lkml.org 
[lkml]   [2022]   [May]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v3 3/4] ARM: dts: imx6qdl-colibri: backlight pwm: Simplify inverted backlight
Hi Max,

On Fri, May 13, 2022 at 7:27 AM Max Krummenacher <max.oss.09@gmail.com> wrote:
>
> From: Max Krummenacher <max.krummenacher@toradex.com>
>
> Set #pwm-cells to the default 3 to gain access to the parameter
> which allows inverting the PWM signal. This is useful to specify
> a backlight which has its highest brightness at 0.
>
> With the change to use the PWM with inverted polarity the PWM signal
> is inverted to how it was before this patch.
> This changes the meaning of the values in the brightness-levels
> property. I.e. the duty-cycle changes from x/255 to (255-x)/255.
> Keeping the brightness-levels will then have a big brightness
> jump from 0 to 127 duty cycle, the other 6 steps will then be
> barely noticeable.
>
> Change the brightness-levels to provide the same brightness-levels
> as before.
>
> Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>

Thanks for the rework:

Reviewed-by: Fabio Estevam <festevam@gmail.com>

\
 
 \ /
  Last update: 2022-05-13 12:54    [W:0.047 / U:1.048 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site