Re: [PATCH 2/9] dt-bindings: i2c: qcom-cci: add description of a vbus-supply property

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

On Thu, 10 Feb 2022 at 20:36, Mark Brown <broonie@kernel.org> wrote:
>
> On Thu, Feb 10, 2022 at 08:32:09PM +0300, Dmitry Baryshkov wrote:
> > On Thu, 10 Feb 2022 at 18:45, Mark Brown <broonie@kernel.org> wrote:
>
> > > I would hope it's a temporary thing given the namespace collision
> > > issues...
>
> > Which collision? CCI doesn't have a separate vbus power input (and
> > probably never will).
>
> That "probably" there is doing some work, and if you're doing something
> at the I2C core level (as it seems should be done) it needs to cope with
> all possible controllers and devices.
>
> > > Do these controllers actually have a supply called vbus?
>
> > No. It's a separate entity, a regulator-controller pull-up for the bus.
> > So far we'd like to hear better suggestions. Using regulator-always-on
> > doesn't sound like a good idea, it will increase unnecessary power
> > drain.
>
> Please see my suggestions elsewhere in the thread.

Please excuse me. I missed the e-mail suggesting to move support for
that into the core level.
I'd second a request to handle the adapter->bus_regulator in the core code.
Would you be ok with the 'external-sda-scl-supply' property? Would you
demand that it's completely handled by the core layer (including DT
parsing) or should we let a driver parse the DT property?


-- 
With best wishes
Dmitry