[Intel-gfx] Developing a new backlight driver for specific OLED screen

[Jani Nikula]

On Fri, 09 Sep 2022, "Aurélien" <aurelien.intel at ap2c.com> wrote:
> But since this display is independent from the GPU i didn't want to
> link both code.

If it's eDP and uses some proprietary DPCD brightness control mechanism,
I think in practice it usually is somewhat dependent on the GPU.

(OTOH I realize you don't mention eDP. If it's not eDP, DDC/CI is the
more likely way to control brightness than DPCD.)

> For sure. It's an OLED display. Thus there is no backlight. It uses
> specific registers to control the brightness of the screen.

As Lyude said, we have a bunch of "backlight" terminology for historical
reasons, but basically the DP aux, or DPCD, brightness control is mostly
agnostic to the display technology.

> Unfortunately I guess the mechanism is not shared with many OLED
> displays...

Do you have a spec for it? How does it differ from the VESA eDP DPCD
brightness control?


BR,
Jani.


-- 
Jani Nikula, Intel Open Source Graphics Center