[PATCH v3 2/2] arm64: dts: qcom: pm8998: Add pm8998 thermal zone

[Matthias Kaehlcke <mka@chromium.org>]

The thermal zone uses spmi-temp-alarm as sensor. If the sensor is
configured without an IIO input it always reports 37°C for temperatures
below the first hardware trip point at 105°C. This hardware trip point
is configured as critical trip point, to initiate a system shutdown
before the temperature reaches the next hardware trip point at 125°C,
where the PMIC performs a partial shutdown.

The temperature of the critical trip point can be increased after
adding the die temperature ADC as IIO input for spmi-temp-alarm, which
significantly increases the precision of the temperature measurements.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---
Changes in v3:
- moved 'thermal-zones' node to the beginning of the .dtsi

Changes in v2:
- defined 'thermal-zones' node in pm8998.dtsi instead of using a label
  to refer to it
- use 105°C hardware trip point as critical trip point
- reduced number of trip points to 2
- lowered temperature of passive trip point
- updated trip point names and added labels
- updated commit message
---
 arch/arm64/boot/dts/qcom/pm8998.dtsi | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/pm8998.dtsi b/arch/arm64/boot/dts/qcom/pm8998.dtsi
index 7eea94701b23..52c5e797aab2 100644
--- a/arch/arm64/boot/dts/qcom/pm8998.dtsi
+++ b/arch/arm64/boot/dts/qcom/pm8998.dtsi
@@ -3,6 +3,31 @@
 
 #include <dt-bindings/spmi/spmi.h>
 #include <dt-bindings/interrupt-controller/irq.h>
+#include <dt-bindings/thermal/thermal.h>
+
+/ {
+	thermal-zones {
+		pm8998 {
+			polling-delay-passive = <250>;
+			polling-delay = <1000>;
+
+			thermal-sensors = <&pm8998_temp>;
+
+			trips {
+				pm8998_alert0: pm8998-alert0 {
+					temperature = <95000>;
+					hysteresis = <2000>;
+					type = "passive";
+				};
+				pm8998_crit: pm8998-crit {
+					temperature = <105000>;
+					hysteresis = <2000>;
+					type = "critical";
+				};
+			};
+		};
+	};
+};
 
 &spmi_bus {
 	pm8998_lsid0: pmic@0 {
-- 
2.18.0.203.gfac676dfb9-goog