Re: [PATCH v6 3/7] dt: qcom: 8996: thermal: Move to DT initialisation

From: Amit Kucheria
Date: Thu Jul 12 2018 - 01:04:22 EST


On Thu, Jul 12, 2018 at 12:09 AM Doug Anderson <dianders@xxxxxxxxxxxx> wrote:
>
> Hi,
>
> On Mon, Jul 9, 2018 at 4:43 AM, Amit Kucheria <amit.kucheria@xxxxxxxxxx> wrote:
> > We also split up the regmap address space into two, one for the TM
> > registers, the other for the SROT registers. This was required to deal with
> > different address offsets for the TM and SROT registers across different
> > SoC families.
>
> The splitting into two regions is actually optional and that should
> probably be mentioned in the commit message.

On the contrary, after this refactor, all new platforms with the
v2.x.y TSENS IP should use two regions. The only reason for patch 2 is
that we're stuck with supporting old 8996/8916 DTs. I'd prefer to
phase out support for the old DTs if possible. I don't want to
encourage any new bindings with a single address space.

> > Since tsens-common.c/init_common() currently only registers one address
> > space, the order is important (TM before SROT). This is OK since the code
> > doesn't really use the SROT functionality yet.
>
> Nowhere in the commit message does this say you're also adding a 2nd
> block of thermal sensors. It seems like you should say that
> somewhere.
>
> ...and it should also be obvious in ${SUBJECT}.

Fixed.

> > Signed-off-by: Amit Kucheria <amit.kucheria@xxxxxxxxxx>
> > ---
> > arch/arm64/boot/dts/qcom/msm8996.dtsi | 12 +++++++++++-
> > 1 file changed, 11 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/arm64/boot/dts/qcom/msm8996.dtsi b/arch/arm64/boot/dts/qcom/msm8996.dtsi
> > index 8c7f9ca..6c8a857 100644
> > --- a/arch/arm64/boot/dts/qcom/msm8996.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/msm8996.dtsi
> > @@ -461,7 +461,17 @@
> >
> > tsens0: thermal-sensor@4a8000 {
> > compatible = "qcom,msm8996-tsens";
> > - reg = <0x4a8000 0x2000>;
> > + reg = <0x4a9000 0x1000>, /* TM */
> > + <0x4a8000 0x1000>; /* SROT */
>
> Note that the unit address is supposed to match the first "reg"
> address, so either these should be reversed or you should update your
> node name. AKA your node name should be this now:
>
> tsens0: thermal-sensor@4a9000

Fixed.

>
> > + #qcom,sensors = <13>;
>
> As per my responses to other patches, " #qcom,sensors" is undocumented
> and doesn't appear to be read by the driver.

This feature was merged earlier. See commit 6d7c70d1cd6526 (thermal:
qcom: tsens: Allow number of sensors to come from DT)

Regards,
Amit