freebsd-nq/sys/dev/xe/if_xe.c

/*-
 * Copyright (c) 1998, 1999, 2003  Scott Mitchell
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
/*
 * Portions of this software were derived from Werner Koch's xirc2ps driver
 * for Linux under the terms of the following license (from v1.30 of the
 * xirc2ps driver):
 *
 * Copyright (c) 1997 by Werner Koch (dd9jn)
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, and the entire permission notice in its entirety,
 *    including the disclaimer of warranties.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote
 *    products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.	IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

/*		
 * FreeBSD device driver for Xircom CreditCard PCMCIA Ethernet adapters.  The
 * following cards are currently known to work with the driver:
 *   Xircom CreditCard 10/100 (CE3)
 *   Xircom CreditCard Ethernet + Modem 28 (CEM28)
 *   Xircom CreditCard Ethernet 10/100 + Modem 56 (CEM56)
 *   Xircom RealPort Ethernet 10
 *   Xircom RealPort Ethernet 10/100
 *   Xircom RealPort Ethernet 10/100 + Modem 56 (REM56, REM56G)
 *   Intel EtherExpress Pro/100 PC Card Mobile Adapter 16 (Pro/100 M16A)
 *   Compaq Netelligent 10/100 PC Card (CPQ-10/100)
 *
 * Some other cards *should* work, but support for them is either broken or in 
 * an unknown state at the moment.  I'm always interested in hearing from
 * people who own any of these cards:
 *   Xircom CreditCard 10Base-T (PS-CE2-10)
 *   Xircom CreditCard Ethernet + ModemII (CEM2)
 *   Xircom CEM28 and CEM33 Ethernet/Modem cards (may be variants of CEM2?)
 *
 * Thanks to all who assisted with the development and testing of the driver,
 * especially: Werner Koch, Duke Kamstra, Duncan Barclay, Jason George, Dru
 * Nelson, Mike Kephart, Bill Rainey and Douglas Rand.  Apologies if I've left
 * out anyone who deserves a mention here.
 *
 * Special thanks to Ade Lovett for both hosting the mailing list and doing
 * the CEM56/REM56 support code; and the FreeBSD UK Users' Group for hosting
 * the web pages.
 *
 * Author email: <scott@uk.freebsd.org>
 * Driver web page: http://ukug.uk.freebsd.org/~scott/xe_drv/
 */


#include <sys/param.h>
#include <sys/cdefs.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <sys/sysctl.h>

#include <sys/module.h>
#include <sys/bus.h>

#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/rman.h>
 
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <net/if_dl.h>
#include <net/if_media.h>
#include <net/if_mib.h>
#include <net/bpf.h>

#include <dev/xe/if_xereg.h>
#include <dev/xe/if_xevar.h>

/*
 * MII command structure
 */
struct xe_mii_frame {
  u_int8_t  mii_stdelim;
  u_int8_t  mii_opcode;
  u_int8_t  mii_phyaddr;
  u_int8_t  mii_regaddr;
  u_int8_t  mii_turnaround;
  u_int16_t mii_data;
};

/*
 * Media autonegotiation progress constants
 */
#define XE_AUTONEG_NONE		0	/* No autonegotiation in progress */
#define XE_AUTONEG_WAITING	1	/* Waiting for transmitter to go idle */
#define XE_AUTONEG_STARTED	2	/* Waiting for autonegotiation to complete */
#define XE_AUTONEG_100TX	3	/* Trying to force 100baseTX link */
#define XE_AUTONEG_FAIL		4	/* Autonegotiation failed */

/*
 * Multicast hashing CRC constants
 */
#define XE_CRC_POLY  0x04c11db6

/*
 * Prototypes start here
 */
static void      xe_init		(void *xscp);
static void      xe_start		(struct ifnet *ifp);
static int       xe_ioctl		(struct ifnet *ifp, u_long command, caddr_t data);
static void      xe_watchdog		(struct ifnet *ifp);
static int       xe_media_change	(struct ifnet *ifp);
static void      xe_media_status	(struct ifnet *ifp, struct ifmediareq *mrp);
static timeout_t xe_setmedia;
static void      xe_reset		(struct xe_softc *scp);
static void      xe_stop		(struct xe_softc *scp);
static void      xe_enable_intr		(struct xe_softc *scp);
static void      xe_disable_intr	(struct xe_softc *scp);
static void      xe_set_multicast	(struct xe_softc *scp);
static void      xe_set_addr		(struct xe_softc *scp, u_int8_t* addr, unsigned idx);
static void      xe_mchash		(struct xe_softc *scp, const uint8_t *addr);
static int       xe_pio_write_packet	(struct xe_softc *scp, struct mbuf *mbp);

/*
 * MII functions
 */
static void      xe_mii_sync		(struct xe_softc *scp);
static int       xe_mii_init    	(struct xe_softc *scp);
static void      xe_mii_send		(struct xe_softc *scp, u_int32_t bits, int cnt);
static int       xe_mii_readreg		(struct xe_softc *scp, struct xe_mii_frame *frame);
static int       xe_mii_writereg	(struct xe_softc *scp, struct xe_mii_frame *frame);
static u_int16_t xe_phy_readreg		(struct xe_softc *scp, u_int16_t reg);
static void      xe_phy_writereg	(struct xe_softc *scp, u_int16_t reg, u_int16_t data);

/*
 * Debugging functions
 */
static void      xe_mii_dump		(struct xe_softc *scp);
#if 0
static void      xe_reg_dump		(struct xe_softc *scp);
#endif

/*
 * Debug logging levels - set with hw.xe.debug sysctl
 * 0 = None
 * 1 = More hardware details, probe/attach progress
 * 2 = Most function calls, ioctls and media selection progress
 * 3 = Everything - interrupts, packets in/out and multicast address setup
 */
#define XE_DEBUG
#ifdef XE_DEBUG

/* sysctl vars */
SYSCTL_NODE(_hw, OID_AUTO, xe, CTLFLAG_RD, 0, "if_xe parameters");

int xe_debug = 0;
SYSCTL_INT(_hw_xe, OID_AUTO, debug, CTLFLAG_RW,
		   &xe_debug, 0, "if_xe debug level");

#define DEVPRINTF(level, arg) if (xe_debug >= (level)) device_printf arg
#define DPRINTF(level, arg) if (xe_debug >= (level)) printf arg
#define XE_MII_DUMP(scp) if (xe_debug >= 3) xe_mii_dump(scp)
#if 0
#define XE_REG_DUMP(scp) if (xe_debug >= 3) xe_reg_dump(scp)
#endif
#else
#define DEVPRINTF(level, arg)
#define DPRINTF(level, arg)
#define XE_MII_DUMP(scp)
#if 0
#define XE_REG_DUMP(scp)
#endif
#endif


/*
 * Attach a device.
 */
int
xe_attach (device_t dev)
{
  struct xe_softc *scp = device_get_softc(dev);

  DEVPRINTF(2, (dev, "attach\n"));

  /* Initialise stuff... */
  scp->dev = dev;
  scp->ifp = &scp->arpcom.ac_if;
  scp->ifm = &scp->ifmedia;
  scp->autoneg_status = XE_AUTONEG_NONE;

  /* Initialise the ifnet structure */
  scp->ifp->if_softc = scp;
  if_initname(scp->ifp, device_get_name(dev), device_get_unit(dev));
  scp->ifp->if_timer = 0;
  scp->ifp->if_flags = (IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST);
  scp->ifp->if_linkmib = &scp->mibdata;
  scp->ifp->if_linkmiblen = sizeof scp->mibdata;
  scp->ifp->if_output = ether_output;
  scp->ifp->if_start = xe_start;
  scp->ifp->if_ioctl = xe_ioctl;
  scp->ifp->if_watchdog = xe_watchdog;
  scp->ifp->if_init = xe_init;
  scp->ifp->if_baudrate = 100000000;
  scp->ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;

  /* Initialise the ifmedia structure */
  ifmedia_init(scp->ifm, 0, xe_media_change, xe_media_status);
  callout_handle_init(&scp->chand);

  /* Add supported media types */
  if (scp->mohawk) {
    ifmedia_add(scp->ifm, IFM_ETHER|IFM_100_TX, 0, NULL);
    ifmedia_add(scp->ifm, IFM_ETHER|IFM_10_T|IFM_FDX, 0, NULL);
    ifmedia_add(scp->ifm, IFM_ETHER|IFM_10_T|IFM_HDX, 0, NULL);
  }
  ifmedia_add(scp->ifm, IFM_ETHER|IFM_10_T, 0, NULL);
  if (scp->ce2)
    ifmedia_add(scp->ifm, IFM_ETHER|IFM_10_2, 0, NULL);
  ifmedia_add(scp->ifm, IFM_ETHER|IFM_AUTO, 0, NULL);

  /* Default is to autoselect best supported media type */
  ifmedia_set(scp->ifm, IFM_ETHER|IFM_AUTO);

  /* Get the hardware into a known state */
  xe_reset(scp);

  /* Get hardware version numbers */
  XE_SELECT_PAGE(4);
  scp->version = XE_INB(XE_BOV);
  if (scp->mohawk)
    scp->srev = (XE_INB(XE_BOV) & 0x70) >> 4;
  else
    scp->srev = (XE_INB(XE_BOV) & 0x30) >> 4;

  /* Print some useful information */
  device_printf(dev, "%s %s, version 0x%02x/0x%02x%s%s\n",
	 scp->vendor,
	 scp->card_type,
	 scp->version,
	 scp->srev,
	 scp->mohawk ? ", 100Mbps capable" : "",
	 scp->modem ?  ", with modem"      : "");
  if (scp->mohawk) {
    XE_SELECT_PAGE(0x10);
    DEVPRINTF(1, (dev, "DingoID=0x%04x, RevisionID=0x%04x, VendorID=0x%04x\n",
	   XE_INW(XE_DINGOID),
	   XE_INW(XE_RevID),
	   XE_INW(XE_VendorID)));
  }
  if (scp->ce2) {
    XE_SELECT_PAGE(0x45);
    DEVPRINTF(1, (dev, "CE2 version = 0x%#02x\n", XE_INB(XE_REV)));
  }

  /* Attach the interface */
  ether_ifattach(scp->ifp, scp->arpcom.ac_enaddr);

  /* Done */
  return 0;
}


/*
 * Complete hardware intitialisation and enable output.  Exits without doing
 * anything if there's no address assigned to the card, or if media selection
 * is in progress (the latter implies we've already run this function).
 */
static void
xe_init(void *xscp) {
  struct xe_softc *scp = xscp;
  unsigned i;
  int s;

  if (scp->autoneg_status != XE_AUTONEG_NONE) return;

  DEVPRINTF(2, (scp->dev, "init\n"));

  s = splimp();

  /* Reset transmitter flags */
  scp->tx_queued = 0;
  scp->tx_tpr = 0;
  scp->tx_timeouts = 0;
  scp->tx_thres = 64;
  scp->tx_min = ETHER_MIN_LEN - ETHER_CRC_LEN;
  scp->ifp->if_timer = 0;

  /* Soft reset the card */
  XE_SELECT_PAGE(0);
  XE_OUTB(XE_CR, XE_CR_SOFT_RESET);
  DELAY(40000);
  XE_OUTB(XE_CR, 0);
  DELAY(40000);

  if (scp->mohawk) {
    /*
     * set GP1 and GP2 as outputs (bits 2 & 3)
     * set GP1 low to power on the ML6692 (bit 0)
     * set GP2 high to power on the 10Mhz chip (bit 1)
     */
    XE_SELECT_PAGE(4);
    XE_OUTB(XE_GPR0, XE_GPR0_GP2_SELECT|XE_GPR0_GP1_SELECT|XE_GPR0_GP2_OUT);
  }

  /* Shut off interrupts */
  xe_disable_intr(scp);

  /* Wait for everything to wake up */
  DELAY(500000);

  /* Check for PHY */
  if (scp->mohawk)
    scp->phy_ok = xe_mii_init(scp);

  /* Disable 'source insertion' (not sure what that means) */
  XE_SELECT_PAGE(0x42);
  XE_OUTB(XE_SWC0, XE_SWC0_NO_SRC_INSERT);

  /* Set 8K/24K Tx/Rx buffer split */
  if (scp->srev != 1) {
    XE_SELECT_PAGE(2);
    XE_OUTW(XE_RBS, 0x2000);
  }

  /* Enable early transmit mode on Mohawk/Dingo */
  if (scp->mohawk) {
    XE_SELECT_PAGE(0x03);
    XE_OUTW(XE_TPT, scp->tx_thres);
    XE_SELECT_PAGE(0x01);
    XE_OUTB(XE_ECR, XE_INB(XE_ECR) | XE_ECR_EARLY_TX);
  }

  /* Put MAC address in first 'individual address' register */
  XE_SELECT_PAGE(0x50);
  for (i = 0; i < 6; i++)
    XE_OUTB(0x08 + i, scp->arpcom.ac_enaddr[scp->mohawk ? 5 - i : i]);

  /* Set up multicast addresses */
  xe_set_multicast(scp);

  /* Fix the receive data offset -- reset can leave it off-by-one */
  XE_SELECT_PAGE(0);
  XE_OUTW(XE_DO, 0x2000);

  /* Set interrupt masks */
  XE_SELECT_PAGE(1);
  XE_OUTB(XE_IMR0, XE_IMR0_TX_PACKET | XE_IMR0_MAC_INTR | XE_IMR0_RX_PACKET);

  /* Set MAC interrupt masks */
  XE_SELECT_PAGE(0x40);
  XE_OUTB(XE_RX0Msk,
	  ~(XE_RX0M_RX_OVERRUN | XE_RX0M_CRC_ERROR
	    | XE_RX0M_ALIGN_ERROR | XE_RX0M_LONG_PACKET));
  XE_OUTB(XE_TX0Msk,
	  ~(XE_TX0M_SQE_FAIL | XE_TX0M_LATE_COLLISION | XE_TX0M_TX_UNDERRUN
	    | XE_TX0M_16_COLLISIONS | XE_TX0M_NO_CARRIER));

  /* Clear MAC status registers */
  XE_SELECT_PAGE(0x40);
  XE_OUTB(XE_RST0, 0x00);
  XE_OUTB(XE_TXST0, 0x00);

  /* Enable receiver and put MAC online */
  XE_SELECT_PAGE(0x40);
  XE_OUTB(XE_CMD0, XE_CMD0_RX_ENABLE|XE_CMD0_ONLINE);

  /* Set up IMR, enable interrupts */
  xe_enable_intr(scp);

  /* Start media selection */
  xe_setmedia(scp);

  /* Enable output */
  scp->ifp->if_flags |= IFF_RUNNING;
  scp->ifp->if_flags &= ~IFF_OACTIVE;

  (void)splx(s);
}


/*
 * Start output on interface.  Should be called at splimp() priority.  Check
 * that the output is idle (ie, IFF_OACTIVE is not set) before calling this
 * function.  If media selection is in progress we set IFF_OACTIVE ourselves
 * and return immediately.
 */
static void
xe_start(struct ifnet *ifp) {
  struct xe_softc *scp = ifp->if_softc;
  struct mbuf *mbp;

  if (scp->autoneg_status != XE_AUTONEG_NONE) {
    ifp->if_flags |= IFF_OACTIVE;
    return;
  }

  DEVPRINTF(3, (scp->dev, "start\n"));

  /*
   * Loop while there are packets to be sent, and space to send them.
   */
  while (1) {
    /* Suck a packet off the send queue */
    IF_DEQUEUE(&ifp->if_snd, mbp);

    if (mbp == NULL) {
      /*
       * We are using the !OACTIVE flag to indicate to the outside world that
       * we can accept an additional packet rather than that the transmitter
       * is _actually_ active. Indeed, the transmitter may be active, but if
       * we haven't filled all the buffers with data then we still want to
       * accept more.
       */
      ifp->if_flags &= ~IFF_OACTIVE;
      return;
    }

    if (xe_pio_write_packet(scp, mbp) != 0) {
      /* Push the packet back onto the queue */
      IF_PREPEND(&ifp->if_snd, mbp);
      ifp->if_flags |= IFF_OACTIVE;
      return;
    }

    /* Tap off here if there is a bpf listener */
    BPF_MTAP(ifp, mbp);

    /* In case we don't hear from the card again... */
    ifp->if_timer = 5;
    scp->tx_queued++;

    m_freem(mbp);
  }
}


/*
 * Process an ioctl request.  Adapted from the ed driver.
 */
static int
xe_ioctl (register struct ifnet *ifp, u_long command, caddr_t data) {
  struct xe_softc *scp;
  int s, error;

  scp = ifp->if_softc;
  error = 0;

  s = splimp();

  switch (command) {

  case SIOCSIFFLAGS:
    DEVPRINTF(2, (scp->dev, "ioctl: SIOCSIFFLAGS: 0x%04x\n", ifp->if_flags));
    /*
     * If the interface is marked up and stopped, then start it.  If it is
     * marked down and running, then stop it.
     */
    if (ifp->if_flags & IFF_UP) {
      if (!(ifp->if_flags & IFF_RUNNING)) {
	xe_reset(scp);
	xe_init(scp);
      }
    }
    else {
      if (ifp->if_flags & IFF_RUNNING)
	xe_stop(scp);
    }
    /* FALL THROUGH  (handle changes to PROMISC/ALLMULTI flags) */

  case SIOCADDMULTI:
  case SIOCDELMULTI:
    DEVPRINTF(2, (scp->dev, "ioctl: SIOC{ADD,DEL}MULTI\n"));
    /*
     * Multicast list has (maybe) changed; set the hardware filters
     * accordingly.
     */
    xe_set_multicast(scp);
    error = 0;
    break;

  case SIOCSIFMEDIA:
  case SIOCGIFMEDIA:
    DEVPRINTF(3, (scp->dev, "ioctl: bounce to ifmedia_ioctl\n"));
    /*
     * Someone wants to get/set media options.
     */
    error = ifmedia_ioctl(ifp, (struct ifreq *)data, &scp->ifmedia, command);
    break;

  default:
    DEVPRINTF(3, (scp->dev, "ioctl: bounce to ether_ioctl\n"));
    error = ether_ioctl(ifp, command, data);
  }

  (void)splx(s);

  return error;
}


/*
 * Card interrupt handler.
 *
 * This function is probably more complicated than it needs to be, as it
 * attempts to deal with the case where multiple packets get sent between
 * interrupts.  This is especially annoying when working out the collision
 * stats.  Not sure whether this case ever really happens or not (maybe on a
 * slow/heavily loaded machine?) so it's probably best to leave this like it
 * is.
 *
 * Note that the crappy PIO used to get packets on and off the card means that 
 * you will spend a lot of time in this routine -- I can get my P150 to spend
 * 90% of its time servicing interrupts if I really hammer the network.  Could 
 * fix this, but then you'd start dropping/losing packets.  The moral of this
 * story?  If you want good network performance _and_ some cycles left over to 
 * get your work done, don't buy a Xircom card.  Or convince them to tell me
 * how to do memory-mapped I/O :)
 */
static void
xe_intr(void *xscp) 
{
  struct xe_softc *scp = (struct xe_softc *) xscp;
  struct ifnet *ifp;
  u_int8_t psr, isr, esr, rsr, rst0, txst0, txst1, coll;

  ifp = &scp->arpcom.ac_if;

  /* Disable interrupts */
  if (scp->mohawk)
    XE_OUTB(XE_CR, 0);

  /* Cache current register page */
  psr = XE_INB(XE_PR);

  /* Read ISR to see what caused this interrupt */
  while ((isr = XE_INB(XE_ISR)) != 0) {

    /* 0xff might mean the card is no longer around */
    if (isr == 0xff) {
      DEVPRINTF(3, (scp->dev, "intr: interrupt received for missing card?\n"));
      break;
    }

    /* Read other status registers */
    XE_SELECT_PAGE(0x40);
    rst0 = XE_INB(XE_RST0);
    XE_OUTB(XE_RST0, 0);
    txst0 = XE_INB(XE_TXST0);
    txst1 = XE_INB(XE_TXST1);
    coll = txst1 & XE_TXST1_RETRY_COUNT;
    XE_OUTB(XE_TXST0, 0);
    XE_OUTB(XE_TXST1, 0);
    XE_SELECT_PAGE(0);

    DEVPRINTF(3, (scp->dev, "intr: ISR=0x%02x, RST=0x%02x, TXT=0x%02x%02x, COLL=0x%01x\n", isr, rst0, txst1, txst0, coll));

    if (isr & XE_ISR_TX_PACKET) {
      u_int8_t tpr, sent;

      /* Update packet count, accounting for rollover */
      tpr = XE_INB(XE_TPR);
      sent = -scp->tx_tpr + tpr;

      /* Update statistics if we actually sent anything */
      if (sent > 0) {
	scp->tx_tpr = tpr;
	scp->tx_queued -= sent;
	ifp->if_opackets += sent;
	ifp->if_collisions += coll;

	/*
	 * According to the Xircom manual, Dingo will sometimes manage to
	 * transmit a packet with triggering an interrupt.  If this happens,
	 * we have sent > 1 and the collision count only reflects collisions
	 * on the last packet sent (the one that triggered the interrupt).
	 * Collision stats might therefore be a bit low, but there doesn't
	 * seem to be anything we can do about that.
	 */

	switch (coll) {
	case 0:
	  break;
	case 1:
	  scp->mibdata.dot3StatsSingleCollisionFrames++;
	  scp->mibdata.dot3StatsCollFrequencies[0]++;
	  break;
	default:
	  scp->mibdata.dot3StatsMultipleCollisionFrames++;
	  scp->mibdata.dot3StatsCollFrequencies[coll-1]++;
	}
      }
      ifp->if_timer = 0;
      ifp->if_flags &= ~IFF_OACTIVE;
    }

    /* Handle most MAC interrupts */
    if (isr & XE_ISR_MAC_INTR) {

#if 0
      /* Carrier sense lost -- only in 10Mbit HDX mode */
      if (txst0 & XE_TXST0_NO_CARRIER || !(txst1 & XE_TXST1_LINK_STATUS)) {
	/* XXX - Need to update media status here */
	device_printf(scp->dev, "no carrier\n");
	ifp->if_oerrors++;
	scp->mibdata.dot3StatsCarrierSenseErrors++;
      }
#endif
      /* Excessive collisions -- try sending again */
      if (txst0 & XE_TXST0_16_COLLISIONS) {
	ifp->if_collisions += 16;
	ifp->if_oerrors++;
	scp->mibdata.dot3StatsExcessiveCollisions++;
	scp->mibdata.dot3StatsMultipleCollisionFrames++;
	scp->mibdata.dot3StatsCollFrequencies[15]++;
	XE_OUTB(XE_CR, XE_CR_RESTART_TX);
      }
      /* Transmit underrun -- increase early transmit threshold */
      if (txst0 & XE_TXST0_TX_UNDERRUN && scp->mohawk) {
	DEVPRINTF(1, (scp->dev, "transmit underrun"));
	if (scp->tx_thres < ETHER_MAX_LEN) {
	  if ((scp->tx_thres += 64) > ETHER_MAX_LEN)
	    scp->tx_thres = ETHER_MAX_LEN;
	  DPRINTF(1, (": increasing transmit threshold to %u", scp->tx_thres));
	  XE_SELECT_PAGE(0x3);
	  XE_OUTW(XE_TPT, scp->tx_thres);
	  XE_SELECT_PAGE(0x0);
	}
	DPRINTF(1, ("\n"));
	ifp->if_oerrors++;
	scp->mibdata.dot3StatsInternalMacTransmitErrors++;
      }
      /* Late collision -- just complain about it */
      if (txst0 & XE_TXST0_LATE_COLLISION) {
	device_printf(scp->dev, "late collision\n");
	ifp->if_oerrors++;
	scp->mibdata.dot3StatsLateCollisions++;
      }
      /* SQE test failure -- just complain about it */
      if (txst0 & XE_TXST0_SQE_FAIL) {
	device_printf(scp->dev, "SQE test failure\n");
	ifp->if_oerrors++;
	scp->mibdata.dot3StatsSQETestErrors++;
      }
      /* Packet too long -- what happens to these */
      if (rst0 & XE_RST0_LONG_PACKET) {
	device_printf(scp->dev, "received giant packet\n");
	ifp->if_ierrors++;
	scp->mibdata.dot3StatsFrameTooLongs++;
      }
      /* CRC error -- packet dropped */
      if (rst0 & XE_RST0_CRC_ERROR) {
	device_printf(scp->dev, "CRC error\n");
	ifp->if_ierrors++;
	scp->mibdata.dot3StatsFCSErrors++;
      }
    }

    /* Handle received packet(s) */
    while ((esr = XE_INB(XE_ESR)) & XE_ESR_FULL_PACKET_RX) {
      rsr = XE_INB(XE_RSR);

    DEVPRINTF(3, (scp->dev, "intr: ESR=0x%02x, RSR=0x%02x\n", esr, rsr));

      /* Make sure packet is a good one */
      if (rsr & XE_RSR_RX_OK) {
	struct ether_header *ehp;
	struct mbuf *mbp;
	u_int16_t len;

	len = XE_INW(XE_RBC) - ETHER_CRC_LEN;

    DEVPRINTF(3, (scp->dev, "intr: receive length = %d\n", len));

	if (len == 0) {
	  ifp->if_iqdrops++;
	  continue;
	}

	/*
	 * Allocate mbuf to hold received packet.  If the mbuf header isn't
	 * big enough, we attach an mbuf cluster to hold the packet.  Note the
	 * +=2 to align the packet data on a 32-bit boundary, and the +3 to
	 * allow for the possibility of reading one more byte than the actual
	 * packet length (we always read 16-bit words).
	 * XXX - Surely there's a better way to do this alignment?
	 */
	MGETHDR(mbp, M_DONTWAIT, MT_DATA);
	if (mbp == NULL) {
	  ifp->if_iqdrops++;
	  continue;
	}

	if (len + 3 > MHLEN) {
	  MCLGET(mbp, M_DONTWAIT);
	  if ((mbp->m_flags & M_EXT) == 0) {
	    m_freem(mbp);
	    ifp->if_iqdrops++;
	    continue;
	  }
	}

	mbp->m_data += 2;
	ehp = mtod(mbp, struct ether_header *);

	/*
	 * Now get the packet in PIO mode, including the Ethernet header but
	 * omitting the trailing CRC.
	 */

	/*
	 * Work around a bug in CE2 cards.  There seems to be a problem with
	 * duplicated and extraneous bytes in the receive buffer, but without
	 * any real documentation for the CE2 it's hard to tell for sure.
	 * XXX - Needs testing on CE2 hardware
	 */
	if (scp->srev == 0) {
	  u_short rhs;

	  XE_SELECT_PAGE(5);
	  rhs = XE_INW(XE_RHSA);
	  XE_SELECT_PAGE(0);

	  rhs += 3;			 /* Skip control info */

	  if (rhs >= 0x8000)
	    rhs = 0;

	  if (rhs + len > 0x8000) {
	    int i;

	    for (i = 0; i < len; i++, rhs++) {
	      ((char *)ehp)[i] = XE_INB(XE_EDP);
	      if (rhs == 0x8000) {
		rhs = 0;
		i--;
	      }
	    }
	  }
	  else
	    bus_space_read_multi_2(scp->bst, scp->bsh, XE_EDP, 
				   (u_int16_t *) ehp, (len + 1) >> 1);
	}
	else
	  bus_space_read_multi_2(scp->bst, scp->bsh, XE_EDP, 
				 (u_int16_t *) ehp, (len + 1) >> 1);

	/* Deliver packet to upper layers */
	mbp->m_pkthdr.rcvif = ifp;
	mbp->m_pkthdr.len = mbp->m_len = len;
	(*ifp->if_input)(ifp, mbp);
	ifp->if_ipackets++;
      }

      /* Packet alignment error -- drop packet */
      else if (rsr & XE_RSR_ALIGN_ERROR) {
	device_printf(scp->dev, "alignment error\n");
	scp->mibdata.dot3StatsAlignmentErrors++;
	ifp->if_ierrors++;
      }

      /* Skip to next packet, if there is one */
      XE_OUTW(XE_DO, 0x8000);
    }

    /* Clear receiver overruns now we have some free buffer space */
    if (rst0 & XE_RST0_RX_OVERRUN) {
      DEVPRINTF(1, (scp->dev, "receive overrun\n"));
      ifp->if_ierrors++;
      scp->mibdata.dot3StatsInternalMacReceiveErrors++;
      XE_OUTB(XE_CR, XE_CR_CLEAR_OVERRUN);
    }
  }

  /* Restore saved page */
  XE_SELECT_PAGE(psr);

  /* Re-enable interrupts */
  XE_OUTB(XE_CR, XE_CR_ENABLE_INTR);

  return;
}


/*
 * Device timeout/watchdog routine.  Called automatically if we queue a packet 
 * for transmission but don't get an interrupt within a specified timeout
 * (usually 5 seconds).  When this happens we assume the worst and reset the
 * card.
 */
static void
xe_watchdog(struct ifnet *ifp) {
  struct xe_softc *scp = ifp->if_softc;

  device_printf(scp->dev, "watchdog timeout: resetting card\n");
  scp->tx_timeouts++;
  ifp->if_oerrors += scp->tx_queued;
  xe_stop(scp);
  xe_reset(scp);
  xe_init(scp);
}


/*
 * Change media selection.
 */
static int
xe_media_change(struct ifnet *ifp) {
  struct xe_softc *scp = ifp->if_softc;

  DEVPRINTF(2, (scp->dev, "media_change\n"));

  if (IFM_TYPE(scp->ifm->ifm_media) != IFM_ETHER)
    return(EINVAL);

  /*
   * Some card/media combos aren't always possible -- filter those out here.
   */
  if ((IFM_SUBTYPE(scp->ifm->ifm_media) == IFM_AUTO ||
       IFM_SUBTYPE(scp->ifm->ifm_media) == IFM_100_TX) && !scp->phy_ok)
    return (EINVAL);

  xe_setmedia(scp);

  return 0;
}


/*
 * Return current media selection.
 */
static void
xe_media_status(struct ifnet *ifp, struct ifmediareq *mrp) {
  struct xe_softc *scp = ifp->if_softc;

  DEVPRINTF(3, (scp->dev, "media_status\n"));

  /* XXX - This is clearly wrong.  Will fix once I have CE2 working */
  mrp->ifm_status = IFM_AVALID | IFM_ACTIVE;
  mrp->ifm_active = ((struct xe_softc *)ifp->if_softc)->media;

  return;
}


/*
 * Select active media.
 */
static void xe_setmedia(void *xscp) {
  struct xe_softc *scp = xscp;
  u_int16_t bmcr, bmsr, anar, lpar;

  DEVPRINTF(2, (scp->dev, "setmedia\n"));

  /* Cancel any pending timeout */
  untimeout(xe_setmedia, scp, scp->chand);
  xe_disable_intr(scp);

  /* Select media */
  scp->media = IFM_ETHER;
  switch (IFM_SUBTYPE(scp->ifm->ifm_media)) {

   case IFM_AUTO:	/* Autoselect media */
    scp->media = IFM_ETHER|IFM_AUTO;

    /*
     * Autoselection is really awful.  It goes something like this:
     *
     * Wait until the transmitter goes idle (2sec timeout).
     * Reset card
     *   IF a 100Mbit PHY exists
     *     Start NWAY autonegotiation (3.5sec timeout)
     *     IF that succeeds
     *       Select 100baseTX or 10baseT, whichever was detected
     *     ELSE
     *       Reset card
     *       IF a 100Mbit PHY exists
     *         Try to force a 100baseTX link (3sec timeout)
     *         IF that succeeds
     *           Select 100baseTX
     *         ELSE
     *           Disable the PHY
     *         ENDIF
     *       ENDIF
     *     ENDIF
     *   ENDIF
     * IF nothing selected so far
     *   IF a 100Mbit PHY exists
     *     Select 10baseT
     *   ELSE
     *     Select 10baseT or 10base2, whichever is connected
     *   ENDIF
     * ENDIF
     */
    switch (scp->autoneg_status) {

    case XE_AUTONEG_NONE:
      DEVPRINTF(2, (scp->dev, "Waiting for idle transmitter\n"));
      scp->arpcom.ac_if.if_flags |= IFF_OACTIVE;
      scp->autoneg_status = XE_AUTONEG_WAITING;
      /* FALL THROUGH */

    case XE_AUTONEG_WAITING:
      if (scp->tx_queued != 0) {
	scp->chand = timeout(xe_setmedia, scp, hz/2);
	return;
      }
      if (scp->phy_ok) {
	DEVPRINTF(2, (scp->dev, "Starting autonegotiation\n"));
	bmcr = xe_phy_readreg(scp, PHY_BMCR);
	bmcr &= ~(PHY_BMCR_AUTONEGENBL);
	xe_phy_writereg(scp, PHY_BMCR, bmcr);
	anar = xe_phy_readreg(scp, PHY_ANAR);
	anar &= ~(PHY_ANAR_100BT4|PHY_ANAR_100BTXFULL|PHY_ANAR_10BTFULL);
	anar |= PHY_ANAR_100BTXHALF|PHY_ANAR_10BTHALF;
	xe_phy_writereg(scp, PHY_ANAR, anar);
	bmcr |= PHY_BMCR_AUTONEGENBL|PHY_BMCR_AUTONEGRSTR;
	xe_phy_writereg(scp, PHY_BMCR, bmcr);
	scp->autoneg_status = XE_AUTONEG_STARTED;
 	scp->chand = timeout(xe_setmedia, scp, hz * 7/2);
	return;
      }
      else {
	scp->autoneg_status = XE_AUTONEG_FAIL;
      }
      break;

     case XE_AUTONEG_STARTED:
      bmsr = xe_phy_readreg(scp, PHY_BMSR);
      lpar = xe_phy_readreg(scp, PHY_LPAR);
      if (bmsr & (PHY_BMSR_AUTONEGCOMP|PHY_BMSR_LINKSTAT)) {
	DEVPRINTF(2, (scp->dev, "Autonegotiation complete!\n"));
	/*
	 * XXX - Shouldn't have to do this, but (on my hub at least) the
	 * XXX - transmitter won't work after a successful autoneg.  So we see 
	 * XXX - what the negotiation result was and force that mode.  I'm
	 * XXX - sure there is an easy fix for this.
	 */
	if (lpar & PHY_LPAR_100BTXHALF) {
	  xe_phy_writereg(scp, PHY_BMCR, PHY_BMCR_SPEEDSEL);
	  XE_MII_DUMP(scp);
	  XE_SELECT_PAGE(2);
	  XE_OUTB(XE_MSR, XE_INB(XE_MSR) | 0x08);
	  scp->media = IFM_ETHER|IFM_100_TX;
	  scp->autoneg_status = XE_AUTONEG_NONE;
	}
	else {
	  /*
	   * XXX - Bit of a hack going on in here.
	   * XXX - This is derived from Ken Hughes patch to the Linux driver
	   * XXX - to make it work with 10Mbit _autonegotiated_ links on CE3B
	   * XXX - cards.  What's a CE3B and how's it differ from a plain CE3?
	   * XXX - these are the things we need to find out.
	   */
	  xe_phy_writereg(scp, PHY_BMCR, 0x0000);
	  XE_SELECT_PAGE(2);
	  /* BEGIN HACK */
	  XE_OUTB(XE_MSR, XE_INB(XE_MSR) | 0x08);
	  XE_SELECT_PAGE(0x42);
	  XE_OUTB(XE_SWC1, 0x80);
	  scp->media = IFM_ETHER|IFM_10_T;
	  scp->autoneg_status = XE_AUTONEG_NONE;
	  /* END HACK */
	  /*XE_OUTB(XE_MSR, XE_INB(XE_MSR) & ~0x08);*/	/* Disable PHY? */
	  /*scp->autoneg_status = XE_AUTONEG_FAIL;*/
	}
      }
      else {
	DEVPRINTF(2, (scp->dev, "Autonegotiation failed; trying 100baseTX\n"));
	XE_MII_DUMP(scp);
	if (scp->phy_ok) {
	  xe_phy_writereg(scp, PHY_BMCR, PHY_BMCR_SPEEDSEL);
	  scp->autoneg_status = XE_AUTONEG_100TX;
	  scp->chand = timeout(xe_setmedia, scp, hz * 3);
	  return;
	}
	else {
	  scp->autoneg_status = XE_AUTONEG_FAIL;
	}
      }
      break;

     case XE_AUTONEG_100TX:
      (void)xe_phy_readreg(scp, PHY_BMSR);
      bmsr = xe_phy_readreg(scp, PHY_BMSR);
      if (bmsr & PHY_BMSR_LINKSTAT) {
	DEVPRINTF(2, (scp->dev, "Got 100baseTX link!\n"));
	XE_MII_DUMP(scp);
	XE_SELECT_PAGE(2);
	XE_OUTB(XE_MSR, XE_INB(XE_MSR) | 0x08);
	scp->media = IFM_ETHER|IFM_100_TX;
	scp->autoneg_status = XE_AUTONEG_NONE;
      }
      else {
	DEVPRINTF(2, (scp->dev, "Autonegotiation failed; disabling PHY\n"));
	XE_MII_DUMP(scp);
	xe_phy_writereg(scp, PHY_BMCR, 0x0000);
	XE_SELECT_PAGE(2);
	XE_OUTB(XE_MSR, XE_INB(XE_MSR) & ~0x08);	/* Disable PHY? */
	scp->autoneg_status = XE_AUTONEG_FAIL;
      }
      break;
    }

    /*
     * If we got down here _and_ autoneg_status is XE_AUTONEG_FAIL, then
     * either autonegotiation failed, or never got started to begin with.  In
     * either case, select a suitable 10Mbit media and hope it works.  We
     * don't need to reset the card again, since it will have been done
     * already by the big switch above.
     */
    if (scp->autoneg_status == XE_AUTONEG_FAIL) {
      DEVPRINTF(2, (scp->dev, "Selecting 10baseX\n"));
      if (scp->mohawk) {
	XE_SELECT_PAGE(0x42);
	XE_OUTB(XE_SWC1, 0x80);
	scp->media = IFM_ETHER|IFM_10_T;
	scp->autoneg_status = XE_AUTONEG_NONE;
      }
      else {
	XE_SELECT_PAGE(4);
	XE_OUTB(XE_GPR0, 4);
	DELAY(50000);
	XE_SELECT_PAGE(0x42);
	XE_OUTB(XE_SWC1, (XE_INB(XE_ESR) & XE_ESR_MEDIA_SELECT) ? 0x80 : 0xc0);
	scp->media = IFM_ETHER|((XE_INB(XE_ESR) & XE_ESR_MEDIA_SELECT) ? IFM_10_T : IFM_10_2);
	scp->autoneg_status = XE_AUTONEG_NONE;
      }
    }
    break;


    /*
     * If a specific media has been requested, we just reset the card and
     * select it (one small exception -- if 100baseTX is requested by there is 
     * no PHY, we fall back to 10baseT operation).
     */
   case IFM_100_TX:	/* Force 100baseTX */
    if (scp->phy_ok) {
      DEVPRINTF(2, (scp->dev, "Selecting 100baseTX\n"));
      XE_SELECT_PAGE(0x42);
      XE_OUTB(XE_SWC1, 0);
      xe_phy_writereg(scp, PHY_BMCR, PHY_BMCR_SPEEDSEL);
      XE_SELECT_PAGE(2);
      XE_OUTB(XE_MSR, XE_INB(XE_MSR) | 0x08);
      scp->media |= IFM_100_TX;
      break;
    }
    /* FALLTHROUGH */

   case IFM_10_T:	/* Force 10baseT */
    DEVPRINTF(2, (scp->dev, "Selecting 10baseT\n"));
    if (scp->phy_ok) {
      xe_phy_writereg(scp, PHY_BMCR, 0x0000);
      XE_SELECT_PAGE(2);
      XE_OUTB(XE_MSR, XE_INB(XE_MSR) & ~0x08);	/* Disable PHY */
    }
    XE_SELECT_PAGE(0x42);
    XE_OUTB(XE_SWC1, 0x80);
    scp->media |= IFM_10_T;
    break;

   case IFM_10_2:
    DEVPRINTF(2, (scp->dev, "Selecting 10base2\n"));
    XE_SELECT_PAGE(0x42);
    XE_OUTB(XE_SWC1, 0xc0);
    scp->media |= IFM_10_2;
    break;
  }


  /*
   * Finally, the LEDs are set to match whatever media was chosen and the
   * transmitter is unblocked. 
   */
  DEVPRINTF(2, (scp->dev, "Setting LEDs\n"));
  XE_SELECT_PAGE(2);
  switch (IFM_SUBTYPE(scp->media)) {
   case IFM_100_TX:
   case IFM_10_T:
    XE_OUTB(XE_LED, 0x3b);
    if (scp->dingo)
      XE_OUTB(0x0b, 0x04);	/* 100Mbit LED */
    break;

   case IFM_10_2:
    XE_OUTB(XE_LED, 0x3a);
    break;
  }

  /* Restart output? */
  xe_enable_intr(scp);
  scp->ifp->if_flags &= ~IFF_OACTIVE;
  xe_start(scp->ifp);
}


/*
 * Hard reset (power cycle) the card.
 */
static void
xe_reset(struct xe_softc *scp) {
  int s;

  DEVPRINTF(2, (scp->dev, "reset\n"));

  s = splimp();

  /* Power down */
  XE_SELECT_PAGE(4);
  XE_OUTB(XE_GPR1, 0);
  DELAY(40000);

  /* Power up again */
  if (scp->mohawk)
    XE_OUTB(XE_GPR1, XE_GPR1_POWER_DOWN);
  else
    XE_OUTB(XE_GPR1, XE_GPR1_POWER_DOWN|XE_GPR1_AIC);

  DELAY(40000);
  XE_SELECT_PAGE(0);

  (void)splx(s);
}


/*
 * Take interface offline.  This is done by powering down the device, which I
 * assume means just shutting down the transceiver and Ethernet logic.  This
 * requires a _hard_ reset to recover from, as we need to power up again.
 */
static void
xe_stop(struct xe_softc *scp) {
  int s;

  DEVPRINTF(2, (scp->dev, "stop\n"));

  s = splimp();

  /*
   * Shut off interrupts.
   */
  xe_disable_intr(scp);

  /*
   * Power down.
   */
  XE_SELECT_PAGE(4);
  XE_OUTB(XE_GPR1, 0);
  XE_SELECT_PAGE(0);
  if (scp->mohawk) {
    /*
     * set GP1 and GP2 as outputs (bits 2 & 3)
     * set GP1 high to power on the ML6692 (bit 0)
     * set GP2 low to power on the 10Mhz chip (bit 1)
     */
    XE_SELECT_PAGE(4);
    XE_OUTB(XE_GPR0, XE_GPR0_GP2_SELECT|XE_GPR0_GP1_SELECT|XE_GPR0_GP1_OUT);
  }

  /*
   * ~IFF_RUNNING == interface down.
   */
  scp->ifp->if_flags &= ~IFF_RUNNING;
  scp->ifp->if_flags &= ~IFF_OACTIVE;
  scp->ifp->if_timer = 0;

  (void)splx(s);
}


/*
 * Enable interrupts from the card.
 */
static void
xe_enable_intr(struct xe_softc *scp) {

  DEVPRINTF(2, (scp->dev, "enable_intr\n"));

  XE_SELECT_PAGE(0);
  XE_OUTB(XE_CR, XE_CR_ENABLE_INTR);	/* Enable interrupts */
  if (scp->modem && !scp->dingo) {	/* This bit is just magic */
    if (!(XE_INB(0x10) & 0x01)) {
      XE_OUTB(0x10, 0x11);		/* Unmask master int enable bit */
    }
  }
}


/*
 * Disable interrupts from the card.
 */
static void
xe_disable_intr(struct xe_softc *scp) {

  DEVPRINTF(2, (scp->dev, "disable_intr\n"));

  XE_SELECT_PAGE(0);
  XE_OUTB(XE_CR, 0);			/* Disable interrupts */
  if (scp->modem && !scp->dingo) {	/* More magic */
    XE_OUTB(0x10, 0x10);		/* Mask the master int enable bit */
  }
}


/*
 * Set up multicast filter and promiscuous modes.
 */
static void
xe_set_multicast(struct xe_softc *scp) {
  struct ifnet *ifp;
  struct ifmultiaddr *maddr;
  unsigned count, i;

  DEVPRINTF(2, (scp->dev, "set_multicast\n"));

  ifp = &scp->arpcom.ac_if;
  XE_SELECT_PAGE(0x42);

  /* Handle PROMISC flag */
  if (ifp->if_flags & IFF_PROMISC) {
    XE_OUTB(XE_SWC1, XE_INB(XE_SWC1) | XE_SWC1_PROMISCUOUS);
    return;
  }
  else
    XE_OUTB(XE_SWC1, XE_INB(XE_SWC1) & ~XE_SWC1_PROMISCUOUS);

  /* Handle ALLMULTI flag */
  if (ifp->if_flags & IFF_ALLMULTI) {
    XE_OUTB(XE_SWC1, XE_INB(XE_SWC1) | XE_SWC1_ALLMULTI);
    return;
  }
  else
    XE_OUTB(XE_SWC1, XE_INB(XE_SWC1) & ~XE_SWC1_ALLMULTI);

  /* Iterate over multicast address list */
  count = 0;
#if __FreeBSD_version < 500000
  LIST_FOREACH(maddr, &ifp->if_multiaddrs, ifma_link) {
#else
  TAILQ_FOREACH(maddr, &ifp->if_multiaddrs, ifma_link) {
#endif
    if (maddr->ifma_addr->sa_family != AF_LINK)
      continue;

    count++;

    if (count < 10)
      /* First 9 use Individual Addresses for exact matching */
      xe_set_addr(scp, LLADDR((struct sockaddr_dl *)maddr->ifma_addr), count);
    else
      if (scp->mohawk)
	/* Use hash filter on Mohawk and Dingo */
	xe_mchash(scp, LLADDR((struct sockaddr_dl *)maddr->ifma_addr));
      else
	/* Nowhere else to put them on CE2 */
	break;
  }

  DEVPRINTF(2, (scp->dev, "set_multicast: count = %u\n", count));

  /* Now do some cleanup and enable multicast handling as needed */
  if (count == 0) {
    /* Disable all multicast handling */
    XE_SELECT_PAGE(0x42);
    XE_OUTB(XE_SWC1, XE_INB(XE_SWC1) & ~(XE_SWC1_IA_ENABLE|XE_SWC1_ALLMULTI));
    if (scp->mohawk) {
      XE_SELECT_PAGE(0x02);
      XE_OUTB(XE_MSR, XE_INB(XE_MSR) & ~XE_MSR_HASH_TABLE);
    }
  }
  else if (count < 10) {
    /* Full in any unused Individual Addresses with our MAC address */
    for (i = count + 1; i < 10; i++)
      xe_set_addr(scp, (u_int8_t *)(&scp->arpcom.ac_enaddr), i);
    /* Enable Individual Address matching only */
    XE_SELECT_PAGE(0x42);
    XE_OUTB(XE_SWC1, (XE_INB(XE_SWC1) & ~XE_SWC1_ALLMULTI) | XE_SWC1_IA_ENABLE);
    if (scp->mohawk) {
      XE_SELECT_PAGE(0x02);
      XE_OUTB(XE_MSR, XE_INB(XE_MSR) & ~XE_MSR_HASH_TABLE);
    }
  }    
  else {
    if (scp->mohawk) {
      /* Check whether hash table is full */
      XE_SELECT_PAGE(0x58);
      for (i = 0x08; i < 0x10; i++)
	if (XE_INB(i) != 0xff)
	  break;
      if (i == 0x10) {
	/* Hash table full - enable promiscuous multicast matching */
	XE_SELECT_PAGE(0x42);
	XE_OUTB(XE_SWC1, (XE_INB(XE_SWC1) & ~XE_SWC1_IA_ENABLE) | XE_SWC1_ALLMULTI);
	XE_SELECT_PAGE(0x02);
	XE_OUTB(XE_MSR, XE_INB(XE_MSR) & ~XE_MSR_HASH_TABLE);
      }
      else {
	/* Enable hash table and Individual Address matching */
	XE_SELECT_PAGE(0x42);
	XE_OUTB(XE_SWC1, (XE_INB(XE_SWC1) & ~XE_SWC1_ALLMULTI) | XE_SWC1_IA_ENABLE);
	XE_SELECT_PAGE(0x02);
	XE_OUTB(XE_MSR, XE_INB(XE_MSR) | XE_MSR_HASH_TABLE);
      }
    }
    else {
      /* Enable promiscuous multicast matching */
      XE_SELECT_PAGE(0x42);
      XE_OUTB(XE_SWC1, (XE_INB(XE_SWC1) & ~XE_SWC1_IA_ENABLE) | XE_SWC1_ALLMULTI);
    }
  }

  XE_SELECT_PAGE(0);
}


/*
 * Copy the Ethernet multicast address in addr to the on-chip registers for
 * Individual Address idx.  Assumes that addr is really a multicast address
 * and that idx > 0 (slot 0 is always used for the card MAC address).
 */
static void
xe_set_addr(struct xe_softc *scp, u_int8_t* addr, unsigned idx) {
  u_int8_t page, reg;
  unsigned i;

  /*
   * Individual Addresses are stored in registers 8-F of pages 0x50-0x57.  IA1
   * therefore starts at register 0xE on page 0x50.  The expressions below
   * compute the starting page and register for any IA index > 0.
   */
  --idx;
  page = 0x50 + idx%4 + idx/4*3;
  reg = 0x0e - 2 * (idx%4);

  DEVPRINTF(3, (scp->dev, "set_addr: idx = %u, page = 0x%02x, reg = 0x%02x\n",
		idx+1, page, reg));

  /*
   * Copy the IA bytes.  Note that the byte order is reversed for Mohawk and
   * Dingo wrt. CE2 hardware.
   */
  XE_SELECT_PAGE(page);
  for (i = 0; i < 6; i++) {
    if (i > 0) {
      DPRINTF(3, (":%02x", addr[i]));
    }
    else {
      DEVPRINTF(3, (scp->dev, "set_addr: %02x", addr[0]));
    }
    XE_OUTB(reg, addr[scp->mohawk ? 5 - i : i]);
    if (++reg == 0x10) {
      reg = 0x08;
      XE_SELECT_PAGE(++page);
    }
  }
  DPRINTF(3, ("\n"));
}


/*
 * Set the appropriate bit in the multicast hash table for the supplied
 * Ethernet multicast address addr.  Assumes that addr is really a multicast
 * address.
 */
static void
xe_mchash(struct xe_softc* scp, const uint8_t *addr) {
  uint32_t crc = 0xffffffff;
  int idx, bit;
  uint8_t carry, byte, data, crc31, hash;

  /* Compute CRC of the address -- standard Ethernet CRC function */
  for (data = *addr++, idx = 0; idx < 6; idx++, data >>= 1) {
    for (bit = 1; bit <= 8; bit++) {
      if (crc & 0x80000000)
	crc31 = 0x01;
      else
	crc31 = 0;
      carry = crc31 ^ (data & 0x01);
      crc <<= 1;
      data >>= 1;
	crc = (crc ^ XE_CRC_POLY) | (carry|0x1);
    }
  }

  DEVPRINTF(3, (scp->dev, "set_hash: CRC = 0x%08x\n", crc));

  /*
   * Convert a CRC into an index into the multicast hash table.  What we do is
   * take the most-significant 6 bits of the CRC, reverse them, and use that as
   * the bit number in the hash table.  Bits 5:3 of the result give the byte
   * within the table (0-7); bits 2:0 give the bit number within that byte (also
   * 0-7), ie. the number of shifts needed to get it into the lsb position.
   */
  for (idx = 0, hash = 0; idx < 6; idx++) {
    hash >>= 1;
    if (crc & 0x80000000) {
      hash |= 0x20;
    }
    crc <<= 1;
  }

  /* Top 3 bits of hash give register - 8, bottom 3 give bit within register */
  byte = hash >> 3 | 0x08;
  carry = 0x01 << (hash & 0x07);

  DEVPRINTF(3, (scp->dev, "set_hash: hash = 0x%02x, byte = 0x%02x, carry = 0x%02x\n", hash, byte, carry));

  XE_SELECT_PAGE(0x58);
  XE_OUTB(byte, XE_INB(byte) | carry);
}


/*
 * Write an outgoing packet to the card using programmed I/O.
 */
static int
xe_pio_write_packet(struct xe_softc *scp, struct mbuf *mbp) {
  unsigned len, pad;
  unsigned char wantbyte;
  u_int8_t *data;
  u_int8_t savebyte[2];

  /* Get total packet length */
  if (mbp->m_flags & M_PKTHDR)
    len = mbp->m_pkthdr.len;
  else {
    struct mbuf* mbp2 = mbp;
    for (len = 0; mbp2 != NULL; len += mbp2->m_len, mbp2 = mbp2->m_next);
  }

  DEVPRINTF(3, (scp->dev, "pio_write_packet: len = %u\n", len));

  /* Packets < minimum length may need to be padded out */
  pad = 0;
  if (len < scp->tx_min) {
    pad = scp->tx_min - len;
    len = scp->tx_min;
  }

  /* Check transmit buffer space */
  XE_SELECT_PAGE(0);
  XE_OUTW(XE_TRS, len+2);	/* Only effective on rev. 1 CE2 cards */
  if ((XE_INW(XE_TSO) & 0x7fff) <= len + 2)
    return 1;

  /* Send packet length to card */
  XE_OUTW(XE_EDP, len);

  /*
   * Write packet to card using PIO (code stolen from the ed driver)
   */
  wantbyte = 0;
  while (mbp != NULL) {
    len = mbp->m_len;
    if (len > 0) {
      data = mtod(mbp, caddr_t);
      if (wantbyte) {		/* Finish the last word */
	savebyte[1] = *data;
	XE_OUTW(XE_EDP, *(u_short *)savebyte);
	data++;
	len--;
	wantbyte = 0;
      }
      if (len > 1) {		/* Output contiguous words */
	bus_space_write_multi_2(scp->bst, scp->bsh, XE_EDP, (u_int16_t *) data,
				len >> 1);
	data += len & ~1;
	len &= 1;
      }
      if (len == 1) {		/* Save last byte, if necessary */
	savebyte[0] = *data;
	wantbyte = 1;
      }
    }
    mbp = mbp->m_next;
  }

  /*
   * Send last byte of odd-length packets
   */
  if (wantbyte)
    XE_OUTB(XE_EDP, savebyte[0]);

  /*
   * Can just tell CE3 cards to send; short packets will be padded out with
   * random cruft automatically.  For CE2, manually pad the packet with
   * garbage; it will be sent when the required number or bytes have been
   * delivered to the card.
   */
  if (scp->mohawk)
    XE_OUTB(XE_CR, XE_CR_TX_PACKET | XE_CR_RESTART_TX | XE_CR_ENABLE_INTR);
  else if (pad > 0) {
    if (pad & 0x01)
      XE_OUTB(XE_EDP, 0xaa);
    pad >>= 1;
    while (pad > 0) {
      XE_OUTW(XE_EDP, 0xdead);
      pad--;
    }
  }

  return 0;
}



/**************************************************************
 *                                                            *
 *                  M I I  F U N C T I O N S                  *
 *                                                            *
 **************************************************************/

/*
 * Alternative MII/PHY handling code adapted from the xl driver.  It doesn't
 * seem to work any better than the xirc2_ps stuff, but it's cleaner code.
 * XXX - this stuff shouldn't be here.  It should all be abstracted off to
 * XXX - some kind of common MII-handling code, shared by all drivers.  But
 * XXX - that's a whole other mission.
 */
#define XE_MII_SET(x)	XE_OUTB(XE_GPR2, (XE_INB(XE_GPR2) | 0x04) | (x))
#define XE_MII_CLR(x)	XE_OUTB(XE_GPR2, (XE_INB(XE_GPR2) | 0x04) & ~(x))


/*
 * Sync the PHYs by setting data bit and strobing the clock 32 times.
 */
static void
xe_mii_sync(struct xe_softc *scp) {
  register int i;

  XE_SELECT_PAGE(2);
  XE_MII_SET(XE_MII_DIR|XE_MII_WRD);

  for (i = 0; i < 32; i++) {
    XE_MII_SET(XE_MII_CLK);
    DELAY(1);
    XE_MII_CLR(XE_MII_CLK);
    DELAY(1);
  }
}


/*
 * Look for a MII-compliant PHY.  If we find one, reset it.
 */
static int
xe_mii_init(struct xe_softc *scp) {
  u_int16_t status;

  status = xe_phy_readreg(scp, PHY_BMSR);
  if ((status & 0xff00) != 0x7800) {
    DEVPRINTF(2, (scp->dev, "no PHY found, %0x\n", status));
    return 0;
  }
  else {
    DEVPRINTF(2, (scp->dev, "PHY OK!\n"));

    /* Reset the PHY */
    xe_phy_writereg(scp, PHY_BMCR, PHY_BMCR_RESET);
    DELAY(500);
    while(xe_phy_readreg(scp, PHY_BMCR) & PHY_BMCR_RESET);
    XE_MII_DUMP(scp);
    return 1;
  }
}


/*
 * Clock a series of bits through the MII.
 */
static void
xe_mii_send(struct xe_softc *scp, u_int32_t bits, int cnt) {
  int i;

  XE_SELECT_PAGE(2);
  XE_MII_CLR(XE_MII_CLK);
  
  for (i = (0x1 << (cnt - 1)); i; i >>= 1) {
    if (bits & i) {
      XE_MII_SET(XE_MII_WRD);
    } else {
      XE_MII_CLR(XE_MII_WRD);
    }
    DELAY(1);
    XE_MII_CLR(XE_MII_CLK);
    DELAY(1);
    XE_MII_SET(XE_MII_CLK);
  }
}


/*
 * Read an PHY register through the MII.
 */
static int
xe_mii_readreg(struct xe_softc *scp, struct xe_mii_frame *frame) {
  int i, ack, s;

  s = splimp();

  /*
   * Set up frame for RX.
   */
  frame->mii_stdelim = XE_MII_STARTDELIM;
  frame->mii_opcode = XE_MII_READOP;
  frame->mii_turnaround = 0;
  frame->mii_data = 0;
	
  XE_SELECT_PAGE(2);
  XE_OUTB(XE_GPR2, 0);

  /*
   * Turn on data xmit.
   */
  XE_MII_SET(XE_MII_DIR);

  xe_mii_sync(scp);

  /*	
   * Send command/address info.
   */
  xe_mii_send(scp, frame->mii_stdelim, 2);
  xe_mii_send(scp, frame->mii_opcode, 2);
  xe_mii_send(scp, frame->mii_phyaddr, 5);
  xe_mii_send(scp, frame->mii_regaddr, 5);

  /* Idle bit */
  XE_MII_CLR((XE_MII_CLK|XE_MII_WRD));
  DELAY(1);
  XE_MII_SET(XE_MII_CLK);
  DELAY(1);

  /* Turn off xmit. */
  XE_MII_CLR(XE_MII_DIR);

  /* Check for ack */
  XE_MII_CLR(XE_MII_CLK);
  DELAY(1);
  ack = XE_INB(XE_GPR2) & XE_MII_RDD;
  XE_MII_SET(XE_MII_CLK);
  DELAY(1);

  /*
   * Now try reading data bits. If the ack failed, we still
   * need to clock through 16 cycles to keep the PHY(s) in sync.
   */
  if (ack) {
    for(i = 0; i < 16; i++) {
      XE_MII_CLR(XE_MII_CLK);
      DELAY(1);
      XE_MII_SET(XE_MII_CLK);
      DELAY(1);
    }
    goto fail;
  }

  for (i = 0x8000; i; i >>= 1) {
    XE_MII_CLR(XE_MII_CLK);
    DELAY(1);
    if (!ack) {
      if (XE_INB(XE_GPR2) & XE_MII_RDD)
	frame->mii_data |= i;
      DELAY(1);
    }
    XE_MII_SET(XE_MII_CLK);
    DELAY(1);
  }

fail:

  XE_MII_CLR(XE_MII_CLK);
  DELAY(1);
  XE_MII_SET(XE_MII_CLK);
  DELAY(1);

  splx(s);

  if (ack)
    return(1);
  return(0);
}


/*
 * Write to a PHY register through the MII.
 */
static int
xe_mii_writereg(struct xe_softc *scp, struct xe_mii_frame *frame) {
  int s;

  s = splimp();

  /*
   * Set up frame for TX.
   */
  frame->mii_stdelim = XE_MII_STARTDELIM;
  frame->mii_opcode = XE_MII_WRITEOP;
  frame->mii_turnaround = XE_MII_TURNAROUND;
	
  XE_SELECT_PAGE(2);

  /*		
   * Turn on data output.
   */
  XE_MII_SET(XE_MII_DIR);

  xe_mii_sync(scp);

  xe_mii_send(scp, frame->mii_stdelim, 2);
  xe_mii_send(scp, frame->mii_opcode, 2);
  xe_mii_send(scp, frame->mii_phyaddr, 5);
  xe_mii_send(scp, frame->mii_regaddr, 5);
  xe_mii_send(scp, frame->mii_turnaround, 2);
  xe_mii_send(scp, frame->mii_data, 16);

  /* Idle bit. */
  XE_MII_SET(XE_MII_CLK);
  DELAY(1);
  XE_MII_CLR(XE_MII_CLK);
  DELAY(1);

  /*
   * Turn off xmit.
   */
  XE_MII_CLR(XE_MII_DIR);

  splx(s);

  return(0);
}


/*
 * Read a register from the PHY.
 */
static u_int16_t
xe_phy_readreg(struct xe_softc *scp, u_int16_t reg) {
  struct xe_mii_frame frame;

  bzero((char *)&frame, sizeof(frame));

  frame.mii_phyaddr = 0;
  frame.mii_regaddr = reg;
  xe_mii_readreg(scp, &frame);

  return(frame.mii_data);
}


/*
 * Write to a PHY register.
 */
static void
xe_phy_writereg(struct xe_softc *scp, u_int16_t reg, u_int16_t data) {
  struct xe_mii_frame frame;

  bzero((char *)&frame, sizeof(frame));

  frame.mii_phyaddr = 0;
  frame.mii_regaddr = reg;
  frame.mii_data = data;
  xe_mii_writereg(scp, &frame);

  return;
}


/*
 * A bit of debugging code.
 */
static void
xe_mii_dump(struct xe_softc *scp) {
  int i, s;

  s = splimp();

  device_printf(scp->dev, "MII registers: ");
  for (i = 0; i < 2; i++) {
    printf(" %d:%04x", i, xe_phy_readreg(scp, i));
  }
  for (i = 4; i < 7; i++) {
    printf(" %d:%04x", i, xe_phy_readreg(scp, i));
  }
  printf("\n");

  (void)splx(s);
}

#if 0
void
xe_reg_dump(struct xe_softc *scp) {
  int page, i, s;

  s = splimp();

  device_printf(scp->dev, "Common registers: ");
  for (i = 0; i < 8; i++) {
    printf(" %2.2x", XE_INB(i));
  }
  printf("\n");

  for (page = 0; page <= 8; page++) {
    device_printf(scp->dev, "Register page %2.2x: ", page);
    XE_SELECT_PAGE(page);
    for (i = 8; i < 16; i++) {
      printf(" %2.2x", XE_INB(i));
    }
    printf("\n");
  }

  for (page = 0x10; page < 0x5f; page++) {
    if ((page >= 0x11 && page <= 0x3f) ||
	(page == 0x41) ||
	(page >= 0x43 && page <= 0x4f) ||
	(page >= 0x59))
      continue;
    device_printf(scp->dev, "Register page %2.2x: ", page);
    XE_SELECT_PAGE(page);
    for (i = 8; i < 16; i++) {
      printf(" %2.2x", XE_INB(i));
    }
    printf("\n");
  }

  (void)splx(s);
}
#endif

int
xe_activate(device_t dev)
{
	struct xe_softc *sc = device_get_softc(dev);
	int start, err, i;

	DEVPRINTF(2, (dev, "activate\n"));

	if (!sc->modem) {
		sc->port_rid = 0;	/* 0 is managed by pccard */
		sc->port_res = bus_alloc_resource(dev, SYS_RES_IOPORT,
		    &sc->port_rid, 0, ~0, 16, RF_ACTIVE);
	}
	else if (sc->dingo) {
		/*
		 * Find a 16 byte aligned ioport for the card.
		 */
		DEVPRINTF(1, (dev, "Finding an aligned port for RealPort\n"));
		sc->port_rid = 1;	/* 0 is managed by pccard */
		start = 0x100;
		do {
			sc->port_res = bus_alloc_resource(dev,
			    SYS_RES_IOPORT, &sc->port_rid, start, 0x3ff, 16,
			    RF_ACTIVE);
			if (sc->port_res == 0)
				break;		/* we failed */
			if ((rman_get_start(sc->port_res) & 0xf) == 0)
				break;		/* good */
			bus_release_resource(dev, SYS_RES_IOPORT, sc->port_rid, 
			    sc->port_res);
			start = (rman_get_start(sc->port_res) + 15) & ~0xf;
		} while (1);
		DEVPRINTF(1, (dev, "RealPort port 0x%0lx, size 0x%0lx\n",
		    bus_get_resource_start(dev, SYS_RES_IOPORT, sc->port_rid),
		    bus_get_resource_count(dev, SYS_RES_IOPORT, sc->port_rid)));
	}
	else if (sc->ce2) {
	    /*
	     * Find contiguous I/O port for the Ethernet function on CEM2 and
	     * CEM3 cards.  We allocate window 0 wherever pccard has decided
	     * it should be, then find an available window adjacent to it for
	     * the second function.  Not sure that both windows are actually
	     * needed.
	     */
	    DEVPRINTF(1, (dev, "Finding I/O port for CEM2/CEM3\n"));
	    sc->ce2_port_rid = 0;	/* 0 is managed by pccard */
	    sc->ce2_port_res = bus_alloc_resource(dev, SYS_RES_IOPORT,
						  &sc->ce2_port_rid, 0, ~0,
						  8, RF_ACTIVE);
	    if (!sc->ce2_port_res) {
		DEVPRINTF(1, (dev, "Cannot allocate I/O port for modem\n"));
		return ENOMEM;
	    }

	    sc->port_rid = 1;
	    start = bus_get_resource_start(dev, SYS_RES_IOPORT,
					   sc->ce2_port_rid);
	    for (i = 0; i < 2; i++) {
		start += (i == 0 ? 8 : -24);
		sc->port_res = bus_alloc_resource(dev, SYS_RES_IOPORT,
						  &sc->port_rid, start,
						  start + 18, 18, RF_ACTIVE);
		if (sc->port_res == 0)
		    continue;	/* Failed, try again if possible */
		if (bus_get_resource_start(dev, SYS_RES_IOPORT,
					   sc->port_rid) == start)
		    break;	/* Success! */

		bus_release_resource(dev, SYS_RES_IOPORT, sc->port_rid,
				     sc->port_res);
		sc->port_res = 0;
	    }
		DEVPRINTF(1, (dev, "CEM2/CEM3 port 0x%0lx, size 0x%0lx\n",
		    bus_get_resource_start(dev, SYS_RES_IOPORT, sc->port_rid),
		    bus_get_resource_count(dev, SYS_RES_IOPORT, sc->port_rid)));
	}

	if (!sc->port_res) {
		DEVPRINTF(1, (dev, "Cannot allocate ioport\n"));
		return ENOMEM;
	}

	sc->irq_rid = 0;
	sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &sc->irq_rid, 
	    RF_ACTIVE);
	if (!sc->irq_res) {
		DEVPRINTF(1, (dev, "Cannot allocate irq\n"));
		xe_deactivate(dev);
		return ENOMEM;
	}
	if ((err = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_NET, xe_intr, sc,
	    &sc->intrhand)) != 0) {
		xe_deactivate(dev);
		return err;
	}

	sc->bst = rman_get_bustag(sc->port_res);
	sc->bsh = rman_get_bushandle(sc->port_res);
	return (0);
}

void
xe_deactivate(device_t dev)
{
	struct xe_softc *sc = device_get_softc(dev);
	
	DEVPRINTF(2, (dev, "deactivate\n"));
	xe_disable_intr(sc);

	if (sc->intrhand)
		bus_teardown_intr(dev, sc->irq_res, sc->intrhand);
	sc->intrhand = 0;
	if (sc->port_res)
		bus_release_resource(dev, SYS_RES_IOPORT, sc->port_rid, 
		    sc->port_res);
	sc->port_res = 0;
	if (sc->ce2_port_res)
	    bus_release_resource(dev, SYS_RES_IOPORT, sc->ce2_port_rid,
				 sc->ce2_port_res);
	sc->ce2_port_res = 0;
	if (sc->irq_res)
		bus_release_resource(dev, SYS_RES_IRQ, sc->irq_rid, 
		    sc->irq_res);
	sc->irq_res = 0;
	return;
}