ARM: dts: sun8i: Add backlight / pwm nodes to sun8i-a23-gt90h-v4

Add nodes for the backlight / pwm found on a23-gt90h-v4 tablets.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun8i-a23-gt90h-v4.dts

@@ -47,6 +47,7 @@
 #include <dt-bindings/gpio/gpio.h>
 #include <dt-bindings/input/input.h>
 #include <dt-bindings/pinctrl/sun4i-a10.h>
+#include <dt-bindings/pwm/pwm.h>
 
 / {
 	model = "Allwinner GT90H Quad Core Tablet (v4)";
@@ -56,6 +57,16 @@ aliases {
 		serial0 = &r_uart;
 	};
 
+	backlight: backlight {
+		compatible = "pwm-backlight";
+		pinctrl-names = "default";
+		pinctrl-0 = <&bl_en_pin_gt90h>;
+		pwms = <&pwm 0 50000 PWM_POLARITY_INVERTED>;
+		brightness-levels = <0 10 20 30 40 50 60 70 80 90 100>;
+		default-brightness-level = <8>;
+		enable-gpios = <&pio 7 6 GPIO_ACTIVE_HIGH>; /* PH6 */
+	};
+
 	chosen {
 		stdout-path = "serial0:115200n8";
 	};
@@ -115,6 +126,13 @@ &mmc0 {
 };
 
 &pio {
+	bl_en_pin_gt90h: bl_en_pin@0 {
+		allwinner,pins = "PH6";
+		allwinner,function = "gpio_in";
+		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
+		allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
+	};
+
 	mmc0_cd_pin_gt90h: mmc0_cd_pin@0 {
 		allwinner,pins = "PB4";
 		allwinner,function = "gpio_in";
@@ -123,6 +141,12 @@ mmc0_cd_pin_gt90h: mmc0_cd_pin@0 {
 	};
 };
 
+&pwm {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pwm0_pins>;
+	status = "okay";
+};
+
 &r_rsb {
 	status = "okay";