Re: [PATCH V3 11/17] dt-bindings: arm: mediatek: Add #reset-cells property for MT8192-sys-clock

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

On 25/04/2022 04:37, Rex-BC Chen wrote:
>>> +  '#reset-cells':
>>> +    maximum: 2
>>
>> Why this is a maximum? Usually this is const, so how do you use it
>> (with
>> what values)?
>>
> We need to let the driver compatible with previous setting in
> drivers/clk/mediatek/reset.c

Then it should be enum [1, 2], because '0' is not valid.

> There are two use cases in our reset driver:
> (Refer to [1])
> 
> 1. #reset-cells = <1>
>    When we input the argument, the older driver
> use is to calculate  
>    bank and bit by different method. From the implementation of
>    reset_xlate(), we can see if the argument number is 1, it will
>    return directly.

I understand this is an old binding with older compatibles, so this
should be restricted per each variant (allOf:if:then)... but wait, old
binding did not allow any reset-cells! You add an entirely new binding
property and already want to support some older (deprecated?) way.

> 
> 2. #reset-cells = <2>
>    The input arguments is offset and bit. When we input two arguments,
>    we can use reset_xlate() to calculate the corresponding id to assert
>    and deassert.
> 
> [1]:
> https://lore.kernel.org/all/20220422060152.13534-10-rex-bc.chen@mediatek.com/
> 
> If it's acceptable, I will add this in commit message.


Best regards,
Krzysztof