All machines of the Asurada platform have a touchscreen at address 0x10
in the I2C0 bus, but the devices vary: Spherion has the Elan eKTH3500
touchscreen, while Hayato has a generic HID-over-i2c touchscreen.

Add common support for the touchscreens on the platform and the
specifics in each board file.

Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
---

(no changes since v1)

 .../dts/mediatek/mt8192-asurada-hayato-r1.dts |  7 ++++++
 .../mediatek/mt8192-asurada-spherion-r0.dts   |  4 +++
 .../boot/dts/mediatek/mt8192-asurada.dtsi     | 25 +++++++++++++++++++
 3 files changed, 36 insertions(+)

diff --git a/arch/arm64/boot/dts/mediatek/mt8192-asurada-hayato-r1.dts b/arch/arm64/boot/dts/mediatek/mt8192-asurada-hayato-r1.dts
index ca18fcf2ad4f..1e91491945f6 100644
--- a/arch/arm64/boot/dts/mediatek/mt8192-asurada-hayato-r1.dts
+++ b/arch/arm64/boot/dts/mediatek/mt8192-asurada-hayato-r1.dts
@@ -38,3 +38,10 @@ MATRIX_KEY(0x00, 0x04, KEY_VOLUMEUP)
 		CROS_STD_MAIN_KEYMAP
 	>;
 };
+
+&touchscreen {
+	compatible = "hid-over-i2c";
+	post-power-on-delay-ms = <10>;
+	hid-descr-addr = <0x0001>;
+	vdd-supply = <&pp3300_u>;
+};
diff --git a/arch/arm64/boot/dts/mediatek/mt8192-asurada-spherion-r0.dts b/arch/arm64/boot/dts/mediatek/mt8192-asurada-spherion-r0.dts
index 30b03895de41..42db81e95fae 100644
--- a/arch/arm64/boot/dts/mediatek/mt8192-asurada-spherion-r0.dts
+++ b/arch/arm64/boot/dts/mediatek/mt8192-asurada-spherion-r0.dts
@@ -40,3 +40,7 @@ MATRIX_KEY(0x00, 0x04, KEY_VOLUMEUP)
 		CROS_STD_MAIN_KEYMAP
 	>;
 };
+
+&touchscreen {
+	compatible = "elan,ekth3500";
+};
diff --git a/arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi b/arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi
index 4de4235cb768..6eace280c14a 100644
--- a/arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8192-asurada.dtsi
@@ -92,6 +92,13 @@ &i2c0 {
 	clock-frequency = <400000>;
 	pinctrl-names = "default";
 	pinctrl-0 = <&i2c0_pins>;
+
+	touchscreen: touchscreen@10 {
+		reg = <0x10>;
+		interrupts-extended = <&pio 21 IRQ_TYPE_LEVEL_LOW>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&touchscreen_pins>;
+	};
 };
 
 &i2c1 {
@@ -454,6 +461,24 @@ pins-int-n {
 			bias-pull-up = <MTK_PUPD_SET_R1R0_11>;
 		};
 	};
+
+	touchscreen_pins: touchscreen-default-pins {
+		pins-irq {
+			pinmux = <PINMUX_GPIO21__FUNC_GPIO21>;
+			input-enable;
+			bias-pull-up;
+		};
+
+		pins-reset {
+			pinmux = <PINMUX_GPIO137__FUNC_GPIO137>;
+			output-high;
+		};
+
+		pins-report-sw {
+			pinmux = <PINMUX_GPIO138__FUNC_GPIO138>;
+			output-low;
+		};
+	};
 };
 
 &spi1 {
-- 
2.36.1