ataflop.c

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/*
 *  drivers/block/ataflop.c
 *
 *  Copyright (C) 1993  Greg Harp
 *  Atari Support by Bjoern Brauel, Roman Hodek
 *
 *  Big cleanup Sep 11..14 1994 Roman Hodek:
 *   - Driver now works interrupt driven
 *   - Support for two drives; should work, but I cannot test that :-(
 *   - Reading is done in whole tracks and buffered to speed up things
 *   - Disk change detection and drive deselecting after motor-off
 *     similar to TOS
 *   - Autodetection of disk format (DD/HD); untested yet, because I
 *     don't have an HD drive :-(
 *
 *  Fixes Nov 13 1994 Martin Schaller:
 *   - Autodetection works now
 *   - Support for 5 1/4'' disks
 *   - Removed drive type (unknown on atari)
 *   - Do seeks with 8 Mhz
 *
 *  Changes by Andreas Schwab:
 *   - After errors in multiple read mode try again reading single sectors
 *  (Feb 1995):
 *   - Clean up error handling
 *   - Set blk_size for proper size checking
 *   - Initialize track register when testing presence of floppy
 *   - Implement some ioctl's
 *
 *  Changes by Torsten Lang:
 *   - When probing the floppies we should add the FDCCMDADD_H flag since
 *     the FDC will otherwise wait forever when no disk is inserted...
 *
 * ++ Freddi Aschwanden (fa) 20.9.95 fixes for medusa:
 *  - MFPDELAY() after each FDC access -> atari 
 *  - more/other disk formats
 *  - DMA to the block buffer directly if we have a 32bit DMA
 *  - for medusa, the step rate is always 3ms
 *  - on medusa, use only cache_push()
 * Roman:
 *  - Make disk format numbering independent from minors
 *  - Let user set max. supported drive type (speeds up format
 *    detection, saves buffer space)
 *
 * Roman 10/15/95:
 *  - implement some more ioctls
 *  - disk formatting
 *  
 * Andreas 95/12/12:
 *  - increase gap size at start of track for HD/ED disks
 *
 * Michael (MSch) 11/07/96:
 *  - implemented FDSETPRM and FDDEFPRM ioctl
 *
 * Andreas (97/03/19):
 *  - implemented missing BLK* ioctls
 *
 *  Things left to do:
 *   - Formatting
 *   - Maybe a better strategy for disk change detection (does anyone
 *     know one?)
 */

#include <linux/module.h>

#include <linux/fd.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/mutex.h>

#include <asm/atafd.h>
#include <asm/atafdreg.h>
#include <asm/atariints.h>
#include <asm/atari_stdma.h>
#include <asm/atari_stram.h>

#define FD_MAX_UNITS 2

#undef DEBUG

static DEFINE_MUTEX(ataflop_mutex);
static struct request *fd_request;
static int fdc_queue;

/* Disk types: DD, HD, ED */
static struct atari_disk_type {
    const char  *name;
    unsigned    spt;        /* sectors per track */
    unsigned    blocks;     /* total number of blocks */
    unsigned    fdc_speed;  /* fdc_speed setting */
    unsigned    stretch;    /* track doubling ? */
} atari_disk_type[] = {
    { "d360",  9, 720, 0, 0},   /*  0: 360kB diskette */
    { "D360",  9, 720, 0, 1},   /*  1: 360kb in 720k or 1.2MB drive */
    { "D720",  9,1440, 0, 0},   /*  2: 720kb in 720k or 1.2MB drive */
    { "D820", 10,1640, 0, 0},   /*  3: DD disk with 82 tracks/10 sectors */
/* formats above are probed for type DD */
#define MAX_TYPE_DD 3
    { "h1200",15,2400, 3, 0},   /*  4: 1.2MB diskette */
    { "H1440",18,2880, 3, 0},   /*  5: 1.4 MB diskette (HD) */
    { "H1640",20,3280, 3, 0},   /*  6: 1.64MB diskette (fat HD) 82 tr 20 sec */
/* formats above are probed for types DD and HD */
#define MAX_TYPE_HD 6
    { "E2880",36,5760, 3, 0},   /*  7: 2.8 MB diskette (ED) */
    { "E3280",40,6560, 3, 0},   /*  8: 3.2 MB diskette (fat ED) 82 tr 40 sec */
/* formats above are probed for types DD, HD and ED */
#define MAX_TYPE_ED 8
/* types below are never autoprobed */
    { "H1680",21,3360, 3, 0},   /*  9: 1.68MB diskette (fat HD) 80 tr 21 sec */
    { "h410",10,820, 0, 1},     /* 10: 410k diskette 41 tr 10 sec, stretch */
    { "h1476",18,2952, 3, 0},   /* 11: 1.48MB diskette 82 tr 18 sec */
    { "H1722",21,3444, 3, 0},   /* 12: 1.72MB diskette 82 tr 21 sec */
    { "h420",10,840, 0, 1},     /* 13: 420k diskette 42 tr 10 sec, stretch */
    { "H830",10,1660, 0, 0},    /* 14: 820k diskette 83 tr 10 sec */
    { "h1494",18,2952, 3, 0},   /* 15: 1.49MB diskette 83 tr 18 sec */
    { "H1743",21,3486, 3, 0},   /* 16: 1.74MB diskette 83 tr 21 sec */
    { "h880",11,1760, 0, 0},    /* 17: 880k diskette 80 tr 11 sec */
    { "D1040",13,2080, 0, 0},   /* 18: 1.04MB diskette 80 tr 13 sec */
    { "D1120",14,2240, 0, 0},   /* 19: 1.12MB diskette 80 tr 14 sec */
    { "h1600",20,3200, 3, 0},   /* 20: 1.60MB diskette 80 tr 20 sec */
    { "H1760",22,3520, 3, 0},   /* 21: 1.76MB diskette 80 tr 22 sec */
    { "H1920",24,3840, 3, 0},   /* 22: 1.92MB diskette 80 tr 24 sec */
    { "E3200",40,6400, 3, 0},   /* 23: 3.2MB diskette 80 tr 40 sec */
    { "E3520",44,7040, 3, 0},   /* 24: 3.52MB diskette 80 tr 44 sec */
    { "E3840",48,7680, 3, 0},   /* 25: 3.84MB diskette 80 tr 48 sec */
    { "H1840",23,3680, 3, 0},   /* 26: 1.84MB diskette 80 tr 23 sec */
    { "D800",10,1600, 0, 0},    /* 27: 800k diskette 80 tr 10 sec */
};

static int StartDiskType[] = {
    MAX_TYPE_DD,
    MAX_TYPE_HD,
    MAX_TYPE_ED
};

#define TYPE_DD     0
#define TYPE_HD     1
#define TYPE_ED     2

static int DriveType = TYPE_HD;

static DEFINE_SPINLOCK(ataflop_lock);

/* Array for translating minors into disk formats */
static struct {
    int      index;
    unsigned drive_types;
} minor2disktype[] = {
    {  0, TYPE_DD },    /*  1: d360 */
    {  4, TYPE_HD },    /*  2: h1200 */
    {  1, TYPE_DD },    /*  3: D360 */
    {  2, TYPE_DD },    /*  4: D720 */
    {  1, TYPE_DD },    /*  5: h360 = D360 */
    {  2, TYPE_DD },    /*  6: h720 = D720 */
    {  5, TYPE_HD },    /*  7: H1440 */
    {  7, TYPE_ED },    /*  8: E2880 */
/* some PC formats :-) */
    {  8, TYPE_ED },    /*  9: E3280    <- was "CompaQ" == E2880 for PC */
    {  5, TYPE_HD },    /* 10: h1440 = H1440 */
    {  9, TYPE_HD },    /* 11: H1680 */
    { 10, TYPE_DD },    /* 12: h410  */
    {  3, TYPE_DD },    /* 13: H820     <- == D820, 82x10 */
    { 11, TYPE_HD },    /* 14: h1476 */
    { 12, TYPE_HD },    /* 15: H1722 */
    { 13, TYPE_DD },    /* 16: h420  */
    { 14, TYPE_DD },    /* 17: H830  */
    { 15, TYPE_HD },    /* 18: h1494 */
    { 16, TYPE_HD },    /* 19: H1743 */
    { 17, TYPE_DD },    /* 20: h880  */
    { 18, TYPE_DD },    /* 21: D1040 */
    { 19, TYPE_DD },    /* 22: D1120 */
    { 20, TYPE_HD },    /* 23: h1600 */
    { 21, TYPE_HD },    /* 24: H1760 */
    { 22, TYPE_HD },    /* 25: H1920 */
    { 23, TYPE_ED },    /* 26: E3200 */
    { 24, TYPE_ED },    /* 27: E3520 */
    { 25, TYPE_ED },    /* 28: E3840 */
    { 26, TYPE_HD },    /* 29: H1840 */
    { 27, TYPE_DD },    /* 30: D800  */
    {  6, TYPE_HD },    /* 31: H1640    <- was H1600 == h1600 for PC */
};

#define NUM_DISK_MINORS ARRAY_SIZE(minor2disktype)

/*
 * Maximum disk size (in kilobytes). This default is used whenever the
 * current disk size is unknown.
 */
#define MAX_DISK_SIZE 3280

/*
 * MSch: User-provided type information. 'drive' points to
 * the respective entry of this array. Set by FDSETPRM ioctls.
 */
static struct atari_disk_type user_params[FD_MAX_UNITS];

/*
 * User-provided permanent type information. 'drive' points to
 * the respective entry of this array.  Set by FDDEFPRM ioctls, 
 * restored upon disk change by floppy_revalidate() if valid (as seen by
 * default_params[].blocks > 0 - a bit in unit[].flags might be used for this?)
 */
static struct atari_disk_type default_params[FD_MAX_UNITS];

/* current info on each unit */
static struct atari_floppy_struct {
    int connected;              /* !=0 : drive is connected */
    int autoprobe;              /* !=0 : do autoprobe       */

    struct atari_disk_type  *disktype;  /* current type of disk */

    int track;      /* current head position or -1 if
                   unknown */
    unsigned int steprate;  /* steprate setting */
    unsigned int wpstat;    /* current state of WP signal (for
                   disk change detection) */
    int flags;      /* flags */
    struct gendisk *disk;
    int ref;
    int type;
} unit[FD_MAX_UNITS];

#define UD  unit[drive]
#define UDT unit[drive].disktype
#define SUD unit[SelectedDrive]
#define SUDT    unit[SelectedDrive].disktype


#define FDC_READ(reg) ({            \
    /* unsigned long __flags; */        \
    unsigned short __val;           \
    /* local_irq_save(__flags); */      \
    dma_wd.dma_mode_status = 0x80 | (reg);  \
    udelay(25);                 \
    __val = dma_wd.fdc_acces_seccount;      \
    MFPDELAY();                 \
    /* local_irq_restore(__flags); */       \
    __val & 0xff;               \
})

#define FDC_WRITE(reg,val)          \
    do {                    \
    /* unsigned long __flags; */        \
    /* local_irq_save(__flags); */      \
    dma_wd.dma_mode_status = 0x80 | (reg);  \
    udelay(25);             \
    dma_wd.fdc_acces_seccount = (val);  \
    MFPDELAY();             \
        /* local_irq_restore(__flags); */   \
    } while(0)


/* Buffering variables:
 * First, there is a DMA buffer in ST-RAM that is used for floppy DMA
 * operations. Second, a track buffer is used to cache a whole track
 * of the disk to save read operations. These are two separate buffers
 * because that allows write operations without clearing the track buffer.
 */

static int MaxSectors[] = {
    11, 22, 44
};
static int BufferSize[] = {
    15*512, 30*512, 60*512
};

#define BUFFER_SIZE (BufferSize[DriveType])

unsigned char *DMABuffer;             /* buffer for writes */
static unsigned long PhysDMABuffer;   /* physical address */

static int UseTrackbuffer = -1;       /* Do track buffering? */
module_param(UseTrackbuffer, int, 0);

unsigned char *TrackBuffer;           /* buffer for reads */
static unsigned long PhysTrackBuffer; /* physical address */
static int BufferDrive, BufferSide, BufferTrack;
static int read_track;      /* non-zero if we are reading whole tracks */

#define SECTOR_BUFFER(sec)  (TrackBuffer + ((sec)-1)*512)
#define IS_BUFFERED(drive,side,track) \
    (BufferDrive == (drive) && BufferSide == (side) && BufferTrack == (track))

/*
 * These are global variables, as that's the easiest way to give
 * information to interrupts. They are the data used for the current
 * request.
 */
static int SelectedDrive = 0;
static int ReqCmd, ReqBlock;
static int ReqSide, ReqTrack, ReqSector, ReqCnt;
static int HeadSettleFlag = 0;
static unsigned char *ReqData, *ReqBuffer;
static int MotorOn = 0, MotorOffTrys;
static int IsFormatting = 0, FormatError;

static int UserSteprate[FD_MAX_UNITS] = { -1, -1 };
module_param_array(UserSteprate, int, NULL, 0);

/* Synchronization of FDC access. */
static volatile int fdc_busy = 0;
static DECLARE_WAIT_QUEUE_HEAD(fdc_wait);
static DECLARE_WAIT_QUEUE_HEAD(format_wait);

static unsigned long changed_floppies = 0xff, fake_change = 0;
#define CHECK_CHANGE_DELAY  HZ/2

#define FD_MOTOR_OFF_DELAY  (3*HZ)
#define FD_MOTOR_OFF_MAXTRY (10*20)

#define FLOPPY_TIMEOUT      (6*HZ)
#define RECALIBRATE_ERRORS  4   /* After this many errors the drive
                     * will be recalibrated. */
#define MAX_ERRORS      8   /* After this many errors the driver
                     * will give up. */


/*
 * The driver is trying to determine the correct media format
 * while Probing is set. fd_rwsec_done() clears it after a
 * successful access.
 */
static int Probing = 0;

/* This flag is set when a dummy seek is necessary to make the WP
 * status bit accessible.
 */
static int NeedSeek = 0;


#ifdef DEBUG
#define DPRINT(a)   printk a
#else
#define DPRINT(a)
#endif

/***************************** Prototypes *****************************/

static void fd_select_side( int side );
static void fd_select_drive( int drive );
static void fd_deselect( void );
static void fd_motor_off_timer( unsigned long dummy );
static void check_change( unsigned long dummy );
static irqreturn_t floppy_irq (int irq, void *dummy);
static void fd_error( void );
static int do_format(int drive, int type, struct atari_format_descr *desc);
static void do_fd_action( int drive );
static void fd_calibrate( void );
static void fd_calibrate_done( int status );
static void fd_seek( void );
static void fd_seek_done( int status );
static void fd_rwsec( void );
static void fd_readtrack_check( unsigned long dummy );
static void fd_rwsec_done( int status );
static void fd_rwsec_done1(int status);
static void fd_writetrack( void );
static void fd_writetrack_done( int status );
static void fd_times_out( unsigned long dummy );
static void finish_fdc( void );
static void finish_fdc_done( int dummy );
static void setup_req_params( int drive );
static void redo_fd_request( void);
static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, unsigned int
                     cmd, unsigned long param);
static void fd_probe( int drive );
static int fd_test_drive_present( int drive );
static void config_types( void );
static int floppy_open(struct block_device *bdev, fmode_t mode);
static int floppy_release(struct gendisk *disk, fmode_t mode);

/************************* End of Prototypes **************************/

static DEFINE_TIMER(motor_off_timer, fd_motor_off_timer, 0, 0);
static DEFINE_TIMER(readtrack_timer, fd_readtrack_check, 0, 0);
static DEFINE_TIMER(timeout_timer, fd_times_out, 0, 0);
static DEFINE_TIMER(fd_timer, check_change, 0, 0);
    
static void fd_end_request_cur(int err)
{
    if (!__blk_end_request_cur(fd_request, err))
        fd_request = NULL;
}

static inline void start_motor_off_timer(void)
{
    mod_timer(&motor_off_timer, jiffies + FD_MOTOR_OFF_DELAY);
    MotorOffTrys = 0;
}

static inline void start_check_change_timer( void )
{
    mod_timer(&fd_timer, jiffies + CHECK_CHANGE_DELAY);
}

static inline void start_timeout(void)
{
    mod_timer(&timeout_timer, jiffies + FLOPPY_TIMEOUT);
}

static inline void stop_timeout(void)
{
    del_timer(&timeout_timer);
}

/* Select the side to use. */

static void fd_select_side( int side )
{
    unsigned long flags;

    /* protect against various other ints mucking around with the PSG */
    local_irq_save(flags);
  
    sound_ym.rd_data_reg_sel = 14; /* Select PSG Port A */
    sound_ym.wd_data = (side == 0) ? sound_ym.rd_data_reg_sel | 0x01 :
                                     sound_ym.rd_data_reg_sel & 0xfe;

    local_irq_restore(flags);
}


/* Select a drive, update the FDC's track register and set the correct
 * clock speed for this disk's type.
 */

static void fd_select_drive( int drive )
{
    unsigned long flags;
    unsigned char tmp;
  
    if (drive == SelectedDrive)
      return;

    /* protect against various other ints mucking around with the PSG */
    local_irq_save(flags);
    sound_ym.rd_data_reg_sel = 14; /* Select PSG Port A */
    tmp = sound_ym.rd_data_reg_sel;
    sound_ym.wd_data = (tmp | DSKDRVNONE) & ~(drive == 0 ? DSKDRV0 : DSKDRV1);
    atari_dont_touch_floppy_select = 1;
    local_irq_restore(flags);

    /* restore track register to saved value */
    FDC_WRITE( FDCREG_TRACK, UD.track );
    udelay(25);

    /* select 8/16 MHz */
    if (UDT)
        if (ATARIHW_PRESENT(FDCSPEED))
            dma_wd.fdc_speed = UDT->fdc_speed;
    
    SelectedDrive = drive;
}


/* Deselect both drives. */

static void fd_deselect( void )
{
    unsigned long flags;

    /* protect against various other ints mucking around with the PSG */
    local_irq_save(flags);
    atari_dont_touch_floppy_select = 0;
    sound_ym.rd_data_reg_sel=14;    /* Select PSG Port A */
    sound_ym.wd_data = (sound_ym.rd_data_reg_sel |
                (MACH_IS_FALCON ? 3 : 7)); /* no drives selected */
    /* On Falcon, the drive B select line is used on the printer port, so
     * leave it alone... */
    SelectedDrive = -1;
    local_irq_restore(flags);
}


/* This timer function deselects the drives when the FDC switched the
 * motor off. The deselection cannot happen earlier because the FDC
 * counts the index signals, which arrive only if one drive is selected.
 */

static void fd_motor_off_timer( unsigned long dummy )
{
    unsigned char status;

    if (SelectedDrive < 0)
        /* no drive selected, needn't deselect anyone */
        return;

    if (stdma_islocked())
        goto retry;

    status = FDC_READ( FDCREG_STATUS );

    if (!(status & 0x80)) {
        /* motor already turned off by FDC -> deselect drives */
        MotorOn = 0;
        fd_deselect();
        return;
    }
    /* not yet off, try again */

  retry:
    /* Test again later; if tested too often, it seems there is no disk
     * in the drive and the FDC will leave the motor on forever (or,
     * at least until a disk is inserted). So we'll test only twice
     * per second from then on...
     */
    mod_timer(&motor_off_timer,
          jiffies + (MotorOffTrys++ < FD_MOTOR_OFF_MAXTRY ? HZ/20 : HZ/2));
}


/* This function is repeatedly called to detect disk changes (as good
 * as possible) and keep track of the current state of the write protection.
 */

static void check_change( unsigned long dummy )
{
    static int    drive = 0;

    unsigned long flags;
    unsigned char old_porta;
    int           stat;

    if (++drive > 1 || !UD.connected)
        drive = 0;

    /* protect against various other ints mucking around with the PSG */
    local_irq_save(flags);

    if (!stdma_islocked()) {
        sound_ym.rd_data_reg_sel = 14;
        old_porta = sound_ym.rd_data_reg_sel;
        sound_ym.wd_data = (old_porta | DSKDRVNONE) &
                           ~(drive == 0 ? DSKDRV0 : DSKDRV1);
        stat = !!(FDC_READ( FDCREG_STATUS ) & FDCSTAT_WPROT);
        sound_ym.wd_data = old_porta;

        if (stat != UD.wpstat) {
            DPRINT(( "wpstat[%d] = %d\n", drive, stat ));
            UD.wpstat = stat;
            set_bit (drive, &changed_floppies);
        }
    }
    local_irq_restore(flags);

    start_check_change_timer();
}

 
/* Handling of the Head Settling Flag: This flag should be set after each
 * seek operation, because we don't use seeks with verify.
 */

static inline void set_head_settle_flag(void)
{
    HeadSettleFlag = FDCCMDADD_E;
}

static inline int get_head_settle_flag(void)
{
    int tmp = HeadSettleFlag;
    HeadSettleFlag = 0;
    return( tmp );
}

static inline void copy_buffer(void *from, void *to)
{
    ulong *p1 = (ulong *)from, *p2 = (ulong *)to;
    int cnt;

    for (cnt = 512/4; cnt; cnt--)
        *p2++ = *p1++;
}

  
  

/* General Interrupt Handling */

static void (*FloppyIRQHandler)( int status ) = NULL;

static irqreturn_t floppy_irq (int irq, void *dummy)
{
    unsigned char status;
    void (*handler)( int );

    handler = xchg(&FloppyIRQHandler, NULL);

    if (handler) {
        nop();
        status = FDC_READ( FDCREG_STATUS );
        DPRINT(("FDC irq, status = %02x handler = %08lx\n",status,(unsigned long)handler));
        handler( status );
    }
    else {
        DPRINT(("FDC irq, no handler\n"));
    }
    return IRQ_HANDLED;
}


/* Error handling: If some error happened, retry some times, then
 * recalibrate, then try again, and fail after MAX_ERRORS.
 */

static void fd_error( void )
{
    if (IsFormatting) {
        IsFormatting = 0;
        FormatError = 1;
        wake_up( &format_wait );
        return;
    }

    if (!fd_request)
        return;

    fd_request->errors++;
    if (fd_request->errors >= MAX_ERRORS) {
        printk(KERN_ERR "fd%d: too many errors.\n", SelectedDrive );
        fd_end_request_cur(-EIO);
    }
    else if (fd_request->errors == RECALIBRATE_ERRORS) {
        printk(KERN_WARNING "fd%d: recalibrating\n", SelectedDrive );
        if (SelectedDrive != -1)
            SUD.track = -1;
    }
    redo_fd_request();
}



#define SET_IRQ_HANDLER(proc) do { FloppyIRQHandler = (proc); } while(0)


/* ---------- Formatting ---------- */

#define FILL(n,val)     \
    do {            \
    memset( p, val, n );    \
    p += n;         \
    } while(0)

static int do_format(int drive, int type, struct atari_format_descr *desc)
{
    unsigned char   *p;
    int sect, nsect;
    unsigned long   flags;

    DPRINT(("do_format( dr=%d tr=%d he=%d offs=%d )\n",
        drive, desc->track, desc->head, desc->sect_offset ));

    local_irq_save(flags);
    while( fdc_busy ) sleep_on( &fdc_wait );
    fdc_busy = 1;
    stdma_lock(floppy_irq, NULL);
    atari_turnon_irq( IRQ_MFP_FDC ); /* should be already, just to be sure */
    local_irq_restore(flags);

    if (type) {
        if (--type >= NUM_DISK_MINORS ||
            minor2disktype[type].drive_types > DriveType) {
            redo_fd_request();
            return -EINVAL;
        }
        type = minor2disktype[type].index;
        UDT = &atari_disk_type[type];
    }

    if (!UDT || desc->track >= UDT->blocks/UDT->spt/2 || desc->head >= 2) {
        redo_fd_request();
        return -EINVAL;
    }

    nsect = UDT->spt;
    p = TrackBuffer;
    /* The track buffer is used for the raw track data, so its
       contents become invalid! */
    BufferDrive = -1;
    /* stop deselect timer */
    del_timer( &motor_off_timer );

    FILL( 60 * (nsect / 9), 0x4e );
    for( sect = 0; sect < nsect; ++sect ) {
        FILL( 12, 0 );
        FILL( 3, 0xf5 );
        *p++ = 0xfe;
        *p++ = desc->track;
        *p++ = desc->head;
        *p++ = (nsect + sect - desc->sect_offset) % nsect + 1;
        *p++ = 2;
        *p++ = 0xf7;
        FILL( 22, 0x4e );
        FILL( 12, 0 );
        FILL( 3, 0xf5 );
        *p++ = 0xfb;
        FILL( 512, 0xe5 );
        *p++ = 0xf7;
        FILL( 40, 0x4e );
    }
    FILL( TrackBuffer+BUFFER_SIZE-p, 0x4e );

    IsFormatting = 1;
    FormatError = 0;
    ReqTrack = desc->track;
    ReqSide  = desc->head;
    do_fd_action( drive );

    sleep_on( &format_wait );

    redo_fd_request();
    return( FormatError ? -EIO : 0 );   
}


/* do_fd_action() is the general procedure for a fd request: All
 * required parameter settings (drive select, side select, track
 * position) are checked and set if needed. For each of these
 * parameters and the actual reading or writing exist two functions:
 * one that starts the setting (or skips it if possible) and one
 * callback for the "done" interrupt. Each done func calls the next
 * set function to propagate the request down to fd_rwsec_done().
 */

static void do_fd_action( int drive )
{
    DPRINT(("do_fd_action\n"));
    
    if (UseTrackbuffer && !IsFormatting) {
    repeat:
        if (IS_BUFFERED( drive, ReqSide, ReqTrack )) {
        if (ReqCmd == READ) {
            copy_buffer( SECTOR_BUFFER(ReqSector), ReqData );
            if (++ReqCnt < blk_rq_cur_sectors(fd_request)) {
            /* read next sector */
            setup_req_params( drive );
            goto repeat;
            }
            else {
            /* all sectors finished */
            fd_end_request_cur(0);
            redo_fd_request();
            return;
            }
        }
        else {
            /* cmd == WRITE, pay attention to track buffer
             * consistency! */
            copy_buffer( ReqData, SECTOR_BUFFER(ReqSector) );
        }
        }
    }

    if (SelectedDrive != drive)
        fd_select_drive( drive );
    
    if (UD.track == -1)
        fd_calibrate();
    else if (UD.track != ReqTrack << UDT->stretch)
        fd_seek();
    else if (IsFormatting)
        fd_writetrack();
    else
        fd_rwsec();
}


/* Seek to track 0 if the current track is unknown */

static void fd_calibrate( void )
{
    if (SUD.track >= 0) {
        fd_calibrate_done( 0 );
        return;
    }

    if (ATARIHW_PRESENT(FDCSPEED))
        dma_wd.fdc_speed = 0;   /* always seek with 8 Mhz */;
    DPRINT(("fd_calibrate\n"));
    SET_IRQ_HANDLER( fd_calibrate_done );
    /* we can't verify, since the speed may be incorrect */
    FDC_WRITE( FDCREG_CMD, FDCCMD_RESTORE | SUD.steprate );

    NeedSeek = 1;
    MotorOn = 1;
    start_timeout();
    /* wait for IRQ */
}


static void fd_calibrate_done( int status )
{
    DPRINT(("fd_calibrate_done()\n"));
    stop_timeout();
    
    /* set the correct speed now */
    if (ATARIHW_PRESENT(FDCSPEED))
        dma_wd.fdc_speed = SUDT->fdc_speed;
    if (status & FDCSTAT_RECNF) {
        printk(KERN_ERR "fd%d: restore failed\n", SelectedDrive );
        fd_error();
    }
    else {
        SUD.track = 0;
        fd_seek();
    }
}
  
  
/* Seek the drive to the requested track. The drive must have been
 * calibrated at some point before this.
 */
  
static void fd_seek( void )
{
    if (SUD.track == ReqTrack << SUDT->stretch) {
        fd_seek_done( 0 );
        return;
    }

    if (ATARIHW_PRESENT(FDCSPEED)) {
        dma_wd.fdc_speed = 0;   /* always seek witch 8 Mhz */
        MFPDELAY();
    }

    DPRINT(("fd_seek() to track %d\n",ReqTrack));
    FDC_WRITE( FDCREG_DATA, ReqTrack << SUDT->stretch);
    udelay(25);
    SET_IRQ_HANDLER( fd_seek_done );
    FDC_WRITE( FDCREG_CMD, FDCCMD_SEEK | SUD.steprate );

    MotorOn = 1;
    set_head_settle_flag();
    start_timeout();
    /* wait for IRQ */
}


static void fd_seek_done( int status )
{
    DPRINT(("fd_seek_done()\n"));
    stop_timeout();
    
    /* set the correct speed */
    if (ATARIHW_PRESENT(FDCSPEED))
        dma_wd.fdc_speed = SUDT->fdc_speed;
    if (status & FDCSTAT_RECNF) {
        printk(KERN_ERR "fd%d: seek error (to track %d)\n",
                SelectedDrive, ReqTrack );
        /* we don't know exactly which track we are on now! */
        SUD.track = -1;
        fd_error();
    }
    else {
        SUD.track = ReqTrack << SUDT->stretch;
        NeedSeek = 0;
        if (IsFormatting)
            fd_writetrack();
        else
            fd_rwsec();
    }
}


/* This does the actual reading/writing after positioning the head
 * over the correct track.
 */

static int MultReadInProgress = 0;


static void fd_rwsec( void )
{
    unsigned long paddr, flags;
    unsigned int  rwflag, old_motoron;
    unsigned int track;
    
    DPRINT(("fd_rwsec(), Sec=%d, Access=%c\n",ReqSector, ReqCmd == WRITE ? 'w' : 'r' ));
    if (ReqCmd == WRITE) {
        if (ATARIHW_PRESENT(EXTD_DMA)) {
            paddr = virt_to_phys(ReqData);
        }
        else {
            copy_buffer( ReqData, DMABuffer );
            paddr = PhysDMABuffer;
        }
        dma_cache_maintenance( paddr, 512, 1 );
        rwflag = 0x100;
    }
    else {
        if (read_track)
            paddr = PhysTrackBuffer;
        else
            paddr = ATARIHW_PRESENT(EXTD_DMA) ? 
                virt_to_phys(ReqData) : PhysDMABuffer;
        rwflag = 0;
    }

    fd_select_side( ReqSide );
  
    /* Start sector of this operation */
    FDC_WRITE( FDCREG_SECTOR, read_track ? 1 : ReqSector );
    MFPDELAY();
    /* Cheat for track if stretch != 0 */
    if (SUDT->stretch) {
        track = FDC_READ( FDCREG_TRACK);
        MFPDELAY();
        FDC_WRITE( FDCREG_TRACK, track >> SUDT->stretch);
    }
    udelay(25);
  
    /* Setup DMA */
    local_irq_save(flags);
    dma_wd.dma_lo = (unsigned char)paddr;
    MFPDELAY();
    paddr >>= 8;
    dma_wd.dma_md = (unsigned char)paddr;
    MFPDELAY();
    paddr >>= 8;
    if (ATARIHW_PRESENT(EXTD_DMA))
        st_dma_ext_dmahi = (unsigned short)paddr;
    else
        dma_wd.dma_hi = (unsigned char)paddr;
    MFPDELAY();
    local_irq_restore(flags);
  
    /* Clear FIFO and switch DMA to correct mode */  
    dma_wd.dma_mode_status = 0x90 | rwflag;  
    MFPDELAY();
    dma_wd.dma_mode_status = 0x90 | (rwflag ^ 0x100);  
    MFPDELAY();
    dma_wd.dma_mode_status = 0x90 | rwflag;
    MFPDELAY();
  
    /* How many sectors for DMA */
    dma_wd.fdc_acces_seccount = read_track ? SUDT->spt : 1;
  
    udelay(25);  
  
    /* Start operation */
    dma_wd.dma_mode_status = FDCSELREG_STP | rwflag;
    udelay(25);
    SET_IRQ_HANDLER( fd_rwsec_done );
    dma_wd.fdc_acces_seccount =
      (get_head_settle_flag() |
       (rwflag ? FDCCMD_WRSEC : (FDCCMD_RDSEC | (read_track ? FDCCMDADD_M : 0))));

    old_motoron = MotorOn;
    MotorOn = 1;
    NeedSeek = 1;
    /* wait for interrupt */

    if (read_track) {
        /* If reading a whole track, wait about one disk rotation and
         * then check if all sectors are read. The FDC will even
         * search for the first non-existent sector and need 1 sec to
         * recognise that it isn't present :-(
         */
        MultReadInProgress = 1;
        mod_timer(&readtrack_timer,
              /* 1 rot. + 5 rot.s if motor was off  */
              jiffies + HZ/5 + (old_motoron ? 0 : HZ));
    }
    start_timeout();
}

    
static void fd_readtrack_check( unsigned long dummy )
{
    unsigned long flags, addr, addr2;

    local_irq_save(flags);

    if (!MultReadInProgress) {
        /* This prevents a race condition that could arise if the
         * interrupt is triggered while the calling of this timer
         * callback function takes place. The IRQ function then has
         * already cleared 'MultReadInProgress'  when flow of control
         * gets here.
         */
        local_irq_restore(flags);
        return;
    }

    /* get the current DMA address */
    /* ++ f.a. read twice to avoid being fooled by switcher */
    addr = 0;
    do {
        addr2 = addr;
        addr = dma_wd.dma_lo & 0xff;
        MFPDELAY();
        addr |= (dma_wd.dma_md & 0xff) << 8;
        MFPDELAY();
        if (ATARIHW_PRESENT( EXTD_DMA ))
            addr |= (st_dma_ext_dmahi & 0xffff) << 16;
        else
            addr |= (dma_wd.dma_hi & 0xff) << 16;
        MFPDELAY();
    } while(addr != addr2);
  
    if (addr >= PhysTrackBuffer + SUDT->spt*512) {
        /* already read enough data, force an FDC interrupt to stop
         * the read operation
         */
        SET_IRQ_HANDLER( NULL );
        MultReadInProgress = 0;
        local_irq_restore(flags);
        DPRINT(("fd_readtrack_check(): done\n"));
        FDC_WRITE( FDCREG_CMD, FDCCMD_FORCI );
        udelay(25);

        /* No error until now -- the FDC would have interrupted
         * otherwise!
         */
        fd_rwsec_done1(0);
    }
    else {
        /* not yet finished, wait another tenth rotation */
        local_irq_restore(flags);
        DPRINT(("fd_readtrack_check(): not yet finished\n"));
        mod_timer(&readtrack_timer, jiffies + HZ/5/10);
    }
}


static void fd_rwsec_done( int status )
{
    DPRINT(("fd_rwsec_done()\n"));

    if (read_track) {
        del_timer(&readtrack_timer);
        if (!MultReadInProgress)
            return;
        MultReadInProgress = 0;
    }
    fd_rwsec_done1(status);
}

static void fd_rwsec_done1(int status)
{
    unsigned int track;

    stop_timeout();
    
    /* Correct the track if stretch != 0 */
    if (SUDT->stretch) {
        track = FDC_READ( FDCREG_TRACK);
        MFPDELAY();
        FDC_WRITE( FDCREG_TRACK, track << SUDT->stretch);
    }

    if (!UseTrackbuffer) {
        dma_wd.dma_mode_status = 0x90;
        MFPDELAY();
        if (!(dma_wd.dma_mode_status & 0x01)) {
            printk(KERN_ERR "fd%d: DMA error\n", SelectedDrive );
            goto err_end;
        }
    }
    MFPDELAY();

    if (ReqCmd == WRITE && (status & FDCSTAT_WPROT)) {
        printk(KERN_NOTICE "fd%d: is write protected\n", SelectedDrive );
        goto err_end;
    }   
    if ((status & FDCSTAT_RECNF) &&
        /* RECNF is no error after a multiple read when the FDC
           searched for a non-existent sector! */
        !(read_track && FDC_READ(FDCREG_SECTOR) > SUDT->spt)) {
        if (Probing) {
            if (SUDT > atari_disk_type) {
                if (SUDT[-1].blocks > ReqBlock) {
                /* try another disk type */
                SUDT--;
                set_capacity(unit[SelectedDrive].disk,
                            SUDT->blocks);
                } else
                Probing = 0;
            }
            else {
                if (SUD.flags & FTD_MSG)
                    printk(KERN_INFO "fd%d: Auto-detected floppy type %s\n",
                           SelectedDrive, SUDT->name );
                Probing=0;
            }
        } else {    
/* record not found, but not probing. Maybe stretch wrong ? Restart probing */
            if (SUD.autoprobe) {
                SUDT = atari_disk_type + StartDiskType[DriveType];
                set_capacity(unit[SelectedDrive].disk,
                            SUDT->blocks);
                Probing = 1;
            }
        }
        if (Probing) {
            if (ATARIHW_PRESENT(FDCSPEED)) {
                dma_wd.fdc_speed = SUDT->fdc_speed;
                MFPDELAY();
            }
            setup_req_params( SelectedDrive );
            BufferDrive = -1;
            do_fd_action( SelectedDrive );
            return;
        }

        printk(KERN_ERR "fd%d: sector %d not found (side %d, track %d)\n",
               SelectedDrive, FDC_READ (FDCREG_SECTOR), ReqSide, ReqTrack );
        goto err_end;
    }
    if (status & FDCSTAT_CRC) {
        printk(KERN_ERR "fd%d: CRC error (side %d, track %d, sector %d)\n",
               SelectedDrive, ReqSide, ReqTrack, FDC_READ (FDCREG_SECTOR) );
        goto err_end;
    }
    if (status & FDCSTAT_LOST) {
        printk(KERN_ERR "fd%d: lost data (side %d, track %d, sector %d)\n",
               SelectedDrive, ReqSide, ReqTrack, FDC_READ (FDCREG_SECTOR) );
        goto err_end;
    }

    Probing = 0;
    
    if (ReqCmd == READ) {
        if (!read_track) {
            void *addr;
            addr = ATARIHW_PRESENT( EXTD_DMA ) ? ReqData : DMABuffer;
            dma_cache_maintenance( virt_to_phys(addr), 512, 0 );
            if (!ATARIHW_PRESENT( EXTD_DMA ))
                copy_buffer (addr, ReqData);
        } else {
            dma_cache_maintenance( PhysTrackBuffer, MaxSectors[DriveType] * 512, 0 );
            BufferDrive = SelectedDrive;
            BufferSide  = ReqSide;
            BufferTrack = ReqTrack;
            copy_buffer (SECTOR_BUFFER (ReqSector), ReqData);
        }
    }
  
    if (++ReqCnt < blk_rq_cur_sectors(fd_request)) {
        /* read next sector */
        setup_req_params( SelectedDrive );
        do_fd_action( SelectedDrive );
    }
    else {
        /* all sectors finished */
        fd_end_request_cur(0);
        redo_fd_request();
    }
    return;
  
  err_end:
    BufferDrive = -1;
    fd_error();
}


static void fd_writetrack( void )
{
    unsigned long paddr, flags;
    unsigned int track;
    
    DPRINT(("fd_writetrack() Tr=%d Si=%d\n", ReqTrack, ReqSide ));

    paddr = PhysTrackBuffer;
    dma_cache_maintenance( paddr, BUFFER_SIZE, 1 );

    fd_select_side( ReqSide );
  
    /* Cheat for track if stretch != 0 */
    if (SUDT->stretch) {
        track = FDC_READ( FDCREG_TRACK);
        MFPDELAY();
        FDC_WRITE(FDCREG_TRACK,track >> SUDT->stretch);
    }
    udelay(40);
  
    /* Setup DMA */
    local_irq_save(flags);
    dma_wd.dma_lo = (unsigned char)paddr;
    MFPDELAY();
    paddr >>= 8;
    dma_wd.dma_md = (unsigned char)paddr;
    MFPDELAY();
    paddr >>= 8;
    if (ATARIHW_PRESENT( EXTD_DMA ))
        st_dma_ext_dmahi = (unsigned short)paddr;
    else
        dma_wd.dma_hi = (unsigned char)paddr;
    MFPDELAY();
    local_irq_restore(flags);
  
    /* Clear FIFO and switch DMA to correct mode */  
    dma_wd.dma_mode_status = 0x190;  
    MFPDELAY();
    dma_wd.dma_mode_status = 0x90;  
    MFPDELAY();
    dma_wd.dma_mode_status = 0x190;
    MFPDELAY();
  
    /* How many sectors for DMA */
    dma_wd.fdc_acces_seccount = BUFFER_SIZE/512;
    udelay(40);  
  
    /* Start operation */
    dma_wd.dma_mode_status = FDCSELREG_STP | 0x100;
    udelay(40);
    SET_IRQ_HANDLER( fd_writetrack_done );
    dma_wd.fdc_acces_seccount = FDCCMD_WRTRA | get_head_settle_flag(); 

    MotorOn = 1;
    start_timeout();
    /* wait for interrupt */
}


static void fd_writetrack_done( int status )
{
    DPRINT(("fd_writetrack_done()\n"));

    stop_timeout();

    if (status & FDCSTAT_WPROT) {
        printk(KERN_NOTICE "fd%d: is write protected\n", SelectedDrive );
        goto err_end;
    }   
    if (status & FDCSTAT_LOST) {
        printk(KERN_ERR "fd%d: lost data (side %d, track %d)\n",
                SelectedDrive, ReqSide, ReqTrack );
        goto err_end;
    }

    wake_up( &format_wait );
    return;

  err_end:
    fd_error();
}

static void fd_times_out( unsigned long dummy )
{
    atari_disable_irq( IRQ_MFP_FDC );
    if (!FloppyIRQHandler) goto end; /* int occurred after timer was fired, but
                      * before we came here... */

    SET_IRQ_HANDLER( NULL );
    /* If the timeout occurred while the readtrack_check timer was
     * active, we need to cancel it, else bad things will happen */
    if (UseTrackbuffer)
        del_timer( &readtrack_timer );
    FDC_WRITE( FDCREG_CMD, FDCCMD_FORCI );
    udelay( 25 );
    
    printk(KERN_ERR "floppy timeout\n" );
    fd_error();
  end:
    atari_enable_irq( IRQ_MFP_FDC );
}


/* The (noop) seek operation here is needed to make the WP bit in the
 * FDC status register accessible for check_change. If the last disk
 * operation would have been a RDSEC, this bit would always read as 0
 * no matter what :-( To save time, the seek goes to the track we're
 * already on.
 */

static void finish_fdc( void )
{
    if (!NeedSeek) {
        finish_fdc_done( 0 );
    }
    else {
        DPRINT(("finish_fdc: dummy seek started\n"));
        FDC_WRITE (FDCREG_DATA, SUD.track);
        SET_IRQ_HANDLER( finish_fdc_done );
        FDC_WRITE (FDCREG_CMD, FDCCMD_SEEK);
        MotorOn = 1;
        start_timeout();
        /* we must wait for the IRQ here, because the ST-DMA
           is released immediately afterwards and the interrupt
           may be delivered to the wrong driver. */
      }
}


static void finish_fdc_done( int dummy )
{
    unsigned long flags;

    DPRINT(("finish_fdc_done entered\n"));
    stop_timeout();
    NeedSeek = 0;

    if (timer_pending(&fd_timer) && time_before(fd_timer.expires, jiffies + 5))
        /* If the check for a disk change is done too early after this
         * last seek command, the WP bit still reads wrong :-((
         */
        mod_timer(&fd_timer, jiffies + 5);
    else
        start_check_change_timer();
    start_motor_off_timer();

    local_irq_save(flags);
    stdma_release();
    fdc_busy = 0;
    wake_up( &fdc_wait );
    local_irq_restore(flags);

    DPRINT(("finish_fdc() finished\n"));
}

/* The detection of disk changes is a dark chapter in Atari history :-(
 * Because the "Drive ready" signal isn't present in the Atari
 * hardware, one has to rely on the "Write Protect". This works fine,
 * as long as no write protected disks are used. TOS solves this
 * problem by introducing tri-state logic ("maybe changed") and
 * looking at the serial number in block 0. This isn't possible for
 * Linux, since the floppy driver can't make assumptions about the
 * filesystem used on the disk and thus the contents of block 0. I've
 * chosen the method to always say "The disk was changed" if it is
 * unsure whether it was. This implies that every open or mount
 * invalidates the disk buffers if you work with write protected
 * disks. But at least this is better than working with incorrect data
 * due to unrecognised disk changes.
 */

static unsigned int floppy_check_events(struct gendisk *disk,
                    unsigned int clearing)
{
    struct atari_floppy_struct *p = disk->private_data;
    unsigned int drive = p - unit;
    if (test_bit (drive, &fake_change)) {
        /* simulated change (e.g. after formatting) */
        return DISK_EVENT_MEDIA_CHANGE;
    }
    if (test_bit (drive, &changed_floppies)) {
        /* surely changed (the WP signal changed at least once) */
        return DISK_EVENT_MEDIA_CHANGE;
    }
    if (UD.wpstat) {
        /* WP is on -> could be changed: to be sure, buffers should be
         * invalidated...
         */
        return DISK_EVENT_MEDIA_CHANGE;
    }

    return 0;
}

static int floppy_revalidate(struct gendisk *disk)
{
    struct atari_floppy_struct *p = disk->private_data;
    unsigned int drive = p - unit;

    if (test_bit(drive, &changed_floppies) ||
        test_bit(drive, &fake_change) ||
        p->disktype == 0) {
        if (UD.flags & FTD_MSG)
            printk(KERN_ERR "floppy: clear format %p!\n", UDT);
        BufferDrive = -1;
        clear_bit(drive, &fake_change);
        clear_bit(drive, &changed_floppies);
        /* MSch: clearing geometry makes sense only for autoprobe
           formats, for 'permanent user-defined' parameter:
           restore default_params[] here if flagged valid! */
        if (default_params[drive].blocks == 0)
            UDT = NULL;
        else
            UDT = &default_params[drive];
    }
    return 0;
}


/* This sets up the global variables describing the current request. */

static void setup_req_params( int drive )
{
    int block = ReqBlock + ReqCnt;

    ReqTrack = block / UDT->spt;
    ReqSector = block - ReqTrack * UDT->spt + 1;
    ReqSide = ReqTrack & 1;
    ReqTrack >>= 1;
    ReqData = ReqBuffer + 512 * ReqCnt;

    if (UseTrackbuffer)
        read_track = (ReqCmd == READ && fd_request->errors == 0);
    else
        read_track = 0;

    DPRINT(("Request params: Si=%d Tr=%d Se=%d Data=%08lx\n",ReqSide,
            ReqTrack, ReqSector, (unsigned long)ReqData ));
}

/*
 * Round-robin between our available drives, doing one request from each
 */
static struct request *set_next_request(void)
{
    struct request_queue *q;
    int old_pos = fdc_queue;
    struct request *rq = NULL;

    do {
        q = unit[fdc_queue].disk->queue;
        if (++fdc_queue == FD_MAX_UNITS)
            fdc_queue = 0;
        if (q) {
            rq = blk_fetch_request(q);
            if (rq)
                break;
        }
    } while (fdc_queue != old_pos);

    return rq;
}


static void redo_fd_request(void)
{
    int drive, type;
    struct atari_floppy_struct *floppy;

    DPRINT(("redo_fd_request: fd_request=%p dev=%s fd_request->sector=%ld\n",
        fd_request, fd_request ? fd_request->rq_disk->disk_name : "",
        fd_request ? blk_rq_pos(fd_request) : 0 ));

    IsFormatting = 0;

repeat:
    if (!fd_request) {
        fd_request = set_next_request();
        if (!fd_request)
            goto the_end;
    }

    floppy = fd_request->rq_disk->private_data;
    drive = floppy - unit;
    type = floppy->type;
    
    if (!UD.connected) {
        /* drive not connected */
        printk(KERN_ERR "Unknown Device: fd%d\n", drive );
        fd_end_request_cur(-EIO);
        goto repeat;
    }
        
    if (type == 0) {
        if (!UDT) {
            Probing = 1;
            UDT = atari_disk_type + StartDiskType[DriveType];
            set_capacity(floppy->disk, UDT->blocks);
            UD.autoprobe = 1;
        }
    } 
    else {
        /* user supplied disk type */
        if (--type >= NUM_DISK_MINORS) {
            printk(KERN_WARNING "fd%d: invalid disk format", drive );
            fd_end_request_cur(-EIO);
            goto repeat;
        }
        if (minor2disktype[type].drive_types > DriveType)  {
            printk(KERN_WARNING "fd%d: unsupported disk format", drive );
            fd_end_request_cur(-EIO);
            goto repeat;
        }
        type = minor2disktype[type].index;
        UDT = &atari_disk_type[type];
        set_capacity(floppy->disk, UDT->blocks);
        UD.autoprobe = 0;
    }
    
    if (blk_rq_pos(fd_request) + 1 > UDT->blocks) {
        fd_end_request_cur(-EIO);
        goto repeat;
    }

    /* stop deselect timer */
    del_timer( &motor_off_timer );
        
    ReqCnt = 0;
    ReqCmd = rq_data_dir(fd_request);
    ReqBlock = blk_rq_pos(fd_request);
    ReqBuffer = fd_request->buffer;
    setup_req_params( drive );
    do_fd_action( drive );

    return;

  the_end:
    finish_fdc();
}


void do_fd_request(struct request_queue * q)
{
    DPRINT(("do_fd_request for pid %d\n",current->pid));
    while( fdc_busy ) sleep_on( &fdc_wait );
    fdc_busy = 1;
    stdma_lock(floppy_irq, NULL);

    atari_disable_irq( IRQ_MFP_FDC );
    redo_fd_request();
    atari_enable_irq( IRQ_MFP_FDC );
}

static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode,
            unsigned int cmd, unsigned long param)
{
    struct gendisk *disk = bdev->bd_disk;
    struct atari_floppy_struct *floppy = disk->private_data;
    int drive = floppy - unit;
    int type = floppy->type;
    struct atari_format_descr fmt_desc;
    struct atari_disk_type *dtp;
    struct floppy_struct getprm;
    int settype;
    struct floppy_struct setprm;
    void __user *argp = (void __user *)param;

    switch (cmd) {
    case FDGETPRM:
        if (type) {
            if (--type >= NUM_DISK_MINORS)
                return -ENODEV;
            if (minor2disktype[type].drive_types > DriveType)
                return -ENODEV;
            type = minor2disktype[type].index;
            dtp = &atari_disk_type[type];
            if (UD.flags & FTD_MSG)
                printk (KERN_ERR "floppy%d: found dtp %p name %s!\n",
                    drive, dtp, dtp->name);
        }
        else {
            if (!UDT)
                return -ENXIO;
            else
                dtp = UDT;
        }
        memset((void *)&getprm, 0, sizeof(getprm));
        getprm.size = dtp->blocks;
        getprm.sect = dtp->spt;
        getprm.head = 2;
        getprm.track = dtp->blocks/dtp->spt/2;
        getprm.stretch = dtp->stretch;
        if (copy_to_user(argp, &getprm, sizeof(getprm)))
            return -EFAULT;
        return 0;
    }
    switch (cmd) {
    case FDSETPRM:
    case FDDEFPRM:
            /* 
         * MSch 7/96: simple 'set geometry' case: just set the
         * 'default' device params (minor == 0).
         * Currently, the drive geometry is cleared after each
         * disk change and subsequent revalidate()! simple
         * implementation of FDDEFPRM: save geometry from a
         * FDDEFPRM call and restore it in floppy_revalidate() !
         */

        /* get the parameters from user space */
        if (floppy->ref != 1 && floppy->ref != -1)
            return -EBUSY;
        if (copy_from_user(&setprm, argp, sizeof(setprm)))
            return -EFAULT;
        /* 
         * first of all: check for floppy change and revalidate, 
         * or the next access will revalidate - and clear UDT :-(
         */

        if (floppy_check_events(disk, 0))
                floppy_revalidate(disk);

        if (UD.flags & FTD_MSG)
            printk (KERN_INFO "floppy%d: setting size %d spt %d str %d!\n",
            drive, setprm.size, setprm.sect, setprm.stretch);

        /* what if type > 0 here? Overwrite specified entry ? */
        if (type) {
                /* refuse to re-set a predefined type for now */
            redo_fd_request();
            return -EINVAL;
        }

        /* 
         * type == 0: first look for a matching entry in the type list,
         * and set the UD.disktype field to use the perdefined entry.
         * TODO: add user-defined format to head of autoprobe list ? 
         * Useful to include the user-type for future autodetection!
         */

        for (settype = 0; settype < NUM_DISK_MINORS; settype++) {
            int setidx = 0;
            if (minor2disktype[settype].drive_types > DriveType) {
                /* skip this one, invalid for drive ... */
                continue;
            }
            setidx = minor2disktype[settype].index;
            dtp = &atari_disk_type[setidx];

            /* found matching entry ?? */
            if (   dtp->blocks  == setprm.size 
                && dtp->spt     == setprm.sect
                && dtp->stretch == setprm.stretch ) {
                if (UD.flags & FTD_MSG)
                    printk (KERN_INFO "floppy%d: setting %s %p!\n",
                        drive, dtp->name, dtp);
                UDT = dtp;
                set_capacity(floppy->disk, UDT->blocks);

                if (cmd == FDDEFPRM) {
                  /* save settings as permanent default type */
                  default_params[drive].name    = dtp->name;
                  default_params[drive].spt     = dtp->spt;
                  default_params[drive].blocks  = dtp->blocks;
                  default_params[drive].fdc_speed = dtp->fdc_speed;
                  default_params[drive].stretch = dtp->stretch;
                }
                
                return 0;
            }

        }

        /* no matching disk type found above - setting user_params */

            if (cmd == FDDEFPRM) {
            /* set permanent type */
            dtp = &default_params[drive];
        } else
            /* set user type (reset by disk change!) */
            dtp = &user_params[drive];

        dtp->name   = "user format";
        dtp->blocks = setprm.size;
        dtp->spt    = setprm.sect;
        if (setprm.sect > 14) 
            dtp->fdc_speed = 3;
        else
            dtp->fdc_speed = 0;
        dtp->stretch = setprm.stretch;

        if (UD.flags & FTD_MSG)
            printk (KERN_INFO "floppy%d: blk %d spt %d str %d!\n",
                drive, dtp->blocks, dtp->spt, dtp->stretch);

        /* sanity check */
        if (setprm.track != dtp->blocks/dtp->spt/2 ||
            setprm.head != 2) {
            redo_fd_request();
            return -EINVAL;
        }

        UDT = dtp;
        set_capacity(floppy->disk, UDT->blocks);

        return 0;
    case FDMSGON:
        UD.flags |= FTD_MSG;
        return 0;
    case FDMSGOFF:
        UD.flags &= ~FTD_MSG;
        return 0;
    case FDSETEMSGTRESH:
        return -EINVAL;
    case FDFMTBEG:
        return 0;
    case FDFMTTRK:
        if (floppy->ref != 1 && floppy->ref != -1)
            return -EBUSY;
        if (copy_from_user(&fmt_desc, argp, sizeof(fmt_desc)))
            return -EFAULT;
        return do_format(drive, type, &fmt_desc);
    case FDCLRPRM:
        UDT = NULL;
        /* MSch: invalidate default_params */
        default_params[drive].blocks  = 0;
        set_capacity(floppy->disk, MAX_DISK_SIZE * 2);
    case FDFMTEND:
    case FDFLUSH:
        /* invalidate the buffer track to force a reread */
        BufferDrive = -1;
        set_bit(drive, &fake_change);
        check_disk_change(bdev);
        return 0;
    default:
        return -EINVAL;
    }
}

static int fd_ioctl(struct block_device *bdev, fmode_t mode,
                 unsigned int cmd, unsigned long arg)
{
    int ret;

    mutex_lock(&ataflop_mutex);
    ret = fd_locked_ioctl(bdev, mode, cmd, arg);
    mutex_unlock(&ataflop_mutex);

    return ret;
}

/* Initialize the 'unit' variable for drive 'drive' */

static void __init fd_probe( int drive )
{
    UD.connected = 0;
    UDT  = NULL;

    if (!fd_test_drive_present( drive ))
        return;

    UD.connected = 1;
    UD.track     = 0;
    switch( UserSteprate[drive] ) {
    case 2:
        UD.steprate = FDCSTEP_2;
        break;
    case 3:
        UD.steprate = FDCSTEP_3;
        break;
    case 6:
        UD.steprate = FDCSTEP_6;
        break;
    case 12:
        UD.steprate = FDCSTEP_12;
        break;
    default: /* should be -1 for "not set by user" */
        if (ATARIHW_PRESENT( FDCSPEED ) || MACH_IS_MEDUSA)
            UD.steprate = FDCSTEP_3;
        else
            UD.steprate = FDCSTEP_6;
        break;
    }
    MotorOn = 1;    /* from probe restore operation! */
}


/* This function tests the physical presence of a floppy drive (not
 * whether a disk is inserted). This is done by issuing a restore
 * command, waiting max. 2 seconds (that should be enough to move the
 * head across the whole disk) and looking at the state of the "TR00"
 * signal. This should now be raised if there is a drive connected
 * (and there is no hardware failure :-) Otherwise, the drive is
 * declared absent.
 */

static int __init fd_test_drive_present( int drive )
{
    unsigned long timeout;
    unsigned char status;
    int ok;
    
    if (drive >= (MACH_IS_FALCON ? 1 : 2)) return( 0 );
    fd_select_drive( drive );

    /* disable interrupt temporarily */
    atari_turnoff_irq( IRQ_MFP_FDC );
    FDC_WRITE (FDCREG_TRACK, 0xff00);
    FDC_WRITE( FDCREG_CMD, FDCCMD_RESTORE | FDCCMDADD_H | FDCSTEP_6 );

    timeout = jiffies + 2*HZ+HZ/2;
    while (time_before(jiffies, timeout))
        if (!(st_mfp.par_dt_reg & 0x20))
            break;

    status = FDC_READ( FDCREG_STATUS );
    ok = (status & FDCSTAT_TR00) != 0;

    /* force interrupt to abort restore operation (FDC would try
     * about 50 seconds!) */
    FDC_WRITE( FDCREG_CMD, FDCCMD_FORCI );
    udelay(500);
    status = FDC_READ( FDCREG_STATUS );
    udelay(20);

    if (ok) {
        /* dummy seek command to make WP bit accessible */
        FDC_WRITE( FDCREG_DATA, 0 );
        FDC_WRITE( FDCREG_CMD, FDCCMD_SEEK );
        while( st_mfp.par_dt_reg & 0x20 )
            ;
        status = FDC_READ( FDCREG_STATUS );
    }

    atari_turnon_irq( IRQ_MFP_FDC );
    return( ok );
}


/* Look how many and which kind of drives are connected. If there are
 * floppies, additionally start the disk-change and motor-off timers.
 */

static void __init config_types( void )
{
    int drive, cnt = 0;

    /* for probing drives, set the FDC speed to 8 MHz */
    if (ATARIHW_PRESENT(FDCSPEED))
        dma_wd.fdc_speed = 0;

    printk(KERN_INFO "Probing floppy drive(s):\n");
    for( drive = 0; drive < FD_MAX_UNITS; drive++ ) {
        fd_probe( drive );
        if (UD.connected) {
            printk(KERN_INFO "fd%d\n", drive);
            ++cnt;
        }
    }

    if (FDC_READ( FDCREG_STATUS ) & FDCSTAT_BUSY) {
        /* If FDC is still busy from probing, give it another FORCI
         * command to abort the operation. If this isn't done, the FDC
         * will interrupt later and its IRQ line stays low, because
         * the status register isn't read. And this will block any
         * interrupts on this IRQ line :-(
         */
        FDC_WRITE( FDCREG_CMD, FDCCMD_FORCI );
        udelay(500);
        FDC_READ( FDCREG_STATUS );
        udelay(20);
    }
    
    if (cnt > 0) {
        start_motor_off_timer();
        if (cnt == 1) fd_select_drive( 0 );
        start_check_change_timer();
    }
}

/*
 * floppy_open check for aliasing (/dev/fd0 can be the same as
 * /dev/PS0 etc), and disallows simultaneous access to the same
 * drive with different device numbers.
 */

static int floppy_open(struct block_device *bdev, fmode_t mode)
{
    struct atari_floppy_struct *p = bdev->bd_disk->private_data;
    int type  = MINOR(bdev->bd_dev) >> 2;

    DPRINT(("fd_open: type=%d\n",type));
    if (p->ref && p->type != type)
        return -EBUSY;

    if (p->ref == -1 || (p->ref && mode & FMODE_EXCL))
        return -EBUSY;

    if (mode & FMODE_EXCL)
        p->ref = -1;
    else
        p->ref++;

    p->type = type;

    if (mode & FMODE_NDELAY)
        return 0;

    if (mode & (FMODE_READ|FMODE_WRITE)) {
        check_disk_change(bdev);
        if (mode & FMODE_WRITE) {
            if (p->wpstat) {
                if (p->ref < 0)
                    p->ref = 0;
                else
                    p->ref--;
                return -EROFS;
            }
        }
    }
    return 0;
}

static int floppy_unlocked_open(struct block_device *bdev, fmode_t mode)
{
    int ret;

    mutex_lock(&ataflop_mutex);
    ret = floppy_open(bdev, mode);
    mutex_unlock(&ataflop_mutex);

    return ret;
}

static int floppy_release(struct gendisk *disk, fmode_t mode)
{
    struct atari_floppy_struct *p = disk->private_data;
    mutex_lock(&ataflop_mutex);
    if (p->ref < 0)
        p->ref = 0;
    else if (!p->ref--) {
        printk(KERN_ERR "floppy_release with fd_ref == 0");
        p->ref = 0;
    }
    mutex_unlock(&ataflop_mutex);
    return 0;
}

static const struct block_device_operations floppy_fops = {
    .owner      = THIS_MODULE,
    .open       = floppy_unlocked_open,
    .release    = floppy_release,
    .ioctl      = fd_ioctl,
    .check_events   = floppy_check_events,
    .revalidate_disk= floppy_revalidate,
};

static struct kobject *floppy_find(dev_t dev, int *part, void *data)
{
    int drive = *part & 3;
    int type  = *part >> 2;
    if (drive >= FD_MAX_UNITS || type > NUM_DISK_MINORS)
        return NULL;
    *part = 0;
    return get_disk(unit[drive].disk);
}

static int __init atari_floppy_init (void)
{
    int i;

    if (!MACH_IS_ATARI)
        /* Amiga, Mac, ... don't have Atari-compatible floppy :-) */
        return -ENODEV;

    if (register_blkdev(FLOPPY_MAJOR,"fd"))
        return -EBUSY;

    for (i = 0; i < FD_MAX_UNITS; i++) {
        unit[i].disk = alloc_disk(1);
        if (!unit[i].disk)
            goto Enomem;
    }

    if (UseTrackbuffer < 0)
        /* not set by user -> use default: for now, we turn
           track buffering off for all Medusas, though it
           could be used with ones that have a counter
           card. But the test is too hard :-( */
        UseTrackbuffer = !MACH_IS_MEDUSA;

    /* initialize variables */
    SelectedDrive = -1;
    BufferDrive = -1;

    DMABuffer = atari_stram_alloc(BUFFER_SIZE+512, "ataflop");
    if (!DMABuffer) {
        printk(KERN_ERR "atari_floppy_init: cannot get dma buffer\n");
        goto Enomem;
    }
    TrackBuffer = DMABuffer + 512;
    PhysDMABuffer = virt_to_phys(DMABuffer);
    PhysTrackBuffer = virt_to_phys(TrackBuffer);
    BufferDrive = BufferSide = BufferTrack = -1;

    for (i = 0; i < FD_MAX_UNITS; i++) {
        unit[i].track = -1;
        unit[i].flags = 0;
        unit[i].disk->major = FLOPPY_MAJOR;
        unit[i].disk->first_minor = i;
        sprintf(unit[i].disk->disk_name, "fd%d", i);
        unit[i].disk->fops = &floppy_fops;
        unit[i].disk->private_data = &unit[i];
        unit[i].disk->queue = blk_init_queue(do_fd_request,
                    &ataflop_lock);
        if (!unit[i].disk->queue)
            goto Enomem;
        set_capacity(unit[i].disk, MAX_DISK_SIZE * 2);
        add_disk(unit[i].disk);
    }

    blk_register_region(MKDEV(FLOPPY_MAJOR, 0), 256, THIS_MODULE,
                floppy_find, NULL, NULL);

    printk(KERN_INFO "Atari floppy driver: max. %cD, %strack buffering\n",
           DriveType == 0 ? 'D' : DriveType == 1 ? 'H' : 'E',
           UseTrackbuffer ? "" : "no ");
    config_types();

    return 0;
Enomem:
    while (i--) {
        struct request_queue *q = unit[i].disk->queue;

        put_disk(unit[i].disk);
        if (q)
            blk_cleanup_queue(q);
    }

    unregister_blkdev(FLOPPY_MAJOR, "fd");
    return -ENOMEM;
}

#ifndef MODULE
static int __init atari_floppy_setup(char *str)
{
    int ints[3 + FD_MAX_UNITS];
    int i;

    if (!MACH_IS_ATARI)
        return 0;

    str = get_options(str, 3 + FD_MAX_UNITS, ints);
    
    if (ints[0] < 1) {
        printk(KERN_ERR "ataflop_setup: no arguments!\n" );
        return 0;
    }
    else if (ints[0] > 2+FD_MAX_UNITS) {
        printk(KERN_ERR "ataflop_setup: too many arguments\n" );
    }

    if (ints[1] < 0 || ints[1] > 2)
        printk(KERN_ERR "ataflop_setup: bad drive type\n" );
    else
        DriveType = ints[1];

    if (ints[0] >= 2)
        UseTrackbuffer = (ints[2] > 0);

    for( i = 3; i <= ints[0] && i-3 < FD_MAX_UNITS; ++i ) {
        if (ints[i] != 2 && ints[i] != 3 && ints[i] != 6 && ints[i] != 12)
            printk(KERN_ERR "ataflop_setup: bad steprate\n" );
        else
            UserSteprate[i-3] = ints[i];
    }
    return 1;
}

__setup("floppy=", atari_floppy_setup);
#endif

static void __exit atari_floppy_exit(void)
{
    int i;
    blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256);
    for (i = 0; i < FD_MAX_UNITS; i++) {
        struct request_queue *q = unit[i].disk->queue;

        del_gendisk(unit[i].disk);
        put_disk(unit[i].disk);
        blk_cleanup_queue(q);
    }
    unregister_blkdev(FLOPPY_MAJOR, "fd");

    del_timer_sync(&fd_timer);
    atari_stram_free( DMABuffer );
}

module_init(atari_floppy_init)
module_exit(atari_floppy_exit)

MODULE_LICENSE("GPL");