dt-bindings: input: i2c-hid: Introduce Ilitek ili9882t

The ili9882t touch screen chip same as Elan eKTH6915 controller
has a reset gpio. The difference is that ili9882t needs to use
vccio-supply instead of vcc33-supply. Doug's series[1] allows panels
and touchscreens to power on/off together, let's add a phandle for this.

[1]: https://lore.kernel.org/r/20230607215224.2067679-1-dianders@chromium.org

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Cong Yang <yangcong5@huaqin.corp-partner.google.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20230802071947.1683318-2-yangcong5@huaqin.corp-partner.google.com
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>

Author: Cong Yang

Documentation/devicetree/bindings/input/ilitek,ili9882t.yaml

@@ -0,0 +1,67 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/ilitek,ili9882t.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Ilitek ili9882t touchscreen controller
+
+maintainers:
+  - Cong Yang <yangcong5@huaqin.corp-partner.google.com>
+
+description:
+  Supports the Ilitek ili9882t touchscreen controller.
+  This touchscreen controller uses the i2c-hid protocol with a reset GPIO.
+
+allOf:
+  - $ref: /schemas/input/touchscreen/touchscreen.yaml#
+
+properties:
+  compatible:
+    const: ilitek,ili9882t
+
+  reg:
+    const: 0x41
+
+  interrupts:
+    maxItems: 1
+
+  panel: true
+
+  reset-gpios:
+    maxItems: 1
+    description: Reset GPIO.
+
+  vccio-supply:
+    description: The 1.8V supply to the touchscreen.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - panel
+  - vccio-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      touchscreen: touchscreen@41 {
+        compatible = "ilitek,ili9882t";
+        reg = <0x41>;
+
+        interrupt-parent = <&pio>;
+        interrupts = <12 IRQ_TYPE_LEVEL_LOW>;
+
+        panel = <&panel>;
+        reset-gpios = <&pio 60 GPIO_ACTIVE_LOW>;
+        vccio-supply = <&mt6366_vio18_reg>;
+      };
+    };