[PATCH v2 16/29] net: add support for nvmem to eth_platform_get_mac_address()

Bartosz Golaszewski
2018-08-10T08:05:13Z

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Many non-DT platforms read the MAC address from EEPROM. Usually it's
either done with callbacks defined in board files or from SoC-specific
ethernet drivers.

In order to generalize this, try to read the MAC from nvmem in
eth_platform_get_mac_address() using a standard lookup name:
"mac-address".

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
net/ethernet/eth.c | 38 ++++++++++++++++++++++++++++++++++++++
1 file changed, 38 insertions(+)

diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
index d01dd55de037..f6f6af05fb58 100644
--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -54,6 +54,7 @@
#include <linux/if_ether.h>
#include <linux/of_net.h>
#include <linux/pci.h>
+#include <linux/nvmem-consumer.h>
#include <net/dst.h>
#include <net/arp.h>
#include <net/sock.h>
@@ -557,6 +558,39 @@ static int mac_address_from_arch(u8 *mac_addr)
return 0;
}

+static int mac_address_from_nvmem(struct device *dev, u8 *mac_addr)
+{
+ const unsigned char *addr;
+ struct nvmem_cell *cell;
+ size_t alen;
+ int rv = 0;
+
+ cell = nvmem_cell_get(dev, "mac-address");
+ if (IS_ERR(cell))
+ return PTR_ERR(cell);
+
+ addr = nvmem_cell_read(cell, &alen);
+ if (IS_ERR(addr)) {
+ rv = PTR_ERR(addr);
+ goto put_nvmem;
+ }
+
+ if (alen != ETH_ALEN || !is_valid_ether_addr(addr)) {
+ rv = -ENODEV;
+ goto free_addr;
+ }
+
+ ether_addr_copy(mac_addr, addr);
+
+free_addr:
+ kfree(addr);
+
+put_nvmem:
+ nvmem_cell_put(cell);
+
+ return rv;
+}
+
int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr)
{
int rv;
@@ -569,6 +603,10 @@ int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr)
if (!rv)
return 0;

+ rv = mac_address_from_nvmem(dev, mac_addr);
+ if (!rv)
+ return 0;
+
return -ENODEV;
}
EXPORT_SYMBOL(eth_platform_get_mac_address);
--
2.18.0