[PATCH v4 18/24] ARM: tegra: Add CPU thermal zones to Nyan device-tree

[Dmitry Osipenko]

CPU of Nyan Chromebooks is overheating badly because apparently hardware
soctherm controller doesn't work well. Add CPU thermal zones to enable
software thermal control over CPU and fix the overheat trouble.

Tested-by: Thomas Graichen <thomas.graichen@xxxxxxxxx> # T124 Nyan Big
Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
 arch/arm/boot/dts/tegra124-nyan.dtsi | 49 +++++++++++++++++++++++++++-
 1 file changed, 48 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/tegra124-nyan.dtsi b/arch/arm/boot/dts/tegra124-nyan.dtsi
index ec01a23d4d47..b16cce7476ef 100644
--- a/arch/arm/boot/dts/tegra124-nyan.dtsi
+++ b/arch/arm/boot/dts/tegra124-nyan.dtsi
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <dt-bindings/input/input.h>
+#include <dt-bindings/thermal/thermal.h>
 #include "tegra124.dtsi"
 
 / {
@@ -87,7 +88,7 @@ acodec: audio-codec@10 {
 			interrupts = <TEGRA_GPIO(H, 4) IRQ_TYPE_EDGE_FALLING>;
 		};
 
-		temperature-sensor@4c {
+		tmp451: temperature-sensor@4c {
 			compatible = "ti,tmp451";
 			reg = <0x4c>;
 			interrupt-parent = <&gpio>;
@@ -789,6 +790,52 @@ gpio-restart {
 		gpios = <&gpio TEGRA_GPIO(I, 5) GPIO_ACTIVE_LOW>;
 		priority = <200>;
 	};
+
+	cpus {
+		cpu0: cpu@0 {
+			#cooling-cells = <2>;
+		};
+
+		cpu1: cpu@1 {
+			#cooling-cells = <2>;
+		};
+
+		cpu2: cpu@2 {
+			#cooling-cells = <2>;
+		};
+
+		cpu3: cpu@3 {
+			#cooling-cells = <2>;
+		};
+	};
+
+	thermal-zones {
+		cpu-skin-thermal {
+			polling-delay-passive = <1000>; /* milliseconds */
+			polling-delay = <5000>; /* milliseconds */
+
+			thermal-sensors = <&tmp451 0>;
+
+			trips {
+				cpu_passive_trip: cpu-alert0 {
+					/* throttle at 70C until temperature drops to 69.8C */
+					temperature = <70000>;
+					hysteresis = <200>;
+					type = "passive";
+				};
+			};
+
+			cooling-maps {
+				map0 {
+					trip = <&cpu_passive_trip>;
+					cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+							 <&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+							 <&cpu2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+							 <&cpu3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+				};
+			};
+		};
+	};
 };
 
 #include "cros-ec-keyboard.dtsi"
-- 
2.33.1