Re: [PATCH v1 2/3] arm64: dts: qcom: sm8450: Add opp table support to PCIe

[Krishna Chaitanya Chundru]

On 8/16/2023 12:35 PM, Pavan Kondeti wrote:
> On Tue, Aug 15, 2023 at 05:56:47PM +0530, Krishna chaitanya chundru wrote:
> > PCIe needs to choose the appropriate performance state of RPMH power
> > domain based upon the PCIe gen speed.
> >
> > So, let's add the OPP table support to specify RPMH performance states.
> >
> > Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
> > ---
> >   arch/arm64/boot/dts/qcom/sm8450.dtsi | 47 ++++++++++++++++++++++++++++++++++++
> >   1 file changed, 47 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/qcom/sm8450.dtsi b/arch/arm64/boot/dts/qcom/sm8450.dtsi
> > index 595533a..681ea9c 100644
> > --- a/arch/arm64/boot/dts/qcom/sm8450.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/sm8450.dtsi
> > @@ -381,6 +381,49 @@
> >   		};
> >   	};
> >   
> > +	pcie0_opp_table: opp-table-pcie0 {
> > +		compatible = "operating-points-v2";
> > +
> > +		opp-2500000 {
> > +			opp-hz = /bits/ 64 <2500000>;
> > +			opp-level = <RPMH_REGULATOR_LEVEL_LOW_SVS>;
> > +		};
> > +
> > +		opp-5000000 {
> > +			opp-hz = /bits/ 64 <5000000>;
> > +			opp-level = <RPMH_REGULATOR_LEVEL_LOW_SVS>;
> > +		};
> > +
> > +		opp-8000000 {
> > +			opp-hz = /bits/ 64 <8000000>;
> > +			opp-level = <RPMH_REGULATOR_LEVEL_LOW_SVS>;
> > +		};
> > +	};
> > +
> > +	pcie1_opp_table: opp-table-pcie1 {
> > +		compatible = "operating-points-v2";
> > +
> > +		opp-2500000 {
> > +			opp-hz = /bits/ 64 <2500000>;
> > +			opp-level = <RPMH_REGULATOR_LEVEL_LOW_SVS>;
> > +		};
> > +
> > +		opp-5000000 {
> > +			opp-hz = /bits/ 64 <5000000>;
> > +			opp-level = <RPMH_REGULATOR_LEVEL_LOW_SVS>;
> > +		};
> > +
> > +		opp-8000000 {
> > +			opp-hz = /bits/ 64 <8000000>;
> > +			opp-level = <RPMH_REGULATOR_LEVEL_LOW_SVS>;
> > +		};
> > +
> > +		opp-16000000 {
> > +			opp-hz = /bits/ 64 <16000000>;
> > +			opp-level = <RPMH_REGULATOR_LEVEL_NOM>;
> > +		};
> > +	};
> > +
> Should not we using required-opps property to pass the
> rpmhpd_opp_xxx phandle so that when this OPP is selected based on your
> clock rate, the appropriate OPP (voltage) would be selected on the RPMH side?
>
> Please see SDHCI/MMC voting (sdhc2_opp_table) as an example.

Sure I will try to use rpmhpd_opp_xxx phandle in next patch

- KC

> Thanks,
> Pavan