driver-api/gpio/board.rst

7 Note that it only applies to the new descriptor-based interface. For a
8 description of the deprecated integer-based GPIO interface please refer to
20 -----------
25 GPIOs mappings are defined in the consumer device's node, in a property named
26 <function>-gpios, where <function> is the function the driver will request
32 		led-gpios = <&gpio 15 GPIO_ACTIVE_HIGH>, /* red */
36 		power-gpios = <&gpio 1 GPIO_ACTIVE_LOW>;
39 Properties named <function>-gpio are also considered valid and old bindings use
43 This property will make GPIOs 15, 16 and 17 available to the driver under the
57 The second parameter of the gpiod_get() functions, the con_id string, has to be
58 the <function>-prefix of the GPIO suffixes ("gpios" or "gpio", automatically
60 "led-gpios" example, use the prefix without the "-" as con_id parameter: "led".
63 with the string passed in con_id to get the resulting string
64 (``snprintf(... "%s-%s", con_id, gpio_suffixes[]``).
67 ----
85 			ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
88 					"led-gpios",
95 				Package () { "power-gpios", Package () { ^FOO, 3, 0, 0 } },
101 Documentation/firmware-guide/acpi/gpio-properties.rst.
104 -------------
118   - key is either the label of the gpiod_chip instance providing the GPIO, or
120   - chip_hwnum is the hardware number of the GPIO within the chip, or U16_MAX
122   - con_id is the name of the GPIO function from the device point of view. It
124   - idx is the index of the GPIO within the function.
125   - flags is defined to specify the following properties:
126 	* GPIO_ACTIVE_HIGH	- GPIO line is active high
127 	* GPIO_ACTIVE_LOW	- GPIO line is active low
128 	* GPIO_OPEN_DRAIN	- GPIO line is set up as open drain
129 	* GPIO_OPEN_SOURCE	- GPIO line is set up as open source
130 	* GPIO_PERSISTENT	- GPIO line is persistent during
132 	* GPIO_TRANSITORY	- GPIO line is transitory and may loose its
147 .. code-block:: c
174 Since the "led" GPIOs are mapped as active-high, this example will switch their
176 as active-low, its actual signal will be 0 after this code. Contrary to the
177 legacy integer GPIO interface, the active-low property is handled during
181 the new descriptor-oriented interface.
185 .. code-block:: c
196 The line will be hogged as soon as the gpiochip is created or - in case the
197 chip was created earlier - when the hog table is registered.
200 --------------
202 also request an array of pins assigned to the function.  The way those pins are
203 mapped to the device determines if the array qualifies for fast bitmap
204 processing.  If yes, a bitmap is passed over get/set array functions directly
207 In order to qualify for fast bitmap processing, the array must meet the
210 - pin hardware number of array member 0 must also be 0,
211 - pin hardware numbers of consecutive array members which belong to the same
212   chip as member 0 does must also match their array indexes.
218 If the array applies for fast bitmap processing path, pins which belong to