[PATCH v2 0/3] drm/mediatek: Add support for OF graphs

AngeloGioacchino Del Regno
2024-04-09T12:02:17Z

Changes in v2:
- Fixed wrong `required` block indentation in commit [2/3]

The display IPs in MediaTek SoCs are *VERY* flexible and those support
being interconnected with different instances of DDP IPs (for example,
merge0 or merge1) and/or with different DDP IPs (for example, rdma can
be connected with either color, dpi, dsi, merge, etc), forming a full
Display Data Path that ends with an actual display.

This series was born because of an issue that I've found while enabling
support for MT8195/MT8395 boards with DSI output as main display: the
current mtk_drm_route variations would not work as currently, the driver
hardcodes a display path for Chromebooks, which have a DisplayPort panel
with DSC support, instead of a DSI panel without DSC support.

There are other reasons for which I wrote this series, and I find that
hardcoding those paths - when a HW path is clearly board-specific - is
highly suboptimal. Also, let's not forget about keeping this driver from
becoming a huge list of paths for each combination of SoC->board->disp
and... this and that.

For more information, please look at the commit description for each of
the commits included in this series.

Please don't mind about the missing OVL_ADAPTOR support for OF graphs
in this series: that needs a bit more thinking and a bit more work, and
will come in a second series that will go on top of this a bit later,
as the OF graph support for *at least* the primary display is essential
*right now* to enable support for the MT8195/8395 EVK, Kontron SoM,
Radxa NIO-12L and all of the other non-Chromebook boards to co-exist
with Chromebooks.

Besides, this is also a valid option for MT8188 Chromebooks which might
have different DSI-or-eDP displays depending on the model (as far as I
can see from the mtk_drm_route attempt for this SoC that is already
present in this driver).

This series was tested on MT8195 Cherry Tomato and on MT8395 Radxa
NIO-12L with both hardcoded paths, OF graph support and partially
hardcoded paths (meaning main display through OF graph and external
display hardcoded, because of OVL_ADAPTOR).

AngeloGioacchino Del Regno (3):
dt-bindings: display: mediatek: Add OF graph support for board path
dt-bindings: arm: mediatek: mmsys: Add OF graph support for board path
drm/mediatek: Implement OF graphs support for display paths

.../bindings/arm/mediatek/mediatek,mmsys.yaml | 23 ++
.../display/mediatek/mediatek,aal.yaml | 40 +++
.../display/mediatek/mediatek,ccorr.yaml | 21 ++
.../display/mediatek/mediatek,color.yaml | 22 ++
.../display/mediatek/mediatek,dither.yaml | 22 ++
.../display/mediatek/mediatek,dpi.yaml | 25 +-
.../display/mediatek/mediatek,dsc.yaml | 24 ++
.../display/mediatek/mediatek,dsi.yaml | 27 +-
.../display/mediatek/mediatek,ethdr.yaml | 22 ++
.../display/mediatek/mediatek,gamma.yaml | 19 ++
.../display/mediatek/mediatek,merge.yaml | 23 ++
.../display/mediatek/mediatek,od.yaml | 22 ++
.../display/mediatek/mediatek,ovl-2l.yaml | 22 ++
.../display/mediatek/mediatek,ovl.yaml | 22 ++
.../display/mediatek/mediatek,postmask.yaml | 21 ++
.../display/mediatek/mediatek,rdma.yaml | 22 ++
.../display/mediatek/mediatek,ufoe.yaml | 21 ++
drivers/gpu/drm/mediatek/mtk_dpi.c | 16 +-
drivers/gpu/drm/mediatek/mtk_drm_drv.c | 255 ++++++++++++++++--
drivers/gpu/drm/mediatek/mtk_drm_drv.h | 2 +-
drivers/gpu/drm/mediatek/mtk_dsi.c | 10 +-
21 files changed, 645 insertions(+), 36 deletions(-)

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2.44.0