LXR linux/drivers/of/of

   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/nvmem-consumer.h>
  11#include <linux/of_net.h>
  12#include <linux/phy.h>
  13#include <linux/export.h>
  14
  15/**
  16 * of_get_phy_mode - Get phy mode for given device_node
  17 * @np: Pointer to the given device_node
  18 *
  19 * The function gets phy interface string from property 'phy-mode' or
  20 * 'phy-connection-type', and return its index in phy_modes table, or errno in
  21 * error case.
  22 */
  23int of_get_phy_mode(struct device_node *np)
  24{
  25        const char *pm;
  26        int err, i;
  27
  28        err = of_property_read_string(np, "phy-mode", &pm);
  29        if (err < 0)
  30                err = of_property_read_string(np, "phy-connection-type", &pm);
  31        if (err < 0)
  32                return err;
  33
  34        for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
  35                if (!strcasecmp(pm, phy_modes(i)))
  36                        return i;
  37
  38        return -ENODEV;
  39}
  40EXPORT_SYMBOL_GPL(of_get_phy_mode);
  41
  42static const void *of_get_mac_addr(struct device_node *np, const char *name)
  43{
  44        struct property *pp = of_find_property(np, name, NULL);
  45
  46        if (pp && pp->length == ETH_ALEN && is_valid_ether_addr(pp->value))
  47                return pp->value;
  48        return NULL;
  49}
  50
  51/**
  52 * Search the device tree for the best MAC address to use.  'mac-address' is
  53 * checked first, because that is supposed to contain to "most recent" MAC
  54 * address. If that isn't set, then 'local-mac-address' is checked next,
  55 * because that is the default address.  If that isn't set, then the obsolete
  56 * 'address' is checked, just in case we're using an old device tree.
  57 *
  58 * Note that the 'address' property is supposed to contain a virtual address of
  59 * the register set, but some DTS files have redefined that property to be the
  60 * MAC address.
  61 *
  62 * All-zero MAC addresses are rejected, because those could be properties that
  63 * exist in the device tree, but were not set by U-Boot.  For example, the
  64 * DTS could define 'mac-address' and 'local-mac-address', with zero MAC
  65 * addresses.  Some older U-Boots only initialized 'local-mac-address'.  In
  66 * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
  67 * but is all zeros.
  68*/
  69const void *of_get_mac_address(struct device_node *np)
  70{
  71        const void *addr;
  72
  73        addr = of_get_mac_addr(np, "mac-address");
  74        if (addr)
  75                return addr;
  76
  77        addr = of_get_mac_addr(np, "local-mac-address");
  78        if (addr)
  79                return addr;
  80
  81        return of_get_mac_addr(np, "address");
  82}
  83EXPORT_SYMBOL(of_get_mac_address);
  84
  85/**
  86 * Obtain the MAC address from an nvmem provider named 'mac-address' through
  87 * device tree.
  88 * On success, copies the new address into memory pointed to by addr and
  89 * returns 0. Returns a negative error code otherwise.
  90 * @np:         Device tree node containing the nvmem-cells phandle
  91 * @addr:       Pointer to receive the MAC address using ether_addr_copy()
  92 */
  93int of_get_nvmem_mac_address(struct device_node *np, void *addr)
  94{
  95        struct nvmem_cell *cell;
  96        const void *mac;
  97        size_t len;
  98        int ret;
  99
 100        cell = of_nvmem_cell_get(np, "mac-address");
 101        if (IS_ERR(cell))
 102                return PTR_ERR(cell);
 103
 104        mac = nvmem_cell_read(cell, &len);
 105
 106        nvmem_cell_put(cell);
 107
 108        if (IS_ERR(mac))
 109                return PTR_ERR(mac);
 110
 111        if (len < ETH_ALEN || !is_valid_ether_addr(mac)) {
 112                ret = -EINVAL;
 113        } else {
 114                ether_addr_copy(addr, mac);
 115                ret = 0;
 116        }
 117
 118        kfree(mac);
 119
 120        return ret;
 121}
 122EXPORT_SYMBOL(of_get_nvmem_mac_address);
 123