ARM: dts: sun8i: tbs-a711: Add support for volume keys input

TBS A711 tablet has volume up/down keys connected to r_lradc. Add
support for these keys.

Signed-off-by: Ondrej Jirman <[e-mail]>
Signed-off-by: Maxime Ripard <[e-mail]>

arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts

···
 
 #include <dt-bindings/gpio/gpio.h>
 #include <dt-bindings/pwm/pwm.h>
+#include <dt-bindings/input/input.h>
 
 / {
 	model = "TBS A711 Tablet";
···
 	pinctrl-names = "default";
 	pinctrl-0 = <&pwm_pin>;
 	status = "okay";
+};
+
+&r_lradc {
+	vref-supply = <&reg_aldo2>;
+	status = "okay";
+
+	button@210 {
+		label = "Volume Up";
+		linux,code = <KEY_VOLUMEUP>;
+		channel = <0>;
+		voltage = <210000>;
+	};
+
+	button@410 {
+		label = "Volume Down";
+		linux,code = <KEY_VOLUMEDOWN>;
+		channel = <0>;
+		voltage = <410000>;
+	};
 };
 
 &r_rsb {