Re: [PATCH v2 61/66] dt-bindings: media: Add Allwinner A31 ISP bindings documentation

[Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>]

Hi Paul,

Thank you for the patch.

On Sat, Feb 05, 2022 at 07:54:24PM +0100, Paul Kocialkowski wrote:
> This introduces YAML bindings documentation for the Allwinner A31 Image
> Signal Processor (ISP).
> 
> Signed-off-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx>
> ---
>  .../media/allwinner,sun6i-a31-isp.yaml        | 117 ++++++++++++++++++
>  1 file changed, 117 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/media/allwinner,sun6i-a31-isp.yaml
> 
> diff --git a/Documentation/devicetree/bindings/media/allwinner,sun6i-a31-isp.yaml b/Documentation/devicetree/bindings/media/allwinner,sun6i-a31-isp.yaml
> new file mode 100644
> index 000000000000..2d87022c43ce
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/allwinner,sun6i-a31-isp.yaml
> @@ -0,0 +1,117 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/allwinner,sun6i-a31-isp.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Allwinner A31 Image Signal Processor Driver (ISP) Device Tree Bindings
> +
> +maintainers:
> +  - Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx>
> +
> +properties:
> +  compatible:
> +    enum:
> +      - allwinner,sun6i-a31-isp
> +      - allwinner,sun8i-v3s-isp
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  clocks:
> +    items:
> +      - description: Bus Clock
> +      - description: Module Clock
> +      - description: DRAM Clock

That's interesting, does the ISP have a dedicated DRAM ?

> +
> +  clock-names:
> +    items:
> +      - const: bus
> +      - const: mod
> +      - const: ram
> +
> +  resets:
> +    maxItems: 1
> +
> +  ports:
> +    $ref: /schemas/graph.yaml#/properties/ports
> +
> +    properties:
> +      port@0:
> +        $ref: /schemas/graph.yaml#/$defs/port-base
> +        description: CSI0 input port
> +
> +        properties:
> +          reg:
> +            const: 0
> +
> +          endpoint:
> +            $ref: video-interfaces.yaml#
> +            unevaluatedProperties: false

If no other property than remote-endpoint are allowed, I'd write

          endpoint:
            $ref: video-interfaces.yaml#
	    remote-endpoint: true
            additionalProperties: false

Same below.

> +
> +        additionalProperties: false
> +
> +      port@1:
> +        $ref: /schemas/graph.yaml#/$defs/port-base
> +        description: CSI1 input port
> +
> +        properties:
> +          reg:
> +            const: 0

This should be 1.

> +
> +          endpoint:
> +            $ref: video-interfaces.yaml#
> +            unevaluatedProperties: false
> +
> +        additionalProperties: false
> +
> +    anyOf:
> +      - required:
> +        - port@0
> +      - required:
> +        - port@1

As ports are an intrinsic property of the ISP, both should be required,
but they don't have to be connected.

By the way, how do you select at runtime which CSI-2 RX the ISP gets its
image stream from ? Is it configured through registers of the ISP ?

> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +  - clocks
> +  - clock-names
> +  - resets
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/clock/sun8i-v3s-ccu.h>
> +    #include <dt-bindings/reset/sun8i-v3s-ccu.h>
> +
> +    isp: isp@1cb8000 {
> +        compatible = "allwinner,sun8i-v3s-isp";
> +        reg = <0x01cb8000 0x1000>;
> +        interrupts = <GIC_SPI 83 IRQ_TYPE_LEVEL_HIGH>;
> +        clocks = <&ccu CLK_BUS_CSI>,
> +             <&ccu CLK_CSI1_SCLK>,
> +             <&ccu CLK_DRAM_CSI>;
> +        clock-names = "bus", "mod", "ram";
> +        resets = <&ccu RST_BUS_CSI>;
> +
> +        ports {
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +
> +            port@0 {
> +                reg = <0>;
> +
> +                isp_in_csi0: endpoint {
> +                    remote-endpoint = <&csi0_out_isp>;
> +                };
> +            };
> +        };
> +    };
> +
> +...

-- 
Regards,

Laurent Pinchart