Re: 回复: [PATCH v2 1/2] ASoC: dt-bindings: Add bindings for Cadence I2S-MC controller

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 26/03/2024 14:43, Xingyu Wu wrote:
>>>>> +
>>>>> +properties:
>>>>> +  compatible:
>>>>> +    enum:
>>>>> +      - cdns,i2s-mc
>>>>
>>>> Why did this appear? Who asked for this? Usually these blocks are not
>>>> usable on their own.
>>>
>>> I wonder if I should keep the original IP compatible. Do I not need it?
>>
>> As I said, it is not usable on its own, so unless you have other arguments then no.
>> But my point was that no one asked for this.
> 
> I want to keep the original IP compatible which can distinguish from the JH8100 SoC.
> Can I write it like this:
> compatible:
>    enum:
>           - starfive,jh8100-i2s
>    const: cdns,i2s-mc
> 
> and I write this in the DTS:
> compatible = "starfive,jh8100-i2s", "cdns,i2s-mc";

Can you provide any rationale for this? I asked "unless you have other
arguments", so where are the arguments?

Nothing was explained in patch changelog. Nothing was provided in this
email thread.

> 
>>
>>>
>>>>
>>>>> +      - starfive,jh8100-i2s
>>>>> +
>>>>> +  reg:
>>>>> +    maxItems: 1
>>>>> +
>>>>> +  interrupts:
>>>>> +    description:
>>>>> +      The interrupt line number for the I2S controller. Add this
>>>>> +      parameter if the I2S controller that you are using does not
>>>>> +      using DMA.
>>>>
>>>> That's still wrong. You already got comment on this. Either you have interrupt
>> or not.
>>>> You do not add interrupts, based on your choice or not of having DMA.
>>>> Drop the comment.
>>>
>>> Do I keep this property and drop this description?
>>
>> Drop description. Keep property, if your hardware has interrupts.
>>
> 
> Will drop.
> 
>> ...
>>
>>>>
>>>>> +  - compatible
>>>>> +  - reg
>>>>> +  - clocks
>>>>> +  - clock-names
>>>>> +  - resets
>>>>> +
>>>>> +oneOf:
>>>>> +  - required:
>>>>> +      - dmas
>>>>> +      - dma-names
>>>>> +  - required:
>>>>> +      - interrupts
>>>>
>>>> This won't work. Provide both interrupts and dmas, and then test your DTS.
>>>
>>> I provided both properties in the DTS and test by dtbs_check. Then it printed
>> that:
>>> 'More than one condition true in one of shema: ...'
>>
>> Exactly. Having both properties is a correct DTS. Interrupts do not disappear just
>> because you decide to describe DMA. It is OS choice what to use if both are
>> provided.
>>
> 
> But this I2S can only use either DMA or interrupts.

Just like many other components. DTS should reflect hardware. Hardware
has interrupts and DMA, right?

> 
> Can I use the config (like SND_SOC_CADENCE_I2S_MC_PCM)  to choose DMA or
> interrupt if having both them in DTS?

Don't know, I tend to focus here on bindings.

Best regards,
Krzysztof