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 *mac; 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 mac = nvmem_cell_read(cell, &len); 82 nvmem_cell_put(cell); 83 84 if (IS_ERR(mac)) 85 return PTR_ERR(mac); 86 87 if (len != ETH_ALEN || !is_valid_ether_addr(mac)) { 88 kfree(mac); 89 return -EINVAL; 90 } 91 92 memcpy(addr, mac, ETH_ALEN); 93 kfree(mac); 94 95 return 0; 96 } 97 98 /** 99 * of_get_mac_address() 100 * @np: Caller's Device Node 101 * @addr: Pointer to a six-byte array for the result 102 * 103 * Search the device tree for the best MAC address to use. 'mac-address' is 104 * checked first, because that is supposed to contain to "most recent" MAC 105 * address. If that isn't set, then 'local-mac-address' is checked next, 106 * because that is the default address. If that isn't set, then the obsolete 107 * 'address' is checked, just in case we're using an old device tree. If any 108 * of the above isn't set, then try to get MAC address from nvmem cell named 109 * 'mac-address'. 110 * 111 * Note that the 'address' property is supposed to contain a virtual address of 112 * the register set, but some DTS files have redefined that property to be the 113 * MAC address. 114 * 115 * All-zero MAC addresses are rejected, because those could be properties that 116 * exist in the device tree, but were not set by U-Boot. For example, the 117 * DTS could define 'mac-address' and 'local-mac-address', with zero MAC 118 * addresses. Some older U-Boots only initialized 'local-mac-address'. In 119 * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists 120 * but is all zeros. 121 * 122 * Return: 0 on success and errno in case of error. 123 */ 124 int of_get_mac_address(struct device_node *np, u8 *addr) 125 { 126 int ret; 127 128 if (!np) 129 return -ENODEV; 130 131 ret = of_get_mac_addr(np, "mac-address", addr); 132 if (!ret) 133 return 0; 134 135 ret = of_get_mac_addr(np, "local-mac-address", addr); 136 if (!ret) 137 return 0; 138 139 ret = of_get_mac_addr(np, "address", addr); 140 if (!ret) 141 return 0; 142 143 return of_get_mac_addr_nvmem(np, addr); 144 } 145 EXPORT_SYMBOL(of_get_mac_address); 146 147 /** 148 * of_get_ethdev_address() 149 * @np: Caller's Device Node 150 * @dev: Pointer to netdevice which address will be updated 151 * 152 * Search the device tree for the best MAC address to use. 153 * If found set @dev->dev_addr to that address. 154 * 155 * See documentation of of_get_mac_address() for more information on how 156 * the best address is determined. 157 * 158 * Return: 0 on success and errno in case of error. 159 */ 160 int of_get_ethdev_address(struct device_node *np, struct net_device *dev) 161 { 162 u8 addr[ETH_ALEN]; 163 int ret; 164 165 ret = of_get_mac_address(np, addr); 166 if (!ret) 167 eth_hw_addr_set(dev, addr); 168 return ret; 169 } 170 EXPORT_SYMBOL(of_get_ethdev_address); 171