Messages in this thread | | | Date | Thu, 16 Aug 2012 12:42:24 -0600 | From | Stephen Warren <> | Subject | Re: [PATCH v4 2/3] pwm_backlight: use power sequences |
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On 08/16/2012 12:08 AM, Alexandre Courbot wrote: > Make use of the power sequences specified in the device tree or platform > data to control how the backlight is powered on and off.
> +++ b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt
> 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 > @@ -10,19 +9,72 @@ Required properties: > 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) > + - pwms: OF device-tree PWM specification (see PWM binding[0]). Exactly one PWM > + must be specified
There's probably no need to move that entry just to change it?
> Optional properties: > - - pwm-names: a list of names for the PWM devices specified in the > - "pwms" property (see PWM binding[0])
> + - *-supply: regulators used within a power sequence > + - *-gpio: GPIOs used within a power sequence
I don't think these really warrant mentioning here; such properties are part of the standard regulator and GPIO bindings, and are required as a side-effect of a power sequence using a resource of those types, rather than being something actively defined or needed directly by the pwm-backlight binding.
> + - pwm-names: name for the PWM device specified in the "pwms" property (see PWM > + binding[0]). Necessary if power sequences are used
> + - power-on-sequence: Power sequence (see Power sequences[1]) used to bring the > + backlight on. This sequence must reference the PWM specified in the pwms > + property by its name. It can also reference other resources supported by > + the power sequences mechanism > + - power-off-sequence: Power sequence (see Power sequences[1]) used to bring > + the backlight off. This sequence must reference the PWM specified in the > + pwms property by its name. It can also reference other resources supported > + by the power sequences mechanism
For these two, I would personally simply say that the pwm-backlight binding requires that two power sequences named "on" and "off" must exists, and are to defined according to [1].
> [0]: Documentation/devicetree/bindings/pwm/pwm.txt > +[1]: Documentation/devicetree/bindings/power_seq/power_seq.txt
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