dt-bindings: touchscreen: Add CY8CTMA140 bindings

This adds device tree bindings for the Cypress CY8CTMA140 touchscreen.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20200506123435.187432-1-linus.walleij@linaro.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Documentation/devicetree/bindings/input/touchscreen/cypress,cy8ctma140.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/touchscreen/cypress,cy8ctma140.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Cypress CY8CTMA140 series touchscreen controller bindings
+
+maintainers:
+  - Linus Walleij <linus.walleij@linaro.org>
+
+allOf:
+  - $ref: touchscreen.yaml#
+
+properties:
+  compatible:
+    const: cypress,cy8ctma140
+
+  reg:
+    const: 0x20
+
+  clock-frequency:
+    description: I2C client clock frequency, defined for host
+    minimum: 100000
+    maximum: 400000
+
+  interrupts:
+    maxItems: 1
+
+  vcpin-supply:
+    description: Analog power supply regulator on VCPIN pin
+
+  vdd-supply:
+    description: Digital power supply regulator on VDD pin
+
+  touchscreen-inverted-x: true
+  touchscreen-inverted-y: true
+  touchscreen-size-x: true
+  touchscreen-size-y: true
+  touchscreen-swapped-x-y: true
+  touchscreen-max-pressure: true
+
+additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - touchscreen-size-x
+  - touchscreen-size-y
+  - touchscreen-max-pressure
+
+examples:
+- |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      touchscreen@20 {
+        compatible = "cypress,cy8ctma140";
+        reg = <0x20>;
+        touchscreen-size-x = <480>;
+        touchscreen-size-y = <800>;
+        touchscreen-max-pressure = <255>;
+        interrupt-parent = <&gpio6>;
+        interrupts = <26 IRQ_TYPE_EDGE_FALLING>;
+        vdd-supply = <&ab8500_ldo_aux2_reg>;
+        vcpin-supply = <&ab8500_ldo_aux2_reg>;
+      };
+    };
+
+...