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Date:   Tue, 22 Dec 2020 09:09:07 +0200
From:   Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To:     Liu Ying <victor.liu@nxp.com>
Cc:     dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-media@vger.kernel.org, airlied@linux.ie, daniel@ffwll.ch,
        robh+dt@kernel.org, shawnguo@kernel.org, s.hauer@pengutronix.de,
        kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com,
        mchehab@kernel.org, a.hajda@samsung.com, narmstrong@baylibre.com,
        jonas@kwiboo.se, jernej.skrabec@siol.net, kishon@ti.com,
        vkoul@kernel.org
Subject: Re: [PATCH 06/14] dt-bindings: display: bridge: Add i.MX8qm/qxp
 display pixel link binding
Message-ID: <X+Gbk3uN870B/B7P@pendragon.ideasonboard.com>
References: <1608199173-28760-1-git-send-email-victor.liu@nxp.com>
 <1608199173-28760-7-git-send-email-victor.liu@nxp.com>
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In-Reply-To: <1608199173-28760-7-git-send-email-victor.liu@nxp.com>
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Hi Liu,

Thank you for the patch.

On Thu, Dec 17, 2020 at 05:59:25PM +0800, Liu Ying wrote:
> This patch adds bindings for i.MX8qm/qxp display pixel link.
> 
> Signed-off-by: Liu Ying <victor.liu@nxp.com>
> ---
>  .../display/bridge/fsl,imx8qxp-pixel-link.yaml     | 128 +++++++++++++++++++++
>  1 file changed, 128 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/bridge/fsl,imx8qxp-pixel-link.yaml
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/fsl,imx8qxp-pixel-link.yaml b/Documentation/devicetree/bindings/display/bridge/fsl,imx8qxp-pixel-link.yaml
> new file mode 100644
> index 00000000..fd24a0e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/fsl,imx8qxp-pixel-link.yaml
> @@ -0,0 +1,128 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/bridge/fsl,imx8qxp-pixel-link.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Freescale i.MX8qm/qxp Display Pixel Link
> +
> +maintainers:
> +  - Liu Ying <victor.liu@nxp.com>
> +
> +description: |
> +  The Freescale i.MX8qm/qxp Display Pixel Link(DPL) forms a standard
> +  asynchronous linkage between pixel sources(display controller or
> +  camera module) and pixel consumers(imaging or displays).
> +  It consists of two distinct functions, a pixel transfer function and a
> +  control interface.  Multiple pixel channels can exist per one control channel.
> +  This binding documentation is only for pixel links whose pixel sources are
> +  display controllers.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - fsl,imx8qm-dc-pixel-link
> +      - fsl,imx8qxp-dc-pixel-link
> +
> +  ports:
> +    type: object
> +    description: |
> +      A node containing pixel link input & output port nodes with endpoint
> +      definitions as documented in
> +      Documentation/devicetree/bindings/media/video-interfaces.txt
> +      Documentation/devicetree/bindings/graph.txt

With Rob's patch that convert both of these to YAML, I think you can
drop the references to these documents, and use

  $ref: /schemas/graph.yaml#/properties/ports

in the ports node, and

  $ref: /schemas/graph.yaml#/$defs/port-base
  unevaluatedProperties: false

in the port nodes, dropping the type property. You will also be able to
drop

  additionalProperties: false

for the ports node.

> +
> +    properties:
> +      '#address-cells':
> +        const: 1
> +
> +      '#size-cells':
> +        const: 0
> +
> +      port@0:
> +        type: object
> +        description: The pixel link input port node from upstream video source.
> +
> +        properties:
> +          reg:
> +            const: 0
> +
> +        required:
> +          - reg
> +
> +    patternProperties:
> +      "^port@[1-4]$":
> +        type: object
> +        description: The pixel link output port node to downstream bridge.
> +
> +        properties:
> +          reg:
> +            enum: [ 1, 2, 3, 4 ]
> +
> +        required:
> +          - reg
> +
> +    required:
> +      - "#address-cells"
> +      - "#size-cells"
> +      - port@0
> +
> +    anyOf:
> +      - required:
> +          - port@1
> +      - required:
> +          - port@2
> +      - required:
> +          - port@3
> +      - required:
> +          - port@4

Do all DPL instances have four output ports ? If so I would make all of
them mandatory, as they describe the hardware. They can be left without
any endpoing if they're not connected to anything.

> +
> +    additionalProperties: false
> +
> +required:
> +  - compatible
> +  - ports
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    dc0-pixel-link0 {
> +        compatible = "fsl,imx8qxp-dc-pixel-link";
> +
> +        ports {
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +
> +            /* from dc0 pixel combiner channel0 */
> +            port@0 {
> +                reg = <0>;
> +
> +                dc0_pixel_link0_dc0_pixel_combiner_ch0: endpoint {
> +                    remote-endpoint = <&dc0_pixel_combiner_ch0_dc0_pixel_link0>;
> +                };
> +            };
> +
> +            /* to PXL2DPIs in MIPI/LVDS combo subsystems */
> +            port@1 {
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +                reg = <1>;
> +
> +                dc0_pixel_link0_mipi_lvds_0_pxl2dpi: endpoint@0 {
> +                    reg = <0>;
> +                    remote-endpoint = <&mipi_lvds_0_pxl2dpi_dc0_pixel_link0>;
> +                };
> +
> +                dc0_pixel_link0_mipi_lvds_1_pxl2dpi: endpoint@1 {
> +                    reg = <1>;
> +                    remote-endpoint = <&mipi_lvds_1_pxl2dpi_dc0_pixel_link0>;
> +                };
> +            };
> +
> +            /* to imaging subsystem */
> +            port@4 {
> +                reg = <4>;
> +            };
> +        };
> +    };

-- 
Regards,

Laurent Pinchart