drivers/net/ethernet/seeq/ether3.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/drivers/acorn/net/ether3.c
 *
 *  Copyright (C) 1995-2000 Russell King
 *
 * SEEQ nq8005 ethernet driver for Acorn/ANT Ether3 card
 *  for Acorn machines
 *
 * By Russell King, with some suggestions from borris@ant.co.uk
 *
 * Changelog:
 * 1.04	RMK	29/02/1996	Won't pass packets that are from our ethernet
 *				address up to the higher levels - they're
 *				silently ignored.  I/F can now be put into
 *				multicast mode.  Receiver routine optimised.
 * 1.05	RMK	30/02/1996	Now claims interrupt at open when part of
 *				the kernel rather than when a module.
 * 1.06	RMK	02/03/1996	Various code cleanups
 * 1.07	RMK	13/10/1996	Optimised interrupt routine and transmit
 *				routines.
 * 1.08	RMK	14/10/1996	Fixed problem with too many packets,
 *				prevented the kernel message about dropped
 *				packets appearing too many times a second.
 *				Now does not disable all IRQs, only the IRQ
 *				used by this card.
 * 1.09	RMK	10/11/1996	Only enables TX irq when buffer space is low,
 *				but we still service the TX queue if we get a
 *				RX interrupt.
 * 1.10	RMK	15/07/1997	Fixed autoprobing of NQ8004.
 * 1.11	RMK	16/11/1997	Fixed autoprobing of NQ8005A.
 * 1.12	RMK	31/12/1997	Removed reference to dev_tint for Linux 2.1.
 *      RMK	27/06/1998	Changed asm/delay.h to linux/delay.h.
 * 1.13	RMK	29/06/1998	Fixed problem with transmission of packets.
 *				Chip seems to have a bug in, whereby if the
 *				packet starts two bytes from the end of the
 *				buffer, it corrupts the receiver chain, and
 *				never updates the transmit status correctly.
 * 1.14	RMK	07/01/1998	Added initial code for ETHERB addressing.
 * 1.15	RMK	30/04/1999	More fixes to the transmit routine for buggy
 *				hardware.
 * 1.16	RMK	10/02/2000	Updated for 2.3.43
 * 1.17	RMK	13/05/2000	Updated for 2.3.99-pre8
 */

#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/errno.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/bitops.h>

#include <asm/ecard.h>
#include <asm/io.h>

static char version[] = "ether3 ethernet driver (c) 1995-2000 R.M.King v1.17\n";

#include "ether3.h"

static unsigned int net_debug = NET_DEBUG;

static void	ether3_setmulticastlist(struct net_device *dev);
static int	ether3_rx(struct net_device *dev, unsigned int maxcnt);
static void	ether3_tx(struct net_device *dev);
static int	ether3_open (struct net_device *dev);
static netdev_tx_t	ether3_sendpacket(struct sk_buff *skb,
					  struct net_device *dev);
static irqreturn_t ether3_interrupt (int irq, void *dev_id);
static int	ether3_close (struct net_device *dev);
static void	ether3_setmulticastlist (struct net_device *dev);
static void	ether3_timeout(struct net_device *dev, unsigned int txqueue);

#define BUS_16		2
#define BUS_8		1
#define BUS_UNKNOWN	0

/* --------------------------------------------------------------------------- */

typedef enum {
	buffer_write,
	buffer_read
} buffer_rw_t;

/*
 * ether3 read/write.  Slow things down a bit...
 * The SEEQ8005 doesn't like us writing to its registers
 * too quickly.
 */
static inline void ether3_outb(int v, void __iomem *r)
{
	writeb(v, r);
	udelay(1);
}

static inline void ether3_outw(int v, void __iomem *r)
{
	writew(v, r);
	udelay(1);
}
#define ether3_inb(r)		({ unsigned int __v = readb((r)); udelay(1); __v; })
#define ether3_inw(r)		({ unsigned int __v = readw((r)); udelay(1); __v; })

static int
ether3_setbuffer(struct net_device *dev, buffer_rw_t read, int start)
{
	int timeout = 1000;

	ether3_outw(priv(dev)->regs.config1 | CFG1_LOCBUFMEM, REG_CONFIG1);
	ether3_outw(priv(dev)->regs.command | CMD_FIFOWRITE, REG_COMMAND);

	while ((ether3_inw(REG_STATUS) & STAT_FIFOEMPTY) == 0) {
		if (!timeout--) {
			printk("%s: setbuffer broken\n", dev->name);
			priv(dev)->broken = 1;
			return 1;
		}
		udelay(1);
	}

	if (read == buffer_read) {
		ether3_outw(start, REG_DMAADDR);
		ether3_outw(priv(dev)->regs.command | CMD_FIFOREAD, REG_COMMAND);
	} else {
		ether3_outw(priv(dev)->regs.command | CMD_FIFOWRITE, REG_COMMAND);
		ether3_outw(start, REG_DMAADDR);
	}
	return 0;
}

/*
 * write data to the buffer memory
 */
#define ether3_writebuffer(dev,data,length)			\
	writesw(REG_BUFWIN, (data), (length) >> 1)

#define ether3_writeword(dev,data)				\
	writew((data), REG_BUFWIN)

#define ether3_writelong(dev,data)	{			\
	void __iomem *reg_bufwin = REG_BUFWIN;			\
	writew((data), reg_bufwin);				\
	writew((data) >> 16, reg_bufwin);			\
}

/*
 * read data from the buffer memory
 */
#define ether3_readbuffer(dev,data,length)			\
	readsw(REG_BUFWIN, (data), (length) >> 1)

#define ether3_readword(dev)					\
	readw(REG_BUFWIN)

#define ether3_readlong(dev)	 				\
	readw(REG_BUFWIN) | (readw(REG_BUFWIN) << 16)

/*
 * Switch LED off...
 */
static void ether3_ledoff(struct timer_list *t)
{
	struct dev_priv *private = from_timer(private, t, timer);
	struct net_device *dev = private->dev;

	ether3_outw(priv(dev)->regs.config2 |= CFG2_CTRLO, REG_CONFIG2);
}

/*
 * switch LED on...
 */
static inline void ether3_ledon(struct net_device *dev)
{
	del_timer(&priv(dev)->timer);
	priv(dev)->timer.expires = jiffies + HZ / 50; /* leave on for 1/50th second */
	add_timer(&priv(dev)->timer);
	if (priv(dev)->regs.config2 & CFG2_CTRLO)
		ether3_outw(priv(dev)->regs.config2 &= ~CFG2_CTRLO, REG_CONFIG2);
}

/*
 * Read the ethernet address string from the on board rom.
 * This is an ascii string!!!
 */
static int
ether3_addr(char *addr, struct expansion_card *ec)
{
	struct in_chunk_dir cd;
	char *s;
	
	if (ecard_readchunk(&cd, ec, 0xf5, 0) && (s = strchr(cd.d.string, '('))) {
		int i;
		for (i = 0; i<6; i++) {
			addr[i] = simple_strtoul(s + 1, &s, 0x10);
			if (*s != (i==5?')' : ':' ))
				break;
		}
		if (i == 6)
			return 0;
	}
	/* I wonder if we should even let the user continue in this case
	 *   - no, it would be better to disable the device
	 */
	printk(KERN_ERR "ether3: Couldn't read a valid MAC address from card.\n");
	return -ENODEV;
}

/* --------------------------------------------------------------------------- */

static int
ether3_ramtest(struct net_device *dev, unsigned char byte)
{
	unsigned char *buffer = kmalloc(RX_END, GFP_KERNEL);
	int i,ret = 0;
	int max_errors = 4;
	int bad = -1;

	if (!buffer)
		return 1;

	memset(buffer, byte, RX_END);
	ether3_setbuffer(dev, buffer_write, 0);
	ether3_writebuffer(dev, buffer, TX_END);
	ether3_setbuffer(dev, buffer_write, RX_START);
	ether3_writebuffer(dev, buffer + RX_START, RX_LEN);
	memset(buffer, byte ^ 0xff, RX_END);
	ether3_setbuffer(dev, buffer_read, 0);
	ether3_readbuffer(dev, buffer, TX_END);
	ether3_setbuffer(dev, buffer_read, RX_START);
	ether3_readbuffer(dev, buffer + RX_START, RX_LEN);

	for (i = 0; i < RX_END; i++) {
		if (buffer[i] != byte) {
			if (max_errors > 0 && bad != buffer[i]) {
				printk("%s: RAM failed with (%02X instead of %02X) at 0x%04X",
				       dev->name, buffer[i], byte, i);
				ret = 2;
				max_errors--;
				bad = i;
			}
		} else {
			if (bad != -1) {
				if (bad != i - 1)
					printk(" - 0x%04X\n", i - 1);
				printk("\n");
				bad = -1;
			}
		}
	}
	if (bad != -1)
		printk(" - 0xffff\n");
	kfree(buffer);

	return ret;
}

/* ------------------------------------------------------------------------------- */

static int ether3_init_2(struct net_device *dev)
{
	int i;

	priv(dev)->regs.config1 = CFG1_RECVCOMPSTAT0|CFG1_DMABURST8;
	priv(dev)->regs.config2 = CFG2_CTRLO|CFG2_RECVCRC|CFG2_ERRENCRC;
	priv(dev)->regs.command = 0;

	/*
	 * Set up our hardware address
	 */
	ether3_outw(priv(dev)->regs.config1 | CFG1_BUFSELSTAT0, REG_CONFIG1);
	for (i = 0; i < 6; i++)
		ether3_outb(dev->dev_addr[i], REG_BUFWIN);

	if (dev->flags & IFF_PROMISC)
		priv(dev)->regs.config1 |= CFG1_RECVPROMISC;
	else if (dev->flags & IFF_MULTICAST)
		priv(dev)->regs.config1 |= CFG1_RECVSPECBRMULTI;
	else
		priv(dev)->regs.config1 |= CFG1_RECVSPECBROAD;

	/*
	 * There is a problem with the NQ8005 in that it occasionally loses the
	 * last two bytes.  To get round this problem, we receive the CRC as
	 * well.  That way, if we do lose the last two, then it doesn't matter.
	 */
	ether3_outw(priv(dev)->regs.config1 | CFG1_TRANSEND, REG_CONFIG1);
	ether3_outw((TX_END>>8) - 1, REG_BUFWIN);
	ether3_outw(priv(dev)->rx_head, REG_RECVPTR);
	ether3_outw(0, REG_TRANSMITPTR);
	ether3_outw(priv(dev)->rx_head >> 8, REG_RECVEND);
	ether3_outw(priv(dev)->regs.config2, REG_CONFIG2);
	ether3_outw(priv(dev)->regs.config1 | CFG1_LOCBUFMEM, REG_CONFIG1);
	ether3_outw(priv(dev)->regs.command, REG_COMMAND);

	i = ether3_ramtest(dev, 0x5A);
	if(i)
		return i;
	i = ether3_ramtest(dev, 0x1E);
	if(i)
		return i;

	ether3_setbuffer(dev, buffer_write, 0);
	ether3_writelong(dev, 0);
	return 0;
}

static void
ether3_init_for_open(struct net_device *dev)
{
	int i;

	/* Reset the chip */
	ether3_outw(CFG2_RESET, REG_CONFIG2);
	udelay(4);

	priv(dev)->regs.command = 0;
	ether3_outw(CMD_RXOFF|CMD_TXOFF, REG_COMMAND);
	while (ether3_inw(REG_STATUS) & (STAT_RXON|STAT_TXON))
		barrier();

	ether3_outw(priv(dev)->regs.config1 | CFG1_BUFSELSTAT0, REG_CONFIG1);
	for (i = 0; i < 6; i++)
		ether3_outb(dev->dev_addr[i], REG_BUFWIN);

	priv(dev)->tx_head	= 0;
	priv(dev)->tx_tail	= 0;
	priv(dev)->regs.config2 |= CFG2_CTRLO;
	priv(dev)->rx_head	= RX_START;

	ether3_outw(priv(dev)->regs.config1 | CFG1_TRANSEND, REG_CONFIG1);
	ether3_outw((TX_END>>8) - 1, REG_BUFWIN);
	ether3_outw(priv(dev)->rx_head, REG_RECVPTR);
	ether3_outw(priv(dev)->rx_head >> 8, REG_RECVEND);
	ether3_outw(0, REG_TRANSMITPTR);
	ether3_outw(priv(dev)->regs.config2, REG_CONFIG2);
	ether3_outw(priv(dev)->regs.config1 | CFG1_LOCBUFMEM, REG_CONFIG1);

	ether3_setbuffer(dev, buffer_write, 0);
	ether3_writelong(dev, 0);

	priv(dev)->regs.command = CMD_ENINTRX | CMD_ENINTTX;
	ether3_outw(priv(dev)->regs.command | CMD_RXON, REG_COMMAND);
}

static inline int
ether3_probe_bus_8(struct net_device *dev, int val)
{
	int write_low, write_high, read_low, read_high;

	write_low = val & 255;
	write_high = val >> 8;

	printk(KERN_DEBUG "ether3_probe: write8 [%02X:%02X]", write_high, write_low);

	ether3_outb(write_low, REG_RECVPTR);
	ether3_outb(write_high, REG_RECVPTR + 4);

	read_low = ether3_inb(REG_RECVPTR);
	read_high = ether3_inb(REG_RECVPTR + 4);

	printk(", read8 [%02X:%02X]\n", read_high, read_low);

	return read_low == write_low && read_high == write_high;
}

static inline int
ether3_probe_bus_16(struct net_device *dev, int val)
{
	int read_val;

	ether3_outw(val, REG_RECVPTR);
	read_val = ether3_inw(REG_RECVPTR);

	printk(KERN_DEBUG "ether3_probe: write16 [%04X], read16 [%04X]\n", val, read_val);

	return read_val == val;
}

/*
 * 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
ether3_open(struct net_device *dev)
{
	if (request_irq(dev->irq, ether3_interrupt, 0, "ether3", dev))
		return -EAGAIN;

	ether3_init_for_open(dev);

	netif_start_queue(dev);

	return 0;
}

/*
 * The inverse routine to ether3_open().
 */
static int
ether3_close(struct net_device *dev)
{
	netif_stop_queue(dev);

	disable_irq(dev->irq);

	ether3_outw(CMD_RXOFF|CMD_TXOFF, REG_COMMAND);
	priv(dev)->regs.command = 0;
	while (ether3_inw(REG_STATUS) & (STAT_RXON|STAT_TXON))
		barrier();
	ether3_outb(0x80, REG_CONFIG2 + 4);
	ether3_outw(0, REG_COMMAND);

	free_irq(dev->irq, dev);

	return 0;
}

/*
 * Set or clear promiscuous/multicast mode filter for this adaptor.
 *
 * We don't attempt any packet filtering.  The card may have a SEEQ 8004
 * in which does not have the other ethernet address registers present...
 */
static void ether3_setmulticastlist(struct net_device *dev)
{
	priv(dev)->regs.config1 &= ~CFG1_RECVPROMISC;

	if (dev->flags & IFF_PROMISC) {
		/* promiscuous mode */
		priv(dev)->regs.config1 |= CFG1_RECVPROMISC;
	} else if (dev->flags & IFF_ALLMULTI || !netdev_mc_empty(dev)) {
		priv(dev)->regs.config1 |= CFG1_RECVSPECBRMULTI;
	} else
		priv(dev)->regs.config1 |= CFG1_RECVSPECBROAD;

	ether3_outw(priv(dev)->regs.config1 | CFG1_LOCBUFMEM, REG_CONFIG1);
}

static void ether3_timeout(struct net_device *dev, unsigned int txqueue)
{
	unsigned long flags;

	del_timer(&priv(dev)->timer);

	local_irq_save(flags);
	printk(KERN_ERR "%s: transmit timed out, network cable problem?\n", dev->name);
	printk(KERN_ERR "%s: state: { status=%04X cfg1=%04X cfg2=%04X }\n", dev->name,
		ether3_inw(REG_STATUS), ether3_inw(REG_CONFIG1), ether3_inw(REG_CONFIG2));
	printk(KERN_ERR "%s: { rpr=%04X rea=%04X tpr=%04X }\n", dev->name,
		ether3_inw(REG_RECVPTR), ether3_inw(REG_RECVEND), ether3_inw(REG_TRANSMITPTR));
	printk(KERN_ERR "%s: tx head=%X tx tail=%X\n", dev->name,
		priv(dev)->tx_head, priv(dev)->tx_tail);
	ether3_setbuffer(dev, buffer_read, priv(dev)->tx_tail);
	printk(KERN_ERR "%s: packet status = %08X\n", dev->name, ether3_readlong(dev));
	local_irq_restore(flags);

	priv(dev)->regs.config2 |= CFG2_CTRLO;
	dev->stats.tx_errors += 1;
	ether3_outw(priv(dev)->regs.config2, REG_CONFIG2);
	priv(dev)->tx_head = priv(dev)->tx_tail = 0;

	netif_wake_queue(dev);
}

/*
 * Transmit a packet
 */
static netdev_tx_t
ether3_sendpacket(struct sk_buff *skb, struct net_device *dev)
{
	unsigned long flags;
	unsigned int length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
	unsigned int ptr, next_ptr;

	if (priv(dev)->broken) {
		dev_kfree_skb(skb);
		dev->stats.tx_dropped++;
		netif_start_queue(dev);
		return NETDEV_TX_OK;
	}

	length = (length + 1) & ~1;
	if (length != skb->len) {
		if (skb_padto(skb, length))
			goto out;
	}

	next_ptr = (priv(dev)->tx_head + 1) & 15;

	local_irq_save(flags);

	if (priv(dev)->tx_tail == next_ptr) {
		local_irq_restore(flags);
		return NETDEV_TX_BUSY;	/* unable to queue */
	}

	ptr		 = 0x600 * priv(dev)->tx_head;
	priv(dev)->tx_head = next_ptr;
	next_ptr	*= 0x600;

#define TXHDR_FLAGS (TXHDR_TRANSMIT|TXHDR_CHAINCONTINUE|TXHDR_DATAFOLLOWS|TXHDR_ENSUCCESS)

	ether3_setbuffer(dev, buffer_write, next_ptr);
	ether3_writelong(dev, 0);
	ether3_setbuffer(dev, buffer_write, ptr);
	ether3_writelong(dev, 0);
	ether3_writebuffer(dev, skb->data, length);
	ether3_writeword(dev, htons(next_ptr));
	ether3_writeword(dev, TXHDR_CHAINCONTINUE >> 16);
	ether3_setbuffer(dev, buffer_write, ptr);
	ether3_writeword(dev, htons((ptr + length + 4)));
	ether3_writeword(dev, TXHDR_FLAGS >> 16);
	ether3_ledon(dev);

	if (!(ether3_inw(REG_STATUS) & STAT_TXON)) {
		ether3_outw(ptr, REG_TRANSMITPTR);
		ether3_outw(priv(dev)->regs.command | CMD_TXON, REG_COMMAND);
	}

	next_ptr = (priv(dev)->tx_head + 1) & 15;
	local_irq_restore(flags);

	dev_kfree_skb(skb);

	if (priv(dev)->tx_tail == next_ptr)
		netif_stop_queue(dev);

 out:
	return NETDEV_TX_OK;
}

static irqreturn_t
ether3_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = (struct net_device *)dev_id;
	unsigned int status, handled = IRQ_NONE;

#if NET_DEBUG > 1
	if(net_debug & DEBUG_INT)
		printk("eth3irq: %d ", irq);
#endif

	status = ether3_inw(REG_STATUS);

	if (status & STAT_INTRX) {
		ether3_outw(CMD_ACKINTRX | priv(dev)->regs.command, REG_COMMAND);
		ether3_rx(dev, 12);
		handled = IRQ_HANDLED;
	}

	if (status & STAT_INTTX) {
		ether3_outw(CMD_ACKINTTX | priv(dev)->regs.command, REG_COMMAND);
		ether3_tx(dev);
		handled = IRQ_HANDLED;
	}

#if NET_DEBUG > 1
	if(net_debug & DEBUG_INT)
		printk("done\n");
#endif
	return handled;
}

/*
 * If we have a good packet(s), get it/them out of the buffers.
 */
static int ether3_rx(struct net_device *dev, unsigned int maxcnt)
{
	unsigned int next_ptr = priv(dev)->rx_head, received = 0;

	ether3_ledon(dev);

	do {
		unsigned int this_ptr, status;
		unsigned char addrs[16];

		/*
		 * read the first 16 bytes from the buffer.
		 * This contains the status bytes etc and ethernet addresses,
		 * and we also check the source ethernet address to see if
		 * it originated from us.
		 */
		{
			unsigned int temp_ptr;
			ether3_setbuffer(dev, buffer_read, next_ptr);
			temp_ptr = ether3_readword(dev);
			status = ether3_readword(dev);
			if ((status & (RXSTAT_DONE | RXHDR_CHAINCONTINUE | RXHDR_RECEIVE)) !=
				(RXSTAT_DONE | RXHDR_CHAINCONTINUE) || !temp_ptr)
				break;

			this_ptr = next_ptr + 4;
			next_ptr = ntohs(temp_ptr);
		}
		ether3_setbuffer(dev, buffer_read, this_ptr);
		ether3_readbuffer(dev, addrs+2, 12);

if (next_ptr < RX_START || next_ptr >= RX_END) {
 printk("%s: bad next pointer @%04X: ", dev->name, priv(dev)->rx_head);
 printk("%02X %02X %02X %02X ", next_ptr >> 8, next_ptr & 255, status & 255, status >> 8);
 printk("%pM %pM\n", addrs + 2, addrs + 8);
 next_ptr = priv(dev)->rx_head;
 break;
}
		/*
		 * ignore our own packets...
	 	 */
		if (!(*(unsigned long *)&dev->dev_addr[0] ^ *(unsigned long *)&addrs[2+6]) &&
		    !(*(unsigned short *)&dev->dev_addr[4] ^ *(unsigned short *)&addrs[2+10])) {
			maxcnt ++; /* compensate for loopedback packet */
			ether3_outw(next_ptr >> 8, REG_RECVEND);
		} else
		if (!(status & (RXSTAT_OVERSIZE|RXSTAT_CRCERROR|RXSTAT_DRIBBLEERROR|RXSTAT_SHORTPACKET))) {
			unsigned int length = next_ptr - this_ptr;
			struct sk_buff *skb;

			if (next_ptr <= this_ptr)
				length += RX_END - RX_START;

			skb = netdev_alloc_skb(dev, length + 2);
			if (skb) {
				unsigned char *buf;

				skb_reserve(skb, 2);
				buf = skb_put(skb, length);
				ether3_readbuffer(dev, buf + 12, length - 12);
				ether3_outw(next_ptr >> 8, REG_RECVEND);
				*(unsigned short *)(buf + 0)	= *(unsigned short *)(addrs + 2);
				*(unsigned long *)(buf + 2)	= *(unsigned long *)(addrs + 4);
				*(unsigned long *)(buf + 6)	= *(unsigned long *)(addrs + 8);
				*(unsigned short *)(buf + 10)	= *(unsigned short *)(addrs + 12);
				skb->protocol = eth_type_trans(skb, dev);
				netif_rx(skb);
				received ++;
			} else {
				ether3_outw(next_ptr >> 8, REG_RECVEND);
				dev->stats.rx_dropped++;
				goto done;
			}
		} else {
			struct net_device_stats *stats = &dev->stats;
			ether3_outw(next_ptr >> 8, REG_RECVEND);
			if (status & RXSTAT_OVERSIZE)	  stats->rx_over_errors ++;
			if (status & RXSTAT_CRCERROR)	  stats->rx_crc_errors ++;
			if (status & RXSTAT_DRIBBLEERROR) stats->rx_fifo_errors ++;
			if (status & RXSTAT_SHORTPACKET)  stats->rx_length_errors ++;
			stats->rx_errors++;
		}
	}
	while (-- maxcnt);

done:
	dev->stats.rx_packets += received;
	priv(dev)->rx_head = next_ptr;
	/*
	 * If rx went off line, then that means that the buffer may be full.  We
	 * have dropped at least one packet.
	 */
	if (!(ether3_inw(REG_STATUS) & STAT_RXON)) {
		dev->stats.rx_dropped++;
		ether3_outw(next_ptr, REG_RECVPTR);
		ether3_outw(priv(dev)->regs.command | CMD_RXON, REG_COMMAND);
	}

	return maxcnt;
}

/*
 * Update stats for the transmitted packet(s)
 */
static void ether3_tx(struct net_device *dev)
{
	unsigned int tx_tail = priv(dev)->tx_tail;
	int max_work = 14;

	do {
	    	unsigned long status;

		/*
	    	 * Read the packet header
		 */
	    	ether3_setbuffer(dev, buffer_read, tx_tail * 0x600);
		status = ether3_readlong(dev);

		/*
		 * Check to see if this packet has been transmitted
		 */
		if ((status & (TXSTAT_DONE | TXHDR_TRANSMIT)) !=
		    (TXSTAT_DONE | TXHDR_TRANSMIT))
			break;

		/*
		 * Update errors
		 */
		if (!(status & (TXSTAT_BABBLED | TXSTAT_16COLLISIONS)))
			dev->stats.tx_packets++;
		else {
			dev->stats.tx_errors++;
			if (status & TXSTAT_16COLLISIONS)
				dev->stats.collisions += 16;
			if (status & TXSTAT_BABBLED)
				dev->stats.tx_fifo_errors++;
		}

		tx_tail = (tx_tail + 1) & 15;
	} while (--max_work);

	if (priv(dev)->tx_tail != tx_tail) {
		priv(dev)->tx_tail = tx_tail;
		netif_wake_queue(dev);
	}
}

static void ether3_banner(void)
{
	static unsigned version_printed = 0;

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

static const struct net_device_ops ether3_netdev_ops = {
	.ndo_open		= ether3_open,
	.ndo_stop		= ether3_close,
	.ndo_start_xmit		= ether3_sendpacket,
	.ndo_set_rx_mode	= ether3_setmulticastlist,
	.ndo_tx_timeout		= ether3_timeout,
	.ndo_validate_addr	= eth_validate_addr,
	.ndo_set_mac_address	= eth_mac_addr,
};

static int
ether3_probe(struct expansion_card *ec, const struct ecard_id *id)
{
	const struct ether3_data *data = id->data;
	struct net_device *dev;
	int bus_type, ret;

	ether3_banner();

	ret = ecard_request_resources(ec);
	if (ret)
		goto out;

	dev = alloc_etherdev(sizeof(struct dev_priv));
	if (!dev) {
		ret = -ENOMEM;
		goto release;
	}

	SET_NETDEV_DEV(dev, &ec->dev);

	priv(dev)->base = ecardm_iomap(ec, ECARD_RES_MEMC, 0, 0);
	if (!priv(dev)->base) {
		ret = -ENOMEM;
		goto free;
	}

	ec->irqaddr = priv(dev)->base + data->base_offset;
	ec->irqmask = 0xf0;

	priv(dev)->seeq = priv(dev)->base + data->base_offset;
	dev->irq = ec->irq;

	ether3_addr(dev->dev_addr, ec);

	priv(dev)->dev = dev;
	timer_setup(&priv(dev)->timer, ether3_ledoff, 0);

	/* Reset card...
	 */
	ether3_outb(0x80, REG_CONFIG2 + 4);
	bus_type = BUS_UNKNOWN;
	udelay(4);

	/* Test using Receive Pointer (16-bit register) to find out
	 * how the ether3 is connected to the bus...
	 */
	if (ether3_probe_bus_8(dev, 0x100) &&
	    ether3_probe_bus_8(dev, 0x201))
		bus_type = BUS_8;

	if (bus_type == BUS_UNKNOWN &&
	    ether3_probe_bus_16(dev, 0x101) &&
	    ether3_probe_bus_16(dev, 0x201))
		bus_type = BUS_16;

	switch (bus_type) {
	case BUS_UNKNOWN:
		printk(KERN_ERR "%s: unable to identify bus width\n", dev->name);
		ret = -ENODEV;
		goto free;

	case BUS_8:
		printk(KERN_ERR "%s: %s found, but is an unsupported "
			"8-bit card\n", dev->name, data->name);
		ret = -ENODEV;
		goto free;

	default:
		break;
	}

	if (ether3_init_2(dev)) {
		ret = -ENODEV;
		goto free;
	}

	dev->netdev_ops		= &ether3_netdev_ops;
	dev->watchdog_timeo	= 5 * HZ / 100;

	ret = register_netdev(dev);
	if (ret)
		goto free;

	printk("%s: %s in slot %d, %pM\n",
	       dev->name, data->name, ec->slot_no, dev->dev_addr);

	ecard_set_drvdata(ec, dev);
	return 0;

 free:
	free_netdev(dev);
 release:
	ecard_release_resources(ec);
 out:
	return ret;
}

static void ether3_remove(struct expansion_card *ec)
{
	struct net_device *dev = ecard_get_drvdata(ec);

	ecard_set_drvdata(ec, NULL);

	unregister_netdev(dev);
	free_netdev(dev);
	ecard_release_resources(ec);
}

static struct ether3_data ether3 = {
	.name		= "ether3",
	.base_offset	= 0,
};

static struct ether3_data etherb = {
	.name		= "etherb",
	.base_offset	= 0x800,
};

static const struct ecard_id ether3_ids[] = {
	{ MANU_ANT2, PROD_ANT_ETHER3, &ether3 },
	{ MANU_ANT,  PROD_ANT_ETHER3, &ether3 },
	{ MANU_ANT,  PROD_ANT_ETHERB, &etherb },
	{ 0xffff, 0xffff }
};

static struct ecard_driver ether3_driver = {
	.probe		= ether3_probe,
	.remove		= ether3_remove,
	.id_table	= ether3_ids,
	.drv = {
		.name	= "ether3",
	},
};

static int __init ether3_init(void)
{
	return ecard_register_driver(&ether3_driver);
}

static void __exit ether3_exit(void)
{
	ecard_remove_driver(&ether3_driver);
}

module_init(ether3_init);
module_exit(ether3_exit);

MODULE_LICENSE("GPL");