Re: [PATCH v2 6/6] dt-bindings: dma: Convert Qualcomm BAM DMA binding to json format

From: Krzysztof Kozlowski
Date: Mon Apr 11 2022 - 07:38:52 EST


On 11/04/2022 12:58, Kuldeep Singh wrote:
>> This is something new and it seems only one SoC defines it (not even one
>> BAM version). I wonder whether this is actually correct or this
>> particular version of BAM is slightly different. Maybe someone could
>> clarify it, but if no - looks ok.
>
> Yes, sdm845.dtsi uses 4 entries and rest 1.

Yes, I know. This does not solve my wonder.

>
>>
>>> +
>>> + num-channels:
>>> + $ref: /schemas/types.yaml#/definitions/uint32
>>> + description:
>>> + Indicates supported number of DMA channels in a remotely controlled bam.
>>> +
>>> + qcom,controlled-remotely:
>>> + $ref: /schemas/types.yaml#/definitions/flag
>>
>> type: boolean
>
> Boolean comes under flag in types.yaml
>
> definitions:
> flag:
> oneOf:
> - type: boolean
> const: true
> - type: 'null'
>
> I have seen other boolean properties(spi-cpol, spi-cpha and bunch of
> others) using type flag. I think we should keep flag here.

type:boolean is just shorter and example-schema recommends it. If you
want to base on something (as a template, pattern) then the
example-schema is the source, the preferred one.

>>> +required:
>>> + - compatible
>>> + - "#dma-cells"
>>> + - interrupts
>>> + - reg
>>
>> clocks, clock-names, qcom-ee - these are required according to old bindings.
>
> I missed qcom,ee. Will add in v3.
>
> For clocks and clock-names , there are two platforms(msm8996.dtsi,
> sdm845.dtsi) where these properties are missing. And I don't want to add
> some random values. Shall I skip them here? and let board owners add
> them later.

These are required, so the SoC DTSI should be fixed. Not with random
clocks but something proper. :)

Best regards,
Krzysztof