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Message-ID: <7e30f558-d42e-9751-7729-f0422f3926fa@denx.de>
Date:   Wed, 3 Aug 2022 10:21:19 +0200
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Subject: Re: [PATCH v3 2/4] dt-bindings: display: add new bus-format property
 for panel-dpi
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To:     Max Krummenacher <max.oss.09@gmail.com>,
        max.krummenacher@toradex.com
Cc:     Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Rob Herring <robh@kernel.org>,
        Dave Stevenson <dave.stevenson@raspberrypi.com>,
        Maxime Ripard <mripard@kernel.org>,
        Christoph Niedermaier <cniedermaier@dh-electronics.com>,
        Francesco Dolcini <francesco.dolcini@toradex.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        David Airlie <airlied@linux.ie>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Sam Ravnborg <sam@ravnborg.org>,
        Thierry Reding <thierry.reding@gmail.com>,
        devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org
References: <20220628181838.2031-1-max.oss.09@gmail.com>
 <20220628181838.2031-3-max.oss.09@gmail.com>
From:   Marek Vasut <marex@denx.de>
In-Reply-To: <20220628181838.2031-3-max.oss.09@gmail.com>
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On 6/28/22 20:18, Max Krummenacher wrote:

Hello Max,

[...]

> diff --git a/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml b/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml
> index dae0676b5c6e..52f5db03b6a8 100644
> --- a/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml
> +++ b/Documentation/devicetree/bindings/display/panel/panel-dpi.yaml
> @@ -26,7 +26,28 @@ properties:
>     height-mm: true
>     label: true
>     panel-timing: true
> -  port: true
> +
> +  port:
> +    $ref: /schemas/graph.yaml#/$defs/port-base
> +    description:
> +      Input port node, receives the panel data.
> +
> +    properties:
> +      endpoint:
> +        $ref: /schemas/graph.yaml#/$defs/endpoint-base
> +
> +        properties:
> +          bus-format:
> +            $ref: /schemas/types.yaml#/definitions/uint32
> +            minimum: 0x1001
> +            maximum: 0x1fff
> +            description: |
> +              Describes how the display panel is connected to the display interface.
> +              Valid values are defined in <dt-bindings/display/dt-media-bus-format.h>.
> +              The mapping between the color/significance of the panel lines to the
> +              parallel data lines are defined in:
> +              https://www.kernel.org/doc/html/v5.17/userspace-api/media/v4l/subdev-formats.html#packed-rgb-formats

I am not sure whether I should re-open this discussion, but I still 
wonder, wouldn't it be better to describe the DPI bus color channel 
ordering (RGB, BGR, ...), width of each color channel in bits, pixel 
format (RGB, YUV, ...) instead of using specific constants for the 
entire format ?