mediatek: fix PWM fan on BPi-R4

Add additional PWM fan cooling step and enable fan on BPi-R4.

Suggested-by: Frank Wunderlich <[email protected]>
Signed-off-by: Daniel Golle <[email protected]>

target/linux/mediatek/files-6.6/arch/arm64/boot/dts/mediatek/mt7988a-bananapi-bpi-r4.dtsi

@@ -297,6 +297,15 @@
 	status = "okay";
 };
 
+&pwm {
+	status = "okay";
+};
+
+&fan {
+	pwms = <&pwm 0 50000>;
+	status = "okay";
+};
+
 &ssusb1 {
 	status = "okay";
 };

target/linux/mediatek/files-6.6/arch/arm64/boot/dts/mediatek/mt7988a.dtsi

@@ -149,8 +149,8 @@
 
 	fan: pwm-fan {
 		compatible = "pwm-fan";
-		/* cooling level (0, 1, 2) : (0% duty, 50% duty, 100% duty) */
-		cooling-levels = <0 128 255>;
+		/* cooling level (0, 1, 2, 3) : (0% duty, 30% duty, 50% duty, 100% duty) */
+		cooling-levels = <0 80 128 255>;
 		#cooling-cells = <2>;
 		#thermal-sensor-cells = <1>;
 		status = "disabled";