# 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:
  $nodename:
    pattern: "^mdio(@.*)?"

  "#address-cells":
    const: 1

  "#size-cells":
    const: 0

  reset-gpios:
    maxItems: 1
    description:
      The phandle and specifier for the GPIO that controls the RESET
      lines of all devices on that MDIO bus.

  reset-delay-us:
    description:
      RESET pulse width in microseconds. It applies to all MDIO devices
      and must therefore be appropriately determined based on all devices
      requirements (maximum value of all per-device RESET pulse widths).

  clock-frequency:
    description:
      Desired MDIO bus clock frequency in Hz. Values greater than IEEE 802.3
      defined 2.5MHz should only be used when all devices on the bus support
      the given clock speed.

  suppress-preamble:
    description:
      The 32 bit preamble should be suppressed. In order for this to
      work, all devices on the bus must support suppressed preamble.
    type: boolean

patternProperties:
  "^ethernet-phy@[0-9a-f]+$":
    type: object

    properties:
      reg:
        minimum: 0
        maximum: 31
        description:
          The ID number for the device.

      broken-turn-around:
        $ref: /schemas/types.yaml#definitions/flag
        description:
          If set, indicates the MDIO device does not correctly release
          the turn around line low at end of the control phase of the
          MDIO transaction.

      resets:
        maxItems: 1

      reset-names:
        const: phy

      reset-gpios:
        maxItems: 1
        description:
          The GPIO phandle and specifier for the MDIO reset signal.

      reset-assert-us:
        description:
          Delay after the reset was asserted in microseconds. If this
          property is missing the delay will be skipped.

      reset-deassert-us:
        description:
          Delay after the reset was deasserted in microseconds. If
          this property is missing the delay will be skipped.

    required:
      - reg

examples:
  - |
    davinci_mdio: mdio@5c030000 {
        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>;
        };
    };