Hi,

On Mon, Feb 22, 2021 at 12:45 PM Stephen Boyd [off-list ref] wrote:

Quoting Matthias Kaehlcke (2021-02-22 12:38:46)

quoted

On Mon, Feb 22, 2021 at 12:20:04PM -0800, Stephen Boyd wrote:

quoted

Quoting Matthias Kaehlcke (2021-02-19 18:10:59)

quoted

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.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---

 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(+)

diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r0.dts b/arch/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 = "google,lazor-rev0", "qcom,sc7180";
 };

+/*
+ * rev <= 3 are stuffed with a 47k NTC as charger thermistor which is currently
+ * not supported by the PM6150 ADC driver. Delete the thermal zone and 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;

Can we disable pm6150_adc_tm instead on <= rev3 boards? It would be the
same number of lines, but is simpler to reason about disabled nodes vs.
deleted nodes usually.

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.

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?

FWIW: +1 to what Stephen suggests assuming it works.

-Doug