ether3.c

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/*
 *  linux/drivers/acorn/net/ether3.c
 *
 *  Copyright (C) 1995-2000 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * SEEQ nq8005 ethernet driver for Acorn/ANT Ether3 card
 *  for Acorn machines
 *
 * By Russell King, with some suggestions from [email protected]
 *
 * 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[] __devinitdata = "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 int  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);

#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(unsigned long data)
{
    struct net_device *dev = (struct net_device *)data;
    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 */
    priv(dev)->timer.data = (unsigned long)dev;
    priv(dev)->timer.function = ether3_ledoff;
    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 __devinit
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 __devinit
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 __devinit 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 (!is_valid_ether_addr(dev->dev_addr)) {
        printk(KERN_WARNING "%s: invalid ethernet MAC address\n",
            dev->name);
        return -EINVAL;
    }

    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 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 int
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) {
 int i;
 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);
 for (i = 2; i < 14; i++)
   printk("%02X ", addrs[i]);
 printk("\n");
 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
                goto dropping;
        } 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;

dropping:{
    static unsigned long last_warned;

    ether3_outw(next_ptr >> 8, REG_RECVEND);
    /*
     * Don't print this message too many times...
     */
    if (time_after(jiffies, last_warned + 10 * HZ)) {
        last_warned = jiffies;
        printk("%s: memory squeeze, dropping packet.\n", dev->name);
    }
    dev->stats.rx_dropped++;
    goto done;
    }
}

/*
 * 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 __devinit 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_change_mtu     = eth_change_mtu,
    .ndo_set_mac_address    = eth_mac_addr,
};

static int __devinit
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);

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

    /* 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 __devexit 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     = __devexit_p(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");