ARM: dts: ux500: Add touchscreen to the Skomer

This adds touchscreen support to the Ux500 Samsung
GT-S7710 "Skomer" mobile phone.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20200516212913.485365-1-linus.walleij@linaro.org

arch/arm/boot/dts/ste-ux500-samsung-skomer.dts

@@ -367,7 +367,28 @@ i2c@80110000 {
 			pinctrl-0 = <&i2c3_c_2_default>;
 			pinctrl-1 = <&i2c3_c_2_sleep>;
 
-			/* TODO: this should be used by the Cypress TMA140 touchscreen */
+			/* Cypress CY8CTMA140 touchscreen */
+			touchscreen@20 {
+				compatible = "cypress,cy8ctma140";
+				clock-frequency = <400000>;
+				reg = <0x20>;
+
+				touchscreen-size-x = <480>;
+				touchscreen-size-y = <800>;
+				touchscreen-max-pressure = <255>;
+
+				/* GPIO218 for IRQ */
+				interrupt-parent = <&gpio6>;
+				interrupts = <26 IRQ_TYPE_EDGE_FALLING>;
+
+				/* VDD is "digital supply" nominally 1.71-3.6V */
+				vdd-supply = <&ab8500_ldo_aux2_reg>;
+				/* VCPIN is "analog supply", 2.7-3.6 V */
+				vcpin-supply = <&ab8500_ldo_aux2_reg>;
+
+				pinctrl-names = "default";
+				pinctrl-0 = <&tma140_skomer_default>;
+			};
 		};
 
 		mcde@a0350000 {
@@ -562,6 +583,15 @@ skomer_cfg1 {
 			};
 		};
 	};
+	/* Interrupt line for the Cypress TMA140 touchscreen */
+	touchscreen {
+		tma140_skomer_default: tma140_skomer {
+			skomer_cfg1 {
+				pins = "GPIO218_AH11";
+				ste,config = <&gpio_in_nopull>;
+			};
+		};
+	};
 };
 
 &ab8505_gpio {