Re: [PATCH v3 1/3] dt-bindings: display: samsung,exynos7-decon: add properties for iommus and ports

[Krzysztof Kozlowski <krzk@kernel.org>]

On 27/06/2025 17:03, Kaustabh Chakraborty wrote:
> On 2025-06-27 14:44, Krzysztof Kozlowski wrote:
>> On 27/06/2025 15:44, Kaustabh Chakraborty wrote:
>>>>> a/Documentation/devicetree/bindings/display/samsung/samsung,exynos7-decon.yaml
>>>>> +++
>>>>> b/Documentation/devicetree/bindings/display/samsung/samsung,exynos7-decon.yaml
>>>>> @@ -80,6 +80,14 @@ properties:
>>>>>        - const: vsync
>>>>>        - const: lcd_sys
>>>>>
>>>>> +  iommus:
>>>>> +    maxItems: 1
>>>>> +
>>>>> +  ports:
>>>>> +    $ref: /schemas/graph.yaml#/properties/ports
>>>>> +    description:
>>>>> +      Contains a port which is connected to mic or dsim node.
>>>>
>>>> You need to list and describe the ports.
>>>
>>> -    description:
>>> -      Contains a port which is connected to mic or dsim node.
>>> +    properties:
>>> +      port@0:
>>> +        $ref: /schemas/graph.yaml#/properties/port
>>> +        description:
>>> +          Input port which is connected to either a Mobile Image
>>> +          Compressor (MIC) or a DSI Master device.
>>
>>
>> If this is only one port, then just 'port' property, but I have doubts
>> it should be one, because even you mentioned two - MIC could be the
>> input and MIPI DSIM would be the output.
> 
> DECON is the first device in the pipeline. So it should only have
> output.
> 
> It's either:
> DECON -> DSIM -> panel
> or
> DECON -> MIC -> DSIM -> panel
> 
> Exynos7870 doesn't have MIC, but other SoCs may have one.

Could be without ports entirely, but it is also fine to list port under.

> 
>>
>> Maybe if the MIC is integral part, it would not have been an input, but
>> then only 'port'.
>>
>>>
>>> I assume you want something like this?
>>> Is the formatting correct? Should there be a space between
>>> ports:$ref and ports:properties?
>>
>> Look at toshiba,tc358768.yaml or the simple-bridge (except you should
>> name the input and output ports).
> 
> Okay, thanks!
> 
> Therefore this:
> 
> -    description:
> -      Contains a port which is connected to mic or dsim node.
> +
> +    properties:
> +      port:
> +        $ref: /schemas/graph.yaml#/properties/port
> +        description:
> +          Output port which is connected to either a Mobile Image
> +          Compressor (MIC) or a DSI Master device.

and additionalProperties: false in ports level.


Best regards,
Krzysztof