diff options
| -rw-r--r-- | doc/device-tree-bindings/gpio/gpio-samsung.txt | 41 |
1 files changed, 41 insertions, 0 deletions
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 0000000..5375625 --- /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; + }; |