drivers/of/of_net.c

   1 /*
   2  * OF helpers for network devices.
   3  *
   4  * This file is released under the GPLv2
   5  *
   6  * Initially copied out of arch/powerpc/kernel/prom_parse.c
   7  */
   8 #include <linux/etherdevice.h>
   9 #include <linux/kernel.h>
  10 #include <linux/of_net.h>
  11 #include <linux/phy.h>
  12 #include <linux/export.h>
  13
  14 /**
  15  * of_get_phy_mode - Get phy mode for given device_node
  16  * @np: Pointer to the given device_node
  17  *
  18  * The function gets phy interface string from property 'phy-mode' or
  19  * 'phy-connection-type', and return its index in phy_modes table, or errno in
  20  * error case.
  21  */
  22 int of_get_phy_mode(struct device_node *np)
  23 {
  24         const char *pm;
  25         int err, i;
  26
  27         err = of_property_read_string(np, "phy-mode", &pm);
  28         if (err < 0)
  29                 err = of_property_read_string(np, "phy-connection-type", &pm);
  30         if (err < 0)
  31                 return err;
  32
  33         for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
  34                 if (!strcasecmp(pm, phy_modes(i)))
  35                         return i;
  36
  37         return -ENODEV;
  38 }
  39 EXPORT_SYMBOL_GPL(of_get_phy_mode);
  40
  41 static const void *of_get_mac_addr(struct device_node *np, const char *name)
  42 {
  43         struct property *pp = of_find_property(np, name, NULL);
  44
  45         if (pp && pp->length == ETH_ALEN && is_valid_ether_addr(pp->value))
  46                 return pp->value;
  47         return NULL;
  48 }
  49
  50 /**
  51  * Search the device tree for the best MAC address to use.  'mac-address' is
  52  * checked first, because that is supposed to contain to "most recent" MAC
  53  * address. If that isn't set, then 'local-mac-address' is checked next,
  54  * because that is the default address.  If that isn't set, then the obsolete
  55  * 'address' is checked, just in case we're using an old device tree.
  56  *
  57  * Note that the 'address' property is supposed to contain a virtual address of
  58  * the register set, but some DTS files have redefined that property to be the
  59  * MAC address.
  60  *
  61  * All-zero MAC addresses are rejected, because those could be properties that
  62  * exist in the device tree, but were not set by U-Boot.  For example, the
  63  * DTS could define 'mac-address' and 'local-mac-address', with zero MAC
  64  * addresses.  Some older U-Boots only initialized 'local-mac-address'.  In
  65  * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
  66  * but is all zeros.
  67 */
  68 const void *of_get_mac_address(struct device_node *np)
  69 {
  70         const void *addr;
  71
  72         addr = of_get_mac_addr(np, "mac-address");
  73         if (addr)
  74                 return addr;
  75
  76         addr = of_get_mac_addr(np, "local-mac-address");
  77         if (addr)
  78                 return addr;
  79
  80         return of_get_mac_addr(np, "address");
  81 }
  82 EXPORT_SYMBOL(of_get_mac_address);