seagate.c

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/*
 *    seagate.c Copyright (C) 1992, 1993 Drew Eckhardt
 *      low level scsi driver for ST01/ST02, Future Domain TMC-885,
 *      TMC-950 by Drew Eckhardt <[e-mail]>
 *
 *      Note : TMC-880 boards don't work because they have two bits in
 *              the status register flipped, I'll fix this "RSN"
 *	[why do I have strong feeling that above message is from 1993? :-)
 *	        [e-mail]]
 *
 *      This card does all the I/O via memory mapped I/O, so there is no need
 *      to check or allocate a region of the I/O address space.
 */

/* 1996 - to use new read{b,w,l}, write{b,w,l}, and phys_to_virt
 * macros, replaced assembler routines with C. There's probably a
 * performance hit, but I only have a cdrom and can't tell. Define
 * SEAGATE_USE_ASM if you want the old assembler code -- SJT
 *
 * 1998-jul-29 - created DPRINTK macros and made it work under 
 * linux 2.1.112, simplified some #defines etc. <[e-mail]>
 *
 * Aug 2000 - aeb - deleted seagate_st0x_biosparam(). It would try to
 * read the physical disk geometry, a bad mistake. Of course it doesnt
 * matter much what geometry one invents, but on large disks it
 * returned 256 (or more) heads, causing all kind of failures.
 * Of course this means that people might see a different geometry now,
 * so boot parameters may be necessary in some cases.
 */

/*
 * Configuration :
 * To use without BIOS -DOVERRIDE=base_address -DCONTROLLER=FD or SEAGATE
 * -DIRQ will override the default of 5.
 * Note: You can now set these options from the kernel's "command line".
 * The syntax is:
 *
 *     st0x=ADDRESS,IRQ                (for a Seagate controller)
 * or:
 *     tmc8xx=ADDRESS,IRQ              (for a TMC-8xx or TMC-950 controller)
 * eg:
 *     tmc8xx=0xC8000,15
 *
 * will configure the driver for a TMC-8xx style controller using IRQ 15
 * with a base address of 0xC8000.
 *
 * -DARBITRATE 
 *      Will cause the host adapter to arbitrate for the
 *      bus for better SCSI-II compatibility, rather than just
 *      waiting for BUS FREE and then doing its thing.  Should
 *      let us do one command per Lun when I integrate my
 *      reorganization changes into the distribution sources.
 *
 * -DDEBUG=65535
 *      Will activate debug code.
 *
 * -DFAST or -DFAST32 
 *      Will use blind transfers where possible
 *
 * -DPARITY  
 *      This will enable parity.
 *
 * -DSEAGATE_USE_ASM
 *      Will use older seagate assembly code. should be (very small amount)
 *      Faster.
 *
 * -DSLOW_RATE=50
 *      Will allow compatibility with broken devices that don't
 *      handshake fast enough (ie, some CD ROM's) for the Seagate
 *      code.
 *
 *      50 is some number, It will let you specify a default
 *      transfer rate if handshaking isn't working correctly.
 *
 * -DOLDCNTDATASCEME  There is a new sceme to set the CONTROL
 *                    and DATA reigsters which complies more closely
 *                    with the SCSI2 standard. This hopefully eliminates
 *                    the need to swap the order these registers are
 *                    'messed' with. It makes the following two options
 *                    obsolete. To reenable the old sceme define this.
 *
 * The following to options are patches from the SCSI.HOWTO
 *
 * -DSWAPSTAT  This will swap the definitions for STAT_MSG and STAT_CD.
 *
 * -DSWAPCNTDATA  This will swap the order that seagate.c messes with
 *                the CONTROL an DATA registers.
 */

#include <linux/module.h>

#include <asm/io.h>
#include <asm/system.h>
#include <linux/spinlock.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/blk.h>
#include "scsi.h"
#include "hosts.h"
#include "seagate.h"
#include "constants.h"
#include <linux/stat.h>
#include <asm/uaccess.h>
#include "sd.h"
#include <scsi/scsi_ioctl.h>

#ifdef DEBUG
#define DPRINTK( when, msg... ) do { if ( (DEBUG & (when)) == (when) ) printk( msg ); } while (0)
#else
#define DPRINTK( when, msg... ) do { } while (0)
#endif
#define DANY( msg... ) DPRINTK( 0xffff, msg );

#ifndef IRQ
#define IRQ 5
#endif

#ifdef FAST32
#define FAST
#endif

#undef LINKED		/* Linked commands are currently broken! */

#if defined(OVERRIDE) && !defined(CONTROLLER)
#error Please use -DCONTROLLER=SEAGATE or -DCONTROLLER=FD to override controller type
#endif

/*
	Thanks to Brian Antoine for the example code in his Messy-Loss ST-01
		driver, and Mitsugu Suzuki for information on the ST-01
		SCSI host.
*/

/*
	CONTROL defines
*/

#define CMD_RST 		0x01
#define CMD_SEL 		0x02
#define CMD_BSY 		0x04
#define CMD_ATTN    		0x08
#define CMD_START_ARB		0x10
#define CMD_EN_PARITY		0x20
#define CMD_INTR		0x40
#define CMD_DRVR_ENABLE		0x80

/*
	STATUS
*/
#ifdef SWAPSTAT
	#define STAT_MSG		0x08
	#define STAT_CD			0x02
#else
	#define STAT_MSG		0x02
	#define STAT_CD			0x08
#endif

#define STAT_BSY		0x01
#define STAT_IO			0x04
#define STAT_REQ		0x10
#define STAT_SEL		0x20
#define STAT_PARITY		0x40
#define STAT_ARB_CMPL		0x80

/* 
	REQUESTS
*/

#define REQ_MASK (STAT_CD |  STAT_IO | STAT_MSG)
#define REQ_DATAOUT 0
#define REQ_DATAIN STAT_IO
#define REQ_CMDOUT STAT_CD
#define REQ_STATIN (STAT_CD | STAT_IO)
#define REQ_MSGOUT (STAT_MSG | STAT_CD)
#define REQ_MSGIN (STAT_MSG | STAT_CD | STAT_IO)

extern volatile int seagate_st0x_timeout;

#ifdef PARITY
	#define BASE_CMD CMD_EN_PARITY
#else
	#define BASE_CMD  0
#endif

/*
	Debugging code
*/

#define PHASE_BUS_FREE 1
#define PHASE_ARBITRATION 2
#define PHASE_SELECTION 4
#define PHASE_DATAIN 8 
#define PHASE_DATAOUT 0x10
#define PHASE_CMDOUT 0x20
#define PHASE_MSGIN 0x40
#define PHASE_MSGOUT 0x80
#define PHASE_STATUSIN 0x100
#define PHASE_ETC (PHASE_DATAIN | PHASE_DATAOUT | PHASE_CMDOUT | PHASE_MSGIN | PHASE_MSGOUT | PHASE_STATUSIN)
#define PRINT_COMMAND 0x200
#define PHASE_EXIT 0x400
#define PHASE_RESELECT 0x800
#define DEBUG_FAST 0x1000
#define DEBUG_SG   0x2000
#define DEBUG_LINKED	0x4000
#define DEBUG_BORKEN	0x8000

/* 
 *	Control options - these are timeouts specified in .01 seconds.
 */

/* 30, 20 work */
#define ST0X_BUS_FREE_DELAY 25
#define ST0X_SELECTION_DELAY 25

#define SEAGATE 1	/* these determine the type of the controller */
#define FD	2

#define ST0X_ID_STR	"Seagate ST-01/ST-02"
#define FD_ID_STR	"TMC-8XX/TMC-950"


static int internal_command (unsigned char target, unsigned char lun,
                             const void *cmnd,
                             void *buff, int bufflen, int reselect);

static int incommand;                   /* set if arbitration has finished
                                           and we are in some command phase. */

static unsigned int base_address = 0;   /* Where the card ROM starts, used to 
                                           calculate memory mapped register
                                           location.  */

static unsigned long st0x_cr_sr;        /* control register write, status
                                           register read.  256 bytes in
                                           length.
                                           Read is status of SCSI BUS, as per 
                                           STAT masks.  */

static unsigned long st0x_dr;           /* data register, read write 256
                                           bytes in length.  */

static volatile int st0x_aborted = 0;   /* set when we are aborted, ie by a
                                           time out, etc.  */

static unsigned char controller_type = 0;       /* set to SEAGATE for ST0x
                                                   boards or FD for TMC-8xx
                                                   boards */
static int irq = IRQ;

MODULE_PARM(base_address, "i");
MODULE_PARM(controller_type, "b");
MODULE_PARM(irq, "i");

#define retcode(result) (((result) << 16) | (message << 8) | status)
#define STATUS ((u8) isa_readb(st0x_cr_sr))
#define DATA ((u8) isa_readb(st0x_dr))
#define WRITE_CONTROL(d) { isa_writeb((d), st0x_cr_sr); }
#define WRITE_DATA(d) { isa_writeb((d), st0x_dr); }

void st0x_setup (char *str, int *ints)
{
  controller_type = SEAGATE;
  base_address = ints[1];
  irq = ints[2];
}

void tmc8xx_setup (char *str, int *ints)
{
  controller_type = FD;
  base_address = ints[1];
  irq = ints[2];
}

#ifndef OVERRIDE
static unsigned int seagate_bases[] =
{
  0xc8000, 0xca000, 0xcc000,
  0xce000, 0xdc000, 0xde000
};

typedef struct
{
  const unsigned char *signature;
  unsigned offset;
  unsigned length;
  unsigned char type;
}
Signature;

static const Signature __initdata signatures[] =
{
  {"ST01 v1.7  (C) Copyright 1987 Seagate", 15, 37, SEAGATE},
  {"SCSI BIOS 2.00  (C) Copyright 1987 Seagate", 15, 40, SEAGATE},

/*
 * The following two lines are NOT mistakes.  One detects ROM revision
 * 3.0.0, the other 3.2.  Since seagate has only one type of SCSI adapter,
 * and this is not going to change, the "SEAGATE" and "SCSI" together
 * are probably "good enough"
 */

  {"SEAGATE SCSI BIOS ", 16, 17, SEAGATE},
  {"SEAGATE SCSI BIOS ", 17, 17, SEAGATE},

/*
 * However, future domain makes several incompatible SCSI boards, so specific
 * signatures must be used.
 */

  {"FUTURE DOMAIN CORP. (C) 1986-1989 V5.0C2/14/89", 5, 46, FD},
  {"FUTURE DOMAIN CORP. (C) 1986-1989 V6.0A7/28/89", 5, 46, FD},
  {"FUTURE DOMAIN CORP. (C) 1986-1990 V6.0105/31/90", 5, 47, FD},
  {"FUTURE DOMAIN CORP. (C) 1986-1990 V6.0209/18/90", 5, 47, FD},
  {"FUTURE DOMAIN CORP. (C) 1986-1990 V7.009/18/90", 5, 46, FD},
  {"FUTURE DOMAIN CORP. (C) 1992 V8.00.004/02/92", 5, 44, FD},
  {"IBM F1 BIOS V1.1004/30/92", 5, 25, FD},
  {"FUTURE DOMAIN TMC-950", 5, 21, FD},
  /* Added for 2.2.16 by [e-mail] */
  {"IBM F1 V1.2009/22/93", 5, 25, FD},
};

#define NUM_SIGNATURES (sizeof(signatures) / sizeof(Signature))
#endif /* n OVERRIDE */

/*
 * hostno stores the hostnumber, as told to us by the init routine.
 */

static int hostno = -1;
static void seagate_reconnect_intr (int, void *, struct pt_regs *);
static void do_seagate_reconnect_intr (int, void *, struct pt_regs *);

#ifdef FAST
static int fast = 1;
#else
#define fast 0
#endif

#ifdef SLOW_RATE
/*
 * Support for broken devices :
 * The Seagate board has a handshaking problem.  Namely, a lack
 * thereof for slow devices.  You can blast 600K/second through
 * it if you are polling for each byte, more if you do a blind
 * transfer.  In the first case, with a fast device, REQ will
 * transition high-low or high-low-high before your loop restarts
 * and you'll have no problems.  In the second case, the board
 * will insert wait states for up to 13.2 usecs for REQ to
 * transition low->high, and everything will work.
 *
 * However, there's nothing in the state machine that says
 * you *HAVE* to see a high-low-high set of transitions before
 * sending the next byte, and slow things like the Trantor CD ROMS
 * will break because of this.
 *
 * So, we need to slow things down, which isn't as simple as it
 * seems.  We can't slow things down period, because then people
 * who don't recompile their kernels will shoot me for ruining
 * their performance.  We need to do it on a case per case basis.
 *
 * The best for performance will be to, only for borken devices
 * (this is stored on a per-target basis in the scsi_devices array)
 *
 * Wait for a low->high transition before continuing with that
 * transfer.  If we timeout, continue anyways.  We don't need
 * a long timeout, because REQ should only be asserted until the
 * corresponding ACK is received and processed.
 *
 * Note that we can't use the system timer for this, because of
 * resolution, and we *really* can't use the timer chip since
 * gettimeofday() and the beeper routines use that.  So,
 * the best thing for us to do will be to calibrate a timing
 * loop in the initialization code using the timer chip before
 * gettimeofday() can screw with it.
 *
 * FIXME: this is broken (not borken :-). Empty loop costs less than
 * loop with ISA access in it! -- [e-mail]
 */

static int borken_calibration = 0;
static void __init borken_init (void)
{
  register int count = 0, start = jiffies + 1, stop = start + 25;

  while (time_before(jiffies, start)) ;
  for (; time_before(jiffies, stop); ++count) ;

/*
 * Ok, we now have a count for .25 seconds.  Convert to a
 * count per second and divide by transfer rate in K.  */

  borken_calibration = (count * 4) / (SLOW_RATE * 1024);

  if (borken_calibration < 1)
    borken_calibration = 1;
}

static inline void borken_wait (void)
{
  register int count;

  for (count = borken_calibration; count && (STATUS & STAT_REQ); --count) ;
#if (DEBUG & DEBUG_BORKEN)
  if (count)
    printk ("scsi%d : borken timeout\n", hostno);
#endif
}

#endif /* def SLOW_RATE */

/* These beasts only live on ISA, and ISA means 8MHz. Each ULOOP()
 * contains at least one ISA access, which takes more than 0.125
 * usec. So if we loop 8 times time in usec, we are safe.
 */

#define ULOOP( i ) for (clock = i*8;;)
#define TIMEOUT (!(clock--))

int __init seagate_st0x_detect (Scsi_Host_Template * tpnt)
{
  struct Scsi_Host *instance;
  int i, j;

  tpnt->proc_name = "seagate";
/*
 *    First, we try for the manual override.  */