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SubjectRe: [PATCH v4 2/3] pwm_backlight: use power sequences
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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