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 -----------
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
44 "led" function, and GPIO 1 as the "power" GPIO::
48 	red = gpiod_get_index(dev, "led", 0, GPIOD_OUT_HIGH);
49 	green = gpiod_get_index(dev, "led", 1, GPIOD_OUT_HIGH);
50 	blue = gpiod_get_index(dev, "led", 2, GPIOD_OUT_HIGH);
54 The led GPIOs will be active high, while the power GPIO will be active low (i.e.
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".
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
152                         GPIO_LOOKUP_IDX("gpio.0", 15, "led", 0, GPIO_ACTIVE_HIGH),
153                         GPIO_LOOKUP_IDX("gpio.0", 16, "led", 1, GPIO_ACTIVE_HIGH),
154                         GPIO_LOOKUP_IDX("gpio.0", 17, "led", 2, GPIO_ACTIVE_HIGH),
168 	red = gpiod_get_index(dev, "led", 0, GPIOD_OUT_HIGH);
169 	green = gpiod_get_index(dev, "led", 1, GPIOD_OUT_HIGH);
170 	blue = gpiod_get_index(dev, "led", 2, GPIOD_OUT_HIGH);
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 --------------
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
214 Otherwise fast bitmap processing path is not used in order to avoid consecutive
215 pins which belong to the same chip but are not in hardware order being processed