of_net.c 2.4 KB

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