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Commit 9217e566 authored by Mike Looijmans's avatar Mike Looijmans Committed by David S. Miller
Browse files

of_net: Implement of_get_nvmem_mac_address helper 



It's common practice to store MAC addresses for network interfaces into
nvmem devices. However the code to actually do this in the kernel lacks,
so this patch adds of_get_nvmem_mac_address() for drivers to obtain the
address from an nvmem cell provider.

This is particulary useful on devices where the ethernet interface cannot
be configured by the bootloader, for example because it's in an FPGA.

Signed-off-by: default avatarMike Looijmans <mike.looijmans@topic.nl>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 64e828df

Documentation/devicetree/bindings/net/ethernet.txt

+2 −0
Original line number Diff line number Diff line
@@ -10,6 +10,8 @@ Documentation/devicetree/bindings/phy/phy-bindings.txt. 
  the boot program; should be used in cases where the MAC address assigned to

  the device by the boot program is different from the "local-mac-address"

  property;

- nvmem-cells: phandle, reference to an nvmem node for the MAC address;

- nvmem-cell-names: string, should be "mac-address" if nvmem is to be used;

- max-speed: number, specifies maximum speed in Mbit/s supported by the device;

- max-frame-size: number, maximum transfer unit (IEEE defined MTU), rather than

  the maximum frame size (there's contradiction in the Devicetree

drivers/of/of_net.c

+40 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
 */

#include <linux/etherdevice.h>

#include <linux/kernel.h>

#include <linux/nvmem-consumer.h>

#include <linux/of_net.h>

#include <linux/phy.h>

#include <linux/export.h>
@@ -80,3 +81,42 @@ const void *of_get_mac_address(struct device_node *np) 
	return of_get_mac_addr(np, "address");

}

EXPORT_SYMBOL(of_get_mac_address);



/**

 * Obtain the MAC address from an nvmem provider named 'mac-address' through

 * device tree.

 * On success, copies the new address into memory pointed to by addr and

 * returns 0. Returns a negative error code otherwise.

 * @np:		Device tree node containing the nvmem-cells phandle

 * @addr:	Pointer to receive the MAC address using ether_addr_copy()

 */

int of_get_nvmem_mac_address(struct device_node *np, void *addr)

{

	struct nvmem_cell *cell;

	const void *mac;

	size_t len;

	int 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)) {

		ret = -EINVAL;

	} else {

		ether_addr_copy(addr, mac);

		ret = 0;

	}



	kfree(mac);



	return ret;

}

EXPORT_SYMBOL(of_get_nvmem_mac_address);

include/linux/of_net.h

+6 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
struct net_device;

extern int of_get_phy_mode(struct device_node *np);

extern const void *of_get_mac_address(struct device_node *np);

extern int of_get_nvmem_mac_address(struct device_node *np, void *addr);

extern struct net_device *of_find_net_device_by_node(struct device_node *np);

#else

static inline int of_get_phy_mode(struct device_node *np)
@@ -25,6 +26,11 @@ static inline const void *of_get_mac_address(struct device_node *np) 
	return NULL;

}



static inline int of_get_nvmem_mac_address(struct device_node *np, void *addr)

{

	return -ENODEV;

}



static inline struct net_device *of_find_net_device_by_node(struct device_node *np)

{

	return NULL;