1Fixed link Device Tree binding
2------------------------------
3
4Some Ethernet MACs have a "fixed link", and are not connected to a
5normal MDIO-managed PHY device. For those situations, a Device Tree
6binding allows to describe a "fixed link".
7
8Such a fixed link situation is described by creating a 'fixed-link'
9sub-node of the Ethernet MAC device node, with the following
10properties:
11
12* 'speed' (integer, mandatory), to indicate the link speed. Accepted
13  values are 10, 100 and 1000
14* 'full-duplex' (boolean, optional), to indicate that full duplex is
15  used. When absent, half duplex is assumed.
16* 'pause' (boolean, optional), to indicate that pause should be
17  enabled.
18* 'asym-pause' (boolean, optional), to indicate that asym_pause should
19  be enabled.
20* 'link-gpios' ('gpio-list', optional), to indicate if a gpio can be read
21  to determine if the link is up.
22
23Old, deprecated 'fixed-link' binding:
24
25* A 'fixed-link' property in the Ethernet MAC node, with 5 cells, of the
26  form <a b c d e> with the following accepted values:
27  - a: emulated PHY ID, choose any but but unique to the all specified
28    fixed-links, from 0 to 31
29  - b: duplex configuration: 0 for half duplex, 1 for full duplex
30  - c: link speed in Mbits/sec, accepted values are: 10, 100 and 1000
31  - d: pause configuration: 0 for no pause, 1 for pause
32  - e: asymmetric pause configuration: 0 for no asymmetric pause, 1 for
33    asymmetric pause
34
35Examples:
36
37ethernet@0 {
38	...
39	fixed-link {
40	      speed = <1000>;
41	      full-duplex;
42	};
43	...
44};
45
46ethernet@1 {
47	...
48	fixed-link {
49	      speed = <1000>;
50	      pause;
51	      link-gpios = <&gpio0 12 GPIO_ACTIVE_HIGH>;
52	};
53	...
54};
55