| 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); |