[PATCH RFC 0/5] Introduce support for post-blend color pipeline

["Nícolas F. R. A. Prado" <nfraprado@collabora.com>]

This series is based on "Color Pipeline API w/ VKMS" [1]. It reuses the
same concept of a color pipeline API but for the post-blend stage
instead of pre-blend, by attaching the COLOR_PIPELINE property to the
CRTC rather than a plane.

Patch 1 implements the necessary changes in the DRM core to make this
happen. The remaining patches implement support for this API in the
MediaTek DRM driver in particular.

This series has been tested on the MT8195-Tomato Chromebook with a WIP
Weston branch [2]. Both gamma LUT and CTM color transformations have
been simultaneously configured in hardware through the API and validated
(test commits in weston [3] and the kernel [4]).

This is a very early implementation but I'd like to get feedback from
the community before moving forward. For instance one notable thing
missing it to add init helpers for the post-blend case for the remaining
colorop types, as only 3x1d LUT and 3x4 Matrix were needed for gamma LUT
and CTM use cases.

[1] https://lore.kernel.org/all/20250815035047.3319284-1-alex.hung@amd.com/
[2] https://gitlab.collabora.com/nfraprado/weston/-/tree/post-blend-colorops?ref_type=heads
[3] https://gitlab.collabora.com/nfraprado/weston/-/commits/post-blend-color-pipeline-lut-ctm-test?ref_type=tags
[4] https://gitlab.collabora.com/nfraprado/linux/-/commits/post-blend-color-pipeline-ctm-lut-test?ref_type=tags

Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
---
Nícolas F. R. A. Prado (5):
      drm: Support post-blend color pipeline API
      drm/colorop: Export drm_colorop_cleanup() so drivers can extend it
      drm/mediatek: Support post-blend colorops for gamma and ctm
      drm/mediatek: ccorr: Support post-blend color pipeline API
      drm/mediatek: gamma: Support post-blend color pipeline API

 drivers/gpu/drm/drm_atomic.c              |  32 ++++-
 drivers/gpu/drm/drm_atomic_uapi.c         |  50 ++++++-
 drivers/gpu/drm/drm_colorop.c             | 147 +++++++++++++++++----
 drivers/gpu/drm/drm_connector.c           |   1 +
 drivers/gpu/drm/drm_crtc.c                |  77 +++++++++++
 drivers/gpu/drm/drm_crtc_internal.h       |   6 +
 drivers/gpu/drm/drm_ioctl.c               |   7 +
 drivers/gpu/drm/drm_mode_object.c         |  20 +++
 drivers/gpu/drm/drm_plane.c               |  36 +----
 drivers/gpu/drm/mediatek/mtk_crtc.c       | 211 +++++++++++++++++++++++++++++-
 drivers/gpu/drm/mediatek/mtk_ddp_comp.c   |   6 +-
 drivers/gpu/drm/mediatek/mtk_ddp_comp.h   |   2 +
 drivers/gpu/drm/mediatek/mtk_disp_ccorr.c | 100 ++++++++++++--
 drivers/gpu/drm/mediatek/mtk_disp_drv.h   |   6 +-
 drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 107 ++++++++++++---
 include/drm/drm_atomic.h                  |  20 +++
 include/drm/drm_atomic_uapi.h             |   2 +
 include/drm/drm_colorop.h                 |  17 ++-
 include/drm/drm_crtc.h                    |  19 +++
 include/drm/drm_file.h                    |   7 +
 include/uapi/drm/drm.h                    |  16 +++
 21 files changed, 781 insertions(+), 108 deletions(-)
---
base-commit: d152eee7ae3b72e2ce70064a7ad9764f7ba8641d
change-id: 20250730-mtk-post-blend-color-pipeline-498e1a9cc53e

Best regards,
-- 
Nícolas F. R. A. Prado <nfraprado@collabora.com>