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
7 title: MDIO Bus Common Properties
8
9 maintainers:
10 - Andrew Lunn <andrew@lunn.ch>
11 - Florian Fainelli <f.fainelli@gmail.com>
12 - Heiner Kallweit <hkallweit1@gmail.com>
13
14 description:
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
20 properties:
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
61 patternProperties:
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
97 additionalProperties: true
98
99 examples:
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 };
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.