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From:   Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Date:   Sat, 6 May 2023 14:33:11 +0300
Message-ID: <CAA8EJpqg2htfa2QZ7q6SP58N5YAABa8knBn4c5eYqYOU6HQNiA@mail.gmail.com>
Subject: Re: [PATCH v10 8/9] arm64: dts: qcom: ipq9574: Add LDO regulator node
To:     Varadarajan Narayanan <quic_varada@quicinc.com>
Cc:     agross@kernel.org, andersson@kernel.org, konrad.dybcio@linaro.org,
        vkoul@kernel.org, kishon@kernel.org, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, gregkh@linuxfoundation.org,
        mturquette@baylibre.com, sboyd@kernel.org, quic_wcheng@quicinc.com,
        linux-arm-msm@vger.kernel.org, linux-phy@lists.infradead.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-usb@vger.kernel.org, linux-clk@vger.kernel.org
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Precedence: bulk

On Sat, 6 May 2023 at 14:09, Varadarajan Narayanan
<quic_varada@quicinc.com> wrote:
>
> On Fri, May 05, 2023 at 12:29:54PM +0300, Dmitry Baryshkov wrote:
> > On Fri, 5 May 2023 at 11:23, Varadarajan Narayanan
> > <quic_varada@quicinc.com> wrote:
> > >
> > > Add LDO regulator node
> >
> > As this LDO is provided by the PMIC, it would be nice to know why it
> > is modelled as an always-on regulator instead of the proper PMIC
> > regulator. Up to now we were doing this only for the outstanding power
> > rails like CX/MX or EBI.
>
> These are always ON because USB phy doesn't support power
> collapse, and there is a chance that other IP blocks might be
> sharing the rail.

You are describing the software side here. From the hardware point of
view, it is an I2C regulator, which is probably also exported as an
SMD_RPM regulator. Unless you have a good reason not to do so, there
should be a node under rpm-requests, which describes mp5496 regulators
exported via RPM. then USB should refer to those regulators.

>
> Thanks
> Varada
>
> > > Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
> > > ---
> > >  Changes in v10:
> > >         - Add LDO regulator node
> > > ---
> > >  arch/arm64/boot/dts/qcom/ipq9574-rdp433.dts | 7 +++++++
> > >  1 file changed, 7 insertions(+)
> > >
> > > diff --git a/arch/arm64/boot/dts/qcom/ipq9574-rdp433.dts b/arch/arm64/boot/dts/qcom/ipq9574-rdp433.dts
> > > index bdc1434..1f5d14f 100644
> > > --- a/arch/arm64/boot/dts/qcom/ipq9574-rdp433.dts
> > > +++ b/arch/arm64/boot/dts/qcom/ipq9574-rdp433.dts
> > > @@ -60,6 +60,13 @@
> > >                         regulator-min-microvolt = <725000>;
> > >                         regulator-max-microvolt = <1075000>;
> > >                 };
> > > +
> > > +               mp5496_l2: l2 {
> > > +                       regulator-min-microvolt = <1800000>;
> > > +                       regulator-max-microvolt = <1800000>;
> > > +                       regulator-boot-on;
> > > +                       regulator-always-on;
> > > +               };
> > >         };
> > >  };
> > >
> > > --
> > > 2.7.4
> > >
> >
> >
> > --
> > With best wishes
> > Dmitry


-- 
With best wishes
Dmitry