[PATCH v3 1/5] dt-bindings: display: verisilicon,dc: generalize for single-output variants

[Joey Lu]

On 6/8/2026 4:00 PM, Krzysztof Kozlowski wrote:
> On Mon, Jun 08, 2026 at 10:32:33AM +0800, Joey Lu wrote:
>> The existing schema hard-codes the five-clock/three-reset/dual-port
>> topology of the DC8200 IP block, preventing reuse for single-output
>> variants such as the Verisilicon DCUltraLite used in the Nuvoton MA35D1
>> SoC.
>>
>> Rework the schema so that variant-specific constraints are expressed via
>> allOf/if blocks:
>>
>> - Add nuvoton,ma35d1-dcu to the SoC-specific compatible enum.  The
>>    generic verisilicon,dc fallback remains the driver-binding string.
>> - Relax the top-level clocks/resets definitions to minItems ranges so
>>    the base schema accepts both variants.
>> - Keep ports in the global required list and keep additionalProperties
>>    tightened to unevaluatedProperties.
>> - Add an allOf/if block for thead,th1520-dc8200: five-clock (core, axi,
>>    ahb, pix0, pix1), three-reset (core, axi, ahb).
>> - Add an allOf/if block for nuvoton,ma35d1-dcu: two-clock (core, pix0),
>>    one-reset (core).
>> - Fix a stray space in the port at 0 description.
>> - Add a DT example for the Nuvoton MA35D1 DCU Lite using ports/port at 0.
>>
>> Signed-off-by: Joey Lu <a0987203069 at gmail.com>
>> ---
>>   .../bindings/display/verisilicon,dc.yaml      | 103 +++++++++++++++---
>>   1 file changed, 90 insertions(+), 13 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/display/verisilicon,dc.yaml b/Documentation/devicetree/bindings/display/verisilicon,dc.yaml
>> index 9dc35ab973f2..db0260d874c5 100644
>> --- a/Documentation/devicetree/bindings/display/verisilicon,dc.yaml
>> +++ b/Documentation/devicetree/bindings/display/verisilicon,dc.yaml
>> @@ -17,7 +17,8 @@ properties:
>>       items:
>>         - enum:
>>             - thead,th1520-dc8200
>> -      - const: verisilicon,dc # DC IPs have discoverable ID/revision registers
>> +          - nuvoton,ma35d1-dcu
>> +      - const: verisilicon,dc  # DC IPs have discoverable ID/revision registers
> Why do you need to change indentation? Why introducing irrelevant
> changes to the diff?
The extra space was introduced to satisfy `yamllint`'s "too few spaces 
before comment" warning, which requires two spaces before an inline `#`. 
Since this is an unrelated change that pollutes the diff, I will revert 
it to the original single-space form.
>>   
>>     reg:
>>       maxItems: 1
>> @@ -26,6 +27,7 @@ properties:
>>       maxItems: 1
>>   
>>     clocks:
>> +    minItems: 2
>>       items:
>>         - description: DC Core clock
>>         - description: DMA AXI bus clock
> That's not true anymore. In such case the list should also be defined
> per variant and here only min/maxItems.
>
Understood. I will remove the `items:` description list from the 
top-level `clocks:` and keep only `minItems`/`maxItems`. The per-variant 
items descriptions will be moved into the allOf/if blocks.
>> @@ -34,24 +36,19 @@ properties:
>>         - description: Pixel clock of output 1
>>   
>>     clock-names:
>> -    items:
>> -      - const: core
>> -      - const: axi
>> -      - const: ahb
>> -      - const: pix0
>> -      - const: pix1
>> +    minItems: 2
>> +    maxItems: 5
>>   
>>     resets:
>> +    minItems: 1
>>       items:
>>         - description: DC Core reset
>>         - description: DMA AXI bus reset
>>         - description: Configuration AHB bus reset
>>   
>>     reset-names:
>> -    items:
>> -      - const: core
>> -      - const: axi
>> -      - const: ahb
> This stays, with minItems. Variants only need min/maxItems
>
Understood. I will restore the top-level `clock-names` and `reset-names` 
items lists and add `minItems` to each. The per-variant allOf blocks 
will only carry `minItems`/`maxItems`.
>
>> +    minItems: 1
>> +    maxItems: 3
>>   
>>     ports:
>>       $ref: /schemas/graph.yaml#/properties/ports
>> @@ -59,7 +56,7 @@ properties:
>>       properties:
>>         port at 0:
>>           $ref: /schemas/graph.yaml#/properties/port
>> -        description: The first output channel , endpoint 0 should be
>> +        description: The first output channel, endpoint 0 should be
>>             used for DPI format output and endpoint 1 should be used
>>             for DP format output.
>>   
>> @@ -77,7 +74,60 @@ required:
>>     - clock-names
>>     - ports
>>   
>> -additionalProperties: false
>> +allOf:
>> +  - if:
>> +      properties:
>> +        compatible:
>> +          contains:
>> +            const: thead,th1520-dc8200
>> +    then:
>> +      properties:
>> +        clocks:
>> +          minItems: 5
>> +          maxItems: 5
>> +
>> +        clock-names:
>> +          items:
>> +            - const: core
>> +            - const: axi
>> +            - const: ahb
>> +            - const: pix0
>> +            - const: pix1
>> +
>> +        resets:
>> +          minItems: 3
>> +          maxItems: 3
>> +
>> +        reset-names:
> minItems: 3
Understood. I will add `minItems: 3` to `reset-names` in the 
thead,th1520-dc8200 block.
>> +          items:
>> +            - const: core
>> +            - const: axi
>> +            - const: ahb
>> +
>> +  - if:
>> +      properties:
>> +        compatible:
>> +          contains:
>> +            const: nuvoton,ma35d1-dcu
>> +    then:
>> +      properties:
>> +        clocks:
>> +          minItems: 2
>> +          maxItems: 2
>> +
>> +        clock-names:
>> +          items:
>> +            - const: core
>> +            - const: pix0
>> +
>> +        resets:
>> +          maxItems: 1
>> +
>> +        reset-names:
> maxItems: 1
Understood. I will add `maxItems: 1` to `reset-names` in the nuvoton block.
>> +          items:
>> +            - const: core
>> +
>> +unevaluatedProperties: false
> Stop making random changes to the binding.
>
> Best regards,
> Krzysztof

Understood. I will revert to `additionalProperties: false` as in the 
original binding.

Many thanks!