DRM_MODE_CONNECTOR_PANEL? [Was: drm/panel: Add and fill drm_panel type field]

[Daniel Stone]

Hi Linus,

On Fri, 27 Sep 2019 at 13:37, Linus Walleij <linus.walleij at linaro.org> wrote:
> Also the ILI9322 can actually set up gamma correction which is
> very nice for professional applications. I haven't seen any way for
> DRM to do gamma correction properly or any framework for it
> to adjust and propagate gamma to/from userspace (seems like
> another enormous task), but I am pretty sure it will be there one
> of these days so I put in some comments and placeholders.

Gamma correction has been supported since approximately the dawn of
time with a 3x8-bit LUT.

Obviously more modern hardware has far more complex colour management.
This is also supported, and is approximately described here:
https://dri.freedesktop.org/docs/drm/gpu/drm-kms.html#color-management-properties

Both planes and CRTCs can have a LUT -> matrix transform -> LUT
pipeline. There are also additional properties for fixed transforms,
e.g. limited 16-235 <-> full 0-255 range translation.

Cheers,
Daniel