Re: [PATCH V2 1/2] dt-bindings: display: xlnx: Add DSI 2.0 Tx subsystem documentation

[Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>]

Hi GVRao,

Thank you for the patch.

On Thu, Jun 16, 2022 at 07:47:35PM +0530, Venkateshwar Rao Gannavarapu wrote:
> This patch adds dt binding for Xilinx DSI-TX subsystem.
> 
> The Xilinx MIPI DSI (Display serial interface) Transmitter Subsystem
> implements the Mobile Industry Processor Interface (MIPI) based display
> interface. It supports the interface with the programmable logic (FPGA).
> 
> Signed-off-by: Venkateshwar Rao Gannavarapu <venkateshwar.rao.gannavarapu@xxxxxxxxxx>
> ---
>  .../bindings/display/xlnx/xlnx,dsi-tx.yaml         | 101 +++++++++++++++++++++
>  1 file changed, 101 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/xlnx/xlnx,dsi-tx.yaml
> 
> diff --git a/Documentation/devicetree/bindings/display/xlnx/xlnx,dsi-tx.yaml b/Documentation/devicetree/bindings/display/xlnx/xlnx,dsi-tx.yaml
> new file mode 100644
> index 0000000..644934d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/xlnx/xlnx,dsi-tx.yaml
> @@ -0,0 +1,101 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/xlnx/xlnx,dsi-tx.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Xilinx DSI Transmitter subsystem Device Tree Bindings
> +
> +maintainers:
> +  - Venkateshwar Rao Gannavarapu <venkateshwar.rao.gannavarapu@xxxxxxxxxx>
> +
> +description: |
> +  The Xilinx DSI Transmitter Subsystem implements the Mobile Industry
> +  Processor Interface based display interface. It supports the interface
> +  with the programmable logic (FPGA).
> +
> +  For more details refer to PG238 Xilinx MIPI DSI-V2.0 Tx Subsystem.
> +
> +properties:
> +  compatible:
> +    const: xlnx,dsi-tx-v2.0
> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    items:
> +      - description: AXI Lite CPU clock
> +      - description: D-PHY clock
> +
> +  clock-names:
> +    items:
> +      - const: s_axis_aclk
> +      - const: dphy_clk_200M
> +
> +  ports:
> +    $ref: /schemas/graph.yaml#/properties/ports
> +
> +    properties:
> +      port@0:
> +        $ref: /schemas/graph.yaml#/properties/port
> +        description:
> +          This port should be the input endpoint.

Port and endpoint are two different things. You can just write "Input
port of the DSI encoder".

> +
> +      port@1:
> +        $ref: /schemas/graph.yaml#/properties/port
> +        description:
> +          This port should be the output endpoint.

And here, "Output port of the DSI encoder".

> +
> +required:
> +  - "#address-cells"
> +  - "#size-cells"

I think those should be listed in the properties above, with fixed
values.

> +  - compatible
> +  - reg
> +  - clocks
> +  - clock-names
> +  - ports
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    dsi0: dsi_tx@80020000 {
> +        compatible = "xlnx,dsi-tx-v2.0";
> +        reg = <0x80020000 0x20000>;
> +        clocks = <&misc_clk_0>, <&misc_clk_1>;
> +        clock-names = "s_axis_aclk", "dphy_clk_200M";
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        ports {
> +              #address-cells = <1>;
> +              #size-cells = <0>;
> +
> +              port@0 {
> +                    reg = <0>;
> +                    mipi_dsi_in: endpoint {
> +                        remote-endpoint = <&pl_disp>;
> +                    };
> +              };
> +
> +              port@1 {
> +                    reg = <1>;
> +                    mipi_dsi_out: endpoint {
> +                        remote-endpoint = <&panel_in>;
> +                    };
> +              };
> +        };
> +
> +        panel@0 {
> +              compatible = "auo,b101uan01";
> +              reg = <0>;
> +              port {
> +                    panel_in: endpoint {
> +                        remote-endpoint = <&mipi_dsi_out>;
> +                    };
> +              };
> +        };

Does this example validate (with `make dt_binding_check
DT_SCHEMA_FILES=Documentation/devicetree/bindings/display/xlnx/xlnx,dsi-tx.yaml`)
without listing the panel node in the properties ?

> +    };
> +
> +...

-- 
Regards,

Laurent Pinchart