net/core/of_net.c

   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);