Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
In-Reply-To: <YDQWVresOGZGLL6N@google.com>
References: <20210219181032.1.I23e12818c4a841ba9c37c60b3ba8cfeeb048285f@changeid> <20210219181032.3.Ia4c1022191d09fe8c56a16486b77796b83ffcae4@changeid> <161402520418.1254594.7435679604383921403@swboyd.mtv.corp.google.com> <YDQWVresOGZGLL6N@google.com>
Subject: Re: [PATCH 3/3] arm64: dts: qcom: sc7180: Delete charger thermal zone and ADC channel for lazor <= rev3
From:   Stephen Boyd <swboyd@chromium.org>
Cc:     Andy Gross <agross@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
        Douglas Anderson <dianders@chromium.org>,
        devicetree@vger.kernel.org
To:     Matthias Kaehlcke <mka@chromium.org>
Date:   Mon, 22 Feb 2021 12:45:23 -0800
Message-ID: <161402672369.1254594.14091287979440332862@swboyd.mtv.corp.google.com>
User-Agent: alot/0.9.1
Precedence: bulk

Quoting Matthias Kaehlcke (2021-02-22 12:38:46)
> On Mon, Feb 22, 2021 at 12:20:04PM -0800, Stephen Boyd wrote:
> > Quoting Matthias Kaehlcke (2021-02-19 18:10:59)
> > > Lazor rev3 and older are stuffed with a 47k NTC as thermistor for
> > > the charger temperature which currently isn't supported by the
> > > PM6150 ADC driver. Delete the charger thermal zone and ADC channel
> > > to avoid the use of bogus temperature values.
> > >=20
> > > Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> > > ---
> > >=20
> > >  arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r0.dts | 9 +++++++++
> > >  arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r1.dts | 9 +++++++++
> > >  arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r3.dts | 9 +++++++++
> > >  3 files changed, 27 insertions(+)
> > >=20
> > > diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r0.dts b/a=
rch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r0.dts
> > > index 30e3e769d2b4..0974dbd424e1 100644
> > > --- a/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r0.dts
> > > +++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r0.dts
> > > @@ -14,6 +14,15 @@ / {
> > >         compatible =3D "google,lazor-rev0", "qcom,sc7180";
> > >  };
> > > =20
> > > +/*
> > > + * rev <=3D 3 are stuffed with a 47k NTC as charger thermistor which=
 is currently
> > > + * not supported by the PM6150 ADC driver. Delete the thermal zone a=
nd ADC
> > > + * channel to avoid the use of bogus temperature values.
> > > + */
> > > +/delete-node/ &charger_thermal;
> > > +/delete-node/ &pm6150_adc_charger_thm;
> > > +/delete-node/ &pm6150_adc_tm_charger_thm;
> >=20
> > Can we disable pm6150_adc_tm instead on <=3D rev3 boards? It would be t=
he
> > same number of lines, but is simpler to reason about disabled nodes vs.
> > deleted nodes usually.
>=20
> For Lazor theoretically this could be done since it doesn't use other ADC
> channels, however it won't work for other trogdor devices that will be
> upstreamed eventually. Some of these boards have the same problem, however
> they have other thermistors connected to the ADC. One could argue that it=
's
> preferable to do things in a uniform way, but I'm open to do it either way
> for Lazor.
>=20

I see. Can the thermal-zone be disabled then vs. deleting three nodes? I
think the thermal driver uses for_each_available_child_of_node() so that
would work?