Re: [PATCH v4 12/39] dt-bindings: serial: atmel,at91-usart: add compatible for sam9x7.

[<Varshini.Rajendran@xxxxxxxxxxxxx>]

Hi Conor,

On 25/02/24 1:32 am, Conor Dooley wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> On Fri, Feb 23, 2024 at 10:55:59PM +0530, Varshini Rajendran wrote:
>> Add sam9x7 compatible to DT bindings documentation.
>>
>> Signed-off-by: Varshini Rajendran <varshini.rajendran@xxxxxxxxxxxxx>
>> ---
>> Changes in v4:
>> - Fixed the wrong addition of compatible
>> - Added further compatibles that are possible correct (as per DT)
>> ---
>>  .../devicetree/bindings/serial/atmel,at91-usart.yaml | 12 +++++++++---
>>  1 file changed, 9 insertions(+), 3 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml b/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml
>> index 65cb2e5c5eee..30af537e8e81 100644
>> --- a/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml
>> +++ b/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml
>> @@ -23,11 +23,17 @@ properties:
>>            - const: atmel,at91sam9260-dbgu
>>            - const: atmel,at91sam9260-usart
>>        - items:
>> -          - const: microchip,sam9x60-usart
>> +          - enum:
>> +              - microchip,sam9x60-usart
>> +              - microchip,sam9x7-usart
>>            - const: atmel,at91sam9260-usart
>>        - items:
>> -          - const: microchip,sam9x60-dbgu
>> -          - const: microchip,sam9x60-usart
>> +          - enum:
>> +              - microchip,sam9x60-dbgu
>> +              - microchip,sam9x7-dbgu
> 
>> +          - enum:
>> +              - microchip,sam9x60-usart
>> +              - microchip,sam9x7-usart
> 
> This doesn't make sense - this enum should be a const.
> I don't really understand the idea behind of the original binding here that
> allowed:
> "microchip,sam9x60-dbgu", "microchip,sam9x60-usart", "atmel,at91sam9260-dbgu", "atmel,at91sam9260-usart"
> 
> Specifically, I don't get the purpose of the "microchip,sam9x60-usart".
> Either make it
>       - items:
>           - enum:
>               - microchip,sam9x60-dbgu
>               - microchip,sam9x7-dbgu
>           - const: microchip,sam9x60-usart
>           - const: atmel,at91sam9260-dbgu
>           - const: atmel,at91sam9260-usart
> or add
>       - items:
>           - const: microchip,sam9x60-dbgu
>           - const: atmel,at91sam9260-dbgu
>           - const: atmel,at91sam9260-usart
> or explain exactly why this needs to be
> "chipa-dgbu", "chipa-usart", "chipb-dbgu", "chipb-dbgu"
The compatible has to be "chipa-usart", "chipb-usart", "chipa-dbgu", 
"chipb-dbgu" for the device to work as a debug console over UART
wher the chipa-<periph> is the device specific compatible
and the chipb-<periph> is the fallback compatible that the driver 
actually uses.

Maybe putting the 2 compatibles as 2 enums is not right. I will rephrase 
it as below.

       - items:
           - const: microchip,sam9x60-dbgu
           - const: microchip,sam9x60-usart
           - const: atmel,at91sam9260-dbgu
           - const: atmel,at91sam9260-usart
       - items:
           - const: microchip,sam9x7-dbgu
           - const: microchip,sam9x7-usart
           - const: atmel,at91sam9260-dbgu
           - const: atmel,at91sam9260-usart

Hope this is fine.
> 
> Thanks,
> Conor.
> 

-- 
Thanks and Regards,
Varshini Rajendran.