Re: [PATCH 1/6] dt-bindings: clock: qcom,dispcc-sm8x50: add mmcx power domain

[Ulf Hansson <ulf.hansson@linaro.org>]

On Thu, 1 Jul 2021 at 18:39, Dmitry Baryshkov
<dmitry.baryshkov@linaro.org> wrote:
>
> On Thu, 1 Jul 2021 at 19:17, Ulf Hansson <ulf.hansson@linaro.org> wrote:
> >
> > On Wed, 30 Jun 2021 at 15:31, Dmitry Baryshkov
> > <dmitry.baryshkov@linaro.org> wrote:
> > >
> > > On sm8250 dispcc requires MMCX power domain to be powered up before
> > > clock controller's registers become available. For now sm8250 was using
> > > external regulator driven by the power domain to describe this
> > > relationship. Switch into specifying power-domain and required opp-state
> > > directly.
> > >
> > > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> > > ---
> > >  .../bindings/clock/qcom,dispcc-sm8x50.yaml    | 19 +++++++++++++++++++
> > >  1 file changed, 19 insertions(+)
> > >
> > > diff --git a/Documentation/devicetree/bindings/clock/qcom,dispcc-sm8x50.yaml b/Documentation/devicetree/bindings/clock/qcom,dispcc-sm8x50.yaml
> > > index 0cdf53f41f84..48d86fb34fa7 100644
> > > --- a/Documentation/devicetree/bindings/clock/qcom,dispcc-sm8x50.yaml
> > > +++ b/Documentation/devicetree/bindings/clock/qcom,dispcc-sm8x50.yaml
> > > @@ -55,6 +55,16 @@ properties:
> > >    reg:
> > >      maxItems: 1
> > >
> > > +  power-domains:
> > > +    description:
> > > +      A phandle and PM domain specifier for the MMCX power domain.
> > > +    maxItems: 1
> > > +
> >
> > Should you perhaps state that this is a parent domain? Or it isn't?
> >
> > Related to this and because this is a power domain provider, you
> > should probably reference the common power-domain bindings somewhere
> > here. Along the lines of this:
> >
> > - $ref: power-domain.yaml#
> >
> > As an example, you could have a look at
> > Documentation/devicetree/bindings/power/pd-samsung.yaml.
>
> I'll take a look.
>
> >
> > > +  required-opps:
> > > +    description:
> > > +      Performance state to use for MMCX to enable register access.
> > > +    maxItems: 1
> >
> > According to the previous discussions, I was under the assumption that
> > this property belongs to a consumer node rather than in the provider
> > node, no?
>
> It is both a consumer and a provider. It consumes SM8250_MMCX from
> rpmhpd and provides MMSC_GDSC.

That sounds a bit weird to me.

In my view and per the common power domain bindings (as pointed to
above): If a power domain provider is a consumer of another power
domain, that per definition means that there is a parent domain
specified.

[...]

Kind regards
Uffe