Add GPIO hogging documentation to gpio.txt Signed-off-by: Benoit Parrot <bparrot@xxxxxx> --- Changes since v2: * Updated to the latest hog syntax. Changes since v1: * Split the devicetree bindings documentation in its own patch. Documentation/devicetree/bindings/gpio/gpio.txt | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt index 3fb8f53..6d88133 100644 --- a/Documentation/devicetree/bindings/gpio/gpio.txt +++ b/Documentation/devicetree/bindings/gpio/gpio.txt @@ -103,6 +103,22 @@ Every GPIO controller node must contain both an empty "gpio-controller" property, and a #gpio-cells integer property, which indicates the number of cells in a gpio-specifier. +The GPIO chip may contain GPIO hog definitions. GPIO hogging is a mechanism +providing automatic GPIO request and configuration as part of the +gpio-controller's driver probe function. + +Each GPIO hog definition is represented as a child node of the GPIO controller. +Required properties: +- gpio-hog: A property specifying that this child node represent a gpio-hog. +- gpios: Store the gpio information (id, flags, ...). Shall contain the + number of cells specified in its parent node (GPIO controller + node). +- direction: A property specifying the direction/value needed. This property + can take the folowing values: input, output-high, output-low. + +Optional properties: +- line-name: The GPIO label name. If not present the node name is used. + Example of two SOC GPIO banks defined as gpio-controller nodes: qe_pio_a: gpio-controller@1400 { @@ -110,6 +126,13 @@ Example of two SOC GPIO banks defined as gpio-controller nodes: reg = <0x1400 0x18>; gpio-controller; #gpio-cells = <2>; + + line_b { + gpio-hog; + gpios = <6 0>; + direction = "output-low"; + line-name = "foo-bar-gpio"; + }; }; qe_pio_e: gpio-controller@1460 { -- 1.8.5.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html