Re: [PATCH 1/3] dt-bindings: sound: Add Apple MCA I2S transceiver

From: Martin Povišer
Date: Tue Aug 09 2022 - 04:55:57 EST



> On 9. 8. 2022, at 10:47, Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> wrote:
>
> On 09/08/2022 11:40, Martin Povišer wrote:
>>> Describe the items because otherwise you allow any order. The list will
>>> be unfortunately quite long, but still readable enough.
>>
>> Well, I would assume the ‘dmas’ property as described above has an implicit
>> natural order, and the dma-names are tied to it. You order it like the other
>> per-cluster properties, and then within the cluster the order is fixed to
>> 'TXA, RXA, TXB, RXB’ (maybe the word ‘respectively’ thrown into the description
>> would have made it clearer).
>>
>> Anyway that’s just discussing my assumptions. I can roll out the items list
>> for ‘dma-names’, if that’s what you mean. Or do you mean explicitly describing
>> the items in ‘dmas’ too?
>
> The text description of 'dmas' does not mean it will be followed by DTS
> author. In current bindings DTS author can therefore put any order of
> dmas/dma-names. Unrolling the dma-names forces this order to be fixed
> and validated by dtschema.

OK

>>
>>>> + description: |
>>>> + Names for the DMA channels: 'tx'/'rx', then cluster number, then 'a'/'b'
>>>> + based on the associated SERDES unit.
>>>> +
>>
>> (...)
>>
>>>> +
>>>> +additionalProperties: false
>>>> +
>>>> +examples:
>>>> + - |
>>>> + mca: mca@9b600000 {
>>>
>>> You called it I2S transceiver but isn't it also actually I2S controller?
>>> If yes, then the node name should be probably "i2s".
>>
>> It’s a peripheral you use to transmit and receive samples over I2S, frankly
>> I don't know the nomenclature.
>
> Looking at other devices, it's i2s.

OK, thanks.

> Best regards,
> Krzysztof

Best,
Martin