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 #include <linux/phy.h>
12 #include <linux/export.h>
13
14 /**
15 * of_get_phy_mode - Get phy mode for given device_node
16 * @np: Pointer to the given device_node
17 *
18 * The function gets phy interface string from property 'phy-mode' or
19 * 'phy-connection-type', and return its index in phy_modes table, or errno in
20 * error case.
21 */
of_get_phy_mode(struct device_node * np)22 int of_get_phy_mode(struct device_node *np)
23 {
24 const char *pm;
25 int err, i;
26
27 err = of_property_read_string(np, "phy-mode", &pm);
28 if (err < 0)
29 err = of_property_read_string(np, "phy-connection-type", &pm);
30 if (err < 0)
31 return err;
32
33 for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
34 if (!strcasecmp(pm, phy_modes(i)))
35 return i;
36
37 return -ENODEV;
38 }
39 EXPORT_SYMBOL_GPL(of_get_phy_mode);
40
of_get_mac_addr(struct device_node * np,const char * name)41 static const void *of_get_mac_addr(struct device_node *np, const char *name)
42 {
43 struct property *pp = of_find_property(np, name, NULL);
44
45 if (pp && pp->length == ETH_ALEN && is_valid_ether_addr(pp->value))
46 return pp->value;
47 return NULL;
48 }
49
50 /**
51 * Search the device tree for the best MAC address to use. 'mac-address' is
52 * checked first, because that is supposed to contain to "most recent" MAC
53 * address. If that isn't set, then 'local-mac-address' is checked next,
54 * because that is the default address. If that isn't set, then the obsolete
55 * 'address' is checked, just in case we're using an old device tree.
56 *
57 * Note that the 'address' property is supposed to contain a virtual address of
58 * the register set, but some DTS files have redefined that property to be the
59 * MAC address.
60 *
61 * All-zero MAC addresses are rejected, because those could be properties that
62 * exist in the device tree, but were not set by U-Boot. For example, the
63 * DTS could define 'mac-address' and 'local-mac-address', with zero MAC
64 * addresses. Some older U-Boots only initialized 'local-mac-address'. In
65 * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
66 * but is all zeros.
67 */
of_get_mac_address(struct device_node * np)68 const void *of_get_mac_address(struct device_node *np)
69 {
70 const void *addr;
71
72 addr = of_get_mac_addr(np, "mac-address");
73 if (addr)
74 return addr;
75
76 addr = of_get_mac_addr(np, "local-mac-address");
77 if (addr)
78 return addr;
79
80 return of_get_mac_addr(np, "address");
81 }
82 EXPORT_SYMBOL(of_get_mac_address);
83