/*-
 * 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.
 *
 *      $Id: if_xe.c,v 1.20 1999/06/13 19:17:40 scott Exp $
 * $FreeBSD: src/sys/dev/xe/if_xe.c,v 1.39 2003/10/14 22:51:35 rsm Exp $
 */

/*
 * 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.
 */

/*              
 * 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/errno.h>
#include <sys/kernel.h>
#include <sys/malloc.h> /* for M_NOWAIT */
#include <sys/mbuf.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <sys/serialize.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/rman.h>
#include <sys/thread2.h>
#include <sys/interrupt.h>
 
#include <net/ethernet.h>
#include <net/if.h>
#include <net/ifq_var.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 "if_xereg.h"
#include "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_intr                (void *xscp);
static void      xe_start               (struct ifnet *ifp, struct ifaltq_subque *);
static int       xe_ioctl               (struct ifnet *ifp, u_long command, caddr_t data, struct ucred *);
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 timeout_t xe_setmedia_serialized;
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_set_hash            (struct xe_softc *scp, u_int8_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_reg_dump            (struct xe_softc *scp) __unused;
static void      xe_mii_dump            (struct xe_softc *scp);

#define XE_DEBUG

#ifdef XE_DEBUG

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

/*
 * 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
 */
int     xe_debug = 1;
SYSCTL_INT(_hw_xe, OID_AUTO, debug, CTLFLAG_RW, &xe_debug, 0, "xe debug level");

#define DPRINTF(level, arg)     if (xe_debug >= (level)) kprintf arg
#define IFPRINTF(level, arg)    if (xe_debug >= (level)) if_printf arg
#define DEVPRINTF(level, arg)   if (xe_debug >= (level)) device_printf arg
#define XE_MII_DUMP(scp)        if (xe_debug >= 3) xe_mii_dump(scp)
#define XE_REG_DUMP(scp)        if (xe_debug >= 3) xe_reg_dump(scp)

#else   /* !XE_DEBUG */

#define DPRINTF(level, arg)
#define IFPRINTF(level, arg)
#define DEVPRINTF(level, arg)
#define XE_REG_DUMP(scp)
#define XE_MII_DUMP(scp)

#endif  /* XE_DEBUG */

/*
 * The device entry is being removed, probably because someone ejected the
 * card.  The interface should have been brought down manually before calling
 * this function; if not you may well lose packets.  In any case, I shut down
 * the card and the interface, and hope for the best.
 */
int
xe_detach(device_t dev)
{
  struct xe_softc *sc = device_get_softc(dev);
  struct ifnet *ifp = &sc->arpcom.ac_if;

  lwkt_serialize_enter(ifp->if_serializer);

  ifp->if_flags &= ~IFF_RUNNING; 
  callout_stop(&sc->xe_timer);
  bus_teardown_intr(dev, sc->irq_res, sc->intrhand);

  lwkt_serialize_exit(ifp->if_serializer);

  ether_ifdetach(ifp);
  xe_deactivate(dev);

  return 0;
}

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

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

  /* Fill in some private data */
  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_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;
  ifq_set_maxlen(&scp->ifp->if_snd, IFQ_MAXLEN);
  ifq_set_ready(&scp->ifp->if_snd);

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

  /* 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, NULL);

  ifq_set_cpuid(&scp->ifp->if_snd, rman_get_cpuid(scp->irq_res));

  err = bus_setup_intr(dev, scp->irq_res, INTR_MPSAFE,
                       xe_intr, scp, &scp->intrhand,
                       scp->ifp->if_serializer);
  if (err) {
    device_printf(dev, "Setup intr failed\n");
    ether_ifdetach(scp->ifp);
    xe_deactivate(dev);
    return err;
  }

  /* 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;
  u_int i;

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

  IFPRINTF(2, (scp->ifp, "init\n"));

  crit_enter();

  /* 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_serialized(scp);

  /* Enable output */
  scp->ifp->if_flags |= IFF_RUNNING;
  ifq_clr_oactive(&scp->ifp->if_snd);

  crit_exit();
}


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

  ASSERT_ALTQ_SQ_DEFAULT(ifp, ifsq);

  if (scp->autoneg_status != XE_AUTONEG_NONE) {
    ifq_set_oactive(&ifp->if_snd);
    return;
  }

  IFPRINTF(3, (ifp, "start\n"));

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

    if (xe_pio_write_packet(scp, mbp) != 0) {
      ifq_set_oactive(&ifp->if_snd);
      ifq_prepend(&ifp->if_snd, mbp);
      return;
    }

    BPF_MTAP(ifp, mbp);

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

    m_freem(mbp);
  }
}


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

  scp = ifp->if_softc;
  error = 0;

  crit_enter();

  switch (command) {

  case SIOCSIFFLAGS:
    IFPRINTF(2, (ifp, "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:
    IFPRINTF(2, (ifp, "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:
    IFPRINTF(3, (ifp, "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:
    IFPRINTF(3, (ifp, "ioctl: bounce to ether_ioctl\n"));
    error = ether_ioctl(ifp, command, data);
    break;
  }

  crit_exit();

  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) {
      IFPRINTF(3, (ifp, "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);

    IFPRINTF(3, (ifp,
                 "intr: ISR=0x%02x, RST=0x%02x, TXT=0x%02x%02x, COLL=0x%01x\n",
                 isr, rst0, txst1, txst0, coll));

    /* Handle transmitted packet(s) */
    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;
        IFNET_STAT_INC(ifp, opackets, sent);
        IFNET_STAT_INC(ifp, 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;
      ifq_clr_oactive(&ifp->if_snd);
    }

    /* 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) {
        IFNET_STAT_INC(ifp, collisions, 16);
        IFNET_STAT_INC(ifp, oerrors, 1);
        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) {
        IFPRINTF(1, (ifp, "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"));
        IFNET_STAT_INC(ifp, oerrors, 1);
        scp->mibdata.dot3StatsInternalMacTransmitErrors++;
      }
      /* Late collision -- just complain about it */
      if (txst0 & XE_TXST0_LATE_COLLISION) {
        if_printf(ifp, "late collision\n");
        IFNET_STAT_INC(ifp, oerrors, 1);
        scp->mibdata.dot3StatsLateCollisions++;
      }
      /* SQE test failure -- just complain about it */
      if (txst0 & XE_TXST0_SQE_FAIL) {
        if_printf(ifp, "SQE test failure\n");
        IFNET_STAT_INC(ifp, oerrors, 1);
        scp->mibdata.dot3StatsSQETestErrors++;
      }
      /* Packet too long -- what happens to these */
      if (rst0 & XE_RST0_LONG_PACKET) {
        if_printf(ifp, "received giant packet\n");
        IFNET_STAT_INC(ifp, ierrors, 1);
        scp->mibdata.dot3StatsFrameTooLongs++;
      }
      /* CRC error -- packet dropped */
      if (rst0 & XE_RST0_CRC_ERROR) {
        if_printf(ifp, "CRC error\n");
        IFNET_STAT_INC(ifp, ierrors, 1);
        scp->mibdata.dot3StatsFCSErrors++;
      }
    }

    /* Handle received packet(s) */
    while ((esr = XE_INB(XE_ESR)) & XE_ESR_FULL_PACKET_RX) {
      rsr = XE_INB(XE_RSR);
      IFPRINTF(3, (ifp, "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;

        IFPRINTF(3, (ifp, "intr: receive length = %d\n", len));

        if (len == 0) {
          IFNET_STAT_INC(ifp, iqdrops, 1);
          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_NOWAIT, MT_DATA);
        if (mbp == NULL) {
          IFNET_STAT_INC(ifp, iqdrops, 1);
          continue;
        }

        if (len + 3 > MHLEN) {
          MCLGET(mbp, M_NOWAIT);
          if ((mbp->m_flags & M_EXT) == 0) {
            m_freem(mbp);
            IFNET_STAT_INC(ifp, iqdrops, 1);
            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, NULL, -1);
        IFNET_STAT_INC(ifp, ipackets, 1);
      }
      else if (rsr & XE_RSR_ALIGN_ERROR) {
        /* Packet alignment error -- drop packet */
        if_printf(ifp, "alignment error\n");
        scp->mibdata.dot3StatsAlignmentErrors++;
        IFNET_STAT_INC(ifp, ierrors, 1);
      }

      /* 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) {
      IFPRINTF(1, (ifp, "receive overrun\n"));
      IFNET_STAT_INC(ifp, ierrors, 1);
      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);
}


/*
 * 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;

  if_printf(ifp, "watchdog timeout; resetting card\n");
  scp->tx_timeouts++;
  IFNET_STAT_INC(ifp, 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;

  IFPRINTF(2, (ifp, "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_serialized(scp);

  return 0;
}


/*
 * Return current media selection.
 */
static void
xe_media_status(struct ifnet *ifp, struct ifmediareq *mrp) {

  IFPRINTF(3, (ifp, "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;
}

static 
void
xe_setmedia(void *xscp) 
{
    struct xe_softc *scp = xscp;

    lwkt_serialize_enter(scp->arpcom.ac_if.if_serializer);
    xe_setmedia_serialized(xscp);
    lwkt_serialize_exit(scp->arpcom.ac_if.if_serializer);
}

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

  IFPRINTF(2, (scp->ifp, "setmedia\n"));

  /* Cancel any pending timeout */
  callout_stop(&scp->xe_timer);
  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:
      IFPRINTF(2, (scp->ifp, "Waiting for idle transmitter\n"));
      ifq_set_oactive(&scp->arpcom.ac_if.if_snd);
      scp->autoneg_status = XE_AUTONEG_WAITING;
      /* FALL THROUGH */

    case XE_AUTONEG_WAITING:
      if (scp->tx_queued != 0) {
        callout_reset(&scp->xe_timer, hz / 2, xe_setmedia, scp);
        return;
      }
      if (scp->phy_ok) {
        IFPRINTF(2, (scp->ifp, "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;
        callout_reset(&scp->xe_timer, hz * 7 / 2, xe_setmedia, scp);
        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)) {
        IFPRINTF(2, (scp->ifp, "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 {
        IFPRINTF(2, (scp->ifp, "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;
          callout_reset(&scp->xe_timer, hz * 3, xe_setmedia, scp);
          return;
        }
        else {
          scp->autoneg_status = XE_AUTONEG_FAIL;
        }
      }
      break;

     case XE_AUTONEG_100TX:
      xe_phy_readreg(scp, PHY_BMSR);
      bmsr = xe_phy_readreg(scp, PHY_BMSR);
      if (bmsr & PHY_BMSR_LINKSTAT) {
        IFPRINTF(2, (scp->ifp, "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 {
        IFPRINTF(2, (scp->ifp, "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) {
      IFPRINTF(2, (scp->ifp, "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) {
      IFPRINTF(2, (scp->ifp, "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 */
    IFPRINTF(2, (scp->ifp, "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:
    IFPRINTF(2, (scp->ifp, "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. 
   */
  IFPRINTF(2, (scp->ifp, "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);
  ifq_clr_oactive(&scp->ifp->if_snd);
  if_devstart(scp->ifp);
}


/*
 * Hard reset (power cycle) the card.
 */
static void
xe_reset(struct xe_softc *scp) {
  IFPRINTF(2, (scp->ifp, "hard_reset\n"));

  crit_enter();

  /* 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);

  crit_exit();
}


/*
 * 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) {
  IFPRINTF(2, (scp->ifp, "stop\n"));

  crit_enter();

  /*
   * 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;
  ifq_clr_oactive(&scp->ifp->if_snd);
  scp->ifp->if_timer = 0;

  crit_exit();
}


/*
 * Enable interrupts from the card.
 */
static void
xe_enable_intr(struct xe_softc *scp) {
  IFPRINTF(2, (scp->ifp, "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) {
  IFPRINTF(2, (scp->ifp, "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 *ifma;
  u_int count, i;

  ifp = &scp->arpcom.ac_if;

  IFPRINTF(2, (ifp, "set_multicast\n"));

  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;
  TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
    if (ifma->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 *)ifma->ifma_addr), count);
    else
      if (scp->mohawk)
        /* Use hash filter on Mohawk and Dingo */
        xe_set_hash(scp, LLADDR((struct sockaddr_dl *)ifma->ifma_addr));
      else
        /* Nowhere else to put them on CE2 */
        break;
  }

  IFPRINTF(2, (ifp, "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) {
  uint8_t page, reg;
  u_int 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);

  IFPRINTF(3, (scp->ifp, "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++) {
#ifdef XE_DEBUG
    if (i > 0) {
      DPRINTF(3, (":%02x", addr[i]));
    } else {
      IFPRINTF(3, (scp->ifp, "set_addr: %02x", addr[0]));
    }
#endif
    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_set_hash(struct xe_softc* scp, u_int8_t* addr) {
  u_int32_t crc = 0xffffffff;
  u_int8_t bit, byte, crc31, idx;
  u_int i, j;

  /* Compute CRC of the address -- standard Ethernet CRC function */
  for (i = 0; i < 6; i++) {
    byte = addr[i];
    for (j = 1; j <= 8; j++) {
      if (crc & 0x80000000)
        crc31 = 0x01;
      else
        crc31 = 0;
      bit = crc31 ^ (byte & 0x01);
      crc <<= 1;
      byte >>= 1;
      if (bit)
        crc = (crc ^ XE_CRC_POLY)|1;
    }
  }

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

  /* Hash table index = 6 msbs of CRC, reversed */
  for (i = 0, idx = 0; i < 6; i++) {
    idx >>= 1;
    if (crc & 0x80000000) {
      idx |= 0x20;
    }
    crc <<= 1;
  }
 
  /* Top 3 bits of idx give register - 8, bottom 3 give bit within register */
  byte = idx >> 3 | 0x08;
  bit = 0x01 << (idx & 0x07);

  IFPRINTF(3, (scp->ifp,
               "set_hash: idx = 0x%02x, byte = 0x%02x, bit = 0x%02x\n",
               idx, byte, bit));

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


/*
 * Write an outgoing packet to the card using programmed I/O.
 */
static int
xe_pio_write_packet(struct xe_softc *scp, struct mbuf *mbp) {
  u_int len, pad;
  u_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);
  }

  IFPRINTF(3, (scp->ifp, "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) {
  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) {
    IFPRINTF(2, (scp->ifp, "no PHY found, %0x\n", status));
    return 0;
  }
  else {
    IFPRINTF(2, (scp->ifp, "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;

  crit_enter();

  /*
   * 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);

  crit_exit();

  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) {

  crit_enter();

  /*
   * 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);

  crit_exit();

  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;

  crit_enter();

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

  crit_exit();
}

static void
xe_reg_dump(struct xe_softc *scp) {
  int page, i;

  crit_enter();

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

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

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

  crit_exit();
}

int
xe_activate(device_t dev)
{
        struct xe_softc *sc = device_get_softc(dev);
        int start, 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 == NULL)
                                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) {
                device_printf(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 == NULL)
                    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) {
                device_printf(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) {
                device_printf(dev, "Cannot allocate irq\n");
                xe_deactivate(dev);
                return ENOMEM;
        }

        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->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;
}