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 * @interface: Pointer to the result
 19 *
 20 * The function gets phy interface string from property 'phy-mode' or
 21 * 'phy-connection-type'. The index in phy_modes table is set in
 22 * interface and 0 returned. In case of error interface is set to
 23 * PHY_INTERFACE_MODE_NA and an errno is returned, e.g. -ENODEV.
 24 */
 25int of_get_phy_mode(struct device_node *np, phy_interface_t *interface)
 26{
 27	const char *pm;
 28	int err, i;
 29
 30	*interface = PHY_INTERFACE_MODE_NA;
 31
 32	err = of_property_read_string(np, "phy-mode", &pm);
 33	if (err < 0)
 34		err = of_property_read_string(np, "phy-connection-type", &pm);
 35	if (err < 0)
 36		return err;
 37
 38	for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
 39		if (!strcasecmp(pm, phy_modes(i))) {
 40			*interface = i;
 41			return 0;
 42		}
 43
 44	return -ENODEV;
 45}
 46EXPORT_SYMBOL_GPL(of_get_phy_mode);
 47
 48static const void *of_get_mac_addr(struct device_node *np, const char *name)
 49{
 50	struct property *pp = of_find_property(np, name, NULL);
 51
 52	if (pp && pp->length == ETH_ALEN && is_valid_ether_addr(pp->value))
 53		return pp->value;
 54	return NULL;
 55}
 56
 57static const void *of_get_mac_addr_nvmem(struct device_node *np)
 58{
 59	int ret;
 60	const void *mac;
 61	u8 nvmem_mac[ETH_ALEN];
 62	struct platform_device *pdev = of_find_device_by_node(np);
 63
 64	if (!pdev)
 65		return ERR_PTR(-ENODEV);
 66
 67	ret = nvmem_get_mac_address(&pdev->dev, &nvmem_mac);
 68	if (ret) {
 69		put_device(&pdev->dev);
 70		return ERR_PTR(ret);
 71	}
 72
 73	mac = devm_kmemdup(&pdev->dev, nvmem_mac, ETH_ALEN, GFP_KERNEL);
 74	put_device(&pdev->dev);
 75	if (!mac)
 76		return ERR_PTR(-ENOMEM);
 77
 78	return mac;
 79}
 80
 81/**
 82 * Search the device tree for the best MAC address to use.  'mac-address' is
 83 * checked first, because that is supposed to contain to "most recent" MAC
 84 * address. If that isn't set, then 'local-mac-address' is checked next,
 85 * because that is the default address. If that isn't set, then the obsolete
 86 * 'address' is checked, just in case we're using an old device tree. If any
 87 * of the above isn't set, then try to get MAC address from nvmem cell named
 88 * 'mac-address'.
 89 *
 90 * Note that the 'address' property is supposed to contain a virtual address of
 91 * the register set, but some DTS files have redefined that property to be the
 92 * MAC address.
 93 *
 94 * All-zero MAC addresses are rejected, because those could be properties that
 95 * exist in the device tree, but were not set by U-Boot.  For example, the
 96 * DTS could define 'mac-address' and 'local-mac-address', with zero MAC
 97 * addresses.  Some older U-Boots only initialized 'local-mac-address'.  In
 98 * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
 99 * but is all zeros.
100 *
101 * Return: Will be a valid pointer on success and ERR_PTR in case of error.
102*/
103const void *of_get_mac_address(struct device_node *np)
104{
105	const void *addr;
106
107	addr = of_get_mac_addr(np, "mac-address");
108	if (addr)
109		return addr;
110
111	addr = of_get_mac_addr(np, "local-mac-address");
112	if (addr)
113		return addr;
114
115	addr = of_get_mac_addr(np, "address");
116	if (addr)
117		return addr;
118
119	return of_get_mac_addr_nvmem(np);
120}
121EXPORT_SYMBOL(of_get_mac_address);