Add Device Tree nodes to enable a PWM controlled fan and it's associated
thermal management for the Lichee Pi 4A board.

This enables temperature-controlled active cooling for the Lichee Pi 4A
board based on SoC temperature.

Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>
---
 arch/riscv/boot/dts/thead/th1520-lichee-pi-4a.dts | 67 +++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/arch/riscv/boot/dts/thead/th1520-lichee-pi-4a.dts b/arch/riscv/boot/dts/thead/th1520-lichee-pi-4a.dts
index 4020c727f09e8e2286fdc7fecd79dbd8eba69556..c58c2085ca92a3234f1350500cedae4157f0c35f 100644
--- a/arch/riscv/boot/dts/thead/th1520-lichee-pi-4a.dts
+++ b/arch/riscv/boot/dts/thead/th1520-lichee-pi-4a.dts
@@ -28,9 +28,76 @@ aliases {
 	chosen {
 		stdout-path = "serial0:115200n8";
 	};
+
+	thermal-zones {
+		cpu-thermal {
+			polling-delay = <1000>;
+			polling-delay-passive = <1000>;
+			thermal-sensors = <&pvt 0>;
+
+			trips {
+				fan_config0: fan-trip0 {
+					temperature = <39000>;
+					hysteresis = <5000>;
+					type = "active";
+				};
+
+				fan_config1: fan-trip1 {
+					temperature = <50000>;
+					hysteresis = <5000>;
+					type = "active";
+				};
+
+				fan_config2: fan-trip2 {
+					temperature = <60000>;
+					hysteresis = <5000>;
+					type = "active";
+				};
+			};
+
+			cooling-maps {
+				map-active-0 {
+					cooling-device = <&fan 1 1>;
+					trip = <&fan_config0>;
+				};
+
+				map-active-1 {
+					cooling-device = <&fan 2 2>;
+					trip = <&fan_config1>;
+				};
+
+				map-active-2 {
+					cooling-device = <&fan 3 3>;
+					trip = <&fan_config2>;
+				};
+			};
+		};
+	};
+
+	fan: pwm-fan {
+		pinctrl-names = "default";
+		pinctrl-0 = <&fan_pins>;
+		compatible = "pwm-fan";
+		#cooling-cells = <2>;
+		pwms = <&pwm 1 10000000 0>;
+		cooling-levels = <0 66 196 255>;
+	};
+
 };
 
 &padctrl0_apsys {
+	fan_pins: fan-0 {
+		pwm1-pins {
+			pins = "GPIO3_3"; /* PWM1 */
+			function = "pwm";
+			bias-disable;
+			drive-strength = <25>;
+			input-disable;
+			input-schmitt-disable;
+			slew-rate = <0>;
+		};
+	};
+
 	uart0_pins: uart0-0 {
 		tx-pins {
 			pins = "UART0_TXD";

-- 
2.34.1

On Wed, Jul 02, 2025 at 03:45:36PM +0200, Michal Wilczynski wrote:
> Add Device Tree nodes to enable a PWM controlled fan and it's associated
> thermal management for the Lichee Pi 4A board.
> 
> This enables temperature-controlled active cooling for the Lichee Pi 4A
> board based on SoC temperature.
> 
> Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>

Reviewed-by: Drew Fustini <fustini@kernel.org>

I'll apply this to the thead-dt-for-next branch once the PWM driver is
accepted by Uwe.

Thanks,
Drew