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);