Input: Add touchscreen support for Colibri VF50

The Colibri Vybrid VF50 module supports 4-wire touchscreens using
FETs and ADC inputs. This driver uses the IIO consumer interface
and relies on the vf610_adc driver based on the IIO framework.

Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/Documentation/devicetree/bindings/input/touchscreen/colibri-vf50-ts.txt b/Documentation/devicetree/bindings/input/touchscreen/colibri-vf50-ts.txt
new file mode 100644 (file)
index 0000000..9d9e930
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/colibri-vf50-ts.txt
@@ -0,0 +1,36 @@
+* Toradex Colibri VF50 Touchscreen driver
+
+Required Properties:
+- compatible must be toradex,vf50-touchscreen
+- io-channels: adc channels being used by the Colibri VF50 module
+- xp-gpios: FET gate driver for input of X+
+- xm-gpios: FET gate driver for input of X-
+- yp-gpios: FET gate driver for input of Y+
+- ym-gpios: FET gate driver for input of Y-
+- interrupt-parent: phandle for the interrupt controller
+- interrupts: pen irq interrupt for touch detection
+- pinctrl-names: "idle", "default", "gpios"
+- pinctrl-0: pinctrl node for pen/touch detection state pinmux
+- pinctrl-1: pinctrl node for X/Y and pressure measurement (ADC) state pinmux
+- pinctrl-2: pinctrl node for gpios functioning as FET gate drivers
+- vf50-ts-min-pressure: pressure level at which to stop measuring X/Y values
+
+Example:
+
+       touchctrl: vf50_touchctrl {
+               compatible = "toradex,vf50-touchscreen";
+               io-channels = <&adc1 0>,<&adc0 0>,
+                               <&adc0 1>,<&adc1 2>;
+               xp-gpios = <&gpio0 13 GPIO_ACTIVE_LOW>;
+               xm-gpios = <&gpio2 29 GPIO_ACTIVE_HIGH>;
+               yp-gpios = <&gpio0 12 GPIO_ACTIVE_LOW>;
+               ym-gpios = <&gpio0 4 GPIO_ACTIVE_HIGH>;
+               interrupt-parent = <&gpio0>;
+               interrupts = <8 IRQ_TYPE_LEVEL_LOW>;
+               pinctrl-names = "idle","default","gpios";
+               pinctrl-0 = <&pinctrl_touchctrl_idle>;
+               pinctrl-1 = <&pinctrl_touchctrl_default>;
+               pinctrl-2 = <&pinctrl_touchctrl_gpios>;
+               vf50-ts-min-pressure = <200>;
+               status = "disabled";
+       };

diff --cc drivers/input/touchscreen/Kconfig
Simple merge

diff --cc drivers/input/touchscreen/Makefile
Simple merge

diff --cc drivers/input/touchscreen/colibri-vf50-ts.c
Simple merge