1/*
  2 * OF helpers for network devices.
  3 *
  4 * This file is released under the GPLv2
  5 *
  6 * Initially copied out of arch/powerpc/kernel/prom_parse.c
  7 */
  8#include <linux/etherdevice.h>
  9#include <linux/kernel.h>
 10#include <linux/nvmem-consumer.h>
 11#include <linux/of_net.h>
 12#include <linux/phy.h>
 13#include <linux/export.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
 51/**
 52 * Search the device tree for the best MAC address to use.  'mac-address' is
 53 * checked first, because that is supposed to contain to "most recent" MAC
 54 * address. If that isn't set, then 'local-mac-address' is checked next,
 55 * because that is the default address.  If that isn't set, then the obsolete
 56 * 'address' is checked, just in case we're using an old device tree.
 57 *
 58 * Note that the 'address' property is supposed to contain a virtual address of
 59 * the register set, but some DTS files have redefined that property to be the
 60 * MAC address.
 61 *
 62 * All-zero MAC addresses are rejected, because those could be properties that
 63 * exist in the device tree, but were not set by U-Boot.  For example, the
 64 * DTS could define 'mac-address' and 'local-mac-address', with zero MAC
 65 * addresses.  Some older U-Boots only initialized 'local-mac-address'.  In
 66 * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
 67 * but is all zeros.
 68*/
 69const void *of_get_mac_address(struct device_node *np)
 70{
 71	const void *addr;
 72
 73	addr = of_get_mac_addr(np, "mac-address");
 74	if (addr)
 75		return addr;
 76
 77	addr = of_get_mac_addr(np, "local-mac-address");
 78	if (addr)
 79		return addr;
 80
 81	return of_get_mac_addr(np, "address");
 82}
 83EXPORT_SYMBOL(of_get_mac_address);
 84
 85/**
 86 * Obtain the MAC address from an nvmem provider named 'mac-address' through
 87 * device tree.
 88 * On success, copies the new address into memory pointed to by addr and
 89 * returns 0. Returns a negative error code otherwise.
 90 * @np:		Device tree node containing the nvmem-cells phandle
 91 * @addr:	Pointer to receive the MAC address using ether_addr_copy()
 92 */
 93int of_get_nvmem_mac_address(struct device_node *np, void *addr)
 94{
 95	struct nvmem_cell *cell;
 96	const void *mac;
 97	size_t len;
 98	int ret;
 99
100	cell = of_nvmem_cell_get(np, "mac-address");
101	if (IS_ERR(cell))
102		return PTR_ERR(cell);
103
104	mac = nvmem_cell_read(cell, &len);
105
106	nvmem_cell_put(cell);
107
108	if (IS_ERR(mac))
109		return PTR_ERR(mac);
110
111	if (len < ETH_ALEN || !is_valid_ether_addr(mac)) {
112		ret = -EINVAL;
113	} else {
114		ether_addr_copy(addr, mac);
115		ret = 0;
116	}
117
118	kfree(mac);
119
120	return ret;
121}
122EXPORT_SYMBOL(of_get_nvmem_mac_address);