RE: [PATCH v5 1/2] dt-bindings: it6505: add properties to restrict output bandwidth

[<allen.chen@ite.com.tw>]

Hi rob

-----Original Message-----
From: Rob Herring <robh@kernel.org> 
Sent: Tuesday, October 25, 2022 12:38 AM
To: Allen Chen (陳柏宇) <allen.chen@ite.com.tw>
Cc: Pin-Yen Lin <treapking@chromium.org>; Jau-Chih Tseng (曾昭智) <Jau-Chih.Tseng@ite.com.tw>; Hermes Wu (吳佳宏) <Hermes.Wu@ite.com.tw>; Kenneth Hung (洪家倫) <Kenneth.Hung@ite.com.tw>; Andrzej Hajda <andrzej.hajda@intel.com>; Neil Armstrong <narmstrong@baylibre.com>; Robert Foss <robert.foss@linaro.org>; Laurent Pinchart <Laurent.pinchart@ideasonboard.com>; Jonas Karlman <jonas@kwiboo.se>; Jernej Skrabec <jernej.skrabec@gmail.com>; David Airlie <airlied@linux.ie>; Daniel Vetter <daniel@ffwll.ch>; Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>; open list:DRM DRIVERS <dri-devel@lists.freedesktop.org>; open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS <devicetree@vger.kernel.org>; open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v5 1/2] dt-bindings: it6505: add properties to restrict output bandwidth

On Wed, Oct 19, 2022 at 05:32:13PM +0800, allen wrote:
> From: allen chen <allen.chen@ite.com.tw>
> 
> Add properties to restrict dp output data-lanes and clock.
> 
> Signed-off-by: Pin-Yen Lin <treapking@chromium.org>
> Signed-off-by: Allen Chen <allen.chen@ite.com.tw>
> ---
>  .../bindings/display/bridge/ite,it6505.yaml   | 89 +++++++++++++++++--
>  1 file changed, 83 insertions(+), 6 deletions(-)
> 
> diff --git 
> a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml 
> b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> index 833d11b2303a7..8e607b6929fc9 100644
> --- a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> +++ b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> @@ -52,9 +52,70 @@ properties:
>      maxItems: 1
>      description: extcon specifier for the Power Delivery
>  
> -  port:
> -    $ref: /schemas/graph.yaml#/properties/port
> -    description: A port node pointing to DPI host port node

No existing users you are breaking? The commit msg should explain.

==> There are no it6505 users in community.
> +  ports:
> +    $ref: /schemas/graph.yaml#/properties/ports
> +
> +    properties:
> +      port@0:
> +        $ref: /schemas/graph.yaml#/$defs/port-base
> +        unevaluatedProperties: false
> +        description: A port node pointing to DPI host port node
> +
> +        properties:
> +          endpoint:
> +            $ref: /schemas/graph.yaml#/$defs/endpoint-base
> +            unevaluatedProperties: false
> +
> +            properties:
> +              link-frequencies:
> +                minItems: 1
> +                maxItems: 1
> +                description: Allowed max link frequencies in Hz
> +
> +      port@1:
> +        $ref: /schemas/graph.yaml#/$defs/port-base
> +        unevaluatedProperties: false
> +        description: Video port for DP output
> +
> +        properties:
> +          endpoint:
> +            $ref: /schemas/graph.yaml#/$defs/endpoint-base
> +            unevaluatedProperties: false
> +
> +            properties:
> +              data-lanes:
> +                oneOf:
> +                  - minItems: 1
> +                    maxItems: 1
> +                    uniqueItems: true
> +                    items:
> +                      enum:
> +                        - 0
> +                        - 1
> +                    description: For one lane operation.
> +
> +                  - minItems: 2
> +                    maxItems: 2
> +                    uniqueItems: true
> +                    items:
> +                      enum:
> +                        - 0
> +                        - 1
> +                    description: For two lanes operation.
> +
> +                  - minItems: 4
> +                    maxItems: 4
> +                    uniqueItems: true
> +                    items:
> +                      enum:
> +                        - 0
> +                        - 1
> +                        - 2
> +                        - 3
> +                    description: For four lanes operation.

I would do just:

data-lanes:
  minItems: 1
  items:
    - enum: [ 0, 1 ]
    - const: 1
    - const: 2
    - const: 3

It does allow 3 lanes, but I don't think that's a big deal. What it does doesn't allow is any order and yours does.

Rob