From: David Bauer <mail@david-bauer.net>
Date: Tue, 20 Jul 2021 22:00:10 +0200
Subject: [PATCH] generic: add mac-address property for NVMEM mac addresses

Traversing the device-tree by referencing a network device to determine
a devices labe-mac does not work with the generic nvmem implementation,
as the userspace expects the MAC-address to be available as a
device-tree property.

The legacy mtd-mac-address implementation did create such a node. Do the
same when using the nvmem implementation to allow reading the MAC
address.

Fixes commit d284e6ef0f06 ("treewide: convert mtd-mac-address-increment*
to generic implementation")

Signed-off-by: David Bauer <mail@david-bauer.net>

--- a/drivers/of/of_net.c
+++ b/drivers/of/of_net.c
@@ -61,6 +61,7 @@ static void *of_get_mac_addr_nvmem(struc
 	void *mac;
 	u8 nvmem_mac[ETH_ALEN];
 	struct platform_device *pdev = of_find_device_by_node(np);
+	struct property *prop;
 
 	if (!pdev) {
 		*err = -ENODEV;
@@ -78,10 +79,29 @@ static void *of_get_mac_addr_nvmem(struc
 	put_device(&pdev->dev);
 	if (!mac) {
 		*err = -ENOMEM;
-		return NULL;
+		goto out_err;
+	}
+
+	prop = devm_kzalloc(&pdev->dev, sizeof(*prop), GFP_KERNEL);
+	if (!prop) {
+		*err = -ENOMEM;
+		goto out_err;
+	}
+	prop->name = "mac-address";
+	prop->length = ETH_ALEN;
+	prop->value = devm_kmemdup(&pdev->dev, mac, ETH_ALEN, GFP_KERNEL);
+	if (!prop->value || of_add_property(np, prop)) {
+		*err = -ENOMEM;
+		goto out_err;
 	}
 
 	return mac;
+
+out_err:
+	devm_kfree(&pdev->dev, prop->value);
+	devm_kfree(&pdev->dev, prop);
+	devm_kfree(&pdev->dev, mac);
+	return NULL;
 }
 
 static void *of_get_mac_address_mtd(struct device_node *np)