diff options
| author | Thomas Abraham <thomas.abraham@linaro.org> | 2011-11-07 01:02:21 +0530 |
|---|---|---|
| committer | Kukjin Kim <kgene.kim@samsung.com> | 2011-12-23 10:06:54 +0900 |
| commit | 659d73ada5d6869dc18838c9125731a750389019 (patch) | |
| tree | 1c46b7ee38c09391942f8ded59a16614e166499c /Documentation/devicetree | |
| parent | f983575aa90ceeb2cc7923223882dcf1debf5aa2 (diff) | |
| download | lwn-659d73ada5d6869dc18838c9125731a750389019.tar.gz lwn-659d73ada5d6869dc18838c9125731a750389019.zip | |
gpio/samsung: Add device tree support for EXYNOS4
As gpio chips get registered, a device tree node which represents the
gpio chip is searched and attached to it. A translate function is also
provided to convert the gpio specifier into actual platform settings
for pin function selection, pull up/down and driver strength settings.
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
[kgene.kim@samsung.com: fixed build error]
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Diffstat (limited to 'Documentation/devicetree')
| -rw-r--r-- | Documentation/devicetree/bindings/gpio/gpio-samsung.txt | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio-samsung.txt b/Documentation/devicetree/bindings/gpio/gpio-samsung.txt new file mode 100644 index 000000000000..8f50fe5e6c42 --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/gpio-samsung.txt @@ -0,0 +1,40 @@ +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] + [pull up/down] + [drive strength]> + + Values for gpio specifier: + - Pin number: is a value between 0 to 7. + - Pull Up/Down: 0 - Pull Up/Down Disabled. + 1 - Pull Down Enabled. + 3 - Pull Up Enabled. + - 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; + }; |