dt-bindings: ps2-gpio: convert binding to json-schema

Convert the ps2-gpio dt-binding documentation to DT schema format using
the json-schema.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220529132638.13420-1-danilokrummrich@dk-develop.de

Documentation/devicetree/bindings/serio/ps2-gpio.txt

-Device-Tree binding for ps/2 gpio device
-
-Required properties:
-	- compatible = "ps2-gpio"
-	- data-gpios: the data pin
-	- clk-gpios: the clock pin
-	- interrupts: Should trigger on the falling edge of the clock line.
-
-Optional properties:
-	- write-enable: Indicates whether write function is provided
-	to serio device. Possibly providing the write fn will not work, because
-	of the tough timing requirements.
-
-Example nodes:
-
-ps2@0 {
-	compatible = "ps2-gpio";
-	interrupt-parent = <&gpio>;
-	interrupts = <23 IRQ_TYPE_EDGE_FALLING>;
-	data-gpios = <&gpio 24 GPIO_ACTIVE_HIGH>;
-	clk-gpios = <&gpio 23 GPIO_ACTIVE_HIGH>;
-	write-enable;
-};

Documentation/devicetree/bindings/serio/ps2-gpio.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/serio/ps2-gpio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Bindings for GPIO based PS/2
+
+maintainers:
+  - Danilo Krummrich <danilokrummrich@dk-develop.de>
+
+properties:
+  compatible:
+    const: ps2-gpio
+
+  data-gpios:
+    description:
+      the gpio used for the data signal
+    maxItems: 1
+
+  clk-gpios:
+    description:
+      the gpio used for the clock signal
+    maxItems: 1
+
+  interrupts:
+    description:
+      The given interrupt should trigger on the falling edge of the clock line.
+    maxItems: 1
+
+  write-enable:
+    type: boolean
+    description:
+      Indicates whether write function is provided to serio device. Possibly
+      providing the write function will not work, because of the tough timing
+      requirements.
+
+required:
+  - compatible
+  - data-gpios
+  - clk-gpios
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    ps2 {
+        compatible = "ps2-gpio";
+        interrupt-parent = <&gpio>;
+        interrupts = <23 IRQ_TYPE_EDGE_FALLING>;
+        data-gpios = <&gpio 24 GPIO_ACTIVE_HIGH>;
+        clk-gpios = <&gpio 23 GPIO_ACTIVE_HIGH>;
+        write-enable;
+    };