Re: [PATCH v6 2/5] dt-bindings: pwm-backlight: add PWM delay proprieties.

From: Daniel Thompson
Date: Mon Mar 26 2018 - 11:07:19 EST


On Mon, Mar 26, 2018 at 11:52:10AM +0200, Enric Balletbo i Serra wrote:
> Hardware needs a delay between setting an initial (non-zero) PWM and
> enabling the backlight using GPIO. The post-pwm-on-delay-ms specifies
> this delay in milli seconds. Hardware also needs a delay between disabing
> the backlight using GPIO and setting PWM value to 0. The pwm-off-delay-ms
> is this delay in milli seconds.
>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
> Acked-by: Pavel Machek <pavel@xxxxxx>
> Acked-by: Thierry Reding <thierry.reding@xxxxxxxxx>

Acked-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>

> ---
> Based on the original Huang Lin <hl@xxxxxxxxxxxxxx> work.
> Changes since v5:
> - Add Acked-by: Thierry Reding <thierry.reding@xxxxxxxxx>
> - CC DT mainling list (for some reason dropped at some point, my
> fault)
> Changes since v4:
> - Rebase on top of mainline.
> Changes since v3:
> - Replace us for ms.
> - Add Acked-by: Pavel Machek <pavel@xxxxxx>
> Changes since v2:
> - Use separate properties (Rob Herring)
> Changes since v1:
> - As suggested by Daniel Thompson
> - Do not assume power-on delay and power-off delay will be the same
> ---
> Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt b/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt
> index 764db86d441a..310810906613 100644
> --- a/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt
> +++ b/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt
> @@ -17,6 +17,10 @@ Optional properties:
> "pwms" property (see PWM binding[0])
> - enable-gpios: contains a single GPIO specifier for the GPIO which enables
> and disables the backlight (see GPIO binding[1])
> + - post-pwm-on-delay-ms: Delay in ms between setting an initial (non-zero) PWM
> + 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.
>
> [0]: Documentation/devicetree/bindings/pwm/pwm.txt
> [1]: Documentation/devicetree/bindings/gpio/gpio.txt
> @@ -32,4 +36,6 @@ Example:
>
> power-supply = <&vdd_bl_reg>;
> enable-gpios = <&gpio 58 0>;
> + post-pwm-on-delay-ms = <10>;
> + pwm-off-delay-ms = <10>;
> };
> --
> 2.16.2
>