1# SPDX-License-Identifier: GPL-2.0
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/net/mdio.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: MDIO Bus Generic Binding
8
9maintainers:
10  - Andrew Lunn <andrew@lunn.ch>
11  - Florian Fainelli <f.fainelli@gmail.com>
12  - Heiner Kallweit <hkallweit1@gmail.com>
13
14description:
15  These are generic properties that can apply to any MDIO bus. Any
16  MDIO bus must have a list of child nodes, one per device on the
17  bus. These should follow the generic ethernet-phy.yaml document, or
18  a device specific binding document.
19
20properties:
21  $nodename:
22    pattern: "^mdio(@.*)?"
23
24  "#address-cells":
25    const: 1
26
27  "#size-cells":
28    const: 0
29
30  reset-gpios:
31    maxItems: 1
32    description:
33      The phandle and specifier for the GPIO that controls the RESET
34      lines of all devices on that MDIO bus.
35
36  reset-delay-us:
37    description:
38      RESET pulse width in microseconds. It applies to all MDIO devices
39      and must therefore be appropriately determined based on all devices
40      requirements (maximum value of all per-device RESET pulse widths).
41
42  clock-frequency:
43    description:
44      Desired MDIO bus clock frequency in Hz. Values greater than IEEE 802.3
45      defined 2.5MHz should only be used when all devices on the bus support
46      the given clock speed.
47
48  suppress-preamble:
49    description:
50      The 32 bit preamble should be suppressed. In order for this to
51      work, all devices on the bus must support suppressed preamble.
52    type: boolean
53
54patternProperties:
55  "^ethernet-phy@[0-9a-f]+$":
56    type: object
57
58    properties:
59      reg:
60        minimum: 0
61        maximum: 31
62        description:
63          The ID number for the device.
64
65      broken-turn-around:
66        $ref: /schemas/types.yaml#definitions/flag
67        description:
68          If set, indicates the MDIO device does not correctly release
69          the turn around line low at end of the control phase of the
70          MDIO transaction.
71
72      resets:
73        maxItems: 1
74
75      reset-names:
76        const: phy
77
78      reset-gpios:
79        maxItems: 1
80        description:
81          The GPIO phandle and specifier for the MDIO reset signal.
82
83      reset-assert-us:
84        description:
85          Delay after the reset was asserted in microseconds. If this
86          property is missing the delay will be skipped.
87
88      reset-deassert-us:
89        description:
90          Delay after the reset was deasserted in microseconds. If
91          this property is missing the delay will be skipped.
92
93    required:
94      - reg
95
96examples:
97  - |
98    davinci_mdio: mdio@5c030000 {
99        reg = <0x5c030000 0x1000>;
100        #address-cells = <1>;
101        #size-cells = <0>;
102
103        reset-gpios = <&gpio2 5 1>;
104        reset-delay-us = <2>;
105
106        ethphy0: ethernet-phy@1 {
107            reg = <1>;
108        };
109
110        ethphy1: ethernet-phy@3 {
111            reg = <3>;
112        };
113    };
114