linux/drivers/of/of_net.c
Michael Walle f10843e04a of: net: fix of_get_mac_addr_nvmem() for non-platform devices
of_get_mac_address() already supports fetching the MAC address by an
nvmem provider. But until now, it was just working for platform devices.
Esp. it was not working for DSA ports and PCI devices. It gets more
common that PCI devices have a device tree binding since SoCs contain
integrated root complexes.

Use the nvmem of_* binding to fetch the nvmem cells by a struct
device_node. We still have to try to read the cell by device first
because there might be a nvmem_cell_lookup associated with that device.

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-13 14:35:02 -07:00

146 lines
3.8 KiB
C

// 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);