From 3e3ed6cdc49d758719c148a78c8b04c243ef74d0 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Fri, 16 Dec 2011 21:25:29 +0100 Subject: pwm-backlight: Add rudimentary device tree support This commit adds very basic support for device tree probing. Currently, only a PWM and a list of distinct brightness levels can be specified. Enabling or disabling backlight power via GPIOs is not yet supported. Reviewed-by: Shawn Guo Reviewed-by: Mark Brown Signed-off-by: Thierry Reding --- .../bindings/video/backlight/pwm-backlight.txt | 28 ++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt (limited to 'Documentation/devicetree/bindings/video') diff --git a/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt new file mode 100644 index 00000000000..1e4fc727f3b --- /dev/null +++ b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt @@ -0,0 +1,28 @@ +pwm-backlight bindings + +Required properties: + - compatible: "pwm-backlight" + - pwms: OF device-tree PWM specification (see PWM binding[0]) + - brightness-levels: Array of distinct brightness levels. Typically these + are in the range from 0 to 255, but any range starting at 0 will do. + The actual brightness level (PWM duty cycle) will be interpolated + from these values. 0 means a 0% duty cycle (darkest/off), while the + last value in the array represents a 100% duty cycle (brightest). + - default-brightness-level: the default brightness level (index into the + array defined by the "brightness-levels" property) + +Optional properties: + - pwm-names: a list of names for the PWM devices specified in the + "pwms" property (see PWM binding[0]) + +[0]: Documentation/devicetree/bindings/pwm/pwm.txt + +Example: + + backlight { + compatible = "pwm-backlight"; + pwms = <&pwm 0 5000000>; + + brightness-levels = <0 4 8 16 32 64 128 255>; + default-brightness-level = <6>; + }; -- cgit v1.2.3-70-g09d2