dt-bindings: HID: i2c-hid: add dedicated Ilitek ILI2901 schema

The Ilitek ILI2901 touch screen controller was apparently incorrectly
added to the Elan eKTH6915 schema simply because it also has a reset
gpio and is currently managed by the Elan driver in Linux.

The two controllers are not related even if an unfortunate wording in
the commit message adding the Ilitek compatible made it sound like they
were.

Add a dedicated schema for the ILI2901 which does not specify the I2C
address (which is likely 0x41 rather than 0x10 as for other Ilitek touch
controllers) to avoid cluttering the Elan schema with unrelated devices
and to make it easier to find the correct schema when adding further
Ilitek controllers.

Fixes: d74ac6f6 ("dt-bindings: HID: i2c-hid: elan: Introduce Ilitek ili2901")
Cc: Zhengqiao Xia <xiazhengqiao@huaqin.corp-partner.google.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20240507144821.12275-2-johan+linaro@kernel.orgSigned-off-by: Benjamin Tissoires <bentiss@kernel.org>

Documentation/devicetree/bindings/input/elan,ekth6915.yaml

@@ -20,7 +20,6 @@ properties:
   compatible:
     enum:
       - elan,ekth6915
-      - ilitek,ili2901
 
   reg:
     const: 0x10

Documentation/devicetree/bindings/input/ilitek,ili2901.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/ilitek,ili2901.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Ilitek ILI2901 touchscreen controller
+
+maintainers:
+  - Jiri Kosina <jkosina@suse.com>
+
+description:
+  Supports the Ilitek ILI2901 touchscreen controller.
+  This touchscreen controller uses the i2c-hid protocol with a reset GPIO.
+
+allOf:
+  - $ref: /schemas/input/touchscreen/touchscreen.yaml#
+
+properties:
+  compatible:
+    enum:
+      - ilitek,ili2901
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  panel: true
+
+  reset-gpios:
+    maxItems: 1
+
+  vcc33-supply: true
+
+  vccio-supply: true
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - vcc33-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@41 {
+        compatible = "ilitek,ili2901";
+        reg = <0x41>;
+
+        interrupt-parent = <&tlmm>;
+        interrupts = <9 IRQ_TYPE_LEVEL_LOW>;
+
+        reset-gpios = <&tlmm 8 GPIO_ACTIVE_LOW>;
+        vcc33-supply = <&pp3300_ts>;
+      };
+    };