RE: [PATCH v4 1/2] dt-bindings: it6505: add properties to restrict output bandwidth

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

Hi

-----Original Message-----
From: Rob Herring <robh@kernel.org> 
Sent: Friday, October 14, 2022 3:20 AM
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>; 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>; Kenneth Hung (洪家倫) <Kenneth.Hung@ite.com.tw>; Hermes Wu (吳佳宏) <Hermes.Wu@ite.com.tw>; Andrzej Hajda <andrzej.hajda@intel.com>; Neil Armstrong <narmstrong@baylibre.com>; Robert Foss <robert.foss@linaro.org>; 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 v4 1/2] dt-bindings: it6505: add properties to restrict output bandwidth

On Thu, Oct 13, 2022 at 02:05:45PM +0300, Laurent Pinchart wrote:
> Hi Allen,
> 
> Thank you for the patch.
> 
> On Thu, Oct 13, 2022 at 06:51:13PM +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   | 43 +++++++++++++++++++
> >  1 file changed, 43 insertions(+)
> > 
> > diff --git 
> > a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml 
> > b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> > index 833d11b2303a7..f2c3d1d10359e 100644
> > --- 
> > a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> > +++ b/Documentation/devicetree/bindings/display/bridge/ite,it6505.ya
> > +++ ml
> > @@ -52,10 +52,51 @@ properties:
> >      maxItems: 1
> >      description: extcon specifier for the Power Delivery
> >  
> > +  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.
> 
> The data lanes should be in the output endpoint. If there's no output 
> port, one should be added.
> 
==> In this dt-binding, our output point is "extcon" so doesn't have output endpoint.
I don't know how to add the endpoint.
If need to add the endpoint to this dt-binding, what is your recommend about adding the endpoint?
By the way, Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> said we could put "data-lanes" here.
> > +
> >    port:
> >      $ref: /schemas/graph.yaml#/properties/port

To fix the error, this must be:

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

> >      description: A port node pointing to DPI host port node
> >  
> > +    properties:
> > +      endpoint:
> > +        $ref: /schemas/graph.yaml#/$defs/endpoint-base
> > +
> > +        properties:
> > +          link-frequencies:
> > +            minItems: 1
> > +            maxItems: 1
> > +            description: Allowed max link frequencies in Hz.
> > +
> >  required:
> >    - compatible
> >    - ovdd-supply
> > @@ -84,10 +125,12 @@ examples:
> >              pwr18-supply = <&it6505_pp18_reg>;
> >              reset-gpios = <&pio 179 1>;
> >              extcon = <&usbc_extcon>;
> > +            data-lanes = <0 1>;
> >  
> >              port {
> >                  it6505_in: endpoint {
> >                      remote-endpoint = <&dpi_out>;
> > +                    link-frequencies = /bits/ 64 <150000000>;
> >                  };
> >              };
> >          };
> 
> --
> Regards,
> 
> Laurent Pinchart
>