dt-bindings: pinctrl: rt2880: add binding document

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

%YAML 1.2

---

$id: http://devicetree.org/schemas/pinctrl/ralink,rt2880-pinmux.yaml#

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

title: Ralink rt2880 pinmux controller

maintainers:

  - Sergio Paracuellos <sergio.paracuellos@gmail.com>

description:

  The rt2880 pinmux can only set the muxing of pin groups. muxing indiviual pins

  is not supported. There is no pinconf support.

properties:

  compatible:

    enum:

      - ralink,rt2880-pinmux

  pinctrl-0:

    description:

      A phandle to the node containing the subnodes containing default

      configurations. This is for pinctrl hogs.

  pinctrl-names:

    description:

      A pinctrl state named "default" can be defined.

    const: default

required:

  - compatible

patternProperties:

  '[a-z0-9_-]+':

    if:

      type: object

      description: node for pinctrl.

      $ref: "pinmux-node.yaml"

    then:

      properties:

        groups:

          description: Name of the pin group to use for the functions.

          enum: [i2c, spi, uart1, uart2, uart3, rgmii1, rgmii2, mdio,

                 pcie, sdhci]

        function:

          description: The mux function to select

          enum: [gpio, i2c, spi, uart1, uart2, uart3, rgmii1, rgmii2,

                 mdio, nand1, nand2, sdhci]

additionalProperties: false

examples:

  # Pinmux controller node

  - |

    pinctrl {

      compatible = "ralink,rt2880-pinmux";

      pinctrl-names = "default";

      pinctrl-0 = <&state_default>;

      state_default: pinctrl0 {

      };

      i2c_pins: i2c0 {

        i2c0 {

          groups = "i2c";

          function = "i2c";

        };

      };

    };