KS8851: Fix MAC address write order

The MAC address register was being written in the wrong order, so add
a new address macro to convert mac-address byte to register address and
a ks8851_wrreg8() function to write each byte without having to worry
about any difficult byte swapping.

Fixes a bug reported by Doong, Ping of Micrel.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ks8851.c

@@ -170,6 +170,36 @@ static void ks8851_wrreg16(struct ks8851_net *ks, unsigned reg, unsigned val)
 		ks_err(ks, "spi_sync() failed\n");
 }
 
+/**
+ * ks8851_wrreg8 - write 8bit register value to chip
+ * @ks: The chip state
+ * @reg: The register address
+ * @val: The value to write
+ *
+ * Issue a write to put the value @val into the register specified in @reg.
+ */
+static void ks8851_wrreg8(struct ks8851_net *ks, unsigned reg, unsigned val)
+{
+	struct spi_transfer *xfer = &ks->spi_xfer1;
+	struct spi_message *msg = &ks->spi_msg1;
+	__le16 txb[2];
+	int ret;
+	int bit;
+
+	bit = 1 << (reg & 3);
+
+	txb[0] = cpu_to_le16(MK_OP(bit, reg) | KS_SPIOP_WR);
+	txb[1] = val;
+
+	xfer->tx_buf = txb;
+	xfer->rx_buf = NULL;
+	xfer->len = 3;
+
+	ret = spi_sync(ks->spidev, msg);
+	if (ret < 0)
+		ks_err(ks, "spi_sync() failed\n");
+}
+
 /**
  * ks8851_rx_1msg - select whether to use one or two messages for spi read
  * @ks: The device structure
@@ -322,13 +352,12 @@ static void ks8851_soft_reset(struct ks8851_net *ks, unsigned op)
 static int ks8851_write_mac_addr(struct net_device *dev)
 {
 	struct ks8851_net *ks = netdev_priv(dev);
-	u16 *mcp = (u16 *)dev->dev_addr;
+	int i;
 
 	mutex_lock(&ks->lock);
 
-	ks8851_wrreg16(ks, KS_MARL, mcp[0]);
-	ks8851_wrreg16(ks, KS_MARM, mcp[1]);
-	ks8851_wrreg16(ks, KS_MARH, mcp[2]);
+	for (i = 0; i < ETH_ALEN; i++)
+		ks8851_wrreg8(ks, KS_MAR(i), dev->dev_addr[i]);
 
 	mutex_unlock(&ks->lock);
 

drivers/net/ks8851.h

@@ -16,6 +16,7 @@
 #define CCR_32PIN				(1 << 0)
 
 /* MAC address registers */
+#define KS_MAR(_m)				0x15 - (_m)
 #define KS_MARL					0x10
 #define KS_MARM					0x12
 #define KS_MARH					0x14