arm64: dts: msm8916-samsung-a2015: add tactile buttons and hall sensor

Add nodes for basic GPIO connected hardware to the Samsung A3/A5 common dtsi.
This includes the Volume UP button, the Home button, and the hall sensor used
to sense "smart cover" open state. Related to that, add a node for the Volume
DOWN button, which is handled by the pm8916 as is common with msm8916 devices.

Tested-by: Stephan Gerhold <stephan@gerhold.net> # a5u
Reviewed-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Michael Srba <Michael.Srba@seznam.cz>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

arch/arm64/boot/dts/qcom/msm8916-samsung-a2015-common.dtsi

@@ -3,6 +3,7 @@
 #include "msm8916.dtsi"
 #include "pm8916.dtsi"
 #include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
 #include <dt-bindings/interrupt-controller/irq.h>
 
 / {
@@ -91,6 +92,44 @@ wcnss@a21b000 {
 		etm@85f000 { status = "disabled"; };
 	};
 
+	gpio-keys {
+		compatible = "gpio-keys";
+
+		pinctrl-names = "default";
+		pinctrl-0 = <&gpio_keys_default>;
+
+		label = "GPIO Buttons";
+
+		volume-up {
+			label = "Volume Up";
+			gpios = <&msmgpio 107 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_VOLUMEUP>;
+		};
+
+		home {
+			label = "Home";
+			gpios = <&msmgpio 109 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_HOMEPAGE>;
+		};
+	};
+
+	gpio-hall-sensor {
+		compatible = "gpio-keys";
+
+		pinctrl-names = "default";
+		pinctrl-0 = <&gpio_hall_sensor_default>;
+
+		label = "GPIO Hall Effect Sensor";
+
+		hall-sensor {
+			label = "Hall Effect Sensor";
+			gpios = <&msmgpio 52 GPIO_ACTIVE_LOW>;
+			linux,input-type = <EV_SW>;
+			linux,code = <SW_LID>;
+			linux,can-disable;
+		};
+	};
+
 	i2c-muic {
 		compatible = "i2c-gpio";
 		sda-gpios = <&msmgpio 105 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
@@ -113,6 +152,30 @@ muic: sm5502@25 {
 };
 
 &msmgpio {
+	gpio_keys_default: gpio_keys_default {
+		pinmux {
+			function = "gpio";
+			pins = "gpio107", "gpio109";
+		};
+		pinconf {
+			pins = "gpio107", "gpio109";
+			drive-strength = <2>;
+			bias-pull-up;
+		};
+	};
+
+	gpio_hall_sensor_default: gpio_hall_sensor_default {
+		pinmux {
+			function = "gpio";
+			pins = "gpio52";
+		};
+		pinconf {
+			pins = "gpio52";
+			drive-strength = <2>;
+			bias-disable;
+		};
+	};
+
 	muic_int_default: muic_int_default {
 		pinmux {
 			function = "gpio";
@@ -238,3 +301,16 @@ l18 {
 		regulator-max-microvolt = <2700000>;
 	};
 };
+
+&spmi_bus {
+	pm8916@0 {
+		pon@800 {
+			volume-down {
+				compatible = "qcom,pm8941-resin";
+				interrupts = <0x0 0x8 1 IRQ_TYPE_EDGE_BOTH>;
+				bias-pull-up;
+				linux,code = <KEY_VOLUMEDOWN>;
+			};
+		};
+	};
+};