From: Yousong Zhou <yszhou4tech@gmail.com>
Subject: [PATCH] ath79: add nvmem cell mac-address-ascii support

This is needed for devices with mac address stored in ascii format, e.g.
HiWiFi HC6361 to be ported in the following patch.

Submitted-by: Yousong Zhou <yszhou4tech@gmail.com>
---
 net/ethernet/eth.c                            | 83 ++++++++++++------
 1 files changed, 72 insertions(+), 11 deletions(-)

--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -539,6 +539,63 @@ int eth_platform_get_mac_address(struct
 }
 EXPORT_SYMBOL(eth_platform_get_mac_address);
 
+static void *nvmem_cell_get_mac_address(struct nvmem_cell *cell)
+{
+	size_t len;
+	void *mac;
+
+	mac = nvmem_cell_read(cell, &len);
+	if (IS_ERR(mac))
+		return mac;
+	if (len != ETH_ALEN) {
+		kfree(mac);
+		return ERR_PTR(-EINVAL);
+	}
+	return mac;
+}
+
+static void *nvmem_cell_get_mac_address_ascii(struct nvmem_cell *cell)
+{
+	size_t len;
+	int ret;
+	void *mac_ascii;
+	u8 *mac;
+
+	mac_ascii = nvmem_cell_read(cell, &len);
+	if (IS_ERR(mac_ascii))
+		return mac_ascii;
+	if (len != ETH_ALEN*2+5) {
+		kfree(mac_ascii);
+		return ERR_PTR(-EINVAL);
+	}
+	mac = kmalloc(ETH_ALEN, GFP_KERNEL);
+	if (!mac) {
+		kfree(mac_ascii);
+		return ERR_PTR(-ENOMEM);
+	}
+	ret = sscanf(mac_ascii, "%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:%2hhx",
+				&mac[0], &mac[1], &mac[2],
+				&mac[3], &mac[4], &mac[5]);
+	kfree(mac_ascii);
+	if (ret == ETH_ALEN)
+		return mac;
+	kfree(mac);
+	return ERR_PTR(-EINVAL);
+}
+
+static struct nvmem_cell_mac_address_property {
+	char *name;
+	void *(*read)(struct nvmem_cell *);
+} nvmem_cell_mac_address_properties[] = {
+	{
+		.name = "mac-address",
+		.read = nvmem_cell_get_mac_address,
+	}, {
+		.name = "mac-address-ascii",
+		.read = nvmem_cell_get_mac_address_ascii,
+	},
+};
+
 /**
  * Obtain the MAC address from an nvmem cell named 'mac-address' associated
  * with given device.
@@ -552,19 +609,23 @@ int nvmem_get_mac_address(struct device
 {
 	struct nvmem_cell *cell;
 	const void *mac;
-	size_t len;
+	struct nvmem_cell_mac_address_property *property;
+	int i;
 
-	cell = nvmem_cell_get(dev, "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);
+	for (i = 0; i < ARRAY_SIZE(nvmem_cell_mac_address_properties); i++) {
+		property = &nvmem_cell_mac_address_properties[i];
+		cell = nvmem_cell_get(dev, property->name);
+		if (IS_ERR(cell)) {
+			if (i == ARRAY_SIZE(nvmem_cell_mac_address_properties) - 1)
+				return PTR_ERR(cell);
+			continue;
+		}
+		mac = property->read(cell);
+		nvmem_cell_put(cell);
+		break;
+	}
 
-	if (len != ETH_ALEN || !is_valid_ether_addr(mac)) {
+	if (!is_valid_ether_addr(mac)) {
 		kfree(mac);
 		return -EINVAL;
 	}