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