dt-bindings: w1: Convert 1-Wire GPIO binding to a schema

Bitbanged 1-Wire buses are supported by Linux thanks to their device
tree binding.

Now that we have the DT validation in place, let's convert the device
tree bindings for that driver over to a YAML schema.

Cc: Daniel Mack <zonque@gmail.com>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20210901091852.479202-39-maxime@cerno.techSigned-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/w1/w1-gpio.txt

-w1-gpio devicetree bindings
-
-Required properties:
-
- - compatible: "w1-gpio"
- - gpios: one or two GPIO specs:
-		- the first one is used as data I/O pin
-		- the second one is optional. If specified, it is used as
-		  enable pin for an external pin pullup.
-
-Optional properties:
-
- - linux,open-drain: if specified, the data pin is considered in
-		     open-drain mode.
-
-Also refer to the generic w1.txt document.
-
-Examples:
-
-	onewire {
-		compatible = "w1-gpio";
-		gpios = <&gpio 0 GPIO_ACTIVE_HIGH>;
-
-		battery {
-			// ...
-		};
-	};

Documentation/devicetree/bindings/w1/w1-gpio.yaml

+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/w1/w1-gpio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Bitbanged GPIO 1-Wire Bus Device Tree Bindings
+
+maintainers:
+  - Daniel Mack <zonque@gmail.com>
+
+properties:
+  compatible:
+    const: w1-gpio
+
+  gpios:
+    minItems: 1
+    maxItems: 2
+    items:
+      - description: Data I/O pin
+      - description: Enable pin for an external pull-up resistor
+
+  linux,open-drain:
+    type: boolean
+    description: >
+      If specified, the data pin is considered in open-drain mode.
+
+required:
+  - compatible
+  - gpios
+
+additionalProperties:
+  type: object
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    onewire {
+        compatible = "w1-gpio";
+        gpios = <&gpio 0 GPIO_ACTIVE_HIGH>;
+    };
+
+...