summaryrefslogblamecommitdiffstats
path: root/drivers/block/ataflop.c
blob: 30166774327da97aca0582abed0f37b0c5720b95 (plain) (tree)
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066



























































































                                                                          
                       

























































































                                                                                       
                                                  
























































































                                                                               
                                     























                                                                              
                                               












































                                                                            
                                                     



























                                                                           



                                                               





































































































































































































                                                                                   
                                                    



















































































                                                                                                   
                                             




















































































































































































































































































































































































































                                                                                            
                                                     
















                                                                                                
                                                                                  





















































































































































































































































































                                                                                                 
                                   


























































                                                                           
                                                                         
















                                                                                     
                                             

























                                                        
                                            



























                                                                                         
                                                 








                                                                         
                                                     















                                                                                 
                                                                

















                                                                        
                                                                  

































                                                                                   
                                                       






































































                                                                                   
                                                                      



































































































































































                                                                              
                                                                  

                              
                                      





                            
                                        

                         
                                                      
                                                 
                                                 



























                                                                             


                                           



















                                                                            
                               
 
































































                                                                              

                                               
 
                                   
              




                                                       


                                                                   
                         


















                                                                                  
                 

 



                                          

















                                                           
/*
 *  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 <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 struct request_queue *floppy_queue;

#define QUEUE (floppy_queue)
#define CURRENT elv_next_request(floppy_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_ioctl( struct inode *inode, struct file *filp, 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 inode *inode, struct file *filp );
static int floppy_release( struct inode * inode, struct file * filp );

/************************* 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 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 (!CURRENT)
		return;

	CURRENT->errors++;
	if (CURRENT->errors >= MAX_ERRORS) {
		printk(KERN_ERR "fd%d: too many errors.\n", SelectedDrive );
		end_request(CURRENT, 0);
	}
	else if (CURRENT->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 < CURRENT->current_nr_sectors) {
			/* read next sector */
			setup_req_params( drive );
			goto repeat;
		    }
		    else {
			/* all sectors finished */
			CURRENT->nr_sectors -= CURRENT->current_nr_sectors;
			CURRENT->sector += CURRENT->current_nr_sectors;
			end_request(CURRENT, 1);
			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 < CURRENT->current_nr_sectors) {
		/* read next sector */
		setup_req_params( SelectedDrive );
		do_fd_action( SelectedDrive );
	}
	else {
		/* all sectors finished */
		CURRENT->nr_sectors -= CURRENT->current_nr_sectors;
		CURRENT->sector += CURRENT->current_nr_sectors;
		end_request(CURRENT, 1);
		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 int check_floppy_change(struct gendisk *disk)
{
	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 1;
	}
	if (test_bit (drive, &changed_floppies)) {
		/* surely changed (the WP signal changed at least once) */
		return 1;
	}
	if (UD.wpstat) {
		/* WP is on -> could be changed: to be sure, buffers should be
		 * invalidated...
		 */
		return 1;
	}

	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 && CURRENT->errors == 0);
	else
		read_track = 0;

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


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

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

	IsFormatting = 0;

repeat:

	if (!CURRENT)
		goto the_end;

	floppy = CURRENT->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 );
		end_request(CURRENT, 0);
		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 );
			end_request(CURRENT, 0);
			goto repeat;
		}
		if (minor2disktype[type].drive_types > DriveType)  {
			printk(KERN_WARNING "fd%d: unsupported disk format", drive );
			end_request(CURRENT, 0);
			goto repeat;
		}
		type = minor2disktype[type].index;
		UDT = &atari_disk_type[type];
		set_capacity(floppy->disk, UDT->blocks);
		UD.autoprobe = 0;
	}
	
	if (CURRENT->sector + 1 > UDT->blocks) {
		end_request(CURRENT, 0);
		goto repeat;
	}

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

	return;

  the_end:
	finish_fdc();
}


void do_fd_request(struct request_queue * q)
{
 	unsigned long flags;

	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 );
	local_save_flags(flags);	/* The request function is called with ints
	local_irq_disable();		 * disabled... so must save the IPL for later */ 
	redo_fd_request();
	local_irq_restore(flags);
	atari_enable_irq( IRQ_MFP_FDC );
}

static int fd_ioctl(struct inode *inode, struct file *filp,
		    unsigned int cmd, unsigned long param)
{
	struct gendisk *disk = inode->i_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 (check_floppy_change(disk))
		        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 (!dtp || 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(inode->i_bdev);
		return 0;
	default:
		return -EINVAL;
	}
}


/* 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 (!(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( 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 inode *inode, struct file *filp )
{
	struct atari_floppy_struct *p = inode->i_bdev->bd_disk->private_data;
	int type  = iminor(inode) >> 2;

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

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

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

	p->type = type;

	if (filp->f_mode & FMODE_NDELAY)
		return 0;

	if (filp->f_mode & (FMODE_READ|FMODE_WRITE)) {
		check_disk_change(inode->i_bdev);
		if (filp->f_mode & FMODE_WRITE) {
			if (p->wpstat) {
				if (p->ref < 0)
					p->ref = 0;
				else
					p->ref--;
				floppy_release(inode, filp);
				return -EROFS;
			}
		}
	}
	return 0;
}


static int floppy_release( struct inode * inode, struct file * filp )
{
	struct atari_floppy_struct *p = inode->i_bdev->bd_disk->private_data;
	if (p->ref < 0)
		p->ref = 0;
	else if (!p->ref--) {
		printk(KERN_ERR "floppy_release with fd_ref == 0");
		p->ref = 0;
	}
	return 0;
}

static struct block_device_operations floppy_fops = {
	.owner		= THIS_MODULE,
	.__open		= floppy_open,
	.__release	= floppy_release,
	.__ioctl		= fd_ioctl,
	.media_changed	= check_floppy_change,
	.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;

	floppy_queue = blk_init_queue(do_fd_request, &ataflop_lock);
	if (!floppy_queue)
		goto Enomem;

	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 = floppy_queue;
		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--)
		put_disk(unit[i].disk);
	if (floppy_queue)
		blk_cleanup_queue(floppy_queue);
	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++) {
		del_gendisk(unit[i].disk);
		put_disk(unit[i].disk);
	}
	unregister_blkdev(FLOPPY_MAJOR, "fd");

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

module_init(atari_floppy_init)
module_exit(atari_floppy_exit)

MODULE_LICENSE("GPL");