driver-api/gpio/board.rst

14 -----------
20 <function>-gpios, where <function> is the function the driver will request
26 		led-gpios = <&gpio 15 GPIO_ACTIVE_HIGH>, /* red */
30 		power-gpios = <&gpio 1 GPIO_ACTIVE_LOW>;
33 Properties named <function>-gpio are also considered valid and old bindings use
38 "led" function, and GPIO 1 as the "power" GPIO::
40 	struct gpio_desc *red, *green, *blue, *power;
46 	power = gpiod_get(dev, "power", GPIOD_OUT_HIGH);
48 The led GPIOs will be active high, while the power GPIO will be active low (i.e.
49 gpiod_is_active_low(power) will be true).
52 the <function>-prefix of the GPIO suffixes ("gpios" or "gpio", automatically
54 "led-gpios" example, use the prefix without the "-" as con_id parameter: "led".
58 (``snprintf(... "%s-%s", con_id, gpio_suffixes[]``).
61 ----
75 				"\\_SB.GPI0", 0, ResourceConsumer) { 1 } // power
79 			ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
82 					"led-gpios",
89 				Package () { "power-gpios", Package () { ^FOO, 3, 0, 0 } },
95 Documentation/firmware-guide/acpi/gpio-properties.rst.
98 -------------
112   - key is either the label of the gpiod_chip instance providing the GPIO, or
114   - chip_hwnum is the hardware number of the GPIO within the chip, or U16_MAX
116   - con_id is the name of the GPIO function from the device point of view. It
118   - idx is the index of the GPIO within the function.
119   - flags is defined to specify the following properties:
120 	* GPIO_ACTIVE_HIGH	- GPIO line is active high
121 	* GPIO_ACTIVE_LOW	- GPIO line is active low
122 	* GPIO_OPEN_DRAIN	- GPIO line is set up as open drain
123 	* GPIO_OPEN_SOURCE	- GPIO line is set up as open source
124 	* GPIO_PERSISTENT	- GPIO line is persistent during
126 	* GPIO_TRANSITORY	- GPIO line is transitory and may loose its
141 .. code-block:: c
149                         GPIO_LOOKUP("gpio.0", 1, "power", GPIO_ACTIVE_LOW),
160 	struct gpio_desc *red, *green, *blue, *power;
166 	power = gpiod_get(dev, "power", GPIOD_OUT_HIGH);
168 Since the "led" GPIOs are mapped as active-high, this example will switch their
169 signals to 1, i.e. enabling the LEDs. And for the "power" GPIO, which is mapped
170 as active-low, its actual signal will be 0 after this code. Contrary to the
171 legacy integer GPIO interface, the active-low property is handled during
175 the new descriptor-oriented interface.
179 .. code-block:: c
190 The line will be hogged as soon as the gpiochip is created or - in case the
191 chip was created earlier - when the hog table is registered.
194 --------------
204 - pin hardware number of array member 0 must also be 0,
205 - pin hardware numbers of consecutive array members which belong to the same