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/phy.h> 12 #include <linux/export.h> 13 #include <linux/device.h> 14 #include <linux/nvmem-consumer.h> 15 16 /** 17 * of_get_phy_mode - Get phy mode for given device_node 18 * @np: Pointer to the given device_node 19 * @interface: Pointer to the result 20 * 21 * The function gets phy interface string from property 'phy-mode' or 22 * 'phy-connection-type'. The index in phy_modes table is set in 23 * interface and 0 returned. In case of error interface is set to 24 * PHY_INTERFACE_MODE_NA and an errno is returned, e.g. -ENODEV. 25 */ 26 int of_get_phy_mode(struct device_node *np, phy_interface_t *interface) 27 { 28 const char *pm; 29 int err, i; 30 31 *interface = PHY_INTERFACE_MODE_NA; 32 33 err = of_property_read_string(np, "phy-mode", &pm); 34 if (err < 0) 35 err = of_property_read_string(np, "phy-connection-type", &pm); 36 if (err < 0) 37 return err; 38 39 for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++) 40 if (!strcasecmp(pm, phy_modes(i))) { 41 *interface = i; 42 return 0; 43 } 44 45 return -ENODEV; 46 } 47 EXPORT_SYMBOL_GPL(of_get_phy_mode); 48 49 static int of_get_mac_addr(struct device_node *np, const char *name, u8 *addr) 50 { 51 struct property *pp = of_find_property(np, name, NULL); 52 53 if (pp && pp->length == ETH_ALEN && is_valid_ether_addr(pp->value)) { 54 memcpy(addr, pp->value, ETH_ALEN); 55 return 0; 56 } 57 return -ENODEV; 58 } 59 60 static int of_get_mac_addr_nvmem(struct device_node *np, u8 *addr) 61 { 62 struct platform_device *pdev = of_find_device_by_node(np); 63 struct nvmem_cell *cell; 64 const void *buf; 65 size_t len; 66 int ret; 67 68 /* Try lookup by device first, there might be a nvmem_cell_lookup 69 * associated with a given device. 70 */ 71 if (pdev) { 72 ret = nvmem_get_mac_address(&pdev->dev, addr); 73 put_device(&pdev->dev); 74 return ret; 75 } 76 77 cell = of_nvmem_cell_get(np, "mac-address"); 78 if (IS_ERR(cell)) 79 return PTR_ERR(cell); 80 81 buf = nvmem_cell_read(cell, &len); 82 nvmem_cell_put(cell); 83 84 if (IS_ERR(buf)) 85 return PTR_ERR(buf); 86 87 ret = 0; 88 if (len == ETH_ALEN) { 89 if (is_valid_ether_addr(buf)) 90 memcpy(addr, buf, ETH_ALEN); 91 else 92 ret = -EINVAL; 93 } else if (len == 3 * ETH_ALEN - 1) { 94 u8 mac[ETH_ALEN]; 95 96 if (mac_pton(buf, mac)) 97 memcpy(addr, mac, ETH_ALEN); 98 else 99 ret = -EINVAL; 100 } else { 101 ret = -EINVAL; 102 } 103 104 kfree(buf); 105 106 return ret; 107 } 108 109 /** 110 * of_get_mac_address() 111 * @np: Caller's Device Node 112 * @addr: Pointer to a six-byte array for the result 113 * 114 * Search the device tree for the best MAC address to use. 'mac-address' is 115 * checked first, because that is supposed to contain to "most recent" MAC 116 * address. If that isn't set, then 'local-mac-address' is checked next, 117 * because that is the default address. If that isn't set, then the obsolete 118 * 'address' is checked, just in case we're using an old device tree. If any 119 * of the above isn't set, then try to get MAC address from nvmem cell named 120 * 'mac-address'. 121 * 122 * Note that the 'address' property is supposed to contain a virtual address of 123 * the register set, but some DTS files have redefined that property to be the 124 * MAC address. 125 * 126 * All-zero MAC addresses are rejected, because those could be properties that 127 * exist in the device tree, but were not set by U-Boot. For example, the 128 * DTS could define 'mac-address' and 'local-mac-address', with zero MAC 129 * addresses. Some older U-Boots only initialized 'local-mac-address'. In 130 * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists 131 * but is all zeros. 132 * 133 * Return: 0 on success and errno in case of error. 134 */ 135 int of_get_mac_address(struct device_node *np, u8 *addr) 136 { 137 int ret; 138 139 if (!np) 140 return -ENODEV; 141 142 ret = of_get_mac_addr(np, "mac-address", addr); 143 if (!ret) 144 return 0; 145 146 ret = of_get_mac_addr(np, "local-mac-address", addr); 147 if (!ret) 148 return 0; 149 150 ret = of_get_mac_addr(np, "address", addr); 151 if (!ret) 152 return 0; 153 154 return of_get_mac_addr_nvmem(np, addr); 155 } 156 EXPORT_SYMBOL(of_get_mac_address); 157 158 /** 159 * of_get_ethdev_address() 160 * @np: Caller's Device Node 161 * @dev: Pointer to netdevice which address will be updated 162 * 163 * Search the device tree for the best MAC address to use. 164 * If found set @dev->dev_addr to that address. 165 * 166 * See documentation of of_get_mac_address() for more information on how 167 * the best address is determined. 168 * 169 * Return: 0 on success and errno in case of error. 170 */ 171 int of_get_ethdev_address(struct device_node *np, struct net_device *dev) 172 { 173 u8 addr[ETH_ALEN]; 174 int ret; 175 176 ret = of_get_mac_address(np, addr); 177 if (!ret) 178 eth_hw_addr_set(dev, addr); 179 return ret; 180 } 181 EXPORT_SYMBOL(of_get_ethdev_address); 182