ARM: dts: qcom: apq8060-dragonboard: Add TMA340 to APQ8060 DragonBoard

This adds the CY8CTMA340 Touchscreen to the APQ8060 DragonBoard.

Tested without display by issuing cat /dev/input/input/event3
which produces appropriate noise and interrupts on the dedicated
GPIO line.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20220913132846.305716-3-linus.walleij@linaro.org

arch/arm/boot/dts/qcom-apq8060-dragonboard.dts

@@ -159,6 +159,19 @@ data {
 				};
 			};
 
+			dragon_gsbi3_i2c_pins: gsbi3_i2c {
+				mux {
+					pins = "gpio43", "gpio44";
+					function = "gsbi3";
+				};
+				pinconf {
+					pins = "gpio43", "gpio44";
+					drive-strength = <8>;
+					/* These have external pull-up 2.2kOhm to 1.8V */
+					bias-disable;
+				};
+			};
+
 			dragon_gsbi8_i2c_pins: gsbi8_i2c {
 				mux {
 					pins = "gpio64", "gpio65";
@@ -240,6 +253,22 @@ irq {
 					bias-pull-up;
 				};
 			};
+
+			dragon_tma340_gpios: tma340 {
+				reset {
+					/* RESET line, TS_ATTN, WAKE_CTP */
+					pins = "gpio58";
+					function = "gpio";
+					drive-strength = <6>;
+					bias-disable;
+				};
+				irq {
+					pins = "gpio61"; /* IRQ line */
+					function = "gpio";
+					drive-strength = <2>;
+					bias-pull-up;
+				};
+			};
 		};
 
 		qcom,ssbi@500000 {
@@ -444,6 +473,45 @@ led@133 {
 			};
 		};
 
+		gsbi@16200000 {
+			qcom,mode = <GSBI_PROT_I2C>;
+			status = "okay";
+
+			gsbi3_i2c: i2c@16280000 {
+				pinctrl-names = "default";
+				pinctrl-0 = <&dragon_gsbi3_i2c_pins>;
+				status = "okay";
+
+				touchscreen@24 {
+					compatible = "cypress,cy8ctma340";
+					reg = <0x24>;
+					/* Certainly we can do at least 400 kHz */
+					clock-frequency = <400000>;
+					/* IRQ on GPIO61 called /CTP_INT */
+					interrupt-parent = <&tlmm>;
+					interrupts = <61 IRQ_TYPE_EDGE_FALLING>;
+					/*
+					 * The I2C bus is using a PCA9306 level translator from L16A
+					 * to L2B so these two voltages are needed and L16A is
+					 * kind of the IO voltage, however L16Aisn't really fed to
+					 * the TMA340, which relies entirely on L2B (PM8901 L2).
+					 */
+					vcpin-supply = <&pm8058_l16>;
+					vdd-supply = <&pm8901_l2>;
+					/* GPIO58, called WAKE_CTP */
+					reset-gpios = <&tlmm 58 GPIO_ACTIVE_LOW>;
+					touchscreen-size-x = <480>;
+					touchscreen-size-y = <800>;
+					active-interval-ms = <0>;
+					touch-timeout-ms = <255>;
+					lowpower-interval-ms = <10>;
+					bootloader-key = /bits/ 8 <0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x07>;
+					pinctrl-names = "default";
+					pinctrl-0 = <&dragon_tma340_gpios>;
+				};
+			};
+		};
+
 		gsbi@19800000 {
 			status = "okay";
 			qcom,mode = <GSBI_PROT_I2C>;
@@ -634,7 +702,8 @@ l1 {
 					bias-pull-down;
 				};
 				l2 {
-					regulator-min-microvolt = <2850000>;
+					/* TMA340 requires strictly 3.3V */
+					regulator-min-microvolt = <3300000>;
 					regulator-max-microvolt = <3300000>;
 					bias-pull-down;
 				};