Commit Graph

48 Commits

Author SHA1 Message Date
37644cac6e Merge tag 'gpio-updates-for-v6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio updates from Bartosz Golaszewski:
 "Here are the updates for this merge window from the GPIO subsystem.

  We have more lines removed than added thanks to dropping of a driver
  for a platform that's no longer supported. Otherwise the changes are
  pretty straightforward: support for some new models, various
  improvements to existing drivers, some tweaks to the core library code
  and DT bindings updates.

  Summary:

   - remove gpio-vr41xx driver as the only platform using it got dropped
     too

   - add support for suspend/resume to gpio-davinci

   - improvements to the GPIO character device code

   - add support for disabling bias for in-kernel users (up until now
     only user-space could set it)

   - drop unused devm_gpio_free()

   - fix a refcount issue in gpiolib OF

   - use device match helpers where applicable

   - add support for a new model to gpio-rockchip

   - non-functional improvements in gpio-adp5588

   - improve and simplify teardown in gpio-twl4030 and gpio-ucb1400

   - modernize the gpio-74xx-mmio and gpio-adnp drivers

   - coding style improvements in gpio-xilinx, gpio-104-idi-48

   - support new model (pca9571) in gpio-pca9570

   - convert the DT bindings to YAML for gpio-mvebu and update the
     document

   - don't return error codes from remove() in gpio-brcmstb

   - add a library for the intel 8255 PPI interface and use it in
     drivers

   - reduce using magic numbers and improve code readability in several
     drivers

   - convert DT bindings to YAML for gpio-tpic2810

   - add new models to DT bindings for gpio-frl-imx

   - Kconfig improvements

   - other minor tweaks and improvements"

* tag 'gpio-updates-for-v6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (52 commits)
  dt-bindings: gpio: fsl-imx-gpio: Add i.MXRT compatibles
  gpio: 74xx-mmio: Use bits instead of plain numbers for flags
  gpio: xilinx: add missing blank line after declarations
  MAINTAINERS: Update Intel 8255 GPIO driver file list
  gpio: gpio-mm: Implement and utilize register structures
  gpio: 104-idi-48: Implement and utilize register structures
  gpio: 104-dio-48e: Implement and utilize register structures
  gpio: i8255: Introduce the Intel 8255 interface library module
  gpio: 104-idio-16: Implement and utilize register structures
  gpio: ws16c48: Implement and utilize register structures
  gpio: remove VR41XX related gpio driver
  dt-bindings: gpio: add pull-disable flag
  gpiolib: acpi: support bias pull disable
  gpiolib: of: support bias pull disable
  gpiolib: add support for bias pull disable
  gpio: 74xx-mmio: use bits.h macros for all masks
  gpio: 74xx-mmio: Check MMIO_74XX_DIR_IN flag in mmio_74xx_dir_in()
  gpio: 74xx-mmio: Make use of device properties
  gpiolib: cdev: compile out HTE unless CONFIG_HTE selected
  gpiolib: cdev: consolidate edge detector configuration flags
  ...
2022-08-04 18:34:05 -07:00
272ddba004 gpiolib: cdev: compile out HTE unless CONFIG_HTE selected
The majority of builds do not include HTE, so compile out hte
functionality unless CONFIG_HTE is selected.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-07-19 10:02:46 +02:00
b1a92e9456 gpiolib: cdev: consolidate edge detector configuration flags
Combine the polarity_change flag, struct line eflags, and hte enable
flag into a single flag variable.

The combination of these flags describes the configuration state
of the edge detector, so formalize and clarify that by combining
them into a single variable, edflags, in struct line.

The edflags is a subset of the GPIO_V2_LINE_FLAGsb relevant to
the edge detector, and is also a superset of the eflags it replaces.
The eflags name is still used to describe the subset of edflags
corresponding to the rising/falling edge flags where edflags is
masked down to that subset.

This consolidation reduces the number of variables being passed,
simplifies state comparisons, and provides a more extensible
foundation should additional edge sources be integrated in the
future.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-07-19 10:02:12 +02:00
242202329f gpiolib: cdev: simplify line event identification
Reorganise line event identification code to reduce code duplication,
and replace if-else initializers with a helper function to improve
readability.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2022-07-19 10:01:25 +02:00
cfa53463ac gpiolib: cdev: replace if-else chains with switches
Improve readability by replacing if-else chains with switch
statements.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-07-19 10:01:25 +02:00
2487a81223 gpiolib: cdev: simplify parameter in call to hte_edge_setup
Improve readability by using the GPIO_V2_LINE_FLAG_EDGE_BOTH instead
of combining the rising and falling edge flags.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Dipen Patel <dipenp@nvidia.com>
Tested-by: Dipen Patel <dipenp@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-07-19 10:01:25 +02:00
160d6e4029 gpiolib: cdev: simplify linereq_free
The edge detector is only ever started after the line desc has been
determined, so move edge_detector_stop() inside the line desc check,
and merge the two checked regions into one.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Dipen Patel <dipenp@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-07-19 10:01:22 +02:00
80e19f34c2 Merge tag 'hte/for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux
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
2022-07-18 11:47:04 -07:00
c8e27a4a51 gpiolib: cdev: fix null pointer dereference in linereq_free()
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: 2068339a6c ("gpiolib: cdev: Add hardware timestamp clock type")
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-07-07 12:18:18 +02:00
85ff37e302 gpiolib: cdev: Fix kernel doc for struct line
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: 2068339a6c ("gpiolib: cdev: Add hardware timestamp clock type")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Dipen Patel <dipenp@nvidia.com>
Acked-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2022-06-17 12:58:57 +02:00
2981436374 Merge tag 'hte/for-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux
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 <linux/version.h>
  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
2022-06-05 09:12:28 -07:00
2068339a6c gpiolib: cdev: Add hardware timestamp clock type
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 <dipenp@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2022-05-04 11:06:13 +02:00
1cef8b5019 gpiolib: Get rid of redundant 'else'
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 <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-04-05 14:20:07 +02:00
95a4eed7dd gpiolib: Never return internal error codes to user space
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: d7c51b47ac ("gpio: userspace ABI for reading/writing GPIO lines")
Fixes: 61f922db72 ("gpio: userspace ABI for reading GPIO line events")
Fixes: 3c0d9c635a ("gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL")
Reported-by: Suresh Balakrishnan <suresh.balakrishnan@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-02-08 10:34:15 +01:00
cb8f63b8cb gpiolib: cdev: zero padding during conversion to gpioline_info_changed
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: aad955842d ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Signed-off-by: Gabriel Knezek <gabeknez@linux.microsoft.com>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2021-06-22 09:54:13 +02:00
03a58ea590 gpiolib: cdev: clear debounce period if line set to output
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: 65cff70464 ("gpiolib: cdev: support setting debounce")
Cc: stable@vger.kernel.org
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2021-01-27 15:52:13 +01:00
2e202ad873 gpiolib: cdev: fix frame size warning in gpio_ioctl()
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: aad955842d ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2021-01-03 16:32:21 +01:00
40b37008eb Merge tag 'gpio-updates-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux into devel
gpio updates for v5.11-rc1

- several refactoring patches of the core gpiolib code
- add support for NXP PCAL9554B/C to gpio-pca953x
- allow probing mockup devices from device tree
- refactoring and improvements to gpio-rcar
- improvements to locking in gpio-tegra
- code shrink in gpiolib devres
- get the irq offset from device tree in gpio-sifive
- major refactoring of gpio-exar
- convert gpio-mvebu pwm access to regmap
- create a new submenu for virtual GPIO drivers
- fix clang fall-through warnings treewide
- minor driver refactoring and tweaks sprinkled all over
2020-12-09 15:17:24 +01:00
a0db197f53 gpiolib: cdev: Flag invalid GPIOs as used
When reporting the state of a GPIO to userspace, we never check
for the actual validity of the line, meaning we report invalid
lines as being usable. A subsequent request will fail though,
which is an inconsistent behaviour from a userspace perspective.

Instead, let's check for the validity of the line and report it
as used if it is invalid. This allows a tool such as gpioinfo
to report something sensible:

gpiochip3 - 4 lines:
	line   0:      unnamed       unused   input  active-high
	line   1:      unnamed       kernel   input  active-high [used]
	line   2:      unnamed       kernel   input  active-high [used]
	line   3:      unnamed       unused   input  active-high

In this example, lines 1 and 2 are invalid, and cannot be used by
userspace.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20201204164739.781812-2-maz@kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-12-09 10:23:04 +01:00
26d060e47e gpiolib: cdev: allow edge event timestamps to be configured as REALTIME
Using CLOCK_REALTIME as the source for event timestamps is crucial for
some specific applications, particularly those requiring timetamps
relative to a PTP clock, so provide an option to switch the event
timestamp source from the default CLOCK_MONOTONIC to CLOCK_REALTIME.

Note that CLOCK_REALTIME was the default source clock for GPIO until
Linux 5.7 when it was changed to CLOCK_MONOTONIC due to issues with the
shifting of the realtime clock.
Providing this option maintains the CLOCK_MONOTONIC as the default,
while also providing a path forward for those dependent on the pre-5.7
behaviour.

Suggested-by: Jack Winch <sunt.un.morcov@gmail.com>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20201014231158.34117-2-warthog618@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-12-05 23:22:47 +01:00
5e2ca893d7 gpiolib: cdev: add GPIO_V2_LINE_FLAG_EDGE_BOTH and use it in edge_irq_thread()
Add GPIO_V2_LINE_FLAG_EDGE_BOTH macro and use it in edge_irq_thread() to
improve readability of edge handling cases.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-10-30 15:53:19 +01:00
163d1719d3 gpiolib: Switch to use compat_need_64bit_alignment_fixup() helper
Use the new compat_need_64bit_alignment_fixup() helper to avoid
ugly ifdeffery in IOCTL compatibility code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Kent Gibson <warthog618@gmail.com>
Depends-on: 527c412519 ("compat: add a compat_need_64bit_alignment_fixup() helper")
Link: https://lore.kernel.org/r/20201014103315.82662-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-10-28 15:47:00 +01:00
3ffb7c45d1 gpiolib: cdev: document that line eflags are shared
The line.eflags field is shared so document this fact and highlight it
throughout using READ_ONCE() and WRITE_ONCE() accessors.

Also use a local copy of the eflags in edge_irq_thread() to ensure
consistent control flow even if eflags changes.  This is only a defensive
measure as edge_irq_thread() is currently disabled when the eflags are
changed.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-10-26 15:26:31 +01:00
0486beaf88 Merge tag 'gpio-v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO updates from Linus Walleij:
 "This time very little driver changes but lots of core changes.

  We have some interesting cooperative work for ARM and Intel alike,
  making the GPIO subsystem more and more suitable for industrial
  systems and the like, in addition to the in-kernel users.

  We touch driver core (device properties) and lib/* by adding one
  simple string array free function, these are authored by Andy
  Shevchenko who is a well known and recognized core helpers maintainers
  so this should be fine.

  We also see some Android GKI-related modularization in the MXC
  drivers.

  Core changes:

   - The big core change is the updated (v2) userspace character device
     API.

     This corrects badly designed 64-bit alignment around the line
     events. We also add the debounce request feature. This echoes the
     often quotes passage from Frederick Brooks "The mythical man-month"
     to always throw one away, which we have seen before in things such
     as V4L2. So we put in a new one and deprecate and obsolete the old
     one.

   - All example tools in tools/gpio/* are migrated to the new API to
     set a good example. The libgpiod userspace library has been
     augmented to use this new API pretty much from day 1.

   - Some misc API hardening by using strn* function calls has been
     added as well.

   - Use the simpler IDA interface for GPIO chip instance enumeration.

   - Add device core function for counting string arrays in device
     properties.

   - Provide a generic library function kfree_strarray() that can be
     used throughout the kernel.

  Driver enhancements:

   - The DesignWare dwapb-gpio driver has been enhanced and now uses the
     IRQ handling in the gpiolib core.

   - The mockup and aggregator drivers have seen some substantial code
     clean-up and now use more of the core kernel inftrastructure.

   - Misc cleanups using dev_err_probe().

   - The MXC drivers (Freescale/NXP) can now be built modularized, which
     makes modularized GKI Android kernels happy"

* tag 'gpio-v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (73 commits)
  gpiolib: Update header block in gpiolib-cdev.h
  gpiolib: cdev: switch from kstrdup() to kstrndup()
  docs: gpio: add a new document to its index.rst
  gpio: pca953x: Add support for the NXP PCAL9554B/C
  tools: gpio: add debounce support to gpio-event-mon
  tools: gpio: add multi-line monitoring to gpio-event-mon
  tools: gpio: port gpio-event-mon to v2 uAPI
  tools: gpio: port gpio-hammer to v2 uAPI
  tools: gpio: rename nlines to num_lines
  tools: gpio: port gpio-watch to v2 uAPI
  tools: gpio: port lsgpio to v2 uAPI
  gpio: uapi: document uAPI v1 as deprecated
  gpiolib: cdev: support setting debounce
  gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL
  gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL
  gpiolib: cdev: support edge detection for uAPI v2
  gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL
  gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL
  gpiolib: add build option for CDEV v1 ABI
  gpiolib: make cdev a build option
  ...
2020-10-13 10:09:33 -07:00
f188ac1251 gpiolib: cdev: switch from kstrdup() to kstrndup()
Use kstrndup() to copy line labels from the userspace provided char
array, rather than ensuring the char array contains a null terminator
and using kstrdup().

Note that the length provided to kstrndup() still assumes that the char
array does contain a null terminator, so the maximum string length is one
less than the array.  This is consistent with the previous behaviour.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20201005070246.20927-1-warthog618@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-10-08 22:57:16 +02:00
47e538d86d gpiolib: Disable compat ->read() code in UML case
It appears that UML (arch/um) has no compat.h header defined and hence
can't compile a recently provided piece of code in GPIO library.

Disable compat ->read() code in UML case to avoid compilation errors.

While at it, use pattern which is already being used in the kernel elsewhere.

Fixes: 5ad284ab3a ("gpiolib: Fix line event handling in syscall compatible mode")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20201005131044.87276-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-10-07 11:42:03 +02:00
65cff70464 gpiolib: cdev: support setting debounce
Add support for setting debounce on a line via the GPIO uAPI.
Where debounce is not supported by hardware, a software debounce is
provided.

The implementation of the software debouncer waits for the line to be
stable for the debounce period before determining if a level change,
and a corresponding edge event, has occurred.  This provides maximum
protection against glitches, but also introduces a debounce_period
latency to edge events.

The software debouncer is integrated with the edge detection as it
utilises the line interrupt, and integration is simpler than getting
the two to interwork.  Where software debounce AND edge detection is
required, the debouncer provides both.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-09-30 10:57:04 +02:00
7b8e00d981 gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL
Add support for the GPIO_V2_LINE_SET_VALUES_IOCTL.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-09-30 10:57:02 +02:00
a54756cb24 gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL
Add support for GPIO_V2_LINE_SET_CONFIG_IOCTL, the uAPI v2
line set config ioctl.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-09-30 10:56:59 +02:00
73e0341992 gpiolib: cdev: support edge detection for uAPI v2
Add support for edge detection to lines requested using
GPIO_V2_GET_LINE_IOCTL.

The edge_detector implementation is based on the v1 lineevent
implementation.  Unlike the v1 implementation, an overflow of the event
buffer results in discarding older events, rather than the most
recent, so the final event in a burst will correspond to the current
state of the line.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-09-30 10:56:56 +02:00
aad955842d gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL
Add support for GPIO_V2_GET_LINEINFO_IOCTL and
GPIO_V2_GET_LINEINFO_WATCH_IOCTL.

The core of this change is the event kfifo switching to contain
struct gpioline_info_changed_v2, instead of v1 as v2 is richer.

The two uAPI versions are mostly independent - other than where they both
provide line info changes via reads on the chip fd.  As the info change
structs differ between v1 and v2, the infowatch implementation tracks which
version of the infowatch ioctl, either GPIO_GET_LINEINFO_WATCH_IOCTL or
GPIO_V2_GET_LINEINFO_WATCH_IOCTL, initiates the initial watch and returns
the corresponding info change struct to the read.  The version supported
on that fd locks to that version on the first watch request, so subsequent
watches from that process must use the same uAPI version.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-09-30 10:56:52 +02:00
3c0d9c635a gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL
Add support for requesting lines using the GPIO_V2_GET_LINE_IOCTL, and
returning their current values using GPIO_V2_LINE_GET_VALUES_IOCTL.

The struct linereq implementation is based on the v1 struct linehandle
implementation.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-09-30 10:56:49 +02:00
69e4e13688 gpiolib: cdev: replace strncpy() with strscpy()
Replace usage of strncpy() with strscpy() to remove -Wstringop-truncation
warnings.

The structures being populated are zeroed, to prevent stack leakage as
they are returned to userspace, so strscpy() performs the equivalent
function without the warnings.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-09-30 10:56:27 +02:00
0dc11e3ad3 gpiolib: cdev: gpio_desc_to_lineinfo() should set info offset
Set the value of the line info offset in gpio_desc_to_lineinfo(), rather
than relying on it being passed in the info.  This makes the function
behave as you would expect from the name - it generates the line info
corresponding to a given GPIO desc.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-09-30 10:56:23 +02:00
5ad284ab3a gpiolib: Fix line event handling in syscall compatible mode
The introduced line event handling ABI in the commit

  61f922db72 ("gpio: userspace ABI for reading GPIO line events")

missed the fact that 64-bit kernel may serve for 32-bit applications.
In such case the very first check in the lineevent_read() will fail
due to alignment differences.

To workaround this introduce lineevent_get_size() helper which returns actual
size of the structure in user space.

Fixes: 61f922db72 ("gpio: userspace ABI for reading GPIO line events")
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-09-17 12:03:37 +02:00
4682427241 gpiolib: cdev: refactor lineevent cleanup into lineevent_free
Consolidate the cleanup of lineevents, currently duplicated in
lineevent_create and lineevent_release, into a helper function
lineevent_free.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-07-12 10:22:01 +02:00
883f919818 gpiolib: cdev: refactor linehandle cleanup into linehandle_free
Consolidate the cleanup of linehandles, currently duplicated in
linehandle_create and linehandle_release, into a helper function
linehandle_free.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-07-12 10:22:01 +02:00
1bf7ba4001 gpiolib: cdev: remove recalculation of offset
Remove recalculation of offset from desc, where desc itself was calculated
from offset.

There is no benefit from the desc -> hwgpio conversion in this context.
The only implicit benefit of the offset -> desc -> hwgpio is
the range check in the offset -> desc, but where desc is required you
still get that, and where desc isn't required it is simpler to perform
the range check directly.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-07-12 10:22:01 +02:00
f30ef3e837 gpiolib: cdev: fix minor race in GET_LINEINFO_WATCH
Merge separate usage of test_bit/set_bit into test_and_set_bit to remove
the possibility of a race between the test and set.

Similarly test_bit and clear_bit.

In the existing code it is possible for two threads to race past the
test_bit and then set or clear the watch bit, and neither return EBUSY.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-07-12 10:22:01 +02:00
e2b781c5f0 gpiolib: cdev: rename priv to cdev
Rename priv to cdev to improve readability.

The name "priv" indicates that the object is pointed to by
file->private_data, not what the object is actually is.
As it is always used to point to a struct gpio_chardev_data, renaming
it to cdev is more appropriate.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-07-12 10:22:00 +02:00
6accc376a7 gpiolib: cdev: use blocking notifier call chain instead of atomic
Replace usage of atomic_notifier_call_chain with
blocking_notifier_call_chain as the notifier function,
lineinfo_changed_notify, calls gpio_desc_to_lineinfo,
which calls pinctrl_gpio_can_use_line, which can sleep.

The chain isn't being called from an atomic context so the
the blocking notifier is a suitable substitute.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-07-12 10:22:00 +02:00
0cdc85a371 gpiolib: cdev: remove pointless decrement of i
Remove pointless decrement of variable, and associated comment.

While i is used subsequently, it is re-initialized so this decrement
serves no purpose.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-07-12 10:22:00 +02:00
52b7b596dd gpiolib: cdev: rename numdescs to num_descs
Rename numdescs to num_descs to be more consistent with the naming of
other counters and improve readability.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-07-12 10:22:00 +02:00
49bc52798d gpiolib: cdev: rename 'filep' and 'filp' to 'file' to be consistent with other use
Rename 'filep' and 'filp' to 'file' to be consistent with other use
and improve readability.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-07-12 10:22:00 +02:00
c274b58a4b gpiolib: cdev: refactor gpiohandle_flags_to_desc_flags
Refactor the mapping from handle flags to desc flags into a helper
function.

The assign_bit is overkill where it is replacing the set_bit cases, as is
rechecking bits known to be clear in some circumstances, but the DRY
simplification more than makes up for any performance degradation,
especially as this is not a hot path.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-07-12 10:22:00 +02:00
a18512e3f1 gpiolib: cdev: minor indentation fixes
Make indentation consistent with other use to improve readability.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-07-12 10:22:00 +02:00
d189f6270f gpiolib: cdev: sort includes
Sort the includes of gpiolib-cdev.c to make it easier to identify if a
module is included and to avoid duplication.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-07-12 10:22:00 +02:00
925ca36913 gpiolib: split character device into gpiolib-cdev
Split the cdev specific functionality out of gpiolib.c and into
gpiolib-cdev.c. This improves the readability and maintainability of both
the cdev and core gpiolib code.

Suggested-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20200616093615.5167-1-warthog618@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-06-20 22:38:37 +02:00