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