include/asm-generic/gpio.h

15  * Generic GPIO API for U-Boot
29  * Each GPIO can be an input or output. If an input then its value can
35  * In some cases the operation may fail, for example if the GPIO number
36  * is out of range, or the GPIO is not available because its pin is
43  * Request a GPIO. This should be called before any of the other functions
44  * are used on this GPIO.
49  * @param gpio	GPIO number
50  * @param label	User label for this GPIO
53 int gpio_request(unsigned gpio, const char *label);
57  * Stop using the GPIO.  This function should not alter pin configuration.
59  * @param gpio	GPIO number
62 int gpio_free(unsigned gpio);
66  * Make a GPIO an input.
68  * @param gpio	GPIO number
71 int gpio_direction_input(unsigned gpio);
75  * Make a GPIO an output, and set its value.
77  * @param gpio	GPIO number
78  * @param value	GPIO value (0 for low or 1 for high)
81 int gpio_direction_output(unsigned gpio, int value);
85  * Get a GPIO's value. This will work whether the GPIO is an input
88  * @param gpio	GPIO number
91 int gpio_get_value(unsigned gpio);
95  * Set an output GPIO's value. The GPIO must already be an output or
98  * @param gpio	GPIO number
99  * @param value	GPIO value (0 for low or 1 for high)
102 int gpio_set_value(unsigned gpio, int value);
104 /* State of a GPIO, as reported by get_function() */
110 	GPIOF_FUNC,		/* Not used as a GPIO */
118 	struct udevice *dev;	/* Device, NULL for invalid GPIO */
121 #define GPIOD_IS_OUT		(1 << 1)	/* GPIO is an output */
122 #define GPIOD_IS_IN		(1 << 2)	/* GPIO is an input */
126 	uint offset;		/* GPIO offset within the device */
128 	 * We could consider adding the GPIO label in here. Possibly we could
129 	 * use this structure for internal GPIO information.
134  * dm_gpio_is_valid() - Check if a GPIO is valid
136  * @desc:	GPIO description containing device, offset and flags,
146  * gpio_get_status() - get the current GPIO status as a string
148  * Obtain the current GPIO status as a string which can be presented to the
153  * which means this is GPIO bank b, offset 4, currently set to input, current
159  * @offset:	Offset of device GPIO to check
166  * gpio_get_function() - get the current function for a GPIO pin
168  * Note this returns GPIOF_UNUSED if the GPIO is not requested.
173  * @offset:	Offset of device GPIO to check
174  * @namep:	If non-NULL, this is set to the name given when the GPIO
178  * GPIOF_UNUSED if the GPIO has not been requested. Otherwise returns the
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
192  * @offset:	Offset of device GPIO to check
193  * @namep:	If non-NULL, this is set to the name given when the GPIO
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
208 int gpio_requestf(unsigned gpio, const char *fmt, ...)
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
229  * new DM GPIO API, this should be really easy to flip over to the Linux
230  * GPIO API-alike interface.
238  * Note that @offset is the offset from the base GPIO of the device. So
239  * offset 0 is the device's first GPIO and offset o-1 is the last GPIO,
240  * where o is the number of GPIO lines controlled by the device. A device
245  * The uclass combines all GPIO devices together to provide a consistent
247  * all devices. Be careful not to confuse offset with gpio in the parameters.
260 	 * get_function() Get the GPIO function
263 	 * @offset:  GPIO offset within that device
269 	 * xlate() - Translate phandle arguments into a GPIO description
286 	 * @dev:	GPIO device
287 	 * @desc:	Place to put GPIO description
298  * The uclass combines all active GPIO devices into a unified numbering
302  * To implement driver model support in your GPIO driver, add a probe
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
310  * @gpio_base: Base GPIO number for this device. For the first active device
313  * @name: Array of pointers to the name for each GPIO in this bank. The
314  * value of the pointer will be NULL if the GPIO has not been claimed.
323 /* Access the GPIO operations for a device */
327  * gpio_get_bank_info - Return information about a GPIO bank/device
329  * This looks up a device and returns both its GPIO base name and the number
339  * dm_gpio_lookup_name() - Look up a named GPIO and return its description
341  * The name of a GPIO is typically its bank name followed by a number from 0.
342  * For example A0 is the first GPIO in bank A. Each bank is a separate driver
352  * gpio_hog_lookup_name() - Look up a named GPIO and return the gpio descr.
355  * @desc:	Returns GPIO description, on success, else NULL
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
371  * This is used to convert a named GPIO into a device, offset and GPIO
374  * @name: GPIO name to look up
375  * @devp: Returns pointer to device which contains this GPIO
377  * @gpiop: Returns the absolute GPIO number, numbered from 0
385  * This puts the value of the first GPIO into bit 0, the second into bit 1,
396  * This puts the value of the first GPIO into bit 0, the second into bit 1,
409  * @fmt:		format string for GPIO names, e.g. "board_id%d"
415  * gpio_request_by_name() - Locate and request a GPIO by name
418  * tree property) and requesting the GPIO for use. The property must exist
421  * Use @flags to specify whether the GPIO should be an input or output. In
423  * bindings don't provide this information. Specifically, when the GPIO uclass
427  * If we find that requesting the GPIO is not always needed we could add a
431  * requests a GPIO which subsequently is unbound, the @desc->dev pointer
432  * will be invalid. However this will only happen if the GPIO device is
437  * The device tree binding is doc/device-tree-bindings/gpio/gpio.txt in
441  * @dev:	Device requesting the GPIO
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)
444  * @desc:	Returns GPIO description information. If there is no such
445  *		GPIO, dev->dev will be NULL.
446  * @flags:	Indicates the GPIO input/output settings (GPIOD_...)
447  * @return 0 if OK, -ENOENT if the GPIO does not exist, -EINVAL if there is
449  * -EBUSY if a GPIO was already requested)
467  * @dev:	Device requesting the GPIO
468  * @list_name:	Name of GPIO list (e.g. "board-id-gpios")
469  * @desc_list:	Returns a list of GPIO description information
472  * @flags:	Indicates the GPIO input/output settings (GPIOD_...)
480  * dm_gpio_request() - manually request a GPIO
485  * @desc:	GPIO description of GPIO to request (see dm_gpio_lookup_name())
486  * @label:	Label to attach to the GPIO while claimed
497  * @dev:	Device requesting the GPIO
498  * @list_name:	Name of GPIO list (e.g. "board-id-gpios")
524  * gpio_dev_request_index() - request single GPIO from gpio device
526  * @dev:	GPIO device
527  * @nodename:	Name of node for which gpio gets requested, used
528  *		for the gpio label name
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)
532  * @dtflags:	GPIO flags read from DT defined see GPIOD_*
533  * @desc:	returns GPIO descriptor filled from this function
541  * dm_gpio_free() - Free a single GPIO
545  * @dev:	Device which requested the GPIO
546  * @desc:	GPIO to free
573  * dm_gpio_get_value() - Get the value of a GPIO
581  * @desc:	GPIO description containing device, offset and flags,
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
595  * @desc:	GPIO description containing device, offset and flags,
597  * @return Value of open drain mode for GPIO (0 for inactive, 1 for active) or
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
610  * output), the GPIO's pin is connected to the collector (for a NPN transistor)
615  * @desc:	GPIO description containing device, offset and flags,
622  * dm_gpio_set_dir() - Set the direction for a GPIO
627  * @desc:	GPIO description containing device, offset and flags,
638  * cases the GPIO description does not include direction information.
641  * @desc:	GPIO description containing device, offset and flags,
649  * gpio_get_number() - Get the global GPIO number of a GPIO
652  * that should be used for gpio_get_value() etc. to access this GPIO.
654  * @desc:	GPIO description containing device, offset and flags,
656  * @return GPIO number, or -ve if not found