- pre3:

[davej-history.git] / drivers / scsi / in2000.c

/*
 *    in2000.c -  Linux device driver for the
 *                Always IN2000 ISA SCSI card.
 *
 * Copyright (c) 1996 John Shifflett, GeoLog Consulting
 *    john@geolog.com
 *    jshiffle@netcom.com
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 *
 * Drew Eckhardt's excellent 'Generic NCR5380' sources provided
 * much of the inspiration and some of the code for this driver.
 * The Linux IN2000 driver distributed in the Linux kernels through
 * version 1.2.13 was an extremely valuable reference on the arcane
 * (and still mysterious) workings of the IN2000's fifo. It also
 * is where I lifted in2000_biosparam(), the gist of the card
 * detection scheme, and other bits of code. Many thanks to the
 * talented and courageous people who wrote, contributed to, and
 * maintained that driver (including Brad McLean, Shaun Savage,
 * Bill Earnest, Larry Doolittle, Roger Sunshine, John Luckey,
 * Matt Postiff, Peter Lu, zerucha@shell.portal.com, and Eric
 * Youngdale). I should also mention the driver written by
 * Hamish Macdonald for the (GASP!) Amiga A2091 card, included
 * in the Linux-m68k distribution; it gave me a good initial
 * understanding of the proper way to run a WD33c93 chip, and I
 * ended up stealing lots of code from it.
 *
 * _This_ driver is (I feel) an improvement over the old one in
 * several respects:
 *    -  All problems relating to the data size of a SCSI request are
 *          gone (as far as I know). The old driver couldn't handle
 *          swapping to partitions because that involved 4k blocks, nor
 *          could it deal with the st.c tape driver unmodified, because
 *          that usually involved 4k - 32k blocks. The old driver never
 *          quite got away from a morbid dependence on 2k block sizes -
 *          which of course is the size of the card's fifo.
 *
 *    -  Target Disconnection/Reconnection is now supported. Any
 *          system with more than one device active on the SCSI bus
 *          will benefit from this. The driver defaults to what I'm
 *          calling 'adaptive disconnect' - meaning that each command
 *          is evaluated individually as to whether or not it should
 *          be run with the option to disconnect/reselect (if the
 *          device chooses), or as a "SCSI-bus-hog".
 *
 *    -  Synchronous data transfers are now supported. Because there
 *          are a few devices (and many improperly terminated systems)
 *          that choke when doing sync, the default is sync DISABLED
 *          for all devices. This faster protocol can (and should!)
 *          be enabled on selected devices via the command-line.
 *
 *    -  Runtime operating parameters can now be specified through
 *       either the LILO or the 'insmod' command line. For LILO do:
 *          "in2000=blah,blah,blah"
 *       and with insmod go like:
 *          "insmod /usr/src/linux/modules/in2000.o setup_strings=blah,blah"
 *       The defaults should be good for most people. See the comment
 *       for 'setup_strings' below for more details.
 *
 *    -  The old driver relied exclusively on what the Western Digital
 *          docs call "Combination Level 2 Commands", which are a great
 *          idea in that the CPU is relieved of a lot of interrupt
 *          overhead. However, by accepting a certain (user-settable)
 *          amount of additional interrupts, this driver achieves
 *          better control over the SCSI bus, and data transfers are
 *          almost as fast while being much easier to define, track,
 *          and debug.
 *
 *    -  You can force detection of a card whose BIOS has been disabled.
 *
 *    -  Multiple IN2000 cards might almost be supported. I've tried to
 *       keep it in mind, but have no way to test...
 *
 *
 * TODO:
 *       tagged queuing. multiple cards.
 *
 *
 * NOTE:
 *       When using this or any other SCSI driver as a module, you'll
 *       find that with the stock kernel, at most _two_ SCSI hard
 *       drives will be linked into the device list (ie, usable).
 *       If your IN2000 card has more than 2 disks on its bus, you
 *       might want to change the define of 'SD_EXTRA_DEVS' in the
 *       'hosts.h' file from 2 to whatever is appropriate. It took
 *       me a while to track down this surprisingly obscure and
 *       undocumented little "feature".
 *
 *
 * People with bug reports, wish-lists, complaints, comments,
 * or improvements are asked to pah-leeez email me (John Shifflett)
 * at john@geolog.com or jshiffle@netcom.com! I'm anxious to get
 * this thing into as good a shape as possible, and I'm positive
 * there are lots of lurking bugs and "Stupid Places".
 *
 */

#include <linux/module.h>

#include <asm/system.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <asm/io.h>
#include <linux/ioport.h>
#include <linux/blkdev.h>

#include <linux/blk.h>
#include <linux/stat.h>

#include "scsi.h"
#include "sd.h"
#include "hosts.h"

#define IN2000_VERSION    "1.33"
#define IN2000_DATE       "26/August/1998"

#include "in2000.h"


/*
 * 'setup_strings' is a single string used to pass operating parameters and
 * settings from the kernel/module command-line to the driver. 'setup_args[]'
 * is an array of strings that define the compile-time default values for
 * these settings. If Linux boots with a LILO or insmod command-line, those
 * settings are combined with 'setup_args[]'. Note that LILO command-lines
 * are prefixed with "in2000=" while insmod uses a "setup_strings=" prefix.
 * The driver recognizes the following keywords (lower case required) and
 * arguments:
 *
 * -  ioport:addr    -Where addr is IO address of a (usually ROM-less) card.
 * -  noreset        -No optional args. Prevents SCSI bus reset at boot time.
 * -  nosync:x       -x is a bitmask where the 1st 7 bits correspond with
 *                    the 7 possible SCSI devices (bit 0 for device #0, etc).
 *                    Set a bit to PREVENT sync negotiation on that device.
 *                    The driver default is sync DISABLED on all devices.
 * -  period:ns      -ns is the minimum # of nanoseconds in a SCSI data transfer
 *                    period. Default is 500; acceptable values are 250 - 1000.
 * -  disconnect:x   -x = 0 to never allow disconnects, 2 to always allow them.
 *                    x = 1 does 'adaptive' disconnects, which is the default
 *                    and generally the best choice.
 * -  debug:x        -If 'DEBUGGING_ON' is defined, x is a bitmask that causes
 *                    various types of debug output to printed - see the DB_xxx
 *                    defines in in2000.h
 * -  proc:x         -If 'PROC_INTERFACE' is defined, x is a bitmask that
 *                    determines how the /proc interface works and what it
 *                    does - see the PR_xxx defines in in2000.h
 *
 * Syntax Notes:
 * -  Numeric arguments can be decimal or the '0x' form of hex notation. There
 *    _must_ be a colon between a keyword and its numeric argument, with no
 *    spaces.
 * -  Keywords are separated by commas, no spaces, in the standard kernel
 *    command-line manner.
 * -  A keyword in the 'nth' comma-separated command-line member will overwrite
 *    the 'nth' element of setup_args[]. A blank command-line member (in
 *    other words, a comma with no preceding keyword) will _not_ overwrite
 *    the corresponding setup_args[] element.
 *
 * A few LILO examples (for insmod, use 'setup_strings' instead of 'in2000'):
 * -  in2000=ioport:0x220,noreset
 * -  in2000=period:250,disconnect:2,nosync:0x03
 * -  in2000=debug:0x1e
 * -  in2000=proc:3
 */

/* Normally, no defaults are specified... */
static char *setup_args[] =
      {"","","","","","","","",""};

/* filled in by 'insmod' */
static char *setup_strings = 0;

#ifdef MODULE_PARM
MODULE_PARM(setup_strings, "s");
#endif


static struct Scsi_Host *instance_list = 0;



static inline uchar read_3393(struct IN2000_hostdata *hostdata, uchar reg_num)
{
   write1_io(reg_num,IO_WD_ADDR);
   return read1_io(IO_WD_DATA);
}


#define READ_AUX_STAT() read1_io(IO_WD_ASR)


static inline void write_3393(struct IN2000_hostdata *hostdata, uchar reg_num, uchar value)
{
   write1_io(reg_num,IO_WD_ADDR);
   write1_io(value,IO_WD_DATA);
}


static inline void write_3393_cmd(struct IN2000_hostdata *hostdata, uchar cmd)
{
/*   while (READ_AUX_STAT() & ASR_CIP)
      printk("|");*/
   write1_io(WD_COMMAND,IO_WD_ADDR);
   write1_io(cmd,IO_WD_DATA);
}


static uchar read_1_byte(struct IN2000_hostdata *hostdata)
{
uchar asr, x = 0;

   write_3393(hostdata,WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
   write_3393_cmd(hostdata,WD_CMD_TRANS_INFO|0x80);
   do {
      asr = READ_AUX_STAT();
      if (asr & ASR_DBR)
         x = read_3393(hostdata,WD_DATA);
      } while (!(asr & ASR_INT));
   return x;
}


static void write_3393_count(struct IN2000_hostdata *hostdata, unsigned long value)
{
   write1_io(WD_TRANSFER_COUNT_MSB,IO_WD_ADDR);
   write1_io((value >> 16),IO_WD_DATA);
   write1_io((value >> 8),IO_WD_DATA);
   write1_io(value,IO_WD_DATA);
}


static unsigned long read_3393_count(struct IN2000_hostdata *hostdata)
{
unsigned long value;

   write1_io(WD_TRANSFER_COUNT_MSB,IO_WD_ADDR);
   value = read1_io(IO_WD_DATA) << 16;
   value |= read1_io(IO_WD_DATA) << 8;
   value |= read1_io(IO_WD_DATA);
   return value;
}


/* The 33c93 needs to be told which direction a command transfers its
 * data; we use this function to figure it out. Returns true if there
 * will be a DATA_OUT phase with this command, false otherwise.
 * (Thanks to Joerg Dorchain for the research and suggestion.)
 */
static int is_dir_out(Scsi_Cmnd *cmd)
{
   switch (cmd->cmnd[0]) {
      case WRITE_6:           case WRITE_10:          case WRITE_12:
      case WRITE_LONG:        case WRITE_SAME:        case WRITE_BUFFER:
      case WRITE_VERIFY:      case WRITE_VERIFY_12:      
      case COMPARE:           case COPY:              case COPY_VERIFY:
      case SEARCH_EQUAL:      case SEARCH_HIGH:       case SEARCH_LOW:
      case SEARCH_EQUAL_12:   case SEARCH_HIGH_12:    case SEARCH_LOW_12:      
      case FORMAT_UNIT:       case REASSIGN_BLOCKS:   case RESERVE:
      case MODE_SELECT:       case MODE_SELECT_10:    case LOG_SELECT:
      case SEND_DIAGNOSTIC:   case CHANGE_DEFINITION: case UPDATE_BLOCK:
      case SET_WINDOW:        case MEDIUM_SCAN:       case SEND_VOLUME_TAG:
      case 0xea:
         return 1;
      default:
         return 0;
      }
}



static struct sx_period sx_table[] = {
   {  1, 0x20},
   {252, 0x20},
   {376, 0x30},
   {500, 0x40},
   {624, 0x50},
   {752, 0x60},
   {876, 0x70},
   {1000,0x00},
   {0,   0} };

static int round_period(unsigned int period)
{
int x;

   for (x=1; sx_table[x].period_ns; x++) {
      if ((period <= sx_table[x-0].period_ns) &&
          (period >  sx_table[x-1].period_ns)) {
         return x;
         }
      }
   return 7;
}

static uchar calc_sync_xfer(unsigned int period, unsigned int offset)
{
uchar result;

   period *= 4;   /* convert SDTR code to ns */
   result = sx_table[round_period(period)].reg_value;
   result |= (offset < OPTIMUM_SX_OFF)?offset:OPTIMUM_SX_OFF;
   return result;
}



static void in2000_execute(struct Scsi_Host *instance);

int in2000_queuecommand (Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *))
{
struct IN2000_hostdata *hostdata;
Scsi_Cmnd *tmp;
unsigned long flags;

   hostdata = (struct IN2000_hostdata *)cmd->host->hostdata;

DB(DB_QUEUE_COMMAND,printk("Q-%d-%02x-%ld(",cmd->target,cmd->cmnd[0],cmd->pid))

/* Set up a few fields in the Scsi_Cmnd structure for our own use:
 *  - host_scribble is the pointer to the next cmd in the input queue
 *  - scsi_done points to the routine we call when a cmd is finished
 *  - result is what you'd expect
 */

   cmd->host_scribble = NULL;
   cmd->scsi_done = done;
   cmd->result = 0;

/* We use the Scsi_Pointer structure that's included with each command
 * as a scratchpad (as it's intended to be used!). The handy thing about
 * the SCp.xxx fields is that they're always associated with a given
 * cmd, and are preserved across disconnect-reselect. This means we
 * can pretty much ignore SAVE_POINTERS and RESTORE_POINTERS messages
 * if we keep all the critical pointers and counters in SCp:
 *  - SCp.ptr is the pointer into the RAM buffer
 *  - SCp.this_residual is the size of that buffer
 *  - SCp.buffer points to the current scatter-gather buffer
 *  - SCp.buffers_residual tells us how many S.G. buffers there are
 *  - SCp.have_data_in helps keep track of >2048 byte transfers
 *  - SCp.sent_command is not used
 *  - SCp.phase records this command's SRCID_ER bit setting
 */

   if (cmd->use_sg) {
      cmd->SCp.buffer = (struct scatterlist *)cmd->buffer;
      cmd->SCp.buffers_residual = cmd->use_sg - 1;
      cmd->SCp.ptr = (char *)cmd->SCp.buffer->address;
      cmd->SCp.this_residual = cmd->SCp.buffer->length;
      }
   else {
      cmd->SCp.buffer = NULL;
      cmd->SCp.buffers_residual = 0;
      cmd->SCp.ptr = (char *)cmd->request_buffer;
      cmd->SCp.this_residual = cmd->request_bufflen;
      }
   cmd->SCp.have_data_in = 0;

/* We don't set SCp.phase here - that's done in in2000_execute() */

/* WD docs state that at the conclusion of a "LEVEL2" command, the
 * status byte can be retrieved from the LUN register. Apparently,
 * this is the case only for *uninterrupted* LEVEL2 commands! If
 * there are any unexpected phases entered, even if they are 100%
 * legal (different devices may choose to do things differently),
 * the LEVEL2 command sequence is exited. This often occurs prior
 * to receiving the status byte, in which case the driver does a
 * status phase interrupt and gets the status byte on its own.
 * While such a command can then be "resumed" (ie restarted to
 * finish up as a LEVEL2 command), the LUN register will NOT be
 * a valid status byte at the command's conclusion, and we must
 * use the byte obtained during the earlier interrupt. Here, we
 * preset SCp.Status to an illegal value (0xff) so that when
 * this command finally completes, we can tell where the actual
 * status byte is stored.
 */

   cmd->SCp.Status = ILLEGAL_STATUS_BYTE;

/* We need to disable interrupts before messing with the input
 * queue and calling in2000_execute().
 */

   save_flags(flags);
   cli();

   /*
    * Add the cmd to the end of 'input_Q'. Note that REQUEST_SENSE
    * commands are added to the head of the queue so that the desired
    * sense data is not lost before REQUEST_SENSE executes.
    */

   if (!(hostdata->input_Q) || (cmd->cmnd[0] == REQUEST_SENSE)) {
      cmd->host_scribble = (uchar *)hostdata->input_Q;
      hostdata->input_Q = cmd;
      }
   else {   /* find the end of the queue */
      for (tmp=(Scsi_Cmnd *)hostdata->input_Q; tmp->host_scribble;
            tmp=(Scsi_Cmnd *)tmp->host_scribble)
         ;
      tmp->host_scribble = (uchar *)cmd;
      }

/* We know that there's at least one command in 'input_Q' now.
 * Go see if any of them are runnable!
 */

   in2000_execute(cmd->host);

DB(DB_QUEUE_COMMAND,printk(")Q-%ld ",cmd->pid))

   restore_flags(flags);
   return 0;
}



/*
 * This routine attempts to start a scsi command. If the host_card is
 * already connected, we give up immediately. Otherwise, look through
 * the input_Q, using the first command we find that's intended
 * for a currently non-busy target/lun.
 * Note that this function is always called with interrupts already
 * disabled (either from in2000_queuecommand() or in2000_intr()).
 */
static void in2000_execute (struct Scsi_Host *instance)
{
struct IN2000_hostdata *hostdata;
Scsi_Cmnd *cmd, *prev;
int i;
unsigned short *sp;
unsigned short f;
unsigned short flushbuf[16];


   hostdata = (struct IN2000_hostdata *)instance->hostdata;

DB(DB_EXECUTE,printk("EX("))

   if (hostdata->selecting || hostdata->connected) {

DB(DB_EXECUTE,printk(")EX-0 "))

      return;
      }

    /*
     * Search through the input_Q for a command destined
     * for an idle target/lun.
     */

   cmd = (Scsi_Cmnd *)hostdata->input_Q;
   prev = 0;
   while (cmd) {
      if (!(hostdata->busy[cmd->target] & (1 << cmd->lun)))
         break;
      prev = cmd;
      cmd = (Scsi_Cmnd *)cmd->host_scribble;
      }

   /* quit if queue empty or all possible targets are busy */

   if (!cmd) {

DB(DB_EXECUTE,printk(")EX-1 "))

      return;
      }

   /*  remove command from queue */
   
   if (prev)
      prev->host_scribble = cmd->host_scribble;
   else
      hostdata->input_Q = (Scsi_Cmnd *)cmd->host_scribble;

#ifdef PROC_STATISTICS
   hostdata->cmd_cnt[cmd->target]++;
#endif

/*
 * Start the selection process
 */

   if (is_dir_out(cmd))
      write_3393(hostdata,WD_DESTINATION_ID, cmd->target);
   else
      write_3393(hostdata,WD_DESTINATION_ID, cmd->target | DSTID_DPD);

/* Now we need to figure out whether or not this command is a good
 * candidate for disconnect/reselect. We guess to the best of our
 * ability, based on a set of hierarchical rules. When several
 * devices are operating simultaneously, disconnects are usually
 * an advantage. In a single device system, or if only 1 device
 * is being accessed, transfers usually go faster if disconnects
 * are not allowed:
 *
 * + Commands should NEVER disconnect if hostdata->disconnect =
 *   DIS_NEVER (this holds for tape drives also), and ALWAYS
 *   disconnect if hostdata->disconnect = DIS_ALWAYS.
 * + Tape drive commands should always be allowed to disconnect.
 * + Disconnect should be allowed if disconnected_Q isn't empty.
 * + Commands should NOT disconnect if input_Q is empty.
 * + Disconnect should be allowed if there are commands in input_Q
 *   for a different target/lun. In this case, the other commands
 *   should be made disconnect-able, if not already.
 *
 * I know, I know - this code would flunk me out of any
 * "C Programming 101" class ever offered. But it's easy
 * to change around and experiment with for now.
 */

   cmd->SCp.phase = 0;  /* assume no disconnect */
   if (hostdata->disconnect == DIS_NEVER)
      goto no;
   if (hostdata->disconnect == DIS_ALWAYS)
      goto yes;
   if (cmd->device->type == 1)   /* tape drive? */
      goto yes;
   if (hostdata->disconnected_Q) /* other commands disconnected? */
      goto yes;
   if (!(hostdata->input_Q))     /* input_Q empty? */
      goto no;
   for (prev=(Scsi_Cmnd *)hostdata->input_Q; prev;
         prev=(Scsi_Cmnd *)prev->host_scribble) {
      if ((prev->target != cmd->target) || (prev->lun != cmd->lun)) {
         for (prev=(Scsi_Cmnd *)hostdata->input_Q; prev;
               prev=(Scsi_Cmnd *)prev->host_scribble)
            prev->SCp.phase = 1;
         goto yes;
         }
      }
   goto no;

yes:
   cmd->SCp.phase = 1;

#ifdef PROC_STATISTICS
   hostdata->disc_allowed_cnt[cmd->target]++;
#endif

no:
   write_3393(hostdata,WD_SOURCE_ID,((cmd->SCp.phase)?SRCID_ER:0));

   write_3393(hostdata,WD_TARGET_LUN, cmd->lun);
   write_3393(hostdata,WD_SYNCHRONOUS_TRANSFER,hostdata->sync_xfer[cmd->target]);
   hostdata->busy[cmd->target] |= (1 << cmd->lun);

   if ((hostdata->level2 <= L2_NONE) ||
       (hostdata->sync_stat[cmd->target] == SS_UNSET)) {

         /*
          * Do a 'Select-With-ATN' command. This will end with
          * one of the following interrupts:
          *    CSR_RESEL_AM:  failure - can try again later.
          *    CSR_TIMEOUT:   failure - give up.
          *    CSR_SELECT:    success - proceed.
          */

      hostdata->selecting = cmd;

/* Every target has its own synchronous transfer setting, kept in
 * the sync_xfer array, and a corresponding status byte in sync_stat[].
 * Each target's sync_stat[] entry is initialized to SS_UNSET, and its
 * sync_xfer[] entry is initialized to the default/safe value. SS_UNSET
 * means that the parameters are undetermined as yet, and that we
 * need to send an SDTR message to this device after selection is
 * complete. We set SS_FIRST to tell the interrupt routine to do so,
 * unless we don't want to even _try_ synchronous transfers: In this
 * case we set SS_SET to make the defaults final.
 */
      if (hostdata->sync_stat[cmd->target] == SS_UNSET) {
         if (hostdata->sync_off & (1 << cmd->target))
            hostdata->sync_stat[cmd->target] = SS_SET;
         else
            hostdata->sync_stat[cmd->target] = SS_FIRST;
         }
      hostdata->state = S_SELECTING;
      write_3393_count(hostdata,0); /* this guarantees a DATA_PHASE interrupt */
      write_3393_cmd(hostdata,WD_CMD_SEL_ATN);
      }

   else {

         /*
          * Do a 'Select-With-ATN-Xfer' command. This will end with
          * one of the following interrupts:
          *    CSR_RESEL_AM:  failure - can try again later.
          *    CSR_TIMEOUT:   failure - give up.
          *    anything else: success - proceed.
          */

      hostdata->connected = cmd;
      write_3393(hostdata,WD_COMMAND_PHASE, 0);

   /* copy command_descriptor_block into WD chip
    * (take advantage of auto-incrementing)
    */

      write1_io(WD_CDB_1, IO_WD_ADDR);
      for (i=0; i<cmd->cmd_len; i++)
         write1_io(cmd->cmnd[i], IO_WD_DATA);

   /* The wd33c93 only knows about Group 0, 1, and 5 commands when
    * it's doing a 'select-and-transfer'. To be safe, we write the
    * size of the CDB into the OWN_ID register for every case. This
    * way there won't be problems with vendor-unique, audio, etc.
    */

      write_3393(hostdata, WD_OWN_ID, cmd->cmd_len);

   /* When doing a non-disconnect command, we can save ourselves a DATA
    * phase interrupt later by setting everything up now. With writes we
    * need to pre-fill the fifo; if there's room for the 32 flush bytes,
    * put them in there too - that'll avoid a fifo interrupt. Reads are
    * somewhat simpler.
    * KLUDGE NOTE: It seems that you can't completely fill the fifo here:
    * This results in the IO_FIFO_COUNT register rolling over to zero,
    * and apparently the gate array logic sees this as empty, not full,
    * so the 3393 chip is never signalled to start reading from the
    * fifo. Or maybe it's seen as a permanent fifo interrupt condition.
    * Regardless, we fix this by temporarily pretending that the fifo
    * is 16 bytes smaller. (I see now that the old driver has a comment
    * about "don't fill completely" in an analogous place - must be the
    * same deal.) This results in CDROM, swap partitions, and tape drives
    * needing an extra interrupt per write command - I think we can live
    * with that!
    */

      if (!(cmd->SCp.phase)) {
         write_3393_count(hostdata, cmd->SCp.this_residual);
         write_3393(hostdata,WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_BUS);
         write1_io(0, IO_FIFO_WRITE);  /* clear fifo counter, write mode */

         if (is_dir_out(cmd)) {
            hostdata->fifo = FI_FIFO_WRITING;
            if ((i = cmd->SCp.this_residual) > (IN2000_FIFO_SIZE - 16) )
               i = IN2000_FIFO_SIZE - 16;
            cmd->SCp.have_data_in = i;    /* this much data in fifo */
            i >>= 1;                      /* Gulp. Assuming modulo 2. */
            sp = (unsigned short *)cmd->SCp.ptr;
            f = hostdata->io_base + IO_FIFO;

#ifdef FAST_WRITE_IO

            FAST_WRITE2_IO();
#else
            while (i--)
               write2_io(*sp++,IO_FIFO);

#endif

      /* Is there room for the flush bytes? */

            if (cmd->SCp.have_data_in <= ((IN2000_FIFO_SIZE - 16) - 32)) {
               sp = flushbuf;
               i = 16;

#ifdef FAST_WRITE_IO

               FAST_WRITE2_IO();
#else
               while (i--)
                  write2_io(0,IO_FIFO);

#endif

               }
            }

         else {
            write1_io(0, IO_FIFO_READ);   /* put fifo in read mode */
            hostdata->fifo = FI_FIFO_READING;
            cmd->SCp.have_data_in = 0;    /* nothing transfered yet */
            }

         }
      else {
         write_3393_count(hostdata,0); /* this guarantees a DATA_PHASE interrupt */
         }
      hostdata->state = S_RUNNING_LEVEL2;
      write_3393_cmd(hostdata,WD_CMD_SEL_ATN_XFER);
      }

   /*
    * Since the SCSI bus can handle only 1 connection at a time,
    * we get out of here now. If the selection fails, or when
    * the command disconnects, we'll come back to this routine
    * to search the input_Q again...
    */
      
DB(DB_EXECUTE,printk("%s%ld)EX-2 ",(cmd->SCp.phase)?"d:":"",cmd->pid))

}



static void transfer_pio(uchar *buf, int cnt,
                  int data_in_dir, struct IN2000_hostdata *hostdata)
{
uchar asr;

DB(DB_TRANSFER,printk("(%p,%d,%s)",buf,cnt,data_in_dir?"in":"out"))

   write_3393(hostdata,WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
   write_3393_count(hostdata,cnt);
   write_3393_cmd(hostdata,WD_CMD_TRANS_INFO);
   if (data_in_dir) {
      do {
         asr = READ_AUX_STAT();
         if (asr & ASR_DBR)
            *buf++ = read_3393(hostdata,WD_DATA);
         } while (!(asr & ASR_INT));
      }
   else {
      do {
         asr = READ_AUX_STAT();
         if (asr & ASR_DBR)
            write_3393(hostdata,WD_DATA, *buf++);
         } while (!(asr & ASR_INT));
      }

   /* Note: we are returning with the interrupt UN-cleared.
   * Since (presumably) an entire I/O operation has
   * completed, the bus phase is probably different, and
   * the interrupt routine will discover this when it
   * responds to the uncleared int.
   */

}



static void transfer_bytes(Scsi_Cmnd *cmd, int data_in_dir)
{
struct IN2000_hostdata *hostdata;
unsigned short *sp;
unsigned short f;
int i;

   hostdata = (struct IN2000_hostdata *)cmd->host->hostdata;

/* Normally, you'd expect 'this_residual' to be non-zero here.
 * In a series of scatter-gather transfers, however, this
 * routine will usually be called with 'this_residual' equal
 * to 0 and 'buffers_residual' non-zero. This means that a
 * previous transfer completed, clearing 'this_residual', and
 * now we need to setup the next scatter-gather buffer as the
 * source or destination for THIS transfer.
 */
   if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
      ++cmd->SCp.buffer;
      --cmd->SCp.buffers_residual;
      cmd->SCp.this_residual = cmd->SCp.buffer->length;
      cmd->SCp.ptr = cmd->SCp.buffer->address;
      }

/* Set up hardware registers */

   write_3393(hostdata,WD_SYNCHRONOUS_TRANSFER,hostdata->sync_xfer[cmd->target]);
   write_3393_count(hostdata,cmd->SCp.this_residual);
   write_3393(hostdata,WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_BUS);
   write1_io(0,IO_FIFO_WRITE); /* zero counter, assume write */

/* Reading is easy. Just issue the command and return - we'll
 * get an interrupt later when we have actual data to worry about.
 */

   if (data_in_dir) {
      write1_io(0,IO_FIFO_READ);
      if ((hostdata->level2 >= L2_DATA) ||
          (hostdata->level2 == L2_BASIC && cmd->SCp.phase == 0)) {
         write_3393(hostdata,WD_COMMAND_PHASE,0x45);
         write_3393_cmd(hostdata,WD_CMD_SEL_ATN_XFER);
         hostdata->state = S_RUNNING_LEVEL2;
         }
      else
         write_3393_cmd(hostdata,WD_CMD_TRANS_INFO);
      hostdata->fifo = FI_FIFO_READING;
      cmd->SCp.have_data_in = 0;
      return;
      }

/* Writing is more involved - we'll start the WD chip and write as
 * much data to the fifo as we can right now. Later interrupts will
 * write any bytes that don't make it at this stage.
 */

      if ((hostdata->level2 >= L2_DATA) ||
          (hostdata->level2 == L2_BASIC && cmd->SCp.phase == 0)) {
      write_3393(hostdata,WD_COMMAND_PHASE,0x45);
      write_3393_cmd(hostdata,WD_CMD_SEL_ATN_XFER);
      hostdata->state = S_RUNNING_LEVEL2;
      }
   else
      write_3393_cmd(hostdata,WD_CMD_TRANS_INFO);
   hostdata->fifo = FI_FIFO_WRITING;
   sp = (unsigned short *)cmd->SCp.ptr;

   if ((i = cmd->SCp.this_residual) > IN2000_FIFO_SIZE)
      i = IN2000_FIFO_SIZE;
   cmd->SCp.have_data_in = i;
   i >>= 1;    /* Gulp. We assume this_residual is modulo 2 */
   f = hostdata->io_base + IO_FIFO;

#ifdef FAST_WRITE_IO

   FAST_WRITE2_IO();
#else
   while (i--)
      write2_io(*sp++,IO_FIFO);

#endif

}


/* We need to use spin_lock_irqsave() & spin_unlock_irqrestore() in this
 * function in order to work in an SMP environment. (I'd be surprised
 * if the driver is ever used by anyone on a real multi-CPU motherboard,
 * but it _does_ need to be able to compile and run in an SMP kernel.)
 */

static void in2000_intr (int irqnum, void * dev_id, struct pt_regs *ptregs)
{
struct Scsi_Host *instance;
struct IN2000_hostdata *hostdata;
Scsi_Cmnd *patch, *cmd;
uchar asr, sr, phs, id, lun, *ucp, msg;
int i,j;
unsigned long length;
unsigned short *sp;
unsigned short f;
unsigned long flags;

   for (instance = instance_list; instance; instance = instance->next) {
      if (instance->irq == irqnum)
         break;
      }
   if (!instance) {
      printk("*** Hmm... interrupts are screwed up! ***\n");
      return;
      }
   hostdata = (struct IN2000_hostdata *)instance->hostdata;

/* Get the spin_lock and disable further ints, for SMP */

   CLISPIN_LOCK(flags);

#ifdef PROC_STATISTICS
   hostdata->int_cnt++;
#endif

/* The IN2000 card has 2 interrupt sources OR'ed onto its IRQ line - the
 * WD3393 chip and the 2k fifo (which is actually a dual-port RAM combined
 * with a big logic array, so it's a little different than what you might
 * expect). As far as I know, there's no reason that BOTH can't be active
 * at the same time, but there's a problem: while we can read the 3393
 * to tell if _it_ wants an interrupt, I don't know of a way to ask the
 * fifo the same question. The best we can do is check the 3393 and if
 * it _isn't_ the source of the interrupt, then we can be pretty sure
 * that the fifo is the culprit.
 *  UPDATE: I have it on good authority (Bill Earnest) that bit 0 of the
 *          IO_FIFO_COUNT register mirrors the fifo interrupt state. I
 *          assume that bit clear means interrupt active. As it turns
 *          out, the driver really doesn't need to check for this after
 *          all, so my remarks above about a 'problem' can safely be
 *          ignored. The way the logic is set up, there's no advantage
 *          (that I can see) to worrying about it.
 *
 * It seems that the fifo interrupt signal is negated when we extract
 * bytes during read or write bytes during write.
 *  - fifo will interrupt when data is moving from it to the 3393, and
 *    there are 31 (or less?) bytes left to go. This is sort of short-
 *    sighted: what if you don't WANT to do more? In any case, our
 *    response is to push more into the fifo - either actual data or
 *    dummy bytes if need be. Note that we apparently have to write at
 *    least 32 additional bytes to the fifo after an interrupt in order
 *    to get it to release the ones it was holding on to - writing fewer
 *    than 32 will result in another fifo int.
 *  UPDATE: Again, info from Bill Earnest makes this more understandable:
 *          32 bytes = two counts of the fifo counter register. He tells
 *          me that the fifo interrupt is a non-latching signal derived
 *          from a straightforward boolean interpretation of the 7
 *          highest bits of the fifo counter and the fifo-read/fifo-write
 *          state. Who'd a thought?
 */

   write1_io(0, IO_LED_ON);
   asr = READ_AUX_STAT();
   if (!(asr & ASR_INT)) {    /* no WD33c93 interrupt? */

/* Ok. This is definitely a FIFO-only interrupt.
 *
 * If FI_FIFO_READING is set, there are up to 2048 bytes waiting to be read,
 * maybe more to come from the SCSI bus. Read as many as we can out of the
 * fifo and into memory at the location of SCp.ptr[SCp.have_data_in], and
 * update have_data_in afterwards.
 *
 * If we have FI_FIFO_WRITING, the FIFO has almost run out of bytes to move
 * into the WD3393 chip (I think the interrupt happens when there are 31
 * bytes left, but it may be fewer...). The 3393 is still waiting, so we
 * shove some more into the fifo, which gets things moving again. If the
 * original SCSI command specified more than 2048 bytes, there may still
 * be some of that data left: fine - use it (from SCp.ptr[SCp.have_data_in]).
 * Don't forget to update have_data_in. If we've already written out the
 * entire buffer, feed 32 dummy bytes to the fifo - they're needed to
 * push out the remaining real data.
 *    (Big thanks to Bill Earnest for getting me out of the mud in here.)
 */

      cmd = (Scsi_Cmnd *)hostdata->connected;   /* assume we're connected */
CHECK_NULL(cmd,"fifo_int")

      if (hostdata->fifo == FI_FIFO_READING) {

DB(DB_FIFO,printk("{R:%02x} ",read1_io(IO_FIFO_COUNT)))

         sp = (unsigned short *)(cmd->SCp.ptr + cmd->SCp.have_data_in);
         i = read1_io(IO_FIFO_COUNT) & 0xfe;
         i <<= 2;    /* # of words waiting in the fifo */
         f = hostdata->io_base + IO_FIFO;

#ifdef FAST_READ_IO

         FAST_READ2_IO();
#else
         while (i--)
            *sp++ = read2_io(IO_FIFO);

#endif

         i = sp - (unsigned short *)(cmd->SCp.ptr + cmd->SCp.have_data_in);
         i <<= 1;
         cmd->SCp.have_data_in += i;
         }

      else if (hostdata->fifo == FI_FIFO_WRITING) {

DB(DB_FIFO,printk("{W:%02x} ",read1_io(IO_FIFO_COUNT)))

/* If all bytes have been written to the fifo, flush out the stragglers.
 * Note that while writing 16 dummy words seems arbitrary, we don't
 * have another choice that I can see. What we really want is to read
 * the 3393 transfer count register (that would tell us how many bytes
 * needed flushing), but the TRANSFER_INFO command hasn't completed
 * yet (not enough bytes!) and that register won't be accessible. So,
 * we use 16 words - a number obtained through trial and error.
 *  UPDATE: Bill says this is exactly what Always does, so there.
 *          More thanks due him for help in this section.
 */

         if (cmd->SCp.this_residual == cmd->SCp.have_data_in) {
            i = 16;
            while (i--)          /* write 32 dummy bytes */
               write2_io(0,IO_FIFO);
            }

/* If there are still bytes left in the SCSI buffer, write as many as we
 * can out to the fifo.
 */

         else {
            sp = (unsigned short *)(cmd->SCp.ptr + cmd->SCp.have_data_in);
            i = cmd->SCp.this_residual - cmd->SCp.have_data_in;   /* bytes yet to go */
            j = read1_io(IO_FIFO_COUNT) & 0xfe;
            j <<= 2;    /* how many words the fifo has room for */
            if ((j << 1) > i)
               j = (i >> 1);
            while (j--)
               write2_io(*sp++,IO_FIFO);

            i = sp - (unsigned short *)(cmd->SCp.ptr + cmd->SCp.have_data_in);
            i <<= 1;
            cmd->SCp.have_data_in += i;
            }
         }

      else {
            printk("*** Spurious FIFO interrupt ***");
            }

      write1_io(0, IO_LED_OFF);

/* release the SMP spin_lock and restore irq state */
      CLISPIN_UNLOCK(flags);
      return;
      }

/* This interrupt was triggered by the WD33c93 chip. The fifo interrupt
 * may also be asserted, but we don't bother to check it: we get more
 * detailed info from FIFO_READING and FIFO_WRITING (see below).
 */

   cmd = (Scsi_Cmnd *)hostdata->connected;   /* assume we're connected */
   sr = read_3393(hostdata,WD_SCSI_STATUS);  /* clear the interrupt */
   phs = read_3393(hostdata,WD_COMMAND_PHASE);

   if (!cmd && (sr != CSR_RESEL_AM && sr != CSR_TIMEOUT && sr != CSR_SELECT)) {
      printk("\nNR:wd-intr-1\n");
      write1_io(0, IO_LED_OFF);

/* release the SMP spin_lock and restore irq state */
      CLISPIN_UNLOCK(flags);
      return;
      }

DB(DB_INTR,printk("{%02x:%02x-",asr,sr))

/* After starting a FIFO-based transfer, the next _WD3393_ interrupt is
 * guaranteed to be in response to the completion of the transfer.
 * If we were reading, there's probably data in the fifo that needs
 * to be copied into RAM - do that here. Also, we have to update
 * 'this_residual' and 'ptr' based on the contents of the
 * TRANSFER_COUNT register, in case the device decided to do an
 * intermediate disconnect (a device may do this if it has to
 * do a seek,  or just to be nice and let other devices have
 * some bus time during long transfers).
 * After doing whatever is necessary with the fifo, we go on and
 * service the WD3393 interrupt normally.
 */

   if (hostdata->fifo == FI_FIFO_READING) {

/* buffer index = start-of-buffer + #-of-bytes-already-read */

      sp = (unsigned short *)(cmd->SCp.ptr + cmd->SCp.have_data_in);

/* bytes remaining in fifo = (total-wanted - #-not-got) - #-already-read */

      i = (cmd->SCp.this_residual - read_3393_count(hostdata)) - cmd->SCp.have_data_in;
      i >>= 1;    /* Gulp. We assume this will always be modulo 2 */
      f = hostdata->io_base + IO_FIFO;

#ifdef FAST_READ_IO

      FAST_READ2_IO();
#else
      while (i--)
         *sp++ = read2_io(IO_FIFO);

#endif

      hostdata->fifo = FI_FIFO_UNUSED;
      length = cmd->SCp.this_residual;
      cmd->SCp.this_residual = read_3393_count(hostdata);
      cmd->SCp.ptr += (length - cmd->SCp.this_residual);

DB(DB_TRANSFER,printk("(%p,%d)",cmd->SCp.ptr,cmd->SCp.this_residual))

      }

   else if (hostdata->fifo == FI_FIFO_WRITING) {
      hostdata->fifo = FI_FIFO_UNUSED;
      length = cmd->SCp.this_residual;
      cmd->SCp.this_residual = read_3393_count(hostdata);
      cmd->SCp.ptr += (length - cmd->SCp.this_residual);

DB(DB_TRANSFER,printk("(%p,%d)",cmd->SCp.ptr,cmd->SCp.this_residual))

      }

/* Respond to the specific WD3393 interrupt - there are quite a few! */

   switch (sr) {

      case CSR_TIMEOUT:
DB(DB_INTR,printk("TIMEOUT"))

         if (hostdata->state == S_RUNNING_LEVEL2)
            hostdata->connected = NULL;
         else {
            cmd = (Scsi_Cmnd *)hostdata->selecting;   /* get a valid cmd */
CHECK_NULL(cmd,"csr_timeout")
            hostdata->selecting = NULL;
            }

         cmd->result = DID_NO_CONNECT << 16;
         hostdata->busy[cmd->target] &= ~(1 << cmd->lun);
         hostdata->state = S_UNCONNECTED;
         cmd->scsi_done(cmd);

/* We are not connected to a target - check to see if there
 * are commands waiting to be executed.
 */

         in2000_execute(instance);
         break;


/* Note: this interrupt should not occur in a LEVEL2 command */

      case CSR_SELECT:
DB(DB_INTR,printk("SELECT"))
         hostdata->connected = cmd = (Scsi_Cmnd *)hostdata->selecting;
CHECK_NULL(cmd,"csr_select")
         hostdata->selecting = NULL;

      /* construct an IDENTIFY message with correct disconnect bit */

         hostdata->outgoing_msg[0] = (0x80 | 0x00 | cmd->lun);
         if (cmd->SCp.phase)
            hostdata->outgoing_msg[0] |= 0x40;

         if (hostdata->sync_stat[cmd->target] == SS_FIRST) {
#ifdef SYNC_DEBUG
printk(" sending SDTR ");
#endif

            hostdata->sync_stat[cmd->target] = SS_WAITING;

      /* tack on a 2nd message to ask about synchronous transfers */

            hostdata->outgoing_msg[1] = EXTENDED_MESSAGE;
            hostdata->outgoing_msg[2] = 3;
            hostdata->outgoing_msg[3] = EXTENDED_SDTR;
            hostdata->outgoing_msg[4] = OPTIMUM_SX_PER/4;
            hostdata->outgoing_msg[5] = OPTIMUM_SX_OFF;
            hostdata->outgoing_len = 6;
            }
         else
            hostdata->outgoing_len = 1;

         hostdata->state = S_CONNECTED;
         break;


      case CSR_XFER_DONE|PHS_DATA_IN:
      case CSR_UNEXP    |PHS_DATA_IN:
      case CSR_SRV_REQ  |PHS_DATA_IN:
DB(DB_INTR,printk("IN-%d.%d",cmd->SCp.this_residual,cmd->SCp.buffers_residual))
         transfer_bytes(cmd, DATA_IN_DIR);
         if (hostdata->state != S_RUNNING_LEVEL2)
            hostdata->state = S_CONNECTED;
         break;


      case CSR_XFER_DONE|PHS_DATA_OUT:
      case CSR_UNEXP    |PHS_DATA_OUT:
      case CSR_SRV_REQ  |PHS_DATA_OUT:
DB(DB_INTR,printk("OUT-%d.%d",cmd->SCp.this_residual,cmd->SCp.buffers_residual))
         transfer_bytes(cmd, DATA_OUT_DIR);
         if (hostdata->state != S_RUNNING_LEVEL2)
            hostdata->state = S_CONNECTED;
         break;


/* Note: this interrupt should not occur in a LEVEL2 command */

      case CSR_XFER_DONE|PHS_COMMAND:
      case CSR_UNEXP    |PHS_COMMAND:
      case CSR_SRV_REQ  |PHS_COMMAND:
DB(DB_INTR,printk("CMND-%02x,%ld",cmd->cmnd[0],cmd->pid))
         transfer_pio(cmd->cmnd, cmd->cmd_len, DATA_OUT_DIR, hostdata);
         hostdata->state = S_CONNECTED;
         break;


      case CSR_XFER_DONE|PHS_STATUS:
      case CSR_UNEXP    |PHS_STATUS:
      case CSR_SRV_REQ  |PHS_STATUS:
DB(DB_INTR,printk("STATUS="))

         cmd->SCp.Status = read_1_byte(hostdata);
DB(DB_INTR,printk("%02x",cmd->SCp.Status))
         if (hostdata->level2 >= L2_BASIC) {
            sr = read_3393(hostdata,WD_SCSI_STATUS);  /* clear interrupt */
            hostdata->state = S_RUNNING_LEVEL2;
            write_3393(hostdata,WD_COMMAND_PHASE, 0x50);
            write_3393_cmd(hostdata,WD_CMD_SEL_ATN_XFER);
            }
         else {
            hostdata->state = S_CONNECTED;
            }
         break;


      case CSR_XFER_DONE|PHS_MESS_IN:
      case CSR_UNEXP    |PHS_MESS_IN:
      case CSR_SRV_REQ  |PHS_MESS_IN:
DB(DB_INTR,printk("MSG_IN="))

         msg = read_1_byte(hostdata);
         sr = read_3393(hostdata,WD_SCSI_STATUS);  /* clear interrupt */

         hostdata->incoming_msg[hostdata->incoming_ptr] = msg;
         if (hostdata->incoming_msg[0] == EXTENDED_MESSAGE)
            msg = EXTENDED_MESSAGE;
         else
            hostdata->incoming_ptr = 0;

         cmd->SCp.Message = msg;
         switch (msg) {

            case COMMAND_COMPLETE:
DB(DB_INTR,printk("CCMP-%ld",cmd->pid))
               write_3393_cmd(hostdata,WD_CMD_NEGATE_ACK);
               hostdata->state = S_PRE_CMP_DISC;
               break;

            case SAVE_POINTERS:
DB(DB_INTR,printk("SDP"))
               write_3393_cmd(hostdata,WD_CMD_NEGATE_ACK);
               hostdata->state = S_CONNECTED;
               break;

            case RESTORE_POINTERS:
DB(DB_INTR,printk("RDP"))
               if (hostdata->level2 >= L2_BASIC) {
                  write_3393(hostdata,WD_COMMAND_PHASE, 0x45);
                  write_3393_cmd(hostdata,WD_CMD_SEL_ATN_XFER);
                  hostdata->state = S_RUNNING_LEVEL2;
                  }
               else {
                  write_3393_cmd(hostdata,WD_CMD_NEGATE_ACK);
                  hostdata->state = S_CONNECTED;
                  }
               break;

            case DISCONNECT:
DB(DB_INTR,printk("DIS"))
               cmd->device->disconnect = 1;
               write_3393_cmd(hostdata,WD_CMD_NEGATE_ACK);
               hostdata->state = S_PRE_TMP_DISC;
               break;

            case MESSAGE_REJECT:
DB(DB_INTR,printk("REJ"))
#ifdef SYNC_DEBUG
printk("-REJ-");
#endif
               if (hostdata->sync_stat[cmd->target] == SS_WAITING)
                  hostdata->sync_stat[cmd->target] = SS_SET;
               write_3393_cmd(hostdata,WD_CMD_NEGATE_ACK);
               hostdata->state = S_CONNECTED;
               break;

            case EXTENDED_MESSAGE:
DB(DB_INTR,printk("EXT"))

               ucp = hostdata->incoming_msg;

#ifdef SYNC_DEBUG
printk("%02x",ucp[hostdata->incoming_ptr]);
#endif
         /* Is this the last byte of the extended message? */

               if ((hostdata->incoming_ptr >= 2) &&
                   (hostdata->incoming_ptr == (ucp[1] + 1))) {

                  switch (ucp[2]) {   /* what's the EXTENDED code? */
                     case EXTENDED_SDTR:
                        id = calc_sync_xfer(ucp[3],ucp[4]);
                        if (hostdata->sync_stat[cmd->target] != SS_WAITING) {

/* A device has sent an unsolicited SDTR message; rather than go
 * through the effort of decoding it and then figuring out what
 * our reply should be, we're just gonna say that we have a
 * synchronous fifo depth of 0. This will result in asynchronous
 * transfers - not ideal but so much easier.
 * Actually, this is OK because it assures us that if we don't
 * specifically ask for sync transfers, we won't do any.
 */

                           write_3393_cmd(hostdata,WD_CMD_ASSERT_ATN); /* want MESS_OUT */
                           hostdata->outgoing_msg[0] = EXTENDED_MESSAGE;
                           hostdata->outgoing_msg[1] = 3;
                           hostdata->outgoing_msg[2] = EXTENDED_SDTR;
                           hostdata->outgoing_msg[3] = hostdata->default_sx_per/4;
                           hostdata->outgoing_msg[4] = 0;
                           hostdata->outgoing_len = 5;
                           hostdata->sync_xfer[cmd->target] =
                                       calc_sync_xfer(hostdata->default_sx_per/4,0);
                           }
                        else {
                           hostdata->sync_xfer[cmd->target] = id;
                           }
#ifdef SYNC_DEBUG
printk("sync_xfer=%02x",hostdata->sync_xfer[cmd->target]);
#endif
                        hostdata->sync_stat[cmd->target] = SS_SET;
                        write_3393_cmd(hostdata,WD_CMD_NEGATE_ACK);
                        hostdata->state = S_CONNECTED;
                        break;
                     case EXTENDED_WDTR:
                        write_3393_cmd(hostdata,WD_CMD_ASSERT_ATN); /* want MESS_OUT */
                        printk("sending WDTR ");
                        hostdata->outgoing_msg[0] = EXTENDED_MESSAGE;
                        hostdata->outgoing_msg[1] = 2;
                        hostdata->outgoing_msg[2] = EXTENDED_WDTR;
                        hostdata->outgoing_msg[3] = 0;   /* 8 bit transfer width */
                        hostdata->outgoing_len = 4;
                        write_3393_cmd(hostdata,WD_CMD_NEGATE_ACK);
                        hostdata->state = S_CONNECTED;
                        break;
                     default:
                        write_3393_cmd(hostdata,WD_CMD_ASSERT_ATN); /* want MESS_OUT */
                        printk("Rejecting Unknown Extended Message(%02x). ",ucp[2]);
                        hostdata->outgoing_msg[0] = MESSAGE_REJECT;
                        hostdata->outgoing_len = 1;
                        write_3393_cmd(hostdata,WD_CMD_NEGATE_ACK);
                        hostdata->state = S_CONNECTED;
                        break;
                     }
                  hostdata->incoming_ptr = 0;
                  }

         /* We need to read more MESS_IN bytes for the extended message */

               else {
                  hostdata->incoming_ptr++;
                  write_3393_cmd(hostdata,WD_CMD_NEGATE_ACK);
                  hostdata->state = S_CONNECTED;
                  }
               break;

            default:
               printk("Rejecting Unknown Message(%02x) ",msg);
               write_3393_cmd(hostdata,WD_CMD_ASSERT_ATN); /* want MESS_OUT */
               hostdata->outgoing_msg[0] = MESSAGE_REJECT;
               hostdata->outgoing_len = 1;
               write_3393_cmd(hostdata,WD_CMD_NEGATE_ACK);
               hostdata->state = S_CONNECTED;
            }
         break;


/* Note: this interrupt will occur only after a LEVEL2 command */

      case CSR_SEL_XFER_DONE:

/* Make sure that reselection is enabled at this point - it may
 * have been turned off for the command that just completed.
 */

         write_3393(hostdata,WD_SOURCE_ID, SRCID_ER);
         if (phs == 0x60) {
DB(DB_INTR,printk("SX-DONE-%ld",cmd->pid))
            cmd->SCp.Message = COMMAND_COMPLETE;
            lun = read_3393(hostdata,WD_TARGET_LUN);
DB(DB_INTR,printk(":%d.%d",cmd->SCp.Status,lun))
            hostdata->connected = NULL;
            hostdata->busy[cmd->target] &= ~(1 << cmd->lun);
            hostdata->state = S_UNCONNECTED;
            if (cmd->SCp.Status == ILLEGAL_STATUS_BYTE)
               cmd->SCp.Status = lun;
            if (cmd->cmnd[0] == REQUEST_SENSE && cmd->SCp.Status != GOOD)
               cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
            else
               cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
            cmd->scsi_done(cmd);

/* We are no longer connected to a target - check to see if
 * there are commands waiting to be executed.
 */

            in2000_execute(instance);
            }
         else {
            printk("%02x:%02x:%02x-%ld: Unknown SEL_XFER_DONE phase!!---",asr,sr,phs,cmd->pid);
            }
         break;


/* Note: this interrupt will occur only after a LEVEL2 command */

      case CSR_SDP:
DB(DB_INTR,printk("SDP"))
            hostdata->state = S_RUNNING_LEVEL2;
            write_3393(hostdata,WD_COMMAND_PHASE, 0x41);
            write_3393_cmd(hostdata,WD_CMD_SEL_ATN_XFER);
         break;


      case CSR_XFER_DONE|PHS_MESS_OUT:
      case CSR_UNEXP    |PHS_MESS_OUT:
      case CSR_SRV_REQ  |PHS_MESS_OUT:
DB(DB_INTR,printk("MSG_OUT="))

/* To get here, we've probably requested MESSAGE_OUT and have
 * already put the correct bytes in outgoing_msg[] and filled
 * in outgoing_len. We simply send them out to the SCSI bus.
 * Sometimes we get MESSAGE_OUT phase when we're not expecting
 * it - like when our SDTR message is rejected by a target. Some
 * targets send the REJECT before receiving all of the extended
 * message, and then seem to go back to MESSAGE_OUT for a byte
 * or two. Not sure why, or if I'm doing something wrong to
 * cause this to happen. Regardless, it seems that sending
 * NOP messages in these situations results in no harm and
 * makes everyone happy.
 */

         if (hostdata->outgoing_len == 0) {
            hostdata->outgoing_len = 1;
            hostdata->outgoing_msg[0] = NOP;
            }
         transfer_pio(hostdata->outgoing_msg, hostdata->outgoing_len,
                      DATA_OUT_DIR, hostdata);
DB(DB_INTR,printk("%02x",hostdata->outgoing_msg[0]))
         hostdata->outgoing_len = 0;
         hostdata->state = S_CONNECTED;
         break;

 
      case CSR_UNEXP_DISC:

/* I think I've seen this after a request-sense that was in response
 * to an error condition, but not sure. We certainly need to do
 * something when we get this interrupt - the question is 'what?'.
 * Let's think positively, and assume some command has finished
 * in a legal manner (like a command that provokes a request-sense),
 * so we treat it as a normal command-complete-disconnect.
 */


/* Make sure that reselection is enabled at this point - it may
 * have been turned off for the command that just completed.
 */

         write_3393(hostdata,WD_SOURCE_ID, SRCID_ER);
         if (cmd == NULL) {
            printk(" - Already disconnected! ");
            hostdata->state = S_UNCONNECTED;

/* release the SMP spin_lock and restore irq state */
            CLISPIN_UNLOCK(flags);
            return;
            }
DB(DB_INTR,printk("UNEXP_DISC-%ld",cmd->pid))
         hostdata->connected = NULL;
         hostdata->busy[cmd->target] &= ~(1 << cmd->lun);
         hostdata->state = S_UNCONNECTED;
         if (cmd->cmnd[0] == REQUEST_SENSE && cmd->SCp.Status != GOOD)
            cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
         else
            cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
         cmd->scsi_done(cmd);

/* We are no longer connected to a target - check to see if
 * there are commands waiting to be executed.
 */

         in2000_execute(instance);
         break;


      case CSR_DISC:

/* Make sure that reselection is enabled at this point - it may
 * have been turned off for the command that just completed.
 */

         write_3393(hostdata,WD_SOURCE_ID, SRCID_ER);
DB(DB_INTR,printk("DISC-%ld",cmd->pid))
         if (cmd == NULL) {
            printk(" - Already disconnected! ");
            hostdata->state = S_UNCONNECTED;
            }
         switch (hostdata->state) {
            case S_PRE_CMP_DISC:
               hostdata->connected = NULL;
               hostdata->busy[cmd->target] &= ~(1 << cmd->lun);
               hostdata->state = S_UNCONNECTED;
DB(DB_INTR,printk(":%d",cmd->SCp.Status))
               if (cmd->cmnd[0] == REQUEST_SENSE && cmd->SCp.Status != GOOD)
                  cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
               else
                  cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
               cmd->scsi_done(cmd);
               break;
            case S_PRE_TMP_DISC:
            case S_RUNNING_LEVEL2:
               cmd->host_scribble = (uchar *)hostdata->disconnected_Q;
               hostdata->disconnected_Q = cmd;
               hostdata->connected = NULL;
               hostdata->state = S_UNCONNECTED;

#ifdef PROC_STATISTICS
               hostdata->disc_done_cnt[cmd->target]++;
#endif

               break;
            default:
               printk("*** Unexpected DISCONNECT interrupt! ***");
               hostdata->state = S_UNCONNECTED;
            }

/* We are no longer connected to a target - check to see if
 * there are commands waiting to be executed.
 */

         in2000_execute(instance);
         break;


      case CSR_RESEL_AM:
DB(DB_INTR,printk("RESEL"))

   /* First we have to make sure this reselection didn't */
   /* happen during Arbitration/Selection of some other device. */
   /* If yes, put losing command back on top of input_Q. */

         if (hostdata->level2 <= L2_NONE) {

            if (hostdata->selecting) {
               cmd = (Scsi_Cmnd *)hostdata->selecting;
               hostdata->selecting = NULL;
               hostdata->busy[cmd->target] &= ~(1 << cmd->lun);
               cmd->host_scribble = (uchar *)hostdata->input_Q;
               hostdata->input_Q = cmd;
               }
            }

         else {

            if (cmd) {
               if (phs == 0x00) {
                  hostdata->busy[cmd->target] &= ~(1 << cmd->lun);
                  cmd->host_scribble = (uchar *)hostdata->input_Q;
                  hostdata->input_Q = cmd;
                  }
               else {
                  printk("---%02x:%02x:%02x-TROUBLE: Intrusive ReSelect!---",asr,sr,phs);
                  while (1)
                     printk("\r");
                  }
               }

            }

   /* OK - find out which device reselected us. */

         id = read_3393(hostdata,WD_SOURCE_ID);
         id &= SRCID_MASK;

   /* and extract the lun from the ID message. (Note that we don't
    * bother to check for a valid message here - I guess this is
    * not the right way to go, but....)
    */

         lun = read_3393(hostdata,WD_DATA);
         if (hostdata->level2 < L2_RESELECT)
            write_3393_cmd(hostdata,WD_CMD_NEGATE_ACK);
         lun &= 7;

   /* Now we look for the command that's reconnecting. */

         cmd = (Scsi_Cmnd *)hostdata->disconnected_Q;
         patch = NULL;
         while (cmd) {
            if (id == cmd->target && lun == cmd->lun)
               break;
            patch = cmd;
            cmd = (Scsi_Cmnd *)cmd->host_scribble;
            }

   /* Hmm. Couldn't find a valid command.... What to do? */

         if (!cmd) {
            printk("---TROUBLE: target %d.%d not in disconnect queue---",id,lun);
            break;
            }

   /* Ok, found the command - now start it up again. */

         if (patch)
            patch->host_scribble = cmd->host_scribble;
         else
            hostdata->disconnected_Q = (Scsi_Cmnd *)cmd->host_scribble;
         hostdata->connected = cmd;

   /* We don't need to worry about 'initialize_SCp()' or 'hostdata->busy[]'
    * because these things are preserved over a disconnect.
    * But we DO need to fix the DPD bit so it's correct for this command.
    */

         if (is_dir_out(cmd))
            write_3393(hostdata,WD_DESTINATION_ID,cmd->target);
         else
            write_3393(hostdata,WD_DESTINATION_ID,cmd->target | DSTID_DPD);
         if (hostdata->level2 >= L2_RESELECT) {
            write_3393_count(hostdata,0); /* we want a DATA_PHASE interrupt */
            write_3393(hostdata,WD_COMMAND_PHASE, 0x45);
            write_3393_cmd(hostdata,WD_CMD_SEL_ATN_XFER);
            hostdata->state = S_RUNNING_LEVEL2;
            }
         else
            hostdata->state = S_CONNECTED;

DB(DB_INTR,printk("-%ld",cmd->pid))
         break;

      default:
         printk("--UNKNOWN INTERRUPT:%02x:%02x:%02x--",asr,sr,phs);
      }

   write1_io(0, IO_LED_OFF);

DB(DB_INTR,printk("} "))

/* release the SMP spin_lock and restore irq state */
   CLISPIN_UNLOCK(flags);

}



#define RESET_CARD         0
#define RESET_CARD_AND_BUS 1
#define B_FLAG 0x80

static int reset_hardware(struct Scsi_Host *instance, int type)
{
struct IN2000_hostdata *hostdata;
int qt,x;
unsigned long flags;

   hostdata = (struct IN2000_hostdata *)instance->hostdata;

   write1_io(0, IO_LED_ON);
   if (type == RESET_CARD_AND_BUS) {
      write1_io(0,IO_CARD_RESET);
      x = read1_io(IO_HARDWARE);
      }
   x = read_3393(hostdata,WD_SCSI_STATUS);   /* clear any WD intrpt */
   write_3393(hostdata,WD_OWN_ID, instance->this_id |
                           OWNID_EAF | OWNID_RAF | OWNID_FS_8);
   write_3393(hostdata,WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
   write_3393(hostdata,WD_SYNCHRONOUS_TRANSFER,
              calc_sync_xfer(hostdata->default_sx_per/4,DEFAULT_SX_OFF));
   save_flags(flags);
   cli();
   write1_io(0,IO_FIFO_WRITE);            /* clear fifo counter */
   write1_io(0,IO_FIFO_READ);             /* start fifo out in read mode */
   write_3393(hostdata,WD_COMMAND, WD_CMD_RESET);
   while (!(READ_AUX_STAT() & ASR_INT))
      ;                                   /* wait for RESET to complete */

   x = read_3393(hostdata,WD_SCSI_STATUS);   /* clear interrupt */
   restore_flags(flags);
   write_3393(hostdata,WD_QUEUE_TAG,0xa5);   /* any random number */
   qt = read_3393(hostdata,WD_QUEUE_TAG);
   if (qt == 0xa5) {
      x |= B_FLAG;
      write_3393(hostdata,WD_QUEUE_TAG,0);
      }
   write_3393(hostdata,WD_TIMEOUT_PERIOD, TIMEOUT_PERIOD_VALUE);
   write_3393(hostdata,WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
   write1_io(0, IO_LED_OFF);
   return x;
}



int in2000_reset(Scsi_Cmnd *cmd, unsigned int reset_flags)
{
unsigned long flags;
struct Scsi_Host *instance;
struct IN2000_hostdata *hostdata;
int x;

   instance = cmd->host;
   hostdata = (struct IN2000_hostdata *)instance->hostdata;

   printk("scsi%d: Reset. ", instance->host_no);
   save_flags(flags);
   cli();

   /* do scsi-reset here */

   reset_hardware(instance, RESET_CARD_AND_BUS);
   for (x = 0; x < 8; x++) {
      hostdata->busy[x] = 0;
      hostdata->sync_xfer[x] = calc_sync_xfer(DEFAULT_SX_PER/4,DEFAULT_SX_OFF);
      hostdata->sync_stat[x] = SS_UNSET;  /* using default sync values */
      }
   hostdata->input_Q = NULL;
   hostdata->selecting = NULL;
   hostdata->connected = NULL;
   hostdata->disconnected_Q = NULL;
   hostdata->state = S_UNCONNECTED;
   hostdata->fifo = FI_FIFO_UNUSED;
   hostdata->incoming_ptr = 0;
   hostdata->outgoing_len = 0;

   cmd->result = DID_RESET << 16;
   restore_flags(flags);
   return 0;
}



int in2000_abort (Scsi_Cmnd *cmd)
{
struct Scsi_Host *instance;
struct IN2000_hostdata *hostdata;
Scsi_Cmnd *tmp, *prev;
unsigned long flags;
uchar sr, asr;
unsigned long timeout;

   save_flags (flags);
   cli();

   instance = cmd->host;
   hostdata = (struct IN2000_hostdata *)instance->hostdata;

   printk ("scsi%d: Abort-", instance->host_no);
   printk("(asr=%02x,count=%ld,resid=%d,buf_resid=%d,have_data=%d,FC=%02x)- ",
            READ_AUX_STAT(),read_3393_count(hostdata),cmd->SCp.this_residual,cmd->SCp.buffers_residual,
            cmd->SCp.have_data_in,read1_io(IO_FIFO_COUNT));

/*
 * Case 1 : If the command hasn't been issued yet, we simply remove it
 *     from the inout_Q.
 */

   tmp = (Scsi_Cmnd *)hostdata->input_Q;
   prev = 0;
   while (tmp) {
      if (tmp == cmd) {
         if (prev)
            prev->host_scribble = cmd->host_scribble;
         cmd->host_scribble = NULL;
         cmd->result = DID_ABORT << 16;
         printk("scsi%d: Abort - removing command %ld from input_Q. ",
           instance->host_no, cmd->pid);
         cmd->scsi_done(cmd);
         restore_flags(flags);
         return SCSI_ABORT_SUCCESS;
         }
      prev = tmp;
      tmp = (Scsi_Cmnd *)tmp->host_scribble;
      }

/*
 * Case 2 : If the command is connected, we're going to fail the abort
 *     and let the high level SCSI driver retry at a later time or
 *     issue a reset.
 *
 *     Timeouts, and therefore aborted commands, will be highly unlikely
 *     and handling them cleanly in this situation would make the common
 *     case of noresets less efficient, and would pollute our code.  So,
 *     we fail.
 */

   if (hostdata->connected == cmd) {

      printk("scsi%d: Aborting connected command %ld - ",
              instance->host_no, cmd->pid);

      printk("sending wd33c93 ABORT command - ");
      write_3393(hostdata, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
      write_3393_cmd(hostdata, WD_CMD_ABORT);

/* Now we have to attempt to flush out the FIFO... */

      printk("flushing fifo - ");
      timeout = 1000000;
      do {
         asr = READ_AUX_STAT();
         if (asr & ASR_DBR)
            read_3393(hostdata, WD_DATA);
         } while (!(asr & ASR_INT) && timeout-- > 0);
      sr = read_3393(hostdata, WD_SCSI_STATUS);
      printk("asr=%02x, sr=%02x, %ld bytes un-transferred (timeout=%ld) - ",
             asr, sr, read_3393_count(hostdata), timeout);

   /*
    * Abort command processed.
    * Still connected.
    * We must disconnect.
    */

      printk("sending wd33c93 DISCONNECT command - ");
      write_3393_cmd(hostdata, WD_CMD_DISCONNECT);

      timeout = 1000000;
      asr = READ_AUX_STAT();
      while ((asr & ASR_CIP) && timeout-- > 0)
         asr = READ_AUX_STAT();
      sr = read_3393(hostdata, WD_SCSI_STATUS);
      printk("asr=%02x, sr=%02x.",asr,sr);

      hostdata->busy[cmd->target] &= ~(1 << cmd->lun);
      hostdata->connected = NULL;
      hostdata->state = S_UNCONNECTED;
      cmd->result = DID_ABORT << 16;
      cmd->scsi_done(cmd);

      in2000_execute (instance);

      restore_flags(flags);
      return SCSI_ABORT_SUCCESS;
      }

/*
 * Case 3: If the command is currently disconnected from the bus,
 * we're not going to expend much effort here: Let's just return
 * an ABORT_SNOOZE and hope for the best...
 */

   for (tmp=(Scsi_Cmnd *)hostdata->disconnected_Q; tmp;
         tmp=(Scsi_Cmnd *)tmp->host_scribble)
      if (cmd == tmp) {
         restore_flags(flags);
         printk("Sending ABORT_SNOOZE. ");
         return SCSI_ABORT_SNOOZE;
         }

/*
 * Case 4 : If we reached this point, the command was not found in any of
 *     the queues.
 *
 * We probably reached this point because of an unlikely race condition
 * between the command completing successfully and the abortion code,
 * so we won't panic, but we will notify the user in case something really
 * broke.
 */

   in2000_execute (instance);

   restore_flags(flags);
   printk("scsi%d: warning : SCSI command probably completed successfully"
      "         before abortion. ", instance->host_no);
   return SCSI_ABORT_NOT_RUNNING;
}



#define MAX_IN2000_HOSTS 3
#define MAX_SETUP_ARGS (sizeof(setup_args) / sizeof(char *))
#define SETUP_BUFFER_SIZE 200
static char setup_buffer[SETUP_BUFFER_SIZE];
static char setup_used[MAX_SETUP_ARGS];
static int done_setup = 0;

void __init in2000_setup (char *str, int *ints)
{
int i;
char *p1,*p2;

   strncpy(setup_buffer,str,SETUP_BUFFER_SIZE);
   setup_buffer[SETUP_BUFFER_SIZE - 1] = '\0';
   p1 = setup_buffer;
   i = 0;
   while (*p1 && (i < MAX_SETUP_ARGS)) {
      p2 = strchr(p1, ',');
      if (p2) {
         *p2 = '\0';
         if (p1 != p2)
            setup_args[i] = p1;
         p1 = p2 + 1;
         i++;
         }
      else {
         setup_args[i] = p1;
         break;
         }
      }
   for (i=0; i<MAX_SETUP_ARGS; i++)
      setup_used[i] = 0;
   done_setup = 1;
}


/* check_setup_args() returns index if key found, 0 if not
 */

static int __init check_setup_args(char *key, int *flags, int *val, char *buf)
{
int x;
char *cp;

   for  (x=0; x<MAX_SETUP_ARGS; x++) {
      if (setup_used[x])
         continue;
      if (!strncmp(setup_args[x], key, strlen(key)))
         break;
      }
   if (x == MAX_SETUP_ARGS)
      return 0;
   setup_used[x] = 1;
   cp = setup_args[x] + strlen(key);
   *val = -1;
   if (*cp != ':')
      return ++x;
   cp++;
   if ((*cp >= '0') && (*cp <= '9')) {
      *val = simple_strtoul(cp,NULL,0);
      }
   return ++x;
}



/* The "correct" (ie portable) way to access memory-mapped hardware
 * such as the IN2000 EPROM and dip switch is through the use of
 * special macros declared in 'asm/io.h'. We use readb() and readl()
 * when reading from the card's BIOS area in in2000_detect().
 */
static const unsigned int *bios_tab[] in2000__INITDATA = {
   (unsigned int *)0xc8000,
   (unsigned int *)0xd0000,
   (unsigned int *)0xd8000,
   0
   };

static const unsigned short base_tab[] in2000__INITDATA = {
   0x220,
   0x200,
   0x110,
   0x100,
   };

static const int int_tab[] in2000__INITDATA = {
   15,
   14,
   11,
   10
   };


int __init in2000_detect(Scsi_Host_Template * tpnt)
{
struct Scsi_Host *instance;
struct IN2000_hostdata *hostdata;
int detect_count;
int bios;
int x;
unsigned short base;
uchar switches;
uchar hrev;
int flags;
int val;
char buf[32];

/* Thanks to help from Bill Earnest, probing for IN2000 cards is a
 * pretty straightforward and fool-proof operation. There are 3
 * possible locations for the IN2000 EPROM in memory space - if we
 * find a BIOS signature, we can read the dip switch settings from
 * the byte at BIOS+32 (shadowed in by logic on the card). From 2
 * of the switch bits we get the card's address in IO space. There's
 * an image of the dip switch there, also, so we have a way to back-
 * check that this really is an IN2000 card. Very nifty. Use the
 * 'ioport:xx' command-line parameter if your BIOS EPROM is absent
 * or disabled.
 */

   if (!done_setup && setup_strings)
      in2000_setup(setup_strings,0);

   detect_count = 0;
   for (bios = 0; bios_tab[bios]; bios++) {
      if (check_setup_args("ioport",&flags,&val,buf)) {
         base = val;
         switches = ~inb(base + IO_SWITCHES) & 0xff;
         printk("Forcing IN2000 detection at IOport 0x%x ",base);
         bios = 2;
         }
/*
 * There have been a couple of BIOS versions with different layouts
 * for the obvious ID strings. We look for the 2 most common ones and
 * hope that they cover all the cases...
 */
      else if (readl(bios_tab[bios]+0x04) == 0x41564f4e ||
               readl(bios_tab[bios]+0x0c) == 0x61776c41) {
         printk("Found IN2000 BIOS at 0x%x ",(unsigned int)bios_tab[bios]);

/* Read the switch image that's mapped into EPROM space */

         switches = ~((readb(bios_tab[bios]+0x08) & 0xff));

/* Find out where the IO space is */

         x = switches & (SW_ADDR0 | SW_ADDR1);
         base = base_tab[x];

/* Check for the IN2000 signature in IO space. */

         x = ~inb(base + IO_SWITCHES) & 0xff;
         if (x != switches) {
            printk("Bad IO signature: %02x vs %02x.\n",x,switches);
            continue;
            }
         }
      else
         continue;

/* OK. We have a base address for the IO ports - run a few safety checks */

      if (!(switches & SW_BIT7)) {        /* I _think_ all cards do this */
         printk("There is no IN-2000 SCSI card at IOport 0x%03x!\n",base);
         continue;
         }

/* Let's assume any hardware version will work, although the driver
 * has only been tested on 0x21, 0x22, 0x25, 0x26, and 0x27. We'll
 * print out the rev number for reference later, but accept them all.
 */

      hrev = inb(base + IO_HARDWARE);

  /* Bit 2 tells us if interrupts are disabled */
      if (switches & SW_DISINT) {
         printk("The IN-2000 SCSI card at IOport 0x%03x ",base);
         printk("is not configured for interrupt operation!\n");
         printk("This driver requires an interrupt: cancelling detection.\n");
         continue;
         }

/* Ok. We accept that there's an IN2000 at ioaddr 'base'. Now
 * initialize it.
 */

      tpnt->proc_name = "in2000";
      instance  = scsi_register(tpnt, sizeof(struct IN2000_hostdata));
      if(instance == NULL)
        continue;
      detect_count++;
      if (!instance_list)
         instance_list = instance;
      hostdata = (struct IN2000_hostdata *)instance->hostdata;
      instance->io_port = hostdata->io_base = base;
      hostdata->dip_switch = switches;
      hostdata->hrev = hrev;

      write1_io(0,IO_FIFO_WRITE);            /* clear fifo counter */
      write1_io(0,IO_FIFO_READ);             /* start fifo out in read mode */
      write1_io(0,IO_INTR_MASK);    /* allow all ints */
      x = int_tab[(switches & (SW_INT0 | SW_INT1)) >> SW_INT_SHIFT];
      if (request_irq(x, in2000_intr, SA_INTERRUPT, "in2000", NULL)) {
         printk("in2000_detect: Unable to allocate IRQ.\n");
         detect_count--;
         continue;
         }
      instance->irq = x;
      instance->n_io_port = 13;
      request_region(base, 13, "in2000"); /* lock in this IO space for our use */

      for (x = 0; x < 8; x++) {
         hostdata->busy[x] = 0;
         hostdata->sync_xfer[x] = calc_sync_xfer(DEFAULT_SX_PER/4,DEFAULT_SX_OFF);
         hostdata->sync_stat[x] = SS_UNSET;  /* using default sync values */
#ifdef PROC_STATISTICS
         hostdata->cmd_cnt[x] = 0;
         hostdata->disc_allowed_cnt[x] = 0;
         hostdata->disc_done_cnt[x] = 0;
#endif
         }
      hostdata->input_Q = NULL;
      hostdata->selecting = NULL;
      hostdata->connected = NULL;
      hostdata->disconnected_Q = NULL;
      hostdata->state = S_UNCONNECTED;
      hostdata->fifo = FI_FIFO_UNUSED;
      hostdata->level2 = L2_BASIC;
      hostdata->disconnect = DIS_ADAPTIVE;
      hostdata->args = DEBUG_DEFAULTS;
      hostdata->incoming_ptr = 0;
      hostdata->outgoing_len = 0;
      hostdata->default_sx_per = DEFAULT_SX_PER;

/* Older BIOS's had a 'sync on/off' switch - use its setting */

      if (readl(bios_tab[bios]+0x04) == 0x41564f4e && (switches & SW_SYNC_DOS5))
         hostdata->sync_off = 0x00;    /* sync defaults to on */
      else
         hostdata->sync_off = 0xff;    /* sync defaults to off */

#ifdef PROC_INTERFACE
      hostdata->proc = PR_VERSION|PR_INFO|PR_STATISTICS|
                       PR_CONNECTED|PR_INPUTQ|PR_DISCQ|
                       PR_STOP;
#ifdef PROC_STATISTICS
      hostdata->int_cnt = 0;
#endif
#endif

      if (check_setup_args("nosync",&flags,&val,buf))
         hostdata->sync_off = val;

      if (check_setup_args("period",&flags,&val,buf))
         hostdata->default_sx_per = sx_table[round_period((unsigned int)val)].period_ns;

      if (check_setup_args("disconnect",&flags,&val,buf)) {
         if ((val >= DIS_NEVER) && (val <= DIS_ALWAYS))
            hostdata->disconnect = val;
         else
            hostdata->disconnect = DIS_ADAPTIVE;
         }

      if (check_setup_args("noreset",&flags,&val,buf))
         hostdata->args ^= A_NO_SCSI_RESET;

      if (check_setup_args("level2",&flags,&val,buf))
         hostdata->level2 = val;

      if (check_setup_args("debug",&flags,&val,buf))
         hostdata->args = (val & DB_MASK);

#ifdef PROC_INTERFACE
      if (check_setup_args("proc",&flags,&val,buf))
         hostdata->proc = val;
#endif


      x = reset_hardware(instance,(hostdata->args & A_NO_SCSI_RESET)?RESET_CARD:RESET_CARD_AND_BUS);

      hostdata->microcode = read_3393(hostdata,WD_CDB_1);
      if (x & 0x01) {
         if (x & B_FLAG)
            hostdata->chip = C_WD33C93B;
         else
            hostdata->chip = C_WD33C93A;
         }
      else
         hostdata->chip = C_WD33C93;

      printk("dip_switch=%02x irq=%d ioport=%02x floppy=%s sync/DOS5=%s ",
                  (switches & 0x7f),
                  instance->irq,hostdata->io_base,
                  (switches & SW_FLOPPY)?"Yes":"No",
                  (switches & SW_SYNC_DOS5)?"Yes":"No");
      printk("hardware_ver=%02x chip=%s microcode=%02x\n",
                  hrev,
                  (hostdata->chip==C_WD33C93)?"WD33c93":
                  (hostdata->chip==C_WD33C93A)?"WD33c93A":
                  (hostdata->chip==C_WD33C93B)?"WD33c93B":"unknown",
                  hostdata->microcode);
#ifdef DEBUGGING_ON
      printk("setup_args = ");
      for (x=0; x<MAX_SETUP_ARGS; x++)
         printk("%s,",setup_args[x]);
      printk("\n");
#endif
      if (hostdata->sync_off == 0xff)
         printk("Sync-transfer DISABLED on all devices: ENABLE from command-line\n");
      printk("IN2000 driver version %s - %s\n",IN2000_VERSION,IN2000_DATE);
      }

   return detect_count;
}


/* NOTE: I lifted this function straight out of the old driver,
 *       and have not tested it. Presumably it does what it's
 *       supposed to do...
 */

int in2000_biosparam(Disk *disk, kdev_t dev, int *iinfo)
{
int size;

   size  = disk->capacity;
   iinfo[0] = 64;
   iinfo[1] = 32;
   iinfo[2] = size >> 11;

/* This should approximate the large drive handling that the DOS ASPI manager
   uses.  Drives very near the boundaries may not be handled correctly (i.e.
   near 2.0 Gb and 4.0 Gb) */

   if (iinfo[2] > 1024) {
      iinfo[0] = 64;
      iinfo[1] = 63;
      iinfo[2] = disk->capacity / (iinfo[0] * iinfo[1]);
      }
   if (iinfo[2] > 1024) {
      iinfo[0] = 128;
      iinfo[1] = 63;
      iinfo[2] = disk->capacity / (iinfo[0] * iinfo[1]);
      }
   if (iinfo[2] > 1024) {
      iinfo[0] = 255;
      iinfo[1] = 63;
      iinfo[2] = disk->capacity / (iinfo[0] * iinfo[1]);
      }
    return 0;
}


int in2000_proc_info(char *buf, char **start, off_t off, int len, int hn, int in)
{

#ifdef PROC_INTERFACE

char *bp;
char tbuf[128];
unsigned long flags;
struct Scsi_Host *instance;
struct IN2000_hostdata *hd;
Scsi_Cmnd *cmd;
int x,i;
static int stop = 0;

   for (instance=instance_list; instance; instance=instance->next) {
      if (instance->host_no == hn)
         break;
      }
   if (!instance) {
      printk("*** Hmm... Can't find host #%d!\n",hn);
      return (-ESRCH);
      }
   hd = (struct IN2000_hostdata *)instance->hostdata;

/* If 'in' is TRUE we need to _read_ the proc file. We accept the following
 * keywords (same format as command-line, but only ONE per read):
 *    debug
 *    disconnect
 *    period
 *    resync
 *    proc
 */

   if (in) {
      buf[len] = '\0';
      bp = buf;
      if (!strncmp(bp,"debug:",6)) {
         bp += 6;
         hd->args = simple_strtoul(bp,NULL,0) & DB_MASK;
         }
      else if (!strncmp(bp,"disconnect:",11)) {
         bp += 11;
         x = simple_strtoul(bp,NULL,0);
         if (x < DIS_NEVER || x > DIS_ALWAYS)
            x = DIS_ADAPTIVE;
         hd->disconnect = x;
         }
      else if (!strncmp(bp,"period:",7)) {
         bp += 7;
         x = simple_strtoul(bp,NULL,0);
         hd->default_sx_per = sx_table[round_period((unsigned int)x)].period_ns;
         }
      else if (!strncmp(bp,"resync:",7)) {
         bp += 7;
         x = simple_strtoul(bp,NULL,0);
         for (i=0; i<7; i++)
            if (x & (1<<i))
               hd->sync_stat[i] = SS_UNSET;
         }
      else if (!strncmp(bp,"proc:",5)) {
         bp += 5;
         hd->proc = simple_strtoul(bp,NULL,0);
         }
      else if (!strncmp(bp,"level2:",7)) {
         bp += 7;
         hd->level2 = simple_strtoul(bp,NULL,0);
         }
      return len;
      }

   save_flags(flags);
   cli();
   bp = buf;
   *bp = '\0';
   if (hd->proc & PR_VERSION) {
      sprintf(tbuf,"\nVersion %s - %s. Compiled %s %s",
            IN2000_VERSION,IN2000_DATE,__DATE__,__TIME__);
      strcat(bp,tbuf);
      }
   if (hd->proc & PR_INFO) {
      sprintf(tbuf,"\ndip_switch=%02x: irq=%d io=%02x floppy=%s sync/DOS5=%s",
                  (hd->dip_switch & 0x7f), instance->irq, hd->io_base,
                  (hd->dip_switch & 0x40)?"Yes":"No",
                  (hd->dip_switch & 0x20)?"Yes":"No");
      strcat(bp,tbuf);
      strcat(bp,"\nsync_xfer[] =       ");
      for (x=0; x<7; x++) {
         sprintf(tbuf,"\t%02x",hd->sync_xfer[x]);
         strcat(bp,tbuf);
         }
      strcat(bp,"\nsync_stat[] =       ");
      for (x=0; x<7; x++) {
         sprintf(tbuf,"\t%02x",hd->sync_stat[x]);
         strcat(bp,tbuf);
         }
      }
#ifdef PROC_STATISTICS
   if (hd->proc & PR_STATISTICS) {
      strcat(bp,"\ncommands issued:    ");
      for (x=0; x<7; x++) {
         sprintf(tbuf,"\t%ld",hd->cmd_cnt[x]);
         strcat(bp,tbuf);
         }
      strcat(bp,"\ndisconnects allowed:");
      for (x=0; x<7; x++) {
         sprintf(tbuf,"\t%ld",hd->disc_allowed_cnt[x]);
         strcat(bp,tbuf);
         }
      strcat(bp,"\ndisconnects done:   ");
      for (x=0; x<7; x++) {
         sprintf(tbuf,"\t%ld",hd->disc_done_cnt[x]);
         strcat(bp,tbuf);
         }
      sprintf(tbuf,"\ninterrupts:      \t%ld",hd->int_cnt);
      strcat(bp,tbuf);
      }
#endif
   if (hd->proc & PR_CONNECTED) {
      strcat(bp,"\nconnected:     ");
      if (hd->connected) {
         cmd = (Scsi_Cmnd *)hd->connected;
         sprintf(tbuf," %ld-%d:%d(%02x)",
               cmd->pid, cmd->target, cmd->lun, cmd->cmnd[0]);
         strcat(bp,tbuf);
         }
      }
   if (hd->proc & PR_INPUTQ) {
      strcat(bp,"\ninput_Q:       ");
      cmd = (Scsi_Cmnd *)hd->input_Q;
      while (cmd) {
         sprintf(tbuf," %ld-%d:%d(%02x)",
               cmd->pid, cmd->target, cmd->lun, cmd->cmnd[0]);
         strcat(bp,tbuf);
         cmd = (Scsi_Cmnd *)cmd->host_scribble;
         }
      }
   if (hd->proc & PR_DISCQ) {
      strcat(bp,"\ndisconnected_Q:");
      cmd = (Scsi_Cmnd *)hd->disconnected_Q;
      while (cmd) {
         sprintf(tbuf," %ld-%d:%d(%02x)",
               cmd->pid, cmd->target, cmd->lun, cmd->cmnd[0]);
         strcat(bp,tbuf);
         cmd = (Scsi_Cmnd *)cmd->host_scribble;
         }
      }
   if (hd->proc & PR_TEST) {
      ;  /* insert your own custom function here */
      }
   strcat(bp,"\n");
   restore_flags(flags);
   *start = buf;
   if (stop) {
      stop = 0;
      return 0;         /* return 0 to signal end-of-file */
      }
   if (off > 0x40000)   /* ALWAYS stop after 256k bytes have been read */
      stop = 1;;
   if (hd->proc & PR_STOP)    /* stop every other time */
      stop = 1;
   return strlen(bp);

#else    /* PROC_INTERFACE */

   return 0;

#endif   /* PROC_INTERFACE */

}


static Scsi_Host_Template driver_template = IN2000;
#include "scsi_module.c"