[PATCH 3/8] arm64: dts: qcom: msm8939-samsung-a7: Add touch key

["Lin, Meng-Bo" <linmengbo0689@protonmail.com>]

Add the CORERIVER TC360 touch key together with the necessary
fixed regulator for it.

Note that for some reason Samsung decided to connect this to GPIOs
where no hardware I2C bus is available, so we need to fall back
to software bit-banging using i2c-gpio.

Signed-off-by: Lin, Meng-Bo <linmengbo0689@protonmail.com>
---
 .../boot/dts/qcom/msm8939-samsung-a7.dts      | 85 +++++++++++++++++++
 1 file changed, 85 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/msm8939-samsung-a7.dts b/arch/arm64/boot/dts/qcom/msm8939-samsung-a7.dts
index cf2738bc3313..98a2738eb8ea 100644
--- a/arch/arm64/boot/dts/qcom/msm8939-samsung-a7.dts
+++ b/arch/arm64/boot/dts/qcom/msm8939-samsung-a7.dts
@@ -68,6 +68,63 @@ button-home {
 			linux,code = <KEY_HOMEPAGE>;
 		};
 	};
+
+	i2c-tkey {
+		compatible = "i2c-gpio";
+		sda-gpios = <&tlmm 16 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
+		scl-gpios = <&tlmm 17 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
+
+		pinctrl-0 = <&tkey_i2c_default>;
+		pinctrl-names = "default";
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		touchkey@20 {
+			/* Note: Actually an ABOV MCU that implements same interface */
+			compatible = "coreriver,tc360-touchkey";
+			reg = <0x20>;
+
+			interrupt-parent = <&tlmm>;
+			interrupts = <20 IRQ_TYPE_EDGE_FALLING>;
+
+			vcc-supply = <&reg_touch_key>;
+			vdd-supply = <&reg_keyled>;
+			vddio-supply = <&pm8916_l6>;
+
+			linux,keycodes = <KEY_APPSELECT KEY_BACK>;
+
+			pinctrl-0 = <&tkey_default>;
+			pinctrl-names = "default";
+		};
+	};
+
+	reg_keyled: regulator-keyled {
+		compatible = "regulator-fixed";
+		regulator-name = "keyled";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+
+		/* NOTE: On some variants e.g. SM-A700FD it's GPIO 91 */
+		gpio = <&tlmm 100 GPIO_ACTIVE_HIGH>;
+		enable-active-high;
+
+		pinctrl-0 = <&tkey_led_en_default>;
+		pinctrl-names = "default";
+	};
+
+	reg_touch_key: regulator-touch-key {
+		compatible = "regulator-fixed";
+		regulator-name = "touch_key";
+		regulator-min-microvolt = <2800000>;
+		regulator-max-microvolt = <2800000>;
+
+		gpio = <&tlmm 56 GPIO_ACTIVE_HIGH>;
+		enable-active-high;
+
+		pinctrl-0 = <&tkey_en_default>;
+		pinctrl-names = "default";
+	};
 };
 
 &blsp_i2c1 {
@@ -160,4 +217,32 @@ sdc2_cd_default: sdc2-cd-default-state {
 		drive-strength = <2>;
 		bias-pull-up;
 	};
+
+	tkey_default: tkey-default-state {
+		pins = "gpio20";
+		function = "gpio";
+		drive-strength = <2>;
+		bias-disable;
+	};
+
+	tkey_en_default: tkey-en-default-state {
+		pins = "gpio56";
+		function = "gpio";
+		drive-strength = <2>;
+		bias-disable;
+	};
+
+	tkey_i2c_default: tkey-i2c-default-state {
+		pins = "gpio16", "gpio17";
+		function = "gpio";
+		drive-strength = <2>;
+		bias-disable;
+	};
+
+	tkey_led_en_default: tkey-led-en-default-state {
+		pins = "gpio100";
+		function = "gpio";
+		drive-strength = <2>;
+		bias-disable;
+	};
 };
-- 
2.39.2