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path: root/drivers/gpio
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2024-02-12gpio: remove the RW semaphore from the GPIO deviceBartosz Golaszewski
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>
2024-02-12gpio: protect the pointer to gpio_chip in gpio_device with SRCUBartosz Golaszewski
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>
2024-02-12gpio: add SRCU infrastructure to struct gpio_deviceBartosz Golaszewski
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>
2024-02-12gpio: add the can_sleep flag to struct gpio_deviceBartosz Golaszewski
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>
2024-02-12gpio: remove unnecessary checks from gpiod_to_chip()Bartosz Golaszewski
We don't need to check the gdev pointer in struct gpio_desc - it's always assigned and never cleared. It's also pointless to check gdev->chip before we actually serialize access to it. 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>
2024-02-12gpio: reduce the functionality of validate_desc()Bartosz Golaszewski
Checking desc->gdev->chip for NULL without holding it in place with some serializing mechanism is pointless. Remove this check. Also don't check desc->gdev for NULL as it can never happen. We'll be protecting gdev->chip with SRCU soon but we will provide a dedicated, automatic class for that. 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>
2024-02-12gpio: don't dereference gdev->chip in gpiochip_setup_dev()Bartosz Golaszewski
We don't need to dereference gdev->chip in gpiochip_setup_dev() as at the time it's called, the label in the associated struct gpio_device is already set. 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>
2024-02-12gpio: sysfs: don't access gdev->chip if it's not neededBartosz Golaszewski
Don't dereference gdev->chip if the same information can be obtained from struct gpio_device. Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> 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>
2024-02-12gpio: cdev: don't access gdev->chip if it's not neededBartosz Golaszewski
The variable holding the number of GPIO lines is duplicated in GPIO device so read it instead of unnecessarily dereferencing the chip pointer. 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>
2024-02-12gpio: cdev: replace gpiochip_get_desc() with gpio_device_get_desc()Bartosz Golaszewski
gpio_device_get_desc() is the safer alternative to gpiochip_get_desc(). As we don't really need to dereference the chip pointer to retrieve the descriptors in character device code, let's use it. 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>
2024-02-12gpio: sysfs: pass the GPIO device - not chip - to sysfs callbacksBartosz Golaszewski
We're working towards protecting the chip pointer in struct gpio_device with SRCU. In order to use it in sysfs callbacks we must pass the pointer to the GPIO device that wraps the chip instead of the address of the chip itself as the user data. 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>
2024-02-12gpio: sysfs: extend the critical section for unregistering sysfs devicesBartosz Golaszewski
Checking the gdev->mockdev pointer for NULL must be part of the critical section. 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>
2024-02-12gpio: remove unneeded code from gpio_device_get_desc()Bartosz Golaszewski
The GPIO chip pointer is unused. Let's remove it. 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>
2024-02-12gpio: reinforce desc->flags handlingBartosz Golaszewski
We now removed the gpio_lock spinlock and modified the places previously protected by it to handle desc->flags access in a consistent way. Let's improve other places that were previously unprotected by reading the flags field of gpio_desc once and using the stored value for logic consistency. If we need to modify the field, let's also write it back once with a consistent value resulting from the function's logic. 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>
2024-02-12gpio: remove gpio_lockBartosz Golaszewski
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>
2024-02-12gpio: sysfs: use gpio_device_find() to iterate over existing devicesBartosz Golaszewski
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>
2024-02-12gpio: protect the descriptor label with SRCUBartosz Golaszewski
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>
2024-02-12gpio: add SRCU infrastructure to struct gpio_descBartosz Golaszewski
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>
2024-02-12gpio: don't set label from irq helpersBartosz Golaszewski
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. Don't actually set the label to "interrupt" in the above case but rather use the newly added gpiod_get_label() helper to hide the logic that atomically checks the descriptor flags and returns the address of a static "interrupt" string. 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>
2024-02-12gpio: provide and use gpiod_get_label()Bartosz Golaszewski
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>
2024-02-12gpio: remove unused logging helpersBartosz Golaszewski
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>
2024-02-12gpio: of: assign and read the hog pointer atomicallyBartosz Golaszewski
The device nodes representing GPIO hogs cannot be deleted without unregistering the GPIO chip so there's no need to serialize their access. However we must ensure that users can get the right address so write and read it atomically. 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>
2024-02-12gpio: protect the list of GPIO devices with SRCUBartosz Golaszewski
We're working towards removing the "multi-function" GPIO spinlock that's implemented terribly wrong. We tried using an RW-semaphore to protect the list of GPIO devices but it turned out that we still have old code using legacy GPIO calls that need to translate the global GPIO number to the address of the associated descriptor and - to that end - traverse the list while holding the lock. If we change the spinlock to a sleeping lock then we'll end up with "scheduling while atomic" bugs. Let's allow lockless traversal of the list using SRCU and only use the mutex when modyfing the list. While at it: let's protect the period between when we start the lookup and when we finally request the descriptor (increasing the reference count of the GPIO device) with the SRCU read lock. 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>
2024-02-12gpio: constify opaque pointer in gpio_device_find() match functionKrzysztof Kozlowski
The match function used in gpio_device_find() should not modify the contents of passed opaque pointer, because such modification would not be necessary for actual matching and it could lead to quite unreadable, spaghetti code. Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> [Bartosz: fix coding style in header] Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-02-12Merge tag 'v6.8-rc4' into gpio/for-nextBartosz Golaszewski
Linux 6.8-rc4 Pulling this for a bugfix upstream with which the gpio/for-next branch conflicts.
2024-02-08gpio: set device type for GPIO chipsBartosz Golaszewski
It's useful to have the device type information for those sub-devices that are actually GPIO chips registered with GPIOLIB. While at it: use the device type struct to setup the release callback which is the preferred way to use the device API. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-08gpio: remove GPIO device from the list unconditionally in error pathBartosz Golaszewski
Since commit 48e1b4d369cf ("gpiolib: remove the GPIO device from the list when it's unregistered") we remove the GPIO device entry from the global list (used to order devices by their GPIO ranges) when unregistering the chip, not when releasing the device. It will not happen when the last reference is put anymore. This means, we need to remove it in error path in gpiochip_add_data_with_key() unconditionally, without checking if the device's .release() callback is set. Fixes: 48e1b4d369cf ("gpiolib: remove the GPIO device from the list when it's unregistered") Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-02-05gpio: gpiolib: make gpio_bus_type constRicardo B. Marliere
Now that the driver core can properly handle constant struct bus_type, move the gpio_bus_type variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-02-02gpio: vf610: enable COMPILE_TESTMartin Kaiser
Enable COMPILE_TEST for the vf610 gpio driver to support test builds on systems without this hardware. Signed-off-by: Martin Kaiser <martin@kaiser.cx> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-02-02gpio: vf610: allow disabling the vf610 driverMartin Kaiser
The vf610 gpio driver is enabled by default for all i.MX machines, without any option to disable it in a board-specific config file. Most i.MX chipsets have no hardware for this driver. Change the default to enable GPIO_VF610 for SOC_VF610 and disable it otherwise. Add a text description after the bool type, this makes the driver selectable by make config etc. Fixes: 30a35c07d9e9 ("gpio: vf610: drop the SOC_VF610 dependency for GPIO_VF610") Signed-off-by: Martin Kaiser <martin@kaiser.cx> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-29gpio: unexport GPIO irq domain functions only used internallyBartosz Golaszewski
There are no external users for the irq domain helpers so unexport them and remove the prototypes from the driver header. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-29gpio: cdev: remove leftover function pointer typedefsBartosz Golaszewski
The locking wrappers were replaces with lock guards. These typedefs are no longer needed. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Kent Gibson <warthog618@gmail.com>
2024-01-22gpio: eic-sprd: Clear interrupt after set the interrupt typeWenhua Lin
The raw interrupt status of eic maybe set before the interrupt is enabled, since the eic interrupt has a latch function, which would trigger the interrupt event once enabled it from user side. To solve this problem, interrupts generated before setting the interrupt trigger type are ignored. Fixes: 25518e024e3a ("gpio: Add Spreadtrum EIC driver support") Acked-by: Chunyan Zhang <zhang.lyra@gmail.com> Signed-off-by: Wenhua Lin <Wenhua.Lin@unisoc.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-22gpio: eic-sprd: Optimize the calculation method of eic numberWenhua Lin
The num_eics is a default value, but some SoCs support more than 8. In order to adapt to all projects, the total number of eics is automatically calculated through dts. Signed-off-by: Wenhua Lin <Wenhua.Lin@unisoc.com> Acked-by: Chunyan Zhang <zhang.lyra@gmail.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-22gpiolib: acpi: Ignore touchpad wakeup on GPD G1619-04Mario Limonciello
Spurious wakeups are reported on the GPD G1619-04 which can be absolved by programming the GPIO to ignore wakeups. Cc: stable@vger.kernel.org Reported-and-tested-by: George Melikov <mail@gmelikov.ru> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3073 Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-22gpio: legacy: mark old interfaces as deprecated in kernel docsBartosz Golaszewski
We've recently had someone try to use of_get_named_gpio() in new code. Mark legacy interfaces as deprecated in kernel docs to avoid any confusion. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-18Merge tag 'gpio-fixes-for-v6.8-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux Pull gpio fixes from Bartosz Golaszewski: "Apart from some regular driver fixes there's a relatively big revert of the locking changes that were introduced to GPIOLIB in this merge window. This is because it turned out that some legacy GPIO interfaces - that need to translate a number from the global GPIO numberspace to the address of the relevant descriptor, thus running a GPIO device lookup and taking the GPIO device list lock - are still used in old code from atomic context resulting in "scheduling while atomic" errors. I'll try to make the read-only part of the list access entirely lockless using SRCU but this will take some time so let's go back to the old global spinlock for now. Summary: - revert the changes aiming to use a read-write semaphore to protect the list of GPIO devices due to calls to legacy API taking that lock from atomic context in old code - fix inverted logic in DEFINE_FREE() for GPIO device references - check the return value of bgpio_init() in gpio-mlxbf3 - fix node address in the DT bindings example for gpio-xilinx - fix signedness bug in gpio-rtd - fix kernel-doc warnings in gpio-en7523" * tag 'gpio-fixes-for-v6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: gpiolib: revert the attempt to protect the GPIO device list with an rwsem gpio: EN7523: fix kernel-doc warnings gpiolib: Fix scope-based gpio_device refcounting gpio: mlxbf3: add an error code check in mlxbf3_gpio_probe dt-bindings: gpio: xilinx: Fix node address in gpio gpio: rtd: Fix signedness bug in probe
2024-01-18Merge tag 'backlight-next-6.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight Pull backlight updates from Lee Jones: "New Drivers: - Add support for Monolithic Power Systems MP3309C WLED Step-up Converter Fix-ups: - Use/convert to new/better APIs/helpers/MACROs instead of hand-rolling implementations - Device Tree Binding updates - Demote non-kerneldoc header comments - Improve error handling; return proper error values, simplify, avoid duplicates, etc - Convert over to the new (kinda) GPIOD API Bug Fixes: - Fix uninitialised local variable" * tag 'backlight-next-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight: backlight: hx8357: Convert to agnostic GPIO API backlight: ili922x: Add an error code check in ili922x_write() backlight: ili922x: Drop kernel-doc for local macros backlight: mp3309c: Fix uninitialized local variable backlight: pwm_bl: Use dev_err_probe backlight: mp3309c: Add support for MPS MP3309C dt-bindings: backlight: mp3309c: Remove two required properties
2024-01-17gpiolib: revert the attempt to protect the GPIO device list with an rwsemBartosz Golaszewski
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>
2024-01-15gpio: EN7523: fix kernel-doc warningsRandy Dunlap
Add "struct" keyword and explain the @dir array differently to prevent kernel-doc warnings: gpio-en7523.c:22: warning: cannot understand function prototype: 'struct airoha_gpio_ctrl ' gpio-en7523.c:27: warning: Function parameter or struct member 'dir' not described in 'airoha_gpio_ctrl' gpio-en7523.c:27: warning: Excess struct member 'dir0' description in 'airoha_gpio_ctrl' gpio-en7523.c:27: warning: Excess struct member 'dir1' description in 'airoha_gpio_ctrl' Fixes: 0868ad385aff ("gpio: Add support for Airoha EN7523 GPIO controller") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-15gpio: mlxbf3: add an error code check in mlxbf3_gpio_probeSu Hui
Clang static checker warning: Value stored to 'ret' is never read. bgpio_init() returns error code if failed, it's better to add this check. Fixes: cd33f216d241 ("gpio: mlxbf3: Add gpio driver support") Signed-off-by: Su Hui <suhui@nfschina.com> [Bartosz: add the Fixes: tag] Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-15gpio: rtd: Fix signedness bug in probeDan Carpenter
The "data->irqs[]" array holds unsigned int so this error handling will not work correctly. Fixes: eee636bff0dc ("gpio: rtd: Add support for Realtek DHC(Digital Home Center) RTD SoCs") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-04gpiolib: replace the GPIO device mutex with a read-write semaphoreBartosz Golaszewski
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>
2024-01-04gpiolib: remove the GPIO device from the list when it's unregisteredBartosz Golaszewski
If we wait until the GPIO device's .release() callback gets invoked before we remove it from the global device list, then we risk that someone will look it up using gpio_device_find() between where we dropped the last reference and before .release() is done taking a reference again to an object that's being released. The device must be removed when it's being unregistered - just like how we remove it from the GPIO bus. Fixes: ff2b13592299 ("gpio: make the gpiochip a real device") Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2024-01-03gpio: nuvoton: Add Nuvoton NPCM sgpio driverJim Liu
Add Nuvoton BMC NPCM7xx/NPCM8xx sgpio driver support. Nuvoton NPCM SGPIO module is combine serial to parallel IC (HC595) and parallel to serial IC (HC165), and use APB3 clock to control it. This interface has 4 pins (D_out , D_in, S_CLK, LDSH). BMC can use this driver to increase 64 GPI pins and 64 GPO pins to use. Signed-off-by: Jim Liu <JJLIU0@nuvoton.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-03gpio: rtd: Add support for Realtek DHC(Digital Home Center) RTD SoCsTzuyi Chang
This driver enables configuration of GPIO direction, GPIO values, GPIO debounce settings and handles GPIO interrupts. Signed-off-by: Tzuyi Chang <tychang@realtek.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-03gpio: pmic-eic-sprd: Configure the bit corresponding to the EIC through offsetWenhua Lin
A bank PMIC EIC contains 16 EICs, and the operating registers are BIT0-BIT15, such as BIT0 of the register operated by EIC0. Using the one-dimensional array reg[CACHE_NR_REGS] for maintenance will cause the configuration of other EICs to be affected when operating a certain EIC. In order to solve this problem, configure the bit corresponding to the EIC through offset. Signed-off-by: Wenhua Lin <Wenhua.Lin@unisoc.com> Reviewed-by: Chunyan Zhang <zhang.lyra@gmail.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-02gpio: dwapb: Use generic request, free and set_configEmil Renner Berthing
This way GPIO will be denied on pins already claimed by other devices and basic pin configuration (pull-up, pull-down etc.) can be done through the userspace GPIO API. Signed-off-by: Emil Renner Berthing <emil.renner.berthing@canonical.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Serge Semin <fancer.lancer@gmail.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2023-12-27gpio: sysfs: drop tabs from local variable declarationsBartosz Golaszewski
Older code has an annoying habit of putting tabs between the type and the name of the variable. This doesn't really add to readability and newer code doesn't do it so make the entire file consistent. 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>
2023-12-27gpiolib: drop tabs from local variable declarationsBartosz Golaszewski
Older code has an annoying habit of putting tabs between the type and the name of the variable. This doesn't really add to readability and newer code doesn't do it so make the entire file consistent. While at it: convert 'unsigned' to 'unsigned int'. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>