include/asm-generic/gpio.h

1 /* SPDX-License-Identifier: GPL-2.0+ */
15  * Generic GPIO API for U-Boot
17  * --
20  *    - gpio_request_by_name()
21  *    - dm_gpio_get_value() etc.
24  * --
26  * GPIOs are numbered from 0 to GPIO_COUNT-1 which value is defined
35  * In some cases the operation may fail, for example if the GPIO number
37  * being used by another function. In that case, functions may return
38  * an error value of -1.
51  * @return 0 if ok, -1 on error
60  * @return 0 if ok, -1 on error
69  * @return 0 if ok, -1 on error
79  * @return 0 if ok, -1 on error
89  * @return 0 if low, 1 if high, -1 on error
100  * @return 0 if ok, -1 on error
128 	 * We could consider adding the GPIO label in here. Possibly we could
134  * dm_gpio_is_valid() - Check if a GPIO is valid
142 	return desc->dev != NULL;  in dm_gpio_is_valid()
146  * gpio_get_status() - get the current GPIO status as a string
151  * "b4:  in: 1 [x] sdmmc_cd"
166  * gpio_get_function() - get the current function for a GPIO pin
174  * @namep:	If non-NULL, this is set to the name given when the GPIO
175  *		was requested, or -1 if it has not been requested
176  * @return  -ENODATA if the driver returned an unknown function,
177  * -ENODEV if the device is not active, -EINVAL if the offset is invalid.
184  * gpio_get_raw_function() - get the current raw function for a GPIO pin
186  * Note this does not return GPIOF_UNUSED - it will always return the GPIO
193  * @namep:	If non-NULL, this is set to the name given when the GPIO
194  *		was requested, or -1 if it has not been requested
195  * @return  -ENODATA if the driver returned an unknown function,
196  * -ENODEV if the device is not active, -EINVAL if the offset is invalid.
202  * gpio_requestf() - request a GPIO using a format string for the owner
205  * a printf()-format string for the GPIO owner. It calls gpio_request() with
214  * gpio_xlate_offs_flags() - implementation for common use of dm_gpio_ops.xlate
217  * GPIOD_ACTIVE_LOW if the GPIO_ACTIVE_LOW flag is present in args[1].
223  * struct struct dm_gpio_ops - Driver model GPIO operations
228  * This is trying to be close to Linux GPIO API. Once the U-Boot uses the
230  * GPIO API-alike interface.
235  * gpio_request() and gpio_free() are optional - if NULL then they will
239  * offset 0 is the device's first GPIO and offset o-1 is the last GPIO,
241  * is typically used to control a single bank of GPIOs. Within complex
246  * numbering from 0 to n-1, where n is the number of GPIOs in total across
247  * all devices. Be careful not to confuse offset with gpio in the parameters.
264 	 * @return current function - GPIOF_...
269 	 * xlate() - Translate phandle arguments into a GPIO description
271 	 * This function should set up the fields in desc according to the
272 	 * information in the arguments. The uclass will have set up:
274 	 *   @desc->dev to @dev
275 	 *   @desc->flags to 0
276 	 *   @desc->offset to 0
279 	 * which will parse offset and the GPIO_ACTIVE_LOW flag in the first
282 	 * Note that @dev is passed in as a parameter to follow driver model
284 	 * desc->dev.
288 	 * @args:	Arguments provided in description
289 	 * @return 0 if OK, -ve on error
296  * struct gpio_dev_priv - information about a device used by the uclass
302  * To implement driver model support in your GPIO driver, add a probe
303  * handler, and set @gpio_count and @bank_name correctly in that handler.
304  * This tells the uclass the name of the GPIO bank and the number of GPIOs
307  * @bank_name: Name of the GPIO device (e.g 'a' means GPIOs will be called
309  * @gpio_count: Number of GPIOs in this device
312  * @gpio_base for device 1 will equal the number of GPIOs in device 0.
313  * @name: Array of pointers to the name for each GPIO in this bank. The
324 #define gpio_get_ops(dev)	((struct dm_gpio_ops *)(dev)->driver->ops)
327  * gpio_get_bank_info - Return information about a GPIO bank/device
330  * of GPIOs it controls.
333  * @offset_count: Returns number of GPIOs within this bank
339  * dm_gpio_lookup_name() - Look up a named GPIO and return its description
342  * For example A0 is the first GPIO in bank A. Each bank is a separate driver
347  * @return 0 if OK, -ve on error
352  * gpio_hog_lookup_name() - Look up a named GPIO and return the gpio descr.
356  * @return:	Returns 0 if OK, else -ENODEV
361  * gpio_hog_probe_all() - probe all gpio devices with
362  * gpio-hog subnodes.
369  * gpio_lookup_name - Look up a GPIO name and return its details
383  * gpio_get_values_as_int() - Turn the values of a list of GPIOs into an int
388  * @gpio_list: List of GPIOs to collect
389  * @return resulting integer value, or -ve on error
394  * dm_gpio_get_values_as_int() - Turn the values of a list of GPIOs into an int
399  * @desc_list: List of GPIOs to collect
400  * @count: Number of GPIOs
401  * @return resulting integer value, or -ve on error
406  * gpio_claim_vector() - claim a number of GPIOs for input
408  * @gpio_num_array:	array of gpios to claim, terminated by -1
410  * @return 0 if OK, -ve on error
415  * gpio_request_by_name() - Locate and request a GPIO by name
417  * This operates by looking up the given list name in the device (device
419  * in @dev's node.
421  * Use @flags to specify whether the GPIO should be an input or output. In
431  * requests a GPIO which subsequently is unbound, the @desc->dev pointer
434  * for now. There is no real use case for unbinding drivers in normal
437  * The device tree binding is doc/device-tree-bindings/gpio/gpio.txt in
438  * generate terms and each specific device may add additional details in
439  * a binding file in the same directory.
442  * @list_name:	Name of GPIO list (e.g. "board-id-gpios")
443  * @index:	Index number of the GPIO in that list use request (0=first)
445  *		GPIO, dev->dev will be NULL.
447  * @return 0 if OK, -ENOENT if the GPIO does not exist, -EINVAL if there is
448  * something wrong with the list, or other -ve for another error (e.g.
449  * -EBUSY if a GPIO was already requested)
455  * gpio_request_list_by_name() - Request a list of GPIOs
457  * Reads all the GPIOs from a list and requests them. See
459  * misused to hold unrelated or optional GPIOs. They should only be used
463  * This function will either succeed, and request all GPIOs in the list, or
464  * fail and request none (it will free already-requested GPIOs in case of
465  * an error part-way through).
468  * @list_name:	Name of GPIO list (e.g. "board-id-gpios")
470  * @max_count:	Maximum number of GPIOs to return (@desc_list must be at least
473  * @return number of GPIOs requested, or -ve on error
480  * dm_gpio_request() - manually request a GPIO
483  * use gpio_request_by_name() to pull GPIOs from the device tree.
487  * @return 0 if OK, -ve on error
492  * gpio_get_list_count() - Returns the number of GPIOs in a list
494  * Counts the GPIOs in a list. See gpio_request_by_name() for additional
498  * @list_name:	Name of GPIO list (e.g. "board-id-gpios")
499  * @return number of GPIOs (0 for an empty property) or -ENOENT if the list
505  * gpio_request_by_name_nodev() - request GPIOs without a device
514  * gpio_request_list_by_name_nodev() - request GPIOs without a device
524  * gpio_dev_request_index() - request single GPIO from gpio device
529  * @list_name:	Name of GPIO list (e.g. "board-id-gpios")
530  * @index:	Index number of the GPIO in that list use request (0=first)
541  * dm_gpio_free() - Free a single GPIO
543  * This frees a single GPIOs previously returned from gpio_request_by_name().
547  * @return 0 if OK, -ve on error
552  * gpio_free_list() - Free a list of GPIOs
554  * This frees a list of GPIOs previously returned from
557  * @dev:	Device which requested the GPIOs
558  * @desc:	List of GPIOs to free
559  * @count:	Number of GPIOs in the list
560  * @return 0 if OK, -ve on error
565  * gpio_free_list_nodev() - free GPIOs without a device
573  * dm_gpio_get_value() - Get the value of a GPIO
583  * @return GPIO value (0 for inactive, 1 for active) or -ve on error
590  * dm_gpio_get_open_drain() - Check if open-drain-mode of a GPIO is active
592  * This checks if open-drain-mode for a GPIO is enabled or not. This method is
598  *	   -ve on error
603  * dm_gpio_set_open_drain() - Switch open-drain-mode of a GPIO on or off
605  * This enables or disables open-drain mode for a GPIO. This method is
609  * In open-drain mode, instead of actively driving the output (Push-pull
617  * @return 0 if OK, -ve on error
622  * dm_gpio_set_dir() - Set the direction for a GPIO
629  * @return 0 if OK, -ve on error
634  * dm_gpio_set_dir_flags() - Set direction using specific flags
637  * instead of being used from desc->flags. This is needed because in many
639  * Note that desc->flags is updated by this function.
644  * @return 0 if OK, -ve on error, in which case desc->flags is not updated
649  * gpio_get_number() - Get the global GPIO number of a GPIO
656  * @return GPIO number, or -ve if not found