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, propname: "phy-mode" , out_string: &pm); |
35 | if (err < 0) |
36 | err = of_property_read_string(np, propname: "phy-connection-type" , out_string: &pm); |
37 | if (err < 0) |
38 | return err; |
39 | |
40 | for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++) |
41 | if (!strcasecmp(s1: pm, s2: phy_modes(interface: 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(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(dev: &pdev->dev, addrbuf: addr); |
74 | put_device(dev: &pdev->dev); |
75 | return ret; |
76 | } |
77 | |
78 | cell = of_nvmem_cell_get(np, id: "mac-address" ); |
79 | if (IS_ERR(ptr: cell)) |
80 | return PTR_ERR(ptr: cell); |
81 | |
82 | mac = nvmem_cell_read(cell, len: &len); |
83 | nvmem_cell_put(cell); |
84 | |
85 | if (IS_ERR(ptr: mac)) |
86 | return PTR_ERR(ptr: mac); |
87 | |
88 | if (len != ETH_ALEN || !is_valid_ether_addr(addr: mac)) { |
89 | kfree(objp: mac); |
90 | return -EINVAL; |
91 | } |
92 | |
93 | memcpy(addr, mac, ETH_ALEN); |
94 | kfree(objp: 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, name: "mac-address" , addr); |
134 | if (!ret) |
135 | return 0; |
136 | |
137 | ret = of_get_mac_addr(np, name: "local-mac-address" , addr); |
138 | if (!ret) |
139 | return 0; |
140 | |
141 | ret = of_get_mac_addr(np, name: "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 | |