Commit | Line | Data |
---|---|---|
4b6ba8aa DD |
1 | /* |
2 | * OF helpers for network devices. | |
3 | * | |
4 | * This file is released under the GPLv2 | |
5 | * | |
6 | * Initially copied out of arch/powerpc/kernel/prom_parse.c | |
7 | */ | |
8 | #include <linux/etherdevice.h> | |
9 | #include <linux/kernel.h> | |
10 | #include <linux/of_net.h> | |
11 | ||
12 | /** | |
13 | * Search the device tree for the best MAC address to use. 'mac-address' is | |
14 | * checked first, because that is supposed to contain to "most recent" MAC | |
15 | * address. If that isn't set, then 'local-mac-address' is checked next, | |
16 | * because that is the default address. If that isn't set, then the obsolete | |
17 | * 'address' is checked, just in case we're using an old device tree. | |
18 | * | |
19 | * Note that the 'address' property is supposed to contain a virtual address of | |
20 | * the register set, but some DTS files have redefined that property to be the | |
21 | * MAC address. | |
22 | * | |
23 | * All-zero MAC addresses are rejected, because those could be properties that | |
24 | * exist in the device tree, but were not set by U-Boot. For example, the | |
25 | * DTS could define 'mac-address' and 'local-mac-address', with zero MAC | |
26 | * addresses. Some older U-Boots only initialized 'local-mac-address'. In | |
27 | * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists | |
28 | * but is all zeros. | |
29 | */ | |
30 | const void *of_get_mac_address(struct device_node *np) | |
31 | { | |
32 | struct property *pp; | |
33 | ||
34 | pp = of_find_property(np, "mac-address", NULL); | |
35 | if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value)) | |
36 | return pp->value; | |
37 | ||
38 | pp = of_find_property(np, "local-mac-address", NULL); | |
39 | if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value)) | |
40 | return pp->value; | |
41 | ||
42 | pp = of_find_property(np, "address", NULL); | |
43 | if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value)) | |
44 | return pp->value; | |
45 | ||
46 | return NULL; | |
47 | } | |
48 | EXPORT_SYMBOL(of_get_mac_address); |