Re: [PATCH v10 8/9] arm64: dts: qcom: ipq9574: Add LDO regulator node

From: Varadarajan Narayanan <quic_varada@quicinc.com>
To: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
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>
Subject: Re: [PATCH v10 8/9] arm64: dts: qcom: ipq9574: Add LDO regulator node
Date: Mon, 8 May 2023 10:46:58 +0530	[thread overview]
Message-ID: <20230508051657.GA24472@varda-linux.qualcomm.com> (raw)
In-Reply-To: <CAA8EJpqg2htfa2QZ7q6SP58N5YAABa8knBn4c5eYqYOU6HQNiA@mail.gmail.com>

On Sat, May 06, 2023 at 02:33:11PM +0300, Dmitry Baryshkov wrote:
> 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.

Yes. It is a part of rpm-requests. That is why have mentioned V10
is dependent on
https://lore.kernel.org/lkml/20230407155727.20615-1-quic_devipriy@quicinc.com/T/.
The 4th patch of the above series
(https://lore.kernel.org/lkml/20230407155727.20615-1-quic_devipriy@quicinc.com/T/#mea3f0ea37c53cf5e39e10cd6cf3bed5243cec629)
adds the rpm_requests node and this regulator definition is added
to it. Hope that is ok.

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