Commit 2b6433f3 authored by AngeloGioacchino Del Regno's avatar AngeloGioacchino Del Regno Committed by Chun-Kuang Hu
Browse files

dt-bindings: display: mediatek: Add OF graph support for board path 



The display IPs in MediaTek SoCs 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.

The final display pipeline is effectively board specific, as it does
depend on the display that is attached to it, and eventually on the
sensors supported by the board (for example, Adaptive Ambient Light
would need an Ambient Light Sensor, otherwise it's pointless!), other
than the output type.

Add support for OF graphs to most of the MediaTek DDP (display) bindings
to add flexibility to build custom hardware paths, hence enabling board
specific configuration of the display pipeline and allowing to finally
migrate away from using hardcoded paths.

Please note that - while this commit retains retro-compatibility with
old device trees - it will break the ABI for mediatek,dsi and for
mediatek,dpi for the sake of consistency between the `ports` in all
MediaTek DRM drivers versus DRM bridge drivers as in the previous
binding, MediaTek was using `port` (implicitly, port@0) as an OUTPUT,
while now the first port is an INPUT, and the second one is an OUTPUT,
which is consistent with other DRM drivers which can be chained to
drm/mediatek.

As for maintainability concerns, I am aware that the old device tree
will not be actively tested anymore, but retrocompatibility breakages
will *not* be more likely to happen in the future because any addition
to the graph (new drivers) will be done only for features present on
newer SoCs, keeping the old ones (and their default pipeline) untouched.

Reviewed-by: default avatarRob Herring (Arm) <robh@kernel.org>
Reviewed-by: default avatarAlexandre Mergnat <amergnat@baylibre.com>
Tested-by: default avatarAlexandre Mergnat <amergnat@baylibre.com>
Reviewed-by: default avatarCK Hu <ck.hu@mediatek.com>
Tested-by: Michael Walle <mwalle@kernel.org> # on kontron-sbc-i1200
Signed-off-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20241017103809.156056-2-angelogioacchino.delregno@collabora.com/


Signed-off-by: default avatarChun-Kuang Hu <chunkuang.hu@kernel.org>
parent 9852d85e

Documentation/devicetree/bindings/display/mediatek/mediatek,aal.yaml

+40 −0
Original line number Diff line number Diff line
@@ -62,6 +62,27 @@ properties: 
    $ref: /schemas/types.yaml#/definitions/phandle-array

    maxItems: 1



  ports:

    $ref: /schemas/graph.yaml#/properties/ports

    description:

      Input and output ports can have multiple endpoints, each of those

      connects to either the primary, secondary, etc, display pipeline.



    properties:

      port@0:

        $ref: /schemas/graph.yaml#/properties/port

        description: AAL input port



      port@1:

        $ref: /schemas/graph.yaml#/properties/port

        description:

          AAL output to the next component's input, for example could be one

          of many gamma, overdrive or other blocks.



    required:

      - port@0

      - port@1



required:

  - compatible

  - reg
@@ -89,5 +110,24 @@ examples: 
           power-domains = <&scpsys MT8173_POWER_DOMAIN_MM>;

           clocks = <&mmsys CLK_MM_DISP_AAL>;

           mediatek,gce-client-reg = <&gce SUBSYS_1401XXXX 0x5000 0x1000>;



           ports {

               #address-cells = <1>;

               #size-cells = <0>;



               port@0 {

                   reg = <0>;

                   aal0_in: endpoint {

                       remote-endpoint = <&ccorr0_out>;

                   };

               };



               port@1 {

                   reg = <1>;

                   aal0_out: endpoint {

                       remote-endpoint = <&gamma0_in>;

                   };

               };

           };

       };

    };

Documentation/devicetree/bindings/display/mediatek/mediatek,ccorr.yaml

+21 −0
Original line number Diff line number Diff line
@@ -57,6 +57,27 @@ properties: 
    $ref: /schemas/types.yaml#/definitions/phandle-array

    maxItems: 1



  ports:

    $ref: /schemas/graph.yaml#/properties/ports

    description:

      Input and output ports can have multiple endpoints, each of those

      connects to either the primary, secondary, etc, display pipeline.



    properties:

      port@0:

        $ref: /schemas/graph.yaml#/properties/port

        description: CCORR input port



      port@1:

        $ref: /schemas/graph.yaml#/properties/port

        description:

          CCORR output to the input of the next desired component in the

          display pipeline, usually only one of the available AAL blocks.



    required:

      - port@0

      - port@1



required:

  - compatible

  - reg

Documentation/devicetree/bindings/display/mediatek/mediatek,color.yaml

+22 −0
Original line number Diff line number Diff line
@@ -65,6 +65,28 @@ properties: 
    $ref: /schemas/types.yaml#/definitions/phandle-array

    maxItems: 1



  ports:

    $ref: /schemas/graph.yaml#/properties/ports

    description:

      Input and output ports can have multiple endpoints, each of those

      connects to either the primary, secondary, etc, display pipeline.



    properties:

      port@0:

        $ref: /schemas/graph.yaml#/properties/port

        description: COLOR input port



      port@1:

        $ref: /schemas/graph.yaml#/properties/port

        description:

          COLOR output to the input of the next desired component in the

          display pipeline, for example one of the available CCORR or AAL

          blocks.



    required:

      - port@0

      - port@1



required:

  - compatible

  - reg

Documentation/devicetree/bindings/display/mediatek/mediatek,dither.yaml

+22 −0
Original line number Diff line number Diff line
@@ -56,6 +56,28 @@ properties: 
    $ref: /schemas/types.yaml#/definitions/phandle-array

    maxItems: 1



  ports:

    $ref: /schemas/graph.yaml#/properties/ports

    description:

      Input and output ports can have multiple endpoints, each of those

      connects to either the primary, secondary, etc, display pipeline.



    properties:

      port@0:

        $ref: /schemas/graph.yaml#/properties/port

        description: DITHER input, usually from a POSTMASK or GAMMA block.



      port@1:

        $ref: /schemas/graph.yaml#/properties/port

        description:

          DITHER output to the input of the next desired component in the

          display pipeline, for example one of the available DSC compressors,

          DP_INTF, DSI, LVDS or others.



    required:

      - port@0

      - port@1



required:

  - compatible

  - reg

Documentation/devicetree/bindings/display/mediatek/mediatek,dpi.yaml

+23 −2
Original line number Diff line number Diff line
@@ -71,13 +71,34 @@ properties: 
      Output port node. This port should be connected to the input port of an

      attached HDMI, LVDS or DisplayPort encoder chip.



  ports:

    $ref: /schemas/graph.yaml#/properties/ports



    properties:

      port@0:

        $ref: /schemas/graph.yaml#/properties/port

        description: DPI input port



      port@1:

        $ref: /schemas/graph.yaml#/properties/port

        description: DPI output to an HDMI, LVDS or DisplayPort encoder input



    required:

      - port@0

      - port@1



required:

  - compatible

  - reg

  - interrupts

  - clocks

  - clock-names



oneOf:

  - required:

      - port

  - required:

      - ports



allOf:

  - if:
@@ -100,7 +121,7 @@ examples: 
    #include <dt-bindings/interrupt-controller/arm-gic.h>

    #include <dt-bindings/clock/mt8173-clk.h>



    dpi0: dpi@1401d000 {

    dpi: dpi@1401d000 {

        compatible = "mediatek,mt8173-dpi";

        reg = <0x1401d000 0x1000>;

        interrupts = <GIC_SPI 194 IRQ_TYPE_LEVEL_LOW>;