xref: /linux/Documentation/devicetree/bindings/net/mdio.yaml (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0) 
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 Common Properties
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  $nodename:
22    pattern: '^mdio(-(bus|external))?(@.+|-([0-9]+))?$'
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  reset-post-delay-us:
43    description:
44      Delay after reset deassert in microseconds. It applies to all MDIO
45      devices and it's determined by how fast all devices are ready for
46      communication. This delay happens just before e.g. Ethernet PHY
47      type ID auto detection.
48
49  clock-frequency:
50    description:
51      Desired MDIO bus clock frequency in Hz. Values greater than IEEE 802.3
52      defined 2.5MHz should only be used when all devices on the bus support
53      the given clock speed.
54
55  suppress-preamble:
56    description:
57      The 32 bit preamble should be suppressed. In order for this to
58      work, all devices on the bus must support suppressed preamble.
59    type: boolean
60
61patternProperties:
62  '@[0-9a-f]+$':
63    type: object
64
65    properties:
66      reg:
67        minimum: 0
68        maximum: 31
69        description:
70          The ID number for the device.
71
72      broken-turn-around:
73        $ref: /schemas/types.yaml#/definitions/flag
74        description:
75          If set, indicates the MDIO device does not correctly release
76          the turn around line low at end of the control phase of the
77          MDIO transaction.
78
79      reset-gpios:
80        maxItems: 1
81        description:
82          The GPIO phandle and specifier for the MDIO reset signal.
83
84      reset-assert-us:
85        description:
86          Delay after the reset was asserted in microseconds. If this
87          property is missing the delay will be skipped.
88
89      reset-deassert-us:
90        description:
91          Delay after the reset was deasserted in microseconds. If
92          this property is missing the delay will be skipped.
93
94    required:
95      - reg
96
97additionalProperties: true
98
99examples:
100  - |
101    davinci_mdio: mdio@5c030000 {
102        reg = <0x5c030000 0x1000>;
103        #address-cells = <1>;
104        #size-cells = <0>;
105
106        reset-gpios = <&gpio2 5 1>;
107        reset-delay-us = <2>;
108
109        ethphy0: ethernet-phy@1 {
110            reg = <1>;
111        };
112
113        ethphy1: ethernet-phy@3 {
114            reg = <3>;
115        };
116    };
117