Input: add support for ChipOne icn8318 based touchscreens

The ChipOne icn8318 is an i2c capacitive touchscreen controller typically
used in cheap android tablets, this commit adds a driver for it.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/input/touchscreen/chipone_icn8318.txt b/Documentation/devicetree/bindings/input/touchscreen/chipone_icn8318.txt
new file mode 100644
index 000000000000..d11f8d615b5d
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/chipone_icn8318.txt
@@ -0,0 +1,46 @@
+* ChipOne icn8318 I2C touchscreen controller
+
+Required properties:
+ - compatible		  : "chipone,icn8318"
+ - reg			  : I2C slave address of the chip (0x40)
+ - interrupt-parent	  : a phandle pointing to the interrupt controller
+			    serving the interrupt for this chip
+ - interrupts		  : interrupt specification for the icn8318 interrupt
+ - wake-gpios		  : GPIO specification for the WAKE input
+ - touchscreen-size-x	  : horizontal resolution of touchscreen (in pixels)
+ - touchscreen-size-y	  : vertical resolution of touchscreen (in pixels)
+
+Optional properties:
+ - pinctrl-names	  : should be "default"
+ - pinctrl-0:		  : a phandle pointing to the pin settings for the
+			    control gpios
+ - touchscreen-fuzz-x	  : horizontal noise value of the absolute input
+			    device (in pixels)
+ - touchscreen-fuzz-y	  : vertical noise value of the absolute input
+			    device (in pixels)
+ - touchscreen-inverted-x : X axis is inverted (boolean)
+ - touchscreen-inverted-y : Y axis is inverted (boolean)
+ - touchscreen-swapped-x-y	  : X and Y axis are swapped (boolean)
+			    Swapping is done after inverting the axis
+
+Example:
+
+i2c@00000000 {
+	/* ... */
+
+	chipone_icn8318@40 {
+		compatible = "chipone,icn8318";
+		reg = <0x40>;
+		interrupt-parent = <&pio>;
+		interrupts = <9 IRQ_TYPE_EDGE_FALLING>; /* EINT9 (PG9) */
+		pinctrl-names = "default";
+		pinctrl-0 = <&ts_wake_pin_p66>;
+		wake-gpios = <&pio 1 3 GPIO_ACTIVE_HIGH>; /* PB3 */
+		touchscreen-size-x = <800>;
+		touchscreen-size-y = <480>;
+		touchscreen-inverted-x;
+		touchscreen-swapped-x-y;
+	};
+
+	/* ... */
+};