linux.git/drivers/gpio/gpiolib-cdev.c, branch v5.19

Merge tag 'hte/for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux

2022-07-18T18:47:04+00:00

Pull hardware timestamp fix from Thierry Reding:
 "A single fix for an out-of-sync kerneldoc comment"

* tag 'hte/for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux:
  gpiolib: cdev: Fix kernel doc for struct line

gpiolib: cdev: fix null pointer dereference in linereq_free()

2022-07-07T10:18:18+00:00

Fix a kernel NULL pointer dereference reported by gpio kselftests.

linereq_free() can be called as part of the cleanup of a failed request,
at which time the desc for a line may not have been determined, so it
is unsafe to dereference without a check.

Add a check prior to dereferencing the line desc.

Fixes: 2068339a6c35 ("gpiolib: cdev: Add hardware timestamp clock type")
Signed-off-by: Kent Gibson 
Signed-off-by: Bartosz Golaszewski

gpiolib: cdev: Fix kernel doc for struct line

2022-06-17T10:58:57+00:00

Kernel doc validator is not happy:
  gpiolib-cdev.c:487: warning: Function parameter or member 'hdesc' not described in 'line'
  gpiolib-cdev.c:487: warning: Function parameter or member 'raw_level' not described in 'line'
  gpiolib-cdev.c:487: warning: Function parameter or member 'total_discard_seq' not described in 'line'
  gpiolib-cdev.c:487: warning: Function parameter or member 'last_seqno' not described in 'line'

Describe above mentioned parameters.

Fixes: 2068339a6c35 ("gpiolib: cdev: Add hardware timestamp clock type")
Signed-off-by: Andy Shevchenko 
Acked-by: Dipen Patel 
Acked-by: Bartosz Golaszewski 
Signed-off-by: Thierry Reding

Merge tag 'hte/for-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux

2022-06-05T16:12:28+00:00

Pull hardware timestamping subsystem from Thierry Reding:
 "This contains the new HTE (hardware timestamping engine) subsystem
  that has been in the works for a couple of months now.

  The infrastructure provided allows for drivers to register as hardware
  timestamp providers, while consumers will be able to request events
  that they are interested in (such as GPIOs and IRQs) to be timestamped
  by the hardware providers.

  Note that this currently supports only one provider, but there seems
  to be enough interest in this functionality and we expect to see more
  drivers added once this is merged"

[ Linus Walleij mentions the Intel PMC in the Elkhart and Tiger Lake
  platforms as another future timestamp provider ]

* tag 'hte/for-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux:
  dt-bindings: timestamp: Correct id path
  dt-bindings: Renamed hte directory to timestamp
  hte: Uninitialized variable in hte_ts_get()
  hte: Fix off by one in hte_push_ts_ns()
  hte: Fix possible use-after-free in tegra_hte_test_remove()
  hte: Remove unused including 
  MAINTAINERS: Add HTE Subsystem
  hte: Add Tegra HTE test driver
  tools: gpio: Add new hardware clock type
  gpiolib: cdev: Add hardware timestamp clock type
  gpio: tegra186: Add HTE support
  gpiolib: Add HTE support
  dt-bindings: Add HTE bindings
  hte: Add Tegra194 HTE kernel provider
  drivers: Add hardware timestamp engine (HTE) subsystem
  Documentation: Add HTE subsystem guide

gpiolib: cdev: Add hardware timestamp clock type

2022-05-04T09:06:13+00:00

This patch adds new clock type for the GPIO controller which can
timestamp gpio lines in using hardware means. To expose such
functionalities to the userspace, code has been added where
during line create or set config API calls, it checks for new
clock type and if requested, calls HTE API. During line change
event, the HTE subsystem pushes timestamp data to userspace
through gpiolib-cdev.

Signed-off-by: Dipen Patel 
Acked-by: Linus Walleij 
Reported-by: kernel test robot 
Reported-by: Dan Carpenter 
Signed-off-by: Thierry Reding

gpiolib: Get rid of redundant 'else'

2022-04-05T12:20:07+00:00

In the snippets like the following

	if (...)
		return / goto / break / continue ...;
	else
		...

the 'else' is redundant. Get rid of it. In case of IOCTLs use
switch-case pattern that seems the usual in such cases.

While at it, clarify necessity of else in gpiod_direction_output()
by attaching else if to the closing curly brace on a previous line.

Signed-off-by: Andy Shevchenko 
Signed-off-by: Bartosz Golaszewski

gpiolib: Never return internal error codes to user space

2022-02-08T09:34:15+00:00

Currently it's possible that character device interface may return
the error codes which are not supposed to be seen by user space.
In this case it's EPROBE_DEFER.

Wrap it to return -ENODEV instead as sysfs does.

Fixes: d7c51b47ac11 ("gpio: userspace ABI for reading/writing GPIO lines")
Fixes: 61f922db7221 ("gpio: userspace ABI for reading GPIO line events")
Fixes: 3c0d9c635ae2 ("gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL")
Reported-by: Suresh Balakrishnan 
Signed-off-by: Andy Shevchenko 
Signed-off-by: Bartosz Golaszewski

gpiolib: cdev: zero padding during conversion to gpioline_info_changed

2021-06-22T07:54:13+00:00

When userspace requests a GPIO v1 line info changed event,
lineinfo_watch_read() populates and returns the gpioline_info_changed
structure. It contains 5 words of padding at the end which are not
initialized before being returned to userspace.

Zero the structure in gpio_v2_line_info_change_to_v1() before populating
its contents.

Fixes: aad955842d1c ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Signed-off-by: Gabriel Knezek 
Reviewed-by: Kent Gibson 
Signed-off-by: Bartosz Golaszewski

gpiolib: cdev: clear debounce period if line set to output

2021-01-27T14:52:13+00:00

When set_config changes a line from input to output debounce is
implicitly disabled, as debounce makes no sense for outputs, but the
debounce period is not being cleared and is still reported in the
line info.

So clear the debounce period when the debouncer is stopped in
edge_detector_stop().

Fixes: 65cff7046406 ("gpiolib: cdev: support setting debounce")
Cc: stable@vger.kernel.org
Signed-off-by: Kent Gibson 
Reviewed-by: Linus Walleij 
Signed-off-by: Bartosz Golaszewski

gpiolib: cdev: fix frame size warning in gpio_ioctl()

2021-01-03T15:32:21+00:00

The kernel test robot reports the following warning in [1]:

 drivers/gpio/gpiolib-cdev.c: In function 'gpio_ioctl':
 >>drivers/gpio/gpiolib-cdev.c:1437:1: warning: the frame size of 1040 bytes is larger than 1024 bytes [-Wframe-larger-than=]

Refactor gpio_ioctl() to handle each ioctl in its own helper function
and so reduce the variables stored on the stack to those explicitly
required to service the ioctl at hand.

The lineinfo_get_v1() helper handles both the GPIO_GET_LINEINFO_IOCTL
and GPIO_GET_LINEINFO_WATCH_IOCTL, as per the corresponding v2
implementation - lineinfo_get().

[1] https://lore.kernel.org/lkml/202012270910.VW3qc1ER-lkp@intel.com/

Fixes: aad955842d1c ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Reported-by: kernel test robot 
Signed-off-by: Kent Gibson 
Reviewed-by: Linus Walleij 
Signed-off-by: Bartosz Golaszewski