dt-bindings: net: Add a YAML schemas for the generic MDIO options

Common MDIO bus properties.

These are generic properties that can apply to any MDIO bus.

Optional properties:

- reset-gpios: One GPIO that control the RESET lines of all PHYs on that MDIO

  bus.

- reset-delay-us: RESET pulse width in microseconds.

A list of child nodes, one per device on the bus is expected. These

should follow the generic phy.txt, or a device specific binding document.

The 'reset-delay-us' indicates the RESET signal pulse width in microseconds and

applies to all PHY devices. It must therefore be appropriately determined based

on all PHY requirements (maximum value of all per-PHY RESET pulse widths).

Example :

This example shows these optional properties, plus other properties

required for the TI Davinci MDIO driver.

	davinci_mdio: ethernet@5c030000 {

		compatible = "ti,davinci_mdio";

		reg = <0x5c030000 0x1000>;

		#address-cells = <1>;

		#size-cells = <0>;

		reset-gpios = <&gpio2 5 GPIO_ACTIVE_LOW>;

		reset-delay-us = <2>;

		ethphy0: ethernet-phy@1 {

			reg = <1>;

		};

		ethphy1: ethernet-phy@3 {

			reg = <3>;

		};

	};

This file has moved to mdio.yaml.

# SPDX-License-Identifier: GPL-2.0

%YAML 1.2

---

$id: http://devicetree.org/schemas/net/mdio.yaml#

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

title: MDIO Bus Generic Binding

maintainers:

  - Andrew Lunn <andrew@lunn.ch>

  - Florian Fainelli <f.fainelli@gmail.com>

  - Heiner Kallweit <hkallweit1@gmail.com>

description:

  These are generic properties that can apply to any MDIO bus. Any

  MDIO bus must have a list of child nodes, one per device on the

  bus. These should follow the generic ethernet-phy.yaml document, or

  a device specific binding document.

properties:

  reset-gpios:

    maxItems: 1

    description:

      The phandle and specifier for the GPIO that controls the RESET

      lines of all PHYs on that MDIO bus.

  reset-delay-us:

    description:

      RESET pulse width in microseconds. It applies to all PHY devices

      and must therefore be appropriately determined based on all PHY

      requirements (maximum value of all per-PHY RESET pulse widths).

examples:

  - |

    davinci_mdio: mdio@5c030000 {

        compatible = "ti,davinci_mdio";

        reg = <0x5c030000 0x1000>;

        #address-cells = <1>;

        #size-cells = <0>;

        reset-gpios = <&gpio2 5 1>;

        reset-delay-us = <2>;

        ethphy0: ethernet-phy@1 {

            reg = <1>;

        };

        ethphy1: ethernet-phy@3 {

            reg = <3>;

        };

    };