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

Laurent Pinchart
2022-02-07T15:51:32Z

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@bootlin.com>
> ---
> .../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@bootlin.com>
> +
> +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