1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * OF helpers for network devices.
4 *
5 * Initially copied out of arch/powerpc/kernel/prom_parse.c
6 */
7 #include <linux/etherdevice.h>
8 #include <linux/kernel.h>
9 #include <linux/of_net.h>
10 #include <linux/of_platform.h>
11 #include <linux/platform_device.h>
12 #include <linux/phy.h>
13 #include <linux/export.h>
14 #include <linux/device.h>
15 #include <linux/nvmem-consumer.h>
16
17 /**
18 * of_get_phy_mode - Get phy mode for given device_node
19 * @np: Pointer to the given device_node
20 * @interface: Pointer to the result
21 *
22 * The function gets phy interface string from property 'phy-mode' or
23 * 'phy-connection-type'. The index in phy_modes table is set in
24 * interface and 0 returned. In case of error interface is set to
25 * PHY_INTERFACE_MODE_NA and an errno is returned, e.g. -ENODEV.
26 */
27 int of_get_phy_mode(struct device_node *np, phy_interface_t *interface)
28 {
29 const char *pm;
30 int err, i;
31
32 *interface = PHY_INTERFACE_MODE_NA;
33
34 err = of_property_read_string(np, "phy-mode", &pm);
35 if (err < 0)
36 err = of_property_read_string(np, "phy-connection-type", &pm);
37 if (err < 0)
38 return err;
39
40 for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
41 if (!strcasecmp(pm, phy_modes(i))) {
42 *interface = i;
43 return 0;
44 }
45
46 return -ENODEV;
47 }
48 EXPORT_SYMBOL_GPL(of_get_phy_mode);
49
50 static int of_get_mac_addr(struct device_node *np, const char *name, u8 *addr)
51 {
52 struct property *pp = of_find_property(np, name, NULL);
53
54 if (pp && pp->length == ETH_ALEN && is_valid_ether_addr(pp->value)) {
55 memcpy(addr, pp->value, ETH_ALEN);
56 return 0;
57 }
58 return -ENODEV;
59 }
60
61 int of_get_mac_address_nvmem(struct device_node *np, u8 *addr)
62 {
63 struct platform_device *pdev = of_find_device_by_node(np);
64 struct nvmem_cell *cell;
65 const void *mac;
66 size_t len;
67 int ret;
68
69 /* Try lookup by device first, there might be a nvmem_cell_lookup
70 * associated with a given device.
71 */
72 if (pdev) {
73 ret = nvmem_get_mac_address(&pdev->dev, addr);
74 put_device(&pdev->dev);
75 return ret;
76 }
77
78 cell = of_nvmem_cell_get(np, "mac-address");
79 if (IS_ERR(cell))
80 return PTR_ERR(cell);
81
82 mac = nvmem_cell_read(cell, &len);
83 nvmem_cell_put(cell);
84
85 if (IS_ERR(mac))
86 return PTR_ERR(mac);
87
88 if (len != ETH_ALEN || !is_valid_ether_addr(mac)) {
89 kfree(mac);
90 return -EINVAL;
91 }
92
93 memcpy(addr, mac, ETH_ALEN);
94 kfree(mac);
95
96 return 0;
97 }
98 EXPORT_SYMBOL(of_get_mac_address_nvmem);
99
100 /**
101 * of_get_mac_address()
102 * @np: Caller's Device Node
103 * @addr: Pointer to a six-byte array for the result
104 *
105 * Search the device tree for the best MAC address to use. 'mac-address' is
106 * checked first, because that is supposed to contain to "most recent" MAC
107 * address. If that isn't set, then 'local-mac-address' is checked next,
108 * because that is the default address. If that isn't set, then the obsolete
109 * 'address' is checked, just in case we're using an old device tree. If any
110 * of the above isn't set, then try to get MAC address from nvmem cell named
111 * 'mac-address'.
112 *
113 * Note that the 'address' property is supposed to contain a virtual address of
114 * the register set, but some DTS files have redefined that property to be the
115 * MAC address.
116 *
117 * All-zero MAC addresses are rejected, because those could be properties that
118 * exist in the device tree, but were not set by U-Boot. For example, the
119 * DTS could define 'mac-address' and 'local-mac-address', with zero MAC
120 * addresses. Some older U-Boots only initialized 'local-mac-address'. In
121 * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
122 * but is all zeros.
123 *
124 * Return: 0 on success and errno in case of error.
125 */
126 int of_get_mac_address(struct device_node *np, u8 *addr)
127 {
128 int ret;
129
130 if (!np)
131 return -ENODEV;
132
133 ret = of_get_mac_addr(np, "mac-address", addr);
134 if (!ret)
135 return 0;
136
137 ret = of_get_mac_addr(np, "local-mac-address", addr);
138 if (!ret)
139 return 0;
140
141 ret = of_get_mac_addr(np, "address", addr);
142 if (!ret)
143 return 0;
144
145 return of_get_mac_address_nvmem(np, addr);
146 }
147 EXPORT_SYMBOL(of_get_mac_address);
148
149 /**
150 * of_get_ethdev_address()
151 * @np: Caller's Device Node
152 * @dev: Pointer to netdevice which address will be updated
153 *
154 * Search the device tree for the best MAC address to use.
155 * If found set @dev->dev_addr to that address.
156 *
157 * See documentation of of_get_mac_address() for more information on how
158 * the best address is determined.
159 *
160 * Return: 0 on success and errno in case of error.
161 */
162 int of_get_ethdev_address(struct device_node *np, struct net_device *dev)
163 {
164 u8 addr[ETH_ALEN];
165 int ret;
166
167 ret = of_get_mac_address(np, addr);
168 if (!ret)
169 eth_hw_addr_set(dev, addr);
170 return ret;
171 }
172 EXPORT_SYMBOL(of_get_ethdev_address);
173
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