Re: [PATCH v12 1/3] dt-bindings: display: mediatek: Add OF graph support for board path

[Rob Herring <robh@kernel.org>]

On Mon, Oct 14, 2024 at 3:51 AM AngeloGioacchino Del Regno
<angelogioacchino.delregno@collabora.com> wrote:
>
> 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.
>
> Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
> Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
> Tested-by: Alexandre Mergnat <amergnat@baylibre.com>
> Reviewed-by: CK Hu <ck.hu@mediatek.com>
> Tested-by: Michael Walle <mwalle@kernel.org> # on kontron-sbc-i1200
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> ---
>  .../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 ++++++++++
>  16 files changed, 372 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/display/mediatek/mediatek,aal.yaml b/Documentation/devicetree/bindings/display/mediatek/mediatek,aal.yaml
> index cf24434854ff..47ddba5c41af 100644
> --- a/Documentation/devicetree/bindings/display/mediatek/mediatek,aal.yaml
> +++ b/Documentation/devicetree/bindings/display/mediatek/mediatek,aal.yaml
> @@ -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>;
> +                   };
> +               };
> +           };
>         };
>      };
> diff --git a/Documentation/devicetree/bindings/display/mediatek/mediatek,ccorr.yaml b/Documentation/devicetree/bindings/display/mediatek/mediatek,ccorr.yaml
> index 9f8366763831..fca8e7bb0cbc 100644
> --- a/Documentation/devicetree/bindings/display/mediatek/mediatek,ccorr.yaml
> +++ b/Documentation/devicetree/bindings/display/mediatek/mediatek,ccorr.yaml
> @@ -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
> diff --git a/Documentation/devicetree/bindings/display/mediatek/mediatek,color.yaml b/Documentation/devicetree/bindings/display/mediatek/mediatek,color.yaml
> index 7df786bbad20..6160439ce4d7 100644
> --- a/Documentation/devicetree/bindings/display/mediatek/mediatek,color.yaml
> +++ b/Documentation/devicetree/bindings/display/mediatek/mediatek,color.yaml
> @@ -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
> diff --git a/Documentation/devicetree/bindings/display/mediatek/mediatek,dither.yaml b/Documentation/devicetree/bindings/display/mediatek/mediatek,dither.yaml
> index 6fceb1f95d2a..abaf27916d13 100644
> --- a/Documentation/devicetree/bindings/display/mediatek/mediatek,dither.yaml
> +++ b/Documentation/devicetree/bindings/display/mediatek/mediatek,dither.yaml
> @@ -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
> diff --git a/Documentation/devicetree/bindings/display/mediatek/mediatek,dpi.yaml b/Documentation/devicetree/bindings/display/mediatek/mediatek,dpi.yaml
> index 3a82aec9021c..b567e3d58aa1 100644
> --- a/Documentation/devicetree/bindings/display/mediatek/mediatek,dpi.yaml
> +++ b/Documentation/devicetree/bindings/display/mediatek/mediatek,dpi.yaml
> @@ -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

This is wrong. The existing 'port' is the output. 'port' and 'port@0'
are treated as the same thing. Since you are adding an input port, the
new port has to be 'port@1' (or any number but 0).

I haven't looked at the driver code, but it should request port 0 and
always get the output port. And requesting port 1 will return an error
or the input port.

Rob