* [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator
@ 2021-12-07 9:34 Bartosz Golaszewski
2021-12-07 9:34 ` [PATCH v13 1/7] gpiolib: provide gpiod_remove_hogs() Bartosz Golaszewski
` (7 more replies)
0 siblings, 8 replies; 14+ messages in thread
From: Bartosz Golaszewski @ 2021-12-07 9:34 UTC (permalink / raw)
To: Kent Gibson, Linus Walleij, Andy Shevchenko, Shuah Khan,
Geert Uytterhoeven, Viresh Kumar
Cc: linux-gpio, linux-kernel, linux-kselftest, Bartosz Golaszewski
Hopefully this will be the last iteration of this series. Just some
minor changes requested by Andy in this one.
Tested both with configfs as well as device-tree.
v1 -> v2:
- add selftests for gpio-sim
- add helper programs for selftests
- update the configfs rename callback to work with the new API introduced in
v5.11
- fix a missing quote in the documentation
- use !! whenever using bits operation that are required to return 0 or 1
- use provided bitmap API instead of reimplementing copy or fill operations
- fix a deadlock in gpio_sim_direction_output()
- add new read-only configfs attributes for mapping of configfs items to GPIO
device names
- and address other minor issues pointed out in reviews of v1
v2 -> v3:
- use devm_bitmap_alloc() instead of the zalloc variant if we're initializing
the bitmap with 1s
- drop the patch exporting device_is_bound()
- don't return -ENODEV from dev_nam and chip_name configfs attributes, return
a string indicating that the device is not available yet ('n/a')
- fix indentation where it makes sense
- don't protect IDA functions which use their own locking and where it's not
needed
- use kmemdup() instead of kzalloc() + memcpy()
- collected review tags
- minor coding style fixes
v3 -> v4:
- return 'none' instead of 'n/a' from dev_name and chip_name before the device
is registered
- use sysfs_emit() instead of s*printf()
- drop GPIO_SIM_MAX_PROP as it's only used in an array's definition where it's
fine to hardcode the value
v4 -> v5:
- drop lib patches that are already upstream
- use BIT() instead of (1UL << bit) for flags
- fix refcounting for the configfs_dirent in rename()
- drop d_move() from the rename() callback
- free memory allocated for the live and pending groups in configfs_d_iput()
and not in detach_groups()
- make sure that if a group of some name is in the live directory, a new group
with the same name cannot be created in the pending directory
v5 -> v6:
- go back to using (1UL << bit) instead of BIT()
- if the live group dentry doesn't exist for whatever reason at the time when
mkdir() in the pending group is called (would be a BUG()), return -ENOENT
instead of -EEXIST which should only be returned if given subsystem already
exists in either live or pending group
v6 -> v7:
- as detailed by Andy in commit 6fda593f3082 ("gpio: mockup: Convert to use
software nodes") removing device properties after the platform device is
removed but before the GPIO device gets dropped can lead to a use-after-free
bug - use software nodes to manually control the freeing of the properties
v7 -> v8:
- fixed some minor coding style issues as pointed out by Andy
v8 -> v9:
- dropped the patches implementing committable-items and reworked the
driver to not use them
- reworked the gpio-line-names property and configuring specific lines
in general
- many smaller tweaks here and there
v9 -> v10:
- make writing to 'live' wait for the probe to finish and report an
error to user-space if it failed
- add the ability to hog lines from the kernel-space
- rework locking (drop separate locks for line context objects)
- rework the sysfs interface (create a separate group for each line with
a constant number of attributes instead of going the other way around)
v10 -> v11:
- rework the configfs structure to represent a deeper hierarchy that
gpiolib supports, namely: multiple banks per platform device
v11 -> v12:
- simplify patch 2/7 by removing any mentions of OF from gpiolib.c
- improve the documentation by adding rest markups
- add a device-tree sample to the docs
- drop some trailing whitespaces from the driver
- make gpio_sim_make_bank_swnode() static
- fix coding style in patch 6/7
- add patch 3/7 that makes the OF part of gpiolib prefer to use gpio_chip's fwnode (if set) over of_node
v12 -> v13:
- mentioned ACPI not being converted yet in patch 3/7
- avoided one allocation in gpio_sim_strdup_trimmed() by using memmove()
- use kstrtobool() where applicable
- allow all bases in gpio_sim_bank_config_num_lines_store()
- remove unnecessary commas
- use sysfs_match_string() where applicable
- drop unneeded curr_var local variable
Bartosz Golaszewski (7):
gpiolib: provide gpiod_remove_hogs()
gpiolib: allow to specify the firmware node in struct gpio_chip
gpiolib: of: make fwnode take precedence in struct gpio_chip
gpio: sim: new testing module
selftests: gpio: provide a helper for reading chip info
selftests: gpio: add a helper for reading GPIO line names
selftests: gpio: add test cases for gpio-sim
Documentation/admin-guide/gpio/gpio-sim.rst | 134 ++
drivers/gpio/Kconfig | 8 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-sim.c | 1589 +++++++++++++++++
drivers/gpio/gpiolib-of.c | 3 +
drivers/gpio/gpiolib.c | 18 +-
include/linux/gpio/driver.h | 2 +
include/linux/gpio/machine.h | 2 +
tools/testing/selftests/gpio/.gitignore | 2 +
tools/testing/selftests/gpio/Makefile | 4 +-
tools/testing/selftests/gpio/config | 1 +
tools/testing/selftests/gpio/gpio-chip-info.c | 57 +
tools/testing/selftests/gpio/gpio-line-name.c | 55 +
tools/testing/selftests/gpio/gpio-sim.sh | 396 ++++
14 files changed, 2269 insertions(+), 3 deletions(-)
create mode 100644 Documentation/admin-guide/gpio/gpio-sim.rst
create mode 100644 drivers/gpio/gpio-sim.c
create mode 100644 tools/testing/selftests/gpio/gpio-chip-info.c
create mode 100644 tools/testing/selftests/gpio/gpio-line-name.c
create mode 100755 tools/testing/selftests/gpio/gpio-sim.sh
--
2.25.1
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v13 1/7] gpiolib: provide gpiod_remove_hogs()
2021-12-07 9:34 [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator Bartosz Golaszewski
@ 2021-12-07 9:34 ` Bartosz Golaszewski
2021-12-07 9:34 ` [PATCH v13 2/7] gpiolib: allow to specify the firmware node in struct gpio_chip Bartosz Golaszewski
` (6 subsequent siblings)
7 siblings, 0 replies; 14+ messages in thread
From: Bartosz Golaszewski @ 2021-12-07 9:34 UTC (permalink / raw)
To: Kent Gibson, Linus Walleij, Andy Shevchenko, Shuah Khan,
Geert Uytterhoeven, Viresh Kumar
Cc: linux-gpio, linux-kernel, linux-kselftest, Bartosz Golaszewski
Currently all users of gpiod_add_hogs() call it only once at system
init so there never was any need for a mechanism allowing to remove
them. Now the upcoming gpio-sim will need to tear down chips with hogged
lines so provide a function that allows to remove hogs.
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
---
drivers/gpio/gpiolib.c | 11 +++++++++++
include/linux/gpio/machine.h | 2 ++
2 files changed, 13 insertions(+)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index abfbf546d159..22b98a590a88 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -3540,6 +3540,17 @@ void gpiod_add_hogs(struct gpiod_hog *hogs)
}
EXPORT_SYMBOL_GPL(gpiod_add_hogs);
+void gpiod_remove_hogs(struct gpiod_hog *hogs)
+{
+ struct gpiod_hog *hog;
+
+ mutex_lock(&gpio_machine_hogs_mutex);
+ for (hog = &hogs[0]; hog->chip_label; hog++)
+ list_del(&hog->list);
+ mutex_unlock(&gpio_machine_hogs_mutex);
+}
+EXPORT_SYMBOL_GPL(gpiod_remove_hogs);
+
static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
{
const char *dev_id = dev ? dev_name(dev) : NULL;
diff --git a/include/linux/gpio/machine.h b/include/linux/gpio/machine.h
index d755e529c1e3..2647dd10b541 100644
--- a/include/linux/gpio/machine.h
+++ b/include/linux/gpio/machine.h
@@ -100,6 +100,7 @@ void gpiod_add_lookup_table(struct gpiod_lookup_table *table);
void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n);
void gpiod_remove_lookup_table(struct gpiod_lookup_table *table);
void gpiod_add_hogs(struct gpiod_hog *hogs);
+void gpiod_remove_hogs(struct gpiod_hog *hogs);
#else /* ! CONFIG_GPIOLIB */
static inline
void gpiod_add_lookup_table(struct gpiod_lookup_table *table) {}
@@ -108,6 +109,7 @@ void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n) {}
static inline
void gpiod_remove_lookup_table(struct gpiod_lookup_table *table) {}
static inline void gpiod_add_hogs(struct gpiod_hog *hogs) {}
+static inline void gpiod_remove_hogs(struct gpiod_hog *hogs) {}
#endif /* CONFIG_GPIOLIB */
#endif /* __LINUX_GPIO_MACHINE_H */
--
2.25.1
^ permalink raw reply related [flat|nested] 14+ messages in thread
* [PATCH v13 2/7] gpiolib: allow to specify the firmware node in struct gpio_chip
2021-12-07 9:34 [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator Bartosz Golaszewski
2021-12-07 9:34 ` [PATCH v13 1/7] gpiolib: provide gpiod_remove_hogs() Bartosz Golaszewski
@ 2021-12-07 9:34 ` Bartosz Golaszewski
2021-12-07 12:24 ` Andy Shevchenko
2021-12-07 9:34 ` [PATCH v13 3/7] gpiolib: of: make fwnode take precedence " Bartosz Golaszewski
` (5 subsequent siblings)
7 siblings, 1 reply; 14+ messages in thread
From: Bartosz Golaszewski @ 2021-12-07 9:34 UTC (permalink / raw)
To: Kent Gibson, Linus Walleij, Andy Shevchenko, Shuah Khan,
Geert Uytterhoeven, Viresh Kumar
Cc: linux-gpio, linux-kernel, linux-kselftest, Bartosz Golaszewski
Software nodes allow us to represent hierarchies for device components
that don't have their struct device representation yet - for instance:
banks of GPIOs under a common GPIO expander. The core gpiolib core
however doesn't offer any way of passing this information from the
drivers.
This extends struct gpio_chip with a pointer to fwnode that can be set
by the driver and used to pass device properties for child nodes.
This is similar to how we handle device-tree sub-nodes with
CONFIG_OF_GPIO enabled.
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
---
drivers/gpio/gpiolib.c | 7 ++++++-
include/linux/gpio/driver.h | 2 ++
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 22b98a590a88..6af732bf4c99 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -593,13 +593,18 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
struct lock_class_key *lock_key,
struct lock_class_key *request_key)
{
- struct fwnode_handle *fwnode = gc->parent ? dev_fwnode(gc->parent) : NULL;
+ struct fwnode_handle *fwnode = NULL;
unsigned long flags;
int ret = 0;
unsigned i;
int base = gc->base;
struct gpio_device *gdev;
+ if (gc->fwnode)
+ fwnode = gc->fwnode;
+ else if (gc->parent)
+ fwnode = dev_fwnode(gc->parent);
+
/*
* First: allocate and populate the internal stat container, and
* set up the struct device.
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index a673a359e20b..b0728c8ad90c 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -289,6 +289,7 @@ struct gpio_irq_chip {
* number or the name of the SoC IP-block implementing it.
* @gpiodev: the internal state holder, opaque struct
* @parent: optional parent device providing the GPIOs
+ * @fwnode: optional fwnode providing this controller's properties
* @owner: helps prevent removal of modules exporting active GPIOs
* @request: optional hook for chip-specific activation, such as
* enabling module power and clock; may sleep
@@ -377,6 +378,7 @@ struct gpio_chip {
const char *label;
struct gpio_device *gpiodev;
struct device *parent;
+ struct fwnode_handle *fwnode;
struct module *owner;
int (*request)(struct gpio_chip *gc,
--
2.25.1
^ permalink raw reply related [flat|nested] 14+ messages in thread
* [PATCH v13 3/7] gpiolib: of: make fwnode take precedence in struct gpio_chip
2021-12-07 9:34 [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator Bartosz Golaszewski
2021-12-07 9:34 ` [PATCH v13 1/7] gpiolib: provide gpiod_remove_hogs() Bartosz Golaszewski
2021-12-07 9:34 ` [PATCH v13 2/7] gpiolib: allow to specify the firmware node in struct gpio_chip Bartosz Golaszewski
@ 2021-12-07 9:34 ` Bartosz Golaszewski
2021-12-07 12:24 ` Andy Shevchenko
2021-12-07 9:34 ` [PATCH v13 4/7] gpio: sim: new testing module Bartosz Golaszewski
` (4 subsequent siblings)
7 siblings, 1 reply; 14+ messages in thread
From: Bartosz Golaszewski @ 2021-12-07 9:34 UTC (permalink / raw)
To: Kent Gibson, Linus Walleij, Andy Shevchenko, Shuah Khan,
Geert Uytterhoeven, Viresh Kumar
Cc: linux-gpio, linux-kernel, linux-kselftest, Bartosz Golaszewski
If the driver sets the fwnode in struct gpio_chip, let it take
precedence over the of_node. This only affects OF-based systems,
ACPI needs to be converted separately.
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
---
drivers/gpio/gpiolib-of.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 0ad288ab6262..91dcf2c6cdd8 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -1046,6 +1046,9 @@ void of_gpio_dev_init(struct gpio_chip *gc, struct gpio_device *gdev)
if (gc->parent)
gdev->dev.of_node = gc->parent->of_node;
+ if (gc->fwnode)
+ gc->of_node = to_of_node(gc->fwnode);
+
/* If the gpiochip has an assigned OF node this takes precedence */
if (gc->of_node)
gdev->dev.of_node = gc->of_node;
--
2.25.1
^ permalink raw reply related [flat|nested] 14+ messages in thread
* [PATCH v13 4/7] gpio: sim: new testing module
2021-12-07 9:34 [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator Bartosz Golaszewski
` (2 preceding siblings ...)
2021-12-07 9:34 ` [PATCH v13 3/7] gpiolib: of: make fwnode take precedence " Bartosz Golaszewski
@ 2021-12-07 9:34 ` Bartosz Golaszewski
2021-12-07 13:58 ` Andy Shevchenko
2021-12-07 9:34 ` [PATCH v13 5/7] selftests: gpio: provide a helper for reading chip info Bartosz Golaszewski
` (3 subsequent siblings)
7 siblings, 1 reply; 14+ messages in thread
From: Bartosz Golaszewski @ 2021-12-07 9:34 UTC (permalink / raw)
To: Kent Gibson, Linus Walleij, Andy Shevchenko, Shuah Khan,
Geert Uytterhoeven, Viresh Kumar
Cc: linux-gpio, linux-kernel, linux-kselftest, Bartosz Golaszewski
Implement a new, modern GPIO testing module controlled by configfs
attributes instead of module parameters. The goal of this driver is
to provide a replacement for gpio-mockup that will be easily extensible
with new features and doesn't require reloading the module to change
the setup.
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
---
Documentation/admin-guide/gpio/gpio-sim.rst | 134 ++
drivers/gpio/Kconfig | 8 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-sim.c | 1589 +++++++++++++++++++
4 files changed, 1732 insertions(+)
create mode 100644 Documentation/admin-guide/gpio/gpio-sim.rst
create mode 100644 drivers/gpio/gpio-sim.c
diff --git a/Documentation/admin-guide/gpio/gpio-sim.rst b/Documentation/admin-guide/gpio/gpio-sim.rst
new file mode 100644
index 000000000000..d8a90c81b9ee
--- /dev/null
+++ b/Documentation/admin-guide/gpio/gpio-sim.rst
@@ -0,0 +1,134 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Configfs GPIO Simulator
+=======================
+
+The configfs GPIO Simulator (gpio-sim) provides a way to create simulated GPIO
+chips for testing purposes. The lines exposed by these chips can be accessed
+using the standard GPIO character device interface as well as manipulated
+using sysfs attributes.
+
+Creating simulated chips
+------------------------
+
+The gpio-sim module registers a configfs subsystem called ``'gpio-sim'``. For
+details of the configfs filesystem, please refer to the configfs documentation.
+
+The user can create a hierarchy of configfs groups and items as well as modify
+values of exposed attributes. Once the chip is instantiated, this hierarchy
+will be translated to appropriate device properties. The general structure is:
+
+**Group:** ``/config/gpio-sim``
+
+This is the top directory of the gpio-sim configfs tree.
+
+**Group:** ``/config/gpio-sim/gpio-device``
+
+**Attribute:** ``/config/gpio-sim/gpio-device/dev_name``
+
+**Attribute:** ``/config/gpio-sim/gpio-device/live``
+
+This is a directory representing a GPIO platform device. The ``'dev_name'``
+attribute is read-only and allows the user-space to read the platform device
+name (e.g. ``'gpio-sim.0'``). The ``'live'`` attribute allows to trigger the
+actual creation of the device once it's fully configured. The accepted values
+are: ``'1'`` to enable the simulated device and ``'0'`` to disable and tear
+it down.
+
+**Group:** ``/config/gpio-sim/gpio-device/gpio-bankX``
+
+**Attribute:** ``/config/gpio-sim/gpio-device/gpio-bankX/chip_name``
+
+**Attribute:** ``/config/gpio-sim/gpio-device/gpio-bankX/num_lines``
+
+This group represents a bank of GPIOs under the top platform device. The
+``'chip_name'`` attribute is read-only and allows the user-space to read the
+device name of the bank device. The ``'num_lines'`` attribute allows to specify
+the number of lines exposed by this bank.
+
+**Group:** ``/config/gpio-sim/gpio-device/gpio-bankX/lineY``
+
+**Attribute:** ``/config/gpio-sim/gpio-device/gpio-bankX/lineY/name``
+
+This group represents a single line at the offset Y. The 'name' attribute
+allows to set the line name as represented by the 'gpio-line-names' property.
+
+**Item:** ``/config/gpio-sim/gpio-device/gpio-bankX/lineY/hog``
+
+**Attribute:** ``/config/gpio-sim/gpio-device/gpio-bankX/lineY/hog/name``
+
+**Attribute:** ``/config/gpio-sim/gpio-device/gpio-bankX/lineY/hog/direction``
+
+This item makes the gpio-sim module hog the associated line. The ``'name'``
+attribute specifies the in-kernel consumer name to use. The ``'direction'``
+attribute specifies the hog direction and must be one of: ``'input'``,
+``'output-high'`` and ``'output-low'``.
+
+Inside each bank directory, there's a set of attributes that can be used to
+configure the new chip. Additionally the user can ``mkdir()`` subdirectories
+inside the chip's directory that allow to pass additional configuration for
+specific lines. The name of those subdirectories must take the form of:
+``'line<offset>'`` (e.g. ``'line0'``, ``'line20'``, etc.) as the name will be
+used by the module to assign the config to the specific line at given offset.
+
+Once the confiuration is complete, the ``'live'`` attribute must be set to 1 in
+order to instantiate the chip. It can be set back to 0 to destroy the simulated
+chip. The module will synchronously wait for the new simulated device to be
+successfully probed and if this doesn't happen, writing to ``'live'`` will
+result in an error.
+
+Simulated GPIO chips can also be defined in device-tree. The compatible string
+must be: ``"gpio-simulator"``. Supported properties are:
+
+ ``"gpio-sim,label"`` - chip label
+
+Other standard GPIO properties (like ``"gpio-line-names"``, ``"ngpios"`` or
+``"gpio-hog"``) are also supported. Please refer to the GPIO documentation for
+details.
+
+An example device-tree code defining a GPIO simulator:
+
+.. code-block :: none
+
+ gpio-sim {
+ compatible = "gpio-simulator";
+
+ bank0 {
+ gpio-controller;
+ #gpio-cells = <2>;
+ ngpios = <16>;
+ gpio-sim,label = "dt-bank0";
+ gpio-line-names = "", "sim-foo", "", "sim-bar";
+ };
+
+ bank1 {
+ gpio-controller;
+ #gpio-cells = <2>;
+ ngpios = <8>;
+ gpio-sim,label = "dt-bank1";
+
+ line3 {
+ gpio-hog;
+ gpios = <3 0>;
+ output-high;
+ line-name = "sim-hog-from-dt";
+ };
+ };
+ };
+
+Manipulating simulated lines
+----------------------------
+
+Each simulated GPIO chip creates a separate sysfs group under its device
+directory for each exposed line
+(e.g. ``/sys/devices/platform/gpio-sim.X/gpiochipY/``). The name of each group
+is of the form: ``'sim_gpioX'`` where X is the offset of the line. Inside each
+group there are two attibutes:
+
+ ``pull`` - allows to read and set the current simulated pull setting for
+ every line, when writing the value must be one of: ``'pull-up'``,
+ ``'pull-down'``
+
+ ``value`` - allows to read the current value of the line which may be
+ different from the pull if the line is being driven from
+ user-space
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 60d9374c72c0..9acdb4d1047b 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1694,6 +1694,14 @@ config GPIO_VIRTIO
These virtual GPIOs can be routed to real GPIOs or attached to
simulators on the host (like QEMU).
+config GPIO_SIM
+ tristate "GPIO Simulator Module"
+ select IRQ_SIM
+ select CONFIGFS_FS
+ help
+ This enables the GPIO simulator - a configfs-based GPIO testing
+ driver.
+
endmenu
endif
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 71ee9fc2ff83..f21577de2474 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -133,6 +133,7 @@ obj-$(CONFIG_GPIO_SAMA5D2_PIOBU) += gpio-sama5d2-piobu.o
obj-$(CONFIG_GPIO_SCH311X) += gpio-sch311x.o
obj-$(CONFIG_GPIO_SCH) += gpio-sch.o
obj-$(CONFIG_GPIO_SIFIVE) += gpio-sifive.o
+obj-$(CONFIG_GPIO_SIM) += gpio-sim.o
obj-$(CONFIG_GPIO_SIOX) += gpio-siox.o
obj-$(CONFIG_GPIO_SL28CPLD) += gpio-sl28cpld.o
obj-$(CONFIG_GPIO_SODAVILLE) += gpio-sodaville.o
diff --git a/drivers/gpio/gpio-sim.c b/drivers/gpio/gpio-sim.c
new file mode 100644
index 000000000000..3defd76c095d
--- /dev/null
+++ b/drivers/gpio/gpio-sim.c
@@ -0,0 +1,1589 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * GPIO testing driver based on configfs.
+ *
+ * Copyright (C) 2021 Bartosz Golaszewski <brgl@bgdev.pl>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/bitmap.h>
+#include <linux/completion.h>
+#include <linux/configfs.h>
+#include <linux/device.h>
+#include <linux/gpio/driver.h>
+#include <linux/gpio/machine.h>
+#include <linux/idr.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irq_sim.h>
+#include <linux/list.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/string_helpers.h>
+#include <linux/sysfs.h>
+
+#include "gpiolib.h"
+
+#define GPIO_SIM_PROP_MAX 4 /* Max 3 properties + sentinel. */
+#define GPIO_SIM_NUM_ATTRS 3 /* value, pull and sentinel */
+
+static DEFINE_IDA(gpio_sim_ida);
+
+struct gpio_sim_chip {
+ struct gpio_chip gc;
+ unsigned long *direction_map;
+ unsigned long *value_map;
+ unsigned long *pull_map;
+ struct irq_domain *irq_sim;
+ struct mutex lock;
+ const struct attribute_group **attr_groups;
+};
+
+struct gpio_sim_attribute {
+ struct device_attribute dev_attr;
+ unsigned int offset;
+};
+
+static struct gpio_sim_attribute *
+to_gpio_sim_attr(struct device_attribute *dev_attr)
+{
+ return container_of(dev_attr, struct gpio_sim_attribute, dev_attr);
+}
+
+static int gpio_sim_apply_pull(struct gpio_sim_chip *chip,
+ unsigned int offset, int value)
+{
+ int irq, irq_type, ret;
+ struct gpio_desc *desc;
+ struct gpio_chip *gc;
+
+ gc = &chip->gc;
+ desc = &gc->gpiodev->descs[offset];
+
+ mutex_lock(&chip->lock);
+
+ if (test_bit(FLAG_REQUESTED, &desc->flags) &&
+ !test_bit(FLAG_IS_OUT, &desc->flags)) {
+ if (value == !!test_bit(offset, chip->value_map))
+ goto set_pull;
+
+ /*
+ * This is fine - it just means, nobody is listening
+ * for interrupts on this line, otherwise
+ * irq_create_mapping() would have been called from
+ * the to_irq() callback.
+ */
+ irq = irq_find_mapping(chip->irq_sim, offset);
+ if (!irq)
+ goto set_value;
+
+ irq_type = irq_get_trigger_type(irq);
+
+ if ((value && (irq_type & IRQ_TYPE_EDGE_RISING)) ||
+ (!value && (irq_type & IRQ_TYPE_EDGE_FALLING))) {
+ ret = irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING,
+ true);
+ if (ret)
+ goto set_pull;
+ }
+ }
+
+set_value:
+ /* Change the value unless we're actively driving the line. */
+ if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
+ !test_bit(FLAG_IS_OUT, &desc->flags))
+ __assign_bit(offset, chip->value_map, value);
+
+set_pull:
+ __assign_bit(offset, chip->pull_map, value);
+ mutex_unlock(&chip->lock);
+ return 0;
+}
+
+static int gpio_sim_get(struct gpio_chip *gc, unsigned int offset)
+{
+ struct gpio_sim_chip *chip = gpiochip_get_data(gc);
+ int ret;
+
+ mutex_lock(&chip->lock);
+ ret = !!test_bit(offset, chip->value_map);
+ mutex_unlock(&chip->lock);
+
+ return ret;
+}
+
+static void gpio_sim_set(struct gpio_chip *gc, unsigned int offset, int value)
+{
+ struct gpio_sim_chip *chip = gpiochip_get_data(gc);
+
+ mutex_lock(&chip->lock);
+ __assign_bit(offset, chip->value_map, value);
+ mutex_unlock(&chip->lock);
+}
+
+static int gpio_sim_get_multiple(struct gpio_chip *gc,
+ unsigned long *mask, unsigned long *bits)
+{
+ struct gpio_sim_chip *chip = gpiochip_get_data(gc);
+
+ mutex_lock(&chip->lock);
+ bitmap_copy(bits, chip->value_map, gc->ngpio);
+ mutex_unlock(&chip->lock);
+
+ return 0;
+}
+
+static void gpio_sim_set_multiple(struct gpio_chip *gc,
+ unsigned long *mask, unsigned long *bits)
+{
+ struct gpio_sim_chip *chip = gpiochip_get_data(gc);
+
+ mutex_lock(&chip->lock);
+ bitmap_copy(chip->value_map, bits, gc->ngpio);
+ mutex_unlock(&chip->lock);
+}
+
+static int gpio_sim_direction_output(struct gpio_chip *gc,
+ unsigned int offset, int value)
+{
+ struct gpio_sim_chip *chip = gpiochip_get_data(gc);
+
+ mutex_lock(&chip->lock);
+ __clear_bit(offset, chip->direction_map);
+ __assign_bit(offset, chip->value_map, value);
+ mutex_unlock(&chip->lock);
+
+ return 0;
+}
+
+static int gpio_sim_direction_input(struct gpio_chip *gc, unsigned int offset)
+{
+ struct gpio_sim_chip *chip = gpiochip_get_data(gc);
+
+ mutex_lock(&chip->lock);
+ __set_bit(offset, chip->direction_map);
+ mutex_unlock(&chip->lock);
+
+ return 0;
+}
+
+static int gpio_sim_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+ struct gpio_sim_chip *chip = gpiochip_get_data(gc);
+ int direction;
+
+ mutex_lock(&chip->lock);
+ direction = !!test_bit(offset, chip->direction_map);
+ mutex_unlock(&chip->lock);
+
+ return direction ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT;
+}
+
+static int gpio_sim_set_config(struct gpio_chip *gc,
+ unsigned int offset, unsigned long config)
+{
+ struct gpio_sim_chip *chip = gpiochip_get_data(gc);
+
+ switch (pinconf_to_config_param(config)) {
+ case PIN_CONFIG_BIAS_PULL_UP:
+ return gpio_sim_apply_pull(chip, offset, 1);
+ case PIN_CONFIG_BIAS_PULL_DOWN:
+ return gpio_sim_apply_pull(chip, offset, 0);
+ default:
+ break;
+ }
+
+ return -ENOTSUPP;
+}
+
+static int gpio_sim_to_irq(struct gpio_chip *gc, unsigned int offset)
+{
+ struct gpio_sim_chip *chip = gpiochip_get_data(gc);
+
+ return irq_create_mapping(chip->irq_sim, offset);
+}
+
+static void gpio_sim_free(struct gpio_chip *gc, unsigned int offset)
+{
+ struct gpio_sim_chip *chip = gpiochip_get_data(gc);
+
+ mutex_lock(&chip->lock);
+ __assign_bit(offset, chip->value_map, !!test_bit(offset, chip->pull_map));
+ mutex_unlock(&chip->lock);
+}
+
+static ssize_t gpio_sim_sysfs_val_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
+ struct gpio_sim_chip *chip = dev_get_drvdata(dev);
+ int val;
+
+ mutex_lock(&chip->lock);
+ val = !!test_bit(line_attr->offset, chip->value_map);
+ mutex_unlock(&chip->lock);
+
+ return sysfs_emit(buf, "%d\n", val);
+}
+
+static ssize_t gpio_sim_sysfs_val_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ /*
+ * Not assigning this function will result in write() returning -EIO
+ * which is confusing. Return -EPERM explicitly.
+ */
+ return -EPERM;
+}
+
+static const char *const gpio_sim_sysfs_pull_strings[] = {
+ [0] = "pull-down",
+ [1] = "pull-up"
+};
+
+static ssize_t gpio_sim_sysfs_pull_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
+ struct gpio_sim_chip *chip = dev_get_drvdata(dev);
+ int pull;
+
+ mutex_lock(&chip->lock);
+ pull = !!test_bit(line_attr->offset, chip->pull_map);
+ mutex_unlock(&chip->lock);
+
+ return sysfs_emit(buf, "%s\n", gpio_sim_sysfs_pull_strings[pull]);
+}
+
+static ssize_t gpio_sim_sysfs_pull_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
+ struct gpio_sim_chip *chip = dev_get_drvdata(dev);
+ int ret, pull;
+
+ pull = sysfs_match_string(gpio_sim_sysfs_pull_strings, buf);
+ if (pull < 0)
+ return -EINVAL;
+
+ ret = gpio_sim_apply_pull(chip, line_attr->offset, pull);
+ if (ret)
+ return ret;
+
+ return len;
+}
+
+static void gpio_sim_mutex_destroy(void *data)
+{
+ struct mutex *lock = data;
+
+ mutex_destroy(lock);
+}
+
+static void gpio_sim_sysfs_remove(void *data)
+{
+ struct gpio_sim_chip *chip = data;
+
+ sysfs_remove_groups(&chip->gc.gpiodev->dev.kobj, chip->attr_groups);
+}
+
+static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip)
+{
+ struct device_attribute *val_dev_attr, *pull_dev_attr;
+ struct gpio_sim_attribute *val_attr, *pull_attr;
+ unsigned int num_lines = chip->gc.ngpio;
+ struct device *dev = chip->gc.parent;
+ struct attribute_group *attr_group;
+ struct attribute **attrs;
+ int i, ret;
+
+ chip->attr_groups = devm_kcalloc(dev, sizeof(*chip->attr_groups),
+ num_lines + 1, GFP_KERNEL);
+ if (!chip->attr_groups)
+ return -ENOMEM;
+
+ for (i = 0; i < num_lines; i++) {
+ attr_group = devm_kzalloc(dev, sizeof(*attr_group), GFP_KERNEL);
+ attrs = devm_kcalloc(dev, sizeof(*attrs),
+ GPIO_SIM_NUM_ATTRS, GFP_KERNEL);
+ val_attr = devm_kzalloc(dev, sizeof(*val_attr), GFP_KERNEL);
+ pull_attr = devm_kzalloc(dev, sizeof(*pull_attr), GFP_KERNEL);
+ if (!attr_group || !attrs || !val_attr || !pull_attr)
+ return -ENOMEM;
+
+ attr_group->name = devm_kasprintf(dev, GFP_KERNEL,
+ "sim_gpio%u", i);
+ if (!attr_group->name)
+ return -ENOMEM;
+
+ val_attr->offset = pull_attr->offset = i;
+
+ val_dev_attr = &val_attr->dev_attr;
+ pull_dev_attr = &pull_attr->dev_attr;
+
+ sysfs_attr_init(&val_dev_attr->attr);
+ sysfs_attr_init(&pull_dev_attr->attr);
+
+ val_dev_attr->attr.name = "value";
+ pull_dev_attr->attr.name = "pull";
+
+ val_dev_attr->attr.mode = pull_dev_attr->attr.mode = 0644;
+
+ val_dev_attr->show = gpio_sim_sysfs_val_show;
+ val_dev_attr->store = gpio_sim_sysfs_val_store;
+ pull_dev_attr->show = gpio_sim_sysfs_pull_show;
+ pull_dev_attr->store = gpio_sim_sysfs_pull_store;
+
+ attrs[0] = &val_dev_attr->attr;
+ attrs[1] = &pull_dev_attr->attr;
+
+ attr_group->attrs = attrs;
+ chip->attr_groups[i] = attr_group;
+ }
+
+ ret = sysfs_create_groups(&chip->gc.gpiodev->dev.kobj,
+ chip->attr_groups);
+ if (ret)
+ return ret;
+
+ return devm_add_action_or_reset(dev, gpio_sim_sysfs_remove, chip);
+}
+
+static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
+{
+ struct gpio_sim_chip *chip;
+ struct gpio_chip *gc;
+ const char *label;
+ u32 num_lines;
+ int ret;
+
+ ret = fwnode_property_read_u32(swnode, "ngpios", &num_lines);
+ if (ret)
+ return ret;
+
+ ret = fwnode_property_read_string(swnode, "gpio-sim,label", &label);
+ if (ret) {
+ label = devm_kasprintf(dev, GFP_KERNEL, "%s-%s",
+ dev_name(dev), fwnode_get_name(swnode));
+ if (!label)
+ return -ENOMEM;
+ }
+
+ chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+
+ chip->direction_map = devm_bitmap_alloc(dev, num_lines, GFP_KERNEL);
+ if (!chip->direction_map)
+ return -ENOMEM;
+
+ /* Default to input mode. */
+ bitmap_fill(chip->direction_map, num_lines);
+
+ chip->value_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL);
+ if (!chip->value_map)
+ return -ENOMEM;
+
+ chip->pull_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL);
+ if (!chip->pull_map)
+ return -ENOMEM;
+
+ chip->irq_sim = devm_irq_domain_create_sim(dev, NULL, num_lines);
+ if (IS_ERR(chip->irq_sim))
+ return PTR_ERR(chip->irq_sim);
+
+ mutex_init(&chip->lock);
+ ret = devm_add_action_or_reset(dev, gpio_sim_mutex_destroy,
+ &chip->lock);
+ if (ret)
+ return ret;
+
+ gc = &chip->gc;
+ gc->base = -1;
+ gc->ngpio = num_lines;
+ gc->label = label;
+ gc->owner = THIS_MODULE;
+ gc->parent = dev;
+ gc->fwnode = swnode;
+ gc->get = gpio_sim_get;
+ gc->set = gpio_sim_set;
+ gc->get_multiple = gpio_sim_get_multiple;
+ gc->set_multiple = gpio_sim_set_multiple;
+ gc->direction_output = gpio_sim_direction_output;
+ gc->direction_input = gpio_sim_direction_input;
+ gc->get_direction = gpio_sim_get_direction;
+ gc->set_config = gpio_sim_set_config;
+ gc->to_irq = gpio_sim_to_irq;
+ gc->free = gpio_sim_free;
+
+ ret = devm_gpiochip_add_data(dev, gc, chip);
+ if (ret)
+ return ret;
+
+ /* Used by sysfs and configfs callbacks. */
+ dev_set_drvdata(&gc->gpiodev->dev, chip);
+
+ return gpio_sim_setup_sysfs(chip);
+}
+
+static int gpio_sim_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct fwnode_handle *swnode;
+ int ret;
+
+ device_for_each_child_node(dev, swnode) {
+ ret = gpio_sim_add_bank(swnode, dev);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id gpio_sim_of_match[] = {
+ { .compatible = "gpio-simulator" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, gpio_sim_of_match);
+
+static struct platform_driver gpio_sim_driver = {
+ .driver = {
+ .name = "gpio-sim",
+ .of_match_table = gpio_sim_of_match,
+ },
+ .probe = gpio_sim_probe,
+};
+
+struct gpio_sim_device {
+ struct config_group group;
+
+ /*
+ * If pdev is NULL, the device is 'pending' (waiting for configuration).
+ * Once the pointer is assigned, the device has been created and the
+ * item is 'live'.
+ */
+ struct platform_device *pdev;
+ int id;
+
+ /*
+ * Each configfs filesystem operation is protected with the subsystem
+ * mutex. Each separate attribute is protected with the buffer mutex.
+ * This structure however can be modified by callbacks of different
+ * attributes so we need another lock.
+ *
+ * We use this lock fo protecting all data structures owned by this
+ * object too.
+ */
+ struct mutex lock;
+
+ /*
+ * This is used to synchronously wait for the driver's probe to complete
+ * and notify the user-space about any errors.
+ */
+ struct notifier_block bus_notifier;
+ struct completion probe_completion;
+ bool driver_bound;
+
+ struct gpiod_hog *hogs;
+
+ struct list_head bank_list;
+};
+
+/* This is called with dev->lock already taken. */
+static int gpio_sim_bus_notifier_call(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct gpio_sim_device *simdev = container_of(nb,
+ struct gpio_sim_device,
+ bus_notifier);
+ struct device *dev = data;
+ char devname[32];
+
+ snprintf(devname, sizeof(devname), "gpio-sim.%u", simdev->id);
+
+ if (strcmp(dev_name(dev), devname) == 0) {
+ if (action == BUS_NOTIFY_BOUND_DRIVER)
+ simdev->driver_bound = true;
+ else if (action == BUS_NOTIFY_DRIVER_NOT_BOUND)
+ simdev->driver_bound = false;
+ else
+ return NOTIFY_DONE;
+
+ complete(&simdev->probe_completion);
+ return NOTIFY_OK;
+ }
+
+ return NOTIFY_DONE;
+}
+
+static struct gpio_sim_device *to_gpio_sim_device(struct config_item *item)
+{
+ struct config_group *group = to_config_group(item);
+
+ return container_of(group, struct gpio_sim_device, group);
+}
+
+struct gpio_sim_bank {
+ struct config_group group;
+
+ /*
+ * We could have used the ci_parent field of the config_item but
+ * configfs is stupid and calls the item's release callback after
+ * already having cleared the parent pointer even though the parent
+ * is guaranteed to survive the child...
+ *
+ * So we need to store the pointer to the parent struct here. We can
+ * dereference it anywhere we need with no checks and no locking as
+ * it's guaranteed to survive the childred and protected by configfs
+ * locks.
+ *
+ * Same for other structures.
+ */
+ struct gpio_sim_device *parent;
+ struct list_head siblings;
+
+ char *label;
+ unsigned int num_lines;
+
+ struct list_head line_list;
+
+ struct fwnode_handle *swnode;
+};
+
+static struct gpio_sim_bank *to_gpio_sim_bank(struct config_item *item)
+{
+ struct config_group *group = to_config_group(item);
+
+ return container_of(group, struct gpio_sim_bank, group);
+}
+
+static struct gpio_sim_device *
+gpio_sim_bank_get_device(struct gpio_sim_bank *bank)
+{
+ return bank->parent;
+}
+
+struct gpio_sim_hog;
+
+struct gpio_sim_line {
+ struct config_group group;
+
+ struct gpio_sim_bank *parent;
+ struct list_head siblings;
+
+ unsigned int offset;
+ char *name;
+
+ /* There can only be one hog per line. */
+ struct gpio_sim_hog *hog;
+};
+
+static struct gpio_sim_line *to_gpio_sim_line(struct config_item *item)
+{
+ struct config_group *group = to_config_group(item);
+
+ return container_of(group, struct gpio_sim_line, group);
+}
+
+static struct gpio_sim_device *
+gpio_sim_line_get_device(struct gpio_sim_line *line)
+{
+ struct gpio_sim_bank *bank = line->parent;
+
+ return gpio_sim_bank_get_device(bank);
+}
+
+struct gpio_sim_hog {
+ struct config_item item;
+ struct gpio_sim_line *parent;
+
+ char *name;
+ int dir;
+};
+
+static struct gpio_sim_hog *to_gpio_sim_hog(struct config_item *item)
+{
+ return container_of(item, struct gpio_sim_hog, item);
+}
+
+static struct gpio_sim_device *gpio_sim_hog_get_device(struct gpio_sim_hog *hog)
+{
+ struct gpio_sim_line *line = hog->parent;
+
+ return gpio_sim_line_get_device(line);
+}
+
+static bool gpio_sim_device_is_live_unlocked(struct gpio_sim_device *dev)
+{
+ return !!dev->pdev;
+}
+
+static char *gpio_sim_strdup_trimmed(const char *str, size_t count)
+{
+ char *dup, *trimmed;
+
+ dup = kstrndup(str, count, GFP_KERNEL);
+ if (!dup)
+ return NULL;
+
+ trimmed = strstrip(dup);
+ memmove(dup, trimmed, strlen(trimmed) + 1);
+
+ return dup;
+}
+
+static ssize_t gpio_sim_device_config_dev_name_show(struct config_item *item,
+ char *page)
+{
+ struct gpio_sim_device *dev = to_gpio_sim_device(item);
+ struct platform_device *pdev;
+ int ret;
+
+ mutex_lock(&dev->lock);
+ pdev = dev->pdev;
+ if (pdev)
+ ret = sprintf(page, "%s\n", dev_name(&pdev->dev));
+ else
+ ret = sprintf(page, "gpio-sim.%d\n", dev->id);
+ mutex_unlock(&dev->lock);
+
+ return ret;
+}
+
+CONFIGFS_ATTR_RO(gpio_sim_device_config_, dev_name);
+
+static ssize_t
+gpio_sim_device_config_live_show(struct config_item *item, char *page)
+{
+ struct gpio_sim_device *dev = to_gpio_sim_device(item);
+ bool live;
+
+ mutex_lock(&dev->lock);
+ live = gpio_sim_device_is_live_unlocked(dev);
+ mutex_unlock(&dev->lock);
+
+ return sprintf(page, "%c\n", live ? '1' : '0');
+}
+
+static char **gpio_sim_make_line_names(struct gpio_sim_bank *bank,
+ unsigned int *line_names_size)
+{
+ unsigned int max_offset = 0;
+ bool has_line_names = false;
+ struct gpio_sim_line *line;
+ char **line_names;
+
+ list_for_each_entry(line, &bank->line_list, siblings) {
+ if (line->name) {
+ if (line->offset > max_offset)
+ max_offset = line->offset;
+
+ /*
+ * max_offset can stay at 0 so it's not an indicator
+ * of whether line names were configured at all.
+ */
+ has_line_names = true;
+ }
+ }
+
+ if (!has_line_names)
+ /*
+ * This is not an error - NULL means, there are no line
+ * names configured.
+ */
+ return NULL;
+
+ *line_names_size = max_offset + 1;
+
+ line_names = kcalloc(*line_names_size, sizeof(*line_names), GFP_KERNEL);
+ if (!line_names)
+ return ERR_PTR(-ENOMEM);
+
+ list_for_each_entry(line, &bank->line_list, siblings)
+ line_names[line->offset] = line->name;
+
+ return line_names;
+}
+
+static void gpio_sim_remove_hogs(struct gpio_sim_device *dev)
+{
+ struct gpiod_hog *hog;
+
+ if (!dev->hogs)
+ return;
+
+ gpiod_remove_hogs(dev->hogs);
+
+ for (hog = dev->hogs; !hog->chip_label; hog++) {
+ kfree(hog->chip_label);
+ kfree(hog->line_name);
+ }
+
+ kfree(dev->hogs);
+ dev->hogs = NULL;
+}
+
+static int gpio_sim_add_hogs(struct gpio_sim_device *dev)
+{
+ unsigned int num_hogs = 0, idx = 0;
+ struct gpio_sim_bank *bank;
+ struct gpio_sim_line *line;
+ struct gpiod_hog *hog;
+
+ list_for_each_entry(bank, &dev->bank_list, siblings) {
+ list_for_each_entry(line, &bank->line_list, siblings) {
+ if (line->hog)
+ num_hogs++;
+ }
+ }
+
+ if (!num_hogs)
+ return 0;
+
+ /* Allocate one more for the sentinel. */
+ dev->hogs = kcalloc(num_hogs + 1, sizeof(*dev->hogs), GFP_KERNEL);
+ if (!dev->hogs)
+ return -ENOMEM;
+
+ list_for_each_entry(bank, &dev->bank_list, siblings) {
+ list_for_each_entry(line, &bank->line_list, siblings) {
+ if (!line->hog)
+ continue;
+
+ hog = &dev->hogs[idx++];
+
+ /*
+ * We need to make this string manually because at this
+ * point the device doesn't exist yet and so dev_name()
+ * is not available.
+ */
+ hog->chip_label = kasprintf(GFP_KERNEL,
+ "gpio-sim.%u-%s", dev->id,
+ fwnode_get_name(bank->swnode));
+ if (!hog->chip_label) {
+ gpio_sim_remove_hogs(dev);
+ return -ENOMEM;
+ }
+
+ /*
+ * We need to duplicate this because the hog config
+ * item can be removed at any time (and we can't block
+ * it) and gpiolib doesn't make a deep copy of the hog
+ * data.
+ */
+ if (line->hog->name) {
+ hog->line_name = kstrdup(line->hog->name,
+ GFP_KERNEL);
+ if (!hog->line_name) {
+ gpio_sim_remove_hogs(dev);
+ return -ENOMEM;
+ }
+ }
+
+ hog->chip_hwnum = line->offset;
+ hog->dflags = line->hog->dir;
+ }
+ }
+
+ gpiod_add_hogs(dev->hogs);
+
+ return 0;
+}
+
+static struct fwnode_handle *
+gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank,
+ struct fwnode_handle *parent)
+{
+ struct property_entry properties[GPIO_SIM_PROP_MAX];
+ unsigned int prop_idx = 0, line_names_size = 0;
+ struct fwnode_handle *swnode;
+ char **line_names;
+
+ memset(properties, 0, sizeof(properties));
+
+ properties[prop_idx++] = PROPERTY_ENTRY_U32("ngpios", bank->num_lines);
+
+ if (bank->label)
+ properties[prop_idx++] = PROPERTY_ENTRY_STRING("gpio-sim,label",
+ bank->label);
+
+ line_names = gpio_sim_make_line_names(bank, &line_names_size);
+ if (IS_ERR(line_names))
+ return ERR_CAST(line_names);
+
+ if (line_names)
+ properties[prop_idx++] = PROPERTY_ENTRY_STRING_ARRAY_LEN(
+ "gpio-line-names",
+ line_names, line_names_size);
+
+ swnode = fwnode_create_software_node(properties, parent);
+ kfree(line_names);
+ return swnode;
+}
+
+static void gpio_sim_remove_swnode_recursive(struct fwnode_handle *swnode)
+{
+ struct fwnode_handle *child;
+
+ fwnode_for_each_child_node(swnode, child)
+ fwnode_remove_software_node(child);
+
+ fwnode_remove_software_node(swnode);
+}
+
+static bool gpio_sim_bank_labels_non_unique(struct gpio_sim_device *dev)
+{
+ struct gpio_sim_bank *this, *pos;
+
+ list_for_each_entry(this, &dev->bank_list, siblings) {
+ list_for_each_entry(pos, &dev->bank_list, siblings) {
+ if (this == pos || (!this->label || !pos->label))
+ continue;
+
+ if (strcmp(this->label, pos->label) == 0)
+ return true;
+ }
+ }
+
+ return false;
+}
+
+static int gpio_sim_device_activate_unlocked(struct gpio_sim_device *dev)
+{
+ struct platform_device_info pdevinfo;
+ struct fwnode_handle *swnode;
+ struct platform_device *pdev;
+ struct gpio_sim_bank *bank;
+ int ret;
+
+ if (list_empty(&dev->bank_list))
+ return -ENODATA;
+
+ /*
+ * Non-unique GPIO device labels are a corner-case we don't support
+ * as it would interfere with machine hogging mechanism and has little
+ * use in real life.
+ */
+ if (gpio_sim_bank_labels_non_unique(dev))
+ return -EINVAL;
+
+ memset(&pdevinfo, 0, sizeof(pdevinfo));
+
+ swnode = fwnode_create_software_node(NULL, NULL);
+ if (IS_ERR(swnode))
+ return PTR_ERR(swnode);
+
+ list_for_each_entry(bank, &dev->bank_list, siblings) {
+ bank->swnode = gpio_sim_make_bank_swnode(bank, swnode);
+ if (ret) {
+ gpio_sim_remove_swnode_recursive(swnode);
+ return ret;
+ }
+ }
+
+ ret = gpio_sim_add_hogs(dev);
+ if (ret) {
+ gpio_sim_remove_swnode_recursive(swnode);
+ return ret;
+ }
+
+ pdevinfo.name = "gpio-sim";
+ pdevinfo.fwnode = swnode;
+ pdevinfo.id = dev->id;
+
+ reinit_completion(&dev->probe_completion);
+ dev->driver_bound = false;
+ bus_register_notifier(&platform_bus_type, &dev->bus_notifier);
+
+ pdev = platform_device_register_full(&pdevinfo);
+ if (IS_ERR(pdev)) {
+ bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier);
+ gpio_sim_remove_hogs(dev);
+ gpio_sim_remove_swnode_recursive(swnode);
+ return PTR_ERR(pdev);
+ }
+
+ wait_for_completion(&dev->probe_completion);
+ bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier);
+
+ if (!dev->driver_bound) {
+ /* Probe failed, check kernel log. */
+ platform_device_unregister(pdev);
+ gpio_sim_remove_hogs(dev);
+ gpio_sim_remove_swnode_recursive(swnode);
+ return -ENXIO;
+ }
+
+ dev->pdev = pdev;
+
+ return 0;
+}
+
+static void gpio_sim_device_deactivate_unlocked(struct gpio_sim_device *dev)
+{
+ struct fwnode_handle *swnode;
+
+ swnode = dev_fwnode(&dev->pdev->dev);
+ platform_device_unregister(dev->pdev);
+ gpio_sim_remove_swnode_recursive(swnode);
+ dev->pdev = NULL;
+ gpio_sim_remove_hogs(dev);
+}
+
+static ssize_t
+gpio_sim_device_config_live_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ struct gpio_sim_device *dev = to_gpio_sim_device(item);
+ bool live;
+ int ret;
+
+ ret = kstrtobool(page, &live);
+ if (ret)
+ return ret;
+
+ mutex_lock(&dev->lock);
+
+ if ((!live && !gpio_sim_device_is_live_unlocked(dev)) ||
+ (live && gpio_sim_device_is_live_unlocked(dev)))
+ ret = -EPERM;
+ else if (live)
+ ret = gpio_sim_device_activate_unlocked(dev);
+ else
+ gpio_sim_device_deactivate_unlocked(dev);
+
+ mutex_unlock(&dev->lock);
+
+ return ret ?: count;
+}
+
+CONFIGFS_ATTR(gpio_sim_device_config_, live);
+
+static struct configfs_attribute *gpio_sim_device_config_attrs[] = {
+ &gpio_sim_device_config_attr_dev_name,
+ &gpio_sim_device_config_attr_live,
+ NULL
+};
+
+struct gpio_sim_chip_name_ctx {
+ struct gpio_sim_device *dev;
+ char *page;
+};
+
+static int gpio_sim_emit_chip_name(struct device *dev, void *data)
+{
+ struct gpio_sim_chip_name_ctx *ctx = data;
+ struct fwnode_handle *swnode;
+ struct gpio_sim_bank *bank;
+
+ /* This would be the sysfs device exported in /sys/class/gpio. */
+ if (dev->class)
+ return 0;
+
+ swnode = dev_fwnode(dev);
+
+ list_for_each_entry(bank, &ctx->dev->bank_list, siblings) {
+ if (bank->swnode == swnode)
+ return sprintf(ctx->page, "%s\n", dev_name(dev));
+ }
+
+ return -ENODATA;
+}
+
+static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item,
+ char *page)
+{
+ struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
+ struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
+ struct gpio_sim_chip_name_ctx ctx = { dev, page };
+ int ret;
+
+ mutex_lock(&dev->lock);
+ if (gpio_sim_device_is_live_unlocked(dev))
+ ret = device_for_each_child(&dev->pdev->dev, &ctx,
+ gpio_sim_emit_chip_name);
+ else
+ ret = sprintf(page, "none\n");
+ mutex_unlock(&dev->lock);
+
+ return ret;
+}
+
+CONFIGFS_ATTR_RO(gpio_sim_bank_config_, chip_name);
+
+static ssize_t
+gpio_sim_bank_config_label_show(struct config_item *item, char *page)
+{
+ struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
+ struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
+ int ret;
+
+ mutex_lock(&dev->lock);
+ ret = sprintf(page, "%s\n", bank->label ?: "");
+ mutex_unlock(&dev->lock);
+
+ return ret;
+}
+
+static ssize_t gpio_sim_bank_config_label_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
+ struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
+ char *trimmed;
+
+ mutex_lock(&dev->lock);
+
+ if (gpio_sim_device_is_live_unlocked(dev)) {
+ mutex_unlock(&dev->lock);
+ return -EBUSY;
+ }
+
+ trimmed = gpio_sim_strdup_trimmed(page, count);
+ if (!trimmed) {
+ mutex_unlock(&dev->lock);
+ return -ENOMEM;
+ }
+
+ kfree(bank->label);
+ bank->label = trimmed;
+
+ mutex_unlock(&dev->lock);
+ return count;
+}
+
+CONFIGFS_ATTR(gpio_sim_bank_config_, label);
+
+static ssize_t
+gpio_sim_bank_config_num_lines_show(struct config_item *item, char *page)
+{
+ struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
+ struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
+ int ret;
+
+ mutex_lock(&dev->lock);
+ ret = sprintf(page, "%u\n", bank->num_lines);
+ mutex_unlock(&dev->lock);
+
+ return ret;
+}
+
+static ssize_t
+gpio_sim_bank_config_num_lines_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
+ struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
+ unsigned int num_lines;
+ int ret;
+
+ ret = kstrtouint(page, 0, &num_lines);
+ if (ret)
+ return ret;
+
+ if (num_lines == 0)
+ return -EINVAL;
+
+ mutex_lock(&dev->lock);
+
+ if (gpio_sim_device_is_live_unlocked(dev)) {
+ mutex_unlock(&dev->lock);
+ return -EBUSY;
+ }
+
+ bank->num_lines = num_lines;
+
+ mutex_unlock(&dev->lock);
+ return count;
+}
+
+CONFIGFS_ATTR(gpio_sim_bank_config_, num_lines);
+
+static struct configfs_attribute *gpio_sim_bank_config_attrs[] = {
+ &gpio_sim_bank_config_attr_chip_name,
+ &gpio_sim_bank_config_attr_label,
+ &gpio_sim_bank_config_attr_num_lines,
+ NULL
+};
+
+static ssize_t
+gpio_sim_line_config_name_show(struct config_item *item, char *page)
+{
+ struct gpio_sim_line *line = to_gpio_sim_line(item);
+ struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
+ int ret;
+
+ mutex_lock(&dev->lock);
+ ret = sprintf(page, "%s\n", line->name ?: "");
+ mutex_unlock(&dev->lock);
+
+ return ret;
+}
+
+static ssize_t gpio_sim_line_config_name_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ struct gpio_sim_line *line = to_gpio_sim_line(item);
+ struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
+ char *trimmed;
+
+ mutex_lock(&dev->lock);
+
+ if (gpio_sim_device_is_live_unlocked(dev)) {
+ mutex_unlock(&dev->lock);
+ return -EBUSY;
+ }
+
+ trimmed = gpio_sim_strdup_trimmed(page, count);
+ if (!trimmed) {
+ mutex_unlock(&dev->lock);
+ return -ENOMEM;
+ }
+
+ kfree(line->name);
+ line->name = trimmed;
+
+ mutex_unlock(&dev->lock);
+
+ return count;
+}
+
+CONFIGFS_ATTR(gpio_sim_line_config_, name);
+
+static struct configfs_attribute *gpio_sim_line_config_attrs[] = {
+ &gpio_sim_line_config_attr_name,
+ NULL
+};
+
+static ssize_t gpio_sim_hog_config_name_show(struct config_item *item,
+ char *page)
+{
+ struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
+ struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
+ int ret;
+
+ mutex_lock(&dev->lock);
+ ret = sprintf(page, "%s\n", hog->name ?: "");
+ mutex_unlock(&dev->lock);
+
+ return ret;
+}
+
+static ssize_t gpio_sim_hog_config_name_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
+ struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
+ char *trimmed;
+
+ mutex_lock(&dev->lock);
+
+ if (gpio_sim_device_is_live_unlocked(dev)) {
+ mutex_unlock(&dev->lock);
+ return -EBUSY;
+ }
+
+ trimmed = gpio_sim_strdup_trimmed(page, count);
+ if (!trimmed) {
+ mutex_unlock(&dev->lock);
+ return -ENOMEM;
+ }
+
+ kfree(hog->name);
+ hog->name = trimmed;
+
+ mutex_unlock(&dev->lock);
+
+ return count;
+}
+
+CONFIGFS_ATTR(gpio_sim_hog_config_, name);
+
+static ssize_t gpio_sim_hog_config_direction_show(struct config_item *item,
+ char *page)
+{
+ struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
+ struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
+ char *repr;
+ int dir;
+
+ mutex_lock(&dev->lock);
+ dir = hog->dir;
+ mutex_unlock(&dev->lock);
+
+ switch (dir) {
+ case GPIOD_IN:
+ repr = "input";
+ break;
+ case GPIOD_OUT_HIGH:
+ repr = "output-high";
+ break;
+ case GPIOD_OUT_LOW:
+ repr = "output-low";
+ break;
+ default:
+ /* This would be a programmer bug. */
+ WARN(1, "Unexpected hog direction value: %d", dir);
+ return -EINVAL;
+ }
+
+ return sprintf(page, "%s\n", repr);
+}
+
+static ssize_t
+gpio_sim_hog_config_direction_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
+ struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
+ char *trimmed;
+ int dir;
+
+ mutex_lock(&dev->lock);
+
+ if (gpio_sim_device_is_live_unlocked(dev)) {
+ mutex_unlock(&dev->lock);
+ return -EBUSY;
+ }
+
+ trimmed = gpio_sim_strdup_trimmed(page, count);
+ if (!trimmed) {
+ mutex_unlock(&dev->lock);
+ return -ENOMEM;
+ }
+
+ if (strcmp(trimmed, "input") == 0)
+ dir = GPIOD_IN;
+ else if (strcmp(trimmed, "output-high") == 0)
+ dir = GPIOD_OUT_HIGH;
+ else if (strcmp(trimmed, "output-low") == 0)
+ dir = GPIOD_OUT_LOW;
+ else
+ dir = -EINVAL;
+
+ kfree(trimmed);
+
+ if (dir < 0) {
+ mutex_unlock(&dev->lock);
+ return dir;
+ }
+
+ hog->dir = dir;
+
+ mutex_unlock(&dev->lock);
+
+ return count;
+}
+
+CONFIGFS_ATTR(gpio_sim_hog_config_, direction);
+
+static struct configfs_attribute *gpio_sim_hog_config_attrs[] = {
+ &gpio_sim_hog_config_attr_name,
+ &gpio_sim_hog_config_attr_direction,
+ NULL
+};
+
+static void gpio_sim_hog_config_item_release(struct config_item *item)
+{
+ struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
+ struct gpio_sim_line *line = hog->parent;
+ struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
+
+ mutex_lock(&dev->lock);
+ line->hog = NULL;
+ mutex_unlock(&dev->lock);
+
+ kfree(hog->name);
+ kfree(hog);
+}
+
+struct configfs_item_operations gpio_sim_hog_config_item_ops = {
+ .release = gpio_sim_hog_config_item_release,
+};
+
+static const struct config_item_type gpio_sim_hog_config_type = {
+ .ct_item_ops = &gpio_sim_hog_config_item_ops,
+ .ct_attrs = gpio_sim_hog_config_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct config_item *
+gpio_sim_line_config_make_hog_item(struct config_group *group, const char *name)
+{
+ struct gpio_sim_line *line = to_gpio_sim_line(&group->cg_item);
+ struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
+ struct gpio_sim_hog *hog;
+
+ if (strcmp(name, "hog") != 0)
+ return ERR_PTR(-EINVAL);
+
+ mutex_lock(&dev->lock);
+
+ hog = kzalloc(sizeof(*hog), GFP_KERNEL);
+ if (!hog) {
+ mutex_unlock(&dev->lock);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ config_item_init_type_name(&hog->item, name,
+ &gpio_sim_hog_config_type);
+
+ hog->dir = GPIOD_IN;
+ hog->name = NULL;
+ hog->parent = line;
+ line->hog = hog;
+
+ mutex_unlock(&dev->lock);
+
+ return &hog->item;
+}
+
+static void gpio_sim_line_config_group_release(struct config_item *item)
+{
+ struct gpio_sim_line *line = to_gpio_sim_line(item);
+ struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
+
+ mutex_lock(&dev->lock);
+ list_del(&line->siblings);
+ mutex_unlock(&dev->lock);
+
+ kfree(line->name);
+ kfree(line);
+}
+
+static struct configfs_item_operations gpio_sim_line_config_item_ops = {
+ .release = gpio_sim_line_config_group_release,
+};
+
+static struct configfs_group_operations gpio_sim_line_config_group_ops = {
+ .make_item = gpio_sim_line_config_make_hog_item,
+};
+
+static const struct config_item_type gpio_sim_line_config_type = {
+ .ct_item_ops = &gpio_sim_line_config_item_ops,
+ .ct_group_ops = &gpio_sim_line_config_group_ops,
+ .ct_attrs = gpio_sim_line_config_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct config_group *
+gpio_sim_bank_config_make_line_group(struct config_group *group,
+ const char *name)
+{
+ struct gpio_sim_bank *bank = to_gpio_sim_bank(&group->cg_item);
+ struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
+ struct gpio_sim_line *line;
+ unsigned int offset;
+ int ret, nchar;
+
+ ret = sscanf(name, "line%u%n", &offset, &nchar);
+ if (ret != 1 || nchar != strlen(name))
+ return ERR_PTR(-EINVAL);
+
+ mutex_lock(&dev->lock);
+
+ if (gpio_sim_device_is_live_unlocked(dev)) {
+ mutex_unlock(&dev->lock);
+ return ERR_PTR(-EBUSY);
+ }
+
+ line = kzalloc(sizeof(*line), GFP_KERNEL);
+ if (!line) {
+ mutex_unlock(&dev->lock);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ config_group_init_type_name(&line->group, name,
+ &gpio_sim_line_config_type);
+
+ line->parent = bank;
+ line->offset = offset;
+ list_add_tail(&line->siblings, &bank->line_list);
+
+ mutex_unlock(&dev->lock);
+
+ return &line->group;
+}
+
+static void gpio_sim_bank_config_group_release(struct config_item *item)
+{
+ struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
+ struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
+
+ mutex_lock(&dev->lock);
+ list_del(&bank->siblings);
+ mutex_unlock(&dev->lock);
+
+ kfree(bank->label);
+ kfree(bank);
+}
+
+static struct configfs_item_operations gpio_sim_bank_config_item_ops = {
+ .release = gpio_sim_bank_config_group_release,
+};
+
+static struct configfs_group_operations gpio_sim_bank_config_group_ops = {
+ .make_group = gpio_sim_bank_config_make_line_group,
+};
+
+static const struct config_item_type gpio_sim_bank_config_group_type = {
+ .ct_item_ops = &gpio_sim_bank_config_item_ops,
+ .ct_group_ops = &gpio_sim_bank_config_group_ops,
+ .ct_attrs = gpio_sim_bank_config_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct config_group *
+gpio_sim_device_config_make_bank_group(struct config_group *group,
+ const char *name)
+{
+ struct gpio_sim_device *dev = to_gpio_sim_device(&group->cg_item);
+ struct gpio_sim_bank *bank;
+
+ mutex_lock(&dev->lock);
+
+ if (gpio_sim_device_is_live_unlocked(dev)) {
+ mutex_unlock(&dev->lock);
+ return ERR_PTR(-EBUSY);
+ }
+
+ bank = kzalloc(sizeof(*bank), GFP_KERNEL);
+ if (!bank) {
+ mutex_unlock(&dev->lock);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ config_group_init_type_name(&bank->group, name,
+ &gpio_sim_bank_config_group_type);
+ bank->num_lines = 1;
+ bank->parent = dev;
+ INIT_LIST_HEAD(&bank->line_list);
+ list_add_tail(&bank->siblings, &dev->bank_list);
+
+ mutex_unlock(&dev->lock);
+
+ return &bank->group;
+}
+
+static void gpio_sim_device_config_group_release(struct config_item *item)
+{
+ struct gpio_sim_device *dev = to_gpio_sim_device(item);
+
+ mutex_lock(&dev->lock);
+ if (gpio_sim_device_is_live_unlocked(dev))
+ gpio_sim_device_deactivate_unlocked(dev);
+ mutex_unlock(&dev->lock);
+
+ mutex_destroy(&dev->lock);
+ ida_free(&gpio_sim_ida, dev->id);
+ kfree(dev);
+}
+
+static struct configfs_item_operations gpio_sim_device_config_item_ops = {
+ .release = gpio_sim_device_config_group_release,
+};
+
+static struct configfs_group_operations gpio_sim_device_config_group_ops = {
+ .make_group = gpio_sim_device_config_make_bank_group,
+};
+
+static const struct config_item_type gpio_sim_device_config_group_type = {
+ .ct_item_ops = &gpio_sim_device_config_item_ops,
+ .ct_group_ops = &gpio_sim_device_config_group_ops,
+ .ct_attrs = gpio_sim_device_config_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct config_group *
+gpio_sim_config_make_device_group(struct config_group *group, const char *name)
+{
+ struct gpio_sim_device *dev;
+ int id;
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return ERR_PTR(-ENOMEM);
+
+ id = ida_alloc(&gpio_sim_ida, GFP_KERNEL);
+ if (id < 0) {
+ kfree(dev);
+ return ERR_PTR(id);
+ }
+
+ config_group_init_type_name(&dev->group, name,
+ &gpio_sim_device_config_group_type);
+ dev->id = id;
+ mutex_init(&dev->lock);
+ INIT_LIST_HEAD(&dev->bank_list);
+
+ dev->bus_notifier.notifier_call = gpio_sim_bus_notifier_call;
+ init_completion(&dev->probe_completion);
+
+ return &dev->group;
+}
+
+static struct configfs_group_operations gpio_sim_config_group_ops = {
+ .make_group = gpio_sim_config_make_device_group,
+};
+
+static const struct config_item_type gpio_sim_config_type = {
+ .ct_group_ops = &gpio_sim_config_group_ops,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct configfs_subsystem gpio_sim_config_subsys = {
+ .su_group = {
+ .cg_item = {
+ .ci_namebuf = "gpio-sim",
+ .ci_type = &gpio_sim_config_type,
+ },
+ },
+};
+
+static int __init gpio_sim_init(void)
+{
+ int ret;
+
+ ret = platform_driver_register(&gpio_sim_driver);
+ if (ret) {
+ pr_err("Error %d while registering the platform driver\n", ret);
+ return ret;
+ }
+
+ config_group_init(&gpio_sim_config_subsys.su_group);
+ mutex_init(&gpio_sim_config_subsys.su_mutex);
+ ret = configfs_register_subsystem(&gpio_sim_config_subsys);
+ if (ret) {
+ pr_err("Error %d while registering the configfs subsystem %s\n",
+ ret, gpio_sim_config_subsys.su_group.cg_item.ci_namebuf);
+ mutex_destroy(&gpio_sim_config_subsys.su_mutex);
+ platform_driver_unregister(&gpio_sim_driver);
+ return ret;
+ }
+
+ return 0;
+}
+module_init(gpio_sim_init);
+
+static void __exit gpio_sim_exit(void)
+{
+ configfs_unregister_subsystem(&gpio_sim_config_subsys);
+ mutex_destroy(&gpio_sim_config_subsys.su_mutex);
+ platform_driver_unregister(&gpio_sim_driver);
+}
+module_exit(gpio_sim_exit);
+
+MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl");
+MODULE_DESCRIPTION("GPIO Simulator Module");
+MODULE_LICENSE("GPL");
--
2.25.1
^ permalink raw reply related [flat|nested] 14+ messages in thread
* [PATCH v13 5/7] selftests: gpio: provide a helper for reading chip info
2021-12-07 9:34 [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator Bartosz Golaszewski
` (3 preceding siblings ...)
2021-12-07 9:34 ` [PATCH v13 4/7] gpio: sim: new testing module Bartosz Golaszewski
@ 2021-12-07 9:34 ` Bartosz Golaszewski
2021-12-07 9:34 ` [PATCH v13 6/7] selftests: gpio: add a helper for reading GPIO line names Bartosz Golaszewski
` (2 subsequent siblings)
7 siblings, 0 replies; 14+ messages in thread
From: Bartosz Golaszewski @ 2021-12-07 9:34 UTC (permalink / raw)
To: Kent Gibson, Linus Walleij, Andy Shevchenko, Shuah Khan,
Geert Uytterhoeven, Viresh Kumar
Cc: linux-gpio, linux-kernel, linux-kselftest, Bartosz Golaszewski
Add a simple program that allows to retrieve chip properties from the
GPIO character device. This will be used in gpio-sim selftests.
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
---
tools/testing/selftests/gpio/.gitignore | 1 +
tools/testing/selftests/gpio/Makefile | 2 +-
tools/testing/selftests/gpio/gpio-chip-info.c | 57 +++++++++++++++++++
3 files changed, 59 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/gpio/gpio-chip-info.c
diff --git a/tools/testing/selftests/gpio/.gitignore b/tools/testing/selftests/gpio/.gitignore
index a4969f7ee020..4ea4f58dab1a 100644
--- a/tools/testing/selftests/gpio/.gitignore
+++ b/tools/testing/selftests/gpio/.gitignore
@@ -1,2 +1,3 @@
# SPDX-License-Identifier: GPL-2.0-only
gpio-mockup-cdev
+gpio-chip-info
diff --git a/tools/testing/selftests/gpio/Makefile b/tools/testing/selftests/gpio/Makefile
index d7b312b44a62..a40b818c394e 100644
--- a/tools/testing/selftests/gpio/Makefile
+++ b/tools/testing/selftests/gpio/Makefile
@@ -2,7 +2,7 @@
TEST_PROGS := gpio-mockup.sh
TEST_FILES := gpio-mockup-sysfs.sh
-TEST_GEN_PROGS_EXTENDED := gpio-mockup-cdev
+TEST_GEN_PROGS_EXTENDED := gpio-mockup-cdev gpio-chip-info
CFLAGS += -O2 -g -Wall -I../../../../usr/include/
include ../lib.mk
diff --git a/tools/testing/selftests/gpio/gpio-chip-info.c b/tools/testing/selftests/gpio/gpio-chip-info.c
new file mode 100644
index 000000000000..fdc07e742fba
--- /dev/null
+++ b/tools/testing/selftests/gpio/gpio-chip-info.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * GPIO character device helper for reading chip information.
+ *
+ * Copyright (C) 2021 Bartosz Golaszewski <brgl@bgdev.pl>
+ */
+
+#include <fcntl.h>
+#include <linux/gpio.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+
+static void print_usage(void)
+{
+ printf("usage:\n");
+ printf(" gpio-chip-info <chip path> [name|label|num-lines]\n");
+}
+
+int main(int argc, char **argv)
+{
+ struct gpiochip_info info;
+ int fd, ret;
+
+ if (argc != 3) {
+ print_usage();
+ return EXIT_FAILURE;
+ }
+
+ fd = open(argv[1], O_RDWR);
+ if (fd < 0) {
+ perror("unable to open the GPIO chip");
+ return EXIT_FAILURE;
+ }
+
+ memset(&info, 0, sizeof(info));
+ ret = ioctl(fd, GPIO_GET_CHIPINFO_IOCTL, &info);
+ if (ret) {
+ perror("chip info ioctl failed");
+ return EXIT_FAILURE;
+ }
+
+ if (strcmp(argv[2], "name") == 0) {
+ printf("%s\n", info.name);
+ } else if (strcmp(argv[2], "label") == 0) {
+ printf("%s\n", info.label);
+ } else if (strcmp(argv[2], "num-lines") == 0) {
+ printf("%u\n", info.lines);
+ } else {
+ fprintf(stderr, "unknown command: %s\n", argv[2]);
+ return EXIT_FAILURE;
+ }
+
+ return EXIT_SUCCESS;
+}
--
2.25.1
^ permalink raw reply related [flat|nested] 14+ messages in thread
* [PATCH v13 6/7] selftests: gpio: add a helper for reading GPIO line names
2021-12-07 9:34 [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator Bartosz Golaszewski
` (4 preceding siblings ...)
2021-12-07 9:34 ` [PATCH v13 5/7] selftests: gpio: provide a helper for reading chip info Bartosz Golaszewski
@ 2021-12-07 9:34 ` Bartosz Golaszewski
2021-12-07 9:34 ` [PATCH v13 7/7] selftests: gpio: add test cases for gpio-sim Bartosz Golaszewski
2021-12-09 0:54 ` [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator Linus Walleij
7 siblings, 0 replies; 14+ messages in thread
From: Bartosz Golaszewski @ 2021-12-07 9:34 UTC (permalink / raw)
To: Kent Gibson, Linus Walleij, Andy Shevchenko, Shuah Khan,
Geert Uytterhoeven, Viresh Kumar
Cc: linux-gpio, linux-kernel, linux-kselftest, Bartosz Golaszewski
Add a simple program that allows to read GPIO line names from the
character device. This will be used in gpio-sim selftests.
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
---
tools/testing/selftests/gpio/.gitignore | 1 +
tools/testing/selftests/gpio/Makefile | 2 +-
tools/testing/selftests/gpio/gpio-line-name.c | 55 +++++++++++++++++++
3 files changed, 57 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/gpio/gpio-line-name.c
diff --git a/tools/testing/selftests/gpio/.gitignore b/tools/testing/selftests/gpio/.gitignore
index 4ea4f58dab1a..ededb077a3a6 100644
--- a/tools/testing/selftests/gpio/.gitignore
+++ b/tools/testing/selftests/gpio/.gitignore
@@ -1,3 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
gpio-mockup-cdev
gpio-chip-info
+gpio-line-name
diff --git a/tools/testing/selftests/gpio/Makefile b/tools/testing/selftests/gpio/Makefile
index a40b818c394e..293aa9749408 100644
--- a/tools/testing/selftests/gpio/Makefile
+++ b/tools/testing/selftests/gpio/Makefile
@@ -2,7 +2,7 @@
TEST_PROGS := gpio-mockup.sh
TEST_FILES := gpio-mockup-sysfs.sh
-TEST_GEN_PROGS_EXTENDED := gpio-mockup-cdev gpio-chip-info
+TEST_GEN_PROGS_EXTENDED := gpio-mockup-cdev gpio-chip-info gpio-line-name
CFLAGS += -O2 -g -Wall -I../../../../usr/include/
include ../lib.mk
diff --git a/tools/testing/selftests/gpio/gpio-line-name.c b/tools/testing/selftests/gpio/gpio-line-name.c
new file mode 100644
index 000000000000..e635cfadbded
--- /dev/null
+++ b/tools/testing/selftests/gpio/gpio-line-name.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * GPIO character device helper for reading line names.
+ *
+ * Copyright (C) 2021 Bartosz Golaszewski <brgl@bgdev.pl>
+ */
+
+#include <fcntl.h>
+#include <linux/gpio.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+
+static void print_usage(void)
+{
+ printf("usage:\n");
+ printf(" gpio-line-name <chip path> <line offset>\n");
+}
+
+int main(int argc, char **argv)
+{
+ struct gpio_v2_line_info info;
+ int fd, ret;
+ char *endp;
+
+ if (argc != 3) {
+ print_usage();
+ return EXIT_FAILURE;
+ }
+
+ fd = open(argv[1], O_RDWR);
+ if (fd < 0) {
+ perror("unable to open the GPIO chip");
+ return EXIT_FAILURE;
+ }
+
+ memset(&info, 0, sizeof(info));
+ info.offset = strtoul(argv[2], &endp, 10);
+ if (*endp != '\0') {
+ print_usage();
+ return EXIT_FAILURE;
+ }
+
+ ret = ioctl(fd, GPIO_V2_GET_LINEINFO_IOCTL, &info);
+ if (ret) {
+ perror("line info ioctl failed");
+ return EXIT_FAILURE;
+ }
+
+ printf("%s\n", info.name);
+
+ return EXIT_SUCCESS;
+}
--
2.25.1
^ permalink raw reply related [flat|nested] 14+ messages in thread
* [PATCH v13 7/7] selftests: gpio: add test cases for gpio-sim
2021-12-07 9:34 [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator Bartosz Golaszewski
` (5 preceding siblings ...)
2021-12-07 9:34 ` [PATCH v13 6/7] selftests: gpio: add a helper for reading GPIO line names Bartosz Golaszewski
@ 2021-12-07 9:34 ` Bartosz Golaszewski
2021-12-09 0:54 ` [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator Linus Walleij
7 siblings, 0 replies; 14+ messages in thread
From: Bartosz Golaszewski @ 2021-12-07 9:34 UTC (permalink / raw)
To: Kent Gibson, Linus Walleij, Andy Shevchenko, Shuah Khan,
Geert Uytterhoeven, Viresh Kumar
Cc: linux-gpio, linux-kernel, linux-kselftest, Bartosz Golaszewski
Add a set of tests for the new gpio-sim module. This is a pure shell
test-suite and uses the helper programs available in the gpio selftests
directory. These test-cases only test the functionalities exposed by the
gpio-sim driver, not those handled by core gpiolib code.
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
---
tools/testing/selftests/gpio/Makefile | 2 +-
tools/testing/selftests/gpio/config | 1 +
tools/testing/selftests/gpio/gpio-sim.sh | 396 +++++++++++++++++++++++
3 files changed, 398 insertions(+), 1 deletion(-)
create mode 100755 tools/testing/selftests/gpio/gpio-sim.sh
diff --git a/tools/testing/selftests/gpio/Makefile b/tools/testing/selftests/gpio/Makefile
index 293aa9749408..71b306602368 100644
--- a/tools/testing/selftests/gpio/Makefile
+++ b/tools/testing/selftests/gpio/Makefile
@@ -1,6 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
-TEST_PROGS := gpio-mockup.sh
+TEST_PROGS := gpio-mockup.sh gpio-sim.sh
TEST_FILES := gpio-mockup-sysfs.sh
TEST_GEN_PROGS_EXTENDED := gpio-mockup-cdev gpio-chip-info gpio-line-name
CFLAGS += -O2 -g -Wall -I../../../../usr/include/
diff --git a/tools/testing/selftests/gpio/config b/tools/testing/selftests/gpio/config
index ce100342c20b..409a8532facc 100644
--- a/tools/testing/selftests/gpio/config
+++ b/tools/testing/selftests/gpio/config
@@ -1,3 +1,4 @@
CONFIG_GPIOLIB=y
CONFIG_GPIO_CDEV=y
CONFIG_GPIO_MOCKUP=m
+CONFIG_GPIO_SIM=m
diff --git a/tools/testing/selftests/gpio/gpio-sim.sh b/tools/testing/selftests/gpio/gpio-sim.sh
new file mode 100755
index 000000000000..d335a975890c
--- /dev/null
+++ b/tools/testing/selftests/gpio/gpio-sim.sh
@@ -0,0 +1,396 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2021 Bartosz Golaszewski <brgl@bgdev.pl>
+
+BASE_DIR=`dirname $0`
+CONFIGFS_DIR="/sys/kernel/config/gpio-sim"
+MODULE="gpio-sim"
+
+fail() {
+ echo "$*" >&2
+ echo "GPIO $MODULE test FAIL"
+ exit 1
+}
+
+skip() {
+ echo "$*" >&2
+ echo "GPIO $MODULE test SKIP"
+ exit 4
+}
+
+remove_chip() {
+ local CHIP=$1
+
+ for FILE in $CONFIGFS_DIR/$CHIP/*; do
+ BANK=`basename $FILE`
+ if [ "$BANK" == "live" ] || [ "$BANK" == "dev_name" ]; then
+ continue
+ fi
+
+ LINES=`ls $CONFIGFS_DIR/$CHIP/$BANK/ | egrep ^line`
+ if [ "$?" == 0 ]; then
+ for LINE in $LINES; do
+ if [ -e $CONFIGFS_DIR/$CHIP/$BANK/$LINE/hog ]; then
+ rmdir $CONFIGFS_DIR/$CHIP/$BANK/$LINE/hog || \
+ fail "Unable to remove the hog"
+ fi
+
+ rmdir $CONFIGFS_DIR/$CHIP/$BANK/$LINE || \
+ fail "Unable to remove the line"
+ done
+ fi
+
+ rmdir $CONFIGFS_DIR/$CHIP/$BANK
+ done
+
+ rmdir $CONFIGFS_DIR/$CHIP || fail "Unable to remove the chip"
+}
+
+configfs_cleanup() {
+ for CHIP in `ls $CONFIGFS_DIR/`; do
+ remove_chip $CHIP
+ done
+}
+
+create_chip() {
+ local CHIP=$1
+
+ mkdir $CONFIGFS_DIR/$CHIP
+}
+
+create_bank() {
+ local CHIP=$1
+ local BANK=$2
+
+ mkdir $CONFIGFS_DIR/$CHIP/$BANK
+}
+
+set_label() {
+ local CHIP=$1
+ local BANK=$2
+ local LABEL=$3
+
+ echo $LABEL > $CONFIGFS_DIR/$CHIP/$BANK/label || fail "Unable to set the chip label"
+}
+
+set_num_lines() {
+ local CHIP=$1
+ local BANK=$2
+ local NUM_LINES=$3
+
+ echo $NUM_LINES > $CONFIGFS_DIR/$CHIP/$BANK/num_lines || \
+ fail "Unable to set the number of lines"
+}
+
+set_line_name() {
+ local CHIP=$1
+ local BANK=$2
+ local OFFSET=$3
+ local NAME=$4
+ local LINE_DIR=$CONFIGFS_DIR/$CHIP/$BANK/line$OFFSET
+
+ test -d $LINE_DIR || mkdir $LINE_DIR
+ echo $NAME > $LINE_DIR/name || fail "Unable to set the line name"
+}
+
+enable_chip() {
+ local CHIP=$1
+
+ echo 1 > $CONFIGFS_DIR/$CHIP/live || fail "Unable to enable the chip"
+}
+
+disable_chip() {
+ local CHIP=$1
+
+ echo 0 > $CONFIGFS_DIR/$CHIP/live || fail "Unable to disable the chip"
+}
+
+configfs_chip_name() {
+ local CHIP=$1
+ local BANK=$2
+
+ cat $CONFIGFS_DIR/$CHIP/$BANK/chip_name 2> /dev/null || \
+ fail "unable to read the chip name from configfs"
+}
+
+configfs_dev_name() {
+ local CHIP=$1
+
+ cat $CONFIGFS_DIR/$CHIP/dev_name 2> /dev/null || \
+ fail "unable to read the device name from configfs"
+}
+
+get_chip_num_lines() {
+ local CHIP=$1
+ local BANK=$2
+
+ $BASE_DIR/gpio-chip-info /dev/`configfs_chip_name $CHIP $BANK` num-lines || \
+ fail "unable to read the number of lines from the character device"
+}
+
+get_chip_label() {
+ local CHIP=$1
+ local BANK=$2
+
+ $BASE_DIR/gpio-chip-info /dev/`configfs_chip_name $CHIP $BANK` label || \
+ fail "unable to read the chip label from the character device"
+}
+
+get_line_name() {
+ local CHIP=$1
+ local BANK=$2
+ local OFFSET=$3
+
+ $BASE_DIR/gpio-line-name /dev/`configfs_chip_name $CHIP $BANK` $OFFSET || \
+ fail "unable to read the line name from the character device"
+}
+
+sysfs_set_pull() {
+ local DEV=$1
+ local BANK=$2
+ local OFFSET=$3
+ local PULL=$4
+ local DEVNAME=`configfs_dev_name $DEV`
+ local CHIPNAME=`configfs_chip_name $DEV $BANK`
+ local SYSFSPATH="/sys/devices/platform/$DEVNAME/$CHIPNAME/sim_gpio$OFFSET/pull"
+
+ echo $PULL > $SYSFSPATH || fail "Unable to set line pull in sysfs"
+}
+
+# Load the gpio-sim module. This will pull in configfs if needed too.
+modprobe gpio-sim || skip "unable to load the gpio-sim module"
+# Make sure configfs is mounted at /sys/kernel/config. Wait a bit if needed.
+for IDX in `seq 5`; do
+ if [ "$IDX" -eq "5" ]; then
+ skip "configfs not mounted at /sys/kernel/config"
+ fi
+
+ mountpoint -q /sys/kernel/config && break
+ sleep 0.1
+done
+# If the module was already loaded: remove all previous chips
+configfs_cleanup
+
+trap "exit 1" SIGTERM SIGINT
+trap configfs_cleanup EXIT
+
+echo "1. chip_name and dev_name attributes"
+
+echo "1.1. Chip name is communicated to user"
+create_chip chip
+create_bank chip bank
+enable_chip chip
+test -n `cat $CONFIGFS_DIR/chip/bank/chip_name` || fail "chip_name doesn't work"
+remove_chip chip
+
+echo "1.2. chip_name returns 'none' if the chip is still pending"
+create_chip chip
+create_bank chip bank
+test "`cat $CONFIGFS_DIR/chip/bank/chip_name`" = "none" || \
+ fail "chip_name doesn't return 'none' for a pending chip"
+remove_chip chip
+
+echo "1.3. Device name is communicated to user"
+create_chip chip
+create_bank chip bank
+enable_chip chip
+test -n `cat $CONFIGFS_DIR/chip/dev_name` || fail "dev_name doesn't work"
+remove_chip chip
+
+echo "2. Creating and configuring simulated chips"
+
+echo "2.1. Default number of lines is 1"
+create_chip chip
+create_bank chip bank
+enable_chip chip
+test "`get_chip_num_lines chip bank`" = "1" || fail "default number of lines is not 1"
+remove_chip chip
+
+echo "2.2. Number of lines can be specified"
+create_chip chip
+create_bank chip bank
+set_num_lines chip bank 16
+enable_chip chip
+test "`get_chip_num_lines chip bank`" = "16" || fail "number of lines is not 16"
+remove_chip chip
+
+echo "2.3. Label can be set"
+create_chip chip
+create_bank chip bank
+set_label chip bank foobar
+enable_chip chip
+test "`get_chip_label chip bank`" = "foobar" || fail "label is incorrect"
+remove_chip chip
+
+echo "2.4. Label can be left empty"
+create_chip chip
+create_bank chip bank
+enable_chip chip
+test -z "`cat $CONFIGFS_DIR/chip/bank/label`" || fail "label is not empty"
+remove_chip chip
+
+echo "2.5. Line names can be configured"
+create_chip chip
+create_bank chip bank
+set_num_lines chip bank 16
+set_line_name chip bank 0 foo
+set_line_name chip bank 2 bar
+enable_chip chip
+test "`get_line_name chip bank 0`" = "foo" || fail "line name is incorrect"
+test "`get_line_name chip bank 2`" = "bar" || fail "line name is incorrect"
+remove_chip chip
+
+echo "2.6. Line config can remain unused if offset is greater than number of lines"
+create_chip chip
+create_bank chip bank
+set_num_lines chip bank 2
+set_line_name chip bank 5 foobar
+enable_chip chip
+test "`get_line_name chip bank 0`" = "" || fail "line name is incorrect"
+test "`get_line_name chip bank 1`" = "" || fail "line name is incorrect"
+remove_chip chip
+
+echo "2.7. Line configfs directory names are sanitized"
+create_chip chip
+create_bank chip bank
+mkdir $CONFIGFS_DIR/chip/bank/line12foobar 2> /dev/null && \
+ fail "invalid configfs line name accepted"
+mkdir $CONFIGFS_DIR/chip/bank/line_no_offset 2> /dev/null && \
+ fail "invalid configfs line name accepted"
+remove_chip chip
+
+echo "2.8. Multiple chips can be created"
+CHIPS="chip0 chip1 chip2"
+for CHIP in $CHIPS; do
+ create_chip $CHIP
+ create_bank $CHIP bank
+ enable_chip $CHIP
+done
+for CHIP in $CHIPS; do
+ remove_chip $CHIP
+done
+
+echo "2.9. Can't modify settings when chip is live"
+create_chip chip
+create_bank chip bank
+enable_chip chip
+echo foobar > $CONFIGFS_DIR/chip/bank/label 2> /dev/null && \
+ fail "Setting label of a live chip should fail"
+echo 8 > $CONFIGFS_DIR/chip/bank/num_lines 2> /dev/null && \
+ fail "Setting number of lines of a live chip should fail"
+remove_chip chip
+
+echo "2.10. Can't create line items when chip is live"
+create_chip chip
+create_bank chip bank
+enable_chip chip
+mkdir $CONFIGFS_DIR/chip/bank/line0 2> /dev/null && fail "Creating line item should fail"
+remove_chip chip
+
+echo "2.11. Probe errors are propagated to user-space"
+create_chip chip
+create_bank chip bank
+set_num_lines chip bank 99999
+echo 1 > $CONFIGFS_DIR/chip/live 2> /dev/null && fail "Probe error was not propagated"
+remove_chip chip
+
+echo "2.12. Cannot enable a chip without any GPIO banks"
+create_chip chip
+echo 1 > $CONFIGFS_DIR/chip/live 2> /dev/null && fail "Chip enabled without any GPIO banks"
+remove_chip chip
+
+echo "2.13. Duplicate chip labels are not allowed"
+create_chip chip
+create_bank chip bank0
+set_label chip bank0 foobar
+create_bank chip bank1
+set_label chip bank1 foobar
+echo 1 > $CONFIGFS_DIR/chip/live 2> /dev/null && fail "Duplicate chip labels were not rejected"
+remove_chip chip
+
+echo "2.14. Lines can be hogged"
+create_chip chip
+create_bank chip bank
+set_num_lines chip bank 8
+mkdir -p $CONFIGFS_DIR/chip/bank/line4/hog
+enable_chip chip
+$BASE_DIR/gpio-mockup-cdev -s 1 /dev/`configfs_chip_name chip bank` 4 2> /dev/null && \
+ fail "Setting the value of a hogged line shouldn't succeed"
+remove_chip chip
+
+echo "3. Controlling simulated chips"
+
+echo "3.1. Pull can be set over sysfs"
+create_chip chip
+create_bank chip bank
+set_num_lines chip bank 8
+enable_chip chip
+sysfs_set_pull chip bank 0 pull-up
+$BASE_DIR/gpio-mockup-cdev /dev/`configfs_chip_name chip bank` 0
+test "$?" = "1" || fail "pull set incorrectly"
+sysfs_set_pull chip bank 0 pull-down
+$BASE_DIR/gpio-mockup-cdev /dev/`configfs_chip_name chip bank` 1
+test "$?" = "0" || fail "pull set incorrectly"
+remove_chip chip
+
+echo "3.2. Pull can be read from sysfs"
+create_chip chip
+create_bank chip bank
+set_num_lines chip bank 8
+enable_chip chip
+DEVNAME=`configfs_dev_name chip`
+CHIPNAME=`configfs_chip_name chip bank`
+SYSFS_PATH=/sys/devices/platform/$DEVNAME/$CHIPNAME/sim_gpio0/pull
+test `cat $SYSFS_PATH` = "pull-down" || fail "reading the pull failed"
+sysfs_set_pull chip bank 0 pull-up
+test `cat $SYSFS_PATH` = "pull-up" || fail "reading the pull failed"
+remove_chip chip
+
+echo "3.3. Incorrect input in sysfs is rejected"
+create_chip chip
+create_bank chip bank
+set_num_lines chip bank 8
+enable_chip chip
+DEVNAME=`configfs_dev_name chip`
+CHIPNAME=`configfs_chip_name chip bank`
+SYSFS_PATH="/sys/devices/platform/$DEVNAME/$CHIPNAME/sim_gpio0/pull"
+echo foobar > $SYSFS_PATH 2> /dev/null && fail "invalid input not detected"
+remove_chip chip
+
+echo "3.4. Can't write to value"
+create_chip chip
+create_bank chip bank
+enable_chip chip
+DEVNAME=`configfs_dev_name chip`
+CHIPNAME=`configfs_chip_name chip bank`
+SYSFS_PATH="/sys/devices/platform/$DEVNAME/$CHIPNAME/sim_gpio0/value"
+echo 1 > $SYSFS_PATH 2> /dev/null && fail "writing to 'value' succeeded unexpectedly"
+remove_chip chip
+
+echo "4. Simulated GPIO chips are functional"
+
+echo "4.1. Values can be read from sysfs"
+create_chip chip
+create_bank chip bank
+set_num_lines chip bank 8
+enable_chip chip
+DEVNAME=`configfs_dev_name chip`
+CHIPNAME=`configfs_chip_name chip bank`
+SYSFS_PATH="/sys/devices/platform/$DEVNAME/$CHIPNAME/sim_gpio0/value"
+test `cat $SYSFS_PATH` = "0" || fail "incorrect value read from sysfs"
+$BASE_DIR/gpio-mockup-cdev -s 1 /dev/`configfs_chip_name chip bank` 0 &
+sleep 0.1 # FIXME Any better way?
+test `cat $SYSFS_PATH` = "1" || fail "incorrect value read from sysfs"
+kill $!
+remove_chip chip
+
+echo "4.2. Bias settings work correctly"
+create_chip chip
+create_bank chip bank
+set_num_lines chip bank 8
+enable_chip chip
+$BASE_DIR/gpio-mockup-cdev -b pull-up /dev/`configfs_chip_name chip bank` 0
+test `cat $SYSFS_PATH` = "1" || fail "bias setting does not work"
+remove_chip chip
+
+echo "GPIO $MODULE test PASS"
--
2.25.1
^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: [PATCH v13 2/7] gpiolib: allow to specify the firmware node in struct gpio_chip
2021-12-07 9:34 ` [PATCH v13 2/7] gpiolib: allow to specify the firmware node in struct gpio_chip Bartosz Golaszewski
@ 2021-12-07 12:24 ` Andy Shevchenko
0 siblings, 0 replies; 14+ messages in thread
From: Andy Shevchenko @ 2021-12-07 12:24 UTC (permalink / raw)
To: Bartosz Golaszewski
Cc: Kent Gibson, Linus Walleij, Shuah Khan, Geert Uytterhoeven,
Viresh Kumar, linux-gpio, linux-kernel, linux-kselftest
On Tue, Dec 07, 2021 at 10:34:07AM +0100, Bartosz Golaszewski wrote:
> Software nodes allow us to represent hierarchies for device components
> that don't have their struct device representation yet - for instance:
> banks of GPIOs under a common GPIO expander. The core gpiolib core
> however doesn't offer any way of passing this information from the
> drivers.
>
> This extends struct gpio_chip with a pointer to fwnode that can be set
> by the driver and used to pass device properties for child nodes.
>
> This is similar to how we handle device-tree sub-nodes with
> CONFIG_OF_GPIO enabled.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
> ---
> drivers/gpio/gpiolib.c | 7 ++++++-
> include/linux/gpio/driver.h | 2 ++
> 2 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 22b98a590a88..6af732bf4c99 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -593,13 +593,18 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
> struct lock_class_key *lock_key,
> struct lock_class_key *request_key)
> {
> - struct fwnode_handle *fwnode = gc->parent ? dev_fwnode(gc->parent) : NULL;
> + struct fwnode_handle *fwnode = NULL;
> unsigned long flags;
> int ret = 0;
> unsigned i;
> int base = gc->base;
> struct gpio_device *gdev;
>
> + if (gc->fwnode)
> + fwnode = gc->fwnode;
> + else if (gc->parent)
> + fwnode = dev_fwnode(gc->parent);
> +
> /*
> * First: allocate and populate the internal stat container, and
> * set up the struct device.
> diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
> index a673a359e20b..b0728c8ad90c 100644
> --- a/include/linux/gpio/driver.h
> +++ b/include/linux/gpio/driver.h
> @@ -289,6 +289,7 @@ struct gpio_irq_chip {
> * number or the name of the SoC IP-block implementing it.
> * @gpiodev: the internal state holder, opaque struct
> * @parent: optional parent device providing the GPIOs
> + * @fwnode: optional fwnode providing this controller's properties
> * @owner: helps prevent removal of modules exporting active GPIOs
> * @request: optional hook for chip-specific activation, such as
> * enabling module power and clock; may sleep
> @@ -377,6 +378,7 @@ struct gpio_chip {
> const char *label;
> struct gpio_device *gpiodev;
> struct device *parent;
> + struct fwnode_handle *fwnode;
> struct module *owner;
>
> int (*request)(struct gpio_chip *gc,
> --
> 2.25.1
>
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v13 3/7] gpiolib: of: make fwnode take precedence in struct gpio_chip
2021-12-07 9:34 ` [PATCH v13 3/7] gpiolib: of: make fwnode take precedence " Bartosz Golaszewski
@ 2021-12-07 12:24 ` Andy Shevchenko
0 siblings, 0 replies; 14+ messages in thread
From: Andy Shevchenko @ 2021-12-07 12:24 UTC (permalink / raw)
To: Bartosz Golaszewski
Cc: Kent Gibson, Linus Walleij, Shuah Khan, Geert Uytterhoeven,
Viresh Kumar, linux-gpio, linux-kernel, linux-kselftest
On Tue, Dec 07, 2021 at 10:34:08AM +0100, Bartosz Golaszewski wrote:
> If the driver sets the fwnode in struct gpio_chip, let it take
> precedence over the of_node. This only affects OF-based systems,
> ACPI needs to be converted separately.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Thanks!
> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
> ---
> drivers/gpio/gpiolib-of.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
> index 0ad288ab6262..91dcf2c6cdd8 100644
> --- a/drivers/gpio/gpiolib-of.c
> +++ b/drivers/gpio/gpiolib-of.c
> @@ -1046,6 +1046,9 @@ void of_gpio_dev_init(struct gpio_chip *gc, struct gpio_device *gdev)
> if (gc->parent)
> gdev->dev.of_node = gc->parent->of_node;
>
> + if (gc->fwnode)
> + gc->of_node = to_of_node(gc->fwnode);
> +
> /* If the gpiochip has an assigned OF node this takes precedence */
> if (gc->of_node)
> gdev->dev.of_node = gc->of_node;
> --
> 2.25.1
>
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v13 4/7] gpio: sim: new testing module
2021-12-07 9:34 ` [PATCH v13 4/7] gpio: sim: new testing module Bartosz Golaszewski
@ 2021-12-07 13:58 ` Andy Shevchenko
0 siblings, 0 replies; 14+ messages in thread
From: Andy Shevchenko @ 2021-12-07 13:58 UTC (permalink / raw)
To: Bartosz Golaszewski
Cc: Kent Gibson, Linus Walleij, Shuah Khan, Geert Uytterhoeven,
Viresh Kumar, linux-gpio, linux-kernel, linux-kselftest
On Tue, Dec 07, 2021 at 10:34:09AM +0100, Bartosz Golaszewski wrote:
> Implement a new, modern GPIO testing module controlled by configfs
> attributes instead of module parameters. The goal of this driver is
> to provide a replacement for gpio-mockup that will be easily extensible
> with new features and doesn't require reloading the module to change
> the setup.
A couple of nit-picks, you may fix without resend.
...
> +static const char *const gpio_sim_sysfs_pull_strings[] = {
> + [0] = "pull-down",
> + [1] = "pull-up"
+ Comma
> +};
> +
> +static ssize_t gpio_sim_sysfs_pull_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
> + struct gpio_sim_chip *chip = dev_get_drvdata(dev);
> + int pull;
> +
> + mutex_lock(&chip->lock);
> + pull = !!test_bit(line_attr->offset, chip->pull_map);
> + mutex_unlock(&chip->lock);
> +
> + return sysfs_emit(buf, "%s\n", gpio_sim_sysfs_pull_strings[pull]);
> +}
> +
> +static ssize_t gpio_sim_sysfs_pull_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
> + struct gpio_sim_chip *chip = dev_get_drvdata(dev);
> + int ret, pull;
> +
> + pull = sysfs_match_string(gpio_sim_sysfs_pull_strings, buf);
> + if (pull < 0)
> + return -EINVAL;
return pull;
> +
> + ret = gpio_sim_apply_pull(chip, line_attr->offset, pull);
> + if (ret)
> + return ret;
> +
> + return len;
> +}
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator
2021-12-07 9:34 [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator Bartosz Golaszewski
` (6 preceding siblings ...)
2021-12-07 9:34 ` [PATCH v13 7/7] selftests: gpio: add test cases for gpio-sim Bartosz Golaszewski
@ 2021-12-09 0:54 ` Linus Walleij
2021-12-10 19:08 ` Bartosz Golaszewski
7 siblings, 1 reply; 14+ messages in thread
From: Linus Walleij @ 2021-12-09 0:54 UTC (permalink / raw)
To: Bartosz Golaszewski
Cc: Kent Gibson, Andy Shevchenko, Shuah Khan, Geert Uytterhoeven,
Viresh Kumar, linux-gpio, linux-kernel, linux-kselftest
On Tue, Dec 7, 2021 at 10:34 AM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> Hopefully this will be the last iteration of this series. Just some
> minor changes requested by Andy in this one.
>
> Tested both with configfs as well as device-tree.
This patch set:
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Thanks for your perseverance!!
Yours,
Linus Walleij
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator
2021-12-09 0:54 ` [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator Linus Walleij
@ 2021-12-10 19:08 ` Bartosz Golaszewski
2021-12-13 13:01 ` Bartosz Golaszewski
0 siblings, 1 reply; 14+ messages in thread
From: Bartosz Golaszewski @ 2021-12-10 19:08 UTC (permalink / raw)
To: Linus Walleij
Cc: Kent Gibson, Andy Shevchenko, Shuah Khan, Geert Uytterhoeven,
Viresh Kumar, open list:GPIO SUBSYSTEM,
Linux Kernel Mailing List, linux-kselftest
On Thu, Dec 9, 2021 at 1:54 AM Linus Walleij <linus.walleij@linaro.org> wrote:
>
> On Tue, Dec 7, 2021 at 10:34 AM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
>
> > Hopefully this will be the last iteration of this series. Just some
> > minor changes requested by Andy in this one.
> >
> > Tested both with configfs as well as device-tree.
>
> This patch set:
> Acked-by: Linus Walleij <linus.walleij@linaro.org>
>
> Thanks for your perseverance!!
>
> Yours,
> Linus Walleij
Thanks, if there are no objections, I'll queue this series on Monday
to give it some time in next.
Bart
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator
2021-12-10 19:08 ` Bartosz Golaszewski
@ 2021-12-13 13:01 ` Bartosz Golaszewski
0 siblings, 0 replies; 14+ messages in thread
From: Bartosz Golaszewski @ 2021-12-13 13:01 UTC (permalink / raw)
To: Linus Walleij
Cc: Kent Gibson, Andy Shevchenko, Shuah Khan, Geert Uytterhoeven,
Viresh Kumar, open list:GPIO SUBSYSTEM,
Linux Kernel Mailing List, linux-kselftest
On Fri, Dec 10, 2021 at 8:08 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
>
> On Thu, Dec 9, 2021 at 1:54 AM Linus Walleij <linus.walleij@linaro.org> wrote:
> >
> > On Tue, Dec 7, 2021 at 10:34 AM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> >
> > > Hopefully this will be the last iteration of this series. Just some
> > > minor changes requested by Andy in this one.
> > >
> > > Tested both with configfs as well as device-tree.
> >
> > This patch set:
> > Acked-by: Linus Walleij <linus.walleij@linaro.org>
> >
> > Thanks for your perseverance!!
> >
> > Yours,
> > Linus Walleij
>
> Thanks, if there are no objections, I'll queue this series on Monday
> to give it some time in next.
>
> Bart
Queued for v5.17.
Bart
^ permalink raw reply [flat|nested] 14+ messages in thread
end of thread, other threads:[~2021-12-13 13:01 UTC | newest]
Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-12-07 9:34 [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator Bartosz Golaszewski
2021-12-07 9:34 ` [PATCH v13 1/7] gpiolib: provide gpiod_remove_hogs() Bartosz Golaszewski
2021-12-07 9:34 ` [PATCH v13 2/7] gpiolib: allow to specify the firmware node in struct gpio_chip Bartosz Golaszewski
2021-12-07 12:24 ` Andy Shevchenko
2021-12-07 9:34 ` [PATCH v13 3/7] gpiolib: of: make fwnode take precedence " Bartosz Golaszewski
2021-12-07 12:24 ` Andy Shevchenko
2021-12-07 9:34 ` [PATCH v13 4/7] gpio: sim: new testing module Bartosz Golaszewski
2021-12-07 13:58 ` Andy Shevchenko
2021-12-07 9:34 ` [PATCH v13 5/7] selftests: gpio: provide a helper for reading chip info Bartosz Golaszewski
2021-12-07 9:34 ` [PATCH v13 6/7] selftests: gpio: add a helper for reading GPIO line names Bartosz Golaszewski
2021-12-07 9:34 ` [PATCH v13 7/7] selftests: gpio: add test cases for gpio-sim Bartosz Golaszewski
2021-12-09 0:54 ` [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator Linus Walleij
2021-12-10 19:08 ` Bartosz Golaszewski
2021-12-13 13:01 ` Bartosz Golaszewski
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