Re: [PATCH 1/2] dt-bindings: pwm-backlight: Add pwm-delay-us property

From: Pavel Machek
Date: Wed Jun 28 2017 - 09:30:23 EST


On Wed 2017-06-28 13:16:31, Enric Balletbo i Serra wrote:
> From: huang lin <hl@xxxxxxxxxxxxxx>
>
> Add a pwm-delay-us property to specify the delay between setting an
> initial (non-zero) PWM value and enabling the backlight, and also the
> delay between disabling the backlight and setting PWM value to 0.



> Signed-off-by: huang lin <hl@xxxxxxxxxxxxxx>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt b/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt
> index 764db86..f75b08f 100644
> --- a/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt
> +++ b/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt
> @@ -17,6 +17,9 @@ 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])
> + - pwm-delay-us: delay between setting an initial (non-zero) PWM value and
> + enabling the backlight, and also the delay between disabling
> + the backlight and setting PWM value to 0.
>

I understood it as "you set PWM and it takes a while for display to
light up"
but that's not correct. Changelog from second patch makes it
clear. Please
clarify it here, too.

Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html