Re: [RFC PATCH 2/8] dt-bindings: display: add versilicon,dc

[Rob Herring <robh@kernel.org>]

On Fri, Aug 15, 2025 at 12:40:42AM +0800, Icenowy Zheng wrote:
> Verisilicon has a series of display controllers prefixed with DC and
> with self-identification facility like their GC series GPUs.
> 
> Add a device tree binding for it.
> 
> Depends on the specific DC model, it can have either one or two display
> outputs, and each display output could be set to DPI signal or "DP"
> signal (which seems to be some plain parallel bus to HDMI controllers).
> 
> Signed-off-by: Icenowy Zheng <uwu@icenowy.me>
> ---
>  .../bindings/display/verisilicon,dc.yaml      | 127 ++++++++++++++++++
>  1 file changed, 127 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/verisilicon,dc.yaml
> 
> diff --git a/Documentation/devicetree/bindings/display/verisilicon,dc.yaml b/Documentation/devicetree/bindings/display/verisilicon,dc.yaml
> new file mode 100644
> index 0000000000000..2f71a811786aa
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/verisilicon,dc.yaml
> @@ -0,0 +1,127 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/verisilicon,dc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Verisilicon DC-series display controllers
> +
> +maintainers:
> +  - Icenowy Zheng <uwu@icenowy.me>
> +
> +properties:
> +  $nodename:
> +    pattern: "^display@[0-9a-f]+$"
> +
> +  compatible:
> +    const: verisilicon,dc

If the clocks or resets varies by platform, then you need an SoC 
specific compatible still. If these clocks/resets are straight from the 
RTL and any other number of clocks/resets is wrong, then we can stick 
with just this compatible.

> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  clocks:
> +    items:
> +      - description: DC Core clock
> +      - description: DMA AXI bus clock
> +      - description: Configuration AHB bus clock
> +      - description: Pixel clock of output 0
> +      - description: Pixel clock of output 1
> +    minItems: 4

Generally we put this before 'items'.

> +
> +  clock-names:
> +    items:
> +      - const: core
> +      - const: axi
> +      - const: ahb
> +      - const: pix0
> +      - const: pix1
> +    minItems: 4
> +
> +  resets:
> +    items:
> +      - description: DC Core reset
> +      - description: DMA AXI bus reset
> +      - description: Configuration AHB bus reset
> +
> +  reset-names:
> +    items:
> +      - const: core
> +      - const: axi
> +      - const: ahb
> +
> +  ports:
> +    $ref: /schemas/graph.yaml#/properties/ports
> +
> +    properties:
> +      port@0:
> +        $ref: /schemas/graph.yaml#/properties/port
> +        description: The first output channel, endpoint 0 should be
> +          used for DPI format output and endpoint 1 should be used
> +          for DP format output.
> +
> +      port@1:
> +        $ref: /schemas/graph.yaml#/properties/port
> +        description: The second output channel if the DC variant
> +          supports and used. Follow the same endpoint addressing
> +          rule with the first port.
> +
> +    required:
> +      - port@0
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +  - clocks
> +  - clock-names
> +  - ports
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    #include <dt-bindings/clock/thead,th1520-clk-ap.h>
> +    #include <dt-bindings/reset/thead,th1520-reset.h>
> +    soc {
> +      #address-cells = <2>;
> +      #size-cells = <2>;
> +
> +      display@ffef600000 {
> +        compatible = "verisilicon,dc";
> +        reg = <0xff 0xef600000 0x0 0x100000>;
> +        interrupts = <93 IRQ_TYPE_LEVEL_HIGH>;
> +        clocks = <&clk_vo CLK_DPU_CCLK>,
> +           <&clk_vo CLK_DPU_ACLK>,
> +           <&clk_vo CLK_DPU_HCLK>,
> +           <&clk_vo CLK_DPU_PIXELCLK0>,
> +           <&clk_vo CLK_DPU_PIXELCLK1>;
> +        clock-names = "core", "axi", "ahb", "pix0", "pix1";
> +        resets = <&rst TH1520_RESET_ID_DPU_CORE>,
> +           <&rst TH1520_RESET_ID_DPU_AXI>,
> +           <&rst TH1520_RESET_ID_DPU_AHB>;
> +        reset-names = "core", "axi", "ahb";
> +
> +        ports {
> +          #address-cells = <1>;
> +          #size-cells = <0>;
> +          port@0 {
> +            reg = <0>;
> +          };
> +
> +          port@1 {
> +            reg = <1>;
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +
> +            dpu_out_dp1: endpoint@1 {
> +              reg = <1>;
> +              remote-endpoint = <&hdmi_in>;
> +            };
> +          };
> +        };
> +      };
> +    };
> -- 
> 2.50.1
>