arm64: dts: rockchip: Add support for volume keys to rk3399-pinephone-pro

These are implemented via regular ADC, so regular polling is needed,
for these keys to work.

Co-developed-by: Martijn Braam <martijn@brixit.nl>
Signed-off-by: Martijn Braam <martijn@brixit.nl>
Co-developed-by: Kamil Trzciński <ayufan@ayufan.eu>
Signed-off-by: Kamil Trzciński <ayufan@ayufan.eu>
Signed-off-by: Ondrej Jirman <megi@xff.cz>
Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Tested-by: Ondrej Jirman <megi@xff.cz>
Link: https://lore.kernel.org/r/20230405123813.2272919-1-pbrobinson@gmail.com
[increased Volume-Down voltage to 600mV as suggested by Ondrej]
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

diff --git a/arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts b/arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts
index 475ba78..61f3fec 100644 (file)
--- a/arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts
@@ -10,6 +10,7 @@
  */
 
 /dts-v1/;
+#include <dt-bindings/input/gpio-keys.h>
 #include <dt-bindings/input/linux-event-codes.h>
 #include "rk3399.dtsi"
 #include "rk3399-opp.dtsi"
@@ -29,6 +30,26 @@
                stdout-path = "serial2:115200n8";
        };
 
+       adc-keys {
+               compatible = "adc-keys";
+               io-channels = <&saradc 1>;
+               io-channel-names = "buttons";
+               keyup-threshold-microvolt = <1600000>;
+               poll-interval = <100>;
+
+               button-up {
+                       label = "Volume Up";
+                       linux,code = <KEY_VOLUMEUP>;
+                       press-threshold-microvolt = <100000>;
+               };
+
+               button-down {
+                       label = "Volume Down";
+                       linux,code = <KEY_VOLUMEDOWN>;
+                       press-threshold-microvolt = <600000>;
+               };
+       };
+
        backlight: backlight {
                compatible = "pwm-backlight";
                pwms = <&pwm0 0 50000 0>;
@@ -519,6 +540,11 @@
        status = "okay";
 };
 
+&saradc {
+       vref-supply = <&vcca1v8_s3>;
+       status = "okay";
+};
+
 &sdmmc {
        bus-width = <4>;
        cap-sd-highspeed;