/* $Id: aha1542.c,v 1.1 1992/07/24 06:27:38 root Exp root $
 *  linux/kernel/aha1542.c
 *
 *  Copyright (C) 1992  Tommy Thorn
 *  Copyright (C) 1993, 1994, 1995 Eric Youngdale
 *
 *  Modified by Eric Youngdale
 *        Use request_irq and request_dma to help prevent unexpected conflicts
 *        Set up on-board DMA controller, such that we do not have to
 *        have the bios enabled to use the aha1542.
 *  Modified by David Gentzel
 *	  Don't call request_dma if dma mask is 0 (for BusLogic BT-445S VL-Bus
 *        controller).
 *  Modified by Matti Aarnio
 *        Accept parameters from LILO cmd-line. -- 1-Oct-94
 */

#ifdef MODULE
#include <linux/autoconf.h>
#include <linux/module.h>
#endif

#include <linux/kernel.h>
#include <linux/head.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include <asm/dma.h>
#include <asm/system.h>
#include <asm/io.h>
#include <linux/blk.h>
#include "scsi.h"
#include "hosts.h"


#include "aha1542.h"

#include<linux/stat.h>

struct proc_dir_entry proc_scsi_aha1542 = {
    PROC_SCSI_AHA1542, 7, "aha1542",
    S_IFDIR | S_IRUGO | S_IXUGO, 2
};

#ifdef DEBUG
#define DEB(x) x
#else
#define DEB(x)
#endif
/*
static const char RCSid[] = "$Header: /usr/src/linux/kernel/blk_drv/scsi/RCS/aha1542.c,v 1.1 1992/07/24 06:27:38 root Exp root $";
*/

/* The adaptec can be configured for quite a number of addresses, but
I generally do not want the card poking around at random.  We allow
two addresses - this allows people to use the Adaptec with a Midi
card, which also used 0x330 -- can be overridden with LILO! */

#define MAXBOARDS 2	/* Increase this and the sizes of the
			   arrays below, if you need more.. */

static unsigned int bases[MAXBOARDS]={0x330, 0x334};

/* set by aha1542_setup according to the command line */
static int setup_called[MAXBOARDS]   = {0,0};
static int setup_buson[MAXBOARDS]    = {0,0};
static int setup_busoff[MAXBOARDS]   = {0,0};
static int setup_dmaspeed[MAXBOARDS] = {-1,-1};

static char *setup_str[MAXBOARDS] = {(char *)NULL,(char *)NULL};

/*
 * LILO params:  aha1542=<PORTBASE>[,<BUSON>,<BUSOFF>[,<DMASPEED>]]
 *
 * Where:  <PORTBASE> is any of the valid AHA addresses:
 *			0x130, 0x134, 0x230, 0x234, 0x330, 0x334
 *	   <BUSON>  is the time (in microsecs) that AHA spends on the AT-bus
 *		    when transferring data.  1542A power-on default is 11us,
 *		    valid values are in range: 2..15 (decimal)
 *	   <BUSOFF> is the time that AHA spends OFF THE BUS after while
 *		    it is transferring data (not to monopolize the bus).
 *		    Power-on default is 4us, valid range: 1..64 microseconds.
 *	   <DMASPEED> Default is jumper selected (1542A: on the J1),
 *		    but experimenter can alter it with this.
 *		    Valid values: 5, 6, 7, 8, 10 (MB/s)
 *		    Factory default is 5 MB/s.
 */


/* The DMA-Controller.  We need to fool with this because we want to 
   be able to use the aha1542 without having to have the bios enabled */
#define DMA_MODE_REG	0xd6
#define DMA_MASK_REG	0xd4
#define	CASCADE		0xc0

#define BIOS_TRANSLATION_1632 0  /* Used by some old 1542A boards */
#define BIOS_TRANSLATION_6432 1 /* Default case these days */
#define BIOS_TRANSLATION_25563 2 /* Big disk case */

struct aha1542_hostdata{
	/* This will effectively start both of them at the first mailbox */
	int bios_translation;   /* Mapping bios uses - for compatibility */
	int aha1542_last_mbi_used;
	int aha1542_last_mbo_used;
	Scsi_Cmnd * SCint[AHA1542_MAILBOXES];
	struct mailbox mb[2*AHA1542_MAILBOXES];
	struct ccb ccb[AHA1542_MAILBOXES];
};

#define HOSTDATA(host) ((struct aha1542_hostdata *) &host->hostdata)

static struct Scsi_Host * aha_host[7] = {NULL,};  /* One for each IRQ level (9-15) */




#define WAITnexttimeout 3000000

static void setup_mailboxes(int base_io, struct Scsi_Host * shpnt);
static int aha1542_restart(struct Scsi_Host * shost);

#define aha1542_intr_reset(base)  outb(IRST, CONTROL(base))

#define WAIT(port, mask, allof, noneof)					\
 { register WAITbits;							\
   register WAITtimeout = WAITnexttimeout;				\
   while (1) {								\
     WAITbits = inb(port) & (mask);					\
     if ((WAITbits & (allof)) == (allof) && ((WAITbits & (noneof)) == 0)) \
       break;                                                         	\
     if (--WAITtimeout == 0) goto fail;					\
   }									\
 }

/* Similar to WAIT, except we use the udelay call to regulate the
   amount of time we wait.  */
#define WAITd(port, mask, allof, noneof, timeout)			\
 { register WAITbits;							\
   register WAITtimeout = timeout;					\
   while (1) {								\
     WAITbits = inb(port) & (mask);					\
     if ((WAITbits & (allof)) == (allof) && ((WAITbits & (noneof)) == 0)) \
       break;                                                         	\
     udelay(1000);							\
     if (--WAITtimeout == 0) goto fail;					\
   }									\
 }

static void aha1542_stat(void)
{
/*    int s = inb(STATUS), i = inb(INTRFLAGS);
  printk("status=%x intrflags=%x\n", s, i, WAITnexttimeout-WAITtimeout); */
}

/* This is a bit complicated, but we need to make sure that an interrupt
   routine does not send something out while we are in the middle of this.
   Fortunately, it is only at boot time that multi-byte messages
   are ever sent. */
static int aha1542_out(unsigned int base, unchar *cmdp, int len)
{
  unsigned long flags = 0;
  
  save_flags(flags);
  if(len == 1) {
    while(1==1){
	WAIT(STATUS(base), CDF, 0, CDF);
	cli();
	if(inb(STATUS(base)) & CDF) {restore_flags(flags); continue;}
	outb(*cmdp, DATA(base));
	restore_flags(flags);
	return 0;
      }
  } else {
    cli();
    while (len--)
      {
	WAIT(STATUS(base), CDF, 0, CDF);
	outb(*cmdp++, DATA(base));
      }
    restore_flags(flags);
  }
    return 0;
  fail:
    restore_flags(flags);
    printk("aha1542_out failed(%d): ", len+1); aha1542_stat();
    return 1;
}

/* Only used at boot time, so we do not need to worry about latency as much
   here */
static int aha1542_in(unsigned int base, unchar *cmdp, int len)
{
    unsigned long flags;

    save_flags(flags);
    cli();
    while (len--)
      {
	  WAIT(STATUS(base), DF, DF, 0);
	  *cmdp++ = inb(DATA(base));
      }
    restore_flags(flags);
    return 0;
  fail:
    restore_flags(flags);
    printk("aha1542_in failed(%d): ", len+1); aha1542_stat();
    return 1;
}

/* Similar to aha1542_in, except that we wait a very short period of time.
   We use this if we know the board is alive and awake, but we are not sure
   if the board will respond the the command we are about to send or not */
static int aha1542_in1(unsigned int base, unchar *cmdp, int len)
{
    unsigned long flags;
    
    save_flags(flags);
    cli();
    while (len--)
      {
	  WAITd(STATUS(base), DF, DF, 0, 100);
	  *cmdp++ = inb(DATA(base));
      }
    restore_flags(flags);
    return 0;
  fail:
    restore_flags(flags);
    return 1;
}

static int makecode(unsigned hosterr, unsigned scsierr)
{
    switch (hosterr) {
      case 0x0:
      case 0xa: /* Linked command complete without error and linked normally */
      case 0xb: /* Linked command complete without error, interrupt generated */
	hosterr = 0;
	break;

      case 0x11: /* Selection time out-The initiator selection or target
		    reselection was not complete within the SCSI Time out period */
	hosterr = DID_TIME_OUT;
	break;

      case 0x12: /* Data overrun/underrun-The target attempted to transfer more data
		    than was allocated by the Data Length field or the sum of the
		    Scatter / Gather Data Length fields. */

      case 0x13: /* Unexpected bus free-The target dropped the SCSI BSY at an unexpected time. */

      case 0x15: /* MBO command was not 00, 01 or 02-The first byte of the CB was
		    invalid. This usually indicates a software failure. */

      case 0x16: /* Invalid CCB Operation Code-The first byte of the CCB was invalid.
		    This usually indicates a software failure. */

      case 0x17: /* Linked CCB does not have the same LUN-A subsequent CCB of a set
		    of linked CCB's does not specify the same logical unit number as
		    the first. */
      case 0x18: /* Invalid Target Direction received from Host-The direction of a
		    Target Mode CCB was invalid. */

      case 0x19: /* Duplicate CCB Received in Target Mode-More than once CCB was
		    received to service data transfer between the same target LUN
		    and initiator SCSI ID in the same direction. */

      case 0x1a: /* Invalid CCB or Segment List Parameter-A segment list with a zero
		    length segment or invalid segment list boundaries was received.
		    A CCB parameter was invalid. */
	DEB(printk("Aha1542: %x %x\n", hosterr, scsierr));
	hosterr = DID_ERROR; /* Couldn't find any better */
	break;

      case 0x14: /* Target bus phase sequence failure-An invalid bus phase or bus
		    phase sequence was requested by the target. The host adapter
		    will generate a SCSI Reset Condition, notifying the host with
		    a SCRD interrupt */
	hosterr = DID_RESET;
	break;
      default:
	printk("makecode: unknown hoststatus %x\n", hosterr);
	break;
    }
    return scsierr|(hosterr << 16);
}

static int aha1542_test_port(int bse, struct Scsi_Host * shpnt)
{
    int i;
    unchar inquiry_cmd[] = {CMD_INQUIRY };
    unchar inquiry_result[4];
    unchar *cmdp;
    int len;
    volatile int debug = 0;
    
    /* Quick and dirty test for presence of the card. */
    if(inb(STATUS(bse)) == 0xff) return 0;

    /* Reset the adapter. I ought to make a hard reset, but it's not really necessary */
    
    /*  DEB(printk("aha1542_test_port called \n")); */

    /* In case some other card was probing here, reset interrupts */
    aha1542_intr_reset(bse);     /* reset interrupts, so they don't block */	

    outb(SRST|IRST/*|SCRST*/, CONTROL(bse));

    i = jiffies + 2;
    while (i>jiffies); /* Wait a little bit for things to settle down. */
    
    debug = 1;
    /* Expect INIT and IDLE, any of the others are bad */
    WAIT(STATUS(bse), STATMASK, INIT|IDLE, STST|DIAGF|INVDCMD|DF|CDF);
    
    debug = 2;
    /* Shouldn't have generated any interrupts during reset */
    if (inb(INTRFLAGS(bse))&INTRMASK) goto fail;


    /* Perform a host adapter inquiry instead so we do not need to set
       up the mailboxes ahead of time */

    aha1542_out(bse, inquiry_cmd, 1);

    debug = 3;
    len = 4;
    cmdp = &inquiry_result[0];

    while (len--)
      {
	  WAIT(STATUS(bse), DF, DF, 0);
	  *cmdp++ = inb(DATA(bse));
      }
    
    debug = 8;
    /* Reading port should reset DF */
    if (inb(STATUS(bse)) & DF) goto fail;
    
    debug = 9;
    /* When HACC, command is completed, and we're though testing */
    WAIT(INTRFLAGS(bse), HACC, HACC, 0);
    /* now initialize adapter */
    
    debug = 10;
    /* Clear interrupts */
    outb(IRST, CONTROL(bse));
    
    debug = 11;

    return debug;				/* 1 = ok */
  fail:
    return 0;					/* 0 = not ok */
}

/* A "high" level interrupt handler */
static void aha1542_intr_handle(int irq, struct pt_regs *regs)
{
    void (*my_done)(Scsi_Cmnd *) = NULL;
    int errstatus, mbi, mbo, mbistatus;
    int number_serviced;
    unsigned int flags;
    struct Scsi_Host * shost;
    Scsi_Cmnd * SCtmp;
    int flag;
    int needs_restart;
    struct mailbox * mb;
    struct ccb  *ccb;

    shost = aha_host[irq - 9];
    if(!shost) panic("Splunge!");

    mb = HOSTDATA(shost)->mb;
    ccb = HOSTDATA(shost)->ccb;

#ifdef DEBUG
    {
    flag = inb(INTRFLAGS(shost->io_port));
    printk("aha1542_intr_handle: ");
    if (!(flag&ANYINTR)) printk("no interrupt?");
    if (flag&MBIF) printk("MBIF ");
    if (flag&MBOA) printk("MBOF ");
    if (flag&HACC) printk("HACC ");
    if (flag&SCRD) printk("SCRD ");
    printk("status %02x\n", inb(STATUS(shost->io_port)));
  };
#endif
    number_serviced = 0;
    needs_restart = 0;

    while(1==1){
      flag = inb(INTRFLAGS(shost->io_port));

      /* Check for unusual interrupts.  If any of these happen, we should
	 probably do something special, but for now just printing a message
	 is sufficient.  A SCSI reset detected is something that we really
	 need to deal with in some way. */
      if (flag & ~MBIF) {
	if (flag&MBOA) printk("MBOF ");
	if (flag&HACC) printk("HACC ");
	if (flag&SCRD) {
	  needs_restart = 1;
	  printk("SCRD ");
	}
      }

      aha1542_intr_reset(shost->io_port);

      save_flags(flags);
      cli();
      mbi = HOSTDATA(shost)->aha1542_last_mbi_used + 1;
      if (mbi >= 2*AHA1542_MAILBOXES) mbi = AHA1542_MAILBOXES;
      
      do{
	if(mb[mbi].status != 0) break;
	mbi++;
	if (mbi >= 2*AHA1542_MAILBOXES) mbi = AHA1542_MAILBOXES;
      } while (mbi != HOSTDATA(shost)->aha1542_last_mbi_used);
      
      if(mb[mbi].status == 0){
	restore_flags(flags);
	/* Hmm, no mail.  Must have read it the last time around */
	if (!number_serviced && !needs_restart)
	  printk("aha1542.c: interrupt received, but no mail.\n");
	/* We detected a reset.  Restart all pending commands for
	   devices that use the hard reset option */
	if(needs_restart) aha1542_restart(shost);
	return;
      };

      mbo = (scsi2int(mb[mbi].ccbptr) - ((unsigned int) &ccb[0])) / sizeof(struct ccb);
      mbistatus = mb[mbi].status;
      mb[mbi].status = 0;
      HOSTDATA(shost)->aha1542_last_mbi_used = mbi;
      restore_flags(flags);
      
#ifdef DEBUG
      {
	if (ccb[mbo].tarstat|ccb[mbo].hastat)
	  printk("aha1542_command: returning %x (status %d)\n", 
		 ccb[mbo].tarstat + ((int) ccb[mbo].hastat << 16), mb[mbi].status);
      };
#endif

      if(mbistatus == 3) continue; /* Aborted command not found */

#ifdef DEBUG
      printk("...done %d %d\n",mbo, mbi);
#endif
      
      SCtmp = HOSTDATA(shost)->SCint[mbo];

      if (!SCtmp || !SCtmp->scsi_done) {
	printk("aha1542_intr_handle: Unexpected interrupt\n");
	printk("tarstat=%x, hastat=%x idlun=%x ccb#=%d \n", ccb[mbo].tarstat, 
	       ccb[mbo].hastat, ccb[mbo].idlun, mbo);
	return;
      }
      
      my_done = SCtmp->scsi_done;
      if (SCtmp->host_scribble) scsi_free(SCtmp->host_scribble, 512);
      
      /* Fetch the sense data, and tuck it away, in the required slot.  The
	 Adaptec automatically fetches it, and there is no guarantee that
	 we will still have it in the cdb when we come back */
      if (ccb[mbo].tarstat == 2)
	memcpy(SCtmp->sense_buffer, &ccb[mbo].cdb[ccb[mbo].cdblen], 
	       sizeof(SCtmp->sense_buffer));
      
      
      /* is there mail :-) */
      
      /* more error checking left out here */
      if (mbistatus != 1)
	/* This is surely wrong, but I don't know what's right */
	errstatus = makecode(ccb[mbo].hastat, ccb[mbo].tarstat);
      else
	errstatus = 0;
      
#ifdef DEBUG
      if(errstatus) printk("(aha1542 error:%x %x %x) ",errstatus, 
			   ccb[mbo].hastat, ccb[mbo].tarstat);
#endif

      if (ccb[mbo].tarstat == 2) {
#ifdef DEBUG
	int i;
#endif
	DEB(printk("aha1542_intr_handle: sense:"));
#ifdef DEBUG
	for (i = 0; i < 12; i++)
	  printk("%02x ", ccb[mbo].cdb[ccb[mbo].cdblen+i]);
	printk("\n");
#endif
	/*
	  DEB(printk("aha1542_intr_handle: buf:"));
	  for (i = 0; i < bufflen; i++)
	  printk("%02x ", ((unchar *)buff)[i]);
	  printk("\n");
	  */
      }
      DEB(if (errstatus) printk("aha1542_intr_handle: returning %6x\n", errstatus));
      SCtmp->result = errstatus;
      HOSTDATA(shost)->SCint[mbo] = NULL;  /* This effectively frees up the mailbox slot, as
			     far as queuecommand is concerned */
      my_done(SCtmp);
      number_serviced++;
    };
}

int aha1542_queuecommand(Scsi_Cmnd * SCpnt, void (*done)(Scsi_Cmnd *))
{
    unchar ahacmd = CMD_START_SCSI;
    unchar direction;
    unchar *cmd = (unchar *) SCpnt->cmnd;
    unchar target = SCpnt->target;
    unchar lun = SCpnt->lun;
    unsigned long flags;
    void *buff = SCpnt->request_buffer;
    int bufflen = SCpnt->request_bufflen;
    int mbo;
    struct mailbox * mb;
    struct ccb  *ccb;

    DEB(int i);

    mb = HOSTDATA(SCpnt->host)->mb;
    ccb = HOSTDATA(SCpnt->host)->ccb;

    DEB(if (target > 1) {
      SCpnt->result = DID_TIME_OUT << 16;
      done(SCpnt); return 0;});
    
    if(*cmd == REQUEST_SENSE){
#ifndef DEBUG
      if (bufflen != sizeof(SCpnt->sense_buffer)) {
	printk("Wrong buffer length supplied for request sense (%d)\n",bufflen);
      };
#endif
      SCpnt->result = 0;
      done(SCpnt); 
      return 0;
    };

#ifdef DEBUG
    if (*cmd == READ_10 || *cmd == WRITE_10)
      i = xscsi2int(cmd+2);
    else if (*cmd == READ_6 || *cmd == WRITE_6)
      i = scsi2int(cmd+2);
    else
      i = -1;
    if (done)
      printk("aha1542_queuecommand: dev %d cmd %02x pos %d len %d ", target, *cmd, i, bufflen);
    else
      printk("aha1542_command: dev %d cmd %02x pos %d len %d ", target, *cmd, i, bufflen);
    aha1542_stat();
    printk("aha1542_queuecommand: dumping scsi cmd:");
    for (i = 0; i < SCpnt->cmd_len; i++) printk("%02x ", cmd[i]);
    printk("\n");
    if (*cmd == WRITE_10 || *cmd == WRITE_6)
      return 0; /* we are still testing, so *don't* write */
#endif
/* Use the outgoing mailboxes in a round-robin fashion, because this
   is how the host adapter will scan for them */

    save_flags(flags);
    cli();
    mbo = HOSTDATA(SCpnt->host)->aha1542_last_mbo_used + 1;
    if (mbo >= AHA1542_MAILBOXES) mbo = 0;

    do{
      if(mb[mbo].status == 0 && HOSTDATA(SCpnt->host)->SCint[mbo] == NULL)
	break;
      mbo++;
      if (mbo >= AHA1542_MAILBOXES) mbo = 0;
    } while (mbo != HOSTDATA(SCpnt->host)->aha1542_last_mbo_used);

    if(mb[mbo].status || HOSTDATA(SCpnt->host)->SCint[mbo])
      panic("Unable to find empty mailbox for aha1542.\n");

    HOSTDATA(SCpnt->host)->SCint[mbo] = SCpnt;  /* This will effectively prevent someone else from
			    screwing with this cdb. */

    HOSTDATA(SCpnt->host)->aha1542_last_mbo_used = mbo;    
    restore_flags(flags);

#ifdef DEBUG
    printk("Sending command (%d %x)...",mbo, done);
#endif

    any2scsi(mb[mbo].ccbptr, &ccb[mbo]); /* This gets trashed for some reason*/

    memset(&ccb[mbo], 0, sizeof(struct ccb));

    ccb[mbo].cdblen = SCpnt->cmd_len;

    direction = 0;
    if (*cmd == READ_10 || *cmd == READ_6)
	direction = 8;
    else if (*cmd == WRITE_10 || *cmd == WRITE_6)
	direction = 16;

    memcpy(ccb[mbo].cdb, cmd, ccb[mbo].cdblen);

    if (SCpnt->use_sg) {
      struct scatterlist * sgpnt;
      struct chain * cptr;
#ifdef DEBUG
      unsigned char * ptr;
#endif
      int i;
      ccb[mbo].op = 2;	      /* SCSI Initiator Command  w/scatter-gather*/
      SCpnt->host_scribble = (unsigned char *) scsi_malloc(512);
      sgpnt = (struct scatterlist *) SCpnt->request_buffer;
      cptr = (struct chain *) SCpnt->host_scribble; 
      if (cptr == NULL) panic("aha1542.c: unable to allocate DMA memory\n");
      for(i=0; i<SCpnt->use_sg; i++) {
	if(sgpnt[i].length == 0 || SCpnt->use_sg > 16 || 
	   (((int)sgpnt[i].address) & 1) || (sgpnt[i].length & 1)){
	  unsigned char * ptr;
	  printk("Bad segment list supplied to aha1542.c (%d, %d)\n",SCpnt->use_sg,i);
	  for(i=0;i<SCpnt->use_sg;i++){
	    printk("%d: %x %x %d\n",i,(unsigned int) sgpnt[i].address, (unsigned int) sgpnt[i].alt_address,
		   sgpnt[i].length);
	  };
	  printk("cptr %x: ",(unsigned int) cptr);
	  ptr = (unsigned char *) &cptr[i];
	  for(i=0;i<18;i++) printk("%02x ", ptr[i]);
	  panic("Foooooooood fight!");
	};
	any2scsi(cptr[i].dataptr, sgpnt[i].address);
	if(((unsigned  int) sgpnt[i].address) & 0xff000000) goto baddma;
	any2scsi(cptr[i].datalen, sgpnt[i].length);
      };
      any2scsi(ccb[mbo].datalen, SCpnt->use_sg * sizeof(struct chain));
      any2scsi(ccb[mbo].dataptr, cptr);
#ifdef DEBUG
      printk("cptr %x: ",cptr);
      ptr = (unsigned char *) cptr;
      for(i=0;i<18;i++) printk("%02x ", ptr[i]);
#endif
    } else {
      ccb[mbo].op = 0;	      /* SCSI Initiator Command */
      SCpnt->host_scribble = NULL;
      any2scsi(ccb[mbo].datalen, bufflen);
      if(((unsigned int) buff & 0xff000000)) goto baddma;
      any2scsi(ccb[mbo].dataptr, buff);
    };
    ccb[mbo].idlun = (target&7)<<5 | direction | (lun & 7); /*SCSI Target Id*/
    ccb[mbo].rsalen = 12;
    ccb[mbo].linkptr[0] = ccb[mbo].linkptr[1] = ccb[mbo].linkptr[2] = 0;
    ccb[mbo].commlinkid = 0;

#ifdef DEBUG
    { int i;
    printk("aha1542_command: sending.. ");
    for (i = 0; i < sizeof(ccb[mbo])-10; i++)
      printk("%02x ", ((unchar *)&ccb[mbo])[i]);
    };
#endif
    
    if (done) {
	DEB(printk("aha1542_queuecommand: now waiting for interrupt "); aha1542_stat());
	SCpnt->scsi_done = done;
	mb[mbo].status = 1;
	aha1542_out(SCpnt->host->io_port, &ahacmd, 1);		/* start scsi command */
	DEB(aha1542_stat());
    }
    else
      printk("aha1542_queuecommand: done can't be NULL\n");
    
    return 0;
 baddma:
    panic("Buffer at address  > 16Mb used for 1542B");
}

static void internal_done(Scsi_Cmnd * SCpnt)
{
	SCpnt->SCp.Status++;
}

int aha1542_command(Scsi_Cmnd * SCpnt)
{
    DEB(printk("aha1542_command: ..calling aha1542_queuecommand\n"));

    aha1542_queuecommand(SCpnt, internal_done);

    SCpnt->SCp.Status = 0;
    while (!SCpnt->SCp.Status)
    	barrier();
    return SCpnt->result;
}

/* Initialize mailboxes */
static void setup_mailboxes(int bse, struct Scsi_Host * shpnt)
{
    int i;
    struct mailbox * mb;
    struct ccb  *ccb;

    unchar cmd[5] = {CMD_MBINIT, AHA1542_MAILBOXES, 0, 0, 0};

    mb = HOSTDATA(shpnt)->mb;
    ccb = HOSTDATA(shpnt)->ccb;

    for(i=0; i<AHA1542_MAILBOXES; i++){
      mb[i].status = mb[AHA1542_MAILBOXES+i].status = 0;
      any2scsi(mb[i].ccbptr, &ccb[i]);
    };
    aha1542_intr_reset(bse);     /* reset interrupts, so they don't block */	
    any2scsi((cmd+2), mb);
    aha1542_out(bse, cmd, 5);
    WAIT(INTRFLAGS(bse), INTRMASK, HACC, 0);
    while (0) {
      fail:
	printk("aha1542_detect: failed setting up mailboxes\n");
    }
    aha1542_intr_reset(bse);
}

static int aha1542_getconfig(int base_io, unsigned char * irq_level, unsigned char * dma_chan, unsigned char * scsi_id)
{
  unchar inquiry_cmd[] = {CMD_RETCONF };
  unchar inquiry_result[3];
  int i;
  i = inb(STATUS(base_io));
  if (i & DF) {
    i = inb(DATA(base_io));
  };
  aha1542_out(base_io, inquiry_cmd, 1);
  aha1542_in(base_io, inquiry_result, 3);
  WAIT(INTRFLAGS(base_io), INTRMASK, HACC, 0);
  while (0) {
  fail:
    printk("aha1542_detect: query board settings\n");
  }
  aha1542_intr_reset(base_io);
  switch(inquiry_result[0]){
  case 0x80:
    *dma_chan = 7;
    break;
  case 0x40:
    *dma_chan = 6;
    break;
  case 0x20:
    *dma_chan = 5;
    break;
  case 0x01:
    printk("DMA priority 0 not available for Adaptec driver\n");
    return -1;
  case 0:
    /* This means that the adapter, although Adaptec 1542 compatible, doesn't use a DMA channel.
       Currently only aware of the BusLogic BT-445S VL-Bus adapter which needs this. */
    *dma_chan = 0xFF;
    break;
  default:
    printk("Unable to determine Adaptec DMA priority.  Disabling board\n");
    return -1;
  };
  switch(inquiry_result[1]){
  case 0x40:
    *irq_level = 15;
    break;
  case 0x20:
    *irq_level = 14;
    break;
  case 0x8:
    *irq_level = 12;
    break;
  case 0x4:
    *irq_level = 11;
    break;
  case 0x2:
    *irq_level = 10;
    break;
  case 0x1:
    *irq_level = 9;
    break;
  default:
    printk("Unable to determine Adaptec IRQ level.  Disabling board\n");
    return -1;
  };
  *scsi_id=inquiry_result[2] & 7;
  return 0;
}

/* This function should only be called for 1542C boards - we can detect
   the special firmware settings and unlock the board */

static int aha1542_mbenable(int base)
{
  static unchar mbenable_cmd[3];
  static unchar mbenable_result[2];
  int retval;
  
  retval = BIOS_TRANSLATION_6432;

  mbenable_cmd[0]=CMD_EXTBIOS;
  aha1542_out(base,mbenable_cmd,1);
  if(aha1542_in1(base,mbenable_result,2))
    return retval;
  WAITd(INTRFLAGS(base),INTRMASK,HACC,0,100);
  aha1542_intr_reset(base);
  
  if ((mbenable_result[0] & 0x08) || mbenable_result[1]) {
     mbenable_cmd[0]=CMD_MBENABLE;
     mbenable_cmd[1]=0;
     mbenable_cmd[2]=mbenable_result[1];
     if(mbenable_result[1] & 1) retval = BIOS_TRANSLATION_25563;
     aha1542_out(base,mbenable_cmd,3);
     WAIT(INTRFLAGS(base),INTRMASK,HACC,0);
  };
  while(0) {
fail:
    printk("aha1542_mbenable: Mailbox init failed\n");
  }
aha1542_intr_reset(base);
return retval;
}

/* Query the board to find out if it is a 1542 or a 1740, or whatever. */
static int aha1542_query(int base_io, int * transl)
{
  unchar inquiry_cmd[] = {CMD_INQUIRY };
  unchar inquiry_result[4];
  int i;
  i = inb(STATUS(base_io));
  if (i & DF) {
    i = inb(DATA(base_io));
  };
  aha1542_out(base_io, inquiry_cmd, 1);
  aha1542_in(base_io, inquiry_result, 4);
  WAIT(INTRFLAGS(base_io), INTRMASK, HACC, 0);
  while (0) {
  fail:
    printk("aha1542_detect: query card type\n");
  }
  aha1542_intr_reset(base_io);

  *transl = BIOS_TRANSLATION_6432; /* Default case */

/* For an AHA1740 series board, we ignore the board since there is a
   hardware bug which can lead to wrong blocks being returned if the board
   is operating in the 1542 emulation mode.  Since there is an extended mode
   driver, we simply ignore the board and let the 1740 driver pick it up.
*/

  if (inquiry_result[0] == 0x43) {
    printk("aha1542.c: Emulation mode not supported for AHA 174N hardware.\n");
    return 1;
  };

  /* Always call this - boards that do not support extended bios translation
     will ignore the command, and we will set the proper default */

  *transl = aha1542_mbenable(base_io);

  return 0;
}

/* called from init/main.c */
void aha1542_setup( char *str, int *ints)
{
    const char *ahausage = "aha1542: usage: aha1542=<PORTBASE>[,<BUSON>,<BUSOFF>[,<DMASPEED>]]\n";
    static int setup_idx = 0;
    int setup_portbase;

    if(setup_idx >= MAXBOARDS)
      {
	printk("aha1542: aha1542_setup called too many times! Bad LILO params ?\n");
	printk("   Entryline 1: %s\n",setup_str[0]);
	printk("   Entryline 2: %s\n",setup_str[1]);
	printk("   This line:   %s\n",str);
	return;
      }
    if (ints[0] < 1 || ints[0] > 4)
      {
	printk("aha1542: %s\n", str );
	printk(ahausage);
	printk("aha1542: Wrong parameters may cause system malfunction.. We try anyway..\n");
      }

    setup_called[setup_idx]=ints[0];
    setup_str[setup_idx]=str;

    setup_portbase             = ints[0] >= 1 ? ints[1] : 0; /* Preserve the default value.. */
    setup_buson   [setup_idx]  = ints[0] >= 2 ? ints[2] : 7;
    setup_busoff  [setup_idx]  = ints[0] >= 3 ? ints[3] : 5;
    if (ints[0] >= 4) {
      int atbt = -1;
      switch (ints[4]) {
	case 5:
	    atbt = 0x00;
	    break;
	case 6:
	    atbt = 0x04;
	    break;
	case 7:
	    atbt = 0x01;
	    break;
	case 8:
	    atbt = 0x02;
	    break;
	case 10:
	    atbt = 0x03;
	    break;
	default:
	    printk("aha1542: %s\n", str );
	    printk(ahausage);
	    printk("aha1542: Valid values for DMASPEED are 5-8, 10 MB/s.  Using jumper defaults.\n");
	    break;
      }
      setup_dmaspeed[setup_idx]  = atbt;
    }

    if (setup_portbase != 0)
      bases[setup_idx] = setup_portbase;

    ++setup_idx;
}

/* return non-zero on detection */
int aha1542_detect(Scsi_Host_Template * tpnt)
{
    unsigned char dma_chan;
    unsigned char irq_level;
    unsigned char scsi_id;
    unsigned long flags;
    unsigned int base_io;
    int trans;
    struct Scsi_Host * shpnt = NULL;
    int count = 0;
    int indx;

    DEB(printk("aha1542_detect: \n"));

    tpnt->proc_dir = &proc_scsi_aha1542;

    for(indx = 0; indx < sizeof(bases)/sizeof(bases[0]); indx++)
	    if(bases[indx] != 0 && !check_region(bases[indx], 4)) { 
		    shpnt = scsi_register(tpnt,
					  sizeof(struct aha1542_hostdata));

		    /* For now we do this - until kmalloc is more intelligent
		       we are resigned to stupid hacks like this */
		    if ((unsigned int) shpnt > 0xffffff) {
		      printk("Invalid address for shpnt with 1542.\n");
		      goto unregister;
		    }

		    if(!aha1542_test_port(bases[indx], shpnt)) goto unregister;


		    base_io = bases[indx];
		    
		    /* Set the Bus on/off-times as not to ruin floppy performance */
	    {
		    unchar oncmd[] = {CMD_BUSON_TIME, 7};
		    unchar offcmd[] = {CMD_BUSOFF_TIME, 5};

		    if(setup_called[indx])
		      {
			oncmd[1]  = setup_buson[indx];
			offcmd[1] = setup_busoff[indx];
		      }
		    
		    aha1542_intr_reset(base_io);
		    aha1542_out(base_io, oncmd, 2);
		    WAIT(INTRFLAGS(base_io), INTRMASK, HACC, 0);
		    aha1542_intr_reset(base_io);
		    aha1542_out(base_io, offcmd, 2);
		    WAIT(INTRFLAGS(base_io), INTRMASK, HACC, 0);
		    if (setup_dmaspeed[indx] >= 0)
		      {
			unchar dmacmd[] = {CMD_DMASPEED, 0};
			dmacmd[1] = setup_dmaspeed[indx];
			aha1542_intr_reset(base_io);
			aha1542_out(base_io, dmacmd, 2);
			WAIT(INTRFLAGS(base_io), INTRMASK, HACC, 0);
		      }
		    while (0) {
		    fail:
			    printk("aha1542_detect: setting bus on/off-time failed\n");
		    }
		    aha1542_intr_reset(base_io);
	    }
		    if(aha1542_query(base_io, &trans))  goto unregister;
		    
		    if (aha1542_getconfig(base_io, &irq_level, &dma_chan, &scsi_id) == -1)  goto unregister;
		    
		    printk("Configuring Adaptec (SCSI-ID %d) at IO:%x, IRQ %d", scsi_id, base_io, irq_level);
		    if (dma_chan != 0xFF)
			    printk(", DMA priority %d", dma_chan);
		    printk("\n");
		    
		    DEB(aha1542_stat());
		    setup_mailboxes(base_io, shpnt);
		    
		    DEB(aha1542_stat());
		    
		    DEB(printk("aha1542_detect: enable interrupt channel %d\n", irq_level));
		    save_flags(flags);
		    cli();
		    if (request_irq(irq_level,aha1542_intr_handle, 0, "aha1542")) {
			    printk("Unable to allocate IRQ for adaptec controller.\n");
			    goto unregister;
		    }
		    
		    if (dma_chan != 0xFF) {
			    if (request_dma(dma_chan,"aha1542")) {
				    printk("Unable to allocate DMA channel for Adaptec.\n");
				    free_irq(irq_level);
				    goto unregister;
			    }
			    
			    if (dma_chan >= 5) {
				    outb((dma_chan - 4) | CASCADE, DMA_MODE_REG);
				    outb(dma_chan - 4, DMA_MASK_REG);
			    }
		    }
		    aha_host[irq_level - 9] = shpnt;
 		    shpnt->this_id = scsi_id;
 		    shpnt->unique_id = base_io;
		    shpnt->io_port = base_io;
		    shpnt->n_io_port = 4;  /* Number of bytes of I/O space used */
		    shpnt->dma_channel = dma_chan;
		    shpnt->irq = irq_level;
		    HOSTDATA(shpnt)->bios_translation  = trans;
		    if(trans == 2) 
		      printk("aha1542.c: Using extended bios translation\n");
		    HOSTDATA(shpnt)->aha1542_last_mbi_used  = (2*AHA1542_MAILBOXES - 1);
		    HOSTDATA(shpnt)->aha1542_last_mbo_used  = (AHA1542_MAILBOXES - 1);
		    memset(HOSTDATA(shpnt)->SCint, 0, sizeof(HOSTDATA(shpnt)->SCint));
		    restore_flags(flags);
#if 0
		    DEB(printk(" *** READ CAPACITY ***\n"));
		    
	    {
		    unchar buf[8];
		    static unchar cmd[] = {	READ_CAPACITY, 0, 0, 0, 0, 0, 0, 0, 0, 0};
		    int i;
		    
		    for (i = 0; i < sizeof(buf); ++i) buf[i] = 0x87;
		    for (i = 0; i < 2; ++i)
			    if (!aha1542_command(i, cmd, buf, sizeof(buf))) {
				    printk("aha_detect: LU %d sector_size %d device_size %d\n",
					   i, xscsi2int(buf+4), xscsi2int(buf));
			    }
	    }
		    
		    DEB(printk(" *** NOW RUNNING MY OWN TEST *** \n"));
		    
		    for (i = 0; i < 4; ++i)
		    {
			    unsigned char cmd[10];
			    static buffer[512];
			    
			    cmd[0] = READ_10;
			    cmd[1] = 0;
			    xany2scsi(cmd+2, i);
			    cmd[6] = 0;
			    cmd[7] = 0;
			    cmd[8] = 1;
			    cmd[9] = 0;
			    aha1542_command(0, cmd, buffer, 512);
		    }
#endif    
		    request_region(bases[indx], 4,"aha1542");  /* Register the IO ports that we use */
		    count++;
		    continue;
	    unregister:
		    scsi_unregister(shpnt);
		    continue;
		    
	    };
	
    return count;
}

static int aha1542_restart(struct Scsi_Host * shost)
{
  int i;
  int count = 0;
#if 0
  unchar ahacmd = CMD_START_SCSI;
#endif

  for(i=0; i< AHA1542_MAILBOXES; i++)
   if(HOSTDATA(shost)->SCint[i] && 
      !(HOSTDATA(shost)->SCint[i]->device->soft_reset))
     {
#if 0
	HOSTDATA(shost)->mb[i].status = 1; /* Indicate ready to restart... */
#endif
	count++;
     }     

  printk("Potential to restart %d stalled commands...\n", count);
#if 0
  /* start scsi command */
  if (count) aha1542_out(shost->io_port, &ahacmd, 1);
#endif
  return 0;
}

/* The abort command does not leave the device in a clean state where
   it is available to be used again.  Until this gets worked out, we will
   leave it commented out.  */

int aha1542_abort(Scsi_Cmnd * SCpnt)
{
#if 0
  unchar ahacmd = CMD_START_SCSI;
  unsigned long flags;
  struct mailbox * mb;
  int mbi, mbo, i;

  printk("In aha1542_abort: %x %x\n",
	 inb(STATUS(SCpnt->host->io_port)),
	 inb(INTRFLAGS(SCpnt->host->io_port)));

  save_flags(flags);
  cli();
  mb = HOSTDATA(SCpnt->host)->mb;
  mbi = HOSTDATA(SCpnt->host)->aha1542_last_mbi_used + 1;
  if (mbi >= 2*AHA1542_MAILBOXES) mbi = AHA1542_MAILBOXES;
  
  do{
    if(mb[mbi].status != 0) break;
    mbi++;
    if (mbi >= 2*AHA1542_MAILBOXES) mbi = AHA1542_MAILBOXES;
  } while (mbi != HOSTDATA(SCpnt->host)->aha1542_last_mbi_used);
  restore_flags(flags);

  if(mb[mbi].status) {
    printk("Lost interrupt discovered on irq %d - attempting to recover\n", 
	   SCpnt->host->irq);
    aha1542_intr_handle(SCpnt->host->irq, NULL);
    return 0;
  }

  /* OK, no lost interrupt.  Try looking to see how many pending commands
     we think we have. */

  for(i=0; i< AHA1542_MAILBOXES; i++)
   if(HOSTDATA(SCpnt->host)->SCint[i])
     {
       if(HOSTDATA(SCpnt->host)->SCint[i] == SCpnt) {
	 printk("Timed out command pending for %s\n",
		kdevname(SCpnt->request.rq_dev));
	 if (HOSTDATA(SCpnt->host)->mb[i].status) {
	   printk("OGMB still full - restarting\n");
	   aha1542_out(SCpnt->host->io_port, &ahacmd, 1);
	 };
       } else
	 printk("Other pending command %s\n",
		kdevname(SCpnt->request.rq_dev));
     }

#endif

    DEB(printk("aha1542_abort\n"));
#if 0
    save_flags(flags);
    cli();
    for(mbo = 0; mbo < AHA1542_MAILBOXES; mbo++)
      if (SCpnt == HOSTDATA(SCpnt->host)->SCint[mbo]){
	mb[mbo].status = 2;  /* Abort command */
	aha1542_out(SCpnt->host->io_port, &ahacmd, 1); /* start scsi command */
	restore_flags(flags);
	break;
      };
#endif
    return SCSI_ABORT_SNOOZE;
}

/* We do not implement a reset function here, but the upper level code
   assumes that it will get some kind of response for the command in
   SCpnt.  We must oblige, or the command will hang the scsi system.
   For a first go, we assume that the 1542 notifies us with all of the
   pending commands (it does implement soft reset, after all). */

int aha1542_reset(Scsi_Cmnd * SCpnt)
{
    unchar ahacmd = CMD_START_SCSI;
    int i;

    /*
     * See if a bus reset was suggested.
     */
    if( SCpnt->host->suggest_bus_reset )
      {
	/* 
	 * This does a scsi reset for all devices on the bus.
	 * In principle, we could also reset the 1542 - should
	 * we do this?  Try this first, and we can add that later
	 * if it turns out to be useful.
	 */
	outb(HRST | SCRST, CONTROL(SCpnt->host->io_port));

	/*
	 * Wait for the thing to settle down a bit.  Unfortunately
	 * this is going to basically lock up the machine while we
	 * wait for this to complete.  To be 100% correct, we need to
	 * check for timeout, and if we are doing something like this
	 * we are pretty desperate anyways.
	 */
	WAIT(STATUS(SCpnt->host->io_port), 
	     STATMASK, INIT|IDLE, STST|DIAGF|INVDCMD|DF|CDF);

	/*
	 * We need to do this too before the 1542 can interact with
	 * us again.
	 */
	setup_mailboxes(SCpnt->host->io_port, SCpnt->host);

	/*
	 * Now try and pick up the pieces.  Restart all commands
	 * that are currently active on the bus, and reset all of
	 * the datastructures.  We have some time to kill while
	 * things settle down, so print a nice message.
	 */
	printk("Sent BUS RESET to scsi host %d\n", SCpnt->host->host_no);

	for(i=0; i< AHA1542_MAILBOXES; i++)
	  if(HOSTDATA(SCpnt->host)->SCint[i] != NULL)
	    {
	      Scsi_Cmnd * SCtmp;
	      SCtmp = HOSTDATA(SCpnt->host)->SCint[i];
	      SCtmp->result = DID_RESET << 16;
	      if (SCtmp->host_scribble) scsi_free(SCtmp->host_scribble, 512);
	      printk("Sending DID_RESET for target %d\n", SCpnt->target);
	      SCtmp->scsi_done(SCpnt);
	      
	      HOSTDATA(SCpnt->host)->SCint[i] = NULL;
	      HOSTDATA(SCpnt->host)->mb[i].status = 0;
	    }
	/*
	 * Now tell the mid-level code what we did here.  Since
	 * we have restarted all of the outstanding commands,
	 * then report SUCCESS.
	 */
	return (SCSI_RESET_SUCCESS | SCSI_RESET_BUS_RESET);
fail:
	printk("aha1542.c: Unable to perform hard reset.\n");
	printk("Power cycle machine to reset\n");
	return (SCSI_RESET_ERROR | SCSI_RESET_BUS_RESET);


      }
    else
      {
	/* This does a selective reset of just the one device */
	/* First locate the ccb for this command */
	for(i=0; i< AHA1542_MAILBOXES; i++)
	  if(HOSTDATA(SCpnt->host)->SCint[i] == SCpnt)
	    {
	      HOSTDATA(SCpnt->host)->ccb[i].op = 0x81;  /* BUS DEVICE RESET */
	      /* Now tell the 1542 to flush all pending commands for this target */
	      aha1542_out(SCpnt->host->io_port, &ahacmd, 1);
	      
	      /* Here is the tricky part.  What to do next.  Do we get an interrupt
		 for the commands that we aborted with the specified target, or
		 do we generate this on our own?  Try it without first and see
		 what happens */
	      printk("Sent BUS DEVICE RESET to target %d\n", SCpnt->target);
	      
	      /* If the first does not work, then try the second.  I think the
		 first option is more likely to be correct. Free the command
		 block for all commands running on this target... */
	      for(i=0; i< AHA1542_MAILBOXES; i++)
		if(HOSTDATA(SCpnt->host)->SCint[i] &&
		   HOSTDATA(SCpnt->host)->SCint[i]->target == SCpnt->target)
		  {
		    Scsi_Cmnd * SCtmp;
		    SCtmp = HOSTDATA(SCpnt->host)->SCint[i];
		    SCtmp->result = DID_RESET << 16;
		    if (SCtmp->host_scribble) scsi_free(SCtmp->host_scribble, 512);
		    printk("Sending DID_RESET for target %d\n", SCpnt->target);
		    SCtmp->scsi_done(SCpnt);
		    
		    HOSTDATA(SCpnt->host)->SCint[i] = NULL;
		    HOSTDATA(SCpnt->host)->mb[i].status = 0;
		  }
	      return SCSI_RESET_SUCCESS;
	    }
      }
    /* No active command at this time, so this means that each time we got
       some kind of response the last time through.  Tell the mid-level code
       to request sense information in order to decide what to do next. */
    return SCSI_RESET_PUNT;
}

#include "sd.h"

int aha1542_biosparam(Scsi_Disk * disk, kdev_t dev, int * ip)
{
  int translation_algorithm;
  int size = disk->capacity;

  translation_algorithm = HOSTDATA(disk->device->host)->bios_translation;
  /* Should this be > 1024, or >= 1024?  Enquiring minds want to know. */
  if((size>>11) > 1024 && translation_algorithm == 2) {
    /* Please verify that this is the same as what DOS returns */
    ip[0] = 255;
    ip[1] = 63;
    ip[2] = size /255/63;
  } else {
    ip[0] = 64;
    ip[1] = 32;
    ip[2] = size >> 11;
  };
/*  if (ip[2] >= 1024) ip[2] = 1024; */
  return 0;
}


#ifdef MODULE
/* Eventually this will go into an include file, but this will be later */
Scsi_Host_Template driver_template = AHA1542;

#include "scsi_module.c"
#endif