drivers/net/isa-skeleton.c - kernel/msm - Gitiles

 /* isa-skeleton.c: A network driver outline for linux.
  *
  *	Written 1993-94 by Donald Becker.
  *
  *	Copyright 1993 United States Government as represented by the
  *	Director, National Security Agency.
  *
  *	This software may be used and distributed according to the terms
  *	of the GNU General Public License, incorporated herein by reference.
  *
  *	The author may be reached as becker@scyld.com, or C/O
  *	Scyld Computing Corporation
  *	410 Severn Ave., Suite 210
  *	Annapolis MD 21403
  *
  *	This file is an outline for writing a network device driver for the
  *	the Linux operating system.
  *
  *	To write (or understand) a driver, have a look at the "loopback.c" file to
  *	get a feel of what is going on, and then use the code below as a skeleton
  *	for the new driver.
  *
  */

 static const char *version =
 	"isa-skeleton.c:v1.51 9/24/94 Donald Becker (becker@cesdis.gsfc.nasa.gov)\n";

 /*
  *  Sources:
  *	List your sources of programming information to document that
  *	the driver is your own creation, and give due credit to others
  *	that contributed to the work. Remember that GNU project code
  *	cannot use proprietary or trade secret information. Interface
  *	definitions are generally considered non-copyrightable to the
  *	extent that the same names and structures must be used to be
  *	compatible.
  *
  *	Finally, keep in mind that the Linux kernel is has an API, not
  *	ABI. Proprietary object-code-only distributions are not permitted
  *	under the GPL.
  */

 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/fcntl.h>
 #include <linux/interrupt.h>
 #include <linux/ioport.h>
 #include <linux/in.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/spinlock.h>
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/skbuff.h>
 #include <linux/bitops.h>

 #include <asm/system.h>
 #include <asm/io.h>
 #include <asm/dma.h>

 /*
  * The name of the card. Is used for messages and in the requests for
  * io regions, irqs and dma channels
  */
 static const char* cardname = "netcard";

 /* First, a few definitions that the brave might change. */

 /* A zero-terminated list of I/O addresses to be probed. */
 static unsigned int netcard_portlist[] __initdata =
    { 0x200, 0x240, 0x280, 0x2C0, 0x300, 0x320, 0x340, 0};

 /* use 0 for production, 1 for verification, >2 for debug */
 #ifndef NET_DEBUG
 #define NET_DEBUG 2
 #endif
 static unsigned int net_debug = NET_DEBUG;

 /* The number of low I/O ports used by the ethercard. */
 #define NETCARD_IO_EXTENT	32

 #define MY_TX_TIMEOUT  ((400*HZ)/1000)

 /* Information that need to be kept for each board. */
 struct net_local {
 	struct net_device_stats stats;
 	long open_time;			/* Useless example local info. */

 	/* Tx control lock.  This protects the transmit buffer ring
 	 * state along with the "tx full" state of the driver.  This
 	 * means all netif_queue flow control actions are protected
 	 * by this lock as well.
 	 */
 	spinlock_t lock;
 };

 /* The station (ethernet) address prefix, used for IDing the board. */
 #define SA_ADDR0 0x00
 #define SA_ADDR1 0x42
 #define SA_ADDR2 0x65

 /* Index to functions, as function prototypes. */

 static int	netcard_probe1(struct net_device *dev, int ioaddr);
 static int	net_open(struct net_device *dev);
 static int	net_send_packet(struct sk_buff *skb, struct net_device *dev);
 static irqreturn_t net_interrupt(int irq, void *dev_id);
 static void	net_rx(struct net_device *dev);
 static int	net_close(struct net_device *dev);
 static struct	net_device_stats *net_get_stats(struct net_device *dev);
 static void	set_multicast_list(struct net_device *dev);
 static void     net_tx_timeout(struct net_device *dev);


 /* Example routines you must write ;->. */
 #define tx_done(dev) 1
 static void	hardware_send_packet(short ioaddr, char *buf, int length);
 static void 	chipset_init(struct net_device *dev, int startp);

 /*
  * Check for a network adaptor of this type, and return '0' iff one exists.
  * If dev->base_addr == 0, probe all likely locations.
  * If dev->base_addr == 1, always return failure.
  * If dev->base_addr == 2, allocate space for the device and return success
  * (detachable devices only).
  */
 static int __init do_netcard_probe(struct net_device *dev)
 {
 	int i;
 	int base_addr = dev->base_addr;
 	int irq = dev->irq;

 	if (base_addr > 0x1ff)    /* Check a single specified location. */
 		return netcard_probe1(dev, base_addr);
 	else if (base_addr != 0)  /* Don't probe at all. */
 		return -ENXIO;

 	for (i = 0; netcard_portlist[i]; i++) {
 		int ioaddr = netcard_portlist[i];
 		if (netcard_probe1(dev, ioaddr) == 0)
 			return 0;
 		dev->irq = irq;
 	}

 	return -ENODEV;
 }

 static void cleanup_card(struct net_device *dev)
 {
 #ifdef jumpered_dma
 	free_dma(dev->dma);
 #endif
 #ifdef jumpered_interrupts
 	free_irq(dev->irq, dev);
 #endif
 	release_region(dev->base_addr, NETCARD_IO_EXTENT);
 }

 #ifndef MODULE
 struct net_device * __init netcard_probe(int unit)
 {
 	struct net_device *dev = alloc_etherdev(sizeof(struct net_local));
 	int err;

 	if (!dev)
 		return ERR_PTR(-ENOMEM);

 	sprintf(dev->name, "eth%d", unit);
 	netdev_boot_setup_check(dev);

 	err = do_netcard_probe(dev);
 	if (err)
 		goto out;
 	return dev;
 out:
 	free_netdev(dev);
 	return ERR_PTR(err);
 }
 #endif

 static const struct net_device_ops netcard_netdev_ops = {
 	.ndo_open		= net_open,
 	.ndo_stop		= net_close,
 	.ndo_start_xmit		= net_send_packet,
 	.ndo_get_stats		= net_get_stats,
 	.ndo_set_multicast_list	= set_multicast_list,
 	.ndo_tx_timeout		= net_tx_timeout,
 	.ndo_validate_addr	= eth_validate_addr,
 	.ndo_set_mac_address	= eth_mac_addr,
 	.ndo_change_mtu		= eth_change_mtu,
 };

 /*
  * This is the real probe routine. Linux has a history of friendly device
  * probes on the ISA bus. A good device probes avoids doing writes, and
  * verifies that the correct device exists and functions.
  */
 static int __init netcard_probe1(struct net_device *dev, int ioaddr)
 {
 	struct net_local *np;
 	static unsigned version_printed;
 	int i;
 	int err = -ENODEV;

 	/* Grab the region so that no one else tries to probe our ioports. */
 	if (!request_region(ioaddr, NETCARD_IO_EXTENT, cardname))
 		return -EBUSY;

 	/*
 	 * For ethernet adaptors the first three octets of the station address
 	 * contains the manufacturer's unique code. That might be a good probe
 	 * method. Ideally you would add additional checks.
 	 */
 	if (inb(ioaddr + 0) != SA_ADDR0
 		||	 inb(ioaddr + 1) != SA_ADDR1
 		||	 inb(ioaddr + 2) != SA_ADDR2)
 		goto out;

 	if (net_debug  &&  version_printed++ == 0)
 		printk(KERN_DEBUG "%s", version);

 	printk(KERN_INFO "%s: %s found at %#3x, ", dev->name, cardname, ioaddr);

 	/* Fill in the 'dev' fields. */
 	dev->base_addr = ioaddr;

 	/* Retrieve and print the ethernet address. */
 	for (i = 0; i < 6; i++)
 		dev->dev_addr[i] = inb(ioaddr + i);

 	printk("%pM", dev->dev_addr);

 	err = -EAGAIN;
 #ifdef jumpered_interrupts
 	/*
 	 * If this board has jumpered interrupts, allocate the interrupt
 	 * vector now. There is no point in waiting since no other device
 	 * can use the interrupt, and this marks the irq as busy. Jumpered
 	 * interrupts are typically not reported by the boards, and we must
 	 * used autoIRQ to find them.
 	 */

 	if (dev->irq == -1)
 		;	/* Do nothing: a user-level program will set it. */
 	else if (dev->irq < 2) {	/* "Auto-IRQ" */
 		unsigned long irq_mask = probe_irq_on();
 		/* Trigger an interrupt here. */

 		dev->irq = probe_irq_off(irq_mask);
 		if (net_debug >= 2)
 			printk(" autoirq is %d", dev->irq);
 	} else if (dev->irq == 2)
 		/*
 		 * Fixup for users that don't know that IRQ 2 is really
 		 * IRQ9, or don't know which one to set.
 		 */
 		dev->irq = 9;

 	{
 		int irqval = request_irq(dev->irq, &net_interrupt, 0, cardname, dev);
 		if (irqval) {
 			printk("%s: unable to get IRQ %d (irqval=%d).\n",
 				   dev->name, dev->irq, irqval);
 			goto out;
 		}
 	}
 #endif	/* jumpered interrupt */
 #ifdef jumpered_dma
 	/*
 	 * If we use a jumpered DMA channel, that should be probed for and
 	 * allocated here as well. See lance.c for an example.
 	 */
 	if (dev->dma == 0) {
 		if (request_dma(dev->dma, cardname)) {
 			printk("DMA %d allocation failed.\n", dev->dma);
 			goto out1;
 		} else
 			printk(", assigned DMA %d.\n", dev->dma);
 	} else {
 		short dma_status, new_dma_status;

 		/* Read the DMA channel status registers. */
 		dma_status = ((inb(DMA1_STAT_REG) >> 4) & 0x0f) |
 			(inb(DMA2_STAT_REG) & 0xf0);
 		/* Trigger a DMA request, perhaps pause a bit. */
 		outw(0x1234, ioaddr + 8);
 		/* Re-read the DMA status registers. */
 		new_dma_status = ((inb(DMA1_STAT_REG) >> 4) & 0x0f) |
 			(inb(DMA2_STAT_REG) & 0xf0);
 		/*
 		 * Eliminate the old and floating requests,
 		 * and DMA4 the cascade.
 		 */
 		new_dma_status ^= dma_status;
 		new_dma_status &= ~0x10;
 		for (i = 7; i > 0; i--)
 			if (test_bit(i, &new_dma_status)) {
 				dev->dma = i;
 				break;
 			}
 		if (i <= 0) {
 			printk("DMA probe failed.\n");
 			goto out1;
 		}
 		if (request_dma(dev->dma, cardname)) {
 			printk("probed DMA %d allocation failed.\n", dev->dma);
 			goto out1;
 		}
 	}
 #endif	/* jumpered DMA */

 	np = netdev_priv(dev);
 	spin_lock_init(&np->lock);

         dev->netdev_ops		= &netcard_netdev_ops;
         dev->watchdog_timeo	= MY_TX_TIMEOUT;

 	err = register_netdev(dev);
 	if (err)
 		goto out2;
 	return 0;
 out2:
 #ifdef jumpered_dma
 	free_dma(dev->dma);
 #endif
 out1:
 #ifdef jumpered_interrupts
 	free_irq(dev->irq, dev);
 #endif
 out:
 	release_region(base_addr, NETCARD_IO_EXTENT);
 	return err;
 }

 static void net_tx_timeout(struct net_device *dev)
 {
 	struct net_local *np = netdev_priv(dev);

 	printk(KERN_WARNING "%s: transmit timed out, %s?\n", dev->name,
 	       tx_done(dev) ? "IRQ conflict" : "network cable problem");

 	/* Try to restart the adaptor. */
 	chipset_init(dev, 1);

 	np->stats.tx_errors++;

 	/* If we have space available to accept new transmit
 	 * requests, wake up the queueing layer.  This would
 	 * be the case if the chipset_init() call above just
 	 * flushes out the tx queue and empties it.
 	 *
 	 * If instead, the tx queue is retained then the
 	 * netif_wake_queue() call should be placed in the
 	 * TX completion interrupt handler of the driver instead
 	 * of here.
 	 */
 	if (!tx_full(dev))
 		netif_wake_queue(dev);
 }

 /*
  * 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
 net_open(struct net_device *dev)
 {
 	struct net_local *np = netdev_priv(dev);
 	int ioaddr = dev->base_addr;
 	/*
 	 * This is used if the interrupt line can turned off (shared).
 	 * See 3c503.c for an example of selecting the IRQ at config-time.
 	 */
 	if (request_irq(dev->irq, &net_interrupt, 0, cardname, dev)) {
 		return -EAGAIN;
 	}
 	/*
 	 * Always allocate the DMA channel after the IRQ,
 	 * and clean up on failure.
 	 */
 	if (request_dma(dev->dma, cardname)) {
 		free_irq(dev->irq, dev);
 		return -EAGAIN;
 	}

 	/* Reset the hardware here. Don't forget to set the station address. */
 	chipset_init(dev, 1);
 	outb(0x00, ioaddr);
 	np->open_time = jiffies;

 	/* We are now ready to accept transmit requeusts from
 	 * the queueing layer of the networking.
 	 */
 	netif_start_queue(dev);

 	return 0;
 }

 /* This will only be invoked if your driver is _not_ in XOFF state.
  * What this means is that you need not check it, and that this
  * invariant will hold if you make sure that the netif_*_queue()
  * calls are done at the proper times.
  */
 static int net_send_packet(struct sk_buff *skb, struct net_device *dev)
 {
 	struct net_local *np = netdev_priv(dev);
 	int ioaddr = dev->base_addr;
 	short length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
 	unsigned char *buf = skb->data;

 	/* 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.
 	 */

 #if TX_RING
 	/* This is the most common case for modern hardware.
 	 * The spinlock protects this code from the TX complete
 	 * hardware interrupt handler.  Queue flow control is
 	 * thus managed under this lock as well.
 	 */
 	spin_lock_irq(&np->lock);

 	add_to_tx_ring(np, skb, length);
 	dev->trans_start = jiffies;

 	/* If we just used up the very last entry in the
 	 * TX ring on this device, tell the queueing
 	 * layer to send no more.
 	 */
 	if (tx_full(dev))
 		netif_stop_queue(dev);

 	/* When the TX completion hw interrupt arrives, this
 	 * is when the transmit statistics are updated.
 	 */

 	spin_unlock_irq(&np->lock);
 #else
 	/* This is the case for older hardware which takes
 	 * a single transmit buffer at a time, and it is
 	 * just written to the device via PIO.
 	 *
 	 * No spin locking is needed since there is no TX complete
 	 * event.  If by chance your card does have a TX complete
 	 * hardware IRQ then you may need to utilize np->lock here.
 	 */
 	hardware_send_packet(ioaddr, buf, length);
 	np->stats.tx_bytes += skb->len;

 	dev->trans_start = jiffies;

 	/* You might need to clean up and record Tx statistics here. */
 	if (inw(ioaddr) == /*RU*/81)
 		np->stats.tx_aborted_errors++;
 	dev_kfree_skb (skb);
 #endif

 	return NETDEV_TX_OK;
 }

 #if TX_RING
 /* This handles TX complete events posted by the device
  * via interrupts.
  */
 void net_tx(struct net_device *dev)
 {
 	struct net_local *np = netdev_priv(dev);
 	int entry;

 	/* This protects us from concurrent execution of
 	 * our dev->hard_start_xmit function above.
 	 */
 	spin_lock(&np->lock);

 	entry = np->tx_old;
 	while (tx_entry_is_sent(np, entry)) {
 		struct sk_buff *skb = np->skbs[entry];

 		np->stats.tx_bytes += skb->len;
 		dev_kfree_skb_irq (skb);

 		entry = next_tx_entry(np, entry);
 	}
 	np->tx_old = entry;

 	/* If we had stopped the queue due to a "tx full"
 	 * condition, and space has now been made available,
 	 * wake up the queue.
 	 */
 	if (netif_queue_stopped(dev) && ! tx_full(dev))
 		netif_wake_queue(dev);

 	spin_unlock(&np->lock);
 }
 #endif

 /*
  * The typical workload of the driver:
  * Handle the network interface interrupts.
  */
 static irqreturn_t net_interrupt(int irq, void *dev_id)
 {
 	struct net_device *dev = dev_id;
 	struct net_local *np;
 	int ioaddr, status;
 	int handled = 0;

 	ioaddr = dev->base_addr;

 	np = netdev_priv(dev);
 	status = inw(ioaddr + 0);

 	if (status == 0)
 		goto out;
 	handled = 1;

 	if (status & RX_INTR) {
 		/* Got a packet(s). */
 		net_rx(dev);
 	}
 #if TX_RING
 	if (status & TX_INTR) {
 		/* Transmit complete. */
 		net_tx(dev);
 		np->stats.tx_packets++;
 		netif_wake_queue(dev);
 	}
 #endif
 	if (status & COUNTERS_INTR) {
 		/* Increment the appropriate 'localstats' field. */
 		np->stats.tx_window_errors++;
 	}
 out:
 	return IRQ_RETVAL(handled);
 }

 /* We have a good packet(s), get it/them out of the buffers. */
 static void
 net_rx(struct net_device *dev)
 {
 	struct net_local *lp = netdev_priv(dev);
 	int ioaddr = dev->base_addr;
 	int boguscount = 10;

 	do {
 		int status = inw(ioaddr);
 		int pkt_len = inw(ioaddr);

 		if (pkt_len == 0)		/* Read all the frames? */
 			break;			/* Done for now */

 		if (status & 0x40) {	/* There was an error. */
 			lp->stats.rx_errors++;
 			if (status & 0x20) lp->stats.rx_frame_errors++;
 			if (status & 0x10) lp->stats.rx_over_errors++;
 			if (status & 0x08) lp->stats.rx_crc_errors++;
 			if (status & 0x04) lp->stats.rx_fifo_errors++;
 		} else {
 			/* Malloc up new buffer. */
 			struct sk_buff *skb;

 			lp->stats.rx_bytes+=pkt_len;

 			skb = dev_alloc_skb(pkt_len);
 			if (skb == NULL) {
 				printk(KERN_NOTICE "%s: Memory squeeze, dropping packet.\n",
 					   dev->name);
 				lp->stats.rx_dropped++;
 				break;
 			}
 			skb->dev = dev;

 			/* 'skb->data' points to the start of sk_buff data area. */
 			memcpy(skb_put(skb,pkt_len), (void*)dev->rmem_start,
 				   pkt_len);
 			/* or */
 			insw(ioaddr, skb->data, (pkt_len + 1) >> 1);

 			netif_rx(skb);
 			lp->stats.rx_packets++;
 			lp->stats.rx_bytes += pkt_len;
 		}
 	} while (--boguscount);

 	return;
 }

 /* The inverse routine to net_open(). */
 static int
 net_close(struct net_device *dev)
 {
 	struct net_local *lp = netdev_priv(dev);
 	int ioaddr = dev->base_addr;

 	lp->open_time = 0;

 	netif_stop_queue(dev);

 	/* Flush the Tx and disable Rx here. */

 	disable_dma(dev->dma);

 	/* If not IRQ or DMA jumpered, free up the line. */
 	outw(0x00, ioaddr+0);	/* Release the physical interrupt line. */

 	free_irq(dev->irq, dev);
 	free_dma(dev->dma);

 	/* Update the statistics here. */

 	return 0;

 }

 /*
  * Get the current statistics.
  * This may be called with the card open or closed.
  */
 static struct net_device_stats *net_get_stats(struct net_device *dev)
 {
 	struct net_local *lp = netdev_priv(dev);
 	short ioaddr = dev->base_addr;

 	/* Update the statistics from the device registers. */
 	lp->stats.rx_missed_errors = inw(ioaddr+1);
 	return &lp->stats;
 }

 /*
  * Set or clear the multicast filter for this adaptor.
  * num_addrs == -1	Promiscuous mode, receive all packets
  * num_addrs == 0	Normal mode, clear multicast list
  * num_addrs > 0	Multicast mode, receive normal and MC packets,
  *			and do best-effort filtering.
  */
 static void
 set_multicast_list(struct net_device *dev)
 {
 	short ioaddr = dev->base_addr;
 	if (dev->flags&IFF_PROMISC)
 	{
 		/* Enable promiscuous mode */
 		outw(MULTICAST|PROMISC, ioaddr);
 	}
 	else if((dev->flags&IFF_ALLMULTI) || dev->mc_count > HW_MAX_ADDRS)
 	{
 		/* Disable promiscuous mode, use normal mode. */
 		hardware_set_filter(NULL);

 		outw(MULTICAST, ioaddr);
 	}
 	else if(dev->mc_count)
 	{
 		/* Walk the address list, and load the filter */
 		hardware_set_filter(dev->mc_list);

 		outw(MULTICAST, ioaddr);
 	}
 	else
 		outw(0, ioaddr);
 }

 #ifdef MODULE

 static struct net_device *this_device;
 static int io = 0x300;
 static int irq;
 static int dma;
 static int mem;
 MODULE_LICENSE("GPL");

 int init_module(void)
 {
 	struct net_device *dev;
 	int result;

 	if (io == 0)
 		printk(KERN_WARNING "%s: You shouldn't use auto-probing with insmod!\n",
 			   cardname);
 	dev = alloc_etherdev(sizeof(struct net_local));
 	if (!dev)
 		return -ENOMEM;

 	/* Copy the parameters from insmod into the device structure. */
 	dev->base_addr = io;
 	dev->irq       = irq;
 	dev->dma       = dma;
 	dev->mem_start = mem;
 	if (do_netcard_probe(dev) == 0) {
 		this_device = dev;
 		return 0;
 	}
 	free_netdev(dev);
 	return -ENXIO;
 }

 void
 cleanup_module(void)
 {
 	unregister_netdev(this_device);
 	cleanup_card(this_device);
 	free_netdev(this_device);
 }

 #endif /* MODULE */
	/* isa-skeleton.c: A network driver outline for linux.
	*
	* Written 1993-94 by Donald Becker.
	*
	* Copyright 1993 United States Government as represented by the
	* Director, National Security Agency.
	*
	* This software may be used and distributed according to the terms
	* of the GNU General Public License, incorporated herein by reference.
	*
	* The author may be reached as becker@scyld.com, or C/O
	* Scyld Computing Corporation
	* 410 Severn Ave., Suite 210
	* Annapolis MD 21403
	*
	* This file is an outline for writing a network device driver for the
	* the Linux operating system.
	*
	* To write (or understand) a driver, have a look at the "loopback.c" file to
	* get a feel of what is going on, and then use the code below as a skeleton
	* for the new driver.
	*
	*/

	static const char *version =
	"isa-skeleton.c:v1.51 9/24/94 Donald Becker (becker@cesdis.gsfc.nasa.gov)\n";

	/*
	* Sources:
	* List your sources of programming information to document that
	* the driver is your own creation, and give due credit to others
	* that contributed to the work. Remember that GNU project code
	* cannot use proprietary or trade secret information. Interface
	* definitions are generally considered non-copyrightable to the
	* extent that the same names and structures must be used to be
	* compatible.
	*
	* Finally, keep in mind that the Linux kernel is has an API, not
	* ABI. Proprietary object-code-only distributions are not permitted
	* under the GPL.
	*/

	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/types.h>
	#include <linux/fcntl.h>
	#include <linux/interrupt.h>
	#include <linux/ioport.h>
	#include <linux/in.h>
	#include <linux/slab.h>
	#include <linux/string.h>
	#include <linux/spinlock.h>
	#include <linux/errno.h>
	#include <linux/init.h>
	#include <linux/netdevice.h>
	#include <linux/etherdevice.h>
	#include <linux/skbuff.h>
	#include <linux/bitops.h>

	#include <asm/system.h>
	#include <asm/io.h>
	#include <asm/dma.h>

	/*
	* The name of the card. Is used for messages and in the requests for
	* io regions, irqs and dma channels
	*/
	static const char* cardname = "netcard";

	/* First, a few definitions that the brave might change. */

	/* A zero-terminated list of I/O addresses to be probed. */
	static unsigned int netcard_portlist[] __initdata =
	{ 0x200, 0x240, 0x280, 0x2C0, 0x300, 0x320, 0x340, 0};

	/* use 0 for production, 1 for verification, >2 for debug */
	#ifndef NET_DEBUG
	#define NET_DEBUG 2
	#endif
	static unsigned int net_debug = NET_DEBUG;

	/* The number of low I/O ports used by the ethercard. */
	#define NETCARD_IO_EXTENT 32

	#define MY_TX_TIMEOUT ((400*HZ)/1000)

	/* Information that need to be kept for each board. */
	struct net_local {
	struct net_device_stats stats;
	long open_time; /* Useless example local info. */

	/* Tx control lock. This protects the transmit buffer ring
	* state along with the "tx full" state of the driver. This
	* means all netif_queue flow control actions are protected
	* by this lock as well.
	*/
	spinlock_t lock;
	};

	/* The station (ethernet) address prefix, used for IDing the board. */
	#define SA_ADDR0 0x00
	#define SA_ADDR1 0x42
	#define SA_ADDR2 0x65

	/* Index to functions, as function prototypes. */

	static int netcard_probe1(struct net_device *dev, int ioaddr);
	static int net_open(struct net_device *dev);
	static int net_send_packet(struct sk_buff skb, struct net_device dev);
	static irqreturn_t net_interrupt(int irq, void *dev_id);
	static void net_rx(struct net_device *dev);
	static int net_close(struct net_device *dev);
	static struct net_device_stats net_get_stats(struct net_device dev);
	static void set_multicast_list(struct net_device *dev);
	static void net_tx_timeout(struct net_device *dev);


	/* Example routines you must write ;->. */
	#define tx_done(dev) 1
	static void hardware_send_packet(short ioaddr, char *buf, int length);
	static void chipset_init(struct net_device *dev, int startp);

	/*
	* Check for a network adaptor of this type, and return '0' iff one exists.
	* If dev->base_addr == 0, probe all likely locations.
	* If dev->base_addr == 1, always return failure.
	* If dev->base_addr == 2, allocate space for the device and return success
	* (detachable devices only).
	*/
	static int __init do_netcard_probe(struct net_device *dev)
	{
	int i;
	int base_addr = dev->base_addr;
	int irq = dev->irq;

	if (base_addr > 0x1ff) /* Check a single specified location. */
	return netcard_probe1(dev, base_addr);
	else if (base_addr != 0) /* Don't probe at all. */
	return -ENXIO;

	for (i = 0; netcard_portlist[i]; i++) {
	int ioaddr = netcard_portlist[i];
	if (netcard_probe1(dev, ioaddr) == 0)
	return 0;
	dev->irq = irq;
	}

	return -ENODEV;
	}

	static void cleanup_card(struct net_device *dev)
	{
	#ifdef jumpered_dma
	free_dma(dev->dma);
	#endif
	#ifdef jumpered_interrupts
	free_irq(dev->irq, dev);
	#endif
	release_region(dev->base_addr, NETCARD_IO_EXTENT);
	}

	#ifndef MODULE
	struct net_device * __init netcard_probe(int unit)
	{
	struct net_device *dev = alloc_etherdev(sizeof(struct net_local));
	int err;

	if (!dev)
	return ERR_PTR(-ENOMEM);

	sprintf(dev->name, "eth%d", unit);
	netdev_boot_setup_check(dev);

	err = do_netcard_probe(dev);
	if (err)
	goto out;
	return dev;
	out:
	free_netdev(dev);
	return ERR_PTR(err);
	}
	#endif

	static const struct net_device_ops netcard_netdev_ops = {
	.ndo_open = net_open,
	.ndo_stop = net_close,
	.ndo_start_xmit = net_send_packet,
	.ndo_get_stats = net_get_stats,
	.ndo_set_multicast_list = set_multicast_list,
	.ndo_tx_timeout = net_tx_timeout,
	.ndo_validate_addr = eth_validate_addr,
	.ndo_set_mac_address = eth_mac_addr,
	.ndo_change_mtu = eth_change_mtu,
	};

	/*
	* This is the real probe routine. Linux has a history of friendly device
	* probes on the ISA bus. A good device probes avoids doing writes, and
	* verifies that the correct device exists and functions.
	*/
	static int __init netcard_probe1(struct net_device *dev, int ioaddr)
	{
	struct net_local *np;
	static unsigned version_printed;
	int i;
	int err = -ENODEV;

	/* Grab the region so that no one else tries to probe our ioports. */
	if (!request_region(ioaddr, NETCARD_IO_EXTENT, cardname))
	return -EBUSY;

	/*
	* For ethernet adaptors the first three octets of the station address
	* contains the manufacturer's unique code. That might be a good probe
	* method. Ideally you would add additional checks.
	*/
	if (inb(ioaddr + 0) != SA_ADDR0
	\|\| inb(ioaddr + 1) != SA_ADDR1
	\|\| inb(ioaddr + 2) != SA_ADDR2)
	goto out;

	if (net_debug && version_printed++ == 0)
	printk(KERN_DEBUG "%s", version);

	printk(KERN_INFO "%s: %s found at %#3x, ", dev->name, cardname, ioaddr);

	/* Fill in the 'dev' fields. */
	dev->base_addr = ioaddr;

	/* Retrieve and print the ethernet address. */
	for (i = 0; i < 6; i++)
	dev->dev_addr[i] = inb(ioaddr + i);

	printk("%pM", dev->dev_addr);

	err = -EAGAIN;
	#ifdef jumpered_interrupts
	/*
	* If this board has jumpered interrupts, allocate the interrupt
	* vector now. There is no point in waiting since no other device
	* can use the interrupt, and this marks the irq as busy. Jumpered
	* interrupts are typically not reported by the boards, and we must
	* used autoIRQ to find them.
	*/

	if (dev->irq == -1)
	; /* Do nothing: a user-level program will set it. */
	else if (dev->irq < 2) { /* "Auto-IRQ" */
	unsigned long irq_mask = probe_irq_on();
	/* Trigger an interrupt here. */

	dev->irq = probe_irq_off(irq_mask);
	if (net_debug >= 2)
	printk(" autoirq is %d", dev->irq);
	} else if (dev->irq == 2)
	/*
	* Fixup for users that don't know that IRQ 2 is really
	* IRQ9, or don't know which one to set.
	*/
	dev->irq = 9;

	{
	int irqval = request_irq(dev->irq, &net_interrupt, 0, cardname, dev);
	if (irqval) {
	printk("%s: unable to get IRQ %d (irqval=%d).\n",
	dev->name, dev->irq, irqval);
	goto out;
	}
	}
	#endif /* jumpered interrupt */
	#ifdef jumpered_dma
	/*
	* If we use a jumpered DMA channel, that should be probed for and
	* allocated here as well. See lance.c for an example.
	*/
	if (dev->dma == 0) {
	if (request_dma(dev->dma, cardname)) {
	printk("DMA %d allocation failed.\n", dev->dma);
	goto out1;
	} else
	printk(", assigned DMA %d.\n", dev->dma);
	} else {
	short dma_status, new_dma_status;

	/* Read the DMA channel status registers. */
	dma_status = ((inb(DMA1_STAT_REG) >> 4) & 0x0f) \|
	(inb(DMA2_STAT_REG) & 0xf0);
	/* Trigger a DMA request, perhaps pause a bit. */
	outw(0x1234, ioaddr + 8);
	/* Re-read the DMA status registers. */
	new_dma_status = ((inb(DMA1_STAT_REG) >> 4) & 0x0f) \|
	(inb(DMA2_STAT_REG) & 0xf0);
	/*
	* Eliminate the old and floating requests,
	* and DMA4 the cascade.
	*/
	new_dma_status ^= dma_status;
	new_dma_status &= ~0x10;
	for (i = 7; i > 0; i--)
	if (test_bit(i, &new_dma_status)) {
	dev->dma = i;
	break;
	}
	if (i <= 0) {
	printk("DMA probe failed.\n");
	goto out1;
	}
	if (request_dma(dev->dma, cardname)) {
	printk("probed DMA %d allocation failed.\n", dev->dma);
	goto out1;
	}
	}
	#endif /* jumpered DMA */

	np = netdev_priv(dev);
	spin_lock_init(&np->lock);

	dev->netdev_ops = &netcard_netdev_ops;
	dev->watchdog_timeo = MY_TX_TIMEOUT;

	err = register_netdev(dev);
	if (err)
	goto out2;
	return 0;
	out2:
	#ifdef jumpered_dma
	free_dma(dev->dma);
	#endif
	out1:
	#ifdef jumpered_interrupts
	free_irq(dev->irq, dev);
	#endif
	out:
	release_region(base_addr, NETCARD_IO_EXTENT);
	return err;
	}

	static void net_tx_timeout(struct net_device *dev)
	{
	struct net_local *np = netdev_priv(dev);

	printk(KERN_WARNING "%s: transmit timed out, %s?\n", dev->name,
	tx_done(dev) ? "IRQ conflict" : "network cable problem");

	/* Try to restart the adaptor. */
	chipset_init(dev, 1);

	np->stats.tx_errors++;

	/* If we have space available to accept new transmit
	* requests, wake up the queueing layer. This would
	* be the case if the chipset_init() call above just
	* flushes out the tx queue and empties it.
	*
	* If instead, the tx queue is retained then the
	* netif_wake_queue() call should be placed in the
	* TX completion interrupt handler of the driver instead
	* of here.
	*/
	if (!tx_full(dev))
	netif_wake_queue(dev);
	}

	/*
	* 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
	net_open(struct net_device *dev)
	{
	struct net_local *np = netdev_priv(dev);
	int ioaddr = dev->base_addr;
	/*
	* This is used if the interrupt line can turned off (shared).
	* See 3c503.c for an example of selecting the IRQ at config-time.
	*/
	if (request_irq(dev->irq, &net_interrupt, 0, cardname, dev)) {
	return -EAGAIN;
	}
	/*
	* Always allocate the DMA channel after the IRQ,
	* and clean up on failure.
	*/
	if (request_dma(dev->dma, cardname)) {
	free_irq(dev->irq, dev);
	return -EAGAIN;
	}

	/* Reset the hardware here. Don't forget to set the station address. */
	chipset_init(dev, 1);
	outb(0x00, ioaddr);
	np->open_time = jiffies;

	/* We are now ready to accept transmit requeusts from
	* the queueing layer of the networking.
	*/
	netif_start_queue(dev);

	return 0;
	}

	/* This will only be invoked if your driver is _not_ in XOFF state.
	* What this means is that you need not check it, and that this
	* invariant will hold if you make sure that the netif_*_queue()
	* calls are done at the proper times.
	*/
	static int net_send_packet(struct sk_buff skb, struct net_device dev)
	{
	struct net_local *np = netdev_priv(dev);
	int ioaddr = dev->base_addr;
	short length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
	unsigned char *buf = skb->data;

	/* 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.
	*/

	#if TX_RING
	/* This is the most common case for modern hardware.
	* The spinlock protects this code from the TX complete
	* hardware interrupt handler. Queue flow control is
	* thus managed under this lock as well.
	*/
	spin_lock_irq(&np->lock);

	add_to_tx_ring(np, skb, length);
	dev->trans_start = jiffies;

	/* If we just used up the very last entry in the
	* TX ring on this device, tell the queueing
	* layer to send no more.
	*/
	if (tx_full(dev))
	netif_stop_queue(dev);

	/* When the TX completion hw interrupt arrives, this
	* is when the transmit statistics are updated.
	*/

	spin_unlock_irq(&np->lock);
	#else
	/* This is the case for older hardware which takes
	* a single transmit buffer at a time, and it is
	* just written to the device via PIO.
	*
	* No spin locking is needed since there is no TX complete
	* event. If by chance your card does have a TX complete
	* hardware IRQ then you may need to utilize np->lock here.
	*/
	hardware_send_packet(ioaddr, buf, length);
	np->stats.tx_bytes += skb->len;

	dev->trans_start = jiffies;

	/* You might need to clean up and record Tx statistics here. */
	if (inw(ioaddr) == /RU/81)
	np->stats.tx_aborted_errors++;
	dev_kfree_skb (skb);
	#endif

	return NETDEV_TX_OK;
	}

	#if TX_RING
	/* This handles TX complete events posted by the device
	* via interrupts.
	*/
	void net_tx(struct net_device *dev)
	{
	struct net_local *np = netdev_priv(dev);
	int entry;

	/* This protects us from concurrent execution of
	* our dev->hard_start_xmit function above.
	*/
	spin_lock(&np->lock);

	entry = np->tx_old;
	while (tx_entry_is_sent(np, entry)) {
	struct sk_buff *skb = np->skbs[entry];

	np->stats.tx_bytes += skb->len;
	dev_kfree_skb_irq (skb);

	entry = next_tx_entry(np, entry);
	}
	np->tx_old = entry;

	/* If we had stopped the queue due to a "tx full"
	* condition, and space has now been made available,
	* wake up the queue.
	*/
	if (netif_queue_stopped(dev) && ! tx_full(dev))
	netif_wake_queue(dev);

	spin_unlock(&np->lock);
	}
	#endif

	/*
	* The typical workload of the driver:
	* Handle the network interface interrupts.
	*/
	static irqreturn_t net_interrupt(int irq, void *dev_id)
	{
	struct net_device *dev = dev_id;
	struct net_local *np;
	int ioaddr, status;
	int handled = 0;

	ioaddr = dev->base_addr;

	np = netdev_priv(dev);
	status = inw(ioaddr + 0);

	if (status == 0)
	goto out;
	handled = 1;

	if (status & RX_INTR) {
	/* Got a packet(s). */
	net_rx(dev);
	}
	#if TX_RING
	if (status & TX_INTR) {
	/* Transmit complete. */
	net_tx(dev);
	np->stats.tx_packets++;
	netif_wake_queue(dev);
	}
	#endif
	if (status & COUNTERS_INTR) {
	/* Increment the appropriate 'localstats' field. */
	np->stats.tx_window_errors++;
	}
	out:
	return IRQ_RETVAL(handled);
	}

	/* We have a good packet(s), get it/them out of the buffers. */
	static void
	net_rx(struct net_device *dev)
	{
	struct net_local *lp = netdev_priv(dev);
	int ioaddr = dev->base_addr;
	int boguscount = 10;

	do {
	int status = inw(ioaddr);
	int pkt_len = inw(ioaddr);

	if (pkt_len == 0) /* Read all the frames? */
	break; /* Done for now */

	if (status & 0x40) { /* There was an error. */
	lp->stats.rx_errors++;
	if (status & 0x20) lp->stats.rx_frame_errors++;
	if (status & 0x10) lp->stats.rx_over_errors++;
	if (status & 0x08) lp->stats.rx_crc_errors++;
	if (status & 0x04) lp->stats.rx_fifo_errors++;
	} else {
	/* Malloc up new buffer. */
	struct sk_buff *skb;

	lp->stats.rx_bytes+=pkt_len;

	skb = dev_alloc_skb(pkt_len);
	if (skb == NULL) {
	printk(KERN_NOTICE "%s: Memory squeeze, dropping packet.\n",
	dev->name);
	lp->stats.rx_dropped++;
	break;
	}
	skb->dev = dev;

	/* 'skb->data' points to the start of sk_buff data area. */
	memcpy(skb_put(skb,pkt_len), (void*)dev->rmem_start,
	pkt_len);
	/* or */
	insw(ioaddr, skb->data, (pkt_len + 1) >> 1);

	netif_rx(skb);
	lp->stats.rx_packets++;
	lp->stats.rx_bytes += pkt_len;
	}
	} while (--boguscount);

	return;
	}

	/* The inverse routine to net_open(). */
	static int
	net_close(struct net_device *dev)
	{
	struct net_local *lp = netdev_priv(dev);
	int ioaddr = dev->base_addr;

	lp->open_time = 0;

	netif_stop_queue(dev);

	/* Flush the Tx and disable Rx here. */

	disable_dma(dev->dma);

	/* If not IRQ or DMA jumpered, free up the line. */
	outw(0x00, ioaddr+0); /* Release the physical interrupt line. */

	free_irq(dev->irq, dev);
	free_dma(dev->dma);

	/* Update the statistics here. */

	return 0;

	}

	/*
	* Get the current statistics.
	* This may be called with the card open or closed.
	*/
	static struct net_device_stats net_get_stats(struct net_device dev)
	{
	struct net_local *lp = netdev_priv(dev);
	short ioaddr = dev->base_addr;

	/* Update the statistics from the device registers. */
	lp->stats.rx_missed_errors = inw(ioaddr+1);
	return &lp->stats;
	}

	/*
	* Set or clear the multicast filter for this adaptor.
	* num_addrs == -1 Promiscuous mode, receive all packets
	* num_addrs == 0 Normal mode, clear multicast list
	* num_addrs > 0 Multicast mode, receive normal and MC packets,
	* and do best-effort filtering.
	*/
	static void
	set_multicast_list(struct net_device *dev)
	{
	short ioaddr = dev->base_addr;
	if (dev->flags&IFF_PROMISC)
	{
	/* Enable promiscuous mode */
	outw(MULTICAST\|PROMISC, ioaddr);
	}
	else if((dev->flags&IFF_ALLMULTI) \|\| dev->mc_count > HW_MAX_ADDRS)
	{
	/* Disable promiscuous mode, use normal mode. */
	hardware_set_filter(NULL);

	outw(MULTICAST, ioaddr);
	}
	else if(dev->mc_count)
	{
	/* Walk the address list, and load the filter */
	hardware_set_filter(dev->mc_list);

	outw(MULTICAST, ioaddr);
	}
	else
	outw(0, ioaddr);
	}

	#ifdef MODULE

	static struct net_device *this_device;
	static int io = 0x300;
	static int irq;
	static int dma;
	static int mem;
	MODULE_LICENSE("GPL");

	int init_module(void)
	{
	struct net_device *dev;
	int result;

	if (io == 0)
	printk(KERN_WARNING "%s: You shouldn't use auto-probing with insmod!\n",
	cardname);
	dev = alloc_etherdev(sizeof(struct net_local));
	if (!dev)
	return -ENOMEM;

	/* Copy the parameters from insmod into the device structure. */
	dev->base_addr = io;
	dev->irq = irq;
	dev->dma = dma;
	dev->mem_start = mem;
	if (do_netcard_probe(dev) == 0) {
	this_device = dev;
	return 0;
	}
	free_netdev(dev);
	return -ENXIO;
	}

	void
	cleanup_module(void)
	{
	unregister_netdev(this_device);
	cleanup_card(this_device);
	free_netdev(this_device);
	}

	#endif /* MODULE */