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author | Sascha Hauer <s.hauer@pengutronix.de> | 2018-09-11 08:26:30 +0200 |
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committer | Sascha Hauer <s.hauer@pengutronix.de> | 2018-09-11 17:23:13 +0200 |
commit | 35f607bc7da71b302fd6bf3d6d48d7ea66df1195 (patch) | |
tree | dd2cf14c56430d21079c794fa6e03d7f5d91070e /dts/Bindings/leds/backlight/pwm-backlight.txt | |
parent | 625eea2765d94aee016cf25d9cabecde8eae0775 (diff) | |
download | barebox-35f607bc7da71b302fd6bf3d6d48d7ea66df1195.tar.gz barebox-35f607bc7da71b302fd6bf3d6d48d7ea66df1195.tar.xz |
dts: update to v4.19-rc1
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'dts/Bindings/leds/backlight/pwm-backlight.txt')
-rw-r--r-- | dts/Bindings/leds/backlight/pwm-backlight.txt | 34 |
1 files changed, 27 insertions, 7 deletions
diff --git a/dts/Bindings/leds/backlight/pwm-backlight.txt b/dts/Bindings/leds/backlight/pwm-backlight.txt index 3108109066..64fa2fbd98 100644 --- a/dts/Bindings/leds/backlight/pwm-backlight.txt +++ b/dts/Bindings/leds/backlight/pwm-backlight.txt @@ -3,13 +3,6 @@ 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) - power-supply: regulator for supply voltage Optional properties: @@ -21,6 +14,19 @@ Optional properties: and enabling the backlight using GPIO. - pwm-off-delay-ms: Delay in ms between disabling the backlight using GPIO and setting PWM value to 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). + - num-interpolated-steps: Number of interpolated steps between each value + of brightness-levels table. This way a high + resolution pwm duty cycle can be used without + having to list out every possible value in the + brightness-level array. [0]: Documentation/devicetree/bindings/pwm/pwm.txt [1]: Documentation/devicetree/bindings/gpio/gpio.txt @@ -39,3 +45,17 @@ Example: post-pwm-on-delay-ms = <10>; pwm-off-delay-ms = <10>; }; + +Example using num-interpolation-steps: + + backlight { + compatible = "pwm-backlight"; + pwms = <&pwm 0 5000000>; + + brightness-levels = <0 2048 4096 8192 16384 65535>; + num-interpolated-steps = <2048>; + default-brightness-level = <4096>; + + power-supply = <&vdd_bl_reg>; + enable-gpios = <&gpio 58 0>; + }; |