On Thu 2017-07-13 09:22:15, Enric Balletbo Serra wrote: > Rob, > > 2017-07-06 20:23 GMT+02:00 Enric Balletbo Serra <eballetbo at gmail.com>: > > Hi Rob, > > > > 2017-07-06 19:07 GMT+02:00 Rob Herring <robh+dt at kernel.org>: > >> On Fri, Jun 30, 2017 at 6:21 AM, Enric Balletbo i Serra > >> <enric.balletbo at collabora.com> wrote: > >>> From: huang lin <hl at rock-chips.com> > >>> > >>> 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 at rock-chips.com> > >>> Signed-off-by: Enric Balletbo i Serra <enric.balletbo at collabora.com> > >>> --- > >>> Changes since v1: > >>> - As suggested by Daniel Thompson > >>> - Do not assume power-on delay and power-off delay will be the same > >>> > >>> v1: https://lkml.org/lkml/2017/6/28/219 > >>> > >>> 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 764db86..49b037e 100644 > >>> --- a/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt > >>> +++ b/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt > >>> @@ -17,6 +17,11 @@ 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. > >>> + The 1st cell is the pre-delay in micro seconds. > >>> + The 2nd cell is the post-delay in micro seconds. > >> > >> pre and post imply a time before and after a certain event, but these > >> are for 2 different events. These are more like an enable/on delay and > >> disable/off delay which probably should be separate properties. What > >> happens when we need the opposite sequence or a different sequence? > >> Maybe some panel requires the PWM to be 0 until some time after > >> enabling. > >> > > A second proposal, what do you think? > > - post-pwm-on-delay-us: Delay in us after setting an initial (non-zero) PWM > and enabling the backlight using GPIO. This says "PWM on", "enable GPIO", "delay". Which is not what you want. -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 181 bytes Desc: Digital signature URL: <http://lists.infradead.org/pipermail/linux-rockchip/attachments/20170713/235baf71/attachment.sig>
