ARM: tegra: paz00: Add CPU thermal zone

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@protonmail.ch>
Tested-by: Paul Fertser <fercerpav@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

diff --git a/arch/arm/boot/dts/tegra20-paz00.dts b/arch/arm/boot/dts/tegra20-paz00.dts
index 63d6241..3180bff 100644 (file)
--- 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 @@
                        };
                };
 
-               adt7461@4c {
+               adt7461: temperature-sensor@4c {
                        compatible = "adi,adt7461";
                        reg = <0x4c>;
+                       #thermal-sensor-cells = <1>;
                };
        };
 
@@ -655,11 +658,46 @@
                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>;
+                               };
+                       };
                };
        };
 };