summaryrefslogtreecommitdiff
path: root/sys/dev/isa/fd.c
blob: adf1e65526c8b09b43d122d2dec55cc26b71b760 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
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
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
/*	$OpenBSD: fd.c,v 1.41 1999/10/07 18:47:19 downsj Exp $	*/
/*	$NetBSD: fd.c,v 1.90 1996/05/12 23:12:03 mycroft Exp $	*/

/*-
 * Copyright (c) 1993, 1994, 1995, 1996 Charles Hannum.
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Don Ahn.
 *
 * Portions Copyright (c) 1993, 1994 by
 *  jc@irbs.UUCP (John Capo)
 *  vak@zebub.msk.su (Serge Vakulenko)
 *  ache@astral.msk.su (Andrew A. Chernov)
 *  joerg_wunsch@uriah.sax.de (Joerg Wunsch)
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)fd.c	7.4 (Berkeley) 5/25/91
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/device.h>
#include <sys/disklabel.h>
#include <sys/dkstat.h>
#include <sys/disk.h>
#include <sys/buf.h>
#include <sys/malloc.h>
#include <sys/uio.h>
#include <sys/mtio.h>
#include <sys/proc.h>
#include <sys/syslog.h>
#include <sys/queue.h>

#include <machine/cpu.h>
#include <machine/bus.h>
#include <machine/conf.h>
#include <machine/intr.h>
#include <machine/ioctl_fd.h>

#include <dev/isa/isavar.h>
#include <dev/isa/isadmavar.h>
#include <dev/isa/fdreg.h>

#if defined(i386)
#include <i386/isa/nvram.h>
#endif

#include <dev/isa/fdlink.h>

/* XXX misuse a flag to identify format operation */
#define B_FORMAT B_XXX

#define b_cylin b_resid

/* fd_type struct now in ioctl_fd.h */

/* The order of entries in the following table is important -- BEWARE! */
struct fd_type fd_types[] = {
        { 18,2,36,2,0xff,0xcf,0x1b,0x6c,80,2880,1,FDC_500KBPS,"1.44MB"    }, /* 1.44MB diskette */
        { 15,2,30,2,0xff,0xdf,0x1b,0x54,80,2400,1,FDC_500KBPS, "1.2MB"    }, /* 1.2 MB AT-diskettes */
        {  9,2,18,2,0xff,0xdf,0x23,0x50,40, 720,2,FDC_300KBPS, "360KB/AT" }, /* 360kB in 1.2MB drive */
        {  9,2,18,2,0xff,0xdf,0x2a,0x50,40, 720,1,FDC_250KBPS, "360KB/PC" }, /* 360kB PC diskettes */
        {  9,2,18,2,0xff,0xdf,0x2a,0x50,80,1440,1,FDC_250KBPS, "720KB"    }, /* 3.5" 720kB diskette */
        {  9,2,18,2,0xff,0xdf,0x23,0x50,80,1440,1,FDC_300KBPS, "720KB/x"  }, /* 720kB in 1.2MB drive */
        {  9,2,18,2,0xff,0xdf,0x2a,0x50,40, 720,2,FDC_250KBPS, "360KB/x"  }, /* 360kB in 720kB drive */
	{ 36,2,72,2,0xff,0xaf,0x1b,0x54,80,5760,1,FDC_500KBPS,"2.88MB"    },  /* 2.88MB diskette */
	{  8,2,16,3,0xff,0xdf,0x35,0x74,77,1232,1,FDC_500KBPS,"1.2MB/[1024bytes/sector]" }	/* 1.2 MB japanese format */
};

/* software state, per disk (with up to 4 disks per ctlr) */
struct fd_softc {
	struct device sc_dev;
	struct disk sc_dk;

	struct fd_type *sc_deftype;	/* default type descriptor */
	struct fd_type *sc_type;	/* current type descriptor */

	daddr_t	sc_blkno;	/* starting block number */
	int sc_bcount;		/* byte count left */
 	int sc_opts;			/* user-set options */
	int sc_skip;		/* bytes already transferred */
	int sc_nblks;		/* number of blocks currently tranferring */
	int sc_nbytes;		/* number of bytes currently tranferring */

	int sc_drive;		/* physical unit number */
	int sc_flags;
#define	FD_OPEN		0x01		/* it's open */
#define	FD_MOTOR	0x02		/* motor should be on */
#define	FD_MOTOR_WAIT	0x04		/* motor coming up */
	int sc_cylin;		/* where we think the head is */

	void *sc_sdhook;	/* saved shutdown hook for drive. */

	TAILQ_ENTRY(fd_softc) sc_drivechain;
	int sc_ops;		/* I/O ops since last switch */
	struct buf sc_q;	/* head of buf chain */
};

/* floppy driver configuration */
int fdprobe __P((struct device *, void *, void *));
void fdattach __P((struct device *, struct device *, void *));

struct cfattach fd_ca = {
	sizeof(struct fd_softc), fdprobe, fdattach
};

struct cfdriver fd_cd = {
	NULL, "fd", DV_DISK
};

void fdgetdisklabel __P((struct fd_softc *));
int fd_get_parms __P((struct fd_softc *));
void fdstrategy __P((struct buf *));
void fdstart __P((struct fd_softc *));
int fdintr __P((struct fdc_softc *));

struct dkdriver fddkdriver = { fdstrategy };

void fd_set_motor __P((struct fdc_softc *fdc, int reset));
void fd_motor_off __P((void *arg));
void fd_motor_on __P((void *arg));
void fdfinish __P((struct fd_softc *fd, struct buf *bp));
int fdformat __P((dev_t, struct fd_formb *, struct proc *));
__inline struct fd_type *fd_dev_to_type __P((struct fd_softc *, dev_t));
void fdretry __P((struct fd_softc *));
void fdtimeout __P((void *));

int
fdprobe(parent, match, aux)
	struct device *parent;
	void *match, *aux;
{
	struct fdc_softc *fdc = (void *)parent;
	struct cfdata *cf = match;
	struct fdc_attach_args *fa = aux;
	int drive = fa->fa_drive;
	bus_space_tag_t iot = fdc->sc_iot;
	bus_space_handle_t ioh = fdc->sc_ioh;
	int n;

	if (cf->cf_loc[0] != -1 && cf->cf_loc[0] != drive)
		return 0;
	/*
	 * XXX
	 * This is to work around some odd interactions between this driver
	 * and SMC Ethernet cards.
	 */
	if (cf->cf_loc[0] == -1 && drive >= 2)
		return 0;

	/*
	 * We want to keep the flags config gave us.
	 */
	fa->fa_flags = cf->cf_flags;

	/* select drive and turn on motor */
	bus_space_write_1(iot, ioh, fdout, drive | FDO_FRST | FDO_MOEN(drive));
	/* wait for motor to spin up */
	delay(250000);
	out_fdc(iot, ioh, NE7CMD_RECAL);
	out_fdc(iot, ioh, drive);
	/* wait for recalibrate */
	delay(2000000);
	out_fdc(iot, ioh, NE7CMD_SENSEI);
	n = fdcresult(fdc);
#ifdef FD_DEBUG
	{
		int i;
		printf("fdprobe: status");
		for (i = 0; i < n; i++)
			printf(" %x", fdc->sc_status[i]);
		printf("\n");
	}
#endif

	/* turn off motor */
	delay(250000);
	bus_space_write_1(iot, ioh, fdout, FDO_FRST);

	/* flags & 0x20 forces the drive to be found even if it won't probe */
	if (!(fa->fa_flags & 0x20) && (n != 2 || (fdc->sc_status[0] & 0xf8) != 0x20))
		return 0;

	return 1;
}

/*
 * Controller is working, and drive responded.  Attach it.
 */
void
fdattach(parent, self, aux)
	struct device *parent, *self;
	void *aux;
{
	struct fdc_softc *fdc = (void *)parent;
	struct fd_softc *fd = (void *)self;
	struct fdc_attach_args *fa = aux;
	struct fd_type *type = fa->fa_deftype;
	int drive = fa->fa_drive;

	if (!type || (fa->fa_flags & 0x10)) {
		/* The config has overridden this. */
		switch (fa->fa_flags & 0x07) {
		case 1:	/* 2.88MB */
			type = &fd_types[7];
			break;
		case 2:	/* 1.44MB */
			type = &fd_types[0];
			break;
		case 3: /* 1.2MB */
			type = &fd_types[1];
			break;
		case 4: /* 720K */
			type = &fd_types[4];
			break;
		case 5: /* 360K */
			type = &fd_types[3];
			break;
		case 6:	/* 1.2 MB japanese format */
			type = &fd_types[8];
			break;
		}
	}

	if (type)
		printf(": %s %d cyl, %d head, %d sec\n", type->name,
		    type->tracks, type->heads, type->sectrac);
	else
		printf(": density unknown\n");

	fd->sc_cylin = -1;
	fd->sc_drive = drive;
	fd->sc_deftype = type;
	fdc->sc_type[drive] = FDC_TYPE_DISK;
	fdc->sc_link.fdlink.sc_fd[drive] = fd;

	/*
	 * Initialize and attach the disk structure.
	 */
	fd->sc_dk.dk_name = fd->sc_dev.dv_xname;
	fd->sc_dk.dk_driver = &fddkdriver;
	disk_attach(&fd->sc_dk);

	dk_establish(&fd->sc_dk, &fd->sc_dev);
	/* Needed to power off if the motor is on when we halt. */
	fd->sc_sdhook = shutdownhook_establish(fd_motor_off, fd);
}

/*
 * Translate nvram type into internal data structure.  Return NULL for
 * none/unknown/unusable.
 */
struct fd_type *
fd_nvtotype(fdc, nvraminfo, drive)
	char *fdc;
	int nvraminfo, drive;
{
	int type;

	type = (drive == 0 ? nvraminfo : nvraminfo << 4) & 0xf0;
	switch (type) {
	case NVRAM_DISKETTE_NONE:
		return NULL;
	case NVRAM_DISKETTE_12M:
		return &fd_types[1];
	case NVRAM_DISKETTE_TYPE5:
	case NVRAM_DISKETTE_TYPE6:
		return &fd_types[7];
	case NVRAM_DISKETTE_144M:
		return &fd_types[0];
	case NVRAM_DISKETTE_360K:
		return &fd_types[3];
	case NVRAM_DISKETTE_720K:
		return &fd_types[4];
	default:
		printf("%s: drive %d: unknown device type 0x%x\n",
		    fdc, drive, type);
		return NULL;
	}
}

__inline struct fd_type *
fd_dev_to_type(fd, dev)
	struct fd_softc *fd;
	dev_t dev;
{
	int type = FDTYPE(dev);

	if (type > (sizeof(fd_types) / sizeof(fd_types[0])))
		return NULL;
	return type ? &fd_types[type - 1] : fd->sc_deftype;
}

void
fdstrategy(bp)
	register struct buf *bp;	/* IO operation to perform */
{
	struct fd_softc *fd = fd_cd.cd_devs[FDUNIT(bp->b_dev)];
	int sz;
 	int s;
	int fd_bsize = 128 << fd->sc_type->secsize;
	int bf = fd_bsize / DEV_BSIZE;

	/* Valid unit, controller, and request? */
	if (bp->b_blkno < 0 ||
	    (((bp->b_blkno % bf) != 0 ||
	      (bp->b_bcount % fd_bsize) != 0) &&
	     (bp->b_flags & B_FORMAT) == 0)) {
		bp->b_error = EINVAL;
		goto bad;
	}

	/* If it's a null transfer, return immediately. */
	if (bp->b_bcount == 0)
		goto done;

	sz = howmany(bp->b_bcount, DEV_BSIZE);

	if (bp->b_blkno + sz > fd->sc_type->size * bf) {
		sz = fd->sc_type->size * bf - bp->b_blkno;
		if (sz == 0)
			/* If exactly at end of disk, return EOF. */
			goto done;
		if (sz < 0) {
			/* If past end of disk, return EINVAL. */
			bp->b_error = EINVAL;
			goto bad;
		}
		/* Otherwise, truncate request. */
		bp->b_bcount = sz << DEV_BSHIFT;
	}

 	bp->b_cylin = bp->b_blkno / (fd_bsize / DEV_BSIZE) / fd->sc_type->seccyl;

#ifdef FD_DEBUG
	printf("fdstrategy: b_blkno %d b_bcount %d blkno %d cylin %d sz %d\n",
	    bp->b_blkno, bp->b_bcount, fd->sc_blkno, bp->b_cylin, sz);
#endif

	/* Queue transfer on drive, activate drive and controller if idle. */
	s = splbio();
	disksort(&fd->sc_q, bp);
	untimeout(fd_motor_off, fd); /* a good idea */
	if (!fd->sc_q.b_active)
		fdstart(fd);
#ifdef DIAGNOSTIC
	else {
		struct fdc_softc *fdc = (void *)fd->sc_dev.dv_parent;
		if (fdc->sc_state == DEVIDLE) {
			printf("fdstrategy: controller inactive\n");
			fdcstart(fdc);
		}
	}
#endif
	splx(s);
	return;

bad:
	bp->b_flags |= B_ERROR;
done:
	/* Toss transfer; we're done early. */
	bp->b_resid = bp->b_bcount;
	biodone(bp);
}

void
fdstart(fd)
	struct fd_softc *fd;
{
	struct fdc_softc *fdc = (void *)fd->sc_dev.dv_parent;
	int active = (fdc->sc_link.fdlink.sc_drives.tqh_first != NULL);

	/* Link into controller queue. */
	fd->sc_q.b_active = 1;
	TAILQ_INSERT_TAIL(&fdc->sc_link.fdlink.sc_drives, fd, sc_drivechain);

	/* If controller not already active, start it. */
	if (!active)
		fdcstart(fdc);
}

void
fdfinish(fd, bp)
	struct fd_softc *fd;
	struct buf *bp;
{
	struct fdc_softc *fdc = (void *)fd->sc_dev.dv_parent;

	/*
	 * Move this drive to the end of the queue to give others a `fair'
	 * chance.  We only force a switch if N operations are completed while
	 * another drive is waiting to be serviced, since there is a long motor
	 * startup delay whenever we switch.
	 */
	if (fd->sc_drivechain.tqe_next && ++fd->sc_ops >= 8) {
		fd->sc_ops = 0;
		TAILQ_REMOVE(&fdc->sc_link.fdlink.sc_drives, fd, sc_drivechain);
		if (bp->b_actf) {
			TAILQ_INSERT_TAIL(&fdc->sc_link.fdlink.sc_drives, fd,
					  sc_drivechain);
		} else
			fd->sc_q.b_active = 0;
	}
	bp->b_resid = fd->sc_bcount;
	fd->sc_skip = 0;
	fd->sc_q.b_actf = bp->b_actf;

	biodone(bp);
	/* turn off motor 5s from now */
	timeout(fd_motor_off, fd, 5 * hz);
	fdc->sc_state = DEVIDLE;
}

int
fdread(dev, uio, flags)
	dev_t dev;
	struct uio *uio;
	int flags;
{

	return (physio(fdstrategy, NULL, dev, B_READ, minphys, uio));
}

int
fdwrite(dev, uio, flags)
	dev_t dev;
	struct uio *uio;
	int flags;
{

	return (physio(fdstrategy, NULL, dev, B_WRITE, minphys, uio));
}

void
fd_set_motor(fdc, reset)
	struct fdc_softc *fdc;
	int reset;
{
	struct fd_softc *fd;
	u_char status;
	int n;

	if ((fd = fdc->sc_link.fdlink.sc_drives.tqh_first) != NULL)
		status = fd->sc_drive;
	else
		status = 0;
	if (!reset)
		status |= FDO_FRST | FDO_FDMAEN;
	for (n = 0; n < 4; n++)
		if ((fd = fdc->sc_link.fdlink.sc_fd[n])
		    && (fd->sc_flags & FD_MOTOR))
			status |= FDO_MOEN(n);
	bus_space_write_1(fdc->sc_iot, fdc->sc_ioh, fdout, status);
}

void
fd_motor_off(arg)
	void *arg;
{
	struct fd_softc *fd = arg;
	int s;

	s = splbio();
	fd->sc_flags &= ~(FD_MOTOR | FD_MOTOR_WAIT);
	fd_set_motor((struct fdc_softc *)fd->sc_dev.dv_parent, 0);
	splx(s);
}

void
fd_motor_on(arg)
	void *arg;
{
	struct fd_softc *fd = arg;
	struct fdc_softc *fdc = (void *)fd->sc_dev.dv_parent;
	int s;

	s = splbio();
	fd->sc_flags &= ~FD_MOTOR_WAIT;
	if ((fdc->sc_link.fdlink.sc_drives.tqh_first == fd)
	    && (fdc->sc_state == MOTORWAIT))
		(void) fdintr(fdc);
	splx(s);
}

int
fdopen(dev, flags, mode, p)
	dev_t dev;
	int flags;
	int mode;
	struct proc *p;
{
 	int unit;
	struct fd_softc *fd;
	struct fd_type *type;

	unit = FDUNIT(dev);
	if (unit >= fd_cd.cd_ndevs)
		return ENXIO;
	fd = fd_cd.cd_devs[unit];
	if (fd == 0)
		return ENXIO;
	type = fd_dev_to_type(fd, dev);
	if (type == NULL)
		return ENXIO;

	if ((fd->sc_flags & FD_OPEN) != 0 &&
	    fd->sc_type != type)
		return EBUSY;

	fd->sc_type = type;
	fd->sc_cylin = -1;
	fd->sc_flags |= FD_OPEN;

	return 0;
}

int
fdclose(dev, flags, mode, p)
	dev_t dev;
	int flags;
	int mode;
	struct proc *p;
{
	struct fd_softc *fd = fd_cd.cd_devs[FDUNIT(dev)];

	fd->sc_flags &= ~FD_OPEN;
	fd->sc_opts &= ~FDOPT_NORETRY;
	return 0;
}

int
fdsize(dev)
	dev_t dev;
{

	/* Swapping to floppies would not make sense. */
	return -1;
}

int
fddump(dev, blkno, va, size)
	dev_t dev;
	daddr_t blkno;
	caddr_t va;
	size_t size;
{

	/* Not implemented. */
	return ENXIO;
}

/*
 * Called from the controller.
 */
int
fdintr(fdc)
	struct fdc_softc *fdc;
{
#define	st0	fdc->sc_status[0]
#define	cyl	fdc->sc_status[1]
	struct fd_softc *fd;
	struct buf *bp;
	bus_space_tag_t iot = fdc->sc_iot;
	bus_space_handle_t ioh = fdc->sc_ioh;
	bus_space_handle_t ioh_ctl = fdc->sc_ioh_ctl;
	int read, head, sec, i, nblks;
	struct fd_type *type;
	struct fd_formb *finfo = NULL;
	int fd_bsize, bf;

loop:
	/* Is there a transfer to this drive?  If not, deactivate drive. */
	fd = fdc->sc_link.fdlink.sc_drives.tqh_first;
	if (fd == NULL) {
		fdc->sc_state = DEVIDLE;
		return 1;
	}
	fd_bsize = 128 << fd->sc_type->secsize;
	bf = fd_bsize / FDC_BSIZE;

	bp = fd->sc_q.b_actf;
	if (bp == NULL) {
		fd->sc_ops = 0;
		TAILQ_REMOVE(&fdc->sc_link.fdlink.sc_drives, fd, sc_drivechain);
		fd->sc_q.b_active = 0;
		goto loop;
	}

	if (bp->b_flags & B_FORMAT)
	    finfo = (struct fd_formb *)bp->b_data;

	switch (fdc->sc_state) {
	case DEVIDLE:
		fdc->sc_errors = 0;
		fd->sc_skip = 0;
		fd->sc_bcount = bp->b_bcount;
		fd->sc_blkno = bp->b_blkno / (fd_bsize / DEV_BSIZE);
		untimeout(fd_motor_off, fd);
		if ((fd->sc_flags & FD_MOTOR_WAIT) != 0) {
			fdc->sc_state = MOTORWAIT;
			return 1;
		}
		if ((fd->sc_flags & FD_MOTOR) == 0) {
			/* Turn on the motor, being careful about pairing. */
			struct fd_softc *ofd =
				fdc->sc_link.fdlink.sc_fd[fd->sc_drive ^ 1];
			if (ofd && ofd->sc_flags & FD_MOTOR) {
				untimeout(fd_motor_off, ofd);
				ofd->sc_flags &= ~(FD_MOTOR | FD_MOTOR_WAIT);
			}
			fd->sc_flags |= FD_MOTOR | FD_MOTOR_WAIT;
			fd_set_motor(fdc, 0);
			fdc->sc_state = MOTORWAIT;
			/* Allow .25s for motor to stabilize. */
			timeout(fd_motor_on, fd, hz / 4);
			return 1;
		}
		/* Make sure the right drive is selected. */
		fd_set_motor(fdc, 0);

		/* fall through */
	case DOSEEK:
	doseek:
		if (fd->sc_cylin == bp->b_cylin)
			goto doio;

		out_fdc(iot, ioh, NE7CMD_SPECIFY);/* specify command */
		out_fdc(iot, ioh, fd->sc_type->steprate);
		out_fdc(iot, ioh, 6);		/* XXX head load time == 6ms */

		out_fdc(iot, ioh, NE7CMD_SEEK);	/* seek function */
		out_fdc(iot, ioh, fd->sc_drive);	/* drive number */
		out_fdc(iot, ioh, bp->b_cylin * fd->sc_type->step);

		fd->sc_cylin = -1;
		fdc->sc_state = SEEKWAIT;

		fd->sc_dk.dk_seek++;
		disk_busy(&fd->sc_dk);

		timeout(fdtimeout, fd, 4 * hz);
		return 1;

	case DOIO:
	doio:
		type = fd->sc_type;
		if (finfo)
		    fd->sc_skip = (char *)&(finfo->fd_formb_cylno(0)) -
			(char *)finfo;
		sec = fd->sc_blkno % type->seccyl;
		nblks = type->seccyl - sec;
		nblks = min(nblks, fd->sc_bcount / fd_bsize);
		nblks = min(nblks, FDC_MAXIOSIZE / fd_bsize);
		fd->sc_nblks = nblks;
		fd->sc_nbytes = finfo ? bp->b_bcount : nblks * fd_bsize;
		head = sec / type->sectrac;
		sec -= head * type->sectrac;
#ifdef DIAGNOSTIC
		{int block;
		 block = (fd->sc_cylin * type->heads + head) * type->sectrac + sec;
		 if (block != fd->sc_blkno) {
			 printf("fdintr: block %d != blkno %d\n", block, fd->sc_blkno);
#ifdef DDB
			 Debugger();
#endif
		 }}
#endif
		read = bp->b_flags & B_READ ? DMAMODE_READ : DMAMODE_WRITE;
		isadma_start(bp->b_data + fd->sc_skip, fd->sc_nbytes,
		    fdc->sc_drq, read);
		bus_space_write_1(iot, ioh_ctl, fdctl, type->rate);
#ifdef FD_DEBUG
		printf("fdintr: %s drive %d track %d head %d sec %d nblks %d\n",
		    read ? "read" : "write", fd->sc_drive, fd->sc_cylin, head,
		    sec, nblks);
#endif
		if (finfo) {
                        /* formatting */
			if (out_fdc(iot, ioh, NE7CMD_FORMAT) < 0) {
			    fdc->sc_errors = 4;
			    fdretry(fd);
			    goto loop;
			}
                        out_fdc(iot, ioh, (head << 2) | fd->sc_drive);
                        out_fdc(iot, ioh, finfo->fd_formb_secshift);
                        out_fdc(iot, ioh, finfo->fd_formb_nsecs);
                        out_fdc(iot, ioh, finfo->fd_formb_gaplen);
                        out_fdc(iot, ioh, finfo->fd_formb_fillbyte);
		} else {
			if (read)
				out_fdc(iot, ioh, NE7CMD_READ);	/* READ */
			else
				out_fdc(iot, ioh, NE7CMD_WRITE);/* WRITE */
			out_fdc(iot, ioh, (head << 2) | fd->sc_drive);
			out_fdc(iot, ioh, fd->sc_cylin);	/* track */
			out_fdc(iot, ioh, head);
			out_fdc(iot, ioh, sec + 1);		/* sec +1 */
			out_fdc(iot, ioh, type->secsize);	/* sec size */
			out_fdc(iot, ioh, type->sectrac);	/* secs/track */
			out_fdc(iot, ioh, type->gap1);		/* gap1 size */
			out_fdc(iot, ioh, type->datalen);	/* data len */
		}
		fdc->sc_state = IOCOMPLETE;

		disk_busy(&fd->sc_dk);

		/* allow 2 seconds for operation */
		timeout(fdtimeout, fd, 2 * hz);
		return 1;				/* will return later */

	case SEEKWAIT:
		untimeout(fdtimeout, fd);
		fdc->sc_state = SEEKCOMPLETE;
		/* allow 1/50 second for heads to settle */
		timeout(fdcpseudointr, fdc, hz / 50);
		return 1;

	case SEEKCOMPLETE:
		disk_unbusy(&fd->sc_dk, 0);	/* no data on seek */

		/* Make sure seek really happened. */
		out_fdc(iot, ioh, NE7CMD_SENSEI);
		if (fdcresult(fdc) != 2 || (st0 & 0xf8) != 0x20 ||
		    cyl != bp->b_cylin * fd->sc_type->step) {
#ifdef FD_DEBUG
			fdcstatus(&fd->sc_dev, 2, "seek failed");
#endif
			fdretry(fd);
			goto loop;
		}
		fd->sc_cylin = bp->b_cylin;
		goto doio;

	case IOTIMEDOUT:
		isadma_abort(fdc->sc_drq);
	case SEEKTIMEDOUT:
	case RECALTIMEDOUT:
	case RESETTIMEDOUT:
		fdretry(fd);
		goto loop;

	case IOCOMPLETE: /* IO DONE, post-analyze */
		untimeout(fdtimeout, fd);

		disk_unbusy(&fd->sc_dk, (bp->b_bcount - bp->b_resid));

		if (fdcresult(fdc) != 7 || (st0 & 0xf8) != 0) {
			isadma_abort(fdc->sc_drq);
#ifdef FD_DEBUG
			fdcstatus(&fd->sc_dev, 7, bp->b_flags & B_READ ?
			    "read failed" : "write failed");
			printf("blkno %d nblks %d\n",
			    fd->sc_blkno, fd->sc_nblks);
#endif
			fdretry(fd);
			goto loop;
		}
		read = bp->b_flags & B_READ ? DMAMODE_READ : DMAMODE_WRITE;
		isadma_done(fdc->sc_drq);
		if (fdc->sc_errors) {
			diskerr(bp, "fd", "soft error", LOG_PRINTF,
			    fd->sc_skip / fd_bsize, (struct disklabel *)NULL);
			printf("\n");
			fdc->sc_errors = 0;
		}
		fd->sc_blkno += fd->sc_nblks;
		fd->sc_skip += fd->sc_nbytes;
		fd->sc_bcount -= fd->sc_nbytes;
		if (!finfo && fd->sc_bcount > 0) {
			bp->b_cylin = fd->sc_blkno / fd->sc_type->seccyl;
			goto doseek;
		}
		fdfinish(fd, bp);
		goto loop;

	case DORESET:
		/* try a reset, keep motor on */
		fd_set_motor(fdc, 1);
		delay(100);
		fd_set_motor(fdc, 0);
		fdc->sc_state = RESETCOMPLETE;
		timeout(fdtimeout, fd, hz / 2);
		return 1;			/* will return later */

	case RESETCOMPLETE:
		untimeout(fdtimeout, fd);
		/* clear the controller output buffer */
		for (i = 0; i < 4; i++) {
			out_fdc(iot, ioh, NE7CMD_SENSEI);
			(void) fdcresult(fdc);
		}

		/* fall through */
	case DORECAL:
		out_fdc(iot, ioh, NE7CMD_RECAL);	/* recal function */
		out_fdc(iot, ioh, fd->sc_drive);
		fdc->sc_state = RECALWAIT;
		timeout(fdtimeout, fd, 5 * hz);
		return 1;			/* will return later */

	case RECALWAIT:
		untimeout(fdtimeout, fd);
		fdc->sc_state = RECALCOMPLETE;
		/* allow 1/30 second for heads to settle */
		timeout(fdcpseudointr, fdc, hz / 30);
		return 1;			/* will return later */

	case RECALCOMPLETE:
		out_fdc(iot, ioh, NE7CMD_SENSEI);
		if (fdcresult(fdc) != 2 || (st0 & 0xf8) != 0x20 || cyl != 0) {
#ifdef FD_DEBUG
			fdcstatus(&fd->sc_dev, 2, "recalibrate failed");
#endif
			fdretry(fd);
			goto loop;
		}
		fd->sc_cylin = 0;
		goto doseek;

	case MOTORWAIT:
		if (fd->sc_flags & FD_MOTOR_WAIT)
			return 1;		/* time's not up yet */
		goto doseek;

	default:
		fdcstatus(&fd->sc_dev, 0, "stray interrupt");
		return 1;
	}
#ifdef DIAGNOSTIC
	panic("fdintr: impossible");
#endif
#undef	st0
#undef	cyl
}

void
fdtimeout(arg)
	void *arg;
{
	struct fd_softc *fd = arg;
	struct fdc_softc *fdc = (void *)fd->sc_dev.dv_parent;
	int s;

	s = splbio();
#ifdef DEBUG
	log(LOG_ERR,"fdtimeout: state %d\n", fdc->sc_state);
#endif
	fdcstatus(&fd->sc_dev, 0, "timeout");

	if (fd->sc_q.b_actf)
		fdc->sc_state++;
	else
		fdc->sc_state = DEVIDLE;

	(void) fdintr(fdc);
	splx(s);
}

void
fdretry(fd)
	struct fd_softc *fd;
{
	struct fdc_softc *fdc = (void *)fd->sc_dev.dv_parent;
	struct buf *bp = fd->sc_q.b_actf;

	if (fd->sc_opts & FDOPT_NORETRY)
	    goto fail;
	switch (fdc->sc_errors) {
	case 0:
		/* try again */
		fdc->sc_state = DOSEEK;
		break;

	case 1: case 2: case 3:
		/* didn't work; try recalibrating */
		fdc->sc_state = DORECAL;
		break;

	case 4:
		/* still no go; reset the bastard */
		fdc->sc_state = DORESET;
		break;

	default:
	fail:
		diskerr(bp, "fd", "hard error", LOG_PRINTF,
		    fd->sc_skip / (128 << fd->sc_type->secsize),
		    (struct disklabel *)NULL);
		printf(" (st0 %b st1 %b st2 %b cyl %d head %d sec %d)\n",
		    fdc->sc_status[0], NE7_ST0BITS,
		    fdc->sc_status[1], NE7_ST1BITS,
		    fdc->sc_status[2], NE7_ST2BITS,
		    fdc->sc_status[3], fdc->sc_status[4], fdc->sc_status[5]);

		bp->b_flags |= B_ERROR;
		bp->b_error = EIO;
		fdfinish(fd, bp);
	}
	fdc->sc_errors++;
}

int
fdioctl(dev, cmd, addr, flag, p)
	dev_t dev;
	u_long cmd;
	caddr_t addr;
	int flag;
	struct proc *p;
{
	struct fd_softc *fd = fd_cd.cd_devs[FDUNIT(dev)];
	struct disklabel dl, *lp = &dl;
	struct cpu_disklabel cdl;
	char *errstring;
	int error;

	switch (cmd) {
	case MTIOCTOP:
		if (((struct mtop *)addr)->mt_op != MTOFFL)
			return EIO;
		return (0);
	case DIOCGDINFO:
		bzero(lp, sizeof(*lp));
		bzero(&cdl, sizeof(struct cpu_disklabel));

		lp->d_secsize = 128 << fd->sc_type->secsize;
		lp->d_secpercyl = fd->sc_type->seccyl;
		lp->d_ntracks = fd->sc_type->heads;
		lp->d_nsectors = fd->sc_type->sectrac;
		lp->d_ncylinders = fd->sc_type->tracks;

		strncpy(lp->d_typename, "floppy disk", 16);
		lp->d_type = DTYPE_FLOPPY;
		strncpy(lp->d_packname, "fictitious", 16);
		lp->d_secperunit = fd->sc_type->size;
		lp->d_rpm = 300;
		lp->d_interleave = 1;
		lp->d_flags = D_REMOVABLE;

		lp->d_partitions[RAW_PART].p_offset = 0;
		lp->d_partitions[RAW_PART].p_size =
		    lp->d_secperunit * (lp->d_secsize / DEV_BSIZE);
		lp->d_partitions[RAW_PART].p_fstype = FS_UNUSED;
		lp->d_npartitions = RAW_PART + 1;

		lp->d_magic = DISKMAGIC;
		lp->d_magic2 = DISKMAGIC;
		lp->d_checksum = dkcksum(lp);

		errstring = readdisklabel(dev, fdstrategy, lp, &cdl, 0);
		if (errstring) {
			/*printf("%s: %s\n", fd->sc_dev.dv_xname, errstring); */
		}

		*(struct disklabel *)addr = *lp;
		return 0;

	case DIOCWLABEL:
		if ((flag & FWRITE) == 0)
			return EBADF;
		/* XXX do something */
		return 0;

	case DIOCWDINFO:
		if ((flag & FWRITE) == 0)
			return EBADF;

		error = setdisklabel(lp, (struct disklabel *)addr, 0, NULL);
		if (error)
			return error;

		error = writedisklabel(dev, fdstrategy, lp, NULL);
		return error;

        case FD_FORM:
                if((flag & FWRITE) == 0)
                        return EBADF;  /* must be opened for writing */
                else if(((struct fd_formb *)addr)->format_version !=
                        FD_FORMAT_VERSION)
                        return EINVAL; /* wrong version of formatting prog */
                else
                        return fdformat(dev, (struct fd_formb *)addr, p);
                break;

        case FD_GTYPE:                  /* get drive type */
                *(struct fd_type *)addr = *fd->sc_type;
		return 0;

        case FD_GOPTS:                  /* get drive options */
                *(int *)addr = fd->sc_opts;
                return 0;
                
        case FD_SOPTS:                  /* set drive options */
                fd->sc_opts = *(int *)addr;
		return 0;

	default:
		return ENOTTY;
	}

#ifdef DIAGNOSTIC
	panic("fdioctl: impossible");
#endif
}

int
fdformat(dev, finfo, p)
        dev_t dev;
        struct fd_formb *finfo;
        struct proc *p;
{
        int rv = 0, s;
	struct fd_softc *fd = fd_cd.cd_devs[FDUNIT(dev)];
	struct fd_type *type = fd->sc_type;
        struct buf *bp;
	int fd_bsize = 128 << fd->sc_type->secsize;

        /* set up a buffer header for fdstrategy() */
        bp = (struct buf *)malloc(sizeof(struct buf), M_TEMP, M_NOWAIT);
        if(bp == 0)
                return ENOBUFS;
        bzero((void *)bp, sizeof(struct buf));
        bp->b_flags = B_BUSY | B_PHYS | B_FORMAT;
        bp->b_proc = p;
        bp->b_dev = dev;

        /*
         * calculate a fake blkno, so fdstrategy() would initiate a
         * seek to the requested cylinder
         */
        bp->b_blkno = (finfo->cyl * (type->sectrac * type->heads)
                + finfo->head * type->sectrac) * fd_bsize / DEV_BSIZE;

        bp->b_bcount = sizeof(struct fd_idfield_data) * finfo->fd_formb_nsecs;
        bp->b_data = (caddr_t)finfo;
        
#ifdef DEBUG
	printf("fdformat: blkno %x count %x\n", bp->b_blkno, bp->b_bcount);
#endif

        /* now do the format */
        fdstrategy(bp);

        /* ...and wait for it to complete */
        s = splbio();
        while(!(bp->b_flags & B_DONE))
        {
                rv = tsleep((caddr_t)bp, PRIBIO, "fdform", 0);
                if(rv == EWOULDBLOCK)
		    /*break*/;
        }
        splx(s);
        
        if(rv == EWOULDBLOCK) {
                /* timed out */
                rv = EIO;
		/* XXX what to do to the buf? it will eventually fall
		   out as finished, but ... ?*/
		/*biodone(bp);*/
	}
        if(bp->b_flags & B_ERROR)
                rv = bp->b_error;
        free(bp, M_TEMP);
        return rv;
}