drivers/net/de600.c - kernel/msm-4.9 - Gitiles

 static const char version[] = "de600.c: $Revision: 1.41-2.5 $,  Bjorn Ekwall (bj0rn@blox.se)\n";
 /*
  *	de600.c
  *
  *	Linux driver for the D-Link DE-600 Ethernet pocket adapter.
  *
  *	Portions (C) Copyright 1993, 1994 by Bjorn Ekwall
  *	The Author may be reached as bj0rn@blox.se
  *
  *	Based on adapter information gathered from DE600.ASM by D-Link Inc.,
  *	as included on disk C in the v.2.11 of PC/TCP from FTP Software.
  *	For DE600.asm:
  *		Portions (C) Copyright 1990 D-Link, Inc.
  *		Copyright, 1988-1992, Russell Nelson, Crynwr Software
  *
  *	Adapted to the sample network driver core for linux,
  *	written by: Donald Becker <becker@super.org>
  *		(Now at <becker@scyld.com>)
  *
  **************************************************************/
 /*
  *	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, or (at your option)
  *	any later version.
  *
  *	This program is distributed in the hope that it will be useful,
  *	but WITHOUT ANY WARRANTY; without even the implied warranty of
  *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *	GNU General Public License for more details.
  *
  *	You should have received a copy of the GNU General Public License
  *	along with this program; if not, write to the Free Software
  *	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  *
  **************************************************************/

 /* Add more time here if your adapter won't work OK: */
 #define DE600_SLOW_DOWN	udelay(delay_time)

 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/fcntl.h>
 #include <linux/string.h>
 #include <linux/interrupt.h>
 #include <linux/ioport.h>
 #include <linux/in.h>
 #include <asm/system.h>
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/delay.h>
 #include <linux/inet.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/skbuff.h>

 #include <asm/io.h>

 #include "de600.h"

 static unsigned int check_lost = 1;
 module_param(check_lost, bool, 0);
 MODULE_PARM_DESC(check_lost, "If set then check for unplugged de600");

 static unsigned int delay_time = 10;
 module_param(delay_time, int, 0);
 MODULE_PARM_DESC(delay_time, "DE-600 deley on I/O in microseconds");


 /*
  * D-Link driver variables:
  */

 static volatile int		rx_page;

 #define TX_PAGES 2
 static volatile int		tx_fifo[TX_PAGES];
 static volatile int		tx_fifo_in;
 static volatile int		tx_fifo_out;
 static volatile int		free_tx_pages = TX_PAGES;
 static int			was_down;
 static DEFINE_SPINLOCK(de600_lock);

 static inline u8 de600_read_status(struct net_device *dev)
 {
 	u8 status;

 	outb_p(STATUS, DATA_PORT);
 	status = inb(STATUS_PORT);
 	outb_p(NULL_COMMAND | HI_NIBBLE, DATA_PORT);

 	return status;
 }

 static inline u8 de600_read_byte(unsigned char type, struct net_device *dev)
 {
 	/* dev used by macros */
 	u8 lo;
 	outb_p((type), DATA_PORT);
 	lo = ((unsigned char)inb(STATUS_PORT)) >> 4;
 	outb_p((type) | HI_NIBBLE, DATA_PORT);
 	return ((unsigned char)inb(STATUS_PORT) & (unsigned char)0xf0) | lo;
 }

 /*
  * Open/initialize the board.  This is called (in the current kernel)
  * after booting when 'ifconfig <dev->name> $IP_ADDR' is run (in rc.inet1).
  *
  * 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 a non-reboot way to recover if something goes wrong.
  */

 static int de600_open(struct net_device *dev)
 {
 	unsigned long flags;
 	int ret = request_irq(DE600_IRQ, de600_interrupt, 0, dev->name, dev);
 	if (ret) {
 		printk(KERN_ERR "%s: unable to get IRQ %d\n", dev->name, DE600_IRQ);
 		return ret;
 	}
 	spin_lock_irqsave(&de600_lock, flags);
 	ret = adapter_init(dev);
 	spin_unlock_irqrestore(&de600_lock, flags);
 	return ret;
 }

 /*
  * The inverse routine to de600_open().
  */

 static int de600_close(struct net_device *dev)
 {
 	select_nic();
 	rx_page = 0;
 	de600_put_command(RESET);
 	de600_put_command(STOP_RESET);
 	de600_put_command(0);
 	select_prn();
 	free_irq(DE600_IRQ, dev);
 	return 0;
 }

 static inline void trigger_interrupt(struct net_device *dev)
 {
 	de600_put_command(FLIP_IRQ);
 	select_prn();
 	DE600_SLOW_DOWN;
 	select_nic();
 	de600_put_command(0);
 }

 /*
  * Copy a buffer to the adapter transmit page memory.
  * Start sending.
  */

 static int de600_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	unsigned long flags;
 	int	transmit_from;
 	int	len;
 	int	tickssofar;
 	u8	*buffer = skb->data;
 	int	i;

 	if (free_tx_pages <= 0) {	/* Do timeouts, to avoid hangs. */
 		tickssofar = jiffies - dev->trans_start;
 		if (tickssofar < 5)
 			return 1;
 		/* else */
 		printk(KERN_WARNING "%s: transmit timed out (%d), %s?\n", dev->name, tickssofar, "network cable problem");
 		/* Restart the adapter. */
 		spin_lock_irqsave(&de600_lock, flags);
 		if (adapter_init(dev)) {
 			spin_unlock_irqrestore(&de600_lock, flags);
 			return 1;
 		}
 		spin_unlock_irqrestore(&de600_lock, flags);
 	}

 	/* Start real output */
 	pr_debug("de600_start_xmit:len=%d, page %d/%d\n", skb->len, tx_fifo_in, free_tx_pages);

 	if ((len = skb->len) < RUNT)
 		len = RUNT;

 	spin_lock_irqsave(&de600_lock, flags);
 	select_nic();
 	tx_fifo[tx_fifo_in] = transmit_from = tx_page_adr(tx_fifo_in) - len;
 	tx_fifo_in = (tx_fifo_in + 1) % TX_PAGES; /* Next free tx page */

 	if(check_lost)
 	{
 		/* This costs about 40 instructions per packet... */
 		de600_setup_address(NODE_ADDRESS, RW_ADDR);
 		de600_read_byte(READ_DATA, dev);
 		if (was_down || (de600_read_byte(READ_DATA, dev) != 0xde)) {
 			if (adapter_init(dev)) {
 				spin_unlock_irqrestore(&de600_lock, flags);
 				return 1;
 			}
 		}
 	}

 	de600_setup_address(transmit_from, RW_ADDR);
 	for (i = 0;  i < skb->len ; ++i, ++buffer)
 		de600_put_byte(*buffer);
 	for (; i < len; ++i)
 		de600_put_byte(0);

 	if (free_tx_pages-- == TX_PAGES) { /* No transmission going on */
 		dev->trans_start = jiffies;
 		netif_start_queue(dev); /* allow more packets into adapter */
 		/* Send page and generate a faked interrupt */
 		de600_setup_address(transmit_from, TX_ADDR);
 		de600_put_command(TX_ENABLE);
 	}
 	else {
 		if (free_tx_pages)
 			netif_start_queue(dev);
 		else
 			netif_stop_queue(dev);
 		select_prn();
 	}
 	spin_unlock_irqrestore(&de600_lock, flags);
 	dev_kfree_skb(skb);
 	return 0;
 }

 /*
  * The typical workload of the driver:
  * Handle the network interface interrupts.
  */

 static irqreturn_t de600_interrupt(int irq, void *dev_id)
 {
 	struct net_device	*dev = dev_id;
 	u8		irq_status;
 	int		retrig = 0;
 	int		boguscount = 0;

 	spin_lock(&de600_lock);

 	select_nic();
 	irq_status = de600_read_status(dev);

 	do {
 		pr_debug("de600_interrupt (%02X)\n", irq_status);

 		if (irq_status & RX_GOOD)
 			de600_rx_intr(dev);
 		else if (!(irq_status & RX_BUSY))
 			de600_put_command(RX_ENABLE);

 		/* Any transmission in progress? */
 		if (free_tx_pages < TX_PAGES)
 			retrig = de600_tx_intr(dev, irq_status);
 		else
 			retrig = 0;

 		irq_status = de600_read_status(dev);
 	} while ( (irq_status & RX_GOOD) || ((++boguscount < 100) && retrig) );
 	/*
 	 * Yeah, it _looks_ like busy waiting, smells like busy waiting
 	 * and I know it's not PC, but please, it will only occur once
 	 * in a while and then only for a loop or so (< 1ms for sure!)
 	 */

 	/* Enable adapter interrupts */
 	select_prn();
 	if (retrig)
 		trigger_interrupt(dev);
 	spin_unlock(&de600_lock);
 	return IRQ_HANDLED;
 }

 static int de600_tx_intr(struct net_device *dev, int irq_status)
 {
 	/*
 	 * Returns 1 if tx still not done
 	 */

 	/* Check if current transmission is done yet */
 	if (irq_status & TX_BUSY)
 		return 1; /* tx not done, try again */

 	/* else */
 	/* If last transmission OK then bump fifo index */
 	if (!(irq_status & TX_FAILED16)) {
 		tx_fifo_out = (tx_fifo_out + 1) % TX_PAGES;
 		++free_tx_pages;
 		dev->stats.tx_packets++;
 		netif_wake_queue(dev);
 	}

 	/* More to send, or resend last packet? */
 	if ((free_tx_pages < TX_PAGES) || (irq_status & TX_FAILED16)) {
 		dev->trans_start = jiffies;
 		de600_setup_address(tx_fifo[tx_fifo_out], TX_ADDR);
 		de600_put_command(TX_ENABLE);
 		return 1;
 	}
 	/* else */

 	return 0;
 }

 /*
  * We have a good packet, get it out of the adapter.
  */
 static void de600_rx_intr(struct net_device *dev)
 {
 	struct sk_buff	*skb;
 	int		i;
 	int		read_from;
 	int		size;
 	unsigned char	*buffer;

 	/* Get size of received packet */
 	size = de600_read_byte(RX_LEN, dev);	/* low byte */
 	size += (de600_read_byte(RX_LEN, dev) << 8);	/* high byte */
 	size -= 4;	/* Ignore trailing 4 CRC-bytes */

 	/* Tell adapter where to store next incoming packet, enable receiver */
 	read_from = rx_page_adr();
 	next_rx_page();
 	de600_put_command(RX_ENABLE);

 	if ((size < 32)  ||  (size > 1535)) {
 		printk(KERN_WARNING "%s: Bogus packet size %d.\n", dev->name, size);
 		if (size > 10000)
 			adapter_init(dev);
 		return;
 	}

 	skb = dev_alloc_skb(size+2);
 	if (skb == NULL) {
 		printk("%s: Couldn't allocate a sk_buff of size %d.\n", dev->name, size);
 		return;
 	}
 	/* else */

 	skb_reserve(skb,2);	/* Align */

 	/* 'skb->data' points to the start of sk_buff data area. */
 	buffer = skb_put(skb,size);

 	/* copy the packet into the buffer */
 	de600_setup_address(read_from, RW_ADDR);
 	for (i = size; i > 0; --i, ++buffer)
 		*buffer = de600_read_byte(READ_DATA, dev);

 	skb->protocol=eth_type_trans(skb,dev);

 	netif_rx(skb);

 	/* update stats */
 	dev->stats.rx_packets++; /* count all receives */
 	dev->stats.rx_bytes += size; /* count all received bytes */

 	/*
 	 * If any worth-while packets have been received, netif_rx()
 	 * will work on them when we get to the tasklets.
 	 */
 }

 static const struct net_device_ops de600_netdev_ops = {
 	.ndo_open		= de600_open,
 	.ndo_stop		= de600_close,
 	.ndo_start_xmit		= de600_start_xmit,
 	.ndo_change_mtu		= eth_change_mtu,
 	.ndo_set_mac_address 	= eth_mac_addr,
 	.ndo_validate_addr	= eth_validate_addr,
 };


 static struct net_device * __init de600_probe(void)
 {
 	int	i;
 	struct net_device *dev;
 	int err;

 	dev = alloc_etherdev(0);
 	if (!dev)
 		return ERR_PTR(-ENOMEM);


 	if (!request_region(DE600_IO, 3, "de600")) {
 		printk(KERN_WARNING "DE600: port 0x%x busy\n", DE600_IO);
 		err = -EBUSY;
 		goto out;
 	}

 	printk(KERN_INFO "%s: D-Link DE-600 pocket adapter", dev->name);
 	/* Alpha testers must have the version number to report bugs. */
 	pr_debug("%s", version);

 	/* probe for adapter */
 	err = -ENODEV;
 	rx_page = 0;
 	select_nic();
 	(void)de600_read_status(dev);
 	de600_put_command(RESET);
 	de600_put_command(STOP_RESET);
 	if (de600_read_status(dev) & 0xf0) {
 		printk(": not at I/O %#3x.\n", DATA_PORT);
 		goto out1;
 	}

 	/*
 	 * Maybe we found one,
 	 * have to check if it is a D-Link DE-600 adapter...
 	 */

 	/* Get the adapter ethernet address from the ROM */
 	de600_setup_address(NODE_ADDRESS, RW_ADDR);
 	for (i = 0; i < ETH_ALEN; i++) {
 		dev->dev_addr[i] = de600_read_byte(READ_DATA, dev);
 		dev->broadcast[i] = 0xff;
 	}

 	/* Check magic code */
 	if ((dev->dev_addr[1] == 0xde) && (dev->dev_addr[2] == 0x15)) {
 		/* OK, install real address */
 		dev->dev_addr[0] = 0x00;
 		dev->dev_addr[1] = 0x80;
 		dev->dev_addr[2] = 0xc8;
 		dev->dev_addr[3] &= 0x0f;
 		dev->dev_addr[3] |= 0x70;
 	} else {
 		printk(" not identified in the printer port\n");
 		goto out1;
 	}

 	printk(", Ethernet Address: %pM\n", dev->dev_addr);

 	dev->netdev_ops = &de600_netdev_ops;

 	dev->flags&=~IFF_MULTICAST;

 	select_prn();

 	err = register_netdev(dev);
 	if (err)
 		goto out1;

 	return dev;

 out1:
 	release_region(DE600_IO, 3);
 out:
 	free_netdev(dev);
 	return ERR_PTR(err);
 }

 static int adapter_init(struct net_device *dev)
 {
 	int	i;

 	select_nic();
 	rx_page = 0; /* used by RESET */
 	de600_put_command(RESET);
 	de600_put_command(STOP_RESET);

 	/* Check if it is still there... */
 	/* Get the some bytes of the adapter ethernet address from the ROM */
 	de600_setup_address(NODE_ADDRESS, RW_ADDR);
 	de600_read_byte(READ_DATA, dev);
 	if ((de600_read_byte(READ_DATA, dev) != 0xde) ||
 	    (de600_read_byte(READ_DATA, dev) != 0x15)) {
 	/* was: if (de600_read_status(dev) & 0xf0) { */
 		printk("Something has happened to the DE-600!  Please check it and do a new ifconfig!\n");
 		/* Goodbye, cruel world... */
 		dev->flags &= ~IFF_UP;
 		de600_close(dev);
 		was_down = 1;
 		netif_stop_queue(dev); /* Transmit busy...  */
 		return 1; /* failed */
 	}

 	if (was_down) {
 		printk(KERN_INFO "%s: Thanks, I feel much better now!\n", dev->name);
 		was_down = 0;
 	}

 	tx_fifo_in = 0;
 	tx_fifo_out = 0;
 	free_tx_pages = TX_PAGES;


 	/* set the ether address. */
 	de600_setup_address(NODE_ADDRESS, RW_ADDR);
 	for (i = 0; i < ETH_ALEN; i++)
 		de600_put_byte(dev->dev_addr[i]);

 	/* where to start saving incoming packets */
 	rx_page = RX_BP | RX_BASE_PAGE;
 	de600_setup_address(MEM_4K, RW_ADDR);
 	/* Enable receiver */
 	de600_put_command(RX_ENABLE);
 	select_prn();

 	netif_start_queue(dev);

 	return 0; /* OK */
 }

 static struct net_device *de600_dev;

 static int __init de600_init(void)
 {
 	de600_dev = de600_probe();
 	if (IS_ERR(de600_dev))
 		return PTR_ERR(de600_dev);
 	return 0;
 }

 static void __exit de600_exit(void)
 {
 	unregister_netdev(de600_dev);
 	release_region(DE600_IO, 3);
 	free_netdev(de600_dev);
 }

 module_init(de600_init);
 module_exit(de600_exit);

 MODULE_LICENSE("GPL");
	static const char version[] = "de600.c: $Revision: 1.41-2.5 $, Bjorn Ekwall (bj0rn@blox.se)\n";
	/*
	* de600.c
	*
	* Linux driver for the D-Link DE-600 Ethernet pocket adapter.
	*
	* Portions (C) Copyright 1993, 1994 by Bjorn Ekwall
	* The Author may be reached as bj0rn@blox.se
	*
	* Based on adapter information gathered from DE600.ASM by D-Link Inc.,
	* as included on disk C in the v.2.11 of PC/TCP from FTP Software.
	* For DE600.asm:
	* Portions (C) Copyright 1990 D-Link, Inc.
	* Copyright, 1988-1992, Russell Nelson, Crynwr Software
	*
	* Adapted to the sample network driver core for linux,
	* written by: Donald Becker <becker@super.org>
	* (Now at <becker@scyld.com>)
	*
	**************************************************************/
	/*
	* 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, or (at your option)
	* any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	*
	**************************************************************/

	/* Add more time here if your adapter won't work OK: */
	#define DE600_SLOW_DOWN udelay(delay_time)

	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/types.h>
	#include <linux/fcntl.h>
	#include <linux/string.h>
	#include <linux/interrupt.h>
	#include <linux/ioport.h>
	#include <linux/in.h>
	#include <asm/system.h>
	#include <linux/errno.h>
	#include <linux/init.h>
	#include <linux/delay.h>
	#include <linux/inet.h>
	#include <linux/netdevice.h>
	#include <linux/etherdevice.h>
	#include <linux/skbuff.h>

	#include <asm/io.h>

	#include "de600.h"

	static unsigned int check_lost = 1;
	module_param(check_lost, bool, 0);
	MODULE_PARM_DESC(check_lost, "If set then check for unplugged de600");

	static unsigned int delay_time = 10;
	module_param(delay_time, int, 0);
	MODULE_PARM_DESC(delay_time, "DE-600 deley on I/O in microseconds");


	/*
	* D-Link driver variables:
	*/

	static volatile int rx_page;

	#define TX_PAGES 2
	static volatile int tx_fifo[TX_PAGES];
	static volatile int tx_fifo_in;
	static volatile int tx_fifo_out;
	static volatile int free_tx_pages = TX_PAGES;
	static int was_down;
	static DEFINE_SPINLOCK(de600_lock);

	static inline u8 de600_read_status(struct net_device *dev)
	{
	u8 status;

	outb_p(STATUS, DATA_PORT);
	status = inb(STATUS_PORT);
	outb_p(NULL_COMMAND \| HI_NIBBLE, DATA_PORT);

	return status;
	}

	static inline u8 de600_read_byte(unsigned char type, struct net_device *dev)
	{
	/* dev used by macros */
	u8 lo;
	outb_p((type), DATA_PORT);
	lo = ((unsigned char)inb(STATUS_PORT)) >> 4;
	outb_p((type) \| HI_NIBBLE, DATA_PORT);
	return ((unsigned char)inb(STATUS_PORT) & (unsigned char)0xf0) \| lo;
	}

	/*
	* Open/initialize the board. This is called (in the current kernel)
	* after booting when 'ifconfig <dev->name> $IP_ADDR' is run (in rc.inet1).
	*
	* 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 a non-reboot way to recover if something goes wrong.
	*/

	static int de600_open(struct net_device *dev)
	{
	unsigned long flags;
	int ret = request_irq(DE600_IRQ, de600_interrupt, 0, dev->name, dev);
	if (ret) {
	printk(KERN_ERR "%s: unable to get IRQ %d\n", dev->name, DE600_IRQ);
	return ret;
	}
	spin_lock_irqsave(&de600_lock, flags);
	ret = adapter_init(dev);
	spin_unlock_irqrestore(&de600_lock, flags);
	return ret;
	}

	/*
	* The inverse routine to de600_open().
	*/

	static int de600_close(struct net_device *dev)
	{
	select_nic();
	rx_page = 0;
	de600_put_command(RESET);
	de600_put_command(STOP_RESET);
	de600_put_command(0);
	select_prn();
	free_irq(DE600_IRQ, dev);
	return 0;
	}

	static inline void trigger_interrupt(struct net_device *dev)
	{
	de600_put_command(FLIP_IRQ);
	select_prn();
	DE600_SLOW_DOWN;
	select_nic();
	de600_put_command(0);
	}

	/*
	* Copy a buffer to the adapter transmit page memory.
	* Start sending.
	*/

	static int de600_start_xmit(struct sk_buff skb, struct net_device dev)
	{
	unsigned long flags;
	int transmit_from;
	int len;
	int tickssofar;
	u8 *buffer = skb->data;
	int i;

	if (free_tx_pages <= 0) { /* Do timeouts, to avoid hangs. */
	tickssofar = jiffies - dev->trans_start;
	if (tickssofar < 5)
	return 1;
	/* else */
	printk(KERN_WARNING "%s: transmit timed out (%d), %s?\n", dev->name, tickssofar, "network cable problem");
	/* Restart the adapter. */
	spin_lock_irqsave(&de600_lock, flags);
	if (adapter_init(dev)) {
	spin_unlock_irqrestore(&de600_lock, flags);
	return 1;
	}
	spin_unlock_irqrestore(&de600_lock, flags);
	}

	/* Start real output */
	pr_debug("de600_start_xmit:len=%d, page %d/%d\n", skb->len, tx_fifo_in, free_tx_pages);

	if ((len = skb->len) < RUNT)
	len = RUNT;

	spin_lock_irqsave(&de600_lock, flags);
	select_nic();
	tx_fifo[tx_fifo_in] = transmit_from = tx_page_adr(tx_fifo_in) - len;
	tx_fifo_in = (tx_fifo_in + 1) % TX_PAGES; /* Next free tx page */

	if(check_lost)
	{
	/* This costs about 40 instructions per packet... */
	de600_setup_address(NODE_ADDRESS, RW_ADDR);
	de600_read_byte(READ_DATA, dev);
	if (was_down \|\| (de600_read_byte(READ_DATA, dev) != 0xde)) {
	if (adapter_init(dev)) {
	spin_unlock_irqrestore(&de600_lock, flags);
	return 1;
	}
	}
	}

	de600_setup_address(transmit_from, RW_ADDR);
	for (i = 0; i < skb->len ; ++i, ++buffer)
	de600_put_byte(*buffer);
	for (; i < len; ++i)
	de600_put_byte(0);

	if (free_tx_pages-- == TX_PAGES) { /* No transmission going on */
	dev->trans_start = jiffies;
	netif_start_queue(dev); /* allow more packets into adapter */
	/* Send page and generate a faked interrupt */
	de600_setup_address(transmit_from, TX_ADDR);
	de600_put_command(TX_ENABLE);
	}
	else {
	if (free_tx_pages)
	netif_start_queue(dev);
	else
	netif_stop_queue(dev);
	select_prn();
	}
	spin_unlock_irqrestore(&de600_lock, flags);
	dev_kfree_skb(skb);
	return 0;
	}

	/*
	* The typical workload of the driver:
	* Handle the network interface interrupts.
	*/

	static irqreturn_t de600_interrupt(int irq, void *dev_id)
	{
	struct net_device *dev = dev_id;
	u8 irq_status;
	int retrig = 0;
	int boguscount = 0;

	spin_lock(&de600_lock);

	select_nic();
	irq_status = de600_read_status(dev);

	do {
	pr_debug("de600_interrupt (%02X)\n", irq_status);

	if (irq_status & RX_GOOD)
	de600_rx_intr(dev);
	else if (!(irq_status & RX_BUSY))
	de600_put_command(RX_ENABLE);

	/* Any transmission in progress? */
	if (free_tx_pages < TX_PAGES)
	retrig = de600_tx_intr(dev, irq_status);
	else
	retrig = 0;

	irq_status = de600_read_status(dev);
	} while ( (irq_status & RX_GOOD) \|\| ((++boguscount < 100) && retrig) );
	/*
	* Yeah, it _looks_ like busy waiting, smells like busy waiting
	* and I know it's not PC, but please, it will only occur once
	* in a while and then only for a loop or so (< 1ms for sure!)
	*/

	/* Enable adapter interrupts */
	select_prn();
	if (retrig)
	trigger_interrupt(dev);
	spin_unlock(&de600_lock);
	return IRQ_HANDLED;
	}

	static int de600_tx_intr(struct net_device *dev, int irq_status)
	{
	/*
	* Returns 1 if tx still not done
	*/

	/* Check if current transmission is done yet */
	if (irq_status & TX_BUSY)
	return 1; /* tx not done, try again */

	/* else */
	/* If last transmission OK then bump fifo index */
	if (!(irq_status & TX_FAILED16)) {
	tx_fifo_out = (tx_fifo_out + 1) % TX_PAGES;
	++free_tx_pages;
	dev->stats.tx_packets++;
	netif_wake_queue(dev);
	}

	/* More to send, or resend last packet? */
	if ((free_tx_pages < TX_PAGES) \|\| (irq_status & TX_FAILED16)) {
	dev->trans_start = jiffies;
	de600_setup_address(tx_fifo[tx_fifo_out], TX_ADDR);
	de600_put_command(TX_ENABLE);
	return 1;
	}
	/* else */

	return 0;
	}

	/*
	* We have a good packet, get it out of the adapter.
	*/
	static void de600_rx_intr(struct net_device *dev)
	{
	struct sk_buff *skb;
	int i;
	int read_from;
	int size;
	unsigned char *buffer;

	/* Get size of received packet */
	size = de600_read_byte(RX_LEN, dev); /* low byte */
	size += (de600_read_byte(RX_LEN, dev) << 8); /* high byte */
	size -= 4; /* Ignore trailing 4 CRC-bytes */

	/* Tell adapter where to store next incoming packet, enable receiver */
	read_from = rx_page_adr();
	next_rx_page();
	de600_put_command(RX_ENABLE);

	if ((size < 32) \|\| (size > 1535)) {
	printk(KERN_WARNING "%s: Bogus packet size %d.\n", dev->name, size);
	if (size > 10000)
	adapter_init(dev);
	return;
	}

	skb = dev_alloc_skb(size+2);
	if (skb == NULL) {
	printk("%s: Couldn't allocate a sk_buff of size %d.\n", dev->name, size);
	return;
	}
	/* else */

	skb_reserve(skb,2); /* Align */

	/* 'skb->data' points to the start of sk_buff data area. */
	buffer = skb_put(skb,size);

	/* copy the packet into the buffer */
	de600_setup_address(read_from, RW_ADDR);
	for (i = size; i > 0; --i, ++buffer)
	*buffer = de600_read_byte(READ_DATA, dev);

	skb->protocol=eth_type_trans(skb,dev);

	netif_rx(skb);

	/* update stats */
	dev->stats.rx_packets++; /* count all receives */
	dev->stats.rx_bytes += size; /* count all received bytes */

	/*
	* If any worth-while packets have been received, netif_rx()
	* will work on them when we get to the tasklets.
	*/
	}

	static const struct net_device_ops de600_netdev_ops = {
	.ndo_open = de600_open,
	.ndo_stop = de600_close,
	.ndo_start_xmit = de600_start_xmit,
	.ndo_change_mtu = eth_change_mtu,
	.ndo_set_mac_address = eth_mac_addr,
	.ndo_validate_addr = eth_validate_addr,
	};


	static struct net_device * __init de600_probe(void)
	{
	int i;
	struct net_device *dev;
	int err;

	dev = alloc_etherdev(0);
	if (!dev)
	return ERR_PTR(-ENOMEM);


	if (!request_region(DE600_IO, 3, "de600")) {
	printk(KERN_WARNING "DE600: port 0x%x busy\n", DE600_IO);
	err = -EBUSY;
	goto out;
	}

	printk(KERN_INFO "%s: D-Link DE-600 pocket adapter", dev->name);
	/* Alpha testers must have the version number to report bugs. */
	pr_debug("%s", version);

	/* probe for adapter */
	err = -ENODEV;
	rx_page = 0;
	select_nic();
	(void)de600_read_status(dev);
	de600_put_command(RESET);
	de600_put_command(STOP_RESET);
	if (de600_read_status(dev) & 0xf0) {
	printk(": not at I/O %#3x.\n", DATA_PORT);
	goto out1;
	}

	/*
	* Maybe we found one,
	* have to check if it is a D-Link DE-600 adapter...
	*/

	/* Get the adapter ethernet address from the ROM */
	de600_setup_address(NODE_ADDRESS, RW_ADDR);
	for (i = 0; i < ETH_ALEN; i++) {
	dev->dev_addr[i] = de600_read_byte(READ_DATA, dev);
	dev->broadcast[i] = 0xff;
	}

	/* Check magic code */
	if ((dev->dev_addr[1] == 0xde) && (dev->dev_addr[2] == 0x15)) {
	/* OK, install real address */
	dev->dev_addr[0] = 0x00;
	dev->dev_addr[1] = 0x80;
	dev->dev_addr[2] = 0xc8;
	dev->dev_addr[3] &= 0x0f;
	dev->dev_addr[3] \|= 0x70;
	} else {
	printk(" not identified in the printer port\n");
	goto out1;
	}

	printk(", Ethernet Address: %pM\n", dev->dev_addr);

	dev->netdev_ops = &de600_netdev_ops;

	dev->flags&=~IFF_MULTICAST;

	select_prn();

	err = register_netdev(dev);
	if (err)
	goto out1;

	return dev;

	out1:
	release_region(DE600_IO, 3);
	out:
	free_netdev(dev);
	return ERR_PTR(err);
	}

	static int adapter_init(struct net_device *dev)
	{
	int i;

	select_nic();
	rx_page = 0; /* used by RESET */
	de600_put_command(RESET);
	de600_put_command(STOP_RESET);

	/* Check if it is still there... */
	/* Get the some bytes of the adapter ethernet address from the ROM */
	de600_setup_address(NODE_ADDRESS, RW_ADDR);
	de600_read_byte(READ_DATA, dev);
	if ((de600_read_byte(READ_DATA, dev) != 0xde) \|\|
	(de600_read_byte(READ_DATA, dev) != 0x15)) {
	/* was: if (de600_read_status(dev) & 0xf0) { */
	printk("Something has happened to the DE-600! Please check it and do a new ifconfig!\n");
	/* Goodbye, cruel world... */
	dev->flags &= ~IFF_UP;
	de600_close(dev);
	was_down = 1;
	netif_stop_queue(dev); /* Transmit busy... */
	return 1; /* failed */
	}

	if (was_down) {
	printk(KERN_INFO "%s: Thanks, I feel much better now!\n", dev->name);
	was_down = 0;
	}

	tx_fifo_in = 0;
	tx_fifo_out = 0;
	free_tx_pages = TX_PAGES;


	/* set the ether address. */
	de600_setup_address(NODE_ADDRESS, RW_ADDR);
	for (i = 0; i < ETH_ALEN; i++)
	de600_put_byte(dev->dev_addr[i]);

	/* where to start saving incoming packets */
	rx_page = RX_BP \| RX_BASE_PAGE;
	de600_setup_address(MEM_4K, RW_ADDR);
	/* Enable receiver */
	de600_put_command(RX_ENABLE);
	select_prn();

	netif_start_queue(dev);

	return 0; /* OK */
	}

	static struct net_device *de600_dev;

	static int __init de600_init(void)
	{
	de600_dev = de600_probe();
	if (IS_ERR(de600_dev))
	return PTR_ERR(de600_dev);
	return 0;
	}

	static void __exit de600_exit(void)
	{
	unregister_netdev(de600_dev);
	release_region(DE600_IO, 3);
	free_netdev(de600_dev);
	}

	module_init(de600_init);
	module_exit(de600_exit);

	MODULE_LICENSE("GPL");