Re: [PATCH 2/3] dt-bindings: clock: qcom,gcc-sc7180: document CX power domain

[Rajendra Nayak]

On 4/11/2023 4:57 PM, Konrad Dybcio wrote:
> On 11.04.2023 06:56, Rajendra Nayak wrote:
> > On 4/8/2023 7:33 PM, Konrad Dybcio wrote:
> > > On 8.04.2023 15:48, Krzysztof Kozlowski wrote:
> > > > The GCC clock controller needs CX power domain, at least according to
> > > > DTS:
> > > >
> > > >     sc7180-trogdor-pompom-r3.dtb: clock-controller@100000: Unevaluated properties are not allowed ('power-domains' was unexpected)
> > > >
> > > > Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
> > > > ---
> > > +CC Rajendra (author of 5d6fc6321db1 ("arm64: dts: qcom:
> > > sc7180: Add required-opps for USB"))
> > >
> > > Rajendra, shouldn't SC7180 GCC have PM ops to make sure a vote
> > > is only there when AP is active?
> So IIUC, CX is never supposed to be shut down?

Atleast sc7180 and sc7280 do not support full CX shutdown (or power
collapse as its called), it only transitions to a Retention state
and even that in the system-wide suspend path only

> Konrad
> > hmm, I am not quite sure why we would want the performance votes
> > from peripherals dropped when CPUs go down in idle?
> >
> > > Are all GDSCs powered by CX?
> > > If not, wouldn't this also need power-domain-names to
> > > facilitate e.g. potential MX-powered ones?
> >
> > For sc7180 GCC, yes.
> >
> > > Konrad
> > > >    .../devicetree/bindings/clock/qcom,gcc-sc7180.yaml         | 7 +++++++
> > > >    1 file changed, 7 insertions(+)
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/clock/qcom,gcc-sc7180.yaml b/Documentation/devicetree/bindings/clock/qcom,gcc-sc7180.yaml
> > > > index 06dce0c6b7d0..8bf9b6f49550 100644
> > > > --- a/Documentation/devicetree/bindings/clock/qcom,gcc-sc7180.yaml
> > > > +++ b/Documentation/devicetree/bindings/clock/qcom,gcc-sc7180.yaml
> > > > @@ -32,6 +32,10 @@ properties:
> > > >          - const: bi_tcxo_ao
> > > >          - const: sleep_clk
> > > >    +  power-domains:
> > > > +    items:
> > > > +      - description: CX domain
> > > > +
> > > >    required:
> > > >      - compatible
> > > >      - clocks
> > > > @@ -45,6 +49,8 @@ unevaluatedProperties: false
> > > >    examples:
> > > >      - |
> > > >        #include <dt-bindings/clock/qcom,rpmh.h>
> > > > +    #include <dt-bindings/power/qcom-rpmpd.h>
> > > > +
> > > >        clock-controller@100000 {
> > > >          compatible = "qcom,gcc-sc7180";
> > > >          reg = <0x00100000 0x1f0000>;
> > > > @@ -52,6 +58,7 @@ examples:
> > > >                   <&rpmhcc RPMH_CXO_CLK_A>,
> > > >                   <&sleep_clk>;
> > > >          clock-names = "bi_tcxo", "bi_tcxo_ao", "sleep_clk";
> > > > +      power-domains = <&rpmhpd SC7180_CX>;
> > > >          #clock-cells = <1>;
> > > >          #reset-cells = <1>;
> > > >          #power-domain-cells = <1>;