[PATCH] smsc95xx: Add module parameter to override MAC address

[Sebastien Jan <s-jan@ti.com>]

Define a new module parameter 'macaddr' to override the MAC address
fetched either from eeprom, or randomly generated.

The expected MAC address shall be in the 01:23:45:67:89:AB format.

Signed-off-by: Sebastien Jan <s-jan@ti.com>
---
 drivers/net/usb/smsc95xx.c |   56 ++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 56 insertions(+), 0 deletions(-)

diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c
index 3135af6..0ba06d9 100644
--- a/drivers/net/usb/smsc95xx.c
+++ b/drivers/net/usb/smsc95xx.c
@@ -46,6 +46,7 @@
 #define SMSC95XX_INTERNAL_PHY_ID	(1)
 #define SMSC95XX_TX_OVERHEAD		(8)
 #define SMSC95XX_TX_OVERHEAD_CSUM	(12)
+#define MAC_ADDR_LEN			(6)
 
 struct smsc95xx_priv {
 	u32 mac_cr;
@@ -63,6 +64,10 @@ static int turbo_mode = true;
 module_param(turbo_mode, bool, 0644);
 MODULE_PARM_DESC(turbo_mode, "Enable multiple frames per Rx transaction");
 
+static char *macaddr = ":";
+module_param(macaddr, charp, 0);
+MODULE_PARM_DESC(macaddr, "MAC address");
+
 static int smsc95xx_read_reg(struct usbnet *dev, u32 index, u32 *data)
 {
 	u32 *buf = kmalloc(4, GFP_KERNEL);
@@ -637,8 +642,59 @@ static int smsc95xx_ioctl(struct net_device *netdev, struct ifreq *rq, int cmd)
 	return generic_mii_ioctl(&dev->mii, if_mii(rq), cmd, NULL);
 }
 
+/* Check the macaddr module parameter for a MAC address */
+static int smsc95xx_is_macaddr_param(struct usbnet *dev, u8 *dev_mac)
+{
+	int i, j, got_num, num;
+	u8 mtbl[MAC_ADDR_LEN];
+
+	if (macaddr[0] == ':')
+		return 0;
+
+	i = 0;
+	j = 0;
+	num = 0;
+	got_num = 0;
+	while (j < MAC_ADDR_LEN) {
+		if (macaddr[i] && macaddr[i] != ':') {
+			got_num++;
+			if ('0' <= macaddr[i] && macaddr[i] <= '9')
+				num = num * 16 + macaddr[i] - '0';
+			else if ('A' <= macaddr[i] && macaddr[i] <= 'F')
+				num = num * 16 + 10 + macaddr[i] - 'A';
+			else if ('a' <= macaddr[i] && macaddr[i] <= 'f')
+				num = num * 16 + 10 + macaddr[i] - 'a';
+			else
+				break;
+			i++;
+		} else if (got_num == 2) {
+			mtbl[j++] = (u8) num;
+			num = 0;
+			got_num = 0;
+			i++;
+		} else {
+			break;
+		}
+	}
+
+	if (j == MAC_ADDR_LEN && !macaddr[i]) {
+		netif_dbg(dev, ifup, dev->net, "Overriding MAC address with: "
+		"%02x:%02x:%02x:%02x:%02x:%02x\n", mtbl[0], mtbl[1], mtbl[2],
+						mtbl[3], mtbl[4], mtbl[5]);
+		for (i = 0; i < MAC_ADDR_LEN; i++)
+			dev_mac[i] = mtbl[i];
+		return 1;
+	} else {
+		return 0;
+	}
+}
+
 static void smsc95xx_init_mac_address(struct usbnet *dev)
 {
+	/* Check module parameters */
+	if (smsc95xx_is_macaddr_param(dev, dev->net->dev_addr))
+		return;
+
 	/* try reading mac address from EEPROM */
 	if (smsc95xx_read_eeprom(dev, EEPROM_MAC_OFFSET, ETH_ALEN,
 			dev->net->dev_addr) == 0) {
-- 
1.6.3.3