[PATCH 3/3] arm64: dts: rockchip: Add PWM fan to Radxa ROCK 3B

[Adam Wermuth]

The ROCK 3B has a 2-pin fan header powered from vcc5v0_sys and
switched by a MOSFET driven from PWM8 (pwm8m0 pins). Enable the PWM
controller, describe the fan as a pwm-fan cooling device and add
active trip points to the CPU thermal zone:

 - 50 C: fan at 25%
 - 60 C: fan at 50-75%
 - 70 C: fan at 100%

each with 5 C hysteresis. The existing passive and critical trip
points are left unchanged.

Signed-off-by: Adam Wermuth <adam at wermuth.pl>
---
 .../boot/dts/rockchip/rk3568-rock-3b.dts      | 51 +++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/arch/arm64/boot/dts/rockchip/rk3568-rock-3b.dts b/arch/arm64/boot/dts/rockchip/rk3568-rock-3b.dts
index 908bb4425e81..815f67988ab7 100644
--- a/arch/arm64/boot/dts/rockchip/rk3568-rock-3b.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3568-rock-3b.dts
@@ -24,6 +24,14 @@ chosen {
 		stdout-path = "serial2:1500000n8";
 	};
 
+	fan: fan {
+		compatible = "pwm-fan";
+		cooling-levels = <0 64 128 192 255>;
+		fan-supply = <&vcc5v0_sys>;
+		pwms = <&pwm8 0 10000 0>;
+		#cooling-cells = <2>;
+	};
+
 	hdmi-con {
 		compatible = "hdmi-connector";
 		type = "a";
@@ -200,6 +208,45 @@ &cpu3 {
 	cpu-supply = <&vdd_cpu>;
 };
 
+&cpu_thermal {
+	trips {
+		cpu_fan0: cpu-fan0 {
+			hysteresis = <5000>;
+			temperature = <50000>;
+			type = "active";
+		};
+
+		cpu_fan1: cpu-fan1 {
+			hysteresis = <5000>;
+			temperature = <60000>;
+			type = "active";
+		};
+
+		cpu_fan2: cpu-fan2 {
+			hysteresis = <5000>;
+			temperature = <70000>;
+			type = "active";
+		};
+	};
+
+	cooling-maps {
+		map1 {
+			trip = <&cpu_fan0>;
+			cooling-device = <&fan THERMAL_NO_LIMIT 1>;
+		};
+
+		map2 {
+			trip = <&cpu_fan1>;
+			cooling-device = <&fan 2 3>;
+		};
+
+		map3 {
+			trip = <&cpu_fan2>;
+			cooling-device = <&fan 4 THERMAL_NO_LIMIT>;
+		};
+	};
+};
+
 &gmac0 {
 	assigned-clocks = <&cru SCLK_GMAC0_RX_TX>, <&cru SCLK_GMAC0>;
 	assigned-clock-parents = <&cru SCLK_GMAC0_RGMII_SPEED>, <&cru CLK_MAC0_2TOP>;
@@ -708,6 +755,10 @@ &pmu_io_domains {
 	status = "okay";
 };
 
+&pwm8 {
+	status = "okay";
+};
+
 &saradc {
 	vref-supply = <&vcca_1v8>;
 	status = "okay";
-- 
2.43.0