[PATCH 4/4] ARM: dts: helios4: wire LM75 into a thermal zone with fan cooling

Rosen Penev rosenp at gmail.com
Sun Jun 28 16:00:42 PDT 2026


The LM75 temperature sensor on i2c0 creates a hwmon interface but was
not referenced by any thermal zone, producing:
  hwmon hwmon0: temp1_input not attached to any thermal zone

Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp at gmail.com>
---
 .../boot/dts/marvell/armada-388-helios4.dts   | 33 +++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/arch/arm/boot/dts/marvell/armada-388-helios4.dts b/arch/arm/boot/dts/marvell/armada-388-helios4.dts
index 626a7339a5d0..6e0452217265 100644
--- a/arch/arm/boot/dts/marvell/armada-388-helios4.dts
+++ b/arch/arm/boot/dts/marvell/armada-388-helios4.dts
@@ -8,6 +8,7 @@
  */
 
 /dts-v1/;
+#include <dt-bindings/thermal/thermal.h>
 #include "armada-388.dtsi"
 #include "armada-38x-solidrun-microsom.dtsi"
 
@@ -68,6 +69,35 @@ reg_5p0v_usb: regulator-5v-usb {
 		vin-supply = <&reg_12v>;
 	};
 
+	thermal-zones {
+		board-thermal {
+			polling-delay-passive = <2000>;
+			polling-delay = <10000>;
+			thermal-sensors = <&temp_sensor>;
+
+			trips {
+				board_alert: board-alert {
+					temperature = <55000>;
+					hysteresis = <5000>;
+					type = "passive";
+				};
+				board_crit: board-crit {
+					temperature = <85000>;
+					hysteresis = <2000>;
+					type = "critical";
+				};
+			};
+
+			cooling-maps {
+				map0 {
+					trip = <&board_alert>;
+					cooling-device = <&fan1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+							 <&fan2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+				};
+			};
+		};
+	};
+
 	system-leds {
 		compatible = "gpio-leds";
 		pinctrl-names = "default";
@@ -129,6 +159,7 @@ fan1: j10-pwm {
 		pwms = <&gpio1 9 40000>;	/* Target freq:25 kHz */
 		pinctrl-names = "default";
 		pinctrl-0 = <&helios_fan1_pins>;
+		#cooling-cells = <2>;
 	};
 
 	fan2: j17-pwm {
@@ -136,6 +167,7 @@ fan2: j17-pwm {
 		pwms = <&gpio1 23 40000>;	/* Target freq:25 kHz */
 		pinctrl-names = "default";
 		pinctrl-0 = <&helios_fan2_pins>;
+		#cooling-cells = <2>;
 	};
 
 	usb2_phy: usb2-phy {
@@ -201,6 +233,7 @@ temp_sensor: temp at 4c {
 					compatible = "ti,lm75";
 					reg = <0x4c>;
 					vcc-supply = <&reg_3p3v>;
+					#thermal-sensor-cells = <0>;
 				};
 
 				eeprom at 53 {
-- 
2.54.0




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