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/platform_device.h>
 12#include <linux/phy.h>
 13#include <linux/export.h>
 14#include <linux/device.h>
 15#include <linux/nvmem-consumer.h>
 16
 17/**
 18 * of_get_phy_mode - Get phy mode for given device_node
 19 * @np:	Pointer to the given device_node
 20 * @interface: Pointer to the result
 21 *
 22 * The function gets phy interface string from property 'phy-mode' or
 23 * 'phy-connection-type'. The index in phy_modes table is set in
 24 * interface and 0 returned. In case of error interface is set to
 25 * PHY_INTERFACE_MODE_NA and an errno is returned, e.g. -ENODEV.
 26 */
 27int of_get_phy_mode(struct device_node *np, phy_interface_t *interface)
 28{
 29	const char *pm;
 30	int err, i;
 31
 32	*interface = PHY_INTERFACE_MODE_NA;
 33
 34	err = of_property_read_string(np, "phy-mode", &pm);
 35	if (err < 0)
 36		err = of_property_read_string(np, "phy-connection-type", &pm);
 37	if (err < 0)
 38		return err;
 39
 40	for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
 41		if (!strcasecmp(pm, phy_modes(i))) {
 42			*interface = i;
 43			return 0;
 44		}
 45
 46	return -ENODEV;
 47}
 48EXPORT_SYMBOL_GPL(of_get_phy_mode);
 49
 50static int of_get_mac_addr(struct device_node *np, const char *name, u8 *addr)
 51{
 52	struct property *pp = of_find_property(np, name, NULL);
 53
 54	if (pp && pp->length == ETH_ALEN && is_valid_ether_addr(pp->value)) {
 55		memcpy(addr, pp->value, ETH_ALEN);
 56		return 0;
 57	}
 58	return -ENODEV;
 59}
 60
 61int of_get_mac_address_nvmem(struct device_node *np, u8 *addr)
 62{
 63	struct platform_device *pdev = of_find_device_by_node(np);
 64	struct nvmem_cell *cell;
 65	const void *mac;
 66	size_t len;
 67	int ret;
 68
 69	/* Try lookup by device first, there might be a nvmem_cell_lookup
 70	 * associated with a given device.
 71	 */
 72	if (pdev) {
 73		ret = nvmem_get_mac_address(&pdev->dev, addr);
 74		put_device(&pdev->dev);
 75		return ret;
 76	}
 77
 78	cell = of_nvmem_cell_get(np, "mac-address");
 79	if (IS_ERR(cell))
 80		return PTR_ERR(cell);
 81
 82	mac = nvmem_cell_read(cell, &len);
 83	nvmem_cell_put(cell);
 84
 85	if (IS_ERR(mac))
 86		return PTR_ERR(mac);
 87
 88	if (len != ETH_ALEN || !is_valid_ether_addr(mac)) {
 89		kfree(mac);
 90		return -EINVAL;
 91	}
 92
 93	memcpy(addr, mac, ETH_ALEN);
 94	kfree(mac);
 95
 96	return 0;
 97}
 98EXPORT_SYMBOL(of_get_mac_address_nvmem);
 99
100/**
101 * of_get_mac_address()
102 * @np:		Caller's Device Node
103 * @addr:	Pointer to a six-byte array for the result
104 *
105 * Search the device tree for the best MAC address to use.  'mac-address' is
106 * checked first, because that is supposed to contain to "most recent" MAC
107 * address. If that isn't set, then 'local-mac-address' is checked next,
108 * because that is the default address. If that isn't set, then the obsolete
109 * 'address' is checked, just in case we're using an old device tree. If any
110 * of the above isn't set, then try to get MAC address from nvmem cell named
111 * 'mac-address'.
112 *
113 * Note that the 'address' property is supposed to contain a virtual address of
114 * the register set, but some DTS files have redefined that property to be the
115 * MAC address.
116 *
117 * All-zero MAC addresses are rejected, because those could be properties that
118 * exist in the device tree, but were not set by U-Boot.  For example, the
119 * DTS could define 'mac-address' and 'local-mac-address', with zero MAC
120 * addresses.  Some older U-Boots only initialized 'local-mac-address'.  In
121 * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
122 * but is all zeros.
123 *
124 * Return: 0 on success and errno in case of error.
125*/
126int of_get_mac_address(struct device_node *np, u8 *addr)
127{
128	int ret;
129
130	if (!np)
131		return -ENODEV;
132
133	ret = of_get_mac_addr(np, "mac-address", addr);
134	if (!ret)
135		return 0;
136
137	ret = of_get_mac_addr(np, "local-mac-address", addr);
138	if (!ret)
139		return 0;
140
141	ret = of_get_mac_addr(np, "address", addr);
142	if (!ret)
143		return 0;
144
145	return of_get_mac_address_nvmem(np, addr);
146}
147EXPORT_SYMBOL(of_get_mac_address);
148
149/**
150 * of_get_ethdev_address()
151 * @np:		Caller's Device Node
152 * @dev:	Pointer to netdevice which address will be updated
153 *
154 * Search the device tree for the best MAC address to use.
155 * If found set @dev->dev_addr to that address.
156 *
157 * See documentation of of_get_mac_address() for more information on how
158 * the best address is determined.
159 *
160 * Return: 0 on success and errno in case of error.
161 */
162int of_get_ethdev_address(struct device_node *np, struct net_device *dev)
163{
164	u8 addr[ETH_ALEN];
165	int ret;
166
167	ret = of_get_mac_address(np, addr);
168	if (!ret)
169		eth_hw_addr_set(dev, addr);
170	return ret;
171}
172EXPORT_SYMBOL(of_get_ethdev_address);