From 35ea1bfde30a541188ffd24cdf9b3ba79b0e4684 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Mon, 5 Jan 2015 20:05:24 -0700 Subject: dm: exynos: Bring in GPIO device tree binding At present the exynos GPIO driver does not fully support the existing device tree binding, but add the binding file to cover the existing partial support. Signed-off-by: Simon Glass --- doc/device-tree-bindings/gpio/gpio-samsung.txt | 41 ++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 doc/device-tree-bindings/gpio/gpio-samsung.txt (limited to 'doc/device-tree-bindings/gpio') diff --git a/doc/device-tree-bindings/gpio/gpio-samsung.txt b/doc/device-tree-bindings/gpio/gpio-samsung.txt new file mode 100644 index 0000000000..5375625e8c --- /dev/null +++ b/doc/device-tree-bindings/gpio/gpio-samsung.txt @@ -0,0 +1,41 @@ +Samsung Exynos4 GPIO Controller + +Required properties: +- compatible: Compatible property value should be "samsung,exynos4-gpio>". + +- reg: Physical base address of the controller and length of memory mapped + region. + +- #gpio-cells: Should be 4. The syntax of the gpio specifier used by client nodes + should be the following with values derived from the SoC user manual. + <[phandle of the gpio controller node] + [pin number within the gpio controller] + [mux function] + [flags and pull up/down] + [drive strength]> + + Values for gpio specifier: + - Pin number: is a value between 0 to 7. + - Flags and Pull Up/Down: 0 - Pull Up/Down Disabled. + 1 - Pull Down Enabled. + 3 - Pull Up Enabled. + Bit 16 (0x00010000) - Input is active low. + - Drive Strength: 0 - 1x, + 1 - 3x, + 2 - 2x, + 3 - 4x + +- gpio-controller: Specifies that the node is a gpio controller. +- #address-cells: should be 1. +- #size-cells: should be 1. + +Example: + + gpa0: gpio-controller@11400000 { + #address-cells = <1>; + #size-cells = <1>; + compatible = "samsung,exynos4-gpio"; + reg = <0x11400000 0x20>; + #gpio-cells = <4>; + gpio-controller; + }; -- cgit v1.2.1