[ Upstream commit bdbbae241a ]
While any of the GPIO cdev syscalls is in progress, the kernel can call
gpiochip_remove() (for instance, when a USB GPIO expander is disconnected)
which will set gdev->chip to NULL after which any subsequent access will
cause a crash.
To avoid that: use an RW-semaphore in which the syscalls take it for
reading (so that we don't needlessly prohibit the user-space from calling
syscalls simultaneously) while gpiochip_remove() takes it for writing so
that it can only happen once all syscalls return.
Fixes: d7c51b47ac ("gpio: userspace ABI for reading/writing GPIO lines")
Fixes: 3c0d9c635a ("gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL")
Fixes: aad955842d ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Fixes: a54756cb24 ("gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL")
Fixes: 7b8e00d981 ("gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
[Nick: fixed a build failure with CDEV_V1 disabled]
Co-authored-by: Nick Hainke <vincent@systemli.org>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 533aae7c94 ]
There are several places where we can crash the kernel by requesting
lines, unbinding the GPIO device, then calling any of the system calls
relevant to the GPIO character device's annonymous file descriptors:
ioctl(), read(), poll().
While I observed it with the GPIO simulator, it will also happen for any
of the GPIO devices that can be hot-unplugged - for instance any HID GPIO
expander (e.g. CP2112).
This affects both v1 and v2 uAPI.
This fixes it partially by checking if gdev->chip is not NULL but it
doesn't entirely remedy the situation as we still have a race condition
in which another thread can remove the device after the check.
Fixes: d7c51b47ac ("gpio: userspace ABI for reading/writing GPIO lines")
Fixes: 3c0d9c635a ("gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL")
Fixes: aad955842d ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Fixes: a54756cb24 ("gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL")
Fixes: 7b8e00d981 ("gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
New drivers:
- add a new driver for the IMX System Controller Unit GPIOs
GPIO core:
- add fdinfo output for the GPIO character device file descriptors (allows
user-space to determine which processes own which GPIO lines)
- improvements to OF GPIO code
- new quirk for Asus UM325UAZ in gpiolib-acpi
- new quirk for Freescale SPI in gpiolib-of
Driver improvements:
- add a new macro that reduces the amount of boilerplate code in ISA drivers
and use it in relevant drivers
- support two new models in gpio-pca953x
- support new model in gpio-f7188x
- convert more drivers to use immutable irq chips
- other minor tweaks
Device-tree bindings:
- add DT bindings for gpio-imx-scu
- convert Xilinx GPIO bindings to YAML
- reference the properties from the SPI peripheral device-tree bindings
instead of providing custom ones in the GPIO controller document
- add parsing of GPIO hog nodes to the DT bindings for gpio-mpfs-gpio
- relax the node name requirements in gpio-stmpe
- add new models for gpio-rcar and gpio-pxa95xx
- add a new vendor prefix: Diodes (for Diodes, Inc.)
Misc:
- pulled in the immutable branch from the x86 platform drivers tree including
support for a new simatic board that depends on GPIO changes
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Merge tag 'gpio-updates-for-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio updates from Bartosz Golaszewski:
"We have a single new driver, support for a bunch of new models,
improvements in drivers and core gpiolib code as well device-tree
bindings changes.
Summary:
New driver:
- IMX System Controller Unit GPIOs
GPIO core:
- add fdinfo output for the GPIO character device file descriptors
(allows user-space to determine which processes own which GPIO
lines)
- improvements to OF GPIO code
- new quirk for Asus UM325UAZ in gpiolib-acpi
- new quirk for Freescale SPI in gpiolib-of
Driver improvements:
- add a new macro that reduces the amount of boilerplate code in ISA
drivers and use it in relevant drivers
- support two new models in gpio-pca953x
- support new model in gpio-f7188x
- convert more drivers to use immutable irq chips
- other minor tweaks
Device-tree bindings:
- add DT bindings for gpio-imx-scu
- convert Xilinx GPIO bindings to YAML
- reference the properties from the SPI peripheral device-tree
bindings instead of providing custom ones in the GPIO controller
document
- add parsing of GPIO hog nodes to the DT bindings for gpio-mpfs-gpio
- relax the node name requirements in gpio-stmpe
- add new models for gpio-rcar and gpio-pxa95xx
- add a new vendor prefix: Diodes (for Diodes, Inc.)
Misc:
- pulled in the immutable branch from the x86 platform drivers tree
including support for a new simatic board that depends on GPIO
changes"
* tag 'gpio-updates-for-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (36 commits)
gpio: tc3589x: Make irqchip immutable
gpiolib: cdev: add fdinfo output for line request file descriptors
gpio: twl4030: Reorder functions which allows to drop a forward declaraion
gpiolib: fix OOB access in quirk callbacks
gpiolib: of: factor out conversion from OF flags
gpiolib: rework quirk handling in of_find_gpio()
gpiolib: of: make Freescale SPI quirk similar to all others
gpiolib: of: do not ignore requested index when applying quirks
gpio: ws16c48: Ensure number of irq matches number of base
gpio: 104-idio-16: Ensure number of irq matches number of base
gpio: 104-idi-48: Ensure number of irq matches number of base
gpio: 104-dio-48e: Ensure number of irq matches number of base
counter: 104-quad-8: Ensure number of irq matches number of base
isa: Introduce the module_isa_driver_with_irq helper macro
gpio: pca953x: Add support for PCAL6534
gpio: pca953x: Swap if statements to save later complexity
gpio: pca953x: Fix pca953x_gpio_set_pull_up_down()
dt-bindings: gpio: pca95xx: add entry for pcal6534 and PI4IOE5V6534Q
dt-bindings: vendor-prefixes: add Diodes
gpio: mt7621: Switch to use platform_get_irq() function
...
Add fdinfo output for file descriptors created for user-space line
requests in GPIO uAPI v2. The fdinfo file now contains the name of the
GPIO chip that is the "parent" of the request as well as offsets of
the lines requested. This allows user-space to parse the /proc/$PID/fdinfo
entries and deduce the PID of the process that requested a specific line.
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
When running gpio test on nxp-ls1028 platform with below command
gpiomon --num-events=3 --rising-edge gpiochip1 25
There will be a warning trace as below:
Call trace:
free_irq+0x204/0x360
lineevent_free+0x64/0x70
gpio_ioctl+0x598/0x6a0
__arm64_sys_ioctl+0xb4/0x100
invoke_syscall+0x5c/0x130
......
el0t_64_sync+0x1a0/0x1a4
The reason of this issue is that calling request_threaded_irq()
function failed, and then lineevent_free() is invoked to release
the resource. Since the lineevent_state::irq was already set, so
the subsequent invocation of free_irq() would trigger the above
warning call trace. To fix this issue, set the lineevent_state::irq
after the IRQ register successfully.
Fixes: 4682427241 ("gpiolib: cdev: refactor lineevent cleanup into lineevent_free")
Cc: stable@vger.kernel.org
Signed-off-by: Meng Li <Meng.Li@windriver.com>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
- 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
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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
...
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>
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>
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>
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>
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>
This contains a single fix for an out-of-sync kerneldoc comment.
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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
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>
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>
This contains the new HTE 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.
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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
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>
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>
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>
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>
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>
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>
- 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
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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
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>
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>
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>
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>
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>
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.
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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
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Bartosz Golaszewski