Re: [PATCH v2 07/66] dt-bindings: media: sun6i-a31-csi: Add MIPI CSI-2 input port

Laurent Pinchart
2022-02-07T16:18:56Z

Hi Paul,

Thank you for the patch.

On Sat, Feb 05, 2022 at 07:53:30PM +0100, Paul Kocialkowski wrote:
> The A31 CSI controller supports two distinct input interfaces:
> parallel and an external MIPI CSI-2 bridge. The parallel interface
> is often connected to a set of hardware pins while the MIPI CSI-2
> bridge is an internal FIFO-ish link. As a result, these two inputs
> are distinguished as two different ports.
>
> Note that only one of the two may be present on a controller instance.
> For example, the V3s has one controller dedicated to MIPI-CSI2 and one
> dedicated to parallel.

Is it that only one of the two is present, or only one of the two is
connected ? In the latter case I'd make both ports required, but with
only one of them connected.

> Update the binding with an explicit ports node that holds two distinct
> port nodes: one for parallel input and one for MIPI CSI-2.
>
> This is backward-compatible with the single-port approach that was
> previously taken for representing the parallel interface port, which
> stays enumerated as fwnode port 0.
>
> Note that additional ports may be added in the future, especially to
> support feeding the CSI controller's output to the ISP.
>
> Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> Reviewed-by: Rob Herring <robh@kernel.org>
> Acked-by: Maxime Ripard <mripard@kernel.org>
> ---
> .../media/allwinner,sun6i-a31-csi.yaml | 60 +++++++++++++++----
> 1 file changed, 47 insertions(+), 13 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/media/allwinner,sun6i-a31-csi.yaml b/Documentation/devicetree/bindings/media/allwinner,sun6i-a31-csi.yaml
> index 8b568072a069..3cc61866ea89 100644
> --- a/Documentation/devicetree/bindings/media/allwinner,sun6i-a31-csi.yaml
> +++ b/Documentation/devicetree/bindings/media/allwinner,sun6i-a31-csi.yaml
> @@ -61,6 +61,34 @@ properties:
>
> additionalProperties: false
>
> + ports:
> + $ref: /schemas/graph.yaml#/properties/ports
> +
> + properties:
> + port@0:
> + $ref: "#/properties/port"
> + unevaluatedProperties: false
> +
> + port@1:
> + $ref: /schemas/graph.yaml#/$defs/port-base
> + description: MIPI CSI-2 bridge input port
> +
> + properties:
> + reg:
> + const: 1
> +
> + endpoint:
> + $ref: video-interfaces.yaml#
> + unevaluatedProperties: false
> +
> + additionalProperties: false
> +
> + anyOf:
> + - required:
> + - port@0
> + - required:
> + - port@1
> +
> required:
> - compatible
> - reg

Shouldn't you specify that either port or ports is required, but not
both ? I'd also add a comment in the port node to tell it's deprecated,
and that ports should be used instead.

> @@ -89,19 +117,25 @@ examples:
> "ram";
> resets = <&ccu RST_BUS_CSI>;
>
> - port {
> - /* Parallel bus endpoint */
> - csi1_ep: endpoint {
> - remote-endpoint = <&adv7611_ep>;
> - bus-width = <16>;
> -
> - /*
> - * If hsync-active/vsync-active are missing,
> - * embedded BT.656 sync is used.
> - */
> - hsync-active = <0>; /* Active low */
> - vsync-active = <0>; /* Active low */
> - pclk-sample = <1>; /* Rising */
> + ports {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + port@0 {
> + reg = <0>;
> + /* Parallel bus endpoint */
> + csi1_ep: endpoint {
> + remote-endpoint = <&adv7611_ep>;
> + bus-width = <16>;
> +
> + /*
> + * If hsync-active/vsync-active are missing,
> + * embedded BT.656 sync is used.
> + */
> + hsync-active = <0>; /* Active low */
> + vsync-active = <0>; /* Active low */
> + pclk-sample = <1>; /* Rising */

Wrong indentation.

> + };
> };
> };
> };

--
Regards,

Laurent Pinchart