Hi Geert,
On Fri, Jul 08, 2022 at 08:20:45PM +0200, Geert Uytterhoeven wrote:
Hi all,
A long outstanding issue with the DRM subsystem has been the lack of
support for low-color displays, as used typically on older desktop
systems, and on small embedded displays.
IT is super to have this addressed - thanks!
This patch series adds support for color-indexed frame buffer formats
with 2, 4, and 16 colors. It has been tested on ARAnyM using a
work-in-progress Atari DRM driver supporting 2, 4, 16, 256, and 65536
colors, with text console operation, fbtest, and modetest.
Overview:
- Patch 1 introduces a helper, to be used by later patches in the
series,
- Patch 2 introduces a flag to indicate color-indexed formats,
- Patches 3 and 4 correct calculations of bits per pixel for sub-byte
pixel formats,
- Patches 5 and 6 introduce the new C[124] formats,
- Patch 7 fixes an untested code path,
- Patch 8 documents the use of "red" for light-on-dark displays,
- Patches 9 and 10 add more fourcc codes for light-on-dark and
dark-on-light frame buffer formats, which may be useful for e.g. the
ssd130x and repaper drivers.
Applied all patches to drm-misc (drm-misc-next), including the last two
RFC patches as we then have the formats ready when a user pops up.
Sam
