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 * It maps 'enum phy_interface_t' found in include/linux/phy.h
16 * into the device tree binding of 'phy-mode', so that Ethernet
17 * device driver can get phy interface from device tree.
18 */
19 static const char *phy_modes[] = {
20 [PHY_INTERFACE_MODE_NA] = "",
21 [PHY_INTERFACE_MODE_MII] = "mii",
22 [PHY_INTERFACE_MODE_GMII] = "gmii",
23 [PHY_INTERFACE_MODE_SGMII] = "sgmii",
24 [PHY_INTERFACE_MODE_TBI] = "tbi",
25 [PHY_INTERFACE_MODE_RMII] = "rmii",
26 [PHY_INTERFACE_MODE_RGMII] = "rgmii",
27 [PHY_INTERFACE_MODE_RGMII_ID] = "rgmii-id",
28 [PHY_INTERFACE_MODE_RGMII_RXID] = "rgmii-rxid",
29 [PHY_INTERFACE_MODE_RGMII_TXID] = "rgmii-txid",
30 [PHY_INTERFACE_MODE_RTBI] = "rtbi",
31 [PHY_INTERFACE_MODE_SMII] = "smii",
32 };
33
34 /**
35 * of_get_phy_mode - Get phy mode for given device_node
36 * @np: Pointer to the given device_node
37 *
38 * The function gets phy interface string from property 'phy-mode',
39 * and return its index in phy_modes table, or errno in error case.
40 */
of_get_phy_mode(struct device_node * np)41 const int of_get_phy_mode(struct device_node *np)
42 {
43 const char *pm;
44 int err, i;
45
46 err = of_property_read_string(np, "phy-mode", &pm);
47 if (err < 0)
48 return err;
49
50 for (i = 0; i < ARRAY_SIZE(phy_modes); i++)
51 if (!strcasecmp(pm, phy_modes[i]))
52 return i;
53
54 return -ENODEV;
55 }
56 EXPORT_SYMBOL_GPL(of_get_phy_mode);
57
58 /**
59 * Search the device tree for the best MAC address to use. 'mac-address' is
60 * checked first, because that is supposed to contain to "most recent" MAC
61 * address. If that isn't set, then 'local-mac-address' is checked next,
62 * because that is the default address. If that isn't set, then the obsolete
63 * 'address' is checked, just in case we're using an old device tree.
64 *
65 * Note that the 'address' property is supposed to contain a virtual address of
66 * the register set, but some DTS files have redefined that property to be the
67 * MAC address.
68 *
69 * All-zero MAC addresses are rejected, because those could be properties that
70 * exist in the device tree, but were not set by U-Boot. For example, the
71 * DTS could define 'mac-address' and 'local-mac-address', with zero MAC
72 * addresses. Some older U-Boots only initialized 'local-mac-address'. In
73 * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
74 * but is all zeros.
75 */
of_get_mac_address(struct device_node * np)76 const void *of_get_mac_address(struct device_node *np)
77 {
78 struct property *pp;
79
80 pp = of_find_property(np, "mac-address", NULL);
81 if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value))
82 return pp->value;
83
84 pp = of_find_property(np, "local-mac-address", NULL);
85 if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value))
86 return pp->value;
87
88 pp = of_find_property(np, "address", NULL);
89 if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value))
90 return pp->value;
91
92 return NULL;
93 }
94 EXPORT_SYMBOL(of_get_mac_address);
95