Re: [PATCH v3 02/12] dt-bindings: phy: tegra20-usb-phy: Document properties needed for OTG mode

From: Dmitry Osipenko
Date: Thu Jul 15 2021 - 11:36:41 EST


15.07.2021 02:10, Rob Herring пишет:
> On Tue, Jul 13, 2021 at 02:33:11AM +0300, Dmitry Osipenko wrote:
>> 12.07.2021 18:41, Rob Herring пишет:
>>>> + nvidia,pmc:
>>>> + $ref: /schemas/types.yaml#/definitions/phandle
>>>> + description:
>>>> + Phandle to Power Management controller.
>>>> +
>>> Add a cell to this for the PHY reg offset and then get rid of the index:
>>>
>>>> + nvidia,phy-instance:
>>>> + $ref: /schemas/types.yaml#/definitions/uint32
>>>> + minimum: 0
>>>> + maximum: 2
>>>> + description: Unique hardware ID.
>>
>> The instance ID belongs to the USB h/w and not to PMC. It may look like
>> I added the ID just to get offsets within PMC, but it's not like that.
>> The Tegra documentation explicitly assigns unique IDs to the USB
>> controllers and PHYs. Hence this ID should be the property of the PHY
>> hardware, IMO.
>
> It looks like the use is calculating register offsets in a PMC register.
> That's quite common and including that with the phandle is the preferred
> way to describe it.
>
> Lots of docs have UART1, UART2, UART3, etc. module numbering. We don't
> copy that into DT.

Alright. Judging by downstream code, we will need to use that ID only
for PMC offsets.