/* fdomain.c -- Future Domain TMC-16x0 SCSI driver
 * Created: Sun May  3 18:53:19 1992 by faith@cs.unc.edu
 * Revised: Sun Jan 23 08:59:04 1994 by faith@cs.unc.edu
 * Author: Rickard E. Faith, faith@cs.unc.edu
 * Copyright 1992, 1993, 1994 Rickard E. Faith
 *
 * $Id: fdomain.c,v 5.9 1994/01/23 13:59:14 root Exp $

 * 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.

 **************************************************************************
 
 DESCRIPTION:

 This is the Linux low-level SCSI driver for Future Domain TMC-1660/1680
 and TMC-1650/1670 SCSI host adapters.  The 1650 and 1670 have a 25-pin
 external connector, whereas the 1660 and 1680 have a SCSI-2 50-pin
 high-density external connector.  The 1670 and 1680 have floppy disk
 controllers built in.

 Future Domain's older boards are based on the TMC-1800 chip, and the
 driver was originally written for a TMC-1680 board with the TMC-1800
 chip.  More recently, boards are being produced with the TMC-18C50 chip.
 The latest and greatest board may not work with this driver.  If you have
 to patch this driver so that it will recognize your board's BIOS
 signature, then the driver may fail to function after the board is
 detected.

 If you have a TMC-8xx or TMC-9xx board, then this is not the driver for
 your board.  Please refer to the Seagate driver for more information and
 possible support.

 

 REFERENCES USED:

 "TMC-1800 SCSI Chip Specification (FDC-1800T)", Future Domain Corporation,
 1990.

 "Technical Reference Manual: 18C50 SCSI Host Adapter Chip", Future Domain
 Corporation, January 1992.

 "LXT SCSI Products: Specifications and OEM Technical Manual (Revision
 B/September 1991)", Maxtor Corporation, 1991.

 "7213S product Manual (Revision P3)", Maxtor Corporation, 1992.

 "Draft Proposed American National Standard: Small Computer System
 Interface - 2 (SCSI-2)", Global Engineering Documents. (X3T9.2/86-109,
 revision 10h, October 17, 1991)

 Private communications, Drew Eckhardt (drew@cs.colorado.edu) and Eric
 Youngdale (eric@tantalus.nrl.navy.mil), 1992.


 
 NOTES ON REFERENCES:

 The Maxtor manuals were free.  Maxtor telephone technical support is
 great!

 The Future Domain manuals were $25 and $35.  They document the chip, not
 the TMC-16x0 boards, so some information I had to guess at.  In 1992,
 Future Domain sold DOS BIOS source for $250 and the UN*X driver source was
 $750, but these required a non-disclosure agreement, so even if I could
 have afforded them, they would *not* have been useful for writing this
 publically distributable driver.  Future Domain technical support has
 provided some information on the phone and have sent a few useful FAXs.
 They have been much more helpful since they started to recognize that the
 word "Linux" refers to an operating system :-).

 

 ALPHA TESTERS:

 There are many other alpha testers that come and go as the driver
 develops.  The people listed here were most helpful in times of greatest
 need (mostly early on -- I've probably left out a few worthy people in
 more recent times):

 Todd Carrico (todd@wutc.wustl.edu), Dan Poirier (poirier@cs.unc.edu ), Ken
 Corey (kenc@sol.acs.unt.edu), C. de Bruin (bruin@bruin@sterbbs.nl), Sakari
 Aaltonen (sakaria@vipunen.hit.fi), John Rice (rice@xanth.cs.odu.edu), Brad
 Yearwood (brad@optilink.com), and Ray Toy (toy@soho.crd.ge.com).

 Special thanks to Tien-Wan Yang (twyang@cs.uh.edu), who graciously lent me
 his 18C50-based card for debugging.  He is the sole reason that this
 driver works with the 18C50 chip.

 All of the alpha testers deserve much thanks.
 

 
 NOTES ON USER DEFINABLE OPTIONS:

 DEBUG: This turns on the printing of various debug informaiton.

 ENABLE_PARITY: This turns on SCSI parity checking.  With the current
 driver, all attached devices must support SCSI parity.  If none of your
 devices support parity, then you can probably get the driver to work by
 turning this option off.  I have no way of testing this, however.

 FIFO_COUNT: The host adapter has an 8K cache.  When this many 512 byte
 blocks are filled by the SCSI device, an interrupt will be raised.
 Therefore, this could be as low as 0, or as high as 16.  Note, however,
 that values which are too high or too low seem to prevent any interrupts
 from occuring, and thereby lock up the machine.  I have found that 2 is a
 good number, but throughput may be increased by changing this value to
 values which are close to 2.  Please let me know if you try any different
 values.

 DO_DETECT: This activates some old scan code which was needed before the
 high level drivers got fixed.  If you are having toruble with the driver,
 turning this on should not hurt, and might help.  Please let me know if
 this is the case, since this code will be removed from future drivers.

 RESELECTION: This is no longer an option, since I gave up trying to
 implement it in version 4.x of this driver.  It did not improve
 performance at all and made the driver unstable (because I never found one
 of the two race conditions which were introduced by multiple outstanding
 commands).  The instability seems a very high price to pay just so that
 you don't have to wait for the tape to rewind.  When I have time, I will
 work on this again.  In the interim, if anyone want to work on the code, I
 can give them my latest version.

 **************************************************************************/

#include <linux/sched.h>
#include <asm/io.h>
#include "../block/blk.h"
#include "scsi.h"
#include "hosts.h"
#include "fdomain.h"
#include <asm/system.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/ioport.h>

#define VERSION          "$Revision: 5.9 $"

/* START OF USER DEFINABLE OPTIONS */

#define DEBUG            1	/* Enable debugging output */
#define ENABLE_PARITY    1	/* Enable SCSI Parity */
#define FIFO_COUNT       2	/* Number of 512 byte blocks before INTR */
#define DO_DETECT        0	/* Do device detection here (see scsi.c) */

/* END OF USER DEFINABLE OPTIONS */

#if DEBUG
#define EVERY_ACCESS     0	/* Write a line on every scsi access */
#define ERRORS_ONLY      1	/* Only write a line if there is an error */
#define DEBUG_DETECT     0	/* Debug fdomain_16x0_detect() */
#define DEBUG_MESSAGES   1	/* Debug MESSAGE IN phase */
#define DEBUG_ABORT      1	/* Debug abort() routine */
#define DEBUG_RESET      1	/* Debug reset() routine */
#define DEBUG_RACE       1      /* Debug interrupt-driven race condition */
#else
#define EVERY_ACCESS     0	/* LEAVE THESE ALONE--CHANGE THE ONES ABOVE */
#define ERRORS_ONLY      0
#define DEBUG_DETECT     0
#define DEBUG_MESSAGES   0
#define DEBUG_ABORT      0
#define DEBUG_RESET      0
#define DEBUG_RACE       0
#endif

/* Errors are reported on the line, so we don't need to report them again */
#if EVERY_ACCESS
#undef ERRORS_ONLY
#define ERRORS_ONLY      0
#endif

#if ENABLE_PARITY
#define PARITY_MASK      0x08
#else
#define PARITY_MASK      0x00
#endif

enum chip_type {
   unknown          = 0x00,
   tmc1800          = 0x01,
   tmc18c50         = 0x02,
};

enum {
   in_arbitration   = 0x02,
   in_selection     = 0x04,
   in_other         = 0x08,
   disconnect       = 0x10,
   aborted          = 0x20,
   sent_ident       = 0x40,
};

enum in_port_type {
   Read_SCSI_Data   =  0,
   SCSI_Status      =  1,
   TMC_Status       =  2,
   FIFO_Status      =  3,	/* tmc18c50 only */
   Interrupt_Cond   =  4,	/* tmc18c50 only */
   LSB_ID_Code      =  5,
   MSB_ID_Code      =  6,
   Read_Loopback    =  7,
   SCSI_Data_NoACK  =  8,
   Interrupt_Status =  9,
   Configuration1   = 10,
   Configuration2   = 11,	/* tmc18c50 only */
   Read_FIFO        = 12,
   FIFO_Data_Count  = 14
};

enum out_port_type {
   Write_SCSI_Data  =  0,
   SCSI_Cntl        =  1,
   Interrupt_Cntl   =  2,
   SCSI_Mode_Cntl   =  3,
   TMC_Cntl         =  4,
   Memory_Cntl      =  5,	/* tmc18c50 only */
   Write_Loopback   =  7,
   Write_FIFO       = 12
};

static int               port_base         = 0;
static void              *bios_base        = NULL;
static int               bios_major        = 0;
static int               bios_minor        = 0;
static int               interrupt_level   = 0;
static int               this_host         = 0;
static volatile int      in_command        = 0;
static Scsi_Cmnd         *current_SC       = NULL;
static enum chip_type    chip              = unknown;
static int               adapter_mask      = 0x40;
#if DEBUG_RACE
static volatile int      in_interrupt_flag = 0;
#endif

static int               SCSI_Mode_Cntl_port;
static int               FIFO_Data_Count_port;
static int               Interrupt_Cntl_port;
static int               Interrupt_Status_port;
static int               Read_FIFO_port;
static int               Read_SCSI_Data_port;
static int               SCSI_Cntl_port;
static int               SCSI_Data_NoACK_port;
static int               SCSI_Status_port;
static int               TMC_Cntl_port;
static int               TMC_Status_port;
static int               Write_FIFO_port;
static int               Write_SCSI_Data_port;

extern void              fdomain_16x0_intr( int unused );

static void *addresses[] = {
   (void *)0xc8000,
   (void *)0xca000,
   (void *)0xce000,
   (void *)0xde000 };
#define ADDRESS_COUNT (sizeof( addresses ) / sizeof( unsigned ))
		       
static unsigned short ports[] = { 0x140, 0x150, 0x160, 0x170 };
#define PORT_COUNT (sizeof( ports ) / sizeof( unsigned short ))

static unsigned short ints[] = { 3, 5, 10, 11, 12, 14, 15, 0 };

/*

  READ THIS BEFORE YOU ADD A SIGNATURE!

  READING THIS SHORT NOTE CAN SAVE YOU LOTS OF TIME!

  READ EVERY WORD, ESPECIALLY THE WORD *NOT*

  This driver works *ONLY* for Future Domain cards using the TMC-1800 or
  the TMC-18C50 chip.  This includes models TMC-1650, 1660, 1670, and 1680.

  The following BIOS signature signatures are for boards which do *NOT*
  work with this driver (these TMC-8xx and TMC-9xx boards may work with the
  Seagate driver):

  FUTURE DOMAIN CORP. (C) 1986-1988 V4.0I 03/16/88
  FUTURE DOMAIN CORP. (C) 1986-1989 V5.0C2/14/89
  FUTURE DOMAIN CORP. (C) 1986-1989 V6.0A7/28/89
  FUTURE DOMAIN CORP. (C) 1986-1990 V6.0105/31/90
  FUTURE DOMAIN CORP. (C) 1986-1990 V6.0209/18/90
  FUTURE DOMAIN CORP. (C) 1986-1990 V7.009/18/90
  FUTURE DOMAIN CORP. (C) 1992 V8.00.004/02/92

*/

struct signature {
   char *signature;
   int  sig_offset;
   int  sig_length;
   int  major_bios_version;
   int  minor_bios_version;
} signatures[] = {
   /*          1         2         3         4         5         6 */
   /* 123456789012345678901234567890123456789012345678901234567890 */
   { "FUTURE DOMAIN CORP. (C) 1986-1990 1800-V2.07/28/89", 5, 50,  2,  0 },
   { "FUTURE DOMAIN CORP. (C) 1986-1990 1800-V1.07/28/89", 5, 50,  2,  0 },
   { "FUTURE DOMAIN CORP. (C) 1992 V3.00.004/02/92",       5, 44,  3,  0 },
   { "FUTURE DOMAIN TMC-18XX (C) 1993 V3.203/12/93",       5, 44,  3,  2 },
   { "FUTURE DOMAIN TMC-18XX",                             5, 22, -1, -1 },

   /* READ NOTICE ABOVE *BEFORE* YOU WASTE YOUR TIME ADDING A SIGANTURE
    Also, fix the disk geometry code for your signature and send your
    changes for faith@cs.unc.edu.  Above all, do *NOT* change any old
    signatures!

    Note that the last line will match a "generic" 18XX bios.  Because
    Future Domain has changed the host SCSI ID and/or the location of the
    geometry information in the on-board RAM area for each of the first
    three BIOS's, it is still important to enter a fully qualified
    signature in the table for any new BIOS's (after the host SCSI ID and
    geometry location are verified.) */
};

#define SIGNATURE_COUNT (sizeof( signatures ) / sizeof( struct signature ))

static void print_banner( void )
{
   printk( "%s", fdomain_16x0_info() );
   printk( "Future Domain: BIOS version %d.%d, %s\n",
	   bios_major, bios_minor,
	   chip == tmc1800 ? "TMC-1800"
	   : (chip == tmc18c50 ? "TMC-18C50" : "Unknown") );
   
   if (interrupt_level) {
      printk( "Future Domain: BIOS at %x; port base at %x; using IRQ %d\n",
	      (unsigned)bios_base, port_base, interrupt_level );
   } else {
      printk( "Future Domain: BIOS at %x; port base at %x; *NO* IRQ\n",
	      (unsigned)bios_base, port_base );
   }
}

static void do_pause( unsigned amount )	/* Pause for amount*10 milliseconds */
{
   unsigned long the_time = jiffies + amount; /* 0.01 seconds per jiffy */

   while (jiffies < the_time);
}

inline static void fdomain_make_bus_idle( void )
{
   outb( 0, SCSI_Cntl_port );
   outb( 0, SCSI_Mode_Cntl_port );
   if (chip == tmc18c50)
	 outb( 0x21 | PARITY_MASK, TMC_Cntl_port ); /* Clear forced intr. */
   else
	 outb( 0x01 | PARITY_MASK, TMC_Cntl_port );
}

static int fdomain_is_valid_port( int port )
{
   int options;

#if DEBUG_DETECT 
   printk( " (%x%x),",
	   inb( port + MSB_ID_Code ), inb( port + LSB_ID_Code ) );
#endif

   /* The MCA ID is a unique id for each MCA compatible board.  We