arm64: dts: qcom: msm8916-samsung-e2015: Add touchkey

On the Samsung Galaxy E5 and E7 the touch key is supplied by a single
fixed regulator (enabled via GPIO 97) that supplies both MCU and LED.
Add it to the device tree.
Signed-off-by: Lin, Meng-Bo <linmengbo0689@protonmail.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20220724095426.14189-1-linmengbo0689@protonmail.com

arch/arm64/boot/dts/qcom/msm8916-samsung-e2015-common.dtsi

@@ -38,6 +38,19 @@ reg_motor_vdd: regulator-motor-vdd {
 		pinctrl-names = "default";
 		pinctrl-0 = <&motor_en_default>;
 	};
+
+	reg_touch_key: regulator-touch-key {
+		compatible = "regulator-fixed";
+		regulator-name = "touch_key";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+
+		gpio = <&msmgpio 97 GPIO_ACTIVE_HIGH>;
+		enable-active-high;
+
+		pinctrl-names = "default";
+		pinctrl-0 = <&tkey_en_default>;
+	};
 };
 
 &blsp_i2c2 {
@@ -48,6 +61,11 @@ &blsp_i2c2 {
 	/delete-node/ magnetometer@12;
 };
 
+&touchkey {
+	vcc-supply = <&reg_touch_key>;
+	vdd-supply = <&reg_touch_key>;
+};
+
 &msmgpio {
 	motor_en_default: motor-en-default {
 		pins = "gpio76";
@@ -56,4 +74,12 @@ motor_en_default: motor-en-default {
 		drive-strength = <2>;
 		bias-disable;
 	};
+
+	tkey_en_default: tkey-en-default {
+		pins = "gpio97";
+		function = "gpio";
+
+		drive-strength = <2>;
+		bias-disable;
+	};
 };

arch/arm64/boot/dts/qcom/msm8916-samsung-grandmax.dts

@@ -41,6 +41,10 @@ &reg_motor_vdd {
 	gpio = <&msmgpio 72 GPIO_ACTIVE_HIGH>;
 };
 
+&reg_touch_key {
+	status = "disabled";
+};
+
 &msmgpio {
 	gpio_leds_default: gpio-led-default {
 		pins = "gpio60";