dt-bindings: gpio: Add binding documentation for Etron EJ168/EJ188/EJ198

# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)

%YAML 1.2

---

$id: http://devicetree.org/schemas/usb/etron,ej1x8.yaml#

$schema: http://devicetree.org/meta-schemas/core.yaml#

title: EJ168/EJ188/EJ198 xHCI controllers with four GPIO lines

maintainers:

  - Martin Blumenstingl <martin.blumenstingl@googlemail.com>

allOf:

  - $ref: "usb-hcd.yaml#"

properties:

  compatible:

    enum:

      - pci1b6f,7023

      - pci1b6f,7052

  reg:

    maxItems: 1

  "#gpio-cells":

    const: 2

  gpio-controller: true

required:

  - compatible

  - reg

additionalProperties: false

examples:

  - |

      pcie {

        #address-cells = <3>;

        #size-cells = <2>;

        usb@0,0,0 {

          compatible = "pci1b6f,7023";

          reg = <0x0 0x0 0x0 0x0 0x1000>;

          gpio-controller;

          #gpio-cells = <2>;

        };

      };

...