name and associated component memory */
- kfree(p->dev_attr.attr.name);
- kfree(p->component);
- list_del(&p->l);
- kfree(p);
- }
-}
-
-static int counter_signal_ext_register(
- struct counter_device_attr_group *const group,
- struct counter_signal *const signal)
-{
- const size_t num_ext = signal->num_ext;
- size_t i;
- const struct counter_signal_ext *ext;
- struct counter_signal_ext_unit *signal_ext_comp;
- struct counter_attr_parm parm;
- int err;
-
- /* Create an attribute for each extension */
- for (i = 0 ; i < num_ext; i++) {
- ext = signal->ext + i;
-
- /* Allocate signal_ext attribute component */
- signal_ext_comp = kmalloc(sizeof(*signal_ext_comp), GFP_KERNEL);
- if (!signal_ext_comp) {
- err = -ENOMEM;
- goto err_free_attr_list;
- }
- signal_ext_comp->signal = signal;
- signal_ext_comp->ext = ext;
-
- /* Allocate a Counter device attribute */
- parm.group = group;
- parm.prefix = "";
- parm.name = ext->name;
- parm.show = (ext->read) ? counter_signal_ext_show : NULL;
- parm.store = (ext->write) ? counter_signal_ext_store : NULL;
- parm.component = signal_ext_comp;
- err = counter_attribute_create(&parm);
- if (err) {
- kfree(signal_ext_comp);
- goto err_free_attr_list;
- }
- }
-
- return 0;
-
-err_free_attr_list:
- counter_device_attr_list_free(&group->attr_list);
- return err;
-}
-
-static int counter_signal_attributes_create(
- struct counter_device_attr_group *const group,
- const struct counter_device *const counter,
- struct counter_signal *const signal)
-{
- struct counter_signal_unit *signal_comp;
- struct counter_attr_parm parm;
- int err;
-
- /* Allocate Signal attribute component */
- signal_comp = kmalloc(sizeof(*signal_comp), GFP_KERNEL);
- if (!signal_comp)
- return -ENOMEM;
- signal_comp->signal = signal;
-
- /* Create main Signal attribute */
- parm.group = group;
- parm.prefix = "";
- parm.name = "signal";
- parm.show = (counter->ops->signal_read) ? counter_signal_show : NULL;
- parm.store = NULL;
- parm.component = signal_comp;
- err = counter_attribute_create(&parm);
- if (err) {
- kfree(signal_comp);
- return err;
- }
-
- /* Create Signal name attribute */
- err = counter_name_attribute_create(group, signal->name);
- if (err)
- goto err_free_attr_list;
-
- /* Register Signal extension attributes */
- err = counter_signal_ext_register(group, signal);
- if (err)
- goto err_free_attr_list;
-
- return 0;
-
-err_free_attr_list:
- counter_device_attr_list_free(&group->attr_list);
- return err;
-}
-
-static int counter_signals_register(
- struct counter_device_attr_group *const groups_list,
- const struct counter_device *const counter)
-{
- const size_t num_signals = counter->num_signals;
- size_t i;
- struct counter_signal *signal;
- const char *name;
- int err;
-
- /* Register each Signal */
- for (i = 0; i < num_signals; i++) {
- signal = counter->signals + i;
-
- /* Generate Signal attribute directory name */
- name = kasprintf(GFP_KERNEL, "signal%d", signal->id);
- if (!name) {
- err = -ENOMEM;
- goto err_free_attr_groups;
- }
- groups_list[i].attr_group.name = name;
-
- /* Create all attributes associated with Signal */
- err = counter_signal_attributes_create(groups_list + i, counter,
- signal);
- if (err)
- goto err_free_attr_groups;
- }
-
- return 0;
-
-err_free_attr_groups:
- do {
- kfree(groups_list[i].attr_group.name);
- counter_device_attr_list_free(&groups_list[i].attr_list);
- } while (i--);
- return err;
-}
-
-static const char *const counter_synapse_action_str[] = {
- [COUNTER_SYNAPSE_ACTION_NONE] = "none",
- [COUNTER_SYNAPSE_ACTION_RISING_EDGE] = "rising edge",
- [COUNTER_SYNAPSE_ACTION_FALLING_EDGE] = "falling edge",
- [COUNTER_SYNAPSE_ACTION_BOTH_EDGES] = "both edges"
-};
-
-struct counter_action_unit {
- struct counter_synapse *synapse;
- struct counter_count *count;
-};
-
-static ssize_t counter_action_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- const struct counter_device_attr *const devattr = to_counter_attr(attr);
- int err;
- struct counter_device *const counter = dev_get_drvdata(dev);
- const struct counter_action_unit *const component = devattr->component;
- struct counter_count *const count = component->count;
- struct counter_synapse *const synapse = component->synapse;
- size_t action_index;
- enum counter_synapse_action action;
-
- err = counter->ops->action_get(counter, count, synapse, &action_index);
- if (err)
- return err;
-
- synapse->action = action_index;
-
- action = synapse->actions_list[action_index];
- return sprintf(buf, "%s\n", counter_synapse_action_str[action]);
-}
-
-static ssize_t counter_action_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t len)
-{
- const struct counter_device_attr *const devattr = to_counter_attr(attr);
- const struct counter_action_unit *const component = devattr->component;
- struct counter_synapse *const synapse = component->synapse;
- size_t action_index;
- const size_t num_actions = synapse->num_actions;
- enum counter_synapse_action action;
- int err;
- struct counter_device *const counter = dev_get_drvdata(dev);
- struct counter_count *const count = component->count;
-
- /* Find requested action mode */
- for (action_index = 0; action_index < num_actions; action_index++) {
- action = synapse->actions_list[action_index];
- if (sysfs_streq(buf, counter_synapse_action_str[action]))
- break;
- }
- /* If requested action mode not found */
- if (action_index >= num_actions)
- return -EINVAL;
-
- err = counter->ops->action_set(counter, count, synapse, action_index);
- if (err)
- return err;
-
- synapse->action = action_index;
-
- return len;
-}
-
-struct counter_action_avail_unit {
- const enum counter_synapse_action *actions_list;
- size_t num_actions;
-};
-
-static ssize_t counter_synapse_action_available_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- const struct counter_device_attr *const devattr = to_counter_attr(attr);
- const struct counter_action_avail_unit *const component = devattr->component;
- size_t i;
- enum counter_synapse_action action;
- ssize_t len = 0;
-
- for (i = 0; i < component->num_actions; i++) {
- action = component->actions_list[i];
- len += sprintf(buf + len, "%s\n",
- counter_synapse_action_str[action]);
- }
-
- return len;
-}
-
-static int counter_synapses_register(
- struct counter_device_attr_group *const group,
- const struct counter_device *const counter,
- struct counter_count *const count, const char *const count_attr_name)
-{
- size_t i;
- struct counter_synapse *synapse;
- const char *prefix;
- struct counter_action_unit *action_comp;
- struct counter_attr_parm parm;
- int err;
- struct counter_action_avail_unit *avail_comp;
-
- /* Register each Synapse */
- for (i = 0; i < count->num_synapses; i++) {
- synapse = count->synapses + i;
-
- /* Generate attribute prefix */
- prefix = kasprintf(GFP_KERNEL, "signal%d_",
- synapse->signal->id);
- if (!prefix) {
- err = -ENOMEM;
- goto err_free_attr_list;
- }
-
- /* Allocate action attribute component */
- action_comp = kmalloc(sizeof(*action_comp), GFP_KERNEL);
- if (!action_comp) {
- err = -ENOMEM;
- goto err_free_prefix;
- }
- action_comp->synapse = synapse;
- action_comp->count = count;
-
- /* Create action attribute */
- parm.group = group;
- parm.prefix = prefix;
- parm.name = "action";
- parm.show = (counter->ops->action_get) ? counter_action_show : NULL;
- parm.store = (counter->ops->action_set) ? counter_action_store : NULL;
- parm.component = action_comp;
- err = counter_attribute_create(&parm);
- if (err) {
- kfree(action_comp);
- goto err_free_prefix;
- }
-
- /* Allocate action available attribute component */
- avail_comp = kmalloc(sizeof(*avail_comp), GFP_KERNEL);
- if (!avail_comp) {
- err = -ENOMEM;
- goto err_free_prefix;
- }
- avail_comp->actions_list = synapse->actions_list;
- avail_comp->num_actions = synapse->num_actions;
-
- /* Create action_available attribute */
- parm.group = group;
- parm.prefix = prefix;
- parm.name = "action_available";
- parm.show = counter_synapse_action_available_show;
- parm.store = NULL;
- parm.component = avail_comp;
- err = counter_attribute_create(&parm);
- if (err) {
- kfree(avail_comp);
- goto err_free_prefix;
- }
-
- kfree(prefix);
- }
-
- return 0;
-
-err_free_prefix:
- kfree(prefix);
-err_free_attr_list:
- counter_device_attr_list_free(&group->attr_list);
- return err;
-}
-
-struct counter_count_unit {
- struct counter_count *count;
-};
-
-static ssize_t counter_count_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- struct counter_device *const counter = dev_get_drvdata(dev);
- const struct counter_device_attr *const devattr = to_counter_attr(attr);
- const struct counter_count_unit *const component = devattr->component;
- struct counter_count *const count = component->count;
- int err;
- unsigned long val;
-
- err = counter->ops->count_read(counter, count, &val);
- if (err)
- return err;
-
- return sprintf(buf, "%lu\n", val);
-}
-
-static ssize_t counter_count_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t len)
-{
- struct counter_device *const counter = dev_get_drvdata(dev);
- const struct counter_device_attr *const devattr = to_counter_attr(attr);
- const struct counter_count_unit *const component = devattr->component;
- struct counter_count *const count = component->count;
- int err;
- unsigned long val;
-
- err = kstrtoul(buf, 0, &val);
- if (err)
- return err;
-
- err = counter->ops->count_write(counter, count, val);
- if (err)
- return err;
-
- return len;
-}
-
-static const char *const counter_count_function_str[] = {
- [COUNTER_COUNT_FUNCTION_INCREASE] = "increase",
- [COUNTER_COUNT_FUNCTION_DECREASE] = "decrease",
- [COUNTER_COUNT_FUNCTION_PULSE_DIRECTION] = "pulse-direction",
- [COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A] = "quadrature x1 a",
- [COUNTER_COUNT_FUNCTION_QUADRATURE_X1_B] = "quadrature x1 b",
- [COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A] = "quadrature x2 a",
- [COUNTER_COUNT_FUNCTION_QUADRATURE_X2_B] = "quadrature x2 b",
- [COUNTER_COUNT_FUNCTION_QUADRATURE_X4] = "quadrature x4"
-};
-
-static ssize_t counter_function_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- int err;
- struct counter_device *const counter = dev_get_drvdata(dev);
- const struct counter_device_attr *const devattr = to_counter_attr(attr);
- const struct counter_count_unit *const component = devattr->component;
- struct counter_count *const count = component->count;
- size_t func_index;
- enum counter_count_function function;
-
- err = counter->ops->function_get(counter, count, &func_index);
- if (err)
- return err;
-
- count->function = func_index;
-
- function = count->functions_list[func_index];
- return sprintf(buf, "%s\n", counter_count_function_str[function]);
-}
-
-static ssize_t counter_function_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t len)
-{
- const struct counter_device_attr *const devattr = to_counter_attr(attr);
- const struct counter_count_unit *const component = devattr->component;
- struct counter_count *const count = component->count;
- const size_t num_functions = count->num_functions;
- size_t func_index;
- enum counter_count_function function;
- int err;
- struct counter_device *const counter = dev_get_drvdata(dev);
-
- /* Find requested Count function mode */
- for (func_index = 0; func_index < num_functions; func_index++) {
- function = count->functions_list[func_index];
- if (sysfs_streq(buf, counter_count_function_str[function]))
- break;
- }
- /* Return error if requested Count function mode not found */
- if (func_index >= num_functions)
- return -EINVAL;
-
- err = counter->ops->function_set(counter, count, func_index);
- if (err)
- return err;
-
- count->function = func_index;
-
- return len;
-}
-
-struct counter_count_ext_unit {
- struct counter_count *count;
- const struct counter_count_ext *ext;
-};
-
-static ssize_t counter_count_ext_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- const struct counter_device_attr *const devattr = to_counter_attr(attr);
- const struct counter_count_ext_unit *const comp = devattr->component;
- const struct counter_count_ext *const ext = comp->ext;
-
- return ext->read(dev_get_drvdata(dev), comp->count, ext->priv, buf);
-}
-
-static ssize_t counter_count_ext_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t len)
-{
- const struct counter_device_attr *const devattr = to_counter_attr(attr);
- const struct counter_count_ext_unit *const comp = devattr->component;
- const struct counter_count_ext *const ext = comp->ext;
-
- return ext->write(dev_get_drvdata(dev), comp->count, ext->priv, buf,
- len);
-}
-
-static int counter_count_ext_register(
- struct counter_device_attr_group *const group,
- struct counter_count *const count)
-{
- size_t i;
- const struct counter_count_ext *ext;
- struct counter_count_ext_unit *count_ext_comp;
- struct counter_attr_parm parm;
- int err;
-
- /* Create an attribute for each extension */
- for (i = 0 ; i < count->num_ext; i++) {
- ext = count->ext + i;
-
- /* Allocate count_ext attribute component */
- count_ext_comp = kmalloc(sizeof(*count_ext_comp), GFP_KERNEL);
- if (!count_ext_comp) {
- err = -ENOMEM;
- goto err_free_attr_list;
- }
- count_ext_comp->count = count;
- count_ext_comp->ext = ext;
-
- /* Allocate count_ext attribute */
- parm.group = group;
- parm.prefix = "";
- parm.name = ext->name;
- parm.show = (ext->read) ? counter_count_ext_show : NULL;
- parm.store = (ext->write) ? counter_count_ext_store : NULL;
- parm.component = count_ext_comp;
- err = counter_attribute_create(&parm);
- if (err) {
- kfree(count_ext_comp);
- goto err_free_attr_list;
- }
- }
-
- return 0;
-
-err_free_attr_list:
- counter_device_attr_list_free(&group->attr_list);
- return err;
-}
-
-struct counter_func_avail_unit {
- const enum counter_count_function *functions_list;
- size_t num_functions;
-};
-
-static ssize_t counter_count_function_available_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- const struct counter_device_attr *const devattr = to_counter_attr(attr);
- const struct counter_func_avail_unit *const component = devattr->component;
- const enum counter_count_function *const func_list = component->functions_list;
- const size_t num_functions = component->num_functions;
- size_t i;
- enum counter_count_function function;
- ssize_t len = 0;
-
- for (i = 0; i < num_functions; i++) {
- function = func_list[i];
- len += sprintf(buf + len, "%s\n",
- counter_count_function_str[function]);
- }
-
- return len;
-}
-
-static int counter_count_attributes_create(
- struct counter_device_attr_group *const group,
- const struct counter_device *const counter,
- struct counter_count *const count)
-{
- struct counter_count_unit *count_comp;
- struct counter_attr_parm parm;
- int err;
- struct counter_count_unit *func_comp;
- struct counter_func_avail_unit *avail_comp;
-
- /* Allocate count attribute component */
- count_comp = kmalloc(sizeof(*count_comp), GFP_KERNEL);
- if (!count_comp)
- return -ENOMEM;
- count_comp->count = count;
-
- /* Create main Count attribute */
- parm.group = group;
- parm.prefix = "";
- parm.name = "count";
- parm.show = (counter->ops->count_read) ? counter_count_show : NULL;
- parm.store = (counter->ops->count_write) ? counter_count_store : NULL;
- parm.component = count_comp;
- err = counter_attribute_create(&parm);
- if (err) {
- kfree(count_comp);
- return err;
- }
-
- /* Allocate function attribute component */
- func_comp = kmalloc(sizeof(*func_comp), GFP_KERNEL);
- if (!func_comp) {
- err = -ENOMEM;
- goto err_free_attr_list;
- }
- func_comp->count = count;
-
- /* Create Count function attribute */
- parm.group = group;
- parm.prefix = "";
- parm.name = "function";
- parm.show = (counter->ops->function_get) ? counter_function_show : NULL;
- parm.store = (counter->ops->function_set) ? counter_function_store : NULL;
- parm.component = func_comp;
- err = counter_attribute_create(&parm);
- if (err) {
- kfree(func_comp);
- goto err_free_attr_list;
- }
-
- /* Allocate function available attribute component */
- avail_comp = kmalloc(sizeof(*avail_comp), GFP_KERNEL);
- if (!avail_comp) {
- err = -ENOMEM;
- goto err_free_attr_list;
- }
- avail_comp->functions_list = count->functions_list;
- avail_comp->num_functions = count->num_functions;
-
- /* Create Count function_available attribute */
- parm.group = group;
- parm.prefix = "";
- parm.name = "function_available";
- parm.show = counter_count_function_available_show;
- parm.store = NULL;
- parm.component = avail_comp;
- err = counter_attribute_create(&parm);
- if (err) {
- kfree(avail_comp);
- goto err_free_attr_list;
- }
-
- /* Create Count name attribute */
- err = counter_name_attribute_create(group, count->name);
- if (err)
- goto err_free_attr_list;
-
- /* Register Count extension attributes */
- err = counter_count_ext_register(group, count);
- if (err)
- goto err_free_attr_list;
-
- return 0;
-
-err_free_attr_list:
- counter_device_attr_list_free(&group->attr_list);
- return err;
-}
-
-static int counter_counts_register(
- struct counter_device_attr_group *const groups_list,
- const struct counter_device *const counter)
-{
- size_t i;
- struct counter_count *count;
- const char *name;
- int err;
-
- /* Register each Count */
- for (i = 0; i < counter->num_counts; i++) {
- count = counter->counts + i;
-
- /* Generate Count attribute directory name */
- name = kasprintf(GFP_KERNEL, "count%d", count->id);
- if (!name) {
- err = -ENOMEM;
- goto err_free_attr_groups;
- }
- groups_list[i].attr_group.name = name;
-
- /* Register the Synapses associated with each Count */
- err = counter_synapses_register(groups_list + i, counter, count,
- name);
- if (err)
- goto err_free_attr_groups;
-
- /* Create all attributes associated with Count */
- err = counter_count_attributes_create(groups_list + i, counter,
- count);
- if (err)
- goto err_free_attr_groups;
- }
-
- return 0;
-
-err_free_attr_groups:
- do {
- kfree(groups_list[i].attr_group.name);
- counter_device_attr_list_free(&groups_list[i].attr_list);
- } while (i--);
- return err;
-}
-
-struct counter_size_unit {
- size_t size;
-};
-
-static ssize_t counter_device_attr_size_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- const struct counter_size_unit *const comp = to_counter_attr(attr)->component;
-
- return sprintf(buf, "%zu\n", comp->size);
-}
-
-static int counter_size_attribute_create(
- struct counter_device_attr_group *const group,
- const size_t size, const char *const name)
-{
- struct counter_size_unit *size_comp;
- struct counter_attr_parm parm;
- int err;
-
- /* Allocate size attribute component */
- size_comp = kmalloc(sizeof(*size_comp), GFP_KERNEL);
- if (!size_comp)
- return -ENOMEM;
- size_comp->size = size;
-
- parm.group = group;
- parm.prefix = "";
- parm.name = name;
- parm.show = counter_device_attr_size_show;
- parm.store = NULL;
- parm.component = size_comp;
- err = counter_attribute_create(&parm);
- if (err)
- goto err_free_size_comp;
-
- return 0;
-
-err_free_size_comp:
- kfree(size_comp);
- return err;
-}
-
-struct counter_ext_unit {
- const struct counter_device_ext *ext;
-};
-
-static ssize_t counter_device_ext_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- const struct counter_device_attr *const devattr = to_counter_attr(attr);
- const struct counter_ext_unit *const component = devattr->component;
- const struct counter_device_ext *const ext = component->ext;
-
- return ext->read(dev_get_drvdata(dev), ext->priv, buf);
-}
-
-static ssize_t counter_device_ext_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t len)
-{
- const struct counter_device_attr *const devattr = to_counter_attr(attr);
- const struct counter_ext_unit *const component = devattr->component;
- const struct counter_device_ext *const ext = component->ext;
-
- return ext->write(dev_get_drvdata(dev), ext->priv, buf, len);
-}
-
-static int counter_device_ext_register(
- struct counter_device_attr_group *const group,
- struct counter_device *const counter)
-{
- size_t i;
- struct counter_ext_unit *ext_comp;
- struct counter_attr_parm parm;
- int err;
-
- /* Create an attribute for each extension */
- for (i = 0 ; i < counter->num_ext; i++) {
- /* Allocate extension attribute component */
- ext_comp = kmalloc(sizeof(*ext_comp), GFP_KERNEL);
- if (!ext_comp) {
- err = -ENOMEM;
- goto err_free_attr_list;
- }
-
- ext_comp->ext = counter->ext + i;
-
- /* Allocate extension attribute */
- parm.group = group;
- parm.prefix = "";
- parm.name = counter->ext[i].name;
- parm.show = (counter->ext[i].read) ? counter_device_ext_show : NULL;
- parm.store = (counter->ext[i].write) ? counter_device_ext_store : NULL;
- parm.component = ext_comp;
- err = counter_attribute_create(&parm);
- if (err) {
- kfree(ext_comp);
- goto err_free_attr_list;
- }
- }
-
- return 0;
-
-err_free_attr_list:
- counter_device_attr_list_free(&group->attr_list);
- return err;
-}
-
-static int counter_global_attr_register(
- struct counter_device_attr_group *const group,
- struct counter_device *const counter)
-{
- int err;
-
- /* Create name attribute */
- err = counter_name_attribute_create(group, counter->name);
- if (err)
- return err;
-
- /* Create num_counts attribute */
- err = counter_size_attribute_create(group, counter->num_counts,
- "num_counts");
- if (err)
- goto err_free_attr_list;
-
- /* Create num_signals attribute */
- err = counter_size_attribute_create(group, counter->num_signals,
- "num_signals");
- if (err)
- goto err_free_attr_list;
-
- /* Register Counter device extension attributes */
- err = counter_device_ext_register(group, counter);
- if (err)
- goto err_free_attr_list;
-
- return 0;
-
-err_free_attr_list:
- counter_device_attr_list_free(&group->attr_list);
- return err;
-}
-
-static void counter_device_groups_list_free(
- struct counter_device_attr_group *const groups_list,
- const size_t num_groups)
-{
- struct counter_device_attr_group *group;
- size_t i;
-
- /* loop through all attribute groups (signals, counts, global, etc.) */
- for (i = 0; i < num_groups; i++) {
- group = groups_list + i;
-
- /* free all attribute group and associated attributes memory */
- kfree(group->attr_group.name);
- kfree(group->attr_group.attrs);
- counter_device_attr_list_free(&group->attr_list);
- }
-
- kfree(groups_list);
-}
-
-static int counter_device_groups_list_prepare(
- struct counter_device *const counter)
-{
- const size_t total_num_groups =
- counter->num_signals + counter->num_counts + 1;
- struct counter_device_attr_group *groups_list;
- size_t i;
- int err;
- size_t num_groups = 0;
-
- /* Allocate space for attribute groups (signals, counts, and ext) */
- groups_list = kcalloc(total_num_groups, sizeof(*groups_list),
- GFP_KERNEL);
- if (!groups_list)
- return -ENOMEM;
-
- /* Initialize attribute lists */
- for (i = 0; i < total_num_groups; i++)
- INIT_LIST_HEAD(&groups_list[i].attr_list);
-
- /* Register Signals */
- err = counter_signals_register(groups_list, counter);
- if (err)
- goto err_free_groups_list;
- num_groups += counter->num_signals;
-
- /* Register Counts and respective Synapses */
- err = counter_counts_register(groups_list + num_groups, counter);
- if (err)
- goto err_free_groups_list;
- num_groups += counter->num_counts;
-
- /* Register Counter global attributes */
- err = counter_global_attr_register(groups_list + num_groups, counter);
- if (err)
- goto err_free_groups_list;
- num_groups++;
-
- /* Store groups_list in device_state */
- counter->device_state->groups_list = groups_list;
- counter->device_state->num_groups = num_groups;
-
- return 0;
-
-err_free_groups_list:
- counter_device_groups_list_free(groups_list, num_groups);
- return err;
-}
-
-static int counter_device_groups_prepare(
- struct counter_device_state *const device_state)
-{
- size_t i, j;
- struct counter_device_attr_group *group;
- int err;
- struct counter_device_attr *p;
-
- /* Allocate attribute groups for association with device */
- device_state->groups = kcalloc(device_state->num_groups + 1,
- sizeof(*device_state->groups),
- GFP_KERNEL);
- if (!device_state->groups)
- return -ENOMEM;
-
- /* Prepare each group of attributes for association */
- for (i = 0; i < device_state->num_groups; i++) {
- group = device_state->groups_list + i;
-
- /* Allocate space for attribute pointers in attribute group */
- group->attr_group.attrs = kcalloc(group->num_attr + 1,
- sizeof(*group->attr_group.attrs), GFP_KERNEL);
- if (!group->attr_group.attrs) {
- err = -ENOMEM;
- goto err_free_groups;
- }
-
- /* Add attribute pointers to attribute group */
- j = 0;
- list_for_each_entry(p, &group->attr_list, l)
- group->attr_group.attrs[j++] = &p->dev_attr.attr;
-
- /* Group attributes in attribute group */
- device_state->groups[i] = &group->attr_group;
- }
- /* Associate attributes with device */
- device_state->dev.groups = device_state->groups;
-
- return 0;
-
-err_free_groups:
- do {
- group = device_state->groups_list + i;
- kfree(group->attr_group.attrs);
- group->attr_group.attrs = NULL;
- } while (i--);
- kfree(device_state->groups);
- return err;
-}
-
-/* Provides a unique ID for each counter device */
-static DEFINE_IDA(counter_ida);
-
-static void counter_device_release(struct device *dev)
-{
- struct counter_device *const counter = dev_get_drvdata(dev);
- struct counter_device_state *const device_state = counter->device_state;
-
- kfree(device_state->groups);
- counter_device_groups_list_free(device_state->groups_list,
- device_state->num_groups);
- ida_simple_remove(&counter_ida, device_state->id);
- kfree(device_state);
-}
-
-static struct device_type counter_device_type = {
- .name = "counter_device",
- .release = counter_device_release
-};
-
-static struct bus_type counter_bus_type = {
- .name = "counter"
-};
-
-/**
- * counter_register - register Counter to the system
- * @counter: pointer to Counter to register
- *
- * This function registers a Counter to the system. A sysfs "counter" directory
- * will be created and populated with sysfs attributes correlating with the
- * Counter Signals, Synapses, and Counts respectively.
- */
-int counter_register(struct counter_device *const counter)
-{
- struct counter_device_state *device_state;
- int err;
-
- /* Allocate internal state container for Counter device */
- device_state = kzalloc(sizeof(*device_state), GFP_KERNEL);
- if (!device_state)
- return -ENOMEM;
- counter->device_state = device_state;
-
- /* Acquire unique ID */
- device_state->id = ida_simple_get(&counter_ida, 0, 0, GFP_KERNEL);
- if (device_state->id < 0) {
- err = device_state->id;
- goto err_free_device_state;
- }
-
- /* Configure device structure for Counter */
- device_state->dev.type = &counter_device_type;
- device_state->dev.bus = &counter_bus_type;
- if (counter->parent) {
- device_state->dev.parent = counter->parent;
- device_state->dev.of_node = counter->parent->of_node;
- }
- dev_set_name(&device_state->dev, "counter%d", device_state->id);
- device_initialize(&device_state->dev);
- dev_set_drvdata(&device_state->dev, counter);
-
- /* Prepare device attributes */
- err = counter_device_groups_list_prepare(counter);
- if (err)
- goto err_free_id;
-
- /* Organize device attributes to groups and match to device */
- err = counter_device_groups_prepare(device_state);
- if (err)
- goto err_free_groups_list;
-
- /* Add device to system */
- err = device_add(&device_state->dev);
- if (err)
- goto err_free_groups;
-
- return 0;
-
-err_free_groups:
- kfree(device_state->groups);
-err_free_groups_list:
- counter_device_groups_list_free(device_state->groups_list,
- device_state->num_groups);
-err_free_id:
- ida_simple_remove(&counter_ida, device_state->id);
-err_free_device_state:
- kfree(device_state);
- return err;
-}
-EXPORT_SYMBOL_GPL(counter_register);
-
-/**
- * counter_unregister - unregister Counter from the system
- * @counter: pointer to Counter to unregister
- *
- * The Counter is unregistered from the system; all allocated memory is freed.
- */
-void counter_unregister(struct counter_device *const counter)
-{
- if (counter)
- device_del(&counter->device_state->dev);
-}
-EXPORT_SYMBOL_GPL(counter_unregister);
-
-static void devm_counter_unreg(struct device *dev, void *res)
-{
- counter_unregister(*(struct counter_device **)res);
-}
-
-/**
- * devm_counter_register - Resource-managed counter_register
- * @dev: device to allocate counter_device for
- * @counter: pointer to Counter to register
- *
- * Managed counter_register. The Counter registered with this function is
- * automatically unregistered on driver detach. This function calls
- * counter_register internally. Refer to that function for more information.
- *
- * If an Counter registered with this function needs to be unregistered
- * separately, devm_counter_unregister must be used.
- *
- * RETURNS:
- * 0 on success, negative error number on failure.
- */
-int devm_counter_register(struct device *dev,
- struct counter_device *const counter)
-{
- struct counter_device **ptr;
- int ret;
-
- ptr = devres_alloc(devm_counter_unreg, sizeof(*ptr), GFP_KERNEL);
- if (!ptr)
- return -ENOMEM;
-
- ret = counter_register(counter);
- if (!ret) {
- *ptr = counter;
- devres_add(dev, ptr);
- } else {
- devres_free(ptr);
- }
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(devm_counter_register);
-
-static int devm_counter_match(struct device *dev, void *res, void *data)
-{
- struct counter_device **r = res;
-
- if (!r || !*r) {
- WARN_ON(!r || !*r);
- return 0;
- }
-
- return *r == data;
-}
-
-/**
- * devm_counter_unregister - Resource-managed counter_unregister
- * @dev: device this counter_device belongs to
- * @counter: pointer to Counter associated with the device
- *
- * Unregister Counter registered with devm_counter_register.
- */
-void devm_counter_unregister(struct device *dev,
- struct counter_device *const counter)
-{
- int rc;
-
- rc = devres_release(dev, devm_counter_unreg, devm_counter_match,
- counter);
- WARN_ON(rc);
-}
-EXPORT_SYMBOL_GPL(devm_counter_unregister);
-
-static int __init counter_init(void)
-{
- return bus_register(&counter_bus_type);
-}
-
-static void __exit counter_exit(void)
-{
- bus_unregister(&counter_bus_type);
-}
-
-subsys_initcall(counter_init);
-module_exit(counter_exit);
-
-MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
-MODULE_DESCRIPTION("Generic Counter interface");
-MODULE_LICENSE("GPL v2");
diff --git a/drivers/counter/ftm-quaddec.c b/drivers/counter/ftm-quaddec.c
index c2b3fdfd8b77..ea6cb18c7170 100644
--- a/drivers/counter/ftm-quaddec.c
+++ b/drivers/counter/ftm-quaddec.c
@@ -6,6 +6,7 @@
* of ex. a LS1021A
*/
+#include <linux/bits.h>
#include <linux/fsl/ftm.h>
#include <linux/module.h>
#include <linux/platform_device.h>
@@ -14,6 +15,7 @@
#include <linux/mutex.h>
#include <linux/counter.h>
#include <linux/bitfield.h>
+#include <linux/types.h>
#define FTM_FIELD_UPDATE(ftm, offset, mask, val) \
({ \
@@ -114,26 +116,38 @@ static void ftm_quaddec_disable(void *ftm)
ftm_set_write_protection(ftm_qua);
}
-static int ftm_quaddec_get_prescaler(struct counter_device *counter,
- struct counter_count *count,
- size_t *cnt_mode)
+static int ftm_quaddec_prescaler_read(struct counter_device *counter,
+ struct counter_count *count, u8 *cnt_mode)
{
struct ftm_quaddec *ftm = counter->priv;
uint32_t scflags;
ftm_read(ftm, FTM_SC, &scflags);
- *cnt_mode = FIELD_GET(FTM_SC_PS_MASK, scflags);
+ *cnt_mode = BIT(FIELD_GET(FTM_SC_PS_MASK, scflags));
return 0;
}
-static int ftm_quaddec_set_prescaler(struct counter_device *counter,
- struct counter_count *count,
- size_t cnt_mode)
+static int ftm_quaddec_prescaler_write(struct counter_device *counter,
+ struct counter_count *count, u8 cnt_mode)
{
struct ftm_quaddec *ftm = counter->priv;
+ /* Filter valid input */
+ switch (cnt_mode) {
+ case BIT(0):
+ case BIT(1):
+ case BIT(2):
+ case BIT(3):
+ case BIT(4):
+ case BIT(5):
+ case BIT(6):
+ case BIT(7):
+ break;
+ default: return -EINVAL;
+ }
+
mutex_lock(&ftm->ftm_quaddec_mutex);
ftm_clear_write_protection(ftm);
@@ -151,34 +165,35 @@ static const char * const ftm_quaddec_prescaler[] = {
"1", "2", "4", "8", "16", "32", "64", "128"
};
-static struct counter_count_enum_ext ftm_quaddec_prescaler_enum = {
- .items = ftm_quaddec_prescaler,
- .num_items = ARRAY_SIZE(ftm_quaddec_prescaler),
- .get = ftm_quaddec_get_prescaler,
- .set = ftm_quaddec_set_prescaler
-};
+static ssize_t ftm_quaddec_prescaler_available_read(
+ struct counter_device *counter, struct counter_count *count, char *buf,
+ size_t size)
+{
+ size_t i;
+ size_t len = 0;
-enum ftm_quaddec_synapse_action {
- FTM_QUADDEC_SYNAPSE_ACTION_BOTH_EDGES,
-};
+ for (i = 0; i < ARRAY_SIZE(ftm_quaddec_prescaler) && size > 1; i++)
+ len += scnprintf(buf + len, size - len, "%s\n",
+ ftm_quaddec_prescaler[i]);
-static enum counter_synapse_action ftm_quaddec_synapse_actions[] = {
- [FTM_QUADDEC_SYNAPSE_ACTION_BOTH_EDGES] =
+ return len;
+}
+
+static const u8 ftm_quaddec_synapse_actions[] = {
COUNTER_SYNAPSE_ACTION_BOTH_EDGES
};
enum ftm_quaddec_count_function {
- FTM_QUADDEC_COUNT_ENCODER_MODE_1,
+ FTM_QUADDEC_COUNT_ENCODER_MODE_1 = COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
};
-static const enum counter_count_function ftm_quaddec_count_functions[] = {
- [FTM_QUADDEC_COUNT_ENCODER_MODE_1] =
- COUNTER_COUNT_FUNCTION_QUADRATURE_X4
+static const u8 ftm_quaddec_count_functions[] = {
+ FTM_QUADDEC_COUNT_ENCODER_MODE_1
};
static int ftm_quaddec_count_read(struct counter_device *counter,
struct counter_count *count,
- unsigned long *val)
+ u64 *val)
{
struct ftm_quaddec *const ftm = counter->priv;
uint32_t cntval;
@@ -192,7 +207,7 @@ static int ftm_quaddec_count_read(struct counter_device *counter,
static int ftm_quaddec_count_write(struct counter_device *counter,
struct counter_count *count,
- const unsigned long val)
+ const u64 val)
{
struct ftm_quaddec *const ftm = counter->priv;
@@ -208,7 +223,7 @@ static int ftm_quaddec_count_write(struct counter_device *counter,
static int ftm_quaddec_count_function_get(struct counter_device *counter,
struct counter_count *count,
- size_t *function)
+ u8 *function)
{
*function = FTM_QUADDEC_COUNT_ENCODER_MODE_1;
@@ -218,20 +233,13 @@ static int ftm_quaddec_count_function_get(struct counter_device *counter,
static int ftm_quaddec_action_get(struct counter_device *counter,
struct counter_count *count,
struct counter_synapse *synapse,
- size_t *action)
+ u8 *action)
{
- *action = FTM_QUADDEC_SYNAPSE_ACTION_BOTH_EDGES;
+ *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
return 0;
}
-static const struct counter_ops ftm_quaddec_cnt_ops = {
- .count_read = ftm_quaddec_count_read,
- .count_write = ftm_quaddec_count_write,
- .function_get = ftm_quaddec_count_function_get,
- .action_get = ftm_quaddec_action_get,
-};
-
static struct counter_signal ftm_quaddec_signals[] = {
{
.id = 0,
@@ -256,9 +264,11 @@ static struct counter_synapse ftm_quaddec_count_synapses[] = {
}
};
-static const struct counter_count_ext ftm_quaddec_count_ext[] = {
- COUNTER_COUNT_ENUM("prescaler", &ftm_quaddec_prescaler_enum),
- COUNTER_COUNT_ENUM_AVAILABLE("prescaler", &ftm_quaddec_prescaler_enum),
+static struct counter_data ftm_quaddec_count_ext[] = {
+ COUNTER_DATA_COUNT_U8("prescaler", ftm_quaddec_prescaler_read,
+ ftm_quaddec_prescaler_write),
+ COUNTER_DATA_COUNT_STRING("prescaler_available",
+ ftm_quaddec_prescaler_available_read, NULL),
};
static struct counter_count ftm_quaddec_counts = {
@@ -302,7 +312,10 @@ static int ftm_quaddec_probe(struct platform_device *pdev)
}
ftm->counter.name = dev_name(&pdev->dev);
ftm->counter.parent = &pdev->dev;
- ftm->counter.ops = &ftm_quaddec_cnt_ops;
+ ftm->counter.count_read = ftm_quaddec_count_read;
+ ftm->counter.count_write = ftm_quaddec_count_write;
+ ftm->counter.function_read = ftm_quaddec_count_function_get;
+ ftm->counter.action_read = ftm_quaddec_action_get;
ftm->counter.counts = &ftm_quaddec_counts;
ftm->counter.num_counts = 1;
ftm->counter.signals = ftm_quaddec_signals;
diff --git a/drivers/counter/stm32-lptimer-cnt.c b/drivers/counter/stm32-lptimer-cnt.c
index 8e276eb655f5..4a1ec895717c 100644
--- a/drivers/counter/stm32-lptimer-cnt.c
+++ b/drivers/counter/stm32-lptimer-cnt.c
@@ -17,6 +17,7 @@
#include <linux/module.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
+#include <linux/types.h>
struct stm32_lptim_cnt {
struct counter_device counter;
@@ -352,32 +353,46 @@ static const struct iio_chan_spec stm32_lptim_cnt_channels = {
* @STM32_LPTIM_ENCODER_BOTH_EDGE: count on both edges (IN1 & IN2 quadrature)
*/
enum stm32_lptim_cnt_function {
- STM32_LPTIM_COUNTER_INCREASE,
- STM32_LPTIM_ENCODER_BOTH_EDGE,
+ STM32_LPTIM_COUNTER_INCREASE = COUNTER_COUNT_FUNCTION_INCREASE,
+ STM32_LPTIM_ENCODER_BOTH_EDGE = COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
};
-static enum counter_count_function stm32_lptim_cnt_functions[] = {
- [STM32_LPTIM_COUNTER_INCREASE] = COUNTER_COUNT_FUNCTION_INCREASE,
- [STM32_LPTIM_ENCODER_BOTH_EDGE] = COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
+static u8 stm32_lptim_cnt_functions[] = {
+ STM32_LPTIM_COUNTER_INCREASE,
+ STM32_LPTIM_ENCODER_BOTH_EDGE,
};
enum stm32_lptim_synapse_action {
+ /* Index must match with stm32_lptim_cnt_polarity[] (priv->polarity) */
STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE,
STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE,
STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES,
STM32_LPTIM_SYNAPSE_ACTION_NONE,
};
-static enum counter_synapse_action stm32_lptim_cnt_synapse_actions[] = {
- /* Index must match with stm32_lptim_cnt_polarity[] (priv->polarity) */
+static const enum stm32_lptim_synapse_action stm32_lptim_c2l_actions_map[] = {
+ [COUNTER_SYNAPSE_ACTION_RISING_EDGE] = STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE,
+ [COUNTER_SYNAPSE_ACTION_FALLING_EDGE] = STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE,
+ [COUNTER_SYNAPSE_ACTION_BOTH_EDGES] = STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES,
+ [COUNTER_SYNAPSE_ACTION_NONE] = STM32_LPTIM_SYNAPSE_ACTION_NONE,
+};
+
+static const u8 stm32_lptim_l2c_actions_map[] = {
[STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE,
[STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE] = COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
[STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES] = COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
[STM32_LPTIM_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,
};
+static const u8 stm32_lptim_cnt_synapse_actions[] = {
+ COUNTER_SYNAPSE_ACTION_RISING_EDGE,
+ COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
+ COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
+ COUNTER_SYNAPSE_ACTION_NONE,
+};
+
static int stm32_lptim_cnt_read(struct counter_device *counter,
- struct counter_count *count, unsigned long *val)
+ struct counter_count *count, u64 *val)
{
struct stm32_lptim_cnt *const priv = counter->priv;
u32 cnt;
@@ -394,7 +409,7 @@ static int stm32_lptim_cnt_read(struct counter_device *counter,
static int stm32_lptim_cnt_function_get(struct counter_device *counter,
struct counter_count *count,
- size_t *function)
+ u8 *function)
{
struct stm32_lptim_cnt *const priv = counter->priv;
@@ -413,7 +428,7 @@ static int stm32_lptim_cnt_function_get(struct counter_device *counter,
static int stm32_lptim_cnt_function_set(struct counter_device *counter,
struct counter_count *count,
- size_t function)
+ u8 function)
{
struct stm32_lptim_cnt *const priv = counter->priv;
@@ -423,19 +438,20 @@ static int stm32_lptim_cnt_function_set(struct counter_device *counter,
switch (function) {
case STM32_LPTIM_COUNTER_INCREASE:
priv->quadrature_mode = 0;
- return 0;
+ break;
case STM32_LPTIM_ENCODER_BOTH_EDGE:
priv->quadrature_mode = 1;
priv->polarity = STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES;
- return 0;
+ break;
+ default: return -EINVAL;
}
- return -EINVAL;
+ return 0;
}
-static ssize_t stm32_lptim_cnt_enable_read(struct counter_device *counter,
- struct counter_count *count,
- void *private, char *buf)
+static int stm32_lptim_cnt_enable_read(struct counter_device *counter,
+ struct counter_count *count,
+ u8 *enable)
{
struct stm32_lptim_cnt *const priv = counter->priv;
int ret;
@@ -444,22 +460,18 @@ static ssize_t stm32_lptim_cnt_enable_read(struct counter_device *counter,
if (ret < 0)
return ret;
- return scnprintf(buf, PAGE_SIZE, "%u\n", ret);
+ *enable = ret;
+
+ return 0;
}
-static ssize_t stm32_lptim_cnt_enable_write(struct counter_device *counter,
- struct counter_count *count,
- void *private,
- const char *buf, size_t len)
+static int stm32_lptim_cnt_enable_write(struct counter_device *counter,
+ struct counter_count *count,
+ u8 enable)
{
struct stm32_lptim_cnt *const priv = counter->priv;
- bool enable;
int ret;
- ret = kstrtobool(buf, &enable);
- if (ret)
- return ret;
-
/* Check nobody uses the timer, or already disabled/enabled */
ret = stm32_lptim_is_enabled(priv);
if ((ret < 0) || (!ret && !enable))
@@ -475,48 +487,51 @@ static ssize_t stm32_lptim_cnt_enable_write(struct counter_device *counter,
if (ret)
return ret;
- return len;
+ return 0;
}
-static ssize_t stm32_lptim_cnt_ceiling_read(struct counter_device *counter,
- struct counter_count *count,
- void *private, char *buf)
+static int stm32_lptim_cnt_ceiling_read(struct counter_device *counter,
+ struct counter_count *count,
+ u64 *ceiling)
{
struct stm32_lptim_cnt *const priv = counter->priv;
- return stm32_lptim_cnt_get_ceiling(priv, buf);
+ *ceiling = priv->ceiling;
+
+ return 0;
}
-static ssize_t stm32_lptim_cnt_ceiling_write(struct counter_device *counter,
- struct counter_count *count,
- void *private,
- const char *buf, size_t len)
+static int stm32_lptim_cnt_ceiling_write(struct counter_device *counter,
+ struct counter_count *count,
+ u64 ceiling)
{
struct stm32_lptim_cnt *const priv = counter->priv;
- return stm32_lptim_cnt_set_ceiling(priv, buf, len);
+ if (ceiling > STM32_LPTIM_MAX_ARR)
+ return -EINVAL;
+
+ if (stm32_lptim_is_enabled(priv))
+ return -EBUSY;
+
+ priv->ceiling = ceiling;
+
+ return 0;
}
-static const struct counter_count_ext stm32_lptim_cnt_ext[] = {
- {
- .name = "enable",
- .read = stm32_lptim_cnt_enable_read,
- .write = stm32_lptim_cnt_enable_write
- },
- {
- .name = "ceiling",
- .read = stm32_lptim_cnt_ceiling_read,
- .write = stm32_lptim_cnt_ceiling_write
- },
+static struct counter_data stm32_lptim_cnt_ext[] = {
+ COUNTER_DATA_ENABLE(stm32_lptim_cnt_enable_read,
+ stm32_lptim_cnt_enable_write),
+ COUNTER_DATA_CEILING(stm32_lptim_cnt_ceiling_read,
+ stm32_lptim_cnt_ceiling_write),
};
static int stm32_lptim_cnt_action_get(struct counter_device *counter,
struct counter_count *count,
struct counter_synapse *synapse,
- size_t *action)
+ u8 *action)
{
struct stm32_lptim_cnt *const priv = counter->priv;
- size_t function;
+ u8 function;
int err;
err = stm32_lptim_cnt_function_get(counter, count, &function);
@@ -527,25 +542,25 @@ static int stm32_lptim_cnt_action_get(struct counter_device *counter,
case STM32_LPTIM_COUNTER_INCREASE:
/* LP Timer acts as up-counter on input 1 */
if (synapse->signal->id == count->synapses[0].signal->id)
- *action = priv->polarity;
+ *action = stm32_lptim_l2c_actions_map[priv->polarity];
else
- *action = STM32_LPTIM_SYNAPSE_ACTION_NONE;
- return 0;
+ *action = COUNTER_SYNAPSE_ACTION_NONE;
+ break;
case STM32_LPTIM_ENCODER_BOTH_EDGE:
- *action = priv->polarity;
- return 0;
+ *action = stm32_lptim_l2c_actions_map[priv->polarity];
+ break;
}
- return -EINVAL;
+ return 0;
}
static int stm32_lptim_cnt_action_set(struct counter_device *counter,
struct counter_count *count,
struct counter_synapse *synapse,
- size_t action)
+ u8 action)
{
struct stm32_lptim_cnt *const priv = counter->priv;
- size_t function;
+ u8 function;
int err;
if (stm32_lptim_is_enabled(priv))
@@ -556,27 +571,15 @@ static int stm32_lptim_cnt_action_set(struct counter_device *counter,
return err;
/* only set polarity when in counter mode (on input 1) */
- if (function == STM32_LPTIM_COUNTER_INCREASE
- && synapse->signal->id == count->synapses[0].signal->id) {
- switch (action) {
- case STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE:
- case STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE:
- case STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES:
- priv->polarity = action;
- return 0;
- }
- }
+ if (function != STM32_LPTIM_COUNTER_INCREASE
+ || synapse->signal->id != count->synapses[0].signal->id
+ || action == COUNTER_SYNAPSE_ACTION_NONE)
+ return -EINVAL;
- return -EINVAL;
-}
+ priv->polarity = stm32_lptim_c2l_actions_map[action];
-static const struct counter_ops stm32_lptim_cnt_ops = {
- .count_read = stm32_lptim_cnt_read,
- .function_get = stm32_lptim_cnt_function_get,
- .function_set = stm32_lptim_cnt_function_set,
- .action_get = stm32_lptim_cnt_action_get,
- .action_set = stm32_lptim_cnt_action_set,
-};
+ return 0;
+}
static struct counter_signal stm32_lptim_cnt_signals[] = {
{
@@ -660,7 +663,11 @@ static int stm32_lptim_cnt_probe(struct platform_device *pdev)
/* Initialize Counter device */
priv->counter.name = dev_name(&pdev->dev);
priv->counter.parent = &pdev->dev;
- priv->counter.ops = &stm32_lptim_cnt_ops;
+ priv->counter.count_read = stm32_lptim_cnt_read;
+ priv->counter.function_read = stm32_lptim_cnt_function_get;
+ priv->counter.function_write = stm32_lptim_cnt_function_set;
+ priv->counter.action_read = stm32_lptim_cnt_action_get;
+ priv->counter.action_write = stm32_lptim_cnt_action_set;
if (ddata->has_encoder) {
priv->counter.counts = &stm32_lptim_enc_counts;
priv->counter.num_signals = ARRAY_SIZE(stm32_lptim_cnt_signals);
diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
index ef2a974a2f10..502e525836a9 100644
--- a/drivers/counter/stm32-timer-cnt.c
+++ b/drivers/counter/stm32-timer-cnt.c
@@ -13,6 +13,7 @@
#include <linux/module.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
+#include <linux/types.h>
#define TIM_CCMR_CCXS (BIT(8) | BIT(0))
#define TIM_CCMR_MASK (TIM_CCMR_CC1S | TIM_CCMR_CC2S | \
@@ -45,19 +46,19 @@ struct stm32_timer_cnt {
*/
enum stm32_count_function {
STM32_COUNT_SLAVE_MODE_DISABLED = -1,
+ STM32_COUNT_ENCODER_MODE_1 = COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A,
+ STM32_COUNT_ENCODER_MODE_2 = COUNTER_COUNT_FUNCTION_QUADRATURE_X2_B,
+ STM32_COUNT_ENCODER_MODE_3 = COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
+};
+
+static const u8 stm32_count_functions[] = {
STM32_COUNT_ENCODER_MODE_1,
STM32_COUNT_ENCODER_MODE_2,
STM32_COUNT_ENCODER_MODE_3,
};
-static enum counter_count_function stm32_count_functions[] = {
- [STM32_COUNT_ENCODER_MODE_1] = COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A,
- [STM32_COUNT_ENCODER_MODE_2] = COUNTER_COUNT_FUNCTION_QUADRATURE_X2_B,
- [STM32_COUNT_ENCODER_MODE_3] = COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
-};
-
static int stm32_count_read(struct counter_device *counter,
- struct counter_count *count, unsigned long *val)
+ struct counter_count *count, u64 *val)
{
struct stm32_timer_cnt *const priv = counter->priv;
u32 cnt;
@@ -69,8 +70,7 @@ static int stm32_count_read(struct counter_device *counter,
}
static int stm32_count_write(struct counter_device *counter,
- struct counter_count *count,
- const unsigned long val)
+ struct counter_count *count, const u64 val)
{
struct stm32_timer_cnt *const priv = counter->priv;
@@ -81,8 +81,7 @@ static int stm32_count_write(struct counter_device *counter,
}
static int stm32_count_function_get(struct counter_device *counter,
- struct counter_count *count,
- size_t *function)
+ struct counter_count *count, u8 *function)
{
struct stm32_timer_cnt *const priv = counter->priv;
u32 smcr;
@@ -105,8 +104,7 @@ static int stm32_count_function_get(struct counter_device *counter,
}
static int stm32_count_function_set(struct counter_device *counter,
- struct counter_count *count,
- size_t function)
+ struct counter_count *count, u8 function)
{
struct stm32_timer_cnt *const priv = counter->priv;
u32 cr1, sms;
@@ -146,78 +144,67 @@ static int stm32_count_function_set(struct counter_device *counter,
return 0;
}
-static ssize_t stm32_count_direction_read(struct counter_device *counter,
+static int stm32_count_direction_read(struct counter_device *counter,
struct counter_count *count,
- void *private, char *buf)
+ u8 *direction)
{
struct stm32_timer_cnt *const priv = counter->priv;
- const char *direction;
u32 cr1;
regmap_read(priv->regmap, TIM_CR1, &cr1);
- direction = (cr1 & TIM_CR1_DIR) ? "backward" : "forward";
+ *direction = (cr1 & TIM_CR1_DIR) ? COUNTER_COUNT_DIRECTION_BACKWARD :
+ COUNTER_COUNT_DIRECTION_FORWARD;
- return scnprintf(buf, PAGE_SIZE, "%s\n", direction);
+ return 0;
}
-static ssize_t stm32_count_ceiling_read(struct counter_device *counter,
- struct counter_count *count,
- void *private, char *buf)
+static int stm32_count_ceiling_read(struct counter_device *counter,
+ struct counter_count *count, u64 *ceiling)
{
struct stm32_timer_cnt *const priv = counter->priv;
u32 arr;
regmap_read(priv->regmap, TIM_ARR, &arr);
- return snprintf(buf, PAGE_SIZE, "%u\n", arr);
+ *ceiling = arr;
+
+ return 0;
}
-static ssize_t stm32_count_ceiling_write(struct counter_device *counter,
- struct counter_count *count,
- void *private,
- const char *buf, size_t len)
+static int stm32_count_ceiling_write(struct counter_device *counter,
+ struct counter_count *count, u64 ceiling)
{
struct stm32_timer_cnt *const priv = counter->priv;
- unsigned int ceiling;
- int ret;
- ret = kstrtouint(buf, 0, &ceiling);
- if (ret)
- return ret;
+ if (ceiling != (u32)ceiling)
+ return -ERANGE;
/* TIMx_ARR register shouldn't be buffered (ARPE=0) */
regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0);
regmap_write(priv->regmap, TIM_ARR, ceiling);
priv->ceiling = ceiling;
- return len;
+ return 0;
}
-static ssize_t stm32_count_enable_read(struct counter_device *counter,
- struct counter_count *count,
- void *private, char *buf)
+static int stm32_count_enable_read(struct counter_device *counter,
+ struct counter_count *count, u8 *enable)
{
struct stm32_timer_cnt *const priv = counter->priv;
u32 cr1;
regmap_read(priv->regmap, TIM_CR1, &cr1);
- return scnprintf(buf, PAGE_SIZE, "%d\n", (bool)(cr1 & TIM_CR1_CEN));
+ *enable = cr1 & TIM_CR1_CEN;
+
+ return 0;
}
-static ssize_t stm32_count_enable_write(struct counter_device *counter,
- struct counter_count *count,
- void *private,
- const char *buf, size_t len)
+static int stm32_count_enable_write(struct counter_device *counter,
+ struct counter_count *count, u8 enable)
{
struct stm32_timer_cnt *const priv = counter->priv;
- int err;
u32 cr1;
- bool enable;
-
- err = kstrtobool(buf, &enable);
- if (err)
- return err;
if (enable) {
regmap_read(priv->regmap, TIM_CR1, &cr1);
@@ -236,46 +223,30 @@ static ssize_t stm32_count_enable_write(struct counter_device *counter,
/* Keep enabled state to properly handle low power states */
priv->enabled = enable;
- return len;
+ return 0;
}
-static const struct counter_count_ext stm32_count_ext[] = {
- {
- .name = "direction",
- .read = stm32_count_direction_read,
- },
- {
- .name = "enable",
- .read = stm32_count_enable_read,
- .write = stm32_count_enable_write
- },
- {
- .name = "ceiling",
- .read = stm32_count_ceiling_read,
- .write = stm32_count_ceiling_write
- },
-};
-
-enum stm32_synapse_action {
- STM32_SYNAPSE_ACTION_NONE,
- STM32_SYNAPSE_ACTION_BOTH_EDGES
+static struct counter_data stm32_count_ext[] = {
+ COUNTER_DATA_DIRECTION(stm32_count_direction_read),
+ COUNTER_DATA_ENABLE(stm32_count_enable_read, stm32_count_enable_write),
+ COUNTER_DATA_CEILING(stm32_count_ceiling_read,
+ stm32_count_ceiling_write),
};
-static enum counter_synapse_action stm32_synapse_actions[] = {
- [STM32_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,
- [STM32_SYNAPSE_ACTION_BOTH_EDGES] = COUNTER_SYNAPSE_ACTION_BOTH_EDGES
+static const u8 stm32_synapse_actions[] = {
+ COUNTER_SYNAPSE_ACTION_NONE,
+ COUNTER_SYNAPSE_ACTION_BOTH_EDGES
};
static int stm32_action_get(struct counter_device *counter,
struct counter_count *count,
- struct counter_synapse *synapse,
- size_t *action)
+ struct counter_synapse *synapse, u8 *action)
{
- size_t function;
+ u8 function;
int err;
/* Default action mode (e.g. STM32_COUNT_SLAVE_MODE_DISABLED) */
- *action = STM32_SYNAPSE_ACTION_NONE;
+ *action = COUNTER_SYNAPSE_ACTION_NONE;
err = stm32_count_function_get(counter, count, &function);
if (err)
@@ -285,30 +256,22 @@ static int stm32_action_get(struct counter_device *counter,
case STM32_COUNT_ENCODER_MODE_1:
/* counts up/down on TI1FP1 edge depending on TI2FP2 level */
if (synapse->signal->id == count->synapses[0].signal->id)
- *action = STM32_SYNAPSE_ACTION_BOTH_EDGES;
+ *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
break;
case STM32_COUNT_ENCODER_MODE_2:
/* counts up/down on TI2FP2 edge depending on TI1FP1 level */
if (synapse->signal->id == count->synapses[1].signal->id)
- *action = STM32_SYNAPSE_ACTION_BOTH_EDGES;
+ *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
break;
case STM32_COUNT_ENCODER_MODE_3:
/* counts up/down on both TI1FP1 and TI2FP2 edges */
- *action = STM32_SYNAPSE_ACTION_BOTH_EDGES;
+ *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
break;
}
return 0;
}
-static const struct counter_ops stm32_timer_cnt_ops = {
- .count_read = stm32_count_read,
- .count_write = stm32_count_write,
- .function_get = stm32_count_function_get,
- .function_set = stm32_count_function_set,
- .action_get = stm32_action_get,
-};
-
static struct counter_signal stm32_signals[] = {
{
.id = 0,
@@ -363,7 +326,11 @@ static int stm32_timer_cnt_probe(struct platform_device *pdev)
priv->counter.name = dev_name(dev);
priv->counter.parent = dev;
- priv->counter.ops = &stm32_timer_cnt_ops;
+ priv->counter.count_read = stm32_count_read;
+ priv->counter.count_write = stm32_count_write;
+ priv->counter.function_read = stm32_count_function_get;
+ priv->counter.function_write = stm32_count_function_set;
+ priv->counter.action_read = stm32_action_get;
priv->counter.counts = &stm32_counts;
priv->counter.num_counts = 1;
priv->counter.signals = stm32_signals;
diff --git a/drivers/counter/ti-eqep.c b/drivers/counter/ti-eqep.c
index 1ff07faef27f..7152f0b3c2de 100644
--- a/drivers/counter/ti-eqep.c
+++ b/drivers/counter/ti-eqep.c
@@ -13,6 +13,7 @@
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
+#include <linux/types.h>
/* 32-bit registers */
#define QPOSCNT 0x0
@@ -80,12 +81,6 @@ enum {
TI_EQEP_COUNT_FUNC_DOWN_COUNT,
};
-enum {
- TI_EQEP_SYNAPSE_ACTION_BOTH_EDGES,
- TI_EQEP_SYNAPSE_ACTION_RISING_EDGE,
- TI_EQEP_SYNAPSE_ACTION_NONE,
-};
-
struct ti_eqep_cnt {
struct counter_device counter;
struct regmap *regmap32;
@@ -93,7 +88,7 @@ struct ti_eqep_cnt {
};
static int ti_eqep_count_read(struct counter_device *counter,
- struct counter_count *count, unsigned long *val)
+ struct counter_count *count, u64 *val)
{
struct ti_eqep_cnt *priv = counter->priv;
u32 cnt;
@@ -105,7 +100,7 @@ static int ti_eqep_count_read(struct counter_device *counter,
}
static int ti_eqep_count_write(struct counter_device *counter,
- struct counter_count *count, unsigned long val)
+ struct counter_count *count, u64 val)
{
struct ti_eqep_cnt *priv = counter->priv;
u32 max;
@@ -117,33 +112,66 @@ static int ti_eqep_count_write(struct counter_device *counter,
return regmap_write(priv->regmap32, QPOSCNT, val);
}
+static const u8 ti_qep_t2c_functions_map[] = {
+};
+
static int ti_eqep_function_get(struct counter_device *counter,
- struct counter_count *count, size_t *function)
+ struct counter_count *count, u8 *function)
{
struct ti_eqep_cnt *priv = counter->priv;
u32 qdecctl;
regmap_read(priv->regmap16, QDECCTL, &qdecctl);
- *function = (qdecctl & QDECCTL_QSRC) >> QDECCTL_QSRC_SHIFT;
+
+ switch ((qdecctl & QDECCTL_QSRC) >> QDECCTL_QSRC_SHIFT) {
+ case TI_EQEP_COUNT_FUNC_QUAD_COUNT:
+ *function = COUNTER_COUNT_FUNCTION_QUADRATURE_X4;
+ break;
+ case TI_EQEP_COUNT_FUNC_DIR_COUNT:
+ *function = COUNTER_COUNT_FUNCTION_PULSE_DIRECTION;
+ break;
+ case TI_EQEP_COUNT_FUNC_UP_COUNT:
+ *function = COUNTER_COUNT_FUNCTION_INCREASE;
+ break;
+ case TI_EQEP_COUNT_FUNC_DOWN_COUNT:
+ *function = COUNTER_COUNT_FUNCTION_DECREASE;
+ break;
+ }
return 0;
}
static int ti_eqep_function_set(struct counter_device *counter,
- struct counter_count *count, size_t function)
+ struct counter_count *count, u8 function)
{
struct ti_eqep_cnt *priv = counter->priv;
+ unsigned long qsrc;
+
+ switch (function) {
+ case COUNTER_COUNT_FUNCTION_QUADRATURE_X4:
+ qsrc = TI_EQEP_COUNT_FUNC_QUAD_COUNT;
+ break;
+ case COUNTER_COUNT_FUNCTION_PULSE_DIRECTION:
+ qsrc = TI_EQEP_COUNT_FUNC_DIR_COUNT;
+ break;
+ case COUNTER_COUNT_FUNCTION_INCREASE:
+ qsrc = TI_EQEP_COUNT_FUNC_UP_COUNT;
+ break;
+ case COUNTER_COUNT_FUNCTION_DECREASE:
+ qsrc = TI_EQEP_COUNT_FUNC_DOWN_COUNT;
+ break;
+ }
return regmap_write_bits(priv->regmap16, QDECCTL, QDECCTL_QSRC,
- function << QDECCTL_QSRC_SHIFT);
+ qsrc << QDECCTL_QSRC_SHIFT);
}
static int ti_eqep_action_get(struct counter_device *counter,
struct counter_count *count,
- struct counter_synapse *synapse, size_t *action)
+ struct counter_synapse *synapse, u8 *action)
{
struct ti_eqep_cnt *priv = counter->priv;
- size_t function;
+ u8 function;
u32 qdecctl;
int err;
@@ -152,27 +180,27 @@ static int ti_eqep_action_get(struct counter_device *counter,
return err;
switch (function) {
- case TI_EQEP_COUNT_FUNC_QUAD_COUNT:
+ case COUNTER_COUNT_FUNCTION_QUADRATURE_X4:
/* In quadrature mode, the rising and falling edge of both
* QEPA and QEPB trigger QCLK.
*/
- *action = TI_EQEP_SYNAPSE_ACTION_BOTH_EDGES;
+ *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
break;
- case TI_EQEP_COUNT_FUNC_DIR_COUNT:
+ case COUNTER_COUNT_FUNCTION_PULSE_DIRECTION:
/* In direction-count mode only rising edge of QEPA is counted
* and QEPB gives direction.
*/
switch (synapse->signal->id) {
case TI_EQEP_SIGNAL_QEPA:
- *action = TI_EQEP_SYNAPSE_ACTION_RISING_EDGE;
+ *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
break;
default:
- *action = TI_EQEP_SYNAPSE_ACTION_NONE;
+ *action = COUNTER_SYNAPSE_ACTION_NONE;
break;
}
break;
- case TI_EQEP_COUNT_FUNC_UP_COUNT:
- case TI_EQEP_COUNT_FUNC_DOWN_COUNT:
+ case COUNTER_COUNT_FUNCTION_INCREASE:
+ case COUNTER_COUNT_FUNCTION_DECREASE:
/* In up/down-count modes only QEPA is counted and QEPB is not
* used.
*/
@@ -183,134 +211,105 @@ static int ti_eqep_action_get(struct counter_device *counter,
return err;
if (qdecctl & QDECCTL_XCR)
- *action = TI_EQEP_SYNAPSE_ACTION_BOTH_EDGES;
+ *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
else
- *action = TI_EQEP_SYNAPSE_ACTION_RISING_EDGE;
+ *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
break;
default:
- *action = TI_EQEP_SYNAPSE_ACTION_NONE;
+ *action = COUNTER_SYNAPSE_ACTION_NONE;
break;
}
break;
+ default: return -EINVAL;
}
return 0;
}
-static const struct counter_ops ti_eqep_counter_ops = {
- .count_read = ti_eqep_count_read,
- .count_write = ti_eqep_count_write,
- .function_get = ti_eqep_function_get,
- .function_set = ti_eqep_function_set,
- .action_get = ti_eqep_action_get,
-};
-
-static ssize_t ti_eqep_position_ceiling_read(struct counter_device *counter,
- struct counter_count *count,
- void *ext_priv, char *buf)
+static int ti_eqep_position_ceiling_read(struct counter_device *counter,
+ struct counter_count *count,
+ u64 *ceiling)
{
struct ti_eqep_cnt *priv = counter->priv;
u32 qposmax;
regmap_read(priv->regmap32, QPOSMAX, &qposmax);
- return sprintf(buf, "%u\n", qposmax);
+ *ceiling = qposmax;
+
+ return 0;
}
-static ssize_t ti_eqep_position_ceiling_write(struct counter_device *counter,
- struct counter_count *count,
- void *ext_priv, const char *buf,
- size_t len)
+static int ti_eqep_position_ceiling_write(struct counter_device *counter,
+ struct counter_count *count,
+ u64 ceiling)
{
struct ti_eqep_cnt *priv = counter->priv;
- int err;
- u32 res;
- err = kstrtouint(buf, 0, &res);
- if (err < 0)
- return err;
+ if (ceiling != (u32)ceiling)
+ return -ERANGE;
- regmap_write(priv->regmap32, QPOSMAX, res);
+ regmap_write(priv->regmap32, QPOSMAX, ceiling);
- return len;
+ return 0;
}
-static ssize_t ti_eqep_position_floor_read(struct counter_device *counter,
- struct counter_count *count,
- void *ext_priv, char *buf)
+static int ti_eqep_position_floor_read(struct counter_device *counter,
+ struct counter_count *count, u64 *floor)
{
struct ti_eqep_cnt *priv = counter->priv;
u32 qposinit;
regmap_read(priv->regmap32, QPOSINIT, &qposinit);
- return sprintf(buf, "%u\n", qposinit);
+ *floor = qposinit;
+
+ return 0;
}
-static ssize_t ti_eqep_position_floor_write(struct counter_device *counter,
- struct counter_count *count,
- void *ext_priv, const char *buf,
- size_t len)
+static int ti_eqep_position_floor_write(struct counter_device *counter,
+ struct counter_count *count, u64 floor)
{
struct ti_eqep_cnt *priv = counter->priv;
- int err;
- u32 res;
- err = kstrtouint(buf, 0, &res);
- if (err < 0)
- return err;
+ if (floor != (u32)floor)
+ return -ERANGE;
- regmap_write(priv->regmap32, QPOSINIT, res);
+ regmap_write(priv->regmap32, QPOSINIT, floor);
- return len;
+ return 0;
}
-static ssize_t ti_eqep_position_enable_read(struct counter_device *counter,
- struct counter_count *count,
- void *ext_priv, char *buf)
+static int ti_eqep_position_enable_read(struct counter_device *counter,
+ struct counter_count *count, u8 *enable)
{
struct ti_eqep_cnt *priv = counter->priv;
u32 qepctl;
regmap_read(priv->regmap16, QEPCTL, &qepctl);
- return sprintf(buf, "%u\n", !!(qepctl & QEPCTL_PHEN));
+ *enable = !!(qepctl & QEPCTL_PHEN);
+
+ return 0;
}
-static ssize_t ti_eqep_position_enable_write(struct counter_device *counter,
- struct counter_count *count,
- void *ext_priv, const char *buf,
- size_t len)
+static int ti_eqep_position_enable_write(struct counter_device *counter,
+ struct counter_count *count, u8 enable)
{
struct ti_eqep_cnt *priv = counter->priv;
- int err;
- bool res;
- err = kstrtobool(buf, &res);
- if (err < 0)
- return err;
-
- regmap_write_bits(priv->regmap16, QEPCTL, QEPCTL_PHEN, res ? -1 : 0);
+ regmap_write_bits(priv->regmap16, QEPCTL, QEPCTL_PHEN, enable ? -1 : 0);
- return len;
+ return 0;
}
-static struct counter_count_ext ti_eqep_position_ext[] = {
- {
- .name = "ceiling",
- .read = ti_eqep_position_ceiling_read,
- .write = ti_eqep_position_ceiling_write,
- },
- {
- .name = "floor",
- .read = ti_eqep_position_floor_read,
- .write = ti_eqep_position_floor_write,
- },
- {
- .name = "enable",
- .read = ti_eqep_position_enable_read,
- .write = ti_eqep_position_enable_write,
- },
+static struct counter_data ti_eqep_position_ext[] = {
+ COUNTER_DATA_CEILING(ti_eqep_position_ceiling_read,
+ ti_eqep_position_ceiling_write),
+ COUNTER_DATA_FLOOR(ti_eqep_position_floor_read,
+ ti_eqep_position_floor_write),
+ COUNTER_DATA_ENABLE(ti_eqep_position_enable_read,
+ ti_eqep_position_enable_write),
};
static struct counter_signal ti_eqep_signals[] = {
@@ -324,17 +323,17 @@ static struct counter_signal ti_eqep_signals[] = {
},
};
-static const enum counter_count_function ti_eqep_position_functions[] = {
- [TI_EQEP_COUNT_FUNC_QUAD_COUNT] = COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
- [TI_EQEP_COUNT_FUNC_DIR_COUNT] = COUNTER_COUNT_FUNCTION_PULSE_DIRECTION,
- [TI_EQEP_COUNT_FUNC_UP_COUNT] = COUNTER_COUNT_FUNCTION_INCREASE,
- [TI_EQEP_COUNT_FUNC_DOWN_COUNT] = COUNTER_COUNT_FUNCTION_DECREASE,
+static const u8 ti_eqep_position_functions[] = {
+ COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
+ COUNTER_COUNT_FUNCTION_PULSE_DIRECTION,
+ COUNTER_COUNT_FUNCTION_INCREASE,
+ COUNTER_COUNT_FUNCTION_DECREASE,
};
-static const enum counter_synapse_action ti_eqep_position_synapse_actions[] = {
- [TI_EQEP_SYNAPSE_ACTION_BOTH_EDGES] = COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
- [TI_EQEP_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE,
- [TI_EQEP_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,
+static const u8 ti_eqep_position_synapse_actions[] = {
+ COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
+ COUNTER_SYNAPSE_ACTION_RISING_EDGE,
+ COUNTER_SYNAPSE_ACTION_NONE,
};
static struct counter_synapse ti_eqep_position_synapses[] = {
@@ -406,7 +405,11 @@ static int ti_eqep_probe(struct platform_device *pdev)
priv->counter.name = dev_name(dev);
priv->counter.parent = dev;
- priv->counter.ops = &ti_eqep_counter_ops;
+ priv->counter.count_read = ti_eqep_count_read;
+ priv->counter.count_write = ti_eqep_count_write;
+ priv->counter.function_read = ti_eqep_function_get;
+ priv->counter.function_write = ti_eqep_function_set;
+ priv->counter.action_read = ti_eqep_action_get;
priv->counter.counts = ti_eqep_counts;
priv->counter.num_counts = ARRAY_SIZE(ti_eqep_counts);
priv->counter.signals = ti_eqep_signals;
diff --git a/include/linux/counter.h b/include/linux/counter.h
index 9dbd5df4cd34..e8abbaf47a4b 100644
--- a/include/linux/counter.h
+++ b/include/linux/counter.h
@@ -6,418 +6,161 @@
#ifndef _COUNTER_H_
#define _COUNTER_H_
-#include <linux/counter_enum.h>
#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
#include <linux/types.h>
-
-enum counter_count_direction {
- COUNTER_COUNT_DIRECTION_FORWARD = 0,
- COUNTER_COUNT_DIRECTION_BACKWARD
-};
-extern const char *const counter_count_direction_str[2];
-
-enum counter_count_mode {
- COUNTER_COUNT_MODE_NORMAL = 0,
- COUNTER_COUNT_MODE_RANGE_LIMIT,
- COUNTER_COUNT_MODE_NON_RECYCLE,
- COUNTER_COUNT_MODE_MODULO_N
-};
-extern const char *const counter_count_mode_str[4];
+#include <uapi/linux/counter-types.h>
struct counter_device;
+struct counter_count;
+struct counter_synapse;
struct counter_signal;
-/**
- * struct counter_signal_ext - Counter Signal extensions
- * @name: attribute name
- * @read: read callback for this attribute; may be NULL
- * @write: write callback for this attribute; may be NULL
- * @priv: data private to the driver
- */
-struct counter_signal_ext {
+struct counter_data {
+ u8 type;
const char *name;
- ssize_t (*read)(struct counter_device *counter,
- struct counter_signal *signal, void *priv, char *buf);
- ssize_t (*write)(struct counter_device *counter,
- struct counter_signal *signal, void *priv,
- const char *buf, size_t len);
void *priv;
+ union {
+ int (*action_read)(struct counter_device *counter,
+ struct counter_count *count,
+ struct counter_synapse *synapse, u8 *action);
+ ssize_t (*device_string_read)(struct counter_device *counter,
+ char *buf, size_t len);
+ ssize_t (*count_string_read)(struct counter_device *counter,
+ struct counter_count *count,
+ char *buf, size_t len);
+ ssize_t (*signal_string_read)(struct counter_device *counter,
+ struct counter_signal *signal,
+ char *buf, size_t len);
+ int (*device_u8_read)(struct counter_device *counter, u8 *val);
+ int (*count_u8_read)(struct counter_device *counter,
+ struct counter_count *count, u8 *val);
+ int (*signal_u8_read)(struct counter_device *counter,
+ struct counter_signal *signal, u8 *val);
+ int (*device_u64_read)(struct counter_device *counter,
+ u64 *val);
+ int (*count_u64_read)(struct counter_device *counter,
+ struct counter_count *count, u64 *val);
+ int (*signal_u64_read)(struct counter_device *counter,
+ struct counter_signal *signal, u64 *val);
+ };
+ union {
+ int (*action_write)(struct counter_device *counter,
+ struct counter_count *count,
+ struct counter_synapse *synapse, u8 action);
+ ssize_t (*device_string_write)(struct counter_device *counter,
+ const char *buf, size_t len);
+ ssize_t (*count_string_write)(struct counter_device *counter,
+ struct counter_count *count,
+ const char *buf, size_t len);
+ ssize_t (*signal_string_write)(struct counter_device *counter,
+ struct counter_signal *signal,
+ const char *buf, size_t len);
+ int (*device_u8_write)(struct counter_device *counter, u8 val);
+ int (*count_u8_write)(struct counter_device *counter,
+ struct counter_count *count, u8 val);
+ int (*signal_u8_write)(struct counter_device *counter,
+ struct counter_signal *signal, u8 val);
+ int (*device_u64_write)(struct counter_device *counter,
+ u64 val);
+ int (*count_u64_write)(struct counter_device *counter,
+ struct counter_count *count, u64 val);
+ int (*signal_u64_write)(struct counter_device *counter,
+ struct counter_signal *signal, u64 val);
+ };
};
/**
* struct counter_signal - Counter Signal node
- * @id: unique ID used to identify signal
- * @name: device-specific Signal name; ideally, this should match the name
- * as it appears in the datasheet documentation
- * @ext: optional array of Counter Signal extensions
- * @num_ext: number of Counter Signal extensions specified in @ext
- * @priv: optional private data supplied by driver
+ * @id: unique ID used to identify the Signal
+ * @name: device-specific Signal name
+ * @ext: optional array of Signal extensions
+ * @num_ext: number of Signal extensions specified in @ext
*/
struct counter_signal {
int id;
const char *name;
- const struct counter_signal_ext *ext;
+ struct counter_data *ext;
size_t num_ext;
-
- void *priv;
-};
-
-/**
- * struct counter_signal_enum_ext - Signal enum extension attribute
- * @items: Array of strings
- * @num_items: Number of items specified in @items
- * @set: Set callback function; may be NULL
- * @get: Get callback function; may be NULL
- *
- * The counter_signal_enum_ext structure can be used to implement enum style
- * Signal extension attributes. Enum style attributes are those which have a set
- * of strings that map to unsigned integer values. The Generic Counter Signal
- * enum extension helper code takes care of mapping between value and string, as
- * well as generating a "_available" file which contains a list of all available
- * items. The get callback is used to query the currently active item; the index
- * of the item within the respective items array is returned via the 'item'
- * parameter. The set callback is called when the attribute is updated; the
- * 'item' parameter contains the index of the newly activated item within the
- * respective items array.
- */
-struct counter_signal_enum_ext {
- const char * const *items;
- size_t num_items;
- int (*get)(struct counter_device *counter,
- struct counter_signal *signal, size_t *item);
- int (*set)(struct counter_device *counter,
- struct counter_signal *signal, size_t item);
-};
-
-/**
- * COUNTER_SIGNAL_ENUM() - Initialize Signal enum extension
- * @_name: Attribute name
- * @_e: Pointer to a counter_signal_enum_ext structure
- *
- * This should usually be used together with COUNTER_SIGNAL_ENUM_AVAILABLE()
- */
-#define COUNTER_SIGNAL_ENUM(_name, _e) \
-{ \
- .name = (_name), \
- .read = counter_signal_enum_read, \
- .write = counter_signal_enum_write, \
- .priv = (_e) \
-}
-
-/**
- * COUNTER_SIGNAL_ENUM_AVAILABLE() - Initialize Signal enum available extension
- * @_name: Attribute name ("_available" will be appended to the name)
- * @_e: Pointer to a counter_signal_enum_ext structure
- *
- * Creates a read only attribute that lists all the available enum items in a
- * newline separated list. This should usually be used together with
- * COUNTER_SIGNAL_ENUM()
- */
-#define COUNTER_SIGNAL_ENUM_AVAILABLE(_name, _e) \
-{ \
- .name = (_name "_available"), \
- .read = counter_signal_enum_available_read, \
- .priv = (_e) \
-}
-
-enum counter_synapse_action {
- COUNTER_SYNAPSE_ACTION_NONE = 0,
- COUNTER_SYNAPSE_ACTION_RISING_EDGE,
- COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
- COUNTER_SYNAPSE_ACTION_BOTH_EDGES
};
/**
* struct counter_synapse - Counter Synapse node
- * @action: index of current action mode
* @actions_list: array of available action modes
* @num_actions: number of action modes specified in @actions_list
- * @signal: pointer to associated signal
+ * @signal: pointer to the associated Signal
*/
struct counter_synapse {
- size_t action;
- const enum counter_synapse_action *actions_list;
+ const u8 *actions_list;
size_t num_actions;
struct counter_signal *signal;
};
-struct counter_count;
-
-/**
- * struct counter_count_ext - Counter Count extension
- * @name: attribute name
- * @read: read callback for this attribute; may be NULL
- * @write: write callback for this attribute; may be NULL
- * @priv: data private to the driver
- */
-struct counter_count_ext {
- const char *name;
- ssize_t (*read)(struct counter_device *counter,
- struct counter_count *count, void *priv, char *buf);
- ssize_t (*write)(struct counter_device *counter,
- struct counter_count *count, void *priv,
- const char *buf, size_t len);
- void *priv;
-};
-
-enum counter_count_function {
- COUNTER_COUNT_FUNCTION_INCREASE = 0,
- COUNTER_COUNT_FUNCTION_DECREASE,
- COUNTER_COUNT_FUNCTION_PULSE_DIRECTION,
- COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A,
- COUNTER_COUNT_FUNCTION_QUADRATURE_X1_B,
- COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A,
- COUNTER_COUNT_FUNCTION_QUADRATURE_X2_B,
- COUNTER_COUNT_FUNCTION_QUADRATURE_X4
-};
-
/**
* struct counter_count - Counter Count node
- * @id: unique ID used to identify Count
- * @name: device-specific Count name; ideally, this should match
- * the name as it appears in the datasheet documentation
- * @function: index of current function mode
- * @functions_list: array available function modes
+ * @id: unique ID used to identify the Count
+ * @name: device-specific Count name
+ * @functions_list: array of available function modes
* @num_functions: number of function modes specified in @functions_list
- * @synapses: array of synapses for initialization
- * @num_synapses: number of synapses specified in @synapses
- * @ext: optional array of Counter Count extensions
- * @num_ext: number of Counter Count extensions specified in @ext
- * @priv: optional private data supplied by driver
+ * @synapses: array of Synapses for initialization
+ * @num_synapses: number of Synapses specified in @synapses
+ * @ext: optional array of Count extensions
+ * @num_ext: number of Count extensions specified in @ext
*/
struct counter_count {
int id;
const char *name;
- size_t function;
- const enum counter_count_function *functions_list;
+ const u8 *functions_list;
size_t num_functions;
struct counter_synapse *synapses;
size_t num_synapses;
- const struct counter_count_ext *ext;
+ struct counter_data *ext;
size_t num_ext;
-
- void *priv;
};
/**
- * struct counter_count_enum_ext - Count enum extension attribute
- * @items: Array of strings
- * @num_items: Number of items specified in @items
- * @set: Set callback function; may be NULL
- * @get: Get callback function; may be NULL
- *
- * The counter_count_enum_ext structure can be used to implement enum style
- * Count extension attributes. Enum style attributes are those which have a set
- * of strings that map to unsigned integer values. The Generic Counter Count
- * enum extension helper code takes care of mapping between value and string, as
- * well as generating a "_available" file which contains a list of all available
- * items. The get callback is used to query the currently active item; the index
- * of the item within the respective items array is returned via the 'item'
- * parameter. The set callback is called when the attribute is updated; the
- * 'item' parameter contains the index of the newly activated item within the
- * respective items array.
- */
-struct counter_count_enum_ext {
- const char * const *items;
- size_t num_items;
- int (*get)(struct counter_device *counter, struct counter_count *count,
- size_t *item);
- int (*set)(struct counter_device *counter, struct counter_count *count,
- size_t item);
-};
-
-/**
- * COUNTER_COUNT_ENUM() - Initialize Count enum extension
- * @_name: Attribute name
- * @_e: Pointer to a counter_count_enum_ext structure
- *
- * This should usually be used together with COUNTER_COUNT_ENUM_AVAILABLE()
- */
-#define COUNTER_COUNT_ENUM(_name, _e) \
-{ \
- .name = (_name), \
- .read = counter_count_enum_read, \
- .write = counter_count_enum_write, \
- .priv = (_e) \
-}
-
-/**
- * COUNTER_COUNT_ENUM_AVAILABLE() - Initialize Count enum available extension
- * @_name: Attribute name ("_available" will be appended to the name)
- * @_e: Pointer to a counter_count_enum_ext structure
- *
- * Creates a read only attribute that lists all the available enum items in a
- * newline separated list. This should usually be used together with
- * COUNTER_COUNT_ENUM()
- */
-#define COUNTER_COUNT_ENUM_AVAILABLE(_name, _e) \
-{ \
- .name = (_name "_available"), \
- .read = counter_count_enum_available_read, \
- .priv = (_e) \
-}
-
-/**
- * struct counter_device_attr_group - internal container for attribute group
+ * struct counter_attribute_group - internal container for attribute group
* @attr_group: Counter sysfs attributes group
* @attr_list: list to keep track of created Counter sysfs attributes
* @num_attr: number of Counter sysfs attributes
*/
-struct counter_device_attr_group {
+struct counter_attribute_group {
struct attribute_group attr_group;
struct list_head attr_list;
size_t num_attr;
};
-/**
- * struct counter_device_state - internal state container for a Counter device
- * @id: unique ID used to identify the Counter
- * @dev: internal device structure
- * @groups_list: attribute groups list (for Signals, Counts, and ext)
- * @num_groups: number of attribute groups containers
- * @groups: Counter sysfs attribute groups (to populate @dev.groups)
- */
-struct counter_device_state {
- int id;
- struct device dev;
- struct counter_device_attr_group *groups_list;
- size_t num_groups;
- const struct attribute_group **groups;
-};
-
-enum counter_signal_value {
- COUNTER_SIGNAL_LOW = 0,
- COUNTER_SIGNAL_HIGH
-};
-
-/**
- * struct counter_ops - Callbacks from driver
- * @signal_read: optional read callback for Signal attribute. The read
- * value of the respective Signal should be passed back via
- * the val parameter.
- * @count_read: optional read callback for Count attribute. The read
- * value of the respective Count should be passed back via
- * the val parameter.
- * @count_write: optional write callback for Count attribute. The write
- * value for the respective Count is passed in via the val
- * parameter.
- * @function_get: function to get the current count function mode. Returns
- * 0 on success and negative error code on error. The index
- * of the respective Count's returned function mode should
- * be passed back via the function parameter.
- * @function_set: function to set the count function mode. function is the
- * index of the requested function mode from the respective
- * Count's functions_list array.
- * @action_get: function to get the current action mode. Returns 0 on
- * success and negative error code on error. The index of
- * the respective Synapse's returned action mode should be
- * passed back via the action parameter.
- * @action_set: function to set the action mode. action is the index of
- * the requested action mode from the respective Synapse's
- * actions_list array.
- */
-struct counter_ops {
- int (*signal_read)(struct counter_device *counter,
- struct counter_signal *signal,
- enum counter_signal_value *val);
- int (*count_read)(struct counter_device *counter,
- struct counter_count *count, unsigned long *val);
- int (*count_write)(struct counter_device *counter,
- struct counter_count *count, unsigned long val);
- int (*function_get)(struct counter_device *counter,
- struct counter_count *count, size_t *function);
- int (*function_set)(struct counter_device *counter,
- struct counter_count *count, size_t function);
- int (*action_get)(struct counter_device *counter,
- struct counter_count *count,
- struct counter_synapse *synapse, size_t *action);
- int (*action_set)(struct counter_device *counter,
- struct counter_count *count,
- struct counter_synapse *synapse, size_t action);
-};
-
-/**
- * struct counter_device_ext - Counter device extension
- * @name: attribute name
- * @read: read callback for this attribute; may be NULL
- * @write: write callback for this attribute; may be NULL
- * @priv: data private to the driver
- */
-struct counter_device_ext {
- const char *name;
- ssize_t (*read)(struct counter_device *counter, void *priv, char *buf);
- ssize_t (*write)(struct counter_device *counter, void *priv,
- const char *buf, size_t len);
- void *priv;
-};
-
-/**
- * struct counter_device_enum_ext - Counter enum extension attribute
- * @items: Array of strings
- * @num_items: Number of items specified in @items
- * @set: Set callback function; may be NULL
- * @get: Get callback function; may be NULL
- *
- * The counter_device_enum_ext structure can be used to implement enum style
- * Counter extension attributes. Enum style attributes are those which have a
- * set of strings that map to unsigned integer values. The Generic Counter enum
- * extension helper code takes care of mapping between value and string, as well
- * as generating a "_available" file which contains a list of all available
- * items. The get callback is used to query the currently active item; the index
- * of the item within the respective items array is returned via the 'item'
- * parameter. The set callback is called when the attribute is updated; the
- * 'item' parameter contains the index of the newly activated item within the
- * respective items array.
- */
-struct counter_device_enum_ext {
- const char * const *items;
- size_t num_items;
- int (*get)(struct counter_device *counter, size_t *item);
- int (*set)(struct counter_device *counter, size_t item);
-};
-
-/**
- * COUNTER_DEVICE_ENUM() - Initialize Counter enum extension
- * @_name: Attribute name
- * @_e: Pointer to a counter_device_enum_ext structure
- *
- * This should usually be used together with COUNTER_DEVICE_ENUM_AVAILABLE()
- */
-#define COUNTER_DEVICE_ENUM(_name, _e) \
-{ \
- .name = (_name), \
- .read = counter_device_enum_read, \
- .write = counter_device_enum_write, \
- .priv = (_e) \
-}
-
-/**
- * COUNTER_DEVICE_ENUM_AVAILABLE() - Initialize Counter enum available extension
- * @_name: Attribute name ("_available" will be appended to the name)
- * @_e: Pointer to a counter_device_enum_ext structure
- *
- * Creates a read only attribute that lists all the available enum items in a
- * newline separated list. This should usually be used together with
- * COUNTER_DEVICE_ENUM()
- */
-#define COUNTER_DEVICE_ENUM_AVAILABLE(_name, _e) \
-{ \
- .name = (_name "_available"), \
- .read = counter_device_enum_available_read, \
- .priv = (_e) \
-}
-
/**
* struct counter_device - Counter data structure
- * @name: name of the device as it appears in the datasheet
+ * @name: name of the device
* @parent: optional parent device providing the counters
- * @device_state: internal device state container
- * @ops: callbacks from driver
+ * @signal_read: optional read callback for Signals. The read value of
+ * the respective Signal should be passed back via the
+ * value parameter.
+ * @count_read: optional read callback for Counts. The read value of the
+ * respective Count should be passed back via the value
+ * parameter.
+ * @count_write: optional write callback for Counts. The write value for
+ * the respective Count is passed in via the value
+ * parameter.
+ * @function_read: optional read callback the Count function modes. The
+ * read function mode of the respective Count should be
+ * passed back via the function parameter.
+ * @function_write: option write callback for Count function modes. The
+ * function mode to write for the respective Count is
+ * passed in via the function parameter.
+ * @action_read: optional read callback the Synapse action modes. The
+ * read action mode of the respective Synapse should be
+ * passed back via the action parameter.
+ * @action_write: option write callback for Synapse action modes. The
+ * action mode to write for the respective Synapse is
+ * passed in via the action parameter.
* @signals: array of Signals
* @num_signals: number of Signals specified in @signals
* @counts: array of Counts
@@ -425,23 +168,50 @@ struct counter_device_enum_ext {
* @ext: optional array of Counter device extensions
* @num_ext: number of Counter device extensions specified in @ext
* @priv: optional private data supplied by driver
+ * @id: unique ID used to identify the Counter
+ * @dev: internal device structure
+ * @dynamic_names_list: List for dynamic names
+ * @groups_list: attribute groups list (for Signals, Counts, and ext)
+ * @num_groups: number of attribute groups containers
+ * @groups: Counter sysfs attribute groups (to populate @dev.groups)
*/
struct counter_device {
const char *name;
struct device *parent;
- struct counter_device_state *device_state;
- const struct counter_ops *ops;
+ int (*signal_read)(struct counter_device *counter,
+ struct counter_signal *signal, u8 *value);
+ int (*count_read)(struct counter_device *counter,
+ struct counter_count *count, u64 *value);
+ int (*count_write)(struct counter_device *counter,
+ struct counter_count *count, u64 value);
+ int (*function_read)(struct counter_device *counter,
+ struct counter_count *count, u8 *function);
+ int (*function_write)(struct counter_device *counter,
+ struct counter_count *count, u8 function);
+ int (*action_read)(struct counter_device *counter,
+ struct counter_count *count,
+ struct counter_synapse *synapse, u8 *action);
+ int (*action_write)(struct counter_device *counter,
+ struct counter_count *count,
+ struct counter_synapse *synapse, u8 action);
struct counter_signal *signals;
size_t num_signals;
struct counter_count *counts;
size_t num_counts;
- const struct counter_device_ext *ext;
+ struct counter_data *ext;
size_t num_ext;
void *priv;
+
+ int id;
+ struct device dev;
+ struct list_head dynamic_names_list;
+ struct counter_attribute_group *groups_list;
+ size_t num_groups;
+ const struct attribute_group **groups;
};
int counter_register(struct counter_device *const counter);
@@ -451,4 +221,134 @@ int devm_counter_register(struct device *dev,
void devm_counter_unregister(struct device *dev,
struct counter_device *const counter);
+#define COUNTER_DATA_DEVICE_U8(_name, _read, _write) \
+{ \
+ .type = COUNTER_DATA_TYPE_U8, \
+ .name = (_name), \
+ .device_u8_read = (_read), \
+ .device_u8_write = (_write), \
+}
+#define COUNTER_DATA_COUNT_U8(_name, _read, _write) \
+{ \
+ .type = COUNTER_DATA_TYPE_U8, \
+ .name = (_name), \
+ .count_u8_read = (_read), \
+ .count_u8_write = (_write), \
+}
+#define COUNTER_DATA_SIGNAL_U8(_name, _read, _write) \
+{ \
+ .type = COUNTER_DATA_TYPE_U8, \
+ .name = (_name), \
+ .signal_u8_read = (_read), \
+ .signal_u8_write = (_write), \
+}
+
+#define COUNTER_DATA_DEVICE_U64(_name, _read, _write) \
+{ \
+ .type = COUNTER_DATA_TYPE_U64, \
+ .name = (_name), \
+ .device_u64_read = (_read), \
+ .device_u64_write = (_write), \
+}
+#define COUNTER_DATA_COUNT_U64(_name, _read, _write) \
+{ \
+ .type = COUNTER_DATA_TYPE_U64, \
+ .name = (_name), \
+ .count_u64_read = (_read), \
+ .count_u64_write = (_write), \
+}
+#define COUNTER_DATA_SIGNAL_U64(_name, _read, _write) \
+{ \
+ .type = COUNTER_DATA_TYPE_U64, \
+ .name = (_name), \
+ .signal_u64_read = (_read), \
+ .signal_u64_write = (_write), \
+}
+
+#define COUNTER_DATA_DEVICE_STRING(_name, _read, _write) \
+{ \
+ .type = COUNTER_DATA_TYPE_STRING, \
+ .name = (_name), \
+ .device_string_read = (_read), \
+ .device_string_write = (_write), \
+}
+#define COUNTER_DATA_COUNT_STRING(_name, _read, _write) \
+{ \
+ .type = COUNTER_DATA_TYPE_STRING, \
+ .name = (_name), \
+ .count_string_read = (_read), \
+ .count_string_write = (_write), \
+}
+#define COUNTER_DATA_SIGNAL_STRING(_name, _read, _write) \
+{ \
+ .type = COUNTER_DATA_TYPE_STRING, \
+ .name = (_name), \
+ .signal_string_read = (_read), \
+ .signal_string_write = (_write), \
+}
+
+#define COUNTER_DATA_DEVICE_BOOL(_name, _read, _write) \
+{ \
+ .type = COUNTER_DATA_TYPE_BOOL, \
+ .name = (_name), \
+ .device_u8_read = (_read), \
+ .device_u8_write = (_write), \
+}
+#define COUNTER_DATA_COUNT_BOOL(_name, _read, _write) \
+{ \
+ .type = COUNTER_DATA_TYPE_BOOL, \
+ .name = (_name), \
+ .count_u8_read = (_read), \
+ .count_u8_write = (_write), \
+}
+#define COUNTER_DATA_SIGNAL_BOOL(_name, _read, _write) \
+{ \
+ .type = COUNTER_DATA_TYPE_BOOL, \
+ .name = (_name), \
+ .signal_u8_read = (_read), \
+ .signal_u8_write = (_write), \
+}
+
+struct counter_available {
+ const u8 *items;
+ size_t num_items;
+};
+
+#define DEFINE_COUNTER_AVAILABLE(_name, _items) \
+ struct counter_available _name = { \
+ .items = (_items), \
+ .num_items = ARRAY_SIZE(_items), \
+ }
+
+#define COUNTER_DATA_CEILING(_read, _write) \
+ COUNTER_DATA_COUNT_U64("ceiling", _read, _write)
+
+#define COUNTER_DATA_COUNT_MODE(_read, _write, _available) \
+{ \
+ .type = COUNTER_DATA_TYPE_COUNT_MODE, \
+ .name = "count_mode", \
+ .count_u8_read = (_read), \
+ .count_u8_write = (_write), \
+ .priv = &(_available), \
+}
+
+#define COUNTER_DATA_DIRECTION(_read) \
+{ \
+ .type = COUNTER_DATA_TYPE_COUNT_DIRECTION, \
+ .name = "direction", \
+ .count_u8_read = (_read), \
+}
+
+#define COUNTER_DATA_ENABLE(_read, _write) \
+ COUNTER_DATA_COUNT_BOOL("enable", _read, _write)
+
+#define COUNTER_DATA_FLOOR(_read, _write) \
+ COUNTER_DATA_COUNT_U64("floor", _read, _write)
+
+#define COUNTER_DATA_PRESET(_read, _write) \
+ COUNTER_DATA_COUNT_U64("preset", _read, _write)
+
+#define COUNTER_DATA_PRESET_ENABLE(_read, _write) \
+ COUNTER_DATA_COUNT_BOOL("preset_enable", _read, _write)
+
#endif /* _COUNTER_H_ */
diff --git a/include/linux/counter_enum.h b/include/linux/counter_enum.h
deleted file mode 100644
index 9f917298a88f..000000000000
--- a/include/linux/counter_enum.h
+++ /dev/null
@@ -1,45 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Counter interface enum functions
- * Copyright (C) 2018 William Breathitt Gray
- */
-#ifndef _COUNTER_ENUM_H_
-#define _COUNTER_ENUM_H_
-
-#include <linux/types.h>
-
-struct counter_device;
-struct counter_signal;
-struct counter_count;
-
-ssize_t counter_signal_enum_read(struct counter_device *counter,
- struct counter_signal *signal, void *priv,
- char *buf);
-ssize_t counter_signal_enum_write(struct counter_device *counter,
- struct counter_signal *signal, void *priv,
- const char *buf, size_t len);
-
-ssize_t counter_signal_enum_available_read(struct counter_device *counter,
- struct counter_signal *signal,
- void *priv, char *buf);
-
-ssize_t counter_count_enum_read(struct counter_device *counter,
- struct counter_count *count, void *priv,
- char *buf);
-ssize_t counter_count_enum_write(struct counter_device *counter,
- struct counter_count *count, void *priv,
- const char *buf, size_t len);
-
-ssize_t counter_count_enum_available_read(struct counter_device *counter,
- struct counter_count *count,
- void *priv, char *buf);
-
-ssize_t counter_device_enum_read(struct counter_device *counter, void *priv,
- char *buf);
-ssize_t counter_device_enum_write(struct counter_device *counter, void *priv,
- const char *buf, size_t len);
-
-ssize_t counter_device_enum_available_read(struct counter_device *counter,
- void *priv, char *buf);
-
-#endif /* _COUNTER_ENUM_H_ */
diff --git a/include/uapi/linux/counter-types.h b/include/uapi/linux/counter-types.h
new file mode 100644
index 000000000000..d19616df0e1c
--- /dev/null
+++ b/include/uapi/linux/counter-types.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Counter interface data types
+ * Copyright (C) 2020 William Breathitt Gray
+ */
+#ifndef _UAPI_COUNTER_TYPES_H_
+#define _UAPI_COUNTER_TYPES_H_
+
+#define COUNTER_COUNT_DIRECTION_FORWARD 0
+#define COUNTER_COUNT_DIRECTION_BACKWARD 1
+
+#define COUNTER_COUNT_MODE_NORMAL 0
+#define COUNTER_COUNT_MODE_RANGE_LIMIT 1
+#define COUNTER_COUNT_MODE_NON_RECYCLE 2
+#define COUNTER_COUNT_MODE_MODULO_N 3
+
+#define COUNTER_COUNT_FUNCTION_INCREASE 0
+#define COUNTER_COUNT_FUNCTION_DECREASE 1
+#define COUNTER_COUNT_FUNCTION_PULSE_DIRECTION 2
+#define COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A 3
+#define COUNTER_COUNT_FUNCTION_QUADRATURE_X1_B 4
+#define COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A 5
+#define COUNTER_COUNT_FUNCTION_QUADRATURE_X2_B 6
+#define COUNTER_COUNT_FUNCTION_QUADRATURE_X4 7
+
+#define COUNTER_SIGNAL_LOW 0
+#define COUNTER_SIGNAL_HIGH 1
+
+#define COUNTER_SYNAPSE_ACTION_NONE 0
+#define COUNTER_SYNAPSE_ACTION_RISING_EDGE 1
+#define COUNTER_SYNAPSE_ACTION_FALLING_EDGE 2
+#define COUNTER_SYNAPSE_ACTION_BOTH_EDGES 3
+
+#define COUNTER_DATA_TYPE_U8 0
+#define COUNTER_DATA_TYPE_U64 1
+#define COUNTER_DATA_TYPE_STRING 2
+#define COUNTER_DATA_TYPE_BOOL 3
+#define COUNTER_DATA_TYPE_COUNT_FUNCTION 4
+#define COUNTER_DATA_TYPE_SIGNAL 5
+#define COUNTER_DATA_TYPE_SYNAPSE_ACTION 6
+#define COUNTER_DATA_TYPE_ENUM 7
+#define COUNTER_DATA_TYPE_COUNT_DIRECTION 8
+#define COUNTER_DATA_TYPE_COUNT_MODE 9
+
+#endif /* _UAPI_COUNTER_TYPES_H_ */
--
2.26.2
^ permalink raw reply related [flat|nested] 38+ messages in thread
* [PATCH v2 2/4] docs: counter: Update to reflect sysfs internalization
2020-05-16 19:19 ` William Breathitt Gray
@ 2020-05-16 19:20 ` William Breathitt Gray
-1 siblings, 0 replies; 38+ messages in thread
From: William Breathitt Gray @ 2020-05-16 19:20 UTC (permalink / raw)
To: jic23
Cc: kamel.bouhara, gwendal, alexandre.belloni, david, linux-iio,
linux-kernel, linux-stm32, linux-arm-kernel, syednwaris,
patrick.havelange, fabrice.gasnier, mcoquelin.stm32,
alexandre.torgue, William Breathitt Gray
The Counter subsystem architecture and driver implementations have
changed in order to handle Counter sysfs interactions in a more
consistent way. This patch updates the Generic Counter interface
documentation to reflect the changes.
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
Documentation/driver-api/generic-counter.rst | 215 +++++++++++++------
1 file changed, 149 insertions(+), 66 deletions(-)
diff --git a/Documentation/driver-api/generic-counter.rst b/Documentation/driver-api/generic-counter.rst
index e622f8f6e56a..8f85c30dea0b 100644
--- a/Documentation/driver-api/generic-counter.rst
+++ b/Documentation/driver-api/generic-counter.rst
@@ -250,8 +250,8 @@ for defining a counter device.
.. kernel-doc:: drivers/counter/counter.c
:export:
-Implementation
-==============
+Driver Implementation
+=====================
To support a counter device, a driver must first allocate the available
Counter Signals via counter_signal structures. These Signals should
@@ -267,25 +267,58 @@ respective counter_count structure. These counter_count structures are
set to the counts array member of an allocated counter_device structure
before the Counter is registered to the system.
-Driver callbacks should be provided to the counter_device structure via
-a constant counter_ops structure in order to communicate with the
-device: to read and write various Signals and Counts, and to set and get
-the "action mode" and "function mode" for various Synapses and Counts
-respectively.
+Driver callbacks must be provided to the counter_device structure in
+order to communicate with the device: to read and write various Signals
+and Counts, and to set and get the "action mode" and "function mode" for
+various Synapses and Counts respectively.
A defined counter_device structure may be registered to the system by
passing it to the counter_register function, and unregistered by passing
it to the counter_unregister function. Similarly, the
-devm_counter_register and devm_counter_unregister functions may be used
-if device memory-managed registration is desired.
-
-Extension sysfs attributes can be created for auxiliary functionality
-and data by passing in defined counter_device_ext, counter_count_ext,
-and counter_signal_ext structures. In these cases, the
-counter_device_ext structure is used for global/miscellaneous exposure
-and configuration of the respective Counter device, while the
-counter_count_ext and counter_signal_ext structures allow for auxiliary
-exposure and configuration of a specific Count or Signal respectively.
+devm_counter_register function may be used if device memory-managed
+registration is desired.
+
+The struct counter_data structure is used to define counter extensions
+for Signals, Synapses, and Counts.
+
+The "type" member specifies the type of data (e.g. unsigned long,
+boolean, etc.) handled by this extension. The "read" and "write" members
+can then be set by the counter device driver with callbacks to handle
+that data.
+
+Convenience macros such as `COUNTER_DATA_COUNT_U64` are provided for use
+by driver authors. In particular, driver authors are expected to use
+the provided macros for standard Counter subsystem attributes in order
+to maintain a consistent interface for userspace. For example, a counter
+device driver may define several standard attributes like so::
+
+ struct counter_data count_ext[] = {
+ COUNTER_DATA_DIRECTION(count_direction_read),
+ COUNTER_DATA_ENABLE(count_enable_read, count_enable_write),
+ COUNTER_DATA_CEILING(count_ceiling_read, count_ceiling_write),
+ };
+
+This makes it intuitive to see, add, and modify the attributes that are
+supported by this driver ("direction", "enable", and "ceiling") and to
+maintain this code without getting lost in a web of struct braces.
+
+Callbacks must match the function type expected for the respective
+component or extension. These function types are defined in the struct
+counter_data structure as the "`*_read`" and "`*_write`" union members.
+
+The corresponding callback prototypes for the extensions mentioned in
+the previous example above would be::
+
+ int count_direction_read(struct counter_device *counter,
+ struct counter_count *count, u8 *direction);
+ int count_enable_read(struct counter_device *counter,
+ struct counter_count *count, u8 *enable);
+ int count_enable_write(struct counter_device *counter,
+ struct counter_count *count, u8 enable);
+ int count_ceiling_read(struct counter_device *counter,
+ struct counter_count *count, u64 *ceiling);
+ int count_ceiling_write(struct counter_device *counter,
+ struct counter_count *count, u64 ceiling);
Determining the type of extension to create is a matter of scope.
@@ -313,52 +346,102 @@ Determining the type of extension to create is a matter of scope.
chip overheated via a device extension called "error_overtemp":
/sys/bus/counter/devices/counterX/error_overtemp
-Architecture
-============
-
-When the Generic Counter interface counter module is loaded, the
-counter_init function is called which registers a bus_type named
-"counter" to the system. Subsequently, when the module is unloaded, the
-counter_exit function is called which unregisters the bus_type named
-"counter" from the system.
-
-Counter devices are registered to the system via the counter_register
-function, and later removed via the counter_unregister function. The
-counter_register function establishes a unique ID for the Counter
-device and creates a respective sysfs directory, where X is the
-mentioned unique ID:
-
- /sys/bus/counter/devices/counterX
-
-Sysfs attributes are created within the counterX directory to expose
-functionality, configurations, and data relating to the Counts, Signals,
-and Synapses of the Counter device, as well as options and information
-for the Counter device itself.
-
-Each Signal has a directory created to house its relevant sysfs
-attributes, where Y is the unique ID of the respective Signal:
-
- /sys/bus/counter/devices/counterX/signalY
-
-Similarly, each Count has a directory created to house its relevant
-sysfs attributes, where Y is the unique ID of the respective Count:
-
- /sys/bus/counter/devices/counterX/countY
-
-For a more detailed breakdown of the available Generic Counter interface
-sysfs attributes, please refer to the
-Documentation/ABI/testing/sysfs-bus-counter file.
-
-The Signals and Counts associated with the Counter device are registered
-to the system as well by the counter_register function. The
-signal_read/signal_write driver callbacks are associated with their
-respective Signal attributes, while the count_read/count_write and
-function_get/function_set driver callbacks are associated with their
-respective Count attributes; similarly, the same is true for the
-action_get/action_set driver callbacks and their respective Synapse
-attributes. If a driver callback is left undefined, then the respective
-read/write permission is left disabled for the relevant attributes.
-
-Similarly, extension sysfs attributes are created for the defined
-counter_device_ext, counter_count_ext, and counter_signal_ext
-structures that are passed in.
+Subsystem Architecture
+======================
+
+Counter drivers pass and take data natively (i.e. `u8`, `u64`, `char *`,
+etc.) and the shared counter module handles the translation between the
+sysfs interface. This gurantees a standard userspace interface for all
+counter drivers, and helps generalize the Generic Counter driver ABI in
+order to support the Generic Counter chrdev interface without
+significant changes to the existing counter drivers.
+
+A high-level view of how a count value is passed down from a counter
+driver can be exemplified by the following::
+
+ Count data request:
+ ~~~~~~~~~~~~~~~~~~~
+ ----------------------
+ / Counter device \
+ +----------------------+
+ | Count register: 0x28 |
+ +----------------------+
+ |
+ -----------------
+ / raw count data /
+ -----------------
+ |
+ V
+ +----------------------------+
+ | Counter device driver |----------+
+ +----------------------------+ |
+ | Processes data from device | -------------------
+ |----------------------------| / driver callbacks /
+ | Type: unsigned long | -------------------
+ | Value: 42 | |
+ +----------------------------+ |
+ | |
+ ---------------- |
+ / unsigned long / |
+ ---------------- |
+ | |
+ | V
+ | +----------------------+
+ | | Counter core |
+ | +----------------------+
+ | | Routes device driver |
+ | | callbacks to the |
+ | | userspace interfaces |
+ | +----------------------+
+ | |
+ | -------------------
+ | / driver callbacks /
+ | -------------------
+ | |
+ +-------+ |
+ | |
+ | +---------------+
+ | |
+ V |
+ +--------------------+ |
+ | Counter sysfs |<-+
+ +--------------------+
+ | Translates to the |
+ | standard Counter |
+ | sysfs output |
+ |--------------------|
+ | Type: const char * |
+ | Value: "42" |
+ +--------------------+
+ |
+ ---------------
+ / const char * /
+ ---------------
+ |
+ V
+ +--------------------------------------------------+
+ | `/sys/bus/counter/devices/counterX/countY/count` |
+ +--------------------------------------------------+
+ \ Count: "42" /
+ --------------------------------------------------
+
+There are three primary components involved:
+
+Counter device driver
+---------------------
+Communicates with the hardware device to read/write data; e.g. counter
+drivers for quadrature encoders, timers, etc.
+
+Counter core
+------------
+Registers the counter device driver to the system so that the respective
+callbacks are called during userspace interaction.
+
+Counter sysfs
+-------------
+Translates counter data to the standard Counter sysfs interface format
+and vice versa.
+
+Please refer to the `Documentation/ABI/testing/sysfs-bus-counter` file
+for a detailed breakdown of the available Generic Counter interface
+sysfs attributes.
--
2.26.2
^ permalink raw reply related [flat|nested] 38+ messages in thread
* [PATCH v2 2/4] docs: counter: Update to reflect sysfs internalization
@ 2020-05-16 19:20 ` William Breathitt Gray
0 siblings, 0 replies; 38+ messages in thread
From: William Breathitt Gray @ 2020-05-16 19:20 UTC (permalink / raw)
To: jic23
Cc: kamel.bouhara, gwendal, david, linux-iio, patrick.havelange,
alexandre.belloni, linux-kernel, mcoquelin.stm32,
William Breathitt Gray, fabrice.gasnier, syednwaris, linux-stm32,
linux-arm-kernel, alexandre.torgue
The Counter subsystem architecture and driver implementations have
changed in order to handle Counter sysfs interactions in a more
consistent way. This patch updates the Generic Counter interface
documentation to reflect the changes.
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
Documentation/driver-api/generic-counter.rst | 215 +++++++++++++------
1 file changed, 149 insertions(+), 66 deletions(-)
diff --git a/Documentation/driver-api/generic-counter.rst b/Documentation/driver-api/generic-counter.rst
index e622f8f6e56a..8f85c30dea0b 100644
--- a/Documentation/driver-api/generic-counter.rst
+++ b/Documentation/driver-api/generic-counter.rst
@@ -250,8 +250,8 @@ for defining a counter device.
.. kernel-doc:: drivers/counter/counter.c
:export:
-Implementation
-==============
+Driver Implementation
+=====================
To support a counter device, a driver must first allocate the available
Counter Signals via counter_signal structures. These Signals should
@@ -267,25 +267,58 @@ respective counter_count structure. These counter_count structures are
set to the counts array member of an allocated counter_device structure
before the Counter is registered to the system.
-Driver callbacks should be provided to the counter_device structure via
-a constant counter_ops structure in order to communicate with the
-device: to read and write various Signals and Counts, and to set and get
-the "action mode" and "function mode" for various Synapses and Counts
-respectively.
+Driver callbacks must be provided to the counter_device structure in
+order to communicate with the device: to read and write various Signals
+and Counts, and to set and get the "action mode" and "function mode" for
+various Synapses and Counts respectively.
A defined counter_device structure may be registered to the system by
passing it to the counter_register function, and unregistered by passing
it to the counter_unregister function. Similarly, the
-devm_counter_register and devm_counter_unregister functions may be used
-if device memory-managed registration is desired.
-
-Extension sysfs attributes can be created for auxiliary functionality
-and data by passing in defined counter_device_ext, counter_count_ext,
-and counter_signal_ext structures. In these cases, the
-counter_device_ext structure is used for global/miscellaneous exposure
-and configuration of the respective Counter device, while the
-counter_count_ext and counter_signal_ext structures allow for auxiliary
-exposure and configuration of a specific Count or Signal respectively.
+devm_counter_register function may be used if device memory-managed
+registration is desired.
+
+The struct counter_data structure is used to define counter extensions
+for Signals, Synapses, and Counts.
+
+The "type" member specifies the type of data (e.g. unsigned long,
+boolean, etc.) handled by this extension. The "read" and "write" members
+can then be set by the counter device driver with callbacks to handle
+that data.
+
+Convenience macros such as `COUNTER_DATA_COUNT_U64` are provided for use
+by driver authors. In particular, driver authors are expected to use
+the provided macros for standard Counter subsystem attributes in order
+to maintain a consistent interface for userspace. For example, a counter
+device driver may define several standard attributes like so::
+
+ struct counter_data count_ext[] = {
+ COUNTER_DATA_DIRECTION(count_direction_read),
+ COUNTER_DATA_ENABLE(count_enable_read, count_enable_write),
+ COUNTER_DATA_CEILING(count_ceiling_read, count_ceiling_write),
+ };
+
+This makes it intuitive to see, add, and modify the attributes that are
+supported by this driver ("direction", "enable", and "ceiling") and to
+maintain this code without getting lost in a web of struct braces.
+
+Callbacks must match the function type expected for the respective
+component or extension. These function types are defined in the struct
+counter_data structure as the "`*_read`" and "`*_write`" union members.
+
+The corresponding callback prototypes for the extensions mentioned in
+the previous example above would be::
+
+ int count_direction_read(struct counter_device *counter,
+ struct counter_count *count, u8 *direction);
+ int count_enable_read(struct counter_device *counter,
+ struct counter_count *count, u8 *enable);
+ int count_enable_write(struct counter_device *counter,
+ struct counter_count *count, u8 enable);
+ int count_ceiling_read(struct counter_device *counter,
+ struct counter_count *count, u64 *ceiling);
+ int count_ceiling_write(struct counter_device *counter,
+ struct counter_count *count, u64 ceiling);
Determining the type of extension to create is a matter of scope.
@@ -313,52 +346,102 @@ Determining the type of extension to create is a matter of scope.
chip overheated via a device extension called "error_overtemp":
/sys/bus/counter/devices/counterX/error_overtemp
-Architecture
-============
-
-When the Generic Counter interface counter module is loaded, the
-counter_init function is called which registers a bus_type named
-"counter" to the system. Subsequently, when the module is unloaded, the
-counter_exit function is called which unregisters the bus_type named
-"counter" from the system.
-
-Counter devices are registered to the system via the counter_register
-function, and later removed via the counter_unregister function. The
-counter_register function establishes a unique ID for the Counter
-device and creates a respective sysfs directory, where X is the
-mentioned unique ID:
-
- /sys/bus/counter/devices/counterX
-
-Sysfs attributes are created within the counterX directory to expose
-functionality, configurations, and data relating to the Counts, Signals,
-and Synapses of the Counter device, as well as options and information
-for the Counter device itself.
-
-Each Signal has a directory created to house its relevant sysfs
-attributes, where Y is the unique ID of the respective Signal:
-
- /sys/bus/counter/devices/counterX/signalY
-
-Similarly, each Count has a directory created to house its relevant
-sysfs attributes, where Y is the unique ID of the respective Count:
-
- /sys/bus/counter/devices/counterX/countY
-
-For a more detailed breakdown of the available Generic Counter interface
-sysfs attributes, please refer to the
-Documentation/ABI/testing/sysfs-bus-counter file.
-
-The Signals and Counts associated with the Counter device are registered
-to the system as well by the counter_register function. The
-signal_read/signal_write driver callbacks are associated with their
-respective Signal attributes, while the count_read/count_write and
-function_get/function_set driver callbacks are associated with their
-respective Count attributes; similarly, the same is true for the
-action_get/action_set driver callbacks and their respective Synapse
-attributes. If a driver callback is left undefined, then the respective
-read/write permission is left disabled for the relevant attributes.
-
-Similarly, extension sysfs attributes are created for the defined
-counter_device_ext, counter_count_ext, and counter_signal_ext
-structures that are passed in.
+Subsystem Architecture
+======================
+
+Counter drivers pass and take data natively (i.e. `u8`, `u64`, `char *`,
+etc.) and the shared counter module handles the translation between the
+sysfs interface. This gurantees a standard userspace interface for all
+counter drivers, and helps generalize the Generic Counter driver ABI in
+order to support the Generic Counter chrdev interface without
+significant changes to the existing counter drivers.
+
+A high-level view of how a count value is passed down from a counter
+driver can be exemplified by the following::
+
+ Count data request:
+ ~~~~~~~~~~~~~~~~~~~
+ ----------------------
+ / Counter device \
+ +----------------------+
+ | Count register: 0x28 |
+ +----------------------+
+ |
+ -----------------
+ / raw count data /
+ -----------------
+ |
+ V
+ +----------------------------+
+ | Counter device driver |----------+
+ +----------------------------+ |
+ | Processes data from device | -------------------
+ |----------------------------| / driver callbacks /
+ | Type: unsigned long | -------------------
+ | Value: 42 | |
+ +----------------------------+ |
+ | |
+ ---------------- |
+ / unsigned long / |
+ ---------------- |
+ | |
+ | V
+ | +----------------------+
+ | | Counter core |
+ | +----------------------+
+ | | Routes device driver |
+ | | callbacks to the |
+ | | userspace interfaces |
+ | +----------------------+
+ | |
+ | -------------------
+ | / driver callbacks /
+ | -------------------
+ | |
+ +-------+ |
+ | |
+ | +---------------+
+ | |
+ V |
+ +--------------------+ |
+ | Counter sysfs |<-+
+ +--------------------+
+ | Translates to the |
+ | standard Counter |
+ | sysfs output |
+ |--------------------|
+ | Type: const char * |
+ | Value: "42" |
+ +--------------------+
+ |
+ ---------------
+ / const char * /
+ ---------------
+ |
+ V
+ +--------------------------------------------------+
+ | `/sys/bus/counter/devices/counterX/countY/count` |
+ +--------------------------------------------------+
+ \ Count: "42" /
+ --------------------------------------------------
+
+There are three primary components involved:
+
+Counter device driver
+---------------------
+Communicates with the hardware device to read/write data; e.g. counter
+drivers for quadrature encoders, timers, etc.
+
+Counter core
+------------
+Registers the counter device driver to the system so that the respective
+callbacks are called during userspace interaction.
+
+Counter sysfs
+-------------
+Translates counter data to the standard Counter sysfs interface format
+and vice versa.
+
+Please refer to the `Documentation/ABI/testing/sysfs-bus-counter` file
+for a detailed breakdown of the available Generic Counter interface
+sysfs attributes.
--
2.26.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 38+ messages in thread
* [PATCH v2 3/4] counter: Add character device interface
2020-05-16 19:19 ` William Breathitt Gray
@ 2020-05-16 19:20 ` William Breathitt Gray
-1 siblings, 0 replies; 38+ messages in thread
From: William Breathitt Gray @ 2020-05-16 19:20 UTC (permalink / raw)
To: jic23
Cc: kamel.bouhara, gwendal, alexandre.belloni, david, linux-iio,
linux-kernel, linux-stm32, linux-arm-kernel, syednwaris,
patrick.havelange, fabrice.gasnier, mcoquelin.stm32,
alexandre.torgue, William Breathitt Gray
This patch introduces a character device interface for the Counter
subsystem. Device control is exposed through standard character device
read and write operations.
The first 196095 bytes of the character device serve as a control
selection area where control exposure of desired Counter components and
extensions may be selected. Each byte serves as a boolean selection
indicator for a respective Counter component or extension. The format of
this area is as follows:
* For each device extension, a byte is required.
* For each Signal, a byte is reserved for the Signal component, and a
byte is reserved for each Signal extension.
* For each Count, a byte is reserved for the Count component, a byte is
reserved for the count function, a byte is reserved for each Synapse
action, and byte is reserved for each Count extension.
The selected Counter components and extensions may then be interfaced
after the first 196095 bytes via standard character device read/write
operations. The number of bytes available for each component or
extension is dependent on their respective data type: u8 will have 1
byte available, u64 will have 8 bytes available, strings will have 64
bytes available, etc.
A high-level view of how a count value is passed down from a counter
driver can be exemplified by the following:
----------------------
/ Counter device \
+----------------------+
| Count register: 0x28 |
+----------------------+
|
-----------------
/ raw count data /
-----------------
|
V
+----------------------------+
| Counter device driver |----------+
+----------------------------+ |
| Processes data from device | -------------------
|----------------------------| / driver callbacks /
| Type: u64 | -------------------
| Value: 42 | |
+----------------------------+ |
| |
---------- |
/ u64 / |
---------- |
| |
| V
| +----------------------+
| | Counter core |
| +----------------------+
| | Routes device driver |
| | callbacks to the |
| | userspace interfaces |
| +----------------------+
| |
| -------------------
| / driver callbacks /
| -------------------
| |
+-------+---------------+ |
| | |
| +-------|-------+
| | |
V | V
+--------------------+ | +---------------------+
| Counter sysfs |<-+->| Counter chrdev |
+--------------------+ +---------------------+
| Translates to the | | Translates to the |
| standard Counter | | standard Counter |
| sysfs output | | character device |
|--------------------| |---------------------+
| Type: const char * | | Type: u64 |
| Value: "42" | | Value: 42 |
+--------------------+ +---------------------+
| |
--------------- ----------
/ const char * / / u64 /
--------------- ----------
| |
| V
| +-----------+
| | read |
| +-----------+
| \ Count: 42 /
| -----------
|
V
+--------------------------------------------------+
| `/sys/bus/counter/devices/counterX/countY/count` |
+--------------------------------------------------+
\ Count: "42" /
--------------------------------------------------
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
MAINTAINERS | 1 +
drivers/counter/Makefile | 2 +-
drivers/counter/counter-chrdev.c | 656 +++++++++++++++++++++++++++++++
drivers/counter/counter-chrdev.h | 16 +
drivers/counter/counter-core.c | 34 +-
include/linux/counter.h | 16 +
6 files changed, 722 insertions(+), 3 deletions(-)
create mode 100644 drivers/counter/counter-chrdev.c
create mode 100644 drivers/counter/counter-chrdev.h
diff --git a/MAINTAINERS b/MAINTAINERS
index ef72b5755793..150ad8a9bb87 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4365,6 +4365,7 @@ F: Documentation/ABI/testing/sysfs-bus-counter*
F: Documentation/driver-api/generic-counter.rst
F: drivers/counter/
F: include/linux/counter.h
+F: include/uapi/linux/counter.h
F: include/uapi/linux/counter-types.h
CPMAC ETHERNET DRIVER
diff --git a/drivers/counter/Makefile b/drivers/counter/Makefile
index f48e337cbd85..d219b9c058e7 100644
--- a/drivers/counter/Makefile
+++ b/drivers/counter/Makefile
@@ -4,7 +4,7 @@
#
obj-$(CONFIG_COUNTER) += counter.o
-counter-y := counter-core.o counter-sysfs.o
+counter-y := counter-core.o counter-sysfs.o counter-chrdev.o
obj-$(CONFIG_104_QUAD_8) += 104-quad-8.o
obj-$(CONFIG_STM32_TIMER_CNT) += stm32-timer-cnt.o
diff --git a/drivers/counter/counter-chrdev.c b/drivers/counter/counter-chrdev.c
new file mode 100644
index 000000000000..7fd55bf71e47
--- /dev/null
+++ b/drivers/counter/counter-chrdev.c
@@ -0,0 +1,656 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic Counter character device interface
+ * Copyright (C) 2020 William Breathitt Gray
+ */
+
+#include <linux/cdev.h>
+#include <linux/counter.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/fs.h>
+#include <linux/kdev_t.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+
+enum counter_owner_type {
+ COUNTER_OWNER_TYPE_DEVICE,
+ COUNTER_OWNER_TYPE_SIGNAL,
+ COUNTER_OWNER_TYPE_COUNT,
+};
+
+struct counter_control {
+ loff_t offset;
+ size_t size;
+ struct list_head l;
+
+ struct counter_data data;
+ enum counter_owner_type type;
+ void *owner;
+};
+
+static int counter_data_u8_read(struct counter_device *const counter,
+ const struct counter_control *const control,
+ u8 __user *const buf)
+{
+ const struct counter_data *const data = &control->data;
+ int err;
+ u8 val;
+
+ switch (control->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ err = data->device_u8_read(counter, &val);
+ break;
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ err = data->signal_u8_read(counter, control->owner, &val);
+ break;
+ case COUNTER_OWNER_TYPE_COUNT:
+ if (data->type == COUNTER_DATA_TYPE_SYNAPSE_ACTION)
+ err = data->action_read(counter, control->owner,
+ data->priv, &val);
+ else
+ err = data->count_u8_read(counter, control->owner,
+ &val);
+ break;
+ default: return -EINVAL;
+ }
+ if (err)
+ return err;
+
+ return put_user(val, buf);
+}
+
+static int counter_data_u64_read(struct counter_device *const counter,
+ const struct counter_control *const control,
+ char __user *const buf, const size_t len,
+ const size_t offset)
+{
+ const struct counter_data *const data = &control->data;
+ int err;
+ u64 val;
+
+ switch (control->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ err = data->device_u64_read(counter, &val);
+ break;
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ err = data->signal_u64_read(counter, control->owner, &val);
+ break;
+ case COUNTER_OWNER_TYPE_COUNT:
+ err = data->count_u64_read(counter, control->owner, &val);
+ break;
+ default: return -EINVAL;
+ }
+ if (err)
+ return err;
+
+ return copy_to_user(buf, (const char *)&val + offset, len);
+}
+
+static int counter_data_string_read(struct counter_device *const counter,
+ const struct counter_control *const control,
+ char __user *const buf, const size_t len,
+ const size_t offset)
+{
+ const struct counter_data *const data = &control->data;
+ int err;
+ char str[64] = "";
+
+ switch (control->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ err = data->device_string_read(counter, str, sizeof(str));
+ break;
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ err = data->signal_string_read(counter, control->owner, str,
+ sizeof(str));
+ break;
+ case COUNTER_OWNER_TYPE_COUNT:
+ err = data->count_string_read(counter, control->owner, str,
+ sizeof(str));
+ break;
+ default: return -EINVAL;
+ }
+ if (err < 0)
+ return err;
+
+ return copy_to_user(buf, str + offset, len);
+}
+
+static int counter_control_read(struct counter_device *const counter,
+ const struct counter_control *const control,
+ char __user *const buf, const size_t len,
+ const size_t offset)
+{
+ /* Check if read operation is supported */
+ if (!control->data.device_u8_read)
+ return -EFAULT;
+
+ switch (control->data.type) {
+ case COUNTER_DATA_TYPE_U8:
+ case COUNTER_DATA_TYPE_BOOL:
+ case COUNTER_DATA_TYPE_SIGNAL:
+ case COUNTER_DATA_TYPE_COUNT_FUNCTION:
+ case COUNTER_DATA_TYPE_SYNAPSE_ACTION:
+ case COUNTER_DATA_TYPE_COUNT_DIRECTION:
+ case COUNTER_DATA_TYPE_COUNT_MODE:
+ return counter_data_u8_read(counter, control, buf);
+ case COUNTER_DATA_TYPE_U64:
+ return counter_data_u64_read(counter, control, buf, len,
+ offset);
+ case COUNTER_DATA_TYPE_STRING:
+ return counter_data_string_read(counter, control, buf, len,
+ offset);
+ }
+
+ return -EINVAL;
+}
+
+static ssize_t counter_chrdev_read(struct file *filp, char __user *buf,
+ size_t len, loff_t *f_ps)
+{
+ const loff_t start_ps = *f_ps;
+ struct counter_device *const counter = filp->private_data;
+ size_t read_size;
+ struct counter_control *control;
+ int err;
+ loff_t next_control_ps;
+
+ /* Handle Counter control selection */
+ if (*f_ps < COUNTER_SELECTION_SIZE) {
+ read_size = (*f_ps + len > COUNTER_SELECTION_SIZE) ?
+ COUNTER_SELECTION_SIZE - *f_ps : len;
+
+ if (copy_to_user(buf, counter->selection + *f_ps, read_size))
+ return -EFAULT;
+
+ *f_ps += read_size;
+ buf += read_size;
+ len -= read_size;
+ if (!len)
+ goto exit_chrdev_read;
+ }
+
+ /* Handle controls */
+ list_for_each_entry(control, &counter->control_list, l) {
+ next_control_ps = control->offset + control->size;
+
+ /* Find first control item */
+ if (*f_ps >= next_control_ps)
+ continue;
+
+ read_size = (*f_ps + len > next_control_ps) ?
+ next_control_ps - *f_ps : len;
+
+ err = counter_control_read(counter, control, buf, read_size,
+ control->offset - *f_ps);
+ if (err)
+ return err;
+
+ *f_ps += read_size;
+ buf += read_size;
+ len -= read_size;
+ if (!len)
+ goto exit_chrdev_read;
+ }
+
+exit_chrdev_read:
+ return *f_ps - start_ps;
+}
+
+static int counter_control_ext_add(const u8 *const selection,
+ const enum counter_owner_type type,
+ void *const owner, const size_t num_ext,
+ const struct counter_data *const ext,
+ struct list_head *const cntrl_list,
+ loff_t *const offset)
+{
+ struct counter_control *p = list_last_entry(cntrl_list, typeof(*p), l);
+ struct counter_control *n;
+ size_t i;
+ struct counter_control *control;
+ int err;
+
+ for (i = 0; i < num_ext; i++) {
+ /* Check if extension is selected */
+ if (!selection[i])
+ continue;
+
+ /* Generate control list item */
+ control = kzalloc(sizeof(*control), GFP_KERNEL);
+ if (!control) {
+ err = -ENOMEM;
+ goto err_control_ext_create;
+ }
+ list_add_tail(&control->l, cntrl_list);
+
+ /* Configure control list item */
+ control->data = ext[i],
+ control->type = type;
+ control->owner = owner;
+ control->offset = *offset;
+ switch (control->data.type) {
+ case COUNTER_DATA_TYPE_U8:
+ case COUNTER_DATA_TYPE_BOOL:
+ case COUNTER_DATA_TYPE_COUNT_DIRECTION:
+ case COUNTER_DATA_TYPE_COUNT_MODE:
+ control->size = sizeof(u8);
+ break;
+ case COUNTER_DATA_TYPE_U64:
+ control->size = sizeof(u64);
+ break;
+ case COUNTER_DATA_TYPE_STRING:
+ control->size = 64;
+ break;
+ default:
+ err = -EINVAL;
+ goto err_control_ext_create;
+ }
+ *offset += control->size;
+ }
+
+ return 0;
+
+err_control_ext_create:
+ list_for_each_entry_safe_continue(p, n, cntrl_list, l) {
+ list_del(&p->l);
+ kfree(p);
+ }
+ return err;
+}
+
+static void counter_control_list_free(struct list_head *const cntrl_list)
+{
+ struct counter_control *p, *n;
+
+ list_for_each_entry_safe(p, n, cntrl_list, l) {
+ list_del(&p->l);
+ kfree(p);
+ }
+}
+
+static int counter_control_list_create(struct counter_device *const counter)
+{
+ const u8 *selection = counter->selection;
+ loff_t offset = COUNTER_SELECTION_SIZE;
+ size_t i, j;
+ struct counter_signal *signal;
+ struct counter_count *count;
+ struct counter_control *control;
+ int err;
+
+ /* Clean up old list */
+ counter_control_list_free(&counter->control_list);
+
+ /* Handle device extensions */
+ err = counter_control_ext_add(selection, COUNTER_OWNER_TYPE_DEVICE,
+ NULL, counter->num_ext, counter->ext,
+ &counter->control_list, &offset);
+ if (err)
+ goto err_control_create;
+ selection += counter->num_ext;
+
+ /* Handle Signals */
+ for (i = 0; i < counter->num_signals; i++) {
+ signal = counter->signals + i;
+
+ /* Check if Signal is selected */
+ if (*selection++) {
+ /* Generate control list item */
+ control = kzalloc(sizeof(*control), GFP_KERNEL);
+ if (!control) {
+ err = -ENOMEM;
+ goto err_control_create;
+ }
+ list_add_tail(&control->l, &counter->control_list);
+
+ /* Configure control list item */
+ control->data.type = COUNTER_DATA_TYPE_SIGNAL,
+ control->data.signal_u8_read = counter->signal_read;
+ control->type = COUNTER_OWNER_TYPE_SIGNAL;
+ control->owner = signal;
+ control->offset = offset;
+ control->size = sizeof(u8);
+ offset += control->size;
+ }
+
+ /* Handle extensions */
+ err = counter_control_ext_add(selection,
+ COUNTER_OWNER_TYPE_SIGNAL, signal,
+ signal->num_ext, signal->ext,
+ &counter->control_list, &offset);
+ if (err)
+ goto err_control_create;
+ selection += signal->num_ext;
+ }
+
+ /* Handle Counts */
+ for (i = 0; i < counter->num_counts; i++) {
+ count = counter->counts + i;
+
+ /* Check if Count is selected */
+ if (*selection++) {
+ /* Generate control list item */
+ control = kzalloc(sizeof(*control), GFP_KERNEL);
+ if (!control) {
+ err = -ENOMEM;
+ goto err_control_create;
+ }
+ list_add_tail(&control->l, &counter->control_list);
+
+ /* Configure control list item */
+ control->data.type = COUNTER_DATA_TYPE_U64,
+ control->data.count_u64_read = counter->count_read;
+ control->data.count_u64_write = counter->count_write;
+ control->type = COUNTER_OWNER_TYPE_COUNT;
+ control->owner = count;
+ control->offset = offset;
+ control->size = sizeof(u64);
+ offset += control->size;
+ }
+
+ /* Handle count function */
+ if (*selection++) {
+ /* Generate control list item */
+ control = kzalloc(sizeof(*control), GFP_KERNEL);
+ if (!control) {
+ err = -ENOMEM;
+ goto err_control_create;
+ }
+ list_add_tail(&control->l, &counter->control_list);
+
+ /* Configure control list item */
+ control->data.type = COUNTER_DATA_TYPE_COUNT_FUNCTION,
+ control->data.count_u8_read = counter->function_read;
+ control->data.count_u8_write = counter->function_write;
+ control->type = COUNTER_OWNER_TYPE_COUNT;
+ control->owner = count;
+ control->offset = offset;
+ control->size = sizeof(u8);
+ offset += control->size;
+ }
+
+ /* Handle Synapses */
+ for (j = 0; j < count->num_synapses; j++) {
+ /* Check if extension is selected */
+ if (!*selection++)
+ continue;
+
+ /* Generate control list item */
+ control = kzalloc(sizeof(*control), GFP_KERNEL);
+ if (!control) {
+ err = -ENOMEM;
+ goto err_control_create;
+ }
+ list_add_tail(&control->l, &counter->control_list);
+
+ /* Configure control list item */
+ control->data.type = COUNTER_DATA_TYPE_SYNAPSE_ACTION;
+ control->data.action_read = counter->action_read;
+ control->data.action_write = counter->action_write;
+ control->data.priv = count->synapses + j;
+ control->type = COUNTER_OWNER_TYPE_COUNT;
+ control->owner = count;
+ control->offset = offset;
+ control->size = sizeof(u8);
+ offset += control->size;
+ }
+
+ /* Handle extensions */
+ err = counter_control_ext_add(selection,
+ COUNTER_OWNER_TYPE_COUNT, count,
+ count->num_ext, count->ext,
+ &counter->control_list, &offset);
+ if (err)
+ goto err_control_create;
+ selection += count->num_ext;
+ }
+
+ return 0;
+
+err_control_create:
+ counter_control_list_free(&counter->control_list);
+ return err;
+}
+
+static int counter_data_u8_write(struct counter_device *const counter,
+ const struct counter_control *const control,
+ const u8 __user *const buf)
+{
+ const struct counter_data *const data = &control->data;
+ int err;
+ u8 val;
+
+ err = get_user(val, buf);
+ if (err)
+ return err;
+
+ switch (control->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ err = data->device_u8_write(counter, val);
+ break;
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ err = data->signal_u8_write(counter, control->owner, val);
+ break;
+ case COUNTER_OWNER_TYPE_COUNT:
+ if (data->type == COUNTER_DATA_TYPE_SYNAPSE_ACTION)
+ err = data->action_write(counter, control->owner,
+ data->priv, val);
+ else
+ err = data->count_u8_write(counter, control->owner,
+ val);
+ break;
+ default: return -EINVAL;
+ }
+
+ return err;
+}
+
+static int counter_data_u64_write(struct counter_device *const counter,
+ const struct counter_control *const control,
+ const char __user *const buf,
+ const size_t len, const size_t offset)
+{
+ const struct counter_data *const data = &control->data;
+ int err;
+ u64 val = 0;
+
+ err = copy_from_user((char *)&val + offset, buf, len);
+ if (err)
+ return err;
+
+ switch (control->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ err = data->device_u64_write(counter, val);
+ break;
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ err = data->signal_u64_write(counter, control->owner, val);
+ break;
+ case COUNTER_OWNER_TYPE_COUNT:
+ err = data->count_u64_write(counter, control->owner, val);
+ break;
+ default: return -EINVAL;
+ }
+
+ return err;
+}
+
+static int counter_data_string_write(struct counter_device *const counter,
+ const struct counter_control *const control,
+ const char __user *const buf,
+ const size_t len, const size_t offset)
+{
+ const struct counter_data *const data = &control->data;
+ int err;
+ char str[64] = "";
+
+ err = copy_from_user(str + offset, buf, len);
+ if (err)
+ return err;
+
+ switch (control->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ err = data->device_string_write(counter, str, sizeof(str));
+ break;
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ err = data->signal_string_write(counter, control->owner, str,
+ sizeof(str));
+ break;
+ case COUNTER_OWNER_TYPE_COUNT:
+ err = data->count_string_write(counter, control->owner, str,
+ sizeof(str));
+ break;
+ default: return -EINVAL;
+ }
+ if (err < 0)
+ return err;
+
+ return 0;
+}
+
+static int counter_control_write(struct counter_device *const counter,
+ const struct counter_control *const control,
+ const char __user *const buf, const size_t len,
+ const size_t offset)
+{
+ /* Check if write operation is supported */
+ if (!control->data.device_u8_write)
+ return -EFAULT;
+
+ switch (control->data.type) {
+ case COUNTER_DATA_TYPE_U8:
+ case COUNTER_DATA_TYPE_BOOL:
+ case COUNTER_DATA_TYPE_SIGNAL:
+ case COUNTER_DATA_TYPE_COUNT_FUNCTION:
+ case COUNTER_DATA_TYPE_SYNAPSE_ACTION:
+ case COUNTER_DATA_TYPE_COUNT_DIRECTION:
+ case COUNTER_DATA_TYPE_COUNT_MODE:
+ return counter_data_u8_write(counter, control, buf);
+ case COUNTER_DATA_TYPE_U64:
+ return counter_data_u64_write(counter, control, buf, len,
+ offset);
+ case COUNTER_DATA_TYPE_STRING:
+ return counter_data_string_write(counter, control, buf, len,
+ offset);
+ }
+
+ return -EINVAL;
+}
+
+static ssize_t counter_chrdev_write(struct file *filp, const char __user *buf,
+ size_t len, loff_t *f_ps)
+{
+ const loff_t start_ps = *f_ps;
+ struct counter_device *const counter = filp->private_data;
+ size_t write_size;
+ struct counter_control *control;
+ int err;
+ loff_t next_control_ps;
+
+ /* Handle Counter control selection */
+ if (*f_ps < COUNTER_SELECTION_SIZE) {
+ write_size = (*f_ps + len > COUNTER_SELECTION_SIZE) ?
+ COUNTER_SELECTION_SIZE - *f_ps : len;
+ if (copy_from_user(counter->selection + *f_ps, buf, write_size))
+ return -EFAULT;
+
+ /* Create new list based on updated selection array */
+ err = counter_control_list_create(counter);
+ if (err)
+ return err;
+
+ *f_ps += write_size;
+ buf += write_size;
+ len -= write_size;
+ if (!len)
+ goto exit_chrdev_write;
+ }
+
+ /* Handle controls */
+ list_for_each_entry(control, &counter->control_list, l) {
+ next_control_ps = control->offset + control->size;
+
+ /* Find first control item */
+ if (*f_ps >= next_control_ps)
+ continue;
+
+ write_size = (*f_ps + len > next_control_ps) ?
+ next_control_ps - *f_ps : len;
+
+ err = counter_control_write(counter, control, buf, write_size,
+ control->offset - *f_ps);
+ if (err)
+ return err;
+
+ *f_ps += write_size;
+ buf += write_size;
+ len -= write_size;
+ if (!len)
+ goto exit_chrdev_write;
+ }
+
+ return -EFAULT;
+
+exit_chrdev_write:
+ return *f_ps - start_ps;
+}
+
+static int counter_chrdev_open(struct inode *inode, struct file *filp)
+{
+ struct counter_device *const counter = container_of(inode->i_cdev,
+ typeof(*counter),
+ chrdev);
+
+ get_device(&counter->dev);
+ filp->private_data = counter;
+
+ return generic_file_open(inode, filp);
+}
+
+static int counter_chrdev_release(struct inode *inode, struct file *filp)
+{
+ struct counter_device *const counter = container_of(inode->i_cdev,
+ typeof(*counter),
+ chrdev);
+
+ put_device(&counter->dev);
+
+ return 0;
+}
+
+static const struct file_operations counter_fops = {
+ .llseek = generic_file_llseek,
+ .read = counter_chrdev_read,
+ .write = counter_chrdev_write,
+ .open = counter_chrdev_open,
+ .release = counter_chrdev_release,
+};
+
+int counter_chrdev_add(struct counter_device *const counter,
+ const dev_t counter_devt)
+{
+ struct device *const dev = &counter->dev;
+ struct cdev *const chrdev = &counter->chrdev;
+
+ /* Initialize Counter character device control selection */
+ memset(counter->selection, 0, sizeof(counter->selection));
+
+ /* Initialize Counter character device selected controls list */
+ INIT_LIST_HEAD(&counter->control_list);
+
+ /* Initialize character device */
+ cdev_init(chrdev, &counter_fops);
+ dev->devt = MKDEV(MAJOR(counter_devt), counter->id);
+ cdev_set_parent(chrdev, &dev->kobj);
+
+ return cdev_add(chrdev, dev->devt, 1);
+}
+
+void counter_chrdev_free(struct counter_device *const counter)
+{
+ cdev_del(&counter->chrdev);
+ counter_control_list_free(&counter->control_list);
+}
diff --git a/drivers/counter/counter-chrdev.h b/drivers/counter/counter-chrdev.h
new file mode 100644
index 000000000000..7ab0797d3857
--- /dev/null
+++ b/drivers/counter/counter-chrdev.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Counter character device interface
+ * Copyright (C) 2020 William Breathitt Gray
+ */
+#ifndef _COUNTER_CHRDEV_H_
+#define _COUNTER_CHRDEV_H_
+
+#include <linux/counter.h>
+#include <linux/types.h>
+
+int counter_chrdev_add(struct counter_device *const counter,
+ const dev_t counter_devt);
+void counter_chrdev_free(struct counter_device *const counter);
+
+#endif /* _COUNTER_CHRDEV_H_ */
diff --git a/drivers/counter/counter-core.c b/drivers/counter/counter-core.c
index 499664809c75..2d0886648201 100644
--- a/drivers/counter/counter-core.c
+++ b/drivers/counter/counter-core.c
@@ -6,11 +6,14 @@
#include <linux/counter.h>
#include <linux/device.h>
#include <linux/export.h>
+#include <linux/fs.h>
#include <linux/gfp.h>
#include <linux/idr.h>
#include <linux/init.h>
#include <linux/module.h>
+#include <linux/types.h>
+#include "counter-chrdev.h"
#include "counter-sysfs.h"
/* Provides a unique ID for each counter device */
@@ -33,6 +36,8 @@ static struct bus_type counter_bus_type = {
.name = "counter"
};
+static dev_t counter_devt;
+
/**
* counter_register - register Counter to the system
* @counter: pointer to Counter to register
@@ -62,10 +67,15 @@ int counter_register(struct counter_device *const counter)
device_initialize(dev);
dev_set_drvdata(dev, counter);
+ /* Add Counter character device */
+ err = counter_chrdev_add(counter, counter_devt);
+ if (err)
+ goto err_free_id;
+
/* Add Counter sysfs attributes */
err = counter_sysfs_add(counter);
if (err)
- goto err_free_id;
+ goto err_free_chrdev;
/* Add device to system */
err = device_add(dev);
@@ -76,6 +86,8 @@ int counter_register(struct counter_device *const counter)
err_free_sysfs:
counter_sysfs_free(counter);
+err_free_chrdev:
+ counter_chrdev_free(counter);
err_free_id:
ida_simple_remove(&counter_ida, counter->id);
return err;
@@ -93,6 +105,7 @@ void counter_unregister(struct counter_device *const counter)
if (counter) {
device_del(&counter->dev);
counter_sysfs_free(counter);
+ counter_chrdev_free(counter);
}
}
EXPORT_SYMBOL_GPL(counter_unregister);
@@ -139,13 +152,30 @@ int devm_counter_register(struct device *dev,
}
EXPORT_SYMBOL_GPL(devm_counter_register);
+#define COUNTER_DEV_MAX 256
+
static int __init counter_init(void)
{
- return bus_register(&counter_bus_type);
+ int err;
+
+ err = bus_register(&counter_bus_type);
+ if (err < 0)
+ return err;
+
+ err = alloc_chrdev_region(&counter_devt, 0, COUNTER_DEV_MAX, "counter");
+ if (err < 0)
+ goto err_unregister_bus;
+
+ return 0;
+
+err_unregister_bus:
+ bus_unregister(&counter_bus_type);
+ return err;
}
static void __exit counter_exit(void)
{
+ unregister_chrdev_region(counter_devt, COUNTER_DEV_MAX);
bus_unregister(&counter_bus_type);
}
diff --git a/include/linux/counter.h b/include/linux/counter.h
index e8abbaf47a4b..22e91d00a880 100644
--- a/include/linux/counter.h
+++ b/include/linux/counter.h
@@ -6,6 +6,7 @@
#ifndef _COUNTER_H_
#define _COUNTER_H_
+#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/list.h>
@@ -170,6 +171,9 @@ struct counter_attribute_group {
* @priv: optional private data supplied by driver
* @id: unique ID used to identify the Counter
* @dev: internal device structure
+ * @chrdev: internal character device structure
+ * @selection: Counter character device control selection
+ * @control_list: Counter character device selected controls
* @dynamic_names_list: List for dynamic names
* @groups_list: attribute groups list (for Signals, Counts, and ext)
* @num_groups: number of attribute groups containers
@@ -208,6 +212,18 @@ struct counter_device {
int id;
struct device dev;
+ struct cdev chrdev;
+
+#define MAX_EXT 255
+#define MAX_SIGNALS 255
+#define MAX_SYNAPSES 255
+#define MAX_COUNTS 255
+#define SIGNALS_SELECTION_SIZE ((1 + MAX_EXT) * MAX_SIGNALS)
+#define COUNTS_SELECTION_SIZE ((1 + 1 + MAX_SYNAPSES + MAX_EXT) * MAX_COUNTS)
+#define COUNTER_SELECTION_SIZE (MAX_EXT + SIGNALS_SELECTION_SIZE + COUNTS_SELECTION_SIZE)
+ u8 selection[COUNTER_SELECTION_SIZE];
+ struct list_head control_list;
+
struct list_head dynamic_names_list;
struct counter_attribute_group *groups_list;
size_t num_groups;
--
2.26.2
^ permalink raw reply related [flat|nested] 38+ messages in thread
* [PATCH v2 3/4] counter: Add character device interface
@ 2020-05-16 19:20 ` William Breathitt Gray
0 siblings, 0 replies; 38+ messages in thread
From: William Breathitt Gray @ 2020-05-16 19:20 UTC (permalink / raw)
To: jic23
Cc: kamel.bouhara, gwendal, david, linux-iio, patrick.havelange,
alexandre.belloni, linux-kernel, mcoquelin.stm32,
William Breathitt Gray, fabrice.gasnier, syednwaris, linux-stm32,
linux-arm-kernel, alexandre.torgue
This patch introduces a character device interface for the Counter
subsystem. Device control is exposed through standard character device
read and write operations.
The first 196095 bytes of the character device serve as a control
selection area where control exposure of desired Counter components and
extensions may be selected. Each byte serves as a boolean selection
indicator for a respective Counter component or extension. The format of
this area is as follows:
* For each device extension, a byte is required.
* For each Signal, a byte is reserved for the Signal component, and a
byte is reserved for each Signal extension.
* For each Count, a byte is reserved for the Count component, a byte is
reserved for the count function, a byte is reserved for each Synapse
action, and byte is reserved for each Count extension.
The selected Counter components and extensions may then be interfaced
after the first 196095 bytes via standard character device read/write
operations. The number of bytes available for each component or
extension is dependent on their respective data type: u8 will have 1
byte available, u64 will have 8 bytes available, strings will have 64
bytes available, etc.
A high-level view of how a count value is passed down from a counter
driver can be exemplified by the following:
----------------------
/ Counter device \
+----------------------+
| Count register: 0x28 |
+----------------------+
|
-----------------
/ raw count data /
-----------------
|
V
+----------------------------+
| Counter device driver |----------+
+----------------------------+ |
| Processes data from device | -------------------
|----------------------------| / driver callbacks /
| Type: u64 | -------------------
| Value: 42 | |
+----------------------------+ |
| |
---------- |
/ u64 / |
---------- |
| |
| V
| +----------------------+
| | Counter core |
| +----------------------+
| | Routes device driver |
| | callbacks to the |
| | userspace interfaces |
| +----------------------+
| |
| -------------------
| / driver callbacks /
| -------------------
| |
+-------+---------------+ |
| | |
| +-------|-------+
| | |
V | V
+--------------------+ | +---------------------+
| Counter sysfs |<-+->| Counter chrdev |
+--------------------+ +---------------------+
| Translates to the | | Translates to the |
| standard Counter | | standard Counter |
| sysfs output | | character device |
|--------------------| |---------------------+
| Type: const char * | | Type: u64 |
| Value: "42" | | Value: 42 |
+--------------------+ +---------------------+
| |
--------------- ----------
/ const char * / / u64 /
--------------- ----------
| |
| V
| +-----------+
| | read |
| +-----------+
| \ Count: 42 /
| -----------
|
V
+--------------------------------------------------+
| `/sys/bus/counter/devices/counterX/countY/count` |
+--------------------------------------------------+
\ Count: "42" /
--------------------------------------------------
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
MAINTAINERS | 1 +
drivers/counter/Makefile | 2 +-
drivers/counter/counter-chrdev.c | 656 +++++++++++++++++++++++++++++++
drivers/counter/counter-chrdev.h | 16 +
drivers/counter/counter-core.c | 34 +-
include/linux/counter.h | 16 +
6 files changed, 722 insertions(+), 3 deletions(-)
create mode 100644 drivers/counter/counter-chrdev.c
create mode 100644 drivers/counter/counter-chrdev.h
diff --git a/MAINTAINERS b/MAINTAINERS
index ef72b5755793..150ad8a9bb87 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4365,6 +4365,7 @@ F: Documentation/ABI/testing/sysfs-bus-counter*
F: Documentation/driver-api/generic-counter.rst
F: drivers/counter/
F: include/linux/counter.h
+F: include/uapi/linux/counter.h
F: include/uapi/linux/counter-types.h
CPMAC ETHERNET DRIVER
diff --git a/drivers/counter/Makefile b/drivers/counter/Makefile
index f48e337cbd85..d219b9c058e7 100644
--- a/drivers/counter/Makefile
+++ b/drivers/counter/Makefile
@@ -4,7 +4,7 @@
#
obj-$(CONFIG_COUNTER) += counter.o
-counter-y := counter-core.o counter-sysfs.o
+counter-y := counter-core.o counter-sysfs.o counter-chrdev.o
obj-$(CONFIG_104_QUAD_8) += 104-quad-8.o
obj-$(CONFIG_STM32_TIMER_CNT) += stm32-timer-cnt.o
diff --git a/drivers/counter/counter-chrdev.c b/drivers/counter/counter-chrdev.c
new file mode 100644
index 000000000000..7fd55bf71e47
--- /dev/null
+++ b/drivers/counter/counter-chrdev.c
@@ -0,0 +1,656 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic Counter character device interface
+ * Copyright (C) 2020 William Breathitt Gray
+ */
+
+#include <linux/cdev.h>
+#include <linux/counter.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/fs.h>
+#include <linux/kdev_t.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+
+enum counter_owner_type {
+ COUNTER_OWNER_TYPE_DEVICE,
+ COUNTER_OWNER_TYPE_SIGNAL,
+ COUNTER_OWNER_TYPE_COUNT,
+};
+
+struct counter_control {
+ loff_t offset;
+ size_t size;
+ struct list_head l;
+
+ struct counter_data data;
+ enum counter_owner_type type;
+ void *owner;
+};
+
+static int counter_data_u8_read(struct counter_device *const counter,
+ const struct counter_control *const control,
+ u8 __user *const buf)
+{
+ const struct counter_data *const data = &control->data;
+ int err;
+ u8 val;
+
+ switch (control->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ err = data->device_u8_read(counter, &val);
+ break;
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ err = data->signal_u8_read(counter, control->owner, &val);
+ break;
+ case COUNTER_OWNER_TYPE_COUNT:
+ if (data->type == COUNTER_DATA_TYPE_SYNAPSE_ACTION)
+ err = data->action_read(counter, control->owner,
+ data->priv, &val);
+ else
+ err = data->count_u8_read(counter, control->owner,
+ &val);
+ break;
+ default: return -EINVAL;
+ }
+ if (err)
+ return err;
+
+ return put_user(val, buf);
+}
+
+static int counter_data_u64_read(struct counter_device *const counter,
+ const struct counter_control *const control,
+ char __user *const buf, const size_t len,
+ const size_t offset)
+{
+ const struct counter_data *const data = &control->data;
+ int err;
+ u64 val;
+
+ switch (control->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ err = data->device_u64_read(counter, &val);
+ break;
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ err = data->signal_u64_read(counter, control->owner, &val);
+ break;
+ case COUNTER_OWNER_TYPE_COUNT:
+ err = data->count_u64_read(counter, control->owner, &val);
+ break;
+ default: return -EINVAL;
+ }
+ if (err)
+ return err;
+
+ return copy_to_user(buf, (const char *)&val + offset, len);
+}
+
+static int counter_data_string_read(struct counter_device *const counter,
+ const struct counter_control *const control,
+ char __user *const buf, const size_t len,
+ const size_t offset)
+{
+ const struct counter_data *const data = &control->data;
+ int err;
+ char str[64] = "";
+
+ switch (control->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ err = data->device_string_read(counter, str, sizeof(str));
+ break;
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ err = data->signal_string_read(counter, control->owner, str,
+ sizeof(str));
+ break;
+ case COUNTER_OWNER_TYPE_COUNT:
+ err = data->count_string_read(counter, control->owner, str,
+ sizeof(str));
+ break;
+ default: return -EINVAL;
+ }
+ if (err < 0)
+ return err;
+
+ return copy_to_user(buf, str + offset, len);
+}
+
+static int counter_control_read(struct counter_device *const counter,
+ const struct counter_control *const control,
+ char __user *const buf, const size_t len,
+ const size_t offset)
+{
+ /* Check if read operation is supported */
+ if (!control->data.device_u8_read)
+ return -EFAULT;
+
+ switch (control->data.type) {
+ case COUNTER_DATA_TYPE_U8:
+ case COUNTER_DATA_TYPE_BOOL:
+ case COUNTER_DATA_TYPE_SIGNAL:
+ case COUNTER_DATA_TYPE_COUNT_FUNCTION:
+ case COUNTER_DATA_TYPE_SYNAPSE_ACTION:
+ case COUNTER_DATA_TYPE_COUNT_DIRECTION:
+ case COUNTER_DATA_TYPE_COUNT_MODE:
+ return counter_data_u8_read(counter, control, buf);
+ case COUNTER_DATA_TYPE_U64:
+ return counter_data_u64_read(counter, control, buf, len,
+ offset);
+ case COUNTER_DATA_TYPE_STRING:
+ return counter_data_string_read(counter, control, buf, len,
+ offset);
+ }
+
+ return -EINVAL;
+}
+
+static ssize_t counter_chrdev_read(struct file *filp, char __user *buf,
+ size_t len, loff_t *f_ps)
+{
+ const loff_t start_ps = *f_ps;
+ struct counter_device *const counter = filp->private_data;
+ size_t read_size;
+ struct counter_control *control;
+ int err;
+ loff_t next_control_ps;
+
+ /* Handle Counter control selection */
+ if (*f_ps < COUNTER_SELECTION_SIZE) {
+ read_size = (*f_ps + len > COUNTER_SELECTION_SIZE) ?
+ COUNTER_SELECTION_SIZE - *f_ps : len;
+
+ if (copy_to_user(buf, counter->selection + *f_ps, read_size))
+ return -EFAULT;
+
+ *f_ps += read_size;
+ buf += read_size;
+ len -= read_size;
+ if (!len)
+ goto exit_chrdev_read;
+ }
+
+ /* Handle controls */
+ list_for_each_entry(control, &counter->control_list, l) {
+ next_control_ps = control->offset + control->size;
+
+ /* Find first control item */
+ if (*f_ps >= next_control_ps)
+ continue;
+
+ read_size = (*f_ps + len > next_control_ps) ?
+ next_control_ps - *f_ps : len;
+
+ err = counter_control_read(counter, control, buf, read_size,
+ control->offset - *f_ps);
+ if (err)
+ return err;
+
+ *f_ps += read_size;
+ buf += read_size;
+ len -= read_size;
+ if (!len)
+ goto exit_chrdev_read;
+ }
+
+exit_chrdev_read:
+ return *f_ps - start_ps;
+}
+
+static int counter_control_ext_add(const u8 *const selection,
+ const enum counter_owner_type type,
+ void *const owner, const size_t num_ext,
+ const struct counter_data *const ext,
+ struct list_head *const cntrl_list,
+ loff_t *const offset)
+{
+ struct counter_control *p = list_last_entry(cntrl_list, typeof(*p), l);
+ struct counter_control *n;
+ size_t i;
+ struct counter_control *control;
+ int err;
+
+ for (i = 0; i < num_ext; i++) {
+ /* Check if extension is selected */
+ if (!selection[i])
+ continue;
+
+ /* Generate control list item */
+ control = kzalloc(sizeof(*control), GFP_KERNEL);
+ if (!control) {
+ err = -ENOMEM;
+ goto err_control_ext_create;
+ }
+ list_add_tail(&control->l, cntrl_list);
+
+ /* Configure control list item */
+ control->data = ext[i],
+ control->type = type;
+ control->owner = owner;
+ control->offset = *offset;
+ switch (control->data.type) {
+ case COUNTER_DATA_TYPE_U8:
+ case COUNTER_DATA_TYPE_BOOL:
+ case COUNTER_DATA_TYPE_COUNT_DIRECTION:
+ case COUNTER_DATA_TYPE_COUNT_MODE:
+ control->size = sizeof(u8);
+ break;
+ case COUNTER_DATA_TYPE_U64:
+ control->size = sizeof(u64);
+ break;
+ case COUNTER_DATA_TYPE_STRING:
+ control->size = 64;
+ break;
+ default:
+ err = -EINVAL;
+ goto err_control_ext_create;
+ }
+ *offset += control->size;
+ }
+
+ return 0;
+
+err_control_ext_create:
+ list_for_each_entry_safe_continue(p, n, cntrl_list, l) {
+ list_del(&p->l);
+ kfree(p);
+ }
+ return err;
+}
+
+static void counter_control_list_free(struct list_head *const cntrl_list)
+{
+ struct counter_control *p, *n;
+
+ list_for_each_entry_safe(p, n, cntrl_list, l) {
+ list_del(&p->l);
+ kfree(p);
+ }
+}
+
+static int counter_control_list_create(struct counter_device *const counter)
+{
+ const u8 *selection = counter->selection;
+ loff_t offset = COUNTER_SELECTION_SIZE;
+ size_t i, j;
+ struct counter_signal *signal;
+ struct counter_count *count;
+ struct counter_control *control;
+ int err;
+
+ /* Clean up old list */
+ counter_control_list_free(&counter->control_list);
+
+ /* Handle device extensions */
+ err = counter_control_ext_add(selection, COUNTER_OWNER_TYPE_DEVICE,
+ NULL, counter->num_ext, counter->ext,
+ &counter->control_list, &offset);
+ if (err)
+ goto err_control_create;
+ selection += counter->num_ext;
+
+ /* Handle Signals */
+ for (i = 0; i < counter->num_signals; i++) {
+ signal = counter->signals + i;
+
+ /* Check if Signal is selected */
+ if (*selection++) {
+ /* Generate control list item */
+ control = kzalloc(sizeof(*control), GFP_KERNEL);
+ if (!control) {
+ err = -ENOMEM;
+ goto err_control_create;
+ }
+ list_add_tail(&control->l, &counter->control_list);
+
+ /* Configure control list item */
+ control->data.type = COUNTER_DATA_TYPE_SIGNAL,
+ control->data.signal_u8_read = counter->signal_read;
+ control->type = COUNTER_OWNER_TYPE_SIGNAL;
+ control->owner = signal;
+ control->offset = offset;
+ control->size = sizeof(u8);
+ offset += control->size;
+ }
+
+ /* Handle extensions */
+ err = counter_control_ext_add(selection,
+ COUNTER_OWNER_TYPE_SIGNAL, signal,
+ signal->num_ext, signal->ext,
+ &counter->control_list, &offset);
+ if (err)
+ goto err_control_create;
+ selection += signal->num_ext;
+ }
+
+ /* Handle Counts */
+ for (i = 0; i < counter->num_counts; i++) {
+ count = counter->counts + i;
+
+ /* Check if Count is selected */
+ if (*selection++) {
+ /* Generate control list item */
+ control = kzalloc(sizeof(*control), GFP_KERNEL);
+ if (!control) {
+ err = -ENOMEM;
+ goto err_control_create;
+ }
+ list_add_tail(&control->l, &counter->control_list);
+
+ /* Configure control list item */
+ control->data.type = COUNTER_DATA_TYPE_U64,
+ control->data.count_u64_read = counter->count_read;
+ control->data.count_u64_write = counter->count_write;
+ control->type = COUNTER_OWNER_TYPE_COUNT;
+ control->owner = count;
+ control->offset = offset;
+ control->size = sizeof(u64);
+ offset += control->size;
+ }
+
+ /* Handle count function */
+ if (*selection++) {
+ /* Generate control list item */
+ control = kzalloc(sizeof(*control), GFP_KERNEL);
+ if (!control) {
+ err = -ENOMEM;
+ goto err_control_create;
+ }
+ list_add_tail(&control->l, &counter->control_list);
+
+ /* Configure control list item */
+ control->data.type = COUNTER_DATA_TYPE_COUNT_FUNCTION,
+ control->data.count_u8_read = counter->function_read;
+ control->data.count_u8_write = counter->function_write;
+ control->type = COUNTER_OWNER_TYPE_COUNT;
+ control->owner = count;
+ control->offset = offset;
+ control->size = sizeof(u8);
+ offset += control->size;
+ }
+
+ /* Handle Synapses */
+ for (j = 0; j < count->num_synapses; j++) {
+ /* Check if extension is selected */
+ if (!*selection++)
+ continue;
+
+ /* Generate control list item */
+ control = kzalloc(sizeof(*control), GFP_KERNEL);
+ if (!control) {
+ err = -ENOMEM;
+ goto err_control_create;
+ }
+ list_add_tail(&control->l, &counter->control_list);
+
+ /* Configure control list item */
+ control->data.type = COUNTER_DATA_TYPE_SYNAPSE_ACTION;
+ control->data.action_read = counter->action_read;
+ control->data.action_write = counter->action_write;
+ control->data.priv = count->synapses + j;
+ control->type = COUNTER_OWNER_TYPE_COUNT;
+ control->owner = count;
+ control->offset = offset;
+ control->size = sizeof(u8);
+ offset += control->size;
+ }
+
+ /* Handle extensions */
+ err = counter_control_ext_add(selection,
+ COUNTER_OWNER_TYPE_COUNT, count,
+ count->num_ext, count->ext,
+ &counter->control_list, &offset);
+ if (err)
+ goto err_control_create;
+ selection += count->num_ext;
+ }
+
+ return 0;
+
+err_control_create:
+ counter_control_list_free(&counter->control_list);
+ return err;
+}
+
+static int counter_data_u8_write(struct counter_device *const counter,
+ const struct counter_control *const control,
+ const u8 __user *const buf)
+{
+ const struct counter_data *const data = &control->data;
+ int err;
+ u8 val;
+
+ err = get_user(val, buf);
+ if (err)
+ return err;
+
+ switch (control->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ err = data->device_u8_write(counter, val);
+ break;
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ err = data->signal_u8_write(counter, control->owner, val);
+ break;
+ case COUNTER_OWNER_TYPE_COUNT:
+ if (data->type == COUNTER_DATA_TYPE_SYNAPSE_ACTION)
+ err = data->action_write(counter, control->owner,
+ data->priv, val);
+ else
+ err = data->count_u8_write(counter, control->owner,
+ val);
+ break;
+ default: return -EINVAL;
+ }
+
+ return err;
+}
+
+static int counter_data_u64_write(struct counter_device *const counter,
+ const struct counter_control *const control,
+ const char __user *const buf,
+ const size_t len, const size_t offset)
+{
+ const struct counter_data *const data = &control->data;
+ int err;
+ u64 val = 0;
+
+ err = copy_from_user((char *)&val + offset, buf, len);
+ if (err)
+ return err;
+
+ switch (control->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ err = data->device_u64_write(counter, val);
+ break;
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ err = data->signal_u64_write(counter, control->owner, val);
+ break;
+ case COUNTER_OWNER_TYPE_COUNT:
+ err = data->count_u64_write(counter, control->owner, val);
+ break;
+ default: return -EINVAL;
+ }
+
+ return err;
+}
+
+static int counter_data_string_write(struct counter_device *const counter,
+ const struct counter_control *const control,
+ const char __user *const buf,
+ const size_t len, const size_t offset)
+{
+ const struct counter_data *const data = &control->data;
+ int err;
+ char str[64] = "";
+
+ err = copy_from_user(str + offset, buf, len);
+ if (err)
+ return err;
+
+ switch (control->type) {
+ case COUNTER_OWNER_TYPE_DEVICE:
+ err = data->device_string_write(counter, str, sizeof(str));
+ break;
+ case COUNTER_OWNER_TYPE_SIGNAL:
+ err = data->signal_string_write(counter, control->owner, str,
+ sizeof(str));
+ break;
+ case COUNTER_OWNER_TYPE_COUNT:
+ err = data->count_string_write(counter, control->owner, str,
+ sizeof(str));
+ break;
+ default: return -EINVAL;
+ }
+ if (err < 0)
+ return err;
+
+ return 0;
+}
+
+static int counter_control_write(struct counter_device *const counter,
+ const struct counter_control *const control,
+ const char __user *const buf, const size_t len,
+ const size_t offset)
+{
+ /* Check if write operation is supported */
+ if (!control->data.device_u8_write)
+ return -EFAULT;
+
+ switch (control->data.type) {
+ case COUNTER_DATA_TYPE_U8:
+ case COUNTER_DATA_TYPE_BOOL:
+ case COUNTER_DATA_TYPE_SIGNAL:
+ case COUNTER_DATA_TYPE_COUNT_FUNCTION:
+ case COUNTER_DATA_TYPE_SYNAPSE_ACTION:
+ case COUNTER_DATA_TYPE_COUNT_DIRECTION:
+ case COUNTER_DATA_TYPE_COUNT_MODE:
+ return counter_data_u8_write(counter, control, buf);
+ case COUNTER_DATA_TYPE_U64:
+ return counter_data_u64_write(counter, control, buf, len,
+ offset);
+ case COUNTER_DATA_TYPE_STRING:
+ return counter_data_string_write(counter, control, buf, len,
+ offset);
+ }
+
+ return -EINVAL;
+}
+
+static ssize_t counter_chrdev_write(struct file *filp, const char __user *buf,
+ size_t len, loff_t *f_ps)
+{
+ const loff_t start_ps = *f_ps;
+ struct counter_device *const counter = filp->private_data;
+ size_t write_size;
+ struct counter_control *control;
+ int err;
+ loff_t next_control_ps;
+
+ /* Handle Counter control selection */
+ if (*f_ps < COUNTER_SELECTION_SIZE) {
+ write_size = (*f_ps + len > COUNTER_SELECTION_SIZE) ?
+ COUNTER_SELECTION_SIZE - *f_ps : len;
+ if (copy_from_user(counter->selection + *f_ps, buf, write_size))
+ return -EFAULT;
+
+ /* Create new list based on updated selection array */
+ err = counter_control_list_create(counter);
+ if (err)
+ return err;
+
+ *f_ps += write_size;
+ buf += write_size;
+ len -= write_size;
+ if (!len)
+ goto exit_chrdev_write;
+ }
+
+ /* Handle controls */
+ list_for_each_entry(control, &counter->control_list, l) {
+ next_control_ps = control->offset + control->size;
+
+ /* Find first control item */
+ if (*f_ps >= next_control_ps)
+ continue;
+
+ write_size = (*f_ps + len > next_control_ps) ?
+ next_control_ps - *f_ps : len;
+
+ err = counter_control_write(counter, control, buf, write_size,
+ control->offset - *f_ps);
+ if (err)
+ return err;
+
+ *f_ps += write_size;
+ buf += write_size;
+ len -= write_size;
+ if (!len)
+ goto exit_chrdev_write;
+ }
+
+ return -EFAULT;
+
+exit_chrdev_write:
+ return *f_ps - start_ps;
+}
+
+static int counter_chrdev_open(struct inode *inode, struct file *filp)
+{
+ struct counter_device *const counter = container_of(inode->i_cdev,
+ typeof(*counter),
+ chrdev);
+
+ get_device(&counter->dev);
+ filp->private_data = counter;
+
+ return generic_file_open(inode, filp);
+}
+
+static int counter_chrdev_release(struct inode *inode, struct file *filp)
+{
+ struct counter_device *const counter = container_of(inode->i_cdev,
+ typeof(*counter),
+ chrdev);
+
+ put_device(&counter->dev);
+
+ return 0;
+}
+
+static const struct file_operations counter_fops = {
+ .llseek = generic_file_llseek,
+ .read = counter_chrdev_read,
+ .write = counter_chrdev_write,
+ .open = counter_chrdev_open,
+ .release = counter_chrdev_release,
+};
+
+int counter_chrdev_add(struct counter_device *const counter,
+ const dev_t counter_devt)
+{
+ struct device *const dev = &counter->dev;
+ struct cdev *const chrdev = &counter->chrdev;
+
+ /* Initialize Counter character device control selection */
+ memset(counter->selection, 0, sizeof(counter->selection));
+
+ /* Initialize Counter character device selected controls list */
+ INIT_LIST_HEAD(&counter->control_list);
+
+ /* Initialize character device */
+ cdev_init(chrdev, &counter_fops);
+ dev->devt = MKDEV(MAJOR(counter_devt), counter->id);
+ cdev_set_parent(chrdev, &dev->kobj);
+
+ return cdev_add(chrdev, dev->devt, 1);
+}
+
+void counter_chrdev_free(struct counter_device *const counter)
+{
+ cdev_del(&counter->chrdev);
+ counter_control_list_free(&counter->control_list);
+}
diff --git a/drivers/counter/counter-chrdev.h b/drivers/counter/counter-chrdev.h
new file mode 100644
index 000000000000..7ab0797d3857
--- /dev/null
+++ b/drivers/counter/counter-chrdev.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Counter character device interface
+ * Copyright (C) 2020 William Breathitt Gray
+ */
+#ifndef _COUNTER_CHRDEV_H_
+#define _COUNTER_CHRDEV_H_
+
+#include <linux/counter.h>
+#include <linux/types.h>
+
+int counter_chrdev_add(struct counter_device *const counter,
+ const dev_t counter_devt);
+void counter_chrdev_free(struct counter_device *const counter);
+
+#endif /* _COUNTER_CHRDEV_H_ */
diff --git a/drivers/counter/counter-core.c b/drivers/counter/counter-core.c
index 499664809c75..2d0886648201 100644
--- a/drivers/counter/counter-core.c
+++ b/drivers/counter/counter-core.c
@@ -6,11 +6,14 @@
#include <linux/counter.h>
#include <linux/device.h>
#include <linux/export.h>
+#include <linux/fs.h>
#include <linux/gfp.h>
#include <linux/idr.h>
#include <linux/init.h>
#include <linux/module.h>
+#include <linux/types.h>
+#include "counter-chrdev.h"
#include "counter-sysfs.h"
/* Provides a unique ID for each counter device */
@@ -33,6 +36,8 @@ static struct bus_type counter_bus_type = {
.name = "counter"
};
+static dev_t counter_devt;
+
/**
* counter_register - register Counter to the system
* @counter: pointer to Counter to register
@@ -62,10 +67,15 @@ int counter_register(struct counter_device *const counter)
device_initialize(dev);
dev_set_drvdata(dev, counter);
+ /* Add Counter character device */
+ err = counter_chrdev_add(counter, counter_devt);
+ if (err)
+ goto err_free_id;
+
/* Add Counter sysfs attributes */
err = counter_sysfs_add(counter);
if (err)
- goto err_free_id;
+ goto err_free_chrdev;
/* Add device to system */
err = device_add(dev);
@@ -76,6 +86,8 @@ int counter_register(struct counter_device *const counter)
err_free_sysfs:
counter_sysfs_free(counter);
+err_free_chrdev:
+ counter_chrdev_free(counter);
err_free_id:
ida_simple_remove(&counter_ida, counter->id);
return err;
@@ -93,6 +105,7 @@ void counter_unregister(struct counter_device *const counter)
if (counter) {
device_del(&counter->dev);
counter_sysfs_free(counter);
+ counter_chrdev_free(counter);
}
}
EXPORT_SYMBOL_GPL(counter_unregister);
@@ -139,13 +152,30 @@ int devm_counter_register(struct device *dev,
}
EXPORT_SYMBOL_GPL(devm_counter_register);
+#define COUNTER_DEV_MAX 256
+
static int __init counter_init(void)
{
- return bus_register(&counter_bus_type);
+ int err;
+
+ err = bus_register(&counter_bus_type);
+ if (err < 0)
+ return err;
+
+ err = alloc_chrdev_region(&counter_devt, 0, COUNTER_DEV_MAX, "counter");
+ if (err < 0)
+ goto err_unregister_bus;
+
+ return 0;
+
+err_unregister_bus:
+ bus_unregister(&counter_bus_type);
+ return err;
}
static void __exit counter_exit(void)
{
+ unregister_chrdev_region(counter_devt, COUNTER_DEV_MAX);
bus_unregister(&counter_bus_type);
}
diff --git a/include/linux/counter.h b/include/linux/counter.h
index e8abbaf47a4b..22e91d00a880 100644
--- a/include/linux/counter.h
+++ b/include/linux/counter.h
@@ -6,6 +6,7 @@
#ifndef _COUNTER_H_
#define _COUNTER_H_
+#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/list.h>
@@ -170,6 +171,9 @@ struct counter_attribute_group {
* @priv: optional private data supplied by driver
* @id: unique ID used to identify the Counter
* @dev: internal device structure
+ * @chrdev: internal character device structure
+ * @selection: Counter character device control selection
+ * @control_list: Counter character device selected controls
* @dynamic_names_list: List for dynamic names
* @groups_list: attribute groups list (for Signals, Counts, and ext)
* @num_groups: number of attribute groups containers
@@ -208,6 +212,18 @@ struct counter_device {
int id;
struct device dev;
+ struct cdev chrdev;
+
+#define MAX_EXT 255
+#define MAX_SIGNALS 255
+#define MAX_SYNAPSES 255
+#define MAX_COUNTS 255
+#define SIGNALS_SELECTION_SIZE ((1 + MAX_EXT) * MAX_SIGNALS)
+#define COUNTS_SELECTION_SIZE ((1 + 1 + MAX_SYNAPSES + MAX_EXT) * MAX_COUNTS)
+#define COUNTER_SELECTION_SIZE (MAX_EXT + SIGNALS_SELECTION_SIZE + COUNTS_SELECTION_SIZE)
+ u8 selection[COUNTER_SELECTION_SIZE];
+ struct list_head control_list;
+
struct list_head dynamic_names_list;
struct counter_attribute_group *groups_list;
size_t num_groups;
--
2.26.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 38+ messages in thread
* [PATCH v2 4/4] docs: counter: Document character device interface
2020-05-16 19:19 ` William Breathitt Gray
@ 2020-05-16 19:20 ` William Breathitt Gray
-1 siblings, 0 replies; 38+ messages in thread
From: William Breathitt Gray @ 2020-05-16 19:20 UTC (permalink / raw)
To: jic23
Cc: kamel.bouhara, gwendal, alexandre.belloni, david, linux-iio,
linux-kernel, linux-stm32, linux-arm-kernel, syednwaris,
patrick.havelange, fabrice.gasnier, mcoquelin.stm32,
alexandre.torgue, William Breathitt Gray
This patch adds high-level documentation about the Counter subsystem
character device interface.
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
Documentation/driver-api/generic-counter.rst | 112 +++++++++++++------
1 file changed, 76 insertions(+), 36 deletions(-)
diff --git a/Documentation/driver-api/generic-counter.rst b/Documentation/driver-api/generic-counter.rst
index 8f85c30dea0b..58045b33b576 100644
--- a/Documentation/driver-api/generic-counter.rst
+++ b/Documentation/driver-api/generic-counter.rst
@@ -223,19 +223,6 @@ whether an input line is differential or single-ended) and instead focus
on the core idea of what the data and process represent (e.g. position
as interpreted from quadrature encoding data).
-Userspace Interface
-===================
-
-Several sysfs attributes are generated by the Generic Counter interface,
-and reside under the /sys/bus/counter/devices/counterX directory, where
-counterX refers to the respective counter device. Please see
-Documentation/ABI/testing/sysfs-bus-counter for detailed
-information on each Generic Counter interface sysfs attribute.
-
-Through these sysfs attributes, programs and scripts may interact with
-the Generic Counter paradigm Counts, Signals, and Synapses of respective
-counter devices.
-
Driver API
==========
@@ -377,13 +364,13 @@ driver can be exemplified by the following::
+----------------------------+ |
| Processes data from device | -------------------
|----------------------------| / driver callbacks /
- | Type: unsigned long | -------------------
+ | Type: u64 | -------------------
| Value: 42 | |
+----------------------------+ |
| |
- ---------------- |
- / unsigned long / |
- ---------------- |
+ ---------- |
+ / u64 / |
+ ---------- |
| |
| V
| +----------------------+
@@ -398,25 +385,32 @@ driver can be exemplified by the following::
| / driver callbacks /
| -------------------
| |
- +-------+ |
+ +-------+---------------+ |
+ | | |
+ | +-------|-------+
+ | | |
+ V | V
+ +--------------------+ | +---------------------+
+ | Counter sysfs |<-+->| Counter chrdev |
+ +--------------------+ +---------------------+
+ | Translates to the | | Translates to the |
+ | standard Counter | | standard Counter |
+ | sysfs output | | character device |
+ |--------------------| |---------------------+
+ | Type: const char * | | Type: u64 |
+ | Value: "42" | | Value: 42 |
+ +--------------------+ +---------------------+
| |
- | +---------------+
- | |
- V |
- +--------------------+ |
- | Counter sysfs |<-+
- +--------------------+
- | Translates to the |
- | standard Counter |
- | sysfs output |
- |--------------------|
- | Type: const char * |
- | Value: "42" |
- +--------------------+
- |
- ---------------
- / const char * /
- ---------------
+ --------------- ----------
+ / const char * / / u64 /
+ --------------- ----------
+ | |
+ | V
+ | +-----------+
+ | | read |
+ | +-----------+
+ | \ Count: 42 /
+ | -----------
|
V
+--------------------------------------------------+
@@ -425,7 +419,7 @@ driver can be exemplified by the following::
\ Count: "42" /
--------------------------------------------------
-There are three primary components involved:
+There are four primary components involved:
Counter device driver
---------------------
@@ -445,3 +439,49 @@ and vice versa.
Please refer to the `Documentation/ABI/testing/sysfs-bus-counter` file
for a detailed breakdown of the available Generic Counter interface
sysfs attributes.
+
+Counter chrdev
+--------------
+Translates counter data to the standard Counter character device; data
+is transferred via standard character device read/write calls.
+
+Sysfs Interface
+===============
+
+Several sysfs attributes are generated by the Generic Counter interface,
+and reside under the `/sys/bus/counter/devices/counterX` directory,
+where `X` is to the respective counter device id. Please see
+Documentation/ABI/testing/sysfs-bus-counter for detailed information on
+each Generic Counter interface sysfs attribute.
+
+Through these sysfs attributes, programs and scripts may interact with
+the Generic Counter paradigm Counts, Signals, and Synapses of respective
+counter devices.
+
+Counter Character Device
+========================
+
+Counter character device nodes are created under the `/dev` directory as
+`counterX`, where `X` is the respective counter device id. Defines for
+the standard Counter data types are exposed via the userspace
+`include/uapi/linux/counter-types.h` file.
+
+The first 196095 bytes of the character device serve as a control
+selection area where control exposure of desired Counter components and
+extensions may be selected. Each byte serves as a boolean selection
+indicator for a respective Counter component or extension. The format of
+this area is as follows:
+
+* For each device extension, a byte is required.
+* For each Signal, a byte is reserved for the Signal component, and a
+ byte is reserved for each Signal extension.
+* For each Count, a byte is reserved for the Count component, a byte is
+ reserved for the count function, a byte is reserved for each Synapse
+ action, and byte is reserved for each Count extension.
+
+The selected Counter components and extensions may then be interfaced
+after the first 196095 bytes via standard character device read/write
+operations. The number of bytes available for each component or
+extension is dependent on their respective data type: u8 will have 1
+byte available, u64 will have 8 bytes available, strings will have 64
+bytes available, etc.
--
2.26.2
^ permalink raw reply related [flat|nested] 38+ messages in thread
* [PATCH v2 4/4] docs: counter: Document character device interface
@ 2020-05-16 19:20 ` William Breathitt Gray
0 siblings, 0 replies; 38+ messages in thread
From: William Breathitt Gray @ 2020-05-16 19:20 UTC (permalink / raw)
To: jic23
Cc: kamel.bouhara, gwendal, david, linux-iio, patrick.havelange,
alexandre.belloni, linux-kernel, mcoquelin.stm32,
William Breathitt Gray, fabrice.gasnier, syednwaris, linux-stm32,
linux-arm-kernel, alexandre.torgue
This patch adds high-level documentation about the Counter subsystem
character device interface.
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
Documentation/driver-api/generic-counter.rst | 112 +++++++++++++------
1 file changed, 76 insertions(+), 36 deletions(-)
diff --git a/Documentation/driver-api/generic-counter.rst b/Documentation/driver-api/generic-counter.rst
index 8f85c30dea0b..58045b33b576 100644
--- a/Documentation/driver-api/generic-counter.rst
+++ b/Documentation/driver-api/generic-counter.rst
@@ -223,19 +223,6 @@ whether an input line is differential or single-ended) and instead focus
on the core idea of what the data and process represent (e.g. position
as interpreted from quadrature encoding data).
-Userspace Interface
-===================
-
-Several sysfs attributes are generated by the Generic Counter interface,
-and reside under the /sys/bus/counter/devices/counterX directory, where
-counterX refers to the respective counter device. Please see
-Documentation/ABI/testing/sysfs-bus-counter for detailed
-information on each Generic Counter interface sysfs attribute.
-
-Through these sysfs attributes, programs and scripts may interact with
-the Generic Counter paradigm Counts, Signals, and Synapses of respective
-counter devices.
-
Driver API
==========
@@ -377,13 +364,13 @@ driver can be exemplified by the following::
+----------------------------+ |
| Processes data from device | -------------------
|----------------------------| / driver callbacks /
- | Type: unsigned long | -------------------
+ | Type: u64 | -------------------
| Value: 42 | |
+----------------------------+ |
| |
- ---------------- |
- / unsigned long / |
- ---------------- |
+ ---------- |
+ / u64 / |
+ ---------- |
| |
| V
| +----------------------+
@@ -398,25 +385,32 @@ driver can be exemplified by the following::
| / driver callbacks /
| -------------------
| |
- +-------+ |
+ +-------+---------------+ |
+ | | |
+ | +-------|-------+
+ | | |
+ V | V
+ +--------------------+ | +---------------------+
+ | Counter sysfs |<-+->| Counter chrdev |
+ +--------------------+ +---------------------+
+ | Translates to the | | Translates to the |
+ | standard Counter | | standard Counter |
+ | sysfs output | | character device |
+ |--------------------| |---------------------+
+ | Type: const char * | | Type: u64 |
+ | Value: "42" | | Value: 42 |
+ +--------------------+ +---------------------+
| |
- | +---------------+
- | |
- V |
- +--------------------+ |
- | Counter sysfs |<-+
- +--------------------+
- | Translates to the |
- | standard Counter |
- | sysfs output |
- |--------------------|
- | Type: const char * |
- | Value: "42" |
- +--------------------+
- |
- ---------------
- / const char * /
- ---------------
+ --------------- ----------
+ / const char * / / u64 /
+ --------------- ----------
+ | |
+ | V
+ | +-----------+
+ | | read |
+ | +-----------+
+ | \ Count: 42 /
+ | -----------
|
V
+--------------------------------------------------+
@@ -425,7 +419,7 @@ driver can be exemplified by the following::
\ Count: "42" /
--------------------------------------------------
-There are three primary components involved:
+There are four primary components involved:
Counter device driver
---------------------
@@ -445,3 +439,49 @@ and vice versa.
Please refer to the `Documentation/ABI/testing/sysfs-bus-counter` file
for a detailed breakdown of the available Generic Counter interface
sysfs attributes.
+
+Counter chrdev
+--------------
+Translates counter data to the standard Counter character device; data
+is transferred via standard character device read/write calls.
+
+Sysfs Interface
+===============
+
+Several sysfs attributes are generated by the Generic Counter interface,
+and reside under the `/sys/bus/counter/devices/counterX` directory,
+where `X` is to the respective counter device id. Please see
+Documentation/ABI/testing/sysfs-bus-counter for detailed information on
+each Generic Counter interface sysfs attribute.
+
+Through these sysfs attributes, programs and scripts may interact with
+the Generic Counter paradigm Counts, Signals, and Synapses of respective
+counter devices.
+
+Counter Character Device
+========================
+
+Counter character device nodes are created under the `/dev` directory as
+`counterX`, where `X` is the respective counter device id. Defines for
+the standard Counter data types are exposed via the userspace
+`include/uapi/linux/counter-types.h` file.
+
+The first 196095 bytes of the character device serve as a control
+selection area where control exposure of desired Counter components and
+extensions may be selected. Each byte serves as a boolean selection
+indicator for a respective Counter component or extension. The format of
+this area is as follows:
+
+* For each device extension, a byte is required.
+* For each Signal, a byte is reserved for the Signal component, and a
+ byte is reserved for each Signal extension.
+* For each Count, a byte is reserved for the Count component, a byte is
+ reserved for the count function, a byte is reserved for each Synapse
+ action, and byte is reserved for each Count extension.
+
+The selected Counter components and extensions may then be interfaced
+after the first 196095 bytes via standard character device read/write
+operations. The number of bytes available for each component or
+extension is dependent on their respective data type: u8 will have 1
+byte available, u64 will have 8 bytes available, strings will have 64
+bytes available, etc.
--
2.26.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 38+ messages in thread
* Re: [PATCH v2 1/4] counter: Internalize sysfs interface code
2020-05-16 19:19 ` [PATCH v2 1/4] counter: Internalize sysfs interface code William Breathitt Gray
2020-05-20 13:10 ` kbuild test robot
@ 2020-05-20 13:10 ` kbuild test robot
1 sibling, 0 replies; 38+ messages in thread
From: kbuild test robot @ 2020-05-20 13:10 UTC (permalink / raw)
To: William Breathitt Gray, jic23
Cc: kbuild-all, clang-built-linux, kamel.bouhara, gwendal,
alexandre.belloni, david, linux-iio, linux-kernel, linux-stm32,
linux-arm-kernel, syednwaris
[-- Attachment #1: Type: text/plain, Size: 3280 bytes --]
Hi William,
I love your patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v5.7-rc6 next-20200519]
[cannot apply to stm32/stm32-next linux/master]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
url: https://github.com/0day-ci/linux/commits/William-Breathitt-Gray/Introduce-the-Counter-character-device-interface/20200517-032530
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 12bf0b632ed090358cbf03e323e5342212d0b2e4
config: arm64-randconfig-r026-20200519 (attached as .config)
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 135b877874fae96b4372c8a3fbfaa8ff44ff86e3)
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install arm64 cross compiling tool for clang build
# apt-get install binutils-aarch64-linux-gnu
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp@intel.com>
All warnings (new ones prefixed by >>, old ones prefixed by <<):
>> drivers/counter/counter-sysfs.c:850:5: warning: no previous prototype for function 'counter_sysfs_add' [-Wmissing-prototypes]
int counter_sysfs_add(struct counter_device *const counter)
^
drivers/counter/counter-sysfs.c:850:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
int counter_sysfs_add(struct counter_device *const counter)
^
static
>> drivers/counter/counter-sysfs.c:876:6: warning: no previous prototype for function 'counter_sysfs_free' [-Wmissing-prototypes]
void counter_sysfs_free(struct counter_device *const counter)
^
drivers/counter/counter-sysfs.c:876:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void counter_sysfs_free(struct counter_device *const counter)
^
static
2 warnings generated.
vim +/counter_sysfs_add +850 drivers/counter/counter-sysfs.c
849
> 850 int counter_sysfs_add(struct counter_device *const counter)
851 {
852 int err;
853
854 /* Initialize Synapse names list */
855 INIT_LIST_HEAD(&counter->dynamic_names_list);
856
857 /* Prepare device attributes */
858 err = counter_groups_list_prepare(counter);
859 if (err)
860 goto err_free_names;
861
862 /* Organize device attributes to groups and match to device */
863 err = counter_groups_prepare(counter);
864 if (err)
865 goto err_free_groups_list;
866
867 return 0;
868
869 err_free_groups_list:
870 counter_groups_list_free(counter);
871 err_free_names:
872 counter_dynamic_names_free(&counter->dynamic_names_list);
873 return err;
874 }
875
> 876 void counter_sysfs_free(struct counter_device *const counter)
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 38774 bytes --]
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 1/4] counter: Internalize sysfs interface code
@ 2020-05-20 13:10 ` kbuild test robot
0 siblings, 0 replies; 38+ messages in thread
From: kbuild test robot @ 2020-05-20 13:10 UTC (permalink / raw)
To: William Breathitt Gray, jic23
Cc: kamel.bouhara, gwendal, kbuild-all, david, linux-iio,
alexandre.belloni, linux-kernel, clang-built-linux, syednwaris,
linux-stm32, linux-arm-kernel
[-- Attachment #1: Type: text/plain, Size: 3280 bytes --]
Hi William,
I love your patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v5.7-rc6 next-20200519]
[cannot apply to stm32/stm32-next linux/master]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
url: https://github.com/0day-ci/linux/commits/William-Breathitt-Gray/Introduce-the-Counter-character-device-interface/20200517-032530
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 12bf0b632ed090358cbf03e323e5342212d0b2e4
config: arm64-randconfig-r026-20200519 (attached as .config)
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 135b877874fae96b4372c8a3fbfaa8ff44ff86e3)
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install arm64 cross compiling tool for clang build
# apt-get install binutils-aarch64-linux-gnu
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp@intel.com>
All warnings (new ones prefixed by >>, old ones prefixed by <<):
>> drivers/counter/counter-sysfs.c:850:5: warning: no previous prototype for function 'counter_sysfs_add' [-Wmissing-prototypes]
int counter_sysfs_add(struct counter_device *const counter)
^
drivers/counter/counter-sysfs.c:850:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
int counter_sysfs_add(struct counter_device *const counter)
^
static
>> drivers/counter/counter-sysfs.c:876:6: warning: no previous prototype for function 'counter_sysfs_free' [-Wmissing-prototypes]
void counter_sysfs_free(struct counter_device *const counter)
^
drivers/counter/counter-sysfs.c:876:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void counter_sysfs_free(struct counter_device *const counter)
^
static
2 warnings generated.
vim +/counter_sysfs_add +850 drivers/counter/counter-sysfs.c
849
> 850 int counter_sysfs_add(struct counter_device *const counter)
851 {
852 int err;
853
854 /* Initialize Synapse names list */
855 INIT_LIST_HEAD(&counter->dynamic_names_list);
856
857 /* Prepare device attributes */
858 err = counter_groups_list_prepare(counter);
859 if (err)
860 goto err_free_names;
861
862 /* Organize device attributes to groups and match to device */
863 err = counter_groups_prepare(counter);
864 if (err)
865 goto err_free_groups_list;
866
867 return 0;
868
869 err_free_groups_list:
870 counter_groups_list_free(counter);
871 err_free_names:
872 counter_dynamic_names_free(&counter->dynamic_names_list);
873 return err;
874 }
875
> 876 void counter_sysfs_free(struct counter_device *const counter)
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 38774 bytes --]
[-- Attachment #3: Type: text/plain, Size: 176 bytes --]
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 1/4] counter: Internalize sysfs interface code
@ 2020-05-20 13:10 ` kbuild test robot
0 siblings, 0 replies; 38+ messages in thread
From: kbuild test robot @ 2020-05-20 13:10 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 3360 bytes --]
Hi William,
I love your patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v5.7-rc6 next-20200519]
[cannot apply to stm32/stm32-next linux/master]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
url: https://github.com/0day-ci/linux/commits/William-Breathitt-Gray/Introduce-the-Counter-character-device-interface/20200517-032530
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 12bf0b632ed090358cbf03e323e5342212d0b2e4
config: arm64-randconfig-r026-20200519 (attached as .config)
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 135b877874fae96b4372c8a3fbfaa8ff44ff86e3)
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install arm64 cross compiling tool for clang build
# apt-get install binutils-aarch64-linux-gnu
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp@intel.com>
All warnings (new ones prefixed by >>, old ones prefixed by <<):
>> drivers/counter/counter-sysfs.c:850:5: warning: no previous prototype for function 'counter_sysfs_add' [-Wmissing-prototypes]
int counter_sysfs_add(struct counter_device *const counter)
^
drivers/counter/counter-sysfs.c:850:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
int counter_sysfs_add(struct counter_device *const counter)
^
static
>> drivers/counter/counter-sysfs.c:876:6: warning: no previous prototype for function 'counter_sysfs_free' [-Wmissing-prototypes]
void counter_sysfs_free(struct counter_device *const counter)
^
drivers/counter/counter-sysfs.c:876:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void counter_sysfs_free(struct counter_device *const counter)
^
static
2 warnings generated.
vim +/counter_sysfs_add +850 drivers/counter/counter-sysfs.c
849
> 850 int counter_sysfs_add(struct counter_device *const counter)
851 {
852 int err;
853
854 /* Initialize Synapse names list */
855 INIT_LIST_HEAD(&counter->dynamic_names_list);
856
857 /* Prepare device attributes */
858 err = counter_groups_list_prepare(counter);
859 if (err)
860 goto err_free_names;
861
862 /* Organize device attributes to groups and match to device */
863 err = counter_groups_prepare(counter);
864 if (err)
865 goto err_free_groups_list;
866
867 return 0;
868
869 err_free_groups_list:
870 counter_groups_list_free(counter);
871 err_free_names:
872 counter_dynamic_names_free(&counter->dynamic_names_list);
873 return err;
874 }
875
> 876 void counter_sysfs_free(struct counter_device *const counter)
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 38774 bytes --]
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 3/4] counter: Add character device interface
2020-05-16 19:20 ` William Breathitt Gray
(?)
@ 2020-05-20 15:07 ` kbuild test robot
-1 siblings, 0 replies; 38+ messages in thread
From: kbuild test robot @ 2020-05-20 15:07 UTC (permalink / raw)
To: William Breathitt Gray, jic23
Cc: kbuild-all, clang-built-linux, kamel.bouhara, gwendal,
alexandre.belloni, david, linux-iio, linux-kernel, linux-stm32,
linux-arm-kernel, syednwaris
[-- Attachment #1: Type: text/plain, Size: 3301 bytes --]
Hi William,
I love your patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v5.7-rc6 next-20200519]
[cannot apply to stm32/stm32-next linux/master]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
url: https://github.com/0day-ci/linux/commits/William-Breathitt-Gray/Introduce-the-Counter-character-device-interface/20200517-032530
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 12bf0b632ed090358cbf03e323e5342212d0b2e4
config: arm64-randconfig-r026-20200519 (attached as .config)
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 135b877874fae96b4372c8a3fbfaa8ff44ff86e3)
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install arm64 cross compiling tool for clang build
# apt-get install binutils-aarch64-linux-gnu
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp@intel.com>
All warnings (new ones prefixed by >>, old ones prefixed by <<):
>> drivers/counter/counter-chrdev.c:632:5: warning: no previous prototype for function 'counter_chrdev_add' [-Wmissing-prototypes]
int counter_chrdev_add(struct counter_device *const counter,
^
drivers/counter/counter-chrdev.c:632:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
int counter_chrdev_add(struct counter_device *const counter,
^
static
>> drivers/counter/counter-chrdev.c:652:6: warning: no previous prototype for function 'counter_chrdev_free' [-Wmissing-prototypes]
void counter_chrdev_free(struct counter_device *const counter)
^
drivers/counter/counter-chrdev.c:652:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void counter_chrdev_free(struct counter_device *const counter)
^
static
2 warnings generated.
vim +/counter_chrdev_add +632 drivers/counter/counter-chrdev.c
631
> 632 int counter_chrdev_add(struct counter_device *const counter,
633 const dev_t counter_devt)
634 {
635 struct device *const dev = &counter->dev;
636 struct cdev *const chrdev = &counter->chrdev;
637
638 /* Initialize Counter character device control selection */
639 memset(counter->selection, 0, sizeof(counter->selection));
640
641 /* Initialize Counter character device selected controls list */
642 INIT_LIST_HEAD(&counter->control_list);
643
644 /* Initialize character device */
645 cdev_init(chrdev, &counter_fops);
646 dev->devt = MKDEV(MAJOR(counter_devt), counter->id);
647 cdev_set_parent(chrdev, &dev->kobj);
648
649 return cdev_add(chrdev, dev->devt, 1);
650 }
651
> 652 void counter_chrdev_free(struct counter_device *const counter)
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 38774 bytes --]
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 3/4] counter: Add character device interface
@ 2020-05-20 15:07 ` kbuild test robot
0 siblings, 0 replies; 38+ messages in thread
From: kbuild test robot @ 2020-05-20 15:07 UTC (permalink / raw)
To: William Breathitt Gray, jic23
Cc: kamel.bouhara, gwendal, kbuild-all, david, linux-iio,
alexandre.belloni, linux-kernel, clang-built-linux, syednwaris,
linux-stm32, linux-arm-kernel
[-- Attachment #1: Type: text/plain, Size: 3301 bytes --]
Hi William,
I love your patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v5.7-rc6 next-20200519]
[cannot apply to stm32/stm32-next linux/master]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
url: https://github.com/0day-ci/linux/commits/William-Breathitt-Gray/Introduce-the-Counter-character-device-interface/20200517-032530
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 12bf0b632ed090358cbf03e323e5342212d0b2e4
config: arm64-randconfig-r026-20200519 (attached as .config)
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 135b877874fae96b4372c8a3fbfaa8ff44ff86e3)
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install arm64 cross compiling tool for clang build
# apt-get install binutils-aarch64-linux-gnu
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp@intel.com>
All warnings (new ones prefixed by >>, old ones prefixed by <<):
>> drivers/counter/counter-chrdev.c:632:5: warning: no previous prototype for function 'counter_chrdev_add' [-Wmissing-prototypes]
int counter_chrdev_add(struct counter_device *const counter,
^
drivers/counter/counter-chrdev.c:632:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
int counter_chrdev_add(struct counter_device *const counter,
^
static
>> drivers/counter/counter-chrdev.c:652:6: warning: no previous prototype for function 'counter_chrdev_free' [-Wmissing-prototypes]
void counter_chrdev_free(struct counter_device *const counter)
^
drivers/counter/counter-chrdev.c:652:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void counter_chrdev_free(struct counter_device *const counter)
^
static
2 warnings generated.
vim +/counter_chrdev_add +632 drivers/counter/counter-chrdev.c
631
> 632 int counter_chrdev_add(struct counter_device *const counter,
633 const dev_t counter_devt)
634 {
635 struct device *const dev = &counter->dev;
636 struct cdev *const chrdev = &counter->chrdev;
637
638 /* Initialize Counter character device control selection */
639 memset(counter->selection, 0, sizeof(counter->selection));
640
641 /* Initialize Counter character device selected controls list */
642 INIT_LIST_HEAD(&counter->control_list);
643
644 /* Initialize character device */
645 cdev_init(chrdev, &counter_fops);
646 dev->devt = MKDEV(MAJOR(counter_devt), counter->id);
647 cdev_set_parent(chrdev, &dev->kobj);
648
649 return cdev_add(chrdev, dev->devt, 1);
650 }
651
> 652 void counter_chrdev_free(struct counter_device *const counter)
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 38774 bytes --]
[-- Attachment #3: Type: text/plain, Size: 176 bytes --]
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 3/4] counter: Add character device interface
@ 2020-05-20 15:07 ` kbuild test robot
0 siblings, 0 replies; 38+ messages in thread
From: kbuild test robot @ 2020-05-20 15:07 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 3375 bytes --]
Hi William,
I love your patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v5.7-rc6 next-20200519]
[cannot apply to stm32/stm32-next linux/master]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
url: https://github.com/0day-ci/linux/commits/William-Breathitt-Gray/Introduce-the-Counter-character-device-interface/20200517-032530
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 12bf0b632ed090358cbf03e323e5342212d0b2e4
config: arm64-randconfig-r026-20200519 (attached as .config)
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 135b877874fae96b4372c8a3fbfaa8ff44ff86e3)
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install arm64 cross compiling tool for clang build
# apt-get install binutils-aarch64-linux-gnu
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp@intel.com>
All warnings (new ones prefixed by >>, old ones prefixed by <<):
>> drivers/counter/counter-chrdev.c:632:5: warning: no previous prototype for function 'counter_chrdev_add' [-Wmissing-prototypes]
int counter_chrdev_add(struct counter_device *const counter,
^
drivers/counter/counter-chrdev.c:632:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
int counter_chrdev_add(struct counter_device *const counter,
^
static
>> drivers/counter/counter-chrdev.c:652:6: warning: no previous prototype for function 'counter_chrdev_free' [-Wmissing-prototypes]
void counter_chrdev_free(struct counter_device *const counter)
^
drivers/counter/counter-chrdev.c:652:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void counter_chrdev_free(struct counter_device *const counter)
^
static
2 warnings generated.
vim +/counter_chrdev_add +632 drivers/counter/counter-chrdev.c
631
> 632 int counter_chrdev_add(struct counter_device *const counter,
633 const dev_t counter_devt)
634 {
635 struct device *const dev = &counter->dev;
636 struct cdev *const chrdev = &counter->chrdev;
637
638 /* Initialize Counter character device control selection */
639 memset(counter->selection, 0, sizeof(counter->selection));
640
641 /* Initialize Counter character device selected controls list */
642 INIT_LIST_HEAD(&counter->control_list);
643
644 /* Initialize character device */
645 cdev_init(chrdev, &counter_fops);
646 dev->devt = MKDEV(MAJOR(counter_devt), counter->id);
647 cdev_set_parent(chrdev, &dev->kobj);
648
649 return cdev_add(chrdev, dev->devt, 1);
650 }
651
> 652 void counter_chrdev_free(struct counter_device *const counter)
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 38774 bytes --]
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 1/4] counter: Internalize sysfs interface code
2020-05-16 19:19 ` [PATCH v2 1/4] counter: Internalize sysfs interface code William Breathitt Gray
2020-05-20 13:10 ` kbuild test robot
@ 2020-05-24 16:08 ` Jonathan Cameron
1 sibling, 0 replies; 38+ messages in thread
From: Jonathan Cameron @ 2020-05-24 16:08 UTC (permalink / raw)
To: William Breathitt Gray
Cc: kamel.bouhara, gwendal, alexandre.belloni, david, linux-iio,
linux-kernel, linux-stm32, linux-arm-kernel, syednwaris,
patrick.havelange, fabrice.gasnier, mcoquelin.stm32,
alexandre.torgue
On Sat, 16 May 2020 15:19:59 -0400
William Breathitt Gray <vilhelm.gray@gmail.com> wrote:
> This is a reimplementation of the Generic Counter driver interface.
> There are no modifications to the Counter subsystem userspace interface,
> so existing userspace applications should continue to run seamlessly.
>
> Overview
> ========
>
> The purpose of this patch is to internalize the sysfs interface code
> among the various counter drivers into a shared module. Counter drivers
> pass and take data natively (i.e. u8, u64, char *, etc.) and the shared
> counter module handles the translation between the sysfs interface. This
> gurantees a standard userspace interface for all counter drivers, and
> helps generalize the Generic Counter driver ABI in order to support the
> Generic Counter chrdev interface (introduced in a subsequent patch)
> without significant changes to the existing counter drivers.
>
> A high-level view of how a count value is passed down from a counter
> driver can be exemplified by the following:
>
> ----------------------
> / Counter device \
> +----------------------+
> | Count register: 0x28 |
> +----------------------+
> |
> -----------------
> / raw count data /
> -----------------
> |
> V
> +----------------------------+
> | Counter device driver |----------+
> +----------------------------+ |
> | Processes data from device | -------------------
> |----------------------------| / driver callbacks /
> | Type: unsigned long | -------------------
> | Value: 42 | |
> +----------------------------+ |
> | |
> ---------------- |
> / unsigned long / |
> ---------------- |
> | |
> | V
> | +----------------------+
> | | Counter core |
> | +----------------------+
> | | Routes device driver |
> | | callbacks to the |
> | | userspace interfaces |
> | +----------------------+
> | |
> | -------------------
> | / driver callbacks /
> | -------------------
> | |
> +-------+ |
> | |
> | +---------------+
> | |
> V |
> +--------------------+ |
> | Counter sysfs |<-+
> +--------------------+
> | Translates to the |
> | standard Counter |
> | sysfs output |
> |--------------------|
> | Type: const char * |
> | Value: "42" |
> +--------------------+
> |
> ---------------
> / const char * /
> ---------------
> |
> V
> +--------------------------------------------------+
> | `/sys/bus/counter/devices/counterX/countY/count` |
> +--------------------------------------------------+
> \ Count: "42" /
> --------------------------------------------------
>
> There are three primary components involved:
>
> Counter device driver
> ---------------------
> Communicates with the hardware device to read/write data; e.g.
> counter drivers for 104-quad-8, stm32-timer, etc.
>
> Counter core
> ------------
> Registers the counter device driver to the system so that the
> respective callbacks are called during userspace interaction
>
> Counter sysfs
> -------------
> Translates counter data to the standard Counter sysfs interface
> format and vice versa
>
> Driver ABI
> ==========
>
> This reimplementation entails several changes to the driver ABI. In
> particular, the device driver callbacks are now expected to handle
> standard C datatypes rather than translating the sysfs I/O directly.
>
> To that end, the struct counter_data structure is introduced to
> establish counter extensions for Signals, Synapses, and Counts.
>
> The "type" member specifies the type of high-level data (e.g. BOOL,
> COUNT_DIRECTION, etc.) handled by this extension. The "*_read" and
> "*_write" members can then be set by the counter device driver with
> callbacks to handle that data using native C data types (i.e. u8, u64,
> char *, etc.).
>
> Convenience macros such as COUNTER_DATA_COUNT_U64 are provided for use
> by driver authors. In particular, driver authors are expected to use
> the provided macros for standard Counter subsystem attributes in order
> to maintain a consistent interface for userspace. For example, a counter
> device driver may define several standard attributes like so:
>
> struct counter_data count_ext[] = {
> COUNTER_DATA_DIRECTION(count_direction_read),
> COUNTER_DATA_ENABLE(count_enable_read, count_enable_write),
> COUNTER_DATA_CEILING(count_ceiling_read, count_ceiling_write),
> };
>
> This makes it intuitive to see, add, and modify the attributes that are
> supported by this driver ("direction", "enable", and "ceiling") and to
> maintain this code without getting lost in a web of struct braces.
>
> Callbacks must match the function type expected for the respective
> component or extension. These function types are defined in the struct
> counter_data structure as the "*_read" and "*_write" union members.
>
> The corresponding callback prototypes for the extensions above would be:
>
> int count_direction_read(struct counter_device *counter,
> struct counter_count *count, u8 *direction);
> int count_enable_read(struct counter_device *counter,
> struct counter_count *count, u8 *enable);
> int count_enable_write(struct counter_device *counter,
> struct counter_count *count, u8 enable);
> int count_ceiling_read(struct counter_device *counter,
> struct counter_count *count, u64 *ceiling);
> int count_ceiling_write(struct counter_device *counter,
> struct counter_count *count, u64 ceiling);
>
> In this way, driver authors no longer need to mess with sysfs strings
> and are instead able to focus on what they actually care about doing --
> getting data to/from the devices -- while the Generic Counter interface
> handles the translation of that data for them between the various
> userspace interfaces (e.g. sysfs and chardev).
>
> Architecture
> ============
>
> Counter device registration is the same as before: drivers populate a
> struct counter_device with components and callbacks, then pass the
> structure to the devm_counter_register function. However, what's
> different now is how the Counter subsystem code handles this
> registration internally.
>
> Whereas before callbacks would interact directly with sysfs data, this
> interaction is now abstracted and instead callbacks interact with native
> C data types. The counter_data structure forms the basis for Counter
> extentions.
>
> The counter-sysfs.c file contains the code to parse through the
> counter_device structure and register the requested components and
> extensions. Attributes are created and populated based on type, with
> respective translation functions to handle the mapping between sysfs and
> the counter driver callbacks.
>
> The translation performed for each attribute is straightforward: the
> attribute type and data is parsed from the counter_attribute structure,
> the respective counter driver read/write callback is called, and sysfs
> I/O is handled before or after the driver read/write function is called.
>
> Cc: Syed Nayyar Waris <syednwaris@gmail.com>
> Cc: Patrick Havelange <patrick.havelange@essensium.com>
> Cc: Fabrice Gasnier <fabrice.gasnier@st.com>
> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> Cc: Alexandre Torgue <alexandre.torgue@st.com>
> Cc: David Lechner <david@lechnology.com>
> Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Hi William
I've not been through this in great detail, but from
a read through of 104-quad-8 and the core changes this all looks
fairly sensible to me.
Jonathan
> ---
> MAINTAINERS | 2 +-
> drivers/counter/104-quad-8.c | 547 +++++-----
> drivers/counter/Makefile | 1 +
> drivers/counter/counter-core.c | 157 +++
> drivers/counter/counter-sysfs.c | 881 ++++++++++++++++
> drivers/counter/counter-sysfs.h | 14 +
> drivers/counter/counter.c | 1496 ---------------------------
> drivers/counter/ftm-quaddec.c | 89 +-
> drivers/counter/stm32-lptimer-cnt.c | 161 +--
> drivers/counter/stm32-timer-cnt.c | 139 +--
> drivers/counter/ti-eqep.c | 211 ++--
> include/linux/counter.h | 610 +++++------
> include/linux/counter_enum.h | 45 -
> include/uapi/linux/counter-types.h | 45 +
> 14 files changed, 1908 insertions(+), 2490 deletions(-)
> create mode 100644 drivers/counter/counter-core.c
> create mode 100644 drivers/counter/counter-sysfs.c
> create mode 100644 drivers/counter/counter-sysfs.h
> delete mode 100644 drivers/counter/counter.c
> delete mode 100644 include/linux/counter_enum.h
> create mode 100644 include/uapi/linux/counter-types.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 60ed2963efaa..ef72b5755793 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -4365,7 +4365,7 @@ F: Documentation/ABI/testing/sysfs-bus-counter*
> F: Documentation/driver-api/generic-counter.rst
> F: drivers/counter/
> F: include/linux/counter.h
> -F: include/linux/counter_enum.h
> +F: include/uapi/linux/counter-types.h
>
> CPMAC ETHERNET DRIVER
> M: Florian Fainelli <f.fainelli@gmail.com>
> diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c
> index aa13708c2bc3..ff1c8f8d1417 100644
> --- a/drivers/counter/104-quad-8.c
> +++ b/drivers/counter/104-quad-8.c
> @@ -17,6 +17,7 @@
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/moduleparam.h>
> +#include <linux/string.h>
> #include <linux/types.h>
>
> #define QUAD8_EXTENT 32
> @@ -621,7 +622,7 @@ static const struct iio_chan_spec quad8_channels[] = {
> };
>
> static int quad8_signal_read(struct counter_device *counter,
> - struct counter_signal *signal, enum counter_signal_value *val)
> + struct counter_signal *signal, u8 *val)
> {
> const struct quad8_iio *const priv = counter->priv;
> unsigned int state;
> @@ -639,7 +640,7 @@ static int quad8_signal_read(struct counter_device *counter,
> }
>
> static int quad8_count_read(struct counter_device *counter,
> - struct counter_count *count, unsigned long *val)
> + struct counter_count *count, u64 *val)
> {
> struct quad8_iio *const priv = counter->priv;
> const int base_offset = priv->base + 2 * count->id;
> @@ -670,7 +671,7 @@ static int quad8_count_read(struct counter_device *counter,
> }
>
> static int quad8_count_write(struct counter_device *counter,
> - struct counter_count *count, unsigned long val)
> + struct counter_count *count, u64 val)
> {
> struct quad8_iio *const priv = counter->priv;
> const int base_offset = priv->base + 2 * count->id;
> @@ -710,22 +711,16 @@ static int quad8_count_write(struct counter_device *counter,
> return 0;
> }
>
> -enum quad8_count_function {
> - QUAD8_COUNT_FUNCTION_PULSE_DIRECTION = 0,
> - QUAD8_COUNT_FUNCTION_QUADRATURE_X1,
> - QUAD8_COUNT_FUNCTION_QUADRATURE_X2,
> - QUAD8_COUNT_FUNCTION_QUADRATURE_X4
> -};
>
> -static enum counter_count_function quad8_count_functions_list[] = {
> - [QUAD8_COUNT_FUNCTION_PULSE_DIRECTION] = COUNTER_COUNT_FUNCTION_PULSE_DIRECTION,
> - [QUAD8_COUNT_FUNCTION_QUADRATURE_X1] = COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A,
> - [QUAD8_COUNT_FUNCTION_QUADRATURE_X2] = COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A,
> - [QUAD8_COUNT_FUNCTION_QUADRATURE_X4] = COUNTER_COUNT_FUNCTION_QUADRATURE_X4
> +static const u8 quad8_count_functions_list[] = {
> + COUNTER_COUNT_FUNCTION_PULSE_DIRECTION,
> + COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A,
> + COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A,
> + COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
> };
>
> -static int quad8_function_get(struct counter_device *counter,
> - struct counter_count *count, size_t *function)
> +static int quad8_function_read(struct counter_device *counter,
> + struct counter_count *count, u8 *function)
> {
> struct quad8_iio *const priv = counter->priv;
> const int id = count->id;
> @@ -735,25 +730,25 @@ static int quad8_function_get(struct counter_device *counter,
> if (priv->quadrature_mode[id])
> switch (priv->quadrature_scale[id]) {
> case 0:
> - *function = QUAD8_COUNT_FUNCTION_QUADRATURE_X1;
> + *function = COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A;
> break;
> case 1:
> - *function = QUAD8_COUNT_FUNCTION_QUADRATURE_X2;
> + *function = COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A;
> break;
> case 2:
> - *function = QUAD8_COUNT_FUNCTION_QUADRATURE_X4;
> + *function = COUNTER_COUNT_FUNCTION_QUADRATURE_X4;
> break;
> }
> else
> - *function = QUAD8_COUNT_FUNCTION_PULSE_DIRECTION;
> + *function = COUNTER_COUNT_FUNCTION_PULSE_DIRECTION;
>
> mutex_unlock(&priv->lock);
>
> return 0;
> }
>
> -static int quad8_function_set(struct counter_device *counter,
> - struct counter_count *count, size_t function)
> +static int quad8_function_write(struct counter_device *counter,
> + struct counter_count *count, u8 function)
> {
> struct quad8_iio *const priv = counter->priv;
> const int id = count->id;
> @@ -769,7 +764,7 @@ static int quad8_function_set(struct counter_device *counter,
> mode_cfg = priv->count_mode[id] << 1;
> idr_cfg = priv->index_polarity[id] << 1;
>
> - if (function == QUAD8_COUNT_FUNCTION_PULSE_DIRECTION) {
> + if (function == COUNTER_COUNT_FUNCTION_PULSE_DIRECTION) {
> *quadrature_mode = 0;
>
> /* Quadrature scaling only available in quadrature mode */
> @@ -785,15 +780,15 @@ static int quad8_function_set(struct counter_device *counter,
> *quadrature_mode = 1;
>
> switch (function) {
> - case QUAD8_COUNT_FUNCTION_QUADRATURE_X1:
> + case COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A:
> *scale = 0;
> mode_cfg |= QUAD8_CMR_QUADRATURE_X1;
> break;
> - case QUAD8_COUNT_FUNCTION_QUADRATURE_X2:
> + case COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A:
> *scale = 1;
> mode_cfg |= QUAD8_CMR_QUADRATURE_X2;
> break;
> - case QUAD8_COUNT_FUNCTION_QUADRATURE_X4:
> + case COUNTER_COUNT_FUNCTION_QUADRATURE_X4:
> *scale = 2;
> mode_cfg |= QUAD8_CMR_QUADRATURE_X4;
> break;
> @@ -808,8 +803,8 @@ static int quad8_function_set(struct counter_device *counter,
> return 0;
> }
>
> -static void quad8_direction_get(struct counter_device *counter,
> - struct counter_count *count, enum counter_count_direction *direction)
> +static int quad8_direction_read(struct counter_device *counter,
> + struct counter_count *count, u8 *direction)
> {
> const struct quad8_iio *const priv = counter->priv;
> unsigned int ud_flag;
> @@ -820,153 +815,155 @@ static void quad8_direction_get(struct counter_device *counter,
>
> *direction = (ud_flag) ? COUNTER_COUNT_DIRECTION_FORWARD :
> COUNTER_COUNT_DIRECTION_BACKWARD;
> -}
>
> -enum quad8_synapse_action {
> - QUAD8_SYNAPSE_ACTION_NONE = 0,
> - QUAD8_SYNAPSE_ACTION_RISING_EDGE,
> - QUAD8_SYNAPSE_ACTION_FALLING_EDGE,
> - QUAD8_SYNAPSE_ACTION_BOTH_EDGES
> -};
> + return 0;
> +}
>
> -static enum counter_synapse_action quad8_index_actions_list[] = {
> - [QUAD8_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,
> - [QUAD8_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE
> +static const u8 quad8_index_actions_list[] = {
> + COUNTER_SYNAPSE_ACTION_NONE,
> + COUNTER_SYNAPSE_ACTION_RISING_EDGE,
> };
>
> -static enum counter_synapse_action quad8_synapse_actions_list[] = {
> - [QUAD8_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,
> - [QUAD8_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE,
> - [QUAD8_SYNAPSE_ACTION_FALLING_EDGE] = COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
> - [QUAD8_SYNAPSE_ACTION_BOTH_EDGES] = COUNTER_SYNAPSE_ACTION_BOTH_EDGES
> +static const u8 quad8_synapse_actions_list[] = {
> + COUNTER_SYNAPSE_ACTION_NONE,
> + COUNTER_SYNAPSE_ACTION_RISING_EDGE,
> + COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
> + COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
> };
>
> -static int quad8_action_get(struct counter_device *counter,
> - struct counter_count *count, struct counter_synapse *synapse,
> - size_t *action)
> +static int quad8_action_read(struct counter_device *counter,
> + struct counter_count *count,
> + struct counter_synapse *synapse, u8 *action)
> {
> struct quad8_iio *const priv = counter->priv;
> int err;
> - size_t function = 0;
> + u8 function;
> const size_t signal_a_id = count->synapses[0].signal->id;
> - enum counter_count_direction direction;
> + u8 direction;
>
> /* Handle Index signals */
> if (synapse->signal->id >= 16) {
> if (priv->preset_enable[count->id])
> - *action = QUAD8_SYNAPSE_ACTION_RISING_EDGE;
> + *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
> else
> - *action = QUAD8_SYNAPSE_ACTION_NONE;
> + *action = COUNTER_SYNAPSE_ACTION_NONE;
>
> return 0;
> }
>
> - err = quad8_function_get(counter, count, &function);
> + err = quad8_function_read(counter, count, &function);
> if (err)
> return err;
>
> /* Default action mode */
> - *action = QUAD8_SYNAPSE_ACTION_NONE;
> + *action = COUNTER_SYNAPSE_ACTION_NONE;
>
> /* Determine action mode based on current count function mode */
> switch (function) {
> - case QUAD8_COUNT_FUNCTION_PULSE_DIRECTION:
> + case COUNTER_COUNT_FUNCTION_PULSE_DIRECTION:
> if (synapse->signal->id == signal_a_id)
> - *action = QUAD8_SYNAPSE_ACTION_RISING_EDGE;
> + *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
> break;
> - case QUAD8_COUNT_FUNCTION_QUADRATURE_X1:
> + case COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A:
> if (synapse->signal->id == signal_a_id) {
> - quad8_direction_get(counter, count, &direction);
> + err = quad8_direction_read(counter, count, &direction);
> + if (err)
> + return err;
>
> if (direction == COUNTER_COUNT_DIRECTION_FORWARD)
> - *action = QUAD8_SYNAPSE_ACTION_RISING_EDGE;
> + *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
> else
> - *action = QUAD8_SYNAPSE_ACTION_FALLING_EDGE;
> + *action = COUNTER_SYNAPSE_ACTION_FALLING_EDGE;
> }
> break;
> - case QUAD8_COUNT_FUNCTION_QUADRATURE_X2:
> + case COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A:
> if (synapse->signal->id == signal_a_id)
> - *action = QUAD8_SYNAPSE_ACTION_BOTH_EDGES;
> + *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
> break;
> - case QUAD8_COUNT_FUNCTION_QUADRATURE_X4:
> - *action = QUAD8_SYNAPSE_ACTION_BOTH_EDGES;
> + case COUNTER_COUNT_FUNCTION_QUADRATURE_X4:
> + *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
> break;
> }
>
> return 0;
> }
>
> -static const struct counter_ops quad8_ops = {
> - .signal_read = quad8_signal_read,
> - .count_read = quad8_count_read,
> - .count_write = quad8_count_write,
> - .function_get = quad8_function_get,
> - .function_set = quad8_function_set,
> - .action_get = quad8_action_get
> -};
> -
> -static int quad8_index_polarity_get(struct counter_device *counter,
> - struct counter_signal *signal, size_t *index_polarity)
> +static ssize_t quad8_index_polarity_read(struct counter_device *counter,
> + struct counter_signal *signal,
> + char *buf, size_t size)
> {
> const struct quad8_iio *const priv = counter->priv;
> - const size_t channel_id = signal->id - 16;
> -
> - *index_polarity = priv->index_polarity[channel_id];
> + const size_t index = priv->index_polarity[signal->id - 16];
>
> - return 0;
> + return snprintf(buf, size, "%s\n", quad8_index_polarity_modes[index]);
> }
>
> -static int quad8_index_polarity_set(struct counter_device *counter,
> - struct counter_signal *signal, size_t index_polarity)
> +static ssize_t quad8_index_polarity_write(struct counter_device *counter,
> + struct counter_signal *signal,
> + const char *buf, size_t size)
> {
> struct quad8_iio *const priv = counter->priv;
> const size_t channel_id = signal->id - 16;
> const int base_offset = priv->base + 2 * channel_id + 1;
> - unsigned int idr_cfg = index_polarity << 1;
> + int index_polarity;
> + unsigned int idr_cfg;
>
> - mutex_lock(&priv->lock);
> + index_polarity = sysfs_match_string(quad8_index_polarity_modes, buf);
> + if (index_polarity < 0)
> + return index_polarity;
>
> - idr_cfg |= priv->synchronous_mode[channel_id];
> + mutex_lock(&priv->lock);
>
> priv->index_polarity[channel_id] = index_polarity;
>
> /* Load Index Control configuration to Index Control Register */
> + idr_cfg = priv->synchronous_mode[channel_id] | index_polarity << 1;
> outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
>
> mutex_unlock(&priv->lock);
>
> - return 0;
> + return size;
> }
>
> -static struct counter_signal_enum_ext quad8_index_pol_enum = {
> - .items = quad8_index_polarity_modes,
> - .num_items = ARRAY_SIZE(quad8_index_polarity_modes),
> - .get = quad8_index_polarity_get,
> - .set = quad8_index_polarity_set
> -};
> +static ssize_t quad8_index_polarity_available_read(
> + struct counter_device *counter, struct counter_signal *signal,
> + char *buf, size_t size)
> +{
> + size_t i;
> + size_t len = 0;
>
> -static int quad8_synchronous_mode_get(struct counter_device *counter,
> - struct counter_signal *signal, size_t *synchronous_mode)
> + for (i = 0; i < ARRAY_SIZE(quad8_index_polarity_modes) && size > 1; i++)
> + len += scnprintf(buf + len, size - len, "%s\n",
> + quad8_index_polarity_modes[i]);
> +
> + return len;
> +}
> +
> +static ssize_t quad8_synchronous_mode_read(struct counter_device *counter,
> + struct counter_signal *signal,
> + char *buf, size_t size)
> {
> const struct quad8_iio *const priv = counter->priv;
> - const size_t channel_id = signal->id - 16;
> -
> - *synchronous_mode = priv->synchronous_mode[channel_id];
> + const size_t index = priv->synchronous_mode[signal->id - 16];
>
> - return 0;
> + return snprintf(buf, size, "%s\n", quad8_synchronous_modes[index]);
> }
>
> -static int quad8_synchronous_mode_set(struct counter_device *counter,
> - struct counter_signal *signal, size_t synchronous_mode)
> +static ssize_t quad8_synchronous_mode_write(struct counter_device *counter,
> + struct counter_signal *signal,
> + const char *buf, size_t size)
> {
> struct quad8_iio *const priv = counter->priv;
> const size_t channel_id = signal->id - 16;
> const int base_offset = priv->base + 2 * channel_id + 1;
> - unsigned int idr_cfg = synchronous_mode;
> + int synchronous_mode;
> + unsigned int idr_cfg;
>
> - mutex_lock(&priv->lock);
> + synchronous_mode = sysfs_match_string(quad8_synchronous_modes, buf);
> + if (synchronous_mode < 0)
> + return synchronous_mode;
>
> - idr_cfg |= priv->index_polarity[channel_id] << 1;
> + mutex_lock(&priv->lock);
>
> /* Index function must be non-synchronous in non-quadrature mode */
> if (synchronous_mode && !priv->quadrature_mode[channel_id]) {
> @@ -977,29 +974,39 @@ static int quad8_synchronous_mode_set(struct counter_device *counter,
> priv->synchronous_mode[channel_id] = synchronous_mode;
>
> /* Load Index Control configuration to Index Control Register */
> + idr_cfg = synchronous_mode | priv->index_polarity[channel_id] << 1;
> outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
>
> mutex_unlock(&priv->lock);
>
> - return 0;
> + return size;
> }
>
> -static struct counter_signal_enum_ext quad8_syn_mode_enum = {
> - .items = quad8_synchronous_modes,
> - .num_items = ARRAY_SIZE(quad8_synchronous_modes),
> - .get = quad8_synchronous_mode_get,
> - .set = quad8_synchronous_mode_set
> -};
> +static ssize_t quad8_synchronous_mode_available_read(
> + struct counter_device *counter, struct counter_signal *signal,
> + char *buf, size_t size)
> +{
> + size_t i;
> + size_t len = 0;
>
> -static ssize_t quad8_count_floor_read(struct counter_device *counter,
> - struct counter_count *count, void *private, char *buf)
> + for (i = 0; i < ARRAY_SIZE(quad8_synchronous_modes) && size > 1; i++)
> + len += scnprintf(buf + len, size - len, "%s\n",
> + quad8_synchronous_modes[i]);
> +
> + return len;
> +}
> +
> +static int quad8_count_floor_read(struct counter_device *counter,
> + struct counter_count *count, u64 *floor)
> {
> /* Only a floor of 0 is supported */
> - return sprintf(buf, "0\n");
> + *floor = 0;
> +
> + return 0;
> }
>
> -static int quad8_count_mode_get(struct counter_device *counter,
> - struct counter_count *count, size_t *cnt_mode)
> +static int quad8_count_mode_read(struct counter_device *counter,
> + struct counter_count *count, u8 *cnt_mode)
> {
> const struct quad8_iio *const priv = counter->priv;
>
> @@ -1022,35 +1029,36 @@ static int quad8_count_mode_get(struct counter_device *counter,
> return 0;
> }
>
> -static int quad8_count_mode_set(struct counter_device *counter,
> - struct counter_count *count, size_t cnt_mode)
> +static int quad8_count_mode_write(struct counter_device *counter,
> + struct counter_count *count, u8 cnt_mode)
> {
> struct quad8_iio *const priv = counter->priv;
> + unsigned int count_mode;
> unsigned int mode_cfg;
> const int base_offset = priv->base + 2 * count->id + 1;
>
> /* Map Generic Counter count mode to 104-QUAD-8 count mode */
> switch (cnt_mode) {
> case COUNTER_COUNT_MODE_NORMAL:
> - cnt_mode = 0;
> + count_mode = 0;
> break;
> case COUNTER_COUNT_MODE_RANGE_LIMIT:
> - cnt_mode = 1;
> + count_mode = 1;
> break;
> case COUNTER_COUNT_MODE_NON_RECYCLE:
> - cnt_mode = 2;
> + count_mode = 2;
> break;
> case COUNTER_COUNT_MODE_MODULO_N:
> - cnt_mode = 3;
> + count_mode = 3;
> break;
> }
>
> mutex_lock(&priv->lock);
>
> - priv->count_mode[count->id] = cnt_mode;
> + priv->count_mode[count->id] = count_mode;
>
> /* Set count mode configuration value */
> - mode_cfg = cnt_mode << 1;
> + mode_cfg = count_mode << 1;
>
> /* Add quadrature mode configuration */
> if (priv->quadrature_mode[count->id])
> @@ -1064,85 +1072,86 @@ static int quad8_count_mode_set(struct counter_device *counter,
> return 0;
> }
>
> -static struct counter_count_enum_ext quad8_cnt_mode_enum = {
> - .items = counter_count_mode_str,
> - .num_items = ARRAY_SIZE(counter_count_mode_str),
> - .get = quad8_count_mode_get,
> - .set = quad8_count_mode_set
> +static const u8 quad8_cnt_modes[] = {
> + COUNTER_COUNT_MODE_NORMAL,
> + COUNTER_COUNT_MODE_RANGE_LIMIT,
> + COUNTER_COUNT_MODE_NON_RECYCLE,
> + COUNTER_COUNT_MODE_MODULO_N,
> };
>
> -static ssize_t quad8_count_direction_read(struct counter_device *counter,
> - struct counter_count *count, void *priv, char *buf)
> -{
> - enum counter_count_direction dir;
> -
> - quad8_direction_get(counter, count, &dir);
> -
> - return sprintf(buf, "%s\n", counter_count_direction_str[dir]);
> -}
> +static DEFINE_COUNTER_AVAILABLE(quad8_count_mode_available, quad8_cnt_modes);
>
> -static ssize_t quad8_count_enable_read(struct counter_device *counter,
> - struct counter_count *count, void *private, char *buf)
> +static int quad8_count_enable_read(struct counter_device *counter,
> + struct counter_count *count, u8 *enable)
> {
> const struct quad8_iio *const priv = counter->priv;
>
> - return sprintf(buf, "%u\n", priv->ab_enable[count->id]);
> + *enable = priv->ab_enable[count->id];
> +
> + return 0;
> }
>
> -static ssize_t quad8_count_enable_write(struct counter_device *counter,
> - struct counter_count *count, void *private, const char *buf, size_t len)
> +static int quad8_count_enable_write(struct counter_device *counter,
> + struct counter_count *count, u8 enable)
> {
> struct quad8_iio *const priv = counter->priv;
> const int base_offset = priv->base + 2 * count->id;
> - int err;
> - bool ab_enable;
> unsigned int ior_cfg;
>
> - err = kstrtobool(buf, &ab_enable);
> - if (err)
> - return err;
> -
> mutex_lock(&priv->lock);
>
> - priv->ab_enable[count->id] = ab_enable;
> + priv->ab_enable[count->id] = enable;
>
> - ior_cfg = ab_enable | priv->preset_enable[count->id] << 1;
> + ior_cfg = enable | priv->preset_enable[count->id] << 1;
>
> /* Load I/O control configuration */
> outb(QUAD8_CTR_IOR | ior_cfg, base_offset + 1);
>
> mutex_unlock(&priv->lock);
>
> - return len;
> + return 0;
> }
>
> -static int quad8_error_noise_get(struct counter_device *counter,
> - struct counter_count *count, size_t *noise_error)
> +static ssize_t quad8_error_noise_read(struct counter_device *counter,
> + struct counter_count *count, char *buf,
> + size_t size)
> {
> const struct quad8_iio *const priv = counter->priv;
> const int base_offset = priv->base + 2 * count->id + 1;
> + size_t noise_error;
>
> - *noise_error = !!(inb(base_offset) & QUAD8_FLAG_E);
> + noise_error = !!(inb(base_offset) & QUAD8_FLAG_E);
>
> - return 0;
> + return snprintf(buf, size, "%s\n",
> + quad8_noise_error_states[noise_error]);
> }
>
> -static struct counter_count_enum_ext quad8_error_noise_enum = {
> - .items = quad8_noise_error_states,
> - .num_items = ARRAY_SIZE(quad8_noise_error_states),
> - .get = quad8_error_noise_get
> -};
> +static ssize_t quad8_error_noise_available_read(struct counter_device *counter,
> + struct counter_count *count,
> + char *buf, size_t size)
> +{
> + size_t i;
> + size_t len = 0;
> +
> + for (i = 0; i < ARRAY_SIZE(quad8_noise_error_states) && size > 1; i++)
> + len += scnprintf(buf + len, size - len, "%s\n",
> + quad8_noise_error_states[i]);
> +
> + return len;
> +}
>
> -static ssize_t quad8_count_preset_read(struct counter_device *counter,
> - struct counter_count *count, void *private, char *buf)
> +static int quad8_count_preset_read(struct counter_device *counter,
> + struct counter_count *count, u64 *preset)
> {
> const struct quad8_iio *const priv = counter->priv;
>
> - return sprintf(buf, "%u\n", priv->preset[count->id]);
> + *preset = priv->preset[count->id];
> +
> + return 0;
> }
>
> -static void quad8_preset_register_set(struct quad8_iio *quad8iio, int id,
> - unsigned int preset)
> +static void quad8_preset_register_set(struct quad8_iio *const quad8iio,
> + const int id, const u64 preset)
> {
> const unsigned int base_offset = quad8iio->base + 2 * id;
> int i;
> @@ -1157,16 +1166,10 @@ static void quad8_preset_register_set(struct quad8_iio *quad8iio, int id,
> outb(preset >> (8 * i), base_offset);
> }
>
> -static ssize_t quad8_count_preset_write(struct counter_device *counter,
> - struct counter_count *count, void *private, const char *buf, size_t len)
> +static int quad8_count_preset_write(struct counter_device *counter,
> + struct counter_count *count, u64 preset)
> {
> struct quad8_iio *const priv = counter->priv;
> - unsigned int preset;
> - int ret;
> -
> - ret = kstrtouint(buf, 0, &preset);
> - if (ret)
> - return ret;
>
> /* Only 24-bit values are supported */
> if (preset > 0xFFFFFF)
> @@ -1178,11 +1181,11 @@ static ssize_t quad8_count_preset_write(struct counter_device *counter,
>
> mutex_unlock(&priv->lock);
>
> - return len;
> + return 0;
> }
>
> -static ssize_t quad8_count_ceiling_read(struct counter_device *counter,
> - struct counter_count *count, void *private, char *buf)
> +static int quad8_count_ceiling_read(struct counter_device *counter,
> + struct counter_count *count, u64 *ceiling)
> {
> struct quad8_iio *const priv = counter->priv;
>
> @@ -1193,25 +1196,21 @@ static ssize_t quad8_count_ceiling_read(struct counter_device *counter,
> case 1:
> case 3:
> mutex_unlock(&priv->lock);
> - return sprintf(buf, "%u\n", priv->preset[count->id]);
> + return quad8_count_preset_read(counter, count, ceiling);
> }
>
> mutex_unlock(&priv->lock);
>
> /* By default 0x1FFFFFF (25 bits unsigned) is maximum count */
> - return sprintf(buf, "33554431\n");
> + *ceiling = 0x1FFFFFF;
> +
> + return 0;
> }
>
> -static ssize_t quad8_count_ceiling_write(struct counter_device *counter,
> - struct counter_count *count, void *private, const char *buf, size_t len)
> +static int quad8_count_ceiling_write(struct counter_device *counter,
> + struct counter_count *count, u64 ceiling)
> {
> struct quad8_iio *const priv = counter->priv;
> - unsigned int ceiling;
> - int ret;
> -
> - ret = kstrtouint(buf, 0, &ceiling);
> - if (ret)
> - return ret;
>
> /* Only 24-bit values are supported */
> if (ceiling > 0xFFFFFF)
> @@ -1223,36 +1222,33 @@ static ssize_t quad8_count_ceiling_write(struct counter_device *counter,
> switch (priv->count_mode[count->id]) {
> case 1:
> case 3:
> - quad8_preset_register_set(priv, count->id, ceiling);
> - break;
> + return quad8_count_preset_write(counter, count, ceiling);
> }
>
> mutex_unlock(&priv->lock);
>
> - return len;
> + return -EINVAL;
> }
>
> -static ssize_t quad8_count_preset_enable_read(struct counter_device *counter,
> - struct counter_count *count, void *private, char *buf)
> +static int quad8_count_preset_enable_read(struct counter_device *counter,
> + struct counter_count *count,
> + u8 *preset_enable)
> {
> const struct quad8_iio *const priv = counter->priv;
>
> - return sprintf(buf, "%u\n", !priv->preset_enable[count->id]);
> + *preset_enable = !priv->preset_enable[count->id];
> +
> + return 0;
> }
>
> -static ssize_t quad8_count_preset_enable_write(struct counter_device *counter,
> - struct counter_count *count, void *private, const char *buf, size_t len)
> +static int quad8_count_preset_enable_write(struct counter_device *counter,
> + struct counter_count *count,
> + u8 preset_enable)
> {
> struct quad8_iio *const priv = counter->priv;
> const int base_offset = priv->base + 2 * count->id + 1;
> - bool preset_enable;
> - int ret;
> unsigned int ior_cfg;
>
> - ret = kstrtobool(buf, &preset_enable);
> - if (ret)
> - return ret;
> -
> /* Preset enable is active low in Input/Output Control register */
> preset_enable = !preset_enable;
>
> @@ -1260,25 +1256,24 @@ static ssize_t quad8_count_preset_enable_write(struct counter_device *counter,
>
> priv->preset_enable[count->id] = preset_enable;
>
> - ior_cfg = priv->ab_enable[count->id] | (unsigned int)preset_enable << 1;
> + ior_cfg = priv->ab_enable[count->id] | preset_enable << 1;
>
> /* Load I/O control configuration to Input / Output Control Register */
> outb(QUAD8_CTR_IOR | ior_cfg, base_offset);
>
> mutex_unlock(&priv->lock);
>
> - return len;
> + return 0;
> }
>
> -static ssize_t quad8_signal_cable_fault_read(struct counter_device *counter,
> - struct counter_signal *signal,
> - void *private, char *buf)
> +static int quad8_signal_cable_fault_read(struct counter_device *counter,
> + struct counter_signal *signal,
> + u8 *cable_fault)
> {
> const struct quad8_iio *const priv = counter->priv;
> const size_t channel_id = signal->id / 2;
> const bool disabled = !(priv->cable_fault_enable & BIT(channel_id));
> unsigned int status;
> - unsigned int fault;
>
> if (disabled)
> return -EINVAL;
> @@ -1287,36 +1282,31 @@ static ssize_t quad8_signal_cable_fault_read(struct counter_device *counter,
> status = inb(priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS);
>
> /* Mask respective channel and invert logic */
> - fault = !(status & BIT(channel_id));
> + *cable_fault = !(status & BIT(channel_id));
>
> - return sprintf(buf, "%u\n", fault);
> + return 0;
> }
>
> -static ssize_t quad8_signal_cable_fault_enable_read(
> - struct counter_device *counter, struct counter_signal *signal,
> - void *private, char *buf)
> +static int quad8_signal_cable_fault_enable_read(struct counter_device *counter,
> + struct counter_signal *signal,
> + u8 *enable)
> {
> const struct quad8_iio *const priv = counter->priv;
> const size_t channel_id = signal->id / 2;
> - const unsigned int enb = !!(priv->cable_fault_enable & BIT(channel_id));
>
> - return sprintf(buf, "%u\n", enb);
> + *enable = !!(priv->cable_fault_enable & BIT(channel_id));
> +
> + return 0;
> }
>
> -static ssize_t quad8_signal_cable_fault_enable_write(
> - struct counter_device *counter, struct counter_signal *signal,
> - void *private, const char *buf, size_t len)
> +static int quad8_signal_cable_fault_enable_write(struct counter_device *counter,
> + struct counter_signal *signal,
> + u8 enable)
> {
> struct quad8_iio *const priv = counter->priv;
> const size_t channel_id = signal->id / 2;
> - bool enable;
> - int ret;
> unsigned int cable_fault_enable;
>
> - ret = kstrtobool(buf, &enable);
> - if (ret)
> - return ret;
> -
> if (enable)
> priv->cable_fault_enable |= BIT(channel_id);
> else
> @@ -1327,31 +1317,27 @@ static ssize_t quad8_signal_cable_fault_enable_write(
>
> outb(cable_fault_enable, priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS);
>
> - return len;
> + return 0;
> }
>
> -static ssize_t quad8_signal_fck_prescaler_read(struct counter_device *counter,
> - struct counter_signal *signal, void *private, char *buf)
> +static int quad8_signal_fck_prescaler_read(struct counter_device *counter,
> + struct counter_signal *signal,
> + u8 *prescaler)
> {
> const struct quad8_iio *const priv = counter->priv;
> - const size_t channel_id = signal->id / 2;
>
> - return sprintf(buf, "%u\n", priv->fck_prescaler[channel_id]);
> + *prescaler = priv->fck_prescaler[signal->id / 2];
> +
> + return 0;
> }
>
> -static ssize_t quad8_signal_fck_prescaler_write(struct counter_device *counter,
> - struct counter_signal *signal, void *private, const char *buf,
> - size_t len)
> +static int quad8_signal_fck_prescaler_write(struct counter_device *counter,
> + struct counter_signal *signal,
> + u8 prescaler)
> {
> struct quad8_iio *const priv = counter->priv;
> const size_t channel_id = signal->id / 2;
> const int base_offset = priv->base + 2 * channel_id;
> - u8 prescaler;
> - int ret;
> -
> - ret = kstrtou8(buf, 0, &prescaler);
> - if (ret)
> - return ret;
>
> priv->fck_prescaler[channel_id] = prescaler;
>
> @@ -1363,31 +1349,30 @@ static ssize_t quad8_signal_fck_prescaler_write(struct counter_device *counter,
> outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_PRESET_PSC,
> base_offset + 1);
>
> - return len;
> + return 0;
> }
>
> -static const struct counter_signal_ext quad8_signal_ext[] = {
> - {
> - .name = "cable_fault",
> - .read = quad8_signal_cable_fault_read
> - },
> - {
> - .name = "cable_fault_enable",
> - .read = quad8_signal_cable_fault_enable_read,
> - .write = quad8_signal_cable_fault_enable_write
> - },
> - {
> - .name = "filter_clock_prescaler",
> - .read = quad8_signal_fck_prescaler_read,
> - .write = quad8_signal_fck_prescaler_write
> - }
> +static struct counter_data quad8_signal_ext[] = {
> + COUNTER_DATA_SIGNAL_BOOL("cable_fault", quad8_signal_cable_fault_read,
> + NULL),
> + COUNTER_DATA_SIGNAL_BOOL("cable_fault_enable",
> + quad8_signal_cable_fault_enable_read,
> + quad8_signal_cable_fault_enable_write),
> + COUNTER_DATA_SIGNAL_U8("filter_clock_prescaler",
> + quad8_signal_fck_prescaler_read,
> + quad8_signal_fck_prescaler_write)
> };
>
> -static const struct counter_signal_ext quad8_index_ext[] = {
> - COUNTER_SIGNAL_ENUM("index_polarity", &quad8_index_pol_enum),
> - COUNTER_SIGNAL_ENUM_AVAILABLE("index_polarity", &quad8_index_pol_enum),
> - COUNTER_SIGNAL_ENUM("synchronous_mode", &quad8_syn_mode_enum),
> - COUNTER_SIGNAL_ENUM_AVAILABLE("synchronous_mode", &quad8_syn_mode_enum)
> +static struct counter_data quad8_index_ext[] = {
> + COUNTER_DATA_SIGNAL_STRING("index_polarity", quad8_index_polarity_read,
> + quad8_index_polarity_write),
> + COUNTER_DATA_SIGNAL_STRING("index_polarity_available",
> + quad8_index_polarity_available_read, NULL),
> + COUNTER_DATA_SIGNAL_STRING("synchronous_mode",
> + quad8_synchronous_mode_read,
> + quad8_synchronous_mode_write),
> + COUNTER_DATA_SIGNAL_STRING("synchronous_mode_available",
> + quad8_synchronous_mode_available_read, NULL),
> };
>
> #define QUAD8_QUAD_SIGNAL(_id, _name) { \
> @@ -1456,39 +1441,20 @@ static struct counter_synapse quad8_count_synapses[][3] = {
> QUAD8_COUNT_SYNAPSES(6), QUAD8_COUNT_SYNAPSES(7)
> };
>
> -static const struct counter_count_ext quad8_count_ext[] = {
> - {
> - .name = "ceiling",
> - .read = quad8_count_ceiling_read,
> - .write = quad8_count_ceiling_write
> - },
> - {
> - .name = "floor",
> - .read = quad8_count_floor_read
> - },
> - COUNTER_COUNT_ENUM("count_mode", &quad8_cnt_mode_enum),
> - COUNTER_COUNT_ENUM_AVAILABLE("count_mode", &quad8_cnt_mode_enum),
> - {
> - .name = "direction",
> - .read = quad8_count_direction_read
> - },
> - {
> - .name = "enable",
> - .read = quad8_count_enable_read,
> - .write = quad8_count_enable_write
> - },
> - COUNTER_COUNT_ENUM("error_noise", &quad8_error_noise_enum),
> - COUNTER_COUNT_ENUM_AVAILABLE("error_noise", &quad8_error_noise_enum),
> - {
> - .name = "preset",
> - .read = quad8_count_preset_read,
> - .write = quad8_count_preset_write
> - },
> - {
> - .name = "preset_enable",
> - .read = quad8_count_preset_enable_read,
> - .write = quad8_count_preset_enable_write
> - }
> +static struct counter_data quad8_count_ext[] = {
> + COUNTER_DATA_CEILING(quad8_count_ceiling_read,
> + quad8_count_ceiling_write),
> + COUNTER_DATA_FLOOR(quad8_count_floor_read, NULL),
> + COUNTER_DATA_COUNT_MODE(quad8_count_mode_read, quad8_count_mode_write,
> + quad8_count_mode_available),
> + COUNTER_DATA_DIRECTION(quad8_direction_read),
> + COUNTER_DATA_ENABLE(quad8_count_enable_read, quad8_count_enable_write),
> + COUNTER_DATA_COUNT_STRING("error_noise", quad8_error_noise_read, NULL),
> + COUNTER_DATA_COUNT_STRING("error_noise_available",
> + quad8_error_noise_available_read, NULL),
> + COUNTER_DATA_PRESET(quad8_count_preset_read, quad8_count_preset_write),
> + COUNTER_DATA_PRESET_ENABLE(quad8_count_preset_enable_read,
> + quad8_count_preset_enable_write),
> };
>
> #define QUAD8_COUNT(_id, _cntname) { \
> @@ -1544,7 +1510,12 @@ static int quad8_probe(struct device *dev, unsigned int id)
> quad8iio = iio_priv(indio_dev);
> quad8iio->counter.name = dev_name(dev);
> quad8iio->counter.parent = dev;
> - quad8iio->counter.ops = &quad8_ops;
> + quad8iio->counter.signal_read = quad8_signal_read;
> + quad8iio->counter.count_read = quad8_count_read;
> + quad8iio->counter.count_write = quad8_count_write;
> + quad8iio->counter.function_read = quad8_function_read;
> + quad8iio->counter.function_write = quad8_function_write;
> + quad8iio->counter.action_read = quad8_action_read;
> quad8iio->counter.counts = quad8_counts;
> quad8iio->counter.num_counts = ARRAY_SIZE(quad8_counts);
> quad8iio->counter.signals = quad8_signals;
> diff --git a/drivers/counter/Makefile b/drivers/counter/Makefile
> index 55142d1f4c43..f48e337cbd85 100644
> --- a/drivers/counter/Makefile
> +++ b/drivers/counter/Makefile
> @@ -4,6 +4,7 @@
> #
>
> obj-$(CONFIG_COUNTER) += counter.o
> +counter-y := counter-core.o counter-sysfs.o
>
> obj-$(CONFIG_104_QUAD_8) += 104-quad-8.o
> obj-$(CONFIG_STM32_TIMER_CNT) += stm32-timer-cnt.o
> diff --git a/drivers/counter/counter-core.c b/drivers/counter/counter-core.c
> new file mode 100644
> index 000000000000..499664809c75
> --- /dev/null
> +++ b/drivers/counter/counter-core.c
> @@ -0,0 +1,157 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Generic Counter interface
> + * Copyright (C) 2020 William Breathitt Gray
> + */
> +#include <linux/counter.h>
> +#include <linux/device.h>
> +#include <linux/export.h>
> +#include <linux/gfp.h>
> +#include <linux/idr.h>
> +#include <linux/init.h>
> +#include <linux/module.h>
> +
> +#include "counter-sysfs.h"
> +
> +/* Provides a unique ID for each counter device */
> +static DEFINE_IDA(counter_ida);
> +
> +static void counter_device_release(struct device *dev)
> +{
> + struct counter_device *const counter = dev_get_drvdata(dev);
> +
> + counter_sysfs_free(counter);
> + ida_simple_remove(&counter_ida, counter->id);
> +}
> +
> +static struct device_type counter_device_type = {
> + .name = "counter_device",
> + .release = counter_device_release
> +};
> +
> +static struct bus_type counter_bus_type = {
> + .name = "counter"
> +};
> +
> +/**
> + * counter_register - register Counter to the system
> + * @counter: pointer to Counter to register
> + *
> + * This function registers a Counter to the system. A sysfs "counter" directory
> + * will be created and populated with sysfs attributes correlating with the
> + * Counter Signals, Synapses, and Counts respectively.
> + */
> +int counter_register(struct counter_device *const counter)
> +{
> + struct device *const dev = &counter->dev;
> + int err;
> +
> + /* Acquire unique ID */
> + counter->id = ida_simple_get(&counter_ida, 0, 0, GFP_KERNEL);
> + if (counter->id < 0)
> + return counter->id;
> +
> + /* Configure device structure for Counter */
> + dev->type = &counter_device_type;
> + dev->bus = &counter_bus_type;
> + if (counter->parent) {
> + dev->parent = counter->parent;
> + dev->of_node = counter->parent->of_node;
> + }
> + dev_set_name(dev, "counter%d", counter->id);
> + device_initialize(dev);
> + dev_set_drvdata(dev, counter);
> +
> + /* Add Counter sysfs attributes */
> + err = counter_sysfs_add(counter);
> + if (err)
> + goto err_free_id;
> +
> + /* Add device to system */
> + err = device_add(dev);
> + if (err)
> + goto err_free_sysfs;
> +
> + return 0;
> +
> +err_free_sysfs:
> + counter_sysfs_free(counter);
> +err_free_id:
> + ida_simple_remove(&counter_ida, counter->id);
> + return err;
> +}
> +EXPORT_SYMBOL_GPL(counter_register);
> +
> +/**
> + * counter_unregister - unregister Counter from the system
> + * @counter: pointer to Counter to unregister
> + *
> + * The Counter is unregistered from the system; all allocated memory is freed.
> + */
> +void counter_unregister(struct counter_device *const counter)
> +{
> + if (counter) {
> + device_del(&counter->dev);
> + counter_sysfs_free(counter);
> + }
> +}
> +EXPORT_SYMBOL_GPL(counter_unregister);
> +
> +static void devm_counter_unreg(struct device *dev, void *res)
> +{
> + counter_unregister(*(struct counter_device **)res);
> +}
> +
> +/**
> + * devm_counter_register - Resource-managed counter_register
> + * @dev: device to allocate counter_device for
> + * @counter: pointer to Counter to register
> + *
> + * Managed counter_register. The Counter registered with this function is
> + * automatically unregistered on driver detach. This function calls
> + * counter_register internally. Refer to that function for more information.
> + *
> + * If an Counter registered with this function needs to be unregistered
> + * separately, devm_counter_unregister must be used.
> + *
> + * RETURNS:
> + * 0 on success, negative error number on failure.
> + */
> +int devm_counter_register(struct device *dev,
> + struct counter_device *const counter)
> +{
> + struct counter_device **ptr;
> + int ret;
> +
> + ptr = devres_alloc(devm_counter_unreg, sizeof(*ptr), GFP_KERNEL);
> + if (!ptr)
> + return -ENOMEM;
> +
> + ret = counter_register(counter);
> + if (!ret) {
> + *ptr = counter;
> + devres_add(dev, ptr);
> + } else {
> + devres_free(ptr);
> + }
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(devm_counter_register);
> +
> +static int __init counter_init(void)
> +{
> + return bus_register(&counter_bus_type);
> +}
> +
> +static void __exit counter_exit(void)
> +{
> + bus_unregister(&counter_bus_type);
> +}
> +
> +subsys_initcall(counter_init);
> +module_exit(counter_exit);
> +
> +MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
> +MODULE_DESCRIPTION("Generic Counter interface");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/counter/counter-sysfs.c b/drivers/counter/counter-sysfs.c
> new file mode 100644
> index 000000000000..d30a3239eb41
> --- /dev/null
> +++ b/drivers/counter/counter-sysfs.c
> @@ -0,0 +1,881 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Generic Counter sysfs interface
> + * Copyright (C) 2020 William Breathitt Gray
> + */
> +#include <linux/counter.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/gfp.h>
> +#include <linux/kernel.h>
> +#include <linux/list.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/sysfs.h>
> +#include <linux/types.h>
> +
> +enum counter_owner_type {
> + COUNTER_OWNER_TYPE_DEVICE,
> + COUNTER_OWNER_TYPE_SIGNAL,
> + COUNTER_OWNER_TYPE_COUNT,
> +};
> +
> +struct counter_attribute {
> + struct device_attribute dev_attr;
> + struct list_head l;
> +
> + struct counter_data data;
> + enum counter_owner_type type;
> + void *owner;
> +};
> +
> +#define to_counter_attribute(_dev_attr) \
> + container_of(_dev_attr, struct counter_attribute, dev_attr)
> +
> +static const char *const counter_count_function_str[] = {
> + [COUNTER_COUNT_FUNCTION_INCREASE] = "increase",
> + [COUNTER_COUNT_FUNCTION_DECREASE] = "decrease",
> + [COUNTER_COUNT_FUNCTION_PULSE_DIRECTION] = "pulse-direction",
> + [COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A] = "quadrature x1 a",
> + [COUNTER_COUNT_FUNCTION_QUADRATURE_X1_B] = "quadrature x1 b",
> + [COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A] = "quadrature x2 a",
> + [COUNTER_COUNT_FUNCTION_QUADRATURE_X2_B] = "quadrature x2 b",
> + [COUNTER_COUNT_FUNCTION_QUADRATURE_X4] = "quadrature x4"
> +};
> +
> +static const char *const counter_signal_value_str[] = {
> + [COUNTER_SIGNAL_LOW] = "low",
> + [COUNTER_SIGNAL_HIGH] = "high"
> +};
> +
> +static const char *const counter_synapse_action_str[] = {
> + [COUNTER_SYNAPSE_ACTION_NONE] = "none",
> + [COUNTER_SYNAPSE_ACTION_RISING_EDGE] = "rising edge",
> + [COUNTER_SYNAPSE_ACTION_FALLING_EDGE] = "falling edge",
> + [COUNTER_SYNAPSE_ACTION_BOTH_EDGES] = "both edges"
> +};
> +
> +static const char *const counter_count_direction_str[] = {
> + [COUNTER_COUNT_DIRECTION_FORWARD] = "forward",
> + [COUNTER_COUNT_DIRECTION_BACKWARD] = "backward"
> +};
> +
> +static const char *const counter_count_mode_str[] = {
> + [COUNTER_COUNT_MODE_NORMAL] = "normal",
> + [COUNTER_COUNT_MODE_RANGE_LIMIT] = "range limit",
> + [COUNTER_COUNT_MODE_NON_RECYCLE] = "non-recycle",
> + [COUNTER_COUNT_MODE_MODULO_N] = "modulo-n"
> +};
> +
> +static ssize_t counter_data_u8_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + const struct counter_attribute *const a = to_counter_attribute(attr);
> + struct counter_device *const counter = dev_get_drvdata(dev);
> + int err;
> + u8 data;
> +
> + switch (a->type) {
> + case COUNTER_OWNER_TYPE_DEVICE:
> + err = a->data.device_u8_read(counter, &data);
> + break;
> + case COUNTER_OWNER_TYPE_SIGNAL:
> + err = a->data.signal_u8_read(counter, a->owner, &data);
> + break;
> + case COUNTER_OWNER_TYPE_COUNT:
> + if (a->data.type == COUNTER_DATA_TYPE_SYNAPSE_ACTION)
> + err = a->data.action_read(counter, a->owner,
> + a->data.priv, &data);
> + else
> + err = a->data.count_u8_read(counter, a->owner, &data);
> + break;
> + default: return -EINVAL;
> + }
> + if (err)
> + return err;
> +
> + switch (a->data.type) {
> + case COUNTER_DATA_TYPE_BOOL:
> + return sprintf(buf, "%u\n", (unsigned int)!!data);
> + case COUNTER_DATA_TYPE_COUNT_FUNCTION:
> + return sprintf(buf, "%s\n", counter_count_function_str[data]);
> + case COUNTER_DATA_TYPE_SIGNAL:
> + return sprintf(buf, "%s\n", counter_signal_value_str[data]);
> + case COUNTER_DATA_TYPE_SYNAPSE_ACTION:
> + return sprintf(buf, "%s\n", counter_synapse_action_str[data]);
> + case COUNTER_DATA_TYPE_COUNT_DIRECTION:
> + return sprintf(buf, "%s\n", counter_count_direction_str[data]);
> + case COUNTER_DATA_TYPE_COUNT_MODE:
> + return sprintf(buf, "%s\n", counter_count_mode_str[data]);
> + }
> +
> + return sprintf(buf, "%u\n", (unsigned int)data);
> +}
> +
> +static int find_in_string_array(u8 *const item, const u8 *const items,
> + const size_t num_items, const char *const buf,
> + const char *const string_array[])
> +{
> + size_t index;
> +
> + for (index = 0; index < num_items; index++) {
> + *item = items[index];
> + if (sysfs_streq(buf, string_array[*item]))
> + return 0;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static ssize_t counter_data_u8_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + const struct counter_attribute *const a = to_counter_attribute(attr);
> + struct counter_device *const counter = dev_get_drvdata(dev);
> + struct counter_count *const count = a->owner;
> + struct counter_synapse *const synapse = a->data.priv;
> + const struct counter_available *const available = a->data.priv;
> + int err;
> + bool bool_data;
> + u8 data;
> +
> + switch (a->data.type) {
> + case COUNTER_DATA_TYPE_BOOL:
> + err = kstrtobool(buf, &bool_data);
> + data = bool_data;
> + break;
> + case COUNTER_DATA_TYPE_COUNT_FUNCTION:
> + err = find_in_string_array(&data, count->functions_list,
> + count->num_functions, buf,
> + counter_count_function_str);
> + break;
> + case COUNTER_DATA_TYPE_SYNAPSE_ACTION:
> + err = find_in_string_array(&data, synapse->actions_list,
> + synapse->num_actions, buf,
> + counter_synapse_action_str);
> + break;
> + case COUNTER_DATA_TYPE_COUNT_MODE:
> + err = find_in_string_array(&data, available->items,
> + available->num_items, buf,
> + counter_count_mode_str);
> + break;
> + default:
> + err = kstrtou8(buf, 0, &data);
> + break;
> + }
> + if (err)
> + return err;
> +
> + switch (a->type) {
> + case COUNTER_OWNER_TYPE_DEVICE:
> + err = a->data.device_u8_write(counter, data);
> + break;
> + case COUNTER_OWNER_TYPE_SIGNAL:
> + err = a->data.signal_u8_write(counter, a->owner, data);
> + break;
> + case COUNTER_OWNER_TYPE_COUNT:
> + if (a->data.type == COUNTER_DATA_TYPE_SYNAPSE_ACTION)
> + err = a->data.action_write(counter, count, synapse,
> + data);
> + else
> + err = a->data.count_u8_write(counter, count, data);
> + break;
> + }
> + if (err)
> + return err;
> +
> + return len;
> +}
> +
> +static ssize_t counter_data_u64_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + const struct counter_attribute *const a = to_counter_attribute(attr);
> + struct counter_device *const counter = dev_get_drvdata(dev);
> + int err;
> + u64 data;
> +
> + switch (a->type) {
> + case COUNTER_OWNER_TYPE_DEVICE:
> + err = a->data.device_u64_read(counter, &data);
> + break;
> + case COUNTER_OWNER_TYPE_SIGNAL:
> + err = a->data.signal_u64_read(counter, a->owner, &data);
> + break;
> + case COUNTER_OWNER_TYPE_COUNT:
> + err = a->data.count_u64_read(counter, a->owner, &data);
> + break;
> + default: return -EINVAL;
> + }
> + if (err)
> + return err;
> +
> + return sprintf(buf, "%llu\n", (unsigned long long)data);
> +}
> +
> +static ssize_t counter_data_u64_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + const struct counter_attribute *const a = to_counter_attribute(attr);
> + struct counter_device *const counter = dev_get_drvdata(dev);
> + int err;
> + u64 data;
> +
> + err = kstrtou64(buf, 0, &data);
> + if (err)
> + return err;
> +
> + switch (a->type) {
> + case COUNTER_OWNER_TYPE_DEVICE:
> + err = a->data.device_u64_write(counter, data);
> + break;
> + case COUNTER_OWNER_TYPE_SIGNAL:
> + err = a->data.signal_u64_write(counter, a->owner, data);
> + break;
> + case COUNTER_OWNER_TYPE_COUNT:
> + err = a->data.count_u64_write(counter, a->owner, data);
> + break;
> + }
> + if (err)
> + return err;
> +
> + return len;
> +}
> +
> +static ssize_t counter_data_string_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + const struct counter_attribute *const a = to_counter_attribute(attr);
> + struct counter_device *const counter = dev_get_drvdata(dev);
> +
> + switch (a->type) {
> + case COUNTER_OWNER_TYPE_DEVICE:
> + return a->data.device_string_read(counter, buf, PAGE_SIZE);
> + case COUNTER_OWNER_TYPE_SIGNAL:
> + return a->data.signal_string_read(counter, a->owner, buf,
> + PAGE_SIZE);
> + case COUNTER_OWNER_TYPE_COUNT:
> + return a->data.count_string_read(counter, a->owner, buf,
> + PAGE_SIZE);
> + }
> +
> + return -EINVAL;
> +}
> +
> +static ssize_t counter_data_string_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + const struct counter_attribute *const a = to_counter_attribute(attr);
> + struct counter_device *const counter = dev_get_drvdata(dev);
> +
> + switch (a->type) {
> + case COUNTER_OWNER_TYPE_DEVICE:
> + return a->data.device_string_write(counter, buf, len);
> + case COUNTER_OWNER_TYPE_SIGNAL:
> + return a->data.signal_string_write(counter, a->owner, buf, len);
> + case COUNTER_OWNER_TYPE_COUNT:
> + return a->data.count_string_write(counter, a->owner, buf, len);
> + }
> +
> + return -EINVAL;
> +}
> +
> +static ssize_t items_available_show(const u8 *const items,
> + const size_t num_items,
> + const char *const string_array[], char *buf)
> +{
> + size_t len = 0;
> + size_t index;
> +
> + for (index = 0; index < num_items; index++)
> + len += sprintf(buf + len, "%s\n", string_array[items[index]]);
> +
> + return len;
> +}
> +
> +static ssize_t counter_data_available_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + const struct counter_attribute *const a = to_counter_attribute(attr);
> + const struct counter_count *const count = a->owner;
> + const struct counter_synapse *const synapse = a->data.priv;
> + const struct counter_available *const available = a->data.priv;
> +
> + switch (a->data.type) {
> + case COUNTER_DATA_TYPE_COUNT_FUNCTION:
> + return items_available_show(count->functions_list,
> + count->num_functions,
> + counter_count_function_str, buf);
> + case COUNTER_DATA_TYPE_SYNAPSE_ACTION:
> + return items_available_show(synapse->actions_list,
> + synapse->num_actions,
> + counter_synapse_action_str, buf);
> + case COUNTER_DATA_TYPE_COUNT_MODE:
> + return items_available_show(available->items,
> + available->num_items,
> + counter_count_mode_str, buf);
> + }
> +
> + return -EINVAL;
> +}
> +
> +struct counter_dynamic_name {
> + struct list_head l;
> + const char *name;
> +};
> +
> +static int counter_available_attribute_create(
> + struct counter_attribute_group *const group,
> + struct list_head *const names, const struct counter_data *const data,
> + void *const owner)
> +{
> + struct counter_attribute *counter_attr;
> + struct device_attribute *dev_attr;
> + struct counter_dynamic_name *dyn_name;
> +
> + /* Allocate Counter attribute */
> + counter_attr = kzalloc(sizeof(*counter_attr), GFP_KERNEL);
> + if (!counter_attr)
> + return -ENOMEM;
> + list_add(&counter_attr->l, &group->attr_list);
> + group->num_attr++;
> +
> + /* Configure Counter attribute */
> + counter_attr->data = *data;
> + counter_attr->owner = owner;
> +
> + /* Initialize sysfs attribute */
> + dev_attr = &counter_attr->dev_attr;
> + sysfs_attr_init(&dev_attr->attr);
> +
> + /* Generate dynamic name list item */
> + dyn_name = kmalloc(sizeof(*dyn_name), GFP_KERNEL);
> + if (!dyn_name)
> + return -ENOMEM;
> + list_add(&dyn_name->l, names);
> +
> + /* Generate available attribute name */
> + dyn_name->name = kasprintf(GFP_KERNEL, "%s_available", data->name);
> + if (!dyn_name->name)
> + return -ENOMEM;
> +
> + /* Configure device attribute */
> + dev_attr->attr.name = dyn_name->name;
> + dev_attr->attr.mode = 0444;
> + dev_attr->show = counter_data_available_show;
> +
> + return 0;
> +}
> +
> +static int counter_attribute_create(struct counter_attribute_group *const group,
> + struct list_head *const names,
> + const struct counter_data *const data,
> + const enum counter_owner_type type,
> + void *const owner)
> +{
> + struct counter_attribute *counter_attr;
> + struct device_attribute *dev_attr;
> +
> + /* Allocate Counter attribute */
> + counter_attr = kzalloc(sizeof(*counter_attr), GFP_KERNEL);
> + if (!counter_attr)
> + return -ENOMEM;
> + list_add(&counter_attr->l, &group->attr_list);
> + group->num_attr++;
> +
> + /* Configure Counter attribute */
> + counter_attr->data = *data;
> + counter_attr->type = type;
> + counter_attr->owner = owner;
> +
> + /* Configure device attribute */
> + dev_attr = &counter_attr->dev_attr;
> + sysfs_attr_init(&dev_attr->attr);
> + dev_attr->attr.name = data->name;
> + switch (data->type) {
> + case COUNTER_DATA_TYPE_U8:
> + case COUNTER_DATA_TYPE_BOOL:
> + case COUNTER_DATA_TYPE_SIGNAL:
> + case COUNTER_DATA_TYPE_COUNT_FUNCTION:
> + case COUNTER_DATA_TYPE_SYNAPSE_ACTION:
> + case COUNTER_DATA_TYPE_COUNT_DIRECTION:
> + case COUNTER_DATA_TYPE_COUNT_MODE:
> + if (data->device_u8_read) {
> + dev_attr->attr.mode |= 0444;
> + dev_attr->show = counter_data_u8_show;
> + }
> + if (data->device_u8_write) {
> + dev_attr->attr.mode |= 0200;
> + dev_attr->store = counter_data_u8_store;
> + }
> + break;
> + case COUNTER_DATA_TYPE_U64:
> + if (data->device_u64_read) {
> + dev_attr->attr.mode |= 0444;
> + dev_attr->show = counter_data_u64_show;
> + }
> + if (data->device_u64_write) {
> + dev_attr->attr.mode |= 0200;
> + dev_attr->store = counter_data_u64_store;
> + }
> + break;
> + case COUNTER_DATA_TYPE_STRING:
> + if (data->device_string_read) {
> + dev_attr->attr.mode |= 0444;
> + dev_attr->show = counter_data_string_show;
> + }
> + if (data->device_string_write) {
> + dev_attr->attr.mode |= 0200;
> + dev_attr->store = counter_data_string_store;
> + }
> + break;
> + }
> +
> + switch (data->type) {
> + case COUNTER_DATA_TYPE_COUNT_FUNCTION:
> + case COUNTER_DATA_TYPE_SYNAPSE_ACTION:
> + case COUNTER_DATA_TYPE_COUNT_MODE:
> + return counter_available_attribute_create(group, names, data,
> + owner);
> + }
> +
> + return 0;
> +}
> +
> +static struct counter_data counter_signal_data = {
> + .type = COUNTER_DATA_TYPE_SIGNAL,
> + .name = "signal",
> +};
> +
> +static struct counter_data counter_name_data =
> + COUNTER_DATA_DEVICE_STRING("name", NULL, NULL);
> +
> +static ssize_t counter_signal_name_read(struct counter_device *counter,
> + struct counter_signal *signal,
> + char *buf, size_t size)
> +{
> + return snprintf(buf, size, "%s\n", signal->name);
> +}
> +
> +static int counter_signal_attributes_create(
> + struct counter_attribute_group *const group,
> + struct counter_device *const counter,
> + struct counter_signal *const signal)
> +{
> + struct list_head *const names = &counter->dynamic_names_list;
> + const enum counter_owner_type type = COUNTER_OWNER_TYPE_SIGNAL;
> + int err;
> + struct counter_data data;
> + size_t i;
> + const struct counter_data *ext;
> +
> + /* Create main Signal attribute */
> + data = counter_signal_data;
> + data.signal_u8_read = counter->signal_read;
> + err = counter_attribute_create(group, names, &data, type, signal);
> + if (err)
> + return err;
> +
> + /* Create Signal name attribute */
> + data = counter_name_data;
> + data.signal_string_read = counter_signal_name_read;
> + err = counter_attribute_create(group, names, &data, type, signal);
> + if (err)
> + return err;
> +
> + /* Create an attribute for each extension */
> + for (i = 0; i < signal->num_ext; i++) {
> + ext = signal->ext + i;
> + err = counter_attribute_create(group, names, ext, type, signal);
> + if (err)
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +static int counter_signals_register(
> + struct counter_attribute_group *const groups_list,
> + struct counter_device *const counter)
> +{
> + size_t i;
> + struct counter_signal *signal;
> + const char *name;
> + int err;
> +
> + /* Register each Signal */
> + for (i = 0; i < counter->num_signals; i++) {
> + signal = counter->signals + i;
> +
> + /* Generate Signal attribute directory name */
> + name = kasprintf(GFP_KERNEL, "signal%d", signal->id);
> + if (!name)
> + return -ENOMEM;
> + groups_list[i].attr_group.name = name;
> +
> + /* Create all attributes associated with Signal */
> + err = counter_signal_attributes_create(groups_list + i, counter,
> + signal);
> + if (err)
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +static int counter_synapses_register(
> + struct counter_attribute_group *const group,
> + struct counter_device *const counter, struct counter_count *const count)
> +{
> + struct list_head *const names = &counter->dynamic_names_list;
> + const enum counter_owner_type type = COUNTER_OWNER_TYPE_COUNT;
> + size_t i;
> + struct counter_synapse *synapse;
> + int id;
> + struct counter_dynamic_name *dyn_name;
> + struct counter_data data;
> + int err;
> +
> + /* Register each Synapse */
> + for (i = 0; i < count->num_synapses; i++) {
> + synapse = count->synapses + i;
> + id = synapse->signal->id;
> +
> + /* Generate dynamic name list item */
> + dyn_name = kmalloc(sizeof(*dyn_name), GFP_KERNEL);
> + if (!dyn_name)
> + return -ENOMEM;
> + list_add(&dyn_name->l, names);
> +
> + /* Generate Synapse action name */
> + dyn_name->name = kasprintf(GFP_KERNEL, "signal%d_action", id);
> + if (!dyn_name->name)
> + return -ENOMEM;
> +
> + /* Create action attribute */
> + data.type = COUNTER_DATA_TYPE_SYNAPSE_ACTION;
> + data.name = dyn_name->name;
> + data.action_read = counter->action_read;
> + data.action_write = counter->action_write;
> + data.priv = synapse;
> + err = counter_attribute_create(group, names, &data, type,
> + count);
> + if (err)
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +static struct counter_data counter_count_data =
> + COUNTER_DATA_COUNT_U64("count", NULL, NULL);
> +
> +static ssize_t counter_count_name_read(struct counter_device *counter,
> + struct counter_count *count, char *buf,
> + size_t size)
> +{
> + return snprintf(buf, size, "%s\n", count->name);
> +}
> +
> +static struct counter_data counter_count_function_data = {
> + .type = COUNTER_DATA_TYPE_COUNT_FUNCTION,
> + .name = "function",
> +};
> +
> +static int counter_count_attributes_create(
> + struct counter_attribute_group *const group,
> + struct counter_device *const counter,
> + struct counter_count *const count)
> +{
> + struct list_head *const names = &counter->dynamic_names_list;
> + const enum counter_owner_type type = COUNTER_OWNER_TYPE_COUNT;
> + int err;
> + struct counter_data data;
> + size_t i;
> + const struct counter_data *ext;
> +
> + /* Create main Count attribute */
> + data = counter_count_data;
> + data.count_u64_read = counter->count_read;
> + data.count_u64_write = counter->count_write;
> + err = counter_attribute_create(group, names, &data, type, count);
> + if (err)
> + return err;
> +
> + /* Create Count name attribute */
> + data = counter_name_data;
> + data.count_string_read = counter_count_name_read;
> + err = counter_attribute_create(group, names, &data, type, count);
> + if (err)
> + return err;
> +
> + /* Create Count function attribute */
> + data = counter_count_function_data;
> + data.count_u8_read = counter->function_read;
> + data.count_u8_write = counter->function_write;
> + err = counter_attribute_create(group, names, &data, type, count);
> + if (err)
> + return err;
> +
> + /* Create an attribute for each extension */
> + for (i = 0; i < count->num_ext; i++) {
> + ext = count->ext + i;
> + err = counter_attribute_create(group, names, ext, type, count);
> + if (err)
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +static int counter_counts_register(
> + struct counter_attribute_group *const groups_list,
> + struct counter_device *const counter)
> +{
> + size_t i;
> + struct counter_count *count;
> + const char *name;
> + int err;
> +
> + /* Register each Count */
> + for (i = 0; i < counter->num_counts; i++) {
> + count = counter->counts + i;
> +
> + /* Generate Count attribute directory name */
> + name = kasprintf(GFP_KERNEL, "count%d", count->id);
> + if (!name)
> + return -ENOMEM;
> + groups_list[i].attr_group.name = name;
> +
> + /* Register the Synapses associated with each Count */
> + err = counter_synapses_register(groups_list + i, counter,
> + count);
> + if (err)
> + return err;
> +
> + /* Create all attributes associated with Count */
> + err = counter_count_attributes_create(groups_list + i, counter,
> + count);
> + if (err)
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +static ssize_t counter_name_read(struct counter_device *counter, char *buf,
> + size_t size)
> +{
> + return snprintf(buf, size, "%s\n", counter->name);
> +}
> +
> +static int counter_num_signals_read(struct counter_device *counter, u8 *val)
> +{
> + *val = counter->num_signals;
> + return 0;
> +}
> +
> +static int counter_num_counts_read(struct counter_device *counter, u8 *val)
> +{
> + *val = counter->num_counts;
> + return 0;
> +}
> +
> +static struct counter_data counter_num_signals_data =
> + COUNTER_DATA_DEVICE_U8("num_signals", counter_num_signals_read, NULL);
> +
> +static struct counter_data counter_num_counts_data =
> + COUNTER_DATA_DEVICE_U8("num_counts", counter_num_counts_read, NULL);
> +
> +static void counter_groups_list_free(struct counter_device *const counter)
> +{
> + struct counter_attribute_group *group;
> + struct counter_attribute *p, *n;
> +
> + /* Loop through all attribute groups (signals, counts, device, etc.) */
> + while (counter->num_groups--) {
> + group = counter->groups_list + counter->num_groups;
> +
> + /* Free all attribute group and associated attributes memory */
> + kfree(group->attr_group.name);
> + kfree(group->attr_group.attrs);
> +
> + /* Free attribute list */
> + list_for_each_entry_safe(p, n, &group->attr_list, l)
> + kfree(p);
> + }
> +
> + kfree(counter->groups_list);
> +}
> +
> +static int counter_device_register(struct counter_attribute_group *group,
> + struct counter_device *const counter)
> +{
> + struct list_head *const names = &counter->dynamic_names_list;
> + const enum counter_owner_type type = COUNTER_OWNER_TYPE_DEVICE;
> + struct counter_data data;
> + int err;
> + size_t i;
> + const struct counter_data *ext;
> +
> + /* Register Signals */
> + err = counter_signals_register(group, counter);
> + if (err)
> + goto err_free_groups_list;
> + group += counter->num_signals;
> +
> + /* Register Counts and respective Synapses */
> + err = counter_counts_register(group, counter);
> + if (err)
> + goto err_free_groups_list;
> + group += counter->num_counts;
> +
> + /* Create name attribute */
> + data = counter_name_data;
> + data.device_string_read = counter_name_read;
> + err = counter_attribute_create(group, names, &data, type, NULL);
> + if (err)
> + goto err_free_groups_list;
> +
> + /* Create num_signals attribute */
> + data = counter_num_signals_data;
> + err = counter_attribute_create(group, names, &data, type, NULL);
> + if (err)
> + goto err_free_groups_list;
> +
> + /* Create num_counts attribute */
> + data = counter_num_counts_data;
> + err = counter_attribute_create(group, names, &data, type, NULL);
> + if (err)
> + goto err_free_groups_list;
> +
> + /* Create an attribute for each extension */
> + for (i = 0; i < counter->num_ext; i++) {
> + ext = counter->ext + i;
> + err = counter_attribute_create(group, names, ext, type, NULL);
> + if (err)
> + goto err_free_groups_list;
> + }
> +
> + return 0;
> +
> +err_free_groups_list:
> + counter_groups_list_free(counter);
> + return err;
> +}
> +
> +static int counter_groups_list_prepare(struct counter_device *const counter)
> +{
> + const size_t num_grps = counter->num_signals + counter->num_counts + 1;
> + struct counter_attribute_group *groups_list;
> + size_t i;
> +
> + /* Allocate space for attribute groups (signals, counts, and ext) */
> + groups_list = kcalloc(num_grps, sizeof(*groups_list), GFP_KERNEL);
> + if (!groups_list)
> + return -ENOMEM;
> +
> + /* Store groups_list in counter structure */
> + counter->groups_list = groups_list;
> + counter->num_groups = num_grps;
> +
> + /* Initialize attribute lists */
> + for (i = 0; i < num_grps; i++)
> + INIT_LIST_HEAD(&groups_list[i].attr_list);
> +
> + /* Register Counter device attributes */
> + return counter_device_register(groups_list, counter);
> +}
> +
> +static int counter_groups_prepare(struct counter_device *const counter)
> +{
> + size_t i, j;
> + struct counter_attribute_group *group;
> + struct attribute **attrs;
> + int err;
> + struct counter_attribute *p;
> +
> + /* Allocate attribute groups for association with device */
> + counter->groups = kcalloc(counter->num_groups + 1,
> + sizeof(*counter->groups), GFP_KERNEL);
> + if (!counter->groups)
> + return -ENOMEM;
> +
> + /* Prepare each group of attributes for association */
> + for (i = 0; i < counter->num_groups; i++) {
> + group = counter->groups_list + i;
> +
> + /* Allocate space for attribute pointers */
> + attrs = kcalloc(group->num_attr + 1, sizeof(*attrs),
> + GFP_KERNEL);
> + if (!attrs) {
> + err = -ENOMEM;
> + goto err_free_groups;
> + }
> + group->attr_group.attrs = attrs;
> +
> + /* Add attribute pointers to attribute group */
> + j = 0;
> + list_for_each_entry(p, &group->attr_list, l)
> + attrs[j++] = &p->dev_attr.attr;
> +
> + /* Group attributes in attribute group */
> + counter->groups[i] = &group->attr_group;
> + }
> + /* Associate attributes with device */
> + counter->dev.groups = counter->groups;
> +
> + return 0;
> +
> +err_free_groups:
> + kfree(counter->groups);
> + return err;
> +}
> +
> +static void counter_dynamic_names_free(struct list_head *const names)
> +{
> + struct counter_dynamic_name *p, *n;
> +
> + list_for_each_entry_safe(p, n, names, l) {
> + kfree(p->name);
> + kfree(p);
> + }
> +}
> +
> +int counter_sysfs_add(struct counter_device *const counter)
> +{
> + int err;
> +
> + /* Initialize Synapse names list */
> + INIT_LIST_HEAD(&counter->dynamic_names_list);
> +
> + /* Prepare device attributes */
> + err = counter_groups_list_prepare(counter);
> + if (err)
> + goto err_free_names;
> +
> + /* Organize device attributes to groups and match to device */
> + err = counter_groups_prepare(counter);
> + if (err)
> + goto err_free_groups_list;
> +
> + return 0;
> +
> +err_free_groups_list:
> + counter_groups_list_free(counter);
> +err_free_names:
> + counter_dynamic_names_free(&counter->dynamic_names_list);
> + return err;
> +}
> +
> +void counter_sysfs_free(struct counter_device *const counter)
> +{
> + kfree(counter->groups);
> + counter_groups_list_free(counter);
> + counter_dynamic_names_free(&counter->dynamic_names_list);
> +}
> diff --git a/drivers/counter/counter-sysfs.h b/drivers/counter/counter-sysfs.h
> new file mode 100644
> index 000000000000..00e7cd6ea083
> --- /dev/null
> +++ b/drivers/counter/counter-sysfs.h
> @@ -0,0 +1,14 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Counter sysfs interface
> + * Copyright (C) 2020 William Breathitt Gray
> + */
> +#ifndef _COUNTER_SYSFS_H_
> +#define _COUNTER_SYSFS_H_
> +
> +#include <linux/counter.h>
> +
> +int counter_sysfs_add(struct counter_device *const counter);
> +void counter_sysfs_free(struct counter_device *const counter);
> +
> +#endif /* _COUNTER_SYSFS_H_ */
> diff --git a/drivers/counter/counter.c b/drivers/counter/counter.c
> deleted file mode 100644
> index 6a683d086008..000000000000
> --- a/drivers/counter/counter.c
> +++ /dev/null
> @@ -1,1496 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -/*
> - * Generic Counter interface
> - * Copyright (C) 2018 William Breathitt Gray
> - */
> -#include <linux/counter.h>
> -#include <linux/device.h>
> -#include <linux/err.h>
> -#include <linux/export.h>
> -#include <linux/fs.h>
> -#include <linux/gfp.h>
> -#include <linux/idr.h>
> -#include <linux/init.h>
> -#include <linux/kernel.h>
> -#include <linux/list.h>
> -#include <linux/module.h>
> -#include <linux/printk.h>
> -#include <linux/slab.h>
> -#include <linux/string.h>
> -#include <linux/sysfs.h>
> -#include <linux/types.h>
> -
> -const char *const counter_count_direction_str[2] = {
> - [COUNTER_COUNT_DIRECTION_FORWARD] = "forward",
> - [COUNTER_COUNT_DIRECTION_BACKWARD] = "backward"
> -};
> -EXPORT_SYMBOL_GPL(counter_count_direction_str);
> -
> -const char *const counter_count_mode_str[4] = {
> - [COUNTER_COUNT_MODE_NORMAL] = "normal",
> - [COUNTER_COUNT_MODE_RANGE_LIMIT] = "range limit",
> - [COUNTER_COUNT_MODE_NON_RECYCLE] = "non-recycle",
> - [COUNTER_COUNT_MODE_MODULO_N] = "modulo-n"
> -};
> -EXPORT_SYMBOL_GPL(counter_count_mode_str);
> -
> -ssize_t counter_signal_enum_read(struct counter_device *counter,
> - struct counter_signal *signal, void *priv,
> - char *buf)
> -{
> - const struct counter_signal_enum_ext *const e = priv;
> - int err;
> - size_t index;
> -
> - if (!e->get)
> - return -EINVAL;
> -
> - err = e->get(counter, signal, &index);
> - if (err)
> - return err;
> -
> - if (index >= e->num_items)
> - return -EINVAL;
> -
> - return sprintf(buf, "%s\n", e->items[index]);
> -}
> -EXPORT_SYMBOL_GPL(counter_signal_enum_read);
> -
> -ssize_t counter_signal_enum_write(struct counter_device *counter,
> - struct counter_signal *signal, void *priv,
> - const char *buf, size_t len)
> -{
> - const struct counter_signal_enum_ext *const e = priv;
> - ssize_t index;
> - int err;
> -
> - if (!e->set)
> - return -EINVAL;
> -
> - index = __sysfs_match_string(e->items, e->num_items, buf);
> - if (index < 0)
> - return index;
> -
> - err = e->set(counter, signal, index);
> - if (err)
> - return err;
> -
> - return len;
> -}
> -EXPORT_SYMBOL_GPL(counter_signal_enum_write);
> -
> -ssize_t counter_signal_enum_available_read(struct counter_device *counter,
> - struct counter_signal *signal,
> - void *priv, char *buf)
> -{
> - const struct counter_signal_enum_ext *const e = priv;
> - size_t i;
> - size_t len = 0;
> -
> - if (!e->num_items)
> - return 0;
> -
> - for (i = 0; i < e->num_items; i++)
> - len += sprintf(buf + len, "%s\n", e->items[i]);
> -
> - return len;
> -}
> -EXPORT_SYMBOL_GPL(counter_signal_enum_available_read);
> -
> -ssize_t counter_count_enum_read(struct counter_device *counter,
> - struct counter_count *count, void *priv,
> - char *buf)
> -{
> - const struct counter_count_enum_ext *const e = priv;
> - int err;
> - size_t index;
> -
> - if (!e->get)
> - return -EINVAL;
> -
> - err = e->get(counter, count, &index);
> - if (err)
> - return err;
> -
> - if (index >= e->num_items)
> - return -EINVAL;
> -
> - return sprintf(buf, "%s\n", e->items[index]);
> -}
> -EXPORT_SYMBOL_GPL(counter_count_enum_read);
> -
> -ssize_t counter_count_enum_write(struct counter_device *counter,
> - struct counter_count *count, void *priv,
> - const char *buf, size_t len)
> -{
> - const struct counter_count_enum_ext *const e = priv;
> - ssize_t index;
> - int err;
> -
> - if (!e->set)
> - return -EINVAL;
> -
> - index = __sysfs_match_string(e->items, e->num_items, buf);
> - if (index < 0)
> - return index;
> -
> - err = e->set(counter, count, index);
> - if (err)
> - return err;
> -
> - return len;
> -}
> -EXPORT_SYMBOL_GPL(counter_count_enum_write);
> -
> -ssize_t counter_count_enum_available_read(struct counter_device *counter,
> - struct counter_count *count,
> - void *priv, char *buf)
> -{
> - const struct counter_count_enum_ext *const e = priv;
> - size_t i;
> - size_t len = 0;
> -
> - if (!e->num_items)
> - return 0;
> -
> - for (i = 0; i < e->num_items; i++)
> - len += sprintf(buf + len, "%s\n", e->items[i]);
> -
> - return len;
> -}
> -EXPORT_SYMBOL_GPL(counter_count_enum_available_read);
> -
> -ssize_t counter_device_enum_read(struct counter_device *counter, void *priv,
> - char *buf)
> -{
> - const struct counter_device_enum_ext *const e = priv;
> - int err;
> - size_t index;
> -
> - if (!e->get)
> - return -EINVAL;
> -
> - err = e->get(counter, &index);
> - if (err)
> - return err;
> -
> - if (index >= e->num_items)
> - return -EINVAL;
> -
> - return sprintf(buf, "%s\n", e->items[index]);
> -}
> -EXPORT_SYMBOL_GPL(counter_device_enum_read);
> -
> -ssize_t counter_device_enum_write(struct counter_device *counter, void *priv,
> - const char *buf, size_t len)
> -{
> - const struct counter_device_enum_ext *const e = priv;
> - ssize_t index;
> - int err;
> -
> - if (!e->set)
> - return -EINVAL;
> -
> - index = __sysfs_match_string(e->items, e->num_items, buf);
> - if (index < 0)
> - return index;
> -
> - err = e->set(counter, index);
> - if (err)
> - return err;
> -
> - return len;
> -}
> -EXPORT_SYMBOL_GPL(counter_device_enum_write);
> -
> -ssize_t counter_device_enum_available_read(struct counter_device *counter,
> - void *priv, char *buf)
> -{
> - const struct counter_device_enum_ext *const e = priv;
> - size_t i;
> - size_t len = 0;
> -
> - if (!e->num_items)
> - return 0;
> -
> - for (i = 0; i < e->num_items; i++)
> - len += sprintf(buf + len, "%s\n", e->items[i]);
> -
> - return len;
> -}
> -EXPORT_SYMBOL_GPL(counter_device_enum_available_read);
> -
> -struct counter_attr_parm {
> - struct counter_device_attr_group *group;
> - const char *prefix;
> - const char *name;
> - ssize_t (*show)(struct device *dev, struct device_attribute *attr,
> - char *buf);
> - ssize_t (*store)(struct device *dev, struct device_attribute *attr,
> - const char *buf, size_t len);
> - void *component;
> -};
> -
> -struct counter_device_attr {
> - struct device_attribute dev_attr;
> - struct list_head l;
> - void *component;
> -};
> -
> -static int counter_attribute_create(const struct counter_attr_parm *const parm)
> -{
> - struct counter_device_attr *counter_attr;
> - struct device_attribute *dev_attr;
> - int err;
> - struct list_head *const attr_list = &parm->group->attr_list;
> -
> - /* Allocate a Counter device attribute */
> - counter_attr = kzalloc(sizeof(*counter_attr), GFP_KERNEL);
> - if (!counter_attr)
> - return -ENOMEM;
> - dev_attr = &counter_attr->dev_attr;
> -
> - sysfs_attr_init(&dev_attr->attr);
> -
> - /* Configure device attribute */
> - dev_attr->attr.name = kasprintf(GFP_KERNEL, "%s%s", parm->prefix,
> - parm->name);
> - if (!dev_attr->attr.name) {
> - err = -ENOMEM;
> - goto err_free_counter_attr;
> - }
> - if (parm->show) {
> - dev_attr->attr.mode |= 0444;
> - dev_attr->show = parm->show;
> - }
> - if (parm->store) {
> - dev_attr->attr.mode |= 0200;
> - dev_attr->store = parm->store;
> - }
> -
> - /* Store associated Counter component with attribute */
> - counter_attr->component = parm->component;
> -
> - /* Keep track of the attribute for later cleanup */
> - list_add(&counter_attr->l, attr_list);
> - parm->group->num_attr++;
> -
> - return 0;
> -
> -err_free_counter_attr:
> - kfree(counter_attr);
> - return err;
> -}
> -
> -#define to_counter_attr(_dev_attr) \
> - container_of(_dev_attr, struct counter_device_attr, dev_attr)
> -
> -struct counter_signal_unit {
> - struct counter_signal *signal;
> -};
> -
> -static const char *const counter_signal_value_str[] = {
> - [COUNTER_SIGNAL_LOW] = "low",
> - [COUNTER_SIGNAL_HIGH] = "high"
> -};
> -
> -static ssize_t counter_signal_show(struct device *dev,
> - struct device_attribute *attr, char *buf)
> -{
> - struct counter_device *const counter = dev_get_drvdata(dev);
> - const struct counter_device_attr *const devattr = to_counter_attr(attr);
> - const struct counter_signal_unit *const component = devattr->component;
> - struct counter_signal *const signal = component->signal;
> - int err;
> - enum counter_signal_value val;
> -
> - err = counter->ops->signal_read(counter, signal, &val);
> - if (err)
> - return err;
> -
> - return sprintf(buf, "%s\n", counter_signal_value_str[val]);
> -}
> -
> -struct counter_name_unit {
> - const char *name;
> -};
> -
> -static ssize_t counter_device_attr_name_show(struct device *dev,
> - struct device_attribute *attr,
> - char *buf)
> -{
> - const struct counter_name_unit *const comp = to_counter_attr(attr)->component;
> -
> - return sprintf(buf, "%s\n", comp->name);
> -}
> -
> -static int counter_name_attribute_create(
> - struct counter_device_attr_group *const group,
> - const char *const name)
> -{
> - struct counter_name_unit *name_comp;
> - struct counter_attr_parm parm;
> - int err;
> -
> - /* Skip if no name */
> - if (!name)
> - return 0;
> -
> - /* Allocate name attribute component */
> - name_comp = kmalloc(sizeof(*name_comp), GFP_KERNEL);
> - if (!name_comp)
> - return -ENOMEM;
> - name_comp->name = name;
> -
> - /* Allocate Signal name attribute */
> - parm.group = group;
> - parm.prefix = "";
> - parm.name = "name";
> - parm.show = counter_device_attr_name_show;
> - parm.store = NULL;
> - parm.component = name_comp;
> - err = counter_attribute_create(&parm);
> - if (err)
> - goto err_free_name_comp;
> -
> - return 0;
> -
> -err_free_name_comp:
> - kfree(name_comp);
> - return err;
> -}
> -
> -struct counter_signal_ext_unit {
> - struct counter_signal *signal;
> - const struct counter_signal_ext *ext;
> -};
> -
> -static ssize_t counter_signal_ext_show(struct device *dev,
> - struct device_attribute *attr, char *buf)
> -{
> - const struct counter_device_attr *const devattr = to_counter_attr(attr);
> - const struct counter_signal_ext_unit *const comp = devattr->component;
> - const struct counter_signal_ext *const ext = comp->ext;
> -
> - return ext->read(dev_get_drvdata(dev), comp->signal, ext->priv, buf);
> -}
> -
> -static ssize_t counter_signal_ext_store(struct device *dev,
> - struct device_attribute *attr,
> - const char *buf, size_t len)
> -{
> - const struct counter_device_attr *const devattr = to_counter_attr(attr);
> - const struct counter_signal_ext_unit *const comp = devattr->component;
> - const struct counter_signal_ext *const ext = comp->ext;
> -
> - return ext->write(dev_get_drvdata(dev), comp->signal, ext->priv, buf,
> - len);
> -}
> -
> -static void counter_device_attr_list_free(struct list_head *attr_list)
> -{
> - struct counter_device_attr *p, *n;
> -
> - list_for_each_entry_safe(p, n, attr_list, l) {
> - /* free attribute name and associated component memory */
> - kfree(p->dev_attr.attr.name);
> - kfree(p->component);
> - list_del(&p->l);
> - kfree(p);
> - }
> -}
> -
> -static int counter_signal_ext_register(
> - struct counter_device_attr_group *const group,
> - struct counter_signal *const signal)
> -{
> - const size_t num_ext = signal->num_ext;
> - size_t i;
> - const struct counter_signal_ext *ext;
> - struct counter_signal_ext_unit *signal_ext_comp;
> - struct counter_attr_parm parm;
> - int err;
> -
> - /* Create an attribute for each extension */
> - for (i = 0 ; i < num_ext; i++) {
> - ext = signal->ext + i;
> -
> - /* Allocate signal_ext attribute component */
> - signal_ext_comp = kmalloc(sizeof(*signal_ext_comp), GFP_KERNEL);
> - if (!signal_ext_comp) {
> - err = -ENOMEM;
> - goto err_free_attr_list;
> - }
> - signal_ext_comp->signal = signal;
> - signal_ext_comp->ext = ext;
> -
> - /* Allocate a Counter device attribute */
> - parm.group = group;
> - parm.prefix = "";
> - parm.name = ext->name;
> - parm.show = (ext->read) ? counter_signal_ext_show : NULL;
> - parm.store = (ext->write) ? counter_signal_ext_store : NULL;
> - parm.component = signal_ext_comp;
> - err = counter_attribute_create(&parm);
> - if (err) {
> - kfree(signal_ext_comp);
> - goto err_free_attr_list;
> - }
> - }
> -
> - return 0;
> -
> -err_free_attr_list:
> - counter_device_attr_list_free(&group->attr_list);
> - return err;
> -}
> -
> -static int counter_signal_attributes_create(
> - struct counter_device_attr_group *const group,
> - const struct counter_device *const counter,
> - struct counter_signal *const signal)
> -{
> - struct counter_signal_unit *signal_comp;
> - struct counter_attr_parm parm;
> - int err;
> -
> - /* Allocate Signal attribute component */
> - signal_comp = kmalloc(sizeof(*signal_comp), GFP_KERNEL);
> - if (!signal_comp)
> - return -ENOMEM;
> - signal_comp->signal = signal;
> -
> - /* Create main Signal attribute */
> - parm.group = group;
> - parm.prefix = "";
> - parm.name = "signal";
> - parm.show = (counter->ops->signal_read) ? counter_signal_show : NULL;
> - parm.store = NULL;
> - parm.component = signal_comp;
> - err = counter_attribute_create(&parm);
> - if (err) {
> - kfree(signal_comp);
> - return err;
> - }
> -
> - /* Create Signal name attribute */
> - err = counter_name_attribute_create(group, signal->name);
> - if (err)
> - goto err_free_attr_list;
> -
> - /* Register Signal extension attributes */
> - err = counter_signal_ext_register(group, signal);
> - if (err)
> - goto err_free_attr_list;
> -
> - return 0;
> -
> -err_free_attr_list:
> - counter_device_attr_list_free(&group->attr_list);
> - return err;
> -}
> -
> -static int counter_signals_register(
> - struct counter_device_attr_group *const groups_list,
> - const struct counter_device *const counter)
> -{
> - const size_t num_signals = counter->num_signals;
> - size_t i;
> - struct counter_signal *signal;
> - const char *name;
> - int err;
> -
> - /* Register each Signal */
> - for (i = 0; i < num_signals; i++) {
> - signal = counter->signals + i;
> -
> - /* Generate Signal attribute directory name */
> - name = kasprintf(GFP_KERNEL, "signal%d", signal->id);
> - if (!name) {
> - err = -ENOMEM;
> - goto err_free_attr_groups;
> - }
> - groups_list[i].attr_group.name = name;
> -
> - /* Create all attributes associated with Signal */
> - err = counter_signal_attributes_create(groups_list + i, counter,
> - signal);
> - if (err)
> - goto err_free_attr_groups;
> - }
> -
> - return 0;
> -
> -err_free_attr_groups:
> - do {
> - kfree(groups_list[i].attr_group.name);
> - counter_device_attr_list_free(&groups_list[i].attr_list);
> - } while (i--);
> - return err;
> -}
> -
> -static const char *const counter_synapse_action_str[] = {
> - [COUNTER_SYNAPSE_ACTION_NONE] = "none",
> - [COUNTER_SYNAPSE_ACTION_RISING_EDGE] = "rising edge",
> - [COUNTER_SYNAPSE_ACTION_FALLING_EDGE] = "falling edge",
> - [COUNTER_SYNAPSE_ACTION_BOTH_EDGES] = "both edges"
> -};
> -
> -struct counter_action_unit {
> - struct counter_synapse *synapse;
> - struct counter_count *count;
> -};
> -
> -static ssize_t counter_action_show(struct device *dev,
> - struct device_attribute *attr, char *buf)
> -{
> - const struct counter_device_attr *const devattr = to_counter_attr(attr);
> - int err;
> - struct counter_device *const counter = dev_get_drvdata(dev);
> - const struct counter_action_unit *const component = devattr->component;
> - struct counter_count *const count = component->count;
> - struct counter_synapse *const synapse = component->synapse;
> - size_t action_index;
> - enum counter_synapse_action action;
> -
> - err = counter->ops->action_get(counter, count, synapse, &action_index);
> - if (err)
> - return err;
> -
> - synapse->action = action_index;
> -
> - action = synapse->actions_list[action_index];
> - return sprintf(buf, "%s\n", counter_synapse_action_str[action]);
> -}
> -
> -static ssize_t counter_action_store(struct device *dev,
> - struct device_attribute *attr,
> - const char *buf, size_t len)
> -{
> - const struct counter_device_attr *const devattr = to_counter_attr(attr);
> - const struct counter_action_unit *const component = devattr->component;
> - struct counter_synapse *const synapse = component->synapse;
> - size_t action_index;
> - const size_t num_actions = synapse->num_actions;
> - enum counter_synapse_action action;
> - int err;
> - struct counter_device *const counter = dev_get_drvdata(dev);
> - struct counter_count *const count = component->count;
> -
> - /* Find requested action mode */
> - for (action_index = 0; action_index < num_actions; action_index++) {
> - action = synapse->actions_list[action_index];
> - if (sysfs_streq(buf, counter_synapse_action_str[action]))
> - break;
> - }
> - /* If requested action mode not found */
> - if (action_index >= num_actions)
> - return -EINVAL;
> -
> - err = counter->ops->action_set(counter, count, synapse, action_index);
> - if (err)
> - return err;
> -
> - synapse->action = action_index;
> -
> - return len;
> -}
> -
> -struct counter_action_avail_unit {
> - const enum counter_synapse_action *actions_list;
> - size_t num_actions;
> -};
> -
> -static ssize_t counter_synapse_action_available_show(struct device *dev,
> - struct device_attribute *attr, char *buf)
> -{
> - const struct counter_device_attr *const devattr = to_counter_attr(attr);
> - const struct counter_action_avail_unit *const component = devattr->component;
> - size_t i;
> - enum counter_synapse_action action;
> - ssize_t len = 0;
> -
> - for (i = 0; i < component->num_actions; i++) {
> - action = component->actions_list[i];
> - len += sprintf(buf + len, "%s\n",
> - counter_synapse_action_str[action]);
> - }
> -
> - return len;
> -}
> -
> -static int counter_synapses_register(
> - struct counter_device_attr_group *const group,
> - const struct counter_device *const counter,
> - struct counter_count *const count, const char *const count_attr_name)
> -{
> - size_t i;
> - struct counter_synapse *synapse;
> - const char *prefix;
> - struct counter_action_unit *action_comp;
> - struct counter_attr_parm parm;
> - int err;
> - struct counter_action_avail_unit *avail_comp;
> -
> - /* Register each Synapse */
> - for (i = 0; i < count->num_synapses; i++) {
> - synapse = count->synapses + i;
> -
> - /* Generate attribute prefix */
> - prefix = kasprintf(GFP_KERNEL, "signal%d_",
> - synapse->signal->id);
> - if (!prefix) {
> - err = -ENOMEM;
> - goto err_free_attr_list;
> - }
> -
> - /* Allocate action attribute component */
> - action_comp = kmalloc(sizeof(*action_comp), GFP_KERNEL);
> - if (!action_comp) {
> - err = -ENOMEM;
> - goto err_free_prefix;
> - }
> - action_comp->synapse = synapse;
> - action_comp->count = count;
> -
> - /* Create action attribute */
> - parm.group = group;
> - parm.prefix = prefix;
> - parm.name = "action";
> - parm.show = (counter->ops->action_get) ? counter_action_show : NULL;
> - parm.store = (counter->ops->action_set) ? counter_action_store : NULL;
> - parm.component = action_comp;
> - err = counter_attribute_create(&parm);
> - if (err) {
> - kfree(action_comp);
> - goto err_free_prefix;
> - }
> -
> - /* Allocate action available attribute component */
> - avail_comp = kmalloc(sizeof(*avail_comp), GFP_KERNEL);
> - if (!avail_comp) {
> - err = -ENOMEM;
> - goto err_free_prefix;
> - }
> - avail_comp->actions_list = synapse->actions_list;
> - avail_comp->num_actions = synapse->num_actions;
> -
> - /* Create action_available attribute */
> - parm.group = group;
> - parm.prefix = prefix;
> - parm.name = "action_available";
> - parm.show = counter_synapse_action_available_show;
> - parm.store = NULL;
> - parm.component = avail_comp;
> - err = counter_attribute_create(&parm);
> - if (err) {
> - kfree(avail_comp);
> - goto err_free_prefix;
> - }
> -
> - kfree(prefix);
> - }
> -
> - return 0;
> -
> -err_free_prefix:
> - kfree(prefix);
> -err_free_attr_list:
> - counter_device_attr_list_free(&group->attr_list);
> - return err;
> -}
> -
> -struct counter_count_unit {
> - struct counter_count *count;
> -};
> -
> -static ssize_t counter_count_show(struct device *dev,
> - struct device_attribute *attr,
> - char *buf)
> -{
> - struct counter_device *const counter = dev_get_drvdata(dev);
> - const struct counter_device_attr *const devattr = to_counter_attr(attr);
> - const struct counter_count_unit *const component = devattr->component;
> - struct counter_count *const count = component->count;
> - int err;
> - unsigned long val;
> -
> - err = counter->ops->count_read(counter, count, &val);
> - if (err)
> - return err;
> -
> - return sprintf(buf, "%lu\n", val);
> -}
> -
> -static ssize_t counter_count_store(struct device *dev,
> - struct device_attribute *attr,
> - const char *buf, size_t len)
> -{
> - struct counter_device *const counter = dev_get_drvdata(dev);
> - const struct counter_device_attr *const devattr = to_counter_attr(attr);
> - const struct counter_count_unit *const component = devattr->component;
> - struct counter_count *const count = component->count;
> - int err;
> - unsigned long val;
> -
> - err = kstrtoul(buf, 0, &val);
> - if (err)
> - return err;
> -
> - err = counter->ops->count_write(counter, count, val);
> - if (err)
> - return err;
> -
> - return len;
> -}
> -
> -static const char *const counter_count_function_str[] = {
> - [COUNTER_COUNT_FUNCTION_INCREASE] = "increase",
> - [COUNTER_COUNT_FUNCTION_DECREASE] = "decrease",
> - [COUNTER_COUNT_FUNCTION_PULSE_DIRECTION] = "pulse-direction",
> - [COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A] = "quadrature x1 a",
> - [COUNTER_COUNT_FUNCTION_QUADRATURE_X1_B] = "quadrature x1 b",
> - [COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A] = "quadrature x2 a",
> - [COUNTER_COUNT_FUNCTION_QUADRATURE_X2_B] = "quadrature x2 b",
> - [COUNTER_COUNT_FUNCTION_QUADRATURE_X4] = "quadrature x4"
> -};
> -
> -static ssize_t counter_function_show(struct device *dev,
> - struct device_attribute *attr, char *buf)
> -{
> - int err;
> - struct counter_device *const counter = dev_get_drvdata(dev);
> - const struct counter_device_attr *const devattr = to_counter_attr(attr);
> - const struct counter_count_unit *const component = devattr->component;
> - struct counter_count *const count = component->count;
> - size_t func_index;
> - enum counter_count_function function;
> -
> - err = counter->ops->function_get(counter, count, &func_index);
> - if (err)
> - return err;
> -
> - count->function = func_index;
> -
> - function = count->functions_list[func_index];
> - return sprintf(buf, "%s\n", counter_count_function_str[function]);
> -}
> -
> -static ssize_t counter_function_store(struct device *dev,
> - struct device_attribute *attr,
> - const char *buf, size_t len)
> -{
> - const struct counter_device_attr *const devattr = to_counter_attr(attr);
> - const struct counter_count_unit *const component = devattr->component;
> - struct counter_count *const count = component->count;
> - const size_t num_functions = count->num_functions;
> - size_t func_index;
> - enum counter_count_function function;
> - int err;
> - struct counter_device *const counter = dev_get_drvdata(dev);
> -
> - /* Find requested Count function mode */
> - for (func_index = 0; func_index < num_functions; func_index++) {
> - function = count->functions_list[func_index];
> - if (sysfs_streq(buf, counter_count_function_str[function]))
> - break;
> - }
> - /* Return error if requested Count function mode not found */
> - if (func_index >= num_functions)
> - return -EINVAL;
> -
> - err = counter->ops->function_set(counter, count, func_index);
> - if (err)
> - return err;
> -
> - count->function = func_index;
> -
> - return len;
> -}
> -
> -struct counter_count_ext_unit {
> - struct counter_count *count;
> - const struct counter_count_ext *ext;
> -};
> -
> -static ssize_t counter_count_ext_show(struct device *dev,
> - struct device_attribute *attr, char *buf)
> -{
> - const struct counter_device_attr *const devattr = to_counter_attr(attr);
> - const struct counter_count_ext_unit *const comp = devattr->component;
> - const struct counter_count_ext *const ext = comp->ext;
> -
> - return ext->read(dev_get_drvdata(dev), comp->count, ext->priv, buf);
> -}
> -
> -static ssize_t counter_count_ext_store(struct device *dev,
> - struct device_attribute *attr,
> - const char *buf, size_t len)
> -{
> - const struct counter_device_attr *const devattr = to_counter_attr(attr);
> - const struct counter_count_ext_unit *const comp = devattr->component;
> - const struct counter_count_ext *const ext = comp->ext;
> -
> - return ext->write(dev_get_drvdata(dev), comp->count, ext->priv, buf,
> - len);
> -}
> -
> -static int counter_count_ext_register(
> - struct counter_device_attr_group *const group,
> - struct counter_count *const count)
> -{
> - size_t i;
> - const struct counter_count_ext *ext;
> - struct counter_count_ext_unit *count_ext_comp;
> - struct counter_attr_parm parm;
> - int err;
> -
> - /* Create an attribute for each extension */
> - for (i = 0 ; i < count->num_ext; i++) {
> - ext = count->ext + i;
> -
> - /* Allocate count_ext attribute component */
> - count_ext_comp = kmalloc(sizeof(*count_ext_comp), GFP_KERNEL);
> - if (!count_ext_comp) {
> - err = -ENOMEM;
> - goto err_free_attr_list;
> - }
> - count_ext_comp->count = count;
> - count_ext_comp->ext = ext;
> -
> - /* Allocate count_ext attribute */
> - parm.group = group;
> - parm.prefix = "";
> - parm.name = ext->name;
> - parm.show = (ext->read) ? counter_count_ext_show : NULL;
> - parm.store = (ext->write) ? counter_count_ext_store : NULL;
> - parm.component = count_ext_comp;
> - err = counter_attribute_create(&parm);
> - if (err) {
> - kfree(count_ext_comp);
> - goto err_free_attr_list;
> - }
> - }
> -
> - return 0;
> -
> -err_free_attr_list:
> - counter_device_attr_list_free(&group->attr_list);
> - return err;
> -}
> -
> -struct counter_func_avail_unit {
> - const enum counter_count_function *functions_list;
> - size_t num_functions;
> -};
> -
> -static ssize_t counter_count_function_available_show(struct device *dev,
> - struct device_attribute *attr, char *buf)
> -{
> - const struct counter_device_attr *const devattr = to_counter_attr(attr);
> - const struct counter_func_avail_unit *const component = devattr->component;
> - const enum counter_count_function *const func_list = component->functions_list;
> - const size_t num_functions = component->num_functions;
> - size_t i;
> - enum counter_count_function function;
> - ssize_t len = 0;
> -
> - for (i = 0; i < num_functions; i++) {
> - function = func_list[i];
> - len += sprintf(buf + len, "%s\n",
> - counter_count_function_str[function]);
> - }
> -
> - return len;
> -}
> -
> -static int counter_count_attributes_create(
> - struct counter_device_attr_group *const group,
> - const struct counter_device *const counter,
> - struct counter_count *const count)
> -{
> - struct counter_count_unit *count_comp;
> - struct counter_attr_parm parm;
> - int err;
> - struct counter_count_unit *func_comp;
> - struct counter_func_avail_unit *avail_comp;
> -
> - /* Allocate count attribute component */
> - count_comp = kmalloc(sizeof(*count_comp), GFP_KERNEL);
> - if (!count_comp)
> - return -ENOMEM;
> - count_comp->count = count;
> -
> - /* Create main Count attribute */
> - parm.group = group;
> - parm.prefix = "";
> - parm.name = "count";
> - parm.show = (counter->ops->count_read) ? counter_count_show : NULL;
> - parm.store = (counter->ops->count_write) ? counter_count_store : NULL;
> - parm.component = count_comp;
> - err = counter_attribute_create(&parm);
> - if (err) {
> - kfree(count_comp);
> - return err;
> - }
> -
> - /* Allocate function attribute component */
> - func_comp = kmalloc(sizeof(*func_comp), GFP_KERNEL);
> - if (!func_comp) {
> - err = -ENOMEM;
> - goto err_free_attr_list;
> - }
> - func_comp->count = count;
> -
> - /* Create Count function attribute */
> - parm.group = group;
> - parm.prefix = "";
> - parm.name = "function";
> - parm.show = (counter->ops->function_get) ? counter_function_show : NULL;
> - parm.store = (counter->ops->function_set) ? counter_function_store : NULL;
> - parm.component = func_comp;
> - err = counter_attribute_create(&parm);
> - if (err) {
> - kfree(func_comp);
> - goto err_free_attr_list;
> - }
> -
> - /* Allocate function available attribute component */
> - avail_comp = kmalloc(sizeof(*avail_comp), GFP_KERNEL);
> - if (!avail_comp) {
> - err = -ENOMEM;
> - goto err_free_attr_list;
> - }
> - avail_comp->functions_list = count->functions_list;
> - avail_comp->num_functions = count->num_functions;
> -
> - /* Create Count function_available attribute */
> - parm.group = group;
> - parm.prefix = "";
> - parm.name = "function_available";
> - parm.show = counter_count_function_available_show;
> - parm.store = NULL;
> - parm.component = avail_comp;
> - err = counter_attribute_create(&parm);
> - if (err) {
> - kfree(avail_comp);
> - goto err_free_attr_list;
> - }
> -
> - /* Create Count name attribute */
> - err = counter_name_attribute_create(group, count->name);
> - if (err)
> - goto err_free_attr_list;
> -
> - /* Register Count extension attributes */
> - err = counter_count_ext_register(group, count);
> - if (err)
> - goto err_free_attr_list;
> -
> - return 0;
> -
> -err_free_attr_list:
> - counter_device_attr_list_free(&group->attr_list);
> - return err;
> -}
> -
> -static int counter_counts_register(
> - struct counter_device_attr_group *const groups_list,
> - const struct counter_device *const counter)
> -{
> - size_t i;
> - struct counter_count *count;
> - const char *name;
> - int err;
> -
> - /* Register each Count */
> - for (i = 0; i < counter->num_counts; i++) {
> - count = counter->counts + i;
> -
> - /* Generate Count attribute directory name */
> - name = kasprintf(GFP_KERNEL, "count%d", count->id);
> - if (!name) {
> - err = -ENOMEM;
> - goto err_free_attr_groups;
> - }
> - groups_list[i].attr_group.name = name;
> -
> - /* Register the Synapses associated with each Count */
> - err = counter_synapses_register(groups_list + i, counter, count,
> - name);
> - if (err)
> - goto err_free_attr_groups;
> -
> - /* Create all attributes associated with Count */
> - err = counter_count_attributes_create(groups_list + i, counter,
> - count);
> - if (err)
> - goto err_free_attr_groups;
> - }
> -
> - return 0;
> -
> -err_free_attr_groups:
> - do {
> - kfree(groups_list[i].attr_group.name);
> - counter_device_attr_list_free(&groups_list[i].attr_list);
> - } while (i--);
> - return err;
> -}
> -
> -struct counter_size_unit {
> - size_t size;
> -};
> -
> -static ssize_t counter_device_attr_size_show(struct device *dev,
> - struct device_attribute *attr,
> - char *buf)
> -{
> - const struct counter_size_unit *const comp = to_counter_attr(attr)->component;
> -
> - return sprintf(buf, "%zu\n", comp->size);
> -}
> -
> -static int counter_size_attribute_create(
> - struct counter_device_attr_group *const group,
> - const size_t size, const char *const name)
> -{
> - struct counter_size_unit *size_comp;
> - struct counter_attr_parm parm;
> - int err;
> -
> - /* Allocate size attribute component */
> - size_comp = kmalloc(sizeof(*size_comp), GFP_KERNEL);
> - if (!size_comp)
> - return -ENOMEM;
> - size_comp->size = size;
> -
> - parm.group = group;
> - parm.prefix = "";
> - parm.name = name;
> - parm.show = counter_device_attr_size_show;
> - parm.store = NULL;
> - parm.component = size_comp;
> - err = counter_attribute_create(&parm);
> - if (err)
> - goto err_free_size_comp;
> -
> - return 0;
> -
> -err_free_size_comp:
> - kfree(size_comp);
> - return err;
> -}
> -
> -struct counter_ext_unit {
> - const struct counter_device_ext *ext;
> -};
> -
> -static ssize_t counter_device_ext_show(struct device *dev,
> - struct device_attribute *attr, char *buf)
> -{
> - const struct counter_device_attr *const devattr = to_counter_attr(attr);
> - const struct counter_ext_unit *const component = devattr->component;
> - const struct counter_device_ext *const ext = component->ext;
> -
> - return ext->read(dev_get_drvdata(dev), ext->priv, buf);
> -}
> -
> -static ssize_t counter_device_ext_store(struct device *dev,
> - struct device_attribute *attr,
> - const char *buf, size_t len)
> -{
> - const struct counter_device_attr *const devattr = to_counter_attr(attr);
> - const struct counter_ext_unit *const component = devattr->component;
> - const struct counter_device_ext *const ext = component->ext;
> -
> - return ext->write(dev_get_drvdata(dev), ext->priv, buf, len);
> -}
> -
> -static int counter_device_ext_register(
> - struct counter_device_attr_group *const group,
> - struct counter_device *const counter)
> -{
> - size_t i;
> - struct counter_ext_unit *ext_comp;
> - struct counter_attr_parm parm;
> - int err;
> -
> - /* Create an attribute for each extension */
> - for (i = 0 ; i < counter->num_ext; i++) {
> - /* Allocate extension attribute component */
> - ext_comp = kmalloc(sizeof(*ext_comp), GFP_KERNEL);
> - if (!ext_comp) {
> - err = -ENOMEM;
> - goto err_free_attr_list;
> - }
> -
> - ext_comp->ext = counter->ext + i;
> -
> - /* Allocate extension attribute */
> - parm.group = group;
> - parm.prefix = "";
> - parm.name = counter->ext[i].name;
> - parm.show = (counter->ext[i].read) ? counter_device_ext_show : NULL;
> - parm.store = (counter->ext[i].write) ? counter_device_ext_store : NULL;
> - parm.component = ext_comp;
> - err = counter_attribute_create(&parm);
> - if (err) {
> - kfree(ext_comp);
> - goto err_free_attr_list;
> - }
> - }
> -
> - return 0;
> -
> -err_free_attr_list:
> - counter_device_attr_list_free(&group->attr_list);
> - return err;
> -}
> -
> -static int counter_global_attr_register(
> - struct counter_device_attr_group *const group,
> - struct counter_device *const counter)
> -{
> - int err;
> -
> - /* Create name attribute */
> - err = counter_name_attribute_create(group, counter->name);
> - if (err)
> - return err;
> -
> - /* Create num_counts attribute */
> - err = counter_size_attribute_create(group, counter->num_counts,
> - "num_counts");
> - if (err)
> - goto err_free_attr_list;
> -
> - /* Create num_signals attribute */
> - err = counter_size_attribute_create(group, counter->num_signals,
> - "num_signals");
> - if (err)
> - goto err_free_attr_list;
> -
> - /* Register Counter device extension attributes */
> - err = counter_device_ext_register(group, counter);
> - if (err)
> - goto err_free_attr_list;
> -
> - return 0;
> -
> -err_free_attr_list:
> - counter_device_attr_list_free(&group->attr_list);
> - return err;
> -}
> -
> -static void counter_device_groups_list_free(
> - struct counter_device_attr_group *const groups_list,
> - const size_t num_groups)
> -{
> - struct counter_device_attr_group *group;
> - size_t i;
> -
> - /* loop through all attribute groups (signals, counts, global, etc.) */
> - for (i = 0; i < num_groups; i++) {
> - group = groups_list + i;
> -
> - /* free all attribute group and associated attributes memory */
> - kfree(group->attr_group.name);
> - kfree(group->attr_group.attrs);
> - counter_device_attr_list_free(&group->attr_list);
> - }
> -
> - kfree(groups_list);
> -}
> -
> -static int counter_device_groups_list_prepare(
> - struct counter_device *const counter)
> -{
> - const size_t total_num_groups =
> - counter->num_signals + counter->num_counts + 1;
> - struct counter_device_attr_group *groups_list;
> - size_t i;
> - int err;
> - size_t num_groups = 0;
> -
> - /* Allocate space for attribute groups (signals, counts, and ext) */
> - groups_list = kcalloc(total_num_groups, sizeof(*groups_list),
> - GFP_KERNEL);
> - if (!groups_list)
> - return -ENOMEM;
> -
> - /* Initialize attribute lists */
> - for (i = 0; i < total_num_groups; i++)
> - INIT_LIST_HEAD(&groups_list[i].attr_list);
> -
> - /* Register Signals */
> - err = counter_signals_register(groups_list, counter);
> - if (err)
> - goto err_free_groups_list;
> - num_groups += counter->num_signals;
> -
> - /* Register Counts and respective Synapses */
> - err = counter_counts_register(groups_list + num_groups, counter);
> - if (err)
> - goto err_free_groups_list;
> - num_groups += counter->num_counts;
> -
> - /* Register Counter global attributes */
> - err = counter_global_attr_register(groups_list + num_groups, counter);
> - if (err)
> - goto err_free_groups_list;
> - num_groups++;
> -
> - /* Store groups_list in device_state */
> - counter->device_state->groups_list = groups_list;
> - counter->device_state->num_groups = num_groups;
> -
> - return 0;
> -
> -err_free_groups_list:
> - counter_device_groups_list_free(groups_list, num_groups);
> - return err;
> -}
> -
> -static int counter_device_groups_prepare(
> - struct counter_device_state *const device_state)
> -{
> - size_t i, j;
> - struct counter_device_attr_group *group;
> - int err;
> - struct counter_device_attr *p;
> -
> - /* Allocate attribute groups for association with device */
> - device_state->groups = kcalloc(device_state->num_groups + 1,
> - sizeof(*device_state->groups),
> - GFP_KERNEL);
> - if (!device_state->groups)
> - return -ENOMEM;
> -
> - /* Prepare each group of attributes for association */
> - for (i = 0; i < device_state->num_groups; i++) {
> - group = device_state->groups_list + i;
> -
> - /* Allocate space for attribute pointers in attribute group */
> - group->attr_group.attrs = kcalloc(group->num_attr + 1,
> - sizeof(*group->attr_group.attrs), GFP_KERNEL);
> - if (!group->attr_group.attrs) {
> - err = -ENOMEM;
> - goto err_free_groups;
> - }
> -
> - /* Add attribute pointers to attribute group */
> - j = 0;
> - list_for_each_entry(p, &group->attr_list, l)
> - group->attr_group.attrs[j++] = &p->dev_attr.attr;
> -
> - /* Group attributes in attribute group */
> - device_state->groups[i] = &group->attr_group;
> - }
> - /* Associate attributes with device */
> - device_state->dev.groups = device_state->groups;
> -
> - return 0;
> -
> -err_free_groups:
> - do {
> - group = device_state->groups_list + i;
> - kfree(group->attr_group.attrs);
> - group->attr_group.attrs = NULL;
> - } while (i--);
> - kfree(device_state->groups);
> - return err;
> -}
> -
> -/* Provides a unique ID for each counter device */
> -static DEFINE_IDA(counter_ida);
> -
> -static void counter_device_release(struct device *dev)
> -{
> - struct counter_device *const counter = dev_get_drvdata(dev);
> - struct counter_device_state *const device_state = counter->device_state;
> -
> - kfree(device_state->groups);
> - counter_device_groups_list_free(device_state->groups_list,
> - device_state->num_groups);
> - ida_simple_remove(&counter_ida, device_state->id);
> - kfree(device_state);
> -}
> -
> -static struct device_type counter_device_type = {
> - .name = "counter_device",
> - .release = counter_device_release
> -};
> -
> -static struct bus_type counter_bus_type = {
> - .name = "counter"
> -};
> -
> -/**
> - * counter_register - register Counter to the system
> - * @counter: pointer to Counter to register
> - *
> - * This function registers a Counter to the system. A sysfs "counter" directory
> - * will be created and populated with sysfs attributes correlating with the
> - * Counter Signals, Synapses, and Counts respectively.
> - */
> -int counter_register(struct counter_device *const counter)
> -{
> - struct counter_device_state *device_state;
> - int err;
> -
> - /* Allocate internal state container for Counter device */
> - device_state = kzalloc(sizeof(*device_state), GFP_KERNEL);
> - if (!device_state)
> - return -ENOMEM;
> - counter->device_state = device_state;
> -
> - /* Acquire unique ID */
> - device_state->id = ida_simple_get(&counter_ida, 0, 0, GFP_KERNEL);
> - if (device_state->id < 0) {
> - err = device_state->id;
> - goto err_free_device_state;
> - }
> -
> - /* Configure device structure for Counter */
> - device_state->dev.type = &counter_device_type;
> - device_state->dev.bus = &counter_bus_type;
> - if (counter->parent) {
> - device_state->dev.parent = counter->parent;
> - device_state->dev.of_node = counter->parent->of_node;
> - }
> - dev_set_name(&device_state->dev, "counter%d", device_state->id);
> - device_initialize(&device_state->dev);
> - dev_set_drvdata(&device_state->dev, counter);
> -
> - /* Prepare device attributes */
> - err = counter_device_groups_list_prepare(counter);
> - if (err)
> - goto err_free_id;
> -
> - /* Organize device attributes to groups and match to device */
> - err = counter_device_groups_prepare(device_state);
> - if (err)
> - goto err_free_groups_list;
> -
> - /* Add device to system */
> - err = device_add(&device_state->dev);
> - if (err)
> - goto err_free_groups;
> -
> - return 0;
> -
> -err_free_groups:
> - kfree(device_state->groups);
> -err_free_groups_list:
> - counter_device_groups_list_free(device_state->groups_list,
> - device_state->num_groups);
> -err_free_id:
> - ida_simple_remove(&counter_ida, device_state->id);
> -err_free_device_state:
> - kfree(device_state);
> - return err;
> -}
> -EXPORT_SYMBOL_GPL(counter_register);
> -
> -/**
> - * counter_unregister - unregister Counter from the system
> - * @counter: pointer to Counter to unregister
> - *
> - * The Counter is unregistered from the system; all allocated memory is freed.
> - */
> -void counter_unregister(struct counter_device *const counter)
> -{
> - if (counter)
> - device_del(&counter->device_state->dev);
> -}
> -EXPORT_SYMBOL_GPL(counter_unregister);
> -
> -static void devm_counter_unreg(struct device *dev, void *res)
> -{
> - counter_unregister(*(struct counter_device **)res);
> -}
> -
> -/**
> - * devm_counter_register - Resource-managed counter_register
> - * @dev: device to allocate counter_device for
> - * @counter: pointer to Counter to register
> - *
> - * Managed counter_register. The Counter registered with this function is
> - * automatically unregistered on driver detach. This function calls
> - * counter_register internally. Refer to that function for more information.
> - *
> - * If an Counter registered with this function needs to be unregistered
> - * separately, devm_counter_unregister must be used.
> - *
> - * RETURNS:
> - * 0 on success, negative error number on failure.
> - */
> -int devm_counter_register(struct device *dev,
> - struct counter_device *const counter)
> -{
> - struct counter_device **ptr;
> - int ret;
> -
> - ptr = devres_alloc(devm_counter_unreg, sizeof(*ptr), GFP_KERNEL);
> - if (!ptr)
> - return -ENOMEM;
> -
> - ret = counter_register(counter);
> - if (!ret) {
> - *ptr = counter;
> - devres_add(dev, ptr);
> - } else {
> - devres_free(ptr);
> - }
> -
> - return ret;
> -}
> -EXPORT_SYMBOL_GPL(devm_counter_register);
> -
> -static int devm_counter_match(struct device *dev, void *res, void *data)
> -{
> - struct counter_device **r = res;
> -
> - if (!r || !*r) {
> - WARN_ON(!r || !*r);
> - return 0;
> - }
> -
> - return *r == data;
> -}
> -
> -/**
> - * devm_counter_unregister - Resource-managed counter_unregister
> - * @dev: device this counter_device belongs to
> - * @counter: pointer to Counter associated with the device
> - *
> - * Unregister Counter registered with devm_counter_register.
> - */
> -void devm_counter_unregister(struct device *dev,
> - struct counter_device *const counter)
> -{
> - int rc;
> -
> - rc = devres_release(dev, devm_counter_unreg, devm_counter_match,
> - counter);
> - WARN_ON(rc);
> -}
> -EXPORT_SYMBOL_GPL(devm_counter_unregister);
> -
> -static int __init counter_init(void)
> -{
> - return bus_register(&counter_bus_type);
> -}
> -
> -static void __exit counter_exit(void)
> -{
> - bus_unregister(&counter_bus_type);
> -}
> -
> -subsys_initcall(counter_init);
> -module_exit(counter_exit);
> -
> -MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
> -MODULE_DESCRIPTION("Generic Counter interface");
> -MODULE_LICENSE("GPL v2");
> diff --git a/drivers/counter/ftm-quaddec.c b/drivers/counter/ftm-quaddec.c
> index c2b3fdfd8b77..ea6cb18c7170 100644
> --- a/drivers/counter/ftm-quaddec.c
> +++ b/drivers/counter/ftm-quaddec.c
> @@ -6,6 +6,7 @@
> * of ex. a LS1021A
> */
>
> +#include <linux/bits.h>
> #include <linux/fsl/ftm.h>
> #include <linux/module.h>
> #include <linux/platform_device.h>
> @@ -14,6 +15,7 @@
> #include <linux/mutex.h>
> #include <linux/counter.h>
> #include <linux/bitfield.h>
> +#include <linux/types.h>
>
> #define FTM_FIELD_UPDATE(ftm, offset, mask, val) \
> ({ \
> @@ -114,26 +116,38 @@ static void ftm_quaddec_disable(void *ftm)
> ftm_set_write_protection(ftm_qua);
> }
>
> -static int ftm_quaddec_get_prescaler(struct counter_device *counter,
> - struct counter_count *count,
> - size_t *cnt_mode)
> +static int ftm_quaddec_prescaler_read(struct counter_device *counter,
> + struct counter_count *count, u8 *cnt_mode)
> {
> struct ftm_quaddec *ftm = counter->priv;
> uint32_t scflags;
>
> ftm_read(ftm, FTM_SC, &scflags);
>
> - *cnt_mode = FIELD_GET(FTM_SC_PS_MASK, scflags);
> + *cnt_mode = BIT(FIELD_GET(FTM_SC_PS_MASK, scflags));
>
> return 0;
> }
>
> -static int ftm_quaddec_set_prescaler(struct counter_device *counter,
> - struct counter_count *count,
> - size_t cnt_mode)
> +static int ftm_quaddec_prescaler_write(struct counter_device *counter,
> + struct counter_count *count, u8 cnt_mode)
> {
> struct ftm_quaddec *ftm = counter->priv;
>
> + /* Filter valid input */
> + switch (cnt_mode) {
> + case BIT(0):
> + case BIT(1):
> + case BIT(2):
> + case BIT(3):
> + case BIT(4):
> + case BIT(5):
> + case BIT(6):
> + case BIT(7):
> + break;
> + default: return -EINVAL;
> + }
> +
> mutex_lock(&ftm->ftm_quaddec_mutex);
>
> ftm_clear_write_protection(ftm);
> @@ -151,34 +165,35 @@ static const char * const ftm_quaddec_prescaler[] = {
> "1", "2", "4", "8", "16", "32", "64", "128"
> };
>
> -static struct counter_count_enum_ext ftm_quaddec_prescaler_enum = {
> - .items = ftm_quaddec_prescaler,
> - .num_items = ARRAY_SIZE(ftm_quaddec_prescaler),
> - .get = ftm_quaddec_get_prescaler,
> - .set = ftm_quaddec_set_prescaler
> -};
> +static ssize_t ftm_quaddec_prescaler_available_read(
> + struct counter_device *counter, struct counter_count *count, char *buf,
> + size_t size)
> +{
> + size_t i;
> + size_t len = 0;
>
> -enum ftm_quaddec_synapse_action {
> - FTM_QUADDEC_SYNAPSE_ACTION_BOTH_EDGES,
> -};
> + for (i = 0; i < ARRAY_SIZE(ftm_quaddec_prescaler) && size > 1; i++)
> + len += scnprintf(buf + len, size - len, "%s\n",
> + ftm_quaddec_prescaler[i]);
>
> -static enum counter_synapse_action ftm_quaddec_synapse_actions[] = {
> - [FTM_QUADDEC_SYNAPSE_ACTION_BOTH_EDGES] =
> + return len;
> +}
> +
> +static const u8 ftm_quaddec_synapse_actions[] = {
> COUNTER_SYNAPSE_ACTION_BOTH_EDGES
> };
>
> enum ftm_quaddec_count_function {
> - FTM_QUADDEC_COUNT_ENCODER_MODE_1,
> + FTM_QUADDEC_COUNT_ENCODER_MODE_1 = COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
> };
>
> -static const enum counter_count_function ftm_quaddec_count_functions[] = {
> - [FTM_QUADDEC_COUNT_ENCODER_MODE_1] =
> - COUNTER_COUNT_FUNCTION_QUADRATURE_X4
> +static const u8 ftm_quaddec_count_functions[] = {
> + FTM_QUADDEC_COUNT_ENCODER_MODE_1
> };
>
> static int ftm_quaddec_count_read(struct counter_device *counter,
> struct counter_count *count,
> - unsigned long *val)
> + u64 *val)
> {
> struct ftm_quaddec *const ftm = counter->priv;
> uint32_t cntval;
> @@ -192,7 +207,7 @@ static int ftm_quaddec_count_read(struct counter_device *counter,
>
> static int ftm_quaddec_count_write(struct counter_device *counter,
> struct counter_count *count,
> - const unsigned long val)
> + const u64 val)
> {
> struct ftm_quaddec *const ftm = counter->priv;
>
> @@ -208,7 +223,7 @@ static int ftm_quaddec_count_write(struct counter_device *counter,
>
> static int ftm_quaddec_count_function_get(struct counter_device *counter,
> struct counter_count *count,
> - size_t *function)
> + u8 *function)
> {
> *function = FTM_QUADDEC_COUNT_ENCODER_MODE_1;
>
> @@ -218,20 +233,13 @@ static int ftm_quaddec_count_function_get(struct counter_device *counter,
> static int ftm_quaddec_action_get(struct counter_device *counter,
> struct counter_count *count,
> struct counter_synapse *synapse,
> - size_t *action)
> + u8 *action)
> {
> - *action = FTM_QUADDEC_SYNAPSE_ACTION_BOTH_EDGES;
> + *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
>
> return 0;
> }
>
> -static const struct counter_ops ftm_quaddec_cnt_ops = {
> - .count_read = ftm_quaddec_count_read,
> - .count_write = ftm_quaddec_count_write,
> - .function_get = ftm_quaddec_count_function_get,
> - .action_get = ftm_quaddec_action_get,
> -};
> -
> static struct counter_signal ftm_quaddec_signals[] = {
> {
> .id = 0,
> @@ -256,9 +264,11 @@ static struct counter_synapse ftm_quaddec_count_synapses[] = {
> }
> };
>
> -static const struct counter_count_ext ftm_quaddec_count_ext[] = {
> - COUNTER_COUNT_ENUM("prescaler", &ftm_quaddec_prescaler_enum),
> - COUNTER_COUNT_ENUM_AVAILABLE("prescaler", &ftm_quaddec_prescaler_enum),
> +static struct counter_data ftm_quaddec_count_ext[] = {
> + COUNTER_DATA_COUNT_U8("prescaler", ftm_quaddec_prescaler_read,
> + ftm_quaddec_prescaler_write),
> + COUNTER_DATA_COUNT_STRING("prescaler_available",
> + ftm_quaddec_prescaler_available_read, NULL),
> };
>
> static struct counter_count ftm_quaddec_counts = {
> @@ -302,7 +312,10 @@ static int ftm_quaddec_probe(struct platform_device *pdev)
> }
> ftm->counter.name = dev_name(&pdev->dev);
> ftm->counter.parent = &pdev->dev;
> - ftm->counter.ops = &ftm_quaddec_cnt_ops;
> + ftm->counter.count_read = ftm_quaddec_count_read;
> + ftm->counter.count_write = ftm_quaddec_count_write;
> + ftm->counter.function_read = ftm_quaddec_count_function_get;
> + ftm->counter.action_read = ftm_quaddec_action_get;
> ftm->counter.counts = &ftm_quaddec_counts;
> ftm->counter.num_counts = 1;
> ftm->counter.signals = ftm_quaddec_signals;
> diff --git a/drivers/counter/stm32-lptimer-cnt.c b/drivers/counter/stm32-lptimer-cnt.c
> index 8e276eb655f5..4a1ec895717c 100644
> --- a/drivers/counter/stm32-lptimer-cnt.c
> +++ b/drivers/counter/stm32-lptimer-cnt.c
> @@ -17,6 +17,7 @@
> #include <linux/module.h>
> #include <linux/pinctrl/consumer.h>
> #include <linux/platform_device.h>
> +#include <linux/types.h>
>
> struct stm32_lptim_cnt {
> struct counter_device counter;
> @@ -352,32 +353,46 @@ static const struct iio_chan_spec stm32_lptim_cnt_channels = {
> * @STM32_LPTIM_ENCODER_BOTH_EDGE: count on both edges (IN1 & IN2 quadrature)
> */
> enum stm32_lptim_cnt_function {
> - STM32_LPTIM_COUNTER_INCREASE,
> - STM32_LPTIM_ENCODER_BOTH_EDGE,
> + STM32_LPTIM_COUNTER_INCREASE = COUNTER_COUNT_FUNCTION_INCREASE,
> + STM32_LPTIM_ENCODER_BOTH_EDGE = COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
> };
>
> -static enum counter_count_function stm32_lptim_cnt_functions[] = {
> - [STM32_LPTIM_COUNTER_INCREASE] = COUNTER_COUNT_FUNCTION_INCREASE,
> - [STM32_LPTIM_ENCODER_BOTH_EDGE] = COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
> +static u8 stm32_lptim_cnt_functions[] = {
> + STM32_LPTIM_COUNTER_INCREASE,
> + STM32_LPTIM_ENCODER_BOTH_EDGE,
> };
>
> enum stm32_lptim_synapse_action {
> + /* Index must match with stm32_lptim_cnt_polarity[] (priv->polarity) */
> STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE,
> STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE,
> STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES,
> STM32_LPTIM_SYNAPSE_ACTION_NONE,
> };
>
> -static enum counter_synapse_action stm32_lptim_cnt_synapse_actions[] = {
> - /* Index must match with stm32_lptim_cnt_polarity[] (priv->polarity) */
> +static const enum stm32_lptim_synapse_action stm32_lptim_c2l_actions_map[] = {
> + [COUNTER_SYNAPSE_ACTION_RISING_EDGE] = STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE,
> + [COUNTER_SYNAPSE_ACTION_FALLING_EDGE] = STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE,
> + [COUNTER_SYNAPSE_ACTION_BOTH_EDGES] = STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES,
> + [COUNTER_SYNAPSE_ACTION_NONE] = STM32_LPTIM_SYNAPSE_ACTION_NONE,
> +};
> +
> +static const u8 stm32_lptim_l2c_actions_map[] = {
> [STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE,
> [STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE] = COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
> [STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES] = COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
> [STM32_LPTIM_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,
> };
>
> +static const u8 stm32_lptim_cnt_synapse_actions[] = {
> + COUNTER_SYNAPSE_ACTION_RISING_EDGE,
> + COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
> + COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
> + COUNTER_SYNAPSE_ACTION_NONE,
> +};
> +
> static int stm32_lptim_cnt_read(struct counter_device *counter,
> - struct counter_count *count, unsigned long *val)
> + struct counter_count *count, u64 *val)
> {
> struct stm32_lptim_cnt *const priv = counter->priv;
> u32 cnt;
> @@ -394,7 +409,7 @@ static int stm32_lptim_cnt_read(struct counter_device *counter,
>
> static int stm32_lptim_cnt_function_get(struct counter_device *counter,
> struct counter_count *count,
> - size_t *function)
> + u8 *function)
> {
> struct stm32_lptim_cnt *const priv = counter->priv;
>
> @@ -413,7 +428,7 @@ static int stm32_lptim_cnt_function_get(struct counter_device *counter,
>
> static int stm32_lptim_cnt_function_set(struct counter_device *counter,
> struct counter_count *count,
> - size_t function)
> + u8 function)
> {
> struct stm32_lptim_cnt *const priv = counter->priv;
>
> @@ -423,19 +438,20 @@ static int stm32_lptim_cnt_function_set(struct counter_device *counter,
> switch (function) {
> case STM32_LPTIM_COUNTER_INCREASE:
> priv->quadrature_mode = 0;
> - return 0;
> + break;
> case STM32_LPTIM_ENCODER_BOTH_EDGE:
> priv->quadrature_mode = 1;
> priv->polarity = STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES;
> - return 0;
> + break;
> + default: return -EINVAL;
> }
>
> - return -EINVAL;
> + return 0;
> }
>
> -static ssize_t stm32_lptim_cnt_enable_read(struct counter_device *counter,
> - struct counter_count *count,
> - void *private, char *buf)
> +static int stm32_lptim_cnt_enable_read(struct counter_device *counter,
> + struct counter_count *count,
> + u8 *enable)
> {
> struct stm32_lptim_cnt *const priv = counter->priv;
> int ret;
> @@ -444,22 +460,18 @@ static ssize_t stm32_lptim_cnt_enable_read(struct counter_device *counter,
> if (ret < 0)
> return ret;
>
> - return scnprintf(buf, PAGE_SIZE, "%u\n", ret);
> + *enable = ret;
> +
> + return 0;
> }
>
> -static ssize_t stm32_lptim_cnt_enable_write(struct counter_device *counter,
> - struct counter_count *count,
> - void *private,
> - const char *buf, size_t len)
> +static int stm32_lptim_cnt_enable_write(struct counter_device *counter,
> + struct counter_count *count,
> + u8 enable)
> {
> struct stm32_lptim_cnt *const priv = counter->priv;
> - bool enable;
> int ret;
>
> - ret = kstrtobool(buf, &enable);
> - if (ret)
> - return ret;
> -
> /* Check nobody uses the timer, or already disabled/enabled */
> ret = stm32_lptim_is_enabled(priv);
> if ((ret < 0) || (!ret && !enable))
> @@ -475,48 +487,51 @@ static ssize_t stm32_lptim_cnt_enable_write(struct counter_device *counter,
> if (ret)
> return ret;
>
> - return len;
> + return 0;
> }
>
> -static ssize_t stm32_lptim_cnt_ceiling_read(struct counter_device *counter,
> - struct counter_count *count,
> - void *private, char *buf)
> +static int stm32_lptim_cnt_ceiling_read(struct counter_device *counter,
> + struct counter_count *count,
> + u64 *ceiling)
> {
> struct stm32_lptim_cnt *const priv = counter->priv;
>
> - return stm32_lptim_cnt_get_ceiling(priv, buf);
> + *ceiling = priv->ceiling;
> +
> + return 0;
> }
>
> -static ssize_t stm32_lptim_cnt_ceiling_write(struct counter_device *counter,
> - struct counter_count *count,
> - void *private,
> - const char *buf, size_t len)
> +static int stm32_lptim_cnt_ceiling_write(struct counter_device *counter,
> + struct counter_count *count,
> + u64 ceiling)
> {
> struct stm32_lptim_cnt *const priv = counter->priv;
>
> - return stm32_lptim_cnt_set_ceiling(priv, buf, len);
> + if (ceiling > STM32_LPTIM_MAX_ARR)
> + return -EINVAL;
> +
> + if (stm32_lptim_is_enabled(priv))
> + return -EBUSY;
> +
> + priv->ceiling = ceiling;
> +
> + return 0;
> }
>
> -static const struct counter_count_ext stm32_lptim_cnt_ext[] = {
> - {
> - .name = "enable",
> - .read = stm32_lptim_cnt_enable_read,
> - .write = stm32_lptim_cnt_enable_write
> - },
> - {
> - .name = "ceiling",
> - .read = stm32_lptim_cnt_ceiling_read,
> - .write = stm32_lptim_cnt_ceiling_write
> - },
> +static struct counter_data stm32_lptim_cnt_ext[] = {
> + COUNTER_DATA_ENABLE(stm32_lptim_cnt_enable_read,
> + stm32_lptim_cnt_enable_write),
> + COUNTER_DATA_CEILING(stm32_lptim_cnt_ceiling_read,
> + stm32_lptim_cnt_ceiling_write),
> };
>
> static int stm32_lptim_cnt_action_get(struct counter_device *counter,
> struct counter_count *count,
> struct counter_synapse *synapse,
> - size_t *action)
> + u8 *action)
> {
> struct stm32_lptim_cnt *const priv = counter->priv;
> - size_t function;
> + u8 function;
> int err;
>
> err = stm32_lptim_cnt_function_get(counter, count, &function);
> @@ -527,25 +542,25 @@ static int stm32_lptim_cnt_action_get(struct counter_device *counter,
> case STM32_LPTIM_COUNTER_INCREASE:
> /* LP Timer acts as up-counter on input 1 */
> if (synapse->signal->id == count->synapses[0].signal->id)
> - *action = priv->polarity;
> + *action = stm32_lptim_l2c_actions_map[priv->polarity];
> else
> - *action = STM32_LPTIM_SYNAPSE_ACTION_NONE;
> - return 0;
> + *action = COUNTER_SYNAPSE_ACTION_NONE;
> + break;
> case STM32_LPTIM_ENCODER_BOTH_EDGE:
> - *action = priv->polarity;
> - return 0;
> + *action = stm32_lptim_l2c_actions_map[priv->polarity];
> + break;
> }
>
> - return -EINVAL;
> + return 0;
> }
>
> static int stm32_lptim_cnt_action_set(struct counter_device *counter,
> struct counter_count *count,
> struct counter_synapse *synapse,
> - size_t action)
> + u8 action)
> {
> struct stm32_lptim_cnt *const priv = counter->priv;
> - size_t function;
> + u8 function;
> int err;
>
> if (stm32_lptim_is_enabled(priv))
> @@ -556,27 +571,15 @@ static int stm32_lptim_cnt_action_set(struct counter_device *counter,
> return err;
>
> /* only set polarity when in counter mode (on input 1) */
> - if (function == STM32_LPTIM_COUNTER_INCREASE
> - && synapse->signal->id == count->synapses[0].signal->id) {
> - switch (action) {
> - case STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE:
> - case STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE:
> - case STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES:
> - priv->polarity = action;
> - return 0;
> - }
> - }
> + if (function != STM32_LPTIM_COUNTER_INCREASE
> + || synapse->signal->id != count->synapses[0].signal->id
> + || action == COUNTER_SYNAPSE_ACTION_NONE)
> + return -EINVAL;
>
> - return -EINVAL;
> -}
> + priv->polarity = stm32_lptim_c2l_actions_map[action];
>
> -static const struct counter_ops stm32_lptim_cnt_ops = {
> - .count_read = stm32_lptim_cnt_read,
> - .function_get = stm32_lptim_cnt_function_get,
> - .function_set = stm32_lptim_cnt_function_set,
> - .action_get = stm32_lptim_cnt_action_get,
> - .action_set = stm32_lptim_cnt_action_set,
> -};
> + return 0;
> +}
>
> static struct counter_signal stm32_lptim_cnt_signals[] = {
> {
> @@ -660,7 +663,11 @@ static int stm32_lptim_cnt_probe(struct platform_device *pdev)
> /* Initialize Counter device */
> priv->counter.name = dev_name(&pdev->dev);
> priv->counter.parent = &pdev->dev;
> - priv->counter.ops = &stm32_lptim_cnt_ops;
> + priv->counter.count_read = stm32_lptim_cnt_read;
> + priv->counter.function_read = stm32_lptim_cnt_function_get;
> + priv->counter.function_write = stm32_lptim_cnt_function_set;
> + priv->counter.action_read = stm32_lptim_cnt_action_get;
> + priv->counter.action_write = stm32_lptim_cnt_action_set;
> if (ddata->has_encoder) {
> priv->counter.counts = &stm32_lptim_enc_counts;
> priv->counter.num_signals = ARRAY_SIZE(stm32_lptim_cnt_signals);
> diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
> index ef2a974a2f10..502e525836a9 100644
> --- a/drivers/counter/stm32-timer-cnt.c
> +++ b/drivers/counter/stm32-timer-cnt.c
> @@ -13,6 +13,7 @@
> #include <linux/module.h>
> #include <linux/pinctrl/consumer.h>
> #include <linux/platform_device.h>
> +#include <linux/types.h>
>
> #define TIM_CCMR_CCXS (BIT(8) | BIT(0))
> #define TIM_CCMR_MASK (TIM_CCMR_CC1S | TIM_CCMR_CC2S | \
> @@ -45,19 +46,19 @@ struct stm32_timer_cnt {
> */
> enum stm32_count_function {
> STM32_COUNT_SLAVE_MODE_DISABLED = -1,
> + STM32_COUNT_ENCODER_MODE_1 = COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A,
> + STM32_COUNT_ENCODER_MODE_2 = COUNTER_COUNT_FUNCTION_QUADRATURE_X2_B,
> + STM32_COUNT_ENCODER_MODE_3 = COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
> +};
> +
> +static const u8 stm32_count_functions[] = {
> STM32_COUNT_ENCODER_MODE_1,
> STM32_COUNT_ENCODER_MODE_2,
> STM32_COUNT_ENCODER_MODE_3,
> };
>
> -static enum counter_count_function stm32_count_functions[] = {
> - [STM32_COUNT_ENCODER_MODE_1] = COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A,
> - [STM32_COUNT_ENCODER_MODE_2] = COUNTER_COUNT_FUNCTION_QUADRATURE_X2_B,
> - [STM32_COUNT_ENCODER_MODE_3] = COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
> -};
> -
> static int stm32_count_read(struct counter_device *counter,
> - struct counter_count *count, unsigned long *val)
> + struct counter_count *count, u64 *val)
> {
> struct stm32_timer_cnt *const priv = counter->priv;
> u32 cnt;
> @@ -69,8 +70,7 @@ static int stm32_count_read(struct counter_device *counter,
> }
>
> static int stm32_count_write(struct counter_device *counter,
> - struct counter_count *count,
> - const unsigned long val)
> + struct counter_count *count, const u64 val)
> {
> struct stm32_timer_cnt *const priv = counter->priv;
>
> @@ -81,8 +81,7 @@ static int stm32_count_write(struct counter_device *counter,
> }
>
> static int stm32_count_function_get(struct counter_device *counter,
> - struct counter_count *count,
> - size_t *function)
> + struct counter_count *count, u8 *function)
> {
> struct stm32_timer_cnt *const priv = counter->priv;
> u32 smcr;
> @@ -105,8 +104,7 @@ static int stm32_count_function_get(struct counter_device *counter,
> }
>
> static int stm32_count_function_set(struct counter_device *counter,
> - struct counter_count *count,
> - size_t function)
> + struct counter_count *count, u8 function)
> {
> struct stm32_timer_cnt *const priv = counter->priv;
> u32 cr1, sms;
> @@ -146,78 +144,67 @@ static int stm32_count_function_set(struct counter_device *counter,
> return 0;
> }
>
> -static ssize_t stm32_count_direction_read(struct counter_device *counter,
> +static int stm32_count_direction_read(struct counter_device *counter,
> struct counter_count *count,
> - void *private, char *buf)
> + u8 *direction)
> {
> struct stm32_timer_cnt *const priv = counter->priv;
> - const char *direction;
> u32 cr1;
>
> regmap_read(priv->regmap, TIM_CR1, &cr1);
> - direction = (cr1 & TIM_CR1_DIR) ? "backward" : "forward";
> + *direction = (cr1 & TIM_CR1_DIR) ? COUNTER_COUNT_DIRECTION_BACKWARD :
> + COUNTER_COUNT_DIRECTION_FORWARD;
>
> - return scnprintf(buf, PAGE_SIZE, "%s\n", direction);
> + return 0;
> }
>
> -static ssize_t stm32_count_ceiling_read(struct counter_device *counter,
> - struct counter_count *count,
> - void *private, char *buf)
> +static int stm32_count_ceiling_read(struct counter_device *counter,
> + struct counter_count *count, u64 *ceiling)
> {
> struct stm32_timer_cnt *const priv = counter->priv;
> u32 arr;
>
> regmap_read(priv->regmap, TIM_ARR, &arr);
>
> - return snprintf(buf, PAGE_SIZE, "%u\n", arr);
> + *ceiling = arr;
> +
> + return 0;
> }
>
> -static ssize_t stm32_count_ceiling_write(struct counter_device *counter,
> - struct counter_count *count,
> - void *private,
> - const char *buf, size_t len)
> +static int stm32_count_ceiling_write(struct counter_device *counter,
> + struct counter_count *count, u64 ceiling)
> {
> struct stm32_timer_cnt *const priv = counter->priv;
> - unsigned int ceiling;
> - int ret;
>
> - ret = kstrtouint(buf, 0, &ceiling);
> - if (ret)
> - return ret;
> + if (ceiling != (u32)ceiling)
> + return -ERANGE;
>
> /* TIMx_ARR register shouldn't be buffered (ARPE=0) */
> regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0);
> regmap_write(priv->regmap, TIM_ARR, ceiling);
>
> priv->ceiling = ceiling;
> - return len;
> + return 0;
> }
>
> -static ssize_t stm32_count_enable_read(struct counter_device *counter,
> - struct counter_count *count,
> - void *private, char *buf)
> +static int stm32_count_enable_read(struct counter_device *counter,
> + struct counter_count *count, u8 *enable)
> {
> struct stm32_timer_cnt *const priv = counter->priv;
> u32 cr1;
>
> regmap_read(priv->regmap, TIM_CR1, &cr1);
>
> - return scnprintf(buf, PAGE_SIZE, "%d\n", (bool)(cr1 & TIM_CR1_CEN));
> + *enable = cr1 & TIM_CR1_CEN;
> +
> + return 0;
> }
>
> -static ssize_t stm32_count_enable_write(struct counter_device *counter,
> - struct counter_count *count,
> - void *private,
> - const char *buf, size_t len)
> +static int stm32_count_enable_write(struct counter_device *counter,
> + struct counter_count *count, u8 enable)
> {
> struct stm32_timer_cnt *const priv = counter->priv;
> - int err;
> u32 cr1;
> - bool enable;
> -
> - err = kstrtobool(buf, &enable);
> - if (err)
> - return err;
>
> if (enable) {
> regmap_read(priv->regmap, TIM_CR1, &cr1);
> @@ -236,46 +223,30 @@ static ssize_t stm32_count_enable_write(struct counter_device *counter,
> /* Keep enabled state to properly handle low power states */
> priv->enabled = enable;
>
> - return len;
> + return 0;
> }
>
> -static const struct counter_count_ext stm32_count_ext[] = {
> - {
> - .name = "direction",
> - .read = stm32_count_direction_read,
> - },
> - {
> - .name = "enable",
> - .read = stm32_count_enable_read,
> - .write = stm32_count_enable_write
> - },
> - {
> - .name = "ceiling",
> - .read = stm32_count_ceiling_read,
> - .write = stm32_count_ceiling_write
> - },
> -};
> -
> -enum stm32_synapse_action {
> - STM32_SYNAPSE_ACTION_NONE,
> - STM32_SYNAPSE_ACTION_BOTH_EDGES
> +static struct counter_data stm32_count_ext[] = {
> + COUNTER_DATA_DIRECTION(stm32_count_direction_read),
> + COUNTER_DATA_ENABLE(stm32_count_enable_read, stm32_count_enable_write),
> + COUNTER_DATA_CEILING(stm32_count_ceiling_read,
> + stm32_count_ceiling_write),
> };
>
> -static enum counter_synapse_action stm32_synapse_actions[] = {
> - [STM32_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,
> - [STM32_SYNAPSE_ACTION_BOTH_EDGES] = COUNTER_SYNAPSE_ACTION_BOTH_EDGES
> +static const u8 stm32_synapse_actions[] = {
> + COUNTER_SYNAPSE_ACTION_NONE,
> + COUNTER_SYNAPSE_ACTION_BOTH_EDGES
> };
>
> static int stm32_action_get(struct counter_device *counter,
> struct counter_count *count,
> - struct counter_synapse *synapse,
> - size_t *action)
> + struct counter_synapse *synapse, u8 *action)
> {
> - size_t function;
> + u8 function;
> int err;
>
> /* Default action mode (e.g. STM32_COUNT_SLAVE_MODE_DISABLED) */
> - *action = STM32_SYNAPSE_ACTION_NONE;
> + *action = COUNTER_SYNAPSE_ACTION_NONE;
>
> err = stm32_count_function_get(counter, count, &function);
> if (err)
> @@ -285,30 +256,22 @@ static int stm32_action_get(struct counter_device *counter,
> case STM32_COUNT_ENCODER_MODE_1:
> /* counts up/down on TI1FP1 edge depending on TI2FP2 level */
> if (synapse->signal->id == count->synapses[0].signal->id)
> - *action = STM32_SYNAPSE_ACTION_BOTH_EDGES;
> + *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
> break;
> case STM32_COUNT_ENCODER_MODE_2:
> /* counts up/down on TI2FP2 edge depending on TI1FP1 level */
> if (synapse->signal->id == count->synapses[1].signal->id)
> - *action = STM32_SYNAPSE_ACTION_BOTH_EDGES;
> + *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
> break;
> case STM32_COUNT_ENCODER_MODE_3:
> /* counts up/down on both TI1FP1 and TI2FP2 edges */
> - *action = STM32_SYNAPSE_ACTION_BOTH_EDGES;
> + *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
> break;
> }
>
> return 0;
> }
>
> -static const struct counter_ops stm32_timer_cnt_ops = {
> - .count_read = stm32_count_read,
> - .count_write = stm32_count_write,
> - .function_get = stm32_count_function_get,
> - .function_set = stm32_count_function_set,
> - .action_get = stm32_action_get,
> -};
> -
> static struct counter_signal stm32_signals[] = {
> {
> .id = 0,
> @@ -363,7 +326,11 @@ static int stm32_timer_cnt_probe(struct platform_device *pdev)
>
> priv->counter.name = dev_name(dev);
> priv->counter.parent = dev;
> - priv->counter.ops = &stm32_timer_cnt_ops;
> + priv->counter.count_read = stm32_count_read;
> + priv->counter.count_write = stm32_count_write;
> + priv->counter.function_read = stm32_count_function_get;
> + priv->counter.function_write = stm32_count_function_set;
> + priv->counter.action_read = stm32_action_get;
> priv->counter.counts = &stm32_counts;
> priv->counter.num_counts = 1;
> priv->counter.signals = stm32_signals;
> diff --git a/drivers/counter/ti-eqep.c b/drivers/counter/ti-eqep.c
> index 1ff07faef27f..7152f0b3c2de 100644
> --- a/drivers/counter/ti-eqep.c
> +++ b/drivers/counter/ti-eqep.c
> @@ -13,6 +13,7 @@
> #include <linux/platform_device.h>
> #include <linux/pm_runtime.h>
> #include <linux/regmap.h>
> +#include <linux/types.h>
>
> /* 32-bit registers */
> #define QPOSCNT 0x0
> @@ -80,12 +81,6 @@ enum {
> TI_EQEP_COUNT_FUNC_DOWN_COUNT,
> };
>
> -enum {
> - TI_EQEP_SYNAPSE_ACTION_BOTH_EDGES,
> - TI_EQEP_SYNAPSE_ACTION_RISING_EDGE,
> - TI_EQEP_SYNAPSE_ACTION_NONE,
> -};
> -
> struct ti_eqep_cnt {
> struct counter_device counter;
> struct regmap *regmap32;
> @@ -93,7 +88,7 @@ struct ti_eqep_cnt {
> };
>
> static int ti_eqep_count_read(struct counter_device *counter,
> - struct counter_count *count, unsigned long *val)
> + struct counter_count *count, u64 *val)
> {
> struct ti_eqep_cnt *priv = counter->priv;
> u32 cnt;
> @@ -105,7 +100,7 @@ static int ti_eqep_count_read(struct counter_device *counter,
> }
>
> static int ti_eqep_count_write(struct counter_device *counter,
> - struct counter_count *count, unsigned long val)
> + struct counter_count *count, u64 val)
> {
> struct ti_eqep_cnt *priv = counter->priv;
> u32 max;
> @@ -117,33 +112,66 @@ static int ti_eqep_count_write(struct counter_device *counter,
> return regmap_write(priv->regmap32, QPOSCNT, val);
> }
>
> +static const u8 ti_qep_t2c_functions_map[] = {
> +};
> +
> static int ti_eqep_function_get(struct counter_device *counter,
> - struct counter_count *count, size_t *function)
> + struct counter_count *count, u8 *function)
> {
> struct ti_eqep_cnt *priv = counter->priv;
> u32 qdecctl;
>
> regmap_read(priv->regmap16, QDECCTL, &qdecctl);
> - *function = (qdecctl & QDECCTL_QSRC) >> QDECCTL_QSRC_SHIFT;
> +
> + switch ((qdecctl & QDECCTL_QSRC) >> QDECCTL_QSRC_SHIFT) {
> + case TI_EQEP_COUNT_FUNC_QUAD_COUNT:
> + *function = COUNTER_COUNT_FUNCTION_QUADRATURE_X4;
> + break;
> + case TI_EQEP_COUNT_FUNC_DIR_COUNT:
> + *function = COUNTER_COUNT_FUNCTION_PULSE_DIRECTION;
> + break;
> + case TI_EQEP_COUNT_FUNC_UP_COUNT:
> + *function = COUNTER_COUNT_FUNCTION_INCREASE;
> + break;
> + case TI_EQEP_COUNT_FUNC_DOWN_COUNT:
> + *function = COUNTER_COUNT_FUNCTION_DECREASE;
> + break;
> + }
>
> return 0;
> }
>
> static int ti_eqep_function_set(struct counter_device *counter,
> - struct counter_count *count, size_t function)
> + struct counter_count *count, u8 function)
> {
> struct ti_eqep_cnt *priv = counter->priv;
> + unsigned long qsrc;
> +
> + switch (function) {
> + case COUNTER_COUNT_FUNCTION_QUADRATURE_X4:
> + qsrc = TI_EQEP_COUNT_FUNC_QUAD_COUNT;
> + break;
> + case COUNTER_COUNT_FUNCTION_PULSE_DIRECTION:
> + qsrc = TI_EQEP_COUNT_FUNC_DIR_COUNT;
> + break;
> + case COUNTER_COUNT_FUNCTION_INCREASE:
> + qsrc = TI_EQEP_COUNT_FUNC_UP_COUNT;
> + break;
> + case COUNTER_COUNT_FUNCTION_DECREASE:
> + qsrc = TI_EQEP_COUNT_FUNC_DOWN_COUNT;
> + break;
> + }
>
> return regmap_write_bits(priv->regmap16, QDECCTL, QDECCTL_QSRC,
> - function << QDECCTL_QSRC_SHIFT);
> + qsrc << QDECCTL_QSRC_SHIFT);
> }
>
> static int ti_eqep_action_get(struct counter_device *counter,
> struct counter_count *count,
> - struct counter_synapse *synapse, size_t *action)
> + struct counter_synapse *synapse, u8 *action)
> {
> struct ti_eqep_cnt *priv = counter->priv;
> - size_t function;
> + u8 function;
> u32 qdecctl;
> int err;
>
> @@ -152,27 +180,27 @@ static int ti_eqep_action_get(struct counter_device *counter,
> return err;
>
> switch (function) {
> - case TI_EQEP_COUNT_FUNC_QUAD_COUNT:
> + case COUNTER_COUNT_FUNCTION_QUADRATURE_X4:
> /* In quadrature mode, the rising and falling edge of both
> * QEPA and QEPB trigger QCLK.
> */
> - *action = TI_EQEP_SYNAPSE_ACTION_BOTH_EDGES;
> + *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
> break;
> - case TI_EQEP_COUNT_FUNC_DIR_COUNT:
> + case COUNTER_COUNT_FUNCTION_PULSE_DIRECTION:
> /* In direction-count mode only rising edge of QEPA is counted
> * and QEPB gives direction.
> */
> switch (synapse->signal->id) {
> case TI_EQEP_SIGNAL_QEPA:
> - *action = TI_EQEP_SYNAPSE_ACTION_RISING_EDGE;
> + *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
> break;
> default:
> - *action = TI_EQEP_SYNAPSE_ACTION_NONE;
> + *action = COUNTER_SYNAPSE_ACTION_NONE;
> break;
> }
> break;
> - case TI_EQEP_COUNT_FUNC_UP_COUNT:
> - case TI_EQEP_COUNT_FUNC_DOWN_COUNT:
> + case COUNTER_COUNT_FUNCTION_INCREASE:
> + case COUNTER_COUNT_FUNCTION_DECREASE:
> /* In up/down-count modes only QEPA is counted and QEPB is not
> * used.
> */
> @@ -183,134 +211,105 @@ static int ti_eqep_action_get(struct counter_device *counter,
> return err;
>
> if (qdecctl & QDECCTL_XCR)
> - *action = TI_EQEP_SYNAPSE_ACTION_BOTH_EDGES;
> + *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
> else
> - *action = TI_EQEP_SYNAPSE_ACTION_RISING_EDGE;
> + *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
> break;
> default:
> - *action = TI_EQEP_SYNAPSE_ACTION_NONE;
> + *action = COUNTER_SYNAPSE_ACTION_NONE;
> break;
> }
> break;
> + default: return -EINVAL;
> }
>
> return 0;
> }
>
> -static const struct counter_ops ti_eqep_counter_ops = {
> - .count_read = ti_eqep_count_read,
> - .count_write = ti_eqep_count_write,
> - .function_get = ti_eqep_function_get,
> - .function_set = ti_eqep_function_set,
> - .action_get = ti_eqep_action_get,
> -};
> -
> -static ssize_t ti_eqep_position_ceiling_read(struct counter_device *counter,
> - struct counter_count *count,
> - void *ext_priv, char *buf)
> +static int ti_eqep_position_ceiling_read(struct counter_device *counter,
> + struct counter_count *count,
> + u64 *ceiling)
> {
> struct ti_eqep_cnt *priv = counter->priv;
> u32 qposmax;
>
> regmap_read(priv->regmap32, QPOSMAX, &qposmax);
>
> - return sprintf(buf, "%u\n", qposmax);
> + *ceiling = qposmax;
> +
> + return 0;
> }
>
> -static ssize_t ti_eqep_position_ceiling_write(struct counter_device *counter,
> - struct counter_count *count,
> - void *ext_priv, const char *buf,
> - size_t len)
> +static int ti_eqep_position_ceiling_write(struct counter_device *counter,
> + struct counter_count *count,
> + u64 ceiling)
> {
> struct ti_eqep_cnt *priv = counter->priv;
> - int err;
> - u32 res;
>
> - err = kstrtouint(buf, 0, &res);
> - if (err < 0)
> - return err;
> + if (ceiling != (u32)ceiling)
> + return -ERANGE;
>
> - regmap_write(priv->regmap32, QPOSMAX, res);
> + regmap_write(priv->regmap32, QPOSMAX, ceiling);
>
> - return len;
> + return 0;
> }
>
> -static ssize_t ti_eqep_position_floor_read(struct counter_device *counter,
> - struct counter_count *count,
> - void *ext_priv, char *buf)
> +static int ti_eqep_position_floor_read(struct counter_device *counter,
> + struct counter_count *count, u64 *floor)
> {
> struct ti_eqep_cnt *priv = counter->priv;
> u32 qposinit;
>
> regmap_read(priv->regmap32, QPOSINIT, &qposinit);
>
> - return sprintf(buf, "%u\n", qposinit);
> + *floor = qposinit;
> +
> + return 0;
> }
>
> -static ssize_t ti_eqep_position_floor_write(struct counter_device *counter,
> - struct counter_count *count,
> - void *ext_priv, const char *buf,
> - size_t len)
> +static int ti_eqep_position_floor_write(struct counter_device *counter,
> + struct counter_count *count, u64 floor)
> {
> struct ti_eqep_cnt *priv = counter->priv;
> - int err;
> - u32 res;
>
> - err = kstrtouint(buf, 0, &res);
> - if (err < 0)
> - return err;
> + if (floor != (u32)floor)
> + return -ERANGE;
>
> - regmap_write(priv->regmap32, QPOSINIT, res);
> + regmap_write(priv->regmap32, QPOSINIT, floor);
>
> - return len;
> + return 0;
> }
>
> -static ssize_t ti_eqep_position_enable_read(struct counter_device *counter,
> - struct counter_count *count,
> - void *ext_priv, char *buf)
> +static int ti_eqep_position_enable_read(struct counter_device *counter,
> + struct counter_count *count, u8 *enable)
> {
> struct ti_eqep_cnt *priv = counter->priv;
> u32 qepctl;
>
> regmap_read(priv->regmap16, QEPCTL, &qepctl);
>
> - return sprintf(buf, "%u\n", !!(qepctl & QEPCTL_PHEN));
> + *enable = !!(qepctl & QEPCTL_PHEN);
> +
> + return 0;
> }
>
> -static ssize_t ti_eqep_position_enable_write(struct counter_device *counter,
> - struct counter_count *count,
> - void *ext_priv, const char *buf,
> - size_t len)
> +static int ti_eqep_position_enable_write(struct counter_device *counter,
> + struct counter_count *count, u8 enable)
> {
> struct ti_eqep_cnt *priv = counter->priv;
> - int err;
> - bool res;
>
> - err = kstrtobool(buf, &res);
> - if (err < 0)
> - return err;
> -
> - regmap_write_bits(priv->regmap16, QEPCTL, QEPCTL_PHEN, res ? -1 : 0);
> + regmap_write_bits(priv->regmap16, QEPCTL, QEPCTL_PHEN, enable ? -1 : 0);
>
> - return len;
> + return 0;
> }
>
> -static struct counter_count_ext ti_eqep_position_ext[] = {
> - {
> - .name = "ceiling",
> - .read = ti_eqep_position_ceiling_read,
> - .write = ti_eqep_position_ceiling_write,
> - },
> - {
> - .name = "floor",
> - .read = ti_eqep_position_floor_read,
> - .write = ti_eqep_position_floor_write,
> - },
> - {
> - .name = "enable",
> - .read = ti_eqep_position_enable_read,
> - .write = ti_eqep_position_enable_write,
> - },
> +static struct counter_data ti_eqep_position_ext[] = {
> + COUNTER_DATA_CEILING(ti_eqep_position_ceiling_read,
> + ti_eqep_position_ceiling_write),
> + COUNTER_DATA_FLOOR(ti_eqep_position_floor_read,
> + ti_eqep_position_floor_write),
> + COUNTER_DATA_ENABLE(ti_eqep_position_enable_read,
> + ti_eqep_position_enable_write),
> };
>
> static struct counter_signal ti_eqep_signals[] = {
> @@ -324,17 +323,17 @@ static struct counter_signal ti_eqep_signals[] = {
> },
> };
>
> -static const enum counter_count_function ti_eqep_position_functions[] = {
> - [TI_EQEP_COUNT_FUNC_QUAD_COUNT] = COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
> - [TI_EQEP_COUNT_FUNC_DIR_COUNT] = COUNTER_COUNT_FUNCTION_PULSE_DIRECTION,
> - [TI_EQEP_COUNT_FUNC_UP_COUNT] = COUNTER_COUNT_FUNCTION_INCREASE,
> - [TI_EQEP_COUNT_FUNC_DOWN_COUNT] = COUNTER_COUNT_FUNCTION_DECREASE,
> +static const u8 ti_eqep_position_functions[] = {
> + COUNTER_COUNT_FUNCTION_QUADRATURE_X4,
> + COUNTER_COUNT_FUNCTION_PULSE_DIRECTION,
> + COUNTER_COUNT_FUNCTION_INCREASE,
> + COUNTER_COUNT_FUNCTION_DECREASE,
> };
>
> -static const enum counter_synapse_action ti_eqep_position_synapse_actions[] = {
> - [TI_EQEP_SYNAPSE_ACTION_BOTH_EDGES] = COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
> - [TI_EQEP_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE,
> - [TI_EQEP_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,
> +static const u8 ti_eqep_position_synapse_actions[] = {
> + COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
> + COUNTER_SYNAPSE_ACTION_RISING_EDGE,
> + COUNTER_SYNAPSE_ACTION_NONE,
> };
>
> static struct counter_synapse ti_eqep_position_synapses[] = {
> @@ -406,7 +405,11 @@ static int ti_eqep_probe(struct platform_device *pdev)
>
> priv->counter.name = dev_name(dev);
> priv->counter.parent = dev;
> - priv->counter.ops = &ti_eqep_counter_ops;
> + priv->counter.count_read = ti_eqep_count_read;
> + priv->counter.count_write = ti_eqep_count_write;
> + priv->counter.function_read = ti_eqep_function_get;
> + priv->counter.function_write = ti_eqep_function_set;
> + priv->counter.action_read = ti_eqep_action_get;
> priv->counter.counts = ti_eqep_counts;
> priv->counter.num_counts = ARRAY_SIZE(ti_eqep_counts);
> priv->counter.signals = ti_eqep_signals;
> diff --git a/include/linux/counter.h b/include/linux/counter.h
> index 9dbd5df4cd34..e8abbaf47a4b 100644
> --- a/include/linux/counter.h
> +++ b/include/linux/counter.h
> @@ -6,418 +6,161 @@
> #ifndef _COUNTER_H_
> #define _COUNTER_H_
>
> -#include <linux/counter_enum.h>
> #include <linux/device.h>
> +#include <linux/kernel.h>
> +#include <linux/list.h>
> #include <linux/types.h>
> -
> -enum counter_count_direction {
> - COUNTER_COUNT_DIRECTION_FORWARD = 0,
> - COUNTER_COUNT_DIRECTION_BACKWARD
> -};
> -extern const char *const counter_count_direction_str[2];
> -
> -enum counter_count_mode {
> - COUNTER_COUNT_MODE_NORMAL = 0,
> - COUNTER_COUNT_MODE_RANGE_LIMIT,
> - COUNTER_COUNT_MODE_NON_RECYCLE,
> - COUNTER_COUNT_MODE_MODULO_N
> -};
> -extern const char *const counter_count_mode_str[4];
> +#include <uapi/linux/counter-types.h>
>
> struct counter_device;
> +struct counter_count;
> +struct counter_synapse;
> struct counter_signal;
>
> -/**
> - * struct counter_signal_ext - Counter Signal extensions
> - * @name: attribute name
> - * @read: read callback for this attribute; may be NULL
> - * @write: write callback for this attribute; may be NULL
> - * @priv: data private to the driver
> - */
> -struct counter_signal_ext {
> +struct counter_data {
> + u8 type;
> const char *name;
> - ssize_t (*read)(struct counter_device *counter,
> - struct counter_signal *signal, void *priv, char *buf);
> - ssize_t (*write)(struct counter_device *counter,
> - struct counter_signal *signal, void *priv,
> - const char *buf, size_t len);
> void *priv;
> + union {
> + int (*action_read)(struct counter_device *counter,
> + struct counter_count *count,
> + struct counter_synapse *synapse, u8 *action);
> + ssize_t (*device_string_read)(struct counter_device *counter,
> + char *buf, size_t len);
> + ssize_t (*count_string_read)(struct counter_device *counter,
> + struct counter_count *count,
> + char *buf, size_t len);
> + ssize_t (*signal_string_read)(struct counter_device *counter,
> + struct counter_signal *signal,
> + char *buf, size_t len);
> + int (*device_u8_read)(struct counter_device *counter, u8 *val);
> + int (*count_u8_read)(struct counter_device *counter,
> + struct counter_count *count, u8 *val);
> + int (*signal_u8_read)(struct counter_device *counter,
> + struct counter_signal *signal, u8 *val);
> + int (*device_u64_read)(struct counter_device *counter,
> + u64 *val);
> + int (*count_u64_read)(struct counter_device *counter,
> + struct counter_count *count, u64 *val);
> + int (*signal_u64_read)(struct counter_device *counter,
> + struct counter_signal *signal, u64 *val);
> + };
> + union {
> + int (*action_write)(struct counter_device *counter,
> + struct counter_count *count,
> + struct counter_synapse *synapse, u8 action);
> + ssize_t (*device_string_write)(struct counter_device *counter,
> + const char *buf, size_t len);
> + ssize_t (*count_string_write)(struct counter_device *counter,
> + struct counter_count *count,
> + const char *buf, size_t len);
> + ssize_t (*signal_string_write)(struct counter_device *counter,
> + struct counter_signal *signal,
> + const char *buf, size_t len);
> + int (*device_u8_write)(struct counter_device *counter, u8 val);
> + int (*count_u8_write)(struct counter_device *counter,
> + struct counter_count *count, u8 val);
> + int (*signal_u8_write)(struct counter_device *counter,
> + struct counter_signal *signal, u8 val);
> + int (*device_u64_write)(struct counter_device *counter,
> + u64 val);
> + int (*count_u64_write)(struct counter_device *counter,
> + struct counter_count *count, u64 val);
> + int (*signal_u64_write)(struct counter_device *counter,
> + struct counter_signal *signal, u64 val);
> + };
> };
>
> /**
> * struct counter_signal - Counter Signal node
> - * @id: unique ID used to identify signal
> - * @name: device-specific Signal name; ideally, this should match the name
> - * as it appears in the datasheet documentation
> - * @ext: optional array of Counter Signal extensions
> - * @num_ext: number of Counter Signal extensions specified in @ext
> - * @priv: optional private data supplied by driver
> + * @id: unique ID used to identify the Signal
> + * @name: device-specific Signal name
> + * @ext: optional array of Signal extensions
> + * @num_ext: number of Signal extensions specified in @ext
> */
> struct counter_signal {
> int id;
> const char *name;
>
> - const struct counter_signal_ext *ext;
> + struct counter_data *ext;
> size_t num_ext;
> -
> - void *priv;
> -};
> -
> -/**
> - * struct counter_signal_enum_ext - Signal enum extension attribute
> - * @items: Array of strings
> - * @num_items: Number of items specified in @items
> - * @set: Set callback function; may be NULL
> - * @get: Get callback function; may be NULL
> - *
> - * The counter_signal_enum_ext structure can be used to implement enum style
> - * Signal extension attributes. Enum style attributes are those which have a set
> - * of strings that map to unsigned integer values. The Generic Counter Signal
> - * enum extension helper code takes care of mapping between value and string, as
> - * well as generating a "_available" file which contains a list of all available
> - * items. The get callback is used to query the currently active item; the index
> - * of the item within the respective items array is returned via the 'item'
> - * parameter. The set callback is called when the attribute is updated; the
> - * 'item' parameter contains the index of the newly activated item within the
> - * respective items array.
> - */
> -struct counter_signal_enum_ext {
> - const char * const *items;
> - size_t num_items;
> - int (*get)(struct counter_device *counter,
> - struct counter_signal *signal, size_t *item);
> - int (*set)(struct counter_device *counter,
> - struct counter_signal *signal, size_t item);
> -};
> -
> -/**
> - * COUNTER_SIGNAL_ENUM() - Initialize Signal enum extension
> - * @_name: Attribute name
> - * @_e: Pointer to a counter_signal_enum_ext structure
> - *
> - * This should usually be used together with COUNTER_SIGNAL_ENUM_AVAILABLE()
> - */
> -#define COUNTER_SIGNAL_ENUM(_name, _e) \
> -{ \
> - .name = (_name), \
> - .read = counter_signal_enum_read, \
> - .write = counter_signal_enum_write, \
> - .priv = (_e) \
> -}
> -
> -/**
> - * COUNTER_SIGNAL_ENUM_AVAILABLE() - Initialize Signal enum available extension
> - * @_name: Attribute name ("_available" will be appended to the name)
> - * @_e: Pointer to a counter_signal_enum_ext structure
> - *
> - * Creates a read only attribute that lists all the available enum items in a
> - * newline separated list. This should usually be used together with
> - * COUNTER_SIGNAL_ENUM()
> - */
> -#define COUNTER_SIGNAL_ENUM_AVAILABLE(_name, _e) \
> -{ \
> - .name = (_name "_available"), \
> - .read = counter_signal_enum_available_read, \
> - .priv = (_e) \
> -}
> -
> -enum counter_synapse_action {
> - COUNTER_SYNAPSE_ACTION_NONE = 0,
> - COUNTER_SYNAPSE_ACTION_RISING_EDGE,
> - COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
> - COUNTER_SYNAPSE_ACTION_BOTH_EDGES
> };
>
> /**
> * struct counter_synapse - Counter Synapse node
> - * @action: index of current action mode
> * @actions_list: array of available action modes
> * @num_actions: number of action modes specified in @actions_list
> - * @signal: pointer to associated signal
> + * @signal: pointer to the associated Signal
> */
> struct counter_synapse {
> - size_t action;
> - const enum counter_synapse_action *actions_list;
> + const u8 *actions_list;
> size_t num_actions;
>
> struct counter_signal *signal;
> };
>
> -struct counter_count;
> -
> -/**
> - * struct counter_count_ext - Counter Count extension
> - * @name: attribute name
> - * @read: read callback for this attribute; may be NULL
> - * @write: write callback for this attribute; may be NULL
> - * @priv: data private to the driver
> - */
> -struct counter_count_ext {
> - const char *name;
> - ssize_t (*read)(struct counter_device *counter,
> - struct counter_count *count, void *priv, char *buf);
> - ssize_t (*write)(struct counter_device *counter,
> - struct counter_count *count, void *priv,
> - const char *buf, size_t len);
> - void *priv;
> -};
> -
> -enum counter_count_function {
> - COUNTER_COUNT_FUNCTION_INCREASE = 0,
> - COUNTER_COUNT_FUNCTION_DECREASE,
> - COUNTER_COUNT_FUNCTION_PULSE_DIRECTION,
> - COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A,
> - COUNTER_COUNT_FUNCTION_QUADRATURE_X1_B,
> - COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A,
> - COUNTER_COUNT_FUNCTION_QUADRATURE_X2_B,
> - COUNTER_COUNT_FUNCTION_QUADRATURE_X4
> -};
> -
> /**
> * struct counter_count - Counter Count node
> - * @id: unique ID used to identify Count
> - * @name: device-specific Count name; ideally, this should match
> - * the name as it appears in the datasheet documentation
> - * @function: index of current function mode
> - * @functions_list: array available function modes
> + * @id: unique ID used to identify the Count
> + * @name: device-specific Count name
> + * @functions_list: array of available function modes
> * @num_functions: number of function modes specified in @functions_list
> - * @synapses: array of synapses for initialization
> - * @num_synapses: number of synapses specified in @synapses
> - * @ext: optional array of Counter Count extensions
> - * @num_ext: number of Counter Count extensions specified in @ext
> - * @priv: optional private data supplied by driver
> + * @synapses: array of Synapses for initialization
> + * @num_synapses: number of Synapses specified in @synapses
> + * @ext: optional array of Count extensions
> + * @num_ext: number of Count extensions specified in @ext
> */
> struct counter_count {
> int id;
> const char *name;
>
> - size_t function;
> - const enum counter_count_function *functions_list;
> + const u8 *functions_list;
> size_t num_functions;
>
> struct counter_synapse *synapses;
> size_t num_synapses;
>
> - const struct counter_count_ext *ext;
> + struct counter_data *ext;
> size_t num_ext;
> -
> - void *priv;
> };
>
> /**
> - * struct counter_count_enum_ext - Count enum extension attribute
> - * @items: Array of strings
> - * @num_items: Number of items specified in @items
> - * @set: Set callback function; may be NULL
> - * @get: Get callback function; may be NULL
> - *
> - * The counter_count_enum_ext structure can be used to implement enum style
> - * Count extension attributes. Enum style attributes are those which have a set
> - * of strings that map to unsigned integer values. The Generic Counter Count
> - * enum extension helper code takes care of mapping between value and string, as
> - * well as generating a "_available" file which contains a list of all available
> - * items. The get callback is used to query the currently active item; the index
> - * of the item within the respective items array is returned via the 'item'
> - * parameter. The set callback is called when the attribute is updated; the
> - * 'item' parameter contains the index of the newly activated item within the
> - * respective items array.
> - */
> -struct counter_count_enum_ext {
> - const char * const *items;
> - size_t num_items;
> - int (*get)(struct counter_device *counter, struct counter_count *count,
> - size_t *item);
> - int (*set)(struct counter_device *counter, struct counter_count *count,
> - size_t item);
> -};
> -
> -/**
> - * COUNTER_COUNT_ENUM() - Initialize Count enum extension
> - * @_name: Attribute name
> - * @_e: Pointer to a counter_count_enum_ext structure
> - *
> - * This should usually be used together with COUNTER_COUNT_ENUM_AVAILABLE()
> - */
> -#define COUNTER_COUNT_ENUM(_name, _e) \
> -{ \
> - .name = (_name), \
> - .read = counter_count_enum_read, \
> - .write = counter_count_enum_write, \
> - .priv = (_e) \
> -}
> -
> -/**
> - * COUNTER_COUNT_ENUM_AVAILABLE() - Initialize Count enum available extension
> - * @_name: Attribute name ("_available" will be appended to the name)
> - * @_e: Pointer to a counter_count_enum_ext structure
> - *
> - * Creates a read only attribute that lists all the available enum items in a
> - * newline separated list. This should usually be used together with
> - * COUNTER_COUNT_ENUM()
> - */
> -#define COUNTER_COUNT_ENUM_AVAILABLE(_name, _e) \
> -{ \
> - .name = (_name "_available"), \
> - .read = counter_count_enum_available_read, \
> - .priv = (_e) \
> -}
> -
> -/**
> - * struct counter_device_attr_group - internal container for attribute group
> + * struct counter_attribute_group - internal container for attribute group
> * @attr_group: Counter sysfs attributes group
> * @attr_list: list to keep track of created Counter sysfs attributes
> * @num_attr: number of Counter sysfs attributes
> */
> -struct counter_device_attr_group {
> +struct counter_attribute_group {
> struct attribute_group attr_group;
> struct list_head attr_list;
> size_t num_attr;
> };
>
> -/**
> - * struct counter_device_state - internal state container for a Counter device
> - * @id: unique ID used to identify the Counter
> - * @dev: internal device structure
> - * @groups_list: attribute groups list (for Signals, Counts, and ext)
> - * @num_groups: number of attribute groups containers
> - * @groups: Counter sysfs attribute groups (to populate @dev.groups)
> - */
> -struct counter_device_state {
> - int id;
> - struct device dev;
> - struct counter_device_attr_group *groups_list;
> - size_t num_groups;
> - const struct attribute_group **groups;
> -};
> -
> -enum counter_signal_value {
> - COUNTER_SIGNAL_LOW = 0,
> - COUNTER_SIGNAL_HIGH
> -};
> -
> -/**
> - * struct counter_ops - Callbacks from driver
> - * @signal_read: optional read callback for Signal attribute. The read
> - * value of the respective Signal should be passed back via
> - * the val parameter.
> - * @count_read: optional read callback for Count attribute. The read
> - * value of the respective Count should be passed back via
> - * the val parameter.
> - * @count_write: optional write callback for Count attribute. The write
> - * value for the respective Count is passed in via the val
> - * parameter.
> - * @function_get: function to get the current count function mode. Returns
> - * 0 on success and negative error code on error. The index
> - * of the respective Count's returned function mode should
> - * be passed back via the function parameter.
> - * @function_set: function to set the count function mode. function is the
> - * index of the requested function mode from the respective
> - * Count's functions_list array.
> - * @action_get: function to get the current action mode. Returns 0 on
> - * success and negative error code on error. The index of
> - * the respective Synapse's returned action mode should be
> - * passed back via the action parameter.
> - * @action_set: function to set the action mode. action is the index of
> - * the requested action mode from the respective Synapse's
> - * actions_list array.
> - */
> -struct counter_ops {
> - int (*signal_read)(struct counter_device *counter,
> - struct counter_signal *signal,
> - enum counter_signal_value *val);
> - int (*count_read)(struct counter_device *counter,
> - struct counter_count *count, unsigned long *val);
> - int (*count_write)(struct counter_device *counter,
> - struct counter_count *count, unsigned long val);
> - int (*function_get)(struct counter_device *counter,
> - struct counter_count *count, size_t *function);
> - int (*function_set)(struct counter_device *counter,
> - struct counter_count *count, size_t function);
> - int (*action_get)(struct counter_device *counter,
> - struct counter_count *count,
> - struct counter_synapse *synapse, size_t *action);
> - int (*action_set)(struct counter_device *counter,
> - struct counter_count *count,
> - struct counter_synapse *synapse, size_t action);
> -};
> -
> -/**
> - * struct counter_device_ext - Counter device extension
> - * @name: attribute name
> - * @read: read callback for this attribute; may be NULL
> - * @write: write callback for this attribute; may be NULL
> - * @priv: data private to the driver
> - */
> -struct counter_device_ext {
> - const char *name;
> - ssize_t (*read)(struct counter_device *counter, void *priv, char *buf);
> - ssize_t (*write)(struct counter_device *counter, void *priv,
> - const char *buf, size_t len);
> - void *priv;
> -};
> -
> -/**
> - * struct counter_device_enum_ext - Counter enum extension attribute
> - * @items: Array of strings
> - * @num_items: Number of items specified in @items
> - * @set: Set callback function; may be NULL
> - * @get: Get callback function; may be NULL
> - *
> - * The counter_device_enum_ext structure can be used to implement enum style
> - * Counter extension attributes. Enum style attributes are those which have a
> - * set of strings that map to unsigned integer values. The Generic Counter enum
> - * extension helper code takes care of mapping between value and string, as well
> - * as generating a "_available" file which contains a list of all available
> - * items. The get callback is used to query the currently active item; the index
> - * of the item within the respective items array is returned via the 'item'
> - * parameter. The set callback is called when the attribute is updated; the
> - * 'item' parameter contains the index of the newly activated item within the
> - * respective items array.
> - */
> -struct counter_device_enum_ext {
> - const char * const *items;
> - size_t num_items;
> - int (*get)(struct counter_device *counter, size_t *item);
> - int (*set)(struct counter_device *counter, size_t item);
> -};
> -
> -/**
> - * COUNTER_DEVICE_ENUM() - Initialize Counter enum extension
> - * @_name: Attribute name
> - * @_e: Pointer to a counter_device_enum_ext structure
> - *
> - * This should usually be used together with COUNTER_DEVICE_ENUM_AVAILABLE()
> - */
> -#define COUNTER_DEVICE_ENUM(_name, _e) \
> -{ \
> - .name = (_name), \
> - .read = counter_device_enum_read, \
> - .write = counter_device_enum_write, \
> - .priv = (_e) \
> -}
> -
> -/**
> - * COUNTER_DEVICE_ENUM_AVAILABLE() - Initialize Counter enum available extension
> - * @_name: Attribute name ("_available" will be appended to the name)
> - * @_e: Pointer to a counter_device_enum_ext structure
> - *
> - * Creates a read only attribute that lists all the available enum items in a
> - * newline separated list. This should usually be used together with
> - * COUNTER_DEVICE_ENUM()
> - */
> -#define COUNTER_DEVICE_ENUM_AVAILABLE(_name, _e) \
> -{ \
> - .name = (_name "_available"), \
> - .read = counter_device_enum_available_read, \
> - .priv = (_e) \
> -}
> -
> /**
> * struct counter_device - Counter data structure
> - * @name: name of the device as it appears in the datasheet
> + * @name: name of the device
> * @parent: optional parent device providing the counters
> - * @device_state: internal device state container
> - * @ops: callbacks from driver
> + * @signal_read: optional read callback for Signals. The read value of
> + * the respective Signal should be passed back via the
> + * value parameter.
> + * @count_read: optional read callback for Counts. The read value of the
> + * respective Count should be passed back via the value
> + * parameter.
> + * @count_write: optional write callback for Counts. The write value for
> + * the respective Count is passed in via the value
> + * parameter.
> + * @function_read: optional read callback the Count function modes. The
> + * read function mode of the respective Count should be
> + * passed back via the function parameter.
> + * @function_write: option write callback for Count function modes. The
> + * function mode to write for the respective Count is
> + * passed in via the function parameter.
> + * @action_read: optional read callback the Synapse action modes. The
> + * read action mode of the respective Synapse should be
> + * passed back via the action parameter.
> + * @action_write: option write callback for Synapse action modes. The
> + * action mode to write for the respective Synapse is
> + * passed in via the action parameter.
> * @signals: array of Signals
> * @num_signals: number of Signals specified in @signals
> * @counts: array of Counts
> @@ -425,23 +168,50 @@ struct counter_device_enum_ext {
> * @ext: optional array of Counter device extensions
> * @num_ext: number of Counter device extensions specified in @ext
> * @priv: optional private data supplied by driver
> + * @id: unique ID used to identify the Counter
> + * @dev: internal device structure
> + * @dynamic_names_list: List for dynamic names
> + * @groups_list: attribute groups list (for Signals, Counts, and ext)
> + * @num_groups: number of attribute groups containers
> + * @groups: Counter sysfs attribute groups (to populate @dev.groups)
> */
> struct counter_device {
> const char *name;
> struct device *parent;
> - struct counter_device_state *device_state;
>
> - const struct counter_ops *ops;
> + int (*signal_read)(struct counter_device *counter,
> + struct counter_signal *signal, u8 *value);
> + int (*count_read)(struct counter_device *counter,
> + struct counter_count *count, u64 *value);
> + int (*count_write)(struct counter_device *counter,
> + struct counter_count *count, u64 value);
> + int (*function_read)(struct counter_device *counter,
> + struct counter_count *count, u8 *function);
> + int (*function_write)(struct counter_device *counter,
> + struct counter_count *count, u8 function);
> + int (*action_read)(struct counter_device *counter,
> + struct counter_count *count,
> + struct counter_synapse *synapse, u8 *action);
> + int (*action_write)(struct counter_device *counter,
> + struct counter_count *count,
> + struct counter_synapse *synapse, u8 action);
>
> struct counter_signal *signals;
> size_t num_signals;
> struct counter_count *counts;
> size_t num_counts;
>
> - const struct counter_device_ext *ext;
> + struct counter_data *ext;
> size_t num_ext;
>
> void *priv;
> +
> + int id;
> + struct device dev;
> + struct list_head dynamic_names_list;
> + struct counter_attribute_group *groups_list;
> + size_t num_groups;
> + const struct attribute_group **groups;
> };
>
> int counter_register(struct counter_device *const counter);
> @@ -451,4 +221,134 @@ int devm_counter_register(struct device *dev,
> void devm_counter_unregister(struct device *dev,
> struct counter_device *const counter);
>
> +#define COUNTER_DATA_DEVICE_U8(_name, _read, _write) \
> +{ \
> + .type = COUNTER_DATA_TYPE_U8, \
> + .name = (_name), \
> + .device_u8_read = (_read), \
> + .device_u8_write = (_write), \
> +}
> +#define COUNTER_DATA_COUNT_U8(_name, _read, _write) \
> +{ \
> + .type = COUNTER_DATA_TYPE_U8, \
> + .name = (_name), \
> + .count_u8_read = (_read), \
> + .count_u8_write = (_write), \
> +}
> +#define COUNTER_DATA_SIGNAL_U8(_name, _read, _write) \
> +{ \
> + .type = COUNTER_DATA_TYPE_U8, \
> + .name = (_name), \
> + .signal_u8_read = (_read), \
> + .signal_u8_write = (_write), \
> +}
> +
> +#define COUNTER_DATA_DEVICE_U64(_name, _read, _write) \
> +{ \
> + .type = COUNTER_DATA_TYPE_U64, \
> + .name = (_name), \
> + .device_u64_read = (_read), \
> + .device_u64_write = (_write), \
> +}
> +#define COUNTER_DATA_COUNT_U64(_name, _read, _write) \
> +{ \
> + .type = COUNTER_DATA_TYPE_U64, \
> + .name = (_name), \
> + .count_u64_read = (_read), \
> + .count_u64_write = (_write), \
> +}
> +#define COUNTER_DATA_SIGNAL_U64(_name, _read, _write) \
> +{ \
> + .type = COUNTER_DATA_TYPE_U64, \
> + .name = (_name), \
> + .signal_u64_read = (_read), \
> + .signal_u64_write = (_write), \
> +}
> +
> +#define COUNTER_DATA_DEVICE_STRING(_name, _read, _write) \
> +{ \
> + .type = COUNTER_DATA_TYPE_STRING, \
> + .name = (_name), \
> + .device_string_read = (_read), \
> + .device_string_write = (_write), \
> +}
> +#define COUNTER_DATA_COUNT_STRING(_name, _read, _write) \
> +{ \
> + .type = COUNTER_DATA_TYPE_STRING, \
> + .name = (_name), \
> + .count_string_read = (_read), \
> + .count_string_write = (_write), \
> +}
> +#define COUNTER_DATA_SIGNAL_STRING(_name, _read, _write) \
> +{ \
> + .type = COUNTER_DATA_TYPE_STRING, \
> + .name = (_name), \
> + .signal_string_read = (_read), \
> + .signal_string_write = (_write), \
> +}
> +
> +#define COUNTER_DATA_DEVICE_BOOL(_name, _read, _write) \
> +{ \
> + .type = COUNTER_DATA_TYPE_BOOL, \
> + .name = (_name), \
> + .device_u8_read = (_read), \
> + .device_u8_write = (_write), \
> +}
> +#define COUNTER_DATA_COUNT_BOOL(_name, _read, _write) \
> +{ \
> + .type = COUNTER_DATA_TYPE_BOOL, \
> + .name = (_name), \
> + .count_u8_read = (_read), \
> + .count_u8_write = (_write), \
> +}
> +#define COUNTER_DATA_SIGNAL_BOOL(_name, _read, _write) \
> +{ \
> + .type = COUNTER_DATA_TYPE_BOOL, \
> + .name = (_name), \
> + .signal_u8_read = (_read), \
> + .signal_u8_write = (_write), \
> +}
> +
> +struct counter_available {
> + const u8 *items;
> + size_t num_items;
> +};
> +
> +#define DEFINE_COUNTER_AVAILABLE(_name, _items) \
> + struct counter_available _name = { \
> + .items = (_items), \
> + .num_items = ARRAY_SIZE(_items), \
> + }
> +
> +#define COUNTER_DATA_CEILING(_read, _write) \
> + COUNTER_DATA_COUNT_U64("ceiling", _read, _write)
> +
> +#define COUNTER_DATA_COUNT_MODE(_read, _write, _available) \
> +{ \
> + .type = COUNTER_DATA_TYPE_COUNT_MODE, \
> + .name = "count_mode", \
> + .count_u8_read = (_read), \
> + .count_u8_write = (_write), \
> + .priv = &(_available), \
> +}
> +
> +#define COUNTER_DATA_DIRECTION(_read) \
> +{ \
> + .type = COUNTER_DATA_TYPE_COUNT_DIRECTION, \
> + .name = "direction", \
> + .count_u8_read = (_read), \
> +}
> +
> +#define COUNTER_DATA_ENABLE(_read, _write) \
> + COUNTER_DATA_COUNT_BOOL("enable", _read, _write)
> +
> +#define COUNTER_DATA_FLOOR(_read, _write) \
> + COUNTER_DATA_COUNT_U64("floor", _read, _write)
> +
> +#define COUNTER_DATA_PRESET(_read, _write) \
> + COUNTER_DATA_COUNT_U64("preset", _read, _write)
> +
> +#define COUNTER_DATA_PRESET_ENABLE(_read, _write) \
> + COUNTER_DATA_COUNT_BOOL("preset_enable", _read, _write)
> +
> #endif /* _COUNTER_H_ */
> diff --git a/include/linux/counter_enum.h b/include/linux/counter_enum.h
> deleted file mode 100644
> index 9f917298a88f..000000000000
> --- a/include/linux/counter_enum.h
> +++ /dev/null
> @@ -1,45 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -/*
> - * Counter interface enum functions
> - * Copyright (C) 2018 William Breathitt Gray
> - */
> -#ifndef _COUNTER_ENUM_H_
> -#define _COUNTER_ENUM_H_
> -
> -#include <linux/types.h>
> -
> -struct counter_device;
> -struct counter_signal;
> -struct counter_count;
> -
> -ssize_t counter_signal_enum_read(struct counter_device *counter,
> - struct counter_signal *signal, void *priv,
> - char *buf);
> -ssize_t counter_signal_enum_write(struct counter_device *counter,
> - struct counter_signal *signal, void *priv,
> - const char *buf, size_t len);
> -
> -ssize_t counter_signal_enum_available_read(struct counter_device *counter,
> - struct counter_signal *signal,
> - void *priv, char *buf);
> -
> -ssize_t counter_count_enum_read(struct counter_device *counter,
> - struct counter_count *count, void *priv,
> - char *buf);
> -ssize_t counter_count_enum_write(struct counter_device *counter,
> - struct counter_count *count, void *priv,
> - const char *buf, size_t len);
> -
> -ssize_t counter_count_enum_available_read(struct counter_device *counter,
> - struct counter_count *count,
> - void *priv, char *buf);
> -
> -ssize_t counter_device_enum_read(struct counter_device *counter, void *priv,
> - char *buf);
> -ssize_t counter_device_enum_write(struct counter_device *counter, void *priv,
> - const char *buf, size_t len);
> -
> -ssize_t counter_device_enum_available_read(struct counter_device *counter,
> - void *priv, char *buf);
> -
> -#endif /* _COUNTER_ENUM_H_ */
> diff --git a/include/uapi/linux/counter-types.h b/include/uapi/linux/counter-types.h
> new file mode 100644
> index 000000000000..d19616df0e1c
> --- /dev/null
> +++ b/include/uapi/linux/counter-types.h
> @@ -0,0 +1,45 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +/*
> + * Counter interface data types
> + * Copyright (C) 2020 William Breathitt Gray
> + */
> +#ifndef _UAPI_COUNTER_TYPES_H_
> +#define _UAPI_COUNTER_TYPES_H_
> +
> +#define COUNTER_COUNT_DIRECTION_FORWARD 0
> +#define COUNTER_COUNT_DIRECTION_BACKWARD 1
> +
> +#define COUNTER_COUNT_MODE_NORMAL 0
> +#define COUNTER_COUNT_MODE_RANGE_LIMIT 1
> +#define COUNTER_COUNT_MODE_NON_RECYCLE 2
> +#define COUNTER_COUNT_MODE_MODULO_N 3
> +
> +#define COUNTER_COUNT_FUNCTION_INCREASE 0
> +#define COUNTER_COUNT_FUNCTION_DECREASE 1
> +#define COUNTER_COUNT_FUNCTION_PULSE_DIRECTION 2
> +#define COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A 3
> +#define COUNTER_COUNT_FUNCTION_QUADRATURE_X1_B 4
> +#define COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A 5
> +#define COUNTER_COUNT_FUNCTION_QUADRATURE_X2_B 6
> +#define COUNTER_COUNT_FUNCTION_QUADRATURE_X4 7
> +
> +#define COUNTER_SIGNAL_LOW 0
> +#define COUNTER_SIGNAL_HIGH 1
> +
> +#define COUNTER_SYNAPSE_ACTION_NONE 0
> +#define COUNTER_SYNAPSE_ACTION_RISING_EDGE 1
> +#define COUNTER_SYNAPSE_ACTION_FALLING_EDGE 2
> +#define COUNTER_SYNAPSE_ACTION_BOTH_EDGES 3
> +
> +#define COUNTER_DATA_TYPE_U8 0
> +#define COUNTER_DATA_TYPE_U64 1
> +#define COUNTER_DATA_TYPE_STRING 2
> +#define COUNTER_DATA_TYPE_BOOL 3
> +#define COUNTER_DATA_TYPE_COUNT_FUNCTION 4
> +#define COUNTER_DATA_TYPE_SIGNAL 5
> +#define COUNTER_DATA_TYPE_SYNAPSE_ACTION 6
> +#define COUNTER_DATA_TYPE_ENUM 7
> +#define COUNTER_DATA_TYPE_COUNT_DIRECTION 8
> +#define COUNTER_DATA_TYPE_COUNT_MODE 9
> +
> +#endif /* _UAPI_COUNTER_TYPES_H_ */
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 2/4] docs: counter: Update to reflect sysfs internalization
2020-05-16 19:20 ` William Breathitt Gray
@ 2020-05-24 16:12 ` Jonathan Cameron
-1 siblings, 0 replies; 38+ messages in thread
From: Jonathan Cameron @ 2020-05-24 16:12 UTC (permalink / raw)
To: William Breathitt Gray
Cc: kamel.bouhara, gwendal, alexandre.belloni, david, linux-iio,
linux-kernel, linux-stm32, linux-arm-kernel, syednwaris,
patrick.havelange, fabrice.gasnier, mcoquelin.stm32,
alexandre.torgue
On Sat, 16 May 2020 15:20:00 -0400
William Breathitt Gray <vilhelm.gray@gmail.com> wrote:
> The Counter subsystem architecture and driver implementations have
> changed in order to handle Counter sysfs interactions in a more
> consistent way. This patch updates the Generic Counter interface
> documentation to reflect the changes.
>
> Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Looks good to me.
Jonathan
> ---
> Documentation/driver-api/generic-counter.rst | 215 +++++++++++++------
> 1 file changed, 149 insertions(+), 66 deletions(-)
>
> diff --git a/Documentation/driver-api/generic-counter.rst b/Documentation/driver-api/generic-counter.rst
> index e622f8f6e56a..8f85c30dea0b 100644
> --- a/Documentation/driver-api/generic-counter.rst
> +++ b/Documentation/driver-api/generic-counter.rst
> @@ -250,8 +250,8 @@ for defining a counter device.
> .. kernel-doc:: drivers/counter/counter.c
> :export:
>
> -Implementation
> -==============
> +Driver Implementation
> +=====================
>
> To support a counter device, a driver must first allocate the available
> Counter Signals via counter_signal structures. These Signals should
> @@ -267,25 +267,58 @@ respective counter_count structure. These counter_count structures are
> set to the counts array member of an allocated counter_device structure
> before the Counter is registered to the system.
>
> -Driver callbacks should be provided to the counter_device structure via
> -a constant counter_ops structure in order to communicate with the
> -device: to read and write various Signals and Counts, and to set and get
> -the "action mode" and "function mode" for various Synapses and Counts
> -respectively.
> +Driver callbacks must be provided to the counter_device structure in
> +order to communicate with the device: to read and write various Signals
> +and Counts, and to set and get the "action mode" and "function mode" for
> +various Synapses and Counts respectively.
>
> A defined counter_device structure may be registered to the system by
> passing it to the counter_register function, and unregistered by passing
> it to the counter_unregister function. Similarly, the
> -devm_counter_register and devm_counter_unregister functions may be used
> -if device memory-managed registration is desired.
> -
> -Extension sysfs attributes can be created for auxiliary functionality
> -and data by passing in defined counter_device_ext, counter_count_ext,
> -and counter_signal_ext structures. In these cases, the
> -counter_device_ext structure is used for global/miscellaneous exposure
> -and configuration of the respective Counter device, while the
> -counter_count_ext and counter_signal_ext structures allow for auxiliary
> -exposure and configuration of a specific Count or Signal respectively.
> +devm_counter_register function may be used if device memory-managed
> +registration is desired.
> +
> +The struct counter_data structure is used to define counter extensions
> +for Signals, Synapses, and Counts.
> +
> +The "type" member specifies the type of data (e.g. unsigned long,
> +boolean, etc.) handled by this extension. The "read" and "write" members
> +can then be set by the counter device driver with callbacks to handle
> +that data.
> +
> +Convenience macros such as `COUNTER_DATA_COUNT_U64` are provided for use
> +by driver authors. In particular, driver authors are expected to use
> +the provided macros for standard Counter subsystem attributes in order
> +to maintain a consistent interface for userspace. For example, a counter
> +device driver may define several standard attributes like so::
> +
> + struct counter_data count_ext[] = {
> + COUNTER_DATA_DIRECTION(count_direction_read),
> + COUNTER_DATA_ENABLE(count_enable_read, count_enable_write),
> + COUNTER_DATA_CEILING(count_ceiling_read, count_ceiling_write),
> + };
> +
> +This makes it intuitive to see, add, and modify the attributes that are
> +supported by this driver ("direction", "enable", and "ceiling") and to
> +maintain this code without getting lost in a web of struct braces.
> +
> +Callbacks must match the function type expected for the respective
> +component or extension. These function types are defined in the struct
> +counter_data structure as the "`*_read`" and "`*_write`" union members.
> +
> +The corresponding callback prototypes for the extensions mentioned in
> +the previous example above would be::
> +
> + int count_direction_read(struct counter_device *counter,
> + struct counter_count *count, u8 *direction);
> + int count_enable_read(struct counter_device *counter,
> + struct counter_count *count, u8 *enable);
> + int count_enable_write(struct counter_device *counter,
> + struct counter_count *count, u8 enable);
> + int count_ceiling_read(struct counter_device *counter,
> + struct counter_count *count, u64 *ceiling);
> + int count_ceiling_write(struct counter_device *counter,
> + struct counter_count *count, u64 ceiling);
>
> Determining the type of extension to create is a matter of scope.
>
> @@ -313,52 +346,102 @@ Determining the type of extension to create is a matter of scope.
> chip overheated via a device extension called "error_overtemp":
> /sys/bus/counter/devices/counterX/error_overtemp
>
> -Architecture
> -============
> -
> -When the Generic Counter interface counter module is loaded, the
> -counter_init function is called which registers a bus_type named
> -"counter" to the system. Subsequently, when the module is unloaded, the
> -counter_exit function is called which unregisters the bus_type named
> -"counter" from the system.
> -
> -Counter devices are registered to the system via the counter_register
> -function, and later removed via the counter_unregister function. The
> -counter_register function establishes a unique ID for the Counter
> -device and creates a respective sysfs directory, where X is the
> -mentioned unique ID:
> -
> - /sys/bus/counter/devices/counterX
> -
> -Sysfs attributes are created within the counterX directory to expose
> -functionality, configurations, and data relating to the Counts, Signals,
> -and Synapses of the Counter device, as well as options and information
> -for the Counter device itself.
> -
> -Each Signal has a directory created to house its relevant sysfs
> -attributes, where Y is the unique ID of the respective Signal:
> -
> - /sys/bus/counter/devices/counterX/signalY
> -
> -Similarly, each Count has a directory created to house its relevant
> -sysfs attributes, where Y is the unique ID of the respective Count:
> -
> - /sys/bus/counter/devices/counterX/countY
> -
> -For a more detailed breakdown of the available Generic Counter interface
> -sysfs attributes, please refer to the
> -Documentation/ABI/testing/sysfs-bus-counter file.
> -
> -The Signals and Counts associated with the Counter device are registered
> -to the system as well by the counter_register function. The
> -signal_read/signal_write driver callbacks are associated with their
> -respective Signal attributes, while the count_read/count_write and
> -function_get/function_set driver callbacks are associated with their
> -respective Count attributes; similarly, the same is true for the
> -action_get/action_set driver callbacks and their respective Synapse
> -attributes. If a driver callback is left undefined, then the respective
> -read/write permission is left disabled for the relevant attributes.
> -
> -Similarly, extension sysfs attributes are created for the defined
> -counter_device_ext, counter_count_ext, and counter_signal_ext
> -structures that are passed in.
> +Subsystem Architecture
> +======================
> +
> +Counter drivers pass and take data natively (i.e. `u8`, `u64`, `char *`,
> +etc.) and the shared counter module handles the translation between the
> +sysfs interface. This gurantees a standard userspace interface for all
> +counter drivers, and helps generalize the Generic Counter driver ABI in
> +order to support the Generic Counter chrdev interface without
> +significant changes to the existing counter drivers.
> +
> +A high-level view of how a count value is passed down from a counter
> +driver can be exemplified by the following::
> +
> + Count data request:
> + ~~~~~~~~~~~~~~~~~~~
> + ----------------------
> + / Counter device \
> + +----------------------+
> + | Count register: 0x28 |
> + +----------------------+
> + |
> + -----------------
> + / raw count data /
> + -----------------
> + |
> + V
> + +----------------------------+
> + | Counter device driver |----------+
> + +----------------------------+ |
> + | Processes data from device | -------------------
> + |----------------------------| / driver callbacks /
> + | Type: unsigned long | -------------------
> + | Value: 42 | |
> + +----------------------------+ |
> + | |
> + ---------------- |
> + / unsigned long / |
> + ---------------- |
> + | |
> + | V
> + | +----------------------+
> + | | Counter core |
> + | +----------------------+
> + | | Routes device driver |
> + | | callbacks to the |
> + | | userspace interfaces |
> + | +----------------------+
> + | |
> + | -------------------
> + | / driver callbacks /
> + | -------------------
> + | |
> + +-------+ |
> + | |
> + | +---------------+
> + | |
> + V |
> + +--------------------+ |
> + | Counter sysfs |<-+
> + +--------------------+
> + | Translates to the |
> + | standard Counter |
> + | sysfs output |
> + |--------------------|
> + | Type: const char * |
> + | Value: "42" |
> + +--------------------+
> + |
> + ---------------
> + / const char * /
> + ---------------
> + |
> + V
> + +--------------------------------------------------+
> + | `/sys/bus/counter/devices/counterX/countY/count` |
> + +--------------------------------------------------+
> + \ Count: "42" /
> + --------------------------------------------------
> +
> +There are three primary components involved:
> +
> +Counter device driver
> +---------------------
> +Communicates with the hardware device to read/write data; e.g. counter
> +drivers for quadrature encoders, timers, etc.
> +
> +Counter core
> +------------
> +Registers the counter device driver to the system so that the respective
> +callbacks are called during userspace interaction.
> +
> +Counter sysfs
> +-------------
> +Translates counter data to the standard Counter sysfs interface format
> +and vice versa.
> +
> +Please refer to the `Documentation/ABI/testing/sysfs-bus-counter` file
> +for a detailed breakdown of the available Generic Counter interface
> +sysfs attributes.
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 2/4] docs: counter: Update to reflect sysfs internalization
@ 2020-05-24 16:12 ` Jonathan Cameron
0 siblings, 0 replies; 38+ messages in thread
From: Jonathan Cameron @ 2020-05-24 16:12 UTC (permalink / raw)
To: William Breathitt Gray
Cc: kamel.bouhara, gwendal, david, linux-iio, patrick.havelange,
alexandre.belloni, linux-kernel, mcoquelin.stm32,
fabrice.gasnier, syednwaris, linux-stm32, linux-arm-kernel,
alexandre.torgue
On Sat, 16 May 2020 15:20:00 -0400
William Breathitt Gray <vilhelm.gray@gmail.com> wrote:
> The Counter subsystem architecture and driver implementations have
> changed in order to handle Counter sysfs interactions in a more
> consistent way. This patch updates the Generic Counter interface
> documentation to reflect the changes.
>
> Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Looks good to me.
Jonathan
> ---
> Documentation/driver-api/generic-counter.rst | 215 +++++++++++++------
> 1 file changed, 149 insertions(+), 66 deletions(-)
>
> diff --git a/Documentation/driver-api/generic-counter.rst b/Documentation/driver-api/generic-counter.rst
> index e622f8f6e56a..8f85c30dea0b 100644
> --- a/Documentation/driver-api/generic-counter.rst
> +++ b/Documentation/driver-api/generic-counter.rst
> @@ -250,8 +250,8 @@ for defining a counter device.
> .. kernel-doc:: drivers/counter/counter.c
> :export:
>
> -Implementation
> -==============
> +Driver Implementation
> +=====================
>
> To support a counter device, a driver must first allocate the available
> Counter Signals via counter_signal structures. These Signals should
> @@ -267,25 +267,58 @@ respective counter_count structure. These counter_count structures are
> set to the counts array member of an allocated counter_device structure
> before the Counter is registered to the system.
>
> -Driver callbacks should be provided to the counter_device structure via
> -a constant counter_ops structure in order to communicate with the
> -device: to read and write various Signals and Counts, and to set and get
> -the "action mode" and "function mode" for various Synapses and Counts
> -respectively.
> +Driver callbacks must be provided to the counter_device structure in
> +order to communicate with the device: to read and write various Signals
> +and Counts, and to set and get the "action mode" and "function mode" for
> +various Synapses and Counts respectively.
>
> A defined counter_device structure may be registered to the system by
> passing it to the counter_register function, and unregistered by passing
> it to the counter_unregister function. Similarly, the
> -devm_counter_register and devm_counter_unregister functions may be used
> -if device memory-managed registration is desired.
> -
> -Extension sysfs attributes can be created for auxiliary functionality
> -and data by passing in defined counter_device_ext, counter_count_ext,
> -and counter_signal_ext structures. In these cases, the
> -counter_device_ext structure is used for global/miscellaneous exposure
> -and configuration of the respective Counter device, while the
> -counter_count_ext and counter_signal_ext structures allow for auxiliary
> -exposure and configuration of a specific Count or Signal respectively.
> +devm_counter_register function may be used if device memory-managed
> +registration is desired.
> +
> +The struct counter_data structure is used to define counter extensions
> +for Signals, Synapses, and Counts.
> +
> +The "type" member specifies the type of data (e.g. unsigned long,
> +boolean, etc.) handled by this extension. The "read" and "write" members
> +can then be set by the counter device driver with callbacks to handle
> +that data.
> +
> +Convenience macros such as `COUNTER_DATA_COUNT_U64` are provided for use
> +by driver authors. In particular, driver authors are expected to use
> +the provided macros for standard Counter subsystem attributes in order
> +to maintain a consistent interface for userspace. For example, a counter
> +device driver may define several standard attributes like so::
> +
> + struct counter_data count_ext[] = {
> + COUNTER_DATA_DIRECTION(count_direction_read),
> + COUNTER_DATA_ENABLE(count_enable_read, count_enable_write),
> + COUNTER_DATA_CEILING(count_ceiling_read, count_ceiling_write),
> + };
> +
> +This makes it intuitive to see, add, and modify the attributes that are
> +supported by this driver ("direction", "enable", and "ceiling") and to
> +maintain this code without getting lost in a web of struct braces.
> +
> +Callbacks must match the function type expected for the respective
> +component or extension. These function types are defined in the struct
> +counter_data structure as the "`*_read`" and "`*_write`" union members.
> +
> +The corresponding callback prototypes for the extensions mentioned in
> +the previous example above would be::
> +
> + int count_direction_read(struct counter_device *counter,
> + struct counter_count *count, u8 *direction);
> + int count_enable_read(struct counter_device *counter,
> + struct counter_count *count, u8 *enable);
> + int count_enable_write(struct counter_device *counter,
> + struct counter_count *count, u8 enable);
> + int count_ceiling_read(struct counter_device *counter,
> + struct counter_count *count, u64 *ceiling);
> + int count_ceiling_write(struct counter_device *counter,
> + struct counter_count *count, u64 ceiling);
>
> Determining the type of extension to create is a matter of scope.
>
> @@ -313,52 +346,102 @@ Determining the type of extension to create is a matter of scope.
> chip overheated via a device extension called "error_overtemp":
> /sys/bus/counter/devices/counterX/error_overtemp
>
> -Architecture
> -============
> -
> -When the Generic Counter interface counter module is loaded, the
> -counter_init function is called which registers a bus_type named
> -"counter" to the system. Subsequently, when the module is unloaded, the
> -counter_exit function is called which unregisters the bus_type named
> -"counter" from the system.
> -
> -Counter devices are registered to the system via the counter_register
> -function, and later removed via the counter_unregister function. The
> -counter_register function establishes a unique ID for the Counter
> -device and creates a respective sysfs directory, where X is the
> -mentioned unique ID:
> -
> - /sys/bus/counter/devices/counterX
> -
> -Sysfs attributes are created within the counterX directory to expose
> -functionality, configurations, and data relating to the Counts, Signals,
> -and Synapses of the Counter device, as well as options and information
> -for the Counter device itself.
> -
> -Each Signal has a directory created to house its relevant sysfs
> -attributes, where Y is the unique ID of the respective Signal:
> -
> - /sys/bus/counter/devices/counterX/signalY
> -
> -Similarly, each Count has a directory created to house its relevant
> -sysfs attributes, where Y is the unique ID of the respective Count:
> -
> - /sys/bus/counter/devices/counterX/countY
> -
> -For a more detailed breakdown of the available Generic Counter interface
> -sysfs attributes, please refer to the
> -Documentation/ABI/testing/sysfs-bus-counter file.
> -
> -The Signals and Counts associated with the Counter device are registered
> -to the system as well by the counter_register function. The
> -signal_read/signal_write driver callbacks are associated with their
> -respective Signal attributes, while the count_read/count_write and
> -function_get/function_set driver callbacks are associated with their
> -respective Count attributes; similarly, the same is true for the
> -action_get/action_set driver callbacks and their respective Synapse
> -attributes. If a driver callback is left undefined, then the respective
> -read/write permission is left disabled for the relevant attributes.
> -
> -Similarly, extension sysfs attributes are created for the defined
> -counter_device_ext, counter_count_ext, and counter_signal_ext
> -structures that are passed in.
> +Subsystem Architecture
> +======================
> +
> +Counter drivers pass and take data natively (i.e. `u8`, `u64`, `char *`,
> +etc.) and the shared counter module handles the translation between the
> +sysfs interface. This gurantees a standard userspace interface for all
> +counter drivers, and helps generalize the Generic Counter driver ABI in
> +order to support the Generic Counter chrdev interface without
> +significant changes to the existing counter drivers.
> +
> +A high-level view of how a count value is passed down from a counter
> +driver can be exemplified by the following::
> +
> + Count data request:
> + ~~~~~~~~~~~~~~~~~~~
> + ----------------------
> + / Counter device \
> + +----------------------+
> + | Count register: 0x28 |
> + +----------------------+
> + |
> + -----------------
> + / raw count data /
> + -----------------
> + |
> + V
> + +----------------------------+
> + | Counter device driver |----------+
> + +----------------------------+ |
> + | Processes data from device | -------------------
> + |----------------------------| / driver callbacks /
> + | Type: unsigned long | -------------------
> + | Value: 42 | |
> + +----------------------------+ |
> + | |
> + ---------------- |
> + / unsigned long / |
> + ---------------- |
> + | |
> + | V
> + | +----------------------+
> + | | Counter core |
> + | +----------------------+
> + | | Routes device driver |
> + | | callbacks to the |
> + | | userspace interfaces |
> + | +----------------------+
> + | |
> + | -------------------
> + | / driver callbacks /
> + | -------------------
> + | |
> + +-------+ |
> + | |
> + | +---------------+
> + | |
> + V |
> + +--------------------+ |
> + | Counter sysfs |<-+
> + +--------------------+
> + | Translates to the |
> + | standard Counter |
> + | sysfs output |
> + |--------------------|
> + | Type: const char * |
> + | Value: "42" |
> + +--------------------+
> + |
> + ---------------
> + / const char * /
> + ---------------
> + |
> + V
> + +--------------------------------------------------+
> + | `/sys/bus/counter/devices/counterX/countY/count` |
> + +--------------------------------------------------+
> + \ Count: "42" /
> + --------------------------------------------------
> +
> +There are three primary components involved:
> +
> +Counter device driver
> +---------------------
> +Communicates with the hardware device to read/write data; e.g. counter
> +drivers for quadrature encoders, timers, etc.
> +
> +Counter core
> +------------
> +Registers the counter device driver to the system so that the respective
> +callbacks are called during userspace interaction.
> +
> +Counter sysfs
> +-------------
> +Translates counter data to the standard Counter sysfs interface format
> +and vice versa.
> +
> +Please refer to the `Documentation/ABI/testing/sysfs-bus-counter` file
> +for a detailed breakdown of the available Generic Counter interface
> +sysfs attributes.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 4/4] docs: counter: Document character device interface
2020-05-16 19:20 ` William Breathitt Gray
@ 2020-05-24 16:19 ` Jonathan Cameron
-1 siblings, 0 replies; 38+ messages in thread
From: Jonathan Cameron @ 2020-05-24 16:19 UTC (permalink / raw)
To: William Breathitt Gray
Cc: kamel.bouhara, gwendal, alexandre.belloni, david, linux-iio,
linux-kernel, linux-stm32, linux-arm-kernel, syednwaris,
patrick.havelange, fabrice.gasnier, mcoquelin.stm32,
alexandre.torgue
On Sat, 16 May 2020 15:20:02 -0400
William Breathitt Gray <vilhelm.gray@gmail.com> wrote:
> This patch adds high-level documentation about the Counter subsystem
> character device interface.
>
> Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
> ---
> Documentation/driver-api/generic-counter.rst | 112 +++++++++++++------
> 1 file changed, 76 insertions(+), 36 deletions(-)
>
> diff --git a/Documentation/driver-api/generic-counter.rst b/Documentation/driver-api/generic-counter.rst
> index 8f85c30dea0b..58045b33b576 100644
> --- a/Documentation/driver-api/generic-counter.rst
> +++ b/Documentation/driver-api/generic-counter.rst
> @@ -223,19 +223,6 @@ whether an input line is differential or single-ended) and instead focus
> on the core idea of what the data and process represent (e.g. position
> as interpreted from quadrature encoding data).
>
> -Userspace Interface
> -===================
> -
> -Several sysfs attributes are generated by the Generic Counter interface,
> -and reside under the /sys/bus/counter/devices/counterX directory, where
> -counterX refers to the respective counter device. Please see
> -Documentation/ABI/testing/sysfs-bus-counter for detailed
> -information on each Generic Counter interface sysfs attribute.
> -
> -Through these sysfs attributes, programs and scripts may interact with
> -the Generic Counter paradigm Counts, Signals, and Synapses of respective
> -counter devices.
> -
> Driver API
> ==========
>
> @@ -377,13 +364,13 @@ driver can be exemplified by the following::
> +----------------------------+ |
> | Processes data from device | -------------------
> |----------------------------| / driver callbacks /
> - | Type: unsigned long | -------------------
> + | Type: u64 | -------------------
> | Value: 42 | |
> +----------------------------+ |
> | |
> - ---------------- |
> - / unsigned long / |
> - ---------------- |
> + ---------- |
> + / u64 / |
> + ---------- |
> | |
> | V
> | +----------------------+
> @@ -398,25 +385,32 @@ driver can be exemplified by the following::
> | / driver callbacks /
> | -------------------
> | |
> - +-------+ |
> + +-------+---------------+ |
> + | | |
> + | +-------|-------+
> + | | |
> + V | V
> + +--------------------+ | +---------------------+
> + | Counter sysfs |<-+->| Counter chrdev |
> + +--------------------+ +---------------------+
> + | Translates to the | | Translates to the |
> + | standard Counter | | standard Counter |
> + | sysfs output | | character device |
> + |--------------------| |---------------------+
> + | Type: const char * | | Type: u64 |
> + | Value: "42" | | Value: 42 |
> + +--------------------+ +---------------------+
> | |
> - | +---------------+
> - | |
> - V |
> - +--------------------+ |
> - | Counter sysfs |<-+
> - +--------------------+
> - | Translates to the |
> - | standard Counter |
> - | sysfs output |
> - |--------------------|
> - | Type: const char * |
> - | Value: "42" |
> - +--------------------+
> - |
> - ---------------
> - / const char * /
> - ---------------
> + --------------- ----------
> + / const char * / / u64 /
> + --------------- ----------
> + | |
> + | V
> + | +-----------+
> + | | read |
> + | +-----------+
> + | \ Count: 42 /
> + | -----------
> |
> V
> +--------------------------------------------------+
> @@ -425,7 +419,7 @@ driver can be exemplified by the following::
> \ Count: "42" /
> --------------------------------------------------
>
> -There are three primary components involved:
> +There are four primary components involved:
>
> Counter device driver
> ---------------------
> @@ -445,3 +439,49 @@ and vice versa.
> Please refer to the `Documentation/ABI/testing/sysfs-bus-counter` file
> for a detailed breakdown of the available Generic Counter interface
> sysfs attributes.
> +
> +Counter chrdev
> +--------------
> +Translates counter data to the standard Counter character device; data
> +is transferred via standard character device read/write calls.
> +
> +Sysfs Interface
> +===============
> +
> +Several sysfs attributes are generated by the Generic Counter interface,
> +and reside under the `/sys/bus/counter/devices/counterX` directory,
> +where `X` is to the respective counter device id. Please see
> +Documentation/ABI/testing/sysfs-bus-counter for detailed information on
> +each Generic Counter interface sysfs attribute.
> +
> +Through these sysfs attributes, programs and scripts may interact with
> +the Generic Counter paradigm Counts, Signals, and Synapses of respective
> +counter devices.
> +
> +Counter Character Device
> +========================
> +
> +Counter character device nodes are created under the `/dev` directory as
> +`counterX`, where `X` is the respective counter device id. Defines for
> +the standard Counter data types are exposed via the userspace
> +`include/uapi/linux/counter-types.h` file.
> +
> +The first 196095 bytes of the character device serve as a control
> +selection area where control exposure of desired Counter components and
> +extensions may be selected. Each byte serves as a boolean selection
> +indicator for a respective Counter component or extension. The format of
> +this area is as follows:
> +
> +* For each device extension, a byte is required.
> +* For each Signal, a byte is reserved for the Signal component, and a
> + byte is reserved for each Signal extension.
> +* For each Count, a byte is reserved for the Count component, a byte is
> + reserved for the count function, a byte is reserved for each Synapse
> + action, and byte is reserved for each Count extension.
> +
> +The selected Counter components and extensions may then be interfaced
> +after the first 196095 bytes via standard character device read/write
> +operations. The number of bytes available for each component or
> +extension is dependent on their respective data type: u8 will have 1
> +byte available, u64 will have 8 bytes available, strings will have 64
> +bytes available, etc.
From what I recall of the earlier conversation, I'm not sure this is what
was being suggested. I 'think' what people were after was a simple
read interface for just the counters (+ timestamps). This would also
include the option to use select / poll on the counter.
Simply moving over to a read / write really doesn't help for ease of use.
I'm not sure what the right control approach is, or perhaps if we even
need one (could just output all counts provided by hardware once the
chrdev is opened).
Jonathan
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 4/4] docs: counter: Document character device interface
@ 2020-05-24 16:19 ` Jonathan Cameron
0 siblings, 0 replies; 38+ messages in thread
From: Jonathan Cameron @ 2020-05-24 16:19 UTC (permalink / raw)
To: William Breathitt Gray
Cc: kamel.bouhara, gwendal, david, linux-iio, patrick.havelange,
alexandre.belloni, linux-kernel, mcoquelin.stm32,
fabrice.gasnier, syednwaris, linux-stm32, linux-arm-kernel,
alexandre.torgue
On Sat, 16 May 2020 15:20:02 -0400
William Breathitt Gray <vilhelm.gray@gmail.com> wrote:
> This patch adds high-level documentation about the Counter subsystem
> character device interface.
>
> Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
> ---
> Documentation/driver-api/generic-counter.rst | 112 +++++++++++++------
> 1 file changed, 76 insertions(+), 36 deletions(-)
>
> diff --git a/Documentation/driver-api/generic-counter.rst b/Documentation/driver-api/generic-counter.rst
> index 8f85c30dea0b..58045b33b576 100644
> --- a/Documentation/driver-api/generic-counter.rst
> +++ b/Documentation/driver-api/generic-counter.rst
> @@ -223,19 +223,6 @@ whether an input line is differential or single-ended) and instead focus
> on the core idea of what the data and process represent (e.g. position
> as interpreted from quadrature encoding data).
>
> -Userspace Interface
> -===================
> -
> -Several sysfs attributes are generated by the Generic Counter interface,
> -and reside under the /sys/bus/counter/devices/counterX directory, where
> -counterX refers to the respective counter device. Please see
> -Documentation/ABI/testing/sysfs-bus-counter for detailed
> -information on each Generic Counter interface sysfs attribute.
> -
> -Through these sysfs attributes, programs and scripts may interact with
> -the Generic Counter paradigm Counts, Signals, and Synapses of respective
> -counter devices.
> -
> Driver API
> ==========
>
> @@ -377,13 +364,13 @@ driver can be exemplified by the following::
> +----------------------------+ |
> | Processes data from device | -------------------
> |----------------------------| / driver callbacks /
> - | Type: unsigned long | -------------------
> + | Type: u64 | -------------------
> | Value: 42 | |
> +----------------------------+ |
> | |
> - ---------------- |
> - / unsigned long / |
> - ---------------- |
> + ---------- |
> + / u64 / |
> + ---------- |
> | |
> | V
> | +----------------------+
> @@ -398,25 +385,32 @@ driver can be exemplified by the following::
> | / driver callbacks /
> | -------------------
> | |
> - +-------+ |
> + +-------+---------------+ |
> + | | |
> + | +-------|-------+
> + | | |
> + V | V
> + +--------------------+ | +---------------------+
> + | Counter sysfs |<-+->| Counter chrdev |
> + +--------------------+ +---------------------+
> + | Translates to the | | Translates to the |
> + | standard Counter | | standard Counter |
> + | sysfs output | | character device |
> + |--------------------| |---------------------+
> + | Type: const char * | | Type: u64 |
> + | Value: "42" | | Value: 42 |
> + +--------------------+ +---------------------+
> | |
> - | +---------------+
> - | |
> - V |
> - +--------------------+ |
> - | Counter sysfs |<-+
> - +--------------------+
> - | Translates to the |
> - | standard Counter |
> - | sysfs output |
> - |--------------------|
> - | Type: const char * |
> - | Value: "42" |
> - +--------------------+
> - |
> - ---------------
> - / const char * /
> - ---------------
> + --------------- ----------
> + / const char * / / u64 /
> + --------------- ----------
> + | |
> + | V
> + | +-----------+
> + | | read |
> + | +-----------+
> + | \ Count: 42 /
> + | -----------
> |
> V
> +--------------------------------------------------+
> @@ -425,7 +419,7 @@ driver can be exemplified by the following::
> \ Count: "42" /
> --------------------------------------------------
>
> -There are three primary components involved:
> +There are four primary components involved:
>
> Counter device driver
> ---------------------
> @@ -445,3 +439,49 @@ and vice versa.
> Please refer to the `Documentation/ABI/testing/sysfs-bus-counter` file
> for a detailed breakdown of the available Generic Counter interface
> sysfs attributes.
> +
> +Counter chrdev
> +--------------
> +Translates counter data to the standard Counter character device; data
> +is transferred via standard character device read/write calls.
> +
> +Sysfs Interface
> +===============
> +
> +Several sysfs attributes are generated by the Generic Counter interface,
> +and reside under the `/sys/bus/counter/devices/counterX` directory,
> +where `X` is to the respective counter device id. Please see
> +Documentation/ABI/testing/sysfs-bus-counter for detailed information on
> +each Generic Counter interface sysfs attribute.
> +
> +Through these sysfs attributes, programs and scripts may interact with
> +the Generic Counter paradigm Counts, Signals, and Synapses of respective
> +counter devices.
> +
> +Counter Character Device
> +========================
> +
> +Counter character device nodes are created under the `/dev` directory as
> +`counterX`, where `X` is the respective counter device id. Defines for
> +the standard Counter data types are exposed via the userspace
> +`include/uapi/linux/counter-types.h` file.
> +
> +The first 196095 bytes of the character device serve as a control
> +selection area where control exposure of desired Counter components and
> +extensions may be selected. Each byte serves as a boolean selection
> +indicator for a respective Counter component or extension. The format of
> +this area is as follows:
> +
> +* For each device extension, a byte is required.
> +* For each Signal, a byte is reserved for the Signal component, and a
> + byte is reserved for each Signal extension.
> +* For each Count, a byte is reserved for the Count component, a byte is
> + reserved for the count function, a byte is reserved for each Synapse
> + action, and byte is reserved for each Count extension.
> +
> +The selected Counter components and extensions may then be interfaced
> +after the first 196095 bytes via standard character device read/write
> +operations. The number of bytes available for each component or
> +extension is dependent on their respective data type: u8 will have 1
> +byte available, u64 will have 8 bytes available, strings will have 64
> +bytes available, etc.
From what I recall of the earlier conversation, I'm not sure this is what
was being suggested. I 'think' what people were after was a simple
read interface for just the counters (+ timestamps). This would also
include the option to use select / poll on the counter.
Simply moving over to a read / write really doesn't help for ease of use.
I'm not sure what the right control approach is, or perhaps if we even
need one (could just output all counts provided by hardware once the
chrdev is opened).
Jonathan
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 0/4] Introduce the Counter character device interface
2020-05-16 19:19 ` William Breathitt Gray
@ 2020-05-24 16:25 ` Jonathan Cameron
-1 siblings, 0 replies; 38+ messages in thread
From: Jonathan Cameron @ 2020-05-24 16:25 UTC (permalink / raw)
To: William Breathitt Gray
Cc: kamel.bouhara, gwendal, alexandre.belloni, david, linux-iio,
linux-kernel, linux-stm32, linux-arm-kernel, syednwaris,
patrick.havelange, fabrice.gasnier, mcoquelin.stm32,
alexandre.torgue
...
> The following are some questions I have about this patchset:
>
> 1. Should the data format of the character device be configured via a
> sysfs attribute?
>
> In this patchset, the first 196095 bytes of the character device are
> dedicated as a selection area to choose which Counter components or
> extensions should be exposed; the subsequent bytes are the actual
> data for the Counter components and extensions that were selected.
That sounds like the worst of all possible worlds. Reality is you need
to do some magic library so at that point you might as well have ioctl
options to configure it. I wonder if you can keep the data flow
to be a simple 'read' from the chardev but move the control away from
that. Either control via some chrdevs but keep them to the 'set / get'
if this element is going to turn up in the read or not. You rapidly
run into problems though, such as now to see how large a given element
is going to be etc. Plus ioctls are rather messier to extend than
simply adding a new sysfs file. Various subsystems do complex
'descriptor' type approaches to get around this, or you could do
self describing records rather than raw data - like an input
ev_dev event.
>
> Moving this selection to a sysfs attribute and dedicating the
> character device to just data transfer might be a better design. If
> such a design is chosen, should the selection attribute be
> human-readable or binary?
Sysfs basically requires things are more or less human readable.
So if you go that way I think it needs to be.
>
> 2. How much space should allotted for strings?
>
> Each Counter component and extension has a respective size allotted
> for its data (u8 data is allotted 1 byte, u64 data is allotted 8
> bytes, etc.); I have arbitrarily chosen to allot 64 bytes for
> strings. Is this an apt size, or should string data be allotted more
> or less space?
I'd go with that being big enough, but try to keep the expose interface
such that the size can change it it needs to the in the future.
>
> 3. Should the owning component of an extension be handled by the device
> driver or Counter subsystem?
>
> The Counter subsystem figures out the owner (enum counter_owner_type)
> for each component/extension in the counter-sysfs and counter-chrdev
> code. When a callback must be executed, there are various switch
> statements throughout the code to check whether the respective
> Device, Signal, or Count version of the callback should be executed;
> similarly, the appropriate owner type must match for the struct
> counter_data macros such as COUNTER_DATA_DEVICE_U64,
> COUNTER_DATA_SIGNAL_U64, COUNTER_DATA_COUNT_U64, etc.
>
> All this complexity in the Counter subsystem code can be eliminated
> if a single callback type with a `void *owner` parameter is defined
> for use with all three owner types (Device, Signal, and Count). The
> device driver would then be responsible for casting the callback
> argument to the appropriate owner type; but in theory, this should
> not be much of a problem since the device driver is responsible for
> assigning the callbacks to the owning component anyway.
Whilst its more complex for subsytem I think it's better to keep everything
typed if we possibly can. Always a trade off though, so use your discretion.
Jonathan
>
> William Breathitt Gray (4):
> counter: Internalize sysfs interface code
> docs: counter: Update to reflect sysfs internalization
> counter: Add character device interface
> docs: counter: Document character device interface
>
> Documentation/driver-api/generic-counter.rst | 275 +++-
> MAINTAINERS | 3 +-
> drivers/counter/104-quad-8.c | 547 +++----
> drivers/counter/Makefile | 1 +
> drivers/counter/counter-chrdev.c | 656 ++++++++
> drivers/counter/counter-chrdev.h | 16 +
> drivers/counter/counter-core.c | 187 +++
> drivers/counter/counter-sysfs.c | 881 +++++++++++
> drivers/counter/counter-sysfs.h | 14 +
> drivers/counter/counter.c | 1496 ------------------
> drivers/counter/ftm-quaddec.c | 89 +-
> drivers/counter/stm32-lptimer-cnt.c | 161 +-
> drivers/counter/stm32-timer-cnt.c | 139 +-
> drivers/counter/ti-eqep.c | 211 +--
> include/linux/counter.h | 626 ++++----
> include/linux/counter_enum.h | 45 -
> include/uapi/linux/counter-types.h | 45 +
> 17 files changed, 2826 insertions(+), 2566 deletions(-)
> create mode 100644 drivers/counter/counter-chrdev.c
> create mode 100644 drivers/counter/counter-chrdev.h
> create mode 100644 drivers/counter/counter-core.c
> create mode 100644 drivers/counter/counter-sysfs.c
> create mode 100644 drivers/counter/counter-sysfs.h
> delete mode 100644 drivers/counter/counter.c
> delete mode 100644 include/linux/counter_enum.h
> create mode 100644 include/uapi/linux/counter-types.h
>
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 0/4] Introduce the Counter character device interface
@ 2020-05-24 16:25 ` Jonathan Cameron
0 siblings, 0 replies; 38+ messages in thread
From: Jonathan Cameron @ 2020-05-24 16:25 UTC (permalink / raw)
To: William Breathitt Gray
Cc: kamel.bouhara, gwendal, david, linux-iio, patrick.havelange,
alexandre.belloni, linux-kernel, mcoquelin.stm32,
fabrice.gasnier, syednwaris, linux-stm32, linux-arm-kernel,
alexandre.torgue
...
> The following are some questions I have about this patchset:
>
> 1. Should the data format of the character device be configured via a
> sysfs attribute?
>
> In this patchset, the first 196095 bytes of the character device are
> dedicated as a selection area to choose which Counter components or
> extensions should be exposed; the subsequent bytes are the actual
> data for the Counter components and extensions that were selected.
That sounds like the worst of all possible worlds. Reality is you need
to do some magic library so at that point you might as well have ioctl
options to configure it. I wonder if you can keep the data flow
to be a simple 'read' from the chardev but move the control away from
that. Either control via some chrdevs but keep them to the 'set / get'
if this element is going to turn up in the read or not. You rapidly
run into problems though, such as now to see how large a given element
is going to be etc. Plus ioctls are rather messier to extend than
simply adding a new sysfs file. Various subsystems do complex
'descriptor' type approaches to get around this, or you could do
self describing records rather than raw data - like an input
ev_dev event.
>
> Moving this selection to a sysfs attribute and dedicating the
> character device to just data transfer might be a better design. If
> such a design is chosen, should the selection attribute be
> human-readable or binary?
Sysfs basically requires things are more or less human readable.
So if you go that way I think it needs to be.
>
> 2. How much space should allotted for strings?
>
> Each Counter component and extension has a respective size allotted
> for its data (u8 data is allotted 1 byte, u64 data is allotted 8
> bytes, etc.); I have arbitrarily chosen to allot 64 bytes for
> strings. Is this an apt size, or should string data be allotted more
> or less space?
I'd go with that being big enough, but try to keep the expose interface
such that the size can change it it needs to the in the future.
>
> 3. Should the owning component of an extension be handled by the device
> driver or Counter subsystem?
>
> The Counter subsystem figures out the owner (enum counter_owner_type)
> for each component/extension in the counter-sysfs and counter-chrdev
> code. When a callback must be executed, there are various switch
> statements throughout the code to check whether the respective
> Device, Signal, or Count version of the callback should be executed;
> similarly, the appropriate owner type must match for the struct
> counter_data macros such as COUNTER_DATA_DEVICE_U64,
> COUNTER_DATA_SIGNAL_U64, COUNTER_DATA_COUNT_U64, etc.
>
> All this complexity in the Counter subsystem code can be eliminated
> if a single callback type with a `void *owner` parameter is defined
> for use with all three owner types (Device, Signal, and Count). The
> device driver would then be responsible for casting the callback
> argument to the appropriate owner type; but in theory, this should
> not be much of a problem since the device driver is responsible for
> assigning the callbacks to the owning component anyway.
Whilst its more complex for subsytem I think it's better to keep everything
typed if we possibly can. Always a trade off though, so use your discretion.
Jonathan
>
> William Breathitt Gray (4):
> counter: Internalize sysfs interface code
> docs: counter: Update to reflect sysfs internalization
> counter: Add character device interface
> docs: counter: Document character device interface
>
> Documentation/driver-api/generic-counter.rst | 275 +++-
> MAINTAINERS | 3 +-
> drivers/counter/104-quad-8.c | 547 +++----
> drivers/counter/Makefile | 1 +
> drivers/counter/counter-chrdev.c | 656 ++++++++
> drivers/counter/counter-chrdev.h | 16 +
> drivers/counter/counter-core.c | 187 +++
> drivers/counter/counter-sysfs.c | 881 +++++++++++
> drivers/counter/counter-sysfs.h | 14 +
> drivers/counter/counter.c | 1496 ------------------
> drivers/counter/ftm-quaddec.c | 89 +-
> drivers/counter/stm32-lptimer-cnt.c | 161 +-
> drivers/counter/stm32-timer-cnt.c | 139 +-
> drivers/counter/ti-eqep.c | 211 +--
> include/linux/counter.h | 626 ++++----
> include/linux/counter_enum.h | 45 -
> include/uapi/linux/counter-types.h | 45 +
> 17 files changed, 2826 insertions(+), 2566 deletions(-)
> create mode 100644 drivers/counter/counter-chrdev.c
> create mode 100644 drivers/counter/counter-chrdev.h
> create mode 100644 drivers/counter/counter-core.c
> create mode 100644 drivers/counter/counter-sysfs.c
> create mode 100644 drivers/counter/counter-sysfs.h
> delete mode 100644 drivers/counter/counter.c
> delete mode 100644 include/linux/counter_enum.h
> create mode 100644 include/uapi/linux/counter-types.h
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 0/4] Introduce the Counter character device interface
2020-05-24 16:25 ` Jonathan Cameron
@ 2020-05-24 17:54 ` William Breathitt Gray
-1 siblings, 0 replies; 38+ messages in thread
From: William Breathitt Gray @ 2020-05-24 17:54 UTC (permalink / raw)
To: Jonathan Cameron
Cc: kamel.bouhara, gwendal, alexandre.belloni, david, linux-iio,
linux-kernel, linux-stm32, linux-arm-kernel, syednwaris,
patrick.havelange, fabrice.gasnier, mcoquelin.stm32,
alexandre.torgue
[-- Attachment #1: Type: text/plain, Size: 9099 bytes --]
On Sun, May 24, 2020 at 05:25:42PM +0100, Jonathan Cameron wrote:
>
> ...
>
> > The following are some questions I have about this patchset:
> >
> > 1. Should the data format of the character device be configured via a
> > sysfs attribute?
> >
> > In this patchset, the first 196095 bytes of the character device are
> > dedicated as a selection area to choose which Counter components or
> > extensions should be exposed; the subsequent bytes are the actual
> > data for the Counter components and extensions that were selected.
>
> That sounds like the worst of all possible worlds. Reality is you need
> to do some magic library so at that point you might as well have ioctl
> options to configure it. I wonder if you can keep the data flow
> to be a simple 'read' from the chardev but move the control away from
> that. Either control via some chrdevs but keep them to the 'set / get'
> if this element is going to turn up in the read or not. You rapidly
> run into problems though, such as now to see how large a given element
> is going to be etc. Plus ioctls are rather messier to extend than
> simply adding a new sysfs file. Various subsystems do complex
> 'descriptor' type approaches to get around this, or you could do
> self describing records rather than raw data - like an input
> ev_dev event.
Yes I agree, I don't think combining nondata with data is good design --
it's better if users are able to simply perform read/write on the
character device without having to keep track of valid offsets and
controls.
After giving this some more thought, I believe human-readable sysfs
attributes are the way to go to support configuration of the character
device. I am thinking of a system like this:
* Users configure the counter character device via a sysfs attribute
such as /sys/bus/counter/devices/counterX/chrdev_format or similar.
* Users may write to this sysfs attribute to select the components they
want to interface -- the layout can be determined as well from the
order. For example:
# echo "C0 C3 C2" > /sys/bus/counter/devices/counter0/chrdev_format
This would select Counts 0, 3, and 2 (in that order) to be available
in the /dev/counter0 node as a contiguous memory region.
You can select extensions in a similar fashion:
# echo "C4E2 S1E0" > /sys/bus/counter/devices/counter0/chrdev_format
This would select extension 2 from Count 4, and extension 0 from
Signal 1.
* Users may read from this chrdev_format sysfs attribute in order to see
the currently configured format of the character device.
* Users may perform read/write operations on the /dev/counterX node
directly; the layout of the data is what they user has configured via
the chrdev_format sysfs attribute. For example:
# echo "C0 C1 S0 S1" > /sys/bus/counter/devices/counter0/chrdev_format
Yields the following /dev/counter0 memory layout:
+-----------------+------------------+----------+----------+
| Byte 0 - Byte 7 | Byte 8 - Byte 15 | Byte 16 | Byte 17 |
+-----------------+------------------+----------+----------+
| Count 0 | Count 1 | Signal 0 | Signal 2 |
+-----------------+------------------+----------+----------+
* Users may perform select/poll operations on the /dev/counterX node.
Users can be notified if data is available or events have occurred.
The benefit of this design is that the format is robust so users can
choose the components they want to interface and in the layout they
want. For example, if I am writing a userspace application to control a
dual-axis positioning table, I can select the two counts I care about
for the position axes. This allows me to read just those two values
directly from /dev/counterX with a simple read() call, without having to
fumble around seeking to an offset and parsing the layout.
Similarly, support for future extensions is simple to implement. When
timestamp support is implemented, users can just select the desired
timestamp extension and read it directly from the /dev/counterX node;
they should also be able to perform a select()/poll() call to be
notified on new timestamps.
So what do you think of this sort of design? I think there is a useful
robustness to the simplicity of performing a single read/write call on
/dev/counterX.
> >
> > Moving this selection to a sysfs attribute and dedicating the
> > character device to just data transfer might be a better design. If
> > such a design is chosen, should the selection attribute be
> > human-readable or binary?
>
> Sysfs basically requires things are more or less human readable.
> So if you go that way I think it needs to be.
>
> >
> > 2. How much space should allotted for strings?
> >
> > Each Counter component and extension has a respective size allotted
> > for its data (u8 data is allotted 1 byte, u64 data is allotted 8
> > bytes, etc.); I have arbitrarily chosen to allot 64 bytes for
> > strings. Is this an apt size, or should string data be allotted more
> > or less space?
>
> I'd go with that being big enough, but try to keep the expose interface
> such that the size can change it it needs to the in the future.
Following along with the separation of control vs data as discussed
above, we could support a more variable size by exposing it through a
sysfs attribute (maybe a chrdev_string_size attribute or similar).
>
> >
> > 3. Should the owning component of an extension be handled by the device
> > driver or Counter subsystem?
> >
> > The Counter subsystem figures out the owner (enum counter_owner_type)
> > for each component/extension in the counter-sysfs and counter-chrdev
> > code. When a callback must be executed, there are various switch
> > statements throughout the code to check whether the respective
> > Device, Signal, or Count version of the callback should be executed;
> > similarly, the appropriate owner type must match for the struct
> > counter_data macros such as COUNTER_DATA_DEVICE_U64,
> > COUNTER_DATA_SIGNAL_U64, COUNTER_DATA_COUNT_U64, etc.
> >
> > All this complexity in the Counter subsystem code can be eliminated
> > if a single callback type with a `void *owner` parameter is defined
> > for use with all three owner types (Device, Signal, and Count). The
> > device driver would then be responsible for casting the callback
> > argument to the appropriate owner type; but in theory, this should
> > not be much of a problem since the device driver is responsible for
> > assigning the callbacks to the owning component anyway.
>
> Whilst its more complex for subsytem I think it's better to keep everything
> typed if we possibly can. Always a trade off though, so use your discretion.
>
> Jonathan
I'm going to keep it all typed for now since I don't want to make too
many changes at once. Since this is somewhat unrelated to the purpose of
introducing Counter character devices, I'll postpone the discussion to a
later date after the Counter character device interface is merged.
William Breathitt Gray
>
>
> >
> > William Breathitt Gray (4):
> > counter: Internalize sysfs interface code
> > docs: counter: Update to reflect sysfs internalization
> > counter: Add character device interface
> > docs: counter: Document character device interface
> >
> > Documentation/driver-api/generic-counter.rst | 275 +++-
> > MAINTAINERS | 3 +-
> > drivers/counter/104-quad-8.c | 547 +++----
> > drivers/counter/Makefile | 1 +
> > drivers/counter/counter-chrdev.c | 656 ++++++++
> > drivers/counter/counter-chrdev.h | 16 +
> > drivers/counter/counter-core.c | 187 +++
> > drivers/counter/counter-sysfs.c | 881 +++++++++++
> > drivers/counter/counter-sysfs.h | 14 +
> > drivers/counter/counter.c | 1496 ------------------
> > drivers/counter/ftm-quaddec.c | 89 +-
> > drivers/counter/stm32-lptimer-cnt.c | 161 +-
> > drivers/counter/stm32-timer-cnt.c | 139 +-
> > drivers/counter/ti-eqep.c | 211 +--
> > include/linux/counter.h | 626 ++++----
> > include/linux/counter_enum.h | 45 -
> > include/uapi/linux/counter-types.h | 45 +
> > 17 files changed, 2826 insertions(+), 2566 deletions(-)
> > create mode 100644 drivers/counter/counter-chrdev.c
> > create mode 100644 drivers/counter/counter-chrdev.h
> > create mode 100644 drivers/counter/counter-core.c
> > create mode 100644 drivers/counter/counter-sysfs.c
> > create mode 100644 drivers/counter/counter-sysfs.h
> > delete mode 100644 drivers/counter/counter.c
> > delete mode 100644 include/linux/counter_enum.h
> > create mode 100644 include/uapi/linux/counter-types.h
> >
>
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^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 0/4] Introduce the Counter character device interface
@ 2020-05-24 17:54 ` William Breathitt Gray
0 siblings, 0 replies; 38+ messages in thread
From: William Breathitt Gray @ 2020-05-24 17:54 UTC (permalink / raw)
To: Jonathan Cameron
Cc: kamel.bouhara, gwendal, david, linux-iio, patrick.havelange,
alexandre.belloni, linux-kernel, mcoquelin.stm32,
fabrice.gasnier, syednwaris, linux-stm32, linux-arm-kernel,
alexandre.torgue
[-- Attachment #1.1: Type: text/plain, Size: 9099 bytes --]
On Sun, May 24, 2020 at 05:25:42PM +0100, Jonathan Cameron wrote:
>
> ...
>
> > The following are some questions I have about this patchset:
> >
> > 1. Should the data format of the character device be configured via a
> > sysfs attribute?
> >
> > In this patchset, the first 196095 bytes of the character device are
> > dedicated as a selection area to choose which Counter components or
> > extensions should be exposed; the subsequent bytes are the actual
> > data for the Counter components and extensions that were selected.
>
> That sounds like the worst of all possible worlds. Reality is you need
> to do some magic library so at that point you might as well have ioctl
> options to configure it. I wonder if you can keep the data flow
> to be a simple 'read' from the chardev but move the control away from
> that. Either control via some chrdevs but keep them to the 'set / get'
> if this element is going to turn up in the read or not. You rapidly
> run into problems though, such as now to see how large a given element
> is going to be etc. Plus ioctls are rather messier to extend than
> simply adding a new sysfs file. Various subsystems do complex
> 'descriptor' type approaches to get around this, or you could do
> self describing records rather than raw data - like an input
> ev_dev event.
Yes I agree, I don't think combining nondata with data is good design --
it's better if users are able to simply perform read/write on the
character device without having to keep track of valid offsets and
controls.
After giving this some more thought, I believe human-readable sysfs
attributes are the way to go to support configuration of the character
device. I am thinking of a system like this:
* Users configure the counter character device via a sysfs attribute
such as /sys/bus/counter/devices/counterX/chrdev_format or similar.
* Users may write to this sysfs attribute to select the components they
want to interface -- the layout can be determined as well from the
order. For example:
# echo "C0 C3 C2" > /sys/bus/counter/devices/counter0/chrdev_format
This would select Counts 0, 3, and 2 (in that order) to be available
in the /dev/counter0 node as a contiguous memory region.
You can select extensions in a similar fashion:
# echo "C4E2 S1E0" > /sys/bus/counter/devices/counter0/chrdev_format
This would select extension 2 from Count 4, and extension 0 from
Signal 1.
* Users may read from this chrdev_format sysfs attribute in order to see
the currently configured format of the character device.
* Users may perform read/write operations on the /dev/counterX node
directly; the layout of the data is what they user has configured via
the chrdev_format sysfs attribute. For example:
# echo "C0 C1 S0 S1" > /sys/bus/counter/devices/counter0/chrdev_format
Yields the following /dev/counter0 memory layout:
+-----------------+------------------+----------+----------+
| Byte 0 - Byte 7 | Byte 8 - Byte 15 | Byte 16 | Byte 17 |
+-----------------+------------------+----------+----------+
| Count 0 | Count 1 | Signal 0 | Signal 2 |
+-----------------+------------------+----------+----------+
* Users may perform select/poll operations on the /dev/counterX node.
Users can be notified if data is available or events have occurred.
The benefit of this design is that the format is robust so users can
choose the components they want to interface and in the layout they
want. For example, if I am writing a userspace application to control a
dual-axis positioning table, I can select the two counts I care about
for the position axes. This allows me to read just those two values
directly from /dev/counterX with a simple read() call, without having to
fumble around seeking to an offset and parsing the layout.
Similarly, support for future extensions is simple to implement. When
timestamp support is implemented, users can just select the desired
timestamp extension and read it directly from the /dev/counterX node;
they should also be able to perform a select()/poll() call to be
notified on new timestamps.
So what do you think of this sort of design? I think there is a useful
robustness to the simplicity of performing a single read/write call on
/dev/counterX.
> >
> > Moving this selection to a sysfs attribute and dedicating the
> > character device to just data transfer might be a better design. If
> > such a design is chosen, should the selection attribute be
> > human-readable or binary?
>
> Sysfs basically requires things are more or less human readable.
> So if you go that way I think it needs to be.
>
> >
> > 2. How much space should allotted for strings?
> >
> > Each Counter component and extension has a respective size allotted
> > for its data (u8 data is allotted 1 byte, u64 data is allotted 8
> > bytes, etc.); I have arbitrarily chosen to allot 64 bytes for
> > strings. Is this an apt size, or should string data be allotted more
> > or less space?
>
> I'd go with that being big enough, but try to keep the expose interface
> such that the size can change it it needs to the in the future.
Following along with the separation of control vs data as discussed
above, we could support a more variable size by exposing it through a
sysfs attribute (maybe a chrdev_string_size attribute or similar).
>
> >
> > 3. Should the owning component of an extension be handled by the device
> > driver or Counter subsystem?
> >
> > The Counter subsystem figures out the owner (enum counter_owner_type)
> > for each component/extension in the counter-sysfs and counter-chrdev
> > code. When a callback must be executed, there are various switch
> > statements throughout the code to check whether the respective
> > Device, Signal, or Count version of the callback should be executed;
> > similarly, the appropriate owner type must match for the struct
> > counter_data macros such as COUNTER_DATA_DEVICE_U64,
> > COUNTER_DATA_SIGNAL_U64, COUNTER_DATA_COUNT_U64, etc.
> >
> > All this complexity in the Counter subsystem code can be eliminated
> > if a single callback type with a `void *owner` parameter is defined
> > for use with all three owner types (Device, Signal, and Count). The
> > device driver would then be responsible for casting the callback
> > argument to the appropriate owner type; but in theory, this should
> > not be much of a problem since the device driver is responsible for
> > assigning the callbacks to the owning component anyway.
>
> Whilst its more complex for subsytem I think it's better to keep everything
> typed if we possibly can. Always a trade off though, so use your discretion.
>
> Jonathan
I'm going to keep it all typed for now since I don't want to make too
many changes at once. Since this is somewhat unrelated to the purpose of
introducing Counter character devices, I'll postpone the discussion to a
later date after the Counter character device interface is merged.
William Breathitt Gray
>
>
> >
> > William Breathitt Gray (4):
> > counter: Internalize sysfs interface code
> > docs: counter: Update to reflect sysfs internalization
> > counter: Add character device interface
> > docs: counter: Document character device interface
> >
> > Documentation/driver-api/generic-counter.rst | 275 +++-
> > MAINTAINERS | 3 +-
> > drivers/counter/104-quad-8.c | 547 +++----
> > drivers/counter/Makefile | 1 +
> > drivers/counter/counter-chrdev.c | 656 ++++++++
> > drivers/counter/counter-chrdev.h | 16 +
> > drivers/counter/counter-core.c | 187 +++
> > drivers/counter/counter-sysfs.c | 881 +++++++++++
> > drivers/counter/counter-sysfs.h | 14 +
> > drivers/counter/counter.c | 1496 ------------------
> > drivers/counter/ftm-quaddec.c | 89 +-
> > drivers/counter/stm32-lptimer-cnt.c | 161 +-
> > drivers/counter/stm32-timer-cnt.c | 139 +-
> > drivers/counter/ti-eqep.c | 211 +--
> > include/linux/counter.h | 626 ++++----
> > include/linux/counter_enum.h | 45 -
> > include/uapi/linux/counter-types.h | 45 +
> > 17 files changed, 2826 insertions(+), 2566 deletions(-)
> > create mode 100644 drivers/counter/counter-chrdev.c
> > create mode 100644 drivers/counter/counter-chrdev.h
> > create mode 100644 drivers/counter/counter-core.c
> > create mode 100644 drivers/counter/counter-sysfs.c
> > create mode 100644 drivers/counter/counter-sysfs.h
> > delete mode 100644 drivers/counter/counter.c
> > delete mode 100644 include/linux/counter_enum.h
> > create mode 100644 include/uapi/linux/counter-types.h
> >
>
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_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 4/4] docs: counter: Document character device interface
2020-05-16 19:20 ` William Breathitt Gray
@ 2020-05-29 13:26 ` Pavel Machek
-1 siblings, 0 replies; 38+ messages in thread
From: Pavel Machek @ 2020-05-29 13:26 UTC (permalink / raw)
To: William Breathitt Gray
Cc: jic23, kamel.bouhara, gwendal, alexandre.belloni, david,
linux-iio, linux-kernel, linux-stm32, linux-arm-kernel,
syednwaris, patrick.havelange, fabrice.gasnier, mcoquelin.stm32,
alexandre.torgue
On Sat 2020-05-16 15:20:02, William Breathitt Gray wrote:
> This patch adds high-level documentation about the Counter subsystem
> character device interface.
>
> Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
> ---
> Documentation/driver-api/generic-counter.rst | 112 +++++++++++++------
> 1 file changed, 76 insertions(+), 36 deletions(-)
>
> diff --git a/Documentation/driver-api/generic-counter.rst b/Documentation/driver-api/generic-counter.rst
> index 8f85c30dea0b..58045b33b576 100644
> --- a/Documentation/driver-api/generic-counter.rst
> +++ b/Documentation/driver-api/generic-counter.rst
> +
> +Counter chrdev
> +--------------
> +Translates counter data to the standard Counter character device; data
> +is transferred via standard character device read/write calls.
> +
> +Sysfs Interface
> +===============
> +
> +Several sysfs attributes are generated by the Generic Counter interface,
> +and reside under the `/sys/bus/counter/devices/counterX` directory,
> +where `X` is to the respective counter device id. Please see
> +Documentation/ABI/testing/sysfs-bus-counter for detailed information on
> +each Generic Counter interface sysfs attribute.
> +
> +Through these sysfs attributes, programs and scripts may interact with
> +the Generic Counter paradigm Counts, Signals, and Synapses of respective
> +counter devices.
> +
> +Counter Character Device
> +========================
> +
> +Counter character device nodes are created under the `/dev` directory as
> +`counterX`, where `X` is the respective counter device id. Defines for
> +the standard Counter data types are exposed via the userspace
> +`include/uapi/linux/counter-types.h` file.
> +
> +The first 196095 bytes of the character device serve as a control
> +selection area where control exposure of desired Counter components and
> +extensions may be selected. Each byte serves as a boolean selection
> +indicator for a respective Counter component or extension. The format of
> +this area is as follows:
> +
> +* For each device extension, a byte is required.
> +* For each Signal, a byte is reserved for the Signal component, and a
> + byte is reserved for each Signal extension.
> +* For each Count, a byte is reserved for the Count component, a byte is
> + reserved for the count function, a byte is reserved for each Synapse
> + action, and byte is reserved for each Count extension.
> +
> +The selected Counter components and extensions may then be interfaced
> +after the first 196095 bytes via standard character device read/write
> +operations. The number of bytes available for each component or
> +extension is dependent on their respective data type: u8 will have 1
> +byte available, u64 will have 8 bytes available, strings will have 64
> +bytes available, etc.
This looks like very, very strange interface, and not described in detail
required to understand it.
Could you take a look at input subsystem, /dev/input/event0? Perhaps it is
directly usable, and if not something similar should probably be acceptable.
Best regards,
Pavel
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 4/4] docs: counter: Document character device interface
@ 2020-05-29 13:26 ` Pavel Machek
0 siblings, 0 replies; 38+ messages in thread
From: Pavel Machek @ 2020-05-29 13:26 UTC (permalink / raw)
To: William Breathitt Gray
Cc: kamel.bouhara, gwendal, david, linux-iio, patrick.havelange,
alexandre.belloni, linux-kernel, linux-arm-kernel,
mcoquelin.stm32, fabrice.gasnier, syednwaris, linux-stm32, jic23,
alexandre.torgue
On Sat 2020-05-16 15:20:02, William Breathitt Gray wrote:
> This patch adds high-level documentation about the Counter subsystem
> character device interface.
>
> Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
> ---
> Documentation/driver-api/generic-counter.rst | 112 +++++++++++++------
> 1 file changed, 76 insertions(+), 36 deletions(-)
>
> diff --git a/Documentation/driver-api/generic-counter.rst b/Documentation/driver-api/generic-counter.rst
> index 8f85c30dea0b..58045b33b576 100644
> --- a/Documentation/driver-api/generic-counter.rst
> +++ b/Documentation/driver-api/generic-counter.rst
> +
> +Counter chrdev
> +--------------
> +Translates counter data to the standard Counter character device; data
> +is transferred via standard character device read/write calls.
> +
> +Sysfs Interface
> +===============
> +
> +Several sysfs attributes are generated by the Generic Counter interface,
> +and reside under the `/sys/bus/counter/devices/counterX` directory,
> +where `X` is to the respective counter device id. Please see
> +Documentation/ABI/testing/sysfs-bus-counter for detailed information on
> +each Generic Counter interface sysfs attribute.
> +
> +Through these sysfs attributes, programs and scripts may interact with
> +the Generic Counter paradigm Counts, Signals, and Synapses of respective
> +counter devices.
> +
> +Counter Character Device
> +========================
> +
> +Counter character device nodes are created under the `/dev` directory as
> +`counterX`, where `X` is the respective counter device id. Defines for
> +the standard Counter data types are exposed via the userspace
> +`include/uapi/linux/counter-types.h` file.
> +
> +The first 196095 bytes of the character device serve as a control
> +selection area where control exposure of desired Counter components and
> +extensions may be selected. Each byte serves as a boolean selection
> +indicator for a respective Counter component or extension. The format of
> +this area is as follows:
> +
> +* For each device extension, a byte is required.
> +* For each Signal, a byte is reserved for the Signal component, and a
> + byte is reserved for each Signal extension.
> +* For each Count, a byte is reserved for the Count component, a byte is
> + reserved for the count function, a byte is reserved for each Synapse
> + action, and byte is reserved for each Count extension.
> +
> +The selected Counter components and extensions may then be interfaced
> +after the first 196095 bytes via standard character device read/write
> +operations. The number of bytes available for each component or
> +extension is dependent on their respective data type: u8 will have 1
> +byte available, u64 will have 8 bytes available, strings will have 64
> +bytes available, etc.
This looks like very, very strange interface, and not described in detail
required to understand it.
Could you take a look at input subsystem, /dev/input/event0? Perhaps it is
directly usable, and if not something similar should probably be acceptable.
Best regards,
Pavel
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 4/4] docs: counter: Document character device interface
2020-05-29 13:26 ` Pavel Machek
@ 2020-05-31 13:31 ` William Breathitt Gray
-1 siblings, 0 replies; 38+ messages in thread
From: William Breathitt Gray @ 2020-05-31 13:31 UTC (permalink / raw)
To: Pavel Machek
Cc: jic23, kamel.bouhara, gwendal, alexandre.belloni, david,
linux-iio, linux-kernel, linux-stm32, linux-arm-kernel,
syednwaris, patrick.havelange, fabrice.gasnier, mcoquelin.stm32,
alexandre.torgue
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On Fri, May 29, 2020 at 03:26:04PM +0200, Pavel Machek wrote:
> On Sat 2020-05-16 15:20:02, William Breathitt Gray wrote:
> > This patch adds high-level documentation about the Counter subsystem
> > character device interface.
> >
> > Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
> > ---
> > Documentation/driver-api/generic-counter.rst | 112 +++++++++++++------
> > 1 file changed, 76 insertions(+), 36 deletions(-)
> >
> > diff --git a/Documentation/driver-api/generic-counter.rst b/Documentation/driver-api/generic-counter.rst
> > index 8f85c30dea0b..58045b33b576 100644
> > --- a/Documentation/driver-api/generic-counter.rst
> > +++ b/Documentation/driver-api/generic-counter.rst
>
> > +
> > +Counter chrdev
> > +--------------
> > +Translates counter data to the standard Counter character device; data
> > +is transferred via standard character device read/write calls.
> > +
> > +Sysfs Interface
> > +===============
> > +
> > +Several sysfs attributes are generated by the Generic Counter interface,
> > +and reside under the `/sys/bus/counter/devices/counterX` directory,
> > +where `X` is to the respective counter device id. Please see
> > +Documentation/ABI/testing/sysfs-bus-counter for detailed information on
> > +each Generic Counter interface sysfs attribute.
> > +
> > +Through these sysfs attributes, programs and scripts may interact with
> > +the Generic Counter paradigm Counts, Signals, and Synapses of respective
> > +counter devices.
> > +
> > +Counter Character Device
> > +========================
> > +
> > +Counter character device nodes are created under the `/dev` directory as
> > +`counterX`, where `X` is the respective counter device id. Defines for
> > +the standard Counter data types are exposed via the userspace
> > +`include/uapi/linux/counter-types.h` file.
> > +
> > +The first 196095 bytes of the character device serve as a control
> > +selection area where control exposure of desired Counter components and
> > +extensions may be selected. Each byte serves as a boolean selection
> > +indicator for a respective Counter component or extension. The format of
> > +this area is as follows:
> > +
> > +* For each device extension, a byte is required.
> > +* For each Signal, a byte is reserved for the Signal component, and a
> > + byte is reserved for each Signal extension.
> > +* For each Count, a byte is reserved for the Count component, a byte is
> > + reserved for the count function, a byte is reserved for each Synapse
> > + action, and byte is reserved for each Count extension.
> > +
> > +The selected Counter components and extensions may then be interfaced
> > +after the first 196095 bytes via standard character device read/write
> > +operations. The number of bytes available for each component or
> > +extension is dependent on their respective data type: u8 will have 1
> > +byte available, u64 will have 8 bytes available, strings will have 64
> > +bytes available, etc.
>
> This looks like very, very strange interface, and not described in detail
> required to understand it.
>
> Could you take a look at input subsystem, /dev/input/event0? Perhaps it is
> directly usable, and if not something similar should probably be acceptable.
>
> Best regards,
> Pavel
Yes, I don't think this is a good interface afterall. I'm implementing a
different design for v3 that should be more intuitive. The input
subsystem could be useful for streams of events such as timestamps, so
I'll take a look at it as well in case something similar to it could be
used.
William Breathitt Gray
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^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 4/4] docs: counter: Document character device interface
@ 2020-05-31 13:31 ` William Breathitt Gray
0 siblings, 0 replies; 38+ messages in thread
From: William Breathitt Gray @ 2020-05-31 13:31 UTC (permalink / raw)
To: Pavel Machek
Cc: kamel.bouhara, gwendal, david, linux-iio, patrick.havelange,
alexandre.belloni, linux-kernel, linux-arm-kernel,
mcoquelin.stm32, fabrice.gasnier, syednwaris, linux-stm32, jic23,
alexandre.torgue
[-- Attachment #1.1: Type: text/plain, Size: 3654 bytes --]
On Fri, May 29, 2020 at 03:26:04PM +0200, Pavel Machek wrote:
> On Sat 2020-05-16 15:20:02, William Breathitt Gray wrote:
> > This patch adds high-level documentation about the Counter subsystem
> > character device interface.
> >
> > Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
> > ---
> > Documentation/driver-api/generic-counter.rst | 112 +++++++++++++------
> > 1 file changed, 76 insertions(+), 36 deletions(-)
> >
> > diff --git a/Documentation/driver-api/generic-counter.rst b/Documentation/driver-api/generic-counter.rst
> > index 8f85c30dea0b..58045b33b576 100644
> > --- a/Documentation/driver-api/generic-counter.rst
> > +++ b/Documentation/driver-api/generic-counter.rst
>
> > +
> > +Counter chrdev
> > +--------------
> > +Translates counter data to the standard Counter character device; data
> > +is transferred via standard character device read/write calls.
> > +
> > +Sysfs Interface
> > +===============
> > +
> > +Several sysfs attributes are generated by the Generic Counter interface,
> > +and reside under the `/sys/bus/counter/devices/counterX` directory,
> > +where `X` is to the respective counter device id. Please see
> > +Documentation/ABI/testing/sysfs-bus-counter for detailed information on
> > +each Generic Counter interface sysfs attribute.
> > +
> > +Through these sysfs attributes, programs and scripts may interact with
> > +the Generic Counter paradigm Counts, Signals, and Synapses of respective
> > +counter devices.
> > +
> > +Counter Character Device
> > +========================
> > +
> > +Counter character device nodes are created under the `/dev` directory as
> > +`counterX`, where `X` is the respective counter device id. Defines for
> > +the standard Counter data types are exposed via the userspace
> > +`include/uapi/linux/counter-types.h` file.
> > +
> > +The first 196095 bytes of the character device serve as a control
> > +selection area where control exposure of desired Counter components and
> > +extensions may be selected. Each byte serves as a boolean selection
> > +indicator for a respective Counter component or extension. The format of
> > +this area is as follows:
> > +
> > +* For each device extension, a byte is required.
> > +* For each Signal, a byte is reserved for the Signal component, and a
> > + byte is reserved for each Signal extension.
> > +* For each Count, a byte is reserved for the Count component, a byte is
> > + reserved for the count function, a byte is reserved for each Synapse
> > + action, and byte is reserved for each Count extension.
> > +
> > +The selected Counter components and extensions may then be interfaced
> > +after the first 196095 bytes via standard character device read/write
> > +operations. The number of bytes available for each component or
> > +extension is dependent on their respective data type: u8 will have 1
> > +byte available, u64 will have 8 bytes available, strings will have 64
> > +bytes available, etc.
>
> This looks like very, very strange interface, and not described in detail
> required to understand it.
>
> Could you take a look at input subsystem, /dev/input/event0? Perhaps it is
> directly usable, and if not something similar should probably be acceptable.
>
> Best regards,
> Pavel
Yes, I don't think this is a good interface afterall. I'm implementing a
different design for v3 that should be more intuitive. The input
subsystem could be useful for streams of events such as timestamps, so
I'll take a look at it as well in case something similar to it could be
used.
William Breathitt Gray
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^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 0/4] Introduce the Counter character device interface
2020-05-24 17:54 ` William Breathitt Gray
@ 2020-05-31 15:18 ` Jonathan Cameron
-1 siblings, 0 replies; 38+ messages in thread
From: Jonathan Cameron @ 2020-05-31 15:18 UTC (permalink / raw)
To: William Breathitt Gray
Cc: kamel.bouhara, gwendal, alexandre.belloni, david, linux-iio,
linux-kernel, linux-stm32, linux-arm-kernel, syednwaris,
patrick.havelange, fabrice.gasnier, mcoquelin.stm32,
alexandre.torgue
On Sun, 24 May 2020 13:54:39 -0400
William Breathitt Gray <vilhelm.gray@gmail.com> wrote:
> On Sun, May 24, 2020 at 05:25:42PM +0100, Jonathan Cameron wrote:
> >
> > ...
> >
> > > The following are some questions I have about this patchset:
> > >
> > > 1. Should the data format of the character device be configured via a
> > > sysfs attribute?
> > >
> > > In this patchset, the first 196095 bytes of the character device are
> > > dedicated as a selection area to choose which Counter components or
> > > extensions should be exposed; the subsequent bytes are the actual
> > > data for the Counter components and extensions that were selected.
> >
> > That sounds like the worst of all possible worlds. Reality is you need
> > to do some magic library so at that point you might as well have ioctl
> > options to configure it. I wonder if you can keep the data flow
> > to be a simple 'read' from the chardev but move the control away from
> > that. Either control via some chrdevs but keep them to the 'set / get'
> > if this element is going to turn up in the read or not. You rapidly
> > run into problems though, such as now to see how large a given element
> > is going to be etc. Plus ioctls are rather messier to extend than
> > simply adding a new sysfs file. Various subsystems do complex
> > 'descriptor' type approaches to get around this, or you could do
> > self describing records rather than raw data - like an input
> > ev_dev event.
>
> Yes I agree, I don't think combining nondata with data is good design --
> it's better if users are able to simply perform read/write on the
> character device without having to keep track of valid offsets and
> controls.
>
> After giving this some more thought, I believe human-readable sysfs
> attributes are the way to go to support configuration of the character
> device. I am thinking of a system like this:
>
> * Users configure the counter character device via a sysfs attribute
> such as /sys/bus/counter/devices/counterX/chrdev_format or similar.
>
> * Users may write to this sysfs attribute to select the components they
> want to interface -- the layout can be determined as well from the
> order. For example:
>
> # echo "C0 C3 C2" > /sys/bus/counter/devices/counter0/chrdev_format
I guess that 'just' meets the sysfs requirement of one file => one thing.
>
> This would select Counts 0, 3, and 2 (in that order) to be available
> in the /dev/counter0 node as a contiguous memory region.
>
> You can select extensions in a similar fashion:
>
> # echo "C4E2 S1E0" > /sys/bus/counter/devices/counter0/chrdev_format
>
> This would select extension 2 from Count 4, and extension 0 from
> Signal 1.
I'm not totally clear why we'd want to have a chrdev access to extensions.
To be honest I'm not totally sure what an extension is today as it's been
a week ;)
Perhaps an example? I see timestamp below. What is that attached to?
If we gave multiple counters, do they each have a timestamp?
>
> * Users may read from this chrdev_format sysfs attribute in order to see
> the currently configured format of the character device.
>
> * Users may perform read/write operations on the /dev/counterX node
> directly; the layout of the data is what they user has configured via
> the chrdev_format sysfs attribute. For example:
>
> # echo "C0 C1 S0 S1" > /sys/bus/counter/devices/counter0/chrdev_format
>
> Yields the following /dev/counter0 memory layout:
>
> +-----------------+------------------+----------+----------+
> | Byte 0 - Byte 7 | Byte 8 - Byte 15 | Byte 16 | Byte 17 |
> +-----------------+------------------+----------+----------+
> | Count 0 | Count 1 | Signal 0 | Signal 2 |
> +-----------------+------------------+----------+----------+
>
> * Users may perform select/poll operations on the /dev/counterX node.
> Users can be notified if data is available or events have occurred.
One thing to think about early if watermarks. We bolted them on
late in IIO and maybe we could have done it better from the start.
I'd almost guarantee someone will want one fairly soon - particularly
as it's more than possible you'll have a counter device with a
hardware fifo. I have some vague recollection that ti-ecap
stuff could be presented as a short fifo for starters.
>
> The benefit of this design is that the format is robust so users can
> choose the components they want to interface and in the layout they
> want. For example, if I am writing a userspace application to control a
> dual-axis positioning table, I can select the two counts I care about
> for the position axes. This allows me to read just those two values
> directly from /dev/counterX with a simple read() call, without having to
> fumble around seeking to an offset and parsing the layout.
I wonder if I'm over thinking things for counters, but you may run into
the complexity of different counters having different sampling frequencies.
Here you are suggesting a scheme that I think ends up closer to IIO than
input. That makes this case a pain. Input takes the view that it's
fine to have data coming in any order and frequency because every
record is self describing. I'm not sure it matters here, but it is
a nice layer of flexibility, but you do loose the efficiency of
the description being external to the data flow.
>
> Similarly, support for future extensions is simple to implement. When
> timestamp support is implemented, users can just select the desired
> timestamp extension and read it directly from the /dev/counterX node;
> they should also be able to perform a select()/poll() call to be
> notified on new timestamps.
>
> So what do you think of this sort of design? I think there is a useful
> robustness to the simplicity of performing a single read/write call on
> /dev/counterX.
It seems like a reasonable solution to me. The only blurry
boundary to my mind is what level of buffering is behind this.
The things you can do are open, non blocking read, blocking read and select.
If we have a counter that is sampled on demand, then
1) Non blocking read - makes not sense, fair enough I guess, could make it
the same as a blocking read.
2) Blocking read - reads from the sensor.
3) Select, meaningless as all reads are done on demand - so I guess you
hardwire it to return immediately.
4) open. Nothing special
If you have a counter that is self clocking then data gets pushed into some
software structure (probably kfifo)
1) Blocking read, question of semantics to resolve
a) Return when 'some' data is available (like a socket)
b) Return when 'requested amount of data is available'?
2) Non blocking read. Return whatever happens to be available.
3) Select. Semantics to be defined.
a) Some data?
b) Watermark based (default watermark is 0 so any data triggers it)
4) Open. Starts up sampling of configured set - (typically turns on the
device, enables interrupt output etc.)
So some corners to resolve but should all work.
>
> > >
> > > Moving this selection to a sysfs attribute and dedicating the
> > > character device to just data transfer might be a better design. If
> > > such a design is chosen, should the selection attribute be
> > > human-readable or binary?
> >
> > Sysfs basically requires things are more or less human readable.
> > So if you go that way I think it needs to be.
> >
> > >
> > > 2. How much space should allotted for strings?
> > >
> > > Each Counter component and extension has a respective size allotted
> > > for its data (u8 data is allotted 1 byte, u64 data is allotted 8
> > > bytes, etc.); I have arbitrarily chosen to allot 64 bytes for
> > > strings. Is this an apt size, or should string data be allotted more
> > > or less space?
> >
> > I'd go with that being big enough, but try to keep the expose interface
> > such that the size can change it it needs to the in the future.
>
> Following along with the separation of control vs data as discussed
> above, we could support a more variable size by exposing it through a
> sysfs attribute (maybe a chrdev_string_size attribute or similar).
I'm unconvinced you'd ever want to return a string via the chardev.
People are using the chrdev to get efficiency. String based data flows
are rarely that!
>
> >
> > >
> > > 3. Should the owning component of an extension be handled by the device
> > > driver or Counter subsystem?
> > >
> > > The Counter subsystem figures out the owner (enum counter_owner_type)
> > > for each component/extension in the counter-sysfs and counter-chrdev
> > > code. When a callback must be executed, there are various switch
> > > statements throughout the code to check whether the respective
> > > Device, Signal, or Count version of the callback should be executed;
> > > similarly, the appropriate owner type must match for the struct
> > > counter_data macros such as COUNTER_DATA_DEVICE_U64,
> > > COUNTER_DATA_SIGNAL_U64, COUNTER_DATA_COUNT_U64, etc.
> > >
> > > All this complexity in the Counter subsystem code can be eliminated
> > > if a single callback type with a `void *owner` parameter is defined
> > > for use with all three owner types (Device, Signal, and Count). The
> > > device driver would then be responsible for casting the callback
> > > argument to the appropriate owner type; but in theory, this should
> > > not be much of a problem since the device driver is responsible for
> > > assigning the callbacks to the owning component anyway.
> >
> > Whilst its more complex for subsytem I think it's better to keep everything
> > typed if we possibly can. Always a trade off though, so use your discretion.
> >
> > Jonathan
>
> I'm going to keep it all typed for now since I don't want to make too
> many changes at once. Since this is somewhat unrelated to the purpose of
> introducing Counter character devices, I'll postpone the discussion to a
> later date after the Counter character device interface is merged.
Makes sense.
Jonathan
>
> William Breathitt Gray
>
> >
> >
> > >
> > > William Breathitt Gray (4):
> > > counter: Internalize sysfs interface code
> > > docs: counter: Update to reflect sysfs internalization
> > > counter: Add character device interface
> > > docs: counter: Document character device interface
> > >
> > > Documentation/driver-api/generic-counter.rst | 275 +++-
> > > MAINTAINERS | 3 +-
> > > drivers/counter/104-quad-8.c | 547 +++----
> > > drivers/counter/Makefile | 1 +
> > > drivers/counter/counter-chrdev.c | 656 ++++++++
> > > drivers/counter/counter-chrdev.h | 16 +
> > > drivers/counter/counter-core.c | 187 +++
> > > drivers/counter/counter-sysfs.c | 881 +++++++++++
> > > drivers/counter/counter-sysfs.h | 14 +
> > > drivers/counter/counter.c | 1496 ------------------
> > > drivers/counter/ftm-quaddec.c | 89 +-
> > > drivers/counter/stm32-lptimer-cnt.c | 161 +-
> > > drivers/counter/stm32-timer-cnt.c | 139 +-
> > > drivers/counter/ti-eqep.c | 211 +--
> > > include/linux/counter.h | 626 ++++----
> > > include/linux/counter_enum.h | 45 -
> > > include/uapi/linux/counter-types.h | 45 +
> > > 17 files changed, 2826 insertions(+), 2566 deletions(-)
> > > create mode 100644 drivers/counter/counter-chrdev.c
> > > create mode 100644 drivers/counter/counter-chrdev.h
> > > create mode 100644 drivers/counter/counter-core.c
> > > create mode 100644 drivers/counter/counter-sysfs.c
> > > create mode 100644 drivers/counter/counter-sysfs.h
> > > delete mode 100644 drivers/counter/counter.c
> > > delete mode 100644 include/linux/counter_enum.h
> > > create mode 100644 include/uapi/linux/counter-types.h
> > >
> >
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 0/4] Introduce the Counter character device interface
@ 2020-05-31 15:18 ` Jonathan Cameron
0 siblings, 0 replies; 38+ messages in thread
From: Jonathan Cameron @ 2020-05-31 15:18 UTC (permalink / raw)
To: William Breathitt Gray
Cc: kamel.bouhara, gwendal, david, linux-iio, patrick.havelange,
alexandre.belloni, linux-kernel, mcoquelin.stm32,
fabrice.gasnier, syednwaris, linux-stm32, linux-arm-kernel,
alexandre.torgue
On Sun, 24 May 2020 13:54:39 -0400
William Breathitt Gray <vilhelm.gray@gmail.com> wrote:
> On Sun, May 24, 2020 at 05:25:42PM +0100, Jonathan Cameron wrote:
> >
> > ...
> >
> > > The following are some questions I have about this patchset:
> > >
> > > 1. Should the data format of the character device be configured via a
> > > sysfs attribute?
> > >
> > > In this patchset, the first 196095 bytes of the character device are
> > > dedicated as a selection area to choose which Counter components or
> > > extensions should be exposed; the subsequent bytes are the actual
> > > data for the Counter components and extensions that were selected.
> >
> > That sounds like the worst of all possible worlds. Reality is you need
> > to do some magic library so at that point you might as well have ioctl
> > options to configure it. I wonder if you can keep the data flow
> > to be a simple 'read' from the chardev but move the control away from
> > that. Either control via some chrdevs but keep them to the 'set / get'
> > if this element is going to turn up in the read or not. You rapidly
> > run into problems though, such as now to see how large a given element
> > is going to be etc. Plus ioctls are rather messier to extend than
> > simply adding a new sysfs file. Various subsystems do complex
> > 'descriptor' type approaches to get around this, or you could do
> > self describing records rather than raw data - like an input
> > ev_dev event.
>
> Yes I agree, I don't think combining nondata with data is good design --
> it's better if users are able to simply perform read/write on the
> character device without having to keep track of valid offsets and
> controls.
>
> After giving this some more thought, I believe human-readable sysfs
> attributes are the way to go to support configuration of the character
> device. I am thinking of a system like this:
>
> * Users configure the counter character device via a sysfs attribute
> such as /sys/bus/counter/devices/counterX/chrdev_format or similar.
>
> * Users may write to this sysfs attribute to select the components they
> want to interface -- the layout can be determined as well from the
> order. For example:
>
> # echo "C0 C3 C2" > /sys/bus/counter/devices/counter0/chrdev_format
I guess that 'just' meets the sysfs requirement of one file => one thing.
>
> This would select Counts 0, 3, and 2 (in that order) to be available
> in the /dev/counter0 node as a contiguous memory region.
>
> You can select extensions in a similar fashion:
>
> # echo "C4E2 S1E0" > /sys/bus/counter/devices/counter0/chrdev_format
>
> This would select extension 2 from Count 4, and extension 0 from
> Signal 1.
I'm not totally clear why we'd want to have a chrdev access to extensions.
To be honest I'm not totally sure what an extension is today as it's been
a week ;)
Perhaps an example? I see timestamp below. What is that attached to?
If we gave multiple counters, do they each have a timestamp?
>
> * Users may read from this chrdev_format sysfs attribute in order to see
> the currently configured format of the character device.
>
> * Users may perform read/write operations on the /dev/counterX node
> directly; the layout of the data is what they user has configured via
> the chrdev_format sysfs attribute. For example:
>
> # echo "C0 C1 S0 S1" > /sys/bus/counter/devices/counter0/chrdev_format
>
> Yields the following /dev/counter0 memory layout:
>
> +-----------------+------------------+----------+----------+
> | Byte 0 - Byte 7 | Byte 8 - Byte 15 | Byte 16 | Byte 17 |
> +-----------------+------------------+----------+----------+
> | Count 0 | Count 1 | Signal 0 | Signal 2 |
> +-----------------+------------------+----------+----------+
>
> * Users may perform select/poll operations on the /dev/counterX node.
> Users can be notified if data is available or events have occurred.
One thing to think about early if watermarks. We bolted them on
late in IIO and maybe we could have done it better from the start.
I'd almost guarantee someone will want one fairly soon - particularly
as it's more than possible you'll have a counter device with a
hardware fifo. I have some vague recollection that ti-ecap
stuff could be presented as a short fifo for starters.
>
> The benefit of this design is that the format is robust so users can
> choose the components they want to interface and in the layout they
> want. For example, if I am writing a userspace application to control a
> dual-axis positioning table, I can select the two counts I care about
> for the position axes. This allows me to read just those two values
> directly from /dev/counterX with a simple read() call, without having to
> fumble around seeking to an offset and parsing the layout.
I wonder if I'm over thinking things for counters, but you may run into
the complexity of different counters having different sampling frequencies.
Here you are suggesting a scheme that I think ends up closer to IIO than
input. That makes this case a pain. Input takes the view that it's
fine to have data coming in any order and frequency because every
record is self describing. I'm not sure it matters here, but it is
a nice layer of flexibility, but you do loose the efficiency of
the description being external to the data flow.
>
> Similarly, support for future extensions is simple to implement. When
> timestamp support is implemented, users can just select the desired
> timestamp extension and read it directly from the /dev/counterX node;
> they should also be able to perform a select()/poll() call to be
> notified on new timestamps.
>
> So what do you think of this sort of design? I think there is a useful
> robustness to the simplicity of performing a single read/write call on
> /dev/counterX.
It seems like a reasonable solution to me. The only blurry
boundary to my mind is what level of buffering is behind this.
The things you can do are open, non blocking read, blocking read and select.
If we have a counter that is sampled on demand, then
1) Non blocking read - makes not sense, fair enough I guess, could make it
the same as a blocking read.
2) Blocking read - reads from the sensor.
3) Select, meaningless as all reads are done on demand - so I guess you
hardwire it to return immediately.
4) open. Nothing special
If you have a counter that is self clocking then data gets pushed into some
software structure (probably kfifo)
1) Blocking read, question of semantics to resolve
a) Return when 'some' data is available (like a socket)
b) Return when 'requested amount of data is available'?
2) Non blocking read. Return whatever happens to be available.
3) Select. Semantics to be defined.
a) Some data?
b) Watermark based (default watermark is 0 so any data triggers it)
4) Open. Starts up sampling of configured set - (typically turns on the
device, enables interrupt output etc.)
So some corners to resolve but should all work.
>
> > >
> > > Moving this selection to a sysfs attribute and dedicating the
> > > character device to just data transfer might be a better design. If
> > > such a design is chosen, should the selection attribute be
> > > human-readable or binary?
> >
> > Sysfs basically requires things are more or less human readable.
> > So if you go that way I think it needs to be.
> >
> > >
> > > 2. How much space should allotted for strings?
> > >
> > > Each Counter component and extension has a respective size allotted
> > > for its data (u8 data is allotted 1 byte, u64 data is allotted 8
> > > bytes, etc.); I have arbitrarily chosen to allot 64 bytes for
> > > strings. Is this an apt size, or should string data be allotted more
> > > or less space?
> >
> > I'd go with that being big enough, but try to keep the expose interface
> > such that the size can change it it needs to the in the future.
>
> Following along with the separation of control vs data as discussed
> above, we could support a more variable size by exposing it through a
> sysfs attribute (maybe a chrdev_string_size attribute or similar).
I'm unconvinced you'd ever want to return a string via the chardev.
People are using the chrdev to get efficiency. String based data flows
are rarely that!
>
> >
> > >
> > > 3. Should the owning component of an extension be handled by the device
> > > driver or Counter subsystem?
> > >
> > > The Counter subsystem figures out the owner (enum counter_owner_type)
> > > for each component/extension in the counter-sysfs and counter-chrdev
> > > code. When a callback must be executed, there are various switch
> > > statements throughout the code to check whether the respective
> > > Device, Signal, or Count version of the callback should be executed;
> > > similarly, the appropriate owner type must match for the struct
> > > counter_data macros such as COUNTER_DATA_DEVICE_U64,
> > > COUNTER_DATA_SIGNAL_U64, COUNTER_DATA_COUNT_U64, etc.
> > >
> > > All this complexity in the Counter subsystem code can be eliminated
> > > if a single callback type with a `void *owner` parameter is defined
> > > for use with all three owner types (Device, Signal, and Count). The
> > > device driver would then be responsible for casting the callback
> > > argument to the appropriate owner type; but in theory, this should
> > > not be much of a problem since the device driver is responsible for
> > > assigning the callbacks to the owning component anyway.
> >
> > Whilst its more complex for subsytem I think it's better to keep everything
> > typed if we possibly can. Always a trade off though, so use your discretion.
> >
> > Jonathan
>
> I'm going to keep it all typed for now since I don't want to make too
> many changes at once. Since this is somewhat unrelated to the purpose of
> introducing Counter character devices, I'll postpone the discussion to a
> later date after the Counter character device interface is merged.
Makes sense.
Jonathan
>
> William Breathitt Gray
>
> >
> >
> > >
> > > William Breathitt Gray (4):
> > > counter: Internalize sysfs interface code
> > > docs: counter: Update to reflect sysfs internalization
> > > counter: Add character device interface
> > > docs: counter: Document character device interface
> > >
> > > Documentation/driver-api/generic-counter.rst | 275 +++-
> > > MAINTAINERS | 3 +-
> > > drivers/counter/104-quad-8.c | 547 +++----
> > > drivers/counter/Makefile | 1 +
> > > drivers/counter/counter-chrdev.c | 656 ++++++++
> > > drivers/counter/counter-chrdev.h | 16 +
> > > drivers/counter/counter-core.c | 187 +++
> > > drivers/counter/counter-sysfs.c | 881 +++++++++++
> > > drivers/counter/counter-sysfs.h | 14 +
> > > drivers/counter/counter.c | 1496 ------------------
> > > drivers/counter/ftm-quaddec.c | 89 +-
> > > drivers/counter/stm32-lptimer-cnt.c | 161 +-
> > > drivers/counter/stm32-timer-cnt.c | 139 +-
> > > drivers/counter/ti-eqep.c | 211 +--
> > > include/linux/counter.h | 626 ++++----
> > > include/linux/counter_enum.h | 45 -
> > > include/uapi/linux/counter-types.h | 45 +
> > > 17 files changed, 2826 insertions(+), 2566 deletions(-)
> > > create mode 100644 drivers/counter/counter-chrdev.c
> > > create mode 100644 drivers/counter/counter-chrdev.h
> > > create mode 100644 drivers/counter/counter-core.c
> > > create mode 100644 drivers/counter/counter-sysfs.c
> > > create mode 100644 drivers/counter/counter-sysfs.h
> > > delete mode 100644 drivers/counter/counter.c
> > > delete mode 100644 include/linux/counter_enum.h
> > > create mode 100644 include/uapi/linux/counter-types.h
> > >
> >
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^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 0/4] Introduce the Counter character device interface
2020-05-31 15:18 ` Jonathan Cameron
@ 2020-05-31 17:14 ` William Breathitt Gray
-1 siblings, 0 replies; 38+ messages in thread
From: William Breathitt Gray @ 2020-05-31 17:14 UTC (permalink / raw)
To: Jonathan Cameron
Cc: kamel.bouhara, gwendal, alexandre.belloni, david, linux-iio,
linux-kernel, linux-stm32, linux-arm-kernel, syednwaris,
patrick.havelange, fabrice.gasnier, mcoquelin.stm32,
alexandre.torgue
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On Sun, May 31, 2020 at 04:18:13PM +0100, Jonathan Cameron wrote:
> On Sun, 24 May 2020 13:54:39 -0400
> William Breathitt Gray <vilhelm.gray@gmail.com> wrote:
> > After giving this some more thought, I believe human-readable sysfs
> > attributes are the way to go to support configuration of the character
> > device. I am thinking of a system like this:
> >
> > * Users configure the counter character device via a sysfs attribute
> > such as /sys/bus/counter/devices/counterX/chrdev_format or similar.
> >
> > * Users may write to this sysfs attribute to select the components they
> > want to interface -- the layout can be determined as well from the
> > order. For example:
> >
> > # echo "C0 C3 C2" > /sys/bus/counter/devices/counter0/chrdev_format
>
> I guess that 'just' meets the sysfs requirement of one file => one thing.
We can massage this further to make it more apt, but the main idea here
is that configuration should be separate from our data; and that
configuration should be performed via sysfs.
> > This would select Counts 0, 3, and 2 (in that order) to be available
> > in the /dev/counter0 node as a contiguous memory region.
> >
> > You can select extensions in a similar fashion:
> >
> > # echo "C4E2 S1E0" > /sys/bus/counter/devices/counter0/chrdev_format
> >
> > This would select extension 2 from Count 4, and extension 0 from
> > Signal 1.
>
> I'm not totally clear why we'd want to have a chrdev access to extensions.
> To be honest I'm not totally sure what an extension is today as it's been
> a week ;)
In the context of the Counter subsystem, an extension is data/control
that is not one of the core components of the Counter paradigm (i.e. not
a Counter, Signal, nor Synapse). Extensions essentially represent
configuration options for the counter device and auxiliary
functionality.
The "Implementation" section of the Generic Counter documentation
Documentation/driver-api/generic-counter.rst file gives some good
examples of extensions, but I'll provide an example here for the sake of
this new character device interface.
Suppose we have a robot controlling a laser on a dual-axes positioning
table. A counter device is used to track the position of the laser:
Count 0 represents position on the X axis, while Count 1 represents
position on the Y axis. Because this machine is moving across two axes
at the same time, we want to grab both counts together via the
character device subsystem (grabbing them separately via sysfs would be
imprecise due to the inherent latency).
The motors are physically able the robot out of the work area, which is
not something we want to happen. A common setup in systems like this is
to set soft boundaries on the counter device to represent the edge of
the work area; when the boundary is passed, a flag is set high on the
device to indicate the position is out-of-bounds.
On the Counter subsystem side, this counter device would appear as
having four sysfs attributes: count0/count, count0/boundary,
count1/count, and count1/boundary. In terms of the character device
interface, we could perform a setup like this:
# echo "C0E0 C0 C1E1 C1" > counter0/chrdev_format
Yielding the following /dev/counter0 memory layout:
+------------+-----------------+------------+-------------------+
| Byte 0 | Byte 1 - Byte 8 | Byte 9 | Byte 10 - Byte 17 |
+------------+-----------------+------------+-------------------+
| Boundary 0 | Count 0 | Boundary 1 | Count 1 |
+------------+-----------------+------------+-------------------+
Now a single read() operation can grab the counts together as well as
their respective boundary flags to verify whether the current counts are
valid. This is a scenario where using sysfs wouldn't be viable to use:
we could check the count0/boundary sysfs attribute first, but by the
time we read the count0/count sysfs attribute second, the robot has
already moved to a new (possibly invalid) position.
> Perhaps an example? I see timestamp below. What is that attached to?
> If we gave multiple counters, do they each have a timestamp?
Some counter devices feature "timestamp" functionality. I haven't yet
implemented this in the Counter subsystem because it's new functionality
and I want to keep this patchset limited to the existing Counter
subsystem functionality support.
However, to briefly go into the topic (we'll need to discuss this more
in-depth before committing to a Counter subsystem design), some counter
devices can keep track of historic counts based on various events; we
call these "timestamps", although they may not necessary be tied to a
wall-clock time.
For example, quadrature encoders often have an "index" signal in
addition to the quadrature A and B lines. This index signal may be used
to home a positioning device, or perhaps to indicate that a full
revolution -- or some other event -- has occurred. It's common for
quadrature counter devices to provide a FIFO buffer that logs these
"index" events by saving the current count when that respective index
signal goes high. Thus we have a timestamp buffer.
In the context of the Counter subsystem, I believe we will end up
implementing these timestamps as Count extensions (or Device extensions
if it's a single buffer for the entire device). I'm not sure yet what
the sysfs attribute will display, but I'm guessing we'll have a
respective /sys/bus/counter/devices/counterX/countX/timestamps sysfs
attribute or similar.
The character device implementation should be more straight forward I
would imagine. Since it's a memory buffer, I think we can provide access
to that buffer directly in the chrdev:
# echo "C0E0 C1E1" > /sys/bus/counter/devices/counter0/chrdev_format
Yielding the following /dev/counter0 memory layout for 32-byte
timestamps:
+---------------------+---------------------+
| Byte 0 - Byte 31 | Byte 32 - Byte 63 |
+---------------------+---------------------+
| Timestamps Buffer 0 | Timestamps Buffer 1 |
+---------------------+---------------------+
> > * Users may read from this chrdev_format sysfs attribute in order to see
> > the currently configured format of the character device.
> >
> > * Users may perform read/write operations on the /dev/counterX node
> > directly; the layout of the data is what they user has configured via
> > the chrdev_format sysfs attribute. For example:
> >
> > # echo "C0 C1 S0 S1" > /sys/bus/counter/devices/counter0/chrdev_format
> >
> > Yields the following /dev/counter0 memory layout:
> >
> > +-----------------+------------------+----------+----------+
> > | Byte 0 - Byte 7 | Byte 8 - Byte 15 | Byte 16 | Byte 17 |
> > +-----------------+------------------+----------+----------+
> > | Count 0 | Count 1 | Signal 0 | Signal 2 |
> > +-----------------+------------------+----------+----------+
> >
> > * Users may perform select/poll operations on the /dev/counterX node.
> > Users can be notified if data is available or events have occurred.
>
> One thing to think about early if watermarks. We bolted them on
> late in IIO and maybe we could have done it better from the start.
> I'd almost guarantee someone will want one fairly soon - particularly
> as it's more than possible you'll have a counter device with a
> hardware fifo. I have some vague recollection that ti-ecap
> stuff could be presented as a short fifo for starters.
>
> >
> > The benefit of this design is that the format is robust so users can
> > choose the components they want to interface and in the layout they
> > want. For example, if I am writing a userspace application to control a
> > dual-axis positioning table, I can select the two counts I care about
> > for the position axes. This allows me to read just those two values
> > directly from /dev/counterX with a simple read() call, without having to
> > fumble around seeking to an offset and parsing the layout.
>
> I wonder if I'm over thinking things for counters, but you may run into
> the complexity of different counters having different sampling frequencies.
> Here you are suggesting a scheme that I think ends up closer to IIO than
> input. That makes this case a pain. Input takes the view that it's
> fine to have data coming in any order and frequency because every
> record is self describing. I'm not sure it matters here, but it is
> a nice layer of flexibility, but you do loose the efficiency of
> the description being external to the data flow.
I think one of the downsides to using a single a single character device
node to represent the entire counter device is that the frequency of two
individual counts may differ from each other. For example, using the
dual-axes positioning scenario from earlier, one axis might change more
frequently than the other (e.g. a conveyor belt situation where X is
always moving forward, while Y only changes when a part appears within
the work area).
In these cases, I think the Input subsystem approach might be better
because the user can just wait for events at large and handle each event
as it comes in, rather than try to coordinate between them all in a
shared memory space. The shortcoming with this approach is that we lose
the ability to grab Counts together at the same time, such as we require
in the constantly moving robot example earlier.
Perhaps what might work is to implement Counter events (perhaps even
timestamps) using the Input subsystem, and leave the Counter character
device interface to simple read/write operations. But we'll need to
investigate this further because we lack a concept of "events" right now
in the Counter subsystem.
> > Similarly, support for future extensions is simple to implement. When
> > timestamp support is implemented, users can just select the desired
> > timestamp extension and read it directly from the /dev/counterX node;
> > they should also be able to perform a select()/poll() call to be
> > notified on new timestamps.
> >
> > So what do you think of this sort of design? I think there is a useful
> > robustness to the simplicity of performing a single read/write call on
> > /dev/counterX.
>
> It seems like a reasonable solution to me. The only blurry
> boundary to my mind is what level of buffering is behind this.
> The things you can do are open, non blocking read, blocking read and select.
>
> If we have a counter that is sampled on demand, then
> 1) Non blocking read - makes not sense, fair enough I guess, could make it
> the same as a blocking read.
> 2) Blocking read - reads from the sensor.
> 3) Select, meaningless as all reads are done on demand - so I guess you
> hardwire it to return immediately.
> 4) open. Nothing special
>
> If you have a counter that is self clocking then data gets pushed into some
> software structure (probably kfifo)
> 1) Blocking read, question of semantics to resolve
> a) Return when 'some' data is available (like a socket)
> b) Return when 'requested amount of data is available'?
> 2) Non blocking read. Return whatever happens to be available.
> 3) Select. Semantics to be defined.
> a) Some data?
> b) Watermark based (default watermark is 0 so any data triggers it)
> 4) Open. Starts up sampling of configured set - (typically turns on the
> device, enables interrupt output etc.)
>
> So some corners to resolve but should all work.
I'm not familiar with the "watermark" terminology. Would you be able to
explain it bit more for me. Is this simply a flag that indicates if data
has changed from the last time it was checked?
> > > > Moving this selection to a sysfs attribute and dedicating the
> > > > character device to just data transfer might be a better design. If
> > > > such a design is chosen, should the selection attribute be
> > > > human-readable or binary?
> > >
> > > Sysfs basically requires things are more or less human readable.
> > > So if you go that way I think it needs to be.
> > >
> > > >
> > > > 2. How much space should allotted for strings?
> > > >
> > > > Each Counter component and extension has a respective size allotted
> > > > for its data (u8 data is allotted 1 byte, u64 data is allotted 8
> > > > bytes, etc.); I have arbitrarily chosen to allot 64 bytes for
> > > > strings. Is this an apt size, or should string data be allotted more
> > > > or less space?
> > >
> > > I'd go with that being big enough, but try to keep the expose interface
> > > such that the size can change it it needs to the in the future.
> >
> > Following along with the separation of control vs data as discussed
> > above, we could support a more variable size by exposing it through a
> > sysfs attribute (maybe a chrdev_string_size attribute or similar).
>
> I'm unconvinced you'd ever want to return a string via the chardev.
> People are using the chrdev to get efficiency. String based data flows
> are rarely that!
That's a good point. I don't think there is a situation right now where
we need to deliver strings via the character device interface, so I
think I'll remove that in v3.
William Breathitt Gray
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^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 0/4] Introduce the Counter character device interface
@ 2020-05-31 17:14 ` William Breathitt Gray
0 siblings, 0 replies; 38+ messages in thread
From: William Breathitt Gray @ 2020-05-31 17:14 UTC (permalink / raw)
To: Jonathan Cameron
Cc: kamel.bouhara, gwendal, david, linux-iio, patrick.havelange,
alexandre.belloni, linux-kernel, mcoquelin.stm32,
fabrice.gasnier, syednwaris, linux-stm32, linux-arm-kernel,
alexandre.torgue
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On Sun, May 31, 2020 at 04:18:13PM +0100, Jonathan Cameron wrote:
> On Sun, 24 May 2020 13:54:39 -0400
> William Breathitt Gray <vilhelm.gray@gmail.com> wrote:
> > After giving this some more thought, I believe human-readable sysfs
> > attributes are the way to go to support configuration of the character
> > device. I am thinking of a system like this:
> >
> > * Users configure the counter character device via a sysfs attribute
> > such as /sys/bus/counter/devices/counterX/chrdev_format or similar.
> >
> > * Users may write to this sysfs attribute to select the components they
> > want to interface -- the layout can be determined as well from the
> > order. For example:
> >
> > # echo "C0 C3 C2" > /sys/bus/counter/devices/counter0/chrdev_format
>
> I guess that 'just' meets the sysfs requirement of one file => one thing.
We can massage this further to make it more apt, but the main idea here
is that configuration should be separate from our data; and that
configuration should be performed via sysfs.
> > This would select Counts 0, 3, and 2 (in that order) to be available
> > in the /dev/counter0 node as a contiguous memory region.
> >
> > You can select extensions in a similar fashion:
> >
> > # echo "C4E2 S1E0" > /sys/bus/counter/devices/counter0/chrdev_format
> >
> > This would select extension 2 from Count 4, and extension 0 from
> > Signal 1.
>
> I'm not totally clear why we'd want to have a chrdev access to extensions.
> To be honest I'm not totally sure what an extension is today as it's been
> a week ;)
In the context of the Counter subsystem, an extension is data/control
that is not one of the core components of the Counter paradigm (i.e. not
a Counter, Signal, nor Synapse). Extensions essentially represent
configuration options for the counter device and auxiliary
functionality.
The "Implementation" section of the Generic Counter documentation
Documentation/driver-api/generic-counter.rst file gives some good
examples of extensions, but I'll provide an example here for the sake of
this new character device interface.
Suppose we have a robot controlling a laser on a dual-axes positioning
table. A counter device is used to track the position of the laser:
Count 0 represents position on the X axis, while Count 1 represents
position on the Y axis. Because this machine is moving across two axes
at the same time, we want to grab both counts together via the
character device subsystem (grabbing them separately via sysfs would be
imprecise due to the inherent latency).
The motors are physically able the robot out of the work area, which is
not something we want to happen. A common setup in systems like this is
to set soft boundaries on the counter device to represent the edge of
the work area; when the boundary is passed, a flag is set high on the
device to indicate the position is out-of-bounds.
On the Counter subsystem side, this counter device would appear as
having four sysfs attributes: count0/count, count0/boundary,
count1/count, and count1/boundary. In terms of the character device
interface, we could perform a setup like this:
# echo "C0E0 C0 C1E1 C1" > counter0/chrdev_format
Yielding the following /dev/counter0 memory layout:
+------------+-----------------+------------+-------------------+
| Byte 0 | Byte 1 - Byte 8 | Byte 9 | Byte 10 - Byte 17 |
+------------+-----------------+------------+-------------------+
| Boundary 0 | Count 0 | Boundary 1 | Count 1 |
+------------+-----------------+------------+-------------------+
Now a single read() operation can grab the counts together as well as
their respective boundary flags to verify whether the current counts are
valid. This is a scenario where using sysfs wouldn't be viable to use:
we could check the count0/boundary sysfs attribute first, but by the
time we read the count0/count sysfs attribute second, the robot has
already moved to a new (possibly invalid) position.
> Perhaps an example? I see timestamp below. What is that attached to?
> If we gave multiple counters, do they each have a timestamp?
Some counter devices feature "timestamp" functionality. I haven't yet
implemented this in the Counter subsystem because it's new functionality
and I want to keep this patchset limited to the existing Counter
subsystem functionality support.
However, to briefly go into the topic (we'll need to discuss this more
in-depth before committing to a Counter subsystem design), some counter
devices can keep track of historic counts based on various events; we
call these "timestamps", although they may not necessary be tied to a
wall-clock time.
For example, quadrature encoders often have an "index" signal in
addition to the quadrature A and B lines. This index signal may be used
to home a positioning device, or perhaps to indicate that a full
revolution -- or some other event -- has occurred. It's common for
quadrature counter devices to provide a FIFO buffer that logs these
"index" events by saving the current count when that respective index
signal goes high. Thus we have a timestamp buffer.
In the context of the Counter subsystem, I believe we will end up
implementing these timestamps as Count extensions (or Device extensions
if it's a single buffer for the entire device). I'm not sure yet what
the sysfs attribute will display, but I'm guessing we'll have a
respective /sys/bus/counter/devices/counterX/countX/timestamps sysfs
attribute or similar.
The character device implementation should be more straight forward I
would imagine. Since it's a memory buffer, I think we can provide access
to that buffer directly in the chrdev:
# echo "C0E0 C1E1" > /sys/bus/counter/devices/counter0/chrdev_format
Yielding the following /dev/counter0 memory layout for 32-byte
timestamps:
+---------------------+---------------------+
| Byte 0 - Byte 31 | Byte 32 - Byte 63 |
+---------------------+---------------------+
| Timestamps Buffer 0 | Timestamps Buffer 1 |
+---------------------+---------------------+
> > * Users may read from this chrdev_format sysfs attribute in order to see
> > the currently configured format of the character device.
> >
> > * Users may perform read/write operations on the /dev/counterX node
> > directly; the layout of the data is what they user has configured via
> > the chrdev_format sysfs attribute. For example:
> >
> > # echo "C0 C1 S0 S1" > /sys/bus/counter/devices/counter0/chrdev_format
> >
> > Yields the following /dev/counter0 memory layout:
> >
> > +-----------------+------------------+----------+----------+
> > | Byte 0 - Byte 7 | Byte 8 - Byte 15 | Byte 16 | Byte 17 |
> > +-----------------+------------------+----------+----------+
> > | Count 0 | Count 1 | Signal 0 | Signal 2 |
> > +-----------------+------------------+----------+----------+
> >
> > * Users may perform select/poll operations on the /dev/counterX node.
> > Users can be notified if data is available or events have occurred.
>
> One thing to think about early if watermarks. We bolted them on
> late in IIO and maybe we could have done it better from the start.
> I'd almost guarantee someone will want one fairly soon - particularly
> as it's more than possible you'll have a counter device with a
> hardware fifo. I have some vague recollection that ti-ecap
> stuff could be presented as a short fifo for starters.
>
> >
> > The benefit of this design is that the format is robust so users can
> > choose the components they want to interface and in the layout they
> > want. For example, if I am writing a userspace application to control a
> > dual-axis positioning table, I can select the two counts I care about
> > for the position axes. This allows me to read just those two values
> > directly from /dev/counterX with a simple read() call, without having to
> > fumble around seeking to an offset and parsing the layout.
>
> I wonder if I'm over thinking things for counters, but you may run into
> the complexity of different counters having different sampling frequencies.
> Here you are suggesting a scheme that I think ends up closer to IIO than
> input. That makes this case a pain. Input takes the view that it's
> fine to have data coming in any order and frequency because every
> record is self describing. I'm not sure it matters here, but it is
> a nice layer of flexibility, but you do loose the efficiency of
> the description being external to the data flow.
I think one of the downsides to using a single a single character device
node to represent the entire counter device is that the frequency of two
individual counts may differ from each other. For example, using the
dual-axes positioning scenario from earlier, one axis might change more
frequently than the other (e.g. a conveyor belt situation where X is
always moving forward, while Y only changes when a part appears within
the work area).
In these cases, I think the Input subsystem approach might be better
because the user can just wait for events at large and handle each event
as it comes in, rather than try to coordinate between them all in a
shared memory space. The shortcoming with this approach is that we lose
the ability to grab Counts together at the same time, such as we require
in the constantly moving robot example earlier.
Perhaps what might work is to implement Counter events (perhaps even
timestamps) using the Input subsystem, and leave the Counter character
device interface to simple read/write operations. But we'll need to
investigate this further because we lack a concept of "events" right now
in the Counter subsystem.
> > Similarly, support for future extensions is simple to implement. When
> > timestamp support is implemented, users can just select the desired
> > timestamp extension and read it directly from the /dev/counterX node;
> > they should also be able to perform a select()/poll() call to be
> > notified on new timestamps.
> >
> > So what do you think of this sort of design? I think there is a useful
> > robustness to the simplicity of performing a single read/write call on
> > /dev/counterX.
>
> It seems like a reasonable solution to me. The only blurry
> boundary to my mind is what level of buffering is behind this.
> The things you can do are open, non blocking read, blocking read and select.
>
> If we have a counter that is sampled on demand, then
> 1) Non blocking read - makes not sense, fair enough I guess, could make it
> the same as a blocking read.
> 2) Blocking read - reads from the sensor.
> 3) Select, meaningless as all reads are done on demand - so I guess you
> hardwire it to return immediately.
> 4) open. Nothing special
>
> If you have a counter that is self clocking then data gets pushed into some
> software structure (probably kfifo)
> 1) Blocking read, question of semantics to resolve
> a) Return when 'some' data is available (like a socket)
> b) Return when 'requested amount of data is available'?
> 2) Non blocking read. Return whatever happens to be available.
> 3) Select. Semantics to be defined.
> a) Some data?
> b) Watermark based (default watermark is 0 so any data triggers it)
> 4) Open. Starts up sampling of configured set - (typically turns on the
> device, enables interrupt output etc.)
>
> So some corners to resolve but should all work.
I'm not familiar with the "watermark" terminology. Would you be able to
explain it bit more for me. Is this simply a flag that indicates if data
has changed from the last time it was checked?
> > > > Moving this selection to a sysfs attribute and dedicating the
> > > > character device to just data transfer might be a better design. If
> > > > such a design is chosen, should the selection attribute be
> > > > human-readable or binary?
> > >
> > > Sysfs basically requires things are more or less human readable.
> > > So if you go that way I think it needs to be.
> > >
> > > >
> > > > 2. How much space should allotted for strings?
> > > >
> > > > Each Counter component and extension has a respective size allotted
> > > > for its data (u8 data is allotted 1 byte, u64 data is allotted 8
> > > > bytes, etc.); I have arbitrarily chosen to allot 64 bytes for
> > > > strings. Is this an apt size, or should string data be allotted more
> > > > or less space?
> > >
> > > I'd go with that being big enough, but try to keep the expose interface
> > > such that the size can change it it needs to the in the future.
> >
> > Following along with the separation of control vs data as discussed
> > above, we could support a more variable size by exposing it through a
> > sysfs attribute (maybe a chrdev_string_size attribute or similar).
>
> I'm unconvinced you'd ever want to return a string via the chardev.
> People are using the chrdev to get efficiency. String based data flows
> are rarely that!
That's a good point. I don't think there is a situation right now where
we need to deliver strings via the character device interface, so I
think I'll remove that in v3.
William Breathitt Gray
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^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 0/4] Introduce the Counter character device interface
2020-05-31 17:14 ` William Breathitt Gray
@ 2020-06-01 10:31 ` Jonathan Cameron
-1 siblings, 0 replies; 38+ messages in thread
From: Jonathan Cameron @ 2020-06-01 10:31 UTC (permalink / raw)
To: William Breathitt Gray
Cc: Jonathan Cameron, kamel.bouhara, gwendal, alexandre.belloni,
david, linux-iio, linux-kernel, linux-stm32, linux-arm-kernel,
syednwaris, patrick.havelange, fabrice.gasnier, mcoquelin.stm32,
alexandre.torgue
On Sun, 31 May 2020 13:14:06 -0400
William Breathitt Gray <vilhelm.gray@gmail.com> wrote:
> On Sun, May 31, 2020 at 04:18:13PM +0100, Jonathan Cameron wrote:
> > On Sun, 24 May 2020 13:54:39 -0400
> > William Breathitt Gray <vilhelm.gray@gmail.com> wrote:
> > > After giving this some more thought, I believe human-readable sysfs
> > > attributes are the way to go to support configuration of the character
> > > device. I am thinking of a system like this:
> > >
> > > * Users configure the counter character device via a sysfs attribute
> > > such as /sys/bus/counter/devices/counterX/chrdev_format or similar.
> > >
> > > * Users may write to this sysfs attribute to select the components they
> > > want to interface -- the layout can be determined as well from the
> > > order. For example:
> > >
> > > # echo "C0 C3 C2" > /sys/bus/counter/devices/counter0/chrdev_format
> >
> > I guess that 'just' meets the sysfs requirement of one file => one thing.
>
> We can massage this further to make it more apt, but the main idea here
> is that configuration should be separate from our data; and that
> configuration should be performed via sysfs.
>
> > > This would select Counts 0, 3, and 2 (in that order) to be available
> > > in the /dev/counter0 node as a contiguous memory region.
> > >
> > > You can select extensions in a similar fashion:
> > >
> > > # echo "C4E2 S1E0" > /sys/bus/counter/devices/counter0/chrdev_format
> > >
> > > This would select extension 2 from Count 4, and extension 0 from
> > > Signal 1.
> >
> > I'm not totally clear why we'd want to have a chrdev access to extensions.
> > To be honest I'm not totally sure what an extension is today as it's been
> > a week ;)
>
> In the context of the Counter subsystem, an extension is data/control
> that is not one of the core components of the Counter paradigm (i.e. not
> a Counter, Signal, nor Synapse). Extensions essentially represent
> configuration options for the counter device and auxiliary
> functionality.
>
> The "Implementation" section of the Generic Counter documentation
> Documentation/driver-api/generic-counter.rst file gives some good
> examples of extensions, but I'll provide an example here for the sake of
> this new character device interface.
>
> Suppose we have a robot controlling a laser on a dual-axes positioning
> table. A counter device is used to track the position of the laser:
> Count 0 represents position on the X axis, while Count 1 represents
> position on the Y axis. Because this machine is moving across two axes
> at the same time, we want to grab both counts together via the
> character device subsystem (grabbing them separately via sysfs would be
> imprecise due to the inherent latency).
>
> The motors are physically able the robot out of the work area, which is
> not something we want to happen. A common setup in systems like this is
> to set soft boundaries on the counter device to represent the edge of
> the work area; when the boundary is passed, a flag is set high on the
> device to indicate the position is out-of-bounds.
>
> On the Counter subsystem side, this counter device would appear as
> having four sysfs attributes: count0/count, count0/boundary,
> count1/count, and count1/boundary. In terms of the character device
> interface, we could perform a setup like this:
>
> # echo "C0E0 C0 C1E1 C1" > counter0/chrdev_format
>
> Yielding the following /dev/counter0 memory layout:
>
> +------------+-----------------+------------+-------------------+
> | Byte 0 | Byte 1 - Byte 8 | Byte 9 | Byte 10 - Byte 17 |
> +------------+-----------------+------------+-------------------+
> | Boundary 0 | Count 0 | Boundary 1 | Count 1 |
> +------------+-----------------+------------+-------------------+
>
> Now a single read() operation can grab the counts together as well as
> their respective boundary flags to verify whether the current counts are
> valid. This is a scenario where using sysfs wouldn't be viable to use:
> we could check the count0/boundary sysfs attribute first, but by the
> time we read the count0/count sysfs attribute second, the robot has
> already moved to a new (possibly invalid) position.
Ok. So typically something like a condition flag. Data that indeed makes
sense to be associated with a set of counter values.
>
> > Perhaps an example? I see timestamp below. What is that attached to?
> > If we gave multiple counters, do they each have a timestamp?
>
> Some counter devices feature "timestamp" functionality. I haven't yet
> implemented this in the Counter subsystem because it's new functionality
> and I want to keep this patchset limited to the existing Counter
> subsystem functionality support.
>
> However, to briefly go into the topic (we'll need to discuss this more
> in-depth before committing to a Counter subsystem design), some counter
> devices can keep track of historic counts based on various events; we
> call these "timestamps", although they may not necessary be tied to a
> wall-clock time.
>
> For example, quadrature encoders often have an "index" signal in
> addition to the quadrature A and B lines. This index signal may be used
> to home a positioning device, or perhaps to indicate that a full
> revolution -- or some other event -- has occurred. It's common for
> quadrature counter devices to provide a FIFO buffer that logs these
> "index" events by saving the current count when that respective index
> signal goes high. Thus we have a timestamp buffer.
That doesn't sound like a timestamp buffer. You are logging counts,
not the current time. If they are going through a FIFO you might also
capture a freerunning timer though.
>
> In the context of the Counter subsystem, I believe we will end up
> implementing these timestamps as Count extensions (or Device extensions
> if it's a single buffer for the entire device). I'm not sure yet what
> the sysfs attribute will display, but I'm guessing we'll have a
> respective /sys/bus/counter/devices/counterX/countX/timestamps sysfs
> attribute or similar.
>
> The character device implementation should be more straight forward I
> would imagine. Since it's a memory buffer, I think we can provide access
> to that buffer directly in the chrdev:
>
> # echo "C0E0 C1E1" > /sys/bus/counter/devices/counter0/chrdev_format
>
> Yielding the following /dev/counter0 memory layout for 32-byte
> timestamps:
>
> +---------------------+---------------------+
> | Byte 0 - Byte 31 | Byte 32 - Byte 63 |
> +---------------------+---------------------+
> | Timestamps Buffer 0 | Timestamps Buffer 1 |
> +---------------------+---------------------+
As you say, will need more discussion. Lots of fun questions around timestamps
such as what the timebase is, how to relate it to system time etc.
>
> > > * Users may read from this chrdev_format sysfs attribute in order to see
> > > the currently configured format of the character device.
> > >
> > > * Users may perform read/write operations on the /dev/counterX node
> > > directly; the layout of the data is what they user has configured via
> > > the chrdev_format sysfs attribute. For example:
> > >
> > > # echo "C0 C1 S0 S1" > /sys/bus/counter/devices/counter0/chrdev_format
> > >
> > > Yields the following /dev/counter0 memory layout:
> > >
> > > +-----------------+------------------+----------+----------+
> > > | Byte 0 - Byte 7 | Byte 8 - Byte 15 | Byte 16 | Byte 17 |
> > > +-----------------+------------------+----------+----------+
> > > | Count 0 | Count 1 | Signal 0 | Signal 2 |
> > > +-----------------+------------------+----------+----------+
> > >
> > > * Users may perform select/poll operations on the /dev/counterX node.
> > > Users can be notified if data is available or events have occurred.
> >
> > One thing to think about early if watermarks. We bolted them on
> > late in IIO and maybe we could have done it better from the start.
> > I'd almost guarantee someone will want one fairly soon - particularly
> > as it's more than possible you'll have a counter device with a
> > hardware fifo. I have some vague recollection that ti-ecap
> > stuff could be presented as a short fifo for starters.
> >
> > >
> > > The benefit of this design is that the format is robust so users can
> > > choose the components they want to interface and in the layout they
> > > want. For example, if I am writing a userspace application to control a
> > > dual-axis positioning table, I can select the two counts I care about
> > > for the position axes. This allows me to read just those two values
> > > directly from /dev/counterX with a simple read() call, without having to
> > > fumble around seeking to an offset and parsing the layout.
> >
> > I wonder if I'm over thinking things for counters, but you may run into
> > the complexity of different counters having different sampling frequencies.
> > Here you are suggesting a scheme that I think ends up closer to IIO than
> > input. That makes this case a pain. Input takes the view that it's
> > fine to have data coming in any order and frequency because every
> > record is self describing. I'm not sure it matters here, but it is
> > a nice layer of flexibility, but you do loose the efficiency of
> > the description being external to the data flow.
>
> I think one of the downsides to using a single a single character device
> node to represent the entire counter device is that the frequency of two
> individual counts may differ from each other. For example, using the
> dual-axes positioning scenario from earlier, one axis might change more
> frequently than the other (e.g. a conveyor belt situation where X is
> always moving forward, while Y only changes when a part appears within
> the work area).
One option is to allow for either multiple opening of the chardev, or
creation of anon file handles via an IOCTL (like we do for events in IIO).
Makes the sysfs interface more complex, but would allow you to handle multiple
independent raw data streams.
>
> In these cases, I think the Input subsystem approach might be better
> because the user can just wait for events at large and handle each event
> as it comes in, rather than try to coordinate between them all in a
> shared memory space. The shortcoming with this approach is that we lose
> the ability to grab Counts together at the same time, such as we require
> in the constantly moving robot example earlier.
There are approaches like adding a sequence number to allow multiple self
describing records to be associated.
>
> Perhaps what might work is to implement Counter events (perhaps even
> timestamps) using the Input subsystem, and leave the Counter character
> device interface to simple read/write operations. But we'll need to
> investigate this further because we lack a concept of "events" right now
> in the Counter subsystem.
>
> > > Similarly, support for future extensions is simple to implement. When
> > > timestamp support is implemented, users can just select the desired
> > > timestamp extension and read it directly from the /dev/counterX node;
> > > they should also be able to perform a select()/poll() call to be
> > > notified on new timestamps.
> > >
> > > So what do you think of this sort of design? I think there is a useful
> > > robustness to the simplicity of performing a single read/write call on
> > > /dev/counterX.
> >
> > It seems like a reasonable solution to me. The only blurry
> > boundary to my mind is what level of buffering is behind this.
> > The things you can do are open, non blocking read, blocking read and select.
> >
> > If we have a counter that is sampled on demand, then
> > 1) Non blocking read - makes not sense, fair enough I guess, could make it
> > the same as a blocking read.
> > 2) Blocking read - reads from the sensor.
> > 3) Select, meaningless as all reads are done on demand - so I guess you
> > hardwire it to return immediately.
> > 4) open. Nothing special
> >
> > If you have a counter that is self clocking then data gets pushed into some
> > software structure (probably kfifo)
> > 1) Blocking read, question of semantics to resolve
> > a) Return when 'some' data is available (like a socket)
> > b) Return when 'requested amount of data is available'?
> > 2) Non blocking read. Return whatever happens to be available.
> > 3) Select. Semantics to be defined.
> > a) Some data?
> > b) Watermark based (default watermark is 0 so any data triggers it)
> > 4) Open. Starts up sampling of configured set - (typically turns on the
> > device, enables interrupt output etc.)
> >
> > So some corners to resolve but should all work.
>
> I'm not familiar with the "watermark" terminology. Would you be able to
> explain it bit more for me. Is this simply a flag that indicates if data
> has changed from the last time it was checked?
If you have a FIFO, watermark is the fill level at which you indicate you
have data. For a HW FIFO this is usually an interrupt at say 10 elements
queued up. The software is then expected to drain at least 10 elements.
For software fifo the concept is the same, but you are expecting userspace
to drain N elements on each event.
If you are going to deal with remotely high sampling rates you'll need to
support this for both software and hardware FIFOs.
>
> > > > > Moving this selection to a sysfs attribute and dedicating the
> > > > > character device to just data transfer might be a better design. If
> > > > > such a design is chosen, should the selection attribute be
> > > > > human-readable or binary?
> > > >
> > > > Sysfs basically requires things are more or less human readable.
> > > > So if you go that way I think it needs to be.
> > > >
> > > > >
> > > > > 2. How much space should allotted for strings?
> > > > >
> > > > > Each Counter component and extension has a respective size allotted
> > > > > for its data (u8 data is allotted 1 byte, u64 data is allotted 8
> > > > > bytes, etc.); I have arbitrarily chosen to allot 64 bytes for
> > > > > strings. Is this an apt size, or should string data be allotted more
> > > > > or less space?
> > > >
> > > > I'd go with that being big enough, but try to keep the expose interface
> > > > such that the size can change it it needs to the in the future.
> > >
> > > Following along with the separation of control vs data as discussed
> > > above, we could support a more variable size by exposing it through a
> > > sysfs attribute (maybe a chrdev_string_size attribute or similar).
> >
> > I'm unconvinced you'd ever want to return a string via the chardev.
> > People are using the chrdev to get efficiency. String based data flows
> > are rarely that!
>
> That's a good point. I don't think there is a situation right now where
> we need to deliver strings via the character device interface, so I
> think I'll remove that in v3.
Cool. This all seems to be heading in a sensible direction, but as you say
lots still to consider.
Jonathan
>
> William Breathitt Gray
>
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 0/4] Introduce the Counter character device interface
@ 2020-06-01 10:31 ` Jonathan Cameron
0 siblings, 0 replies; 38+ messages in thread
From: Jonathan Cameron @ 2020-06-01 10:31 UTC (permalink / raw)
To: William Breathitt Gray
Cc: kamel.bouhara, gwendal, david, linux-iio, patrick.havelange,
alexandre.belloni, linux-kernel, linux-arm-kernel,
mcoquelin.stm32, fabrice.gasnier, syednwaris, linux-stm32,
Jonathan Cameron, alexandre.torgue
On Sun, 31 May 2020 13:14:06 -0400
William Breathitt Gray <vilhelm.gray@gmail.com> wrote:
> On Sun, May 31, 2020 at 04:18:13PM +0100, Jonathan Cameron wrote:
> > On Sun, 24 May 2020 13:54:39 -0400
> > William Breathitt Gray <vilhelm.gray@gmail.com> wrote:
> > > After giving this some more thought, I believe human-readable sysfs
> > > attributes are the way to go to support configuration of the character
> > > device. I am thinking of a system like this:
> > >
> > > * Users configure the counter character device via a sysfs attribute
> > > such as /sys/bus/counter/devices/counterX/chrdev_format or similar.
> > >
> > > * Users may write to this sysfs attribute to select the components they
> > > want to interface -- the layout can be determined as well from the
> > > order. For example:
> > >
> > > # echo "C0 C3 C2" > /sys/bus/counter/devices/counter0/chrdev_format
> >
> > I guess that 'just' meets the sysfs requirement of one file => one thing.
>
> We can massage this further to make it more apt, but the main idea here
> is that configuration should be separate from our data; and that
> configuration should be performed via sysfs.
>
> > > This would select Counts 0, 3, and 2 (in that order) to be available
> > > in the /dev/counter0 node as a contiguous memory region.
> > >
> > > You can select extensions in a similar fashion:
> > >
> > > # echo "C4E2 S1E0" > /sys/bus/counter/devices/counter0/chrdev_format
> > >
> > > This would select extension 2 from Count 4, and extension 0 from
> > > Signal 1.
> >
> > I'm not totally clear why we'd want to have a chrdev access to extensions.
> > To be honest I'm not totally sure what an extension is today as it's been
> > a week ;)
>
> In the context of the Counter subsystem, an extension is data/control
> that is not one of the core components of the Counter paradigm (i.e. not
> a Counter, Signal, nor Synapse). Extensions essentially represent
> configuration options for the counter device and auxiliary
> functionality.
>
> The "Implementation" section of the Generic Counter documentation
> Documentation/driver-api/generic-counter.rst file gives some good
> examples of extensions, but I'll provide an example here for the sake of
> this new character device interface.
>
> Suppose we have a robot controlling a laser on a dual-axes positioning
> table. A counter device is used to track the position of the laser:
> Count 0 represents position on the X axis, while Count 1 represents
> position on the Y axis. Because this machine is moving across two axes
> at the same time, we want to grab both counts together via the
> character device subsystem (grabbing them separately via sysfs would be
> imprecise due to the inherent latency).
>
> The motors are physically able the robot out of the work area, which is
> not something we want to happen. A common setup in systems like this is
> to set soft boundaries on the counter device to represent the edge of
> the work area; when the boundary is passed, a flag is set high on the
> device to indicate the position is out-of-bounds.
>
> On the Counter subsystem side, this counter device would appear as
> having four sysfs attributes: count0/count, count0/boundary,
> count1/count, and count1/boundary. In terms of the character device
> interface, we could perform a setup like this:
>
> # echo "C0E0 C0 C1E1 C1" > counter0/chrdev_format
>
> Yielding the following /dev/counter0 memory layout:
>
> +------------+-----------------+------------+-------------------+
> | Byte 0 | Byte 1 - Byte 8 | Byte 9 | Byte 10 - Byte 17 |
> +------------+-----------------+------------+-------------------+
> | Boundary 0 | Count 0 | Boundary 1 | Count 1 |
> +------------+-----------------+------------+-------------------+
>
> Now a single read() operation can grab the counts together as well as
> their respective boundary flags to verify whether the current counts are
> valid. This is a scenario where using sysfs wouldn't be viable to use:
> we could check the count0/boundary sysfs attribute first, but by the
> time we read the count0/count sysfs attribute second, the robot has
> already moved to a new (possibly invalid) position.
Ok. So typically something like a condition flag. Data that indeed makes
sense to be associated with a set of counter values.
>
> > Perhaps an example? I see timestamp below. What is that attached to?
> > If we gave multiple counters, do they each have a timestamp?
>
> Some counter devices feature "timestamp" functionality. I haven't yet
> implemented this in the Counter subsystem because it's new functionality
> and I want to keep this patchset limited to the existing Counter
> subsystem functionality support.
>
> However, to briefly go into the topic (we'll need to discuss this more
> in-depth before committing to a Counter subsystem design), some counter
> devices can keep track of historic counts based on various events; we
> call these "timestamps", although they may not necessary be tied to a
> wall-clock time.
>
> For example, quadrature encoders often have an "index" signal in
> addition to the quadrature A and B lines. This index signal may be used
> to home a positioning device, or perhaps to indicate that a full
> revolution -- or some other event -- has occurred. It's common for
> quadrature counter devices to provide a FIFO buffer that logs these
> "index" events by saving the current count when that respective index
> signal goes high. Thus we have a timestamp buffer.
That doesn't sound like a timestamp buffer. You are logging counts,
not the current time. If they are going through a FIFO you might also
capture a freerunning timer though.
>
> In the context of the Counter subsystem, I believe we will end up
> implementing these timestamps as Count extensions (or Device extensions
> if it's a single buffer for the entire device). I'm not sure yet what
> the sysfs attribute will display, but I'm guessing we'll have a
> respective /sys/bus/counter/devices/counterX/countX/timestamps sysfs
> attribute or similar.
>
> The character device implementation should be more straight forward I
> would imagine. Since it's a memory buffer, I think we can provide access
> to that buffer directly in the chrdev:
>
> # echo "C0E0 C1E1" > /sys/bus/counter/devices/counter0/chrdev_format
>
> Yielding the following /dev/counter0 memory layout for 32-byte
> timestamps:
>
> +---------------------+---------------------+
> | Byte 0 - Byte 31 | Byte 32 - Byte 63 |
> +---------------------+---------------------+
> | Timestamps Buffer 0 | Timestamps Buffer 1 |
> +---------------------+---------------------+
As you say, will need more discussion. Lots of fun questions around timestamps
such as what the timebase is, how to relate it to system time etc.
>
> > > * Users may read from this chrdev_format sysfs attribute in order to see
> > > the currently configured format of the character device.
> > >
> > > * Users may perform read/write operations on the /dev/counterX node
> > > directly; the layout of the data is what they user has configured via
> > > the chrdev_format sysfs attribute. For example:
> > >
> > > # echo "C0 C1 S0 S1" > /sys/bus/counter/devices/counter0/chrdev_format
> > >
> > > Yields the following /dev/counter0 memory layout:
> > >
> > > +-----------------+------------------+----------+----------+
> > > | Byte 0 - Byte 7 | Byte 8 - Byte 15 | Byte 16 | Byte 17 |
> > > +-----------------+------------------+----------+----------+
> > > | Count 0 | Count 1 | Signal 0 | Signal 2 |
> > > +-----------------+------------------+----------+----------+
> > >
> > > * Users may perform select/poll operations on the /dev/counterX node.
> > > Users can be notified if data is available or events have occurred.
> >
> > One thing to think about early if watermarks. We bolted them on
> > late in IIO and maybe we could have done it better from the start.
> > I'd almost guarantee someone will want one fairly soon - particularly
> > as it's more than possible you'll have a counter device with a
> > hardware fifo. I have some vague recollection that ti-ecap
> > stuff could be presented as a short fifo for starters.
> >
> > >
> > > The benefit of this design is that the format is robust so users can
> > > choose the components they want to interface and in the layout they
> > > want. For example, if I am writing a userspace application to control a
> > > dual-axis positioning table, I can select the two counts I care about
> > > for the position axes. This allows me to read just those two values
> > > directly from /dev/counterX with a simple read() call, without having to
> > > fumble around seeking to an offset and parsing the layout.
> >
> > I wonder if I'm over thinking things for counters, but you may run into
> > the complexity of different counters having different sampling frequencies.
> > Here you are suggesting a scheme that I think ends up closer to IIO than
> > input. That makes this case a pain. Input takes the view that it's
> > fine to have data coming in any order and frequency because every
> > record is self describing. I'm not sure it matters here, but it is
> > a nice layer of flexibility, but you do loose the efficiency of
> > the description being external to the data flow.
>
> I think one of the downsides to using a single a single character device
> node to represent the entire counter device is that the frequency of two
> individual counts may differ from each other. For example, using the
> dual-axes positioning scenario from earlier, one axis might change more
> frequently than the other (e.g. a conveyor belt situation where X is
> always moving forward, while Y only changes when a part appears within
> the work area).
One option is to allow for either multiple opening of the chardev, or
creation of anon file handles via an IOCTL (like we do for events in IIO).
Makes the sysfs interface more complex, but would allow you to handle multiple
independent raw data streams.
>
> In these cases, I think the Input subsystem approach might be better
> because the user can just wait for events at large and handle each event
> as it comes in, rather than try to coordinate between them all in a
> shared memory space. The shortcoming with this approach is that we lose
> the ability to grab Counts together at the same time, such as we require
> in the constantly moving robot example earlier.
There are approaches like adding a sequence number to allow multiple self
describing records to be associated.
>
> Perhaps what might work is to implement Counter events (perhaps even
> timestamps) using the Input subsystem, and leave the Counter character
> device interface to simple read/write operations. But we'll need to
> investigate this further because we lack a concept of "events" right now
> in the Counter subsystem.
>
> > > Similarly, support for future extensions is simple to implement. When
> > > timestamp support is implemented, users can just select the desired
> > > timestamp extension and read it directly from the /dev/counterX node;
> > > they should also be able to perform a select()/poll() call to be
> > > notified on new timestamps.
> > >
> > > So what do you think of this sort of design? I think there is a useful
> > > robustness to the simplicity of performing a single read/write call on
> > > /dev/counterX.
> >
> > It seems like a reasonable solution to me. The only blurry
> > boundary to my mind is what level of buffering is behind this.
> > The things you can do are open, non blocking read, blocking read and select.
> >
> > If we have a counter that is sampled on demand, then
> > 1) Non blocking read - makes not sense, fair enough I guess, could make it
> > the same as a blocking read.
> > 2) Blocking read - reads from the sensor.
> > 3) Select, meaningless as all reads are done on demand - so I guess you
> > hardwire it to return immediately.
> > 4) open. Nothing special
> >
> > If you have a counter that is self clocking then data gets pushed into some
> > software structure (probably kfifo)
> > 1) Blocking read, question of semantics to resolve
> > a) Return when 'some' data is available (like a socket)
> > b) Return when 'requested amount of data is available'?
> > 2) Non blocking read. Return whatever happens to be available.
> > 3) Select. Semantics to be defined.
> > a) Some data?
> > b) Watermark based (default watermark is 0 so any data triggers it)
> > 4) Open. Starts up sampling of configured set - (typically turns on the
> > device, enables interrupt output etc.)
> >
> > So some corners to resolve but should all work.
>
> I'm not familiar with the "watermark" terminology. Would you be able to
> explain it bit more for me. Is this simply a flag that indicates if data
> has changed from the last time it was checked?
If you have a FIFO, watermark is the fill level at which you indicate you
have data. For a HW FIFO this is usually an interrupt at say 10 elements
queued up. The software is then expected to drain at least 10 elements.
For software fifo the concept is the same, but you are expecting userspace
to drain N elements on each event.
If you are going to deal with remotely high sampling rates you'll need to
support this for both software and hardware FIFOs.
>
> > > > > Moving this selection to a sysfs attribute and dedicating the
> > > > > character device to just data transfer might be a better design. If
> > > > > such a design is chosen, should the selection attribute be
> > > > > human-readable or binary?
> > > >
> > > > Sysfs basically requires things are more or less human readable.
> > > > So if you go that way I think it needs to be.
> > > >
> > > > >
> > > > > 2. How much space should allotted for strings?
> > > > >
> > > > > Each Counter component and extension has a respective size allotted
> > > > > for its data (u8 data is allotted 1 byte, u64 data is allotted 8
> > > > > bytes, etc.); I have arbitrarily chosen to allot 64 bytes for
> > > > > strings. Is this an apt size, or should string data be allotted more
> > > > > or less space?
> > > >
> > > > I'd go with that being big enough, but try to keep the expose interface
> > > > such that the size can change it it needs to the in the future.
> > >
> > > Following along with the separation of control vs data as discussed
> > > above, we could support a more variable size by exposing it through a
> > > sysfs attribute (maybe a chrdev_string_size attribute or similar).
> >
> > I'm unconvinced you'd ever want to return a string via the chardev.
> > People are using the chrdev to get efficiency. String based data flows
> > are rarely that!
>
> That's a good point. I don't think there is a situation right now where
> we need to deliver strings via the character device interface, so I
> think I'll remove that in v3.
Cool. This all seems to be heading in a sensible direction, but as you say
lots still to consider.
Jonathan
>
> William Breathitt Gray
>
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^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 0/4] Introduce the Counter character device interface
2020-05-31 17:14 ` William Breathitt Gray
@ 2020-06-02 15:18 ` David Lechner
-1 siblings, 0 replies; 38+ messages in thread
From: David Lechner @ 2020-06-02 15:18 UTC (permalink / raw)
To: William Breathitt Gray, Jonathan Cameron
Cc: kamel.bouhara, gwendal, alexandre.belloni, linux-iio,
linux-kernel, linux-stm32, linux-arm-kernel, syednwaris,
patrick.havelange, fabrice.gasnier, mcoquelin.stm32,
alexandre.torgue
On 5/31/20 12:14 PM, William Breathitt Gray wrote:
> Yielding the following /dev/counter0 memory layout:
>
> +------------+-----------------+------------+-------------------+
> | Byte 0 | Byte 1 - Byte 8 | Byte 9 | Byte 10 - Byte 17 |
> +------------+-----------------+------------+-------------------+
> | Boundary 0 | Count 0 | Boundary 1 | Count 1 |
> +------------+-----------------+------------+-------------------+
A potential pitfall with this sort of packing is that some platforms
do not support unaligned access, so data would have to be "unpacked"
before it could be used.
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 0/4] Introduce the Counter character device interface
@ 2020-06-02 15:18 ` David Lechner
0 siblings, 0 replies; 38+ messages in thread
From: David Lechner @ 2020-06-02 15:18 UTC (permalink / raw)
To: William Breathitt Gray, Jonathan Cameron
Cc: kamel.bouhara, gwendal, alexandre.torgue, linux-iio,
patrick.havelange, alexandre.belloni, linux-kernel,
mcoquelin.stm32, fabrice.gasnier, syednwaris, linux-stm32,
linux-arm-kernel
On 5/31/20 12:14 PM, William Breathitt Gray wrote:
> Yielding the following /dev/counter0 memory layout:
>
> +------------+-----------------+------------+-------------------+
> | Byte 0 | Byte 1 - Byte 8 | Byte 9 | Byte 10 - Byte 17 |
> +------------+-----------------+------------+-------------------+
> | Boundary 0 | Count 0 | Boundary 1 | Count 1 |
> +------------+-----------------+------------+-------------------+
A potential pitfall with this sort of packing is that some platforms
do not support unaligned access, so data would have to be "unpacked"
before it could be used.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 0/4] Introduce the Counter character device interface
2020-06-02 15:18 ` David Lechner
@ 2020-06-02 15:46 ` William Breathitt Gray
-1 siblings, 0 replies; 38+ messages in thread
From: William Breathitt Gray @ 2020-06-02 15:46 UTC (permalink / raw)
To: David Lechner
Cc: Jonathan Cameron, kamel.bouhara, gwendal, alexandre.belloni,
linux-iio, linux-kernel, linux-stm32, linux-arm-kernel,
syednwaris, patrick.havelange, fabrice.gasnier, mcoquelin.stm32,
alexandre.torgue
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On Tue, Jun 02, 2020 at 10:18:07AM -0500, David Lechner wrote:
> On 5/31/20 12:14 PM, William Breathitt Gray wrote:
> > Yielding the following /dev/counter0 memory layout:
> >
> > +------------+-----------------+------------+-------------------+
> > | Byte 0 | Byte 1 - Byte 8 | Byte 9 | Byte 10 - Byte 17 |
> > +------------+-----------------+------------+-------------------+
> > | Boundary 0 | Count 0 | Boundary 1 | Count 1 |
> > +------------+-----------------+------------+-------------------+
>
> A potential pitfall with this sort of packing is that some platforms
> do not support unaligned access, so data would have to be "unpacked"
> before it could be used.
Since the user defines the format of this data, they could reorganize it
to a more streamline alignment; for example:
# echo "C0 C1 C0E0 C1E0" > counter0/chrdev_format
Yielding the following /dev/counter0 memory layout instead:
+-----------------+------------------+------------+------------+
| Byte 0 - Byte 7 | Byte 8 - Byte 15 | Byte 16 | Byte 17 |
+-----------------+------------------+------------+------------+
| Count 0 | Count 1 | Boundary 0 | Boundary 1 |
+-----------------+------------------+------------+------------+
In the future, we could also define a padding argument to give users
more control over the exact offsets:
# echo "C0E0 P7 C0 C1E0 P7 C1" > counter0/chrdev_format
Yielding the following /dev/counter0 memory layout instead:
+------------+-----------------+------------------+------------+
| Byte 0 | Byte 1 - Byte 7 | Byte 8 - Byte 15 | Byte 16 |
+------------+-----------------+------------------+------------+
| Boundary 0 | Padding | Count 0 | Boundary 1 |
+------------+-----------------+------------------+------------+
+-------------------+-------------------+
| Byte 17 - Byte 23 | Byte 24 - Byte 31 |
+-------------------+-------------------+
| Padding | Count 1 |
+-------------------+-------------------+
I not sure it's best to introduce padding support with this patchset
given how much is already changing, but I don't anticipate packing
alignment to be something difficult to support in the future with this
interface.
William Breathitt Gray
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^ permalink raw reply [flat|nested] 38+ messages in thread
* Re: [PATCH v2 0/4] Introduce the Counter character device interface
@ 2020-06-02 15:46 ` William Breathitt Gray
0 siblings, 0 replies; 38+ messages in thread
From: William Breathitt Gray @ 2020-06-02 15:46 UTC (permalink / raw)
To: David Lechner
Cc: kamel.bouhara, gwendal, alexandre.torgue, linux-iio,
patrick.havelange, alexandre.belloni, linux-kernel,
linux-arm-kernel, mcoquelin.stm32, fabrice.gasnier, syednwaris,
linux-stm32, Jonathan Cameron
[-- Attachment #1.1: Type: text/plain, Size: 2311 bytes --]
On Tue, Jun 02, 2020 at 10:18:07AM -0500, David Lechner wrote:
> On 5/31/20 12:14 PM, William Breathitt Gray wrote:
> > Yielding the following /dev/counter0 memory layout:
> >
> > +------------+-----------------+------------+-------------------+
> > | Byte 0 | Byte 1 - Byte 8 | Byte 9 | Byte 10 - Byte 17 |
> > +------------+-----------------+------------+-------------------+
> > | Boundary 0 | Count 0 | Boundary 1 | Count 1 |
> > +------------+-----------------+------------+-------------------+
>
> A potential pitfall with this sort of packing is that some platforms
> do not support unaligned access, so data would have to be "unpacked"
> before it could be used.
Since the user defines the format of this data, they could reorganize it
to a more streamline alignment; for example:
# echo "C0 C1 C0E0 C1E0" > counter0/chrdev_format
Yielding the following /dev/counter0 memory layout instead:
+-----------------+------------------+------------+------------+
| Byte 0 - Byte 7 | Byte 8 - Byte 15 | Byte 16 | Byte 17 |
+-----------------+------------------+------------+------------+
| Count 0 | Count 1 | Boundary 0 | Boundary 1 |
+-----------------+------------------+------------+------------+
In the future, we could also define a padding argument to give users
more control over the exact offsets:
# echo "C0E0 P7 C0 C1E0 P7 C1" > counter0/chrdev_format
Yielding the following /dev/counter0 memory layout instead:
+------------+-----------------+------------------+------------+
| Byte 0 | Byte 1 - Byte 7 | Byte 8 - Byte 15 | Byte 16 |
+------------+-----------------+------------------+------------+
| Boundary 0 | Padding | Count 0 | Boundary 1 |
+------------+-----------------+------------------+------------+
+-------------------+-------------------+
| Byte 17 - Byte 23 | Byte 24 - Byte 31 |
+-------------------+-------------------+
| Padding | Count 1 |
+-------------------+-------------------+
I not sure it's best to introduce padding support with this patchset
given how much is already changing, but I don't anticipate packing
alignment to be something difficult to support in the future with this
interface.
William Breathitt Gray
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[-- Type: application/pgp-signature, Size: 833 bytes --]
[-- Attachment #2: Type: text/plain, Size: 176 bytes --]
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 38+ messages in thread
end of thread, other threads:[~2020-06-02 15:46 UTC | newest]
Thread overview: 38+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-05-16 19:19 [PATCH v2 0/4] Introduce the Counter character device interface William Breathitt Gray
2020-05-16 19:19 ` William Breathitt Gray
2020-05-16 19:19 ` [PATCH v2 1/4] counter: Internalize sysfs interface code William Breathitt Gray
2020-05-20 13:10 ` kbuild test robot
2020-05-20 13:10 ` kbuild test robot
2020-05-20 13:10 ` kbuild test robot
2020-05-24 16:08 ` Jonathan Cameron
2020-05-16 19:20 ` [PATCH v2 2/4] docs: counter: Update to reflect sysfs internalization William Breathitt Gray
2020-05-16 19:20 ` William Breathitt Gray
2020-05-24 16:12 ` Jonathan Cameron
2020-05-24 16:12 ` Jonathan Cameron
2020-05-16 19:20 ` [PATCH v2 3/4] counter: Add character device interface William Breathitt Gray
2020-05-16 19:20 ` William Breathitt Gray
2020-05-20 15:07 ` kbuild test robot
2020-05-20 15:07 ` kbuild test robot
2020-05-20 15:07 ` kbuild test robot
2020-05-16 19:20 ` [PATCH v2 4/4] docs: counter: Document " William Breathitt Gray
2020-05-16 19:20 ` William Breathitt Gray
2020-05-24 16:19 ` Jonathan Cameron
2020-05-24 16:19 ` Jonathan Cameron
2020-05-29 13:26 ` Pavel Machek
2020-05-29 13:26 ` Pavel Machek
2020-05-31 13:31 ` William Breathitt Gray
2020-05-31 13:31 ` William Breathitt Gray
2020-05-24 16:25 ` [PATCH v2 0/4] Introduce the Counter " Jonathan Cameron
2020-05-24 16:25 ` Jonathan Cameron
2020-05-24 17:54 ` William Breathitt Gray
2020-05-24 17:54 ` William Breathitt Gray
2020-05-31 15:18 ` Jonathan Cameron
2020-05-31 15:18 ` Jonathan Cameron
2020-05-31 17:14 ` William Breathitt Gray
2020-05-31 17:14 ` William Breathitt Gray
2020-06-01 10:31 ` Jonathan Cameron
2020-06-01 10:31 ` Jonathan Cameron
2020-06-02 15:18 ` David Lechner
2020-06-02 15:18 ` David Lechner
2020-06-02 15:46 ` William Breathitt Gray
2020-06-02 15:46 ` William Breathitt Gray
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