path: root/sys/dev/pccard/if_xe.c

/*-
 * Copyright (c) 1998, 1999 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.
 *
 *	$Author_Id: if_xe.c,v 1.19 1999/04/15 22:15:53 scott Exp $
 *	$Id: if_xe.c,v 1.19 1999/04/15 22:15:53 scott 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 10/100 + Modem 56 (CEM56)
 *   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.
 *
 * Contact points:
 *
 * Driver web page: http://ukug.uk.freebsd.org/~scott/xe_drv/
 *
 * Mailing list: http://www.lovett.com/lists/freebsd-xircom/
 * or send "subscribe freebsd-xircom" to <majordomo@lovett.com>
 *
 * Author email: <scott@uk.freebsd.org>
 */


#define XE_DEBUG 1

#include "xe.h"
#include "card.h"
#include "apm.h"
#include "bpfilter.h"

#if NXE > 0

#if NCARD > 0

#include <sys/param.h>
#include <sys/cdefs.h>
#include <sys/conf.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/systm.h>
#include <sys/uio.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>
#if NBPFILTER > 0
#include <net/bpf.h>
#endif /* NBPFILTER > 0 */

#include <i386/isa/isa.h>
#include <i386/isa/isa_device.h>
#include <dev/pccard/if_xereg.h>
#include <machine/clock.h>
#if NAPM > 0
#include <machine/apm_bios.h>
#endif /* NAPM > 0 */

#include <pccard/cardinfo.h>
#include <pccard/cis.h>
#include <pccard/driver.h>
#include <pccard/slot.h>



/*
 * One of these structures per allocated device
 */
struct xe_softc {
  struct arpcom arpcom;
  struct ifmedia ifmedia;
  struct callout_handle chand;
  struct ifmib_iso_8802_3 mibdata;
  struct isa_device *dev;
  struct pccard_devinfo *crd;
  struct ifnet *ifp;
  struct ifmedia *ifm;
  char *card_type;	/* Card model name */
  char *vendor;		/* Card manufacturer */
  int unit;		/* Unit number, from dev->id_unit */
  int srev;     	/* Silicon revision */
  int tx_queued;	/* Packets currently waiting to transmit */
  int tx_ptr;		/* Last value of PTR reg on card */
  int tx_collisions;	/* Collisions since last successful send */
  int tx_timeouts;	/* Count of transmit timeouts */
  int autoneg_status;	/* Autonegotiation progress state */
  int media;		/* Private media word */
  u_char modem;		/* 1 = Multifunction card with modem */
  u_char ce3;      	/* 1 = CE3 class (100Mbit) adapter */
  u_char cem56;    	/* 1 = CEM56 class (CE3 + 56Kbps modem) adapter */
  u_char phy_ok;	/* 1 = MII-compliant PHY found and initialised */
  u_char gone;		/* 1 = Card bailed out */
#if NAPM > 0
  struct apmhook suspend_hook;
  struct apmhook resume_hook;
#endif /* NAPM > 0 */
};

static struct xe_softc *sca[MAXSLOT];
static int iob[MAXSLOT];	/* XXX - very gross */


/*
 * 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;
};

/*
 * For accessing card registers
 */
#define XE_INB(r)         inb(scp->dev->id_iobase+(r))
#define XE_INW(r)         inw(scp->dev->id_iobase+(r))
#define XE_OUTB(r, b)     outb(scp->dev->id_iobase+(r), (b))
#define XE_OUTW(r, w)     outw(scp->dev->id_iobase+(r), (w))
#define XE_SELECT_PAGE(p) XE_OUTB(XE_PSR, (p))

/*
 * Horrid stuff for accessing CIS tuples
 */
#define CARD_MAJOR		50
#define CISTPL_BUFSIZE		512
#define CISTPL_TYPE(tpl)	tpl[0]
#define CISTPL_LEN(tpl)		tpl[2]
#define CISTPL_DATA(tpl,pos)	tpl[4 + ((pos)<<1)]

/*
 * 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 */


/*
 * Prototypes start here
 */
static int       xe_probe		(struct isa_device *dev);
static int       xe_card_init		(struct pccard_devinfo *devi);
static int       xe_attach		(struct isa_device *dev);
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 int       xe_card_intr		(struct pccard_devinfo *devi);
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_hard_reset		(struct xe_softc *scp);
static void      xe_soft_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_setmulti		(struct xe_softc *scp);
static void      xe_setaddrs		(struct xe_softc *scp);
static int       xe_pio_write_packet	(struct xe_softc *scp, struct mbuf *mbp);
static void      xe_card_unload		(struct pccard_devinfo *devi);

/*
 * 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);

/*
 * Debug functions
 */
#ifdef XE_DEBUG
#define XE_REG_DUMP(scp)		xe_reg_dump((scp))
#define XE_MII_DUMP(scp)		xe_mii_dump((scp))
static void      xe_reg_dump		(struct xe_softc *scp);
static void      xe_mii_dump		(struct xe_softc *scp);
#else
#define XE_REG_DUMP(scp)
#define XE_MII_DUMP(scp)
#endif

#if NAPM > 0
/*
 * APM hook functions
 */
static int       xe_suspend		(void *xunit);
static int       xe_resume		(void *xunit);
#endif /* NAPM > 0 */


/*
 * PCMCIA driver hooks
 */
#ifdef PCCARD_MODULE
PCCARD_MODULE(xe, xe_card_init, xe_card_unload, xe_card_intr, 0, net_imask);
#else
static struct pccard_device xe_info = {	/* For pre 3.1-STABLE code */
	"xe",
	xe_card_init,
	xe_card_unload,
	xe_card_intr,
	0,
	&net_imask
};
DATA_SET(pccarddrv_set, xe_info);
#endif /* PCCARD_MODULE */


/*
 * ISA driver hooks.  I'd like to do without these but the kernel config stuff 
 * seems to require them.
 */
struct isa_driver xedriver = {
  xe_probe,
  xe_attach,
  "xe"
};



/*
 * ISA probe routine.
 * All of the supported devices are PCMCIA cards.  I have no idea if it's even 
 * possible to successfully probe/attach these at boot time (pccardd normally
 * does a lot of setup work) so I don't even bother trying.
 */
static int
xe_probe (struct isa_device *dev) {
#ifdef XE_DEBUG
  printf("xe%d: probe, iobase = %#x\n", dev->id_unit, dev->id_iobase);
#endif
  bzero(sca, MAXSLOT * sizeof(sca[0]));
  iob[dev->id_unit] = dev->id_iobase;
  return 0;
}


/*
 * Two routines to read from/write to the attribute memory
 * the write portion is used only for fixing up the RealPort cards,
 * the reader portion was needed for debugging info, and duplicated some
 * code in xe_card_init(), so it appears here instead with suitable
 * modifications to xe_card_init()
 * -aDe Lovett
 */
static int
xe_memwrite(struct pccard_devinfo *devi, off_t offset, u_char byte)
{
  struct iovec iov;
  struct uio uios;

  iov.iov_base = &byte;
  iov.iov_len = sizeof(byte);

  uios.uio_iov = &iov;
  uios.uio_iovcnt = 1;
  uios.uio_offset = offset;
  uios.uio_resid = sizeof(byte);
  uios.uio_segflg = UIO_SYSSPACE;
  uios.uio_rw = UIO_WRITE;
  uios.uio_procp = 0;

  return cdevsw[CARD_MAJOR]->d_write(makedev(CARD_MAJOR, devi->slt->slotnum), &uios, 0);
}


static int
xe_memread(struct pccard_devinfo *devi, off_t offset, u_char *buf, int size)
{
  struct iovec iov;
  struct uio uios;

  iov.iov_base = buf;
  iov.iov_len = size;

  uios.uio_iov = &iov;
  uios.uio_iovcnt = 1;
  uios.uio_offset = offset;
  uios.uio_resid = size;
  uios.uio_segflg = UIO_SYSSPACE;
  uios.uio_rw = UIO_READ;
  uios.uio_procp = 0;

  return cdevsw[CARD_MAJOR]->d_read(makedev(CARD_MAJOR, devi->slt->slotnum), &uios, 0);
}


/*
 * Hacking for RealPort cards
 */
static int
xe_cem56fix(struct xe_softc *scp)
{
  struct pccard_devinfo *devi;
  struct slot *slt;
  struct slot_ctrl *ctrl;
  int ioport, fail;

  /* initialise a few variables */
  devi = scp->crd;
  slt = devi->slt;
  ctrl = slt->ctrl;

  /* allocate a new I/O slot for the ethernet */
  /* XXX: ctrl->mapio() always appears to return 0 (success), so
   *      this may cause problems if another device is listening
   *	  on 0x300 already
   */
  slt->io[1].window = 1;
  slt->io[1].flags = IODF_WS|IODF_16BIT|IODF_ZEROWS|IODF_ACTIVE;
  slt->io[1].size = 0x10;
  if (iob[scp->unit] == -1) {
    for (ioport = 0x300; ioport < 0x400; ioport += 0x10) {
      slt->io[1].start = ioport;
      if ((fail = ctrl->mapio( slt, 1 )) == 0)
	break;
    }
  }
  else {
    ioport = iob[scp->unit];
    slt->io[1].start = ioport;
    fail = ctrl->mapio(slt, 1);
  }

  /* did we find one? */
  if (fail) {
    printf( "xe%d: xe_cem56fix: no free address space\n", scp->unit );
    return -1;
  }


  /* munge the id_iobase entry for use by the rest of the driver */
#ifdef XE_DEBUG
  printf( "xe%d: using 0x%x for RealPort ethernet\n", scp->unit, ioport );
#endif
  scp->dev->id_iobase = ioport;
  scp->dev->id_alive  = 0x10;

  /* magic to set up the ethernet */
  xe_memwrite( devi, 0x800, 0x47 );
  xe_memwrite( devi, 0x80a, ioport & 0xff );
  xe_memwrite( devi, 0x80c, (ioport >> 8) & 0xff );

  xe_memwrite( devi, 0x820, 0x01 );
  xe_memwrite( devi, 0x822, 0x0c );
  xe_memwrite( devi, 0x824, 0x00 );
  xe_memwrite( devi, 0x826, 0x00 );
  xe_memwrite( devi, 0x828, 0x00 );

  /* success! */
  return 0;
}

	
/*
 * PCMCIA probe routine.
 * Probe and identify the device.  Called by the slot manager when the card is 
 * inserted or the machine wakes up from suspend mode.  Assmes that the slot
 * structure has been initialised already.
 */
static int
xe_card_init(struct pccard_devinfo *devi)
{
  struct xe_softc *scp;
  struct isa_device *dev;
  u_char buf[CISTPL_BUFSIZE];
  u_char ver_str[CISTPL_BUFSIZE>>1];
  off_t offs;
  int unit, success, rc, i;

  unit = devi->isahd.id_unit;
  scp = sca[unit];
  dev = &devi->isahd;
  success = 0;

#ifdef XE_DEBUG
  printf("xe: Probing for unit %d\n", unit);
#endif

  /* Check that unit number is OK */
  if (unit > MAXSLOT) {
    printf("xe: bad unit (%d)\n", unit);
    return (ENODEV);
  }

  /* Don't attach an active device */
  if (scp && !scp->gone) {
    printf("xe: unit already attached (%d)\n", unit);
    return (EBUSY);
  }

  /* Allocate per-instance storage */
  if (!scp) {
    if ((scp = malloc(sizeof(*scp), M_DEVBUF, M_NOWAIT)) == NULL) {
      printf("xe%d: failed to allocage driver storage\n", unit);
      return (ENOMEM);
    }
    bzero(scp, sizeof(*scp));
  }

  /* Re-attach an existing device */
  if (scp->gone) {
    scp->gone = 0;
    return 0;
  }

  /* Grep through CIS looking for relevant tuples */
  offs = 0;
  do {
    u_int16_t vendor;
    u_int8_t rev, media, prod;

    /*
     * Read tuples one at a time into buf.  Sucks, but it only happens once.
     * XXX - If the stuff we need isn't in attribute memory, or (worse yet)
     * XXX - attribute memory isn't mapped, we're FUBAR.  Maybe need to do an
     * XXX - ioctl on the card device and follow links?
     * XXX - Not really the driver's problem, PCCARD should handle all this!
     */
    if ((rc = xe_memread( devi, offs, buf, CISTPL_BUFSIZE )) == 0) {

      switch (CISTPL_TYPE(buf)) {

       case 0x15:	/* Grab version string (needed to ID some weird CE2's) */
#ifdef XE_DEBUG
	printf("xe%d: Got version string (0x15)\n", unit);
#endif
	for (i = 0; i < CISTPL_LEN(buf); ver_str[i] = CISTPL_DATA(buf, i++));
	ver_str[i] = '\0';
	ver_str[(CISTPL_BUFSIZE>>1) - 1] = CISTPL_LEN(buf);
	success++;
	break;

       case 0x20:	/* Figure out what type of card we have */
#ifdef XE_DEBUG
	printf("xe%d: Got card ID (0x20)\n", unit);
#endif
	vendor = CISTPL_DATA(buf, 0) + (CISTPL_DATA(buf, 1) << 8);
	rev = CISTPL_DATA(buf, 2);
	media = CISTPL_DATA(buf, 3);
	prod = CISTPL_DATA(buf, 4);

	switch (vendor) {	/* Get vendor ID */
	 case 0x0105:
	  scp->vendor = "Xircom"; break;
	 case 0x0138:
	 case 0x0183:
	  scp->vendor = "Compaq"; break;
	 case 0x0089:
	  scp->vendor = "Intel"; break;
	 default:
	  scp->vendor = "Unknown";
	}

	if (!((prod & 0x40) && (media & 0x01))) {
#ifdef XE_DEBUG
	printf("xe%d: Not a PCMCIA Ethernet card!\n", unit);
#endif
	  rc = ENODEV;		/* Not a PCMCIA Ethernet device */
	}
	else {
	  if (media & 0x10) {	/* Ethernet/modem cards */
#ifdef XE_DEBUG
	printf("xe%d: Card is Ethernet/modem combo\n", unit);
#endif
	    scp->modem = 1;
	    switch (prod & 0x0f) {
	     case 1:
	      scp->card_type = "CEM"; break;
	     case 2:
	      scp->card_type = "CEM2"; break;
	     case 3:
	      scp->card_type = "CEM3"; break;
	     case 4:
	      scp->card_type = "CEM33"; break;
	     case 5:
	      scp->ce3 = 1;
	      scp->card_type = "CEM56M"; break;
	     case 6:
	     case 7:		/* Some kind of RealPort card */
	      scp->ce3 = 1;
	      scp->cem56 = 1;
	      scp->card_type = "CEM56"; break;
	     default:
	      rc = ENODEV;
	    }
	  }
	  else {		/* Ethernet-only cards */
#ifdef XE_DEBUG
	printf("xe%d: Card is Ethernet only\n", unit);
#endif
	    switch (prod & 0x0f) {
	     case 1:
	      scp->card_type = "CE"; break;
	     case 2:
	      scp->card_type = "CE2"; break;
	     case 3:
	      scp->ce3 = 1;
	      scp->card_type = "CE3"; break;
	     default:
	      rc = ENODEV;
	    }
	  }
	}
	success++;
	break;

       case 0x22:	/* Get MAC address */
#ifdef XE_DEBUG
	printf("xe%d: Got MAC address (0x22)\n", unit);
#endif
	if ((CISTPL_LEN(buf) == 8) &&
	    (CISTPL_DATA(buf, 0) == 0x04) &&
	    (CISTPL_DATA(buf, 1) == ETHER_ADDR_LEN)) {
	  for (i = 0; i < ETHER_ADDR_LEN; scp->arpcom.ac_enaddr[i] = CISTPL_DATA(buf, i+2), i++);
	}
	success++;
	break;
       default:
      }
    }

    /* Skip to next tuple */
    offs += ((CISTPL_LEN(buf) + 2) << 1);

  } while ((CISTPL_TYPE(buf) != 0xff) && (CISTPL_LEN(buf) != 0xff) && (rc == 0));


  /* Die now if something went wrong above */
  if ((rc != 0) || (success < 3)) {
    free(scp, M_DEVBUF);
    return rc;
  }

  /* Check for certain strange CE2's that look like CE's */
  if (strcmp(scp->card_type, "CE") == 0) {
    u_char *str = ver_str;
#ifdef XE_DEBUG
    printf("xe%d: Checking for weird CE2 string\n", unit);
#endif
    str += strlen(str) + 1;			/* Skip forward to 3rd version string */
    str += strlen(str) + 1;
    str += strlen(str) + 1;
    for (i = 0; i < strlen(str) - 2; i++) {
      if (bcmp(&str[i], "CE2", 3) ==0) {	/* Look for "CE2" string */
	scp->card_type = "CE2";
      }
    }
  }

  /* Reject unsupported cards */
  if (strcmp(scp->card_type, "CE") == 0 || strcmp(scp->card_type, "CEM") == 0) {
    printf("xe%d: Sorry, your %s card is not supported :(\n", unit, scp->card_type);
    free(scp, M_DEVBUF);
    return ENODEV;
  }

  /* Fill in some private data */
  sca[unit] = scp;
  scp->dev = &devi->isahd;
  scp->crd = devi;
  scp->ifp = &scp->arpcom.ac_if;
  scp->ifm = &scp->ifmedia;
  scp->unit = unit;
  scp->autoneg_status = 0;

  /* Hack RealPorts into submission */
  if (scp->cem56 && xe_cem56fix(scp) < 0) {
    printf( "xe%d: Unable to fix your RealPort\n", unit );
    sca[unit] = 0;
    free(scp, M_DEVBUF);
    return ENODEV;
  }

  /* Attempt to attach the device */
  if (!xe_attach(scp->dev)) {
    sca[unit] = 0;
    free(scp, M_DEVBUF);
    return ENXIO;
  }

#if NAPM > 0
  /* Establish APM hooks once device attached */
  scp->suspend_hook.ah_name = "xe_suspend";
  scp->suspend_hook.ah_fun = xe_suspend;
  scp->suspend_hook.ah_arg = (void *)unit;
  scp->suspend_hook.ah_order = APM_MIN_ORDER;
  apm_hook_establish(APM_HOOK_SUSPEND, &scp->suspend_hook);
  scp->resume_hook.ah_name = "xe_resume";
  scp->resume_hook.ah_fun = xe_resume;
  scp->resume_hook.ah_arg = (void *)unit;
  scp->resume_hook.ah_order = APM_MIN_ORDER;
  apm_hook_establish(APM_HOOK_RESUME, &scp->resume_hook);
#endif /* NAPM > 0 */

  /* Success */
  return 0;
}


/*
 * Attach a device (called when xe_card_init succeeds).  Assume that the probe
 * routine has set up the softc structure correctly and that we can trust the
 * unit number.
 */
static int
xe_attach (struct isa_device *dev) {
  struct xe_softc *scp = sca[dev->id_unit];
  int i;

#ifdef XE_DEBUG
  printf("xe%d: attach\n", scp->unit);
#endif

  /* Initialise the ifnet structure */
  if (!scp->ifp->if_name) {
    scp->ifp->if_softc = scp;
    scp->ifp->if_name = "xe";
    scp->ifp->if_unit = scp->unit;
    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_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);

  /*
   * Fill in supported media types.  Some cards _do_ support full duplex
   * operation, but this driver doesn't, yet.  Therefore we leave those modes
   * out of the list.  We support some form of autoselection in all cases.
   */
  if (scp->ce3) {
    ifmedia_add(scp->ifm, IFM_ETHER|IFM_100_TX, 0, NULL);
    ifmedia_add(scp->ifm, IFM_ETHER|IFM_10_T, 0, NULL);
  }
  else {
    ifmedia_add(scp->ifm, IFM_ETHER|IFM_10_T, 0, NULL);
    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);

  /* Print some useful information */
  printf("\nxe%d: %s %s%s%s\n",
	 scp->unit,
	 scp->vendor,
	 scp->card_type,
	 scp->ce3 ?   ", 100Mbps capable" : "",
	 scp->cem56 ? ", with modem"      : "");
  printf("xe%d: Ethernet address %02x", scp->unit, scp->arpcom.ac_enaddr[0]);
  for (i = 1; i < ETHER_ADDR_LEN; i++) {
    printf(":%02x", scp->arpcom.ac_enaddr[i]);
  }
  printf("\n");

  /* Attach the interface */
  if_attach(scp->ifp);
  ether_ifattach(scp->ifp);

#if NBPFILTER > 0
  /* If BPF is in the kernel, call the attach for it */
#ifdef XE_DEBUG
  printf("xe%d: BPF listener attached\n", scp->unit);
#endif
  bpfattach(scp->ifp, DLT_EN10MB, sizeof(struct ether_header));
#endif

  /* Done */
  return 1;
}


/*
 * Initialize device.  Completes the reset procedure on the card and starts
 * output.  If there's an autonegotiation in progress we DON'T do anything;
 * the media selection code will call us again when it's done.
 */
static void
xe_init(void *xscp) {
  struct xe_softc *scp = xscp;
  int s;

#ifdef XE_DEBUG
  printf("xe%d: init\n", scp->unit);
#endif

  if (scp->gone) return;

  if (TAILQ_EMPTY(&scp->ifp->if_addrhead)) return;

  /* Reset transmitter flags */
  scp->tx_queued = 0;
  scp->tx_ptr = 0;
  scp->tx_collisions = 0;
  scp->ifp->if_timer = 0;

  s = splimp();

  XE_SELECT_PAGE(0x42);
  XE_OUTB(XE_SWC0, 0x20);	/* Disable source insertion (WTF is that?) */

  /*
   * Set the 'local memory dividing line' -- splits the 32K card memory into
   * 8K for transmit buffers and 24K for receive.  This is done automatically
   * on newer revision cards.
   */
  if (scp->srev != 1) {
    XE_SELECT_PAGE(2);
    XE_OUTW(XE_RBS, 0x2000);
  }

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

  /* Fix the data offset register -- reset leaves it off-by-one */
  XE_SELECT_PAGE(0);
  XE_OUTW(XE_DOR, 0x2000);

  /*
   * Set MAC interrupt masks and clear status regs.  The bit names are direct
   * from the Linux code; I have no idea what most of them do.
   */
  XE_SELECT_PAGE(0x40);		/* Bit 7..0 */
  XE_OUTB(XE_RXM0, 0xff);	/* ROK, RAB, rsv, RO,  CRC, AE,  PTL, MP  */
  XE_OUTB(XE_TXM0, 0xff);	/* TOK, TAB, SQE, LL,  TU,  JAB, EXC, CRS */
  XE_OUTB(XE_TXM1, 0xb0);	/* rsv, rsv, PTD, EXT, rsv, rsv, rsv, rsv */
  XE_OUTB(XE_RXS0, 0x00);	/* ROK, RAB, REN, RO,  CRC, AE,  PTL, MP  */
  XE_OUTB(XE_TXS0, 0x00);	/* TOK, TAB, SQE, LL,  TU,  JAB, EXC, CRS */
  XE_OUTB(XE_TXS1, 0x00);	/* TEN, rsv, PTD, EXT, retry_counter:4    */

  /*
   * Check for an in-progress autonegotiation.  If one is active, just set
   * IFF_RUNNING and return.  The media selection code will call us again when 
   * it's done.
   */
  if (scp->autoneg_status) {
    scp->ifp->if_flags |= IFF_RUNNING;
  }
  else {
    /* Enable receiver, put MAC online */
    XE_SELECT_PAGE(0x40);
    XE_OUTB(XE_OCR, XE_OCR_RX_ENABLE|XE_OCR_ONLINE);

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

    /* Attempt to start output */
    scp->ifp->if_flags |= IFF_RUNNING;
    scp->ifp->if_flags &= ~IFF_OACTIVE;
    xe_start(scp->ifp);
  }

  (void)splx(s);
}


/*
 * Start output on interface.  We make two assumptions here:
 *  1) that the current priority is set to splimp _before_ this code
 *     is called *and* is returned to the appropriate priority after
 *     return
 *  2) that the IFF_OACTIVE flag is checked before this code is called
 *     (i.e. that the output part of the interface is idle)
 */
static void
xe_start(struct ifnet *ifp) {
  struct xe_softc *scp = ifp->if_softc;
  struct mbuf *mbp;

  if (scp->gone) return;

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

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

#if NBPFILTER > 0
    /* Tap off here if there is a bpf listener */
    if (ifp->if_bpf) {
#if XE_DEBUG > 1
      printf("xe%d: sending output packet to BPF\n", scp->unit);
#endif
      bpf_mtap(ifp, mbp);
    }
#endif /* NBPFILTER > 0 */

    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 (register struct ifnet *ifp, u_long command, caddr_t data) {
  struct xe_softc *scp;
  int s, error;

  scp = ifp->if_softc;
  error = 0;

  if (scp->gone) {
    return ENXIO;
  }

  s = splimp();

  switch (command) {

   case SIOCSIFADDR:
   case SIOCGIFADDR:
   case SIOCSIFMTU:
    error = ether_ioctl(ifp, command, data);
    break;

   case SIOCSIFFLAGS:
    /*
     * 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_hard_reset(scp);
	xe_setmedia(scp);
	xe_init(scp);
      }
    }
    else {
      if (ifp->if_flags & IFF_RUNNING)
	xe_stop(scp);
    }

   case SIOCADDMULTI:
   case SIOCDELMULTI:
    /*
     * Multicast list has (maybe) changed; set the hardware filter
     * accordingly.  This also serves to deal with promiscuous mode if we have 
     * a BPF listener active.
     */
    xe_setmulti(scp);
    error = 0;
    break;

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

   default:
    error = EINVAL;
  }

  (void)splx(s);

  return error;
}


/*
 * Card interrupt handler: should return true if the interrupt was for us, in
 * case we are sharing our IRQ line with other devices (this will probably be
 * the case for multifunction cards).
 *
 * 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 int
xe_card_intr(struct pccard_devinfo *devi) {
  struct xe_softc *scp;
  struct ifnet *ifp;
  int unit, result;
  u_int16_t rx_bytes, rxs, txs;
  u_int8_t psr, isr, esr, rsr;

  unit = devi->isahd.id_unit;
  scp = sca[unit];
  ifp = &scp->arpcom.ac_if;
  rx_bytes = 0;			/* Bytes received on this interrupt */
  result = 0;			/* Set true if the interrupt is for us */

  if (scp->gone)
    return 0;

  if (scp->ce3) {
    XE_OUTB(XE_CR, 0);		/* Disable interrupts */
  }

  psr = XE_INB(XE_PSR);		/* Stash the current register page */

  /*
   * Read ISR to see what caused this interrupt.  Note that this clears the
   * ISR on CE2 type cards.
   */
  if ((isr = XE_INB(XE_ISR)) && isr != 0xff) {

    result = 1;			/* This device did generate an int */
    esr = XE_INB(XE_ESR);	/* Read the other status registers */
    XE_SELECT_PAGE(0x40);
    rxs = XE_INB(XE_RXS0);
    XE_OUTB(XE_RXS0, ~rxs & 0xff);
    txs = XE_INB(XE_TXS0);
    txs |= XE_INB(XE_TXS1) << 8;
    XE_OUTB(XE_TXS0, 0);
    XE_OUTB(XE_TXS1, 0);
    XE_SELECT_PAGE(0);

#if XE_DEBUG > 3
    printf("xe%d: ISR=%#2.2x ESR=%#2.2x RXS=%#2.2x TXS=%#4.4x\n", unit, isr, esr, rxs, txs);
#endif

    /*
     * Handle transmit interrupts
     */
    if (isr & XE_ISR_TX_PACKET) {
      u_int8_t new_ptr, sent;
      
      if ((new_ptr = XE_INB(XE_PTR)) < scp->tx_ptr)	/* Update packet count */
	sent = (0xff - scp->tx_ptr) + new_ptr;		/* PTR rolled over */
      else
	sent = new_ptr - scp->tx_ptr;

      if (sent > 0) {				/* Packets sent since last interrupt */
	scp->tx_ptr = new_ptr;
	scp->tx_queued -= sent;
	ifp->if_opackets += sent;
	ifp->if_collisions += scp->tx_collisions;

	/*
	 * Collision stats are a PITA.  If multiples frames have been sent, we 
	 * distribute any outstanding collision count equally amongst them.
	 * However, if we're missing interrupts we're quite likely to also
	 * miss some collisions; thus the total count will be off anyway.
	 * Likewise, if we miss a frame dropped due to excessive collisions
	 * any outstanding collisions count will be held against the next
	 * frame to be successfully sent.  Hopefully it averages out in the
	 * end!
	 * XXX - This will screw up if tx_collisions/sent > 14. FIX IT!
	 */
	switch (scp->tx_collisions) {
	 case 0:
	  break;
	 case 1:
	  scp->mibdata.dot3StatsSingleCollisionFrames++;
	  scp->mibdata.dot3StatsCollFrequencies[0]++;
	  break;
	 default:
	  if (sent == 1) {
	    scp->mibdata.dot3StatsMultipleCollisionFrames++;
	    scp->mibdata.dot3StatsCollFrequencies[scp->tx_collisions-1]++;
	  }
	  else {		/* Distribute across multiple frames */
	    scp->mibdata.dot3StatsMultipleCollisionFrames += sent;
	    scp->mibdata.
	      dot3StatsCollFrequencies[scp->tx_collisions/sent] += sent - scp->tx_collisions%sent;
	    scp->mibdata.
	      dot3StatsCollFrequencies[scp->tx_collisions/sent + 1] += scp->tx_collisions%sent;
	  }
	}
	scp->tx_collisions = 0;
      }
      ifp->if_timer = 0;
      ifp->if_flags &= ~IFF_OACTIVE;
    }
    if (txs & 0x0002) {		/* Excessive collisions (packet dropped) */
      ifp->if_collisions += 16;
      ifp->if_oerrors++;
      scp->tx_collisions = 0;
      scp->mibdata.dot3StatsExcessiveCollisions++;
      scp->mibdata.dot3StatsMultipleCollisionFrames++;
      scp->mibdata.dot3StatsCollFrequencies[15]++;
      XE_OUTB(XE_CR, XE_CR_RESTART_TX);
    }
    if (txs & 0x0040)		/* Transmit aborted -- probably collisions */
      scp->tx_collisions++;


    /*
     * Handle receive interrupts 
     */
    while ((esr = XE_INB(XE_ESR)) & XE_ESR_FULL_PKT_RX) {

      if ((rsr = XE_INB(XE_RSR)) & XE_RSR_RX_OK) {
	struct ether_header *ehp;
	struct mbuf *mbp;
	u_int16_t len;

	len = XE_INW(XE_RBC);

	if (len == 0)
	  continue;

#if 0
	/*
	 * Limit the amount of time we spend in this loop, dropping packets if 
	 * necessary.  The Linux code does this with considerably more
	 * finesse, adjusting the threshold dynamically.
	 */
	if ((rx_bytes += len) > 22000) {
	  ifp->if_iqdrops++;
	  scp->mibData.dot3StatsMissedFrames++;
	  XE_OUTW(XE_DOR, 0x8000);
	  continue;
	}
#endif

	if (len & 0x01)
	  len++;

	MGETHDR(mbp, M_DONTWAIT, MT_DATA);	/* Allocate a header mbuf */
	if (mbp != NULL) {
	  mbp->m_pkthdr.rcvif = ifp;
	  mbp->m_pkthdr.len = mbp->m_len = len;

	  /*
	   * If the mbuf header isn't big enough for the packet, attach an
	   * mbuf cluster to hold it.  The +2 is to allow for the nasty little 
	   * alignment hack below.
	   */
	  if (len + 2 > MHLEN) {
	    MCLGET(mbp, M_DONTWAIT);
	    if ((mbp->m_flags & M_EXT) == 0) {
	      m_freem(mbp);
	      mbp = NULL;
	    }
	  }
	}

	if (mbp != NULL) {
	  /*
	   * The Ethernet header is 14 bytes long; thus the actual packet data 
	   * won't be 32-bit aligned when it's dumped into the mbuf.  We
	   * offset everything by 2 bytes to fix this.  Apparently the
	   * alignment is important for NFS, damn its eyes.
	   */
	  mbp->m_data += 2;
	  ehp = mtod(mbp, struct ether_header *);

	  /*
	   * Now get the packet, including the Ethernet header and trailer (?)
	   * We use programmed I/O, because we don't know how to do shared
	   * memory with these cards.  So yes, it's real slow, and heavy on
	   * the interrupts (CPU on my P150 maxed out at ~950KBps incoming).
	   */
	  if (scp->srev == 0) {		/* Workaround a bug in old cards */
	    u_short rhs;

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

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

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

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

	      /*
	       * XXX - This i-- seems very wrong, but it's what the Linux guys 
	       * XXX - do.  Need someone with an old CE2 to test this for me.
	       * XXX - 99/3/28: Changed the first i-- to an i++, maybe that'll
	       * XXX - fix it?  It seems as though the previous version would
	       * XXX - have caused an infinite loop (what, another one?).
	       */
	      for (i = 0; i < len; i++, rhs++) {
		((char *)ehp)[i] = XE_INB(XE_EDP);
		if (rhs == 0x8000) {
		  rhs = 0;
		  i--;
		}
	      }
	    }
	    else
	      insw(scp->dev->id_iobase+XE_EDP, ehp, len >> 1);
	  }
	  else
	    insw(scp->dev->id_iobase+XE_EDP, ehp, len >> 1);

#if NBPFILTER > 0
	  /*
	   * Check if there's a BPF listener on this interface. If so, hand
	   * off the raw packet to bpf.
	   */
	  if (ifp->if_bpf) {
#if XE_DEBUG > 1
	    printf("xe%d: passing input packet to BPF\n", scp->unit);
#endif
	    bpf_mtap(ifp, mbp);

	    /*	
	     * Note that the interface cannot be in promiscuous mode if there
	     * are no BPF listeners.  And if we are in promiscuous mode, we
	     * have to check if this packet is really ours.
	     */
	    if ((ifp->if_flags & IFF_PROMISC) &&
		bcmp(ehp->ether_dhost, scp->arpcom.ac_enaddr, sizeof(ehp->ether_dhost)) != 0 &&
		(rsr & XE_RSR_PHYS_PKT)) {
	      m_freem(mbp);
	      mbp = NULL;
	    }
	  }
#endif /* NBPFILTER > 0 */

	  if (mbp != NULL) {
	    mbp->m_pkthdr.len = mbp->m_len = len - ETHER_HDR_LEN;
	    mbp->m_data += ETHER_HDR_LEN;	/* Strip off Ethernet header */
	    ether_input(ifp, ehp, mbp);		/* Send the packet on its way */
	    ifp->if_ipackets++;			/* Success! */
	  }
	  XE_OUTW(XE_DOR, 0x8000);		/* skip_rx_packet command */
	}
      }
      else if (rsr & XE_RSR_LONG_PKT) {		/* Packet length >1518 bytes */
	scp->mibdata.dot3StatsFrameTooLongs++;
	ifp->if_ierrors++;
      }
      else if (rsr & XE_RSR_CRC_ERR) {		/* Bad checksum on packet */
	scp->mibdata.dot3StatsFCSErrors++;
	ifp->if_ierrors++;
      }
      else if (rsr & XE_RSR_ALIGN_ERR) {	/* Packet alignment error */
	scp->mibdata.dot3StatsAlignmentErrors++;
	ifp->if_ierrors++;
      }
    }
    if (rxs & 0x10) {				/* Receiver overrun */
      scp->mibdata.dot3StatsInternalMacReceiveErrors++;
      ifp->if_ierrors++;
      XE_OUTB(XE_CR, XE_CR_CLEAR_OVERRUN);
    }
  }

  XE_SELECT_PAGE(psr);				/* Restore saved page */
  XE_OUTB(XE_CR, XE_CR_ENABLE_INTR);		/* Re-enable interrupts */

  /* XXX - Could force an int here, instead of dropping packets?     */
  /* XXX - XE_OUTB(XE_CR, XE_CR_ENABLE_INTR|XE_CE_FORCE_INTR); */

  return result;
}


/*
 * 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 (scp->gone) return;

  printf("xe%d: watchdog timeout; resetting card\n", scp->unit);
  scp->tx_timeouts++;
  ifp->if_oerrors += scp->tx_queued;
  xe_stop(scp);
  xe_hard_reset(scp);
  xe_setmedia(scp);
  xe_init(scp);
}


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

#ifdef XE_DEBUG
  printf("xe%d: media_change\n", ifp->if_unit);
#endif

  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) {

#ifdef XE_DEBUG
  printf("xe%d: media_status\n", ifp->if_unit);
#endif

  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;

#ifdef XE_DEBUG
  printf("xe%d: setmedia\n", scp->unit);
#endif

  /* 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:
#ifdef XE_DEBUG
      printf("xe%d: Waiting for idle transmitter\n", scp->unit);
#endif
      scp->arpcom.ac_if.if_flags |= IFF_OACTIVE;
      scp->autoneg_status = XE_AUTONEG_WAITING;
      scp->chand = timeout(xe_setmedia, scp, hz * 2);
      return;

     case XE_AUTONEG_WAITING:
      xe_soft_reset(scp);
      if (scp->phy_ok) {
#ifdef XE_DEBUG
	printf("xe%d: Starting autonegotiation\n", scp->unit);
#endif
	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)) {
#ifdef XE_DEBUG
	printf("xe%d: Autonegotiation complete!\n", scp->unit);
#endif
	/*
	 * 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 {
#ifdef XE_DEBUG
	printf("xe%d: Autonegotiation failed; trying 100baseTX\n", scp->unit);
#endif
	XE_MII_DUMP(scp);
	xe_soft_reset(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) {
#ifdef XE_DEBUG
	printf("xe%d: Got 100baseTX link!\n", scp->unit);
#endif
	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 {
#ifdef XE_DEBUG
	printf("xe%d: Autonegotiation failed; disabling PHY\n", scp->unit);
#endif
	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) {
#ifdef XE_DEBUG
      printf("xe%d: Selecting 10baseX\n", scp->unit);
#endif
      if (scp->ce3) {
	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 */
    xe_soft_reset(scp);
    if (scp->phy_ok) {
#ifdef XE_DEBUG
      printf("xe%d: Selecting 100baseTX\n", scp->unit);
#endif
      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 */
    xe_soft_reset(scp);
#ifdef XE_DEBUG	
    printf("xe%d: Selecting 10baseT\n", scp->unit);
#endif
    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:
    xe_soft_reset(scp);
#ifdef XE_DEBUG
    printf("xe%d: Selecting 10base2\n", scp->unit);
#endif
    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. 
   */
#ifdef XE_DEBUG
  printf("xe%d: Setting LEDs\n", scp->unit);
#endif
  XE_SELECT_PAGE(2);
  switch (IFM_SUBTYPE(scp->media)) {
   case IFM_100_TX:
   case IFM_10_T:
    XE_OUTB(XE_LED, 0x3b);
    if (scp->cem56)
      XE_OUTB(0x0b, 0x04);	/* 100Mbit LED */
    break;

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

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


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

#ifdef XE_DEBUG
  printf("xe%d: hard_reset\n", scp->unit);
#endif

  if (scp->gone) return;

  s = splimp();

  /*
   * Power cycle the card.
   */
  XE_SELECT_PAGE(4);
  XE_OUTB(XE_GPR1, 0);		/* Power off */
  DELAY(40000);

  if (scp->ce3)
    XE_OUTB(XE_GPR1, 1);	/* And back on again */
  else
    XE_OUTB(XE_GPR1, 5);	/* Also set AIC bit, whatever that is */
  DELAY(40000);
  XE_SELECT_PAGE(0);

  (void)splx(s);
}


/*
 * Soft reset the card.  Also makes sure that the ML6692 and 10Mbit controller 
 * are powered up, sets the silicon revision number in softc, disables
 * interrupts and checks for the prescence of a 100Mbit PHY.  This should
 * leave us in a position where we can access the PHY and do media
 * selection. The function imposes a 0.5s delay while the hardware powers up.
 */
static void
xe_soft_reset(struct xe_softc *scp) {
  int s;

#ifdef XE_DEBUG
  printf("xe%d: soft_reset\n", scp->unit);
#endif

  if (scp->gone) return;

  s = splimp();

  /*
   * Reset the card, (again).
   */
  XE_SELECT_PAGE(0);
  XE_OUTB(XE_CR, XE_CR_SOFT_RESET);
  DELAY(40000);
  XE_OUTB(XE_CR, 0);
  DELAY(40000);

  if (scp->ce3) {
    /*
     * 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, 0x0e);
  }

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

  /*
   * Get silicon revision number.
   */
  XE_SELECT_PAGE(4);
  if (scp->ce3)
    scp->srev = (XE_INB(XE_BOV) & 0x70) >> 4;
  else
    scp->srev = (XE_INB(XE_BOV) & 0x30) >> 4;
#ifdef XE_DEBUG
  printf("xe%d: silicon revision = %d\n", scp->unit, scp->srev);
#endif
  
  /*
   * Shut off interrupts.
   */
  xe_disable_intr(scp);

  /*
   * Check for PHY.
   */
  if (scp->ce3) {
    scp->phy_ok = xe_mii_init(scp);
  }

  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;

#ifdef XE_DEBUG
  printf("xe%d: stop\n", scp->unit);
#endif

  if (scp->gone) return;

  s = splimp();

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

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

  /*
   * ~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 Ethernet interrupts from the card.
 */
static void
xe_enable_intr(struct xe_softc *scp) {
#ifdef XE_DEBUG
  printf("xe%d: enable_intr\n", scp->unit);
#endif

  XE_SELECT_PAGE(1);
  XE_OUTB(XE_IMR0, 0xff);		/* Unmask everything */
  XE_OUTB(XE_IMR1, 0x01);		/* Unmask TX underrun detection */
  DELAY(1);

  XE_SELECT_PAGE(0);
  XE_OUTB(XE_CR, XE_CR_ENABLE_INTR);	/* Enable interrupts */
  if (scp->modem && !scp->cem56) {	/* This bit is just magic */
    if (!(XE_INB(0x10) & 0x01)) {
      XE_OUTB(0x10, 0x11);		/* Unmask master int enable bit */
    }
  }
}


/*
 * Disable all Ethernet interrupts from the card.
 */
static void
xe_disable_intr(struct xe_softc *scp) {
#ifdef XE_DEBUG
  printf("xe%d: disable_intr\n", scp->unit);
#endif

  XE_SELECT_PAGE(0);
  XE_OUTB(XE_CR, 0);			/* Disable interrupts */
  if (scp->modem && !scp->cem56) {	/* More magic (does this work?) */
    XE_OUTB(0x10, 0x10);		/* Mask the master int enable bit */
  }

  XE_SELECT_PAGE(1);
  XE_OUTB(XE_IMR0, 0);			/* Forbid all interrupts */
  XE_OUTB(XE_IMR1, 0);
  XE_SELECT_PAGE(0);
}


/*
 * Set up multicast filter and promiscuous mode
 */
static void
xe_setmulti(struct xe_softc *scp) {
  struct ifnet *ifp;
  struct ifmultiaddr *maddr;
  int count;

  ifp = &scp->arpcom.ac_if;
  maddr = ifp->if_multiaddrs.lh_first;

  /* Get length of multicast list */
  for (count = 0; maddr != NULL; maddr = maddr->ifma_link.le_next, count++);

  if ((ifp->if_flags & IFF_PROMISC) || (ifp->if_flags & IFF_ALLMULTI) || (count > 9)) {
    /*
     * Go into promiscuous mode if either of the PROMISC or ALLMULTI flags are
     * set, or if we have been asked to deal with more than 9 multicast
     * addresses.  To do this: set MPE and PME in SWC1
     */
    XE_SELECT_PAGE(0x42);
    XE_OUTB(XE_SWC1, 0x06);
  }
  else if ((ifp->if_flags & IFF_MULTICAST) && (count > 0)) {
    /*
     * Program the filters for up to 9 addresses
     */
    XE_SELECT_PAGE(0x42);
    XE_OUTB(XE_SWC1, 0x01);
    XE_SELECT_PAGE(0x40);
    XE_OUTB(XE_OCR, XE_OCR_OFFLINE);
    /*xe_reg_dump(scp);*/
    xe_setaddrs(scp);
    /*xe_reg_dump(scp);*/
    XE_SELECT_PAGE(0x40);
    XE_OUTB(XE_OCR, XE_OCR_RX_ENABLE|XE_OCR_ONLINE);
  }
  else {
    /*
     * No multicast operation (default)
     */
    XE_SELECT_PAGE(0x42);
    XE_OUTB(XE_SWC1, 0);
  }
  XE_SELECT_PAGE(0);
}


/*
 * Set up all on-chip addresses (for multicast).  AFAICS, there are 10
 * of these things; the first is our MAC address, the other 9 are mcast
 * addresses, padded with the MAC address if there aren't enough.
 * XXX - This doesn't work right, but I'm not sure why yet.  We seem to be
 * XXX - doing much the same as the Linux code, which is weird enough that
 * XXX - it's probably right (despite my earlier comments to the contrary).
 * XXX - I wonder if this thing has a multicast hash filter like most other
 * XXX - Ethernet hardware seems to?
 */
static void
xe_setaddrs(struct xe_softc *scp) {
  struct ifmultiaddr *maddr;
  u_int8_t *addr;
  u_int8_t page, slot, byte, i;

  maddr = scp->arpcom.ac_if.if_multiaddrs.lh_first;

  XE_SELECT_PAGE(page = 0x50);

  for (slot = 0, byte = 8; slot < 10; slot++) {

    if (slot == 0)
      addr = (u_int8_t *)(&scp->arpcom.ac_enaddr);
    else {
      while (maddr != NULL && maddr->ifma_addr->sa_family != AF_LINK)
	maddr = maddr->ifma_link.le_next;
      if (maddr != NULL)
	addr = LLADDR((struct sockaddr_dl *)maddr->ifma_addr);
      else
	addr = (u_int8_t *)(&scp->arpcom.ac_enaddr);
    }

    for (i = 0; i < 6; i++, byte++) {
#if XE_DEBUG > 1
      if (i)
	printf(":%x", addr[i]);
      else
	printf("xe%d: individual addresses %d: %x", scp->unit, slot, addr[0]);
#endif

      if (byte > 15) {
	page++;
	byte = 8;
	XE_SELECT_PAGE(page);
      }

      if (scp->ce3)
	XE_OUTB(byte, addr[5 - i]);
      else
	XE_OUTB(byte, addr[i]);
    }
#if XE_DEBUG > 1
    printf("\n");
#endif
  }

  XE_SELECT_PAGE(0);
}


/*
 * Write an outgoing packet to the card using programmed I/O.
 */
static int
xe_pio_write_packet(struct xe_softc *scp, struct mbuf *mbp) {
  struct mbuf *mbp2;
  u_int16_t len, pad, free, ok;
  u_int8_t *data;
  u_int8_t savebyte[2], wantbyte;

  /* Get total packet length */
  for (len = 0, mbp2 = mbp; mbp2 != NULL; len += mbp2->m_len, mbp2 = mbp2->m_next);

  /* Packets < minimum length may need to be padded out */
  pad = 0;
  if (len < ETHER_MIN_LEN - ETHER_CRC_LEN) {
    pad = (ETHER_MIN_LEN - ETHER_CRC_LEN - len + 1) >> 1;
    len = ETHER_MIN_LEN - ETHER_CRC_LEN;
  }

  /* Check transmit buffer space */
  XE_SELECT_PAGE(0);
  XE_OUTW(XE_TRS, len+2);
  free = XE_INW(XE_TSO);
  ok = free & 0x8000;
  free &= 0x7fff;
  if (free <= 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 */
	outsw(scp->dev->id_iobase+XE_EDP, 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;
  }
  if (wantbyte)			/* Last byte for odd-length packets */
    XE_OUTW(XE_EDP, *(u_short *)savebyte);

  /*
   * For CE3 cards, just tell 'em to send -- apparently the card will pad out
   * short packets with random cruft.  Otherwise, write nonsense words to fill 
   * out the packet.  I guess it is then sent automatically (?)
   */
  if (scp->ce3)
    XE_OUTB(XE_CR, XE_CR_TX_PACKET|XE_CR_ENABLE_INTR);
  else
    while (pad > 0) {
      XE_OUTW(XE_EDP, 0xdead);
      pad--;
    }

  return 0;
}


/*
 * 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.  The 'gone' flag is set, 
 * so hopefully no-one else will try to access the missing card.
 */
static void
xe_card_unload(struct pccard_devinfo *devi) {
  struct xe_softc *scp;
  struct ifnet *ifp;
  int unit;

  unit = devi->isahd.id_unit;
  scp = sca[unit];
  ifp = &scp->arpcom.ac_if;

  if (scp->gone) {
    printf("xe%d: already unloaded\n", unit);
    return;
  }

  if_down(ifp);
  ifp->if_flags &= ~(IFF_RUNNING|IFF_OACTIVE);
  xe_stop(scp);
  scp->gone = 1;
}



/**************************************************************
 *                                                            *
 *                  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.
 */
#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) {
#ifdef XE_DEBUG
    printf("xe%d: no PHY found, %0x\n", scp->unit, status);
#endif
    return 0;
  }
  else {
#ifdef XE_DEBUG
    printf("xe%d: PHY OK!\n", scp->unit);
#endif

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

  /*
   * 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;
}


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

  s = splimp();

  printf("xe%d: MII registers: ", scp->unit);
  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);
}

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

  s = splimp();

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

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

  (void)splx(s);
}
#endif



#if NAPM > 0
/**************************************************************
 *                                                            *
 *                  A P M  F U N C T I O N S                  *
 *                                                            *
 **************************************************************/

/*
 * This is called when we go into suspend/standby mode
 */
static int
xe_suspend(void *xunit) {

#ifdef XE_DEBUG
  struct xe_softc *scp = sca[(int)xunit];

  printf("xe%d: APM suspend\n", scp->unit);
#endif

  return 0;
}

/*
 * This is called when we wake up again
 */
static int
xe_resume(void *xunit) {

#ifdef XE_DEBUG
  struct xe_softc *scp = sca[(int)xunit];

  printf("xe%d: APM resume\n", scp->unit);
#endif

  return 0;
}

#endif /* NAPM > 0 */

#endif /* NCARD > 0 */

#endif /* NXE > 0 */