[PATCH 2/2] net: of: Support adding offset to nvmem MAC addresses

[Linus Walleij]

If a lower-byte MAC address offset is encoded into the device
tree, make sure to add this to the returned address when
looking up a MAC address from NVMEM.

Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
 net/core/of_net.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/net/core/of_net.c b/net/core/of_net.c
index 93ea425b9248a23f4f95a336e9cdbf0053248e32..c98000ec13377ea4b541e182a66be8b1010edc40 100644
--- a/net/core/of_net.c
+++ b/net/core/of_net.c
@@ -64,6 +64,7 @@ int of_get_mac_address_nvmem(struct device_node *np, u8 *addr)
 	struct nvmem_cell *cell;
 	const void *mac;
 	size_t len;
+	u32 offset;
 	int ret;
 
 	/* Try lookup by device first, there might be a nvmem_cell_lookup
@@ -72,7 +73,7 @@ int of_get_mac_address_nvmem(struct device_node *np, u8 *addr)
 	if (pdev) {
 		ret = nvmem_get_mac_address(&pdev->dev, addr);
 		put_device(&pdev->dev);
-		return ret;
+		goto add_offset_exit;
 	}
 
 	cell = of_nvmem_cell_get(np, "mac-address");
@@ -92,8 +93,13 @@ int of_get_mac_address_nvmem(struct device_node *np, u8 *addr)
 
 	memcpy(addr, mac, ETH_ALEN);
 	kfree(mac);
+	ret = 0;
 
-	return 0;
+add_offset_exit:
+	if (!ret && !of_property_read_u32(np, "nvmem-mac-minor-offset", &offset))
+		addr[ETH_ALEN - 1] += offset;
+
+	return ret;
 }
 EXPORT_SYMBOL(of_get_mac_address_nvmem);
 

-- 
2.47.1