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path: root/drivers/gpio/gpio-regmap.c
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2025-10-23gpio: regmap: Bypass cache for aliased inputsSander Vanheule
GPIO chips often have data input and output registers aliased to the same offset. The output register is non-valitile and could in theory be cached. The input register however is volatile by nature and hence should not be cached, resulting in different requirements for reads and writes. The generic gpio chip implementation stores a shadow value of the pin output data, which is updated and written to hardware on output data changes in bgpio_set(), bgpio_set_set(). Pin input values are always obtained by reading the aliased data register from hardware. For gpio-regmap the situation is more complex as the output data could be in multiple registers, but we can use the regmap cache to shadow the output values when marking the data registers as non-volatile. By using regmap_read_bypassed() we can still treat the input values as volatile, irrespective of the regmap config. This ensures proper functioning of writing the output register with regmap_write_bits(), which will then use and update the cache only on data writes, gaining some performance from the cached output values. Signed-off-by: Sander Vanheule <sander@svanheule.net> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Michael Walle <mwalle@kernel.org> Link: https://lore.kernel.org/r/20251021142407.307753-3-sander@svanheule.net Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2025-10-23gpio: regmap: Force writes for aliased data regsSander Vanheule
GPIO chips often have data input and output fields aliased to the same offset. Since gpio-regmap performs a value update before the direction update (to prevent glitches), a pin currently configured as input may cause regmap_update_bits() to not perform a write. This may cause unexpected line states when the current input state equals the requested output state: OUT IN OUT DIR ''''''\...|.../'''''' pin ....../'''|'''\...... (1) (2) (3) 1. Line was configurad as out-low, but is reconfigured to input. External logic results in high value. 2. Set output value high. regmap_update_bits() sees the value is already high and discards the register write. 3. Line is switched to output, maintaining the stale output config (low) instead of the requested config (high). By switching to regmap_write_bits(), a write of the requested output value can be forced, irrespective of the read state. Do this only for aliased registers, so the more efficient regmap_update_bits() can still be used for distinct registers. Signed-off-by: Sander Vanheule <sander@svanheule.net> Reviewed-by: Michael Walle <mwalle@kernel.org> Link: https://lore.kernel.org/r/20251021142407.307753-2-sander@svanheule.net Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2025-10-16gpio: regmap: add the .fixed_direction_output configuration parameterIoana Ciornei
There are GPIO controllers such as the one present in the LX2160ARDB QIXIS FPGA which have fixed-direction input and output GPIO lines mixed together in a single register. This cannot be modeled using the gpio-regmap as-is since there is no way to present the true direction of a GPIO line. In order to make this use case possible, add a new configuration parameter - fixed_direction_output - into the gpio_regmap_config structure. This will enable user drivers to provide a bitmap that represents the fixed direction of the GPIO lines. Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com> Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Michael Walle <mwalle@kernel.org> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2025-10-01Merge tag 'gpio-updates-for-v6.18-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux Pull gpio updates from Bartosz Golaszewski: "There are two new drivers and support for more models in existing ones. The generic GPIO API has been reworked and all users converted which allowed us to move the fields specific to the generic GPIO implementation out of the high-level struct gpio_chip into its own structure that wraps the gpio_chip. Other than that, there's nothing too exciting. Mostly minor tweaks and fixes all over the place, some refactoring and some small new features in helper modules. GPIO core: - add support for sparse pin ranges to the glue between GPIO and pinctrl - use a common prefix across all GPIO descriptor flags for improved namespacing New drivers: - add new GPIO driver for the Nuvoton NCT6694 - add new GPIO driver for MAX7360 Driver improvements: - add support for Tegra 256 to the gpio-tegra186 driver - add support for Loongson-2K0300 to the gpio-loongson-64bit driver - refactor the gpio-aggregator module to expose its GPIO forwarder API to other in-kernel users (to enable merging of a new pinctrl driver that uses it) - convert all remaining drivers to using the modernized generic GPIO chip API and remove the old interface - stop displaying global GPIO numbers in debugfs output of controller drivers - extend the gpio-regmap helper with a new config option and improve its support for GPIO interrupts - remove redundant fast_io parameter from regmap configs in GPIO drivers that already use MMIO regmaps which imply it - add support for a new model in gpio-mmio: ixp4xx expansion bus - order includes alphabetically in a few drivers for better readability - use generic device properties where applicable - use devm_mutex_init() where applicable - extend build coverage of drivers by enabling more to be compiled with COMPILE_TEST enabled - allow building gpio-stmpe as a module - use dev_err_probe() where it makes sense in drivers Late driver fixes: - fix setting GPIO direction to output in gpio-mpfs Documentation: - document the usage of software nodes with GPIO chips Device-tree bindings: - Add DT bindings documents for new hardware: Tegra256, MAX7360 - Document a new model in Loongson bindings: LS2K0300 - Document a new model using the generic GPIO binding: IXP4xx - Convert the DT binding for fsl,mxs-pinctrl to YAML - fix the schema ID in the "trivial" GPIO schema - describe GPIO hogs in the generic GPIO binding" * tag 'gpio-updates-for-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (122 commits) gpio: mpfs: fix setting gpio direction to output gpio: generic: move GPIO_GENERIC_ flags to the correct header gpio: generic: rename BGPIOF_ flags to GPIO_GENERIC_ gpio: nomadik: fix the debugfs helper stub MAINTAINERS: Add entry on MAX7360 driver input: misc: Add support for MAX7360 rotary input: keyboard: Add support for MAX7360 keypad gpio: max7360: Add MAX7360 gpio support gpio: regmap: Allow to provide init_valid_mask callback gpio: regmap: Allow to allocate regmap-irq device pwm: max7360: Add MAX7360 PWM support pinctrl: Add MAX7360 pinctrl driver mfd: Add max7360 support dt-bindings: mfd: gpio: Add MAX7360 rtc: Add Nuvoton NCT6694 RTC support hwmon: Add Nuvoton NCT6694 HWMON support watchdog: Add Nuvoton NCT6694 WDT support can: Add Nuvoton NCT6694 CANFD support i2c: Add Nuvoton NCT6694 I2C support gpio: Add Nuvoton NCT6694 GPIO support ...
2025-09-22gpio: regmap: fix memory leak of gpio_regmap structureIoana Ciornei
The gpio_regmap structure is leaked on the error path. Fix this by jumping to the appropriate kfree instead of returning directly. Fixes: db305161880a ("gpio: regmap: Allow ngpio to be read from the property") Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com> Suggested-by: Michael Walle <mwalle@kernel.org> Reviewed-by: Michael Walle <mwalle@kernel.org> Link: https://lore.kernel.org/r/20250922142427.3310221-7-ioana.ciornei@nxp.com Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2025-09-16gpio: regmap: Allow to provide init_valid_mask callbackMathieu Dubois-Briand
Allows to populate the gpio_regmap_config structure with init_valid_mask() callback to set on the final gpio_chip structure. Reviewed-by: Michael Walle <mwalle@kernel.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com> Link: https://lore.kernel.org/r/20250824-mdb-max7360-support-v14-6-435cfda2b1ea@bootlin.com Signed-off-by: Lee Jones <lee@kernel.org>
2025-09-16gpio: regmap: Allow to allocate regmap-irq deviceMathieu Dubois-Briand
GPIO controller often have support for IRQ: allow to easily allocate both gpio-regmap and regmap-irq in one operation. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com> Link: https://lore.kernel.org/r/20250824-mdb-max7360-support-v14-5-435cfda2b1ea@bootlin.com Signed-off-by: Lee Jones <lee@kernel.org>
2025-08-07treewide: rename GPIO set callbacks back to their original namesBartosz Golaszewski
The conversion of all GPIO drivers to using the .set_rv() and .set_multiple_rv() callbacks from struct gpio_chip (which - unlike their predecessors - return an integer and allow the controller drivers to indicate failures to users) is now complete and the legacy ones have been removed. Rename the new callbacks back to their original names in one sweeping change. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2025-02-26gpio: regmap: use value returning settersBartosz Golaszewski
struct gpio_chip now has additional variants of the set(_multiple) driver callbacks that return an integer to indicate success or failure. Convert the driver to using them. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Michael Walle <mwalle@kernel.org> Acked-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> Link: https://lore.kernel.org/r/20250220-gpio-set-retval-v2-7-bc4cfd38dae3@linaro.org Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2025-02-21gpio: regmap: Allow ngpio to be read from the propertyAndy Shevchenko
GPIOLIB supports the case when number of supported GPIOs can be read from the device property. Enable this for drivers that are using GPIO regmap layer. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Michael Walle <mwalle@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com> Reviewed-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com> Link: https://lore.kernel.org/r/20250213195621.3133406-6-andriy.shevchenko@linux.intel.com Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2025-02-21gpio: regmap: Move optional assignments down in the codeAndy Shevchenko
Move optional assignments down in the code, so they may use some values from the (updated) struct gpio_chip later on. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Michael Walle <mwalle@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com> Reviewed-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com> Link: https://lore.kernel.org/r/20250213195621.3133406-5-andriy.shevchenko@linux.intel.com Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2025-02-21gpio: regmap: Group optional assignments together for better understandingAndy Shevchenko
Group ngpio_per_reg, reg_stride, and reg_mask_xlate assignments together with the respective conditional for better understanding what's going on in the code. While at it, mark ngpio_per_reg as (Optional) in the kernel-doc in accordance with what code actually does. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Michael Walle <mwalle@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com> Reviewed-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com> Link: https://lore.kernel.org/r/20250213195621.3133406-4-andriy.shevchenko@linux.intel.com Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2025-01-13gpio: regmap: Use generic request/free opsSander Vanheule
Set the gpiochip request and free ops to the generic implementations. This way a user can provide a gpio-ranges property defined for a pinmux, easing muxing of gpio functions. Provided that the pin controller implementents the pinmux op .gpio_request_enable(), pins will automatically be muxed to their GPIO function when requested. Signed-off-by: Sander Vanheule <sander@svanheule.net> Acked-by: Michael Walle <mwalle@kernel.org> Link: https://lore.kernel.org/r/20250107201621.12467-1-sander@svanheule.net Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-04-12gpio: regmap: Use -ENOTSUPP consistentlyAndy Shevchenko
The GPIO library expects the drivers to return -ENOTSUPP in some cases and not using analogue POSIX code. Make the driver to follow this. Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Michael Walle <mwalle@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2023-03-06gpio: regmap: Add missing header(s)Andy Shevchenko
Do not imply that some of the generic headers may be always included. Instead, include explicitly what we are direct user of. While at it, split out the GPIO group of headers. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2023-01-30gpio: regmap: use new regmap_might_sleep()Michael Walle
Now that the regmap can be queried whether it might sleep, we can get rid of the conservative setting "can_sleep = true". New drivers which want to use gpio-regmap and can access the registers memory-mapped won't have the restriction that their consumers have to use the gpiod_*cansleep() variants anymore. Signed-off-by: Michael Walle <michael@walle.cc> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2023-01-30gpio: regmap: Always set gpio_chip get_directionWilliam Breathitt Gray
If you only have reg_dat_base set, then it is input-only; if you only have reg_set_base set, then it is output-only. Thus, we can always set gpio_chip get_direction to gpio_regmap_get_direction and return GPIO_LINE_DIRECTION_IN/GPIO_LINE_DIRECTION_OUT given the respective register base addresses configuration. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Michael Walle <michael@walle.cc> Signed-off-by: William Breathitt Gray <william.gray@linaro.org> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2021-12-23gpio: regmap: Switch to use fwnode instead of of_nodeAndy Shevchenko
GPIO library now accepts fwnode as a firmware node, so switch the driver to use it. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Michael Walle <michael@walle.cc> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2021-06-07gpio: regmap: move drvdata to config dataMichael Walle
Drop gpio_regmap_set_drvdata() and instead add it to the configuration data passed to gpio_regmap_register(). gpio_regmap_set_drvdata() can't really be used in a race free way. This is because the gpio_regmap object which is needed by _set_drvdata() is returned by gpio_regmap_register(). On the other hand, the callbacks which use the drvdata might already be called right after the gpiochip_add() call in gpio_regmap_register(). Therefore, we have to provide the drvdata early before we call gpiochip_add(). Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com> Signed-off-by: Michael Walle <michael@walle.cc> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2021-06-04gpio: gpio-regmap: Use devm_add_action_or_reset()Matti Vaittinen
Slightly simplify the devm_gpio_regmap_register() by using the devm_add_action_or_reset(). Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Michael Walle <michael@walle.cc> Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2021-03-29gpio: regmap: set gpio_chip of_nodeÁlvaro Fernández Rojas
This is needed for properly registering GPIO regmap as a child of a regmap pin controller. Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com> Reviewed-by: Michael Walle <michael@walle.cc> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Acked-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Link: https://lore.kernel.org/r/20210324081923.20379-3-noltari@gmail.com Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-06-03gpio: add a reusable generic gpio_chip using regmapMichael Walle
There are quite a lot simple GPIO controller which are using regmap to access the hardware. This driver tries to be a base to unify existing code into one place. This won't cover everything but it should be a good starting point. It does not implement its own irq_chip because there is already a generic one for regmap based devices. Instead, the irq_chip will be instantiated in the parent driver and its irq domain will be associate to this driver. For now it consists of the usual registers, like set (and an optional clear) data register, an input register and direction registers. Out-of-the-box, it supports consecutive register mappings and mappings where the registers have gaps between them with a linear mapping between GPIO offset and bit position. For weirder mappings the user can register its own .xlate(). Signed-off-by: Michael Walle <michael@walle.cc> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/20200528145845.31436-3-michael@walle.cc Signed-off-by: Linus Walleij <linus.walleij@linaro.org>