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| * | | gpio: don't let lockdep complain about inherently dangerous RCU usageBartosz Golaszewski2024-02-151-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are two legacy, deprecated functions - gpiod_to_chip() and gpio_device_get_chip() - that still have users in tree. They return the address of the SRCU-protected chip outside of the read-only critical sections. They are inherently dangerous and the users should convert to safer alternatives. Let's explicitly silence lockdep warnings by using rcu_dereference_check(ptr, 1). While at it: reuse gpio_device_get_chip() in gpiod_to_chip(). 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>
| * | | gpio: use srcu_dereference() with SRCU-protected pointersBartosz Golaszewski2024-02-153-11/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: cdev: use correct pointer accessors with SRCUBartosz Golaszewski2024-02-151-13/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We never dereference the chip pointer in character device code so we can use the lighter rcu_access_pointer() helper. This also makes lockep happier as it no longer complains about suspicious rcu_dereference() usage. 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> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Paul E. McKenney <paulmck@kernel.org>
| * | | gpio: take the SRCU read lock in gpiod_hog()Bartosz Golaszewski2024-02-151-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gpiod_hog() may be called without the gpio_device SRCU read lock taken so we need to do it here as well. It's alright if someone else is already holding the lock as SRCU read critical sections can be nested. 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> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Paul E. McKenney <paulmck@kernel.org>
| * | | gpio: initialize descriptor SRCU structure before adding OF-based chipsBartosz Golaszewski2024-02-141-9/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In certain situations we may end up taking the GPIO descriptor SRCU read lock in of_gpiochip_add() before the SRCU struct is initialized. Move the initialization before the call to of_gpiochip_add(). Fixes: be711caa87c5 ("gpio: add SRCU infrastructure to struct gpio_desc") Fixes: 1f2bcb8c8ccd ("gpio: protect the descriptor label with SRCU") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-lkp/202402122228.e607a080-lkp@intel.com Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
| * | | gpio: mark unsafe gpio_chip manipulators as deprecatedBartosz Golaszewski2024-02-121-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We still have some functions that return the address of the GPIO chip associated with the GPIO device. This is dangerous and the users should find a better solution. Let's add appropriate comments to the kernel docs. 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>
| * | | gpio: remove the RW semaphore from the GPIO deviceBartosz Golaszewski2024-02-122-9/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: protect the pointer to gpio_chip in gpio_device with SRCUBartosz Golaszewski2024-02-124-129/+271
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: add SRCU infrastructure to struct gpio_deviceBartosz Golaszewski2024-02-122-3/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: add the can_sleep flag to struct gpio_deviceBartosz Golaszewski2024-02-122-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: remove unnecessary checks from gpiod_to_chip()Bartosz Golaszewski2024-02-121-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: reduce the functionality of validate_desc()Bartosz Golaszewski2024-02-121-15/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: don't dereference gdev->chip in gpiochip_setup_dev()Bartosz Golaszewski2024-02-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: sysfs: don't access gdev->chip if it's not neededBartosz Golaszewski2024-02-121-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: cdev: don't access gdev->chip if it's not neededBartosz Golaszewski2024-02-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: cdev: replace gpiochip_get_desc() with gpio_device_get_desc()Bartosz Golaszewski2024-02-121-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: sysfs: pass the GPIO device - not chip - to sysfs callbacksBartosz Golaszewski2024-02-121-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: sysfs: extend the critical section for unregistering sysfs devicesBartosz Golaszewski2024-02-121-7/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: remove unneeded code from gpio_device_get_desc()Bartosz Golaszewski2024-02-121-10/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: reinforce desc->flags handlingBartosz Golaszewski2024-02-121-17/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: remove gpio_lockBartosz Golaszewski2024-02-124-98/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: sysfs: use gpio_device_find() to iterate over existing devicesBartosz Golaszewski2024-02-123-25/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: protect the descriptor label with SRCUBartosz Golaszewski2024-02-123-30/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: add SRCU infrastructure to struct gpio_descBartosz Golaszewski2024-02-122-2/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: don't set label from irq helpersBartosz Golaszewski2024-02-121-13/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: provide and use gpiod_get_label()Bartosz Golaszewski2024-02-123-4/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: remove unused logging helpersBartosz Golaszewski2024-02-121-13/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: of: assign and read the hog pointer atomicallyBartosz Golaszewski2024-02-122-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: protect the list of GPIO devices with SRCUBartosz Golaszewski2024-02-121-112/+135
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | gpio: constify opaque pointer in gpio_device_find() match functionKrzysztof Kozlowski2024-02-123-7/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | Merge tag 'v6.8-rc4' into gpio/for-nextBartosz Golaszewski2024-02-123-8/+46
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linux 6.8-rc4 Pulling this for a bugfix upstream with which the gpio/for-next branch conflicts.
| * | | | gpio: set device type for GPIO chipsBartosz Golaszewski2024-02-081-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | | gpio: gpiolib: make gpio_bus_type constRicardo B. Marliere2024-02-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | | gpio: vf610: enable COMPILE_TESTMartin Kaiser2024-02-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | | gpio: vf610: allow disabling the vf610 driverMartin Kaiser2024-02-021-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | | gpio: unexport GPIO irq domain functions only used internallyBartosz Golaszewski2024-01-291-51/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | | gpio: cdev: remove leftover function pointer typedefsBartosz Golaszewski2024-01-291-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | | gpio: eic-sprd: Optimize the calculation method of eic numberWenhua Lin2024-01-221-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | | gpio: legacy: mark old interfaces as deprecated in kernel docsBartosz Golaszewski2024-01-222-0/+14
| | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | | | Merge tag 'pwm/for-6.9-rc1' of ↵Linus Torvalds2024-03-131-9/+9
|\ \ \ \ | |_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux Pull pwm updates from Uwe Kleine-König: "This contains the usual amount of driver and device tree changes. Additionally there is a big rework of how pwm lowlevel drivers are registered to prepare adding character device support. Thanks to Dharma Balasubiramani, Dong Aisheng, Duje Mihanović, Jerome Brunet, Raag Jadav and Rafał Miłecki for their contributions. And sorry for those who still need some patience because I didn't manage to empty my review queue" * tag 'pwm/for-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux: (185 commits) pwm: imx-tpm: fix probe crash due to access registers without clock pwm: meson: generalize 4 inputs clock on meson8 pwm type dt-bindings: pwm: amlogic: Add a new binding for meson8 pwm types dt-bindings: pwm: amlogic: fix s4 bindings pwm: dwc: simplify error handling pwm: dwc: Add 16 channel support for Intel Elkhart Lake pwm: dwc: drop redundant error check staging: greybus: pwm: Make use of devm_pwmchip_alloc() function staging: greybus: pwm: Rework how the number of PWM lines is determined staging: greybus: pwm: Drop unused gb_connection_set_data() staging: greybus: pwm: Rely on pwm framework to pass a valid hwpwm staging: greybus: pwm: Make use of pwmchip_parent() accessor staging: greybus: pwm: Change prototype of helpers to prepare further changes leds: qcom-lpg: Make use of devm_pwmchip_alloc() function drm/bridge: ti-sn65dsi86: Make use of devm_pwmchip_alloc() function drm/bridge: ti-sn65dsi86: Make use of pwmchip_parent() accessor gpio: mvebu: Make use of devm_pwmchip_alloc() function pwm: xilinx: Make use of devm_pwmchip_alloc() function pwm: xilinx: Prepare removing pwm_chip from driver data pwm: vt8500: Make use of devm_pwmchip_alloc() function ...
| * | | gpio: mvebu: Make use of devm_pwmchip_alloc() functionUwe Kleine-König2024-02-221-9/+9
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | This prepares the pwm sub-driver to further changes of the pwm core outlined in the commit introducing devm_pwmchip_alloc(). There is no intended semantical change and the driver should behave as before. Acked-by: Linus Walleij <linus.walleij@linaro.org> Link: https://lore.kernel.org/r/2edc3adbb2c40b76b3b3dac82de82f3036bec1d5.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
* | | gpio: fix resource unwinding order in error pathBartosz Golaszewski2024-03-011-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | Hogs are added *after* ACPI so should be removed *before* in error path. Fixes: a411e81e61df ("gpiolib: add hogs support for machine code") Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
* | | gpiolib: Fix the error path order in gpiochip_add_data_with_key()Andy Shevchenko2024-03-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | After shuffling the code, error path wasn't updated correctly. Fix it here. Fixes: 2f4133bb5f14 ("gpiolib: No need to call gpiochip_remove_pin_ranges() twice") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
* | | gpio: 74x164: Enable output pins after registers are resetArturas Moskvinas2024-03-011-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Chip outputs are enabled[1] before actual reset is performed[2] which might cause pin output value to flip flop if previous pin value was set to 1. Fix that behavior by making sure chip is fully reset before all outputs are enabled. Flip-flop can be noticed when module is removed and inserted again and one of the pins was changed to 1 before removal. 100 microsecond flipping is noticeable on oscilloscope (100khz SPI bus). For a properly reset chip - output is enabled around 100 microseconds (on 100khz SPI bus) later during probing process hence should be irrelevant behavioral change. Fixes: 7ebc194d0fd4 (gpio: 74x164: Introduce 'enable-gpios' property) Link: https://elixir.bootlin.com/linux/v6.7.4/source/drivers/gpio/gpio-74x164.c#L130 [1] Link: https://elixir.bootlin.com/linux/v6.7.4/source/drivers/gpio/gpio-74x164.c#L150 [2] Signed-off-by: Arturas Moskvinas <arturas.moskvinas@gmail.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
* | | gpiolib: Handle no pin_ranges in gpiochip_generic_config()Emil Renner Berthing2024-02-201-0/+5
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Similar to gpiochip_generic_request() and gpiochip_generic_free() the gpiochip_generic_config() function needs to handle the case where there are no pinctrl pins mapped to the GPIOs, usually through the gpio-ranges device tree property. Commit f34fd6ee1be8 ("gpio: dwapb: Use generic request, free and set_config") set the .set_config callback to gpiochip_generic_config() in the dwapb GPIO driver so the GPIO API can set pinctrl configuration for the corresponding pins. Most boards using the dwapb driver do not set the gpio-ranges device tree property though, and in this case gpiochip_generic_config() would return -EPROPE_DEFER rather than the previous -ENOTSUPP return value. This in turn makes gpio_set_config_with_argument_optional() fail and propagate the error to any driver requesting GPIOs. Fixes: 2956b5d94a76 ("pinctrl / gpio: Introduce .set_config() callback for GPIO chips") Reported-by: Jisheng Zhang <jszhang@kernel.org> Closes: https://lore.kernel.org/linux-gpio/ZdC_g3U4l0CJIWzh@xhacker/ Tested-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Emil Renner Berthing <emil.renner.berthing@canonical.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
* | gpio: remove GPIO device from the list unconditionally in error pathBartosz Golaszewski2024-02-081-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | gpio: eic-sprd: Clear interrupt after set the interrupt typeWenhua Lin2024-01-221-4/+28
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* | gpiolib: acpi: Ignore touchpad wakeup on GPD G1619-04Mario Limonciello2024-01-221-0/+14
|/ | | | | | | | | | | | 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>
* Merge tag 'gpio-fixes-for-v6.8-rc1' of ↵Linus Torvalds2024-01-187-98/+111
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * gpiolib: revert the attempt to protect the GPIO device list with an rwsemBartosz Golaszewski2024-01-174-89/+97
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>