/* 8390.c: A general NS8390 ethernet driver core for linux. */
/*
	Written 1992-94 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 Public License, incorporated herein by reference.

	The author may be reached as becker@CESDIS.gsfc.nasa.gov, or C/O
	Center of Excellence in Space Data and Information Sciences
	   Code 930.5, Goddard Space Flight Center, Greenbelt MD 20771
  
  This is the chip-specific code for many 8390-based ethernet adaptors.
  This is not a complete driver, it must be combined with board-specific
  code such as ne.c, wd.c, 3c503.c, etc.

  Changelog:

  Paul Gortmaker	: remove set_bit lock, other cleanups.

  */

static const char *version =
    "8390.c:v1.10 9/23/94 Donald Becker (becker@cesdis.gsfc.nasa.gov)\n";

/*
  Braindamage remaining:
  Much of this code should have been cleaned up, but every attempt 
  has broken some clone part.
  
  Sources:
  The National Semiconductor LAN Databook, and the 3Com 3c503 databook.
  */

#ifdef MODULE
#include <linux/module.h>
#include <linux/version.h>
#endif

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/string.h>
#include <asm/system.h>
#include <asm/segment.h>
#include <asm/bitops.h>
#include <asm/io.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/in.h>
#include <linux/interrupt.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>

#include "8390.h"

/* These are the operational function interfaces to board-specific
   routines.
	void reset_8390(struct device *dev)
		Resets the board associated with DEV, including a hardware reset of
		the 8390.  This is only called when there is a transmit timeout, and
		it is always followed by 8390_init().
	void block_output(struct device *dev, int count, const unsigned char *buf,
					  int start_page)
		Write the COUNT bytes of BUF to the packet buffer at START_PAGE.  The
		"page" value uses the 8390's 256-byte pages.
	int block_input(struct device *dev, int count, char *buf, int ring_offset)
		Read COUNT bytes from the packet buffer into BUF.  Start reading from
		RING_OFFSET, the address as the 8390 sees it.  The first read will
		always be the 4 byte, page aligned 8390 header.  *If* there is a
		subsequent read, it will be of the rest of the packet.
*/
#define ei_reset_8390 (ei_local->reset_8390)
#define ei_block_output (ei_local->block_output)
#define ei_block_input (ei_local->block_input)

/* use 0 for production, 1 for verification, >2 for debug */
#ifdef EI_DEBUG
int ei_debug = EI_DEBUG;
#else
int ei_debug = 1;
#endif

/* Max number of packets received at one Intr.
   Currently this may only be examined by a kernel debugger. */
static int high_water_mark = 0;

/* Index to functions. */
static void ei_tx_intr(struct device *dev);
static void ei_receive(struct device *dev);
static void ei_rx_overrun(struct device *dev);

/* Routines generic to NS8390-based boards. */
static void NS8390_trigger_send(struct device *dev, unsigned int length,
								int start_page);
#ifdef HAVE_MULTICAST
static void set_multicast_list(struct device *dev, int num_addrs, void *addrs);
#endif


/* Open/initialize the board.  This routine goes all-out, setting everything
   up anew at each open, even though many of these registers should only
   need to be set once at boot.
   */
int ei_open(struct device *dev)
{
    struct ei_device *ei_local = (struct ei_device *) dev->priv;
    
    if ( ! ei_local) {
		printk("%s: Opening a non-existent physical device\n", dev->name);
		return ENXIO;
    }
    
    irq2dev_map[dev->irq] = dev;
    NS8390_init(dev, 1);
    dev->start = 1;
    ei_local->irqlock = 0;
    return 0;
}

static int ei_start_xmit(struct sk_buff *skb, struct device *dev)
{
    int e8390_base = dev->base_addr;
    struct ei_device *ei_local = (struct ei_device *) dev->priv;
    int length, send_length;
    
/*
 *  We normally shouldn't be called if dev->tbusy is set, but the
 *  existing code does anyway. If it has been too long since the
 *  last Tx, we assume the board has died and kick it.
 */
 
    if (dev->tbusy) {	/* Do timeouts, just like the 8003 driver. */
		int txsr = inb(e8390_base+EN0_TSR), isr;
		int tickssofar = jiffies - dev->trans_start;
		if (tickssofar < TX_TIMEOUT ||	(tickssofar < (TX_TIMEOUT+5) && ! (txsr & ENTSR_PTX))) {
			return 1;
		}
		isr = inb(e8390_base+EN0_ISR);
		if (dev->start == 0) {
			printk("%s: xmit on stopped card\n", dev->name);
			return 1;
		}
		printk(KERN_DEBUG "%s: transmit timed out, TX status %#2x, ISR %#2x.\n",
			   dev->name, txsr, isr);
		/* Does the 8390 thinks it has posted an interrupt? */
		if (isr)
			printk(KERN_DEBUG "%s: Possible IRQ conflict on IRQ%d?\n", dev->name, dev->irq);
		else {
			/* The 8390 probably hasn't gotten on the cable yet. */
			printk(KERN_DEBUG "%s: Possible network cable problem?\n", dev->name);
			if(ei_local->stat.tx_packets==0)
				ei_local->interface_num ^= 1; 	/* Try a different xcvr.  */
		}
		/* Try to restart the card.  Perhaps the user has fixed something. */
		ei_reset_8390(dev);
		NS8390_init(dev, 1);
		dev->trans_start = jiffies;
    }
    
    /* Sending a NULL skb means some higher layer thinks we've missed an
       tx-done interrupt. Caution: dev_tint() handles the cli()/sti()
       itself. */
    if (skb == NULL) {
		dev_tint(dev);
		return 0;
    }
    
    length = skb->len;
    if (skb->len <= 0)
		return 0;

    /* Mask interrupts from the ethercard. */
    outb_p(0x00, e8390_base + EN0_IMR);
    if (dev->interrupt) {
	printk("%s: Tx request while isr active.\n",dev->name);
	outb_p(ENISR_ALL, e8390_base + EN0_IMR);
	return 1;
    }
    ei_local->irqlock = 1;

    send_length = ETH_ZLEN < length ? length : ETH_ZLEN;

    if (ei_local->pingpong) {
		int output_page;
		if (ei_local->tx1 == 0) {
			output_page = ei_local->tx_start_page;
			ei_local->tx1 = send_length;
			if (ei_debug  &&  ei_local->tx2 > 0)
				printk("%s: idle transmitter tx2=%d, lasttx=%d, txing=%d.\n",
					   dev->name, ei_local->tx2, ei_local->lasttx,
					   ei_local->txing);
		} else if (ei_local->tx2 == 0) {
			output_page = ei_local->tx_start_page + 6;
			ei_local->tx2 = send_length;
			if (ei_debug  &&  ei_local->tx1 > 0)
				printk("%s: idle transmitter, tx1=%d, lasttx=%d, txing=%d.\n",
					   dev->name, ei_local->tx1, ei_local->lasttx,
					   ei_local->txing);
		} else {	/* We should never get here. */
			if (ei_debug)
				printk("%s: No Tx buffers free. irq=%d tx1=%d tx2=%d last=%d\n",
					dev->name, dev->interrupt, ei_local->tx1, 
					ei_local->tx2, ei_local->lasttx);
			ei_local->irqlock = 0;
			dev->tbusy = 1;
			outb_p(ENISR_ALL, e8390_base + EN0_IMR);
			return 1;
		}
		ei_block_output(dev, length, skb->data, output_page);
		if (! ei_local->txing) {
			ei_local->txing = 1;
			NS8390_trigger_send(dev, send_length, output_page);
			dev->trans_start = jiffies;
			if (output_page == ei_local->tx_start_page)
				ei_local->tx1 = -1, ei_local->lasttx = -1;
			else
				ei_local->tx2 = -1, ei_local->lasttx = -2;
		} else
			ei_local->txqueue++;

		dev->tbusy = (ei_local->tx1  &&  ei_local->tx2);
    } else {  /* No pingpong, just a single Tx buffer. */
		ei_block_output(dev, length, skb->data, ei_local->tx_start_page);
		ei_local->txing = 1;
		NS8390_trigger_send(dev, send_length, ei_local->tx_start_page);
		dev->trans_start = jiffies;
		dev->tbusy = 1;
    }
    
    /* Turn 8390 interrupts back on. */
    ei_local->irqlock = 0;
    outb_p(ENISR_ALL, e8390_base + EN0_IMR);

    dev_kfree_skb (skb, FREE_WRITE);
    
    return 0;
}

/* The typical workload of the driver:
   Handle the ether interface interrupts. */
void ei_interrupt(int irq, struct pt_regs * regs)
{
    struct device *dev = (struct device *)(irq2dev_map[irq]);
    int e8390_base;
    int interrupts, nr_serviced = 0;
    struct ei_device *ei_local;
    
    if (dev == NULL) {
		printk ("net_interrupt(): irq %d for unknown device.\n", irq);
		return;
    }
    e8390_base = dev->base_addr;
    ei_local = (struct ei_device *) dev->priv;
    if (dev->interrupt || ei_local->irqlock) {
		/* The "irqlock" check is only for testing. */
		printk(ei_local->irqlock
			   ? "%s: Interrupted while interrupts are masked! isr=%#2x imr=%#2x.\n"
			   : "%s: Reentering the interrupt handler! isr=%#2x imr=%#2x.\n",
			   dev->name, inb_p(e8390_base + EN0_ISR),
			   inb_p(e8390_base + EN0_IMR));
		return;
    }
    
    dev->interrupt = 1;
    
    /* Change to page 0 and read the intr status reg. */
    outb_p(E8390_NODMA+E8390_PAGE0, e8390_base + E8390_CMD);
    if (ei_debug > 3)
		printk("%s: interrupt(isr=%#2.2x).\n", dev->name,
			   inb_p(e8390_base + EN0_ISR));
    
    /* !!Assumption!! -- we stay in page 0.	 Don't break this. */
    while ((interrupts = inb_p(e8390_base + EN0_ISR)) != 0
		   && ++nr_serviced < MAX_SERVICE) {
		if (dev->start == 0) {
			printk("%s: interrupt from stopped card\n", dev->name);
			interrupts = 0;
			break;
		}
		if (interrupts & ENISR_OVER) {
			ei_rx_overrun(dev);
		} else if (interrupts & (ENISR_RX+ENISR_RX_ERR)) {
			/* Got a good (?) packet. */
			ei_receive(dev);
		}
		/* Push the next to-transmit packet through. */
		if (interrupts & ENISR_TX) {
			ei_tx_intr(dev);
		} else if (interrupts & ENISR_COUNTERS) {
			ei_local->stat.rx_frame_errors += inb_p(e8390_base + EN0_COUNTER0);
			ei_local->stat.rx_crc_errors   += inb_p(e8390_base + EN0_COUNTER1);
			ei_local->stat.rx_missed_errors+= inb_p(e8390_base + EN0_COUNTER2);
			outb_p(ENISR_COUNTERS, e8390_base + EN0_ISR); /* Ack intr. */
		}
		
		/* Ignore the transmit errs and reset intr for now. */
		if (interrupts & ENISR_TX_ERR) {
			outb_p(ENISR_TX_ERR, e8390_base + EN0_ISR); /* Ack intr. */
		}

		/* Ignore any RDC interrupts that make it back to here. */
		if (interrupts & ENISR_RDC) {
				outb_p(ENISR_RDC, e8390_base + EN0_ISR);
		}

		outb_p(E8390_NODMA+E8390_PAGE0+E8390_START, e8390_base + E8390_CMD);
    }
    
    if (interrupts && ei_debug) {
		outb_p(E8390_NODMA+E8390_PAGE0+E8390_START, e8390_base + E8390_CMD);
		if (nr_serviced >= MAX_SERVICE) {
			printk("%s: Too much work at interrupt, status %#2.2x\n",
				   dev->name, interrupts);
			outb_p(ENISR_ALL, e8390_base + EN0_ISR); /* Ack. most intrs. */
		} else {
			printk("%s: unknown interrupt %#2x\n", dev->name, interrupts);
			outb_p(0xff, e8390_base + EN0_ISR); /* Ack. all intrs. */
		}
    }
    dev->interrupt = 0;
    return;
}

/* We have finished a transmit: check for errors and then trigger the next
   packet to be sent. */
static void ei_tx_intr(struct device *dev)
{
    int e8390_base = dev->base_addr;
    int status = inb(e8390_base + EN0_TSR);
    struct ei_device *ei_local = (struct ei_device *) dev->priv;
    
    outb_p(ENISR_TX, e8390_base + EN0_ISR); /* Ack intr. */
    
    if (ei_local->pingpong) {
		ei_local->txqueue--;
		if (ei_local->tx1 < 0) {
			if (ei_local->lasttx != 1 && ei_local->lasttx != -1)
				printk("%s: bogus last_tx_buffer %d, tx1=%d.\n",
					   ei_local->name, ei_local->lasttx, ei_local->tx1);
			ei_local->tx1 = 0;
			dev->tbusy = 0;
			if (ei_local->tx2 > 0) {
				ei_local->txing = 1;
				NS8390_trigger_send(dev, ei_local->tx2, ei_local->tx_start_page + 6);
				dev->trans_start = jiffies;
				ei_local->tx2 = -1,
				ei_local->lasttx = 2;
			} else
				ei_local->lasttx = 20, ei_local->txing = 0;
		} else if (ei_local->tx2 < 0) {
			if (ei_local->lasttx != 2  &&  ei_local->lasttx != -2)
				printk("%s: bogus last_tx_buffer %d, tx2=%d.\n",
					   ei_local->name, ei_local->lasttx, ei_local->tx2);
			ei_local->tx2 = 0;
			dev->tbusy = 0;
			if (ei_local->tx1 > 0) {
				ei_local->txing = 1;
				NS8390_trigger_send(dev, ei_local->tx1, ei_local->tx_start_page);
				dev->trans_start = jiffies;
				ei_local->tx1 = -1;
				ei_local->lasttx = 1;
			} else
				ei_local->lasttx = 10, ei_local->txing = 0;
		} else
			printk("%s: unexpected TX-done interrupt, lasttx=%d.\n",
				   dev->name, ei_local->lasttx);
    } else {
		ei_local->txing = 0;
		dev->tbusy = 0;
    }

    /* Minimize Tx latency: update the statistics after we restart TXing. */
	if (status & ENTSR_COL) ei_local->stat.collisions++;
    if (status & ENTSR_PTX)
		ei_local->stat.tx_packets++;
    else {
		ei_local->stat.tx_errors++;
		if (status & ENTSR_ABT) ei_local->stat.tx_aborted_errors++;
		if (status & ENTSR_CRS) ei_local->stat.tx_carrier_errors++;
		if (status & ENTSR_FU)  ei_local->stat.tx_fifo_errors++;
		if (status & ENTSR_CDH) ei_local->stat.tx_heartbeat_errors++;
		if (status & ENTSR_OWC) ei_local->stat.tx_window_errors++;
	}
    
    mark_bh (NET_BH);
}

/* We have a good packet(s), get it/them out of the buffers. */

static void ei_receive(struct device *dev)
{
    int e8390_base = dev->base_addr;
    struct ei_device *ei_local = (struct ei_device *) dev->priv;
    int rxing_page, this_frame, next_frame, current_offset;
    int rx_pkt_count = 0;
    struct e8390_pkt_hdr rx_frame;
    int num_rx_pages = ei_local->stop_page-ei_local->rx_start_page;
    
    while (++rx_pkt_count < 10) {
		int pkt_len;
		
		/* Get the rx page (incoming packet pointer). */
		outb_p(E8390_NODMA+E8390_PAGE1, e8390_base + E8390_CMD);
		rxing_page = inb_p(e8390_base + EN1_CURPAG);
		outb_p(E8390_NODMA+E8390_PAGE0, e8390_base + E8390_CMD);
		
		/* Remove one frame from the ring.  Boundary is always a page behind. */
		this_frame = inb_p(e8390_base + EN0_BOUNDARY) + 1;
		if (this_frame >= ei_local->stop_page)
			this_frame = ei_local->rx_start_page;
		
		/* Someday we'll omit the previous, iff we never get this message.
		   (There is at least one clone claimed to have a problem.)  */
		if (ei_debug > 0  &&  this_frame != ei_local->current_page)
			printk("%s: mismatched read page pointers %2x vs %2x.\n",
				   dev->name, this_frame, ei_local->current_page);
		
		if (this_frame == rxing_page)	/* Read all the frames? */
			break;				/* Done for now */
		
		current_offset = this_frame << 8;
		ei_block_input(dev, sizeof(rx_frame), (char *)&rx_frame,
					   current_offset);
		
		pkt_len = rx_frame.count - sizeof(rx_frame);
		
		next_frame = this_frame + 1 + ((pkt_len+4)>>8);
		
		/* Check for bogosity warned by 3c503 book: the status byte is never
		   written.  This happened a lot during testing! This code should be
		   cleaned up someday. */
		if (rx_frame.next != next_frame
			&& rx_frame.next != next_frame + 1
			&& rx_frame.next != next_frame - num_rx_pages
			&& rx_frame.next != next_frame + 1 - num_rx_pages) {
			ei_local->current_page = rxing_page;
			outb(ei_local->current_page-1, e8390_base+EN0_BOUNDARY);
			ei_local->stat.rx_errors++;
			continue;
		}

		if (pkt_len < 60  ||  pkt_len > 1518) {
			if (ei_debug)
				printk("%s: bogus packet size: %d, status=%#2x nxpg=%#2x.\n",
					   dev->name, rx_frame.count, rx_frame.status,
					   rx_frame.next);
			ei_local->stat.rx_errors++;
		} else if ((rx_frame.status & 0x0F) == ENRSR_RXOK) {
			struct sk_buff *skb;
			
			skb = dev_alloc_skb(pkt_len+2);
			if (skb == NULL) {
				if (ei_debug > 1)
					printk("%s: Couldn't allocate a sk_buff of size %d.\n",
						   dev->name, pkt_len);
				ei_local->stat.rx_dropped++;
				break;
			} else {
				skb_reserve(skb,2);	/* IP headers on 16 byte boundaries */
				skb->dev = dev;
				
				ei_block_input(dev, pkt_len, skb_put(skb,pkt_len),
							   current_offset + sizeof(rx_frame));
				skb->protocol=eth_type_trans(skb,dev);
				netif_rx(skb);
				ei_local->stat.rx_packets++;
			}
		} else {
			int errs = rx_frame.status;
			if (ei_debug)
				printk("%s: bogus packet: status=%#2x nxpg=%#2x size=%d\n",
					   dev->name, rx_frame.status, rx_frame.next,
					   rx_frame.count);
			if (errs & ENRSR_FO)
				ei_local->stat.rx_fifo_errors++;
		}
		next_frame = rx_frame.next;
		
		/* This _should_ never happen: it's here for avoiding bad clones. */
		if (next_frame >= ei_local->stop_page) {
			printk("%s: next frame inconsistency, %#2x\n", dev->name,
				   next_frame);
			next_frame = ei_local->rx_start_page;
		}
		ei_local->current_page = next_frame;
		outb_p(next_frame-1, e8390_base+EN0_BOUNDARY);
    }
    /* If any worth-while packets have been received, netif_rx()
       has done a mark_bh(NET_BH) for us and will work on them
       when we get to the bottom-half routine. */

	/* Record the maximum Rx packet queue. */
	if (rx_pkt_count > high_water_mark)
		high_water_mark = rx_pkt_count;

    /* Bug alert!  Reset ENISR_OVER to avoid spurious overruns! */
    outb_p(ENISR_RX+ENISR_RX_ERR+ENISR_OVER, e8390_base+EN0_ISR);
    return;
}

/* We have a receiver overrun: we have to kick the 8390 to get it started
   again.*/
static void ei_rx_overrun(struct device *dev)
{
    int e8390_base = dev->base_addr;
    int reset_start_time = jiffies;
    struct ei_device *ei_local = (struct ei_device *) dev->priv;
    
    /* We should already be stopped and in page0.  Remove after testing. */
    outb_p(E8390_NODMA+E8390_PAGE0+E8390_STOP, e8390_base+E8390_CMD);
    
    if (ei_debug > 1)
		printk("%s: Receiver overrun.\n", dev->name);
    ei_local->stat.rx_over_errors++;
    
    /* The old Biro driver does dummy = inb_p( RBCR[01] ); at this point.
       It might mean something -- magic to speed up a reset?  A 8390 bug?*/
    
    /* Wait for the reset to complete.	This should happen almost instantly,
	   but could take up to 1.5msec in certain rare instances.  There is no
	   easy way of timing something in that range, so we use 'jiffies' as
	   a sanity check. */
    while ((inb_p(e8390_base+EN0_ISR) & ENISR_RESET) == 0)
		if (jiffies - reset_start_time > 1) {
			printk("%s: reset did not complete at ei_rx_overrun.\n",
				   dev->name);
			NS8390_init(dev, 1);
			return;
		}
    
    /* Remove packets right away. */
    ei_receive(dev);
    
    outb_p(0xff, e8390_base+EN0_ISR);
    /* Generic 8390 insns to start up again, same as in open_8390(). */
    outb_p(E8390_NODMA + E8390_PAGE0 + E8390_START, e8390_base + E8390_CMD);
    outb_p(E8390_TXCONFIG, e8390_base + EN0_TXCR); /* xmit on. */
}

static struct enet_statistics *get_stats(struct device *dev)
{
    short ioaddr = dev->base_addr;
    struct ei_device *ei_local = (struct ei_device *) dev->priv;
    
    /* If the card is stopped, just return the present stats. */
    if (dev->start == 0) return &ei_local->stat;

    /* Read the counter registers, assuming we are in page 0. */
    ei_local->stat.rx_frame_errors += inb_p(ioaddr + EN0_COUNTER0);
    ei_local->stat.rx_crc_errors   += inb_p(ioaddr + EN0_COUNTER1);
    ei_local->stat.rx_missed_errors+= inb_p(ioaddr + EN0_COUNTER2);
    
    return &ei_local->stat;
}

#ifdef HAVE_MULTICAST
/* 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 device *dev, int num_addrs, void *addrs)
{
    short ioaddr = dev->base_addr;
    
    if (num_addrs > 0) {
		/* The multicast-accept list is initialized to accept-all, and we
		   rely on higher-level filtering for now. */
		outb_p(E8390_RXCONFIG | 0x08, ioaddr + EN0_RXCR);
    } else if (num_addrs < 0)
		outb_p(E8390_RXCONFIG | 0x18, ioaddr + EN0_RXCR);
    else
		outb_p(E8390_RXCONFIG, ioaddr + EN0_RXCR);
}
#endif

/* Initialize the rest of the 8390 device structure. */
int ethdev_init(struct device *dev)
{
    if (ei_debug > 1)
		printk(version);
    
    if (dev->priv == NULL) {
		struct ei_device *ei_local;
		
		dev->priv = kmalloc(sizeof(struct ei_device), GFP_KERNEL);
		memset(dev->priv, 0, sizeof(struct ei_device));
		ei_local = (struct ei_device *)dev->priv;
#ifndef NO_PINGPONG
		ei_local->pingpong = 1;
#endif
    }
    
    /* The open call may be overridden by the card-specific code. */
    if (dev->open == NULL)
		dev->open = &ei_open;
    /* We should have a dev->stop entry also. */
    dev->hard_start_xmit = &ei_start_xmit;
    dev->get_stats	= get_stats;
#ifdef HAVE_MULTICAST
    dev->set_multicast_list = &set_multicast_list;
#endif

    ether_setup(dev);
        
    return 0;
}


/* This page of functions should be 8390 generic */
/* Follow National Semi's recommendations for initializing the "NIC". */
void NS8390_init(struct device *dev, int startp)
{
    int e8390_base = dev->base_addr;
    struct ei_device *ei_local = (struct ei_device *) dev->priv;
    int i;
    int endcfg = ei_local->word16 ? (0x48 | ENDCFG_WTS) : 0x48;
    unsigned long flags;
    
    /* Follow National Semi's recommendations for initing the DP83902. */
    outb_p(E8390_NODMA+E8390_PAGE0+E8390_STOP, e8390_base); /* 0x21 */
    outb_p(endcfg, e8390_base + EN0_DCFG);	/* 0x48 or 0x49 */
    /* Clear the remote byte count registers. */
    outb_p(0x00,  e8390_base + EN0_RCNTLO);
    outb_p(0x00,  e8390_base + EN0_RCNTHI);
    /* Set to monitor and loopback mode -- this is vital!. */
    outb_p(E8390_RXOFF, e8390_base + EN0_RXCR); /* 0x20 */
    outb_p(E8390_TXOFF, e8390_base + EN0_TXCR); /* 0x02 */
    /* Set the transmit page and receive ring. */
    outb_p(ei_local->tx_start_page,	 e8390_base + EN0_TPSR);
    ei_local->tx1 = ei_local->tx2 = 0;
    outb_p(ei_local->rx_start_page,	 e8390_base + EN0_STARTPG);
    outb_p(ei_local->stop_page-1, e8390_base + EN0_BOUNDARY); /* 3c503 says 0x3f,NS0x26*/
    ei_local->current_page = ei_local->rx_start_page;		/* assert boundary+1 */
    outb_p(ei_local->stop_page,	  e8390_base + EN0_STOPPG);
    /* Clear the pending interrupts and mask. */
    outb_p(0xFF, e8390_base + EN0_ISR);
    outb_p(0x00,  e8390_base + EN0_IMR);
    
    /* Copy the station address into the DS8390 registers,
       and set the multicast hash bitmap to receive all multicasts. */
    save_flags(flags);
    cli();
    outb_p(E8390_NODMA + E8390_PAGE1 + E8390_STOP, e8390_base); /* 0x61 */
    for(i = 0; i < 6; i++) {
		outb_p(dev->dev_addr[i], e8390_base + EN1_PHYS + i);
    }
    /* Initialize the multicast list to accept-all.  If we enable multicast
       the higher levels can do the filtering. */
    for(i = 0; i < 8; i++)
		outb_p(0xff, e8390_base + EN1_MULT + i);
    
    outb_p(ei_local->rx_start_page,	 e8390_base + EN1_CURPAG);
    outb_p(E8390_NODMA+E8390_PAGE0+E8390_STOP, e8390_base);
    restore_flags(flags);
    dev->tbusy = 0;
    dev->interrupt = 0;
    ei_local->tx1 = ei_local->tx2 = 0;
    ei_local->txing = 0;
    if (startp) {
		outb_p(0xff,  e8390_base + EN0_ISR);
		outb_p(ENISR_ALL,  e8390_base + EN0_IMR);
		outb_p(E8390_NODMA+E8390_PAGE0+E8390_START, e8390_base);
		outb_p(E8390_TXCONFIG, e8390_base + EN0_TXCR); /* xmit on. */
		/* 3c503 TechMan says rxconfig only after the NIC is started. */
		outb_p(E8390_RXCONFIG,	e8390_base + EN0_RXCR); /* rx on,  */
    }
    return;
}

/* Trigger a transmit start, assuming the length is valid. */
static void NS8390_trigger_send(struct device *dev, unsigned int length,
								int start_page)
{
    int e8390_base = dev->base_addr;
    
    outb_p(E8390_NODMA+E8390_PAGE0, e8390_base);
    
    if (inb_p(e8390_base) & E8390_TRANS) {
		printk("%s: trigger_send() called with the transmitter busy.\n",
			   dev->name);
		return;
    }
    outb_p(length & 0xff, e8390_base + EN0_TCNTLO);
    outb_p(length >> 8, e8390_base + EN0_TCNTHI);
    outb_p(start_page, e8390_base + EN0_TPSR);
    outb_p(E8390_NODMA+E8390_TRANS+E8390_START, e8390_base);
    return;
}

#ifdef MODULE
char kernel_version[] = UTS_RELEASE;

int init_module(void)
{
     return 0;
}

void
cleanup_module(void)
{
}
#endif /* MODULE */

/*
 * Local variables:
 *  compile-command: "gcc -D__KERNEL__ -I/usr/src/linux/net/inet -Wall -Wstrict-prototypes -O6 -m486 -c 8390.c"
 *  version-control: t
 *  kept-new-versions: 5
 *  c-indent-level: 4
 *  tab-width: 4
 * End:
 */
