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git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into gpio/for-next
Linux 6.14-rc7
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We use a notifier to implement the mechanism of informing the user-space
about changes in GPIO line status. We register with the notifier when
the GPIO character device file is opened and unregister when the last
reference to the associated file descriptor is dropped.
Since commit fcc8b637c542 ("gpiolib: switch the line state notifier to
atomic") we use the atomic notifier variant. Atomic notifiers call
rcu_synchronize in atomic_notifier_chain_unregister() which caused a
significant performance regression in some circumstances, observed by
user-space when calling close() on the GPIO device file descriptor.
Replace the atomic notifier with the raw variant and provide
synchronization with a read-write spinlock.
Fixes: fcc8b637c542 ("gpiolib: switch the line state notifier to atomic")
Reported-by: David Jander <david@protonic.nl>
Closes: https://lore.kernel.org/all/20250311110034.53959031@erd003.prtnl/
Tested-by: David Jander <david@protonic.nl>
Tested-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20250311-gpiolib-line-state-raw-notifier-v2-1-138374581e1e@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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The valid_mask member of the struct gpio_chip is unconditionally written
by the GPIO core at driver registration. Current documentation does not
mention this but just says the valid_mask is used if it's not NULL. This
lured me to try populating it directly in the GPIO driver probe instead
of using the init_valid_mask() callback. It took some retries with
different bitmaps and eventually a bit of code-reading to understand why
the valid_mask was not obeyed. I could've avoided this trial and error if
the valid_mask was hidden in the struct gpio_device instead of being a
visible member of the struct gpio_chip.
Help the next developer who decides to directly populate the valid_mask
in struct gpio_chip by hiding the valid_mask in struct gpio_device and
keep it internal to the GPIO core.
Suggested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/4547ca90d910d60cab3d56d864d59ddde47a5e93.1741180097.git.mazziesaccount@gmail.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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Align FLAG_* definitions in the struct gpio_desc for better readability.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20250303160341.1322640-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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During the locking rework in GPIOLIB, we omitted one important use-case,
namely: setting and getting values for GPIO descriptor arrays with
array_info present.
This patch does two things: first it makes struct gpio_array store the
address of the underlying GPIO device and not chip. Next: it protects
the chip with SRCU from removal in gpiod_get_array_value_complex() and
gpiod_set_array_value_complex().
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250215095655.23152-1-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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We currently only notify user-space about line config changes that are
made from user-space. Any kernel config changes are not signalled.
Let's improve the situation by emitting the events closer to the source.
To that end let's call the relevant notifier chain from the functions
setting direction, gpiod_set_config(), gpiod_set_consumer_name() and
gpiod_toggle_active_low(). This covers all the options that we can
inform the user-space about. We ignore events which don't have
corresponding flags exported to user-space on purpose - otherwise the
user would see a config-changed event but the associated line-info would
remain unchanged.
gpiod_direction_output/input() can be called from any context.
Fortunately, we now emit line state events using an atomic notifier
chain, so it's no longer an issue.
Let's also add non-notifying wrappers around the direction setters in
order to not emit superfluous reconfigure events when requesting the
lines as the initial config should be part of the request notification.
Use gpio_do_set_config() instead of gpiod_set_debounce() for configuring
debouncing via hardware from the character device code to avoid multiple
reconfigure events.
Reviewed-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20241018-gpio-notify-in-kernel-events-v5-8-c79135e58a1c@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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With everything else ready, we can now switch to using the atomic
notifier for line state events which will allow us to notify user-space
about direction changes from atomic context.
Reviewed-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20241018-gpio-notify-in-kernel-events-v5-7-c79135e58a1c@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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In order to prepare the line state notification mechanism for working in
atomic context as well, add a dedicated, high-priority, ordered
workqueue to GPIO device which will be used to queue the events fron any
context for them to be emitted always in process context.
Reviewed-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20241018-gpio-notify-in-kernel-events-v5-5-c79135e58a1c@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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This effectively reverts commits 9344e34e7992 ("gpiolib: cdev: relocate
debounce_period_us from struct gpio_desc") and d8543cbaf979 ("gpiolib:
remove debounce_period_us from struct gpio_desc") and goes back to
storing the debounce period in microseconds in the GPIO descriptor
We're doing it in preparation for notifying the user-space about
in-kernel line config changes.
Reviewed-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20241018-gpio-notify-in-kernel-events-v5-3-c79135e58a1c@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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There is no need to have and export the count variable for the array
in question. Instead, make it NULL-terminated.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240819142945.327808-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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Introduce a helper macro for_each_gpio_property_name().
With that in place, update users. This, in particular,
will help making the following simplifications easier.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240819142945.327808-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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This function has been deprecated for some time and is now only used
within the GPIOLIB core. Remove it from the public header and unexport
it as all current users are linked against the compilation unit where
it is defined.
Link: https://lore.kernel.org/r/20240625073815.12376-1-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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The gpio_suffixes array is defined in the gpiolib.h header. This means
the array is stored in .rodata of every compilation unit that includes
it. Put the definition for the array in gpiolib.c and export just the
symbol in the header. We need the size of the array so expose it too.
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: https://lore.kernel.org/r/20240612184821.58053-1-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio updates from Bartosz Golaszewski
"This was a quiet release cycle for the GPIO tree and so this
pull-request is relatively small.
We have one new driver, some minor improvements to the GPIO core code
and across several drivers, some DT and documentation updates but in
general nothing stands out or is controversial. All changes have spent
time in next with no reported issues (or ones that were quickly
fixed).
GPIO core:
- remove more unused legacy interfaces (after converting the last
remaining users to better alternatives)
- update kerneldocs
- improve error handling and log messages in GPIO ACPI code
- remove dead code (always true checks) from GPIOLIB
New drivers:
- add a driver for Intel Granite Rapids-D vGPIO
Driver improvements:
- use -ENOTSUPP consistently in gpio-regmap and gpio-pcie-idio-24
- provide an ID table for gpio-cros-ec to avoid a driver name
fallback check
- add support for gpio-ranges for GPIO drivers supporting multiple
GPIO banks
- switch to using dynamic GPIO base in gpio-brcmstb
- fix irq handling in gpio-npcm-sgpio
- switch to memory mapped IO accessors in gpio-sch
DT bindings:
- add support for gpio-ranges to gpio-brcmstb
- add support for a new model and the gpio-line-names property to
gpio-mpfs
Documentation:
- replace leading tabs with spaces in code blocks
- fix typos"
* tag 'gpio-updates-for-v6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (30 commits)
gpio: nuvoton: Fix sgpio irq handle error
gpiolib: Discourage to use formatting strings in line names
gpio: brcmstb: add support for gpio-ranges
gpio: of: support gpio-ranges for multiple gpiochip devices
dt-bindings: gpio: brcmstb: add gpio-ranges
gpio: Add Intel Granite Rapids-D vGPIO driver
gpio: brcmstb: Use dynamic GPIO base numbers
gpiolib: acpi: Set label for IRQ only lines
gpiolib: acpi: Add fwnode name to the GPIO interrupt label
gpiolib: Get rid of never false gpio_is_valid() calls
gpiolib: acpi: Pass con_id instead of property into acpi_dev_gpio_irq_get_by()
gpiolib: acpi: Move acpi_can_fallback_to_crs() out of __acpi_find_gpio()
gpiolib: acpi: Simplify error handling in __acpi_find_gpio()
gpiolib: acpi: Extract __acpi_find_gpio() helper
gpio: sch: Utilise temporary variable for struct device
gpio: sch: Switch to memory mapped IO accessors
gpio: regmap: Use -ENOTSUPP consistently
gpio: pcie-idio-24: Use -ENOTSUPP consistently
Documentation: gpio: Replace leading TABs by spaces in code blocks
gpiolib: acpi: Check for errors first in acpi_find_gpio()
...
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We used a per-descriptor SRCU struct in order to not impose a wait with
synchronize_srcu() for descriptor X on read-only operations of
descriptor Y. Now that we no longer call synchronize_srcu() on
descriptor label change but only when releasing descriptor resources, we
can use a single SRCU structure for all GPIO descriptors in a given chip.
Suggested-by: "Paul E. McKenney" <paulmck@kernel.org>
Acked-by: "Paul E. McKenney" <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20240507172414.28513-1-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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Commit 1f2bcb8c8ccd ("gpio: protect the descriptor label with SRCU")
caused a massive drop in performance of requesting GPIO lines due to the
call to synchronize_srcu() on each label change. Rework the code to not
wait until all read-only users are done with reading the label but
instead atomically replace the label pointer and schedule its release
after all read-only critical sections are done.
To that end wrap the descriptor label in a struct that also contains the
rcu_head struct required for deferring tasks using call_srcu() and stop
using kstrdup_const() as we're required to allocate memory anyway. Just
allocate enough for the label string and rcu_head in one go.
Reported-by: Neil Armstrong <neil.armstrong@linaro.org>
Closes: https://lore.kernel.org/linux-gpio/CAMRc=Mfig2oooDQYTqo23W3PXSdzhVO4p=G4+P8y1ppBOrkrJQ@mail.gmail.com/
Fixes: 1f2bcb8c8ccd ("gpio: protect the descriptor label with SRCU")
Suggested-by: "Paul E. McKenney" <paulmck@kernel.org>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-QRD
Acked-by: "Paul E. McKenney" <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20240507121346.16969-1-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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In the cases when gpio_is_valid() is called with unsigned parameter
the result is always true in the GPIO library code, hence the check
for false won't ever be true. Get rid of such calls.
While at it, move GPIO device base to be unsigned to clearly show
it won't ever be negative. This requires a new definition for the
maximum GPIO number in the system.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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This devm API takes a consumer device as an argument to setup the devm
action, but throws it away when calling further into gpiolib. This leads
to odd debug messages like this:
(NULL device *): using DT '/gpio-keys/switch-pen-insert' for '(null)' GPIO lookup
Let's pass the consumer device down, by directly calling what
fwnode_gpiod_get_index() calls but pass the device used for devm. This
changes the message to look like this instead:
gpio-keys gpio-keys: using DT '/gpio-keys/switch-pen-insert' for '(null)' GPIO lookup
Note that callers of fwnode_gpiod_get_index() will still see the NULL
device pointer debug message, but there's not much we can do about that
because the API doesn't take a struct device.
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Fixes: 8eb1f71e7acc ("gpiolib: consolidate GPIO lookups")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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Lockdep with CONFIG_PROVE_RCU enabled reports false positives about
suspicious rcu_dereference() usage. Let's silence it by using
srcu_dereference() which is the correct helper with SRCU.
Fixes: d83cee3d2bb1 ("gpio: protect the pointer to gpio_chip in gpio_device with SRCU")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202402122234.d85cca9b-lkp@intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
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With all accesses to gdev->chip being protected with SRCU, we can now
remove the RW-semaphore specific to the character device which
fulfilled the same role up to this point.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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Ensure we cannot crash if the GPIO device gets unregistered (and the
chip pointer set to NULL) during any of the API calls.
To that end: wait for all users of gdev->chip to exit their read-only
SRCU critical sections in gpiochip_remove().
For brevity: add a guard class which can be instantiated at the top of
every function requiring read-only access to the chip pointer and use it
in all API calls taking a GPIO descriptor as argument. In places where
we only deal with the GPIO device - use regular guard() helpers and
rcu_dereference() for chip access. Do the same in API calls taking a
const pointer to gpio_desc.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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Add the SRCU struct to GPIO device. It will be used to serialize access
to the GPIO chip pointer. Initialize and clean it up where applicable.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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Duplicating the can_sleep value in GPIO device will allow us to not
needlessly dereference the chip pointer in several places and reduce the
number of SRCU read-only critical sections.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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The "multi-function" gpio_lock is pretty much useless with how it's used
in GPIOLIB currently. Because many GPIO API calls can be called from all
contexts but may also call into sleeping driver callbacks, there are
many places with utterly broken workarounds like yielding the lock to
call a possibly sleeping function and then re-acquiring it again without
taking into account that the protected state may have changed.
It was also used to protect several unrelated things: like individual
descriptors AND the GPIO device list. We now serialize access to these
two with SRCU and so can finally remove the spinlock.
There is of course the question of consistency of lockless access to
GPIO descriptors. Because we only support exclusive access to GPIOs
(officially anyway, I'm looking at you broken
GPIOD_FLAGS_BIT_NONEXCLUSIVE bit...) and the API contract with providers
does not guarantee serialization, it's enough to ensure we cannot
accidentally dereference an invalid pointer and that the state we present
to both users and providers remains consistent. To achieve that: read the
flags field atomically except for a few special cases. Read their current
value before executing callback code and use this value for any subsequent
logic. Modifying the flags depends on the particular use-case and can
differ. For instance: when requesting a GPIO, we need to set the
REQUESTED bit immediately so that the next user trying to request the
same line sees -EBUSY.
While at it: the allocations that used GFP_ATOMIC until this point can
now switch to GFP_KERNEL.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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With the list of GPIO devices now protected with SRCU we can use
gpio_device_find() to traverse it from sysfs.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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In order to ensure that the label is not freed while it's being
accessed, let's protect it with SRCU and synchronize it everytime it's
changed.
Let's modify desc_set_label() to manage the memory used for the label as
it can only be freed once synchronize_srcu() returns.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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Extend the GPIO descriptor with an SRCU structure in order to serialize
the access to the label. Initialize and clean it up where applicable.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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We will soon serialize access to the descriptor label using SRCU. The
write-side of the protection will require calling synchronize_srcu()
which must not be called from atomic context. We have two irq helpers:
gpiochip_lock_as_irq() and gpiochip_unlock_as_irq() that set the label
if the GPIO is not requested but is being used as interrupt. They are
called with a spinlock held from the interrupt subsystem.
They must not do it if we are to use SRCU so instead let's move the
special corner case to a dedicated getter.
First: let's implement and use the getter where it's applicable.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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The general rule of the kernel is to not provide symbols that have no
users upstream. Let's remove logging helpers that are not used anywhere.
This will save us work later when we'll be modifying them to use the
upcoming SRCU infrastructure.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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This reverts commits 1979a2807547 ("gpiolib: replace the GPIO device
mutex with a read-write semaphore") and 65a828bab158 ("gpiolib: use
a mutex to protect the list of GPIO devices").
Unfortunately the legacy GPIO API that's still used in older code has to
translate numbers from the global GPIO numberspace to descriptors. This
results in a GPIO device lookup in every call to legacy functions. Some
of those functions - like gpio_set/get_value() - can be called from
atomic context so taking a sleeping lock that is an RW semaphore results
in an error.
We'll probably have to protect this list with SRCU.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-wireless/f7b5ff1e-8f34-4d98-a7be-b826cb897dc8@moroto.mountain/
Fixes: 1979a2807547 ("gpiolib: replace the GPIO device mutex with a read-write semaphore")
Fixes: 65a828bab158 ("gpiolib: use a mutex to protect the list of GPIO devices")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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There are only two spots where we modify (add to or remove objects from)
the GPIO device list. Readers should be able to access it concurrently.
Replace the mutex with a read-write semaphore and adjust the locking
operations accordingly.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
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cdev is the only user of the debounce_period_us field in
struct gpio_desc, and it no longer uses it, so remove it.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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The global list of GPIO devices is never modified or accessed from
atomic context so it's fine to protect it using a mutex. Add a new
global lock dedicated to the gpio_devices list and use it whenever
accessing or modifying it.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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In order to start migrating away from accessing struct gpio_chip by
users other than their owners, let's first make the reference management
functions for the opaque struct gpio_device public in the driver.h
header.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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It makes sense for a GPIO driver to want to get its own descriptor
without requesting it. After all, the driver knows that it'll still be
valid. Let's move this helper to linux/gpio/driver.h.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
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There are no and never have been any users of gpiod_set_transitory()
outside the core GPIOLIB code. Make it private.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
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Wrap the calls to blocking_notifier_call_chain() for the line state
notifier with a helper that allows us to use fewer lines of code and
simpler syntax.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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Add a new blocking notifier to struct gpio_device and use it to notify
subscribers about the GPIO device being unregistered from the device
model.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
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Change the generic "notifier" name to "line_state_notifier" in order to
reflect its purpose in preparation for adding a second notifier which
will be used to notify wait queues about device unregistering.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
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bgpio_init() uses "sz" argument to populate ngpio, which is not
accurate. Instead, read the "ngpios" property from the DT and if it
doesn't exist, use the "sz" argument. With this change, drivers no
longer need to overwrite the ngpio variable after calling bgpio_init().
If the "ngpios" property is specified, bgpio_bits is calculated
as the round up value of ngpio. At the moment, the only requirement
specified is that the round up value must be a multiple of 8 but
it should also be a power of 2 because we provide accessors based
on the bank size in bgpio_setup_accessors().
Signed-off-by: Asmaa Mnebhi <asmaa@nvidia.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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After adding the missing notifier.h header, let's order all includes
alphabetically.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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gpiolib.h uses notifiers but doesn't include <linux/notifier.h>.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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Introduce gpio_device_get() and gpio_device_put() helpers
and convert existing users.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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user-space
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: d7c51b47ac11 ("gpio: userspace ABI for reading/writing GPIO lines")
Fixes: 3c0d9c635ae2 ("gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL")
Fixes: aad955842d1c ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Fixes: a54756cb24ea ("gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL")
Fixes: 7b8e00d98168 ("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>
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Provide to_gpio_device() helper which can be utilized in the existing
and future code.
While at it, make sure it becomes no-op at compilation time.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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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
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Some GPIO chip can provide hardware timestamp support on its GPIO lines
, in order to support that, additional API needs to be added which
can talk to both GPIO chip and HTE (hardware timestamping engine)
providers if there is any dependencies. This patch introduces optional
hooks to enable and disable hardware timestamping related features
in the GPIO controller chip.
Signed-off-by: Dipen Patel <dipenp@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
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In some cases we want to traverse all GPIO descriptors for given
chip, let's split out for_each_gpio_desc() macro for such cases.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
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The iterator loop is used exclusively to get a descriptor, which in its
turn is what is being used by the caller. Embed the iterator variable
into the loop in the for_each_gpio_desc_with_flag() macro helper.
Suggested-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
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git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio updates from Bartosz Golaszewski:
"Relatively few updates for this release cycle. We have a single new
driver and some minor changes in drivers, more work on limiting the
usage of of_node in drivers and DT updates:
- new driver: gpio-en7523
- dt-bindings: convertion of faraday,ftgpio010 to YAML, new
compatible string in gpio-vf610 and a bugfix in an example
- gpiolib core: several improvements and some code shrink
- documentation: convert all public docs into kerneldoc format
- set IRQ bus token in gpio-crystalcove (addresses a debugfs issue)
- add a missing return value check for kstrdup() in gpio-merrifield
- allow gpio-tps68470 to be built as module
- more work on limiting usage of of_node in GPIO drivers
- several sysfs interface improvements
- use SDPX in gpio-ts4900"
* tag 'gpio-updates-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
gpio: ts4900: Use SPDX header
gpiolib: Use list_first_entry()/list_last_entry()
gpiolib: sysfs: Simplify edge handling in the code
gpiolib: sysfs: Move kstrtox() calls outside of the mutex lock
gpiolib: sysfs: Move sysfs_emit() calls outside of the mutex lock
gpiolib: make struct comments into real kernel docs
dt-bindings: gpio: convert faraday,ftgpio01 to yaml
dt-bindings: gpio: gpio-vf610: Add imx93 compatible string
gpiolib: Simplify error path in gpiod_get_index() when requesting GPIO
gpiolib: Use short form of ternary operator in gpiod_get_index()
gpiolib: Introduce for_each_gpio_desc_with_flag() macro
gpio: Add support for Airoha EN7523 GPIO controller
dt-bindings: arm: airoha: Add binding for Airoha GPIO controller
dt-bindings: gpio: fix gpio-hog example
gpio: tps68470: Allow building as module
gpio: tegra: Get rid of duplicate of_node assignment
gpio: altera-a10sr: Switch to use fwnode instead of of_node
gpio: merrifield: check the return value of devm_kstrdup()
gpio: crystalcove: Set IRQ domain bus token to DOMAIN_BUS_WIRED
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