* [patch v9 0/4] JTAG driver introduction
@ 2017-09-21 9:25 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-21 9:25 UTC (permalink / raw)
To: gregkh, arnd
Cc: linux-kernel, linux-arm-kernel, devicetree, openbmc, joel, jiri,
tklauser, linux-serial, mec, vadimp, system-sw-low-level,
robh+dt, openocd-devel-owner, linux-api, davem, mchehab,
Oleksandr Shamray
When a need raise up to use JTAG interface for system's devices
programming or CPU debugging, usually the user layer
application implements jtag protocol by bit-bang or using a
proprietary connection to vendor hardware.
This method can be slow and not generic.
We propose to implement general JTAG interface and infrastructure
to communicate with user layer application. In such way, we can
have the standard JTAG interface core part and separation from
specific HW implementation.
This allow new capability to debug the CPU or program system's
device via BMC without additional devices nor cost.
This patch purpose is to add JTAG master core infrastructure by
defining new JTAG class and provide generic JTAG interface
to allow hardware specific drivers to connect this interface.
This will enable all JTAG drivers to use the common interface
part and will have separate for hardware implementation.
The JTAG (Joint Test Action Group) core driver provides minimal generic
JTAG interface, which can be used by hardware specific JTAG master
controllers. By providing common interface for the JTAG controllers,
user space device programing is hardware independent.
Modern SoC which in use for embedded system' equipped with
internal JTAG master interface.
This interface is used for programming and debugging system's
hardware components, like CPLD, FPGA, CPU, voltage and
industrial controllers.
Firmware for such devices can be upgraded through JTAG interface during
Runtime. The JTAG standard support for multiple devices programming,
is in case their lines are daisy-chained together.
For example, systems which equipped with host CPU, BMC SoC or/and
number of programmable devices are capable to connect a pin and
select system components dynamically for programming and debugging,
This is using by the BMC which is equipped with internal SoC master
controller.
For example:
BMC JTAG master --> pin selected to CPLDs chain for programming (filed
upgrade, production)
BMC JTAG master --> pin selected to voltage monitors for programming
(field upgrade, production)
BMC JTAG master --> pin selected to host CPU (on-site debugging
and developers debugging)
For example, we can have application in user space which using calls
to JTAG driver executes CPLD programming directly from SVF file
The JTAG standard (IEEE 1149.1) defines the next connector pins:
- TDI (Test Data In);
- TDO (Test Data Out);
- TCK (Test Clock);
- TMS (Test Mode Select);
- TRST (Test Reset) (Optional);
The SoC equipped with JTAG master controller, performs
device programming on command or vector level. For example
a file in a standard SVF (Serial Vector Format) that contains
boundary scan vectors, can be used by sending each vector
to the JTAG interface and the JTAG controller will execute
the programming.
Initial version provides the system calls set for:
- SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
- SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
- RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
number of clocks.
SoC which are not equipped with JTAG master interface, can be built
on top of JTAG core driver infrastructure, by applying bit-banging of
TDI, TDO, TCK and TMS pins within the hardware specific driver.
Oleksandr Shamray (4):
drivers: jtag: Add JTAG core driver
drivers: jtag: Add Aspeed SoC 24xx and 25xx families JTAG master
driver
Documentation: jtag: Add bindings for Aspeed SoC 24xx and 25xx
families JTAG master driver
Documentation: jtag: Add ABI documentation
Documentation/ABI/testing/jatg-cdev | 27 +
.../devicetree/bindings/jtag/aspeed-jtag.txt | 18 +
Documentation/ioctl/ioctl-number.txt | 2 +
MAINTAINERS | 10 +
drivers/Kconfig | 2 +
drivers/Makefile | 1 +
drivers/jtag/Kconfig | 29 +
drivers/jtag/Makefile | 2 +
drivers/jtag/jtag-aspeed.c | 771 ++++++++++++++++++++
drivers/jtag/jtag.c | 298 ++++++++
include/linux/jtag.h | 48 ++
include/uapi/linux/jtag.h | 115 +++
12 files changed, 1323 insertions(+), 0 deletions(-)
create mode 100644 Documentation/ABI/testing/jatg-cdev
create mode 100644 Documentation/devicetree/bindings/jtag/aspeed-jtag.txt
create mode 100644 drivers/jtag/Kconfig
create mode 100644 drivers/jtag/Makefile
create mode 100644 drivers/jtag/jtag-aspeed.c
create mode 100644 drivers/jtag/jtag.c
create mode 100644 include/linux/jtag.h
create mode 100644 include/uapi/linux/jtag.h
^ permalink raw reply [flat|nested] 45+ messages in thread
* [patch v9 0/4] JTAG driver introduction
@ 2017-09-21 9:25 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-21 9:25 UTC (permalink / raw)
To: linux-arm-kernel
When a need raise up to use JTAG interface for system's devices
programming or CPU debugging, usually the user layer
application implements jtag protocol by bit-bang or using a
proprietary connection to vendor hardware.
This method can be slow and not generic.
We propose to implement general JTAG interface and infrastructure
to communicate with user layer application. In such way, we can
have the standard JTAG interface core part and separation from
specific HW implementation.
This allow new capability to debug the CPU or program system's
device via BMC without additional devices nor cost.
This patch purpose is to add JTAG master core infrastructure by
defining new JTAG class and provide generic JTAG interface
to allow hardware specific drivers to connect this interface.
This will enable all JTAG drivers to use the common interface
part and will have separate for hardware implementation.
The JTAG (Joint Test Action Group) core driver provides minimal generic
JTAG interface, which can be used by hardware specific JTAG master
controllers. By providing common interface for the JTAG controllers,
user space device programing is hardware independent.
Modern SoC which in use for embedded system' equipped with
internal JTAG master interface.
This interface is used for programming and debugging system's
hardware components, like CPLD, FPGA, CPU, voltage and
industrial controllers.
Firmware for such devices can be upgraded through JTAG interface during
Runtime. The JTAG standard support for multiple devices programming,
is in case their lines are daisy-chained together.
For example, systems which equipped with host CPU, BMC SoC or/and
number of programmable devices are capable to connect a pin and
select system components dynamically for programming and debugging,
This is using by the BMC which is equipped with internal SoC master
controller.
For example:
BMC JTAG master --> pin selected to CPLDs chain for programming (filed
upgrade, production)
BMC JTAG master --> pin selected to voltage monitors for programming
(field upgrade, production)
BMC JTAG master --> pin selected to host CPU (on-site debugging
and developers debugging)
For example, we can have application in user space which using calls
to JTAG driver executes CPLD programming directly from SVF file
The JTAG standard (IEEE 1149.1) defines the next connector pins:
- TDI (Test Data In);
- TDO (Test Data Out);
- TCK (Test Clock);
- TMS (Test Mode Select);
- TRST (Test Reset) (Optional);
The SoC equipped with JTAG master controller, performs
device programming on command or vector level. For example
a file in a standard SVF (Serial Vector Format) that contains
boundary scan vectors, can be used by sending each vector
to the JTAG interface and the JTAG controller will execute
the programming.
Initial version provides the system calls set for:
- SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
- SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
- RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
number of clocks.
SoC which are not equipped with JTAG master interface, can be built
on top of JTAG core driver infrastructure, by applying bit-banging of
TDI, TDO, TCK and TMS pins within the hardware specific driver.
Oleksandr Shamray (4):
drivers: jtag: Add JTAG core driver
drivers: jtag: Add Aspeed SoC 24xx and 25xx families JTAG master
driver
Documentation: jtag: Add bindings for Aspeed SoC 24xx and 25xx
families JTAG master driver
Documentation: jtag: Add ABI documentation
Documentation/ABI/testing/jatg-cdev | 27 +
.../devicetree/bindings/jtag/aspeed-jtag.txt | 18 +
Documentation/ioctl/ioctl-number.txt | 2 +
MAINTAINERS | 10 +
drivers/Kconfig | 2 +
drivers/Makefile | 1 +
drivers/jtag/Kconfig | 29 +
drivers/jtag/Makefile | 2 +
drivers/jtag/jtag-aspeed.c | 771 ++++++++++++++++++++
drivers/jtag/jtag.c | 298 ++++++++
include/linux/jtag.h | 48 ++
include/uapi/linux/jtag.h | 115 +++
12 files changed, 1323 insertions(+), 0 deletions(-)
create mode 100644 Documentation/ABI/testing/jatg-cdev
create mode 100644 Documentation/devicetree/bindings/jtag/aspeed-jtag.txt
create mode 100644 drivers/jtag/Kconfig
create mode 100644 drivers/jtag/Makefile
create mode 100644 drivers/jtag/jtag-aspeed.c
create mode 100644 drivers/jtag/jtag.c
create mode 100644 include/linux/jtag.h
create mode 100644 include/uapi/linux/jtag.h
^ permalink raw reply [flat|nested] 45+ messages in thread
* [patch v9 1/4] drivers: jtag: Add JTAG core driver
@ 2017-09-21 9:25 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-21 9:25 UTC (permalink / raw)
To: gregkh, arnd
Cc: linux-kernel, linux-arm-kernel, devicetree, openbmc, joel, jiri,
tklauser, linux-serial, mec, vadimp, system-sw-low-level,
robh+dt, openocd-devel-owner, linux-api, davem, mchehab,
Oleksandr Shamray, Jiri Pirko
Initial patch for JTAG driver
JTAG class driver provide infrastructure to support hardware/software
JTAG platform drivers. It provide user layer API interface for flashing
and debugging external devices which equipped with JTAG interface
using standard transactions.
Driver exposes set of IOCTL to user space for:
- XFER:
- SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
- SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
- RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
number of clocks).
- SIOCFREQ/GIOCFREQ for setting and reading JTAG frequency.
Driver core provides set of internal APIs for allocation and
registration:
- jtag_register;
- jtag_unregister;
- jtag_alloc;
- jtag_free;
Platform driver on registration with jtag-core creates the next
entry in dev folder:
/dev/jtagX
Signed-off-by: Oleksandr Shamray <oleksandrs@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
---
V8->v9
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- use get_user() instead of __get_user().
- change jtag->open type from int to atomic_t
- remove spinlock on jtg_open
- remove mutex on jtag_register
- add unregister_chrdev_region on jtag_init err
- add unregister_chrdev_region on jtag_exit
- remove unnecessary pointer casts
- add *data parameter to xfer function prototype
v7->v8
Comments pointed by Moritz Fischer <moritz.fischer@ettus.com>
- Fix misspelling s/friver/driver
v6->v7
Notifications from kbuild test robot <lkp@intel.com>
- Remove include asm/types.h from jtag.h
- Add include <linux/types.h> to jtag.c
v5->v6
v4->v5
v3->v4
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- change transaction pointer tdio type to __u64
- change internal status type from enum to __u32
- reorder jtag_xfer members to avoid the implied padding
- add __packed attribute to jtag_xfer and jtag_run_test_idle
v2->v3
Notifications from kbuild test robot <lkp@intel.com>
- Change include path to <linux/types.h> in jtag.h
v1->v2
Comments pointed by Greg KH <gregkh@linuxfoundation.org>
- Change license type from GPLv2/BSD to GPLv2
- Change type of variables which crossed user/kernel to __type
- Remove "default n" from Kconfig
Comments pointed by Andrew Lunn <andrew@lunn.ch>
- Change list_add_tail in jtag_unregister to list_del
Comments pointed by Neil Armstrong <narmstrong@baylibre.com>
- Add SPDX-License-Identifier instead of license text
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- Change __copy_to_user to memdup_user
- Change __put_user to put_user
- Change type of variables to __type for compatible 32 and 64-bit systems
- Add check for maximum xfer data size
- Change lookup data mechanism to get jtag data from inode
- Add .compat_ioctl to file ops
- Add mem alignment for jtag priv data
Comments pointed by Tobias Klauser <tklauser@distanz.ch>
- Change function names to avoid match with variable types
- Fix description for jtag_ru_test_idle in uapi jtag.h
- Fix misprints IDEL/IDLE, trough/through
---
Documentation/ioctl/ioctl-number.txt | 2 +
MAINTAINERS | 8 +
drivers/Kconfig | 2 +
drivers/Makefile | 1 +
drivers/jtag/Kconfig | 16 ++
drivers/jtag/Makefile | 1 +
drivers/jtag/jtag.c | 298 ++++++++++++++++++++++++++++++++++
include/linux/jtag.h | 48 ++++++
include/uapi/linux/jtag.h | 115 +++++++++++++
9 files changed, 491 insertions(+), 0 deletions(-)
create mode 100644 drivers/jtag/Kconfig
create mode 100644 drivers/jtag/Makefile
create mode 100644 drivers/jtag/jtag.c
create mode 100644 include/linux/jtag.h
create mode 100644 include/uapi/linux/jtag.h
diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index 3e3fdae..1af2508 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -321,6 +321,8 @@ Code Seq#(hex) Include File Comments
0xB0 all RATIO devices in development:
<mailto:vgo@ratio.de>
0xB1 00-1F PPPoX <mailto:mostrows@styx.uwaterloo.ca>
+0xB2 00-0f linux/jtag.h JTAG driver
+ <mailto:oleksandrs@mellanox.com>
0xB3 00 linux/mmc/ioctl.h
0xB4 00-0F linux/gpio.h <mailto:linux-gpio@vger.kernel.org>
0xB5 00-0F uapi/linux/rpmsg.h <mailto:linux-remoteproc@vger.kernel.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index 205d397..141aeaf 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7292,6 +7292,14 @@ L: linux-serial@vger.kernel.org
S: Maintained
F: drivers/tty/serial/jsm/
+JTAG SUBSYSTEM
+M: Oleksandr Shamray <oleksandrs@mellanox.com>
+M: Vadim Pasternak <vadimp@mellanox.com>
+S: Maintained
+F: include/linux/jtag.h
+F: include/uapi/linux/jtag.h
+F: drivers/jtag/
+
K10TEMP HARDWARE MONITORING DRIVER
M: Clemens Ladisch <clemens@ladisch.de>
L: linux-hwmon@vger.kernel.org
diff --git a/drivers/Kconfig b/drivers/Kconfig
index 505c676..2214678 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -208,4 +208,6 @@ source "drivers/tee/Kconfig"
source "drivers/mux/Kconfig"
+source "drivers/jtag/Kconfig"
+
endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index dfdcda0..6a2059b 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -182,3 +182,4 @@ obj-$(CONFIG_FPGA) += fpga/
obj-$(CONFIG_FSI) += fsi/
obj-$(CONFIG_TEE) += tee/
obj-$(CONFIG_MULTIPLEXER) += mux/
+obj-$(CONFIG_JTAG) += jtag/
diff --git a/drivers/jtag/Kconfig b/drivers/jtag/Kconfig
new file mode 100644
index 0000000..0fad1a3
--- /dev/null
+++ b/drivers/jtag/Kconfig
@@ -0,0 +1,16 @@
+menuconfig JTAG
+ tristate "JTAG support"
+ ---help---
+ This provides basic core functionality support for jtag class devices
+ Hardware equipped with JTAG microcontroller which can be built
+ on top of this drivers. Driver exposes the set of IOCTL to the
+ user space for:
+ SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
+ SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
+ RUNTEST (Forces IEEE 1149.1 bus to a run state for specified
+ number of clocks).
+
+ If you want this support, you should say Y here.
+
+ To compile this driver as a module, choose M here: the module will
+ be called jtag.
diff --git a/drivers/jtag/Makefile b/drivers/jtag/Makefile
new file mode 100644
index 0000000..af37493
--- /dev/null
+++ b/drivers/jtag/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_JTAG) += jtag.o
diff --git a/drivers/jtag/jtag.c b/drivers/jtag/jtag.c
new file mode 100644
index 0000000..4fd327a
--- /dev/null
+++ b/drivers/jtag/jtag.c
@@ -0,0 +1,298 @@
+/*
+ * drivers/jtag/jtag.c
+ *
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
+ *
+ * Released under the GPLv2 only.
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/jtag.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/rtnetlink.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <uapi/linux/jtag.h>
+
+struct jtag {
+ struct device *dev;
+ struct cdev cdev;
+ int id;
+ atomic_t open;
+ const struct jtag_ops *ops;
+ unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
+};
+
+static dev_t jtag_devt;
+static DEFINE_IDA(jtag_ida);
+
+void *jtag_priv(struct jtag *jtag)
+{
+ return jtag->priv;
+}
+EXPORT_SYMBOL_GPL(jtag_priv);
+
+static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size)
+{
+ unsigned long size;
+ void *kdata;
+
+ size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
+ kdata = memdup_user(u64_to_user_ptr(udata), size);
+
+ return kdata;
+}
+
+static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
+ unsigned long bit_size)
+{
+ unsigned long size;
+
+ size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
+
+ return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata), size);
+}
+
+static struct class jtag_class = {
+ .name = "jtag",
+ .owner = THIS_MODULE,
+};
+
+static int jtag_run_test_idle_op(struct jtag *jtag,
+ struct jtag_run_test_idle *idle)
+{
+ if (jtag->ops->idle)
+ return jtag->ops->idle(jtag, idle);
+ else
+ return -EOPNOTSUPP;
+}
+
+static int jtag_xfer_op(struct jtag *jtag, struct jtag_xfer *xfer, u8 *data)
+{
+ if (jtag->ops->xfer)
+ return jtag->ops->xfer(jtag, xfer, data);
+ else
+ return -EOPNOTSUPP;
+}
+
+static long jtag_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct jtag *jtag = file->private_data;
+ struct jtag_run_test_idle idle;
+ struct jtag_xfer xfer;
+ u8 *xfer_data;
+ u32 value;
+ int err;
+
+ switch (cmd) {
+ case JTAG_GIOCFREQ:
+ if (jtag->ops->freq_get)
+ err = jtag->ops->freq_get(jtag, &value);
+ else
+ err = -EOPNOTSUPP;
+ if (err)
+ break;
+
+ err = put_user(value, (__u32 *)arg);
+ break;
+
+ case JTAG_SIOCFREQ:
+ err = get_user(value, (__u32 *)arg);
+
+ if (value == 0)
+ err = -EINVAL;
+ if (err)
+ break;
+
+ if (jtag->ops->freq_set)
+ err = jtag->ops->freq_set(jtag, value);
+ else
+ err = -EOPNOTSUPP;
+ break;
+
+ case JTAG_IOCRUNTEST:
+ if (copy_from_user(&idle, (void *)arg,
+ sizeof(struct jtag_run_test_idle)))
+ return -ENOMEM;
+ err = jtag_run_test_idle_op(jtag, &idle);
+ break;
+
+ case JTAG_IOCXFER:
+ if (copy_from_user(&xfer, (void *)arg,
+ sizeof(struct jtag_xfer)))
+ return -EFAULT;
+
+ if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
+ return -EFAULT;
+
+ xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
+ if (!xfer_data)
+ return -ENOMEM;
+
+ err = jtag_xfer_op(jtag, &xfer, xfer_data);
+ if (jtag_copy_to_user(xfer.tdio, xfer_data, xfer.length)) {
+ kfree(xfer_data);
+ return -EFAULT;
+ }
+
+ kfree(xfer_data);
+ if (copy_to_user((void *)arg, &xfer, sizeof(struct jtag_xfer)))
+ return -EFAULT;
+ break;
+
+ case JTAG_GIOCSTATUS:
+ if (jtag->ops->status_get)
+ err = jtag->ops->status_get(jtag, &value);
+ else
+ err = -EOPNOTSUPP;
+ if (err)
+ break;
+
+ err = put_user(value, (__u32 *)arg);
+ break;
+
+ default:
+ return -EINVAL;
+ }
+ return err;
+}
+
+#ifdef CONFIG_COMPAT
+static long jtag_ioctl_compat(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ return jtag_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
+
+static int jtag_open(struct inode *inode, struct file *file)
+{
+ struct jtag *jtag = container_of(inode->i_cdev, struct jtag, cdev);
+
+ if (atomic_read(&jtag->open)) {
+ dev_info(NULL, "jtag already opened\n");
+ return -EBUSY;
+ }
+
+ atomic_inc(&jtag->open);
+ file->private_data = jtag;
+ return 0;
+}
+
+static int jtag_release(struct inode *inode, struct file *file)
+{
+ struct jtag *jtag = file->private_data;
+
+ atomic_dec(&jtag->open);
+ return 0;
+}
+
+static const struct file_operations jtag_fops = {
+ .owner = THIS_MODULE,
+ .open = jtag_open,
+ .release = jtag_release,
+ .llseek = noop_llseek,
+ .unlocked_ioctl = jtag_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = jtag_ioctl_compat,
+#endif
+};
+
+struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops)
+{
+ struct jtag *jtag;
+
+ jtag = kzalloc(sizeof(*jtag) + round_up(priv_size, ARCH_DMA_MINALIGN),
+ GFP_KERNEL);
+ if (!jtag)
+ return NULL;
+
+ jtag->ops = ops;
+ return jtag;
+}
+EXPORT_SYMBOL_GPL(jtag_alloc);
+
+void jtag_free(struct jtag *jtag)
+{
+ kfree(jtag);
+}
+EXPORT_SYMBOL_GPL(jtag_free);
+
+int jtag_register(struct jtag *jtag)
+{
+ int id;
+ int err;
+
+ id = ida_simple_get(&jtag_ida, 0, 0, GFP_KERNEL);
+ if (id < 0)
+ return id;
+
+ jtag->id = id;
+ cdev_init(&jtag->cdev, &jtag_fops);
+ jtag->cdev.owner = THIS_MODULE;
+ err = cdev_add(&jtag->cdev, MKDEV(MAJOR(jtag_devt), jtag->id), 1);
+ if (err)
+ goto err_cdev;
+
+ /* Register this jtag device with the driver core */
+ jtag->dev = device_create(&jtag_class, NULL, MKDEV(MAJOR(jtag_devt),
+ jtag->id),
+ NULL, "jtag%d", jtag->id);
+ if (!jtag->dev)
+ goto err_device_create;
+
+ atomic_set(&jtag->open, 0);
+ dev_set_drvdata(jtag->dev, jtag);
+ return err;
+
+err_device_create:
+ cdev_del(&jtag->cdev);
+err_cdev:
+ ida_simple_remove(&jtag_ida, id);
+ return err;
+}
+EXPORT_SYMBOL_GPL(jtag_register);
+
+void jtag_unregister(struct jtag *jtag)
+{
+ struct device *dev = jtag->dev;
+
+ cdev_del(&jtag->cdev);
+ device_unregister(dev);
+ ida_simple_remove(&jtag_ida, jtag->id);
+}
+EXPORT_SYMBOL_GPL(jtag_unregister);
+
+static int __init jtag_init(void)
+{
+ int err;
+
+ err = alloc_chrdev_region(&jtag_devt, JTAG_FIRST_MINOR,
+ JTAG_MAX_DEVICES, "jtag");
+ if (err)
+ return err;
+
+ err = class_register(&jtag_class);
+ if (err)
+ unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
+
+ return err;
+}
+
+static void __exit jtag_exit(void)
+{
+ class_unregister(&jtag_class);
+ unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
+}
+
+module_init(jtag_init);
+module_exit(jtag_exit);
+
+MODULE_AUTHOR("Oleksandr Shamray <oleksandrs@mellanox.com>");
+MODULE_DESCRIPTION("Generic jtag support");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/jtag.h b/include/linux/jtag.h
new file mode 100644
index 0000000..c016fed
--- /dev/null
+++ b/include/linux/jtag.h
@@ -0,0 +1,48 @@
+/*
+ * drivers/jtag/jtag.c
+ *
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
+ *
+ * Released under the GPLv2 only.
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#ifndef __JTAG_H
+#define __JTAG_H
+
+#include <uapi/linux/jtag.h>
+
+#ifndef ARCH_DMA_MINALIGN
+#define ARCH_DMA_MINALIGN 1
+#endif
+
+#define jtag_u64_to_ptr(arg) ((void *)(uintptr_t)arg)
+
+#define JTAG_MAX_XFER_DATA_LEN 65535
+
+struct jtag;
+/**
+ * struct jtag_ops - callbacks for jtag control functions:
+ *
+ * @freq_get: get frequency function. Filled by device driver
+ * @freq_set: set frequency function. Filled by device driver
+ * @status_get: set status function. Filled by device driver
+ * @idle: set JTAG to idle state function. Filled by device driver
+ * @xfer: send JTAG xfer function. Filled by device driver
+ */
+struct jtag_ops {
+ int (*freq_get)(struct jtag *jtag, u32 *freq);
+ int (*freq_set)(struct jtag *jtag, u32 freq);
+ int (*status_get)(struct jtag *jtag, u32 *state);
+ int (*idle)(struct jtag *jtag, struct jtag_run_test_idle *idle);
+ int (*xfer)(struct jtag *jtag, struct jtag_xfer *xfer);
+};
+
+void *jtag_priv(struct jtag *jtag);
+int jtag_register(struct jtag *jtag);
+void jtag_unregister(struct jtag *jtag);
+struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops);
+void jtag_free(struct jtag *jtag);
+
+#endif /* __JTAG_H */
diff --git a/include/uapi/linux/jtag.h b/include/uapi/linux/jtag.h
new file mode 100644
index 0000000..180bf22
--- /dev/null
+++ b/include/uapi/linux/jtag.h
@@ -0,0 +1,115 @@
+/*
+ * JTAG class driver
+ *
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
+ *
+ * Released under the GPLv2/BSD.
+ * SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+ */
+
+#ifndef __UAPI_LINUX_JTAG_H
+#define __UAPI_LINUX_JTAG_H
+
+/**
+ * enum jtag_xfer_mode:
+ *
+ * @JTAG_XFER_HW_MODE: hardware mode transfer
+ * @JTAG_XFER_SW_MODE: software mode transfer
+ */
+enum jtag_xfer_mode {
+ JTAG_XFER_HW_MODE,
+ JTAG_XFER_SW_MODE,
+};
+
+/**
+ * enum jtag_endstate:
+ *
+ * @JTAG_STATE_IDLE: JTAG state machine IDLE state
+ * @JTAG_STATE_PAUSEIR: JTAG state machine PAUSE_IR state
+ * @JTAG_STATE_PAUSEDR: JTAG state machine PAUSE_DR state
+ */
+enum jtag_endstate {
+ JTAG_STATE_IDLE,
+ JTAG_STATE_PAUSEIR,
+ JTAG_STATE_PAUSEDR,
+};
+
+/**
+ * enum jtag_xfer_type:
+ *
+ * @JTAG_SIR_XFER: SIR transfer
+ * @JTAG_SDR_XFER: SDR transfer
+ */
+enum jtag_xfer_type {
+ JTAG_SIR_XFER,
+ JTAG_SDR_XFER,
+};
+
+/**
+ * enum jtag_xfer_direction:
+ *
+ * @JTAG_READ_XFER: read transfer
+ * @JTAG_WRITE_XFER: write transfer
+ */
+enum jtag_xfer_direction {
+ JTAG_READ_XFER,
+ JTAG_WRITE_XFER,
+};
+
+/**
+ * struct jtag_run_test_idle - forces JTAG state machine to
+ * RUN_TEST/IDLE state
+ *
+ * @mode: access mode
+ * @reset: 0 - run IDLE/PAUSE from current state
+ * 1 - go through TEST_LOGIC/RESET state before IDLE/PAUSE
+ * @end: completion flag
+ * @tck: clock counter
+ *
+ * Structure represents interface to JTAG device for jtag idle
+ * execution.
+ */
+struct jtag_run_test_idle {
+ __u8 mode;
+ __u8 reset;
+ __u8 endstate;
+ __u8 tck;
+};
+
+/**
+ * struct jtag_xfer - jtag xfer:
+ *
+ * @mode: access mode
+ * @type: transfer type
+ * @direction: xfer direction
+ * @length: xfer bits len
+ * @tdio : xfer data array
+ * @endir: xfer end state
+ *
+ * Structure represents interface to Aspeed JTAG device for jtag sdr xfer
+ * execution.
+ */
+struct jtag_xfer {
+ __u8 mode;
+ __u8 type;
+ __u8 direction;
+ __u8 endstate;
+ __u32 length;
+ __u64 tdio;
+};
+
+/* ioctl interface */
+#define __JTAG_IOCTL_MAGIC 0xb2
+
+#define JTAG_IOCRUNTEST _IOW(__JTAG_IOCTL_MAGIC, 0,\
+ struct jtag_run_test_idle)
+#define JTAG_SIOCFREQ _IOW(__JTAG_IOCTL_MAGIC, 1, unsigned int)
+#define JTAG_GIOCFREQ _IOR(__JTAG_IOCTL_MAGIC, 2, unsigned int)
+#define JTAG_IOCXFER _IOWR(__JTAG_IOCTL_MAGIC, 3, struct jtag_xfer)
+#define JTAG_GIOCSTATUS _IOWR(__JTAG_IOCTL_MAGIC, 4, enum jtag_endstate)
+
+#define JTAG_FIRST_MINOR 0
+#define JTAG_MAX_DEVICES 32
+
+#endif /* __UAPI_LINUX_JTAG_H */
--
1.7.1
^ permalink raw reply related [flat|nested] 45+ messages in thread
* [patch v9 1/4] drivers: jtag: Add JTAG core driver
@ 2017-09-21 9:25 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-21 9:25 UTC (permalink / raw)
To: gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r, arnd-r2nGTMty4D4
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
devicetree-u79uwXL29TY76Z2rM5mHXA,
openbmc-uLR06cmDAlY/bJ5BZ2RsiQ, joel-U3u1mxZcP9KHXe+LvDLADg,
jiri-rHqAuBHg3fBzbRFIqnYvSA, tklauser-93Khv+1bN0NyDzI6CaY1VQ,
linux-serial-u79uwXL29TY76Z2rM5mHXA, mec-WqBc5aa1uDFeoWH0uzbU5w,
vadimp-VPRAkNaXOzVWk0Htik3J/w,
system-sw-low-level-VPRAkNaXOzVWk0Htik3J/w,
robh+dt-DgEjT+Ai2ygdnm+yROfE0A,
openocd-devel-owner-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
linux-api-u79uwXL29TY76Z2rM5mHXA, davem-fT/PcQaiUtIeIZ0/mPfg9Q,
mchehab-DgEjT+Ai2ygdnm+yROfE0A, Oleksandr Shamray, Jiri Pirko
Initial patch for JTAG driver
JTAG class driver provide infrastructure to support hardware/software
JTAG platform drivers. It provide user layer API interface for flashing
and debugging external devices which equipped with JTAG interface
using standard transactions.
Driver exposes set of IOCTL to user space for:
- XFER:
- SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
- SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
- RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
number of clocks).
- SIOCFREQ/GIOCFREQ for setting and reading JTAG frequency.
Driver core provides set of internal APIs for allocation and
registration:
- jtag_register;
- jtag_unregister;
- jtag_alloc;
- jtag_free;
Platform driver on registration with jtag-core creates the next
entry in dev folder:
/dev/jtagX
Signed-off-by: Oleksandr Shamray <oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Signed-off-by: Jiri Pirko <jiri-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---
V8->v9
Comments pointed by Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
- use get_user() instead of __get_user().
- change jtag->open type from int to atomic_t
- remove spinlock on jtg_open
- remove mutex on jtag_register
- add unregister_chrdev_region on jtag_init err
- add unregister_chrdev_region on jtag_exit
- remove unnecessary pointer casts
- add *data parameter to xfer function prototype
v7->v8
Comments pointed by Moritz Fischer <moritz.fischer-+aYTwkv1SeIAvxtiuMwx3w@public.gmane.org>
- Fix misspelling s/friver/driver
v6->v7
Notifications from kbuild test robot <lkp-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
- Remove include asm/types.h from jtag.h
- Add include <linux/types.h> to jtag.c
v5->v6
v4->v5
v3->v4
Comments pointed by Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
- change transaction pointer tdio type to __u64
- change internal status type from enum to __u32
- reorder jtag_xfer members to avoid the implied padding
- add __packed attribute to jtag_xfer and jtag_run_test_idle
v2->v3
Notifications from kbuild test robot <lkp-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
- Change include path to <linux/types.h> in jtag.h
v1->v2
Comments pointed by Greg KH <gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>
- Change license type from GPLv2/BSD to GPLv2
- Change type of variables which crossed user/kernel to __type
- Remove "default n" from Kconfig
Comments pointed by Andrew Lunn <andrew-g2DYL2Zd6BY@public.gmane.org>
- Change list_add_tail in jtag_unregister to list_del
Comments pointed by Neil Armstrong <narmstrong-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>
- Add SPDX-License-Identifier instead of license text
Comments pointed by Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
- Change __copy_to_user to memdup_user
- Change __put_user to put_user
- Change type of variables to __type for compatible 32 and 64-bit systems
- Add check for maximum xfer data size
- Change lookup data mechanism to get jtag data from inode
- Add .compat_ioctl to file ops
- Add mem alignment for jtag priv data
Comments pointed by Tobias Klauser <tklauser-93Khv+1bN0NyDzI6CaY1VQ@public.gmane.org>
- Change function names to avoid match with variable types
- Fix description for jtag_ru_test_idle in uapi jtag.h
- Fix misprints IDEL/IDLE, trough/through
---
Documentation/ioctl/ioctl-number.txt | 2 +
MAINTAINERS | 8 +
drivers/Kconfig | 2 +
drivers/Makefile | 1 +
drivers/jtag/Kconfig | 16 ++
drivers/jtag/Makefile | 1 +
drivers/jtag/jtag.c | 298 ++++++++++++++++++++++++++++++++++
include/linux/jtag.h | 48 ++++++
include/uapi/linux/jtag.h | 115 +++++++++++++
9 files changed, 491 insertions(+), 0 deletions(-)
create mode 100644 drivers/jtag/Kconfig
create mode 100644 drivers/jtag/Makefile
create mode 100644 drivers/jtag/jtag.c
create mode 100644 include/linux/jtag.h
create mode 100644 include/uapi/linux/jtag.h
diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index 3e3fdae..1af2508 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -321,6 +321,8 @@ Code Seq#(hex) Include File Comments
0xB0 all RATIO devices in development:
<mailto:vgo-/IYFIZglx74@public.gmane.org>
0xB1 00-1F PPPoX <mailto:mostrows-TTukF6hB3AoKZpuMuFhwt/d9D2ou9A/h@public.gmane.org>
+0xB2 00-0f linux/jtag.h JTAG driver
+ <mailto:oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
0xB3 00 linux/mmc/ioctl.h
0xB4 00-0F linux/gpio.h <mailto:linux-gpio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
0xB5 00-0F uapi/linux/rpmsg.h <mailto:linux-remoteproc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index 205d397..141aeaf 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7292,6 +7292,14 @@ L: linux-serial-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
S: Maintained
F: drivers/tty/serial/jsm/
+JTAG SUBSYSTEM
+M: Oleksandr Shamray <oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
+M: Vadim Pasternak <vadimp-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
+S: Maintained
+F: include/linux/jtag.h
+F: include/uapi/linux/jtag.h
+F: drivers/jtag/
+
K10TEMP HARDWARE MONITORING DRIVER
M: Clemens Ladisch <clemens-P6GI/4k7KOmELgA04lAiVw@public.gmane.org>
L: linux-hwmon-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
diff --git a/drivers/Kconfig b/drivers/Kconfig
index 505c676..2214678 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -208,4 +208,6 @@ source "drivers/tee/Kconfig"
source "drivers/mux/Kconfig"
+source "drivers/jtag/Kconfig"
+
endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index dfdcda0..6a2059b 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -182,3 +182,4 @@ obj-$(CONFIG_FPGA) += fpga/
obj-$(CONFIG_FSI) += fsi/
obj-$(CONFIG_TEE) += tee/
obj-$(CONFIG_MULTIPLEXER) += mux/
+obj-$(CONFIG_JTAG) += jtag/
diff --git a/drivers/jtag/Kconfig b/drivers/jtag/Kconfig
new file mode 100644
index 0000000..0fad1a3
--- /dev/null
+++ b/drivers/jtag/Kconfig
@@ -0,0 +1,16 @@
+menuconfig JTAG
+ tristate "JTAG support"
+ ---help---
+ This provides basic core functionality support for jtag class devices
+ Hardware equipped with JTAG microcontroller which can be built
+ on top of this drivers. Driver exposes the set of IOCTL to the
+ user space for:
+ SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
+ SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
+ RUNTEST (Forces IEEE 1149.1 bus to a run state for specified
+ number of clocks).
+
+ If you want this support, you should say Y here.
+
+ To compile this driver as a module, choose M here: the module will
+ be called jtag.
diff --git a/drivers/jtag/Makefile b/drivers/jtag/Makefile
new file mode 100644
index 0000000..af37493
--- /dev/null
+++ b/drivers/jtag/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_JTAG) += jtag.o
diff --git a/drivers/jtag/jtag.c b/drivers/jtag/jtag.c
new file mode 100644
index 0000000..4fd327a
--- /dev/null
+++ b/drivers/jtag/jtag.c
@@ -0,0 +1,298 @@
+/*
+ * drivers/jtag/jtag.c
+ *
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Oleksandr Shamray <oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
+ *
+ * Released under the GPLv2 only.
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/jtag.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/rtnetlink.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <uapi/linux/jtag.h>
+
+struct jtag {
+ struct device *dev;
+ struct cdev cdev;
+ int id;
+ atomic_t open;
+ const struct jtag_ops *ops;
+ unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
+};
+
+static dev_t jtag_devt;
+static DEFINE_IDA(jtag_ida);
+
+void *jtag_priv(struct jtag *jtag)
+{
+ return jtag->priv;
+}
+EXPORT_SYMBOL_GPL(jtag_priv);
+
+static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size)
+{
+ unsigned long size;
+ void *kdata;
+
+ size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
+ kdata = memdup_user(u64_to_user_ptr(udata), size);
+
+ return kdata;
+}
+
+static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
+ unsigned long bit_size)
+{
+ unsigned long size;
+
+ size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
+
+ return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata), size);
+}
+
+static struct class jtag_class = {
+ .name = "jtag",
+ .owner = THIS_MODULE,
+};
+
+static int jtag_run_test_idle_op(struct jtag *jtag,
+ struct jtag_run_test_idle *idle)
+{
+ if (jtag->ops->idle)
+ return jtag->ops->idle(jtag, idle);
+ else
+ return -EOPNOTSUPP;
+}
+
+static int jtag_xfer_op(struct jtag *jtag, struct jtag_xfer *xfer, u8 *data)
+{
+ if (jtag->ops->xfer)
+ return jtag->ops->xfer(jtag, xfer, data);
+ else
+ return -EOPNOTSUPP;
+}
+
+static long jtag_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct jtag *jtag = file->private_data;
+ struct jtag_run_test_idle idle;
+ struct jtag_xfer xfer;
+ u8 *xfer_data;
+ u32 value;
+ int err;
+
+ switch (cmd) {
+ case JTAG_GIOCFREQ:
+ if (jtag->ops->freq_get)
+ err = jtag->ops->freq_get(jtag, &value);
+ else
+ err = -EOPNOTSUPP;
+ if (err)
+ break;
+
+ err = put_user(value, (__u32 *)arg);
+ break;
+
+ case JTAG_SIOCFREQ:
+ err = get_user(value, (__u32 *)arg);
+
+ if (value == 0)
+ err = -EINVAL;
+ if (err)
+ break;
+
+ if (jtag->ops->freq_set)
+ err = jtag->ops->freq_set(jtag, value);
+ else
+ err = -EOPNOTSUPP;
+ break;
+
+ case JTAG_IOCRUNTEST:
+ if (copy_from_user(&idle, (void *)arg,
+ sizeof(struct jtag_run_test_idle)))
+ return -ENOMEM;
+ err = jtag_run_test_idle_op(jtag, &idle);
+ break;
+
+ case JTAG_IOCXFER:
+ if (copy_from_user(&xfer, (void *)arg,
+ sizeof(struct jtag_xfer)))
+ return -EFAULT;
+
+ if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
+ return -EFAULT;
+
+ xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
+ if (!xfer_data)
+ return -ENOMEM;
+
+ err = jtag_xfer_op(jtag, &xfer, xfer_data);
+ if (jtag_copy_to_user(xfer.tdio, xfer_data, xfer.length)) {
+ kfree(xfer_data);
+ return -EFAULT;
+ }
+
+ kfree(xfer_data);
+ if (copy_to_user((void *)arg, &xfer, sizeof(struct jtag_xfer)))
+ return -EFAULT;
+ break;
+
+ case JTAG_GIOCSTATUS:
+ if (jtag->ops->status_get)
+ err = jtag->ops->status_get(jtag, &value);
+ else
+ err = -EOPNOTSUPP;
+ if (err)
+ break;
+
+ err = put_user(value, (__u32 *)arg);
+ break;
+
+ default:
+ return -EINVAL;
+ }
+ return err;
+}
+
+#ifdef CONFIG_COMPAT
+static long jtag_ioctl_compat(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ return jtag_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
+
+static int jtag_open(struct inode *inode, struct file *file)
+{
+ struct jtag *jtag = container_of(inode->i_cdev, struct jtag, cdev);
+
+ if (atomic_read(&jtag->open)) {
+ dev_info(NULL, "jtag already opened\n");
+ return -EBUSY;
+ }
+
+ atomic_inc(&jtag->open);
+ file->private_data = jtag;
+ return 0;
+}
+
+static int jtag_release(struct inode *inode, struct file *file)
+{
+ struct jtag *jtag = file->private_data;
+
+ atomic_dec(&jtag->open);
+ return 0;
+}
+
+static const struct file_operations jtag_fops = {
+ .owner = THIS_MODULE,
+ .open = jtag_open,
+ .release = jtag_release,
+ .llseek = noop_llseek,
+ .unlocked_ioctl = jtag_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = jtag_ioctl_compat,
+#endif
+};
+
+struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops)
+{
+ struct jtag *jtag;
+
+ jtag = kzalloc(sizeof(*jtag) + round_up(priv_size, ARCH_DMA_MINALIGN),
+ GFP_KERNEL);
+ if (!jtag)
+ return NULL;
+
+ jtag->ops = ops;
+ return jtag;
+}
+EXPORT_SYMBOL_GPL(jtag_alloc);
+
+void jtag_free(struct jtag *jtag)
+{
+ kfree(jtag);
+}
+EXPORT_SYMBOL_GPL(jtag_free);
+
+int jtag_register(struct jtag *jtag)
+{
+ int id;
+ int err;
+
+ id = ida_simple_get(&jtag_ida, 0, 0, GFP_KERNEL);
+ if (id < 0)
+ return id;
+
+ jtag->id = id;
+ cdev_init(&jtag->cdev, &jtag_fops);
+ jtag->cdev.owner = THIS_MODULE;
+ err = cdev_add(&jtag->cdev, MKDEV(MAJOR(jtag_devt), jtag->id), 1);
+ if (err)
+ goto err_cdev;
+
+ /* Register this jtag device with the driver core */
+ jtag->dev = device_create(&jtag_class, NULL, MKDEV(MAJOR(jtag_devt),
+ jtag->id),
+ NULL, "jtag%d", jtag->id);
+ if (!jtag->dev)
+ goto err_device_create;
+
+ atomic_set(&jtag->open, 0);
+ dev_set_drvdata(jtag->dev, jtag);
+ return err;
+
+err_device_create:
+ cdev_del(&jtag->cdev);
+err_cdev:
+ ida_simple_remove(&jtag_ida, id);
+ return err;
+}
+EXPORT_SYMBOL_GPL(jtag_register);
+
+void jtag_unregister(struct jtag *jtag)
+{
+ struct device *dev = jtag->dev;
+
+ cdev_del(&jtag->cdev);
+ device_unregister(dev);
+ ida_simple_remove(&jtag_ida, jtag->id);
+}
+EXPORT_SYMBOL_GPL(jtag_unregister);
+
+static int __init jtag_init(void)
+{
+ int err;
+
+ err = alloc_chrdev_region(&jtag_devt, JTAG_FIRST_MINOR,
+ JTAG_MAX_DEVICES, "jtag");
+ if (err)
+ return err;
+
+ err = class_register(&jtag_class);
+ if (err)
+ unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
+
+ return err;
+}
+
+static void __exit jtag_exit(void)
+{
+ class_unregister(&jtag_class);
+ unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
+}
+
+module_init(jtag_init);
+module_exit(jtag_exit);
+
+MODULE_AUTHOR("Oleksandr Shamray <oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>");
+MODULE_DESCRIPTION("Generic jtag support");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/jtag.h b/include/linux/jtag.h
new file mode 100644
index 0000000..c016fed
--- /dev/null
+++ b/include/linux/jtag.h
@@ -0,0 +1,48 @@
+/*
+ * drivers/jtag/jtag.c
+ *
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Oleksandr Shamray <oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
+ *
+ * Released under the GPLv2 only.
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#ifndef __JTAG_H
+#define __JTAG_H
+
+#include <uapi/linux/jtag.h>
+
+#ifndef ARCH_DMA_MINALIGN
+#define ARCH_DMA_MINALIGN 1
+#endif
+
+#define jtag_u64_to_ptr(arg) ((void *)(uintptr_t)arg)
+
+#define JTAG_MAX_XFER_DATA_LEN 65535
+
+struct jtag;
+/**
+ * struct jtag_ops - callbacks for jtag control functions:
+ *
+ * @freq_get: get frequency function. Filled by device driver
+ * @freq_set: set frequency function. Filled by device driver
+ * @status_get: set status function. Filled by device driver
+ * @idle: set JTAG to idle state function. Filled by device driver
+ * @xfer: send JTAG xfer function. Filled by device driver
+ */
+struct jtag_ops {
+ int (*freq_get)(struct jtag *jtag, u32 *freq);
+ int (*freq_set)(struct jtag *jtag, u32 freq);
+ int (*status_get)(struct jtag *jtag, u32 *state);
+ int (*idle)(struct jtag *jtag, struct jtag_run_test_idle *idle);
+ int (*xfer)(struct jtag *jtag, struct jtag_xfer *xfer);
+};
+
+void *jtag_priv(struct jtag *jtag);
+int jtag_register(struct jtag *jtag);
+void jtag_unregister(struct jtag *jtag);
+struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops);
+void jtag_free(struct jtag *jtag);
+
+#endif /* __JTAG_H */
diff --git a/include/uapi/linux/jtag.h b/include/uapi/linux/jtag.h
new file mode 100644
index 0000000..180bf22
--- /dev/null
+++ b/include/uapi/linux/jtag.h
@@ -0,0 +1,115 @@
+/*
+ * JTAG class driver
+ *
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Oleksandr Shamray <oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
+ *
+ * Released under the GPLv2/BSD.
+ * SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+ */
+
+#ifndef __UAPI_LINUX_JTAG_H
+#define __UAPI_LINUX_JTAG_H
+
+/**
+ * enum jtag_xfer_mode:
+ *
+ * @JTAG_XFER_HW_MODE: hardware mode transfer
+ * @JTAG_XFER_SW_MODE: software mode transfer
+ */
+enum jtag_xfer_mode {
+ JTAG_XFER_HW_MODE,
+ JTAG_XFER_SW_MODE,
+};
+
+/**
+ * enum jtag_endstate:
+ *
+ * @JTAG_STATE_IDLE: JTAG state machine IDLE state
+ * @JTAG_STATE_PAUSEIR: JTAG state machine PAUSE_IR state
+ * @JTAG_STATE_PAUSEDR: JTAG state machine PAUSE_DR state
+ */
+enum jtag_endstate {
+ JTAG_STATE_IDLE,
+ JTAG_STATE_PAUSEIR,
+ JTAG_STATE_PAUSEDR,
+};
+
+/**
+ * enum jtag_xfer_type:
+ *
+ * @JTAG_SIR_XFER: SIR transfer
+ * @JTAG_SDR_XFER: SDR transfer
+ */
+enum jtag_xfer_type {
+ JTAG_SIR_XFER,
+ JTAG_SDR_XFER,
+};
+
+/**
+ * enum jtag_xfer_direction:
+ *
+ * @JTAG_READ_XFER: read transfer
+ * @JTAG_WRITE_XFER: write transfer
+ */
+enum jtag_xfer_direction {
+ JTAG_READ_XFER,
+ JTAG_WRITE_XFER,
+};
+
+/**
+ * struct jtag_run_test_idle - forces JTAG state machine to
+ * RUN_TEST/IDLE state
+ *
+ * @mode: access mode
+ * @reset: 0 - run IDLE/PAUSE from current state
+ * 1 - go through TEST_LOGIC/RESET state before IDLE/PAUSE
+ * @end: completion flag
+ * @tck: clock counter
+ *
+ * Structure represents interface to JTAG device for jtag idle
+ * execution.
+ */
+struct jtag_run_test_idle {
+ __u8 mode;
+ __u8 reset;
+ __u8 endstate;
+ __u8 tck;
+};
+
+/**
+ * struct jtag_xfer - jtag xfer:
+ *
+ * @mode: access mode
+ * @type: transfer type
+ * @direction: xfer direction
+ * @length: xfer bits len
+ * @tdio : xfer data array
+ * @endir: xfer end state
+ *
+ * Structure represents interface to Aspeed JTAG device for jtag sdr xfer
+ * execution.
+ */
+struct jtag_xfer {
+ __u8 mode;
+ __u8 type;
+ __u8 direction;
+ __u8 endstate;
+ __u32 length;
+ __u64 tdio;
+};
+
+/* ioctl interface */
+#define __JTAG_IOCTL_MAGIC 0xb2
+
+#define JTAG_IOCRUNTEST _IOW(__JTAG_IOCTL_MAGIC, 0,\
+ struct jtag_run_test_idle)
+#define JTAG_SIOCFREQ _IOW(__JTAG_IOCTL_MAGIC, 1, unsigned int)
+#define JTAG_GIOCFREQ _IOR(__JTAG_IOCTL_MAGIC, 2, unsigned int)
+#define JTAG_IOCXFER _IOWR(__JTAG_IOCTL_MAGIC, 3, struct jtag_xfer)
+#define JTAG_GIOCSTATUS _IOWR(__JTAG_IOCTL_MAGIC, 4, enum jtag_endstate)
+
+#define JTAG_FIRST_MINOR 0
+#define JTAG_MAX_DEVICES 32
+
+#endif /* __UAPI_LINUX_JTAG_H */
--
1.7.1
^ permalink raw reply related [flat|nested] 45+ messages in thread
* [patch v9 1/4] drivers: jtag: Add JTAG core driver
@ 2017-09-21 9:25 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-21 9:25 UTC (permalink / raw)
To: linux-arm-kernel
Initial patch for JTAG driver
JTAG class driver provide infrastructure to support hardware/software
JTAG platform drivers. It provide user layer API interface for flashing
and debugging external devices which equipped with JTAG interface
using standard transactions.
Driver exposes set of IOCTL to user space for:
- XFER:
- SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
- SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
- RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
number of clocks).
- SIOCFREQ/GIOCFREQ for setting and reading JTAG frequency.
Driver core provides set of internal APIs for allocation and
registration:
- jtag_register;
- jtag_unregister;
- jtag_alloc;
- jtag_free;
Platform driver on registration with jtag-core creates the next
entry in dev folder:
/dev/jtagX
Signed-off-by: Oleksandr Shamray <oleksandrs@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
---
V8->v9
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- use get_user() instead of __get_user().
- change jtag->open type from int to atomic_t
- remove spinlock on jtg_open
- remove mutex on jtag_register
- add unregister_chrdev_region on jtag_init err
- add unregister_chrdev_region on jtag_exit
- remove unnecessary pointer casts
- add *data parameter to xfer function prototype
v7->v8
Comments pointed by Moritz Fischer <moritz.fischer@ettus.com>
- Fix misspelling s/friver/driver
v6->v7
Notifications from kbuild test robot <lkp@intel.com>
- Remove include asm/types.h from jtag.h
- Add include <linux/types.h> to jtag.c
v5->v6
v4->v5
v3->v4
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- change transaction pointer tdio type to __u64
- change internal status type from enum to __u32
- reorder jtag_xfer members to avoid the implied padding
- add __packed attribute to jtag_xfer and jtag_run_test_idle
v2->v3
Notifications from kbuild test robot <lkp@intel.com>
- Change include path to <linux/types.h> in jtag.h
v1->v2
Comments pointed by Greg KH <gregkh@linuxfoundation.org>
- Change license type from GPLv2/BSD to GPLv2
- Change type of variables which crossed user/kernel to __type
- Remove "default n" from Kconfig
Comments pointed by Andrew Lunn <andrew@lunn.ch>
- Change list_add_tail in jtag_unregister to list_del
Comments pointed by Neil Armstrong <narmstrong@baylibre.com>
- Add SPDX-License-Identifier instead of license text
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- Change __copy_to_user to memdup_user
- Change __put_user to put_user
- Change type of variables to __type for compatible 32 and 64-bit systems
- Add check for maximum xfer data size
- Change lookup data mechanism to get jtag data from inode
- Add .compat_ioctl to file ops
- Add mem alignment for jtag priv data
Comments pointed by Tobias Klauser <tklauser@distanz.ch>
- Change function names to avoid match with variable types
- Fix description for jtag_ru_test_idle in uapi jtag.h
- Fix misprints IDEL/IDLE, trough/through
---
Documentation/ioctl/ioctl-number.txt | 2 +
MAINTAINERS | 8 +
drivers/Kconfig | 2 +
drivers/Makefile | 1 +
drivers/jtag/Kconfig | 16 ++
drivers/jtag/Makefile | 1 +
drivers/jtag/jtag.c | 298 ++++++++++++++++++++++++++++++++++
include/linux/jtag.h | 48 ++++++
include/uapi/linux/jtag.h | 115 +++++++++++++
9 files changed, 491 insertions(+), 0 deletions(-)
create mode 100644 drivers/jtag/Kconfig
create mode 100644 drivers/jtag/Makefile
create mode 100644 drivers/jtag/jtag.c
create mode 100644 include/linux/jtag.h
create mode 100644 include/uapi/linux/jtag.h
diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index 3e3fdae..1af2508 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -321,6 +321,8 @@ Code Seq#(hex) Include File Comments
0xB0 all RATIO devices in development:
<mailto:vgo@ratio.de>
0xB1 00-1F PPPoX <mailto:mostrows@styx.uwaterloo.ca>
+0xB2 00-0f linux/jtag.h JTAG driver
+ <mailto:oleksandrs@mellanox.com>
0xB3 00 linux/mmc/ioctl.h
0xB4 00-0F linux/gpio.h <mailto:linux-gpio@vger.kernel.org>
0xB5 00-0F uapi/linux/rpmsg.h <mailto:linux-remoteproc@vger.kernel.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index 205d397..141aeaf 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7292,6 +7292,14 @@ L: linux-serial at vger.kernel.org
S: Maintained
F: drivers/tty/serial/jsm/
+JTAG SUBSYSTEM
+M: Oleksandr Shamray <oleksandrs@mellanox.com>
+M: Vadim Pasternak <vadimp@mellanox.com>
+S: Maintained
+F: include/linux/jtag.h
+F: include/uapi/linux/jtag.h
+F: drivers/jtag/
+
K10TEMP HARDWARE MONITORING DRIVER
M: Clemens Ladisch <clemens@ladisch.de>
L: linux-hwmon at vger.kernel.org
diff --git a/drivers/Kconfig b/drivers/Kconfig
index 505c676..2214678 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -208,4 +208,6 @@ source "drivers/tee/Kconfig"
source "drivers/mux/Kconfig"
+source "drivers/jtag/Kconfig"
+
endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index dfdcda0..6a2059b 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -182,3 +182,4 @@ obj-$(CONFIG_FPGA) += fpga/
obj-$(CONFIG_FSI) += fsi/
obj-$(CONFIG_TEE) += tee/
obj-$(CONFIG_MULTIPLEXER) += mux/
+obj-$(CONFIG_JTAG) += jtag/
diff --git a/drivers/jtag/Kconfig b/drivers/jtag/Kconfig
new file mode 100644
index 0000000..0fad1a3
--- /dev/null
+++ b/drivers/jtag/Kconfig
@@ -0,0 +1,16 @@
+menuconfig JTAG
+ tristate "JTAG support"
+ ---help---
+ This provides basic core functionality support for jtag class devices
+ Hardware equipped with JTAG microcontroller which can be built
+ on top of this drivers. Driver exposes the set of IOCTL to the
+ user space for:
+ SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
+ SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
+ RUNTEST (Forces IEEE 1149.1 bus to a run state for specified
+ number of clocks).
+
+ If you want this support, you should say Y here.
+
+ To compile this driver as a module, choose M here: the module will
+ be called jtag.
diff --git a/drivers/jtag/Makefile b/drivers/jtag/Makefile
new file mode 100644
index 0000000..af37493
--- /dev/null
+++ b/drivers/jtag/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_JTAG) += jtag.o
diff --git a/drivers/jtag/jtag.c b/drivers/jtag/jtag.c
new file mode 100644
index 0000000..4fd327a
--- /dev/null
+++ b/drivers/jtag/jtag.c
@@ -0,0 +1,298 @@
+/*
+ * drivers/jtag/jtag.c
+ *
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
+ *
+ * Released under the GPLv2 only.
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/jtag.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/rtnetlink.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <uapi/linux/jtag.h>
+
+struct jtag {
+ struct device *dev;
+ struct cdev cdev;
+ int id;
+ atomic_t open;
+ const struct jtag_ops *ops;
+ unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
+};
+
+static dev_t jtag_devt;
+static DEFINE_IDA(jtag_ida);
+
+void *jtag_priv(struct jtag *jtag)
+{
+ return jtag->priv;
+}
+EXPORT_SYMBOL_GPL(jtag_priv);
+
+static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size)
+{
+ unsigned long size;
+ void *kdata;
+
+ size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
+ kdata = memdup_user(u64_to_user_ptr(udata), size);
+
+ return kdata;
+}
+
+static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
+ unsigned long bit_size)
+{
+ unsigned long size;
+
+ size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
+
+ return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata), size);
+}
+
+static struct class jtag_class = {
+ .name = "jtag",
+ .owner = THIS_MODULE,
+};
+
+static int jtag_run_test_idle_op(struct jtag *jtag,
+ struct jtag_run_test_idle *idle)
+{
+ if (jtag->ops->idle)
+ return jtag->ops->idle(jtag, idle);
+ else
+ return -EOPNOTSUPP;
+}
+
+static int jtag_xfer_op(struct jtag *jtag, struct jtag_xfer *xfer, u8 *data)
+{
+ if (jtag->ops->xfer)
+ return jtag->ops->xfer(jtag, xfer, data);
+ else
+ return -EOPNOTSUPP;
+}
+
+static long jtag_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct jtag *jtag = file->private_data;
+ struct jtag_run_test_idle idle;
+ struct jtag_xfer xfer;
+ u8 *xfer_data;
+ u32 value;
+ int err;
+
+ switch (cmd) {
+ case JTAG_GIOCFREQ:
+ if (jtag->ops->freq_get)
+ err = jtag->ops->freq_get(jtag, &value);
+ else
+ err = -EOPNOTSUPP;
+ if (err)
+ break;
+
+ err = put_user(value, (__u32 *)arg);
+ break;
+
+ case JTAG_SIOCFREQ:
+ err = get_user(value, (__u32 *)arg);
+
+ if (value == 0)
+ err = -EINVAL;
+ if (err)
+ break;
+
+ if (jtag->ops->freq_set)
+ err = jtag->ops->freq_set(jtag, value);
+ else
+ err = -EOPNOTSUPP;
+ break;
+
+ case JTAG_IOCRUNTEST:
+ if (copy_from_user(&idle, (void *)arg,
+ sizeof(struct jtag_run_test_idle)))
+ return -ENOMEM;
+ err = jtag_run_test_idle_op(jtag, &idle);
+ break;
+
+ case JTAG_IOCXFER:
+ if (copy_from_user(&xfer, (void *)arg,
+ sizeof(struct jtag_xfer)))
+ return -EFAULT;
+
+ if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
+ return -EFAULT;
+
+ xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
+ if (!xfer_data)
+ return -ENOMEM;
+
+ err = jtag_xfer_op(jtag, &xfer, xfer_data);
+ if (jtag_copy_to_user(xfer.tdio, xfer_data, xfer.length)) {
+ kfree(xfer_data);
+ return -EFAULT;
+ }
+
+ kfree(xfer_data);
+ if (copy_to_user((void *)arg, &xfer, sizeof(struct jtag_xfer)))
+ return -EFAULT;
+ break;
+
+ case JTAG_GIOCSTATUS:
+ if (jtag->ops->status_get)
+ err = jtag->ops->status_get(jtag, &value);
+ else
+ err = -EOPNOTSUPP;
+ if (err)
+ break;
+
+ err = put_user(value, (__u32 *)arg);
+ break;
+
+ default:
+ return -EINVAL;
+ }
+ return err;
+}
+
+#ifdef CONFIG_COMPAT
+static long jtag_ioctl_compat(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ return jtag_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
+
+static int jtag_open(struct inode *inode, struct file *file)
+{
+ struct jtag *jtag = container_of(inode->i_cdev, struct jtag, cdev);
+
+ if (atomic_read(&jtag->open)) {
+ dev_info(NULL, "jtag already opened\n");
+ return -EBUSY;
+ }
+
+ atomic_inc(&jtag->open);
+ file->private_data = jtag;
+ return 0;
+}
+
+static int jtag_release(struct inode *inode, struct file *file)
+{
+ struct jtag *jtag = file->private_data;
+
+ atomic_dec(&jtag->open);
+ return 0;
+}
+
+static const struct file_operations jtag_fops = {
+ .owner = THIS_MODULE,
+ .open = jtag_open,
+ .release = jtag_release,
+ .llseek = noop_llseek,
+ .unlocked_ioctl = jtag_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = jtag_ioctl_compat,
+#endif
+};
+
+struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops)
+{
+ struct jtag *jtag;
+
+ jtag = kzalloc(sizeof(*jtag) + round_up(priv_size, ARCH_DMA_MINALIGN),
+ GFP_KERNEL);
+ if (!jtag)
+ return NULL;
+
+ jtag->ops = ops;
+ return jtag;
+}
+EXPORT_SYMBOL_GPL(jtag_alloc);
+
+void jtag_free(struct jtag *jtag)
+{
+ kfree(jtag);
+}
+EXPORT_SYMBOL_GPL(jtag_free);
+
+int jtag_register(struct jtag *jtag)
+{
+ int id;
+ int err;
+
+ id = ida_simple_get(&jtag_ida, 0, 0, GFP_KERNEL);
+ if (id < 0)
+ return id;
+
+ jtag->id = id;
+ cdev_init(&jtag->cdev, &jtag_fops);
+ jtag->cdev.owner = THIS_MODULE;
+ err = cdev_add(&jtag->cdev, MKDEV(MAJOR(jtag_devt), jtag->id), 1);
+ if (err)
+ goto err_cdev;
+
+ /* Register this jtag device with the driver core */
+ jtag->dev = device_create(&jtag_class, NULL, MKDEV(MAJOR(jtag_devt),
+ jtag->id),
+ NULL, "jtag%d", jtag->id);
+ if (!jtag->dev)
+ goto err_device_create;
+
+ atomic_set(&jtag->open, 0);
+ dev_set_drvdata(jtag->dev, jtag);
+ return err;
+
+err_device_create:
+ cdev_del(&jtag->cdev);
+err_cdev:
+ ida_simple_remove(&jtag_ida, id);
+ return err;
+}
+EXPORT_SYMBOL_GPL(jtag_register);
+
+void jtag_unregister(struct jtag *jtag)
+{
+ struct device *dev = jtag->dev;
+
+ cdev_del(&jtag->cdev);
+ device_unregister(dev);
+ ida_simple_remove(&jtag_ida, jtag->id);
+}
+EXPORT_SYMBOL_GPL(jtag_unregister);
+
+static int __init jtag_init(void)
+{
+ int err;
+
+ err = alloc_chrdev_region(&jtag_devt, JTAG_FIRST_MINOR,
+ JTAG_MAX_DEVICES, "jtag");
+ if (err)
+ return err;
+
+ err = class_register(&jtag_class);
+ if (err)
+ unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
+
+ return err;
+}
+
+static void __exit jtag_exit(void)
+{
+ class_unregister(&jtag_class);
+ unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
+}
+
+module_init(jtag_init);
+module_exit(jtag_exit);
+
+MODULE_AUTHOR("Oleksandr Shamray <oleksandrs@mellanox.com>");
+MODULE_DESCRIPTION("Generic jtag support");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/jtag.h b/include/linux/jtag.h
new file mode 100644
index 0000000..c016fed
--- /dev/null
+++ b/include/linux/jtag.h
@@ -0,0 +1,48 @@
+/*
+ * drivers/jtag/jtag.c
+ *
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
+ *
+ * Released under the GPLv2 only.
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#ifndef __JTAG_H
+#define __JTAG_H
+
+#include <uapi/linux/jtag.h>
+
+#ifndef ARCH_DMA_MINALIGN
+#define ARCH_DMA_MINALIGN 1
+#endif
+
+#define jtag_u64_to_ptr(arg) ((void *)(uintptr_t)arg)
+
+#define JTAG_MAX_XFER_DATA_LEN 65535
+
+struct jtag;
+/**
+ * struct jtag_ops - callbacks for jtag control functions:
+ *
+ * @freq_get: get frequency function. Filled by device driver
+ * @freq_set: set frequency function. Filled by device driver
+ * @status_get: set status function. Filled by device driver
+ * @idle: set JTAG to idle state function. Filled by device driver
+ * @xfer: send JTAG xfer function. Filled by device driver
+ */
+struct jtag_ops {
+ int (*freq_get)(struct jtag *jtag, u32 *freq);
+ int (*freq_set)(struct jtag *jtag, u32 freq);
+ int (*status_get)(struct jtag *jtag, u32 *state);
+ int (*idle)(struct jtag *jtag, struct jtag_run_test_idle *idle);
+ int (*xfer)(struct jtag *jtag, struct jtag_xfer *xfer);
+};
+
+void *jtag_priv(struct jtag *jtag);
+int jtag_register(struct jtag *jtag);
+void jtag_unregister(struct jtag *jtag);
+struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops);
+void jtag_free(struct jtag *jtag);
+
+#endif /* __JTAG_H */
diff --git a/include/uapi/linux/jtag.h b/include/uapi/linux/jtag.h
new file mode 100644
index 0000000..180bf22
--- /dev/null
+++ b/include/uapi/linux/jtag.h
@@ -0,0 +1,115 @@
+/*
+ * JTAG class driver
+ *
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
+ *
+ * Released under the GPLv2/BSD.
+ * SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+ */
+
+#ifndef __UAPI_LINUX_JTAG_H
+#define __UAPI_LINUX_JTAG_H
+
+/**
+ * enum jtag_xfer_mode:
+ *
+ * @JTAG_XFER_HW_MODE: hardware mode transfer
+ * @JTAG_XFER_SW_MODE: software mode transfer
+ */
+enum jtag_xfer_mode {
+ JTAG_XFER_HW_MODE,
+ JTAG_XFER_SW_MODE,
+};
+
+/**
+ * enum jtag_endstate:
+ *
+ * @JTAG_STATE_IDLE: JTAG state machine IDLE state
+ * @JTAG_STATE_PAUSEIR: JTAG state machine PAUSE_IR state
+ * @JTAG_STATE_PAUSEDR: JTAG state machine PAUSE_DR state
+ */
+enum jtag_endstate {
+ JTAG_STATE_IDLE,
+ JTAG_STATE_PAUSEIR,
+ JTAG_STATE_PAUSEDR,
+};
+
+/**
+ * enum jtag_xfer_type:
+ *
+ * @JTAG_SIR_XFER: SIR transfer
+ * @JTAG_SDR_XFER: SDR transfer
+ */
+enum jtag_xfer_type {
+ JTAG_SIR_XFER,
+ JTAG_SDR_XFER,
+};
+
+/**
+ * enum jtag_xfer_direction:
+ *
+ * @JTAG_READ_XFER: read transfer
+ * @JTAG_WRITE_XFER: write transfer
+ */
+enum jtag_xfer_direction {
+ JTAG_READ_XFER,
+ JTAG_WRITE_XFER,
+};
+
+/**
+ * struct jtag_run_test_idle - forces JTAG state machine to
+ * RUN_TEST/IDLE state
+ *
+ * @mode: access mode
+ * @reset: 0 - run IDLE/PAUSE from current state
+ * 1 - go through TEST_LOGIC/RESET state before IDLE/PAUSE
+ * @end: completion flag
+ * @tck: clock counter
+ *
+ * Structure represents interface to JTAG device for jtag idle
+ * execution.
+ */
+struct jtag_run_test_idle {
+ __u8 mode;
+ __u8 reset;
+ __u8 endstate;
+ __u8 tck;
+};
+
+/**
+ * struct jtag_xfer - jtag xfer:
+ *
+ * @mode: access mode
+ * @type: transfer type
+ * @direction: xfer direction
+ * @length: xfer bits len
+ * @tdio : xfer data array
+ * @endir: xfer end state
+ *
+ * Structure represents interface to Aspeed JTAG device for jtag sdr xfer
+ * execution.
+ */
+struct jtag_xfer {
+ __u8 mode;
+ __u8 type;
+ __u8 direction;
+ __u8 endstate;
+ __u32 length;
+ __u64 tdio;
+};
+
+/* ioctl interface */
+#define __JTAG_IOCTL_MAGIC 0xb2
+
+#define JTAG_IOCRUNTEST _IOW(__JTAG_IOCTL_MAGIC, 0,\
+ struct jtag_run_test_idle)
+#define JTAG_SIOCFREQ _IOW(__JTAG_IOCTL_MAGIC, 1, unsigned int)
+#define JTAG_GIOCFREQ _IOR(__JTAG_IOCTL_MAGIC, 2, unsigned int)
+#define JTAG_IOCXFER _IOWR(__JTAG_IOCTL_MAGIC, 3, struct jtag_xfer)
+#define JTAG_GIOCSTATUS _IOWR(__JTAG_IOCTL_MAGIC, 4, enum jtag_endstate)
+
+#define JTAG_FIRST_MINOR 0
+#define JTAG_MAX_DEVICES 32
+
+#endif /* __UAPI_LINUX_JTAG_H */
--
1.7.1
^ permalink raw reply related [flat|nested] 45+ messages in thread
* [patch v9 2/4] drivers: jtag: Add Aspeed SoC 24xx and 25xx families JTAG master driver
@ 2017-09-21 9:25 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-21 9:25 UTC (permalink / raw)
To: gregkh, arnd
Cc: linux-kernel, linux-arm-kernel, devicetree, openbmc, joel, jiri,
tklauser, linux-serial, mec, vadimp, system-sw-low-level,
robh+dt, openocd-devel-owner, linux-api, davem, mchehab,
Oleksandr Shamray, Jiri Pirko
Driver adds support of Aspeed 2500/2400 series SOC JTAG master controller.
Driver implements the following jtag ops:
- freq_get;
- freq_set;
- status_get;
- idle;
- xfer;
It has been tested on Mellanox system with BMC equipped with
Aspeed 2520 SoC for programming CPLD devices.
Signed-off-by: Oleksandr Shamray <oleksandrs@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
V8->v9
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- add *data parameter to xfer function prototype
v7->v8
Comments pointed by Joel Stanley <joel.stan@gmail.com>
- aspeed_jtag_init replace goto to return;
- change input variables type from __u32 to u32
in functios freq_get, freq_set, status_get
- change sm_ variables type from char to u8
- in jatg_init add disable clocks on error case
- remove release_mem_region on error case
- remove devm_free_irq on jtag_deinit
- Fix misspelling Disabe/Disable
- Change compatible string to ast2400 and ast2000
v6->v7
Notifications from kbuild test robot <lkp@intel.com>
- Add include <linux/types.h> to jtag-asapeed.c
v5->v6
v4->v5
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- Added HAS_IOMEM dependence in Kconfig to avoid
"undefined reference to `devm_ioremap_resource'" error,
because in some arch this not supported
v3->v4
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- change transaction pointer tdio type to __u64
- change internal status type from enum to __u32
v2->v3
v1->v2
Comments pointed by Greg KH <gregkh@linuxfoundation.org>
- change license type from GPLv2/BSD to GPLv2
Comments pointed by Neil Armstrong <narmstrong@baylibre.com>
- Add clk_prepare_enable/clk_disable_unprepare in clock init/deinit
- Change .compatible to soc-specific compatible names
aspeed,aspeed4000-jtag/aspeed5000-jtag
- Added dt-bindings
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- Reorder functions and removed the forward declarations
- Add static const qualifier to state machine states transitions
- Change .compatible to soc-specific compatible names
aspeed,aspeed4000-jtag/aspeed5000-jtag
- Add dt-bindings
Comments pointed by Randy Dunlap <rdunlap@infradead.org>
- Change module name jtag-aspeed in description in Kconfig
Comments pointed by kbuild test robot <lkp@intel.com>
- Remove invalid include <asm/mach-types.h>
- add resource_size instead of calculation
---
drivers/jtag/Kconfig | 13 +
drivers/jtag/Makefile | 1 +
drivers/jtag/jtag-aspeed.c | 771 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 785 insertions(+), 0 deletions(-)
create mode 100644 drivers/jtag/jtag-aspeed.c
diff --git a/drivers/jtag/Kconfig b/drivers/jtag/Kconfig
index 0fad1a3..098beb0 100644
--- a/drivers/jtag/Kconfig
+++ b/drivers/jtag/Kconfig
@@ -14,3 +14,16 @@ menuconfig JTAG
To compile this driver as a module, choose M here: the module will
be called jtag.
+
+menuconfig JTAG_ASPEED
+ tristate "Aspeed SoC JTAG controller support"
+ depends on JTAG && HAS_IOMEM
+ ---help---
+ This provides a support for Aspeed JTAG device, equipped on
+ Aspeed SoC 24xx and 25xx families. Drivers allows programming
+ of hardware devices, connected to SoC through the JTAG interface.
+
+ If you want this support, you should say Y here.
+
+ To compile this driver as a module, choose M here: the module will
+ be called jtag-aspeed.
diff --git a/drivers/jtag/Makefile b/drivers/jtag/Makefile
index af37493..04a855e 100644
--- a/drivers/jtag/Makefile
+++ b/drivers/jtag/Makefile
@@ -1 +1,2 @@
obj-$(CONFIG_JTAG) += jtag.o
+obj-$(CONFIG_JTAG_ASPEED) += jtag-aspeed.o
diff --git a/drivers/jtag/jtag-aspeed.c b/drivers/jtag/jtag-aspeed.c
new file mode 100644
index 0000000..a8dd4f9
--- /dev/null
+++ b/drivers/jtag/jtag-aspeed.c
@@ -0,0 +1,771 @@
+/*
+ * drivers/jtag/jtag.c
+ *
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
+ *
+ * Released under the GPLv2 only.
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/jtag.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <uapi/linux/jtag.h>
+
+#define ASPEED_JTAG_DATA 0x00
+#define ASPEED_JTAG_INST 0x04
+#define ASPEED_JTAG_CTRL 0x08
+#define ASPEED_JTAG_ISR 0x0C
+#define ASPEED_JTAG_SW 0x10
+#define ASPEED_JTAG_TCK 0x14
+#define ASPEED_JTAG_EC 0x18
+
+#define ASPEED_JTAG_DATA_MSB 0x01
+#define ASPEED_JTAG_DATA_CHUNK_SIZE 0x20
+
+/* ASPEED_JTAG_CTRL: Engine Control */
+#define ASPEED_JTAG_CTL_ENG_EN BIT(31)
+#define ASPEED_JTAG_CTL_ENG_OUT_EN BIT(30)
+#define ASPEED_JTAG_CTL_FORCE_TMS BIT(29)
+#define ASPEED_JTAG_CTL_INST_LEN(x) ((x) << 20)
+#define ASPEED_JTAG_CTL_LASPEED_INST BIT(17)
+#define ASPEED_JTAG_CTL_INST_EN BIT(16)
+#define ASPEED_JTAG_CTL_DR_UPDATE BIT(10)
+#define ASPEED_JTAG_CTL_DATA_LEN(x) ((x) << 4)
+#define ASPEED_JTAG_CTL_LASPEED_DATA BIT(1)
+#define ASPEED_JTAG_CTL_DATA_EN BIT(0)
+
+/* ASPEED_JTAG_ISR : Interrupt status and enable */
+#define ASPEED_JTAG_ISR_INST_PAUSE BIT(19)
+#define ASPEED_JTAG_ISR_INST_COMPLETE BIT(18)
+#define ASPEED_JTAG_ISR_DATA_PAUSE BIT(17)
+#define ASPEED_JTAG_ISR_DATA_COMPLETE BIT(16)
+#define ASPEED_JTAG_ISR_INST_PAUSE_EN BIT(3)
+#define ASPEED_JTAG_ISR_INST_COMPLETE_EN BIT(2)
+#define ASPEED_JTAG_ISR_DATA_PAUSE_EN BIT(1)
+#define ASPEED_JTAG_ISR_DATA_COMPLETE_EN BIT(0)
+#define ASPEED_JTAG_ISR_INT_EN_MASK GENMASK(3, 0)
+#define ASPEED_JTAG_ISR_INT_MASK GENMASK(19, 16)
+
+/* ASPEED_JTAG_SW : Software Mode and Status */
+#define ASPEED_JTAG_SW_MODE_EN BIT(19)
+#define ASPEED_JTAG_SW_MODE_TCK BIT(18)
+#define ASPEED_JTAG_SW_MODE_TMS BIT(17)
+#define ASPEED_JTAG_SW_MODE_TDIO BIT(16)
+
+/* ASPEED_JTAG_TCK : TCK Control */
+#define ASPEED_JTAG_TCK_DIVISOR_MASK GENMASK(10, 0)
+#define ASPEED_JTAG_TCK_GET_DIV(x) ((x) & ASPEED_JTAG_TCK_DIVISOR_MASK)
+
+/* ASPEED_JTAG_EC : Controller set for go to IDLE */
+#define ASPEED_JTAG_EC_GO_IDLE BIT(0)
+
+#define ASPEED_JTAG_IOUT_LEN(len) (ASPEED_JTAG_CTL_ENG_EN |\
+ ASPEED_JTAG_CTL_ENG_OUT_EN |\
+ ASPEED_JTAG_CTL_INST_LEN(len))
+
+#define ASPEED_JTAG_DOUT_LEN(len) (ASPEED_JTAG_CTL_ENG_EN |\
+ ASPEED_JTAG_CTL_ENG_OUT_EN |\
+ ASPEED_JTAG_CTL_DATA_LEN(len))
+
+#define ASPEED_JTAG_TCK_WAIT 10
+#define ASPEED_JTAG_RESET_CNTR 10
+
+#define ASPEED_JTAG_NAME "jtag-aspeed"
+
+struct aspeed_jtag {
+ void __iomem *reg_base;
+ struct device *dev;
+ struct clk *pclk;
+ enum jtag_endstate status;
+ int irq;
+ u32 flag;
+ wait_queue_head_t jtag_wq;
+ bool is_open;
+};
+
+static char *end_status_str[] = {"idle", "ir pause", "drpause"};
+
+static u32 aspeed_jtag_read(struct aspeed_jtag *aspeed_jtag, u32 reg)
+{
+ return readl(aspeed_jtag->reg_base + reg);
+}
+
+static void
+aspeed_jtag_write(struct aspeed_jtag *aspeed_jtag, u32 val, u32 reg)
+{
+ writel(val, aspeed_jtag->reg_base + reg);
+}
+
+static int aspeed_jtag_freq_set(struct jtag *jtag, u32 freq)
+{
+ struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+ unsigned long apb_frq;
+ u32 tck_val;
+ u16 div;
+
+ apb_frq = clk_get_rate(aspeed_jtag->pclk);
+ div = (apb_frq % freq == 0) ? (apb_frq / freq) - 1 : (apb_frq / freq);
+ tck_val = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_TCK);
+ aspeed_jtag_write(aspeed_jtag,
+ (tck_val & ASPEED_JTAG_TCK_DIVISOR_MASK) | div,
+ ASPEED_JTAG_TCK);
+ return 0;
+}
+
+static int aspeed_jtag_freq_get(struct jtag *jtag, u32 *frq)
+{
+ struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+ u32 pclk;
+ u32 tck;
+
+ pclk = clk_get_rate(aspeed_jtag->pclk);
+ tck = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_TCK);
+ *frq = pclk / (ASPEED_JTAG_TCK_GET_DIV(tck) + 1);
+
+ return 0;
+}
+
+static void aspeed_jtag_sw_delay(struct aspeed_jtag *aspeed_jtag, int cnt)
+{
+ int i;
+
+ for (i = 0; i < cnt; i++)
+ aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_SW);
+}
+
+static char aspeed_jtag_tck_cycle(struct aspeed_jtag *aspeed_jtag,
+ u8 tms, u8 tdi)
+{
+ char tdo = 0;
+
+ /* TCK = 0 */
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ (tms * ASPEED_JTAG_SW_MODE_TMS) |
+ (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
+
+ aspeed_jtag_sw_delay(aspeed_jtag, ASPEED_JTAG_TCK_WAIT);
+
+ /* TCK = 1 */
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ ASPEED_JTAG_SW_MODE_TCK |
+ (tms * ASPEED_JTAG_SW_MODE_TMS) |
+ (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
+
+ if (aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_SW) &
+ ASPEED_JTAG_SW_MODE_TDIO)
+ tdo = 1;
+
+ aspeed_jtag_sw_delay(aspeed_jtag, ASPEED_JTAG_TCK_WAIT);
+
+ /* TCK = 0 */
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ (tms * ASPEED_JTAG_SW_MODE_TMS) |
+ (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
+ return tdo;
+}
+
+static void aspeed_jtag_wait_instruction_pause(struct aspeed_jtag *aspeed_jtag)
+{
+ wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+ ASPEED_JTAG_ISR_INST_PAUSE);
+ aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_INST_PAUSE;
+}
+
+static void
+aspeed_jtag_wait_instruction_complete(struct aspeed_jtag *aspeed_jtag)
+{
+ wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+ ASPEED_JTAG_ISR_INST_COMPLETE);
+ aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_INST_COMPLETE;
+}
+
+static void
+aspeed_jtag_wait_data_pause_complete(struct aspeed_jtag *aspeed_jtag)
+{
+ wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+ ASPEED_JTAG_ISR_DATA_PAUSE);
+ aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_DATA_PAUSE;
+}
+
+static void aspeed_jtag_wait_data_complete(struct aspeed_jtag *aspeed_jtag)
+{
+ wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+ ASPEED_JTAG_ISR_DATA_COMPLETE);
+ aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_DATA_COMPLETE;
+}
+
+static void aspeed_jtag_sm_cycle(struct aspeed_jtag *aspeed_jtag, const u8 *tms,
+ int len)
+{
+ int i;
+
+ for (i = 0; i < len; i++)
+ aspeed_jtag_tck_cycle(aspeed_jtag, tms[i], 0);
+}
+
+static void aspeed_jtag_run_test_idle_sw(struct aspeed_jtag *aspeed_jtag,
+ struct jtag_run_test_idle *runtest)
+{
+ static const u8 sm_pause_irpause[] = {1, 1, 1, 1, 0, 1, 0};
+ static const u8 sm_pause_drpause[] = {1, 1, 1, 0, 1, 0};
+ static const u8 sm_idle_irpause[] = {1, 1, 0, 1, 0};
+ static const u8 sm_idle_drpause[] = {1, 0, 1, 0};
+ static const u8 sm_pause_idle[] = {1, 1, 0};
+ int i;
+
+ /* SW mode from idle/pause-> to pause/idle */
+ if (runtest->reset) {
+ for (i = 0; i < ASPEED_JTAG_RESET_CNTR; i++)
+ aspeed_jtag_tck_cycle(aspeed_jtag, 1, 0);
+ }
+
+ switch (aspeed_jtag->status) {
+ case JTAG_STATE_IDLE:
+ switch (runtest->endstate) {
+ case JTAG_STATE_PAUSEIR:
+ /* ->DRSCan->IRSCan->IRCap->IRExit1->PauseIR */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_idle_irpause,
+ sizeof(sm_idle_irpause));
+
+ aspeed_jtag->status = JTAG_STATE_PAUSEIR;
+ break;
+ case JTAG_STATE_PAUSEDR:
+ /* ->DRSCan->DRCap->DRExit1->PauseDR */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_idle_drpause,
+ sizeof(sm_idle_drpause));
+
+ aspeed_jtag->status = JTAG_STATE_PAUSEDR;
+ break;
+ case JTAG_STATE_IDLE:
+ /* IDLE */
+ aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
+ aspeed_jtag->status = JTAG_STATE_IDLE;
+ break;
+ default:
+ break;
+ }
+ break;
+
+ case JTAG_STATE_PAUSEIR:
+ /* Fall-through */
+ case JTAG_STATE_PAUSEDR:
+ /* From IR/DR Pause */
+ switch (runtest->endstate) {
+ case JTAG_STATE_PAUSEIR:
+ /*
+ * to Exit2 IR/DR->Updt IR/DR->DRSCan->IRSCan->IRCap->
+ * IRExit1->PauseIR
+ */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_irpause,
+ sizeof(sm_pause_irpause));
+
+ aspeed_jtag->status = JTAG_STATE_PAUSEIR;
+ break;
+ case JTAG_STATE_PAUSEDR:
+ /*
+ * to Exit2 IR/DR->Updt IR/DR->DRSCan->DRCap->
+ * DRExit1->PauseDR
+ */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_drpause,
+ sizeof(sm_pause_drpause));
+ aspeed_jtag->status = JTAG_STATE_PAUSEDR;
+ break;
+ case JTAG_STATE_IDLE:
+ /* to Exit2 IR/DR->Updt IR/DR->IDLE */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_idle,
+ sizeof(sm_pause_idle));
+ aspeed_jtag->status = JTAG_STATE_IDLE;
+ break;
+ default:
+ break;
+ }
+ break;
+
+ default:
+ dev_err(aspeed_jtag->dev, "aspeed_jtag_run_test_idle error\n");
+ break;
+ }
+
+ /* Stay on IDLE for at least TCK cycle */
+ for (i = 0; i < runtest->tck; i++)
+ aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
+}
+
+/**
+ * aspeed_jtag_run_test_idle:
+ * JTAG reset: generates at least 9 TMS high and 1 TMS low to force
+ * devices into Run-Test/Idle State.
+ */
+static int aspeed_jtag_idle(struct jtag *jtag,
+ struct jtag_run_test_idle *runtest)
+{
+ struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+
+ dev_dbg(aspeed_jtag->dev, "aspeed_jtag runtest, status:%d, mode:%s, state:%s, reset:%d, tck:%d\n",
+ aspeed_jtag->status, runtest->mode ? "SW" : "HW",
+ end_status_str[runtest->endstate], runtest->reset,
+ runtest->tck);
+
+ if (runtest->mode) {
+ aspeed_jtag_run_test_idle_sw(aspeed_jtag, runtest);
+ return 0;
+ }
+
+ /* Disable sw mode */
+ aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_SW);
+ /* x TMS high + 1 TMS low */
+ if (runtest->reset)
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_CTL_ENG_EN |
+ ASPEED_JTAG_CTL_ENG_OUT_EN |
+ ASPEED_JTAG_CTL_FORCE_TMS, ASPEED_JTAG_CTRL);
+ else
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_EC_GO_IDLE,
+ ASPEED_JTAG_EC);
+
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+ aspeed_jtag->status = JTAG_STATE_IDLE;
+ return 0;
+}
+
+static void aspeed_jtag_xfer_sw(struct aspeed_jtag *aspeed_jtag,
+ struct jtag_xfer *xfer, unsigned long *data)
+{
+ unsigned long remain_xfer = xfer->length;
+ unsigned long shift_bits = 0;
+ unsigned long index = 0;
+ unsigned long tdi;
+ char tdo;
+
+ if (xfer->direction == JTAG_READ_XFER)
+ tdi = UINT_MAX;
+ else
+ tdi = data[index];
+
+ while (remain_xfer > 1) {
+ tdo = aspeed_jtag_tck_cycle(aspeed_jtag, 0,
+ tdi & ASPEED_JTAG_DATA_MSB);
+ data[index] |= tdo << (shift_bits %
+ ASPEED_JTAG_DATA_CHUNK_SIZE);
+
+ tdi >>= 1;
+ shift_bits++;
+ remain_xfer--;
+
+ if (shift_bits % ASPEED_JTAG_DATA_CHUNK_SIZE == 0) {
+ dev_dbg(aspeed_jtag->dev, "R/W data[%lu]:%lx\n",
+ index, data[index]);
+
+ tdo = 0;
+ index++;
+
+ if (xfer->direction == JTAG_READ_XFER)
+ tdi = UINT_MAX;
+ else
+ tdi = data[index];
+ }
+ }
+
+ tdo = aspeed_jtag_tck_cycle(aspeed_jtag, 1, tdi & ASPEED_JTAG_DATA_MSB);
+ data[index] |= tdo << (shift_bits % ASPEED_JTAG_DATA_CHUNK_SIZE);
+}
+
+static void aspeed_jtag_xfer_push_data(struct aspeed_jtag *aspeed_jtag,
+ enum jtag_xfer_type type, u32 bits_len)
+{
+ dev_dbg(aspeed_jtag->dev, "shift bits %d\n", bits_len);
+
+ if (type == JTAG_SIR_XFER) {
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_IOUT_LEN(bits_len),
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len) |
+ ASPEED_JTAG_CTL_INST_EN, ASPEED_JTAG_CTRL);
+ } else {
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len),
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len) |
+ ASPEED_JTAG_CTL_DATA_EN, ASPEED_JTAG_CTRL);
+ }
+}
+
+static void aspeed_jtag_xfer_push_data_last(struct aspeed_jtag *aspeed_jtag,
+ enum jtag_xfer_type type,
+ u32 shift_bits,
+ enum jtag_endstate endstate)
+{
+ if (endstate != JTAG_STATE_IDLE) {
+ if (type == JTAG_SIR_XFER) {
+ dev_dbg(aspeed_jtag->dev, "IR Keep Pause\n");
+
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_IOUT_LEN(shift_bits),
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_IOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_INST_EN,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_wait_instruction_pause(aspeed_jtag);
+ } else {
+ dev_dbg(aspeed_jtag->dev, "DR Keep Pause\n");
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_DOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_DR_UPDATE,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_DOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_DR_UPDATE |
+ ASPEED_JTAG_CTL_DATA_EN,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_wait_data_pause_complete(aspeed_jtag);
+ }
+ } else {
+ if (type == JTAG_SIR_XFER) {
+ dev_dbg(aspeed_jtag->dev, "IR go IDLE\n");
+
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_IOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_LASPEED_INST,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_IOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_LASPEED_INST |
+ ASPEED_JTAG_CTL_INST_EN,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_wait_instruction_complete(aspeed_jtag);
+ } else {
+ dev_dbg(aspeed_jtag->dev, "DR go IDLE\n");
+
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_DOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_LASPEED_DATA,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_DOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_LASPEED_DATA |
+ ASPEED_JTAG_CTL_DATA_EN,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_wait_data_complete(aspeed_jtag);
+ }
+ }
+}
+
+static void aspeed_jtag_xfer_hw(struct aspeed_jtag *aspeed_jtag,
+ struct jtag_xfer *xfer, unsigned long *data)
+{
+ unsigned long remain_xfer = xfer->length;
+ unsigned long index = 0;
+ char shift_bits;
+ u32 data_reg;
+
+ data_reg = xfer->type == JTAG_SIR_XFER ?
+ ASPEED_JTAG_INST : ASPEED_JTAG_DATA;
+ while (remain_xfer) {
+ if (xfer->direction == JTAG_WRITE_XFER) {
+ dev_dbg(aspeed_jtag->dev, "W dr->dr_data[%lu]:%lx\n",
+ index, data[index]);
+
+ aspeed_jtag_write(aspeed_jtag, data[index], data_reg);
+ } else {
+ aspeed_jtag_write(aspeed_jtag, 0, data_reg);
+ }
+
+ if (remain_xfer > ASPEED_JTAG_DATA_CHUNK_SIZE) {
+ shift_bits = ASPEED_JTAG_DATA_CHUNK_SIZE;
+
+ /*
+ * Read bytes were not equals to column length
+ * and go to Pause-DR
+ */
+ aspeed_jtag_xfer_push_data(aspeed_jtag, xfer->type,
+ shift_bits);
+ } else {
+ /*
+ * Read bytes equals to column length =>
+ * Update-DR
+ */
+ shift_bits = remain_xfer;
+ aspeed_jtag_xfer_push_data_last(aspeed_jtag, xfer->type,
+ shift_bits,
+ xfer->endstate);
+ }
+
+ if (xfer->direction == JTAG_READ_XFER) {
+ if (shift_bits < ASPEED_JTAG_DATA_CHUNK_SIZE) {
+ data[index] = aspeed_jtag_read(aspeed_jtag,
+ data_reg);
+
+ data[index] >>= ASPEED_JTAG_DATA_CHUNK_SIZE -
+ shift_bits;
+ } else {
+ data[index] = aspeed_jtag_read(aspeed_jtag,
+ data_reg);
+ }
+ dev_dbg(aspeed_jtag->dev, "R dr->dr_data[%lu]:%lx\n",
+ index, data[index]);
+ }
+
+ remain_xfer = remain_xfer - shift_bits;
+ index++;
+ dev_dbg(aspeed_jtag->dev, "remain_xfer %lu\n", remain_xfer);
+ }
+}
+
+static int aspeed_jtag_xfer(struct jtag *jtag, struct jtag_xfer *xfer,
+ u8 *xfer_data)
+{
+ static const u8 sm_update_shiftir[] = {1, 1, 0, 0};
+ static const u8 sm_update_shiftdr[] = {1, 0, 0};
+ static const u8 sm_pause_idle[] = {1, 1, 0};
+ static const u8 sm_pause_update[] = {1, 1};
+ struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+ unsigned long *data = (unsigned long *)xfer_data;
+ unsigned long remain_xfer = xfer->length;
+ unsigned long offset;
+ char dbg_str[256];
+ int pos = 0;
+ int i;
+
+ for (offset = 0, i = 0; offset < xfer->length;
+ offset += ASPEED_JTAG_DATA_CHUNK_SIZE, i++) {
+ pos += snprintf(&dbg_str[pos], sizeof(dbg_str) - pos,
+ "0x%08lx ", data[i]);
+ }
+
+ dev_dbg(aspeed_jtag->dev, "aspeed_jtag %s %s xfer, mode:%s, END:%d, len:%lu, TDI[%s]\n",
+ xfer->type == JTAG_SIR_XFER ? "SIR" : "SDR",
+ xfer->direction == JTAG_READ_XFER ? "READ" : "WRITE",
+ xfer->mode ? "SW" : "HW",
+ xfer->endstate, remain_xfer, dbg_str);
+
+ if (xfer->mode == JTAG_XFER_SW_MODE) {
+ /* SW mode */
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+ if (aspeed_jtag->status != JTAG_STATE_IDLE) {
+ /*IR/DR Pause->Exit2 IR / DR->Update IR /DR */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_update,
+ sizeof(sm_pause_update));
+ }
+
+ if (xfer->type == JTAG_SIR_XFER)
+ /* ->IRSCan->CapIR->ShiftIR */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_update_shiftir,
+ sizeof(sm_update_shiftir));
+ else
+ /* ->DRScan->DRCap->DRShift */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_update_shiftdr,
+ sizeof(sm_update_shiftdr));
+
+ aspeed_jtag_xfer_sw(aspeed_jtag, xfer, data);
+
+ /* DIPause/DRPause */
+ aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
+
+ if (xfer->endstate == JTAG_STATE_IDLE) {
+ /* ->DRExit2->DRUpdate->IDLE */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_idle,
+ sizeof(sm_pause_idle));
+ }
+ } else {
+ /* hw mode */
+ aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_SW);
+ aspeed_jtag_xfer_hw(aspeed_jtag, xfer, data);
+ }
+
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+ aspeed_jtag->status = xfer->endstate;
+ return 0;
+}
+
+static int aspeed_jtag_status_get(struct jtag *jtag, u32 *status)
+{
+ struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+
+ *status = aspeed_jtag->status;
+ return 0;
+}
+
+static irqreturn_t aspeed_jtag_interrupt(s32 this_irq, void *dev_id)
+{
+ struct aspeed_jtag *aspeed_jtag = dev_id;
+ irqreturn_t ret;
+ u32 status;
+
+ status = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_ISR);
+ dev_dbg(aspeed_jtag->dev, "status %x\n", status);
+
+ if (status & ASPEED_JTAG_ISR_INT_MASK) {
+ aspeed_jtag_write(aspeed_jtag,
+ (status & ASPEED_JTAG_ISR_INT_MASK)
+ | (status & ASPEED_JTAG_ISR_INT_EN_MASK),
+ ASPEED_JTAG_ISR);
+ aspeed_jtag->flag |= status & ASPEED_JTAG_ISR_INT_MASK;
+ }
+
+ if (aspeed_jtag->flag) {
+ wake_up_interruptible(&aspeed_jtag->jtag_wq);
+ ret = IRQ_HANDLED;
+ } else {
+ dev_err(aspeed_jtag->dev, "aspeed_jtag irq status:%x\n",
+ status);
+ ret = IRQ_NONE;
+ }
+ return ret;
+}
+
+int aspeed_jtag_init(struct platform_device *pdev,
+ struct aspeed_jtag *aspeed_jtag)
+{
+ struct resource *res;
+ int err;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ aspeed_jtag->reg_base = devm_ioremap_resource(aspeed_jtag->dev, res);
+ if (IS_ERR(aspeed_jtag->reg_base))
+ return -ENOMEM;
+
+ aspeed_jtag->pclk = devm_clk_get(aspeed_jtag->dev, NULL);
+ if (IS_ERR(aspeed_jtag->pclk)) {
+ dev_err(aspeed_jtag->dev, "devm_clk_get failed\n");
+ return PTR_ERR(aspeed_jtag->pclk);
+ }
+
+ clk_prepare_enable(aspeed_jtag->pclk);
+
+ aspeed_jtag->irq = platform_get_irq(pdev, 0);
+ if (aspeed_jtag->irq < 0) {
+ dev_err(aspeed_jtag->dev, "no irq specified\n");
+ err = -ENOENT;
+ goto clk_unprep;
+ }
+
+ /* Enable clock */
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_CTL_ENG_EN |
+ ASPEED_JTAG_CTL_ENG_OUT_EN, ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+ err = devm_request_irq(aspeed_jtag->dev, aspeed_jtag->irq,
+ aspeed_jtag_interrupt, 0,
+ "aspeed-jtag", aspeed_jtag);
+ if (err) {
+ dev_err(aspeed_jtag->dev, "aspeed_jtag unable to get IRQ");
+ goto clk_unprep;
+ }
+ dev_dbg(&pdev->dev, "aspeed_jtag:IRQ %d.\n", aspeed_jtag->irq);
+
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_ISR_INST_PAUSE |
+ ASPEED_JTAG_ISR_INST_COMPLETE |
+ ASPEED_JTAG_ISR_DATA_PAUSE |
+ ASPEED_JTAG_ISR_DATA_COMPLETE |
+ ASPEED_JTAG_ISR_INST_PAUSE_EN |
+ ASPEED_JTAG_ISR_INST_COMPLETE_EN |
+ ASPEED_JTAG_ISR_DATA_PAUSE_EN |
+ ASPEED_JTAG_ISR_DATA_COMPLETE_EN,
+ ASPEED_JTAG_ISR);
+
+ aspeed_jtag->flag = 0;
+ init_waitqueue_head(&aspeed_jtag->jtag_wq);
+ return 0;
+
+clk_unprep:
+ clk_disable_unprepare(aspeed_jtag->pclk);
+ return err;
+}
+
+int aspeed_jtag_deinit(struct platform_device *pdev,
+ struct aspeed_jtag *aspeed_jtag)
+{
+ aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_ISR);
+ /* Disable clock */
+ aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_CTRL);
+ clk_disable_unprepare(aspeed_jtag->pclk);
+ return 0;
+}
+
+static const struct jtag_ops aspeed_jtag_ops = {
+ .freq_get = aspeed_jtag_freq_get,
+ .freq_set = aspeed_jtag_freq_set,
+ .status_get = aspeed_jtag_status_get,
+ .idle = aspeed_jtag_idle,
+ .xfer = aspeed_jtag_xfer
+};
+
+static int aspeed_jtag_probe(struct platform_device *pdev)
+{
+ struct aspeed_jtag *aspeed_jtag;
+ struct jtag *jtag;
+ int err;
+
+ if (!of_device_is_compatible(pdev->dev.of_node, "aspeed,aspeed-jtag"))
+ return -ENOMEM;
+
+ jtag = jtag_alloc(sizeof(*aspeed_jtag), &aspeed_jtag_ops);
+ if (!jtag)
+ return -ENODEV;
+
+ platform_set_drvdata(pdev, jtag);
+ aspeed_jtag = jtag_priv(jtag);
+ aspeed_jtag->dev = &pdev->dev;
+
+ /* Initialize device*/
+ err = aspeed_jtag_init(pdev, aspeed_jtag);
+ if (err)
+ goto err_jtag_init;
+
+ /* Initialize JTAG core structure*/
+ err = jtag_register(jtag);
+ if (err)
+ goto err_jtag_register;
+
+ return 0;
+
+err_jtag_register:
+ aspeed_jtag_deinit(pdev, aspeed_jtag);
+err_jtag_init:
+ jtag_free(jtag);
+ return err;
+}
+
+static int aspeed_jtag_remove(struct platform_device *pdev)
+{
+ struct jtag *jtag;
+
+ jtag = platform_get_drvdata(pdev);
+ aspeed_jtag_deinit(pdev, jtag_priv(jtag));
+ jtag_unregister(jtag);
+ jtag_free(jtag);
+ return 0;
+}
+
+static const struct of_device_id aspeed_jtag_of_match[] = {
+ { .compatible = "aspeed,ast2400-jtag", },
+ { .compatible = "aspeed,ast2500-jtag", },
+ {}
+};
+
+static struct platform_driver aspeed_jtag_driver = {
+ .probe = aspeed_jtag_probe,
+ .remove = aspeed_jtag_remove,
+ .driver = {
+ .name = ASPEED_JTAG_NAME,
+ .of_match_table = aspeed_jtag_of_match,
+ },
+};
+module_platform_driver(aspeed_jtag_driver);
+
+MODULE_AUTHOR("Oleksandr Shamray <oleksandrs@mellanox.com>");
+MODULE_DESCRIPTION("ASPEED JTAG driver");
+MODULE_LICENSE("GPL v2");
--
1.7.1
^ permalink raw reply related [flat|nested] 45+ messages in thread
* [patch v9 2/4] drivers: jtag: Add Aspeed SoC 24xx and 25xx families JTAG master driver
@ 2017-09-21 9:25 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-21 9:25 UTC (permalink / raw)
To: gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r, arnd-r2nGTMty4D4
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
devicetree-u79uwXL29TY76Z2rM5mHXA,
openbmc-uLR06cmDAlY/bJ5BZ2RsiQ, joel-U3u1mxZcP9KHXe+LvDLADg,
jiri-rHqAuBHg3fBzbRFIqnYvSA, tklauser-93Khv+1bN0NyDzI6CaY1VQ,
linux-serial-u79uwXL29TY76Z2rM5mHXA, mec-WqBc5aa1uDFeoWH0uzbU5w,
vadimp-VPRAkNaXOzVWk0Htik3J/w,
system-sw-low-level-VPRAkNaXOzVWk0Htik3J/w,
robh+dt-DgEjT+Ai2ygdnm+yROfE0A,
openocd-devel-owner-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
linux-api-u79uwXL29TY76Z2rM5mHXA, davem-fT/PcQaiUtIeIZ0/mPfg9Q,
mchehab-DgEjT+Ai2ygdnm+yROfE0A, Oleksandr Shamray, Jiri Pirko
Driver adds support of Aspeed 2500/2400 series SOC JTAG master controller.
Driver implements the following jtag ops:
- freq_get;
- freq_set;
- status_get;
- idle;
- xfer;
It has been tested on Mellanox system with BMC equipped with
Aspeed 2520 SoC for programming CPLD devices.
Signed-off-by: Oleksandr Shamray <oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Signed-off-by: Jiri Pirko <jiri-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Acked-by: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
---
V8->v9
Comments pointed by Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
- add *data parameter to xfer function prototype
v7->v8
Comments pointed by Joel Stanley <joel.stan-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
- aspeed_jtag_init replace goto to return;
- change input variables type from __u32 to u32
in functios freq_get, freq_set, status_get
- change sm_ variables type from char to u8
- in jatg_init add disable clocks on error case
- remove release_mem_region on error case
- remove devm_free_irq on jtag_deinit
- Fix misspelling Disabe/Disable
- Change compatible string to ast2400 and ast2000
v6->v7
Notifications from kbuild test robot <lkp-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
- Add include <linux/types.h> to jtag-asapeed.c
v5->v6
v4->v5
Comments pointed by Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
- Added HAS_IOMEM dependence in Kconfig to avoid
"undefined reference to `devm_ioremap_resource'" error,
because in some arch this not supported
v3->v4
Comments pointed by Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
- change transaction pointer tdio type to __u64
- change internal status type from enum to __u32
v2->v3
v1->v2
Comments pointed by Greg KH <gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>
- change license type from GPLv2/BSD to GPLv2
Comments pointed by Neil Armstrong <narmstrong-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>
- Add clk_prepare_enable/clk_disable_unprepare in clock init/deinit
- Change .compatible to soc-specific compatible names
aspeed,aspeed4000-jtag/aspeed5000-jtag
- Added dt-bindings
Comments pointed by Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
- Reorder functions and removed the forward declarations
- Add static const qualifier to state machine states transitions
- Change .compatible to soc-specific compatible names
aspeed,aspeed4000-jtag/aspeed5000-jtag
- Add dt-bindings
Comments pointed by Randy Dunlap <rdunlap-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
- Change module name jtag-aspeed in description in Kconfig
Comments pointed by kbuild test robot <lkp-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
- Remove invalid include <asm/mach-types.h>
- add resource_size instead of calculation
---
drivers/jtag/Kconfig | 13 +
drivers/jtag/Makefile | 1 +
drivers/jtag/jtag-aspeed.c | 771 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 785 insertions(+), 0 deletions(-)
create mode 100644 drivers/jtag/jtag-aspeed.c
diff --git a/drivers/jtag/Kconfig b/drivers/jtag/Kconfig
index 0fad1a3..098beb0 100644
--- a/drivers/jtag/Kconfig
+++ b/drivers/jtag/Kconfig
@@ -14,3 +14,16 @@ menuconfig JTAG
To compile this driver as a module, choose M here: the module will
be called jtag.
+
+menuconfig JTAG_ASPEED
+ tristate "Aspeed SoC JTAG controller support"
+ depends on JTAG && HAS_IOMEM
+ ---help---
+ This provides a support for Aspeed JTAG device, equipped on
+ Aspeed SoC 24xx and 25xx families. Drivers allows programming
+ of hardware devices, connected to SoC through the JTAG interface.
+
+ If you want this support, you should say Y here.
+
+ To compile this driver as a module, choose M here: the module will
+ be called jtag-aspeed.
diff --git a/drivers/jtag/Makefile b/drivers/jtag/Makefile
index af37493..04a855e 100644
--- a/drivers/jtag/Makefile
+++ b/drivers/jtag/Makefile
@@ -1 +1,2 @@
obj-$(CONFIG_JTAG) += jtag.o
+obj-$(CONFIG_JTAG_ASPEED) += jtag-aspeed.o
diff --git a/drivers/jtag/jtag-aspeed.c b/drivers/jtag/jtag-aspeed.c
new file mode 100644
index 0000000..a8dd4f9
--- /dev/null
+++ b/drivers/jtag/jtag-aspeed.c
@@ -0,0 +1,771 @@
+/*
+ * drivers/jtag/jtag.c
+ *
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Oleksandr Shamray <oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
+ *
+ * Released under the GPLv2 only.
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/jtag.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <uapi/linux/jtag.h>
+
+#define ASPEED_JTAG_DATA 0x00
+#define ASPEED_JTAG_INST 0x04
+#define ASPEED_JTAG_CTRL 0x08
+#define ASPEED_JTAG_ISR 0x0C
+#define ASPEED_JTAG_SW 0x10
+#define ASPEED_JTAG_TCK 0x14
+#define ASPEED_JTAG_EC 0x18
+
+#define ASPEED_JTAG_DATA_MSB 0x01
+#define ASPEED_JTAG_DATA_CHUNK_SIZE 0x20
+
+/* ASPEED_JTAG_CTRL: Engine Control */
+#define ASPEED_JTAG_CTL_ENG_EN BIT(31)
+#define ASPEED_JTAG_CTL_ENG_OUT_EN BIT(30)
+#define ASPEED_JTAG_CTL_FORCE_TMS BIT(29)
+#define ASPEED_JTAG_CTL_INST_LEN(x) ((x) << 20)
+#define ASPEED_JTAG_CTL_LASPEED_INST BIT(17)
+#define ASPEED_JTAG_CTL_INST_EN BIT(16)
+#define ASPEED_JTAG_CTL_DR_UPDATE BIT(10)
+#define ASPEED_JTAG_CTL_DATA_LEN(x) ((x) << 4)
+#define ASPEED_JTAG_CTL_LASPEED_DATA BIT(1)
+#define ASPEED_JTAG_CTL_DATA_EN BIT(0)
+
+/* ASPEED_JTAG_ISR : Interrupt status and enable */
+#define ASPEED_JTAG_ISR_INST_PAUSE BIT(19)
+#define ASPEED_JTAG_ISR_INST_COMPLETE BIT(18)
+#define ASPEED_JTAG_ISR_DATA_PAUSE BIT(17)
+#define ASPEED_JTAG_ISR_DATA_COMPLETE BIT(16)
+#define ASPEED_JTAG_ISR_INST_PAUSE_EN BIT(3)
+#define ASPEED_JTAG_ISR_INST_COMPLETE_EN BIT(2)
+#define ASPEED_JTAG_ISR_DATA_PAUSE_EN BIT(1)
+#define ASPEED_JTAG_ISR_DATA_COMPLETE_EN BIT(0)
+#define ASPEED_JTAG_ISR_INT_EN_MASK GENMASK(3, 0)
+#define ASPEED_JTAG_ISR_INT_MASK GENMASK(19, 16)
+
+/* ASPEED_JTAG_SW : Software Mode and Status */
+#define ASPEED_JTAG_SW_MODE_EN BIT(19)
+#define ASPEED_JTAG_SW_MODE_TCK BIT(18)
+#define ASPEED_JTAG_SW_MODE_TMS BIT(17)
+#define ASPEED_JTAG_SW_MODE_TDIO BIT(16)
+
+/* ASPEED_JTAG_TCK : TCK Control */
+#define ASPEED_JTAG_TCK_DIVISOR_MASK GENMASK(10, 0)
+#define ASPEED_JTAG_TCK_GET_DIV(x) ((x) & ASPEED_JTAG_TCK_DIVISOR_MASK)
+
+/* ASPEED_JTAG_EC : Controller set for go to IDLE */
+#define ASPEED_JTAG_EC_GO_IDLE BIT(0)
+
+#define ASPEED_JTAG_IOUT_LEN(len) (ASPEED_JTAG_CTL_ENG_EN |\
+ ASPEED_JTAG_CTL_ENG_OUT_EN |\
+ ASPEED_JTAG_CTL_INST_LEN(len))
+
+#define ASPEED_JTAG_DOUT_LEN(len) (ASPEED_JTAG_CTL_ENG_EN |\
+ ASPEED_JTAG_CTL_ENG_OUT_EN |\
+ ASPEED_JTAG_CTL_DATA_LEN(len))
+
+#define ASPEED_JTAG_TCK_WAIT 10
+#define ASPEED_JTAG_RESET_CNTR 10
+
+#define ASPEED_JTAG_NAME "jtag-aspeed"
+
+struct aspeed_jtag {
+ void __iomem *reg_base;
+ struct device *dev;
+ struct clk *pclk;
+ enum jtag_endstate status;
+ int irq;
+ u32 flag;
+ wait_queue_head_t jtag_wq;
+ bool is_open;
+};
+
+static char *end_status_str[] = {"idle", "ir pause", "drpause"};
+
+static u32 aspeed_jtag_read(struct aspeed_jtag *aspeed_jtag, u32 reg)
+{
+ return readl(aspeed_jtag->reg_base + reg);
+}
+
+static void
+aspeed_jtag_write(struct aspeed_jtag *aspeed_jtag, u32 val, u32 reg)
+{
+ writel(val, aspeed_jtag->reg_base + reg);
+}
+
+static int aspeed_jtag_freq_set(struct jtag *jtag, u32 freq)
+{
+ struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+ unsigned long apb_frq;
+ u32 tck_val;
+ u16 div;
+
+ apb_frq = clk_get_rate(aspeed_jtag->pclk);
+ div = (apb_frq % freq == 0) ? (apb_frq / freq) - 1 : (apb_frq / freq);
+ tck_val = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_TCK);
+ aspeed_jtag_write(aspeed_jtag,
+ (tck_val & ASPEED_JTAG_TCK_DIVISOR_MASK) | div,
+ ASPEED_JTAG_TCK);
+ return 0;
+}
+
+static int aspeed_jtag_freq_get(struct jtag *jtag, u32 *frq)
+{
+ struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+ u32 pclk;
+ u32 tck;
+
+ pclk = clk_get_rate(aspeed_jtag->pclk);
+ tck = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_TCK);
+ *frq = pclk / (ASPEED_JTAG_TCK_GET_DIV(tck) + 1);
+
+ return 0;
+}
+
+static void aspeed_jtag_sw_delay(struct aspeed_jtag *aspeed_jtag, int cnt)
+{
+ int i;
+
+ for (i = 0; i < cnt; i++)
+ aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_SW);
+}
+
+static char aspeed_jtag_tck_cycle(struct aspeed_jtag *aspeed_jtag,
+ u8 tms, u8 tdi)
+{
+ char tdo = 0;
+
+ /* TCK = 0 */
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ (tms * ASPEED_JTAG_SW_MODE_TMS) |
+ (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
+
+ aspeed_jtag_sw_delay(aspeed_jtag, ASPEED_JTAG_TCK_WAIT);
+
+ /* TCK = 1 */
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ ASPEED_JTAG_SW_MODE_TCK |
+ (tms * ASPEED_JTAG_SW_MODE_TMS) |
+ (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
+
+ if (aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_SW) &
+ ASPEED_JTAG_SW_MODE_TDIO)
+ tdo = 1;
+
+ aspeed_jtag_sw_delay(aspeed_jtag, ASPEED_JTAG_TCK_WAIT);
+
+ /* TCK = 0 */
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ (tms * ASPEED_JTAG_SW_MODE_TMS) |
+ (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
+ return tdo;
+}
+
+static void aspeed_jtag_wait_instruction_pause(struct aspeed_jtag *aspeed_jtag)
+{
+ wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+ ASPEED_JTAG_ISR_INST_PAUSE);
+ aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_INST_PAUSE;
+}
+
+static void
+aspeed_jtag_wait_instruction_complete(struct aspeed_jtag *aspeed_jtag)
+{
+ wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+ ASPEED_JTAG_ISR_INST_COMPLETE);
+ aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_INST_COMPLETE;
+}
+
+static void
+aspeed_jtag_wait_data_pause_complete(struct aspeed_jtag *aspeed_jtag)
+{
+ wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+ ASPEED_JTAG_ISR_DATA_PAUSE);
+ aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_DATA_PAUSE;
+}
+
+static void aspeed_jtag_wait_data_complete(struct aspeed_jtag *aspeed_jtag)
+{
+ wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+ ASPEED_JTAG_ISR_DATA_COMPLETE);
+ aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_DATA_COMPLETE;
+}
+
+static void aspeed_jtag_sm_cycle(struct aspeed_jtag *aspeed_jtag, const u8 *tms,
+ int len)
+{
+ int i;
+
+ for (i = 0; i < len; i++)
+ aspeed_jtag_tck_cycle(aspeed_jtag, tms[i], 0);
+}
+
+static void aspeed_jtag_run_test_idle_sw(struct aspeed_jtag *aspeed_jtag,
+ struct jtag_run_test_idle *runtest)
+{
+ static const u8 sm_pause_irpause[] = {1, 1, 1, 1, 0, 1, 0};
+ static const u8 sm_pause_drpause[] = {1, 1, 1, 0, 1, 0};
+ static const u8 sm_idle_irpause[] = {1, 1, 0, 1, 0};
+ static const u8 sm_idle_drpause[] = {1, 0, 1, 0};
+ static const u8 sm_pause_idle[] = {1, 1, 0};
+ int i;
+
+ /* SW mode from idle/pause-> to pause/idle */
+ if (runtest->reset) {
+ for (i = 0; i < ASPEED_JTAG_RESET_CNTR; i++)
+ aspeed_jtag_tck_cycle(aspeed_jtag, 1, 0);
+ }
+
+ switch (aspeed_jtag->status) {
+ case JTAG_STATE_IDLE:
+ switch (runtest->endstate) {
+ case JTAG_STATE_PAUSEIR:
+ /* ->DRSCan->IRSCan->IRCap->IRExit1->PauseIR */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_idle_irpause,
+ sizeof(sm_idle_irpause));
+
+ aspeed_jtag->status = JTAG_STATE_PAUSEIR;
+ break;
+ case JTAG_STATE_PAUSEDR:
+ /* ->DRSCan->DRCap->DRExit1->PauseDR */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_idle_drpause,
+ sizeof(sm_idle_drpause));
+
+ aspeed_jtag->status = JTAG_STATE_PAUSEDR;
+ break;
+ case JTAG_STATE_IDLE:
+ /* IDLE */
+ aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
+ aspeed_jtag->status = JTAG_STATE_IDLE;
+ break;
+ default:
+ break;
+ }
+ break;
+
+ case JTAG_STATE_PAUSEIR:
+ /* Fall-through */
+ case JTAG_STATE_PAUSEDR:
+ /* From IR/DR Pause */
+ switch (runtest->endstate) {
+ case JTAG_STATE_PAUSEIR:
+ /*
+ * to Exit2 IR/DR->Updt IR/DR->DRSCan->IRSCan->IRCap->
+ * IRExit1->PauseIR
+ */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_irpause,
+ sizeof(sm_pause_irpause));
+
+ aspeed_jtag->status = JTAG_STATE_PAUSEIR;
+ break;
+ case JTAG_STATE_PAUSEDR:
+ /*
+ * to Exit2 IR/DR->Updt IR/DR->DRSCan->DRCap->
+ * DRExit1->PauseDR
+ */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_drpause,
+ sizeof(sm_pause_drpause));
+ aspeed_jtag->status = JTAG_STATE_PAUSEDR;
+ break;
+ case JTAG_STATE_IDLE:
+ /* to Exit2 IR/DR->Updt IR/DR->IDLE */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_idle,
+ sizeof(sm_pause_idle));
+ aspeed_jtag->status = JTAG_STATE_IDLE;
+ break;
+ default:
+ break;
+ }
+ break;
+
+ default:
+ dev_err(aspeed_jtag->dev, "aspeed_jtag_run_test_idle error\n");
+ break;
+ }
+
+ /* Stay on IDLE for at least TCK cycle */
+ for (i = 0; i < runtest->tck; i++)
+ aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
+}
+
+/**
+ * aspeed_jtag_run_test_idle:
+ * JTAG reset: generates at least 9 TMS high and 1 TMS low to force
+ * devices into Run-Test/Idle State.
+ */
+static int aspeed_jtag_idle(struct jtag *jtag,
+ struct jtag_run_test_idle *runtest)
+{
+ struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+
+ dev_dbg(aspeed_jtag->dev, "aspeed_jtag runtest, status:%d, mode:%s, state:%s, reset:%d, tck:%d\n",
+ aspeed_jtag->status, runtest->mode ? "SW" : "HW",
+ end_status_str[runtest->endstate], runtest->reset,
+ runtest->tck);
+
+ if (runtest->mode) {
+ aspeed_jtag_run_test_idle_sw(aspeed_jtag, runtest);
+ return 0;
+ }
+
+ /* Disable sw mode */
+ aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_SW);
+ /* x TMS high + 1 TMS low */
+ if (runtest->reset)
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_CTL_ENG_EN |
+ ASPEED_JTAG_CTL_ENG_OUT_EN |
+ ASPEED_JTAG_CTL_FORCE_TMS, ASPEED_JTAG_CTRL);
+ else
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_EC_GO_IDLE,
+ ASPEED_JTAG_EC);
+
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+ aspeed_jtag->status = JTAG_STATE_IDLE;
+ return 0;
+}
+
+static void aspeed_jtag_xfer_sw(struct aspeed_jtag *aspeed_jtag,
+ struct jtag_xfer *xfer, unsigned long *data)
+{
+ unsigned long remain_xfer = xfer->length;
+ unsigned long shift_bits = 0;
+ unsigned long index = 0;
+ unsigned long tdi;
+ char tdo;
+
+ if (xfer->direction == JTAG_READ_XFER)
+ tdi = UINT_MAX;
+ else
+ tdi = data[index];
+
+ while (remain_xfer > 1) {
+ tdo = aspeed_jtag_tck_cycle(aspeed_jtag, 0,
+ tdi & ASPEED_JTAG_DATA_MSB);
+ data[index] |= tdo << (shift_bits %
+ ASPEED_JTAG_DATA_CHUNK_SIZE);
+
+ tdi >>= 1;
+ shift_bits++;
+ remain_xfer--;
+
+ if (shift_bits % ASPEED_JTAG_DATA_CHUNK_SIZE == 0) {
+ dev_dbg(aspeed_jtag->dev, "R/W data[%lu]:%lx\n",
+ index, data[index]);
+
+ tdo = 0;
+ index++;
+
+ if (xfer->direction == JTAG_READ_XFER)
+ tdi = UINT_MAX;
+ else
+ tdi = data[index];
+ }
+ }
+
+ tdo = aspeed_jtag_tck_cycle(aspeed_jtag, 1, tdi & ASPEED_JTAG_DATA_MSB);
+ data[index] |= tdo << (shift_bits % ASPEED_JTAG_DATA_CHUNK_SIZE);
+}
+
+static void aspeed_jtag_xfer_push_data(struct aspeed_jtag *aspeed_jtag,
+ enum jtag_xfer_type type, u32 bits_len)
+{
+ dev_dbg(aspeed_jtag->dev, "shift bits %d\n", bits_len);
+
+ if (type == JTAG_SIR_XFER) {
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_IOUT_LEN(bits_len),
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len) |
+ ASPEED_JTAG_CTL_INST_EN, ASPEED_JTAG_CTRL);
+ } else {
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len),
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len) |
+ ASPEED_JTAG_CTL_DATA_EN, ASPEED_JTAG_CTRL);
+ }
+}
+
+static void aspeed_jtag_xfer_push_data_last(struct aspeed_jtag *aspeed_jtag,
+ enum jtag_xfer_type type,
+ u32 shift_bits,
+ enum jtag_endstate endstate)
+{
+ if (endstate != JTAG_STATE_IDLE) {
+ if (type == JTAG_SIR_XFER) {
+ dev_dbg(aspeed_jtag->dev, "IR Keep Pause\n");
+
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_IOUT_LEN(shift_bits),
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_IOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_INST_EN,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_wait_instruction_pause(aspeed_jtag);
+ } else {
+ dev_dbg(aspeed_jtag->dev, "DR Keep Pause\n");
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_DOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_DR_UPDATE,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_DOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_DR_UPDATE |
+ ASPEED_JTAG_CTL_DATA_EN,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_wait_data_pause_complete(aspeed_jtag);
+ }
+ } else {
+ if (type == JTAG_SIR_XFER) {
+ dev_dbg(aspeed_jtag->dev, "IR go IDLE\n");
+
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_IOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_LASPEED_INST,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_IOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_LASPEED_INST |
+ ASPEED_JTAG_CTL_INST_EN,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_wait_instruction_complete(aspeed_jtag);
+ } else {
+ dev_dbg(aspeed_jtag->dev, "DR go IDLE\n");
+
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_DOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_LASPEED_DATA,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_DOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_LASPEED_DATA |
+ ASPEED_JTAG_CTL_DATA_EN,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_wait_data_complete(aspeed_jtag);
+ }
+ }
+}
+
+static void aspeed_jtag_xfer_hw(struct aspeed_jtag *aspeed_jtag,
+ struct jtag_xfer *xfer, unsigned long *data)
+{
+ unsigned long remain_xfer = xfer->length;
+ unsigned long index = 0;
+ char shift_bits;
+ u32 data_reg;
+
+ data_reg = xfer->type == JTAG_SIR_XFER ?
+ ASPEED_JTAG_INST : ASPEED_JTAG_DATA;
+ while (remain_xfer) {
+ if (xfer->direction == JTAG_WRITE_XFER) {
+ dev_dbg(aspeed_jtag->dev, "W dr->dr_data[%lu]:%lx\n",
+ index, data[index]);
+
+ aspeed_jtag_write(aspeed_jtag, data[index], data_reg);
+ } else {
+ aspeed_jtag_write(aspeed_jtag, 0, data_reg);
+ }
+
+ if (remain_xfer > ASPEED_JTAG_DATA_CHUNK_SIZE) {
+ shift_bits = ASPEED_JTAG_DATA_CHUNK_SIZE;
+
+ /*
+ * Read bytes were not equals to column length
+ * and go to Pause-DR
+ */
+ aspeed_jtag_xfer_push_data(aspeed_jtag, xfer->type,
+ shift_bits);
+ } else {
+ /*
+ * Read bytes equals to column length =>
+ * Update-DR
+ */
+ shift_bits = remain_xfer;
+ aspeed_jtag_xfer_push_data_last(aspeed_jtag, xfer->type,
+ shift_bits,
+ xfer->endstate);
+ }
+
+ if (xfer->direction == JTAG_READ_XFER) {
+ if (shift_bits < ASPEED_JTAG_DATA_CHUNK_SIZE) {
+ data[index] = aspeed_jtag_read(aspeed_jtag,
+ data_reg);
+
+ data[index] >>= ASPEED_JTAG_DATA_CHUNK_SIZE -
+ shift_bits;
+ } else {
+ data[index] = aspeed_jtag_read(aspeed_jtag,
+ data_reg);
+ }
+ dev_dbg(aspeed_jtag->dev, "R dr->dr_data[%lu]:%lx\n",
+ index, data[index]);
+ }
+
+ remain_xfer = remain_xfer - shift_bits;
+ index++;
+ dev_dbg(aspeed_jtag->dev, "remain_xfer %lu\n", remain_xfer);
+ }
+}
+
+static int aspeed_jtag_xfer(struct jtag *jtag, struct jtag_xfer *xfer,
+ u8 *xfer_data)
+{
+ static const u8 sm_update_shiftir[] = {1, 1, 0, 0};
+ static const u8 sm_update_shiftdr[] = {1, 0, 0};
+ static const u8 sm_pause_idle[] = {1, 1, 0};
+ static const u8 sm_pause_update[] = {1, 1};
+ struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+ unsigned long *data = (unsigned long *)xfer_data;
+ unsigned long remain_xfer = xfer->length;
+ unsigned long offset;
+ char dbg_str[256];
+ int pos = 0;
+ int i;
+
+ for (offset = 0, i = 0; offset < xfer->length;
+ offset += ASPEED_JTAG_DATA_CHUNK_SIZE, i++) {
+ pos += snprintf(&dbg_str[pos], sizeof(dbg_str) - pos,
+ "0x%08lx ", data[i]);
+ }
+
+ dev_dbg(aspeed_jtag->dev, "aspeed_jtag %s %s xfer, mode:%s, END:%d, len:%lu, TDI[%s]\n",
+ xfer->type == JTAG_SIR_XFER ? "SIR" : "SDR",
+ xfer->direction == JTAG_READ_XFER ? "READ" : "WRITE",
+ xfer->mode ? "SW" : "HW",
+ xfer->endstate, remain_xfer, dbg_str);
+
+ if (xfer->mode == JTAG_XFER_SW_MODE) {
+ /* SW mode */
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+ if (aspeed_jtag->status != JTAG_STATE_IDLE) {
+ /*IR/DR Pause->Exit2 IR / DR->Update IR /DR */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_update,
+ sizeof(sm_pause_update));
+ }
+
+ if (xfer->type == JTAG_SIR_XFER)
+ /* ->IRSCan->CapIR->ShiftIR */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_update_shiftir,
+ sizeof(sm_update_shiftir));
+ else
+ /* ->DRScan->DRCap->DRShift */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_update_shiftdr,
+ sizeof(sm_update_shiftdr));
+
+ aspeed_jtag_xfer_sw(aspeed_jtag, xfer, data);
+
+ /* DIPause/DRPause */
+ aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
+
+ if (xfer->endstate == JTAG_STATE_IDLE) {
+ /* ->DRExit2->DRUpdate->IDLE */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_idle,
+ sizeof(sm_pause_idle));
+ }
+ } else {
+ /* hw mode */
+ aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_SW);
+ aspeed_jtag_xfer_hw(aspeed_jtag, xfer, data);
+ }
+
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+ aspeed_jtag->status = xfer->endstate;
+ return 0;
+}
+
+static int aspeed_jtag_status_get(struct jtag *jtag, u32 *status)
+{
+ struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+
+ *status = aspeed_jtag->status;
+ return 0;
+}
+
+static irqreturn_t aspeed_jtag_interrupt(s32 this_irq, void *dev_id)
+{
+ struct aspeed_jtag *aspeed_jtag = dev_id;
+ irqreturn_t ret;
+ u32 status;
+
+ status = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_ISR);
+ dev_dbg(aspeed_jtag->dev, "status %x\n", status);
+
+ if (status & ASPEED_JTAG_ISR_INT_MASK) {
+ aspeed_jtag_write(aspeed_jtag,
+ (status & ASPEED_JTAG_ISR_INT_MASK)
+ | (status & ASPEED_JTAG_ISR_INT_EN_MASK),
+ ASPEED_JTAG_ISR);
+ aspeed_jtag->flag |= status & ASPEED_JTAG_ISR_INT_MASK;
+ }
+
+ if (aspeed_jtag->flag) {
+ wake_up_interruptible(&aspeed_jtag->jtag_wq);
+ ret = IRQ_HANDLED;
+ } else {
+ dev_err(aspeed_jtag->dev, "aspeed_jtag irq status:%x\n",
+ status);
+ ret = IRQ_NONE;
+ }
+ return ret;
+}
+
+int aspeed_jtag_init(struct platform_device *pdev,
+ struct aspeed_jtag *aspeed_jtag)
+{
+ struct resource *res;
+ int err;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ aspeed_jtag->reg_base = devm_ioremap_resource(aspeed_jtag->dev, res);
+ if (IS_ERR(aspeed_jtag->reg_base))
+ return -ENOMEM;
+
+ aspeed_jtag->pclk = devm_clk_get(aspeed_jtag->dev, NULL);
+ if (IS_ERR(aspeed_jtag->pclk)) {
+ dev_err(aspeed_jtag->dev, "devm_clk_get failed\n");
+ return PTR_ERR(aspeed_jtag->pclk);
+ }
+
+ clk_prepare_enable(aspeed_jtag->pclk);
+
+ aspeed_jtag->irq = platform_get_irq(pdev, 0);
+ if (aspeed_jtag->irq < 0) {
+ dev_err(aspeed_jtag->dev, "no irq specified\n");
+ err = -ENOENT;
+ goto clk_unprep;
+ }
+
+ /* Enable clock */
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_CTL_ENG_EN |
+ ASPEED_JTAG_CTL_ENG_OUT_EN, ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+ err = devm_request_irq(aspeed_jtag->dev, aspeed_jtag->irq,
+ aspeed_jtag_interrupt, 0,
+ "aspeed-jtag", aspeed_jtag);
+ if (err) {
+ dev_err(aspeed_jtag->dev, "aspeed_jtag unable to get IRQ");
+ goto clk_unprep;
+ }
+ dev_dbg(&pdev->dev, "aspeed_jtag:IRQ %d.\n", aspeed_jtag->irq);
+
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_ISR_INST_PAUSE |
+ ASPEED_JTAG_ISR_INST_COMPLETE |
+ ASPEED_JTAG_ISR_DATA_PAUSE |
+ ASPEED_JTAG_ISR_DATA_COMPLETE |
+ ASPEED_JTAG_ISR_INST_PAUSE_EN |
+ ASPEED_JTAG_ISR_INST_COMPLETE_EN |
+ ASPEED_JTAG_ISR_DATA_PAUSE_EN |
+ ASPEED_JTAG_ISR_DATA_COMPLETE_EN,
+ ASPEED_JTAG_ISR);
+
+ aspeed_jtag->flag = 0;
+ init_waitqueue_head(&aspeed_jtag->jtag_wq);
+ return 0;
+
+clk_unprep:
+ clk_disable_unprepare(aspeed_jtag->pclk);
+ return err;
+}
+
+int aspeed_jtag_deinit(struct platform_device *pdev,
+ struct aspeed_jtag *aspeed_jtag)
+{
+ aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_ISR);
+ /* Disable clock */
+ aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_CTRL);
+ clk_disable_unprepare(aspeed_jtag->pclk);
+ return 0;
+}
+
+static const struct jtag_ops aspeed_jtag_ops = {
+ .freq_get = aspeed_jtag_freq_get,
+ .freq_set = aspeed_jtag_freq_set,
+ .status_get = aspeed_jtag_status_get,
+ .idle = aspeed_jtag_idle,
+ .xfer = aspeed_jtag_xfer
+};
+
+static int aspeed_jtag_probe(struct platform_device *pdev)
+{
+ struct aspeed_jtag *aspeed_jtag;
+ struct jtag *jtag;
+ int err;
+
+ if (!of_device_is_compatible(pdev->dev.of_node, "aspeed,aspeed-jtag"))
+ return -ENOMEM;
+
+ jtag = jtag_alloc(sizeof(*aspeed_jtag), &aspeed_jtag_ops);
+ if (!jtag)
+ return -ENODEV;
+
+ platform_set_drvdata(pdev, jtag);
+ aspeed_jtag = jtag_priv(jtag);
+ aspeed_jtag->dev = &pdev->dev;
+
+ /* Initialize device*/
+ err = aspeed_jtag_init(pdev, aspeed_jtag);
+ if (err)
+ goto err_jtag_init;
+
+ /* Initialize JTAG core structure*/
+ err = jtag_register(jtag);
+ if (err)
+ goto err_jtag_register;
+
+ return 0;
+
+err_jtag_register:
+ aspeed_jtag_deinit(pdev, aspeed_jtag);
+err_jtag_init:
+ jtag_free(jtag);
+ return err;
+}
+
+static int aspeed_jtag_remove(struct platform_device *pdev)
+{
+ struct jtag *jtag;
+
+ jtag = platform_get_drvdata(pdev);
+ aspeed_jtag_deinit(pdev, jtag_priv(jtag));
+ jtag_unregister(jtag);
+ jtag_free(jtag);
+ return 0;
+}
+
+static const struct of_device_id aspeed_jtag_of_match[] = {
+ { .compatible = "aspeed,ast2400-jtag", },
+ { .compatible = "aspeed,ast2500-jtag", },
+ {}
+};
+
+static struct platform_driver aspeed_jtag_driver = {
+ .probe = aspeed_jtag_probe,
+ .remove = aspeed_jtag_remove,
+ .driver = {
+ .name = ASPEED_JTAG_NAME,
+ .of_match_table = aspeed_jtag_of_match,
+ },
+};
+module_platform_driver(aspeed_jtag_driver);
+
+MODULE_AUTHOR("Oleksandr Shamray <oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>");
+MODULE_DESCRIPTION("ASPEED JTAG driver");
+MODULE_LICENSE("GPL v2");
--
1.7.1
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^ permalink raw reply related [flat|nested] 45+ messages in thread
* [patch v9 2/4] drivers: jtag: Add Aspeed SoC 24xx and 25xx families JTAG master driver
@ 2017-09-21 9:25 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-21 9:25 UTC (permalink / raw)
To: linux-arm-kernel
Driver adds support of Aspeed 2500/2400 series SOC JTAG master controller.
Driver implements the following jtag ops:
- freq_get;
- freq_set;
- status_get;
- idle;
- xfer;
It has been tested on Mellanox system with BMC equipped with
Aspeed 2520 SoC for programming CPLD devices.
Signed-off-by: Oleksandr Shamray <oleksandrs@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
V8->v9
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- add *data parameter to xfer function prototype
v7->v8
Comments pointed by Joel Stanley <joel.stan@gmail.com>
- aspeed_jtag_init replace goto to return;
- change input variables type from __u32 to u32
in functios freq_get, freq_set, status_get
- change sm_ variables type from char to u8
- in jatg_init add disable clocks on error case
- remove release_mem_region on error case
- remove devm_free_irq on jtag_deinit
- Fix misspelling Disabe/Disable
- Change compatible string to ast2400 and ast2000
v6->v7
Notifications from kbuild test robot <lkp@intel.com>
- Add include <linux/types.h> to jtag-asapeed.c
v5->v6
v4->v5
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- Added HAS_IOMEM dependence in Kconfig to avoid
"undefined reference to `devm_ioremap_resource'" error,
because in some arch this not supported
v3->v4
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- change transaction pointer tdio type to __u64
- change internal status type from enum to __u32
v2->v3
v1->v2
Comments pointed by Greg KH <gregkh@linuxfoundation.org>
- change license type from GPLv2/BSD to GPLv2
Comments pointed by Neil Armstrong <narmstrong@baylibre.com>
- Add clk_prepare_enable/clk_disable_unprepare in clock init/deinit
- Change .compatible to soc-specific compatible names
aspeed,aspeed4000-jtag/aspeed5000-jtag
- Added dt-bindings
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- Reorder functions and removed the forward declarations
- Add static const qualifier to state machine states transitions
- Change .compatible to soc-specific compatible names
aspeed,aspeed4000-jtag/aspeed5000-jtag
- Add dt-bindings
Comments pointed by Randy Dunlap <rdunlap@infradead.org>
- Change module name jtag-aspeed in description in Kconfig
Comments pointed by kbuild test robot <lkp@intel.com>
- Remove invalid include <asm/mach-types.h>
- add resource_size instead of calculation
---
drivers/jtag/Kconfig | 13 +
drivers/jtag/Makefile | 1 +
drivers/jtag/jtag-aspeed.c | 771 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 785 insertions(+), 0 deletions(-)
create mode 100644 drivers/jtag/jtag-aspeed.c
diff --git a/drivers/jtag/Kconfig b/drivers/jtag/Kconfig
index 0fad1a3..098beb0 100644
--- a/drivers/jtag/Kconfig
+++ b/drivers/jtag/Kconfig
@@ -14,3 +14,16 @@ menuconfig JTAG
To compile this driver as a module, choose M here: the module will
be called jtag.
+
+menuconfig JTAG_ASPEED
+ tristate "Aspeed SoC JTAG controller support"
+ depends on JTAG && HAS_IOMEM
+ ---help---
+ This provides a support for Aspeed JTAG device, equipped on
+ Aspeed SoC 24xx and 25xx families. Drivers allows programming
+ of hardware devices, connected to SoC through the JTAG interface.
+
+ If you want this support, you should say Y here.
+
+ To compile this driver as a module, choose M here: the module will
+ be called jtag-aspeed.
diff --git a/drivers/jtag/Makefile b/drivers/jtag/Makefile
index af37493..04a855e 100644
--- a/drivers/jtag/Makefile
+++ b/drivers/jtag/Makefile
@@ -1 +1,2 @@
obj-$(CONFIG_JTAG) += jtag.o
+obj-$(CONFIG_JTAG_ASPEED) += jtag-aspeed.o
diff --git a/drivers/jtag/jtag-aspeed.c b/drivers/jtag/jtag-aspeed.c
new file mode 100644
index 0000000..a8dd4f9
--- /dev/null
+++ b/drivers/jtag/jtag-aspeed.c
@@ -0,0 +1,771 @@
+/*
+ * drivers/jtag/jtag.c
+ *
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
+ *
+ * Released under the GPLv2 only.
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/jtag.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <uapi/linux/jtag.h>
+
+#define ASPEED_JTAG_DATA 0x00
+#define ASPEED_JTAG_INST 0x04
+#define ASPEED_JTAG_CTRL 0x08
+#define ASPEED_JTAG_ISR 0x0C
+#define ASPEED_JTAG_SW 0x10
+#define ASPEED_JTAG_TCK 0x14
+#define ASPEED_JTAG_EC 0x18
+
+#define ASPEED_JTAG_DATA_MSB 0x01
+#define ASPEED_JTAG_DATA_CHUNK_SIZE 0x20
+
+/* ASPEED_JTAG_CTRL: Engine Control */
+#define ASPEED_JTAG_CTL_ENG_EN BIT(31)
+#define ASPEED_JTAG_CTL_ENG_OUT_EN BIT(30)
+#define ASPEED_JTAG_CTL_FORCE_TMS BIT(29)
+#define ASPEED_JTAG_CTL_INST_LEN(x) ((x) << 20)
+#define ASPEED_JTAG_CTL_LASPEED_INST BIT(17)
+#define ASPEED_JTAG_CTL_INST_EN BIT(16)
+#define ASPEED_JTAG_CTL_DR_UPDATE BIT(10)
+#define ASPEED_JTAG_CTL_DATA_LEN(x) ((x) << 4)
+#define ASPEED_JTAG_CTL_LASPEED_DATA BIT(1)
+#define ASPEED_JTAG_CTL_DATA_EN BIT(0)
+
+/* ASPEED_JTAG_ISR : Interrupt status and enable */
+#define ASPEED_JTAG_ISR_INST_PAUSE BIT(19)
+#define ASPEED_JTAG_ISR_INST_COMPLETE BIT(18)
+#define ASPEED_JTAG_ISR_DATA_PAUSE BIT(17)
+#define ASPEED_JTAG_ISR_DATA_COMPLETE BIT(16)
+#define ASPEED_JTAG_ISR_INST_PAUSE_EN BIT(3)
+#define ASPEED_JTAG_ISR_INST_COMPLETE_EN BIT(2)
+#define ASPEED_JTAG_ISR_DATA_PAUSE_EN BIT(1)
+#define ASPEED_JTAG_ISR_DATA_COMPLETE_EN BIT(0)
+#define ASPEED_JTAG_ISR_INT_EN_MASK GENMASK(3, 0)
+#define ASPEED_JTAG_ISR_INT_MASK GENMASK(19, 16)
+
+/* ASPEED_JTAG_SW : Software Mode and Status */
+#define ASPEED_JTAG_SW_MODE_EN BIT(19)
+#define ASPEED_JTAG_SW_MODE_TCK BIT(18)
+#define ASPEED_JTAG_SW_MODE_TMS BIT(17)
+#define ASPEED_JTAG_SW_MODE_TDIO BIT(16)
+
+/* ASPEED_JTAG_TCK : TCK Control */
+#define ASPEED_JTAG_TCK_DIVISOR_MASK GENMASK(10, 0)
+#define ASPEED_JTAG_TCK_GET_DIV(x) ((x) & ASPEED_JTAG_TCK_DIVISOR_MASK)
+
+/* ASPEED_JTAG_EC : Controller set for go to IDLE */
+#define ASPEED_JTAG_EC_GO_IDLE BIT(0)
+
+#define ASPEED_JTAG_IOUT_LEN(len) (ASPEED_JTAG_CTL_ENG_EN |\
+ ASPEED_JTAG_CTL_ENG_OUT_EN |\
+ ASPEED_JTAG_CTL_INST_LEN(len))
+
+#define ASPEED_JTAG_DOUT_LEN(len) (ASPEED_JTAG_CTL_ENG_EN |\
+ ASPEED_JTAG_CTL_ENG_OUT_EN |\
+ ASPEED_JTAG_CTL_DATA_LEN(len))
+
+#define ASPEED_JTAG_TCK_WAIT 10
+#define ASPEED_JTAG_RESET_CNTR 10
+
+#define ASPEED_JTAG_NAME "jtag-aspeed"
+
+struct aspeed_jtag {
+ void __iomem *reg_base;
+ struct device *dev;
+ struct clk *pclk;
+ enum jtag_endstate status;
+ int irq;
+ u32 flag;
+ wait_queue_head_t jtag_wq;
+ bool is_open;
+};
+
+static char *end_status_str[] = {"idle", "ir pause", "drpause"};
+
+static u32 aspeed_jtag_read(struct aspeed_jtag *aspeed_jtag, u32 reg)
+{
+ return readl(aspeed_jtag->reg_base + reg);
+}
+
+static void
+aspeed_jtag_write(struct aspeed_jtag *aspeed_jtag, u32 val, u32 reg)
+{
+ writel(val, aspeed_jtag->reg_base + reg);
+}
+
+static int aspeed_jtag_freq_set(struct jtag *jtag, u32 freq)
+{
+ struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+ unsigned long apb_frq;
+ u32 tck_val;
+ u16 div;
+
+ apb_frq = clk_get_rate(aspeed_jtag->pclk);
+ div = (apb_frq % freq == 0) ? (apb_frq / freq) - 1 : (apb_frq / freq);
+ tck_val = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_TCK);
+ aspeed_jtag_write(aspeed_jtag,
+ (tck_val & ASPEED_JTAG_TCK_DIVISOR_MASK) | div,
+ ASPEED_JTAG_TCK);
+ return 0;
+}
+
+static int aspeed_jtag_freq_get(struct jtag *jtag, u32 *frq)
+{
+ struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+ u32 pclk;
+ u32 tck;
+
+ pclk = clk_get_rate(aspeed_jtag->pclk);
+ tck = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_TCK);
+ *frq = pclk / (ASPEED_JTAG_TCK_GET_DIV(tck) + 1);
+
+ return 0;
+}
+
+static void aspeed_jtag_sw_delay(struct aspeed_jtag *aspeed_jtag, int cnt)
+{
+ int i;
+
+ for (i = 0; i < cnt; i++)
+ aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_SW);
+}
+
+static char aspeed_jtag_tck_cycle(struct aspeed_jtag *aspeed_jtag,
+ u8 tms, u8 tdi)
+{
+ char tdo = 0;
+
+ /* TCK = 0 */
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ (tms * ASPEED_JTAG_SW_MODE_TMS) |
+ (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
+
+ aspeed_jtag_sw_delay(aspeed_jtag, ASPEED_JTAG_TCK_WAIT);
+
+ /* TCK = 1 */
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ ASPEED_JTAG_SW_MODE_TCK |
+ (tms * ASPEED_JTAG_SW_MODE_TMS) |
+ (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
+
+ if (aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_SW) &
+ ASPEED_JTAG_SW_MODE_TDIO)
+ tdo = 1;
+
+ aspeed_jtag_sw_delay(aspeed_jtag, ASPEED_JTAG_TCK_WAIT);
+
+ /* TCK = 0 */
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ (tms * ASPEED_JTAG_SW_MODE_TMS) |
+ (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
+ return tdo;
+}
+
+static void aspeed_jtag_wait_instruction_pause(struct aspeed_jtag *aspeed_jtag)
+{
+ wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+ ASPEED_JTAG_ISR_INST_PAUSE);
+ aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_INST_PAUSE;
+}
+
+static void
+aspeed_jtag_wait_instruction_complete(struct aspeed_jtag *aspeed_jtag)
+{
+ wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+ ASPEED_JTAG_ISR_INST_COMPLETE);
+ aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_INST_COMPLETE;
+}
+
+static void
+aspeed_jtag_wait_data_pause_complete(struct aspeed_jtag *aspeed_jtag)
+{
+ wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+ ASPEED_JTAG_ISR_DATA_PAUSE);
+ aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_DATA_PAUSE;
+}
+
+static void aspeed_jtag_wait_data_complete(struct aspeed_jtag *aspeed_jtag)
+{
+ wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
+ ASPEED_JTAG_ISR_DATA_COMPLETE);
+ aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_DATA_COMPLETE;
+}
+
+static void aspeed_jtag_sm_cycle(struct aspeed_jtag *aspeed_jtag, const u8 *tms,
+ int len)
+{
+ int i;
+
+ for (i = 0; i < len; i++)
+ aspeed_jtag_tck_cycle(aspeed_jtag, tms[i], 0);
+}
+
+static void aspeed_jtag_run_test_idle_sw(struct aspeed_jtag *aspeed_jtag,
+ struct jtag_run_test_idle *runtest)
+{
+ static const u8 sm_pause_irpause[] = {1, 1, 1, 1, 0, 1, 0};
+ static const u8 sm_pause_drpause[] = {1, 1, 1, 0, 1, 0};
+ static const u8 sm_idle_irpause[] = {1, 1, 0, 1, 0};
+ static const u8 sm_idle_drpause[] = {1, 0, 1, 0};
+ static const u8 sm_pause_idle[] = {1, 1, 0};
+ int i;
+
+ /* SW mode from idle/pause-> to pause/idle */
+ if (runtest->reset) {
+ for (i = 0; i < ASPEED_JTAG_RESET_CNTR; i++)
+ aspeed_jtag_tck_cycle(aspeed_jtag, 1, 0);
+ }
+
+ switch (aspeed_jtag->status) {
+ case JTAG_STATE_IDLE:
+ switch (runtest->endstate) {
+ case JTAG_STATE_PAUSEIR:
+ /* ->DRSCan->IRSCan->IRCap->IRExit1->PauseIR */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_idle_irpause,
+ sizeof(sm_idle_irpause));
+
+ aspeed_jtag->status = JTAG_STATE_PAUSEIR;
+ break;
+ case JTAG_STATE_PAUSEDR:
+ /* ->DRSCan->DRCap->DRExit1->PauseDR */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_idle_drpause,
+ sizeof(sm_idle_drpause));
+
+ aspeed_jtag->status = JTAG_STATE_PAUSEDR;
+ break;
+ case JTAG_STATE_IDLE:
+ /* IDLE */
+ aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
+ aspeed_jtag->status = JTAG_STATE_IDLE;
+ break;
+ default:
+ break;
+ }
+ break;
+
+ case JTAG_STATE_PAUSEIR:
+ /* Fall-through */
+ case JTAG_STATE_PAUSEDR:
+ /* From IR/DR Pause */
+ switch (runtest->endstate) {
+ case JTAG_STATE_PAUSEIR:
+ /*
+ * to Exit2 IR/DR->Updt IR/DR->DRSCan->IRSCan->IRCap->
+ * IRExit1->PauseIR
+ */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_irpause,
+ sizeof(sm_pause_irpause));
+
+ aspeed_jtag->status = JTAG_STATE_PAUSEIR;
+ break;
+ case JTAG_STATE_PAUSEDR:
+ /*
+ * to Exit2 IR/DR->Updt IR/DR->DRSCan->DRCap->
+ * DRExit1->PauseDR
+ */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_drpause,
+ sizeof(sm_pause_drpause));
+ aspeed_jtag->status = JTAG_STATE_PAUSEDR;
+ break;
+ case JTAG_STATE_IDLE:
+ /* to Exit2 IR/DR->Updt IR/DR->IDLE */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_idle,
+ sizeof(sm_pause_idle));
+ aspeed_jtag->status = JTAG_STATE_IDLE;
+ break;
+ default:
+ break;
+ }
+ break;
+
+ default:
+ dev_err(aspeed_jtag->dev, "aspeed_jtag_run_test_idle error\n");
+ break;
+ }
+
+ /* Stay on IDLE for at least TCK cycle */
+ for (i = 0; i < runtest->tck; i++)
+ aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
+}
+
+/**
+ * aspeed_jtag_run_test_idle:
+ * JTAG reset: generates at least 9 TMS high and 1 TMS low to force
+ * devices into Run-Test/Idle State.
+ */
+static int aspeed_jtag_idle(struct jtag *jtag,
+ struct jtag_run_test_idle *runtest)
+{
+ struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+
+ dev_dbg(aspeed_jtag->dev, "aspeed_jtag runtest, status:%d, mode:%s, state:%s, reset:%d, tck:%d\n",
+ aspeed_jtag->status, runtest->mode ? "SW" : "HW",
+ end_status_str[runtest->endstate], runtest->reset,
+ runtest->tck);
+
+ if (runtest->mode) {
+ aspeed_jtag_run_test_idle_sw(aspeed_jtag, runtest);
+ return 0;
+ }
+
+ /* Disable sw mode */
+ aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_SW);
+ /* x TMS high + 1 TMS low */
+ if (runtest->reset)
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_CTL_ENG_EN |
+ ASPEED_JTAG_CTL_ENG_OUT_EN |
+ ASPEED_JTAG_CTL_FORCE_TMS, ASPEED_JTAG_CTRL);
+ else
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_EC_GO_IDLE,
+ ASPEED_JTAG_EC);
+
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+ aspeed_jtag->status = JTAG_STATE_IDLE;
+ return 0;
+}
+
+static void aspeed_jtag_xfer_sw(struct aspeed_jtag *aspeed_jtag,
+ struct jtag_xfer *xfer, unsigned long *data)
+{
+ unsigned long remain_xfer = xfer->length;
+ unsigned long shift_bits = 0;
+ unsigned long index = 0;
+ unsigned long tdi;
+ char tdo;
+
+ if (xfer->direction == JTAG_READ_XFER)
+ tdi = UINT_MAX;
+ else
+ tdi = data[index];
+
+ while (remain_xfer > 1) {
+ tdo = aspeed_jtag_tck_cycle(aspeed_jtag, 0,
+ tdi & ASPEED_JTAG_DATA_MSB);
+ data[index] |= tdo << (shift_bits %
+ ASPEED_JTAG_DATA_CHUNK_SIZE);
+
+ tdi >>= 1;
+ shift_bits++;
+ remain_xfer--;
+
+ if (shift_bits % ASPEED_JTAG_DATA_CHUNK_SIZE == 0) {
+ dev_dbg(aspeed_jtag->dev, "R/W data[%lu]:%lx\n",
+ index, data[index]);
+
+ tdo = 0;
+ index++;
+
+ if (xfer->direction == JTAG_READ_XFER)
+ tdi = UINT_MAX;
+ else
+ tdi = data[index];
+ }
+ }
+
+ tdo = aspeed_jtag_tck_cycle(aspeed_jtag, 1, tdi & ASPEED_JTAG_DATA_MSB);
+ data[index] |= tdo << (shift_bits % ASPEED_JTAG_DATA_CHUNK_SIZE);
+}
+
+static void aspeed_jtag_xfer_push_data(struct aspeed_jtag *aspeed_jtag,
+ enum jtag_xfer_type type, u32 bits_len)
+{
+ dev_dbg(aspeed_jtag->dev, "shift bits %d\n", bits_len);
+
+ if (type == JTAG_SIR_XFER) {
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_IOUT_LEN(bits_len),
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len) |
+ ASPEED_JTAG_CTL_INST_EN, ASPEED_JTAG_CTRL);
+ } else {
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len),
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len) |
+ ASPEED_JTAG_CTL_DATA_EN, ASPEED_JTAG_CTRL);
+ }
+}
+
+static void aspeed_jtag_xfer_push_data_last(struct aspeed_jtag *aspeed_jtag,
+ enum jtag_xfer_type type,
+ u32 shift_bits,
+ enum jtag_endstate endstate)
+{
+ if (endstate != JTAG_STATE_IDLE) {
+ if (type == JTAG_SIR_XFER) {
+ dev_dbg(aspeed_jtag->dev, "IR Keep Pause\n");
+
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_IOUT_LEN(shift_bits),
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_IOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_INST_EN,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_wait_instruction_pause(aspeed_jtag);
+ } else {
+ dev_dbg(aspeed_jtag->dev, "DR Keep Pause\n");
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_DOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_DR_UPDATE,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_DOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_DR_UPDATE |
+ ASPEED_JTAG_CTL_DATA_EN,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_wait_data_pause_complete(aspeed_jtag);
+ }
+ } else {
+ if (type == JTAG_SIR_XFER) {
+ dev_dbg(aspeed_jtag->dev, "IR go IDLE\n");
+
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_IOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_LASPEED_INST,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_IOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_LASPEED_INST |
+ ASPEED_JTAG_CTL_INST_EN,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_wait_instruction_complete(aspeed_jtag);
+ } else {
+ dev_dbg(aspeed_jtag->dev, "DR go IDLE\n");
+
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_DOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_LASPEED_DATA,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag,
+ ASPEED_JTAG_DOUT_LEN(shift_bits) |
+ ASPEED_JTAG_CTL_LASPEED_DATA |
+ ASPEED_JTAG_CTL_DATA_EN,
+ ASPEED_JTAG_CTRL);
+ aspeed_jtag_wait_data_complete(aspeed_jtag);
+ }
+ }
+}
+
+static void aspeed_jtag_xfer_hw(struct aspeed_jtag *aspeed_jtag,
+ struct jtag_xfer *xfer, unsigned long *data)
+{
+ unsigned long remain_xfer = xfer->length;
+ unsigned long index = 0;
+ char shift_bits;
+ u32 data_reg;
+
+ data_reg = xfer->type == JTAG_SIR_XFER ?
+ ASPEED_JTAG_INST : ASPEED_JTAG_DATA;
+ while (remain_xfer) {
+ if (xfer->direction == JTAG_WRITE_XFER) {
+ dev_dbg(aspeed_jtag->dev, "W dr->dr_data[%lu]:%lx\n",
+ index, data[index]);
+
+ aspeed_jtag_write(aspeed_jtag, data[index], data_reg);
+ } else {
+ aspeed_jtag_write(aspeed_jtag, 0, data_reg);
+ }
+
+ if (remain_xfer > ASPEED_JTAG_DATA_CHUNK_SIZE) {
+ shift_bits = ASPEED_JTAG_DATA_CHUNK_SIZE;
+
+ /*
+ * Read bytes were not equals to column length
+ * and go to Pause-DR
+ */
+ aspeed_jtag_xfer_push_data(aspeed_jtag, xfer->type,
+ shift_bits);
+ } else {
+ /*
+ * Read bytes equals to column length =>
+ * Update-DR
+ */
+ shift_bits = remain_xfer;
+ aspeed_jtag_xfer_push_data_last(aspeed_jtag, xfer->type,
+ shift_bits,
+ xfer->endstate);
+ }
+
+ if (xfer->direction == JTAG_READ_XFER) {
+ if (shift_bits < ASPEED_JTAG_DATA_CHUNK_SIZE) {
+ data[index] = aspeed_jtag_read(aspeed_jtag,
+ data_reg);
+
+ data[index] >>= ASPEED_JTAG_DATA_CHUNK_SIZE -
+ shift_bits;
+ } else {
+ data[index] = aspeed_jtag_read(aspeed_jtag,
+ data_reg);
+ }
+ dev_dbg(aspeed_jtag->dev, "R dr->dr_data[%lu]:%lx\n",
+ index, data[index]);
+ }
+
+ remain_xfer = remain_xfer - shift_bits;
+ index++;
+ dev_dbg(aspeed_jtag->dev, "remain_xfer %lu\n", remain_xfer);
+ }
+}
+
+static int aspeed_jtag_xfer(struct jtag *jtag, struct jtag_xfer *xfer,
+ u8 *xfer_data)
+{
+ static const u8 sm_update_shiftir[] = {1, 1, 0, 0};
+ static const u8 sm_update_shiftdr[] = {1, 0, 0};
+ static const u8 sm_pause_idle[] = {1, 1, 0};
+ static const u8 sm_pause_update[] = {1, 1};
+ struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+ unsigned long *data = (unsigned long *)xfer_data;
+ unsigned long remain_xfer = xfer->length;
+ unsigned long offset;
+ char dbg_str[256];
+ int pos = 0;
+ int i;
+
+ for (offset = 0, i = 0; offset < xfer->length;
+ offset += ASPEED_JTAG_DATA_CHUNK_SIZE, i++) {
+ pos += snprintf(&dbg_str[pos], sizeof(dbg_str) - pos,
+ "0x%08lx ", data[i]);
+ }
+
+ dev_dbg(aspeed_jtag->dev, "aspeed_jtag %s %s xfer, mode:%s, END:%d, len:%lu, TDI[%s]\n",
+ xfer->type == JTAG_SIR_XFER ? "SIR" : "SDR",
+ xfer->direction == JTAG_READ_XFER ? "READ" : "WRITE",
+ xfer->mode ? "SW" : "HW",
+ xfer->endstate, remain_xfer, dbg_str);
+
+ if (xfer->mode == JTAG_XFER_SW_MODE) {
+ /* SW mode */
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+ if (aspeed_jtag->status != JTAG_STATE_IDLE) {
+ /*IR/DR Pause->Exit2 IR / DR->Update IR /DR */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_update,
+ sizeof(sm_pause_update));
+ }
+
+ if (xfer->type == JTAG_SIR_XFER)
+ /* ->IRSCan->CapIR->ShiftIR */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_update_shiftir,
+ sizeof(sm_update_shiftir));
+ else
+ /* ->DRScan->DRCap->DRShift */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_update_shiftdr,
+ sizeof(sm_update_shiftdr));
+
+ aspeed_jtag_xfer_sw(aspeed_jtag, xfer, data);
+
+ /* DIPause/DRPause */
+ aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
+
+ if (xfer->endstate == JTAG_STATE_IDLE) {
+ /* ->DRExit2->DRUpdate->IDLE */
+ aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_idle,
+ sizeof(sm_pause_idle));
+ }
+ } else {
+ /* hw mode */
+ aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_SW);
+ aspeed_jtag_xfer_hw(aspeed_jtag, xfer, data);
+ }
+
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+ aspeed_jtag->status = xfer->endstate;
+ return 0;
+}
+
+static int aspeed_jtag_status_get(struct jtag *jtag, u32 *status)
+{
+ struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+
+ *status = aspeed_jtag->status;
+ return 0;
+}
+
+static irqreturn_t aspeed_jtag_interrupt(s32 this_irq, void *dev_id)
+{
+ struct aspeed_jtag *aspeed_jtag = dev_id;
+ irqreturn_t ret;
+ u32 status;
+
+ status = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_ISR);
+ dev_dbg(aspeed_jtag->dev, "status %x\n", status);
+
+ if (status & ASPEED_JTAG_ISR_INT_MASK) {
+ aspeed_jtag_write(aspeed_jtag,
+ (status & ASPEED_JTAG_ISR_INT_MASK)
+ | (status & ASPEED_JTAG_ISR_INT_EN_MASK),
+ ASPEED_JTAG_ISR);
+ aspeed_jtag->flag |= status & ASPEED_JTAG_ISR_INT_MASK;
+ }
+
+ if (aspeed_jtag->flag) {
+ wake_up_interruptible(&aspeed_jtag->jtag_wq);
+ ret = IRQ_HANDLED;
+ } else {
+ dev_err(aspeed_jtag->dev, "aspeed_jtag irq status:%x\n",
+ status);
+ ret = IRQ_NONE;
+ }
+ return ret;
+}
+
+int aspeed_jtag_init(struct platform_device *pdev,
+ struct aspeed_jtag *aspeed_jtag)
+{
+ struct resource *res;
+ int err;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ aspeed_jtag->reg_base = devm_ioremap_resource(aspeed_jtag->dev, res);
+ if (IS_ERR(aspeed_jtag->reg_base))
+ return -ENOMEM;
+
+ aspeed_jtag->pclk = devm_clk_get(aspeed_jtag->dev, NULL);
+ if (IS_ERR(aspeed_jtag->pclk)) {
+ dev_err(aspeed_jtag->dev, "devm_clk_get failed\n");
+ return PTR_ERR(aspeed_jtag->pclk);
+ }
+
+ clk_prepare_enable(aspeed_jtag->pclk);
+
+ aspeed_jtag->irq = platform_get_irq(pdev, 0);
+ if (aspeed_jtag->irq < 0) {
+ dev_err(aspeed_jtag->dev, "no irq specified\n");
+ err = -ENOENT;
+ goto clk_unprep;
+ }
+
+ /* Enable clock */
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_CTL_ENG_EN |
+ ASPEED_JTAG_CTL_ENG_OUT_EN, ASPEED_JTAG_CTRL);
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+ ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+ err = devm_request_irq(aspeed_jtag->dev, aspeed_jtag->irq,
+ aspeed_jtag_interrupt, 0,
+ "aspeed-jtag", aspeed_jtag);
+ if (err) {
+ dev_err(aspeed_jtag->dev, "aspeed_jtag unable to get IRQ");
+ goto clk_unprep;
+ }
+ dev_dbg(&pdev->dev, "aspeed_jtag:IRQ %d.\n", aspeed_jtag->irq);
+
+ aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_ISR_INST_PAUSE |
+ ASPEED_JTAG_ISR_INST_COMPLETE |
+ ASPEED_JTAG_ISR_DATA_PAUSE |
+ ASPEED_JTAG_ISR_DATA_COMPLETE |
+ ASPEED_JTAG_ISR_INST_PAUSE_EN |
+ ASPEED_JTAG_ISR_INST_COMPLETE_EN |
+ ASPEED_JTAG_ISR_DATA_PAUSE_EN |
+ ASPEED_JTAG_ISR_DATA_COMPLETE_EN,
+ ASPEED_JTAG_ISR);
+
+ aspeed_jtag->flag = 0;
+ init_waitqueue_head(&aspeed_jtag->jtag_wq);
+ return 0;
+
+clk_unprep:
+ clk_disable_unprepare(aspeed_jtag->pclk);
+ return err;
+}
+
+int aspeed_jtag_deinit(struct platform_device *pdev,
+ struct aspeed_jtag *aspeed_jtag)
+{
+ aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_ISR);
+ /* Disable clock */
+ aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_CTRL);
+ clk_disable_unprepare(aspeed_jtag->pclk);
+ return 0;
+}
+
+static const struct jtag_ops aspeed_jtag_ops = {
+ .freq_get = aspeed_jtag_freq_get,
+ .freq_set = aspeed_jtag_freq_set,
+ .status_get = aspeed_jtag_status_get,
+ .idle = aspeed_jtag_idle,
+ .xfer = aspeed_jtag_xfer
+};
+
+static int aspeed_jtag_probe(struct platform_device *pdev)
+{
+ struct aspeed_jtag *aspeed_jtag;
+ struct jtag *jtag;
+ int err;
+
+ if (!of_device_is_compatible(pdev->dev.of_node, "aspeed,aspeed-jtag"))
+ return -ENOMEM;
+
+ jtag = jtag_alloc(sizeof(*aspeed_jtag), &aspeed_jtag_ops);
+ if (!jtag)
+ return -ENODEV;
+
+ platform_set_drvdata(pdev, jtag);
+ aspeed_jtag = jtag_priv(jtag);
+ aspeed_jtag->dev = &pdev->dev;
+
+ /* Initialize device*/
+ err = aspeed_jtag_init(pdev, aspeed_jtag);
+ if (err)
+ goto err_jtag_init;
+
+ /* Initialize JTAG core structure*/
+ err = jtag_register(jtag);
+ if (err)
+ goto err_jtag_register;
+
+ return 0;
+
+err_jtag_register:
+ aspeed_jtag_deinit(pdev, aspeed_jtag);
+err_jtag_init:
+ jtag_free(jtag);
+ return err;
+}
+
+static int aspeed_jtag_remove(struct platform_device *pdev)
+{
+ struct jtag *jtag;
+
+ jtag = platform_get_drvdata(pdev);
+ aspeed_jtag_deinit(pdev, jtag_priv(jtag));
+ jtag_unregister(jtag);
+ jtag_free(jtag);
+ return 0;
+}
+
+static const struct of_device_id aspeed_jtag_of_match[] = {
+ { .compatible = "aspeed,ast2400-jtag", },
+ { .compatible = "aspeed,ast2500-jtag", },
+ {}
+};
+
+static struct platform_driver aspeed_jtag_driver = {
+ .probe = aspeed_jtag_probe,
+ .remove = aspeed_jtag_remove,
+ .driver = {
+ .name = ASPEED_JTAG_NAME,
+ .of_match_table = aspeed_jtag_of_match,
+ },
+};
+module_platform_driver(aspeed_jtag_driver);
+
+MODULE_AUTHOR("Oleksandr Shamray <oleksandrs@mellanox.com>");
+MODULE_DESCRIPTION("ASPEED JTAG driver");
+MODULE_LICENSE("GPL v2");
--
1.7.1
^ permalink raw reply related [flat|nested] 45+ messages in thread
* [patch v9 3/4] Documentation: jtag: Add bindings for Aspeed SoC 24xx and 25xx families JTAG master driver
2017-09-21 9:25 ` Oleksandr Shamray
@ 2017-09-21 9:25 ` Oleksandr Shamray
-1 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-21 9:25 UTC (permalink / raw)
To: gregkh, arnd
Cc: linux-kernel, linux-arm-kernel, devicetree, openbmc, joel, jiri,
tklauser, linux-serial, mec, vadimp, system-sw-low-level,
robh+dt, openocd-devel-owner, linux-api, davem, mchehab,
Oleksandr Shamray, Jiri Pirko
It has been tested on Mellanox system with BMC equipped with
Aspeed 2520 SoC for programming CPLD devices.
Signed-off-by: Oleksandr Shamray <oleksandrs@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Rob Herring <robh@kernel.org>
---
v8->v9
v7->v8
Comments pointed by pointed by Joel Stanley <joel.stan@gmail.com>
- Change compatible string to ast2400 and ast2000
V6->v7
Comments pointed by Tobias Klauser <tklauser@distanz.ch>
- Fix spell "Doccumentation" -> "Documentation"
v5->v6
Comments pointed by Tobias Klauser <tklauser@distanz.ch>
- Small nit: s/documentation/Documentation/
v4->v5
V3->v4
Comments pointed by Rob Herring <robh@kernel.org>
- delete unnecessary "status" and "reg-shift" descriptions in
bndings file
v2->v3
Comments pointed by Rob Herring <robh@kernel.org>
- split Aspeed jtag driver and binding to sepatrate patches
- delete unnecessary "status" and "reg-shift" descriptions in
bndings file
---
.../devicetree/bindings/jtag/aspeed-jtag.txt | 18 ++++++++++++++++++
MAINTAINERS | 1 +
2 files changed, 19 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/jtag/aspeed-jtag.txt
diff --git a/Documentation/devicetree/bindings/jtag/aspeed-jtag.txt b/Documentation/devicetree/bindings/jtag/aspeed-jtag.txt
new file mode 100644
index 0000000..8cfc610
--- /dev/null
+++ b/Documentation/devicetree/bindings/jtag/aspeed-jtag.txt
@@ -0,0 +1,18 @@
+Aspeed JTAG driver for ast2400 and ast2500 SoC
+
+Required properties:
+- compatible: Should be one of
+ - "aspeed,ast2400-jtag"
+ - "aspeed,ast2500-jtag"
+- reg contains the offset and length of the JTAG memory
+ region
+- clocks root clock of bus, should reference the APB clock
+- interrupts should contain JTAG controller interrupt
+
+Example:
+jtag: jtag@1e6e4000 {
+ compatible = "aspeed,ast2500-jtag";
+ reg = <0x1e6e4000 0x1c>;
+ clocks = <&clk_apb>;
+ interrupts = <43>;
+};
diff --git a/MAINTAINERS b/MAINTAINERS
index 141aeaf..bfdfa94 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7299,6 +7299,7 @@ S: Maintained
F: include/linux/jtag.h
F: include/uapi/linux/jtag.h
F: drivers/jtag/
+F: Documentation/devicetree/bindings/jtag/
K10TEMP HARDWARE MONITORING DRIVER
M: Clemens Ladisch <clemens@ladisch.de>
--
1.7.1
^ permalink raw reply related [flat|nested] 45+ messages in thread
* [patch v9 3/4] Documentation: jtag: Add bindings for Aspeed SoC 24xx and 25xx families JTAG master driver
@ 2017-09-21 9:25 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-21 9:25 UTC (permalink / raw)
To: linux-arm-kernel
It has been tested on Mellanox system with BMC equipped with
Aspeed 2520 SoC for programming CPLD devices.
Signed-off-by: Oleksandr Shamray <oleksandrs@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Rob Herring <robh@kernel.org>
---
v8->v9
v7->v8
Comments pointed by pointed by Joel Stanley <joel.stan@gmail.com>
- Change compatible string to ast2400 and ast2000
V6->v7
Comments pointed by Tobias Klauser <tklauser@distanz.ch>
- Fix spell "Doccumentation" -> "Documentation"
v5->v6
Comments pointed by Tobias Klauser <tklauser@distanz.ch>
- Small nit: s/documentation/Documentation/
v4->v5
V3->v4
Comments pointed by Rob Herring <robh@kernel.org>
- delete unnecessary "status" and "reg-shift" descriptions in
bndings file
v2->v3
Comments pointed by Rob Herring <robh@kernel.org>
- split Aspeed jtag driver and binding to sepatrate patches
- delete unnecessary "status" and "reg-shift" descriptions in
bndings file
---
.../devicetree/bindings/jtag/aspeed-jtag.txt | 18 ++++++++++++++++++
MAINTAINERS | 1 +
2 files changed, 19 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/jtag/aspeed-jtag.txt
diff --git a/Documentation/devicetree/bindings/jtag/aspeed-jtag.txt b/Documentation/devicetree/bindings/jtag/aspeed-jtag.txt
new file mode 100644
index 0000000..8cfc610
--- /dev/null
+++ b/Documentation/devicetree/bindings/jtag/aspeed-jtag.txt
@@ -0,0 +1,18 @@
+Aspeed JTAG driver for ast2400 and ast2500 SoC
+
+Required properties:
+- compatible: Should be one of
+ - "aspeed,ast2400-jtag"
+ - "aspeed,ast2500-jtag"
+- reg contains the offset and length of the JTAG memory
+ region
+- clocks root clock of bus, should reference the APB clock
+- interrupts should contain JTAG controller interrupt
+
+Example:
+jtag: jtag at 1e6e4000 {
+ compatible = "aspeed,ast2500-jtag";
+ reg = <0x1e6e4000 0x1c>;
+ clocks = <&clk_apb>;
+ interrupts = <43>;
+};
diff --git a/MAINTAINERS b/MAINTAINERS
index 141aeaf..bfdfa94 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7299,6 +7299,7 @@ S: Maintained
F: include/linux/jtag.h
F: include/uapi/linux/jtag.h
F: drivers/jtag/
+F: Documentation/devicetree/bindings/jtag/
K10TEMP HARDWARE MONITORING DRIVER
M: Clemens Ladisch <clemens@ladisch.de>
--
1.7.1
^ permalink raw reply related [flat|nested] 45+ messages in thread
* [patch v9 4/4] Documentation: jtag: Add ABI documentation
@ 2017-09-21 9:25 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-21 9:25 UTC (permalink / raw)
To: gregkh, arnd
Cc: linux-kernel, linux-arm-kernel, devicetree, openbmc, joel, jiri,
tklauser, linux-serial, mec, vadimp, system-sw-low-level,
robh+dt, openocd-devel-owner, linux-api, davem, mchehab,
Oleksandr Shamray
Added document that describe the ABI for JTAG class drivrer
Signed-off-by: Oleksandr Shamray <oleksandrs@mellanox.com>
---
v8->v9
v7->v8
v6->v7
Comments pointed by Pavel Machek <pavel@ucw.cz>
- Added jtag-cdev documentation to Documentation/ABI/testing folder
---
Documentation/ABI/testing/jatg-cdev | 27 +++++++++++++++++++++++++++
MAINTAINERS | 1 +
2 files changed, 28 insertions(+), 0 deletions(-)
create mode 100644 Documentation/ABI/testing/jatg-cdev
diff --git a/Documentation/ABI/testing/jatg-cdev b/Documentation/ABI/testing/jatg-cdev
new file mode 100644
index 0000000..14a3610
--- /dev/null
+++ b/Documentation/ABI/testing/jatg-cdev
@@ -0,0 +1,27 @@
+What: /dev/jtag[0-9]+
+Date: September 2017
+KernelVersion: 4.14
+Contact: oleksandrs@mellanox.com
+Description:
+ The character device files /dev/jtag* are the interface
+ between JTAG master interfase and userspace.
+
+ The ioctl(2)-based ABI is defined and documented in
+ [include/uapi]<linux/jtag.h>.
+
+ The following file operations are supported:
+
+ open(2)
+ The argument flag currently support only one access
+ mode O_RDWR.
+
+ ioctl(2)
+ Initiate various actions.
+ See the inline documentation in [include/uapi]<linux/jtag.h>
+ for descriptions of all ioctls.
+
+ close(2)
+ Stops and free up the I/O contexts that was associated
+ with the file descriptor.
+
+Users: TBD
\ No newline at end of file
diff --git a/MAINTAINERS b/MAINTAINERS
index bfdfa94..dfcf49c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7300,6 +7300,7 @@ F: include/linux/jtag.h
F: include/uapi/linux/jtag.h
F: drivers/jtag/
F: Documentation/devicetree/bindings/jtag/
+F: Documentation/ABI/testing/jtag-cdev
K10TEMP HARDWARE MONITORING DRIVER
M: Clemens Ladisch <clemens@ladisch.de>
--
1.7.1
^ permalink raw reply related [flat|nested] 45+ messages in thread
* [patch v9 4/4] Documentation: jtag: Add ABI documentation
@ 2017-09-21 9:25 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-21 9:25 UTC (permalink / raw)
To: gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r, arnd-r2nGTMty4D4
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
devicetree-u79uwXL29TY76Z2rM5mHXA,
openbmc-uLR06cmDAlY/bJ5BZ2RsiQ, joel-U3u1mxZcP9KHXe+LvDLADg,
jiri-rHqAuBHg3fBzbRFIqnYvSA, tklauser-93Khv+1bN0NyDzI6CaY1VQ,
linux-serial-u79uwXL29TY76Z2rM5mHXA, mec-WqBc5aa1uDFeoWH0uzbU5w,
vadimp-VPRAkNaXOzVWk0Htik3J/w,
system-sw-low-level-VPRAkNaXOzVWk0Htik3J/w,
robh+dt-DgEjT+Ai2ygdnm+yROfE0A,
openocd-devel-owner-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
linux-api-u79uwXL29TY76Z2rM5mHXA, davem-fT/PcQaiUtIeIZ0/mPfg9Q,
mchehab-DgEjT+Ai2ygdnm+yROfE0A, Oleksandr Shamray
Added document that describe the ABI for JTAG class drivrer
Signed-off-by: Oleksandr Shamray <oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---
v8->v9
v7->v8
v6->v7
Comments pointed by Pavel Machek <pavel-+ZI9xUNit7I@public.gmane.org>
- Added jtag-cdev documentation to Documentation/ABI/testing folder
---
Documentation/ABI/testing/jatg-cdev | 27 +++++++++++++++++++++++++++
MAINTAINERS | 1 +
2 files changed, 28 insertions(+), 0 deletions(-)
create mode 100644 Documentation/ABI/testing/jatg-cdev
diff --git a/Documentation/ABI/testing/jatg-cdev b/Documentation/ABI/testing/jatg-cdev
new file mode 100644
index 0000000..14a3610
--- /dev/null
+++ b/Documentation/ABI/testing/jatg-cdev
@@ -0,0 +1,27 @@
+What: /dev/jtag[0-9]+
+Date: September 2017
+KernelVersion: 4.14
+Contact: oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org
+Description:
+ The character device files /dev/jtag* are the interface
+ between JTAG master interfase and userspace.
+
+ The ioctl(2)-based ABI is defined and documented in
+ [include/uapi]<linux/jtag.h>.
+
+ The following file operations are supported:
+
+ open(2)
+ The argument flag currently support only one access
+ mode O_RDWR.
+
+ ioctl(2)
+ Initiate various actions.
+ See the inline documentation in [include/uapi]<linux/jtag.h>
+ for descriptions of all ioctls.
+
+ close(2)
+ Stops and free up the I/O contexts that was associated
+ with the file descriptor.
+
+Users: TBD
\ No newline at end of file
diff --git a/MAINTAINERS b/MAINTAINERS
index bfdfa94..dfcf49c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7300,6 +7300,7 @@ F: include/linux/jtag.h
F: include/uapi/linux/jtag.h
F: drivers/jtag/
F: Documentation/devicetree/bindings/jtag/
+F: Documentation/ABI/testing/jtag-cdev
K10TEMP HARDWARE MONITORING DRIVER
M: Clemens Ladisch <clemens-P6GI/4k7KOmELgA04lAiVw@public.gmane.org>
--
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply related [flat|nested] 45+ messages in thread
* [patch v9 4/4] Documentation: jtag: Add ABI documentation
@ 2017-09-21 9:25 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-21 9:25 UTC (permalink / raw)
To: linux-arm-kernel
Added document that describe the ABI for JTAG class drivrer
Signed-off-by: Oleksandr Shamray <oleksandrs@mellanox.com>
---
v8->v9
v7->v8
v6->v7
Comments pointed by Pavel Machek <pavel@ucw.cz>
- Added jtag-cdev documentation to Documentation/ABI/testing folder
---
Documentation/ABI/testing/jatg-cdev | 27 +++++++++++++++++++++++++++
MAINTAINERS | 1 +
2 files changed, 28 insertions(+), 0 deletions(-)
create mode 100644 Documentation/ABI/testing/jatg-cdev
diff --git a/Documentation/ABI/testing/jatg-cdev b/Documentation/ABI/testing/jatg-cdev
new file mode 100644
index 0000000..14a3610
--- /dev/null
+++ b/Documentation/ABI/testing/jatg-cdev
@@ -0,0 +1,27 @@
+What: /dev/jtag[0-9]+
+Date: September 2017
+KernelVersion: 4.14
+Contact: oleksandrs at mellanox.com
+Description:
+ The character device files /dev/jtag* are the interface
+ between JTAG master interfase and userspace.
+
+ The ioctl(2)-based ABI is defined and documented in
+ [include/uapi]<linux/jtag.h>.
+
+ The following file operations are supported:
+
+ open(2)
+ The argument flag currently support only one access
+ mode O_RDWR.
+
+ ioctl(2)
+ Initiate various actions.
+ See the inline documentation in [include/uapi]<linux/jtag.h>
+ for descriptions of all ioctls.
+
+ close(2)
+ Stops and free up the I/O contexts that was associated
+ with the file descriptor.
+
+Users: TBD
\ No newline at end of file
diff --git a/MAINTAINERS b/MAINTAINERS
index bfdfa94..dfcf49c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7300,6 +7300,7 @@ F: include/linux/jtag.h
F: include/uapi/linux/jtag.h
F: drivers/jtag/
F: Documentation/devicetree/bindings/jtag/
+F: Documentation/ABI/testing/jtag-cdev
K10TEMP HARDWARE MONITORING DRIVER
M: Clemens Ladisch <clemens@ladisch.de>
--
1.7.1
^ permalink raw reply related [flat|nested] 45+ messages in thread
* Re: [patch v9 0/4] JTAG driver introduction
@ 2017-09-28 8:33 ` Geert Uytterhoeven
0 siblings, 0 replies; 45+ messages in thread
From: Geert Uytterhoeven @ 2017-09-28 8:33 UTC (permalink / raw)
To: Oleksandr Shamray
Cc: Greg KH, Arnd Bergmann, linux-kernel, linux-arm-kernel,
devicetree, openbmc, Joel Stanley, Jiri Pirko, Tobias Klauser,
linux-serial, mec, Vadim Pasternak, system-sw-low-level,
Rob Herring, openocd-devel-owner, linux-api, David S. Miller,
Mauro Carvalho Chehab, linux-spi, Mark Brown
Hi Oleksandr,
[My attention was drawn by https://lwn.net/Articles/734440/]
[CC linux-spi, which was never included, while linux-serial was]
On Thu, Sep 21, 2017 at 11:25 AM, Oleksandr Shamray
<oleksandrs@mellanox.com> wrote:
> When a need raise up to use JTAG interface for system's devices
> programming or CPU debugging, usually the user layer
> application implements jtag protocol by bit-bang or using a
> proprietary connection to vendor hardware.
> This method can be slow and not generic.
>
> We propose to implement general JTAG interface and infrastructure
> to communicate with user layer application. In such way, we can
> have the standard JTAG interface core part and separation from
> specific HW implementation.
> This allow new capability to debug the CPU or program system's
> device via BMC without additional devices nor cost.
>
> This patch purpose is to add JTAG master core infrastructure by
> defining new JTAG class and provide generic JTAG interface
> to allow hardware specific drivers to connect this interface.
> This will enable all JTAG drivers to use the common interface
> part and will have separate for hardware implementation.
>
> The JTAG (Joint Test Action Group) core driver provides minimal generic
> JTAG interface, which can be used by hardware specific JTAG master
> controllers. By providing common interface for the JTAG controllers,
> user space device programing is hardware independent.
>
> Modern SoC which in use for embedded system' equipped with
> internal JTAG master interface.
> This interface is used for programming and debugging system's
> hardware components, like CPLD, FPGA, CPU, voltage and
> industrial controllers.
> Firmware for such devices can be upgraded through JTAG interface during
> Runtime. The JTAG standard support for multiple devices programming,
> is in case their lines are daisy-chained together.
>
> For example, systems which equipped with host CPU, BMC SoC or/and
> number of programmable devices are capable to connect a pin and
> select system components dynamically for programming and debugging,
> This is using by the BMC which is equipped with internal SoC master
> controller.
> For example:
>
> BMC JTAG master --> pin selected to CPLDs chain for programming (filed
> upgrade, production)
> BMC JTAG master --> pin selected to voltage monitors for programming
> (field upgrade, production)
> BMC JTAG master --> pin selected to host CPU (on-site debugging
> and developers debugging)
>
> For example, we can have application in user space which using calls
> to JTAG driver executes CPLD programming directly from SVF file
>
> The JTAG standard (IEEE 1149.1) defines the next connector pins:
> - TDI (Test Data In);
> - TDO (Test Data Out);
> - TCK (Test Clock);
> - TMS (Test Mode Select);
> - TRST (Test Reset) (Optional);
>
> The SoC equipped with JTAG master controller, performs
> device programming on command or vector level. For example
> a file in a standard SVF (Serial Vector Format) that contains
> boundary scan vectors, can be used by sending each vector
> to the JTAG interface and the JTAG controller will execute
> the programming.
>
> Initial version provides the system calls set for:
> - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
> - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
> - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
> number of clocks.
>
> SoC which are not equipped with JTAG master interface, can be built
> on top of JTAG core driver infrastructure, by applying bit-banging of
> TDI, TDO, TCK and TMS pins within the hardware specific driver.
Or by using an SPI master?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 45+ messages in thread
* Re: [patch v9 0/4] JTAG driver introduction
@ 2017-09-28 8:33 ` Geert Uytterhoeven
0 siblings, 0 replies; 45+ messages in thread
From: Geert Uytterhoeven @ 2017-09-28 8:33 UTC (permalink / raw)
To: Oleksandr Shamray
Cc: Greg KH, Arnd Bergmann, linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
devicetree-u79uwXL29TY76Z2rM5mHXA,
openbmc-uLR06cmDAlY/bJ5BZ2RsiQ, Joel Stanley, Jiri Pirko,
Tobias Klauser, linux-serial-u79uwXL29TY76Z2rM5mHXA,
mec-WqBc5aa1uDFeoWH0uzbU5w, Vadim Pasternak,
system-sw-low-level-VPRAkNaXOzVWk0Htik3J/w, Rob Herring,
openocd-devel-owner-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
linux-api-u79uwXL29TY76Z2rM5mHXA, David S. Miller,
Mauro Carvalho Chehab
Hi Oleksandr,
[My attention was drawn by https://lwn.net/Articles/734440/]
[CC linux-spi, which was never included, while linux-serial was]
On Thu, Sep 21, 2017 at 11:25 AM, Oleksandr Shamray
<oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org> wrote:
> When a need raise up to use JTAG interface for system's devices
> programming or CPU debugging, usually the user layer
> application implements jtag protocol by bit-bang or using a
> proprietary connection to vendor hardware.
> This method can be slow and not generic.
>
> We propose to implement general JTAG interface and infrastructure
> to communicate with user layer application. In such way, we can
> have the standard JTAG interface core part and separation from
> specific HW implementation.
> This allow new capability to debug the CPU or program system's
> device via BMC without additional devices nor cost.
>
> This patch purpose is to add JTAG master core infrastructure by
> defining new JTAG class and provide generic JTAG interface
> to allow hardware specific drivers to connect this interface.
> This will enable all JTAG drivers to use the common interface
> part and will have separate for hardware implementation.
>
> The JTAG (Joint Test Action Group) core driver provides minimal generic
> JTAG interface, which can be used by hardware specific JTAG master
> controllers. By providing common interface for the JTAG controllers,
> user space device programing is hardware independent.
>
> Modern SoC which in use for embedded system' equipped with
> internal JTAG master interface.
> This interface is used for programming and debugging system's
> hardware components, like CPLD, FPGA, CPU, voltage and
> industrial controllers.
> Firmware for such devices can be upgraded through JTAG interface during
> Runtime. The JTAG standard support for multiple devices programming,
> is in case their lines are daisy-chained together.
>
> For example, systems which equipped with host CPU, BMC SoC or/and
> number of programmable devices are capable to connect a pin and
> select system components dynamically for programming and debugging,
> This is using by the BMC which is equipped with internal SoC master
> controller.
> For example:
>
> BMC JTAG master --> pin selected to CPLDs chain for programming (filed
> upgrade, production)
> BMC JTAG master --> pin selected to voltage monitors for programming
> (field upgrade, production)
> BMC JTAG master --> pin selected to host CPU (on-site debugging
> and developers debugging)
>
> For example, we can have application in user space which using calls
> to JTAG driver executes CPLD programming directly from SVF file
>
> The JTAG standard (IEEE 1149.1) defines the next connector pins:
> - TDI (Test Data In);
> - TDO (Test Data Out);
> - TCK (Test Clock);
> - TMS (Test Mode Select);
> - TRST (Test Reset) (Optional);
>
> The SoC equipped with JTAG master controller, performs
> device programming on command or vector level. For example
> a file in a standard SVF (Serial Vector Format) that contains
> boundary scan vectors, can be used by sending each vector
> to the JTAG interface and the JTAG controller will execute
> the programming.
>
> Initial version provides the system calls set for:
> - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
> - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
> - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
> number of clocks.
>
> SoC which are not equipped with JTAG master interface, can be built
> on top of JTAG core driver infrastructure, by applying bit-banging of
> TDI, TDO, TCK and TMS pins within the hardware specific driver.
Or by using an SPI master?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 45+ messages in thread
* Re: [patch v9 0/4] JTAG driver introduction
@ 2017-09-28 8:33 ` Geert Uytterhoeven
0 siblings, 0 replies; 45+ messages in thread
From: Geert Uytterhoeven @ 2017-09-28 8:33 UTC (permalink / raw)
To: Oleksandr Shamray
Cc: Greg KH, Arnd Bergmann, linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
devicetree-u79uwXL29TY76Z2rM5mHXA,
openbmc-uLR06cmDAlY/bJ5BZ2RsiQ, Joel Stanley, Jiri Pirko,
Tobias Klauser, linux-serial-u79uwXL29TY76Z2rM5mHXA,
mec-WqBc5aa1uDFeoWH0uzbU5w, Vadim Pasternak,
system-sw-low-level-VPRAkNaXOzVWk0Htik3J/w, Rob Herring,
openocd-devel-owner-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
linux-api-u79uwXL29TY76Z2rM5mHXA, David S. Miller,
Mauro Carvalho Chehab, l
Hi Oleksandr,
[My attention was drawn by https://lwn.net/Articles/734440/]
[CC linux-spi, which was never included, while linux-serial was]
On Thu, Sep 21, 2017 at 11:25 AM, Oleksandr Shamray
<oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org> wrote:
> When a need raise up to use JTAG interface for system's devices
> programming or CPU debugging, usually the user layer
> application implements jtag protocol by bit-bang or using a
> proprietary connection to vendor hardware.
> This method can be slow and not generic.
>
> We propose to implement general JTAG interface and infrastructure
> to communicate with user layer application. In such way, we can
> have the standard JTAG interface core part and separation from
> specific HW implementation.
> This allow new capability to debug the CPU or program system's
> device via BMC without additional devices nor cost.
>
> This patch purpose is to add JTAG master core infrastructure by
> defining new JTAG class and provide generic JTAG interface
> to allow hardware specific drivers to connect this interface.
> This will enable all JTAG drivers to use the common interface
> part and will have separate for hardware implementation.
>
> The JTAG (Joint Test Action Group) core driver provides minimal generic
> JTAG interface, which can be used by hardware specific JTAG master
> controllers. By providing common interface for the JTAG controllers,
> user space device programing is hardware independent.
>
> Modern SoC which in use for embedded system' equipped with
> internal JTAG master interface.
> This interface is used for programming and debugging system's
> hardware components, like CPLD, FPGA, CPU, voltage and
> industrial controllers.
> Firmware for such devices can be upgraded through JTAG interface during
> Runtime. The JTAG standard support for multiple devices programming,
> is in case their lines are daisy-chained together.
>
> For example, systems which equipped with host CPU, BMC SoC or/and
> number of programmable devices are capable to connect a pin and
> select system components dynamically for programming and debugging,
> This is using by the BMC which is equipped with internal SoC master
> controller.
> For example:
>
> BMC JTAG master --> pin selected to CPLDs chain for programming (filed
> upgrade, production)
> BMC JTAG master --> pin selected to voltage monitors for programming
> (field upgrade, production)
> BMC JTAG master --> pin selected to host CPU (on-site debugging
> and developers debugging)
>
> For example, we can have application in user space which using calls
> to JTAG driver executes CPLD programming directly from SVF file
>
> The JTAG standard (IEEE 1149.1) defines the next connector pins:
> - TDI (Test Data In);
> - TDO (Test Data Out);
> - TCK (Test Clock);
> - TMS (Test Mode Select);
> - TRST (Test Reset) (Optional);
>
> The SoC equipped with JTAG master controller, performs
> device programming on command or vector level. For example
> a file in a standard SVF (Serial Vector Format) that contains
> boundary scan vectors, can be used by sending each vector
> to the JTAG interface and the JTAG controller will execute
> the programming.
>
> Initial version provides the system calls set for:
> - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
> - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
> - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
> number of clocks.
>
> SoC which are not equipped with JTAG master interface, can be built
> on top of JTAG core driver infrastructure, by applying bit-banging of
> TDI, TDO, TCK and TMS pins within the hardware specific driver.
Or by using an SPI master?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 45+ messages in thread
* Re: [patch v9 0/4] JTAG driver introduction
@ 2017-09-28 8:33 ` Geert Uytterhoeven
0 siblings, 0 replies; 45+ messages in thread
From: Geert Uytterhoeven @ 2017-09-28 8:33 UTC (permalink / raw)
To: Oleksandr Shamray
Cc: Greg KH, Arnd Bergmann, linux-kernel, linux-arm-kernel,
devicetree, openbmc, Joel Stanley, Jiri Pirko, Tobias Klauser,
linux-serial, mec, Vadim Pasternak, system-sw-low-level,
Rob Herring, openocd-devel-owner, linux-api, David S. Miller,
Mauro Carvalho Chehab, linux-spi, Mark Brown
Hi Oleksandr,
[My attention was drawn by https://lwn.net/Articles/734440/]
[CC linux-spi, which was never included, while linux-serial was]
On Thu, Sep 21, 2017 at 11:25 AM, Oleksandr Shamray
<oleksandrs@mellanox.com> wrote:
> When a need raise up to use JTAG interface for system's devices
> programming or CPU debugging, usually the user layer
> application implements jtag protocol by bit-bang or using a
> proprietary connection to vendor hardware.
> This method can be slow and not generic.
>
> We propose to implement general JTAG interface and infrastructure
> to communicate with user layer application. In such way, we can
> have the standard JTAG interface core part and separation from
> specific HW implementation.
> This allow new capability to debug the CPU or program system's
> device via BMC without additional devices nor cost.
>
> This patch purpose is to add JTAG master core infrastructure by
> defining new JTAG class and provide generic JTAG interface
> to allow hardware specific drivers to connect this interface.
> This will enable all JTAG drivers to use the common interface
> part and will have separate for hardware implementation.
>
> The JTAG (Joint Test Action Group) core driver provides minimal generic
> JTAG interface, which can be used by hardware specific JTAG master
> controllers. By providing common interface for the JTAG controllers,
> user space device programing is hardware independent.
>
> Modern SoC which in use for embedded system' equipped with
> internal JTAG master interface.
> This interface is used for programming and debugging system's
> hardware components, like CPLD, FPGA, CPU, voltage and
> industrial controllers.
> Firmware for such devices can be upgraded through JTAG interface during
> Runtime. The JTAG standard support for multiple devices programming,
> is in case their lines are daisy-chained together.
>
> For example, systems which equipped with host CPU, BMC SoC or/and
> number of programmable devices are capable to connect a pin and
> select system components dynamically for programming and debugging,
> This is using by the BMC which is equipped with internal SoC master
> controller.
> For example:
>
> BMC JTAG master --> pin selected to CPLDs chain for programming (filed
> upgrade, production)
> BMC JTAG master --> pin selected to voltage monitors for programming
> (field upgrade, production)
> BMC JTAG master --> pin selected to host CPU (on-site debugging
> and developers debugging)
>
> For example, we can have application in user space which using calls
> to JTAG driver executes CPLD programming directly from SVF file
>
> The JTAG standard (IEEE 1149.1) defines the next connector pins:
> - TDI (Test Data In);
> - TDO (Test Data Out);
> - TCK (Test Clock);
> - TMS (Test Mode Select);
> - TRST (Test Reset) (Optional);
>
> The SoC equipped with JTAG master controller, performs
> device programming on command or vector level. For example
> a file in a standard SVF (Serial Vector Format) that contains
> boundary scan vectors, can be used by sending each vector
> to the JTAG interface and the JTAG controller will execute
> the programming.
>
> Initial version provides the system calls set for:
> - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
> - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
> - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
> number of clocks.
>
> SoC which are not equipped with JTAG master interface, can be built
> on top of JTAG core driver infrastructure, by applying bit-banging of
> TDI, TDO, TCK and TMS pins within the hardware specific driver.
Or by using an SPI master?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 45+ messages in thread
* [patch v9 0/4] JTAG driver introduction
@ 2017-09-28 8:33 ` Geert Uytterhoeven
0 siblings, 0 replies; 45+ messages in thread
From: Geert Uytterhoeven @ 2017-09-28 8:33 UTC (permalink / raw)
To: linux-arm-kernel
Hi Oleksandr,
[My attention was drawn by https://lwn.net/Articles/734440/]
[CC linux-spi, which was never included, while linux-serial was]
On Thu, Sep 21, 2017 at 11:25 AM, Oleksandr Shamray
<oleksandrs@mellanox.com> wrote:
> When a need raise up to use JTAG interface for system's devices
> programming or CPU debugging, usually the user layer
> application implements jtag protocol by bit-bang or using a
> proprietary connection to vendor hardware.
> This method can be slow and not generic.
>
> We propose to implement general JTAG interface and infrastructure
> to communicate with user layer application. In such way, we can
> have the standard JTAG interface core part and separation from
> specific HW implementation.
> This allow new capability to debug the CPU or program system's
> device via BMC without additional devices nor cost.
>
> This patch purpose is to add JTAG master core infrastructure by
> defining new JTAG class and provide generic JTAG interface
> to allow hardware specific drivers to connect this interface.
> This will enable all JTAG drivers to use the common interface
> part and will have separate for hardware implementation.
>
> The JTAG (Joint Test Action Group) core driver provides minimal generic
> JTAG interface, which can be used by hardware specific JTAG master
> controllers. By providing common interface for the JTAG controllers,
> user space device programing is hardware independent.
>
> Modern SoC which in use for embedded system' equipped with
> internal JTAG master interface.
> This interface is used for programming and debugging system's
> hardware components, like CPLD, FPGA, CPU, voltage and
> industrial controllers.
> Firmware for such devices can be upgraded through JTAG interface during
> Runtime. The JTAG standard support for multiple devices programming,
> is in case their lines are daisy-chained together.
>
> For example, systems which equipped with host CPU, BMC SoC or/and
> number of programmable devices are capable to connect a pin and
> select system components dynamically for programming and debugging,
> This is using by the BMC which is equipped with internal SoC master
> controller.
> For example:
>
> BMC JTAG master --> pin selected to CPLDs chain for programming (filed
> upgrade, production)
> BMC JTAG master --> pin selected to voltage monitors for programming
> (field upgrade, production)
> BMC JTAG master --> pin selected to host CPU (on-site debugging
> and developers debugging)
>
> For example, we can have application in user space which using calls
> to JTAG driver executes CPLD programming directly from SVF file
>
> The JTAG standard (IEEE 1149.1) defines the next connector pins:
> - TDI (Test Data In);
> - TDO (Test Data Out);
> - TCK (Test Clock);
> - TMS (Test Mode Select);
> - TRST (Test Reset) (Optional);
>
> The SoC equipped with JTAG master controller, performs
> device programming on command or vector level. For example
> a file in a standard SVF (Serial Vector Format) that contains
> boundary scan vectors, can be used by sending each vector
> to the JTAG interface and the JTAG controller will execute
> the programming.
>
> Initial version provides the system calls set for:
> - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
> - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
> - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
> number of clocks.
>
> SoC which are not equipped with JTAG master interface, can be built
> on top of JTAG core driver infrastructure, by applying bit-banging of
> TDI, TDO, TCK and TMS pins within the hardware specific driver.
Or by using an SPI master?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 45+ messages in thread
* RE: [patch v9 0/4] JTAG driver introduction
@ 2017-09-28 8:53 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-28 8:53 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: Greg KH, Arnd Bergmann, linux-kernel, linux-arm-kernel,
devicetree, openbmc, Joel Stanley, Jiri Pirko, Tobias Klauser,
linux-serial, mec, Vadim Pasternak, system-sw-low-level,
Rob Herring, openocd-devel-owner, linux-api, David S. Miller,
Mauro Carvalho Chehab, linux-spi, Mark Brown
> -----Original Message-----
> From: geert.uytterhoeven@gmail.com [mailto:geert.uytterhoeven@gmail.com]
> On Behalf Of Geert Uytterhoeven
> Sent: Thursday, September 28, 2017 11:33 AM
> To: Oleksandr Shamray <oleksandrs@mellanox.com>
> Cc: Greg KH <gregkh@linuxfoundation.org>; Arnd Bergmann
> <arnd@arndb.de>; linux-kernel@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; devicetree@vger.kernel.org;
> openbmc@lists.ozlabs.org; Joel Stanley <joel@jms.id.au>; Jiri Pirko
> <jiri@resnulli.us>; Tobias Klauser <tklauser@distanz.ch>; linux-
> serial@vger.kernel.org; mec@shout.net; Vadim Pasternak
> <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> level@mellanox.com>; Rob Herring <robh+dt@kernel.org>; openocd-devel-
> owner@lists.sourceforge.net; linux-api@vger.kernel.org; David S. Miller
> <davem@davemloft.net>; Mauro Carvalho Chehab <mchehab@kernel.org>;
> linux-spi <linux-spi@vger.kernel.org>; Mark Brown <broonie@kernel.org>
> Subject: Re: [patch v9 0/4] JTAG driver introduction
>
> Hi Oleksandr,
>
> [My attention was drawn by
> https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flwn.net
> %2FArticles%2F734440%2F&data=02%7C01%7Coleksandrs%40mellanox.com%7
> C97b8ba88686a42daaace08d5064b92eb%7Ca652971c7d2e4d9ba6a4d149256f
> 461b%7C0%7C0%7C636421844026854216&sdata=TeHD4a3%2FBN6a5XG3Jizf5
> pmsyJHJjzkEzkpnqsXC6S0%3D&reserved=0]
> [CC linux-spi, which was never included, while linux-serial was]
>
> On Thu, Sep 21, 2017 at 11:25 AM, Oleksandr Shamray
> <oleksandrs@mellanox.com> wrote:
> > When a need raise up to use JTAG interface for system's devices
> > programming or CPU debugging, usually the user layer application
> > implements jtag protocol by bit-bang or using a proprietary connection
> > to vendor hardware.
> > This method can be slow and not generic.
> >
[..]
> >
> > Initial version provides the system calls set for:
> > - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
> > - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
> > - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
> > number of clocks.
> >
> > SoC which are not equipped with JTAG master interface, can be built on
> > top of JTAG core driver infrastructure, by applying bit-banging of
> > TDI, TDO, TCK and TMS pins within the hardware specific driver.
>
> Or by using an SPI master?
>
I think it depends on how flexible the SPI interface is. If you can set it to transfer
from 1 to n bits at a time, and you control the TMS line in software, you should
be able to use it. If the SPI interface can only transfer a multiple of 8 bits
at a time, then in general it would not be suitable for JTAG.
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-
> m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
^ permalink raw reply [flat|nested] 45+ messages in thread
* RE: [patch v9 0/4] JTAG driver introduction
@ 2017-09-28 8:53 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-28 8:53 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: Greg KH, Arnd Bergmann, linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
devicetree-u79uwXL29TY76Z2rM5mHXA,
openbmc-uLR06cmDAlY/bJ5BZ2RsiQ, Joel Stanley, Jiri Pirko,
Tobias Klauser, linux-serial-u79uwXL29TY76Z2rM5mHXA,
mec-WqBc5aa1uDFeoWH0uzbU5w, Vadim Pasternak, system-sw-low-level,
Rob Herring,
openocd-devel-owner-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
linux-api-u79uwXL29TY76Z2rM5mHXA
> -----Original Message-----
> From: geert.uytterhoeven@gmail.com [mailto:geert.uytterhoeven@gmail.com]
> On Behalf Of Geert Uytterhoeven
> Sent: Thursday, September 28, 2017 11:33 AM
> To: Oleksandr Shamray <oleksandrs@mellanox.com>
> Cc: Greg KH <gregkh@linuxfoundation.org>; Arnd Bergmann
> <arnd@arndb.de>; linux-kernel@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; devicetree@vger.kernel.org;
> openbmc@lists.ozlabs.org; Joel Stanley <joel@jms.id.au>; Jiri Pirko
> <jiri@resnulli.us>; Tobias Klauser <tklauser@distanz.ch>; linux-
> serial@vger.kernel.org; mec@shout.net; Vadim Pasternak
> <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> level@mellanox.com>; Rob Herring <robh+dt@kernel.org>; openocd-devel-
> owner@lists.sourceforge.net; linux-api@vger.kernel.org; David S. Miller
> <davem@davemloft.net>; Mauro Carvalho Chehab <mchehab@kernel.org>;
> linux-spi <linux-spi@vger.kernel.org>; Mark Brown <broonie@kernel.org>
> Subject: Re: [patch v9 0/4] JTAG driver introduction
>
> Hi Oleksandr,
>
> [My attention was drawn by
> https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flwn.net
> %2FArticles%2F734440%2F&data=02%7C01%7Coleksandrs%40mellanox.com%7
> C97b8ba88686a42daaace08d5064b92eb%7Ca652971c7d2e4d9ba6a4d149256f
> 461b%7C0%7C0%7C636421844026854216&sdata=TeHD4a3%2FBN6a5XG3Jizf5
> pmsyJHJjzkEzkpnqsXC6S0%3D&reserved=0]
> [CC linux-spi, which was never included, while linux-serial was]
>
> On Thu, Sep 21, 2017 at 11:25 AM, Oleksandr Shamray
> <oleksandrs@mellanox.com> wrote:
> > When a need raise up to use JTAG interface for system's devices
> > programming or CPU debugging, usually the user layer application
> > implements jtag protocol by bit-bang or using a proprietary connection
> > to vendor hardware.
> > This method can be slow and not generic.
> >
[..]
> >
> > Initial version provides the system calls set for:
> > - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
> > - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
> > - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
> > number of clocks.
> >
> > SoC which are not equipped with JTAG master interface, can be built on
> > top of JTAG core driver infrastructure, by applying bit-banging of
> > TDI, TDO, TCK and TMS pins within the hardware specific driver.
>
> Or by using an SPI master?
>
I think it depends on how flexible the SPI interface is. If you can set it to transfer
from 1 to n bits at a time, and you control the TMS line in software, you should
be able to use it. If the SPI interface can only transfer a multiple of 8 bits
at a time, then in general it would not be suitable for JTAG.
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-
> m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
^ permalink raw reply [flat|nested] 45+ messages in thread
* RE: [patch v9 0/4] JTAG driver introduction
@ 2017-09-28 8:53 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-28 8:53 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: Greg KH, Arnd Bergmann, linux-kernel, linux-arm-kernel,
devicetree, openbmc, Joel Stanley, Jiri Pirko, Tobias Klauser,
linux-serial, mec, Vadim Pasternak, system-sw-low-level,
Rob Herring, openocd-devel-owner, linux-api, David S. Miller,
Mauro Carvalho Chehab, linux-spi, Mark Brown
> -----Original Message-----
> From: geert.uytterhoeven@gmail.com [mailto:geert.uytterhoeven@gmail.com]
> On Behalf Of Geert Uytterhoeven
> Sent: Thursday, September 28, 2017 11:33 AM
> To: Oleksandr Shamray <oleksandrs@mellanox.com>
> Cc: Greg KH <gregkh@linuxfoundation.org>; Arnd Bergmann
> <arnd@arndb.de>; linux-kernel@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; devicetree@vger.kernel.org;
> openbmc@lists.ozlabs.org; Joel Stanley <joel@jms.id.au>; Jiri Pirko
> <jiri@resnulli.us>; Tobias Klauser <tklauser@distanz.ch>; linux-
> serial@vger.kernel.org; mec@shout.net; Vadim Pasternak
> <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> level@mellanox.com>; Rob Herring <robh+dt@kernel.org>; openocd-devel-
> owner@lists.sourceforge.net; linux-api@vger.kernel.org; David S. Miller
> <davem@davemloft.net>; Mauro Carvalho Chehab <mchehab@kernel.org>;
> linux-spi <linux-spi@vger.kernel.org>; Mark Brown <broonie@kernel.org>
> Subject: Re: [patch v9 0/4] JTAG driver introduction
>
> Hi Oleksandr,
>
> [My attention was drawn by
> https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flwn.net
> %2FArticles%2F734440%2F&data=02%7C01%7Coleksandrs%40mellanox.com%7
> C97b8ba88686a42daaace08d5064b92eb%7Ca652971c7d2e4d9ba6a4d149256f
> 461b%7C0%7C0%7C636421844026854216&sdata=TeHD4a3%2FBN6a5XG3Jizf5
> pmsyJHJjzkEzkpnqsXC6S0%3D&reserved=0]
> [CC linux-spi, which was never included, while linux-serial was]
>
> On Thu, Sep 21, 2017 at 11:25 AM, Oleksandr Shamray
> <oleksandrs@mellanox.com> wrote:
> > When a need raise up to use JTAG interface for system's devices
> > programming or CPU debugging, usually the user layer application
> > implements jtag protocol by bit-bang or using a proprietary connection
> > to vendor hardware.
> > This method can be slow and not generic.
> >
[..]
> >
> > Initial version provides the system calls set for:
> > - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
> > - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
> > - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
> > number of clocks.
> >
> > SoC which are not equipped with JTAG master interface, can be built on
> > top of JTAG core driver infrastructure, by applying bit-banging of
> > TDI, TDO, TCK and TMS pins within the hardware specific driver.
>
> Or by using an SPI master?
>
I think it depends on how flexible the SPI interface is. If you can set it to transfer
from 1 to n bits at a time, and you control the TMS line in software, you should
be able to use it. If the SPI interface can only transfer a multiple of 8 bits
at a time, then in general it would not be suitable for JTAG.
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-
> m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
^ permalink raw reply [flat|nested] 45+ messages in thread
* [patch v9 0/4] JTAG driver introduction
@ 2017-09-28 8:53 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-28 8:53 UTC (permalink / raw)
To: linux-arm-kernel
> -----Original Message-----
> From: geert.uytterhoeven at gmail.com [mailto:geert.uytterhoeven at gmail.com]
> On Behalf Of Geert Uytterhoeven
> Sent: Thursday, September 28, 2017 11:33 AM
> To: Oleksandr Shamray <oleksandrs@mellanox.com>
> Cc: Greg KH <gregkh@linuxfoundation.org>; Arnd Bergmann
> <arnd@arndb.de>; linux-kernel at vger.kernel.org; linux-arm-
> kernel at lists.infradead.org; devicetree at vger.kernel.org;
> openbmc at lists.ozlabs.org; Joel Stanley <joel@jms.id.au>; Jiri Pirko
> <jiri@resnulli.us>; Tobias Klauser <tklauser@distanz.ch>; linux-
> serial at vger.kernel.org; mec at shout.net; Vadim Pasternak
> <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> level at mellanox.com>; Rob Herring <robh+dt@kernel.org>; openocd-devel-
> owner at lists.sourceforge.net; linux-api at vger.kernel.org; David S. Miller
> <davem@davemloft.net>; Mauro Carvalho Chehab <mchehab@kernel.org>;
> linux-spi <linux-spi@vger.kernel.org>; Mark Brown <broonie@kernel.org>
> Subject: Re: [patch v9 0/4] JTAG driver introduction
>
> Hi Oleksandr,
>
> [My attention was drawn by
> https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flwn.net
> %2FArticles%2F734440%2F&data=02%7C01%7Coleksandrs%40mellanox.com%7
> C97b8ba88686a42daaace08d5064b92eb%7Ca652971c7d2e4d9ba6a4d149256f
> 461b%7C0%7C0%7C636421844026854216&sdata=TeHD4a3%2FBN6a5XG3Jizf5
> pmsyJHJjzkEzkpnqsXC6S0%3D&reserved=0]
> [CC linux-spi, which was never included, while linux-serial was]
>
> On Thu, Sep 21, 2017 at 11:25 AM, Oleksandr Shamray
> <oleksandrs@mellanox.com> wrote:
> > When a need raise up to use JTAG interface for system's devices
> > programming or CPU debugging, usually the user layer application
> > implements jtag protocol by bit-bang or using a proprietary connection
> > to vendor hardware.
> > This method can be slow and not generic.
> >
[..]
> >
> > Initial version provides the system calls set for:
> > - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
> > - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
> > - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
> > number of clocks.
> >
> > SoC which are not equipped with JTAG master interface, can be built on
> > top of JTAG core driver infrastructure, by applying bit-banging of
> > TDI, TDO, TCK and TMS pins within the hardware specific driver.
>
> Or by using an SPI master?
>
I think it depends on how flexible the SPI interface is. If you can set it to transfer
from 1 to n bits at a time, and you control the TMS line in software, you should
be able to use it. If the SPI interface can only transfer a multiple of 8 bits
at a time, then in general it would not be suitable for JTAG.
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-
> m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
^ permalink raw reply [flat|nested] 45+ messages in thread
* Re: [patch v9 0/4] JTAG driver introduction
2017-09-28 8:53 ` Oleksandr Shamray
(?)
(?)
@ 2017-09-28 9:02 ` Geert Uytterhoeven
-1 siblings, 0 replies; 45+ messages in thread
From: Geert Uytterhoeven @ 2017-09-28 9:02 UTC (permalink / raw)
To: Oleksandr Shamray
Cc: Greg KH, Arnd Bergmann, linux-kernel, linux-arm-kernel,
devicetree, openbmc, Joel Stanley, Jiri Pirko, Tobias Klauser,
linux-serial, mec, Vadim Pasternak, system-sw-low-level,
Rob Herring, openocd-devel-owner, linux-api, David S. Miller,
Mauro Carvalho Chehab, linux-spi, Mark Brown
Hi Oleksandr,
On Thu, Sep 28, 2017 at 10:53 AM, Oleksandr Shamray
<oleksandrs@mellanox.com> wrote:
>> [My attention was drawn by
>> https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flwn.net
>> %2FArticles%2F734440%2F&data=02%7C01%7Coleksandrs%40mellanox.com%7
>> C97b8ba88686a42daaace08d5064b92eb%7Ca652971c7d2e4d9ba6a4d149256f
>> 461b%7C0%7C0%7C636421844026854216&sdata=TeHD4a3%2FBN6a5XG3Jizf5
>> pmsyJHJjzkEzkpnqsXC6S0%3D&reserved=0]
>> [CC linux-spi, which was never included, while linux-serial was]
>>
>> On Thu, Sep 21, 2017 at 11:25 AM, Oleksandr Shamray
>> <oleksandrs@mellanox.com> wrote:
>> > When a need raise up to use JTAG interface for system's devices
>> > programming or CPU debugging, usually the user layer application
>> > implements jtag protocol by bit-bang or using a proprietary connection
>> > to vendor hardware.
>> > This method can be slow and not generic.
>> >
>
>
> [..]
>
>> >
>> > Initial version provides the system calls set for:
>> > - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
>> > - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
>> > - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
>> > number of clocks.
>> >
>> > SoC which are not equipped with JTAG master interface, can be built on
>> > top of JTAG core driver infrastructure, by applying bit-banging of
>> > TDI, TDO, TCK and TMS pins within the hardware specific driver.
>>
>> Or by using an SPI master?
>>
>
> I think it depends on how flexible the SPI interface is. If you can set it to transfer
> from 1 to n bits at a time, and you control the TMS line in software, you should
> be able to use it. If the SPI interface can only transfer a multiple of 8 bits
> at a time, then in general it would not be suitable for JTAG.
Sure, that depends on the actual SPI master interface.
But I guess you can write a generic JTAG-over-SPI driver, and use a tms-gpios
property in DT to specify how to control TMS.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 45+ messages in thread
* Re: [patch v9 0/4] JTAG driver introduction
@ 2017-09-28 9:02 ` Geert Uytterhoeven
0 siblings, 0 replies; 45+ messages in thread
From: Geert Uytterhoeven @ 2017-09-28 9:02 UTC (permalink / raw)
To: Oleksandr Shamray
Cc: Greg KH, Arnd Bergmann, linux-kernel, linux-arm-kernel,
devicetree, openbmc, Joel Stanley, Jiri Pirko, Tobias Klauser,
linux-serial, mec, Vadim Pasternak, system-sw-low-level,
Rob Herring, openocd-devel-owner, linux-api
Hi Oleksandr,
On Thu, Sep 28, 2017 at 10:53 AM, Oleksandr Shamray
<oleksandrs@mellanox.com> wrote:
>> [My attention was drawn by
>> https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flwn.net
>> %2FArticles%2F734440%2F&data=02%7C01%7Coleksandrs%40mellanox.com%7
>> C97b8ba88686a42daaace08d5064b92eb%7Ca652971c7d2e4d9ba6a4d149256f
>> 461b%7C0%7C0%7C636421844026854216&sdata=TeHD4a3%2FBN6a5XG3Jizf5
>> pmsyJHJjzkEzkpnqsXC6S0%3D&reserved=0]
>> [CC linux-spi, which was never included, while linux-serial was]
>>
>> On Thu, Sep 21, 2017 at 11:25 AM, Oleksandr Shamray
>> <oleksandrs@mellanox.com> wrote:
>> > When a need raise up to use JTAG interface for system's devices
>> > programming or CPU debugging, usually the user layer application
>> > implements jtag protocol by bit-bang or using a proprietary connection
>> > to vendor hardware.
>> > This method can be slow and not generic.
>> >
>
>
> [..]
>
>> >
>> > Initial version provides the system calls set for:
>> > - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
>> > - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
>> > - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
>> > number of clocks.
>> >
>> > SoC which are not equipped with JTAG master interface, can be built on
>> > top of JTAG core driver infrastructure, by applying bit-banging of
>> > TDI, TDO, TCK and TMS pins within the hardware specific driver.
>>
>> Or by using an SPI master?
>>
>
> I think it depends on how flexible the SPI interface is. If you can set it to transfer
> from 1 to n bits at a time, and you control the TMS line in software, you should
> be able to use it. If the SPI interface can only transfer a multiple of 8 bits
> at a time, then in general it would not be suitable for JTAG.
Sure, that depends on the actual SPI master interface.
But I guess you can write a generic JTAG-over-SPI driver, and use a tms-gpios
property in DT to specify how to control TMS.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 45+ messages in thread
* Re: [patch v9 0/4] JTAG driver introduction
@ 2017-09-28 9:02 ` Geert Uytterhoeven
0 siblings, 0 replies; 45+ messages in thread
From: Geert Uytterhoeven @ 2017-09-28 9:02 UTC (permalink / raw)
To: Oleksandr Shamray
Cc: Greg KH, Arnd Bergmann, linux-kernel, linux-arm-kernel,
devicetree, openbmc, Joel Stanley, Jiri Pirko, Tobias Klauser,
linux-serial, mec, Vadim Pasternak, system-sw-low-level,
Rob Herring, openocd-devel-owner, linux-api, David S. Miller,
Mauro Carvalho Chehab, linux-spi, Mark Brown
Hi Oleksandr,
On Thu, Sep 28, 2017 at 10:53 AM, Oleksandr Shamray
<oleksandrs@mellanox.com> wrote:
>> [My attention was drawn by
>> https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flwn.net
>> %2FArticles%2F734440%2F&data=02%7C01%7Coleksandrs%40mellanox.com%7
>> C97b8ba88686a42daaace08d5064b92eb%7Ca652971c7d2e4d9ba6a4d149256f
>> 461b%7C0%7C0%7C636421844026854216&sdata=TeHD4a3%2FBN6a5XG3Jizf5
>> pmsyJHJjzkEzkpnqsXC6S0%3D&reserved=0]
>> [CC linux-spi, which was never included, while linux-serial was]
>>
>> On Thu, Sep 21, 2017 at 11:25 AM, Oleksandr Shamray
>> <oleksandrs@mellanox.com> wrote:
>> > When a need raise up to use JTAG interface for system's devices
>> > programming or CPU debugging, usually the user layer application
>> > implements jtag protocol by bit-bang or using a proprietary connection
>> > to vendor hardware.
>> > This method can be slow and not generic.
>> >
>
>
> [..]
>
>> >
>> > Initial version provides the system calls set for:
>> > - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
>> > - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
>> > - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
>> > number of clocks.
>> >
>> > SoC which are not equipped with JTAG master interface, can be built on
>> > top of JTAG core driver infrastructure, by applying bit-banging of
>> > TDI, TDO, TCK and TMS pins within the hardware specific driver.
>>
>> Or by using an SPI master?
>>
>
> I think it depends on how flexible the SPI interface is. If you can set it to transfer
> from 1 to n bits at a time, and you control the TMS line in software, you should
> be able to use it. If the SPI interface can only transfer a multiple of 8 bits
> at a time, then in general it would not be suitable for JTAG.
Sure, that depends on the actual SPI master interface.
But I guess you can write a generic JTAG-over-SPI driver, and use a tms-gpios
property in DT to specify how to control TMS.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 45+ messages in thread
* [patch v9 0/4] JTAG driver introduction
@ 2017-09-28 9:02 ` Geert Uytterhoeven
0 siblings, 0 replies; 45+ messages in thread
From: Geert Uytterhoeven @ 2017-09-28 9:02 UTC (permalink / raw)
To: linux-arm-kernel
Hi Oleksandr,
On Thu, Sep 28, 2017 at 10:53 AM, Oleksandr Shamray
<oleksandrs@mellanox.com> wrote:
>> [My attention was drawn by
>> https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flwn.net
>> %2FArticles%2F734440%2F&data=02%7C01%7Coleksandrs%40mellanox.com%7
>> C97b8ba88686a42daaace08d5064b92eb%7Ca652971c7d2e4d9ba6a4d149256f
>> 461b%7C0%7C0%7C636421844026854216&sdata=TeHD4a3%2FBN6a5XG3Jizf5
>> pmsyJHJjzkEzkpnqsXC6S0%3D&reserved=0]
>> [CC linux-spi, which was never included, while linux-serial was]
>>
>> On Thu, Sep 21, 2017 at 11:25 AM, Oleksandr Shamray
>> <oleksandrs@mellanox.com> wrote:
>> > When a need raise up to use JTAG interface for system's devices
>> > programming or CPU debugging, usually the user layer application
>> > implements jtag protocol by bit-bang or using a proprietary connection
>> > to vendor hardware.
>> > This method can be slow and not generic.
>> >
>
>
> [..]
>
>> >
>> > Initial version provides the system calls set for:
>> > - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
>> > - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
>> > - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
>> > number of clocks.
>> >
>> > SoC which are not equipped with JTAG master interface, can be built on
>> > top of JTAG core driver infrastructure, by applying bit-banging of
>> > TDI, TDO, TCK and TMS pins within the hardware specific driver.
>>
>> Or by using an SPI master?
>>
>
> I think it depends on how flexible the SPI interface is. If you can set it to transfer
> from 1 to n bits at a time, and you control the TMS line in software, you should
> be able to use it. If the SPI interface can only transfer a multiple of 8 bits
> at a time, then in general it would not be suitable for JTAG.
Sure, that depends on the actual SPI master interface.
But I guess you can write a generic JTAG-over-SPI driver, and use a tms-gpios
property in DT to specify how to control TMS.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 45+ messages in thread
* RE: [patch v9 0/4] JTAG driver introduction
@ 2017-09-28 11:11 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-28 11:11 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: Greg KH, Arnd Bergmann, linux-kernel, linux-arm-kernel,
devicetree, openbmc, Joel Stanley, Jiri Pirko, Tobias Klauser,
linux-serial, mec, Vadim Pasternak, system-sw-low-level,
Rob Herring, openocd-devel-owner, linux-api, David S. Miller,
Mauro Carvalho Chehab, linux-spi, Mark Brown
> -----Original Message-----
> From: geert.uytterhoeven@gmail.com [mailto:geert.uytterhoeven@gmail.com]
> On Behalf Of Geert Uytterhoeven
> Sent: Thursday, September 28, 2017 12:02 PM
> To: Oleksandr Shamray <oleksandrs@mellanox.com>
> Cc: Greg KH <gregkh@linuxfoundation.org>; Arnd Bergmann
> <arnd@arndb.de>; linux-kernel@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; devicetree@vger.kernel.org;
> openbmc@lists.ozlabs.org; Joel Stanley <joel@jms.id.au>; Jiri Pirko
> <jiri@resnulli.us>; Tobias Klauser <tklauser@distanz.ch>; linux-
> serial@vger.kernel.org; mec@shout.net; Vadim Pasternak
> <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> level@mellanox.com>; Rob Herring <robh+dt@kernel.org>; openocd-devel-
> owner@lists.sourceforge.net; linux-api@vger.kernel.org; David S. Miller
> <davem@davemloft.net>; Mauro Carvalho Chehab <mchehab@kernel.org>;
> linux-spi <linux-spi@vger.kernel.org>; Mark Brown <broonie@kernel.org>
> Subject: Re: [patch v9 0/4] JTAG driver introduction
>
> Hi Oleksandr,
>
> On Thu, Sep 28, 2017 at 10:53 AM, Oleksandr Shamray
> <oleksandrs@mellanox.com> wrote:
> >> [My attention was drawn by
> >> https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flw
> >> n.net
> >>
> %2FArticles%2F734440%2F&data=02%7C01%7Coleksandrs%40mellanox.com%7
> >>
> C97b8ba88686a42daaace08d5064b92eb%7Ca652971c7d2e4d9ba6a4d149256f
> >>
> 461b%7C0%7C0%7C636421844026854216&sdata=TeHD4a3%2FBN6a5XG3Jizf5
> >> pmsyJHJjzkEzkpnqsXC6S0%3D&reserved=0]
> >> [CC linux-spi, which was never included, while linux-serial was]
> >>
> >> On Thu, Sep 21, 2017 at 11:25 AM, Oleksandr Shamray
> >> <oleksandrs@mellanox.com> wrote:
> >> > When a need raise up to use JTAG interface for system's devices
> >> > programming or CPU debugging, usually the user layer application
> >> > implements jtag protocol by bit-bang or using a proprietary
> >> > connection to vendor hardware.
> >> > This method can be slow and not generic.
> >> >
> >
> >
> > [..]
> >
> >> >
> >> > Initial version provides the system calls set for:
> >> > - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
> >> > - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
> >> > - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
> >> > number of clocks.
> >> >
> >> > SoC which are not equipped with JTAG master interface, can be built
> >> > on top of JTAG core driver infrastructure, by applying bit-banging
> >> > of TDI, TDO, TCK and TMS pins within the hardware specific driver.
> >>
> >> Or by using an SPI master?
> >>
> >
> > I think it depends on how flexible the SPI interface is. If you can
> > set it to transfer from 1 to n bits at a time, and you control the TMS
> > line in software, you should be able to use it. If the SPI interface
> > can only transfer a multiple of 8 bits at a time, then in general it would not be
> suitable for JTAG.
>
> Sure, that depends on the actual SPI master interface.
> But I guess you can write a generic JTAG-over-SPI driver, and use a tms-gpios
> property in DT to specify how to control TMS.
>
Yes, this is a good idea for SoC which are not equipped with JTAG hardware.
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-
> m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
^ permalink raw reply [flat|nested] 45+ messages in thread
* RE: [patch v9 0/4] JTAG driver introduction
@ 2017-09-28 11:11 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-28 11:11 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: Greg KH, Arnd Bergmann, linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
devicetree-u79uwXL29TY76Z2rM5mHXA,
openbmc-uLR06cmDAlY/bJ5BZ2RsiQ, Joel Stanley, Jiri Pirko,
Tobias Klauser, linux-serial-u79uwXL29TY76Z2rM5mHXA,
mec-WqBc5aa1uDFeoWH0uzbU5w, Vadim Pasternak, system-sw-low-level,
Rob Herring,
openocd-devel-owner-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
linux-api-u79uwXL29TY76Z2rM5mHXA
> -----Original Message-----
> From: geert.uytterhoeven@gmail.com [mailto:geert.uytterhoeven@gmail.com]
> On Behalf Of Geert Uytterhoeven
> Sent: Thursday, September 28, 2017 12:02 PM
> To: Oleksandr Shamray <oleksandrs@mellanox.com>
> Cc: Greg KH <gregkh@linuxfoundation.org>; Arnd Bergmann
> <arnd@arndb.de>; linux-kernel@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; devicetree@vger.kernel.org;
> openbmc@lists.ozlabs.org; Joel Stanley <joel@jms.id.au>; Jiri Pirko
> <jiri@resnulli.us>; Tobias Klauser <tklauser@distanz.ch>; linux-
> serial@vger.kernel.org; mec@shout.net; Vadim Pasternak
> <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> level@mellanox.com>; Rob Herring <robh+dt@kernel.org>; openocd-devel-
> owner@lists.sourceforge.net; linux-api@vger.kernel.org; David S. Miller
> <davem@davemloft.net>; Mauro Carvalho Chehab <mchehab@kernel.org>;
> linux-spi <linux-spi@vger.kernel.org>; Mark Brown <broonie@kernel.org>
> Subject: Re: [patch v9 0/4] JTAG driver introduction
>
> Hi Oleksandr,
>
> On Thu, Sep 28, 2017 at 10:53 AM, Oleksandr Shamray
> <oleksandrs@mellanox.com> wrote:
> >> [My attention was drawn by
> >> https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flw
> >> n.net
> >>
> %2FArticles%2F734440%2F&data=02%7C01%7Coleksandrs%40mellanox.com%7
> >>
> C97b8ba88686a42daaace08d5064b92eb%7Ca652971c7d2e4d9ba6a4d149256f
> >>
> 461b%7C0%7C0%7C636421844026854216&sdata=TeHD4a3%2FBN6a5XG3Jizf5
> >> pmsyJHJjzkEzkpnqsXC6S0%3D&reserved=0]
> >> [CC linux-spi, which was never included, while linux-serial was]
> >>
> >> On Thu, Sep 21, 2017 at 11:25 AM, Oleksandr Shamray
> >> <oleksandrs@mellanox.com> wrote:
> >> > When a need raise up to use JTAG interface for system's devices
> >> > programming or CPU debugging, usually the user layer application
> >> > implements jtag protocol by bit-bang or using a proprietary
> >> > connection to vendor hardware.
> >> > This method can be slow and not generic.
> >> >
> >
> >
> > [..]
> >
> >> >
> >> > Initial version provides the system calls set for:
> >> > - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
> >> > - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
> >> > - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
> >> > number of clocks.
> >> >
> >> > SoC which are not equipped with JTAG master interface, can be built
> >> > on top of JTAG core driver infrastructure, by applying bit-banging
> >> > of TDI, TDO, TCK and TMS pins within the hardware specific driver.
> >>
> >> Or by using an SPI master?
> >>
> >
> > I think it depends on how flexible the SPI interface is. If you can
> > set it to transfer from 1 to n bits at a time, and you control the TMS
> > line in software, you should be able to use it. If the SPI interface
> > can only transfer a multiple of 8 bits at a time, then in general it would not be
> suitable for JTAG.
>
> Sure, that depends on the actual SPI master interface.
> But I guess you can write a generic JTAG-over-SPI driver, and use a tms-gpios
> property in DT to specify how to control TMS.
>
Yes, this is a good idea for SoC which are not equipped with JTAG hardware.
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-
> m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
^ permalink raw reply [flat|nested] 45+ messages in thread
* RE: [patch v9 0/4] JTAG driver introduction
@ 2017-09-28 11:11 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-28 11:11 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: Greg KH, Arnd Bergmann, linux-kernel, linux-arm-kernel,
devicetree, openbmc, Joel Stanley, Jiri Pirko, Tobias Klauser,
linux-serial, mec, Vadim Pasternak, system-sw-low-level,
Rob Herring, openocd-devel-owner, linux-api, David S. Miller,
Mauro Carvalho Chehab, linux-spi, Mark Brown
> -----Original Message-----
> From: geert.uytterhoeven@gmail.com [mailto:geert.uytterhoeven@gmail.com]
> On Behalf Of Geert Uytterhoeven
> Sent: Thursday, September 28, 2017 12:02 PM
> To: Oleksandr Shamray <oleksandrs@mellanox.com>
> Cc: Greg KH <gregkh@linuxfoundation.org>; Arnd Bergmann
> <arnd@arndb.de>; linux-kernel@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; devicetree@vger.kernel.org;
> openbmc@lists.ozlabs.org; Joel Stanley <joel@jms.id.au>; Jiri Pirko
> <jiri@resnulli.us>; Tobias Klauser <tklauser@distanz.ch>; linux-
> serial@vger.kernel.org; mec@shout.net; Vadim Pasternak
> <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> level@mellanox.com>; Rob Herring <robh+dt@kernel.org>; openocd-devel-
> owner@lists.sourceforge.net; linux-api@vger.kernel.org; David S. Miller
> <davem@davemloft.net>; Mauro Carvalho Chehab <mchehab@kernel.org>;
> linux-spi <linux-spi@vger.kernel.org>; Mark Brown <broonie@kernel.org>
> Subject: Re: [patch v9 0/4] JTAG driver introduction
>
> Hi Oleksandr,
>
> On Thu, Sep 28, 2017 at 10:53 AM, Oleksandr Shamray
> <oleksandrs@mellanox.com> wrote:
> >> [My attention was drawn by
> >> https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flw
> >> n.net
> >>
> %2FArticles%2F734440%2F&data=02%7C01%7Coleksandrs%40mellanox.com%7
> >>
> C97b8ba88686a42daaace08d5064b92eb%7Ca652971c7d2e4d9ba6a4d149256f
> >>
> 461b%7C0%7C0%7C636421844026854216&sdata=TeHD4a3%2FBN6a5XG3Jizf5
> >> pmsyJHJjzkEzkpnqsXC6S0%3D&reserved=0]
> >> [CC linux-spi, which was never included, while linux-serial was]
> >>
> >> On Thu, Sep 21, 2017 at 11:25 AM, Oleksandr Shamray
> >> <oleksandrs@mellanox.com> wrote:
> >> > When a need raise up to use JTAG interface for system's devices
> >> > programming or CPU debugging, usually the user layer application
> >> > implements jtag protocol by bit-bang or using a proprietary
> >> > connection to vendor hardware.
> >> > This method can be slow and not generic.
> >> >
> >
> >
> > [..]
> >
> >> >
> >> > Initial version provides the system calls set for:
> >> > - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
> >> > - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
> >> > - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
> >> > number of clocks.
> >> >
> >> > SoC which are not equipped with JTAG master interface, can be built
> >> > on top of JTAG core driver infrastructure, by applying bit-banging
> >> > of TDI, TDO, TCK and TMS pins within the hardware specific driver.
> >>
> >> Or by using an SPI master?
> >>
> >
> > I think it depends on how flexible the SPI interface is. If you can
> > set it to transfer from 1 to n bits at a time, and you control the TMS
> > line in software, you should be able to use it. If the SPI interface
> > can only transfer a multiple of 8 bits at a time, then in general it would not be
> suitable for JTAG.
>
> Sure, that depends on the actual SPI master interface.
> But I guess you can write a generic JTAG-over-SPI driver, and use a tms-gpios
> property in DT to specify how to control TMS.
>
Yes, this is a good idea for SoC which are not equipped with JTAG hardware.
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-
> m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
^ permalink raw reply [flat|nested] 45+ messages in thread
* [patch v9 0/4] JTAG driver introduction
@ 2017-09-28 11:11 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-09-28 11:11 UTC (permalink / raw)
To: linux-arm-kernel
> -----Original Message-----
> From: geert.uytterhoeven at gmail.com [mailto:geert.uytterhoeven at gmail.com]
> On Behalf Of Geert Uytterhoeven
> Sent: Thursday, September 28, 2017 12:02 PM
> To: Oleksandr Shamray <oleksandrs@mellanox.com>
> Cc: Greg KH <gregkh@linuxfoundation.org>; Arnd Bergmann
> <arnd@arndb.de>; linux-kernel at vger.kernel.org; linux-arm-
> kernel at lists.infradead.org; devicetree at vger.kernel.org;
> openbmc at lists.ozlabs.org; Joel Stanley <joel@jms.id.au>; Jiri Pirko
> <jiri@resnulli.us>; Tobias Klauser <tklauser@distanz.ch>; linux-
> serial at vger.kernel.org; mec at shout.net; Vadim Pasternak
> <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> level at mellanox.com>; Rob Herring <robh+dt@kernel.org>; openocd-devel-
> owner at lists.sourceforge.net; linux-api at vger.kernel.org; David S. Miller
> <davem@davemloft.net>; Mauro Carvalho Chehab <mchehab@kernel.org>;
> linux-spi <linux-spi@vger.kernel.org>; Mark Brown <broonie@kernel.org>
> Subject: Re: [patch v9 0/4] JTAG driver introduction
>
> Hi Oleksandr,
>
> On Thu, Sep 28, 2017 at 10:53 AM, Oleksandr Shamray
> <oleksandrs@mellanox.com> wrote:
> >> [My attention was drawn by
> >> https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flw
> >> n.net
> >>
> %2FArticles%2F734440%2F&data=02%7C01%7Coleksandrs%40mellanox.com%7
> >>
> C97b8ba88686a42daaace08d5064b92eb%7Ca652971c7d2e4d9ba6a4d149256f
> >>
> 461b%7C0%7C0%7C636421844026854216&sdata=TeHD4a3%2FBN6a5XG3Jizf5
> >> pmsyJHJjzkEzkpnqsXC6S0%3D&reserved=0]
> >> [CC linux-spi, which was never included, while linux-serial was]
> >>
> >> On Thu, Sep 21, 2017 at 11:25 AM, Oleksandr Shamray
> >> <oleksandrs@mellanox.com> wrote:
> >> > When a need raise up to use JTAG interface for system's devices
> >> > programming or CPU debugging, usually the user layer application
> >> > implements jtag protocol by bit-bang or using a proprietary
> >> > connection to vendor hardware.
> >> > This method can be slow and not generic.
> >> >
> >
> >
> > [..]
> >
> >> >
> >> > Initial version provides the system calls set for:
> >> > - SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
> >> > - SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
> >> > - RUNTEST (Forces the IEEE 1149.1 bus to a run state for a specified
> >> > number of clocks.
> >> >
> >> > SoC which are not equipped with JTAG master interface, can be built
> >> > on top of JTAG core driver infrastructure, by applying bit-banging
> >> > of TDI, TDO, TCK and TMS pins within the hardware specific driver.
> >>
> >> Or by using an SPI master?
> >>
> >
> > I think it depends on how flexible the SPI interface is. If you can
> > set it to transfer from 1 to n bits at a time, and you control the TMS
> > line in software, you should be able to use it. If the SPI interface
> > can only transfer a multiple of 8 bits at a time, then in general it would not be
> suitable for JTAG.
>
> Sure, that depends on the actual SPI master interface.
> But I guess you can write a generic JTAG-over-SPI driver, and use a tms-gpios
> property in DT to specify how to control TMS.
>
Yes, this is a good idea for SoC which are not equipped with JTAG hardware.
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-
> m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
^ permalink raw reply [flat|nested] 45+ messages in thread
* Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
@ 2017-10-20 11:55 ` Greg KH
0 siblings, 0 replies; 45+ messages in thread
From: Greg KH @ 2017-10-20 11:55 UTC (permalink / raw)
To: Oleksandr Shamray
Cc: arnd, linux-kernel, linux-arm-kernel, devicetree, openbmc, joel,
jiri, tklauser, linux-serial, mec, vadimp, system-sw-low-level,
robh+dt, openocd-devel-owner, linux-api, davem, mchehab,
Jiri Pirko
On Thu, Sep 21, 2017 at 12:25:29PM +0300, Oleksandr Shamray wrote:
> +struct jtag {
> + struct device *dev;
> + struct cdev cdev;
Why are you using a cdev here and not just a normal misc device? I
forgot if this is what you were doing before, sorry...
> + int id;
> + atomic_t open;
Why do you need this?
> + const struct jtag_ops *ops;
> + unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
Huh? Why is this needed to be dma aligned? Why not just use the
private pointer in struct device?
> +};
> +
> +static dev_t jtag_devt;
> +static DEFINE_IDA(jtag_ida);
> +
> +void *jtag_priv(struct jtag *jtag)
> +{
> + return jtag->priv;
> +}
> +EXPORT_SYMBOL_GPL(jtag_priv);
> +
> +static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size)
> +{
> + unsigned long size;
> + void *kdata;
> +
> + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> + kdata = memdup_user(u64_to_user_ptr(udata), size);
You only use this once, why not just open-code it?
> +
> + return kdata;
> +}
> +
> +static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
> + unsigned long bit_size)
> +{
> + unsigned long size;
> +
> + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> +
> + return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata), size);
Same here, making this a separate function seems odd.
> +}
> +
> +static struct class jtag_class = {
> + .name = "jtag",
> + .owner = THIS_MODULE,
> +};
> +
> +static int jtag_run_test_idle_op(struct jtag *jtag,
> + struct jtag_run_test_idle *idle)
> +{
> + if (jtag->ops->idle)
> + return jtag->ops->idle(jtag, idle);
> + else
> + return -EOPNOTSUPP;
Why is this a function? Why not just do this work in the ioctl?
> +}
> +
> +static int jtag_xfer_op(struct jtag *jtag, struct jtag_xfer *xfer, u8 *data)
> +{
> + if (jtag->ops->xfer)
> + return jtag->ops->xfer(jtag, xfer, data);
> + else
> + return -EOPNOTSUPP;
Same here, doesn't need to be a function.
> +}
> +
> +static long jtag_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> +{
> + struct jtag *jtag = file->private_data;
> + struct jtag_run_test_idle idle;
> + struct jtag_xfer xfer;
> + u8 *xfer_data;
> + u32 value;
> + int err;
> +
> + switch (cmd) {
> + case JTAG_GIOCFREQ:
> + if (jtag->ops->freq_get)
> + err = jtag->ops->freq_get(jtag, &value);
> + else
> + err = -EOPNOTSUPP;
> + if (err)
> + break;
> +
> + err = put_user(value, (__u32 *)arg);
> + break;
Are you sure the return value of put_user is correct here? Shouldn't
you return -EFAULT if err is not 0?
> +
> + case JTAG_SIOCFREQ:
> + err = get_user(value, (__u32 *)arg);
> +
why a blank line?
> + if (value == 0)
> + err = -EINVAL;
Check err first.
> + if (err)
> + break;
And set it properly, again err should be -EFAULT, right?
> +
> + if (jtag->ops->freq_set)
> + err = jtag->ops->freq_set(jtag, value);
> + else
> + err = -EOPNOTSUPP;
> + break;
> +
> + case JTAG_IOCRUNTEST:
> + if (copy_from_user(&idle, (void *)arg,
> + sizeof(struct jtag_run_test_idle)))
> + return -ENOMEM;
> + err = jtag_run_test_idle_op(jtag, &idle);
Who validates the structure fields? Is that up to the individual jtag
driver? Why not do it in the core correctly so that it only has to be
done in one place and you do not have to audit every individual driver?
> + break;
> +
> + case JTAG_IOCXFER:
> + if (copy_from_user(&xfer, (void *)arg,
> + sizeof(struct jtag_xfer)))
> + return -EFAULT;
> +
> + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
> + return -EFAULT;
> +
> + xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
> + if (!xfer_data)
> + return -ENOMEM;
Are you sure that's the correct error value?
> +
> + err = jtag_xfer_op(jtag, &xfer, xfer_data);
> + if (jtag_copy_to_user(xfer.tdio, xfer_data, xfer.length)) {
> + kfree(xfer_data);
> + return -EFAULT;
> + }
> +
> + kfree(xfer_data);
> + if (copy_to_user((void *)arg, &xfer, sizeof(struct jtag_xfer)))
> + return -EFAULT;
> + break;
> +
> + case JTAG_GIOCSTATUS:
> + if (jtag->ops->status_get)
> + err = jtag->ops->status_get(jtag, &value);
> + else
> + err = -EOPNOTSUPP;
> + if (err)
> + break;
> +
> + err = put_user(value, (__u32 *)arg);
Same put_user err issue here.
> + break;
> +
> + default:
> + return -EINVAL;
> + }
> + return err;
> +}
> +
> +#ifdef CONFIG_COMPAT
> +static long jtag_ioctl_compat(struct file *file, unsigned int cmd,
> + unsigned long arg)
> +{
> + return jtag_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
> +}
> +#endif
Why do you need a compat callback for a new ioctl? Create your
structures properly and this should not be needed, right?
> +
> +static int jtag_open(struct inode *inode, struct file *file)
> +{
> + struct jtag *jtag = container_of(inode->i_cdev, struct jtag, cdev);
> +
> + if (atomic_read(&jtag->open)) {
> + dev_info(NULL, "jtag already opened\n");
> + return -EBUSY;
Why do you care if multiple opens can happen?
> + }
> +
> + atomic_inc(&jtag->open);
Oh look, you just raced with two different people opening at the same
time :(
An atomic value is never a replacement for a lock, sorry.
> + file->private_data = jtag;
> + return 0;
> +}
> +
> +static int jtag_release(struct inode *inode, struct file *file)
> +{
> + struct jtag *jtag = file->private_data;
> +
> + atomic_dec(&jtag->open);
Again, not needed.
> + return 0;
> +}
> +
> +static const struct file_operations jtag_fops = {
> + .owner = THIS_MODULE,
> + .open = jtag_open,
> + .release = jtag_release,
> + .llseek = noop_llseek,
> + .unlocked_ioctl = jtag_ioctl,
> +#ifdef CONFIG_COMPAT
> + .compat_ioctl = jtag_ioctl_compat,
> +#endif
> +};
> +
> +struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops)
> +{
> + struct jtag *jtag;
> +
> + jtag = kzalloc(sizeof(*jtag) + round_up(priv_size, ARCH_DMA_MINALIGN),
> + GFP_KERNEL);
> + if (!jtag)
> + return NULL;
> +
> + jtag->ops = ops;
> + return jtag;
> +}
> +EXPORT_SYMBOL_GPL(jtag_alloc);
register should allocate and register the device, why pass a structure
back that the caller then has to do something else with to use it?
> +
> +void jtag_free(struct jtag *jtag)
> +{
> + kfree(jtag);
> +}
> +EXPORT_SYMBOL_GPL(jtag_free);
> +
> +int jtag_register(struct jtag *jtag)
> +{
> + int id;
> + int err;
> +
> + id = ida_simple_get(&jtag_ida, 0, 0, GFP_KERNEL);
> + if (id < 0)
> + return id;
> +
> + jtag->id = id;
> + cdev_init(&jtag->cdev, &jtag_fops);
> + jtag->cdev.owner = THIS_MODULE;
> + err = cdev_add(&jtag->cdev, MKDEV(MAJOR(jtag_devt), jtag->id), 1);
> + if (err)
> + goto err_cdev;
misc device would be so much simpler and easier here :(
> +
> + /* Register this jtag device with the driver core */
> + jtag->dev = device_create(&jtag_class, NULL, MKDEV(MAJOR(jtag_devt),
> + jtag->id),
> + NULL, "jtag%d", jtag->id);
> + if (!jtag->dev)
> + goto err_device_create;
> +
> + atomic_set(&jtag->open, 0);
> + dev_set_drvdata(jtag->dev, jtag);
> + return err;
> +
> +err_device_create:
> + cdev_del(&jtag->cdev);
> +err_cdev:
> + ida_simple_remove(&jtag_ida, id);
> + return err;
> +}
> +EXPORT_SYMBOL_GPL(jtag_register);
> +
> +void jtag_unregister(struct jtag *jtag)
> +{
> + struct device *dev = jtag->dev;
> +
> + cdev_del(&jtag->cdev);
> + device_unregister(dev);
> + ida_simple_remove(&jtag_ida, jtag->id);
> +}
> +EXPORT_SYMBOL_GPL(jtag_unregister);
> +
> +static int __init jtag_init(void)
> +{
> + int err;
> +
> + err = alloc_chrdev_region(&jtag_devt, JTAG_FIRST_MINOR,
> + JTAG_MAX_DEVICES, "jtag");
> + if (err)
> + return err;
> +
> + err = class_register(&jtag_class);
> + if (err)
> + unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
> +
> + return err;
> +}
> +
> +static void __exit jtag_exit(void)
> +{
> + class_unregister(&jtag_class);
> + unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
Your idr leaked memory :(
> +}
> +
> +module_init(jtag_init);
> +module_exit(jtag_exit);
> +
> +MODULE_AUTHOR("Oleksandr Shamray <oleksandrs@mellanox.com>");
> +MODULE_DESCRIPTION("Generic jtag support");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/jtag.h b/include/linux/jtag.h
> new file mode 100644
> index 0000000..c016fed
> --- /dev/null
> +++ b/include/linux/jtag.h
> @@ -0,0 +1,48 @@
> +/*
> + * drivers/jtag/jtag.c
> + *
> + * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
> + * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
> + *
> + * Released under the GPLv2 only.
> + * SPDX-License-Identifier: GPL-2.0
> + */
> +
> +#ifndef __JTAG_H
> +#define __JTAG_H
> +
> +#include <uapi/linux/jtag.h>
> +
> +#ifndef ARCH_DMA_MINALIGN
> +#define ARCH_DMA_MINALIGN 1
> +#endif
> +
> +#define jtag_u64_to_ptr(arg) ((void *)(uintptr_t)arg)
> +
> +#define JTAG_MAX_XFER_DATA_LEN 65535
> +
> +struct jtag;
> +/**
> + * struct jtag_ops - callbacks for jtag control functions:
> + *
> + * @freq_get: get frequency function. Filled by device driver
> + * @freq_set: set frequency function. Filled by device driver
> + * @status_get: set status function. Filled by device driver
> + * @idle: set JTAG to idle state function. Filled by device driver
> + * @xfer: send JTAG xfer function. Filled by device driver
> + */
> +struct jtag_ops {
> + int (*freq_get)(struct jtag *jtag, u32 *freq);
> + int (*freq_set)(struct jtag *jtag, u32 freq);
> + int (*status_get)(struct jtag *jtag, u32 *state);
> + int (*idle)(struct jtag *jtag, struct jtag_run_test_idle *idle);
> + int (*xfer)(struct jtag *jtag, struct jtag_xfer *xfer);
> +};
> +
> +void *jtag_priv(struct jtag *jtag);
> +int jtag_register(struct jtag *jtag);
> +void jtag_unregister(struct jtag *jtag);
> +struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops);
> +void jtag_free(struct jtag *jtag);
> +
> +#endif /* __JTAG_H */
> diff --git a/include/uapi/linux/jtag.h b/include/uapi/linux/jtag.h
> new file mode 100644
> index 0000000..180bf22
> --- /dev/null
> +++ b/include/uapi/linux/jtag.h
> @@ -0,0 +1,115 @@
> +/*
> + * JTAG class driver
> + *
> + * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
> + * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
> + *
> + * Released under the GPLv2/BSD.
> + * SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
> + */
> +
> +#ifndef __UAPI_LINUX_JTAG_H
> +#define __UAPI_LINUX_JTAG_H
> +
> +/**
> + * enum jtag_xfer_mode:
> + *
> + * @JTAG_XFER_HW_MODE: hardware mode transfer
> + * @JTAG_XFER_SW_MODE: software mode transfer
> + */
> +enum jtag_xfer_mode {
> + JTAG_XFER_HW_MODE,
> + JTAG_XFER_SW_MODE,
> +};
> +
> +/**
> + * enum jtag_endstate:
> + *
> + * @JTAG_STATE_IDLE: JTAG state machine IDLE state
> + * @JTAG_STATE_PAUSEIR: JTAG state machine PAUSE_IR state
> + * @JTAG_STATE_PAUSEDR: JTAG state machine PAUSE_DR state
> + */
> +enum jtag_endstate {
> + JTAG_STATE_IDLE,
> + JTAG_STATE_PAUSEIR,
> + JTAG_STATE_PAUSEDR,
> +};
> +
> +/**
> + * enum jtag_xfer_type:
> + *
> + * @JTAG_SIR_XFER: SIR transfer
> + * @JTAG_SDR_XFER: SDR transfer
> + */
> +enum jtag_xfer_type {
> + JTAG_SIR_XFER,
> + JTAG_SDR_XFER,
> +};
> +
> +/**
> + * enum jtag_xfer_direction:
> + *
> + * @JTAG_READ_XFER: read transfer
> + * @JTAG_WRITE_XFER: write transfer
> + */
> +enum jtag_xfer_direction {
> + JTAG_READ_XFER,
> + JTAG_WRITE_XFER,
> +};
> +
> +/**
> + * struct jtag_run_test_idle - forces JTAG state machine to
> + * RUN_TEST/IDLE state
> + *
> + * @mode: access mode
> + * @reset: 0 - run IDLE/PAUSE from current state
> + * 1 - go through TEST_LOGIC/RESET state before IDLE/PAUSE
> + * @end: completion flag
> + * @tck: clock counter
> + *
> + * Structure represents interface to JTAG device for jtag idle
> + * execution.
> + */
> +struct jtag_run_test_idle {
> + __u8 mode;
> + __u8 reset;
> + __u8 endstate;
> + __u8 tck;
> +};
> +
> +/**
> + * struct jtag_xfer - jtag xfer:
> + *
> + * @mode: access mode
> + * @type: transfer type
> + * @direction: xfer direction
> + * @length: xfer bits len
> + * @tdio : xfer data array
> + * @endir: xfer end state
> + *
> + * Structure represents interface to Aspeed JTAG device for jtag sdr xfer
> + * execution.
> + */
> +struct jtag_xfer {
> + __u8 mode;
> + __u8 type;
> + __u8 direction;
> + __u8 endstate;
> + __u32 length;
> + __u64 tdio;
I don't see anything odd here that requires a compat ioctl callback, do
you?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 45+ messages in thread
* Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
@ 2017-10-20 11:55 ` Greg KH
0 siblings, 0 replies; 45+ messages in thread
From: Greg KH @ 2017-10-20 11:55 UTC (permalink / raw)
To: Oleksandr Shamray
Cc: arnd-r2nGTMty4D4, linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
devicetree-u79uwXL29TY76Z2rM5mHXA,
openbmc-uLR06cmDAlY/bJ5BZ2RsiQ, joel-U3u1mxZcP9KHXe+LvDLADg,
jiri-rHqAuBHg3fBzbRFIqnYvSA, tklauser-93Khv+1bN0NyDzI6CaY1VQ,
linux-serial-u79uwXL29TY76Z2rM5mHXA, mec-WqBc5aa1uDFeoWH0uzbU5w,
vadimp-VPRAkNaXOzVWk0Htik3J/w,
system-sw-low-level-VPRAkNaXOzVWk0Htik3J/w,
robh+dt-DgEjT+Ai2ygdnm+yROfE0A,
openocd-devel-owner-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
linux-api-u79uwXL29TY76Z2rM5mHXA, davem-fT/PcQaiUtIeIZ0/mPfg9Q,
mchehab-DgEjT+Ai2ygdnm+yROfE0A, Jiri Pirko
On Thu, Sep 21, 2017 at 12:25:29PM +0300, Oleksandr Shamray wrote:
> +struct jtag {
> + struct device *dev;
> + struct cdev cdev;
Why are you using a cdev here and not just a normal misc device? I
forgot if this is what you were doing before, sorry...
> + int id;
> + atomic_t open;
Why do you need this?
> + const struct jtag_ops *ops;
> + unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
Huh? Why is this needed to be dma aligned? Why not just use the
private pointer in struct device?
> +};
> +
> +static dev_t jtag_devt;
> +static DEFINE_IDA(jtag_ida);
> +
> +void *jtag_priv(struct jtag *jtag)
> +{
> + return jtag->priv;
> +}
> +EXPORT_SYMBOL_GPL(jtag_priv);
> +
> +static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size)
> +{
> + unsigned long size;
> + void *kdata;
> +
> + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> + kdata = memdup_user(u64_to_user_ptr(udata), size);
You only use this once, why not just open-code it?
> +
> + return kdata;
> +}
> +
> +static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
> + unsigned long bit_size)
> +{
> + unsigned long size;
> +
> + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> +
> + return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata), size);
Same here, making this a separate function seems odd.
> +}
> +
> +static struct class jtag_class = {
> + .name = "jtag",
> + .owner = THIS_MODULE,
> +};
> +
> +static int jtag_run_test_idle_op(struct jtag *jtag,
> + struct jtag_run_test_idle *idle)
> +{
> + if (jtag->ops->idle)
> + return jtag->ops->idle(jtag, idle);
> + else
> + return -EOPNOTSUPP;
Why is this a function? Why not just do this work in the ioctl?
> +}
> +
> +static int jtag_xfer_op(struct jtag *jtag, struct jtag_xfer *xfer, u8 *data)
> +{
> + if (jtag->ops->xfer)
> + return jtag->ops->xfer(jtag, xfer, data);
> + else
> + return -EOPNOTSUPP;
Same here, doesn't need to be a function.
> +}
> +
> +static long jtag_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> +{
> + struct jtag *jtag = file->private_data;
> + struct jtag_run_test_idle idle;
> + struct jtag_xfer xfer;
> + u8 *xfer_data;
> + u32 value;
> + int err;
> +
> + switch (cmd) {
> + case JTAG_GIOCFREQ:
> + if (jtag->ops->freq_get)
> + err = jtag->ops->freq_get(jtag, &value);
> + else
> + err = -EOPNOTSUPP;
> + if (err)
> + break;
> +
> + err = put_user(value, (__u32 *)arg);
> + break;
Are you sure the return value of put_user is correct here? Shouldn't
you return -EFAULT if err is not 0?
> +
> + case JTAG_SIOCFREQ:
> + err = get_user(value, (__u32 *)arg);
> +
why a blank line?
> + if (value == 0)
> + err = -EINVAL;
Check err first.
> + if (err)
> + break;
And set it properly, again err should be -EFAULT, right?
> +
> + if (jtag->ops->freq_set)
> + err = jtag->ops->freq_set(jtag, value);
> + else
> + err = -EOPNOTSUPP;
> + break;
> +
> + case JTAG_IOCRUNTEST:
> + if (copy_from_user(&idle, (void *)arg,
> + sizeof(struct jtag_run_test_idle)))
> + return -ENOMEM;
> + err = jtag_run_test_idle_op(jtag, &idle);
Who validates the structure fields? Is that up to the individual jtag
driver? Why not do it in the core correctly so that it only has to be
done in one place and you do not have to audit every individual driver?
> + break;
> +
> + case JTAG_IOCXFER:
> + if (copy_from_user(&xfer, (void *)arg,
> + sizeof(struct jtag_xfer)))
> + return -EFAULT;
> +
> + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
> + return -EFAULT;
> +
> + xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
> + if (!xfer_data)
> + return -ENOMEM;
Are you sure that's the correct error value?
> +
> + err = jtag_xfer_op(jtag, &xfer, xfer_data);
> + if (jtag_copy_to_user(xfer.tdio, xfer_data, xfer.length)) {
> + kfree(xfer_data);
> + return -EFAULT;
> + }
> +
> + kfree(xfer_data);
> + if (copy_to_user((void *)arg, &xfer, sizeof(struct jtag_xfer)))
> + return -EFAULT;
> + break;
> +
> + case JTAG_GIOCSTATUS:
> + if (jtag->ops->status_get)
> + err = jtag->ops->status_get(jtag, &value);
> + else
> + err = -EOPNOTSUPP;
> + if (err)
> + break;
> +
> + err = put_user(value, (__u32 *)arg);
Same put_user err issue here.
> + break;
> +
> + default:
> + return -EINVAL;
> + }
> + return err;
> +}
> +
> +#ifdef CONFIG_COMPAT
> +static long jtag_ioctl_compat(struct file *file, unsigned int cmd,
> + unsigned long arg)
> +{
> + return jtag_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
> +}
> +#endif
Why do you need a compat callback for a new ioctl? Create your
structures properly and this should not be needed, right?
> +
> +static int jtag_open(struct inode *inode, struct file *file)
> +{
> + struct jtag *jtag = container_of(inode->i_cdev, struct jtag, cdev);
> +
> + if (atomic_read(&jtag->open)) {
> + dev_info(NULL, "jtag already opened\n");
> + return -EBUSY;
Why do you care if multiple opens can happen?
> + }
> +
> + atomic_inc(&jtag->open);
Oh look, you just raced with two different people opening at the same
time :(
An atomic value is never a replacement for a lock, sorry.
> + file->private_data = jtag;
> + return 0;
> +}
> +
> +static int jtag_release(struct inode *inode, struct file *file)
> +{
> + struct jtag *jtag = file->private_data;
> +
> + atomic_dec(&jtag->open);
Again, not needed.
> + return 0;
> +}
> +
> +static const struct file_operations jtag_fops = {
> + .owner = THIS_MODULE,
> + .open = jtag_open,
> + .release = jtag_release,
> + .llseek = noop_llseek,
> + .unlocked_ioctl = jtag_ioctl,
> +#ifdef CONFIG_COMPAT
> + .compat_ioctl = jtag_ioctl_compat,
> +#endif
> +};
> +
> +struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops)
> +{
> + struct jtag *jtag;
> +
> + jtag = kzalloc(sizeof(*jtag) + round_up(priv_size, ARCH_DMA_MINALIGN),
> + GFP_KERNEL);
> + if (!jtag)
> + return NULL;
> +
> + jtag->ops = ops;
> + return jtag;
> +}
> +EXPORT_SYMBOL_GPL(jtag_alloc);
register should allocate and register the device, why pass a structure
back that the caller then has to do something else with to use it?
> +
> +void jtag_free(struct jtag *jtag)
> +{
> + kfree(jtag);
> +}
> +EXPORT_SYMBOL_GPL(jtag_free);
> +
> +int jtag_register(struct jtag *jtag)
> +{
> + int id;
> + int err;
> +
> + id = ida_simple_get(&jtag_ida, 0, 0, GFP_KERNEL);
> + if (id < 0)
> + return id;
> +
> + jtag->id = id;
> + cdev_init(&jtag->cdev, &jtag_fops);
> + jtag->cdev.owner = THIS_MODULE;
> + err = cdev_add(&jtag->cdev, MKDEV(MAJOR(jtag_devt), jtag->id), 1);
> + if (err)
> + goto err_cdev;
misc device would be so much simpler and easier here :(
> +
> + /* Register this jtag device with the driver core */
> + jtag->dev = device_create(&jtag_class, NULL, MKDEV(MAJOR(jtag_devt),
> + jtag->id),
> + NULL, "jtag%d", jtag->id);
> + if (!jtag->dev)
> + goto err_device_create;
> +
> + atomic_set(&jtag->open, 0);
> + dev_set_drvdata(jtag->dev, jtag);
> + return err;
> +
> +err_device_create:
> + cdev_del(&jtag->cdev);
> +err_cdev:
> + ida_simple_remove(&jtag_ida, id);
> + return err;
> +}
> +EXPORT_SYMBOL_GPL(jtag_register);
> +
> +void jtag_unregister(struct jtag *jtag)
> +{
> + struct device *dev = jtag->dev;
> +
> + cdev_del(&jtag->cdev);
> + device_unregister(dev);
> + ida_simple_remove(&jtag_ida, jtag->id);
> +}
> +EXPORT_SYMBOL_GPL(jtag_unregister);
> +
> +static int __init jtag_init(void)
> +{
> + int err;
> +
> + err = alloc_chrdev_region(&jtag_devt, JTAG_FIRST_MINOR,
> + JTAG_MAX_DEVICES, "jtag");
> + if (err)
> + return err;
> +
> + err = class_register(&jtag_class);
> + if (err)
> + unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
> +
> + return err;
> +}
> +
> +static void __exit jtag_exit(void)
> +{
> + class_unregister(&jtag_class);
> + unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
Your idr leaked memory :(
> +}
> +
> +module_init(jtag_init);
> +module_exit(jtag_exit);
> +
> +MODULE_AUTHOR("Oleksandr Shamray <oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>");
> +MODULE_DESCRIPTION("Generic jtag support");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/jtag.h b/include/linux/jtag.h
> new file mode 100644
> index 0000000..c016fed
> --- /dev/null
> +++ b/include/linux/jtag.h
> @@ -0,0 +1,48 @@
> +/*
> + * drivers/jtag/jtag.c
> + *
> + * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
> + * Copyright (c) 2017 Oleksandr Shamray <oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> + *
> + * Released under the GPLv2 only.
> + * SPDX-License-Identifier: GPL-2.0
> + */
> +
> +#ifndef __JTAG_H
> +#define __JTAG_H
> +
> +#include <uapi/linux/jtag.h>
> +
> +#ifndef ARCH_DMA_MINALIGN
> +#define ARCH_DMA_MINALIGN 1
> +#endif
> +
> +#define jtag_u64_to_ptr(arg) ((void *)(uintptr_t)arg)
> +
> +#define JTAG_MAX_XFER_DATA_LEN 65535
> +
> +struct jtag;
> +/**
> + * struct jtag_ops - callbacks for jtag control functions:
> + *
> + * @freq_get: get frequency function. Filled by device driver
> + * @freq_set: set frequency function. Filled by device driver
> + * @status_get: set status function. Filled by device driver
> + * @idle: set JTAG to idle state function. Filled by device driver
> + * @xfer: send JTAG xfer function. Filled by device driver
> + */
> +struct jtag_ops {
> + int (*freq_get)(struct jtag *jtag, u32 *freq);
> + int (*freq_set)(struct jtag *jtag, u32 freq);
> + int (*status_get)(struct jtag *jtag, u32 *state);
> + int (*idle)(struct jtag *jtag, struct jtag_run_test_idle *idle);
> + int (*xfer)(struct jtag *jtag, struct jtag_xfer *xfer);
> +};
> +
> +void *jtag_priv(struct jtag *jtag);
> +int jtag_register(struct jtag *jtag);
> +void jtag_unregister(struct jtag *jtag);
> +struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops);
> +void jtag_free(struct jtag *jtag);
> +
> +#endif /* __JTAG_H */
> diff --git a/include/uapi/linux/jtag.h b/include/uapi/linux/jtag.h
> new file mode 100644
> index 0000000..180bf22
> --- /dev/null
> +++ b/include/uapi/linux/jtag.h
> @@ -0,0 +1,115 @@
> +/*
> + * JTAG class driver
> + *
> + * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
> + * Copyright (c) 2017 Oleksandr Shamray <oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> + *
> + * Released under the GPLv2/BSD.
> + * SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
> + */
> +
> +#ifndef __UAPI_LINUX_JTAG_H
> +#define __UAPI_LINUX_JTAG_H
> +
> +/**
> + * enum jtag_xfer_mode:
> + *
> + * @JTAG_XFER_HW_MODE: hardware mode transfer
> + * @JTAG_XFER_SW_MODE: software mode transfer
> + */
> +enum jtag_xfer_mode {
> + JTAG_XFER_HW_MODE,
> + JTAG_XFER_SW_MODE,
> +};
> +
> +/**
> + * enum jtag_endstate:
> + *
> + * @JTAG_STATE_IDLE: JTAG state machine IDLE state
> + * @JTAG_STATE_PAUSEIR: JTAG state machine PAUSE_IR state
> + * @JTAG_STATE_PAUSEDR: JTAG state machine PAUSE_DR state
> + */
> +enum jtag_endstate {
> + JTAG_STATE_IDLE,
> + JTAG_STATE_PAUSEIR,
> + JTAG_STATE_PAUSEDR,
> +};
> +
> +/**
> + * enum jtag_xfer_type:
> + *
> + * @JTAG_SIR_XFER: SIR transfer
> + * @JTAG_SDR_XFER: SDR transfer
> + */
> +enum jtag_xfer_type {
> + JTAG_SIR_XFER,
> + JTAG_SDR_XFER,
> +};
> +
> +/**
> + * enum jtag_xfer_direction:
> + *
> + * @JTAG_READ_XFER: read transfer
> + * @JTAG_WRITE_XFER: write transfer
> + */
> +enum jtag_xfer_direction {
> + JTAG_READ_XFER,
> + JTAG_WRITE_XFER,
> +};
> +
> +/**
> + * struct jtag_run_test_idle - forces JTAG state machine to
> + * RUN_TEST/IDLE state
> + *
> + * @mode: access mode
> + * @reset: 0 - run IDLE/PAUSE from current state
> + * 1 - go through TEST_LOGIC/RESET state before IDLE/PAUSE
> + * @end: completion flag
> + * @tck: clock counter
> + *
> + * Structure represents interface to JTAG device for jtag idle
> + * execution.
> + */
> +struct jtag_run_test_idle {
> + __u8 mode;
> + __u8 reset;
> + __u8 endstate;
> + __u8 tck;
> +};
> +
> +/**
> + * struct jtag_xfer - jtag xfer:
> + *
> + * @mode: access mode
> + * @type: transfer type
> + * @direction: xfer direction
> + * @length: xfer bits len
> + * @tdio : xfer data array
> + * @endir: xfer end state
> + *
> + * Structure represents interface to Aspeed JTAG device for jtag sdr xfer
> + * execution.
> + */
> +struct jtag_xfer {
> + __u8 mode;
> + __u8 type;
> + __u8 direction;
> + __u8 endstate;
> + __u32 length;
> + __u64 tdio;
I don't see anything odd here that requires a compat ioctl callback, do
you?
thanks,
greg k-h
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^ permalink raw reply [flat|nested] 45+ messages in thread
* [patch v9 1/4] drivers: jtag: Add JTAG core driver
@ 2017-10-20 11:55 ` Greg KH
0 siblings, 0 replies; 45+ messages in thread
From: Greg KH @ 2017-10-20 11:55 UTC (permalink / raw)
To: linux-arm-kernel
On Thu, Sep 21, 2017 at 12:25:29PM +0300, Oleksandr Shamray wrote:
> +struct jtag {
> + struct device *dev;
> + struct cdev cdev;
Why are you using a cdev here and not just a normal misc device? I
forgot if this is what you were doing before, sorry...
> + int id;
> + atomic_t open;
Why do you need this?
> + const struct jtag_ops *ops;
> + unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
Huh? Why is this needed to be dma aligned? Why not just use the
private pointer in struct device?
> +};
> +
> +static dev_t jtag_devt;
> +static DEFINE_IDA(jtag_ida);
> +
> +void *jtag_priv(struct jtag *jtag)
> +{
> + return jtag->priv;
> +}
> +EXPORT_SYMBOL_GPL(jtag_priv);
> +
> +static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size)
> +{
> + unsigned long size;
> + void *kdata;
> +
> + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> + kdata = memdup_user(u64_to_user_ptr(udata), size);
You only use this once, why not just open-code it?
> +
> + return kdata;
> +}
> +
> +static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
> + unsigned long bit_size)
> +{
> + unsigned long size;
> +
> + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> +
> + return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata), size);
Same here, making this a separate function seems odd.
> +}
> +
> +static struct class jtag_class = {
> + .name = "jtag",
> + .owner = THIS_MODULE,
> +};
> +
> +static int jtag_run_test_idle_op(struct jtag *jtag,
> + struct jtag_run_test_idle *idle)
> +{
> + if (jtag->ops->idle)
> + return jtag->ops->idle(jtag, idle);
> + else
> + return -EOPNOTSUPP;
Why is this a function? Why not just do this work in the ioctl?
> +}
> +
> +static int jtag_xfer_op(struct jtag *jtag, struct jtag_xfer *xfer, u8 *data)
> +{
> + if (jtag->ops->xfer)
> + return jtag->ops->xfer(jtag, xfer, data);
> + else
> + return -EOPNOTSUPP;
Same here, doesn't need to be a function.
> +}
> +
> +static long jtag_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> +{
> + struct jtag *jtag = file->private_data;
> + struct jtag_run_test_idle idle;
> + struct jtag_xfer xfer;
> + u8 *xfer_data;
> + u32 value;
> + int err;
> +
> + switch (cmd) {
> + case JTAG_GIOCFREQ:
> + if (jtag->ops->freq_get)
> + err = jtag->ops->freq_get(jtag, &value);
> + else
> + err = -EOPNOTSUPP;
> + if (err)
> + break;
> +
> + err = put_user(value, (__u32 *)arg);
> + break;
Are you sure the return value of put_user is correct here? Shouldn't
you return -EFAULT if err is not 0?
> +
> + case JTAG_SIOCFREQ:
> + err = get_user(value, (__u32 *)arg);
> +
why a blank line?
> + if (value == 0)
> + err = -EINVAL;
Check err first.
> + if (err)
> + break;
And set it properly, again err should be -EFAULT, right?
> +
> + if (jtag->ops->freq_set)
> + err = jtag->ops->freq_set(jtag, value);
> + else
> + err = -EOPNOTSUPP;
> + break;
> +
> + case JTAG_IOCRUNTEST:
> + if (copy_from_user(&idle, (void *)arg,
> + sizeof(struct jtag_run_test_idle)))
> + return -ENOMEM;
> + err = jtag_run_test_idle_op(jtag, &idle);
Who validates the structure fields? Is that up to the individual jtag
driver? Why not do it in the core correctly so that it only has to be
done in one place and you do not have to audit every individual driver?
> + break;
> +
> + case JTAG_IOCXFER:
> + if (copy_from_user(&xfer, (void *)arg,
> + sizeof(struct jtag_xfer)))
> + return -EFAULT;
> +
> + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
> + return -EFAULT;
> +
> + xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
> + if (!xfer_data)
> + return -ENOMEM;
Are you sure that's the correct error value?
> +
> + err = jtag_xfer_op(jtag, &xfer, xfer_data);
> + if (jtag_copy_to_user(xfer.tdio, xfer_data, xfer.length)) {
> + kfree(xfer_data);
> + return -EFAULT;
> + }
> +
> + kfree(xfer_data);
> + if (copy_to_user((void *)arg, &xfer, sizeof(struct jtag_xfer)))
> + return -EFAULT;
> + break;
> +
> + case JTAG_GIOCSTATUS:
> + if (jtag->ops->status_get)
> + err = jtag->ops->status_get(jtag, &value);
> + else
> + err = -EOPNOTSUPP;
> + if (err)
> + break;
> +
> + err = put_user(value, (__u32 *)arg);
Same put_user err issue here.
> + break;
> +
> + default:
> + return -EINVAL;
> + }
> + return err;
> +}
> +
> +#ifdef CONFIG_COMPAT
> +static long jtag_ioctl_compat(struct file *file, unsigned int cmd,
> + unsigned long arg)
> +{
> + return jtag_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
> +}
> +#endif
Why do you need a compat callback for a new ioctl? Create your
structures properly and this should not be needed, right?
> +
> +static int jtag_open(struct inode *inode, struct file *file)
> +{
> + struct jtag *jtag = container_of(inode->i_cdev, struct jtag, cdev);
> +
> + if (atomic_read(&jtag->open)) {
> + dev_info(NULL, "jtag already opened\n");
> + return -EBUSY;
Why do you care if multiple opens can happen?
> + }
> +
> + atomic_inc(&jtag->open);
Oh look, you just raced with two different people opening at the same
time :(
An atomic value is never a replacement for a lock, sorry.
> + file->private_data = jtag;
> + return 0;
> +}
> +
> +static int jtag_release(struct inode *inode, struct file *file)
> +{
> + struct jtag *jtag = file->private_data;
> +
> + atomic_dec(&jtag->open);
Again, not needed.
> + return 0;
> +}
> +
> +static const struct file_operations jtag_fops = {
> + .owner = THIS_MODULE,
> + .open = jtag_open,
> + .release = jtag_release,
> + .llseek = noop_llseek,
> + .unlocked_ioctl = jtag_ioctl,
> +#ifdef CONFIG_COMPAT
> + .compat_ioctl = jtag_ioctl_compat,
> +#endif
> +};
> +
> +struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops)
> +{
> + struct jtag *jtag;
> +
> + jtag = kzalloc(sizeof(*jtag) + round_up(priv_size, ARCH_DMA_MINALIGN),
> + GFP_KERNEL);
> + if (!jtag)
> + return NULL;
> +
> + jtag->ops = ops;
> + return jtag;
> +}
> +EXPORT_SYMBOL_GPL(jtag_alloc);
register should allocate and register the device, why pass a structure
back that the caller then has to do something else with to use it?
> +
> +void jtag_free(struct jtag *jtag)
> +{
> + kfree(jtag);
> +}
> +EXPORT_SYMBOL_GPL(jtag_free);
> +
> +int jtag_register(struct jtag *jtag)
> +{
> + int id;
> + int err;
> +
> + id = ida_simple_get(&jtag_ida, 0, 0, GFP_KERNEL);
> + if (id < 0)
> + return id;
> +
> + jtag->id = id;
> + cdev_init(&jtag->cdev, &jtag_fops);
> + jtag->cdev.owner = THIS_MODULE;
> + err = cdev_add(&jtag->cdev, MKDEV(MAJOR(jtag_devt), jtag->id), 1);
> + if (err)
> + goto err_cdev;
misc device would be so much simpler and easier here :(
> +
> + /* Register this jtag device with the driver core */
> + jtag->dev = device_create(&jtag_class, NULL, MKDEV(MAJOR(jtag_devt),
> + jtag->id),
> + NULL, "jtag%d", jtag->id);
> + if (!jtag->dev)
> + goto err_device_create;
> +
> + atomic_set(&jtag->open, 0);
> + dev_set_drvdata(jtag->dev, jtag);
> + return err;
> +
> +err_device_create:
> + cdev_del(&jtag->cdev);
> +err_cdev:
> + ida_simple_remove(&jtag_ida, id);
> + return err;
> +}
> +EXPORT_SYMBOL_GPL(jtag_register);
> +
> +void jtag_unregister(struct jtag *jtag)
> +{
> + struct device *dev = jtag->dev;
> +
> + cdev_del(&jtag->cdev);
> + device_unregister(dev);
> + ida_simple_remove(&jtag_ida, jtag->id);
> +}
> +EXPORT_SYMBOL_GPL(jtag_unregister);
> +
> +static int __init jtag_init(void)
> +{
> + int err;
> +
> + err = alloc_chrdev_region(&jtag_devt, JTAG_FIRST_MINOR,
> + JTAG_MAX_DEVICES, "jtag");
> + if (err)
> + return err;
> +
> + err = class_register(&jtag_class);
> + if (err)
> + unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
> +
> + return err;
> +}
> +
> +static void __exit jtag_exit(void)
> +{
> + class_unregister(&jtag_class);
> + unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
Your idr leaked memory :(
> +}
> +
> +module_init(jtag_init);
> +module_exit(jtag_exit);
> +
> +MODULE_AUTHOR("Oleksandr Shamray <oleksandrs@mellanox.com>");
> +MODULE_DESCRIPTION("Generic jtag support");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/jtag.h b/include/linux/jtag.h
> new file mode 100644
> index 0000000..c016fed
> --- /dev/null
> +++ b/include/linux/jtag.h
> @@ -0,0 +1,48 @@
> +/*
> + * drivers/jtag/jtag.c
> + *
> + * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
> + * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
> + *
> + * Released under the GPLv2 only.
> + * SPDX-License-Identifier: GPL-2.0
> + */
> +
> +#ifndef __JTAG_H
> +#define __JTAG_H
> +
> +#include <uapi/linux/jtag.h>
> +
> +#ifndef ARCH_DMA_MINALIGN
> +#define ARCH_DMA_MINALIGN 1
> +#endif
> +
> +#define jtag_u64_to_ptr(arg) ((void *)(uintptr_t)arg)
> +
> +#define JTAG_MAX_XFER_DATA_LEN 65535
> +
> +struct jtag;
> +/**
> + * struct jtag_ops - callbacks for jtag control functions:
> + *
> + * @freq_get: get frequency function. Filled by device driver
> + * @freq_set: set frequency function. Filled by device driver
> + * @status_get: set status function. Filled by device driver
> + * @idle: set JTAG to idle state function. Filled by device driver
> + * @xfer: send JTAG xfer function. Filled by device driver
> + */
> +struct jtag_ops {
> + int (*freq_get)(struct jtag *jtag, u32 *freq);
> + int (*freq_set)(struct jtag *jtag, u32 freq);
> + int (*status_get)(struct jtag *jtag, u32 *state);
> + int (*idle)(struct jtag *jtag, struct jtag_run_test_idle *idle);
> + int (*xfer)(struct jtag *jtag, struct jtag_xfer *xfer);
> +};
> +
> +void *jtag_priv(struct jtag *jtag);
> +int jtag_register(struct jtag *jtag);
> +void jtag_unregister(struct jtag *jtag);
> +struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops);
> +void jtag_free(struct jtag *jtag);
> +
> +#endif /* __JTAG_H */
> diff --git a/include/uapi/linux/jtag.h b/include/uapi/linux/jtag.h
> new file mode 100644
> index 0000000..180bf22
> --- /dev/null
> +++ b/include/uapi/linux/jtag.h
> @@ -0,0 +1,115 @@
> +/*
> + * JTAG class driver
> + *
> + * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
> + * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
> + *
> + * Released under the GPLv2/BSD.
> + * SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
> + */
> +
> +#ifndef __UAPI_LINUX_JTAG_H
> +#define __UAPI_LINUX_JTAG_H
> +
> +/**
> + * enum jtag_xfer_mode:
> + *
> + * @JTAG_XFER_HW_MODE: hardware mode transfer
> + * @JTAG_XFER_SW_MODE: software mode transfer
> + */
> +enum jtag_xfer_mode {
> + JTAG_XFER_HW_MODE,
> + JTAG_XFER_SW_MODE,
> +};
> +
> +/**
> + * enum jtag_endstate:
> + *
> + * @JTAG_STATE_IDLE: JTAG state machine IDLE state
> + * @JTAG_STATE_PAUSEIR: JTAG state machine PAUSE_IR state
> + * @JTAG_STATE_PAUSEDR: JTAG state machine PAUSE_DR state
> + */
> +enum jtag_endstate {
> + JTAG_STATE_IDLE,
> + JTAG_STATE_PAUSEIR,
> + JTAG_STATE_PAUSEDR,
> +};
> +
> +/**
> + * enum jtag_xfer_type:
> + *
> + * @JTAG_SIR_XFER: SIR transfer
> + * @JTAG_SDR_XFER: SDR transfer
> + */
> +enum jtag_xfer_type {
> + JTAG_SIR_XFER,
> + JTAG_SDR_XFER,
> +};
> +
> +/**
> + * enum jtag_xfer_direction:
> + *
> + * @JTAG_READ_XFER: read transfer
> + * @JTAG_WRITE_XFER: write transfer
> + */
> +enum jtag_xfer_direction {
> + JTAG_READ_XFER,
> + JTAG_WRITE_XFER,
> +};
> +
> +/**
> + * struct jtag_run_test_idle - forces JTAG state machine to
> + * RUN_TEST/IDLE state
> + *
> + * @mode: access mode
> + * @reset: 0 - run IDLE/PAUSE from current state
> + * 1 - go through TEST_LOGIC/RESET state before IDLE/PAUSE
> + * @end: completion flag
> + * @tck: clock counter
> + *
> + * Structure represents interface to JTAG device for jtag idle
> + * execution.
> + */
> +struct jtag_run_test_idle {
> + __u8 mode;
> + __u8 reset;
> + __u8 endstate;
> + __u8 tck;
> +};
> +
> +/**
> + * struct jtag_xfer - jtag xfer:
> + *
> + * @mode: access mode
> + * @type: transfer type
> + * @direction: xfer direction
> + * @length: xfer bits len
> + * @tdio : xfer data array
> + * @endir: xfer end state
> + *
> + * Structure represents interface to Aspeed JTAG device for jtag sdr xfer
> + * execution.
> + */
> +struct jtag_xfer {
> + __u8 mode;
> + __u8 type;
> + __u8 direction;
> + __u8 endstate;
> + __u32 length;
> + __u64 tdio;
I don't see anything odd here that requires a compat ioctl callback, do
you?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 45+ messages in thread
* RE: [patch v9 1/4] drivers: jtag: Add JTAG core driver
2017-10-20 11:55 ` Greg KH
(?)
(?)
@ 2017-10-20 14:34 ` Oleksandr Shamray
-1 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-10-20 14:34 UTC (permalink / raw)
To: Greg KH
Cc: arnd, linux-kernel, linux-arm-kernel, devicetree, openbmc, joel,
jiri, tklauser, linux-serial, mec, Vadim Pasternak,
system-sw-low-level, robh+dt, openocd-devel-owner, linux-api,
davem, mchehab, Jiri Pirko
Hi Greg.
> -----Original Message-----
> From: Greg KH [mailto:gregkh@linuxfoundation.org]
> Sent: Friday, October 20, 2017 2:55 PM
> To: Oleksandr Shamray <oleksandrs@mellanox.com>
> Cc: arnd@arndb.de; linux-kernel@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; devicetree@vger.kernel.org;
> openbmc@lists.ozlabs.org; joel@jms.id.au; jiri@resnulli.us;
> tklauser@distanz.ch; linux-serial@vger.kernel.org; mec@shout.net; Vadim
> Pasternak <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> level@mellanox.com>; robh+dt@kernel.org; openocd-devel-
> owner@lists.sourceforge.net; linux-api@vger.kernel.org;
> davem@davemloft.net; mchehab@kernel.org; Jiri Pirko <jiri@mellanox.com>
> Subject: Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
>
> On Thu, Sep 21, 2017 at 12:25:29PM +0300, Oleksandr Shamray wrote:
> > +struct jtag {
> > + struct device *dev;
> > + struct cdev cdev;
>
> Why are you using a cdev here and not just a normal misc device?
What the benefits to use misc instead of cdev?
> I forgot if this is what you were doing before, sorry...
>
> > + int id;
> > + atomic_t open;
>
> Why do you need this?
This counter used to avoid open at the same time by 2 or more users.
>
> > + const struct jtag_ops *ops;
> > + unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
>
> Huh? Why is this needed to be dma aligned? Why not just use the private
> pointer in struct device?
>
It is critical?
> > +};
> > +
> > +static dev_t jtag_devt;
> > +static DEFINE_IDA(jtag_ida);
> > +
> > +void *jtag_priv(struct jtag *jtag)
> > +{
> > + return jtag->priv;
> > +}
> > +EXPORT_SYMBOL_GPL(jtag_priv);
> > +
> > +static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size) {
> > + unsigned long size;
> > + void *kdata;
> > +
> > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > + kdata = memdup_user(u64_to_user_ptr(udata), size);
>
> You only use this once, why not just open-code it?
I think it makes code more understandable.
>
> > +
> > + return kdata;
> > +}
> > +
> > +static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
> > + unsigned long bit_size)
> > +{
> > + unsigned long size;
> > +
> > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > +
> > + return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata), size);
>
> Same here, making this a separate function seems odd.
Same, I think it makes code more understandable.
>
> > +}
> > +
> > +static struct class jtag_class = {
> > + .name = "jtag",
> > + .owner = THIS_MODULE,
> > +};
> > +
> > +static int jtag_run_test_idle_op(struct jtag *jtag,
> > + struct jtag_run_test_idle *idle) {
> > + if (jtag->ops->idle)
> > + return jtag->ops->idle(jtag, idle);
> > + else
> > + return -EOPNOTSUPP;
>
> Why is this a function? Why not just do this work in the ioctl?
Agree. I will move it just to ioctl function body.
>
> > +}
> > +
> > +static int jtag_xfer_op(struct jtag *jtag, struct jtag_xfer *xfer, u8
> > +*data) {
> > + if (jtag->ops->xfer)
> > + return jtag->ops->xfer(jtag, xfer, data);
> > + else
> > + return -EOPNOTSUPP;
>
> Same here, doesn't need to be a function.
Agree.
>
> > +}
> > +
> > +static long jtag_ioctl(struct file *file, unsigned int cmd, unsigned
> > +long arg) {
> > + struct jtag *jtag = file->private_data;
> > + struct jtag_run_test_idle idle;
> > + struct jtag_xfer xfer;
> > + u8 *xfer_data;
> > + u32 value;
> > + int err;
> > +
> > + switch (cmd) {
> > + case JTAG_GIOCFREQ:
> > + if (jtag->ops->freq_get)
> > + err = jtag->ops->freq_get(jtag, &value);
> > + else
> > + err = -EOPNOTSUPP;
> > + if (err)
> > + break;
> > +
> > + err = put_user(value, (__u32 *)arg);
> > + break;
>
> Are you sure the return value of put_user is correct here? Shouldn't you return
> -EFAULT if err is not 0?
Yes, thanks for point of this.
>
> > +
> > + case JTAG_SIOCFREQ:
> > + err = get_user(value, (__u32 *)arg);
> > +
>
> why a blank line?
Will remove
>
> > + if (value == 0)
> > + err = -EINVAL;
>
> Check err first.
Ok.
>
> > + if (err)
> > + break;
>
> And set it properly, again err should be -EFAULT, right?
Right 😊0
>
> > +
> > + if (jtag->ops->freq_set)
> > + err = jtag->ops->freq_set(jtag, value);
> > + else
> > + err = -EOPNOTSUPP;
> > + break;
> > +
> > + case JTAG_IOCRUNTEST:
> > + if (copy_from_user(&idle, (void *)arg,
> > + sizeof(struct jtag_run_test_idle)))
> > + return -ENOMEM;
> > + err = jtag_run_test_idle_op(jtag, &idle);
>
> Who validates the structure fields? Is that up to the individual jtag driver? Why
> not do it in the core correctly so that it only has to be done in one place and you
> do not have to audit every individual driver?
Input parameters validated by jtag platform driver. I think it not critical.
>
> > + break;
> > +
> > + case JTAG_IOCXFER:
> > + if (copy_from_user(&xfer, (void *)arg,
> > + sizeof(struct jtag_xfer)))
> > + return -EFAULT;
> > +
> > + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
> > + return -EFAULT;
> > +
> > + xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
> > + if (!xfer_data)
> > + return -ENOMEM;
>
> Are you sure that's the correct error value?
I think yes, but what you suggest?
>
> > +
> > + err = jtag_xfer_op(jtag, &xfer, xfer_data);
> > + if (jtag_copy_to_user(xfer.tdio, xfer_data, xfer.length)) {
> > + kfree(xfer_data);
> > + return -EFAULT;
> > + }
> > +
> > + kfree(xfer_data);
> > + if (copy_to_user((void *)arg, &xfer, sizeof(struct jtag_xfer)))
> > + return -EFAULT;
> > + break;
> > +
> > + case JTAG_GIOCSTATUS:
> > + if (jtag->ops->status_get)
> > + err = jtag->ops->status_get(jtag, &value);
> > + else
> > + err = -EOPNOTSUPP;
> > + if (err)
> > + break;
> > +
> > + err = put_user(value, (__u32 *)arg);
>
> Same put_user err issue here.
Yes.
>
> > + break;
> > +
> > + default:
> > + return -EINVAL;
> > + }
> > + return err;
> > +}
> > +
> > +#ifdef CONFIG_COMPAT
> > +static long jtag_ioctl_compat(struct file *file, unsigned int cmd,
> > + unsigned long arg)
> > +{
> > + return jtag_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); }
> > +#endif
>
> Why do you need a compat callback for a new ioctl? Create your structures
> properly and this should not be needed, right?
I does this because Arnd (arndbergmann@gmail.com) writed in review (On Wed, Aug 2, 2017 at 3:18 PM)
[..]
> + .unlocked_ioctl = jtag_ioctl,
> + .open = jtag_open,
> + .release = jtag_release,
> +};
add a compat_ioctl pointer here, after ensuring that all ioctl commands are compatible between 32-bit and 64-bit user space.
[..]
>
> > +
> > +static int jtag_open(struct inode *inode, struct file *file) {
> > + struct jtag *jtag = container_of(inode->i_cdev, struct jtag, cdev);
> > +
> > + if (atomic_read(&jtag->open)) {
> > + dev_info(NULL, "jtag already opened\n");
> > + return -EBUSY;
>
> Why do you care if multiple opens can happen?
Jtag HW not support to using with multiple requests from different users. So we prohibit this.
>
> > + }
> > +
> > + atomic_inc(&jtag->open);
>
> Oh look, you just raced with two different people opening at the same time :(
>
> An atomic value is never a replacement for a lock, sorry.
>
> > + file->private_data = jtag;
> > + return 0;
> > +}
> > +
> > +static int jtag_release(struct inode *inode, struct file *file) {
> > + struct jtag *jtag = file->private_data;
> > +
> > + atomic_dec(&jtag->open);
>
> Again, not needed.
>
> > + return 0;
> > +}
> > +
> > +static const struct file_operations jtag_fops = {
> > + .owner = THIS_MODULE,
> > + .open = jtag_open,
> > + .release = jtag_release,
> > + .llseek = noop_llseek,
> > + .unlocked_ioctl = jtag_ioctl,
> > +#ifdef CONFIG_COMPAT
> > + .compat_ioctl = jtag_ioctl_compat,
> > +#endif
> > +};
> > +
> > +struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops)
> > +{
> > + struct jtag *jtag;
> > +
> > + jtag = kzalloc(sizeof(*jtag) + round_up(priv_size,
> ARCH_DMA_MINALIGN),
> > + GFP_KERNEL);
> > + if (!jtag)
> > + return NULL;
> > +
> > + jtag->ops = ops;
> > + return jtag;
> > +}
> > +EXPORT_SYMBOL_GPL(jtag_alloc);
>
> register should allocate and register the device, why pass a structure back that
> the caller then has to do something else with to use it?
>
Before registration we need to initialize JTAG device HW registers and fill private data with HW specific parameters.
And is I see in other Linux drivers it is a common way to separate allocation device and register it
> > +
> > +void jtag_free(struct jtag *jtag)
> > +{
> > + kfree(jtag);
> > +}
> > +EXPORT_SYMBOL_GPL(jtag_free);
> > +
> > +int jtag_register(struct jtag *jtag)
> > +{
> > + int id;
> > + int err;
> > +
> > + id = ida_simple_get(&jtag_ida, 0, 0, GFP_KERNEL);
> > + if (id < 0)
> > + return id;
> > +
> > + jtag->id = id;
> > + cdev_init(&jtag->cdev, &jtag_fops);
> > + jtag->cdev.owner = THIS_MODULE;
> > + err = cdev_add(&jtag->cdev, MKDEV(MAJOR(jtag_devt), jtag->id), 1);
> > + if (err)
> > + goto err_cdev;
>
> misc device would be so much simpler and easier here :(
>
>
> > +
> > + /* Register this jtag device with the driver core */
> > + jtag->dev = device_create(&jtag_class, NULL,
> MKDEV(MAJOR(jtag_devt),
> > + jtag->id),
> > + NULL, "jtag%d", jtag->id);
> > + if (!jtag->dev)
> > + goto err_device_create;
> > +
> > + atomic_set(&jtag->open, 0);
> > + dev_set_drvdata(jtag->dev, jtag);
> > + return err;
> > +
> > +err_device_create:
> > + cdev_del(&jtag->cdev);
> > +err_cdev:
> > + ida_simple_remove(&jtag_ida, id);
> > + return err;
> > +}
> > +EXPORT_SYMBOL_GPL(jtag_register);
> > +
> > +void jtag_unregister(struct jtag *jtag) {
> > + struct device *dev = jtag->dev;
> > +
> > + cdev_del(&jtag->cdev);
> > + device_unregister(dev);
> > + ida_simple_remove(&jtag_ida, jtag->id); }
> > +EXPORT_SYMBOL_GPL(jtag_unregister);
> > +
> > +static int __init jtag_init(void)
> > +{
> > + int err;
> > +
> > + err = alloc_chrdev_region(&jtag_devt, JTAG_FIRST_MINOR,
> > + JTAG_MAX_DEVICES, "jtag");
> > + if (err)
> > + return err;
> > +
> > + err = class_register(&jtag_class);
> > + if (err)
> > + unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
> > +
> > + return err;
> > +}
> > +
> > +static void __exit jtag_exit(void)
> > +{
> > + class_unregister(&jtag_class);
> > + unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
>
> Your idr leaked memory :(
>
Yes I will add ida_destroy() here.
>
>
> > +}
> > +
> > +module_init(jtag_init);
> > +module_exit(jtag_exit);
> > +
> > +MODULE_AUTHOR("Oleksandr Shamray <oleksandrs@mellanox.com>");
> > +MODULE_DESCRIPTION("Generic jtag support"); MODULE_LICENSE("GPL
> v2");
> > diff --git a/include/linux/jtag.h b/include/linux/jtag.h new file mode
> > 100644 index 0000000..c016fed
> > --- /dev/null
> > +++ b/include/linux/jtag.h
> > @@ -0,0 +1,48 @@
> > +/*
> > + * drivers/jtag/jtag.c
> > + *
> > + * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
> > + * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
> > + *
> > + * Released under the GPLv2 only.
> > + * SPDX-License-Identifier: GPL-2.0
> > + */
> > +
> > +#ifndef __JTAG_H
> > +#define __JTAG_H
> > +
> > +#include <uapi/linux/jtag.h>
> > +
> > +#ifndef ARCH_DMA_MINALIGN
> > +#define ARCH_DMA_MINALIGN 1
> > +#endif
> > +
> > +#define jtag_u64_to_ptr(arg) ((void *)(uintptr_t)arg)
> > +
> > +#define JTAG_MAX_XFER_DATA_LEN 65535
> > +
> > +struct jtag;
> > +/**
> > + * struct jtag_ops - callbacks for jtag control functions:
> > + *
> > + * @freq_get: get frequency function. Filled by device driver
> > + * @freq_set: set frequency function. Filled by device driver
> > + * @status_get: set status function. Filled by device driver
> > + * @idle: set JTAG to idle state function. Filled by device driver
> > + * @xfer: send JTAG xfer function. Filled by device driver */ struct
> > +jtag_ops {
> > + int (*freq_get)(struct jtag *jtag, u32 *freq);
> > + int (*freq_set)(struct jtag *jtag, u32 freq);
> > + int (*status_get)(struct jtag *jtag, u32 *state);
> > + int (*idle)(struct jtag *jtag, struct jtag_run_test_idle *idle);
> > + int (*xfer)(struct jtag *jtag, struct jtag_xfer *xfer); };
> > +
> > +void *jtag_priv(struct jtag *jtag);
> > +int jtag_register(struct jtag *jtag); void jtag_unregister(struct
> > +jtag *jtag); struct jtag *jtag_alloc(size_t priv_size, const struct
> > +jtag_ops *ops); void jtag_free(struct jtag *jtag);
> > +
> > +#endif /* __JTAG_H */
> > diff --git a/include/uapi/linux/jtag.h b/include/uapi/linux/jtag.h new
> > file mode 100644 index 0000000..180bf22
> > --- /dev/null
> > +++ b/include/uapi/linux/jtag.h
> > @@ -0,0 +1,115 @@
> > +/*
> > + * JTAG class driver
> > + *
> > + * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
> > + * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
> > + *
> > + * Released under the GPLv2/BSD.
> > + * SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
> > +
> > +#ifndef __UAPI_LINUX_JTAG_H
> > +#define __UAPI_LINUX_JTAG_H
> > +
> > +/**
> > + * enum jtag_xfer_mode:
> > + *
> > + * @JTAG_XFER_HW_MODE: hardware mode transfer
> > + * @JTAG_XFER_SW_MODE: software mode transfer */ enum
> jtag_xfer_mode
> > +{
> > + JTAG_XFER_HW_MODE,
> > + JTAG_XFER_SW_MODE,
> > +};
> > +
> > +/**
> > + * enum jtag_endstate:
> > + *
> > + * @JTAG_STATE_IDLE: JTAG state machine IDLE state
> > + * @JTAG_STATE_PAUSEIR: JTAG state machine PAUSE_IR state
> > + * @JTAG_STATE_PAUSEDR: JTAG state machine PAUSE_DR state */ enum
> > +jtag_endstate {
> > + JTAG_STATE_IDLE,
> > + JTAG_STATE_PAUSEIR,
> > + JTAG_STATE_PAUSEDR,
> > +};
> > +
> > +/**
> > + * enum jtag_xfer_type:
> > + *
> > + * @JTAG_SIR_XFER: SIR transfer
> > + * @JTAG_SDR_XFER: SDR transfer
> > + */
> > +enum jtag_xfer_type {
> > + JTAG_SIR_XFER,
> > + JTAG_SDR_XFER,
> > +};
> > +
> > +/**
> > + * enum jtag_xfer_direction:
> > + *
> > + * @JTAG_READ_XFER: read transfer
> > + * @JTAG_WRITE_XFER: write transfer
> > + */
> > +enum jtag_xfer_direction {
> > + JTAG_READ_XFER,
> > + JTAG_WRITE_XFER,
> > +};
> > +
> > +/**
> > + * struct jtag_run_test_idle - forces JTAG state machine to
> > + * RUN_TEST/IDLE state
> > + *
> > + * @mode: access mode
> > + * @reset: 0 - run IDLE/PAUSE from current state
> > + * 1 - go through TEST_LOGIC/RESET state before IDLE/PAUSE
> > + * @end: completion flag
> > + * @tck: clock counter
> > + *
> > + * Structure represents interface to JTAG device for jtag idle
> > + * execution.
> > + */
> > +struct jtag_run_test_idle {
> > + __u8 mode;
> > + __u8 reset;
> > + __u8 endstate;
> > + __u8 tck;
> > +};
> > +
> > +/**
> > + * struct jtag_xfer - jtag xfer:
> > + *
> > + * @mode: access mode
> > + * @type: transfer type
> > + * @direction: xfer direction
> > + * @length: xfer bits len
> > + * @tdio : xfer data array
> > + * @endir: xfer end state
> > + *
> > + * Structure represents interface to Aspeed JTAG device for jtag sdr
> > +xfer
> > + * execution.
> > + */
> > +struct jtag_xfer {
> > + __u8 mode;
> > + __u8 type;
> > + __u8 direction;
> > + __u8 endstate;
> > + __u32 length;
> > + __u64 tdio;
>
> I don't see anything odd here that requires a compat ioctl callback, do you?
>
> thanks,
>
> greg k-h
Thanks for your review.
Oleksandr S.
^ permalink raw reply [flat|nested] 45+ messages in thread
* RE: [patch v9 1/4] drivers: jtag: Add JTAG core driver
@ 2017-10-20 14:34 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-10-20 14:34 UTC (permalink / raw)
To: Greg KH
Cc: arnd, linux-kernel, linux-arm-kernel, devicetree, openbmc, joel,
jiri, tklauser, linux-serial, mec, Vadim Pasternak,
system-sw-low-level, robh+dt, openocd-devel-owner
Hi Greg.
> -----Original Message-----
> From: Greg KH [mailto:gregkh@linuxfoundation.org]
> Sent: Friday, October 20, 2017 2:55 PM
> To: Oleksandr Shamray <oleksandrs@mellanox.com>
> Cc: arnd@arndb.de; linux-kernel@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; devicetree@vger.kernel.org;
> openbmc@lists.ozlabs.org; joel@jms.id.au; jiri@resnulli.us;
> tklauser@distanz.ch; linux-serial@vger.kernel.org; mec@shout.net; Vadim
> Pasternak <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> level@mellanox.com>; robh+dt@kernel.org; openocd-devel-
> owner@lists.sourceforge.net; linux-api@vger.kernel.org;
> davem@davemloft.net; mchehab@kernel.org; Jiri Pirko <jiri@mellanox.com>
> Subject: Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
>
> On Thu, Sep 21, 2017 at 12:25:29PM +0300, Oleksandr Shamray wrote:
> > +struct jtag {
> > + struct device *dev;
> > + struct cdev cdev;
>
> Why are you using a cdev here and not just a normal misc device?
What the benefits to use misc instead of cdev?
> I forgot if this is what you were doing before, sorry...
>
> > + int id;
> > + atomic_t open;
>
> Why do you need this?
This counter used to avoid open at the same time by 2 or more users.
>
> > + const struct jtag_ops *ops;
> > + unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
>
> Huh? Why is this needed to be dma aligned? Why not just use the private
> pointer in struct device?
>
It is critical?
> > +};
> > +
> > +static dev_t jtag_devt;
> > +static DEFINE_IDA(jtag_ida);
> > +
> > +void *jtag_priv(struct jtag *jtag)
> > +{
> > + return jtag->priv;
> > +}
> > +EXPORT_SYMBOL_GPL(jtag_priv);
> > +
> > +static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size) {
> > + unsigned long size;
> > + void *kdata;
> > +
> > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > + kdata = memdup_user(u64_to_user_ptr(udata), size);
>
> You only use this once, why not just open-code it?
I think it makes code more understandable.
>
> > +
> > + return kdata;
> > +}
> > +
> > +static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
> > + unsigned long bit_size)
> > +{
> > + unsigned long size;
> > +
> > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > +
> > + return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata), size);
>
> Same here, making this a separate function seems odd.
Same, I think it makes code more understandable.
>
> > +}
> > +
> > +static struct class jtag_class = {
> > + .name = "jtag",
> > + .owner = THIS_MODULE,
> > +};
> > +
> > +static int jtag_run_test_idle_op(struct jtag *jtag,
> > + struct jtag_run_test_idle *idle) {
> > + if (jtag->ops->idle)
> > + return jtag->ops->idle(jtag, idle);
> > + else
> > + return -EOPNOTSUPP;
>
> Why is this a function? Why not just do this work in the ioctl?
Agree. I will move it just to ioctl function body.
>
> > +}
> > +
> > +static int jtag_xfer_op(struct jtag *jtag, struct jtag_xfer *xfer, u8
> > +*data) {
> > + if (jtag->ops->xfer)
> > + return jtag->ops->xfer(jtag, xfer, data);
> > + else
> > + return -EOPNOTSUPP;
>
> Same here, doesn't need to be a function.
Agree.
>
> > +}
> > +
> > +static long jtag_ioctl(struct file *file, unsigned int cmd, unsigned
> > +long arg) {
> > + struct jtag *jtag = file->private_data;
> > + struct jtag_run_test_idle idle;
> > + struct jtag_xfer xfer;
> > + u8 *xfer_data;
> > + u32 value;
> > + int err;
> > +
> > + switch (cmd) {
> > + case JTAG_GIOCFREQ:
> > + if (jtag->ops->freq_get)
> > + err = jtag->ops->freq_get(jtag, &value);
> > + else
> > + err = -EOPNOTSUPP;
> > + if (err)
> > + break;
> > +
> > + err = put_user(value, (__u32 *)arg);
> > + break;
>
> Are you sure the return value of put_user is correct here? Shouldn't you return
> -EFAULT if err is not 0?
Yes, thanks for point of this.
>
> > +
> > + case JTAG_SIOCFREQ:
> > + err = get_user(value, (__u32 *)arg);
> > +
>
> why a blank line?
Will remove
>
> > + if (value == 0)
> > + err = -EINVAL;
>
> Check err first.
Ok.
>
> > + if (err)
> > + break;
>
> And set it properly, again err should be -EFAULT, right?
Right 😊0
>
> > +
> > + if (jtag->ops->freq_set)
> > + err = jtag->ops->freq_set(jtag, value);
> > + else
> > + err = -EOPNOTSUPP;
> > + break;
> > +
> > + case JTAG_IOCRUNTEST:
> > + if (copy_from_user(&idle, (void *)arg,
> > + sizeof(struct jtag_run_test_idle)))
> > + return -ENOMEM;
> > + err = jtag_run_test_idle_op(jtag, &idle);
>
> Who validates the structure fields? Is that up to the individual jtag driver? Why
> not do it in the core correctly so that it only has to be done in one place and you
> do not have to audit every individual driver?
Input parameters validated by jtag platform driver. I think it not critical.
>
> > + break;
> > +
> > + case JTAG_IOCXFER:
> > + if (copy_from_user(&xfer, (void *)arg,
> > + sizeof(struct jtag_xfer)))
> > + return -EFAULT;
> > +
> > + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
> > + return -EFAULT;
> > +
> > + xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
> > + if (!xfer_data)
> > + return -ENOMEM;
>
> Are you sure that's the correct error value?
I think yes, but what you suggest?
>
> > +
> > + err = jtag_xfer_op(jtag, &xfer, xfer_data);
> > + if (jtag_copy_to_user(xfer.tdio, xfer_data, xfer.length)) {
> > + kfree(xfer_data);
> > + return -EFAULT;
> > + }
> > +
> > + kfree(xfer_data);
> > + if (copy_to_user((void *)arg, &xfer, sizeof(struct jtag_xfer)))
> > + return -EFAULT;
> > + break;
> > +
> > + case JTAG_GIOCSTATUS:
> > + if (jtag->ops->status_get)
> > + err = jtag->ops->status_get(jtag, &value);
> > + else
> > + err = -EOPNOTSUPP;
> > + if (err)
> > + break;
> > +
> > + err = put_user(value, (__u32 *)arg);
>
> Same put_user err issue here.
Yes.
>
> > + break;
> > +
> > + default:
> > + return -EINVAL;
> > + }
> > + return err;
> > +}
> > +
> > +#ifdef CONFIG_COMPAT
> > +static long jtag_ioctl_compat(struct file *file, unsigned int cmd,
> > + unsigned long arg)
> > +{
> > + return jtag_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); }
> > +#endif
>
> Why do you need a compat callback for a new ioctl? Create your structures
> properly and this should not be needed, right?
I does this because Arnd (arndbergmann@gmail.com) writed in review (On Wed, Aug 2, 2017 at 3:18 PM)
[..]
> + .unlocked_ioctl = jtag_ioctl,
> + .open = jtag_open,
> + .release = jtag_release,
> +};
add a compat_ioctl pointer here, after ensuring that all ioctl commands are compatible between 32-bit and 64-bit user space.
[..]
>
> > +
> > +static int jtag_open(struct inode *inode, struct file *file) {
> > + struct jtag *jtag = container_of(inode->i_cdev, struct jtag, cdev);
> > +
> > + if (atomic_read(&jtag->open)) {
> > + dev_info(NULL, "jtag already opened\n");
> > + return -EBUSY;
>
> Why do you care if multiple opens can happen?
Jtag HW not support to using with multiple requests from different users. So we prohibit this.
>
> > + }
> > +
> > + atomic_inc(&jtag->open);
>
> Oh look, you just raced with two different people opening at the same time :(
>
> An atomic value is never a replacement for a lock, sorry.
>
> > + file->private_data = jtag;
> > + return 0;
> > +}
> > +
> > +static int jtag_release(struct inode *inode, struct file *file) {
> > + struct jtag *jtag = file->private_data;
> > +
> > + atomic_dec(&jtag->open);
>
> Again, not needed.
>
> > + return 0;
> > +}
> > +
> > +static const struct file_operations jtag_fops = {
> > + .owner = THIS_MODULE,
> > + .open = jtag_open,
> > + .release = jtag_release,
> > + .llseek = noop_llseek,
> > + .unlocked_ioctl = jtag_ioctl,
> > +#ifdef CONFIG_COMPAT
> > + .compat_ioctl = jtag_ioctl_compat,
> > +#endif
> > +};
> > +
> > +struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops)
> > +{
> > + struct jtag *jtag;
> > +
> > + jtag = kzalloc(sizeof(*jtag) + round_up(priv_size,
> ARCH_DMA_MINALIGN),
> > + GFP_KERNEL);
> > + if (!jtag)
> > + return NULL;
> > +
> > + jtag->ops = ops;
> > + return jtag;
> > +}
> > +EXPORT_SYMBOL_GPL(jtag_alloc);
>
> register should allocate and register the device, why pass a structure back that
> the caller then has to do something else with to use it?
>
Before registration we need to initialize JTAG device HW registers and fill private data with HW specific parameters.
And is I see in other Linux drivers it is a common way to separate allocation device and register it
> > +
> > +void jtag_free(struct jtag *jtag)
> > +{
> > + kfree(jtag);
> > +}
> > +EXPORT_SYMBOL_GPL(jtag_free);
> > +
> > +int jtag_register(struct jtag *jtag)
> > +{
> > + int id;
> > + int err;
> > +
> > + id = ida_simple_get(&jtag_ida, 0, 0, GFP_KERNEL);
> > + if (id < 0)
> > + return id;
> > +
> > + jtag->id = id;
> > + cdev_init(&jtag->cdev, &jtag_fops);
> > + jtag->cdev.owner = THIS_MODULE;
> > + err = cdev_add(&jtag->cdev, MKDEV(MAJOR(jtag_devt), jtag->id), 1);
> > + if (err)
> > + goto err_cdev;
>
> misc device would be so much simpler and easier here :(
>
>
> > +
> > + /* Register this jtag device with the driver core */
> > + jtag->dev = device_create(&jtag_class, NULL,
> MKDEV(MAJOR(jtag_devt),
> > + jtag->id),
> > + NULL, "jtag%d", jtag->id);
> > + if (!jtag->dev)
> > + goto err_device_create;
> > +
> > + atomic_set(&jtag->open, 0);
> > + dev_set_drvdata(jtag->dev, jtag);
> > + return err;
> > +
> > +err_device_create:
> > + cdev_del(&jtag->cdev);
> > +err_cdev:
> > + ida_simple_remove(&jtag_ida, id);
> > + return err;
> > +}
> > +EXPORT_SYMBOL_GPL(jtag_register);
> > +
> > +void jtag_unregister(struct jtag *jtag) {
> > + struct device *dev = jtag->dev;
> > +
> > + cdev_del(&jtag->cdev);
> > + device_unregister(dev);
> > + ida_simple_remove(&jtag_ida, jtag->id); }
> > +EXPORT_SYMBOL_GPL(jtag_unregister);
> > +
> > +static int __init jtag_init(void)
> > +{
> > + int err;
> > +
> > + err = alloc_chrdev_region(&jtag_devt, JTAG_FIRST_MINOR,
> > + JTAG_MAX_DEVICES, "jtag");
> > + if (err)
> > + return err;
> > +
> > + err = class_register(&jtag_class);
> > + if (err)
> > + unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
> > +
> > + return err;
> > +}
> > +
> > +static void __exit jtag_exit(void)
> > +{
> > + class_unregister(&jtag_class);
> > + unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
>
> Your idr leaked memory :(
>
Yes I will add ida_destroy() here.
>
>
> > +}
> > +
> > +module_init(jtag_init);
> > +module_exit(jtag_exit);
> > +
> > +MODULE_AUTHOR("Oleksandr Shamray <oleksandrs@mellanox.com>");
> > +MODULE_DESCRIPTION("Generic jtag support"); MODULE_LICENSE("GPL
> v2");
> > diff --git a/include/linux/jtag.h b/include/linux/jtag.h new file mode
> > 100644 index 0000000..c016fed
> > --- /dev/null
> > +++ b/include/linux/jtag.h
> > @@ -0,0 +1,48 @@
> > +/*
> > + * drivers/jtag/jtag.c
> > + *
> > + * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
> > + * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
> > + *
> > + * Released under the GPLv2 only.
> > + * SPDX-License-Identifier: GPL-2.0
> > + */
> > +
> > +#ifndef __JTAG_H
> > +#define __JTAG_H
> > +
> > +#include <uapi/linux/jtag.h>
> > +
> > +#ifndef ARCH_DMA_MINALIGN
> > +#define ARCH_DMA_MINALIGN 1
> > +#endif
> > +
> > +#define jtag_u64_to_ptr(arg) ((void *)(uintptr_t)arg)
> > +
> > +#define JTAG_MAX_XFER_DATA_LEN 65535
> > +
> > +struct jtag;
> > +/**
> > + * struct jtag_ops - callbacks for jtag control functions:
> > + *
> > + * @freq_get: get frequency function. Filled by device driver
> > + * @freq_set: set frequency function. Filled by device driver
> > + * @status_get: set status function. Filled by device driver
> > + * @idle: set JTAG to idle state function. Filled by device driver
> > + * @xfer: send JTAG xfer function. Filled by device driver */ struct
> > +jtag_ops {
> > + int (*freq_get)(struct jtag *jtag, u32 *freq);
> > + int (*freq_set)(struct jtag *jtag, u32 freq);
> > + int (*status_get)(struct jtag *jtag, u32 *state);
> > + int (*idle)(struct jtag *jtag, struct jtag_run_test_idle *idle);
> > + int (*xfer)(struct jtag *jtag, struct jtag_xfer *xfer); };
> > +
> > +void *jtag_priv(struct jtag *jtag);
> > +int jtag_register(struct jtag *jtag); void jtag_unregister(struct
> > +jtag *jtag); struct jtag *jtag_alloc(size_t priv_size, const struct
> > +jtag_ops *ops); void jtag_free(struct jtag *jtag);
> > +
> > +#endif /* __JTAG_H */
> > diff --git a/include/uapi/linux/jtag.h b/include/uapi/linux/jtag.h new
> > file mode 100644 index 0000000..180bf22
> > --- /dev/null
> > +++ b/include/uapi/linux/jtag.h
> > @@ -0,0 +1,115 @@
> > +/*
> > + * JTAG class driver
> > + *
> > + * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
> > + * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
> > + *
> > + * Released under the GPLv2/BSD.
> > + * SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
> > +
> > +#ifndef __UAPI_LINUX_JTAG_H
> > +#define __UAPI_LINUX_JTAG_H
> > +
> > +/**
> > + * enum jtag_xfer_mode:
> > + *
> > + * @JTAG_XFER_HW_MODE: hardware mode transfer
> > + * @JTAG_XFER_SW_MODE: software mode transfer */ enum
> jtag_xfer_mode
> > +{
> > + JTAG_XFER_HW_MODE,
> > + JTAG_XFER_SW_MODE,
> > +};
> > +
> > +/**
> > + * enum jtag_endstate:
> > + *
> > + * @JTAG_STATE_IDLE: JTAG state machine IDLE state
> > + * @JTAG_STATE_PAUSEIR: JTAG state machine PAUSE_IR state
> > + * @JTAG_STATE_PAUSEDR: JTAG state machine PAUSE_DR state */ enum
> > +jtag_endstate {
> > + JTAG_STATE_IDLE,
> > + JTAG_STATE_PAUSEIR,
> > + JTAG_STATE_PAUSEDR,
> > +};
> > +
> > +/**
> > + * enum jtag_xfer_type:
> > + *
> > + * @JTAG_SIR_XFER: SIR transfer
> > + * @JTAG_SDR_XFER: SDR transfer
> > + */
> > +enum jtag_xfer_type {
> > + JTAG_SIR_XFER,
> > + JTAG_SDR_XFER,
> > +};
> > +
> > +/**
> > + * enum jtag_xfer_direction:
> > + *
> > + * @JTAG_READ_XFER: read transfer
> > + * @JTAG_WRITE_XFER: write transfer
> > + */
> > +enum jtag_xfer_direction {
> > + JTAG_READ_XFER,
> > + JTAG_WRITE_XFER,
> > +};
> > +
> > +/**
> > + * struct jtag_run_test_idle - forces JTAG state machine to
> > + * RUN_TEST/IDLE state
> > + *
> > + * @mode: access mode
> > + * @reset: 0 - run IDLE/PAUSE from current state
> > + * 1 - go through TEST_LOGIC/RESET state before IDLE/PAUSE
> > + * @end: completion flag
> > + * @tck: clock counter
> > + *
> > + * Structure represents interface to JTAG device for jtag idle
> > + * execution.
> > + */
> > +struct jtag_run_test_idle {
> > + __u8 mode;
> > + __u8 reset;
> > + __u8 endstate;
> > + __u8 tck;
> > +};
> > +
> > +/**
> > + * struct jtag_xfer - jtag xfer:
> > + *
> > + * @mode: access mode
> > + * @type: transfer type
> > + * @direction: xfer direction
> > + * @length: xfer bits len
> > + * @tdio : xfer data array
> > + * @endir: xfer end state
> > + *
> > + * Structure represents interface to Aspeed JTAG device for jtag sdr
> > +xfer
> > + * execution.
> > + */
> > +struct jtag_xfer {
> > + __u8 mode;
> > + __u8 type;
> > + __u8 direction;
> > + __u8 endstate;
> > + __u32 length;
> > + __u64 tdio;
>
> I don't see anything odd here that requires a compat ioctl callback, do you?
>
> thanks,
>
> greg k-h
Thanks for your review.
Oleksandr S.
^ permalink raw reply [flat|nested] 45+ messages in thread
* RE: [patch v9 1/4] drivers: jtag: Add JTAG core driver
@ 2017-10-20 14:34 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-10-20 14:34 UTC (permalink / raw)
To: Greg KH
Cc: arnd, linux-kernel, linux-arm-kernel, devicetree, openbmc, joel,
jiri, tklauser, linux-serial, mec, Vadim Pasternak,
system-sw-low-level, robh+dt, openocd-devel-owner, linux-api,
davem, mchehab, Jiri Pirko
Hi Greg.
> -----Original Message-----
> From: Greg KH [mailto:gregkh@linuxfoundation.org]
> Sent: Friday, October 20, 2017 2:55 PM
> To: Oleksandr Shamray <oleksandrs@mellanox.com>
> Cc: arnd@arndb.de; linux-kernel@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; devicetree@vger.kernel.org;
> openbmc@lists.ozlabs.org; joel@jms.id.au; jiri@resnulli.us;
> tklauser@distanz.ch; linux-serial@vger.kernel.org; mec@shout.net; Vadim
> Pasternak <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> level@mellanox.com>; robh+dt@kernel.org; openocd-devel-
> owner@lists.sourceforge.net; linux-api@vger.kernel.org;
> davem@davemloft.net; mchehab@kernel.org; Jiri Pirko <jiri@mellanox.com>
> Subject: Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
>
> On Thu, Sep 21, 2017 at 12:25:29PM +0300, Oleksandr Shamray wrote:
> > +struct jtag {
> > + struct device *dev;
> > + struct cdev cdev;
>
> Why are you using a cdev here and not just a normal misc device?
What the benefits to use misc instead of cdev?
> I forgot if this is what you were doing before, sorry...
>
> > + int id;
> > + atomic_t open;
>
> Why do you need this?
This counter used to avoid open at the same time by 2 or more users.
>
> > + const struct jtag_ops *ops;
> > + unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
>
> Huh? Why is this needed to be dma aligned? Why not just use the private
> pointer in struct device?
>
It is critical?
> > +};
> > +
> > +static dev_t jtag_devt;
> > +static DEFINE_IDA(jtag_ida);
> > +
> > +void *jtag_priv(struct jtag *jtag)
> > +{
> > + return jtag->priv;
> > +}
> > +EXPORT_SYMBOL_GPL(jtag_priv);
> > +
> > +static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size) {
> > + unsigned long size;
> > + void *kdata;
> > +
> > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > + kdata = memdup_user(u64_to_user_ptr(udata), size);
>
> You only use this once, why not just open-code it?
I think it makes code more understandable.
>
> > +
> > + return kdata;
> > +}
> > +
> > +static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
> > + unsigned long bit_size)
> > +{
> > + unsigned long size;
> > +
> > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > +
> > + return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata), size);
>
> Same here, making this a separate function seems odd.
Same, I think it makes code more understandable.
>
> > +}
> > +
> > +static struct class jtag_class = {
> > + .name = "jtag",
> > + .owner = THIS_MODULE,
> > +};
> > +
> > +static int jtag_run_test_idle_op(struct jtag *jtag,
> > + struct jtag_run_test_idle *idle) {
> > + if (jtag->ops->idle)
> > + return jtag->ops->idle(jtag, idle);
> > + else
> > + return -EOPNOTSUPP;
>
> Why is this a function? Why not just do this work in the ioctl?
Agree. I will move it just to ioctl function body.
>
> > +}
> > +
> > +static int jtag_xfer_op(struct jtag *jtag, struct jtag_xfer *xfer, u8
> > +*data) {
> > + if (jtag->ops->xfer)
> > + return jtag->ops->xfer(jtag, xfer, data);
> > + else
> > + return -EOPNOTSUPP;
>
> Same here, doesn't need to be a function.
Agree.
>
> > +}
> > +
> > +static long jtag_ioctl(struct file *file, unsigned int cmd, unsigned
> > +long arg) {
> > + struct jtag *jtag = file->private_data;
> > + struct jtag_run_test_idle idle;
> > + struct jtag_xfer xfer;
> > + u8 *xfer_data;
> > + u32 value;
> > + int err;
> > +
> > + switch (cmd) {
> > + case JTAG_GIOCFREQ:
> > + if (jtag->ops->freq_get)
> > + err = jtag->ops->freq_get(jtag, &value);
> > + else
> > + err = -EOPNOTSUPP;
> > + if (err)
> > + break;
> > +
> > + err = put_user(value, (__u32 *)arg);
> > + break;
>
> Are you sure the return value of put_user is correct here? Shouldn't you return
> -EFAULT if err is not 0?
Yes, thanks for point of this.
>
> > +
> > + case JTAG_SIOCFREQ:
> > + err = get_user(value, (__u32 *)arg);
> > +
>
> why a blank line?
Will remove
>
> > + if (value == 0)
> > + err = -EINVAL;
>
> Check err first.
Ok.
>
> > + if (err)
> > + break;
>
> And set it properly, again err should be -EFAULT, right?
Right 😊0
>
> > +
> > + if (jtag->ops->freq_set)
> > + err = jtag->ops->freq_set(jtag, value);
> > + else
> > + err = -EOPNOTSUPP;
> > + break;
> > +
> > + case JTAG_IOCRUNTEST:
> > + if (copy_from_user(&idle, (void *)arg,
> > + sizeof(struct jtag_run_test_idle)))
> > + return -ENOMEM;
> > + err = jtag_run_test_idle_op(jtag, &idle);
>
> Who validates the structure fields? Is that up to the individual jtag driver? Why
> not do it in the core correctly so that it only has to be done in one place and you
> do not have to audit every individual driver?
Input parameters validated by jtag platform driver. I think it not critical.
>
> > + break;
> > +
> > + case JTAG_IOCXFER:
> > + if (copy_from_user(&xfer, (void *)arg,
> > + sizeof(struct jtag_xfer)))
> > + return -EFAULT;
> > +
> > + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
> > + return -EFAULT;
> > +
> > + xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
> > + if (!xfer_data)
> > + return -ENOMEM;
>
> Are you sure that's the correct error value?
I think yes, but what you suggest?
>
> > +
> > + err = jtag_xfer_op(jtag, &xfer, xfer_data);
> > + if (jtag_copy_to_user(xfer.tdio, xfer_data, xfer.length)) {
> > + kfree(xfer_data);
> > + return -EFAULT;
> > + }
> > +
> > + kfree(xfer_data);
> > + if (copy_to_user((void *)arg, &xfer, sizeof(struct jtag_xfer)))
> > + return -EFAULT;
> > + break;
> > +
> > + case JTAG_GIOCSTATUS:
> > + if (jtag->ops->status_get)
> > + err = jtag->ops->status_get(jtag, &value);
> > + else
> > + err = -EOPNOTSUPP;
> > + if (err)
> > + break;
> > +
> > + err = put_user(value, (__u32 *)arg);
>
> Same put_user err issue here.
Yes.
>
> > + break;
> > +
> > + default:
> > + return -EINVAL;
> > + }
> > + return err;
> > +}
> > +
> > +#ifdef CONFIG_COMPAT
> > +static long jtag_ioctl_compat(struct file *file, unsigned int cmd,
> > + unsigned long arg)
> > +{
> > + return jtag_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); }
> > +#endif
>
> Why do you need a compat callback for a new ioctl? Create your structures
> properly and this should not be needed, right?
I does this because Arnd (arndbergmann@gmail.com) writed in review (On Wed, Aug 2, 2017 at 3:18 PM)
[..]
> + .unlocked_ioctl = jtag_ioctl,
> + .open = jtag_open,
> + .release = jtag_release,
> +};
add a compat_ioctl pointer here, after ensuring that all ioctl commands are compatible between 32-bit and 64-bit user space.
[..]
>
> > +
> > +static int jtag_open(struct inode *inode, struct file *file) {
> > + struct jtag *jtag = container_of(inode->i_cdev, struct jtag, cdev);
> > +
> > + if (atomic_read(&jtag->open)) {
> > + dev_info(NULL, "jtag already opened\n");
> > + return -EBUSY;
>
> Why do you care if multiple opens can happen?
Jtag HW not support to using with multiple requests from different users. So we prohibit this.
>
> > + }
> > +
> > + atomic_inc(&jtag->open);
>
> Oh look, you just raced with two different people opening at the same time :(
>
> An atomic value is never a replacement for a lock, sorry.
>
> > + file->private_data = jtag;
> > + return 0;
> > +}
> > +
> > +static int jtag_release(struct inode *inode, struct file *file) {
> > + struct jtag *jtag = file->private_data;
> > +
> > + atomic_dec(&jtag->open);
>
> Again, not needed.
>
> > + return 0;
> > +}
> > +
> > +static const struct file_operations jtag_fops = {
> > + .owner = THIS_MODULE,
> > + .open = jtag_open,
> > + .release = jtag_release,
> > + .llseek = noop_llseek,
> > + .unlocked_ioctl = jtag_ioctl,
> > +#ifdef CONFIG_COMPAT
> > + .compat_ioctl = jtag_ioctl_compat,
> > +#endif
> > +};
> > +
> > +struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops)
> > +{
> > + struct jtag *jtag;
> > +
> > + jtag = kzalloc(sizeof(*jtag) + round_up(priv_size,
> ARCH_DMA_MINALIGN),
> > + GFP_KERNEL);
> > + if (!jtag)
> > + return NULL;
> > +
> > + jtag->ops = ops;
> > + return jtag;
> > +}
> > +EXPORT_SYMBOL_GPL(jtag_alloc);
>
> register should allocate and register the device, why pass a structure back that
> the caller then has to do something else with to use it?
>
Before registration we need to initialize JTAG device HW registers and fill private data with HW specific parameters.
And is I see in other Linux drivers it is a common way to separate allocation device and register it
> > +
> > +void jtag_free(struct jtag *jtag)
> > +{
> > + kfree(jtag);
> > +}
> > +EXPORT_SYMBOL_GPL(jtag_free);
> > +
> > +int jtag_register(struct jtag *jtag)
> > +{
> > + int id;
> > + int err;
> > +
> > + id = ida_simple_get(&jtag_ida, 0, 0, GFP_KERNEL);
> > + if (id < 0)
> > + return id;
> > +
> > + jtag->id = id;
> > + cdev_init(&jtag->cdev, &jtag_fops);
> > + jtag->cdev.owner = THIS_MODULE;
> > + err = cdev_add(&jtag->cdev, MKDEV(MAJOR(jtag_devt), jtag->id), 1);
> > + if (err)
> > + goto err_cdev;
>
> misc device would be so much simpler and easier here :(
>
>
> > +
> > + /* Register this jtag device with the driver core */
> > + jtag->dev = device_create(&jtag_class, NULL,
> MKDEV(MAJOR(jtag_devt),
> > + jtag->id),
> > + NULL, "jtag%d", jtag->id);
> > + if (!jtag->dev)
> > + goto err_device_create;
> > +
> > + atomic_set(&jtag->open, 0);
> > + dev_set_drvdata(jtag->dev, jtag);
> > + return err;
> > +
> > +err_device_create:
> > + cdev_del(&jtag->cdev);
> > +err_cdev:
> > + ida_simple_remove(&jtag_ida, id);
> > + return err;
> > +}
> > +EXPORT_SYMBOL_GPL(jtag_register);
> > +
> > +void jtag_unregister(struct jtag *jtag) {
> > + struct device *dev = jtag->dev;
> > +
> > + cdev_del(&jtag->cdev);
> > + device_unregister(dev);
> > + ida_simple_remove(&jtag_ida, jtag->id); }
> > +EXPORT_SYMBOL_GPL(jtag_unregister);
> > +
> > +static int __init jtag_init(void)
> > +{
> > + int err;
> > +
> > + err = alloc_chrdev_region(&jtag_devt, JTAG_FIRST_MINOR,
> > + JTAG_MAX_DEVICES, "jtag");
> > + if (err)
> > + return err;
> > +
> > + err = class_register(&jtag_class);
> > + if (err)
> > + unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
> > +
> > + return err;
> > +}
> > +
> > +static void __exit jtag_exit(void)
> > +{
> > + class_unregister(&jtag_class);
> > + unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
>
> Your idr leaked memory :(
>
Yes I will add ida_destroy() here.
>
>
> > +}
> > +
> > +module_init(jtag_init);
> > +module_exit(jtag_exit);
> > +
> > +MODULE_AUTHOR("Oleksandr Shamray <oleksandrs@mellanox.com>");
> > +MODULE_DESCRIPTION("Generic jtag support"); MODULE_LICENSE("GPL
> v2");
> > diff --git a/include/linux/jtag.h b/include/linux/jtag.h new file mode
> > 100644 index 0000000..c016fed
> > --- /dev/null
> > +++ b/include/linux/jtag.h
> > @@ -0,0 +1,48 @@
> > +/*
> > + * drivers/jtag/jtag.c
> > + *
> > + * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
> > + * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
> > + *
> > + * Released under the GPLv2 only.
> > + * SPDX-License-Identifier: GPL-2.0
> > + */
> > +
> > +#ifndef __JTAG_H
> > +#define __JTAG_H
> > +
> > +#include <uapi/linux/jtag.h>
> > +
> > +#ifndef ARCH_DMA_MINALIGN
> > +#define ARCH_DMA_MINALIGN 1
> > +#endif
> > +
> > +#define jtag_u64_to_ptr(arg) ((void *)(uintptr_t)arg)
> > +
> > +#define JTAG_MAX_XFER_DATA_LEN 65535
> > +
> > +struct jtag;
> > +/**
> > + * struct jtag_ops - callbacks for jtag control functions:
> > + *
> > + * @freq_get: get frequency function. Filled by device driver
> > + * @freq_set: set frequency function. Filled by device driver
> > + * @status_get: set status function. Filled by device driver
> > + * @idle: set JTAG to idle state function. Filled by device driver
> > + * @xfer: send JTAG xfer function. Filled by device driver */ struct
> > +jtag_ops {
> > + int (*freq_get)(struct jtag *jtag, u32 *freq);
> > + int (*freq_set)(struct jtag *jtag, u32 freq);
> > + int (*status_get)(struct jtag *jtag, u32 *state);
> > + int (*idle)(struct jtag *jtag, struct jtag_run_test_idle *idle);
> > + int (*xfer)(struct jtag *jtag, struct jtag_xfer *xfer); };
> > +
> > +void *jtag_priv(struct jtag *jtag);
> > +int jtag_register(struct jtag *jtag); void jtag_unregister(struct
> > +jtag *jtag); struct jtag *jtag_alloc(size_t priv_size, const struct
> > +jtag_ops *ops); void jtag_free(struct jtag *jtag);
> > +
> > +#endif /* __JTAG_H */
> > diff --git a/include/uapi/linux/jtag.h b/include/uapi/linux/jtag.h new
> > file mode 100644 index 0000000..180bf22
> > --- /dev/null
> > +++ b/include/uapi/linux/jtag.h
> > @@ -0,0 +1,115 @@
> > +/*
> > + * JTAG class driver
> > + *
> > + * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
> > + * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
> > + *
> > + * Released under the GPLv2/BSD.
> > + * SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
> > +
> > +#ifndef __UAPI_LINUX_JTAG_H
> > +#define __UAPI_LINUX_JTAG_H
> > +
> > +/**
> > + * enum jtag_xfer_mode:
> > + *
> > + * @JTAG_XFER_HW_MODE: hardware mode transfer
> > + * @JTAG_XFER_SW_MODE: software mode transfer */ enum
> jtag_xfer_mode
> > +{
> > + JTAG_XFER_HW_MODE,
> > + JTAG_XFER_SW_MODE,
> > +};
> > +
> > +/**
> > + * enum jtag_endstate:
> > + *
> > + * @JTAG_STATE_IDLE: JTAG state machine IDLE state
> > + * @JTAG_STATE_PAUSEIR: JTAG state machine PAUSE_IR state
> > + * @JTAG_STATE_PAUSEDR: JTAG state machine PAUSE_DR state */ enum
> > +jtag_endstate {
> > + JTAG_STATE_IDLE,
> > + JTAG_STATE_PAUSEIR,
> > + JTAG_STATE_PAUSEDR,
> > +};
> > +
> > +/**
> > + * enum jtag_xfer_type:
> > + *
> > + * @JTAG_SIR_XFER: SIR transfer
> > + * @JTAG_SDR_XFER: SDR transfer
> > + */
> > +enum jtag_xfer_type {
> > + JTAG_SIR_XFER,
> > + JTAG_SDR_XFER,
> > +};
> > +
> > +/**
> > + * enum jtag_xfer_direction:
> > + *
> > + * @JTAG_READ_XFER: read transfer
> > + * @JTAG_WRITE_XFER: write transfer
> > + */
> > +enum jtag_xfer_direction {
> > + JTAG_READ_XFER,
> > + JTAG_WRITE_XFER,
> > +};
> > +
> > +/**
> > + * struct jtag_run_test_idle - forces JTAG state machine to
> > + * RUN_TEST/IDLE state
> > + *
> > + * @mode: access mode
> > + * @reset: 0 - run IDLE/PAUSE from current state
> > + * 1 - go through TEST_LOGIC/RESET state before IDLE/PAUSE
> > + * @end: completion flag
> > + * @tck: clock counter
> > + *
> > + * Structure represents interface to JTAG device for jtag idle
> > + * execution.
> > + */
> > +struct jtag_run_test_idle {
> > + __u8 mode;
> > + __u8 reset;
> > + __u8 endstate;
> > + __u8 tck;
> > +};
> > +
> > +/**
> > + * struct jtag_xfer - jtag xfer:
> > + *
> > + * @mode: access mode
> > + * @type: transfer type
> > + * @direction: xfer direction
> > + * @length: xfer bits len
> > + * @tdio : xfer data array
> > + * @endir: xfer end state
> > + *
> > + * Structure represents interface to Aspeed JTAG device for jtag sdr
> > +xfer
> > + * execution.
> > + */
> > +struct jtag_xfer {
> > + __u8 mode;
> > + __u8 type;
> > + __u8 direction;
> > + __u8 endstate;
> > + __u32 length;
> > + __u64 tdio;
>
> I don't see anything odd here that requires a compat ioctl callback, do you?
>
> thanks,
>
> greg k-h
Thanks for your review.
Oleksandr S.
^ permalink raw reply [flat|nested] 45+ messages in thread
* [patch v9 1/4] drivers: jtag: Add JTAG core driver
@ 2017-10-20 14:34 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-10-20 14:34 UTC (permalink / raw)
To: linux-arm-kernel
Hi Greg.
> -----Original Message-----
> From: Greg KH [mailto:gregkh at linuxfoundation.org]
> Sent: Friday, October 20, 2017 2:55 PM
> To: Oleksandr Shamray <oleksandrs@mellanox.com>
> Cc: arnd at arndb.de; linux-kernel at vger.kernel.org; linux-arm-
> kernel at lists.infradead.org; devicetree at vger.kernel.org;
> openbmc at lists.ozlabs.org; joel at jms.id.au; jiri at resnulli.us;
> tklauser at distanz.ch; linux-serial at vger.kernel.org; mec at shout.net; Vadim
> Pasternak <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> level at mellanox.com>; robh+dt at kernel.org; openocd-devel-
> owner at lists.sourceforge.net; linux-api at vger.kernel.org;
> davem at davemloft.net; mchehab at kernel.org; Jiri Pirko <jiri@mellanox.com>
> Subject: Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
>
> On Thu, Sep 21, 2017 at 12:25:29PM +0300, Oleksandr Shamray wrote:
> > +struct jtag {
> > + struct device *dev;
> > + struct cdev cdev;
>
> Why are you using a cdev here and not just a normal misc device?
What the benefits to use misc instead of cdev?
> I forgot if this is what you were doing before, sorry...
>
> > + int id;
> > + atomic_t open;
>
> Why do you need this?
This counter used to avoid open at the same time by 2 or more users.
>
> > + const struct jtag_ops *ops;
> > + unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
>
> Huh? Why is this needed to be dma aligned? Why not just use the private
> pointer in struct device?
>
It is critical?
> > +};
> > +
> > +static dev_t jtag_devt;
> > +static DEFINE_IDA(jtag_ida);
> > +
> > +void *jtag_priv(struct jtag *jtag)
> > +{
> > + return jtag->priv;
> > +}
> > +EXPORT_SYMBOL_GPL(jtag_priv);
> > +
> > +static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size) {
> > + unsigned long size;
> > + void *kdata;
> > +
> > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > + kdata = memdup_user(u64_to_user_ptr(udata), size);
>
> You only use this once, why not just open-code it?
I think it makes code more understandable.
>
> > +
> > + return kdata;
> > +}
> > +
> > +static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
> > + unsigned long bit_size)
> > +{
> > + unsigned long size;
> > +
> > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > +
> > + return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata), size);
>
> Same here, making this a separate function seems odd.
Same, I think it makes code more understandable.
>
> > +}
> > +
> > +static struct class jtag_class = {
> > + .name = "jtag",
> > + .owner = THIS_MODULE,
> > +};
> > +
> > +static int jtag_run_test_idle_op(struct jtag *jtag,
> > + struct jtag_run_test_idle *idle) {
> > + if (jtag->ops->idle)
> > + return jtag->ops->idle(jtag, idle);
> > + else
> > + return -EOPNOTSUPP;
>
> Why is this a function? Why not just do this work in the ioctl?
Agree. I will move it just to ioctl function body.
>
> > +}
> > +
> > +static int jtag_xfer_op(struct jtag *jtag, struct jtag_xfer *xfer, u8
> > +*data) {
> > + if (jtag->ops->xfer)
> > + return jtag->ops->xfer(jtag, xfer, data);
> > + else
> > + return -EOPNOTSUPP;
>
> Same here, doesn't need to be a function.
Agree.
>
> > +}
> > +
> > +static long jtag_ioctl(struct file *file, unsigned int cmd, unsigned
> > +long arg) {
> > + struct jtag *jtag = file->private_data;
> > + struct jtag_run_test_idle idle;
> > + struct jtag_xfer xfer;
> > + u8 *xfer_data;
> > + u32 value;
> > + int err;
> > +
> > + switch (cmd) {
> > + case JTAG_GIOCFREQ:
> > + if (jtag->ops->freq_get)
> > + err = jtag->ops->freq_get(jtag, &value);
> > + else
> > + err = -EOPNOTSUPP;
> > + if (err)
> > + break;
> > +
> > + err = put_user(value, (__u32 *)arg);
> > + break;
>
> Are you sure the return value of put_user is correct here? Shouldn't you return
> -EFAULT if err is not 0?
Yes, thanks for point of this.
>
> > +
> > + case JTAG_SIOCFREQ:
> > + err = get_user(value, (__u32 *)arg);
> > +
>
> why a blank line?
Will remove
>
> > + if (value == 0)
> > + err = -EINVAL;
>
> Check err first.
Ok.
>
> > + if (err)
> > + break;
>
> And set it properly, again err should be -EFAULT, right?
Right ?0
>
> > +
> > + if (jtag->ops->freq_set)
> > + err = jtag->ops->freq_set(jtag, value);
> > + else
> > + err = -EOPNOTSUPP;
> > + break;
> > +
> > + case JTAG_IOCRUNTEST:
> > + if (copy_from_user(&idle, (void *)arg,
> > + sizeof(struct jtag_run_test_idle)))
> > + return -ENOMEM;
> > + err = jtag_run_test_idle_op(jtag, &idle);
>
> Who validates the structure fields? Is that up to the individual jtag driver? Why
> not do it in the core correctly so that it only has to be done in one place and you
> do not have to audit every individual driver?
Input parameters validated by jtag platform driver. I think it not critical.
>
> > + break;
> > +
> > + case JTAG_IOCXFER:
> > + if (copy_from_user(&xfer, (void *)arg,
> > + sizeof(struct jtag_xfer)))
> > + return -EFAULT;
> > +
> > + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
> > + return -EFAULT;
> > +
> > + xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
> > + if (!xfer_data)
> > + return -ENOMEM;
>
> Are you sure that's the correct error value?
I think yes, but what you suggest?
>
> > +
> > + err = jtag_xfer_op(jtag, &xfer, xfer_data);
> > + if (jtag_copy_to_user(xfer.tdio, xfer_data, xfer.length)) {
> > + kfree(xfer_data);
> > + return -EFAULT;
> > + }
> > +
> > + kfree(xfer_data);
> > + if (copy_to_user((void *)arg, &xfer, sizeof(struct jtag_xfer)))
> > + return -EFAULT;
> > + break;
> > +
> > + case JTAG_GIOCSTATUS:
> > + if (jtag->ops->status_get)
> > + err = jtag->ops->status_get(jtag, &value);
> > + else
> > + err = -EOPNOTSUPP;
> > + if (err)
> > + break;
> > +
> > + err = put_user(value, (__u32 *)arg);
>
> Same put_user err issue here.
Yes.
>
> > + break;
> > +
> > + default:
> > + return -EINVAL;
> > + }
> > + return err;
> > +}
> > +
> > +#ifdef CONFIG_COMPAT
> > +static long jtag_ioctl_compat(struct file *file, unsigned int cmd,
> > + unsigned long arg)
> > +{
> > + return jtag_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); }
> > +#endif
>
> Why do you need a compat callback for a new ioctl? Create your structures
> properly and this should not be needed, right?
I does this because Arnd (arndbergmann at gmail.com) writed in review (On Wed, Aug 2, 2017 at 3:18 PM)
[..]
> + .unlocked_ioctl = jtag_ioctl,
> + .open = jtag_open,
> + .release = jtag_release,
> +};
add a compat_ioctl pointer here, after ensuring that all ioctl commands are compatible between 32-bit and 64-bit user space.
[..]
>
> > +
> > +static int jtag_open(struct inode *inode, struct file *file) {
> > + struct jtag *jtag = container_of(inode->i_cdev, struct jtag, cdev);
> > +
> > + if (atomic_read(&jtag->open)) {
> > + dev_info(NULL, "jtag already opened\n");
> > + return -EBUSY;
>
> Why do you care if multiple opens can happen?
Jtag HW not support to using with multiple requests from different users. So we prohibit this.
>
> > + }
> > +
> > + atomic_inc(&jtag->open);
>
> Oh look, you just raced with two different people opening at the same time :(
>
> An atomic value is never a replacement for a lock, sorry.
>
> > + file->private_data = jtag;
> > + return 0;
> > +}
> > +
> > +static int jtag_release(struct inode *inode, struct file *file) {
> > + struct jtag *jtag = file->private_data;
> > +
> > + atomic_dec(&jtag->open);
>
> Again, not needed.
>
> > + return 0;
> > +}
> > +
> > +static const struct file_operations jtag_fops = {
> > + .owner = THIS_MODULE,
> > + .open = jtag_open,
> > + .release = jtag_release,
> > + .llseek = noop_llseek,
> > + .unlocked_ioctl = jtag_ioctl,
> > +#ifdef CONFIG_COMPAT
> > + .compat_ioctl = jtag_ioctl_compat,
> > +#endif
> > +};
> > +
> > +struct jtag *jtag_alloc(size_t priv_size, const struct jtag_ops *ops)
> > +{
> > + struct jtag *jtag;
> > +
> > + jtag = kzalloc(sizeof(*jtag) + round_up(priv_size,
> ARCH_DMA_MINALIGN),
> > + GFP_KERNEL);
> > + if (!jtag)
> > + return NULL;
> > +
> > + jtag->ops = ops;
> > + return jtag;
> > +}
> > +EXPORT_SYMBOL_GPL(jtag_alloc);
>
> register should allocate and register the device, why pass a structure back that
> the caller then has to do something else with to use it?
>
Before registration we need to initialize JTAG device HW registers and fill private data with HW specific parameters.
And is I see in other Linux drivers it is a common way to separate allocation device and register it
> > +
> > +void jtag_free(struct jtag *jtag)
> > +{
> > + kfree(jtag);
> > +}
> > +EXPORT_SYMBOL_GPL(jtag_free);
> > +
> > +int jtag_register(struct jtag *jtag)
> > +{
> > + int id;
> > + int err;
> > +
> > + id = ida_simple_get(&jtag_ida, 0, 0, GFP_KERNEL);
> > + if (id < 0)
> > + return id;
> > +
> > + jtag->id = id;
> > + cdev_init(&jtag->cdev, &jtag_fops);
> > + jtag->cdev.owner = THIS_MODULE;
> > + err = cdev_add(&jtag->cdev, MKDEV(MAJOR(jtag_devt), jtag->id), 1);
> > + if (err)
> > + goto err_cdev;
>
> misc device would be so much simpler and easier here :(
>
>
> > +
> > + /* Register this jtag device with the driver core */
> > + jtag->dev = device_create(&jtag_class, NULL,
> MKDEV(MAJOR(jtag_devt),
> > + jtag->id),
> > + NULL, "jtag%d", jtag->id);
> > + if (!jtag->dev)
> > + goto err_device_create;
> > +
> > + atomic_set(&jtag->open, 0);
> > + dev_set_drvdata(jtag->dev, jtag);
> > + return err;
> > +
> > +err_device_create:
> > + cdev_del(&jtag->cdev);
> > +err_cdev:
> > + ida_simple_remove(&jtag_ida, id);
> > + return err;
> > +}
> > +EXPORT_SYMBOL_GPL(jtag_register);
> > +
> > +void jtag_unregister(struct jtag *jtag) {
> > + struct device *dev = jtag->dev;
> > +
> > + cdev_del(&jtag->cdev);
> > + device_unregister(dev);
> > + ida_simple_remove(&jtag_ida, jtag->id); }
> > +EXPORT_SYMBOL_GPL(jtag_unregister);
> > +
> > +static int __init jtag_init(void)
> > +{
> > + int err;
> > +
> > + err = alloc_chrdev_region(&jtag_devt, JTAG_FIRST_MINOR,
> > + JTAG_MAX_DEVICES, "jtag");
> > + if (err)
> > + return err;
> > +
> > + err = class_register(&jtag_class);
> > + if (err)
> > + unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
> > +
> > + return err;
> > +}
> > +
> > +static void __exit jtag_exit(void)
> > +{
> > + class_unregister(&jtag_class);
> > + unregister_chrdev_region(jtag_devt, JTAG_MAX_DEVICES);
>
> Your idr leaked memory :(
>
Yes I will add ida_destroy() here.
>
>
> > +}
> > +
> > +module_init(jtag_init);
> > +module_exit(jtag_exit);
> > +
> > +MODULE_AUTHOR("Oleksandr Shamray <oleksandrs@mellanox.com>");
> > +MODULE_DESCRIPTION("Generic jtag support"); MODULE_LICENSE("GPL
> v2");
> > diff --git a/include/linux/jtag.h b/include/linux/jtag.h new file mode
> > 100644 index 0000000..c016fed
> > --- /dev/null
> > +++ b/include/linux/jtag.h
> > @@ -0,0 +1,48 @@
> > +/*
> > + * drivers/jtag/jtag.c
> > + *
> > + * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
> > + * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
> > + *
> > + * Released under the GPLv2 only.
> > + * SPDX-License-Identifier: GPL-2.0
> > + */
> > +
> > +#ifndef __JTAG_H
> > +#define __JTAG_H
> > +
> > +#include <uapi/linux/jtag.h>
> > +
> > +#ifndef ARCH_DMA_MINALIGN
> > +#define ARCH_DMA_MINALIGN 1
> > +#endif
> > +
> > +#define jtag_u64_to_ptr(arg) ((void *)(uintptr_t)arg)
> > +
> > +#define JTAG_MAX_XFER_DATA_LEN 65535
> > +
> > +struct jtag;
> > +/**
> > + * struct jtag_ops - callbacks for jtag control functions:
> > + *
> > + * @freq_get: get frequency function. Filled by device driver
> > + * @freq_set: set frequency function. Filled by device driver
> > + * @status_get: set status function. Filled by device driver
> > + * @idle: set JTAG to idle state function. Filled by device driver
> > + * @xfer: send JTAG xfer function. Filled by device driver */ struct
> > +jtag_ops {
> > + int (*freq_get)(struct jtag *jtag, u32 *freq);
> > + int (*freq_set)(struct jtag *jtag, u32 freq);
> > + int (*status_get)(struct jtag *jtag, u32 *state);
> > + int (*idle)(struct jtag *jtag, struct jtag_run_test_idle *idle);
> > + int (*xfer)(struct jtag *jtag, struct jtag_xfer *xfer); };
> > +
> > +void *jtag_priv(struct jtag *jtag);
> > +int jtag_register(struct jtag *jtag); void jtag_unregister(struct
> > +jtag *jtag); struct jtag *jtag_alloc(size_t priv_size, const struct
> > +jtag_ops *ops); void jtag_free(struct jtag *jtag);
> > +
> > +#endif /* __JTAG_H */
> > diff --git a/include/uapi/linux/jtag.h b/include/uapi/linux/jtag.h new
> > file mode 100644 index 0000000..180bf22
> > --- /dev/null
> > +++ b/include/uapi/linux/jtag.h
> > @@ -0,0 +1,115 @@
> > +/*
> > + * JTAG class driver
> > + *
> > + * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
> > + * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@mellanox.com>
> > + *
> > + * Released under the GPLv2/BSD.
> > + * SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
> > +
> > +#ifndef __UAPI_LINUX_JTAG_H
> > +#define __UAPI_LINUX_JTAG_H
> > +
> > +/**
> > + * enum jtag_xfer_mode:
> > + *
> > + * @JTAG_XFER_HW_MODE: hardware mode transfer
> > + * @JTAG_XFER_SW_MODE: software mode transfer */ enum
> jtag_xfer_mode
> > +{
> > + JTAG_XFER_HW_MODE,
> > + JTAG_XFER_SW_MODE,
> > +};
> > +
> > +/**
> > + * enum jtag_endstate:
> > + *
> > + * @JTAG_STATE_IDLE: JTAG state machine IDLE state
> > + * @JTAG_STATE_PAUSEIR: JTAG state machine PAUSE_IR state
> > + * @JTAG_STATE_PAUSEDR: JTAG state machine PAUSE_DR state */ enum
> > +jtag_endstate {
> > + JTAG_STATE_IDLE,
> > + JTAG_STATE_PAUSEIR,
> > + JTAG_STATE_PAUSEDR,
> > +};
> > +
> > +/**
> > + * enum jtag_xfer_type:
> > + *
> > + * @JTAG_SIR_XFER: SIR transfer
> > + * @JTAG_SDR_XFER: SDR transfer
> > + */
> > +enum jtag_xfer_type {
> > + JTAG_SIR_XFER,
> > + JTAG_SDR_XFER,
> > +};
> > +
> > +/**
> > + * enum jtag_xfer_direction:
> > + *
> > + * @JTAG_READ_XFER: read transfer
> > + * @JTAG_WRITE_XFER: write transfer
> > + */
> > +enum jtag_xfer_direction {
> > + JTAG_READ_XFER,
> > + JTAG_WRITE_XFER,
> > +};
> > +
> > +/**
> > + * struct jtag_run_test_idle - forces JTAG state machine to
> > + * RUN_TEST/IDLE state
> > + *
> > + * @mode: access mode
> > + * @reset: 0 - run IDLE/PAUSE from current state
> > + * 1 - go through TEST_LOGIC/RESET state before IDLE/PAUSE
> > + * @end: completion flag
> > + * @tck: clock counter
> > + *
> > + * Structure represents interface to JTAG device for jtag idle
> > + * execution.
> > + */
> > +struct jtag_run_test_idle {
> > + __u8 mode;
> > + __u8 reset;
> > + __u8 endstate;
> > + __u8 tck;
> > +};
> > +
> > +/**
> > + * struct jtag_xfer - jtag xfer:
> > + *
> > + * @mode: access mode
> > + * @type: transfer type
> > + * @direction: xfer direction
> > + * @length: xfer bits len
> > + * @tdio : xfer data array
> > + * @endir: xfer end state
> > + *
> > + * Structure represents interface to Aspeed JTAG device for jtag sdr
> > +xfer
> > + * execution.
> > + */
> > +struct jtag_xfer {
> > + __u8 mode;
> > + __u8 type;
> > + __u8 direction;
> > + __u8 endstate;
> > + __u32 length;
> > + __u64 tdio;
>
> I don't see anything odd here that requires a compat ioctl callback, do you?
>
> thanks,
>
> greg k-h
Thanks for your review.
Oleksandr S.
^ permalink raw reply [flat|nested] 45+ messages in thread
* Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
2017-10-20 14:34 ` Oleksandr Shamray
(?)
(?)
@ 2017-10-20 14:54 ` Greg KH
-1 siblings, 0 replies; 45+ messages in thread
From: Greg KH @ 2017-10-20 14:54 UTC (permalink / raw)
To: Oleksandr Shamray
Cc: arnd, linux-kernel, linux-arm-kernel, devicetree, openbmc, joel,
jiri, tklauser, linux-serial, mec, Vadim Pasternak,
system-sw-low-level, robh+dt, openocd-devel-owner, linux-api,
davem, mchehab, Jiri Pirko
On Fri, Oct 20, 2017 at 02:34:00PM +0000, Oleksandr Shamray wrote:
> Hi Greg.
>
> > -----Original Message-----
> > From: Greg KH [mailto:gregkh@linuxfoundation.org]
> > Sent: Friday, October 20, 2017 2:55 PM
> > To: Oleksandr Shamray <oleksandrs@mellanox.com>
> > Cc: arnd@arndb.de; linux-kernel@vger.kernel.org; linux-arm-
> > kernel@lists.infradead.org; devicetree@vger.kernel.org;
> > openbmc@lists.ozlabs.org; joel@jms.id.au; jiri@resnulli.us;
> > tklauser@distanz.ch; linux-serial@vger.kernel.org; mec@shout.net; Vadim
> > Pasternak <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> > level@mellanox.com>; robh+dt@kernel.org; openocd-devel-
> > owner@lists.sourceforge.net; linux-api@vger.kernel.org;
> > davem@davemloft.net; mchehab@kernel.org; Jiri Pirko <jiri@mellanox.com>
> > Subject: Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
> >
> > On Thu, Sep 21, 2017 at 12:25:29PM +0300, Oleksandr Shamray wrote:
> > > +struct jtag {
> > > + struct device *dev;
> > > + struct cdev cdev;
> >
> > Why are you using a cdev here and not just a normal misc device?
>
> What the benefits to use misc instead of cdev?
Less code, simpler logic, easier to review and understand, etc.
Let me ask you, why use a cdev instead of a misc?
> > I forgot if this is what you were doing before, sorry...
> >
> > > + int id;
> > > + atomic_t open;
> >
> > Why do you need this?
>
> This counter used to avoid open at the same time by 2 or more users.
But it isn't working :)
And why do you care?
> > > + const struct jtag_ops *ops;
> > > + unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
> >
> > Huh? Why is this needed to be dma aligned? Why not just use the private
> > pointer in struct device?
> >
>
> It is critical?
You are saying it is, so you have to justify it. There is a pointer for
you to use, don't make new ones for no reason, right?
> > > +};
> > > +
> > > +static dev_t jtag_devt;
> > > +static DEFINE_IDA(jtag_ida);
> > > +
> > > +void *jtag_priv(struct jtag *jtag)
> > > +{
> > > + return jtag->priv;
> > > +}
> > > +EXPORT_SYMBOL_GPL(jtag_priv);
> > > +
> > > +static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size) {
> > > + unsigned long size;
> > > + void *kdata;
> > > +
> > > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > > + kdata = memdup_user(u64_to_user_ptr(udata), size);
> >
> > You only use this once, why not just open-code it?
>
> I think it makes code more understandable.
As a reviewer, I don't :)
> > > +
> > > + return kdata;
> > > +}
> > > +
> > > +static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
> > > + unsigned long bit_size)
> > > +{
> > > + unsigned long size;
> > > +
> > > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > > +
> > > + return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata), size);
> >
> > Same here, making this a separate function seems odd.
>
> Same, I think it makes code more understandable.
But it doesn't.
> > > +
> > > + if (jtag->ops->freq_set)
> > > + err = jtag->ops->freq_set(jtag, value);
> > > + else
> > > + err = -EOPNOTSUPP;
> > > + break;
> > > +
> > > + case JTAG_IOCRUNTEST:
> > > + if (copy_from_user(&idle, (void *)arg,
> > > + sizeof(struct jtag_run_test_idle)))
> > > + return -ENOMEM;
> > > + err = jtag_run_test_idle_op(jtag, &idle);
> >
> > Who validates the structure fields? Is that up to the individual jtag driver? Why
> > not do it in the core correctly so that it only has to be done in one place and you
> > do not have to audit every individual driver?
>
> Input parameters validated by jtag platform driver. I think it not critical.
Not true at all. It is very critical. Remmeber, "All Input Is Evil!"
You have to validate this. I as a reviewer have to find where you are
validating this data to ensure bad things do not happen. I can't review
that here, now I have to go and review all of the individual drivers,
which is a major pain, don't you agree?
> > > + break;
> > > +
> > > + case JTAG_IOCXFER:
> > > + if (copy_from_user(&xfer, (void *)arg,
> > > + sizeof(struct jtag_xfer)))
> > > + return -EFAULT;
> > > +
> > > + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
> > > + return -EFAULT;
> > > +
> > > + xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
> > > + if (!xfer_data)
> > > + return -ENOMEM;
> >
> > Are you sure that's the correct error value?
>
> I think yes, but what you suggest?
A fault happened, so -EFAULT, right?
> [..]
> > + .unlocked_ioctl = jtag_ioctl,
> > + .open = jtag_open,
> > + .release = jtag_release,
> > +};
>
> add a compat_ioctl pointer here, after ensuring that all ioctl
> commands are compatible between 32-bit and 64-bit user space.
> [..]
And if you do not, what happens? You shouldn't need it as there is no
fixups necessary, or am I mistaken about that?
> > > +static int jtag_open(struct inode *inode, struct file *file) {
> > > + struct jtag *jtag = container_of(inode->i_cdev, struct jtag, cdev);
> > > +
> > > + if (atomic_read(&jtag->open)) {
> > > + dev_info(NULL, "jtag already opened\n");
> > > + return -EBUSY;
> >
> > Why do you care if multiple opens can happen?
>
> Jtag HW not support to using with multiple requests from different users. So we prohibit this.
Why does the kernel care?
And again, your implementation is broken, it's not actually doing this
protection. I recommend just not doing it at all, but if you really are
insisting on it, you have to get it correct :)
thanks,
greg k-h
^ permalink raw reply [flat|nested] 45+ messages in thread
* Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
@ 2017-10-20 14:54 ` Greg KH
0 siblings, 0 replies; 45+ messages in thread
From: Greg KH @ 2017-10-20 14:54 UTC (permalink / raw)
To: Oleksandr Shamray
Cc: arnd, linux-kernel, linux-arm-kernel, devicetree, openbmc, joel,
jiri, tklauser, linux-serial, mec, Vadim Pasternak,
system-sw-low-level, robh+dt, openocd-devel-owner
On Fri, Oct 20, 2017 at 02:34:00PM +0000, Oleksandr Shamray wrote:
> Hi Greg.
>
> > -----Original Message-----
> > From: Greg KH [mailto:gregkh@linuxfoundation.org]
> > Sent: Friday, October 20, 2017 2:55 PM
> > To: Oleksandr Shamray <oleksandrs@mellanox.com>
> > Cc: arnd@arndb.de; linux-kernel@vger.kernel.org; linux-arm-
> > kernel@lists.infradead.org; devicetree@vger.kernel.org;
> > openbmc@lists.ozlabs.org; joel@jms.id.au; jiri@resnulli.us;
> > tklauser@distanz.ch; linux-serial@vger.kernel.org; mec@shout.net; Vadim
> > Pasternak <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> > level@mellanox.com>; robh+dt@kernel.org; openocd-devel-
> > owner@lists.sourceforge.net; linux-api@vger.kernel.org;
> > davem@davemloft.net; mchehab@kernel.org; Jiri Pirko <jiri@mellanox.com>
> > Subject: Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
> >
> > On Thu, Sep 21, 2017 at 12:25:29PM +0300, Oleksandr Shamray wrote:
> > > +struct jtag {
> > > + struct device *dev;
> > > + struct cdev cdev;
> >
> > Why are you using a cdev here and not just a normal misc device?
>
> What the benefits to use misc instead of cdev?
Less code, simpler logic, easier to review and understand, etc.
Let me ask you, why use a cdev instead of a misc?
> > I forgot if this is what you were doing before, sorry...
> >
> > > + int id;
> > > + atomic_t open;
> >
> > Why do you need this?
>
> This counter used to avoid open at the same time by 2 or more users.
But it isn't working :)
And why do you care?
> > > + const struct jtag_ops *ops;
> > > + unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
> >
> > Huh? Why is this needed to be dma aligned? Why not just use the private
> > pointer in struct device?
> >
>
> It is critical?
You are saying it is, so you have to justify it. There is a pointer for
you to use, don't make new ones for no reason, right?
> > > +};
> > > +
> > > +static dev_t jtag_devt;
> > > +static DEFINE_IDA(jtag_ida);
> > > +
> > > +void *jtag_priv(struct jtag *jtag)
> > > +{
> > > + return jtag->priv;
> > > +}
> > > +EXPORT_SYMBOL_GPL(jtag_priv);
> > > +
> > > +static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size) {
> > > + unsigned long size;
> > > + void *kdata;
> > > +
> > > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > > + kdata = memdup_user(u64_to_user_ptr(udata), size);
> >
> > You only use this once, why not just open-code it?
>
> I think it makes code more understandable.
As a reviewer, I don't :)
> > > +
> > > + return kdata;
> > > +}
> > > +
> > > +static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
> > > + unsigned long bit_size)
> > > +{
> > > + unsigned long size;
> > > +
> > > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > > +
> > > + return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata), size);
> >
> > Same here, making this a separate function seems odd.
>
> Same, I think it makes code more understandable.
But it doesn't.
> > > +
> > > + if (jtag->ops->freq_set)
> > > + err = jtag->ops->freq_set(jtag, value);
> > > + else
> > > + err = -EOPNOTSUPP;
> > > + break;
> > > +
> > > + case JTAG_IOCRUNTEST:
> > > + if (copy_from_user(&idle, (void *)arg,
> > > + sizeof(struct jtag_run_test_idle)))
> > > + return -ENOMEM;
> > > + err = jtag_run_test_idle_op(jtag, &idle);
> >
> > Who validates the structure fields? Is that up to the individual jtag driver? Why
> > not do it in the core correctly so that it only has to be done in one place and you
> > do not have to audit every individual driver?
>
> Input parameters validated by jtag platform driver. I think it not critical.
Not true at all. It is very critical. Remmeber, "All Input Is Evil!"
You have to validate this. I as a reviewer have to find where you are
validating this data to ensure bad things do not happen. I can't review
that here, now I have to go and review all of the individual drivers,
which is a major pain, don't you agree?
> > > + break;
> > > +
> > > + case JTAG_IOCXFER:
> > > + if (copy_from_user(&xfer, (void *)arg,
> > > + sizeof(struct jtag_xfer)))
> > > + return -EFAULT;
> > > +
> > > + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
> > > + return -EFAULT;
> > > +
> > > + xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
> > > + if (!xfer_data)
> > > + return -ENOMEM;
> >
> > Are you sure that's the correct error value?
>
> I think yes, but what you suggest?
A fault happened, so -EFAULT, right?
> [..]
> > + .unlocked_ioctl = jtag_ioctl,
> > + .open = jtag_open,
> > + .release = jtag_release,
> > +};
>
> add a compat_ioctl pointer here, after ensuring that all ioctl
> commands are compatible between 32-bit and 64-bit user space.
> [..]
And if you do not, what happens? You shouldn't need it as there is no
fixups necessary, or am I mistaken about that?
> > > +static int jtag_open(struct inode *inode, struct file *file) {
> > > + struct jtag *jtag = container_of(inode->i_cdev, struct jtag, cdev);
> > > +
> > > + if (atomic_read(&jtag->open)) {
> > > + dev_info(NULL, "jtag already opened\n");
> > > + return -EBUSY;
> >
> > Why do you care if multiple opens can happen?
>
> Jtag HW not support to using with multiple requests from different users. So we prohibit this.
Why does the kernel care?
And again, your implementation is broken, it's not actually doing this
protection. I recommend just not doing it at all, but if you really are
insisting on it, you have to get it correct :)
thanks,
greg k-h
^ permalink raw reply [flat|nested] 45+ messages in thread
* Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
@ 2017-10-20 14:54 ` Greg KH
0 siblings, 0 replies; 45+ messages in thread
From: Greg KH @ 2017-10-20 14:54 UTC (permalink / raw)
To: Oleksandr Shamray
Cc: arnd, linux-kernel, linux-arm-kernel, devicetree, openbmc, joel,
jiri, tklauser, linux-serial, mec, Vadim Pasternak,
system-sw-low-level, robh+dt, openocd-devel-owner, linux-api,
davem, mchehab, Jiri Pirko
On Fri, Oct 20, 2017 at 02:34:00PM +0000, Oleksandr Shamray wrote:
> Hi Greg.
>
> > -----Original Message-----
> > From: Greg KH [mailto:gregkh@linuxfoundation.org]
> > Sent: Friday, October 20, 2017 2:55 PM
> > To: Oleksandr Shamray <oleksandrs@mellanox.com>
> > Cc: arnd@arndb.de; linux-kernel@vger.kernel.org; linux-arm-
> > kernel@lists.infradead.org; devicetree@vger.kernel.org;
> > openbmc@lists.ozlabs.org; joel@jms.id.au; jiri@resnulli.us;
> > tklauser@distanz.ch; linux-serial@vger.kernel.org; mec@shout.net; Vadim
> > Pasternak <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> > level@mellanox.com>; robh+dt@kernel.org; openocd-devel-
> > owner@lists.sourceforge.net; linux-api@vger.kernel.org;
> > davem@davemloft.net; mchehab@kernel.org; Jiri Pirko <jiri@mellanox.com>
> > Subject: Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
> >
> > On Thu, Sep 21, 2017 at 12:25:29PM +0300, Oleksandr Shamray wrote:
> > > +struct jtag {
> > > + struct device *dev;
> > > + struct cdev cdev;
> >
> > Why are you using a cdev here and not just a normal misc device?
>
> What the benefits to use misc instead of cdev?
Less code, simpler logic, easier to review and understand, etc.
Let me ask you, why use a cdev instead of a misc?
> > I forgot if this is what you were doing before, sorry...
> >
> > > + int id;
> > > + atomic_t open;
> >
> > Why do you need this?
>
> This counter used to avoid open at the same time by 2 or more users.
But it isn't working :)
And why do you care?
> > > + const struct jtag_ops *ops;
> > > + unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
> >
> > Huh? Why is this needed to be dma aligned? Why not just use the private
> > pointer in struct device?
> >
>
> It is critical?
You are saying it is, so you have to justify it. There is a pointer for
you to use, don't make new ones for no reason, right?
> > > +};
> > > +
> > > +static dev_t jtag_devt;
> > > +static DEFINE_IDA(jtag_ida);
> > > +
> > > +void *jtag_priv(struct jtag *jtag)
> > > +{
> > > + return jtag->priv;
> > > +}
> > > +EXPORT_SYMBOL_GPL(jtag_priv);
> > > +
> > > +static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size) {
> > > + unsigned long size;
> > > + void *kdata;
> > > +
> > > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > > + kdata = memdup_user(u64_to_user_ptr(udata), size);
> >
> > You only use this once, why not just open-code it?
>
> I think it makes code more understandable.
As a reviewer, I don't :)
> > > +
> > > + return kdata;
> > > +}
> > > +
> > > +static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
> > > + unsigned long bit_size)
> > > +{
> > > + unsigned long size;
> > > +
> > > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > > +
> > > + return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata), size);
> >
> > Same here, making this a separate function seems odd.
>
> Same, I think it makes code more understandable.
But it doesn't.
> > > +
> > > + if (jtag->ops->freq_set)
> > > + err = jtag->ops->freq_set(jtag, value);
> > > + else
> > > + err = -EOPNOTSUPP;
> > > + break;
> > > +
> > > + case JTAG_IOCRUNTEST:
> > > + if (copy_from_user(&idle, (void *)arg,
> > > + sizeof(struct jtag_run_test_idle)))
> > > + return -ENOMEM;
> > > + err = jtag_run_test_idle_op(jtag, &idle);
> >
> > Who validates the structure fields? Is that up to the individual jtag driver? Why
> > not do it in the core correctly so that it only has to be done in one place and you
> > do not have to audit every individual driver?
>
> Input parameters validated by jtag platform driver. I think it not critical.
Not true at all. It is very critical. Remmeber, "All Input Is Evil!"
You have to validate this. I as a reviewer have to find where you are
validating this data to ensure bad things do not happen. I can't review
that here, now I have to go and review all of the individual drivers,
which is a major pain, don't you agree?
> > > + break;
> > > +
> > > + case JTAG_IOCXFER:
> > > + if (copy_from_user(&xfer, (void *)arg,
> > > + sizeof(struct jtag_xfer)))
> > > + return -EFAULT;
> > > +
> > > + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
> > > + return -EFAULT;
> > > +
> > > + xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
> > > + if (!xfer_data)
> > > + return -ENOMEM;
> >
> > Are you sure that's the correct error value?
>
> I think yes, but what you suggest?
A fault happened, so -EFAULT, right?
> [..]
> > + .unlocked_ioctl = jtag_ioctl,
> > + .open = jtag_open,
> > + .release = jtag_release,
> > +};
>
> add a compat_ioctl pointer here, after ensuring that all ioctl
> commands are compatible between 32-bit and 64-bit user space.
> [..]
And if you do not, what happens? You shouldn't need it as there is no
fixups necessary, or am I mistaken about that?
> > > +static int jtag_open(struct inode *inode, struct file *file) {
> > > + struct jtag *jtag = container_of(inode->i_cdev, struct jtag, cdev);
> > > +
> > > + if (atomic_read(&jtag->open)) {
> > > + dev_info(NULL, "jtag already opened\n");
> > > + return -EBUSY;
> >
> > Why do you care if multiple opens can happen?
>
> Jtag HW not support to using with multiple requests from different users. So we prohibit this.
Why does the kernel care?
And again, your implementation is broken, it's not actually doing this
protection. I recommend just not doing it at all, but if you really are
insisting on it, you have to get it correct :)
thanks,
greg k-h
^ permalink raw reply [flat|nested] 45+ messages in thread
* [patch v9 1/4] drivers: jtag: Add JTAG core driver
@ 2017-10-20 14:54 ` Greg KH
0 siblings, 0 replies; 45+ messages in thread
From: Greg KH @ 2017-10-20 14:54 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Oct 20, 2017 at 02:34:00PM +0000, Oleksandr Shamray wrote:
> Hi Greg.
>
> > -----Original Message-----
> > From: Greg KH [mailto:gregkh at linuxfoundation.org]
> > Sent: Friday, October 20, 2017 2:55 PM
> > To: Oleksandr Shamray <oleksandrs@mellanox.com>
> > Cc: arnd at arndb.de; linux-kernel at vger.kernel.org; linux-arm-
> > kernel at lists.infradead.org; devicetree at vger.kernel.org;
> > openbmc at lists.ozlabs.org; joel at jms.id.au; jiri at resnulli.us;
> > tklauser at distanz.ch; linux-serial at vger.kernel.org; mec at shout.net; Vadim
> > Pasternak <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> > level at mellanox.com>; robh+dt at kernel.org; openocd-devel-
> > owner at lists.sourceforge.net; linux-api at vger.kernel.org;
> > davem at davemloft.net; mchehab at kernel.org; Jiri Pirko <jiri@mellanox.com>
> > Subject: Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
> >
> > On Thu, Sep 21, 2017 at 12:25:29PM +0300, Oleksandr Shamray wrote:
> > > +struct jtag {
> > > + struct device *dev;
> > > + struct cdev cdev;
> >
> > Why are you using a cdev here and not just a normal misc device?
>
> What the benefits to use misc instead of cdev?
Less code, simpler logic, easier to review and understand, etc.
Let me ask you, why use a cdev instead of a misc?
> > I forgot if this is what you were doing before, sorry...
> >
> > > + int id;
> > > + atomic_t open;
> >
> > Why do you need this?
>
> This counter used to avoid open at the same time by 2 or more users.
But it isn't working :)
And why do you care?
> > > + const struct jtag_ops *ops;
> > > + unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
> >
> > Huh? Why is this needed to be dma aligned? Why not just use the private
> > pointer in struct device?
> >
>
> It is critical?
You are saying it is, so you have to justify it. There is a pointer for
you to use, don't make new ones for no reason, right?
> > > +};
> > > +
> > > +static dev_t jtag_devt;
> > > +static DEFINE_IDA(jtag_ida);
> > > +
> > > +void *jtag_priv(struct jtag *jtag)
> > > +{
> > > + return jtag->priv;
> > > +}
> > > +EXPORT_SYMBOL_GPL(jtag_priv);
> > > +
> > > +static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size) {
> > > + unsigned long size;
> > > + void *kdata;
> > > +
> > > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > > + kdata = memdup_user(u64_to_user_ptr(udata), size);
> >
> > You only use this once, why not just open-code it?
>
> I think it makes code more understandable.
As a reviewer, I don't :)
> > > +
> > > + return kdata;
> > > +}
> > > +
> > > +static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
> > > + unsigned long bit_size)
> > > +{
> > > + unsigned long size;
> > > +
> > > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > > +
> > > + return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata), size);
> >
> > Same here, making this a separate function seems odd.
>
> Same, I think it makes code more understandable.
But it doesn't.
> > > +
> > > + if (jtag->ops->freq_set)
> > > + err = jtag->ops->freq_set(jtag, value);
> > > + else
> > > + err = -EOPNOTSUPP;
> > > + break;
> > > +
> > > + case JTAG_IOCRUNTEST:
> > > + if (copy_from_user(&idle, (void *)arg,
> > > + sizeof(struct jtag_run_test_idle)))
> > > + return -ENOMEM;
> > > + err = jtag_run_test_idle_op(jtag, &idle);
> >
> > Who validates the structure fields? Is that up to the individual jtag driver? Why
> > not do it in the core correctly so that it only has to be done in one place and you
> > do not have to audit every individual driver?
>
> Input parameters validated by jtag platform driver. I think it not critical.
Not true at all. It is very critical. Remmeber, "All Input Is Evil!"
You have to validate this. I as a reviewer have to find where you are
validating this data to ensure bad things do not happen. I can't review
that here, now I have to go and review all of the individual drivers,
which is a major pain, don't you agree?
> > > + break;
> > > +
> > > + case JTAG_IOCXFER:
> > > + if (copy_from_user(&xfer, (void *)arg,
> > > + sizeof(struct jtag_xfer)))
> > > + return -EFAULT;
> > > +
> > > + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
> > > + return -EFAULT;
> > > +
> > > + xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
> > > + if (!xfer_data)
> > > + return -ENOMEM;
> >
> > Are you sure that's the correct error value?
>
> I think yes, but what you suggest?
A fault happened, so -EFAULT, right?
> [..]
> > + .unlocked_ioctl = jtag_ioctl,
> > + .open = jtag_open,
> > + .release = jtag_release,
> > +};
>
> add a compat_ioctl pointer here, after ensuring that all ioctl
> commands are compatible between 32-bit and 64-bit user space.
> [..]
And if you do not, what happens? You shouldn't need it as there is no
fixups necessary, or am I mistaken about that?
> > > +static int jtag_open(struct inode *inode, struct file *file) {
> > > + struct jtag *jtag = container_of(inode->i_cdev, struct jtag, cdev);
> > > +
> > > + if (atomic_read(&jtag->open)) {
> > > + dev_info(NULL, "jtag already opened\n");
> > > + return -EBUSY;
> >
> > Why do you care if multiple opens can happen?
>
> Jtag HW not support to using with multiple requests from different users. So we prohibit this.
Why does the kernel care?
And again, your implementation is broken, it's not actually doing this
protection. I recommend just not doing it at all, but if you really are
insisting on it, you have to get it correct :)
thanks,
greg k-h
^ permalink raw reply [flat|nested] 45+ messages in thread
* RE: [patch v9 1/4] drivers: jtag: Add JTAG core driver
@ 2017-10-25 15:58 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-10-25 15:58 UTC (permalink / raw)
To: Greg KH
Cc: arnd, linux-kernel, linux-arm-kernel, devicetree, openbmc, joel,
jiri, tklauser, linux-serial, mec, Vadim Pasternak,
system-sw-low-level, robh+dt, openocd-devel-owner, linux-api,
davem, mchehab, Jiri Pirko
> -----Original Message-----
> From: Greg KH [mailto:gregkh@linuxfoundation.org]
> Sent: Friday, October 20, 2017 5:54 PM
> To: Oleksandr Shamray <oleksandrs@mellanox.com>
> Cc: arnd@arndb.de; linux-kernel@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; devicetree@vger.kernel.org;
> openbmc@lists.ozlabs.org; joel@jms.id.au; jiri@resnulli.us;
> tklauser@distanz.ch; linux-serial@vger.kernel.org; mec@shout.net; Vadim
> Pasternak <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> level@mellanox.com>; robh+dt@kernel.org; openocd-devel-
> owner@lists.sourceforge.net; linux-api@vger.kernel.org;
> davem@davemloft.net; mchehab@kernel.org; Jiri Pirko <jiri@mellanox.com>
> Subject: Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
>
> On Fri, Oct 20, 2017 at 02:34:00PM +0000, Oleksandr Shamray wrote:
> > Hi Greg.
> >
> > > -----Original Message-----
> > > From: Greg KH [mailto:gregkh@linuxfoundation.org]
> > > Sent: Friday, October 20, 2017 2:55 PM
> > > To: Oleksandr Shamray <oleksandrs@mellanox.com>
> > > Cc: arnd@arndb.de; linux-kernel@vger.kernel.org; linux-arm-
> > > kernel@lists.infradead.org; devicetree@vger.kernel.org;
> > > openbmc@lists.ozlabs.org; joel@jms.id.au; jiri@resnulli.us;
> > > tklauser@distanz.ch; linux-serial@vger.kernel.org; mec@shout.net;
> > > Vadim Pasternak <vadimp@mellanox.com>; system-sw-low-level
> > > <system-sw-low- level@mellanox.com>; robh+dt@kernel.org;
> > > openocd-devel- owner@lists.sourceforge.net;
> > > linux-api@vger.kernel.org; davem@davemloft.net; mchehab@kernel.org;
> > > Jiri Pirko <jiri@mellanox.com>
> > > Subject: Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
> > >
> > > On Thu, Sep 21, 2017 at 12:25:29PM +0300, Oleksandr Shamray wrote:
> > > > +struct jtag {
> > > > + struct device *dev;
> > > > + struct cdev cdev;
> > >
> > > Why are you using a cdev here and not just a normal misc device?
> >
> > What the benefits to use misc instead of cdev?
>
> Less code, simpler logic, easier to review and understand, etc.
>
> Let me ask you, why use a cdev instead of a misc?
As I know misc device more applicable if we want to create one device f.e. /dev/jtag.
But in current case we can have more than one jtag device /dev/jtag0 ... /dev/jtagN.
So I decided to use cdev.
>
> > > I forgot if this is what you were doing before, sorry...
> > >
> > > > + int id;
> > > > + atomic_t open;
> > >
> > > Why do you need this?
> >
> > This counter used to avoid open at the same time by 2 or more users.
>
> But it isn't working :)
>
> And why do you care?
>
> > > > + const struct jtag_ops *ops;
> > > > + unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
> > >
> > > Huh? Why is this needed to be dma aligned? Why not just use the
> > > private pointer in struct device?
> > >
> >
> > It is critical?
>
> You are saying it is, so you have to justify it. There is a pointer for you to use,
> don't make new ones for no reason, right?
>
You are right. Will remove.
> > > > +};
> > > > +
> > > > +static dev_t jtag_devt;
> > > > +static DEFINE_IDA(jtag_ida);
> > > > +
> > > > +void *jtag_priv(struct jtag *jtag) {
> > > > + return jtag->priv;
> > > > +}
> > > > +EXPORT_SYMBOL_GPL(jtag_priv);
> > > > +
> > > > +static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size) {
> > > > + unsigned long size;
> > > > + void *kdata;
> > > > +
> > > > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > > > + kdata = memdup_user(u64_to_user_ptr(udata), size);
> > >
> > > You only use this once, why not just open-code it?
> >
> > I think it makes code more understandable.
>
> As a reviewer, I don't :)
Ok, I will fix :)
>
> > > > +
> > > > + return kdata;
> > > > +}
> > > > +
> > > > +static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
> > > > + unsigned long bit_size) {
> > > > + unsigned long size;
> > > > +
> > > > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > > > +
> > > > + return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata),
> > > > +size);
> > >
> > > Same here, making this a separate function seems odd.
> >
> > Same, I think it makes code more understandable.
>
> But it doesn't.
>
Ok, I will fix :)
> > > > +
> > > > + if (jtag->ops->freq_set)
> > > > + err = jtag->ops->freq_set(jtag, value);
> > > > + else
> > > > + err = -EOPNOTSUPP;
> > > > + break;
> > > > +
> > > > + case JTAG_IOCRUNTEST:
> > > > + if (copy_from_user(&idle, (void *)arg,
> > > > + sizeof(struct jtag_run_test_idle)))
> > > > + return -ENOMEM;
> > > > + err = jtag_run_test_idle_op(jtag, &idle);
> > >
> > > Who validates the structure fields? Is that up to the individual
> > > jtag driver? Why not do it in the core correctly so that it only
> > > has to be done in one place and you do not have to audit every individual
> driver?
> >
> > Input parameters validated by jtag platform driver. I think it not critical.
>
> Not true at all. It is very critical. Remmeber, "All Input Is Evil!"
>
> You have to validate this. I as a reviewer have to find where you are validating
> this data to ensure bad things do not happen. I can't review that here, now I
> have to go and review all of the individual drivers, which is a major pain, don't
> you agree?
Agree. I will add input parameter checking here before call device driver.
>
> > > > + break;
> > > > +
> > > > + case JTAG_IOCXFER:
> > > > + if (copy_from_user(&xfer, (void *)arg,
> > > > + sizeof(struct jtag_xfer)))
> > > > + return -EFAULT;
> > > > +
> > > > + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
> > > > + return -EFAULT;
> > > > +
> > > > + xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
> > > > + if (!xfer_data)
> > > > + return -ENOMEM;
> > >
> > > Are you sure that's the correct error value?
> >
> > I think yes, but what you suggest?
>
> A fault happened, so -EFAULT, right?
>
Right.
> > [..]
> > > + .unlocked_ioctl = jtag_ioctl,
> > > + .open = jtag_open,
> > > + .release = jtag_release,
> > > +};
> >
> > add a compat_ioctl pointer here, after ensuring that all ioctl
> > commands are compatible between 32-bit and 64-bit user space.
> > [..]
>
> And if you do not, what happens? You shouldn't need it as there is no fixups
> necessary, or am I mistaken about that?
Yes, you are right. In code compat_ioctl called same function as in unlocked_ioctl.
So I can remove compat and system will always call unlocked_ioctl.
>
> > > > +static int jtag_open(struct inode *inode, struct file *file) {
> > > > + struct jtag *jtag = container_of(inode->i_cdev, struct jtag,
> > > > +cdev);
> > > > +
> > > > + if (atomic_read(&jtag->open)) {
> > > > + dev_info(NULL, "jtag already opened\n");
> > > > + return -EBUSY;
> > >
> > > Why do you care if multiple opens can happen?
> >
> > Jtag HW not support to using with multiple requests from different users. So
> we prohibit this.
>
> Why does the kernel care?
>
> And again, your implementation is broken, it's not actually doing this
> protection. I recommend just not doing it at all, but if you really are insisting
> on it, you have to get it correct :)
I will follow your recommendations and remove it.
>
> thanks,
>
> greg k-h
Thanks.
Oleksandr S
^ permalink raw reply [flat|nested] 45+ messages in thread
* RE: [patch v9 1/4] drivers: jtag: Add JTAG core driver
@ 2017-10-25 15:58 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-10-25 15:58 UTC (permalink / raw)
To: Greg KH
Cc: arnd-r2nGTMty4D4, linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
devicetree-u79uwXL29TY76Z2rM5mHXA,
openbmc-uLR06cmDAlY/bJ5BZ2RsiQ, joel-U3u1mxZcP9KHXe+LvDLADg,
jiri-rHqAuBHg3fBzbRFIqnYvSA, tklauser-93Khv+1bN0NyDzI6CaY1VQ,
linux-serial-u79uwXL29TY76Z2rM5mHXA, mec-WqBc5aa1uDFeoWH0uzbU5w,
Vadim Pasternak, system-sw-low-level,
robh+dt-DgEjT+Ai2ygdnm+yROfE0A,
openocd-devel-owner-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f
> -----Original Message-----
> From: Greg KH [mailto:gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org]
> Sent: Friday, October 20, 2017 5:54 PM
> To: Oleksandr Shamray <oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> Cc: arnd-r2nGTMty4D4@public.gmane.org; linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; linux-arm-
> kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org; devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org;
> openbmc-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org; joel-U3u1mxZcP9KHXe+LvDLADg@public.gmane.org; jiri-rHqAuBHg3fBzbRFIqnYvSA@public.gmane.org;
> tklauser-93Khv+1bN0NyDzI6CaY1VQ@public.gmane.org; linux-serial-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; mec-WqBc5aa1uDFeoWH0uzbU5w@public.gmane.org; Vadim
> Pasternak <vadimp-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>; system-sw-low-level <system-sw-low-
> level-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>; robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org; openocd-devel-
> owner-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org; linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org;
> davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org; mchehab-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org; Jiri Pirko <jiri-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> Subject: Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
>
> On Fri, Oct 20, 2017 at 02:34:00PM +0000, Oleksandr Shamray wrote:
> > Hi Greg.
> >
> > > -----Original Message-----
> > > From: Greg KH [mailto:gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org]
> > > Sent: Friday, October 20, 2017 2:55 PM
> > > To: Oleksandr Shamray <oleksandrs-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> > > Cc: arnd-r2nGTMty4D4@public.gmane.org; linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; linux-arm-
> > > kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org; devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org;
> > > openbmc-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org; joel-U3u1mxZcP9KHXe+LvDLADg@public.gmane.org; jiri-rHqAuBHg3fBzbRFIqnYvSA@public.gmane.org;
> > > tklauser-93Khv+1bN0NyDzI6CaY1VQ@public.gmane.org; linux-serial-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; mec-WqBc5aa1uDFeoWH0uzbU5w@public.gmane.org;
> > > Vadim Pasternak <vadimp-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>; system-sw-low-level
> > > <system-sw-low- level-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>; robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org;
> > > openocd-devel- owner-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org;
> > > linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org; mchehab-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org;
> > > Jiri Pirko <jiri-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> > > Subject: Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
> > >
> > > On Thu, Sep 21, 2017 at 12:25:29PM +0300, Oleksandr Shamray wrote:
> > > > +struct jtag {
> > > > + struct device *dev;
> > > > + struct cdev cdev;
> > >
> > > Why are you using a cdev here and not just a normal misc device?
> >
> > What the benefits to use misc instead of cdev?
>
> Less code, simpler logic, easier to review and understand, etc.
>
> Let me ask you, why use a cdev instead of a misc?
As I know misc device more applicable if we want to create one device f.e. /dev/jtag.
But in current case we can have more than one jtag device /dev/jtag0 ... /dev/jtagN.
So I decided to use cdev.
>
> > > I forgot if this is what you were doing before, sorry...
> > >
> > > > + int id;
> > > > + atomic_t open;
> > >
> > > Why do you need this?
> >
> > This counter used to avoid open at the same time by 2 or more users.
>
> But it isn't working :)
>
> And why do you care?
>
> > > > + const struct jtag_ops *ops;
> > > > + unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
> > >
> > > Huh? Why is this needed to be dma aligned? Why not just use the
> > > private pointer in struct device?
> > >
> >
> > It is critical?
>
> You are saying it is, so you have to justify it. There is a pointer for you to use,
> don't make new ones for no reason, right?
>
You are right. Will remove.
> > > > +};
> > > > +
> > > > +static dev_t jtag_devt;
> > > > +static DEFINE_IDA(jtag_ida);
> > > > +
> > > > +void *jtag_priv(struct jtag *jtag) {
> > > > + return jtag->priv;
> > > > +}
> > > > +EXPORT_SYMBOL_GPL(jtag_priv);
> > > > +
> > > > +static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size) {
> > > > + unsigned long size;
> > > > + void *kdata;
> > > > +
> > > > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > > > + kdata = memdup_user(u64_to_user_ptr(udata), size);
> > >
> > > You only use this once, why not just open-code it?
> >
> > I think it makes code more understandable.
>
> As a reviewer, I don't :)
Ok, I will fix :)
>
> > > > +
> > > > + return kdata;
> > > > +}
> > > > +
> > > > +static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
> > > > + unsigned long bit_size) {
> > > > + unsigned long size;
> > > > +
> > > > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > > > +
> > > > + return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata),
> > > > +size);
> > >
> > > Same here, making this a separate function seems odd.
> >
> > Same, I think it makes code more understandable.
>
> But it doesn't.
>
Ok, I will fix :)
> > > > +
> > > > + if (jtag->ops->freq_set)
> > > > + err = jtag->ops->freq_set(jtag, value);
> > > > + else
> > > > + err = -EOPNOTSUPP;
> > > > + break;
> > > > +
> > > > + case JTAG_IOCRUNTEST:
> > > > + if (copy_from_user(&idle, (void *)arg,
> > > > + sizeof(struct jtag_run_test_idle)))
> > > > + return -ENOMEM;
> > > > + err = jtag_run_test_idle_op(jtag, &idle);
> > >
> > > Who validates the structure fields? Is that up to the individual
> > > jtag driver? Why not do it in the core correctly so that it only
> > > has to be done in one place and you do not have to audit every individual
> driver?
> >
> > Input parameters validated by jtag platform driver. I think it not critical.
>
> Not true at all. It is very critical. Remmeber, "All Input Is Evil!"
>
> You have to validate this. I as a reviewer have to find where you are validating
> this data to ensure bad things do not happen. I can't review that here, now I
> have to go and review all of the individual drivers, which is a major pain, don't
> you agree?
Agree. I will add input parameter checking here before call device driver.
>
> > > > + break;
> > > > +
> > > > + case JTAG_IOCXFER:
> > > > + if (copy_from_user(&xfer, (void *)arg,
> > > > + sizeof(struct jtag_xfer)))
> > > > + return -EFAULT;
> > > > +
> > > > + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
> > > > + return -EFAULT;
> > > > +
> > > > + xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
> > > > + if (!xfer_data)
> > > > + return -ENOMEM;
> > >
> > > Are you sure that's the correct error value?
> >
> > I think yes, but what you suggest?
>
> A fault happened, so -EFAULT, right?
>
Right.
> > [..]
> > > + .unlocked_ioctl = jtag_ioctl,
> > > + .open = jtag_open,
> > > + .release = jtag_release,
> > > +};
> >
> > add a compat_ioctl pointer here, after ensuring that all ioctl
> > commands are compatible between 32-bit and 64-bit user space.
> > [..]
>
> And if you do not, what happens? You shouldn't need it as there is no fixups
> necessary, or am I mistaken about that?
Yes, you are right. In code compat_ioctl called same function as in unlocked_ioctl.
So I can remove compat and system will always call unlocked_ioctl.
>
> > > > +static int jtag_open(struct inode *inode, struct file *file) {
> > > > + struct jtag *jtag = container_of(inode->i_cdev, struct jtag,
> > > > +cdev);
> > > > +
> > > > + if (atomic_read(&jtag->open)) {
> > > > + dev_info(NULL, "jtag already opened\n");
> > > > + return -EBUSY;
> > >
> > > Why do you care if multiple opens can happen?
> >
> > Jtag HW not support to using with multiple requests from different users. So
> we prohibit this.
>
> Why does the kernel care?
>
> And again, your implementation is broken, it's not actually doing this
> protection. I recommend just not doing it at all, but if you really are insisting
> on it, you have to get it correct :)
I will follow your recommendations and remove it.
>
> thanks,
>
> greg k-h
Thanks.
Oleksandr S
^ permalink raw reply [flat|nested] 45+ messages in thread
* RE: [patch v9 1/4] drivers: jtag: Add JTAG core driver
@ 2017-10-25 15:58 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-10-25 15:58 UTC (permalink / raw)
To: Greg KH
Cc: arnd, linux-kernel, linux-arm-kernel, devicetree, openbmc, joel,
jiri, tklauser, linux-serial, mec, Vadim Pasternak,
system-sw-low-level, robh+dt, openocd-devel-owner, linux-api,
davem, mchehab, Jiri Pirko
> -----Original Message-----
> From: Greg KH [mailto:gregkh@linuxfoundation.org]
> Sent: Friday, October 20, 2017 5:54 PM
> To: Oleksandr Shamray <oleksandrs@mellanox.com>
> Cc: arnd@arndb.de; linux-kernel@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; devicetree@vger.kernel.org;
> openbmc@lists.ozlabs.org; joel@jms.id.au; jiri@resnulli.us;
> tklauser@distanz.ch; linux-serial@vger.kernel.org; mec@shout.net; Vadim
> Pasternak <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> level@mellanox.com>; robh+dt@kernel.org; openocd-devel-
> owner@lists.sourceforge.net; linux-api@vger.kernel.org;
> davem@davemloft.net; mchehab@kernel.org; Jiri Pirko <jiri@mellanox.com>
> Subject: Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
>
> On Fri, Oct 20, 2017 at 02:34:00PM +0000, Oleksandr Shamray wrote:
> > Hi Greg.
> >
> > > -----Original Message-----
> > > From: Greg KH [mailto:gregkh@linuxfoundation.org]
> > > Sent: Friday, October 20, 2017 2:55 PM
> > > To: Oleksandr Shamray <oleksandrs@mellanox.com>
> > > Cc: arnd@arndb.de; linux-kernel@vger.kernel.org; linux-arm-
> > > kernel@lists.infradead.org; devicetree@vger.kernel.org;
> > > openbmc@lists.ozlabs.org; joel@jms.id.au; jiri@resnulli.us;
> > > tklauser@distanz.ch; linux-serial@vger.kernel.org; mec@shout.net;
> > > Vadim Pasternak <vadimp@mellanox.com>; system-sw-low-level
> > > <system-sw-low- level@mellanox.com>; robh+dt@kernel.org;
> > > openocd-devel- owner@lists.sourceforge.net;
> > > linux-api@vger.kernel.org; davem@davemloft.net; mchehab@kernel.org;
> > > Jiri Pirko <jiri@mellanox.com>
> > > Subject: Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
> > >
> > > On Thu, Sep 21, 2017 at 12:25:29PM +0300, Oleksandr Shamray wrote:
> > > > +struct jtag {
> > > > + struct device *dev;
> > > > + struct cdev cdev;
> > >
> > > Why are you using a cdev here and not just a normal misc device?
> >
> > What the benefits to use misc instead of cdev?
>
> Less code, simpler logic, easier to review and understand, etc.
>
> Let me ask you, why use a cdev instead of a misc?
As I know misc device more applicable if we want to create one device f.e. /dev/jtag.
But in current case we can have more than one jtag device /dev/jtag0 ... /dev/jtagN.
So I decided to use cdev.
>
> > > I forgot if this is what you were doing before, sorry...
> > >
> > > > + int id;
> > > > + atomic_t open;
> > >
> > > Why do you need this?
> >
> > This counter used to avoid open at the same time by 2 or more users.
>
> But it isn't working :)
>
> And why do you care?
>
> > > > + const struct jtag_ops *ops;
> > > > + unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
> > >
> > > Huh? Why is this needed to be dma aligned? Why not just use the
> > > private pointer in struct device?
> > >
> >
> > It is critical?
>
> You are saying it is, so you have to justify it. There is a pointer for you to use,
> don't make new ones for no reason, right?
>
You are right. Will remove.
> > > > +};
> > > > +
> > > > +static dev_t jtag_devt;
> > > > +static DEFINE_IDA(jtag_ida);
> > > > +
> > > > +void *jtag_priv(struct jtag *jtag) {
> > > > + return jtag->priv;
> > > > +}
> > > > +EXPORT_SYMBOL_GPL(jtag_priv);
> > > > +
> > > > +static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size) {
> > > > + unsigned long size;
> > > > + void *kdata;
> > > > +
> > > > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > > > + kdata = memdup_user(u64_to_user_ptr(udata), size);
> > >
> > > You only use this once, why not just open-code it?
> >
> > I think it makes code more understandable.
>
> As a reviewer, I don't :)
Ok, I will fix :)
>
> > > > +
> > > > + return kdata;
> > > > +}
> > > > +
> > > > +static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
> > > > + unsigned long bit_size) {
> > > > + unsigned long size;
> > > > +
> > > > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > > > +
> > > > + return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata),
> > > > +size);
> > >
> > > Same here, making this a separate function seems odd.
> >
> > Same, I think it makes code more understandable.
>
> But it doesn't.
>
Ok, I will fix :)
> > > > +
> > > > + if (jtag->ops->freq_set)
> > > > + err = jtag->ops->freq_set(jtag, value);
> > > > + else
> > > > + err = -EOPNOTSUPP;
> > > > + break;
> > > > +
> > > > + case JTAG_IOCRUNTEST:
> > > > + if (copy_from_user(&idle, (void *)arg,
> > > > + sizeof(struct jtag_run_test_idle)))
> > > > + return -ENOMEM;
> > > > + err = jtag_run_test_idle_op(jtag, &idle);
> > >
> > > Who validates the structure fields? Is that up to the individual
> > > jtag driver? Why not do it in the core correctly so that it only
> > > has to be done in one place and you do not have to audit every individual
> driver?
> >
> > Input parameters validated by jtag platform driver. I think it not critical.
>
> Not true at all. It is very critical. Remmeber, "All Input Is Evil!"
>
> You have to validate this. I as a reviewer have to find where you are validating
> this data to ensure bad things do not happen. I can't review that here, now I
> have to go and review all of the individual drivers, which is a major pain, don't
> you agree?
Agree. I will add input parameter checking here before call device driver.
>
> > > > + break;
> > > > +
> > > > + case JTAG_IOCXFER:
> > > > + if (copy_from_user(&xfer, (void *)arg,
> > > > + sizeof(struct jtag_xfer)))
> > > > + return -EFAULT;
> > > > +
> > > > + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
> > > > + return -EFAULT;
> > > > +
> > > > + xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
> > > > + if (!xfer_data)
> > > > + return -ENOMEM;
> > >
> > > Are you sure that's the correct error value?
> >
> > I think yes, but what you suggest?
>
> A fault happened, so -EFAULT, right?
>
Right.
> > [..]
> > > + .unlocked_ioctl = jtag_ioctl,
> > > + .open = jtag_open,
> > > + .release = jtag_release,
> > > +};
> >
> > add a compat_ioctl pointer here, after ensuring that all ioctl
> > commands are compatible between 32-bit and 64-bit user space.
> > [..]
>
> And if you do not, what happens? You shouldn't need it as there is no fixups
> necessary, or am I mistaken about that?
Yes, you are right. In code compat_ioctl called same function as in unlocked_ioctl.
So I can remove compat and system will always call unlocked_ioctl.
>
> > > > +static int jtag_open(struct inode *inode, struct file *file) {
> > > > + struct jtag *jtag = container_of(inode->i_cdev, struct jtag,
> > > > +cdev);
> > > > +
> > > > + if (atomic_read(&jtag->open)) {
> > > > + dev_info(NULL, "jtag already opened\n");
> > > > + return -EBUSY;
> > >
> > > Why do you care if multiple opens can happen?
> >
> > Jtag HW not support to using with multiple requests from different users. So
> we prohibit this.
>
> Why does the kernel care?
>
> And again, your implementation is broken, it's not actually doing this
> protection. I recommend just not doing it at all, but if you really are insisting
> on it, you have to get it correct :)
I will follow your recommendations and remove it.
>
> thanks,
>
> greg k-h
Thanks.
Oleksandr S
^ permalink raw reply [flat|nested] 45+ messages in thread
* [patch v9 1/4] drivers: jtag: Add JTAG core driver
@ 2017-10-25 15:58 ` Oleksandr Shamray
0 siblings, 0 replies; 45+ messages in thread
From: Oleksandr Shamray @ 2017-10-25 15:58 UTC (permalink / raw)
To: linux-arm-kernel
> -----Original Message-----
> From: Greg KH [mailto:gregkh at linuxfoundation.org]
> Sent: Friday, October 20, 2017 5:54 PM
> To: Oleksandr Shamray <oleksandrs@mellanox.com>
> Cc: arnd at arndb.de; linux-kernel at vger.kernel.org; linux-arm-
> kernel at lists.infradead.org; devicetree at vger.kernel.org;
> openbmc at lists.ozlabs.org; joel at jms.id.au; jiri at resnulli.us;
> tklauser at distanz.ch; linux-serial at vger.kernel.org; mec at shout.net; Vadim
> Pasternak <vadimp@mellanox.com>; system-sw-low-level <system-sw-low-
> level at mellanox.com>; robh+dt at kernel.org; openocd-devel-
> owner at lists.sourceforge.net; linux-api at vger.kernel.org;
> davem at davemloft.net; mchehab at kernel.org; Jiri Pirko <jiri@mellanox.com>
> Subject: Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
>
> On Fri, Oct 20, 2017 at 02:34:00PM +0000, Oleksandr Shamray wrote:
> > Hi Greg.
> >
> > > -----Original Message-----
> > > From: Greg KH [mailto:gregkh at linuxfoundation.org]
> > > Sent: Friday, October 20, 2017 2:55 PM
> > > To: Oleksandr Shamray <oleksandrs@mellanox.com>
> > > Cc: arnd at arndb.de; linux-kernel at vger.kernel.org; linux-arm-
> > > kernel at lists.infradead.org; devicetree at vger.kernel.org;
> > > openbmc at lists.ozlabs.org; joel at jms.id.au; jiri at resnulli.us;
> > > tklauser at distanz.ch; linux-serial at vger.kernel.org; mec at shout.net;
> > > Vadim Pasternak <vadimp@mellanox.com>; system-sw-low-level
> > > <system-sw-low- level@mellanox.com>; robh+dt at kernel.org;
> > > openocd-devel- owner at lists.sourceforge.net;
> > > linux-api at vger.kernel.org; davem at davemloft.net; mchehab at kernel.org;
> > > Jiri Pirko <jiri@mellanox.com>
> > > Subject: Re: [patch v9 1/4] drivers: jtag: Add JTAG core driver
> > >
> > > On Thu, Sep 21, 2017 at 12:25:29PM +0300, Oleksandr Shamray wrote:
> > > > +struct jtag {
> > > > + struct device *dev;
> > > > + struct cdev cdev;
> > >
> > > Why are you using a cdev here and not just a normal misc device?
> >
> > What the benefits to use misc instead of cdev?
>
> Less code, simpler logic, easier to review and understand, etc.
>
> Let me ask you, why use a cdev instead of a misc?
As I know misc device more applicable if we want to create one device f.e. /dev/jtag.
But in current case we can have more than one jtag device /dev/jtag0 ... /dev/jtagN.
So I decided to use cdev.
>
> > > I forgot if this is what you were doing before, sorry...
> > >
> > > > + int id;
> > > > + atomic_t open;
> > >
> > > Why do you need this?
> >
> > This counter used to avoid open at the same time by 2 or more users.
>
> But it isn't working :)
>
> And why do you care?
>
> > > > + const struct jtag_ops *ops;
> > > > + unsigned long priv[0] __aligned(ARCH_DMA_MINALIGN);
> > >
> > > Huh? Why is this needed to be dma aligned? Why not just use the
> > > private pointer in struct device?
> > >
> >
> > It is critical?
>
> You are saying it is, so you have to justify it. There is a pointer for you to use,
> don't make new ones for no reason, right?
>
You are right. Will remove.
> > > > +};
> > > > +
> > > > +static dev_t jtag_devt;
> > > > +static DEFINE_IDA(jtag_ida);
> > > > +
> > > > +void *jtag_priv(struct jtag *jtag) {
> > > > + return jtag->priv;
> > > > +}
> > > > +EXPORT_SYMBOL_GPL(jtag_priv);
> > > > +
> > > > +static u8 *jtag_copy_from_user(__u64 udata, unsigned long bit_size) {
> > > > + unsigned long size;
> > > > + void *kdata;
> > > > +
> > > > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > > > + kdata = memdup_user(u64_to_user_ptr(udata), size);
> > >
> > > You only use this once, why not just open-code it?
> >
> > I think it makes code more understandable.
>
> As a reviewer, I don't :)
Ok, I will fix :)
>
> > > > +
> > > > + return kdata;
> > > > +}
> > > > +
> > > > +static unsigned long jtag_copy_to_user(__u64 udata, u8 *kdata,
> > > > + unsigned long bit_size) {
> > > > + unsigned long size;
> > > > +
> > > > + size = DIV_ROUND_UP(bit_size, BITS_PER_BYTE);
> > > > +
> > > > + return copy_to_user(u64_to_user_ptr(udata), (void *)(kdata),
> > > > +size);
> > >
> > > Same here, making this a separate function seems odd.
> >
> > Same, I think it makes code more understandable.
>
> But it doesn't.
>
Ok, I will fix :)
> > > > +
> > > > + if (jtag->ops->freq_set)
> > > > + err = jtag->ops->freq_set(jtag, value);
> > > > + else
> > > > + err = -EOPNOTSUPP;
> > > > + break;
> > > > +
> > > > + case JTAG_IOCRUNTEST:
> > > > + if (copy_from_user(&idle, (void *)arg,
> > > > + sizeof(struct jtag_run_test_idle)))
> > > > + return -ENOMEM;
> > > > + err = jtag_run_test_idle_op(jtag, &idle);
> > >
> > > Who validates the structure fields? Is that up to the individual
> > > jtag driver? Why not do it in the core correctly so that it only
> > > has to be done in one place and you do not have to audit every individual
> driver?
> >
> > Input parameters validated by jtag platform driver. I think it not critical.
>
> Not true at all. It is very critical. Remmeber, "All Input Is Evil!"
>
> You have to validate this. I as a reviewer have to find where you are validating
> this data to ensure bad things do not happen. I can't review that here, now I
> have to go and review all of the individual drivers, which is a major pain, don't
> you agree?
Agree. I will add input parameter checking here before call device driver.
>
> > > > + break;
> > > > +
> > > > + case JTAG_IOCXFER:
> > > > + if (copy_from_user(&xfer, (void *)arg,
> > > > + sizeof(struct jtag_xfer)))
> > > > + return -EFAULT;
> > > > +
> > > > + if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
> > > > + return -EFAULT;
> > > > +
> > > > + xfer_data = jtag_copy_from_user(xfer.tdio, xfer.length);
> > > > + if (!xfer_data)
> > > > + return -ENOMEM;
> > >
> > > Are you sure that's the correct error value?
> >
> > I think yes, but what you suggest?
>
> A fault happened, so -EFAULT, right?
>
Right.
> > [..]
> > > + .unlocked_ioctl = jtag_ioctl,
> > > + .open = jtag_open,
> > > + .release = jtag_release,
> > > +};
> >
> > add a compat_ioctl pointer here, after ensuring that all ioctl
> > commands are compatible between 32-bit and 64-bit user space.
> > [..]
>
> And if you do not, what happens? You shouldn't need it as there is no fixups
> necessary, or am I mistaken about that?
Yes, you are right. In code compat_ioctl called same function as in unlocked_ioctl.
So I can remove compat and system will always call unlocked_ioctl.
>
> > > > +static int jtag_open(struct inode *inode, struct file *file) {
> > > > + struct jtag *jtag = container_of(inode->i_cdev, struct jtag,
> > > > +cdev);
> > > > +
> > > > + if (atomic_read(&jtag->open)) {
> > > > + dev_info(NULL, "jtag already opened\n");
> > > > + return -EBUSY;
> > >
> > > Why do you care if multiple opens can happen?
> >
> > Jtag HW not support to using with multiple requests from different users. So
> we prohibit this.
>
> Why does the kernel care?
>
> And again, your implementation is broken, it's not actually doing this
> protection. I recommend just not doing it at all, but if you really are insisting
> on it, you have to get it correct :)
I will follow your recommendations and remove it.
>
> thanks,
>
> greg k-h
Thanks.
Oleksandr S
^ permalink raw reply [flat|nested] 45+ messages in thread
end of thread, other threads:[~2017-10-25 15:58 UTC | newest]
Thread overview: 45+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-09-21 9:25 [patch v9 0/4] JTAG driver introduction Oleksandr Shamray
2017-09-21 9:25 ` Oleksandr Shamray
2017-09-21 9:25 ` [patch v9 1/4] drivers: jtag: Add JTAG core driver Oleksandr Shamray
2017-09-21 9:25 ` Oleksandr Shamray
2017-09-21 9:25 ` Oleksandr Shamray
2017-10-20 11:55 ` Greg KH
2017-10-20 11:55 ` Greg KH
2017-10-20 11:55 ` Greg KH
2017-10-20 14:34 ` Oleksandr Shamray
2017-10-20 14:34 ` Oleksandr Shamray
2017-10-20 14:34 ` Oleksandr Shamray
2017-10-20 14:34 ` Oleksandr Shamray
2017-10-20 14:54 ` Greg KH
2017-10-20 14:54 ` Greg KH
2017-10-20 14:54 ` Greg KH
2017-10-20 14:54 ` Greg KH
2017-10-25 15:58 ` Oleksandr Shamray
2017-10-25 15:58 ` Oleksandr Shamray
2017-10-25 15:58 ` Oleksandr Shamray
2017-10-25 15:58 ` Oleksandr Shamray
2017-09-21 9:25 ` [patch v9 2/4] drivers: jtag: Add Aspeed SoC 24xx and 25xx families JTAG master driver Oleksandr Shamray
2017-09-21 9:25 ` Oleksandr Shamray
2017-09-21 9:25 ` Oleksandr Shamray
2017-09-21 9:25 ` [patch v9 3/4] Documentation: jtag: Add bindings for " Oleksandr Shamray
2017-09-21 9:25 ` Oleksandr Shamray
2017-09-21 9:25 ` [patch v9 4/4] Documentation: jtag: Add ABI documentation Oleksandr Shamray
2017-09-21 9:25 ` Oleksandr Shamray
2017-09-21 9:25 ` Oleksandr Shamray
2017-09-28 8:33 ` [patch v9 0/4] JTAG driver introduction Geert Uytterhoeven
2017-09-28 8:33 ` Geert Uytterhoeven
2017-09-28 8:33 ` Geert Uytterhoeven
2017-09-28 8:33 ` Geert Uytterhoeven
2017-09-28 8:33 ` Geert Uytterhoeven
2017-09-28 8:53 ` Oleksandr Shamray
2017-09-28 8:53 ` Oleksandr Shamray
2017-09-28 8:53 ` Oleksandr Shamray
2017-09-28 8:53 ` Oleksandr Shamray
2017-09-28 9:02 ` Geert Uytterhoeven
2017-09-28 9:02 ` Geert Uytterhoeven
2017-09-28 9:02 ` Geert Uytterhoeven
2017-09-28 9:02 ` Geert Uytterhoeven
2017-09-28 11:11 ` Oleksandr Shamray
2017-09-28 11:11 ` Oleksandr Shamray
2017-09-28 11:11 ` Oleksandr Shamray
2017-09-28 11:11 ` Oleksandr Shamray
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