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// SPDX-License-Identifier: GPL-2.0-only
/*
* OF helpers for network devices.
*
* Initially copied out of arch/powerpc/kernel/prom_parse.c
*/
#include <linux/etherdevice.h>
#include <linux/kernel.h>
#include <linux/of_net.h>
#include <linux/of_platform.h>
#include <linux/phy.h>
#include <linux/export.h>
#include <linux/device.h>
#include <linux/nvmem-consumer.h>
/**
* of_get_phy_mode - Get phy mode for given device_node
* @np: Pointer to the given device_node
* @interface: Pointer to the result
*
* The function gets phy interface string from property 'phy-mode' or
* 'phy-connection-type'. The index in phy_modes table is set in
* interface and 0 returned. In case of error interface is set to
* PHY_INTERFACE_MODE_NA and an errno is returned, e.g. -ENODEV.
*/
int of_get_phy_mode(struct device_node *np, phy_interface_t *interface)
{
const char *pm;
int err, i;
*interface = PHY_INTERFACE_MODE_NA;
err = of_property_read_string(np, "phy-mode", &pm);
if (err < 0)
err = of_property_read_string(np, "phy-connection-type", &pm);
if (err < 0)
return err;
for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
if (!strcasecmp(pm, phy_modes(i))) {
*interface = i;
return 0;
}
return -ENODEV;
}
EXPORT_SYMBOL_GPL(of_get_phy_mode);
static int of_get_mac_addr(struct device_node *np, const char *name, u8 *addr)
{
struct property *pp = of_find_property(np, name, NULL);
if (pp && pp->length == ETH_ALEN && is_valid_ether_addr(pp->value)) {
memcpy(addr, pp->value, ETH_ALEN);
return 0;
}
return -ENODEV;
}
static int of_get_mac_addr_nvmem(struct device_node *np, u8 *addr)
{
struct platform_device *pdev = of_find_device_by_node(np);
struct nvmem_cell *cell;
const void *mac;
size_t len;
int ret;
/* Try lookup by device first, there might be a nvmem_cell_lookup
* associated with a given device.
*/
if (pdev) {
ret = nvmem_get_mac_address(&pdev->dev, addr);
put_device(&pdev->dev);
return ret;
}
cell = of_nvmem_cell_get(np, "mac-address");
if (IS_ERR(cell))
return PTR_ERR(cell);
mac = nvmem_cell_read(cell, &len);
nvmem_cell_put(cell);
if (IS_ERR(mac))
return PTR_ERR(mac);
if (len != ETH_ALEN || !is_valid_ether_addr(mac)) {
kfree(mac);
return -EINVAL;
}
memcpy(addr, mac, ETH_ALEN);
kfree(mac);
return 0;
}
/**
* of_get_mac_address()
* @np: Caller's Device Node
* @addr: Pointer to a six-byte array for the result
*
* Search the device tree for the best MAC address to use. 'mac-address' is
* checked first, because that is supposed to contain to "most recent" MAC
* address. If that isn't set, then 'local-mac-address' is checked next,
* because that is the default address. If that isn't set, then the obsolete
* 'address' is checked, just in case we're using an old device tree. If any
* of the above isn't set, then try to get MAC address from nvmem cell named
* 'mac-address'.
*
* Note that the 'address' property is supposed to contain a virtual address of
* the register set, but some DTS files have redefined that property to be the
* MAC address.
*
* All-zero MAC addresses are rejected, because those could be properties that
* exist in the device tree, but were not set by U-Boot. For example, the
* DTS could define 'mac-address' and 'local-mac-address', with zero MAC
* addresses. Some older U-Boots only initialized 'local-mac-address'. In
* this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
* but is all zeros.
*
* Return: 0 on success and errno in case of error.
*/
int of_get_mac_address(struct device_node *np, u8 *addr)
{
int ret;
if (!np)
return -ENODEV;
ret = of_get_mac_addr(np, "mac-address", addr);
if (!ret)
return 0;
ret = of_get_mac_addr(np, "local-mac-address", addr);
if (!ret)
return 0;
ret = of_get_mac_addr(np, "address", addr);
if (!ret)
return 0;
return of_get_mac_addr_nvmem(np, addr);
}
EXPORT_SYMBOL(of_get_mac_address);