dt-bindings: input: document Goodix Berlin Touchscreen IC

Document the Goodix GT9916 wich is part of the "Berlin" serie
of Touchscreen controllers IC from Goodix.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20240129-topic-goodix-berlin-upstream-initial-v15-1-6f7d096c0a0a@linaro.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Documentation/devicetree/bindings/input/touchscreen/goodix,gt9916.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/touchscreen/goodix,gt9916.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Goodix Berlin series touchscreen controller
+
+description: The Goodix Berlin series of touchscreen controllers
+  be connected to either I2C or SPI buses.
+
+maintainers:
+  - Neil Armstrong <neil.armstrong@linaro.org>
+
+allOf:
+  - $ref: touchscreen.yaml#
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+  compatible:
+    enum:
+      - goodix,gt9916
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  reset-gpios:
+    maxItems: 1
+
+  avdd-supply:
+    description: Analog power supply regulator on AVDD pin
+
+  vddio-supply:
+    description: power supply regulator on VDDIO pin
+
+  spi-max-frequency: true
+  touchscreen-inverted-x: true
+  touchscreen-inverted-y: true
+  touchscreen-size-x: true
+  touchscreen-size-y: true
+  touchscreen-swapped-x-y: true
+
+additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - avdd-supply
+  - touchscreen-size-x
+  - touchscreen-size-y
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/gpio/gpio.h>
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      touchscreen@5d {
+        compatible = "goodix,gt9916";
+        reg = <0x5d>;
+        interrupt-parent = <&gpio>;
+        interrupts = <25 IRQ_TYPE_LEVEL_LOW>;
+        reset-gpios = <&gpio1 1 GPIO_ACTIVE_LOW>;
+        avdd-supply = <&ts_avdd>;
+        touchscreen-size-x = <1024>;
+        touchscreen-size-y = <768>;
+      };
+    };
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/gpio/gpio.h>
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      num-cs = <1>;
+      cs-gpios = <&gpio 2 GPIO_ACTIVE_HIGH>;
+      touchscreen@0 {
+        compatible = "goodix,gt9916";
+        reg = <0>;
+        interrupt-parent = <&gpio>;
+        interrupts = <25 IRQ_TYPE_LEVEL_LOW>;
+        reset-gpios = <&gpio1 1 GPIO_ACTIVE_LOW>;
+        avdd-supply = <&ts_avdd>;
+        spi-max-frequency = <1000000>;
+        touchscreen-size-x = <1024>;
+        touchscreen-size-y = <768>;
+      };
+    };
+
+...