Add thermal zone with a passive cooling trip for CPU. Attach it to the
LM90 sensor which monitors CPU temperature. Now CPU frequencies will be
throttled once trip point is reached, preventing critical overheat.
Tested-by: Agneli <poczt@xxxxxxxxxxxxx>
Tested-by: Paul Fertser <fercerpav@xxxxxxxxx>
Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
arch/arm/boot/dts/tegra20-paz00.dts | 42 +++++++++++++++++++++++++++--
1 file changed, 40 insertions(+), 2 deletions(-)
diff --git a/arch/arm/boot/dts/tegra20-paz00.dts b/arch/arm/boot/dts/tegra20-paz00.dts
index 63d62418d4b8..3180bff90756 100644
--- a/arch/arm/boot/dts/tegra20-paz00.dts
+++ b/arch/arm/boot/dts/tegra20-paz00.dts
@@ -2,6 +2,8 @@
/dts-v1/;
#include <dt-bindings/input/input.h>
+#include <dt-bindings/thermal/thermal.h>
+
#include "tegra20.dtsi"
#include "tegra20-cpu-opp.dtsi"
#include "tegra20-cpu-opp-microvolt.dtsi"
@@ -498,9 +500,10 @@ ldo_rtc {
};
};
- adt7461@4c {
+ adt7461: temperature-sensor@4c {
compatible = "adi,adt7461";
reg = <0x4c>;
+ #thermal-sensor-cells = <1>;
};
};
@@ -655,11 +658,46 @@ cpus {
cpu0: cpu@0 {
cpu-supply = <&cpu_vdd_reg>;
operating-points-v2 = <&cpu0_opp_table>;
+ #cooling-cells = <2>;
};
- cpu@1 {
+ cpu1: cpu@1 {
cpu-supply = <&cpu_vdd_reg>;
operating-points-v2 = <&cpu0_opp_table>;
+ #cooling-cells = <2>;
+ };
+ };
+
+ thermal-zones {
+ cpu-thermal {
+ polling-delay-passive = <500>; /* milliseconds */
+ polling-delay = <1500>; /* milliseconds */
+
+ thermal-sensors = <&adt7461 1>;
+
+ trips {
+ trip0: cpu-alert0 {
+ /* start throttling at 80C */
+ temperature = <80000>;
+ hysteresis = <200>;
+ type = "passive";
+ };
+
+ trip1: cpu-crit {
+ /* shut down at 85C */
+ temperature = <85000>;
+ hysteresis = <2000>;
+ type = "critical";
+ };
+ };
+
+ cooling-maps {
+ map0 {
+ trip = <&trip0>;
+ cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+ <&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+ };
+ };
};
};
};
--
2.30.2
