LXR linux/drivers/of/of

   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/phy.h>
  12#include <linux/export.h>
  13#include <linux/device.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
  51static const void *of_get_mac_addr_nvmem(struct device_node *np)
  52{
  53        int ret;
  54        const void *mac;
  55        u8 nvmem_mac[ETH_ALEN];
  56        struct platform_device *pdev = of_find_device_by_node(np);
  57
  58        if (!pdev)
  59                return ERR_PTR(-ENODEV);
  60
  61        ret = nvmem_get_mac_address(&pdev->dev, &nvmem_mac);
  62        if (ret) {
  63                put_device(&pdev->dev);
  64                return ERR_PTR(ret);
  65        }
  66
  67        mac = devm_kmemdup(&pdev->dev, nvmem_mac, ETH_ALEN, GFP_KERNEL);
  68        put_device(&pdev->dev);
  69        if (!mac)
  70                return ERR_PTR(-ENOMEM);
  71
  72        return mac;
  73}
  74
  75/**
  76 * Search the device tree for the best MAC address to use.  'mac-address' is
  77 * checked first, because that is supposed to contain to "most recent" MAC
  78 * address. If that isn't set, then 'local-mac-address' is checked next,
  79 * because that is the default address. If that isn't set, then the obsolete
  80 * 'address' is checked, just in case we're using an old device tree. If any
  81 * of the above isn't set, then try to get MAC address from nvmem cell named
  82 * 'mac-address'.
  83 *
  84 * Note that the 'address' property is supposed to contain a virtual address of
  85 * the register set, but some DTS files have redefined that property to be the
  86 * MAC address.
  87 *
  88 * All-zero MAC addresses are rejected, because those could be properties that
  89 * exist in the device tree, but were not set by U-Boot.  For example, the
  90 * DTS could define 'mac-address' and 'local-mac-address', with zero MAC
  91 * addresses.  Some older U-Boots only initialized 'local-mac-address'.  In
  92 * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
  93 * but is all zeros.
  94 *
  95 * Return: Will be a valid pointer on success and ERR_PTR in case of error.
  96*/
  97const void *of_get_mac_address(struct device_node *np)
  98{
  99        const void *addr;
 100
 101        addr = of_get_mac_addr(np, "mac-address");
 102        if (addr)
 103                return addr;
 104
 105        addr = of_get_mac_addr(np, "local-mac-address");
 106        if (addr)
 107                return addr;
 108
 109        addr = of_get_mac_addr(np, "address");
 110        if (addr)
 111                return addr;
 112
 113        return of_get_mac_addr_nvmem(np);
 114}
 115EXPORT_SYMBOL(of_get_mac_address);
 116