/*
   * Linux Ethernet device driver for the 3Com Etherlink Plus (3C505)
   *      By Craig Southeren, Juha Laiho and Philip Blundell
   *
   * 3c505.c      This module implements an interface to the 3Com
   *              Etherlink Plus (3c505) Ethernet card. Linux device
   *              driver interface reverse engineered from the Linux 3C509
   *              device drivers. Some 3C505 information gleaned from
   *              the Crynwr packet driver. Still this driver would not
   *              be here without 3C505 technical reference provided by
   *              3Com.
   *
   * $Id: 3c505.c,v 1.10 1996/04/16 13:06:27 phil Exp $
   *
   * Authors:     Linux 3c505 device driver by
   *                      Craig Southeren, <craigs@ineluki.apana.org.au>
   *              Final debugging by
   *                      Andrew Tridgell, <tridge@nimbus.anu.edu.au>
   *              Auto irq/address, tuning, cleanup and v1.1.4+ kernel mods by
   *                      Juha Laiho, <jlaiho@ichaos.nullnet.fi>
   *              Linux 3C509 driver by
   *                      Donald Becker, <becker@super.org>
   *			(Now at <becker@scyld.com>)
   *              Crynwr packet driver by
   *                      Krishnan Gopalan and Gregg Stefancik,
   *                      Clemson University Engineering Computer Operations.
   *                      Portions of the code have been adapted from the 3c505
   *                         driver for NCSA Telnet by Bruce Orchard and later
   *                         modified by Warren Van Houten and krus@diku.dk.
   *              3C505 technical information provided by
   *                      Terry Murphy, of 3Com Network Adapter Division
   *              Linux 1.3.0 changes by
   *                      Alan Cox <Alan.Cox@linux.org>
   *              More debugging, DMA support, currently maintained by
   *                      Philip Blundell <philb@gnu.org>
   *              Multicard/soft configurable dma channel/rev 2 hardware support
   *                      by Christopher Collins <ccollins@pcug.org.au>
   *		Ethtool support (jgarzik), 11/17/2001
   */
  
  #define DRV_NAME	"3c505"
  #define DRV_VERSION	"1.10a"
  
  
  /* Theory of operation:
   *
   * The 3c505 is quite an intelligent board.  All communication with it is done
   * by means of Primary Command Blocks (PCBs); these are transferred using PIO
   * through the command register.  The card has 256k of on-board RAM, which is
   * used to buffer received packets.  It might seem at first that more buffers
   * are better, but in fact this isn't true.  From my tests, it seems that
   * more than about 10 buffers are unnecessary, and there is a noticeable
   * performance hit in having more active on the card.  So the majority of the
   * card's memory isn't, in fact, used.  Sadly, the card only has one transmit
   * buffer and, short of loading our own firmware into it (which is what some
   * drivers resort to) there's nothing we can do about this.
   *
   * We keep up to 4 "receive packet" commands active on the board at a time.
   * When a packet comes in, so long as there is a receive command active, the
   * board will send us a "packet received" PCB and then add the data for that
   * packet to the DMA queue.  If a DMA transfer is not already in progress, we
   * set one up to start uploading the data.  We have to maintain a list of
   * backlogged receive packets, because the card may decide to tell us about
   * a newly-arrived packet at any time, and we may not be able to start a DMA
   * transfer immediately (ie one may already be going on).  We can't NAK the
   * PCB, because then it would throw the packet away.
   *
   * Trying to send a PCB to the card at the wrong moment seems to have bad
   * effects.  If we send it a transmit PCB while a receive DMA is happening,
   * it will just NAK the PCB and so we will have wasted our time.  Worse, it
   * sometimes seems to interrupt the transfer.  The majority of the low-level
   * code is protected by one huge semaphore -- "busy" -- which is set whenever
   * it probably isn't safe to do anything to the card.  The receive routine
   * must gain a lock on "busy" before it can start a DMA transfer, and the
   * transmit routine must gain a lock before it sends the first PCB to the card.
   * The send_pcb() routine also has an internal semaphore to protect it against
   * being re-entered (which would be disastrous) -- this is needed because
   * several things can happen asynchronously (re-priming the receiver and
   * asking the card for statistics, for example).  send_pcb() will also refuse
   * to talk to the card at all if a DMA upload is happening.  The higher-level
   * networking code will reschedule a later retry if some part of the driver
   * is blocked.  In practice, this doesn't seem to happen very often.
   */
  
  /* This driver may now work with revision 2.x hardware, since all the read
   * operations on the HCR have been removed (we now keep our own softcopy).
   * But I don't have an old card to test it on.
   *
   * This has had the bad effect that the autoprobe routine is now a bit
   * less friendly to other devices.  However, it was never very good.
   * before, so I doubt it will hurt anybody.
   */
  
  /* The driver is a mess.  I took Craig's and Juha's code, and hacked it firstly
   * to make it more reliable, and secondly to add DMA mode.  Many things could
   * probably be done better; the concurrency protection is particularly awful.
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/string.h>
  #include <linux/interrupt.h>
  #include <linux/errno.h>
  #include <linux/in.h>

  #include <linux/ioport.h>
  #include <linux/spinlock.h>
  #include <linux/ethtool.h>
  #include <linux/delay.h>
  #include <linux/bitops.h>

  #include <linux/gfp.h>

  
  #include <asm/uaccess.h>
  #include <asm/io.h>
  #include <asm/dma.h>
  
  #include <linux/netdevice.h>
  #include <linux/etherdevice.h>
  #include <linux/skbuff.h>
  #include <linux/init.h>
  
  #include "3c505.h"
  
  /*********************************************************
   *
   *  define debug messages here as common strings to reduce space
   *
   *********************************************************/

  #define filename __FILE__

  #define timeout_msg "*** timeout at %s:%s (line %d) ***
  "

  #define TIMEOUT_MSG(lineno) \

  	pr_notice(timeout_msg, filename, __func__, (lineno))

  #define invalid_pcb_msg "*** invalid pcb length %d at %s:%s (line %d) ***
  "

  #define INVALID_PCB_MSG(len) \

  	pr_notice(invalid_pcb_msg, (len), filename, __func__, __LINE__)

  #define search_msg "%s: Looking for 3c505 adapter at address %#x..."

  #define stilllooking_msg "still looking..."

  #define found_msg "found.
  "

  #define notfound_msg "not found (reason = %d)
  "

  #define couldnot_msg "%s: 3c505 not found
  "

  
  /*********************************************************
   *
   *  various other debug stuff
   *
   *********************************************************/
  
  #ifdef ELP_DEBUG
  static int elp_debug = ELP_DEBUG;
  #else
  static int elp_debug;
  #endif
  #define debug elp_debug
  
  /*
   *  0 = no messages (well, some)
   *  1 = messages when high level commands performed
   *  2 = messages when low level commands performed
   *  3 = messages when interrupts received
   */
  
  /*****************************************************************
   *

   * List of I/O-addresses we try to auto-sense
   * Last element MUST BE 0!
   *****************************************************************/
  
  static int addr_list[] __initdata = {0x300, 0x280, 0x310, 0};
  
  /* Dma Memory related stuff */
  
  static unsigned long dma_mem_alloc(int size)
  {
  	int order = get_order(size);
  	return __get_dma_pages(GFP_KERNEL, order);
  }
  
  
  /*****************************************************************
   *
   * Functions for I/O (note the inline !)
   *
   *****************************************************************/
  
  static inline unsigned char inb_status(unsigned int base_addr)
  {
  	return inb(base_addr + PORT_STATUS);
  }
  
  static inline int inb_command(unsigned int base_addr)
  {
  	return inb(base_addr + PORT_COMMAND);
  }
  
  static inline void outb_control(unsigned char val, struct net_device *dev)
  {
  	outb(val, dev->base_addr + PORT_CONTROL);

  	((elp_device *)(netdev_priv(dev)))->hcr_val = val;

  }

  #define HCR_VAL(x)   (((elp_device *)(netdev_priv(x)))->hcr_val)

  
  static inline void outb_command(unsigned char val, unsigned int base_addr)
  {
  	outb(val, base_addr + PORT_COMMAND);
  }
  
  static inline unsigned int backlog_next(unsigned int n)
  {
  	return (n + 1) % BACKLOG_SIZE;
  }
  
  /*****************************************************************
   *
   *  useful functions for accessing the adapter
   *
   *****************************************************************/
  
  /*
   * use this routine when accessing the ASF bits as they are
   * changed asynchronously by the adapter
   */
  
  /* get adapter PCB status */
  #define	GET_ASF(addr) \
  	(get_status(addr)&ASF_PCB_MASK)
  
  static inline int get_status(unsigned int base_addr)
  {
  	unsigned long timeout = jiffies + 10*HZ/100;
  	register int stat1;
  	do {
  		stat1 = inb_status(base_addr);
  	} while (stat1 != inb_status(base_addr) && time_before(jiffies, timeout));
  	if (time_after_eq(jiffies, timeout))
  		TIMEOUT_MSG(__LINE__);
  	return stat1;
  }
  
  static inline void set_hsf(struct net_device *dev, int hsf)
  {

  	elp_device *adapter = netdev_priv(dev);

  	unsigned long flags;
  
  	spin_lock_irqsave(&adapter->lock, flags);
  	outb_control((HCR_VAL(dev) & ~HSF_PCB_MASK) | hsf, dev);
  	spin_unlock_irqrestore(&adapter->lock, flags);
  }

  static bool start_receive(struct net_device *, pcb_struct *);

  static inline void adapter_reset(struct net_device *dev)

  {
  	unsigned long timeout;

  	elp_device *adapter = netdev_priv(dev);

  	unsigned char orig_hcr = adapter->hcr_val;
  
  	outb_control(0, dev);
  
  	if (inb_status(dev->base_addr) & ACRF) {
  		do {
  			inb_command(dev->base_addr);
  			timeout = jiffies + 2*HZ/100;
  			while (time_before_eq(jiffies, timeout) && !(inb_status(dev->base_addr) & ACRF));
  		} while (inb_status(dev->base_addr) & ACRF);
  		set_hsf(dev, HSF_PCB_NAK);
  	}
  	outb_control(adapter->hcr_val | ATTN | DIR, dev);
  	mdelay(10);
  	outb_control(adapter->hcr_val & ~ATTN, dev);
  	mdelay(10);
  	outb_control(adapter->hcr_val | FLSH, dev);
  	mdelay(10);
  	outb_control(adapter->hcr_val & ~FLSH, dev);
  	mdelay(10);
  
  	outb_control(orig_hcr, dev);
  	if (!start_receive(dev, &adapter->tx_pcb))

  		pr_err("%s: start receive command failed
  ", dev->name);

  }
  
  /* Check to make sure that a DMA transfer hasn't timed out.  This should
   * never happen in theory, but seems to occur occasionally if the card gets
   * prodded at the wrong time.
   */
  static inline void check_3c505_dma(struct net_device *dev)
  {

  	elp_device *adapter = netdev_priv(dev);

  	if (adapter->dmaing && time_after(jiffies, adapter->current_dma.start_time + 10)) {
  		unsigned long flags, f;

  		pr_err("%s: DMA %s timed out, %d bytes left
  ", dev->name,
  			adapter->current_dma.direction ? "download" : "upload",
  			get_dma_residue(dev->dma));

  		spin_lock_irqsave(&adapter->lock, flags);
  		adapter->dmaing = 0;
  		adapter->busy = 0;

  		f=claim_dma_lock();
  		disable_dma(dev->dma);
  		release_dma_lock(f);

  		if (adapter->rx_active)
  			adapter->rx_active--;
  		outb_control(adapter->hcr_val & ~(DMAE | TCEN | DIR), dev);
  		spin_unlock_irqrestore(&adapter->lock, flags);
  	}
  }
  
  /* Primitive functions used by send_pcb() */

  static inline bool send_pcb_slow(unsigned int base_addr, unsigned char byte)

  {
  	unsigned long timeout;
  	outb_command(byte, base_addr);
  	for (timeout = jiffies + 5*HZ/100; time_before(jiffies, timeout);) {
  		if (inb_status(base_addr) & HCRE)

  			return false;

  	}

  	pr_warning("3c505: send_pcb_slow timed out
  ");

  	return true;

  }

  static inline bool send_pcb_fast(unsigned int base_addr, unsigned char byte)

  {
  	unsigned int timeout;
  	outb_command(byte, base_addr);
  	for (timeout = 0; timeout < 40000; timeout++) {
  		if (inb_status(base_addr) & HCRE)

  			return false;

  	}

  	pr_warning("3c505: send_pcb_fast timed out
  ");

  	return true;

  }
  
  /* Check to see if the receiver needs restarting, and kick it if so */
  static inline void prime_rx(struct net_device *dev)
  {

  	elp_device *adapter = netdev_priv(dev);

  	while (adapter->rx_active < ELP_RX_PCBS && netif_running(dev)) {
  		if (!start_receive(dev, &adapter->itx_pcb))
  			break;
  	}
  }
  
  /*****************************************************************
   *
   * send_pcb
   *   Send a PCB to the adapter.
   *
   *	output byte to command reg  --<--+
   *	wait until HCRE is non zero      |
   *	loop until all bytes sent   -->--+
   *	set HSF1 and HSF2 to 1
   *	output pcb length
   *	wait until ASF give ACK or NAK
   *	set HSF1 and HSF2 to 0
   *
   *****************************************************************/
  
  /* This can be quite slow -- the adapter is allowed to take up to 40ms
   * to respond to the initial interrupt.
   *
   * We run initially with interrupts turned on, but with a semaphore set
   * so that nobody tries to re-enter this code.  Once the first byte has
   * gone through, we turn interrupts off and then send the others (the
   * timeout is reduced to 500us).
   */

  static bool send_pcb(struct net_device *dev, pcb_struct * pcb)

  {
  	int i;
  	unsigned long timeout;

  	elp_device *adapter = netdev_priv(dev);

  	unsigned long flags;
  
  	check_3c505_dma(dev);
  
  	if (adapter->dmaing && adapter->current_dma.direction == 0)

  		return false;

  
  	/* Avoid contention */
  	if (test_and_set_bit(1, &adapter->send_pcb_semaphore)) {
  		if (elp_debug >= 3) {

  			pr_debug("%s: send_pcb entered while threaded
  ", dev->name);

  		}

  		return false;

  	}
  	/*
  	 * load each byte into the command register and
  	 * wait for the HCRE bit to indicate the adapter
  	 * had read the byte
  	 */
  	set_hsf(dev, 0);
  
  	if (send_pcb_slow(dev->base_addr, pcb->command))
  		goto abort;
  
  	spin_lock_irqsave(&adapter->lock, flags);
  
  	if (send_pcb_fast(dev->base_addr, pcb->length))
  		goto sti_abort;
  
  	for (i = 0; i < pcb->length; i++) {
  		if (send_pcb_fast(dev->base_addr, pcb->data.raw[i]))
  			goto sti_abort;
  	}
  
  	outb_control(adapter->hcr_val | 3, dev);	/* signal end of PCB */
  	outb_command(2 + pcb->length, dev->base_addr);
  
  	/* now wait for the acknowledgement */
  	spin_unlock_irqrestore(&adapter->lock, flags);
  
  	for (timeout = jiffies + 5*HZ/100; time_before(jiffies, timeout);) {
  		switch (GET_ASF(dev->base_addr)) {
  		case ASF_PCB_ACK:
  			adapter->send_pcb_semaphore = 0;

  			return true;

  
  		case ASF_PCB_NAK:
  #ifdef ELP_DEBUG

  			pr_debug("%s: send_pcb got NAK
  ", dev->name);

  #endif
  			goto abort;
  		}
  	}
  
  	if (elp_debug >= 1)

  		pr_debug("%s: timeout waiting for PCB acknowledge (status %02x)
  ",
  			dev->name, inb_status(dev->base_addr));

  	goto abort;
  
        sti_abort:
  	spin_unlock_irqrestore(&adapter->lock, flags);
        abort:
  	adapter->send_pcb_semaphore = 0;

  	return false;

  }
  
  
  /*****************************************************************
   *
   * receive_pcb
   *   Read a PCB from the adapter
   *
   *	wait for ACRF to be non-zero        ---<---+
   *	input a byte                               |
   *	if ASF1 and ASF2 were not both one         |
   *		before byte was read, loop      --->---+
   *	set HSF1 and HSF2 for ack
   *
   *****************************************************************/

  static bool receive_pcb(struct net_device *dev, pcb_struct * pcb)

  {
  	int i, j;
  	int total_length;
  	int stat;
  	unsigned long timeout;
  	unsigned long flags;

  	elp_device *adapter = netdev_priv(dev);

  
  	set_hsf(dev, 0);
  
  	/* get the command code */
  	timeout = jiffies + 2*HZ/100;
  	while (((stat = get_status(dev->base_addr)) & ACRF) == 0 && time_before(jiffies, timeout));
  	if (time_after_eq(jiffies, timeout)) {
  		TIMEOUT_MSG(__LINE__);

  		return false;

  	}
  	pcb->command = inb_command(dev->base_addr);
  
  	/* read the data length */
  	timeout = jiffies + 3*HZ/100;
  	while (((stat = get_status(dev->base_addr)) & ACRF) == 0 && time_before(jiffies, timeout));
  	if (time_after_eq(jiffies, timeout)) {
  		TIMEOUT_MSG(__LINE__);

  		pr_info("%s: status %02x
  ", dev->name, stat);

  		return false;

  	}
  	pcb->length = inb_command(dev->base_addr);
  
  	if (pcb->length > MAX_PCB_DATA) {
  		INVALID_PCB_MSG(pcb->length);
  		adapter_reset(dev);

  		return false;

  	}
  	/* read the data */
  	spin_lock_irqsave(&adapter->lock, flags);

  	for (i = 0; i < MAX_PCB_DATA; i++) {
  		for (j = 0; j < 20000; j++) {
  			stat = get_status(dev->base_addr);
  			if (stat & ACRF)
  				break;
  		}
  		pcb->data.raw[i] = inb_command(dev->base_addr);
  		if ((stat & ASF_PCB_MASK) == ASF_PCB_END || j >= 20000)
  			break;
  	}

  	spin_unlock_irqrestore(&adapter->lock, flags);

  	if (i >= MAX_PCB_DATA) {
  		INVALID_PCB_MSG(i);
  		return false;
  	}

  	if (j >= 20000) {
  		TIMEOUT_MSG(__LINE__);

  		return false;

  	}

  	/* the last "data" byte was really the length! */
  	total_length = pcb->data.raw[i];

  
  	/* safety check total length vs data length */
  	if (total_length != (pcb->length + 2)) {
  		if (elp_debug >= 2)

  			pr_warning("%s: mangled PCB received
  ", dev->name);

  		set_hsf(dev, HSF_PCB_NAK);

  		return false;

  	}
  
  	if (pcb->command == CMD_RECEIVE_PACKET_COMPLETE) {
  		if (test_and_set_bit(0, (void *) &adapter->busy)) {
  			if (backlog_next(adapter->rx_backlog.in) == adapter->rx_backlog.out) {
  				set_hsf(dev, HSF_PCB_NAK);

  				pr_warning("%s: PCB rejected, transfer in progress and backlog full
  ", dev->name);

  				pcb->command = 0;

  				return true;

  			} else {
  				pcb->command = 0xff;
  			}
  		}
  	}
  	set_hsf(dev, HSF_PCB_ACK);

  	return true;

  }
  
  /******************************************************
   *
   *  queue a receive command on the adapter so we will get an
   *  interrupt when a packet is received.
   *
   ******************************************************/

  static bool start_receive(struct net_device *dev, pcb_struct * tx_pcb)

  {

  	bool status;

  	elp_device *adapter = netdev_priv(dev);

  
  	if (elp_debug >= 3)

  		pr_debug("%s: restarting receiver
  ", dev->name);

  	tx_pcb->command = CMD_RECEIVE_PACKET;
  	tx_pcb->length = sizeof(struct Rcv_pkt);
  	tx_pcb->data.rcv_pkt.buf_seg
  	    = tx_pcb->data.rcv_pkt.buf_ofs = 0;		/* Unused */
  	tx_pcb->data.rcv_pkt.buf_len = 1600;
  	tx_pcb->data.rcv_pkt.timeout = 0;	/* set timeout to zero */
  	status = send_pcb(dev, tx_pcb);
  	if (status)
  		adapter->rx_active++;
  	return status;
  }
  
  /******************************************************
   *
   * extract a packet from the adapter
   * this routine is only called from within the interrupt
   * service routine, so no cli/sti calls are needed
   * note that the length is always assumed to be even
   *
   ******************************************************/
  
  static void receive_packet(struct net_device *dev, int len)
  {
  	int rlen;

  	elp_device *adapter = netdev_priv(dev);

  	void *target;
  	struct sk_buff *skb;
  	unsigned long flags;
  
  	rlen = (len + 1) & ~1;
  	skb = dev_alloc_skb(rlen + 2);
  
  	if (!skb) {

  		pr_warning("%s: memory squeeze, dropping packet
  ", dev->name);

  		target = adapter->dma_buffer;
  		adapter->current_dma.target = NULL;
  		/* FIXME: stats */
  		return;
  	}
  
  	skb_reserve(skb, 2);
  	target = skb_put(skb, rlen);
  	if ((unsigned long)(target + rlen) >= MAX_DMA_ADDRESS) {
  		adapter->current_dma.target = target;
  		target = adapter->dma_buffer;
  	} else {
  		adapter->current_dma.target = NULL;
  	}
  
  	/* if this happens, we die */
  	if (test_and_set_bit(0, (void *) &adapter->dmaing))

  		pr_err("%s: rx blocked, DMA in progress, dir %d
  ",
  			dev->name, adapter->current_dma.direction);

  	adapter->current_dma.direction = 0;
  	adapter->current_dma.length = rlen;
  	adapter->current_dma.skb = skb;
  	adapter->current_dma.start_time = jiffies;
  
  	outb_control(adapter->hcr_val | DIR | TCEN | DMAE, dev);
  
  	flags=claim_dma_lock();
  	disable_dma(dev->dma);
  	clear_dma_ff(dev->dma);
  	set_dma_mode(dev->dma, 0x04);	/* dma read */
  	set_dma_addr(dev->dma, isa_virt_to_bus(target));
  	set_dma_count(dev->dma, rlen);
  	enable_dma(dev->dma);
  	release_dma_lock(flags);
  
  	if (elp_debug >= 3) {

  		pr_debug("%s: rx DMA transfer started
  ", dev->name);

  	}
  
  	if (adapter->rx_active)
  		adapter->rx_active--;
  
  	if (!adapter->busy)

  		pr_warning("%s: receive_packet called, busy not set.
  ", dev->name);

  }
  
  /******************************************************
   *
   * interrupt handler
   *
   ******************************************************/

  static irqreturn_t elp_interrupt(int irq, void *dev_id)

  {
  	int len;
  	int dlen;
  	int icount = 0;

  	struct net_device *dev = dev_id;
  	elp_device *adapter = netdev_priv(dev);

  	unsigned long timeout;

  	spin_lock(&adapter->lock);
  
  	do {
  		/*
  		 * has a DMA transfer finished?
  		 */
  		if (inb_status(dev->base_addr) & DONE) {

  			if (!adapter->dmaing)
  				pr_warning("%s: phantom DMA completed
  ", dev->name);
  
  			if (elp_debug >= 3)
  				pr_debug("%s: %s DMA complete, status %02x
  ", dev->name,
  					adapter->current_dma.direction ? "tx" : "rx",
  					inb_status(dev->base_addr));

  
  			outb_control(adapter->hcr_val & ~(DMAE | TCEN | DIR), dev);
  			if (adapter->current_dma.direction) {
  				dev_kfree_skb_irq(adapter->current_dma.skb);
  			} else {
  				struct sk_buff *skb = adapter->current_dma.skb;
  				if (skb) {
  					if (adapter->current_dma.target) {
  				  	/* have already done the skb_put() */
  				  	memcpy(adapter->current_dma.target, adapter->dma_buffer, adapter->current_dma.length);
  					}
  					skb->protocol = eth_type_trans(skb,dev);

  					dev->stats.rx_bytes += skb->len;

  					netif_rx(skb);

  				}
  			}
  			adapter->dmaing = 0;
  			if (adapter->rx_backlog.in != adapter->rx_backlog.out) {
  				int t = adapter->rx_backlog.length[adapter->rx_backlog.out];
  				adapter->rx_backlog.out = backlog_next(adapter->rx_backlog.out);
  				if (elp_debug >= 2)

  					pr_debug("%s: receiving backlogged packet (%d)
  ", dev->name, t);

  				receive_packet(dev, t);
  			} else {
  				adapter->busy = 0;
  			}
  		} else {
  			/* has one timed out? */
  			check_3c505_dma(dev);
  		}
  
  		/*
  		 * receive a PCB from the adapter
  		 */
  		timeout = jiffies + 3*HZ/100;
  		while ((inb_status(dev->base_addr) & ACRF) != 0 && time_before(jiffies, timeout)) {
  			if (receive_pcb(dev, &adapter->irx_pcb)) {

  				switch (adapter->irx_pcb.command)

  				{
  				case 0:
  					break;
  					/*
  					 * received a packet - this must be handled fast
  					 */
  				case 0xff:
  				case CMD_RECEIVE_PACKET_COMPLETE:
  					/* if the device isn't open, don't pass packets up the stack */
  					if (!netif_running(dev))
  						break;
  					len = adapter->irx_pcb.data.rcv_resp.pkt_len;
  					dlen = adapter->irx_pcb.data.rcv_resp.buf_len;
  					if (adapter->irx_pcb.data.rcv_resp.timeout != 0) {

  						pr_err("%s: interrupt - packet not received correctly
  ", dev->name);

  					} else {
  						if (elp_debug >= 3) {

  							pr_debug("%s: interrupt - packet received of length %i (%i)
  ",
  								dev->name, len, dlen);

  						}
  						if (adapter->irx_pcb.command == 0xff) {
  							if (elp_debug >= 2)

  								pr_debug("%s: adding packet to backlog (len = %d)
  ",
  									dev->name, dlen);

  							adapter->rx_backlog.length[adapter->rx_backlog.in] = dlen;
  							adapter->rx_backlog.in = backlog_next(adapter->rx_backlog.in);
  						} else {
  							receive_packet(dev, dlen);
  						}
  						if (elp_debug >= 3)

  							pr_debug("%s: packet received
  ", dev->name);

  					}
  					break;
  
  					/*
  					 * 82586 configured correctly
  					 */
  				case CMD_CONFIGURE_82586_RESPONSE:
  					adapter->got[CMD_CONFIGURE_82586] = 1;
  					if (elp_debug >= 3)

  						pr_debug("%s: interrupt - configure response received
  ", dev->name);

  					break;
  
  					/*
  					 * Adapter memory configuration
  					 */
  				case CMD_CONFIGURE_ADAPTER_RESPONSE:
  					adapter->got[CMD_CONFIGURE_ADAPTER_MEMORY] = 1;
  					if (elp_debug >= 3)

  						pr_debug("%s: Adapter memory configuration %s.
  ", dev->name,

  						       adapter->irx_pcb.data.failed ? "failed" : "succeeded");
  					break;
  
  					/*
  					 * Multicast list loading
  					 */
  				case CMD_LOAD_MULTICAST_RESPONSE:
  					adapter->got[CMD_LOAD_MULTICAST_LIST] = 1;
  					if (elp_debug >= 3)

  						pr_debug("%s: Multicast address list loading %s.
  ", dev->name,

  						       adapter->irx_pcb.data.failed ? "failed" : "succeeded");
  					break;
  
  					/*
  					 * Station address setting
  					 */
  				case CMD_SET_ADDRESS_RESPONSE:
  					adapter->got[CMD_SET_STATION_ADDRESS] = 1;
  					if (elp_debug >= 3)

  						pr_debug("%s: Ethernet address setting %s.
  ", dev->name,

  						       adapter->irx_pcb.data.failed ? "failed" : "succeeded");
  					break;
  
  
  					/*
  					 * received board statistics
  					 */
  				case CMD_NETWORK_STATISTICS_RESPONSE:

  					dev->stats.rx_packets += adapter->irx_pcb.data.netstat.tot_recv;
  					dev->stats.tx_packets += adapter->irx_pcb.data.netstat.tot_xmit;
  					dev->stats.rx_crc_errors += adapter->irx_pcb.data.netstat.err_CRC;
  					dev->stats.rx_frame_errors += adapter->irx_pcb.data.netstat.err_align;
  					dev->stats.rx_fifo_errors += adapter->irx_pcb.data.netstat.err_ovrrun;
  					dev->stats.rx_over_errors += adapter->irx_pcb.data.netstat.err_res;

  					adapter->got[CMD_NETWORK_STATISTICS] = 1;
  					if (elp_debug >= 3)

  						pr_debug("%s: interrupt - statistics response received
  ", dev->name);

  					break;
  
  					/*
  					 * sent a packet
  					 */
  				case CMD_TRANSMIT_PACKET_COMPLETE:
  					if (elp_debug >= 3)

  						pr_debug("%s: interrupt - packet sent
  ", dev->name);

  					if (!netif_running(dev))
  						break;
  					switch (adapter->irx_pcb.data.xmit_resp.c_stat) {
  					case 0xffff:

  						dev->stats.tx_aborted_errors++;

  						pr_info("%s: transmit timed out, network cable problem?
  ", dev->name);

  						break;
  					case 0xfffe:

  						dev->stats.tx_fifo_errors++;

  						pr_info("%s: transmit timed out, FIFO underrun
  ", dev->name);

  						break;
  					}
  					netif_wake_queue(dev);
  					break;
  
  					/*
  					 * some unknown PCB
  					 */
  				default:

  					pr_debug("%s: unknown PCB received - %2.2x
  ",
  						dev->name, adapter->irx_pcb.command);

  					break;
  				}
  			} else {

  				pr_warning("%s: failed to read PCB on interrupt
  ", dev->name);

  				adapter_reset(dev);
  			}
  		}
  
  	} while (icount++ < 5 && (inb_status(dev->base_addr) & (ACRF | DONE)));
  
  	prime_rx(dev);
  
  	/*
  	 * indicate no longer in interrupt routine
  	 */
  	spin_unlock(&adapter->lock);
  	return IRQ_HANDLED;
  }
  
  
  /******************************************************
   *
   * open the board
   *
   ******************************************************/
  
  static int elp_open(struct net_device *dev)
  {

  	elp_device *adapter = netdev_priv(dev);

  	int retval;

  	if (elp_debug >= 3)

  		pr_debug("%s: request to open device
  ", dev->name);

  
  	/*
  	 * make sure we actually found the device
  	 */
  	if (adapter == NULL) {

  		pr_err("%s: Opening a non-existent physical device
  ", dev->name);

  		return -EAGAIN;
  	}
  	/*
  	 * disable interrupts on the board
  	 */
  	outb_control(0, dev);
  
  	/*
  	 * clear any pending interrupts
  	 */
  	inb_command(dev->base_addr);
  	adapter_reset(dev);
  
  	/*
  	 * no receive PCBs active
  	 */
  	adapter->rx_active = 0;
  
  	adapter->busy = 0;
  	adapter->send_pcb_semaphore = 0;
  	adapter->rx_backlog.in = 0;
  	adapter->rx_backlog.out = 0;

  	spin_lock_init(&adapter->lock);
  
  	/*
  	 * install our interrupt service routine
  	 */

  	if ((retval = request_irq(dev->irq, elp_interrupt, 0, dev->name, dev))) {

  		pr_err("%s: could not allocate IRQ%d
  ", dev->name, dev->irq);

  		return retval;
  	}
  	if ((retval = request_dma(dev->dma, dev->name))) {
  		free_irq(dev->irq, dev);

  		pr_err("%s: could not allocate DMA%d channel
  ", dev->name, dev->dma);

  		return retval;
  	}
  	adapter->dma_buffer = (void *) dma_mem_alloc(DMA_BUFFER_SIZE);
  	if (!adapter->dma_buffer) {

  		pr_err("%s: could not allocate DMA buffer
  ", dev->name);

  		free_dma(dev->dma);
  		free_irq(dev->irq, dev);
  		return -ENOMEM;
  	}
  	adapter->dmaing = 0;
  
  	/*
  	 * enable interrupts on the board
  	 */
  	outb_control(CMDE, dev);
  
  	/*
  	 * configure adapter memory: we need 10 multicast addresses, default==0
  	 */
  	if (elp_debug >= 3)

  		pr_debug("%s: sending 3c505 memory configuration command
  ", dev->name);

  	adapter->tx_pcb.command = CMD_CONFIGURE_ADAPTER_MEMORY;
  	adapter->tx_pcb.data.memconf.cmd_q = 10;
  	adapter->tx_pcb.data.memconf.rcv_q = 20;
  	adapter->tx_pcb.data.memconf.mcast = 10;
  	adapter->tx_pcb.data.memconf.frame = 20;
  	adapter->tx_pcb.data.memconf.rcv_b = 20;
  	adapter->tx_pcb.data.memconf.progs = 0;
  	adapter->tx_pcb.length = sizeof(struct Memconf);
  	adapter->got[CMD_CONFIGURE_ADAPTER_MEMORY] = 0;
  	if (!send_pcb(dev, &adapter->tx_pcb))

  		pr_err("%s: couldn't send memory configuration command
  ", dev->name);

  	else {
  		unsigned long timeout = jiffies + TIMEOUT;
  		while (adapter->got[CMD_CONFIGURE_ADAPTER_MEMORY] == 0 && time_before(jiffies, timeout));
  		if (time_after_eq(jiffies, timeout))
  			TIMEOUT_MSG(__LINE__);
  	}
  
  
  	/*
  	 * configure adapter to receive broadcast messages and wait for response
  	 */
  	if (elp_debug >= 3)

  		pr_debug("%s: sending 82586 configure command
  ", dev->name);

  	adapter->tx_pcb.command = CMD_CONFIGURE_82586;
  	adapter->tx_pcb.data.configure = NO_LOOPBACK | RECV_BROAD;
  	adapter->tx_pcb.length = 2;
  	adapter->got[CMD_CONFIGURE_82586] = 0;
  	if (!send_pcb(dev, &adapter->tx_pcb))

  		pr_err("%s: couldn't send 82586 configure command
  ", dev->name);

  	else {
  		unsigned long timeout = jiffies + TIMEOUT;
  		while (adapter->got[CMD_CONFIGURE_82586] == 0 && time_before(jiffies, timeout));
  		if (time_after_eq(jiffies, timeout))
  			TIMEOUT_MSG(__LINE__);
  	}
  
  	/* enable burst-mode DMA */
  	/* outb(0x1, dev->base_addr + PORT_AUXDMA); */
  
  	/*
  	 * queue receive commands to provide buffering
  	 */
  	prime_rx(dev);
  	if (elp_debug >= 3)

  		pr_debug("%s: %d receive PCBs active
  ", dev->name, adapter->rx_active);

  
  	/*
  	 * device is now officially open!
  	 */
  
  	netif_start_queue(dev);
  	return 0;
  }
  
  
  /******************************************************
   *
   * send a packet to the adapter
   *
   ******************************************************/

  static netdev_tx_t send_packet(struct net_device *dev, struct sk_buff *skb)

  {

  	elp_device *adapter = netdev_priv(dev);

  	unsigned long target;
  	unsigned long flags;
  
  	/*
  	 * make sure the length is even and no shorter than 60 bytes
  	 */
  	unsigned int nlen = (((skb->len < 60) ? 60 : skb->len) + 1) & (~1);
  
  	if (test_and_set_bit(0, (void *) &adapter->busy)) {
  		if (elp_debug >= 2)

  			pr_debug("%s: transmit blocked
  ", dev->name);

  		return false;

  	}

  	dev->stats.tx_bytes += nlen;

  	/*
  	 * send the adapter a transmit packet command. Ignore segment and offset
  	 * and make sure the length is even
  	 */
  	adapter->tx_pcb.command = CMD_TRANSMIT_PACKET;
  	adapter->tx_pcb.length = sizeof(struct Xmit_pkt);
  	adapter->tx_pcb.data.xmit_pkt.buf_ofs
  	    = adapter->tx_pcb.data.xmit_pkt.buf_seg = 0;	/* Unused */
  	adapter->tx_pcb.data.xmit_pkt.pkt_len = nlen;
  
  	if (!send_pcb(dev, &adapter->tx_pcb)) {
  		adapter->busy = 0;

  		return false;

  	}
  	/* if this happens, we die */
  	if (test_and_set_bit(0, (void *) &adapter->dmaing))

  		pr_debug("%s: tx: DMA %d in progress
  ", dev->name, adapter->current_dma.direction);

  
  	adapter->current_dma.direction = 1;
  	adapter->current_dma.start_time = jiffies;
  
  	if ((unsigned long)(skb->data + nlen) >= MAX_DMA_ADDRESS || nlen != skb->len) {

  		skb_copy_from_linear_data(skb, adapter->dma_buffer, nlen);

  		memset(adapter->dma_buffer+skb->len, 0, nlen-skb->len);
  		target = isa_virt_to_bus(adapter->dma_buffer);
  	}
  	else {
  		target = isa_virt_to_bus(skb->data);
  	}
  	adapter->current_dma.skb = skb;
  
  	flags=claim_dma_lock();
  	disable_dma(dev->dma);
  	clear_dma_ff(dev->dma);
  	set_dma_mode(dev->dma, 0x48);	/* dma memory -> io */
  	set_dma_addr(dev->dma, target);
  	set_dma_count(dev->dma, nlen);
  	outb_control(adapter->hcr_val | DMAE | TCEN, dev);
  	enable_dma(dev->dma);
  	release_dma_lock(flags);

  	if (elp_debug >= 3)

  		pr_debug("%s: DMA transfer started
  ", dev->name);

  	return true;

  }
  
  /*
   *	The upper layer thinks we timed out
   */

  static void elp_timeout(struct net_device *dev)
  {

  	int stat;
  
  	stat = inb_status(dev->base_addr);

  	pr_warning("%s: transmit timed out, lost %s?
  ", dev->name,
  		   (stat & ACRF) ? "interrupt" : "command");

  	if (elp_debug >= 1)

  		pr_debug("%s: status %#02x
  ", dev->name, stat);

  	dev->trans_start = jiffies; /* prevent tx timeout */

  	dev->stats.tx_dropped++;

  	netif_wake_queue(dev);
  }
  
  /******************************************************
   *
   * start the transmitter
   *    return 0 if sent OK, else return 1
   *
   ******************************************************/

  static netdev_tx_t elp_start_xmit(struct sk_buff *skb, struct net_device *dev)

  {
  	unsigned long flags;

  	elp_device *adapter = netdev_priv(dev);

  	spin_lock_irqsave(&adapter->lock, flags);
  	check_3c505_dma(dev);
  
  	if (elp_debug >= 3)

  		pr_debug("%s: request to send packet of length %d
  ", dev->name, (int) skb->len);

  
  	netif_stop_queue(dev);

  	/*
  	 * send the packet at skb->data for skb->len
  	 */
  	if (!send_packet(dev, skb)) {
  		if (elp_debug >= 2) {

  			pr_debug("%s: failed to transmit packet
  ", dev->name);

  		}
  		spin_unlock_irqrestore(&adapter->lock, flags);

  		return NETDEV_TX_BUSY;

  	}
  	if (elp_debug >= 3)

  		pr_debug("%s: packet of length %d sent
  ", dev->name, (int) skb->len);

  	prime_rx(dev);
  	spin_unlock_irqrestore(&adapter->lock, flags);
  	netif_start_queue(dev);

  	return NETDEV_TX_OK;

  }
  
  /******************************************************
   *
   * return statistics on the board
   *
   ******************************************************/
  
  static struct net_device_stats *elp_get_stats(struct net_device *dev)
  {

  	elp_device *adapter = netdev_priv(dev);

  
  	if (elp_debug >= 3)

  		pr_debug("%s: request for stats
  ", dev->name);

  
  	/* If the device is closed, just return the latest stats we have,
  	   - we cannot ask from the adapter without interrupts */
  	if (!netif_running(dev))

  		return &dev->stats;

  
  	/* send a get statistics command to the board */
  	adapter->tx_pcb.command = CMD_NETWORK_STATISTICS;
  	adapter->tx_pcb.length = 0;
  	adapter->got[CMD_NETWORK_STATISTICS] = 0;
  	if (!send_pcb(dev, &adapter->tx_pcb))

  		pr_err("%s: couldn't send get statistics command
  ", dev->name);

  	else {
  		unsigned long timeout = jiffies + TIMEOUT;
  		while (adapter->got[CMD_NETWORK_STATISTICS] == 0 && time_before(jiffies, timeout));
  		if (time_after_eq(jiffies, timeout)) {
  			TIMEOUT_MSG(__LINE__);

  			return &dev->stats;

  		}
  	}
  
  	/* statistics are now up to date */

  	return &dev->stats;

  }
  
  
  static void netdev_get_drvinfo(struct net_device *dev,
  			       struct ethtool_drvinfo *info)
  {
  	strcpy(info->driver, DRV_NAME);
  	strcpy(info->version, DRV_VERSION);
  	sprintf(info->bus_info, "ISA 0x%lx", dev->base_addr);
  }
  
  static u32 netdev_get_msglevel(struct net_device *dev)
  {
  	return debug;
  }
  
  static void netdev_set_msglevel(struct net_device *dev, u32 level)
  {
  	debug = level;
  }

  static const struct ethtool_ops netdev_ethtool_ops = {

  	.get_drvinfo		= netdev_get_drvinfo,
  	.get_msglevel		= netdev_get_msglevel,
  	.set_msglevel		= netdev_set_msglevel,
  };
  
  /******************************************************
   *
   * close the board
   *
   ******************************************************/
  
  static int elp_close(struct net_device *dev)
  {

  	elp_device *adapter = netdev_priv(dev);

  
  	if (elp_debug >= 3)

  		pr_debug("%s: request to close device
  ", dev->name);

  
  	netif_stop_queue(dev);
  
  	/* Someone may request the device statistic information even when
  	 * the interface is closed. The following will update the statistics
  	 * structure in the driver, so we'll be able to give current statistics.
  	 */
  	(void) elp_get_stats(dev);
  
  	/*
  	 * disable interrupts on the board
  	 */
  	outb_control(0, dev);
  
  	/*
  	 * release the IRQ
  	 */
  	free_irq(dev->irq, dev);
  
  	free_dma(dev->dma);
  	free_pages((unsigned long) adapter->dma_buffer, get_order(DMA_BUFFER_SIZE));
  
  	return 0;
  }
  
  
  /************************************************************
   *
   * Set multicast list
   * num_addrs==0: clear mc_list
   * num_addrs==-1: set promiscuous mode
   * num_addrs>0: set mc_list
   *
   ************************************************************/
  
  static void elp_set_mc_list(struct net_device *dev)
  {

  	elp_device *adapter = netdev_priv(dev);

  	struct netdev_hw_addr *ha;

  	int i;
  	unsigned long flags;
  
  	if (elp_debug >= 3)

  		pr_debug("%s: request to set multicast list
  ", dev->name);

  
  	spin_lock_irqsave(&adapter->lock, flags);

  	if (!(dev->flags & (IFF_PROMISC | IFF_ALLMULTI))) {
  		/* send a "load multicast list" command to the board, max 10 addrs/cmd */
  		/* if num_addrs==0 the list will be cleared */
  		adapter->tx_pcb.command = CMD_LOAD_MULTICAST_LIST;

  		adapter->tx_pcb.length = 6 * netdev_mc_count(dev);

  		i = 0;

  		netdev_for_each_mc_addr(ha, dev)
  			memcpy(adapter->tx_pcb.data.multicast[i++],
  			       ha->addr, 6);

  		adapter->got[CMD_LOAD_MULTICAST_LIST] = 0;
  		if (!send_pcb(dev, &adapter->tx_pcb))

  			pr_err("%s: couldn't send set_multicast command
  ", dev->name);

  		else {
  			unsigned long timeout = jiffies + TIMEOUT;
  			while (adapter->got[CMD_LOAD_MULTICAST_LIST] == 0 && time_before(jiffies, timeout));
  			if (time_after_eq(jiffies, timeout)) {
  				TIMEOUT_MSG(__LINE__);
  			}
  		}

  		if (!netdev_mc_empty(dev))

  			adapter->tx_pcb.data.configure = NO_LOOPBACK | RECV_BROAD | RECV_MULTI;
  		else		/* num_addrs == 0 */
  			adapter->tx_pcb.data.configure = NO_LOOPBACK | RECV_BROAD;
  	} else
  		adapter->tx_pcb.data.configure = NO_LOOPBACK | RECV_PROMISC;
  	/*
  	 * configure adapter to receive messages (as specified above)
  	 * and wait for response
  	 */
  	if (elp_debug >= 3)

  		pr_debug("%s: sending 82586 configure command
  ", dev->name);

  	adapter->tx_pcb.command = CMD_CONFIGURE_82586;
  	adapter->tx_pcb.length = 2;
  	adapter->got[CMD_CONFIGURE_82586] = 0;
  	if (!send_pcb(dev, &adapter->tx_pcb))
  	{
  		spin_unlock_irqrestore(&adapter->lock, flags);

  		pr_err("%s: couldn't send 82586 configure command
  ", dev->name);

  	}
  	else {
  		unsigned long timeout = jiffies + TIMEOUT;
  		spin_unlock_irqrestore(&adapter->lock, flags);
  		while (adapter->got[CMD_CONFIGURE_82586] == 0 && time_before(jiffies, timeout));
  		if (time_after_eq(jiffies, timeout))
  			TIMEOUT_MSG(__LINE__);
  	}
  }
  
  /************************************************************
   *
   * A couple of tests to see if there's 3C505 or not
   * Called only by elp_autodetect
   ************************************************************/
  
  static int __init elp_sense(struct net_device *dev)
  {
  	int addr = dev->base_addr;
  	const char *name = dev->name;
  	byte orig_HSR;
  
  	if (!request_region(addr, ELP_IO_EXTENT, "3c505"))
  		return -ENODEV;
  
  	orig_HSR = inb_status(addr);
  
  	if (elp_debug > 0)

  		pr_debug(search_msg, name, addr);

  
  	if (orig_HSR == 0xff) {
  		if (elp_debug > 0)

  			pr_cont(notfound_msg, 1);

  		goto out;
  	}
  
  	/* Wait for a while; the adapter may still be booting up */
  	if (elp_debug > 0)

  		pr_cont(stilllooking_msg);

  
  	if (orig_HSR & DIR) {
  		/* If HCR.DIR is up, we pull it down. HSR.DIR should follow. */
  		outb(0, dev->base_addr + PORT_CONTROL);

  		msleep(300);

  		if (inb_status(addr) & DIR) {
  			if (elp_debug > 0)

  				pr_cont(notfound_msg, 2);

  			goto out;
  		}
  	} else {
  		/* If HCR.DIR is down, we pull it up. HSR.DIR should follow. */
  		outb(DIR, dev->base_addr + PORT_CONTROL);

  		msleep(300);

  		if (!(inb_status(addr) & DIR)) {
  			if (elp_debug > 0)

  				pr_cont(notfound_msg, 3);

  			goto out;
  		}
  	}
  	/*
  	 * It certainly looks like a 3c505.
  	 */
  	if (elp_debug > 0)

  		pr_cont(found_msg);

  
  	return 0;
  out:
  	release_region(addr, ELP_IO_EXTENT);
  	return -ENODEV;
  }
  
  /*************************************************************
   *
   * Search through addr_list[] and try to find a 3C505
   * Called only by eplus_probe
   *************************************************************/
  
  static int __init elp_autodetect(struct net_device *dev)
  {
  	int idx = 0;
  
  	/* if base address set, then only check that address
  	   otherwise, run through the table */
  	if (dev->base_addr != 0) {	/* dev->base_addr == 0 ==> plain autodetect */
  		if (elp_sense(dev) == 0)
  			return dev->base_addr;
  	} else
  		while ((dev->base_addr = addr_list[idx++])) {
  			if (elp_sense(dev) == 0)
  				return dev->base_addr;
  		}
  
  	/* could not find an adapter */
  	if (elp_debug > 0)

  		pr_debug(couldnot_msg, dev->name);

  
  	return 0;		/* Because of this, the layer above will return -ENODEV */
  }

  static const struct net_device_ops elp_netdev_ops = {
  	.ndo_open		= elp_open,
  	.ndo_stop		= elp_close,
  	.ndo_get_stats 		= elp_get_stats,
  	.ndo_start_xmit		= elp_start_xmit,
  	.ndo_tx_timeout 	= elp_timeout,
  	.ndo_set_multicast_list = elp_set_mc_list,
  	.ndo_change_mtu		= eth_change_mtu,
  	.ndo_set_mac_address 	= eth_mac_addr,
  	.ndo_validate_addr	= eth_validate_addr,
  };

  
  /******************************************************
   *
   * probe for an Etherlink Plus board at the specified address
   *
   ******************************************************/
  
  /* There are three situations we need to be able to detect here:
  
   *  a) the card is idle
   *  b) the card is still booting up
   *  c) the card is stuck in a strange state (some DOS drivers do this)
   *
   * In case (a), all is well.  In case (b), we wait 10 seconds to see if the
   * card finishes booting, and carry on if so.  In case (c), we do a hard reset,
   * loop round, and hope for the best.
   *
   * This is all very unpleasant, but hopefully avoids the problems with the old
   * probe code (which had a 15-second delay if the card was idle, and didn't
   * work at all if it was in a weird state).
   */
  
  static int __init elplus_setup(struct net_device *dev)
  {

  	elp_device *adapter = netdev_priv(dev);

  	int i, tries, tries1, okay;
  	unsigned long timeout;
  	unsigned long cookie = 0;
  	int err = -ENODEV;

  	/*
  	 *  setup adapter structure
  	 */
  
  	dev->base_addr = elp_autodetect(dev);
  	if (!dev->base_addr)
  		return -ENODEV;
  
  	adapter->send_pcb_semaphore = 0;
  
  	for (tries1 = 0; tries1 < 3; tries1++) {
  		outb_control((adapter->hcr_val | CMDE) & ~DIR, dev);
  		/* First try to write just one byte, to see if the card is
  		 * responding at all normally.
  		 */
  		timeout = jiffies + 5*HZ/100;
  		okay = 0;
  		while (time_before(jiffies, timeout) && !(inb_status(dev->base_addr) & HCRE));
  		if ((inb_status(dev->base_addr) & HCRE)) {
  			outb_command(0, dev->base_addr);	/* send a spurious byte */
  			timeout = jiffies + 5*HZ/100;
  			while (time_before(jiffies, timeout) && !(inb_status(dev->base_addr) & HCRE));
  			if (inb_status(dev->base_addr) & HCRE)
  				okay = 1;
  		}
  		if (!okay) {
  			/* Nope, it's ignoring the command register.  This means that
  			 * either it's still booting up, or it's died.
  			 */

  			pr_err("%s: command register wouldn't drain, ", dev->name);

  			if ((inb_status(dev->base_addr) & 7) == 3) {
  				/* If the adapter status is 3, it *could* still be booting.
  				 * Give it the benefit of the doubt for 10 seconds.
  				 */

  				pr_cont("assuming 3c505 still starting
  ");

  				timeout = jiffies + 10*HZ;
  				while (time_before(jiffies, timeout) && (inb_status(dev->base_addr) & 7));
  				if (inb_status(dev->base_addr) & 7) {

  					pr_err("%s: 3c505 failed to start
  ", dev->name);

  				} else {
  					okay = 1;  /* It started */
  				}
  			} else {
  				/* Otherwise, it must just be in a strange
  				 * state.  We probably need to kick it.
  				 */

  				pr_cont("3c505 is sulking
  ");

  			}
  		}
  		for (tries = 0; tries < 5 && okay; tries++) {
  
  			/*
  			 * Try to set the Ethernet address, to make sure that the board
  			 * is working.
  			 */
  			adapter->tx_pcb.command = CMD_STATION_ADDRESS;
  			adapter->tx_pcb.length = 0;
  			cookie = probe_irq_on();
  			if (!send_pcb(dev, &adapter->tx_pcb)) {

  				pr_err("%s: could not send first PCB
  ", dev->name);

  				probe_irq_off(cookie);
  				continue;
  			}
  			if (!receive_pcb(dev, &adapter->rx_pcb)) {

  				pr_err("%s: could not read first PCB
  ", dev->name);

  				probe_irq_off(cookie);
  				continue;
  			}
  			if ((adapter->rx_pcb.command != CMD_ADDRESS_RESPONSE) ||
  			    (adapter->rx_pcb.length != 6)) {

  				pr_err("%s: first PCB wrong (%d, %d)
  ", dev->name,
  					adapter->rx_pcb.command, adapter->rx_pcb.length);

  				probe_irq_off(cookie);
  				continue;
  			}
  			goto okay;
  		}
  		/* It's broken.  Do a hard reset to re-initialise the board,
  		 * and try again.
  		 */

  		pr_info("%s: resetting adapter
  ", dev->name);

  		outb_control(adapter->hcr_val | FLSH | ATTN, dev);
  		outb_control(adapter->hcr_val & ~(FLSH | ATTN), dev);
  	}

  	pr_err("%s: failed to initialise 3c505
  ", dev->name);

  	goto out;
  
        okay:
  	if (dev->irq) {		/* Is there a preset IRQ? */
  		int rpt = probe_irq_off(cookie);
  		if (dev->irq != rpt) {

  			pr_warning("%s: warning, irq %d configured but %d detected
  ", dev->name, dev->irq, rpt);

  		}
  		/* if dev->irq == probe_irq_off(cookie), all is well */
  	} else		       /* No preset IRQ; just use what we can detect */
  		dev->irq = probe_irq_off(cookie);
  	switch (dev->irq) {    /* Legal, sane? */
  	case 0:

  		pr_err("%s: IRQ probe failed: check 3c505 jumpers.
  ",

  		       dev->name);
  		goto out;
  	case 1:
  	case 6:
  	case 8:
  	case 13:

  		pr_err("%s: Impossible IRQ %d reported by probe_irq_off().
  ",

  		       dev->name, dev->irq);
  		       goto out;
  	}
  	/*
  	 *  Now we have the IRQ number so we can disable the interrupts from
  	 *  the board until the board is opened.
  	 */
  	outb_control(adapter->hcr_val & ~CMDE, dev);
  
  	/*
  	 * copy Ethernet address into structure
  	 */
  	for (i = 0; i < 6; i++)
  		dev->dev_addr[i] = adapter->rx_pcb.data.eth_addr[i];
  
  	/* find a DMA channel */
  	if (!dev->dma) {
  		if (dev->mem_start) {
  			dev->dma = dev->mem_start & 7;
  		}
  		else {

  			pr_warning("%s: warning, DMA channel not specified, using default
  ", dev->name);

  			dev->dma = ELP_DMA;
  		}
  	}
  
  	/*
  	 * print remainder of startup message
  	 */

  	pr_info("%s: 3c505 at %#lx, irq %d, dma %d, addr %pM, ",
  		dev->name, dev->base_addr, dev->irq, dev->dma, dev->dev_addr);

  	/*
  	 * read more information from the adapter
  	 */
  
  	adapter->tx_pcb.command = CMD_ADAPTER_INFO;
  	adapter->tx_pcb.length = 0;
  	if (!send_pcb(dev, &adapter->tx_pcb) ||
  	    !receive_pcb(dev, &adapter->rx_pcb) ||
  	    (adapter->rx_pcb.command != CMD_ADAPTER_INFO_RESPONSE) ||
  	    (adapter->rx_pcb.length != 10)) {

  		pr_cont("not responding to second PCB
  ");

  	}

  	pr_cont("rev %d.%d, %dk
  ", adapter->rx_pcb.data.info.major_vers,
  		adapter->rx_pcb.data.info.minor_vers, adapter->rx_pcb.data.info.RAM_sz);

  
  	/*
  	 * reconfigure the adapter memory to better suit our purposes
  	 */
  	adapter->tx_pcb.command = CMD_CONFIGURE_ADAPTER_MEMORY;
  	adapter->tx_pcb.length = 12;
  	adapter->tx_pcb.data.memconf.cmd_q = 8;
  	adapter->tx_pcb.data.memconf.rcv_q = 8;
  	adapter->tx_pcb.data.memconf.mcast = 10;
  	adapter->tx_pcb.data.memconf.frame = 10;
  	adapter->tx_pcb.data.memconf.rcv_b = 10;
  	adapter->tx_pcb.data.memconf.progs = 0;
  	if (!send_pcb(dev, &adapter->tx_pcb) ||
  	    !receive_pcb(dev, &adapter->rx_pcb) ||
  	    (adapter->rx_pcb.command != CMD_CONFIGURE_ADAPTER_RESPONSE) ||
  	    (adapter->rx_pcb.length != 2)) {

  		pr_err("%s: could not configure adapter memory
  ", dev->name);

  	}
  	if (adapter->rx_pcb.data.configure) {

  		pr_err("%s: adapter configuration failed
  ", dev->name);

  	}

  	dev->netdev_ops = &elp_netdev_ops;

  	dev->watchdog_timeo = 10*HZ;

  	dev->ethtool_ops = &netdev_ethtool_ops;		/* local */

  	dev->mem_start = dev->mem_end = 0;
  
  	err = register_netdev(dev);
  	if (err)
  		goto out;
  
  	return 0;
  out:
  	release_region(dev->base_addr, ELP_IO_EXTENT);
  	return err;
  }
  
  #ifndef MODULE
  struct net_device * __init elplus_probe(int unit)
  {
  	struct net_device *dev = alloc_etherdev(sizeof(elp_device));
  	int err;
  	if (!dev)
  		return ERR_PTR(-ENOMEM);
  
  	sprintf(dev->name, "eth%d", unit);
  	netdev_boot_setup_check(dev);
  
  	err = elplus_setup(dev);
  	if (err) {
  		free_netdev(dev);
  		return ERR_PTR(err);
  	}
  	return dev;
  }
  
  #else
  static struct net_device *dev_3c505[ELP_MAX_CARDS];
  static int io[ELP_MAX_CARDS];
  static int irq[ELP_MAX_CARDS];
  static int dma[ELP_MAX_CARDS];
  module_param_array(io, int, NULL, 0);
  module_param_array(irq, int, NULL, 0);
  module_param_array(dma, int, NULL, 0);
  MODULE_PARM_DESC(io, "EtherLink Plus I/O base address(es)");
  MODULE_PARM_DESC(irq, "EtherLink Plus IRQ number(s) (assigned)");
  MODULE_PARM_DESC(dma, "EtherLink Plus DMA channel(s)");

  int __init init_module(void)

  {
  	int this_dev, found = 0;
  
  	for (this_dev = 0; this_dev < ELP_MAX_CARDS; this_dev++) {
  		struct net_device *dev = alloc_etherdev(sizeof(elp_device));
  		if (!dev)
  			break;
  
  		dev->irq = irq[this_dev];
  		dev->base_addr = io[this_dev];
  		if (dma[this_dev]) {
  			dev->dma = dma[this_dev];
  		} else {
  			dev->dma = ELP_DMA;

  			pr_warning("3c505.c: warning, using default DMA channel,
  ");

  		}
  		if (io[this_dev] == 0) {
  			if (this_dev) {
  				free_netdev(dev);
  				break;
  			}

  			pr_notice("3c505.c: module autoprobe not recommended, give io=xx.
  ");

  		}
  		if (elplus_setup(dev) != 0) {

  			pr_warning("3c505.c: Failed to register card at 0x%x.
  ", io[this_dev]);

  			free_netdev(dev);
  			break;
  		}
  		dev_3c505[this_dev] = dev;
  		found++;
  	}
  	if (!found)
  		return -ENODEV;
  	return 0;
  }

  void __exit cleanup_module(void)

  {
  	int this_dev;
  
  	for (this_dev = 0; this_dev < ELP_MAX_CARDS; this_dev++) {
  		struct net_device *dev = dev_3c505[this_dev];
  		if (dev) {
  			unregister_netdev(dev);
  			release_region(dev->base_addr, ELP_IO_EXTENT);
  			free_netdev(dev);
  		}
  	}
  }
  
  #endif				/* MODULE */
  MODULE_LICENSE("GPL");