dt-bindings: input: Goodix SPI HID Touchscreen

The Goodix GT7986U touch controller report touch data according to the
HID protocol through the SPI bus. However, it is incompatible with
Microsoft's HID-over-SPI protocol.
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Charles Wang <charles.goodix@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

Documentation/devicetree/bindings/input/goodix,gt7986u.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/goodix,gt7986u.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: GOODIX GT7986U SPI HID Touchscreen
+
+maintainers:
+  - Charles Wang <charles.goodix@gmail.com>
+
+description: Supports the Goodix GT7986U touchscreen.
+  This touch controller reports data packaged according to the HID protocol,
+  but is incompatible with Microsoft's HID-over-SPI protocol.
+
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+  compatible:
+    enum:
+      - goodix,gt7986u
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  reset-gpios:
+    maxItems: 1
+
+  goodix,hid-report-addr:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      The register address for retrieving HID report data.
+      This address is related to the device firmware and may
+      change after a firmware update.
+
+  spi-max-frequency: true
+
+additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - reset-gpios
+  - goodix,hid-report-addr
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/gpio/gpio.h>
+
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      touchscreen@0 {
+        compatible = "goodix,gt7986u";
+        reg = <0>;
+        interrupt-parent = <&gpio>;
+        interrupts = <25 IRQ_TYPE_LEVEL_LOW>;
+        reset-gpios = <&gpio1 1 GPIO_ACTIVE_LOW>;
+        spi-max-frequency = <10000000>;
+        goodix,hid-report-addr = <0x22c8c>;
+      };
+    };
+
+...