Subject: Re: [PATCH 1/2] add driver for enc28j60 ethernet chip

From: Claudio Lanconelli <[email-masked]>
Date: Thu, 20 Dec 2007 12:47:16 +0100

Here a second version of the patch with applied all changes Jeff and 
Stephen suggest me.
All but NAPI, see comments below at this regard.
Furthermore I fixed also a bug that caused a crash after ifconfig down 
and up cycle and changed the mutex_lock policy.

Jeff Garzik wrote:
>
> comments:
>
> * overall:  a clean driver that looks mostly acceptable, good work
Thanks
> * Why do interrupt work in a kernel thread?  Your comment says you 
> cannot, but does not explain.
The enc28j60 is a SPI to Ethernet adapter, so we cannot access register 
with simple in() out() instructions, but we need to use the SPI 
subsystem. The spi_sync() basic operation to read/write a register is a 
blocking operation, so can't be done in interrupt context.
Since every basic operation like read interrupt flag register call 
spi_sync() we need the work queue for almost everything.

> * should use NAPI
For the reason I just explained I don't think NAPI is a viable way for 
enc28j60.
Furthermore enc28j60 is a 10Mb only device and probably don't suffer to 
interrupt overload.
In my test there are a lot more interrupts from SPI than from enc28j60 
and the enc28j60 interrupts are less than RX+TX packets. See the dump below:

[root@videotron /tmp]# ifconfig
eth0      Link encap:Ethernet  HWaddr 7E:C4:3B:C7:EA:F3
          inet addr:192.168.143.197  Bcast:192.168.143.255  
Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:4972 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2832 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:2009875 (1.9 MiB)  TX bytes:131922 (128.8 KiB)
          Interrupt:18

[root@videotron /tmp]# cat /proc/interrupts
           CPU0
 18:       4316    s3c-ext0  enc28j60
 30:   11591615         s3c  S3C2410 Timer Tick
 32:          0         s3c  s162-lcd
 33:          0         s3c  s3c-mci
 37:         21         s3c  s3c-mci
 38:    2707866         s3c  s3c2410-spi
 42:          0         s3c  ohci_hcd:usb1
 43:         28         s3c  s3c2440-i2c
 45:          1         s3c  s3c2410-spi
 62:          1     s3c-ext  s3c-mci
 73:        342   s3c-uart1  s3c2440-uart
 74:       1225   s3c-uart1  s3c2440-uart
 79:          0     s3c-adc  s3c24xx_action
 80:          0     s3c-adc  s3c24xx_action
Err:          0

I think also USB-ethernet adapter have the same problem, and neither use 
NAPI

Cheers,
Claudio Lanconelli

Signed-off-by: Claudio Lanconelli <[email-masked]>

diff --git a/drivers/net/enc28j60.c b/drivers/net/enc28j60.c
new file mode 100644
index 0000000..0809a6a
--- /dev/null
+++ b/drivers/net/enc28j60.c
@@ -0,0 +1,1600 @@
+/*
+ * Microchip ENC28J60 ethernet driver (MAC + PHY)
+ *
+ * Copyright (C) 2007 Eurek srl
+ * Author: Claudio Lanconelli <[email-masked]>
+ * based on enc28j60.c written by David Anders for 2.4 kernel version
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * $Id: enc28j60.c,v 1.22 2007/12/20 10:47:01 claudio Exp $
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/tcp.h>
+#include <linux/skbuff.h>
+#include <linux/delay.h>
+#include <linux/spi/spi.h>
+
+#include "enc28j60_hw.h"
+
+#define DRV_NAME	"enc28j60"
+#define DRV_VERSION	"1.01"
+
+#define SPI_OPLEN	1
+
+#define ENC28J60_MSG_DEFAULT	\
+	(NETIF_MSG_PROBE | NETIF_MSG_IFUP | NETIF_MSG_IFDOWN | NETIF_MSG_LINK)
+
+/* Buffer size required for the largest SPI transfer (i.e., reading a
+ * frame). */
+#define SPI_TRANSFER_BUF_LEN	(4 + MAX_FRAMELEN)
+
+#define TX_TIMEOUT	(4 * HZ)
+
+/* Max TX retries in case of collision as suggested by errata datasheet */
+#define MAX_TX_RETRYCOUNT	16
+
+enum {
+	RXFILTER_NORMAL,
+	RXFILTER_MULTI,
+	RXFILTER_PROMISC
+};
+
+/* Driver local data */
+struct enc28j60_net {
+	struct net_device *netdev;
+	struct spi_device *spi;
+	struct mutex lock;
+	struct sk_buff *tx_skb;
+	struct work_struct tx_work;
+	struct work_struct irq_work;
+	struct work_struct setrx_work;
+	struct work_struct restart_work;
+	u8 bank;		/* current register bank selected */
+	u16 next_pk_ptr;	/* next packet pointer within FIFO */
+	u16 max_pk_counter;	/* statistics: max packet counter */
+	u16 tx_retry_count;
+	bool hw_enable;
+	bool full_duplex;
+	int rxfilter;
+	u32 msg_enable;
+	u8 spi_transfer_buf[SPI_TRANSFER_BUF_LEN];
+};
+
+/* use ethtool to change the level for any given device */
+static struct {
+	u32 msg_enable;
+} debug = { -1 };
+
+/*
+ * SPI read buffer
+ * wait for the SPI transfer and copy received data to destination
+ */
+static int
+spi_read_buf(struct enc28j60_net *priv, int len, u8 *data)
+{
+	u8 *rx_buf = priv->spi_transfer_buf + 4;
+	u8 *tx_buf = priv->spi_transfer_buf;
+	struct spi_transfer t = {
+		.tx_buf = tx_buf,
+		.rx_buf = rx_buf,
+		.len = SPI_OPLEN + len,
+	};
+	struct spi_message msg;
+	int ret;
+
+	tx_buf[0] = ENC28J60_READ_BUF_MEM;
+	tx_buf[1] = tx_buf[2] = tx_buf[3] = 0;	/* don't care */
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&t, &msg);
+	ret = spi_sync(priv->spi, &msg);
+	if (ret == 0) {
+		memcpy(data, &rx_buf[SPI_OPLEN], len);
+		ret = msg.status;
+	}
+	if (ret && netif_msg_drv(priv))
+		printk(KERN_DEBUG DRV_NAME ": %s() failed: ret = %d\n",
+			__FUNCTION__, ret);
+
+	return ret;
+}
+
+/*
+ * SPI write buffer
+ */
+static int spi_write_buf(struct enc28j60_net *priv, int len,
+			 const u8 *data)
+{
+	int ret;
+
+	if (len > SPI_TRANSFER_BUF_LEN - 1 || len <= 0)
+		ret = -EINVAL;
+	else {
+		priv->spi_transfer_buf[0] = ENC28J60_WRITE_BUF_MEM;
+		memcpy(&priv->spi_transfer_buf[1], data, len);
+		ret = spi_write(priv->spi, priv->spi_transfer_buf, len + 1);
+		if (ret && netif_msg_drv(priv))
+			printk(KERN_DEBUG DRV_NAME ": %s() failed: ret = %d\n",
+				__FUNCTION__, ret);
+	}
+	return ret;
+}
+
+/*
+ * basic SPI read operation
+ */
+static u8 spi_read_op(struct enc28j60_net *priv, u8 op,
+			   u8 addr)
+{
+	u8 tx_buf[2];
+	u8 rx_buf[4];
+	u8 val = 0;
+	int ret;
+	int slen = SPI_OPLEN;
+
+	/* do dummy read if needed */
+	if (addr & SPRD_MASK)
+		slen++;
+
+	tx_buf[0] = op | (addr & ADDR_MASK);
+	ret = spi_write_then_read(priv->spi, tx_buf, 1, rx_buf, slen);
+	if (ret)
+		printk(KERN_DEBUG DRV_NAME ": %s() failed: ret = %d\n",
+			__FUNCTION__, ret);
+	else
+		val = rx_buf[slen - 1];
+
+	return val;
+}
+
+/*
+ * basic SPI write operation
+ */
+static int spi_write_op(struct enc28j60_net *priv, u8 op,
+			u8 addr, u8 val)
+{
+	int ret;
+
+	priv->spi_transfer_buf[0] = op | (addr & ADDR_MASK);
+	priv->spi_transfer_buf[1] = val;
+	ret = spi_write(priv->spi, priv->spi_transfer_buf, 2);
+	if (ret && netif_msg_drv(priv))
+		printk(KERN_DEBUG DRV_NAME ": %s() failed: ret = %d\n",
+			__FUNCTION__, ret);
+	return ret;
+}
+
+static void enc28j60_soft_reset(struct enc28j60_net *priv)
+{
+	if (netif_msg_hw(priv))
+		printk(KERN_DEBUG DRV_NAME ": %s() enter\n", __FUNCTION__);
+
+	spi_write_op(priv, ENC28J60_SOFT_RESET, 0, ENC28J60_SOFT_RESET);
+	/* Errata workaround #1, CLKRDY check is unreliable,
+	 * delay at least 1 mS instead */
+	udelay(2000);
+}
+
+/*
+ * select the current register bank if necessary
+ */
+static void enc28j60_set_bank(struct enc28j60_net *priv, u8 addr)
+{
+	if ((addr & BANK_MASK) != priv->bank) {
+		u8 b = (addr & BANK_MASK) >> 5;
+
+		if (b != (ECON1_BSEL1 | ECON1_BSEL0))
+			spi_write_op(priv, ENC28J60_BIT_FIELD_CLR, ECON1,
+				     ECON1_BSEL1 | ECON1_BSEL0);
+		if (b != 0)
+			spi_write_op(priv, ENC28J60_BIT_FIELD_SET, ECON1, b);
+		priv->bank = (addr & BANK_MASK);
+	}
+}
+
+/*
+ * Register access routines through the SPI bus.
+ * Every register access comes in two flavours:
+ * - nolock_xxx: caller needs to invoke mutex_lock, usually to access
+ *   atomically more than one register
+ * - locked_xxx: caller doesn't need to invoke mutex_lock, single access
+ *
+ * Some registers can be accessed through the bit field clear and
+ * bit field set to avoid a read modify write cycle.
+ */
+
+/*
+ * Register bit field Set
+ */
+static void nolock_reg_bfset(struct enc28j60_net *priv,
+				      u8 addr, u8 mask)
+{
+	enc28j60_set_bank(priv, addr);
+	spi_write_op(priv, ENC28J60_BIT_FIELD_SET, addr, mask);
+}
+
+static void locked_reg_bfset(struct enc28j60_net *priv,
+				      u8 addr, u8 mask)
+{
+	mutex_lock(&priv->lock);
+	nolock_reg_bfset(priv, addr, mask);
+	mutex_unlock(&priv->lock);
+}
+
+/*
+ * Register bit field Clear
+ */
+static void nolock_reg_bfclr(struct enc28j60_net *priv,
+				      u8 addr, u8 mask)
+{
+	enc28j60_set_bank(priv, addr);
+	spi_write_op(priv, ENC28J60_BIT_FIELD_CLR, addr, mask);
+}
+
+static void locked_reg_bfclr(struct enc28j60_net *priv,
+				      u8 addr, u8 mask)
+{
+	mutex_lock(&priv->lock);
+	nolock_reg_bfclr(priv, addr, mask);
+	mutex_unlock(&priv->lock);
+}
+
+/*
+ * Register byte read
+ */
+static int nolock_regb_read(struct enc28j60_net *priv,
+				     u8 address)
+{
+	enc28j60_set_bank(priv, address);
+	return spi_read_op(priv, ENC28J60_READ_CTRL_REG, address);
+}
+
+static int locked_regb_read(struct enc28j60_net *priv,
+				     u8 address)
+{
+	int ret;
+
+	mutex_lock(&priv->lock);
+	ret = nolock_regb_read(priv, address);
+	mutex_unlock(&priv->lock);
+
+	return ret;
+}
+
+/*
+ * Register word read
+ */
+static int nolock_regw_read(struct enc28j60_net *priv,
+				     u8 address)
+{
+	int rl, rh;
+
+	enc28j60_set_bank(priv, address);
+	rl = spi_read_op(priv, ENC28J60_READ_CTRL_REG, address);
+	rh = spi_read_op(priv, ENC28J60_READ_CTRL_REG, address + 1);
+
+	return (rh << 8) | rl;
+}
+
+static int locked_regw_read(struct enc28j60_net *priv,
+				     u8 address)
+{
+	int ret;
+
+	mutex_lock(&priv->lock);
+	ret = nolock_regw_read(priv, address);
+	mutex_unlock(&priv->lock);
+
+	return ret;
+}
+
+/*
+ * Register byte write
+ */
+static void nolock_regb_write(struct enc28j60_net *priv,
+				       u8 address, u8 data)
+{
+	enc28j60_set_bank(priv, address);
+	spi_write_op(priv, ENC28J60_WRITE_CTRL_REG, address, data);
+}
+
+static void locked_regb_write(struct enc28j60_net *priv,
+				       u8 address, u8 data)
+{
+	mutex_lock(&priv->lock);
+	nolock_regb_write(priv, address, data);
+	mutex_unlock(&priv->lock);
+}
+
+/*
+ * Register word write
+ */
+static void nolock_regw_write(struct enc28j60_net *priv,
+				       u8 address, u16 data)
+{
+	enc28j60_set_bank(priv, address);
+	spi_write_op(priv, ENC28J60_WRITE_CTRL_REG, address, (u8) data);
+	spi_write_op(priv, ENC28J60_WRITE_CTRL_REG, address + 1,
+		     (u8) (data >> 8));
+}
+
+static void locked_regw_write(struct enc28j60_net *priv,
+				       u8 address, u16 data)
+{
+	mutex_lock(&priv->lock);
+	nolock_regw_write(priv, address, data);
+	mutex_unlock(&priv->lock);
+}
+
+/*
+ * Buffer memory read
+ * Select the starting address and execute a SPI buffer read
+ */
+static void enc28j60_mem_read(struct enc28j60_net *priv,
+				     u16 addr, int len, u8 *data)
+{
+	mutex_lock(&priv->lock);
+	nolock_regw_write(priv, ERDPTL, addr);
+#ifdef CONFIG_ENC28J60_WRITEVERIFY
+	if (netif_msg_drv(priv)) {
+		u16 reg;
+		reg = nolock_regw_read(priv, ERDPTL);
+		if (reg != addr)
+			printk(KERN_DEBUG DRV_NAME ": %s() error writing ERDPT "
+				"(0x%04x - 0x%04x)\n", __FUNCTION__, reg, addr);
+	}
+#endif
+	spi_read_buf(priv, len, data);
+	mutex_unlock(&priv->lock);
+}
+
+/*
+ * Write packet to enc28j60 TX buffer memory
+ */
+static void
+enc28j60_packet_write(struct enc28j60_net *priv, int len, const u8 *data)
+{
+	mutex_lock(&priv->lock);
+	/* Set the write pointer to start of transmit buffer area */
+	nolock_regw_write(priv, EWRPTL, TXSTART_INIT);
+#ifdef CONFIG_ENC28J60_WRITEVERIFY
+	if (netif_msg_drv(priv)) {
+		u16 reg;
+		reg = nolock_regw_read(priv, EWRPTL);
+		if (reg != TXSTART_INIT)
+			printk(KERN_DEBUG DRV_NAME
+				": %s() ERWPT:0x%04x != 0x%04x\n",
+				__FUNCTION__, reg, TXSTART_INIT);
+	}
+#endif
+	/* Set the TXND pointer to correspond to the packet size given */
+	nolock_regw_write(priv, ETXNDL, TXSTART_INIT + len);
+	/* write per-packet control byte */
+	spi_write_op(priv, ENC28J60_WRITE_BUF_MEM, 0, 0x00);
+	if (netif_msg_hw(priv))
+		printk(KERN_DEBUG DRV_NAME
+			": %s() after control byte ERWPT:0x%04x\n",
+			__FUNCTION__, nolock_regw_read(priv, EWRPTL));
+	/* copy the packet into the transmit buffer */
+	spi_write_buf(priv, len, data);
+	if (netif_msg_hw(priv))
+		printk(KERN_DEBUG DRV_NAME
+			 ": %s() after write packet ERWPT:0x%04x, len=%d\n",
+			 __FUNCTION__, nolock_regw_read(priv, EWRPTL), len);
+	mutex_unlock(&priv->lock);
+}
+
+/*
+ * Wait until the PHY operation is complete.
+ */
+static int wait_phy_ready(struct enc28j60_net *priv)
+{
+	unsigned long timeout = jiffies + 20 * HZ / 1000;
+	int ret = 1;
+
+	/* 20 msec timeout read */
+	while (nolock_regb_read(priv, MISTAT) & MISTAT_BUSY) {
+		if (time_after(jiffies, timeout)) {
+			if (netif_msg_drv(priv))
+				printk(KERN_DEBUG DRV_NAME
+					": PHY ready timeout!\n");
+			ret = 0;
+			break;
+		}
+		cpu_relax();
+	}
+	return ret;
+}
+
+/*
+ * PHY register read
+ * PHY registers are not accessed directly, but through the MII
+ */
+static u16 enc28j60_phy_read(struct enc28j60_net *priv, u8 address)
+{
+	u16 ret;
+
+	mutex_lock(&priv->lock);
+	/* set the PHY register address */
+	nolock_regb_write(priv, MIREGADR, address);
+	/* start the register read operation */
+	nolock_regb_write(priv, MICMD, MICMD_MIIRD);
+	/* wait until the PHY read completes */
+	wait_phy_ready(priv);
+	/* quit reading */
+	nolock_regb_write(priv, MICMD, 0x00);
+	/* return the data */
+	ret  = nolock_regw_read(priv, MIRDL);
+	mutex_unlock(&priv->lock);
+
+	return ret;
+}
+
+static int enc28j60_phy_write(struct enc28j60_net *priv, u8 address, u16 data)
+{
+	int ret;
+
+	mutex_lock(&priv->lock);
+	/* set the PHY register address */
+	nolock_regb_write(priv, MIREGADR, address);
+	/* write the PHY data */
+	nolock_regw_write(priv, MIWRL, data);
+	/* wait until the PHY write completes and return */
+	ret = wait_phy_ready(priv);
+	mutex_unlock(&priv->lock);
+
+	return ret;
+}
+
+/*
+ * Program the hardware MAC address from dev->dev_addr.
+ */
+static int enc28j60_set_hw_macaddr(struct net_device *ndev)
+{
+	int ret;
+	struct enc28j60_net *priv = netdev_priv(ndev);
+
+	mutex_lock(&priv->lock);
+	if (!priv->hw_enable) {
+		if (netif_msg_drv(priv)) {
+			DECLARE_MAC_BUF(mac);
+			printk(KERN_INFO DRV_NAME
+				": %s: Setting MAC address to %s\n",
+				ndev->name, print_mac(mac, ndev->dev_addr));
+		}
+		/* NOTE: MAC address in ENC28J60 is byte-backward */
+		nolock_regb_write(priv, MAADR5, ndev->dev_addr[0]);
+		nolock_regb_write(priv, MAADR4, ndev->dev_addr[1]);
+		nolock_regb_write(priv, MAADR3, ndev->dev_addr[2]);
+		nolock_regb_write(priv, MAADR2, ndev->dev_addr[3]);
+		nolock_regb_write(priv, MAADR1, ndev->dev_addr[4]);
+		nolock_regb_write(priv, MAADR0, ndev->dev_addr[5]);
+		ret = 0;
+	} else {
+		if (netif_msg_drv(priv))
+			printk(KERN_DEBUG DRV_NAME
+				": %s() Hardware must be disabled to set "
+				"Mac address\n", __FUNCTION__);
+		ret = -EBUSY;
+	}
+	mutex_unlock(&priv->lock);
+	return ret;
+}
+
+/*
+ * Store the new hardware address in dev->dev_addr, and update the MAC.
+ */
+static int enc28j60_set_mac_address(struct net_device *dev, void *addr)
+{
+	struct sockaddr *address = addr;
+
+	if (netif_running(dev))
+		return -EBUSY;
+	if (!is_valid_ether_addr(address->sa_data))
+		return -EADDRNOTAVAIL;
+
+	memcpy(dev->dev_addr, address->sa_data, dev->addr_len);
+	return enc28j60_set_hw_macaddr(dev);
+}
+
+/*
+ * Debug routine to dump useful register contents
+ */
+static void enc28j60_dump_regs(struct enc28j60_net *priv, const char *msg)
+{
+	mutex_lock(&priv->lock);
+	printk(KERN_DEBUG DRV_NAME " %s\n"
+		"HwRevID: 0x%02x\n"
+		"Cntrl: ECON1 ECON2 ESTAT  EIR  EIE\n"
+		"       0x%02x  0x%02x  0x%02x  0x%02x  0x%02x\n"
+		"MAC  : MACON1 MACON3 MACON4\n"
+		"       0x%02x   0x%02x   0x%02x\n"
+		"Rx   : ERXST  ERXND  ERXWRPT ERXRDPT ERXFCON EPKTCNT MAMXFL\n"
+		"       0x%04x 0x%04x 0x%04x  0x%04x  "
+		"0x%02x    0x%02x    0x%04x\n"
+		"Tx   : ETXST  ETXND  MACLCON1 MACLCON2 MAPHSUP\n"
+		"       0x%04x 0x%04x 0x%02x     0x%02x     0x%02x\n",
+		msg, nolock_regb_read(priv, EREVID),
+		nolock_regb_read(priv, ECON1), nolock_regb_read(priv, ECON2),
+		nolock_regb_read(priv, ESTAT), nolock_regb_read(priv, EIR),
+		nolock_regb_read(priv, EIE), nolock_regb_read(priv, MACON1),
+		nolock_regb_read(priv, MACON3), nolock_regb_read(priv, MACON4),
+		nolock_regw_read(priv, ERXSTL), nolock_regw_read(priv, ERXNDL),
+		nolock_regw_read(priv, ERXWRPTL),
+		nolock_regw_read(priv, ERXRDPTL),
+		nolock_regb_read(priv, ERXFCON),
+		nolock_regb_read(priv, EPKTCNT),
+		nolock_regw_read(priv, MAMXFLL), nolock_regw_read(priv, ETXSTL),
+		nolock_regw_read(priv, ETXNDL),
+		nolock_regb_read(priv, MACLCON1),
+		nolock_regb_read(priv, MACLCON2),
+		nolock_regb_read(priv, MAPHSUP));
+	mutex_unlock(&priv->lock);
+}
+
+/*
+ * ERXRDPT need to be set always at odd addresses, refer to errata datasheet
+ */
+static u16 erxrdpt_workaround(u16 next_packet_ptr, u16 start, u16 end)
+{
+	u16 erxrdpt;
+
+	if ((next_packet_ptr - 1 < start) || (next_packet_ptr - 1 > end))
+		erxrdpt = end;
+	else
+		erxrdpt = next_packet_ptr - 1;
+
+	return erxrdpt;
+}
+
+static void nolock_rxfifo_init(struct enc28j60_net *priv, u16 start, u16 end)
+{
+	u16 erxrdpt;
+
+	if (start > 0x1FFF || end > 0x1FFF || start > end) {
+		if (netif_msg_drv(priv))
+			printk(KERN_ERR DRV_NAME ": %s(%d, %d) RXFIFO "
+				"bad parameters!\n", __FUNCTION__, start, end);
+		return;
+	}
+	/* set receive buffer start + end */
+	priv->next_pk_ptr = start;
+	nolock_regw_write(priv, ERXSTL, start);
+	erxrdpt = erxrdpt_workaround(priv->next_pk_ptr, start, end);
+	nolock_regw_write(priv, ERXRDPTL, erxrdpt);
+	nolock_regw_write(priv, ERXNDL, end);
+}
+
+static void nolock_txfifo_init(struct enc28j60_net *priv, u16 start, u16 end)
+{
+	if (start > 0x1FFF || end > 0x1FFF || start > end) {
+		if (netif_msg_drv(priv))
+			printk(KERN_ERR DRV_NAME ": %s(%d, %d) TXFIFO "
+				"bad parameters!\n", __FUNCTION__, start, end);
+		return;
+	}
+	/* set transmit buffer start + end */
+	nolock_regw_write(priv, ETXSTL, start);
+	nolock_regw_write(priv, ETXNDL, end);
+}
+
+static int enc28j60_hw_init(struct enc28j60_net *priv)
+{
+	u8 reg;
+
+	if (netif_msg_drv(priv))
+		printk(KERN_DEBUG DRV_NAME ": %s() - %s\n", __FUNCTION__,
+			priv->full_duplex ? "FullDuplex" : "HalfDuplex");
+
+	mutex_lock(&priv->lock);
+	/* first reset the chip */
+	enc28j60_soft_reset(priv);
+	/* Clear ECON1 */
+	spi_write_op(priv, ENC28J60_WRITE_CTRL_REG, ECON1, 0x00);
+	priv->bank = 0;
+	priv->hw_enable = false;
+	priv->tx_retry_count = 0;
+	priv->max_pk_counter = 0;
+	priv->rxfilter = RXFILTER_NORMAL;
+	/* enable address auto increment */
+	nolock_regb_write(priv, ECON2, ECON2_AUTOINC);
+
+	nolock_rxfifo_init(priv, RXSTART_INIT, RXEND_INIT);
+	nolock_txfifo_init(priv, TXSTART_INIT, TXEND_INIT);
+	mutex_unlock(&priv->lock);
+
+	/*
+	 * Check the RevID.
+	 * If it's 0x00 or 0xFF probably the enc28j60 is not mounted or
+	 * damaged
+	 */
+	reg = locked_regb_read(priv, EREVID);
+	if (netif_msg_drv(priv))
+		printk(KERN_INFO DRV_NAME ": chip RevID: 0x%02x\n", reg);
+	if (reg == 0x00 || reg == 0xff) {
+		if (netif_msg_drv(priv))
+			printk(KERN_DEBUG DRV_NAME ": %s() Invalid RevId %d\n",
+				__FUNCTION__, reg);
+		return 0;
+	}
+
+	/* default filter mode: (unicast OR broadcast) AND crc valid */
+	locked_regb_write(priv, ERXFCON,
+			    ERXFCON_UCEN | ERXFCON_CRCEN | ERXFCON_BCEN);
+
+	/* enable MAC receive */
+	locked_regb_write(priv, MACON1,
+			    MACON1_MARXEN | MACON1_TXPAUS | MACON1_RXPAUS);
+	/* enable automatic padding and CRC operations */
+	if (priv->full_duplex) {
+		locked_regb_write(priv, MACON3,
+				    MACON3_PADCFG0 | MACON3_TXCRCEN |
+				    MACON3_FRMLNEN | MACON3_FULDPX);
+		/* set inter-frame gap (non-back-to-back) */
+		locked_regb_write(priv, MAIPGL, 0x12);
+		/* set inter-frame gap (back-to-back) */
+		locked_regb_write(priv, MABBIPG, 0x15);
+	} else {
+		locked_regb_write(priv, MACON3,
+				    MACON3_PADCFG0 | MACON3_TXCRCEN |
+				    MACON3_FRMLNEN);
+		locked_regb_write(priv, MACON4, 1 << 6);	/* DEFER bit */
+		/* set inter-frame gap (non-back-to-back) */
+		locked_regw_write(priv, MAIPGL, 0x0C12);
+		/* set inter-frame gap (back-to-back) */
+		locked_regb_write(priv, MABBIPG, 0x12);
+	}
+	/*
+	 * MACLCON1 (default)
+	 * MACLCON2 (default)
+	 * Set the maximum packet size which the controller will accept
+	 */
+	locked_regw_write(priv, MAMXFLL, MAX_FRAMELEN);
+
+	/* Configure LEDs */
+	if (!enc28j60_phy_write(priv, PHLCON, ENC28J60_LAMPS_MODE))
+		return 0;
+
+	if (priv->full_duplex) {
+		if (!enc28j60_phy_write(priv, PHCON1, PHCON1_PDPXMD))
+			return 0;
+		if (!enc28j60_phy_write(priv, PHCON2, 0x00))
+			return 0;
+	} else {
+		if (!enc28j60_phy_write(priv, PHCON1, 0x00))
+			return 0;
+		if (!enc28j60_phy_write(priv, PHCON2, PHCON2_HDLDIS))
+			return 0;
+	}
+	if (netif_msg_hw(priv))
+		enc28j60_dump_regs(priv, "Hw initialized.");
+
+	return 1;
+}
+
+static void enc28j60_hw_enable(struct enc28j60_net *priv)
+{
+	/* enable interrutps */
+	if (netif_msg_hw(priv))
+		printk(KERN_DEBUG DRV_NAME ": %s() enabling interrupts.\n",
+			__FUNCTION__);
+
+	enc28j60_phy_write(priv, PHIE, PHIE_PGEIE | PHIE_PLNKIE);
+
+	mutex_lock(&priv->lock);
+	nolock_reg_bfclr(priv, EIR, EIR_DMAIF | EIR_LINKIF |
+			 EIR_TXIF | EIR_TXERIF | EIR_RXERIF | EIR_PKTIF);
+	nolock_regb_write(priv, EIE, EIE_INTIE | EIE_PKTIE | EIE_LINKIE |
+			  EIE_TXIE | EIE_TXERIE | EIE_RXERIE);
+
+	/* enable receive logic */
+	nolock_reg_bfset(priv, ECON1, ECON1_RXEN);
+	priv->hw_enable = true;
+	mutex_unlock(&priv->lock);
+}
+
+static void enc28j60_hw_disable(struct enc28j60_net *priv)
+{
+	mutex_lock(&priv->lock);
+	/* disable interrutps and packet reception */
+	nolock_regb_write(priv, EIE, 0x00);
+	nolock_reg_bfclr(priv, ECON1, ECON1_RXEN);
+	priv->hw_enable = false;
+	mutex_unlock(&priv->lock);
+}
+
+static int
+enc28j60_setlink(struct net_device *ndev, u8 autoneg, u16 speed, u8 duplex)
+{
+	struct enc28j60_net *priv = netdev_priv(ndev);
+	int ret = 0;
+
+	if (!priv->hw_enable) {
+		if (autoneg == AUTONEG_DISABLE && speed == SPEED_10) {
+			priv->full_duplex = (duplex == DUPLEX_FULL);
+			if (!enc28j60_hw_init(priv)) {
+				if (netif_msg_drv(priv))
+					dev_err(&ndev->dev,
+						"hw_reset() failed\n");
+				ret = -EINVAL;
+			}
+		} else {
+			if (netif_msg_link(priv))
+				dev_warn(&ndev->dev,
+					"unsupported link setting\n");
+			ret = -EOPNOTSUPP;
+		}
+	} else {
+		if (netif_msg_link(priv))
+			dev_warn(&ndev->dev, "Warning: hw must be disabled "
+				"to set link mode\n");
+		ret = -EBUSY;
+	}
+	return ret;
+}
+
+/*
+ * Read the Transmit Status Vector
+ */
+static void enc28j60_read_tsv(struct enc28j60_net *priv, u8 tsv[TSV_SIZE])
+{
+	int endptr;
+
+	endptr = locked_regw_read(priv, ETXNDL);
+	if (netif_msg_hw(priv))
+		printk(KERN_DEBUG DRV_NAME ": reading TSV at addr:0x%04x\n",
+			 endptr + 1);
+	enc28j60_mem_read(priv, endptr + 1, sizeof(tsv), tsv);
+}
+
+static void enc28j60_dump_tsv(struct enc28j60_net *priv, const char *msg,
+				u8 tsv[TSV_SIZE])
+{
+	u16 tmp1, tmp2;
+
+	printk(KERN_DEBUG DRV_NAME ": %s - TSV:\n", msg);
+	tmp1 = tsv[1];
+	tmp1 <<= 8;
+	tmp1 |= tsv[0];
+
+	tmp2 = tsv[5];
+	tmp2 <<= 8;
+	tmp2 |= tsv[4];
+
+	printk(KERN_DEBUG DRV_NAME ": ByteCount: %d, CollisionCount: %d,"
+		" TotByteOnWire: %d\n", tmp1, tsv[2] & 0x0f, tmp2);
+	printk(KERN_DEBUG DRV_NAME ": TxDone: %d, CRCErr:%d, LenChkErr: %d,"
+		" LenOutOfRange: %d\n", TSV_GETBIT(tsv, TSV_TXDONE),
+		TSV_GETBIT(tsv, TSV_TXCRCERROR),
+		TSV_GETBIT(tsv, TSV_TXLENCHKERROR),
+		TSV_GETBIT(tsv, TSV_TXLENOUTOFRANGE));
+	printk(KERN_DEBUG DRV_NAME ": Multicast: %d, Broadcast: %d, "
+		"PacketDefer: %d, ExDefer: %d\n",
+		TSV_GETBIT(tsv, TSV_TXMULTICAST),
+		TSV_GETBIT(tsv, TSV_TXBROADCAST),
+		TSV_GETBIT(tsv, TSV_TXPACKETDEFER),
+		TSV_GETBIT(tsv, TSV_TXEXDEFER));
+	printk(KERN_DEBUG DRV_NAME ": ExCollision: %d, LateCollision: %d, "
+		 "Giant: %d, Underrun: %d\n",
+		 TSV_GETBIT(tsv, TSV_TXEXCOLLISION),
+		 TSV_GETBIT(tsv, TSV_TXLATECOLLISION),
+		 TSV_GETBIT(tsv, TSV_TXGIANT), TSV_GETBIT(tsv, TSV_TXUNDERRUN));
+	printk(KERN_DEBUG DRV_NAME ": ControlFrame: %d, PauseFrame: %d, "
+		 "BackPressApp: %d, VLanTagFrame: %d\n",
+		 TSV_GETBIT(tsv, TSV_TXCONTROLFRAME),
+		 TSV_GETBIT(tsv, TSV_TXPAUSEFRAME),
+		 TSV_GETBIT(tsv, TSV_BACKPRESSUREAPP),
+		 TSV_GETBIT(tsv, TSV_TXVLANTAGFRAME));
+}
+
+/*
+ * Receive Status vector
+ */
+static void enc28j60_dump_rsv(struct enc28j60_net *priv, const char *msg,
+			      u16 pk_ptr, int len, u16 sts)
+{
+	printk(KERN_DEBUG DRV_NAME ": %s - NextPk: 0x%04x - RSV:\n",
+		msg, pk_ptr);
+	printk(KERN_DEBUG DRV_NAME ": ByteCount: %d, DribbleNibble: %d\n", len,
+		 RSV_GETBIT(sts, RSV_DRIBBLENIBBLE));
+	printk(KERN_DEBUG DRV_NAME ": RxOK: %d, CRCErr:%d, LenChkErr: %d,"
+		 " LenOutOfRange: %d\n", RSV_GETBIT(sts, RSV_RXOK),
+		 RSV_GETBIT(sts, RSV_CRCERROR),
+		 RSV_GETBIT(sts, RSV_LENCHECKERR),
+		 RSV_GETBIT(sts, RSV_LENOUTOFRANGE));
+	printk(KERN_DEBUG DRV_NAME ": Multicast: %d, Broadcast: %d, "
+		 "LongDropEvent: %d, CarrierEvent: %d\n",
+		 RSV_GETBIT(sts, RSV_RXMULTICAST),
+		 RSV_GETBIT(sts, RSV_RXBROADCAST),
+		 RSV_GETBIT(sts, RSV_RXLONGEVDROPEV),
+		 RSV_GETBIT(sts, RSV_CARRIEREV));
+	printk(KERN_DEBUG DRV_NAME ": ControlFrame: %d, PauseFrame: %d,"
+		 " UnknownOp: %d, VLanTagFrame: %d\n",
+		 RSV_GETBIT(sts, RSV_RXCONTROLFRAME),
+		 RSV_GETBIT(sts, RSV_RXPAUSEFRAME),
+		 RSV_GETBIT(sts, RSV_RXUNKNOWNOPCODE),
+		 RSV_GETBIT(sts, RSV_RXTYPEVLAN));
+}
+
+static void dump_packet(const char *msg, int len, const char *data)
+{
+	printk(KERN_DEBUG DRV_NAME ": %s - packet len:%d\n", msg, len);
+	print_hex_dump(KERN_DEBUG, "pk data: ", DUMP_PREFIX_OFFSET, 16, 1,
+			data, len, true);
+}
+
+/*
+ * Hardware receive function.
+ * Read the buffer memory, update the FIFO pointer to free the buffer,
+ * check the status vector and decrement the packet counter.
+ */
+static void enc28j60_hw_rx(struct net_device *ndev)
+{
+	struct enc28j60_net *priv = netdev_priv(ndev);
+	struct sk_buff *skb = NULL;
+	u16 erxrdpt, next_packet, rxstat;
+	u8 rsv[RSV_SIZE];
+	int len;
+
+	if (netif_msg_rx_status(priv))
+		printk(KERN_DEBUG DRV_NAME ": RX pk_addr:0x%04x\n",
+			priv->next_pk_ptr);
+
+	if (unlikely(priv->next_pk_ptr > RXEND_INIT)) {
+		if (netif_msg_rx_err(priv))
+			dev_err(&ndev->dev,
+				"%s() Invalid packet address!! 0x%04x\n",
+				__FUNCTION__, priv->next_pk_ptr);
+		/* packet address corrupted: reset RX logic */
+		mutex_lock(&priv->lock);
+		nolock_reg_bfclr(priv, ECON1, ECON1_RXEN);
+		nolock_reg_bfset(priv, ECON1, ECON1_RXRST);
+		nolock_reg_bfclr(priv, ECON1, ECON1_RXRST);
+		nolock_rxfifo_init(priv, RXSTART_INIT, RXEND_INIT);
+		nolock_reg_bfclr(priv, EIR, EIR_RXERIF);
+		nolock_reg_bfset(priv, ECON1, ECON1_RXEN);
+		mutex_unlock(&priv->lock);
+		ndev->stats.rx_errors++;
+		return;
+	}
+	/* Read next packet pointer and rx status vector */
+	enc28j60_mem_read(priv, priv->next_pk_ptr, sizeof(rsv), rsv);
+
+	next_packet = rsv[1];
+	next_packet <<= 8;
+	next_packet |= rsv[0];
+
+	len = rsv[3];
+	len <<= 8;
+	len |= rsv[2];
+
+	rxstat = rsv[5];
+	rxstat <<= 8;
+	rxstat |= rsv[4];
+
+	if (netif_msg_rx_status(priv))
+		enc28j60_dump_rsv(priv, __FUNCTION__, next_packet, len, rxstat);
+
+	if (!RSV_GETBIT(rxstat, RSV_RXOK)) {
+		if (netif_msg_rx_err(priv))
+			dev_err(&ndev->dev, "Rx Error (%04x)\n", rxstat);
+		ndev->stats.rx_errors++;
+		if (RSV_GETBIT(rxstat, RSV_CRCERROR))
+			ndev->stats.rx_crc_errors++;
+		if (RSV_GETBIT(rxstat, RSV_LENCHECKERR))
+			ndev->stats.rx_frame_errors++;
+	} else {
+		skb = dev_alloc_skb(len);
+		if (!skb) {
+			if (netif_msg_rx_err(priv))
+				dev_err(&ndev->dev,
+					"out of memory for Rx'd frame\n");
+			ndev->stats.rx_dropped++;
+		} else {
+			skb->dev = ndev;
+			/* copy the packet from the receive buffer */
+			enc28j60_mem_read(priv, priv->next_pk_ptr + sizeof(rsv),
+					len, skb_put(skb, len));
+			if (netif_msg_pktdata(priv))
+				dump_packet(__FUNCTION__, skb->len, skb->data);
+			skb->protocol = eth_type_trans(skb, ndev);
+			/* update statistics */
+			ndev->stats.rx_packets++;
+			ndev->stats.rx_bytes += len;
+			ndev->last_rx = jiffies;
+			netif_rx(skb);
+		}
+	}
+	/*
+	 * Move the RX read pointer to the start of the next
+	 * received packet.
+	 * This frees the memory we just read out
+	 */
+	erxrdpt = erxrdpt_workaround(next_packet, RXSTART_INIT, RXEND_INIT);
+	if (netif_msg_hw(priv))
+		printk(KERN_DEBUG DRV_NAME ": %s() ERXRDPT:0x%04x\n",
+			__FUNCTION__, erxrdpt);
+
+	mutex_lock(&priv->lock);
+	nolock_regw_write(priv, ERXRDPTL, erxrdpt);
+#ifdef CONFIG_ENC28J60_WRITEVERIFY
+	if (netif_msg_drv(priv)) {
+		u16 reg;
+		reg = nolock_regw_read(priv, ERXRDPTL);
+		if (reg != erxrdpt)
+			printk(KERN_DEBUG DRV_NAME ": %s() ERXRDPT verify "
+				"error (0x%04x - 0x%04x)\n", __FUNCTION__,
+				reg, erxrdpt);
+	}
+#endif
+	priv->next_pk_ptr = next_packet;
+	/* we are done with this packet, decrement the packet counter */
+	nolock_reg_bfset(priv, ECON2, ECON2_PKTDEC);
+	mutex_unlock(&priv->lock);
+}
+
+/*
+ * Calculate free space in RxFIFO
+ */
+static int enc28j60_get_free_rxfifo(struct enc28j60_net *priv)
+{
+	int epkcnt, erxst, erxnd, erxwr, erxrd;
+	int free_space;
+
+	mutex_lock(&priv->lock);
+	epkcnt = nolock_regb_read(priv, EPKTCNT);
+	if (epkcnt >= 255)
+		free_space = -1;
+	else {
+		erxst = nolock_regw_read(priv, ERXSTL);
+		erxnd = nolock_regw_read(priv, ERXNDL);
+		erxwr = nolock_regw_read(priv, ERXWRPTL);
+		erxrd = nolock_regw_read(priv, ERXRDPTL);
+
+		if (erxwr > erxrd)
+			free_space = (erxnd - erxst) - (erxwr - erxrd);
+		else if (erxwr == erxrd)
+			free_space = (erxnd - erxst);
+		else
+			free_space = erxrd - erxwr - 1;
+	}
+	mutex_unlock(&priv->lock);
+	if (netif_msg_rx_status(priv))
+		printk(KERN_DEBUG DRV_NAME ": %s() free_space = %d\n",
+			__FUNCTION__, free_space);
+	return free_space;
+}
+
+/*
+ * Access the PHY to determine link status
+ */
+static void enc28j60_check_link_status(struct net_device *ndev)
+{
+	struct enc28j60_net *priv = netdev_priv(ndev);
+	u16 reg;
+	int duplex;
+
+	reg = enc28j60_phy_read(priv, PHSTAT2);
+	if (netif_msg_hw(priv))
+		printk(KERN_DEBUG DRV_NAME ": %s() PHSTAT1: %04x, "
+			"PHSTAT2: %04x\n", __FUNCTION__,
+			enc28j60_phy_read(priv, PHSTAT1), reg);
+	duplex = reg & PHSTAT2_DPXSTAT;
+
+	if (reg & PHSTAT2_LSTAT) {
+		netif_carrier_on(ndev);
+		if (netif_msg_ifup(priv))
+			dev_info(&ndev->dev, "link up - %s\n",
+				duplex ? "Full duplex" : "Half duplex");
+	} else {
+		if (netif_msg_ifdown(priv))
+			dev_info(&ndev->dev, "link down\n");
+		netif_carrier_off(ndev);
+	}
+}
+
+static void enc28j60_tx_clear(struct net_device *ndev, bool err)
+{
+	struct enc28j60_net *priv = netdev_priv(ndev);
+
+	if (err)
+		ndev->stats.tx_errors++;
+	else
+		ndev->stats.tx_packets++;
+
+	if (priv->tx_skb) {
+		if (!err)
+			ndev->stats.tx_bytes += priv->tx_skb->len;
+		dev_kfree_skb(priv->tx_skb);
+		priv->tx_skb = NULL;
+	}
+	locked_reg_bfclr(priv, ECON1, ECON1_TXRTS);
+	netif_wake_queue(ndev);
+}
+
+/*
+ * RX handler
+ * ignore PKTIF because is unreliable! (look at the errata datasheet)
+ * check EPKTCNT is the suggested workaround.
+ * We don't need to clear interrupt flag, automatically done when
+ * enc28j60_hw_rx() decrements the packet counter.
+ * Returns how many packet processed.
+ */
+static int enc28j60_rx_interrupt(struct net_device *ndev)
+{
+	struct enc28j60_net *priv = netdev_priv(ndev);
+	int pk_counter, ret;
+
+	pk_counter = locked_regb_read(priv, EPKTCNT);
+	if (pk_counter && netif_msg_intr(priv))
+		printk(KERN_DEBUG DRV_NAME ": intRX, pk_cnt: %d\n", pk_counter);
+	if (pk_counter > priv->max_pk_counter) {
+		/* update statistics */
+		priv->max_pk_counter = pk_counter;
+		if (netif_msg_rx_status(priv) && priv->max_pk_counter > 1)
+			printk(KERN_DEBUG DRV_NAME ": RX max_pk_cnt: %d\n",
+				priv->max_pk_counter);
+	}
+	ret = pk_counter;
+	while (pk_counter-- > 0)
+		enc28j60_hw_rx(ndev);
+
+	return ret;
+}
+
+static void enc28j60_irq_work_handler(struct work_struct *work)
+{
+	struct enc28j60_net *priv =
+		container_of(work, struct enc28j60_net, irq_work);
+	struct net_device *ndev = priv->netdev;
+	int intflags, loop;
+
+	if (netif_msg_intr(priv))
+		printk(KERN_DEBUG DRV_NAME ": %s() enter\n", __FUNCTION__);
+	/* disable further interrupts */
+	locked_reg_bfclr(priv, EIE, EIE_INTIE);
+
+	do {
+		loop = 0;
+		intflags = locked_regb_read(priv, EIR);
+		/* DMA interrupt handler (not currently used) */
+		if ((intflags & EIR_DMAIF) != 0) {
+			loop++;
+			if (netif_msg_intr(priv))
+				printk(KERN_DEBUG DRV_NAME
+					": intDMA(%d)\n", loop);
+			locked_reg_bfclr(priv, EIR, EIR_DMAIF);
+		}
+		/* LINK changed handler */
+		if ((intflags & EIR_LINKIF) != 0) {
+			loop++;
+			if (netif_msg_intr(priv))
+				printk(KERN_DEBUG DRV_NAME
+					": intLINK(%d)\n", loop);
+			enc28j60_check_link_status(ndev);
+			/* read PHIR to clear the flag */
+			enc28j60_phy_read(priv, PHIR);
+		}
+		/* TX complete handler */
+		if ((intflags & EIR_TXIF) != 0) {
+			bool err = false;
+			loop++;
+			if (netif_msg_intr(priv))
+				printk(KERN_DEBUG DRV_NAME
+					": intTX(%d)\n", loop);
+			priv->tx_retry_count = 0;
+			if (locked_regb_read(priv, ESTAT) & ESTAT_TXABRT) {
+				if (netif_msg_tx_err(priv))
+					dev_err(&ndev->dev,
+						"Tx Error (aborted)\n");
+				err = true;
+			}
+			if (netif_msg_tx_done(priv)) {
+				u8 tsv[TSV_SIZE];
+				enc28j60_read_tsv(priv, tsv);
+				enc28j60_dump_tsv(priv, "Tx Done", tsv);
+			}
+			enc28j60_tx_clear(ndev, err);
+			locked_reg_bfclr(priv, EIR, EIR_TXIF);
+		}
+		/* TX Error handler */
+		if ((intflags & EIR_TXERIF) != 0) {
+			u8 tsv[TSV_SIZE];
+
+			loop++;
+			if (netif_msg_intr(priv))
+				printk(KERN_DEBUG DRV_NAME
+					": intTXErr(%d)\n", loop);
+			locked_reg_bfclr(priv, ECON1, ECON1_TXRTS);
+			enc28j60_read_tsv(priv, tsv);
+			if (netif_msg_tx_err(priv))
+				enc28j60_dump_tsv(priv, "Tx Error", tsv);
+			/* Reset TX logic */
+			mutex_lock(&priv->lock);
+			nolock_reg_bfset(priv, ECON1, ECON1_TXRST);
+			nolock_reg_bfclr(priv, ECON1, ECON1_TXRST);
+			nolock_txfifo_init(priv, TXSTART_INIT, TXEND_INIT);
+			mutex_unlock(&priv->lock);
+			/* Transmit Late collision check for retransmit */
+			if (TSV_GETBIT(tsv, TSV_TXLATECOLLISION)) {
+				if (netif_msg_tx_err(priv))
+					printk(KERN_DEBUG DRV_NAME
+						": LateCollision TXErr (%d)\n",
+						priv->tx_retry_count);
+				if (priv->tx_retry_count++ < MAX_TX_RETRYCOUNT)
+					locked_reg_bfset(priv, ECON1,
+							   ECON1_TXRTS);
+				else
+					enc28j60_tx_clear(ndev, true);
+			} else
+				enc28j60_tx_clear(ndev, true);
+			locked_reg_bfclr(priv, EIR, EIR_TXERIF);
+		}
+		/* RX Error handler */
+		if ((intflags & EIR_RXERIF) != 0) {
+			loop++;
+			if (netif_msg_intr(priv))
+				printk(KERN_DEBUG DRV_NAME
+					": intRXErr(%d)\n", loop);
+			/* Check free FIFO space to flag RX overrun */
+			if (enc28j60_get_free_rxfifo(priv) <= 0) {
+				if (netif_msg_rx_err(priv))
+					printk(KERN_DEBUG DRV_NAME
+						": RX Overrun\n");
+				ndev->stats.rx_dropped++;
+			}
+			locked_reg_bfclr(priv, EIR, EIR_RXERIF);
+		}
+		/* RX handler */
+		if (enc28j60_rx_interrupt(ndev))
+			loop++;
+	} while (loop);
+
+	/* re-enable interrupts */
+	locked_reg_bfset(priv, EIE, EIE_INTIE);
+	if (netif_msg_intr(priv))
+		printk(KERN_DEBUG DRV_NAME ": %s() exit\n", __FUNCTION__);
+}
+
+/*
+ * Hardware transmit function.
+ * Fill the buffer memory and send the contents of the transmit buffer
+ * onto the network
+ */
+static void enc28j60_hw_tx(struct enc28j60_net *priv)
+{
+	if (netif_msg_tx_queued(priv))
+		printk(KERN_DEBUG DRV_NAME
+			": Tx Packet Len:%d\n", priv->tx_skb->len);
+
+	if (netif_msg_pktdata(priv))
+		dump_packet(__FUNCTION__,
+			    priv->tx_skb->len, priv->tx_skb->data);
+	enc28j60_packet_write(priv, priv->tx_skb->len, priv->tx_skb->data);
+
+#ifdef CONFIG_ENC28J60_WRITEVERIFY
+	/* readback and verify written data */
+	if (netif_msg_drv(priv)) {
+		int test_len, k;
+		u8 test_buf[64]; /* limit the test to the first 64 bytes */
+		int okflag;
+
+		test_len = priv->tx_skb->len;
+		if (test_len > sizeof(test_buf))
+			test_len = sizeof(test_buf);
+
+		/* + 1 to skip control byte */
+		enc28j60_mem_read(priv, TXSTART_INIT + 1, test_len, test_buf);
+		okflag = 1;
+		for (k = 0; k < test_len; k++) {
+			if (priv->tx_skb->data[k] != test_buf[k]) {
+				printk(KERN_DEBUG DRV_NAME
+					 ": Error, %d location differ: "
+					 "0x%02x-0x%02x\n", k,
+					 priv->tx_skb->data[k], test_buf[k]);
+				okflag = 0;
+			}
+		}
+		if (!okflag)
+			printk(KERN_DEBUG DRV_NAME ": Tx write buffer, "
+				"verify ERROR!\n");
+	}
+#endif
+	/* set TX request flag */
+	locked_reg_bfset(priv, ECON1, ECON1_TXRTS);
+}
+
+static int enc28j60_send_packet(struct sk_buff *skb, struct net_device *dev)
+{
+	struct enc28j60_net *priv = netdev_priv(dev);
+
+	if (netif_msg_tx_queued(priv))
+		printk(KERN_DEBUG DRV_NAME ": %s() enter\n", __FUNCTION__);
+
+	/* If some error occurs while trying to transmit this
+	 * packet, you should return '1' from this function.
+	 * In such a case you _may not_ do anything to the
+	 * SKB, it is still owned by the network queueing
+	 * layer when an error is returned.  This means you
+	 * may not modify any SKB fields, you may not free
+	 * the SKB, etc.
+	 */
+	netif_stop_queue(dev);
+
+	/* save the timestamp */
+	priv->netdev->trans_start = jiffies;
+	/* Remember the skb for deferred processing */
+	priv->tx_skb = skb;
+	schedule_work(&priv->tx_work);
+
+	return 0;
+}
+
+static void enc28j60_tx_work_handler(struct work_struct *work)
+{
+	struct enc28j60_net *priv =
+		container_of(work, struct enc28j60_net, tx_work);
+
+	/* actual delivery of data */
+	enc28j60_hw_tx(priv);
+}
+
+static irqreturn_t enc28j60_irq(int irq, void *dev_id)
+{
+	struct enc28j60_net *priv = dev_id;
+
+	/*
+	 * Can't do anything in interrupt context because we need to
+	 * block (spi_sync() is blocking) so fire of the interrupt
+	 * handling workqueue.
+	 * Remember that we access enc28j60 registers through SPI bus
+	 * via spi_sync() call.
+	 */
+	schedule_work(&priv->irq_work);
+
+	return IRQ_HANDLED;
+}
+
+static void enc28j60_tx_timeout(struct net_device *ndev)
+{
+	struct enc28j60_net *priv = netdev_priv(ndev);
+
+	if (netif_msg_timer(priv))
+		dev_err(&ndev->dev, DRV_NAME " tx timeout\n");
+
+	ndev->stats.tx_errors++;
+	/* can't restart safely under softirq */
+	schedule_work(&priv->restart_work);
+}
+
+/*
+ * Open/initialize the board. This is called (in the current kernel)
+ * sometime after booting when the 'ifconfig' program is run.
+ *
+ * This routine should set everything up anew at each open, even
+ * registers that "should" only need to be set once at boot, so that
+ * there is non-reboot way to recover if something goes wrong.
+ */
+static int enc28j60_net_open(struct net_device *dev)
+{
+	struct enc28j60_net *priv = netdev_priv(dev);
+
+	if (netif_msg_drv(priv))
+		printk(KERN_DEBUG DRV_NAME ": %s() enter\n", __FUNCTION__);
+
+	if (!is_valid_ether_addr(dev->dev_addr)) {
+		if (netif_msg_ifup(priv)) {
+			DECLARE_MAC_BUF(mac);
+			dev_err(&dev->dev, "invalid MAC address %s\n",
+				print_mac(mac, dev->dev_addr));
+		}
+		return -EADDRNOTAVAIL;
+	}
+	/* Reset the hardware here */
+	enc28j60_hw_disable(priv);
+	if (!enc28j60_hw_init(priv)) {
+		if (netif_msg_ifup(priv))
+			dev_err(&dev->dev, "hw_reset() failed\n");
+		return -EINVAL;
+	}
+	/* Update the MAC address (in case user has changed it) */
+	enc28j60_set_hw_macaddr(dev);
+	/* Enable interrupts */
+	enc28j60_hw_enable(priv);
+	/* check link status */
+	enc28j60_check_link_status(dev);
+	/* We are now ready to accept transmit requests from
+	 * the queueing layer of the networking.
+	 */
+	netif_start_queue(dev);
+
+	return 0;
+}
+
+/* The inverse routine to net_open(). */
+static int enc28j60_net_close(struct net_device *dev)
+{
+	struct enc28j60_net *priv = netdev_priv(dev);
+
+	if (netif_msg_drv(priv))
+		printk(KERN_DEBUG DRV_NAME ": %s() enter\n", __FUNCTION__);
+
+	enc28j60_hw_disable(priv);
+	netif_stop_queue(dev);
+
+	return 0;
+}
+
+/*
+ * Set or clear the multicast filter for this adapter
+ * num_addrs == -1	Promiscuous mode, receive all packets
+ * num_addrs == 0	Normal mode, filter out multicast packets
+ * num_addrs > 0	Multicast mode, receive normal and MC packets
+ */
+static void enc28j60_set_multicast_list(struct net_device *dev)
+{
+	struct enc28j60_net *priv = netdev_priv(dev);
+	int oldfilter = priv->rxfilter;
+
+	if (dev->flags & IFF_PROMISC) {
+		if (netif_msg_link(priv))
+			dev_info(&dev->dev, "promiscuous mode\n");
+		priv->rxfilter = RXFILTER_PROMISC;
+	} else if ((dev->flags & IFF_ALLMULTI) || dev->mc_count) {
+		if (netif_msg_link(priv))
+			dev_info(&dev->dev, "%smulticast mode\n",
+				(dev->flags & IFF_ALLMULTI) ? "all-" : "");
+		priv->rxfilter = RXFILTER_MULTI;
+	} else {
+		if (netif_msg_link(priv))
+			dev_info(&dev->dev, "normal mode\n");
+		priv->rxfilter = RXFILTER_NORMAL;
+	}
+
+	if (oldfilter != priv->rxfilter)
+		schedule_work(&priv->setrx_work);
+}
+
+static void enc28j60_setrx_work_handler(struct work_struct *work)
+{
+	struct enc28j60_net *priv =
+		container_of(work, struct enc28j60_net, setrx_work);
+
+	if (priv->rxfilter == RXFILTER_PROMISC) {
+		if (netif_msg_drv(priv))
+			printk(KERN_DEBUG DRV_NAME ": promiscuous mode\n");
+		locked_regb_write(priv, ERXFCON, 0x00);
+	} else if (priv->rxfilter == RXFILTER_MULTI) {
+		if (netif_msg_drv(priv))
+			printk(KERN_DEBUG DRV_NAME ": multicast mode\n");
+		locked_regb_write(priv, ERXFCON,
+					ERXFCON_UCEN | ERXFCON_CRCEN |
+					ERXFCON_BCEN | ERXFCON_MCEN);
+	} else {
+		if (netif_msg_drv(priv))
+			printk(KERN_DEBUG DRV_NAME ": normal mode\n");
+		locked_regb_write(priv, ERXFCON,
+					ERXFCON_UCEN | ERXFCON_CRCEN |
+					ERXFCON_BCEN);
+	}
+}
+
+static void enc28j60_restart_work_handler(struct work_struct *work)
+{
+	struct enc28j60_net *priv =
+			container_of(work, struct enc28j60_net, restart_work);
+	struct net_device *ndev = priv->netdev;
+	int ret;
+
+	rtnl_lock();
+	if (netif_running(ndev)) {
+		enc28j60_net_close(ndev);
+		ret = enc28j60_net_open(ndev);
+		if (unlikely(ret)) {
+			dev_info(&ndev->dev, " could not restart %d\n", ret);
+			dev_close(ndev);
+		}
+	}
+	rtnl_unlock();
+}
+
+/* ......................... ETHTOOL SUPPORT ........................... */
+
+static void
+enc28j60_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
+{
+	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
+	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
+	strlcpy(info->bus_info,
+		dev->dev.parent->bus_id, sizeof(info->bus_info));
+}
+
+static int
+enc28j60_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
+{
+	struct enc28j60_net *priv = netdev_priv(dev);
+
+	cmd->transceiver = XCVR_INTERNAL;
+	cmd->supported	= SUPPORTED_10baseT_Half
+			| SUPPORTED_10baseT_Full
+			| SUPPORTED_TP;
+	cmd->speed	= SPEED_10;
+	cmd->duplex	= priv->full_duplex ? DUPLEX_FULL : DUPLEX_HALF;
+	cmd->port	= PORT_TP;
+	cmd->autoneg	= AUTONEG_DISABLE;
+
+	return 0;
+}
+
+static int
+enc28j60_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
+{
+	return enc28j60_setlink(dev, cmd->autoneg, cmd->speed, cmd->duplex);
+}
+
+static u32 enc28j60_get_msglevel(struct net_device *dev)
+{
+	struct enc28j60_net *priv = netdev_priv(dev);
+	return priv->msg_enable;
+}
+
+static void enc28j60_set_msglevel(struct net_device *dev, u32 val)
+{
+	struct enc28j60_net *priv = netdev_priv(dev);
+	priv->msg_enable = val;
+}
+
+static const struct ethtool_ops enc28j60_ethtool_ops = {
+	.get_settings	= enc28j60_get_settings,
+	.set_settings	= enc28j60_set_settings,
+	.get_drvinfo	= enc28j60_get_drvinfo,
+	.get_msglevel	= enc28j60_get_msglevel,
+	.set_msglevel	= enc28j60_set_msglevel,
+};
+
+static int enc28j60_chipset_init(struct net_device *dev)
+{
+	struct enc28j60_net *priv = netdev_priv(dev);
+
+	return enc28j60_hw_init(priv);
+}
+
+static int __devinit enc28j60_probe(struct spi_device *spi)
+{
+	struct net_device *dev;
+	struct enc28j60_net *priv;
+	int ret = 0;
+
+	if (netif_msg_drv(&debug))
+		dev_info(&spi->dev, DRV_NAME " Ethernet driver %s loaded\n",
+			DRV_VERSION);
+
+	dev = alloc_etherdev(sizeof(struct enc28j60_net));
+	if (!dev) {
+		if (netif_msg_drv(&debug))
+			dev_err(&spi->dev, DRV_NAME
+				": unable to alloc new ethernet\n");
+		ret = -ENOMEM;
+		goto error_alloc;
+	}
+	priv = netdev_priv(dev);
+
+	priv->netdev = dev;	/* priv to netdev reference */
+	priv->spi = spi;	/* priv to spi reference */
+	priv->msg_enable = netif_msg_init(debug.msg_enable,
+						ENC28J60_MSG_DEFAULT);
+	mutex_init(&priv->lock);
+	INIT_WORK(&priv->tx_work, enc28j60_tx_work_handler);
+	INIT_WORK(&priv->setrx_work, enc28j60_setrx_work_handler);
+	INIT_WORK(&priv->irq_work, enc28j60_irq_work_handler);
+	INIT_WORK(&priv->restart_work, enc28j60_restart_work_handler);
+	dev_set_drvdata(&spi->dev, priv);	/* spi to priv reference */
+	SET_NETDEV_DEV(dev, &spi->dev);
+
+	if (!enc28j60_chipset_init(dev)) {
+		if (netif_msg_probe(priv))
+			dev_info(&spi->dev, DRV_NAME " chip not found\n");
+		ret = -EIO;
+		goto error_irq;
+	}
+	random_ether_addr(dev->dev_addr);
+	enc28j60_set_hw_macaddr(dev);
+
+	ret = request_irq(spi->irq, enc28j60_irq, IRQF_TRIGGER_FALLING,
+			  DRV_NAME, priv);
+	if (ret < 0) {
+		if (netif_msg_probe(priv))
+			dev_err(&spi->dev, DRV_NAME ": request irq %d failed "
+				"(ret = %d)\n", spi->irq, ret);
+		goto error_irq;
+	}
+
+	dev->if_port = IF_PORT_10BASET;
+	dev->irq = spi->irq;
+	dev->open = enc28j60_net_open;
+	dev->stop = enc28j60_net_close;
+	dev->hard_start_xmit = enc28j60_send_packet;
+	dev->set_multicast_list = &enc28j60_set_multicast_list;
+	dev->set_mac_address = enc28j60_set_mac_address;
+	dev->tx_timeout = &enc28j60_tx_timeout;
+	dev->watchdog_timeo = TX_TIMEOUT;
+	SET_ETHTOOL_OPS(dev, &enc28j60_ethtool_ops);
+
+	ret = register_netdev(dev);
+	if (ret) {
+		if (netif_msg_probe(priv))
+			dev_err(&spi->dev, "register netdev " DRV_NAME
+				" failed (ret = %d)\n", ret);
+		goto error_register;
+	}
+	dev_info(&dev->dev, DRV_NAME " driver registered\n");
+
+	return 0;
+
+error_register:
+	free_irq(spi->irq, priv);
+error_irq:
+	free_netdev(dev);
+error_alloc:
+	return ret;
+}
+
+static int enc28j60_remove(struct spi_device *spi)
+{
+	struct enc28j60_net *priv = dev_get_drvdata(&spi->dev);
+
+	if (netif_msg_drv(priv))
+		printk(KERN_DEBUG DRV_NAME ": remove\n");
+
+	unregister_netdev(priv->netdev);
+	free_irq(spi->irq, priv);
+	free_netdev(priv->netdev);
+
+	return 0;
+}
+
+static struct spi_driver enc28j60_driver = {
+	.driver = {
+		   .name = DRV_NAME,
+		   .bus = &spi_bus_type,
+		   .owner = THIS_MODULE,
+		   },
+	.probe = enc28j60_probe,
+	.remove = __devexit_p(enc28j60_remove),
+};
+
+static int __init enc28j60_init(void)
+{
+	return spi_register_driver(&enc28j60_driver);
+}
+
+module_init(enc28j60_init);
+
+static void __exit enc28j60_exit(void)
+{
+	spi_unregister_driver(&enc28j60_driver);
+}
+
+module_exit(enc28j60_exit);
+
+MODULE_DESCRIPTION(DRV_NAME " ethernet driver");
+MODULE_AUTHOR("Claudio Lanconelli <[email-masked]>");
+MODULE_LICENSE("GPL");
+module_param_named(debug, debug.msg_enable, int, 0);
+MODULE_PARM_DESC(debug, "Debug verbosity level (0=none, ..., ffff=all)");
diff --git a/drivers/net/enc28j60_hw.h b/drivers/net/enc28j60_hw.h
new file mode 100644
index 0000000..1a0b209
--- /dev/null
+++ b/drivers/net/enc28j60_hw.h
@@ -0,0 +1,309 @@
+/*
+ * enc28j60_hw.h: EDTP FrameThrower style enc28j60 registers
+ *
+ * $Id: enc28j60_hw.h,v 1.9 2007/12/14 11:59:16 claudio Exp $
+ */
+
+#ifndef _ENC28J60_HW_H
+#define _ENC28J60_HW_H
+
+/*
+ * ENC28J60 Control Registers
+ * Control register definitions are a combination of address,
+ * bank number, and Ethernet/MAC/PHY indicator bits.
+ * - Register address	(bits 0-4)
+ * - Bank number	(bits 5-6)
+ * - MAC/MII indicator	(bit 7)
+ */
+#define ADDR_MASK	0x1F
+#define BANK_MASK	0x60
+#define SPRD_MASK	0x80
+/* All-bank registers */
+#define EIE		0x1B
+#define EIR		0x1C
+#define ESTAT		0x1D
+#define ECON2		0x1E
+#define ECON1		0x1F
+/* Bank 0 registers */
+#define ERDPTL		(0x00|0x00)
+#define ERDPTH		(0x01|0x00)
+#define EWRPTL		(0x02|0x00)
+#define EWRPTH		(0x03|0x00)
+#define ETXSTL		(0x04|0x00)
+#define ETXSTH		(0x05|0x00)
+#define ETXNDL		(0x06|0x00)
+#define ETXNDH		(0x07|0x00)
+#define ERXSTL		(0x08|0x00)
+#define ERXSTH		(0x09|0x00)
+#define ERXNDL		(0x0A|0x00)
+#define ERXNDH		(0x0B|0x00)
+#define ERXRDPTL	(0x0C|0x00)
+#define ERXRDPTH	(0x0D|0x00)
+#define ERXWRPTL	(0x0E|0x00)
+#define ERXWRPTH	(0x0F|0x00)
+#define EDMASTL		(0x10|0x00)
+#define EDMASTH		(0x11|0x00)
+#define EDMANDL		(0x12|0x00)
+#define EDMANDH		(0x13|0x00)
+#define EDMADSTL	(0x14|0x00)
+#define EDMADSTH	(0x15|0x00)
+#define EDMACSL		(0x16|0x00)
+#define EDMACSH		(0x17|0x00)
+/* Bank 1 registers */
+#define EHT0		(0x00|0x20)
+#define EHT1		(0x01|0x20)
+#define EHT2		(0x02|0x20)
+#define EHT3		(0x03|0x20)
+#define EHT4		(0x04|0x20)
+#define EHT5		(0x05|0x20)
+#define EHT6		(0x06|0x20)
+#define EHT7		(0x07|0x20)
+#define EPMM0		(0x08|0x20)
+#define EPMM1		(0x09|0x20)
+#define EPMM2		(0x0A|0x20)
+#define EPMM3		(0x0B|0x20)
+#define EPMM4		(0x0C|0x20)
+#define EPMM5		(0x0D|0x20)
+#define EPMM6		(0x0E|0x20)
+#define EPMM7		(0x0F|0x20)
+#define EPMCSL		(0x10|0x20)
+#define EPMCSH		(0x11|0x20)
+#define EPMOL		(0x14|0x20)
+#define EPMOH		(0x15|0x20)
+#define EWOLIE		(0x16|0x20)
+#define EWOLIR		(0x17|0x20)
+#define ERXFCON		(0x18|0x20)
+#define EPKTCNT		(0x19|0x20)
+/* Bank 2 registers */
+#define MACON1		(0x00|0x40|SPRD_MASK)
+/* #define MACON2	(0x01|0x40|SPRD_MASK) */
+#define MACON3		(0x02|0x40|SPRD_MASK)
+#define MACON4		(0x03|0x40|SPRD_MASK)
+#define MABBIPG		(0x04|0x40|SPRD_MASK)
+#define MAIPGL		(0x06|0x40|SPRD_MASK)
+#define MAIPGH		(0x07|0x40|SPRD_MASK)
+#define MACLCON1	(0x08|0x40|SPRD_MASK)
+#define MACLCON2	(0x09|0x40|SPRD_MASK)
+#define MAMXFLL		(0x0A|0x40|SPRD_MASK)
+#define MAMXFLH		(0x0B|0x40|SPRD_MASK)
+#define MAPHSUP		(0x0D|0x40|SPRD_MASK)
+#define MICON		(0x11|0x40|SPRD_MASK)
+#define MICMD		(0x12|0x40|SPRD_MASK)
+#define MIREGADR	(0x14|0x40|SPRD_MASK)
+#define MIWRL		(0x16|0x40|SPRD_MASK)
+#define MIWRH		(0x17|0x40|SPRD_MASK)
+#define MIRDL		(0x18|0x40|SPRD_MASK)
+#define MIRDH		(0x19|0x40|SPRD_MASK)
+/* Bank 3 registers */
+#define MAADR1		(0x00|0x60|SPRD_MASK)
+#define MAADR0		(0x01|0x60|SPRD_MASK)
+#define MAADR3		(0x02|0x60|SPRD_MASK)
+#define MAADR2		(0x03|0x60|SPRD_MASK)
+#define MAADR5		(0x04|0x60|SPRD_MASK)
+#define MAADR4		(0x05|0x60|SPRD_MASK)
+#define EBSTSD		(0x06|0x60)
+#define EBSTCON		(0x07|0x60)
+#define EBSTCSL		(0x08|0x60)
+#define EBSTCSH		(0x09|0x60)
+#define MISTAT		(0x0A|0x60|SPRD_MASK)
+#define EREVID		(0x12|0x60)
+#define ECOCON		(0x15|0x60)
+#define EFLOCON		(0x17|0x60)
+#define EPAUSL		(0x18|0x60)
+#define EPAUSH		(0x19|0x60)
+/* PHY registers */
+#define PHCON1		0x00
+#define PHSTAT1		0x01
+#define PHHID1		0x02
+#define PHHID2		0x03
+#define PHCON2		0x10
+#define PHSTAT2		0x11
+#define PHIE		0x12
+#define PHIR		0x13
+#define PHLCON		0x14
+
+/* ENC28J60 EIE Register Bit Definitions */
+#define EIE_INTIE	0x80
+#define EIE_PKTIE	0x40
+#define EIE_DMAIE	0x20
+#define EIE_LINKIE	0x10
+#define EIE_TXIE	0x08
+/* #define EIE_WOLIE	0x04 (reserved) */
+#define EIE_TXERIE	0x02
+#define EIE_RXERIE	0x01
+/* ENC28J60 EIR Register Bit Definitions */
+#define EIR_PKTIF	0x40
+#define EIR_DMAIF	0x20
+#define EIR_LINKIF	0x10
+#define EIR_TXIF	0x08
+/* #define EIR_WOLIF	0x04 (reserved) */
+#define EIR_TXERIF	0x02
+#define EIR_RXERIF	0x01
+/* ENC28J60 ESTAT Register Bit Definitions */
+#define ESTAT_INT	0x80
+#define ESTAT_LATECOL	0x10
+#define ESTAT_RXBUSY	0x04
+#define ESTAT_TXABRT	0x02
+#define ESTAT_CLKRDY	0x01
+/* ENC28J60 ECON2 Register Bit Definitions */
+#define ECON2_AUTOINC	0x80
+#define ECON2_PKTDEC	0x40
+#define ECON2_PWRSV	0x20
+#define ECON2_VRPS	0x08
+/* ENC28J60 ECON1 Register Bit Definitions */
+#define ECON1_TXRST	0x80
+#define ECON1_RXRST	0x40
+#define ECON1_DMAST	0x20
+#define ECON1_CSUMEN	0x10
+#define ECON1_TXRTS	0x08
+#define ECON1_RXEN	0x04
+#define ECON1_BSEL1	0x02
+#define ECON1_BSEL0	0x01
+/* ENC28J60 MACON1 Register Bit Definitions */
+#define MACON1_LOOPBK	0x10
+#define MACON1_TXPAUS	0x08
+#define MACON1_RXPAUS	0x04
+#define MACON1_PASSALL	0x02
+#define MACON1_MARXEN	0x01
+/* ENC28J60 MACON2 Register Bit Definitions */
+#define MACON2_MARST	0x80
+#define MACON2_RNDRST	0x40
+#define MACON2_MARXRST	0x08
+#define MACON2_RFUNRST	0x04
+#define MACON2_MATXRST	0x02
+#define MACON2_TFUNRST	0x01
+/* ENC28J60 MACON3 Register Bit Definitions */
+#define MACON3_PADCFG2	0x80
+#define MACON3_PADCFG1	0x40
+#define MACON3_PADCFG0	0x20
+#define MACON3_TXCRCEN	0x10
+#define MACON3_PHDRLEN	0x08
+#define MACON3_HFRMLEN	0x04
+#define MACON3_FRMLNEN	0x02
+#define MACON3_FULDPX	0x01
+/* ENC28J60 MICMD Register Bit Definitions */
+#define MICMD_MIISCAN	0x02
+#define MICMD_MIIRD	0x01
+/* ENC28J60 MISTAT Register Bit Definitions */
+#define MISTAT_NVALID	0x04
+#define MISTAT_SCAN	0x02
+#define MISTAT_BUSY	0x01
+/* ENC28J60 ERXFCON Register Bit Definitions */
+#define ERXFCON_UCEN	0x80
+#define ERXFCON_ANDOR	0x40
+#define ERXFCON_CRCEN	0x20
+#define ERXFCON_PMEN	0x10
+#define ERXFCON_MPEN	0x08
+#define ERXFCON_HTEN	0x04
+#define ERXFCON_MCEN	0x02
+#define ERXFCON_BCEN	0x01
+
+/* ENC28J60 PHY PHCON1 Register Bit Definitions */
+#define PHCON1_PRST	0x8000
+#define PHCON1_PLOOPBK	0x4000
+#define PHCON1_PPWRSV	0x0800
+#define PHCON1_PDPXMD	0x0100
+/* ENC28J60 PHY PHSTAT1 Register Bit Definitions */
+#define PHSTAT1_PFDPX	0x1000
+#define PHSTAT1_PHDPX	0x0800
+#define PHSTAT1_LLSTAT	0x0004
+#define PHSTAT1_JBSTAT	0x0002
+/* ENC28J60 PHY PHSTAT2 Register Bit Definitions */
+#define PHSTAT2_TXSTAT	(1 << 13)
+#define PHSTAT2_RXSTAT	(1 << 12)
+#define PHSTAT2_COLSTAT	(1 << 11)
+#define PHSTAT2_LSTAT	(1 << 10)
+#define PHSTAT2_DPXSTAT	(1 << 9)
+#define PHSTAT2_PLRITY	(1 << 5)
+/* ENC28J60 PHY PHCON2 Register Bit Definitions */
+#define PHCON2_FRCLINK	0x4000
+#define PHCON2_TXDIS	0x2000
+#define PHCON2_JABBER	0x0400
+#define PHCON2_HDLDIS	0x0100
+/* ENC28J60 PHY PHIE Register Bit Definitions */
+#define PHIE_PLNKIE	(1 << 4)
+#define PHIE_PGEIE	(1 << 1)
+/* ENC28J60 PHY PHIR Register Bit Definitions */
+#define PHIR_PLNKIF	(1 << 4)
+#define PHIR_PGEIF	(1 << 1)
+
+/* ENC28J60 Packet Control Byte Bit Definitions */
+#define PKTCTRL_PHUGEEN		0x08
+#define PKTCTRL_PPADEN		0x04
+#define PKTCTRL_PCRCEN		0x02
+#define PKTCTRL_POVERRIDE	0x01
+
+/* ENC28J60 Transmit Status Vector */
+#define TSV_TXBYTECNT		0
+#define TSV_TXCOLLISIONCNT	16
+#define TSV_TXCRCERROR		20
+#define TSV_TXLENCHKERROR	21
+#define TSV_TXLENOUTOFRANGE	22
+#define TSV_TXDONE		23
+#define TSV_TXMULTICAST		24
+#define TSV_TXBROADCAST		25
+#define TSV_TXPACKETDEFER	26
+#define TSV_TXEXDEFER		27
+#define TSV_TXEXCOLLISION	28
+#define TSV_TXLATECOLLISION	29
+#define TSV_TXGIANT		30
+#define TSV_TXUNDERRUN		31
+#define TSV_TOTBYTETXONWIRE	32
+#define TSV_TXCONTROLFRAME	48
+#define TSV_TXPAUSEFRAME	49
+#define TSV_BACKPRESSUREAPP	50
+#define TSV_TXVLANTAGFRAME	51
+
+#define TSV_SIZE		7
+#define TSV_BYTEOF(x)		((x) / 8)
+#define TSV_BITMASK(x)		(1 << ((x) % 8))
+#define TSV_GETBIT(x, y)	(((x)[TSV_BYTEOF(y)] & TSV_BITMASK(y)) ? 1 : 0)
+
+/* ENC28J60 Receive Status Vector */
+#define RSV_RXLONGEVDROPEV	16
+#define RSV_CARRIEREV		18
+#define RSV_CRCERROR		20
+#define RSV_LENCHECKERR		21
+#define RSV_LENOUTOFRANGE	22
+#define RSV_RXOK		23
+#define RSV_RXMULTICAST		24
+#define RSV_RXBROADCAST		25
+#define RSV_DRIBBLENIBBLE	26
+#define RSV_RXCONTROLFRAME	27
+#define RSV_RXPAUSEFRAME	28
+#define RSV_RXUNKNOWNOPCODE	29
+#define RSV_RXTYPEVLAN		30
+
+#define RSV_SIZE		6
+#define RSV_BITMASK(x)		(1 << ((x) - 16))
+#define RSV_GETBIT(x, y)	(((x) & RSV_BITMASK(y)) ? 1 : 0)
+
+
+/* SPI operation codes */
+#define ENC28J60_READ_CTRL_REG	0x00
+#define ENC28J60_READ_BUF_MEM	0x3A
+#define ENC28J60_WRITE_CTRL_REG 0x40
+#define ENC28J60_WRITE_BUF_MEM	0x7A
+#define ENC28J60_BIT_FIELD_SET	0x80
+#define ENC28J60_BIT_FIELD_CLR	0xA0
+#define ENC28J60_SOFT_RESET	0xFF
+
+
+/* buffer boundaries applied to internal 8K ram
+ * entire available packet buffer space is allocated.
+ * Give TX buffer space for one full ethernet frame (~1500 bytes)
+ * receive buffer gets the rest */
+#define TXSTART_INIT		0x1A00
+#define TXEND_INIT		0x1FFF
+
+/* Put RX buffer at 0 as suggested by the Errata datasheet */
+#define RXSTART_INIT		0x0000
+#define RXEND_INIT		0x19FF
+
+/* maximum ethernet frame length */
+#define MAX_FRAMELEN		1518
+
+/* Prefered half duplex: LEDA: Link status LEDB: Rx/Tx activity */
+#define ENC28J60_LAMPS_MODE	0x3476
+
+#endif
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index d9107e5..3e196cf 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -922,6 +922,24 @@ config DM9000
 	  To compile this driver as a module, choose M here.  The module
 	  will be called dm9000.
 
+config ENC28J60
+	tristate "ENC28J60 support"
+	depends on EXPERIMENTAL && SPI && NET_ETHERNET
+	select CRC32
+	---help---
+	  Support for the Microchip EN28J60 ethernet chip.
+
+	  To compile this driver as a module, choose M here and read
+	  <file:Documentation/networking/net-modules.txt>.  The module will be
+	  called enc28j60.
+
+config ENC28J60_WRITEVERIFY
+	bool "Enable write verify"
+	depends on ENC28J60
+	---help---
+	  Enable the verify after the buffer write useful for debugging purpose.
+	  If unsure, say N.
+
 config SMC911X
 	tristate "SMSC LAN911[5678] support"
 	select CRC32
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index 0e5fde4..e91e3a3 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -216,6 +216,7 @@ obj-$(CONFIG_DM9000) += dm9000.o
 obj-$(CONFIG_FEC_8XX) += fec_8xx/
 obj-$(CONFIG_PASEMI_MAC) += pasemi_mac.o
 obj-$(CONFIG_MLX4_CORE) += mlx4/
+obj-$(CONFIG_ENC28J60) += enc28j60.o
 
 obj-$(CONFIG_MACB) += macb.o