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/of_platform.h>
  12 #include <linux/phy.h>
  13 #include <linux/export.h>
  14 #include <linux/device.h>
  15
  16 /**
  17  * of_get_phy_mode - Get phy mode for given device_node
  18  * @np: Pointer to the given device_node
  19  *
  20  * The function gets phy interface string from property 'phy-mode' or
  21  * 'phy-connection-type', and return its index in phy_modes table, or errno in
  22  * error case.
  23  */
  24 int of_get_phy_mode(struct device_node *np)
  25 {
  26         const char *pm;
  27         int err, i;
  28
  29         err = of_property_read_string(np, "phy-mode", &pm);
  30         if (err < 0)
  31                 err = of_property_read_string(np, "phy-connection-type", &pm);
  32         if (err < 0)
  33                 return err;
  34
  35         for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
  36                 if (!strcasecmp(pm, phy_modes(i)))
  37                         return i;
  38
  39         return -ENODEV;
  40 }
  41 EXPORT_SYMBOL_GPL(of_get_phy_mode);
  42
  43 static const void *of_get_mac_addr(struct device_node *np, const char *name)
  44 {
  45         struct property *pp = of_find_property(np, name, NULL);
  46
  47         if (pp && pp->length == ETH_ALEN && is_valid_ether_addr(pp->value))
  48                 return pp->value;
  49         return NULL;
  50 }
  51
  52 static const void *of_get_mac_addr_nvmem(struct device_node *np)
  53 {
  54         int ret;
  55         const void *mac;
  56         u8 nvmem_mac[ETH_ALEN];
  57         struct platform_device *pdev = of_find_device_by_node(np);
  58
  59         if (!pdev)
  60                 return ERR_PTR(-ENODEV);
  61
  62         ret = nvmem_get_mac_address(&pdev->dev, &nvmem_mac);
  63         if (ret) {
  64                 put_device(&pdev->dev);
  65                 return ERR_PTR(ret);
  66         }
  67
  68         mac = devm_kmemdup(&pdev->dev, nvmem_mac, ETH_ALEN, GFP_KERNEL);
  69         put_device(&pdev->dev);
  70         if (!mac)
  71                 return ERR_PTR(-ENOMEM);
  72
  73         return mac;
  74 }
  75
  76 /**
  77  * Search the device tree for the best MAC address to use.  'mac-address' is
  78  * checked first, because that is supposed to contain to "most recent" MAC
  79  * address. If that isn't set, then 'local-mac-address' is checked next,
  80  * because that is the default address. If that isn't set, then the obsolete
  81  * 'address' is checked, just in case we're using an old device tree. If any
  82  * of the above isn't set, then try to get MAC address from nvmem cell named
  83  * 'mac-address'.
  84  *
  85  * Note that the 'address' property is supposed to contain a virtual address of
  86  * the register set, but some DTS files have redefined that property to be the
  87  * MAC address.
  88  *
  89  * All-zero MAC addresses are rejected, because those could be properties that
  90  * exist in the device tree, but were not set by U-Boot.  For example, the
  91  * DTS could define 'mac-address' and 'local-mac-address', with zero MAC
  92  * addresses.  Some older U-Boots only initialized 'local-mac-address'.  In
  93  * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
  94  * but is all zeros.
  95  *
  96  * Return: Will be a valid pointer on success and ERR_PTR in case of error.
  97 */
  98 const void *of_get_mac_address(struct device_node *np)
  99 {
 100         const void *addr;
 101
 102         addr = of_get_mac_addr(np, "mac-address");
 103         if (addr)
 104                 return addr;
 105
 106         addr = of_get_mac_addr(np, "local-mac-address");
 107         if (addr)
 108                 return addr;
 109
 110         addr = of_get_mac_addr(np, "address");
 111         if (addr)
 112                 return addr;
 113
 114         return of_get_mac_addr_nvmem(np);
 115 }
 116 EXPORT_SYMBOL(of_get_mac_address);