[PATCH v2] arm64: dts: meson: radxa-zero2: add pwm-fan support

[Christian Hewitt <christianshewitt@gmail.com>]

The A311D on Zero2 needs active cooling and the board includes a header to
connect a simple fan. Add pwm-fan support with basic thermal properties so
the fan runs when connected.

Suggested-by: Yuntian Zhang <yt@radxa.com>
Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
---
Changes since v1: [0]
- Drop min/max state to comply with bindings
- Drop ddr_thermal node
- Add cpu_thermal trips
- Use cooling map2 to avoid clashing with dtsi inherited maps

[0] https://patchwork.kernel.org/project/linux-amlogic/patch/20231028075445.3515664-1-christianshewitt@gmail.com/

 .../dts/amlogic/meson-g12b-radxa-zero2.dts    | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/meson-g12b-radxa-zero2.dts b/arch/arm64/boot/dts/amlogic/meson-g12b-radxa-zero2.dts
index 890f5bfebb03..8445701100d0 100644
--- a/arch/arm64/boot/dts/amlogic/meson-g12b-radxa-zero2.dts
+++ b/arch/arm64/boot/dts/amlogic/meson-g12b-radxa-zero2.dts
@@ -33,6 +33,13 @@ memory@0 {
 		reg = <0x0 0x0 0x0 0x80000000>;
 	};
 
+	fan0: pwm-fan {
+		compatible = "pwm-fan";
+		#cooling-cells = <2>;
+		cooling-levels = <0 64 128 192 255>;
+		pwms = <&pwm_AO_ab 0 40000 0>;
+	};
+
 	gpio-keys-polled {
 		compatible = "gpio-keys-polled";
 		poll-interval = <100>;
@@ -286,6 +293,23 @@ &cpu103 {
 	clock-latency = <50000>;
 };
 
+&cpu_thermal {
+	trips {
+		cpu_active: cpu-active {
+			temperature = <70000>; /* millicelsius */
+			hysteresis = <2000>; /* millicelsius */
+			type = "active";
+		};
+	};
+
+	cooling-maps {
+		map2 {
+			trip = <&cpu_active>;
+			cooling-device = <&fan0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+		};
+	};
+};
+
 &frddr_a {
 	status = "okay";
 };
-- 
2.34.1