Re: [PATCH 0/5] drm/bridge: simple-bridge: Add DPI color encoder support

Alexander Stein
2025-03-04T15:00:33Z

Hi,

Am Dienstag, 4. März 2025, 11:15:25 CET schrieb Liu Ying:
> Hi,
>
> This patch series aims to add DPI color encoder support as a simple DRM
> bridge. A DPI color encoder simply converts input DPI color coding to
> output DPI color coding, like Adafruit Kippah DPI hat[1] which converts
> input 18-bit pixel data to 24-bit pixel data(with 2 low padding bits in
> every color component though). A real use case is that NXP i.MX93 11x11
> EVK[2] and i.MX93 9x9 QSB[3] boards may connect a 24-bit DPI panel through
> the Adafruit Kippah DPI hat. The display pipeline is
>
> i.MX93 LCDIF display controller(RGB888) ->
> i.MX93 parallel display format configuration(RGB666) ->
> on-board Raspiberry Pi compatible interface(RPi)(RGB666) ->
> Adafruit Kippah DPI hat(RGB888 with 2 low padding bits in color components) ->
> 24-bit "ontat,kd50g21-40nt-a1" DPI panel
>
> [1] https://learn.adafruit.com/adafruit-dpi-display-kippah-ttl-tft/downloads
> [2] https://www.nxp.com/design/design-center/development-boards-and-designs/i.MX93EVK
> [3] https://www.nxp.com/design/design-center/development-boards-and-designs/IMX93QSB

Thanks for this series.
Actually I was about to create a similar (dumb) bridge. My use case is wrong
wiring on hardware for DPI displays. The current workaround was to use a
"new" display compatible with bus_format changes from
MEDIA_BUS_FMT_RGB666_1X18 -> MEDIA_BUS_FMT_RGB888_1X24.

I added this new bridge and changed my DT and it works flawlessly.

Best regards
Alexander

> Liu Ying (5):
> dt-bindings: display: Document DPI color codings
> drm/of: Add drm_of_dpi_get_color_coding()
> dt-bindings: display: simple-bridge: Document DPI color encoder
> drm/bridge: simple-bridge: Add DPI color encoder support
> drm/bridge: simple-bridge: Add next panel support
>
> .../display/bridge/simple-bridge.yaml | 89 +++++++++++-
> .../bindings/display/dpi-color-coding.yaml | 90 ++++++++++++
> drivers/gpu/drm/bridge/Kconfig | 1 +
> drivers/gpu/drm/bridge/simple-bridge.c | 132 ++++++++++++++++--
> drivers/gpu/drm/drm_of.c | 43 ++++++
> include/drm/drm_of.h | 7 +
> 6 files changed, 348 insertions(+), 14 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/display/dpi-color-coding.yaml
>
>

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