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/nvmem-consumer.h>
11 #include <linux/of_net.h>
12 #include <linux/phy.h>
13 #include <linux/export.h>
14
15 /**
16 * of_get_phy_mode - Get phy mode for given device_node
17 * @np: Pointer to the given device_node
18 *
19 * The function gets phy interface string from property 'phy-mode' or
20 * 'phy-connection-type', and return its index in phy_modes table, or errno in
21 * error case.
22 */
of_get_phy_mode(struct device_node * np)23 int of_get_phy_mode(struct device_node *np)
24 {
25 const char *pm;
26 int err, i;
27
28 err = of_property_read_string(np, "phy-mode", &pm);
29 if (err < 0)
30 err = of_property_read_string(np, "phy-connection-type", &pm);
31 if (err < 0)
32 return err;
33
34 for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
35 if (!strcasecmp(pm, phy_modes(i)))
36 return i;
37
38 return -ENODEV;
39 }
40 EXPORT_SYMBOL_GPL(of_get_phy_mode);
41
of_get_mac_addr(struct device_node * np,const char * name)42 static const void *of_get_mac_addr(struct device_node *np, const char *name)
43 {
44 struct property *pp = of_find_property(np, name, NULL);
45
46 if (pp && pp->length == ETH_ALEN && is_valid_ether_addr(pp->value))
47 return pp->value;
48 return NULL;
49 }
50
51 /**
52 * Search the device tree for the best MAC address to use. 'mac-address' is
53 * checked first, because that is supposed to contain to "most recent" MAC
54 * address. If that isn't set, then 'local-mac-address' is checked next,
55 * because that is the default address. If that isn't set, then the obsolete
56 * 'address' is checked, just in case we're using an old device tree.
57 *
58 * Note that the 'address' property is supposed to contain a virtual address of
59 * the register set, but some DTS files have redefined that property to be the
60 * MAC address.
61 *
62 * All-zero MAC addresses are rejected, because those could be properties that
63 * exist in the device tree, but were not set by U-Boot. For example, the
64 * DTS could define 'mac-address' and 'local-mac-address', with zero MAC
65 * addresses. Some older U-Boots only initialized 'local-mac-address'. In
66 * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
67 * but is all zeros.
68 */
of_get_mac_address(struct device_node * np)69 const void *of_get_mac_address(struct device_node *np)
70 {
71 const void *addr;
72
73 addr = of_get_mac_addr(np, "mac-address");
74 if (addr)
75 return addr;
76
77 addr = of_get_mac_addr(np, "local-mac-address");
78 if (addr)
79 return addr;
80
81 return of_get_mac_addr(np, "address");
82 }
83 EXPORT_SYMBOL(of_get_mac_address);
84
85 /**
86 * Obtain the MAC address from an nvmem provider named 'mac-address' through
87 * device tree.
88 * On success, copies the new address into memory pointed to by addr and
89 * returns 0. Returns a negative error code otherwise.
90 * @np: Device tree node containing the nvmem-cells phandle
91 * @addr: Pointer to receive the MAC address using ether_addr_copy()
92 */
of_get_nvmem_mac_address(struct device_node * np,void * addr)93 int of_get_nvmem_mac_address(struct device_node *np, void *addr)
94 {
95 struct nvmem_cell *cell;
96 const void *mac;
97 size_t len;
98 int ret;
99
100 cell = of_nvmem_cell_get(np, "mac-address");
101 if (IS_ERR(cell))
102 return PTR_ERR(cell);
103
104 mac = nvmem_cell_read(cell, &len);
105
106 nvmem_cell_put(cell);
107
108 if (IS_ERR(mac))
109 return PTR_ERR(mac);
110
111 if (len < ETH_ALEN || !is_valid_ether_addr(mac)) {
112 ret = -EINVAL;
113 } else {
114 ether_addr_copy(addr, mac);
115 ret = 0;
116 }
117
118 kfree(mac);
119
120 return ret;
121 }
122 EXPORT_SYMBOL(of_get_nvmem_mac_address);
123
