Re: [PATCH v7 03/23] dt-bindings: media: qcom,sm8750-camss: Add SM8750 CAMSS

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Low] dt-bindings: media: qcom,sm8750-camss: invalid 0-based
  data-lanes in example
--

commit cfe5f0b3c8e80533b908dd73b55a048664a6ed2e
Author: Hangxiang Ma <hangxiang.ma@oss.qualcomm.com>

dt-bindings: media: qcom,sm8750-camss: Add SM8750 CAMSS

This commit adds the Device Tree binding schema for the Qualcomm SM8750
Camera Subsystem (CAMSS).

> diff --git a/Documentation/devicetree/bindings/media/qcom,sm8750-camss.yaml b/Documentation/devicetree/bindings/media/qcom,sm8750-camss.yaml
> new file mode 100644
> index 0000000000000..e7ab61d71ffbd
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/qcom,sm8750-camss.yaml
> @@ -0,0 +1,297 @@

[ ... ]

> +        properties:
> +          endpoint:
> +            $ref: video-interfaces.yaml#
> +            unevaluatedProperties: false
> +
> +            properties:
> +              data-lanes:
> +                minItems: 1
> +                maxItems: 4

[ ... ]

> +            ports {
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +
> +                port@0 {
> +                    reg = <0>;
> +
> +                    camss_csiphy0_ep: endpoint {
> +                        data-lanes = <0 1 2 3>;
> +                        remote-endpoint = <&csiphy0_out>;
> +                    };
> +                };
> +            };
> +        };
> +    };

[Severity: Low]
Should data-lanes in the example endpoint be <1 2 3 4> instead of
<0 1 2 3>?

On SM8750, CSIPHY blocks are standalone PHY devices rather than legacy
sub-resources inside the CAMSS node, so camss_detect_legacy_phy() sets
camss->legacy_phy = false and camss_parse_ports() sets lane_base = 1.
camss_parse_endpoint_node() then rejects lane 0 with -EINVAL and fails
probe:

drivers/media/platform/qcom/camss/camss.c:camss_parse_endpoint_node() {
    ...
		if (lane < lane_base || lane - lane_base >= MSM_CSIPHY_MAX_DATA_LANE) {
			dev_err(dev, "invalid data-lane %u\n", lane);
			return -EINVAL;
		}
    ...
}

The endpoint schema for data-lanes could also constrain items to minimum: 1
and maximum: 4 so 0-based lane indices are caught by schema validation.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261114-add-support-for-camss-on-sm8750-v7-0-8ff2a11835f6@oss.qualcomm.com?part=3

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