fd.c revision 1.86.12.2 1 /* $NetBSD: fd.c,v 1.86.12.2 2014/08/20 00:02:43 tls Exp $ */
2
3 /*
4 * Copyright (c) 1994 Christian E. Hopps
5 * Copyright (c) 1996 Ezra Story
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by Christian E. Hopps.
19 * This product includes software developed by Ezra Story.
20 * 4. The name of the author may not be used to endorse or promote products
21 * derived from this software without specific prior written permission
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34
35 #include <sys/cdefs.h>
36 __KERNEL_RCSID(0, "$NetBSD: fd.c,v 1.86.12.2 2014/08/20 00:02:43 tls Exp $");
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/callout.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <sys/buf.h>
44 #include <sys/bufq.h>
45 #include <sys/device.h>
46 #include <sys/ioctl.h>
47 #include <sys/fcntl.h>
48 #include <sys/disklabel.h>
49 #include <sys/disk.h>
50 #include <sys/dkbad.h>
51 #include <sys/proc.h>
52 #include <sys/conf.h>
53
54 #include <machine/cpu.h>
55 #include <amiga/amiga/device.h>
56 #include <amiga/amiga/custom.h>
57 #include <amiga/amiga/cia.h>
58 #include <amiga/amiga/cc.h>
59
60 #include "locators.h"
61
62 enum fdc_bits { FDB_CHANGED = 2, FDB_PROTECT, FDB_CYLZERO, FDB_READY };
63 /*
64 * partitions in fd represent different format floppies
65 * partition a is 0 etc..
66 */
67 enum fd_parttypes {
68 FDAMIGAPART = 0,
69 FDMSDOSPART,
70 FDMAXPARTS
71 };
72
73 #define FDBBSIZE (8192)
74 #define FDSBSIZE (8192)
75
76 #define FDUNIT(dev) DISKUNIT(dev)
77 #define FDPART(dev) DISKPART(dev)
78 #define FDMAKEDEV(m, u, p) MAKEDISKDEV((m), (u), (p))
79
80 /* that's nice, but we don't want to always use this as an amiga drive
81 bunghole :-) */
82 #define FDNHEADS (2) /* amiga drives always have 2 heads */
83 #define FDSECSIZE (512) /* amiga drives always have 512 byte sectors */
84 #define FDSECLWORDS (128)
85
86 #define FDSETTLEDELAY (18000) /* usec delay after seeking after switch dir */
87 #define FDSTEPDELAY (3500) /* usec delay after steping */
88 #define FDPRESIDEDELAY (1000) /* usec delay before writing can occur */
89 #define FDWRITEDELAY (1300) /* usec delay after write */
90
91 #define FDSTEPOUT (1) /* decrease track step */
92 #define FDSTEPIN (0) /* increase track step */
93
94 #define FDCUNITMASK (0x78) /* mask for all units (bits 6-3) */
95
96 #define FDRETRIES (2) /* default number of retries */
97 #define FDMAXUNITS (4) /* maximum number of supported units */
98
99 #define DISKLEN_READ (0) /* fake mask for reading */
100 #define DISKLEN_WRITE (1 << 14) /* bit for writing */
101 #define DISKLEN_DMAEN (1 << 15) /* DMA go */
102 #define DMABUFSZ ((DISKLEN_WRITE - 1) * 2) /* largest DMA possible */
103
104 #define FDMFMSYNC (0x4489)
105 #define FDMFMID (0x5554)
106 #define FDMFMDATA (0x5545)
107 #define FDMFMGAP1 (0x9254)
108 #define FDMFMGAP2 (0xAAAA)
109 #define FDMFMGAP3 (0x9254)
110 #define CRC16POLY (0x1021) /* (x^16) + x^12 + x^5 + x^0 */
111
112 /*
113 * Msdos-type MFM encode/decode
114 */
115 static u_char msdecode[128];
116 static u_char msencode[16] =
117 {
118 0x2a, 0x29, 0x24, 0x25, 0x12, 0x11, 0x14, 0x15,
119 0x4a, 0x49, 0x44, 0x45, 0x52, 0x51, 0x54, 0x55
120 };
121 static u_short mscrctab[256];
122
123 /*
124 5554 aaaa aaaa aaa5 2aa4 4452 aa51
125 00 00 03 02 ac 0d
126 */
127
128 /*
129 * floppy device type
130 */
131 struct fdtype {
132 u_int driveid; /* drive identification (from drive) */
133 u_int ncylinders; /* number of cylinders on drive */
134 u_int amiga_nsectors; /* number of sectors per amiga track */
135 u_int msdos_nsectors; /* number of sectors per msdos track */
136 u_int nreadw; /* number of words (short) read per track */
137 u_int nwritew; /* number of words (short) written per track */
138 u_int gap; /* track gap size in long words */
139 const u_int precomp[2]; /* 1st and 2nd precomp values */
140 const char *desc; /* description of drive type (useq) */
141 };
142
143 /*
144 * floppy disk device data
145 */
146 struct fd_softc {
147 device_t sc_dev; /* generic device info; must come first */
148 struct disk dkdev; /* generic disk info */
149 struct bufq_state *bufq;/* queue pending I/O operations */
150 struct buf curbuf; /* state of current I/O operation */
151 struct callout calibrate_ch;
152 struct callout motor_ch;
153 struct fdtype *type;
154 void *cachep; /* cached track data (write through) */
155 int cachetrk; /* cahced track -1 for none */
156 int hwunit; /* unit for amiga controlling hw */
157 int unitmask; /* mask for cia select deslect */
158 int pstepdir; /* previous step direction */
159 int curcyl; /* current curcyl head positioned on */
160 int flags; /* misc flags */
161 int wlabel;
162 int stepdelay; /* useq to delay after seek user setable */
163 int nsectors; /* number of sectors per track */
164 int openpart; /* which partition [ab] == [12] is open */
165 short retries; /* number of times to retry failed io */
166 short retried; /* number of times current io retried */
167 int bytespersec; /* number of bytes per sector */
168 };
169
170 /* fd_softc->flags */
171 #define FDF_MOTORON (0x01) /* motor is running */
172 #define FDF_MOTOROFF (0x02) /* motor is waiting to be turned off */
173 #define FDF_WMOTOROFF (0x04) /* unit wants a wakeup after off */
174 #define FDF_DIRTY (0x08) /* track cache needs write */
175 #define FDF_WRITEWAIT (0x10) /* need to head select delay on next setpos */
176 #define FDF_HAVELABEL (0x20) /* label is valid */
177 #define FDF_JUSTFLUSH (0x40) /* don't bother caching track. */
178 #define FDF_NOTRACK0 (0x80) /* was not able to recalibrate drive */
179
180 int fdc_wantwakeup;
181 int fdc_side;
182 void *fdc_dmap;
183 struct fd_softc *fdc_indma;
184 int fdc_dmalen;
185 int fdc_dmawrite;
186
187 struct fdcargs {
188 struct fdtype *type;
189 int unit;
190 };
191
192 int fdcmatch(device_t, cfdata_t, void *);
193 void fdcattach(device_t, device_t, void *);
194 int fdcprint(void *, const char *);
195 int fdmatch(device_t, cfdata_t, void *);
196 void fdattach(device_t, device_t, void *);
197
198 void fdintr(int);
199 void fdidxintr(void);
200 int fdloaddisk(struct fd_softc *);
201 void fdgetdefaultlabel(struct fd_softc *, struct disklabel *, int);
202 int fdgetdisklabel(struct fd_softc *, dev_t);
203 int fdsetdisklabel(struct fd_softc *, struct disklabel *);
204 int fdputdisklabel(struct fd_softc *, dev_t);
205 struct fdtype * fdcgetfdtype(int);
206 void fdmotoroff(void *);
207 void fdsetpos(struct fd_softc *, int, int);
208 void fdselunit(struct fd_softc *);
209 void fdstart(struct fd_softc *);
210 void fdcont(struct fd_softc *);
211 void fddmastart(struct fd_softc *, int);
212 void fdcalibrate(void *);
213 void fddmadone(struct fd_softc *, int);
214 void fddone(struct fd_softc *);
215 void fdfindwork(int);
216 void fdminphys(struct buf *);
217 void fdcachetoraw(struct fd_softc *);
218 void amcachetoraw(struct fd_softc *);
219 int amrawtocache(struct fd_softc *);
220 u_long *fdfindsync(u_long *, u_long *);
221 int fdrawtocache(struct fd_softc *);
222 void mscachetoraw(struct fd_softc *);
223 int msrawtocache(struct fd_softc *);
224 u_long *mfmblkencode(u_long *, u_long *, u_long *, int);
225 u_long *mfmblkdecode(u_long *, u_long *, u_long *, int);
226 u_short *msblkdecode(u_short *, u_char *, int);
227 u_short *msblkencode(u_short *, u_char *, int, u_short *);
228
229 /*
230 * read size is (nsectors + 1) * mfm secsize + gap bytes + 2 shorts
231 * write size is nsectors * mfm secsize + gap bytes + 3 shorts
232 * the extra shorts are to deal with a DMA hw bug in the controller
233 * they are probably too much (I belive the bug is 1 short on write and
234 * 3 bits on read) but there is no need to be cheap here.
235 */
236 #define MAXTRKSZ (22 * FDSECSIZE)
237 struct fdtype fdtype[] = {
238 { 0x00000000, 80, 11, 9, 7358, 6815, 414, { 80, 161 }, "3.5dd" },
239 { 0x55555555, 40, 11, 9, 7358, 6815, 414, { 80, 161 }, "5.25dd" },
240 { 0xAAAAAAAA, 80, 22, 18, 14716, 13630, 828, { 80, 161 }, "3.5hd" }
241 };
242 int nfdtype = __arraycount(fdtype);
243
244 CFATTACH_DECL_NEW(fd, sizeof(struct fd_softc),
245 fdmatch, fdattach, NULL, NULL);
246
247 extern struct cfdriver fd_cd;
248
249 dev_type_open(fdopen);
250 dev_type_close(fdclose);
251 dev_type_read(fdread);
252 dev_type_write(fdwrite);
253 dev_type_ioctl(fdioctl);
254 dev_type_strategy(fdstrategy);
255
256 const struct bdevsw fd_bdevsw = {
257 .d_open = fdopen,
258 .d_close = fdclose,
259 .d_strategy = fdstrategy,
260 .d_ioctl = fdioctl,
261 .d_dump = nodump,
262 .d_psize = nosize,
263 .d_discard = nodiscard,
264 .d_flag = D_DISK
265 };
266
267 const struct cdevsw fd_cdevsw = {
268 .d_open = fdopen,
269 .d_close = fdclose,
270 .d_read = fdread,
271 .d_write = fdwrite,
272 .d_ioctl = fdioctl,
273 .d_stop = nostop,
274 .d_tty = notty,
275 .d_poll = nopoll,
276 .d_mmap = nommap,
277 .d_kqfilter = nokqfilter,
278 .d_discard = nodiscard,
279 .d_flag = D_DISK
280 };
281
282 struct dkdriver fddkdriver = { fdstrategy };
283
284 CFATTACH_DECL_NEW(fdc, 0,
285 fdcmatch, fdcattach, NULL, NULL);
286
287 /*
288 * all hw access through macros, this helps to hide the active low
289 * properties
290 */
291
292 #define FDUNITMASK(unit) (1 << (3 + (unit)))
293
294 /*
295 * select units using mask
296 */
297 #define FDSELECT(um) do { ciab.prb &= ~(um); } while (0)
298
299 /*
300 * deselect units using mask
301 */
302 #define FDDESELECT(um) do { ciab.prb |= (um); delay(1); } while (0)
303
304 /*
305 * test hw condition bits
306 */
307 #define FDTESTC(bit) ((ciaa.pra & (1 << (bit))) == 0)
308
309 /*
310 * set motor for select units, true motor on else off
311 */
312 #define FDSETMOTOR(on) do { \
313 if (on) ciab.prb &= ~CIAB_PRB_MTR; else ciab.prb |= CIAB_PRB_MTR; \
314 } while (0)
315
316 /*
317 * set head for select units
318 */
319 #define FDSETHEAD(head) do { \
320 if (head) ciab.prb &= ~CIAB_PRB_SIDE; else ciab.prb |= CIAB_PRB_SIDE; \
321 delay(1); } while (0)
322
323 /*
324 * select direction, true towards spindle else outwards
325 */
326 #define FDSETDIR(in) do { \
327 if (in) ciab.prb &= ~CIAB_PRB_DIR; else ciab.prb |= CIAB_PRB_DIR; \
328 delay(1); } while (0)
329
330 /*
331 * step the selected units
332 */
333 #define FDSTEP do { \
334 ciab.prb &= ~CIAB_PRB_STEP; ciab.prb |= CIAB_PRB_STEP; \
335 } while (0)
336
337 #define FDDMASTART(len, towrite) do { \
338 int dmasz = (len) | ((towrite) ? DISKLEN_WRITE : 0) | DISKLEN_DMAEN; \
339 custom.dsklen = dmasz; custom.dsklen = dmasz; } while (0)
340
341 #define FDDMASTOP do { custom.dsklen = 0; } while (0)
342
343
344 int
345 fdcmatch(device_t parent, cfdata_t cf, void *aux)
346 {
347 static int fdc_matched = 0;
348
349 /* Allow only once instance. */
350 if (matchname("fdc", aux) == 0 || fdc_matched)
351 return(0);
352 if ((fdc_dmap = alloc_chipmem(DMABUFSZ)) == NULL) {
353 printf("fdc: unable to allocate DMA buffer\n");
354 return(0);
355 }
356
357 fdc_matched = 1;
358 return(1);
359 }
360
361 void
362 fdcattach(device_t parent, device_t self, void *aux)
363 {
364 struct fdcargs args;
365
366 printf(": dmabuf pa 0x%x", (unsigned)kvtop(fdc_dmap));
367 printf(": dmabuf ka %p\n", fdc_dmap);
368 args.unit = 0;
369 args.type = fdcgetfdtype(args.unit);
370
371 fdc_side = -1;
372 config_found(self, &args, fdcprint);
373 for (args.unit++; args.unit < FDMAXUNITS; args.unit++) {
374 if ((args.type = fdcgetfdtype(args.unit)) == NULL)
375 continue;
376 config_found(self, &args, fdcprint);
377 }
378 }
379
380 int
381 fdcprint(void *aux, const char *pnp)
382 {
383 struct fdcargs *fcp;
384
385 fcp = aux;
386 if (pnp)
387 aprint_normal("fd%d at %s unit %d:", fcp->unit, pnp,
388 fcp->type->driveid);
389 return(UNCONF);
390 }
391
392 /*ARGSUSED*/
393 int
394 fdmatch(device_t parent, cfdata_t cf, void *aux)
395 {
396 struct fdcargs *fdap;
397
398 fdap = aux;
399 if (cf->cf_loc[FDCCF_UNIT] == fdap->unit ||
400 cf->cf_loc[FDCCF_UNIT] == FDCCF_UNIT_DEFAULT)
401 return(1);
402
403 return(0);
404 }
405
406 void
407 fdattach(device_t parent, device_t self, void *aux)
408 {
409 struct fdcargs *ap;
410 struct fd_softc *sc;
411 int i;
412
413 ap = aux;
414 sc = device_private(self);
415 sc->sc_dev = self;
416
417 bufq_alloc(&sc->bufq, "disksort", BUFQ_SORT_CYLINDER);
418 callout_init(&sc->calibrate_ch, 0);
419 callout_init(&sc->motor_ch, 0);
420
421 sc->curcyl = sc->cachetrk = -1;
422 sc->openpart = -1;
423 sc->type = ap->type;
424 sc->hwunit = ap->unit;
425 sc->unitmask = 1 << (3 + ap->unit);
426 sc->retries = FDRETRIES;
427 sc->stepdelay = FDSTEPDELAY;
428 sc->bytespersec = 512;
429 printf(" unit %d: %s %d cyl, %d head, %d sec [%d sec], 512 bytes/sec\n",
430 sc->hwunit, sc->type->desc, sc->type->ncylinders, FDNHEADS,
431 sc->type->amiga_nsectors, sc->type->msdos_nsectors);
432
433 /*
434 * Initialize and attach the disk structure.
435 */
436 disk_init(&sc->dkdev, device_xname(sc->sc_dev), &fddkdriver);
437 disk_attach(&sc->dkdev);
438
439 /*
440 * calibrate the drive
441 */
442 fdsetpos(sc, 0, 0);
443 fdsetpos(sc, sc->type->ncylinders, 0);
444 fdsetpos(sc, 0, 0);
445 fdmotoroff(sc);
446
447 /*
448 * precalc msdos MFM and CRC
449 */
450 for (i = 0; i < 128; i++)
451 msdecode[i] = 0xff;
452 for (i = 0; i < 16; i++)
453 msdecode[msencode[i]] = i;
454 for (i = 0; i < 256; i++) {
455 mscrctab[i] = (0x1021 * (i & 0xf0)) ^ (0x1021 * (i & 0x0f)) ^
456 (0x1021 * (i >> 4));
457 }
458
459 /*
460 * enable disk related interrupts
461 */
462 custom.dmacon = DMAF_SETCLR | DMAF_MASTER | DMAF_DISK;
463 custom.intena = INTF_SETCLR | INTF_DSKBLK;
464 ciab.icr = CIA_ICR_FLG;
465 }
466
467 /*ARGSUSED*/
468 int
469 fdopen(dev_t dev, int flags, int devtype, struct lwp *l)
470 {
471 struct fd_softc *sc;
472 int wasopen, fwork, error, s;
473
474 error = 0;
475
476 if (FDPART(dev) >= FDMAXPARTS)
477 return(ENXIO);
478
479 if ((sc = getsoftc(fd_cd, FDUNIT(dev))) == NULL)
480 return(ENXIO);
481 if (sc->flags & FDF_NOTRACK0)
482 return(ENXIO);
483 if (sc->cachep == NULL)
484 sc->cachep = malloc(MAXTRKSZ, M_DEVBUF, M_WAITOK);
485
486 s = splbio();
487 /*
488 * if we are sleeping in fdclose(); waiting for a chance to
489 * shut the motor off, do a sleep here also.
490 */
491 while (sc->flags & FDF_WMOTOROFF)
492 tsleep(fdmotoroff, PRIBIO, "fdopen", 0);
493
494 fwork = 0;
495 /*
496 * if not open let user open request type, otherwise
497 * ensure they are trying to open same type.
498 */
499 if (sc->openpart == FDPART(dev))
500 wasopen = 1;
501 else if (sc->openpart == -1) {
502 sc->openpart = FDPART(dev);
503 wasopen = 0;
504 } else {
505 wasopen = 1;
506 error = EPERM;
507 goto done;
508 }
509
510 /*
511 * wait for current io to complete if any
512 */
513 if (fdc_indma) {
514 fwork = 1;
515 fdc_wantwakeup++;
516 tsleep(fdopen, PRIBIO, "fdopen", 0);
517 }
518 if ((error = fdloaddisk(sc)) != 0)
519 goto done;
520 if ((error = fdgetdisklabel(sc, dev)) != 0)
521 goto done;
522 #ifdef FDDEBUG
523 printf(" open successful\n");
524 #endif
525 done:
526 /*
527 * if we requested that fddone()->fdfindwork() wake us, allow it to
528 * complete its job now
529 */
530 if (fwork)
531 fdfindwork(FDUNIT(dev));
532 splx(s);
533
534 /*
535 * if we were not open and we marked us so reverse that.
536 */
537 if (error && wasopen == 0)
538 sc->openpart = -1;
539 return(error);
540 }
541
542 /*ARGSUSED*/
543 int
544 fdclose(dev_t dev, int flags, int devtype, struct lwp *l)
545 {
546 struct fd_softc *sc;
547 int s;
548
549 #ifdef FDDEBUG
550 printf("fdclose()\n");
551 #endif
552 sc = getsoftc(fd_cd, FDUNIT(dev));
553 s = splbio();
554 if (sc->flags & FDF_MOTORON) {
555 sc->flags |= FDF_WMOTOROFF;
556 tsleep(fdmotoroff, PRIBIO, "fdclose", 0);
557 sc->flags &= ~FDF_WMOTOROFF;
558 wakeup(fdmotoroff);
559 }
560 sc->openpart = -1;
561 splx(s);
562 return(0);
563 }
564
565 int
566 fdioctl(dev_t dev, u_long cmd, void *addr, int flag, struct lwp *l)
567 {
568 struct fd_softc *sc;
569 int error, wlab;
570
571 sc = getsoftc(fd_cd, FDUNIT(dev));
572
573 if ((sc->flags & FDF_HAVELABEL) == 0)
574 return(EBADF);
575
576 switch (cmd) {
577 case DIOCSBAD:
578 return(EINVAL);
579 case DIOCSRETRIES:
580 if (*(int *)addr < 0)
581 return(EINVAL);
582 sc->retries = *(int *)addr;
583 return(0);
584 case DIOCSSTEP:
585 if (*(int *)addr < FDSTEPDELAY)
586 return(EINVAL);
587 sc->dkdev.dk_label->d_trkseek = sc->stepdelay = *(int *)addr;
588 return(0);
589 case DIOCGDINFO:
590 *(struct disklabel *)addr = *(sc->dkdev.dk_label);
591 return(0);
592 case DIOCGPART:
593 ((struct partinfo *)addr)->disklab = sc->dkdev.dk_label;
594 ((struct partinfo *)addr)->part =
595 &sc->dkdev.dk_label->d_partitions[FDPART(dev)];
596 return(0);
597 case DIOCSDINFO:
598 if ((flag & FWRITE) == 0)
599 return(EBADF);
600 return(fdsetdisklabel(sc, (struct disklabel *)addr));
601 case DIOCWDINFO:
602 if ((flag & FWRITE) == 0)
603 return(EBADF);
604 if ((error = fdsetdisklabel(sc, (struct disklabel *)addr)) != 0)
605 return(error);
606 wlab = sc->wlabel;
607 sc->wlabel = 1;
608 error = fdputdisklabel(sc, dev);
609 sc->wlabel = wlab;
610 return(error);
611 case DIOCWLABEL:
612 if ((flag & FWRITE) == 0)
613 return(EBADF);
614 sc->wlabel = *(int *)addr;
615 return(0);
616 case DIOCGDEFLABEL:
617 fdgetdefaultlabel(sc, (struct disklabel *)addr, FDPART(dev));
618 return(0);
619 default:
620 return(ENOTTY);
621 }
622 }
623
624 int
625 fdread(dev_t dev, struct uio *uio, int flags)
626 {
627 return (physio(fdstrategy, NULL, dev, B_READ, fdminphys, uio));
628 }
629
630 int
631 fdwrite(dev_t dev, struct uio *uio, int flags)
632 {
633 return (physio(fdstrategy, NULL, dev, B_WRITE, fdminphys, uio));
634 }
635
636
637 void
638 fdintr(int flag)
639 {
640 int s;
641
642 s = splbio();
643 if (fdc_indma)
644 fddmadone(fdc_indma, 0);
645 splx(s);
646 }
647
648 void
649 fdidxintr(void)
650 {
651 if (fdc_indma && fdc_dmalen) {
652 /*
653 * turn off intr and start actual dma
654 */
655 ciab.icr = CIA_ICR_FLG;
656 FDDMASTART(fdc_dmalen, fdc_dmawrite);
657 fdc_dmalen = 0;
658 }
659 }
660
661 void
662 fdstrategy(struct buf *bp)
663 {
664 struct fd_softc *sc;
665 int unit, s;
666
667 unit = FDUNIT(bp->b_dev);
668 sc = getsoftc(fd_cd, unit);
669
670 #ifdef FDDEBUG
671 printf("fdstrategy: %p\n", bp);
672 #endif
673 /*
674 * check for valid partition and bounds
675 */
676 if ((sc->flags & FDF_HAVELABEL) == 0) {
677 bp->b_error = EIO;
678 goto done;
679 }
680 if (bounds_check_with_label(&sc->dkdev, bp, sc->wlabel) <= 0)
681 goto done;
682
683 /*
684 * trans count of zero or bounds check indicates io is done
685 * we are done.
686 */
687 if (bp->b_bcount == 0)
688 goto done;
689
690 bp->b_rawblkno = bp->b_blkno;
691
692 /*
693 * queue the buf and kick the low level code
694 */
695 s = splbio();
696 bufq_put(sc->bufq, bp);
697 fdstart(sc);
698 splx(s);
699 return;
700 done:
701 bp->b_resid = bp->b_bcount;
702 biodone(bp);
703 }
704
705 /*
706 * make sure disk is loaded and label is up-to-date.
707 */
708 int
709 fdloaddisk(struct fd_softc *sc)
710 {
711 /*
712 * if diskchange is low step drive to 0 then up one then to zero.
713 */
714 fdselunit(sc); /* make sure the unit is selected */
715 if (FDTESTC(FDB_CHANGED)) {
716 fdsetpos(sc, 0, 0);
717 sc->cachetrk = -1; /* invalidate the cache */
718 sc->flags &= ~FDF_HAVELABEL;
719 fdsetpos(sc, FDNHEADS, 0);
720 fdsetpos(sc, 0, 0);
721 if (FDTESTC(FDB_CHANGED)) {
722 fdmotoroff(sc);
723 FDDESELECT(sc->unitmask);
724 return(ENXIO);
725 }
726 }
727 FDDESELECT(sc->unitmask);
728 fdmotoroff(sc);
729 sc->type = fdcgetfdtype(sc->hwunit);
730 if (sc->type == NULL)
731 return(ENXIO);
732 if (sc->openpart == FDMSDOSPART)
733 sc->nsectors = sc->type->msdos_nsectors;
734 else
735 sc->nsectors = sc->type->amiga_nsectors;
736 return(0);
737 }
738
739 void
740 fdgetdefaultlabel(struct fd_softc *sc, struct disklabel *lp, int part)
741 /* (variable part) XXX ick */
742 {
743
744 memset(lp, 0, sizeof(struct disklabel));
745 lp->d_secsize = FDSECSIZE;
746 lp->d_ntracks = FDNHEADS;
747 lp->d_ncylinders = sc->type->ncylinders;
748 lp->d_nsectors = sc->nsectors;
749 lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
750 lp->d_type = DTYPE_FLOPPY;
751 lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders;
752 lp->d_rpm = 300; /* good guess I suppose. */
753 lp->d_interleave = 1; /* should change when adding msdos */
754 sc->stepdelay = lp->d_trkseek = FDSTEPDELAY;
755 lp->d_bbsize = 0;
756 lp->d_sbsize = 0;
757 lp->d_partitions[part].p_size = lp->d_secperunit;
758 lp->d_partitions[part].p_fstype = FS_UNUSED;
759 lp->d_partitions[part].p_fsize = 1024;
760 lp->d_partitions[part].p_frag = 8;
761 lp->d_partitions[part].p_cpg = 2; /* adosfs: reserved blocks */
762 lp->d_npartitions = part + 1;
763 lp->d_magic = lp->d_magic2 = DISKMAGIC;
764 lp->d_checksum = dkcksum(lp);
765 }
766
767 /*
768 * read disk label, if present otherwise create one
769 * return a new label if raw part and none found, otherwise err.
770 */
771 int
772 fdgetdisklabel(struct fd_softc *sc, dev_t dev)
773 {
774 struct disklabel *lp, *dlp;
775 struct cpu_disklabel *clp;
776 struct buf *bp;
777 int error, part;
778
779 if (sc->flags & FDF_HAVELABEL &&
780 sc->dkdev.dk_label->d_npartitions == (FDPART(dev) + 1))
781 return(0);
782 #ifdef FDDEBUG
783 printf("fdgetdisklabel()\n");
784 #endif
785 part = FDPART(dev);
786 lp = sc->dkdev.dk_label;
787 clp = sc->dkdev.dk_cpulabel;
788 memset(lp, 0, sizeof(struct disklabel));
789 memset(clp, 0, sizeof(struct cpu_disklabel));
790
791 lp->d_secsize = FDSECSIZE;
792 lp->d_ntracks = FDNHEADS;
793 lp->d_ncylinders = sc->type->ncylinders;
794 lp->d_nsectors = sc->nsectors;
795 lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
796 lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders;
797 lp->d_npartitions = part + 1;
798 lp->d_partitions[part].p_size = lp->d_secperunit;
799 lp->d_partitions[part].p_fstype = FS_UNUSED;
800 lp->d_partitions[part].p_fsize = 1024;
801 lp->d_partitions[part].p_frag = 8;
802 lp->d_partitions[part].p_cpg = 2; /* for adosfs: reserved blks */
803
804 sc->flags |= FDF_HAVELABEL;
805
806 bp = (void *)geteblk((int)lp->d_secsize);
807 bp->b_dev = dev;
808 bp->b_blkno = 0;
809 bp->b_cylinder = 0;
810 bp->b_bcount = FDSECSIZE;
811 bp->b_flags |= B_READ;
812 fdstrategy(bp);
813 if ((error = biowait(bp)) != 0)
814 goto nolabel;
815 dlp = (struct disklabel *)((char*)bp->b_data + LABELOFFSET);
816 if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC ||
817 dkcksum(dlp)) {
818 error = EINVAL;
819 goto nolabel;
820 }
821 memcpy(lp, dlp, sizeof(struct disklabel));
822 if (lp->d_trkseek > FDSTEPDELAY)
823 sc->stepdelay = lp->d_trkseek;
824 brelse(bp, 0);
825 return(0);
826 nolabel:
827 fdgetdefaultlabel(sc, lp, part);
828 brelse(bp, 0);
829 return(0);
830 }
831
832 /*
833 * set the incore copy of this units disklabel
834 */
835 int
836 fdsetdisklabel(struct fd_softc *sc, struct disklabel *lp)
837 {
838 struct disklabel *clp;
839 struct partition *pp;
840
841 /*
842 * must have at least opened raw unit to fetch the
843 * raw_part stuff.
844 */
845 if ((sc->flags & FDF_HAVELABEL) == 0)
846 return(EINVAL);
847 clp = sc->dkdev.dk_label;
848 /*
849 * make sure things check out and we only have one valid
850 * partition
851 */
852 #ifdef FDDEBUG
853 printf("fdsetdisklabel\n");
854 #endif
855 if (lp->d_secsize != FDSECSIZE ||
856 lp->d_nsectors != clp->d_nsectors ||
857 lp->d_ntracks != FDNHEADS ||
858 lp->d_ncylinders != clp->d_ncylinders ||
859 lp->d_secpercyl != clp->d_secpercyl ||
860 lp->d_secperunit != clp->d_secperunit ||
861 lp->d_magic != DISKMAGIC ||
862 lp->d_magic2 != DISKMAGIC ||
863 lp->d_npartitions == 0 ||
864 lp->d_npartitions > FDMAXPARTS ||
865 (lp->d_partitions[0].p_offset && lp->d_partitions[1].p_offset) ||
866 dkcksum(lp))
867 return(EINVAL);
868 /*
869 * if any partitions are present make sure they
870 * represent the currently open type
871 */
872 if ((pp = &lp->d_partitions[0])->p_size) {
873 if ((pp = &lp->d_partitions[1])->p_size == 0)
874 goto done;
875 else if (sc->openpart != 1)
876 return(EINVAL);
877 } else if (sc->openpart != 0)
878 return(EINVAL);
879 /*
880 * make sure selected partition is within bounds
881 * XXX on the second check, its to handle a bug in
882 * XXX the cluster routines as they require mutliples
883 * XXX of PAGE_SIZE currently
884 */
885 if ((pp->p_offset + pp->p_size >= lp->d_secperunit) ||
886 (pp->p_frag * pp->p_fsize % PAGE_SIZE))
887 return(EINVAL);
888 done:
889 memcpy(clp, lp, sizeof(struct disklabel));
890 return(0);
891 }
892
893 /*
894 * write out the incore copy of this units disklabel
895 */
896 int
897 fdputdisklabel(struct fd_softc *sc, dev_t dev)
898 {
899 struct disklabel *lp, *dlp;
900 struct buf *bp;
901 int error;
902
903 if ((sc->flags & FDF_HAVELABEL) == 0)
904 return(EBADF);
905 #ifdef FDDEBUG
906 printf("fdputdisklabel\n");
907 #endif
908 /*
909 * get buf and read in sector 0
910 */
911 lp = sc->dkdev.dk_label;
912 bp = geteblk((int)lp->d_secsize);
913 bp->b_dev = FDMAKEDEV(major(dev), FDUNIT(dev), RAW_PART);
914 bp->b_blkno = 0;
915 bp->b_cylinder = 0;
916 bp->b_bcount = FDSECSIZE;
917 bp->b_flags |= B_READ;
918 fdstrategy(bp);
919 if ((error = biowait(bp)) != 0)
920 goto done;
921 /*
922 * copy disklabel to buf and write it out synchronous
923 */
924 dlp = (struct disklabel *)((char*)bp->b_data + LABELOFFSET);
925 memcpy(dlp, lp, sizeof(struct disklabel));
926 bp->b_blkno = 0;
927 bp->b_cylinder = 0;
928 bp->b_flags &= ~(B_READ);
929 bp->b_oflags &= ~(BO_DONE);
930 bp->b_flags |= B_WRITE;
931 fdstrategy(bp);
932 error = biowait(bp);
933 done:
934 brelse(bp, 0);
935 return(error);
936 }
937
938 /*
939 * figure out drive type or NULL if none.
940 */
941 struct fdtype *
942 fdcgetfdtype(int unit)
943 {
944 struct fdtype *ftp;
945 u_long id, idb;
946 int cnt, umask;
947
948 id = 0;
949 umask = 1 << (3 + unit);
950
951 FDDESELECT(FDCUNITMASK);
952
953 FDSETMOTOR(1);
954 delay(1);
955 FDSELECT(umask);
956 delay(1);
957 FDDESELECT(umask);
958
959 FDSETMOTOR(0);
960 delay(1);
961 FDSELECT(umask);
962 delay(1);
963 FDDESELECT(umask);
964
965 for (idb = 0x80000000; idb; idb >>= 1) {
966 FDSELECT(umask);
967 delay(1);
968 if (FDTESTC(FDB_READY) == 0)
969 id |= idb;
970 FDDESELECT(umask);
971 delay(1);
972 }
973 #ifdef FDDEBUG
974 printf("fdcgettype unit %d id 0x%lx\n", unit, id);
975 #endif
976
977 for (cnt = 0, ftp = fdtype; cnt < nfdtype; ftp++, cnt++)
978 if (ftp->driveid == id)
979 return(ftp);
980 /*
981 * 3.5dd's at unit 0 do not always return id.
982 */
983 if (unit == 0)
984 return(fdtype);
985 return(NULL);
986 }
987
988 /*
989 * turn motor off if possible otherwise mark as needed and will be done
990 * later.
991 */
992 void
993 fdmotoroff(void *arg)
994 {
995 struct fd_softc *sc;
996 int s;
997
998 sc = arg;
999 s = splbio();
1000
1001 #ifdef FDDEBUG
1002 printf("fdmotoroff: unit %d\n", sc->hwunit);
1003 #endif
1004 if ((sc->flags & FDF_MOTORON) == 0)
1005 goto done;
1006 /*
1007 * if we have a timeout on a DMA operation let fddmadone()
1008 * deal with it.
1009 */
1010 if (fdc_indma == sc) {
1011 fddmadone(sc, 1);
1012 goto done;
1013 }
1014 #ifdef FDDEBUG
1015 printf(" motor was on, turning off\n");
1016 #endif
1017
1018 /*
1019 * flush cache if needed
1020 */
1021 if (sc->flags & FDF_DIRTY) {
1022 sc->flags |= FDF_JUSTFLUSH | FDF_MOTOROFF;
1023 #ifdef FDDEBUG
1024 printf(" flushing dirty buffer first\n");
1025 #endif
1026 /*
1027 * if DMA'ing done for now, fddone() will call us again
1028 */
1029 if (fdc_indma)
1030 goto done;
1031 fddmastart(sc, sc->cachetrk);
1032 goto done;
1033 }
1034
1035 /*
1036 * if controller is busy just schedule us to be called back
1037 */
1038 if (fdc_indma) {
1039 /*
1040 * someone else has the controller now
1041 * just set flag and let fddone() call us again.
1042 */
1043 sc->flags |= FDF_MOTOROFF;
1044 goto done;
1045 }
1046
1047 #ifdef FDDEBUG
1048 printf(" hw turning unit off\n");
1049 #endif
1050
1051 sc->flags &= ~(FDF_MOTORON | FDF_MOTOROFF);
1052 FDDESELECT(FDCUNITMASK);
1053 FDSETMOTOR(0);
1054 delay(1);
1055 FDSELECT(sc->unitmask);
1056 delay(4);
1057 FDDESELECT(sc->unitmask);
1058 delay(1);
1059 if (sc->flags & FDF_WMOTOROFF)
1060 wakeup(fdmotoroff);
1061 done:
1062 splx(s);
1063 }
1064
1065 /*
1066 * select drive seek to track exit with motor on.
1067 * fdsetpos(x, 0, 0) does calibrates the drive.
1068 */
1069 void
1070 fdsetpos(struct fd_softc *sc, int trk, int towrite)
1071 {
1072 int nstep, sdir, ondly, ncyl, nside;
1073
1074 FDDESELECT(FDCUNITMASK);
1075 FDSETMOTOR(1);
1076 delay(1);
1077 FDSELECT(sc->unitmask);
1078 delay(1);
1079 if ((sc->flags & FDF_MOTORON) == 0) {
1080 ondly = 0;
1081 while (FDTESTC(FDB_READY) == 0) {
1082 delay(1000);
1083 if (++ondly >= 1000)
1084 break;
1085 }
1086 }
1087 sc->flags |= FDF_MOTORON;
1088
1089 ncyl = trk / FDNHEADS;
1090 nside = trk % FDNHEADS;
1091
1092 if (sc->curcyl == ncyl && fdc_side == nside)
1093 return;
1094
1095 if (towrite)
1096 sc->flags |= FDF_WRITEWAIT;
1097
1098 #ifdef FDDEBUG
1099 printf("fdsetpos: cyl %d head %d towrite %d\n", trk / FDNHEADS,
1100 trk % FDNHEADS, towrite);
1101 #endif
1102 nstep = ncyl - sc->curcyl;
1103 if (nstep) {
1104 /*
1105 * figure direction
1106 */
1107 if (nstep > 0 && ncyl != 0) {
1108 sdir = FDSTEPIN;
1109 FDSETDIR(1);
1110 } else {
1111 nstep = -nstep;
1112 sdir = FDSTEPOUT;
1113 FDSETDIR(0);
1114 }
1115 if (ncyl == 0) {
1116 /*
1117 * either just want cylinder 0 or doing
1118 * a calibrate.
1119 */
1120 nstep = 256;
1121 while (FDTESTC(FDB_CYLZERO) == 0 && nstep--) {
1122 FDSTEP;
1123 delay(sc->stepdelay);
1124 }
1125 if (nstep < 0)
1126 sc->flags |= FDF_NOTRACK0;
1127 } else {
1128 /*
1129 * step the needed amount amount.
1130 */
1131 while (nstep--) {
1132 FDSTEP;
1133 delay(sc->stepdelay);
1134 }
1135 }
1136 /*
1137 * if switched directions
1138 * allow drive to settle.
1139 */
1140 if (sc->pstepdir != sdir)
1141 delay(FDSETTLEDELAY);
1142 sc->pstepdir = sdir;
1143 sc->curcyl = ncyl;
1144 }
1145 if (nside == fdc_side)
1146 return;
1147 /*
1148 * select side
1149 */
1150 fdc_side = nside;
1151 FDSETHEAD(nside);
1152 delay(FDPRESIDEDELAY);
1153 }
1154
1155 void
1156 fdselunit(struct fd_softc *sc)
1157 {
1158 FDDESELECT(FDCUNITMASK); /* deselect all */
1159 FDSETMOTOR(sc->flags & FDF_MOTORON); /* set motor to unit's state */
1160 delay(1);
1161 FDSELECT(sc->unitmask); /* select unit */
1162 delay(1);
1163 }
1164
1165 /*
1166 * process next buf on device queue.
1167 * normall sequence of events:
1168 * fdstart() -> fddmastart();
1169 * fdidxintr();
1170 * fdintr() -> fddmadone() -> fddone();
1171 * if the track is in the cache then fdstart() will short-circuit
1172 * to fddone() else if the track cache is dirty it will flush. If
1173 * the buf is not an entire track it will cache the requested track.
1174 */
1175 void
1176 fdstart(struct fd_softc *sc)
1177 {
1178 int trk, error, write;
1179 struct buf *bp, *dp;
1180 int changed;
1181
1182 #ifdef FDDEBUG
1183 printf("fdstart: unit %d\n", sc->hwunit);
1184 #endif
1185
1186 /*
1187 * if DMA'ing just return. we must have been called from fdstartegy.
1188 */
1189 if (fdc_indma)
1190 return;
1191
1192 /*
1193 * get next buf if there.
1194 */
1195 dp = &sc->curbuf;
1196 if ((bp = bufq_peek(sc->bufq)) == NULL) {
1197 #ifdef FDDEBUG
1198 printf(" nothing to do\n");
1199 #endif
1200 return;
1201 }
1202
1203 /*
1204 * Mark us as busy now, in case fddone() gets called in one
1205 * of the cases below.
1206 */
1207 disk_busy(&sc->dkdev);
1208
1209 /*
1210 * make sure same disk is loaded
1211 */
1212 fdselunit(sc);
1213 changed = FDTESTC(FDB_CHANGED);
1214 FDDESELECT(sc->unitmask);
1215 if (changed) {
1216 /*
1217 * disk missing, invalidate all future io on
1218 * this unit until re-open()'ed also invalidate
1219 * all current io
1220 */
1221 printf("fdstart: disk changed\n");
1222 #ifdef FDDEBUG
1223 printf(" disk was removed invalidating all io\n");
1224 #endif
1225 sc->flags &= ~FDF_HAVELABEL;
1226 for (;;) {
1227 bp = bufq_get(sc->bufq);
1228 bp->b_error = EIO;
1229 if (bufq_peek(sc->bufq) == NULL)
1230 break;
1231 biodone(bp);
1232 }
1233 /*
1234 * do fddone() on last buf to allow other units to start.
1235 */
1236 bufq_put(sc->bufq, bp);
1237 fddone(sc);
1238 return;
1239 }
1240
1241 /*
1242 * we have a valid buf, setup our local version
1243 * we use this count to allow reading over multiple tracks.
1244 * into a single buffer
1245 */
1246 dp->b_bcount = bp->b_bcount;
1247 dp->b_blkno = bp->b_blkno;
1248 dp->b_data = bp->b_data;
1249 dp->b_flags = bp->b_flags;
1250 dp->b_resid = 0;
1251
1252 if (bp->b_flags & B_READ)
1253 write = 0;
1254 else if (FDTESTC(FDB_PROTECT) == 0)
1255 write = 1;
1256 else {
1257 error = EPERM;
1258 goto done;
1259 }
1260
1261 /*
1262 * figure trk given blkno
1263 */
1264 trk = bp->b_blkno / sc->nsectors;
1265
1266 /*
1267 * check to see if same as currently cached track
1268 * if so we need to do no DMA read.
1269 */
1270 if (trk == sc->cachetrk) {
1271 fddone(sc);
1272 return;
1273 }
1274
1275 /*
1276 * if we will be overwriting the entire cache, don't bother to
1277 * fetch it.
1278 */
1279 if (bp->b_bcount == (sc->nsectors * FDSECSIZE) && write &&
1280 bp->b_blkno % sc->nsectors == 0) {
1281 if (sc->flags & FDF_DIRTY)
1282 sc->flags |= FDF_JUSTFLUSH;
1283 else {
1284 sc->cachetrk = trk;
1285 fddone(sc);
1286 return;
1287 }
1288 }
1289
1290 /*
1291 * start DMA read of `trk'
1292 */
1293 fddmastart(sc, trk);
1294 return;
1295 done:
1296 bp->b_error = error;
1297 fddone(sc);
1298 }
1299
1300 /*
1301 * continue a started operation on next track. always begin at
1302 * sector 0 on the next track.
1303 */
1304 void
1305 fdcont(struct fd_softc *sc)
1306 {
1307 struct buf *dp, *bp;
1308 int trk, write;
1309
1310 dp = &sc->curbuf;
1311 bp = bufq_peek(sc->bufq);
1312 dp->b_data = (char*)dp->b_data + (dp->b_bcount - bp->b_resid);
1313 dp->b_blkno += (dp->b_bcount - bp->b_resid) / FDSECSIZE;
1314 dp->b_bcount = bp->b_resid;
1315
1316 /*
1317 * figure trk given blkno
1318 */
1319 trk = dp->b_blkno / sc->nsectors;
1320 #ifdef DEBUG
1321 if (trk != sc->cachetrk + 1 || dp->b_blkno % sc->nsectors != 0)
1322 panic("fdcont: confused");
1323 #endif
1324 if (dp->b_flags & B_READ)
1325 write = 0;
1326 else
1327 write = 1;
1328 /*
1329 * if we will be overwriting the entire cache, don't bother to
1330 * fetch it.
1331 */
1332 if (dp->b_bcount == (sc->nsectors * FDSECSIZE) && write) {
1333 if (sc->flags & FDF_DIRTY)
1334 sc->flags |= FDF_JUSTFLUSH;
1335 else {
1336 sc->cachetrk = trk;
1337 fddone(sc);
1338 return;
1339 }
1340 }
1341 /*
1342 * start DMA read of `trk'
1343 */
1344 fddmastart(sc, trk);
1345 return;
1346 }
1347
1348 void
1349 fddmastart(struct fd_softc *sc, int trk)
1350 {
1351 int adkmask, ndmaw, write, dmatrk;
1352
1353 #ifdef FDDEBUG
1354 printf("fddmastart: unit %d cyl %d head %d", sc->hwunit,
1355 trk / FDNHEADS, trk % FDNHEADS);
1356 #endif
1357 /*
1358 * flush the cached track if dirty else read requested track.
1359 */
1360 if (sc->flags & FDF_DIRTY) {
1361 fdcachetoraw(sc);
1362 ndmaw = sc->type->nwritew;
1363 dmatrk = sc->cachetrk;
1364 write = 1;
1365 } else {
1366 ndmaw = sc->type->nreadw;
1367 dmatrk = trk;
1368 write = 0;
1369 }
1370
1371 #ifdef FDDEBUG
1372 printf(" %s", write ? " flushing cache\n" : " loading cache\n");
1373 #endif
1374 sc->cachetrk = trk;
1375 fdc_indma = sc;
1376 fdsetpos(sc, dmatrk, write);
1377
1378 /*
1379 * setup dma stuff
1380 */
1381 if (write == 0) {
1382 custom.adkcon = ADKF_MSBSYNC;
1383 custom.adkcon = ADKF_SETCLR | ADKF_WORDSYNC | ADKF_FAST;
1384 custom.dsksync = FDMFMSYNC;
1385 } else {
1386 custom.adkcon = ADKF_PRECOMP1 | ADKF_PRECOMP0 | ADKF_WORDSYNC |
1387 ADKF_MSBSYNC;
1388 adkmask = ADKF_SETCLR | ADKF_FAST | ADKF_MFMPREC;
1389 if (dmatrk >= sc->type->precomp[0])
1390 adkmask |= ADKF_PRECOMP0;
1391 if (dmatrk >= sc->type->precomp[1])
1392 adkmask |= ADKF_PRECOMP1;
1393 custom.adkcon = adkmask;
1394 }
1395 custom.dskpt = (u_char *)kvtop(fdc_dmap);
1396
1397 /*
1398 * If writing an MSDOS track, activate disk index pulse
1399 * interrupt, DMA will be started in the intr routine fdidxintr()
1400 * Otherwise, start the DMA here.
1401 */
1402 if (write && sc->openpart == FDMSDOSPART) {
1403 fdc_dmalen = ndmaw;
1404 fdc_dmawrite = write;
1405 ciab.icr = CIA_ICR_IR_SC | CIA_ICR_FLG;
1406 } else {
1407 FDDMASTART(ndmaw, write);
1408 fdc_dmalen = 0;
1409 }
1410
1411 #ifdef FDDEBUG
1412 printf(" DMA started\n");
1413 #endif
1414 }
1415
1416 /*
1417 * recalibrate the drive
1418 */
1419 void
1420 fdcalibrate(void *arg)
1421 {
1422 struct fd_softc *sc;
1423 static int loopcnt;
1424
1425 sc = arg;
1426
1427 if (loopcnt == 0) {
1428 /*
1429 * seek cyl 0
1430 */
1431 fdc_indma = sc;
1432 sc->stepdelay += 900;
1433 if (sc->cachetrk > 1)
1434 fdsetpos(sc, sc->cachetrk % FDNHEADS, 0);
1435 sc->stepdelay -= 900;
1436 }
1437 if (loopcnt++ & 1)
1438 fdsetpos(sc, sc->cachetrk, 0);
1439 else
1440 fdsetpos(sc, sc->cachetrk + FDNHEADS, 0);
1441 /*
1442 * trk++, trk, trk++, trk, trk++, trk, trk++, trk and DMA
1443 */
1444 if (loopcnt < 8)
1445 callout_reset(&sc->calibrate_ch, hz / 8, fdcalibrate, sc);
1446 else {
1447 loopcnt = 0;
1448 fdc_indma = NULL;
1449 callout_reset(&sc->motor_ch, 3 * hz / 2, fdmotoroff, sc);
1450 fddmastart(sc, sc->cachetrk);
1451 }
1452 }
1453
1454 void
1455 fddmadone(struct fd_softc *sc, int timeo)
1456 {
1457 #ifdef FDDEBUG
1458 printf("fddmadone: unit %d, timeo %d\n", sc->hwunit, timeo);
1459 #endif
1460 fdc_indma = NULL;
1461 callout_stop(&sc->motor_ch);
1462 FDDMASTOP;
1463
1464 /*
1465 * guarantee the drive has been at current head and cyl
1466 * for at least FDWRITEDELAY after a write.
1467 */
1468 if (sc->flags & FDF_WRITEWAIT) {
1469 delay(FDWRITEDELAY);
1470 sc->flags &= ~FDF_WRITEWAIT;
1471 }
1472
1473 if ((sc->flags & FDF_MOTOROFF) == 0) {
1474 /*
1475 * motor runs for 1.5 seconds after last DMA
1476 */
1477 callout_reset(&sc->motor_ch, 3 * hz / 2, fdmotoroff, sc);
1478 }
1479 if (sc->flags & FDF_DIRTY) {
1480 /*
1481 * if buffer dirty, the last DMA cleaned it
1482 */
1483 sc->flags &= ~FDF_DIRTY;
1484 if (timeo)
1485 aprint_error_dev(sc->sc_dev,
1486 "write of track cache timed out.\n");
1487 if (sc->flags & FDF_JUSTFLUSH) {
1488 sc->flags &= ~FDF_JUSTFLUSH;
1489 /*
1490 * we are done DMA'ing
1491 */
1492 fddone(sc);
1493 return;
1494 }
1495 /*
1496 * load the cache
1497 */
1498 fddmastart(sc, sc->cachetrk);
1499 return;
1500 }
1501 #ifdef FDDEBUG
1502 else if (sc->flags & FDF_MOTOROFF)
1503 panic("fddmadone: FDF_MOTOROFF with no FDF_DIRTY");
1504 #endif
1505
1506 /*
1507 * cache loaded decode it into cache buffer
1508 */
1509 if (timeo == 0 && fdrawtocache(sc) == 0)
1510 sc->retried = 0;
1511 else {
1512 #ifdef FDDEBUG
1513 if (timeo)
1514 aprint_debug_dev(sc->sc_dev,
1515 "fddmadone: cache load timed out.\n");
1516 #endif
1517 if (sc->retried >= sc->retries) {
1518 sc->retried = 0;
1519 sc->cachetrk = -1;
1520 } else {
1521 sc->retried++;
1522 /*
1523 * this will be restarted at end of calibrate loop.
1524 */
1525 callout_stop(&sc->motor_ch);
1526 fdcalibrate(sc);
1527 return;
1528 }
1529 }
1530 fddone(sc);
1531 }
1532
1533 void
1534 fddone(struct fd_softc *sc)
1535 {
1536 struct buf *dp, *bp;
1537 char *data;
1538 int sz;
1539
1540 #ifdef FDDEBUG
1541 printf("fddone: unit %d\n", sc->hwunit);
1542 #endif
1543 /*
1544 * check to see if unit is just flushing the cache,
1545 * that is we have no io queued.
1546 */
1547 if (sc->flags & FDF_MOTOROFF)
1548 goto nobuf;
1549
1550 dp = &sc->curbuf;
1551 if ((bp = bufq_peek(sc->bufq)) == NULL)
1552 panic ("fddone");
1553 /*
1554 * check for an error that may have occurred
1555 * while getting the track.
1556 */
1557 if (sc->cachetrk == -1) {
1558 sc->retried = 0;
1559 bp->b_error = EIO;
1560 } else if (bp->b_error == 0) {
1561 data = sc->cachep;
1562 /*
1563 * get offset of data in track cache and limit
1564 * the copy size to not exceed the cache's end.
1565 */
1566 data += (dp->b_blkno % sc->nsectors) * FDSECSIZE;
1567 sz = sc->nsectors - dp->b_blkno % sc->nsectors;
1568 sz *= FDSECSIZE;
1569 sz = min(dp->b_bcount, sz);
1570 if (bp->b_flags & B_READ)
1571 memcpy(dp->b_data, data, sz);
1572 else {
1573 memcpy(data, dp->b_data, sz);
1574 sc->flags |= FDF_DIRTY;
1575 }
1576 bp->b_resid = dp->b_bcount - sz;
1577 if (bp->b_resid == 0) {
1578 bp->b_error = 0;
1579 } else {
1580 /*
1581 * not done yet need to read next track
1582 */
1583 fdcont(sc);
1584 return;
1585 }
1586 }
1587 /*
1588 * remove from queue.
1589 */
1590 (void)bufq_get(sc->bufq);
1591
1592 disk_unbusy(&sc->dkdev, (bp->b_bcount - bp->b_resid),
1593 (bp->b_flags & B_READ));
1594
1595 biodone(bp);
1596 nobuf:
1597 fdfindwork(device_unit(sc->sc_dev));
1598 }
1599
1600 void
1601 fdfindwork(int unit)
1602 {
1603 struct fd_softc *ssc, *sc;
1604 int i, last;
1605
1606 /*
1607 * first see if we have any fdopen()'s waiting
1608 */
1609 if (fdc_wantwakeup) {
1610 wakeup(fdopen);
1611 fdc_wantwakeup--;
1612 return;
1613 }
1614
1615 /*
1616 * start next available unit, linear search from the next unit
1617 * wrapping and finally this unit.
1618 */
1619 last = 0;
1620 ssc = NULL;
1621 for (i = unit + 1; last == 0; i++) {
1622 if (i == unit)
1623 last = 1;
1624 if (i >= fd_cd.cd_ndevs) {
1625 i = -1;
1626 continue;
1627 }
1628 if ((sc = device_lookup_private(&fd_cd, i)) == NULL)
1629 continue;
1630
1631 /*
1632 * if unit has requested to be turned off
1633 * and it has no buf's queued do it now
1634 */
1635 if (sc->flags & FDF_MOTOROFF) {
1636 if (bufq_peek(sc->bufq) == NULL)
1637 fdmotoroff(sc);
1638 else {
1639 /*
1640 * we gained a buf request while
1641 * we waited, forget the motoroff
1642 */
1643 sc->flags &= ~FDF_MOTOROFF;
1644 }
1645 /*
1646 * if we now have DMA unit must have needed
1647 * flushing, quit
1648 */
1649 if (fdc_indma)
1650 return;
1651 }
1652 /*
1653 * if we have no start unit and the current unit has
1654 * io waiting choose this unit to start.
1655 */
1656 if (ssc == NULL && bufq_peek(sc->bufq) != NULL)
1657 ssc = sc;
1658 }
1659 if (ssc)
1660 fdstart(ssc);
1661 }
1662
1663 /*
1664 * min byte count to whats left of the track in question
1665 */
1666 void
1667 fdminphys(struct buf *bp)
1668 {
1669 struct fd_softc *sc;
1670 int sec, toff, tsz;
1671
1672 if ((sc = getsoftc(fd_cd, FDUNIT(bp->b_dev))) == NULL)
1673 panic("fdminphys: couldn't get softc");
1674
1675 sec = bp->b_blkno % sc->nsectors;
1676
1677 toff = sec * FDSECSIZE;
1678 tsz = sc->nsectors * FDSECSIZE;
1679 #ifdef FDDEBUG
1680 printf("fdminphys: before %ld", bp->b_bcount);
1681 #endif
1682 bp->b_bcount = min(bp->b_bcount, tsz - toff);
1683 #ifdef FDDEBUG
1684 printf(" after %ld\n", bp->b_bcount);
1685 #endif
1686 minphys(bp);
1687 }
1688
1689 /*
1690 * encode the track cache into raw MFM ready for DMA
1691 * when we go to multiple disk formats, this will call type dependent
1692 * functions
1693 */
1694 void fdcachetoraw(struct fd_softc *sc)
1695 {
1696 if (sc->openpart == FDMSDOSPART)
1697 mscachetoraw(sc);
1698 else
1699 amcachetoraw(sc);
1700 }
1701
1702 /*
1703 * decode raw MFM from DMA into units track cache.
1704 * when we go to multiple disk formats, this will call type dependent
1705 * functions
1706 */
1707 int
1708 fdrawtocache(struct fd_softc *sc)
1709 {
1710
1711 if (sc->openpart == FDMSDOSPART)
1712 return(msrawtocache(sc));
1713 else
1714 return(amrawtocache(sc));
1715 }
1716
1717 void
1718 amcachetoraw(struct fd_softc *sc)
1719 {
1720 static u_long mfmnull[4];
1721 u_long *rp, *crp, *dp, hcksum, dcksum, info;
1722 int sec, i;
1723
1724 rp = fdc_dmap;
1725
1726 /*
1727 * not yet one sector (- 1 long) gap.
1728 * for now use previous drivers values
1729 */
1730 for (i = 0; i < sc->type->gap; i++)
1731 *rp++ = 0xaaaaaaaa;
1732 /*
1733 * process sectors
1734 */
1735 dp = sc->cachep;
1736 info = 0xff000000 | (sc->cachetrk << 16) | sc->nsectors;
1737 for (sec = 0; sec < sc->nsectors; sec++, info += (1 << 8) - 1) {
1738 hcksum = dcksum = 0;
1739 /*
1740 * sector format
1741 * offset description
1742 *-----------------------------------
1743 * 0 null
1744 * 1 sync
1745 * oddbits evenbits
1746 *----------------------
1747 * 2 3 [0xff]b [trk]b [sec]b [togap]b
1748 * 4-7 8-11 null
1749 * 12 13 header cksum [2-11]
1750 * 14 15 data cksum [16-271]
1751 * 16-143 144-271 data
1752 */
1753 *rp = 0xaaaaaaaa;
1754 if (*(rp - 1) & 0x1)
1755 *rp &= 0x7fffffff; /* clock bit correction */
1756 rp++;
1757 *rp++ = (FDMFMSYNC << 16) | FDMFMSYNC;
1758 rp = mfmblkencode(&info, rp, &hcksum, 1);
1759 rp = mfmblkencode(mfmnull, rp, &hcksum, 4);
1760 rp = mfmblkencode(&hcksum, rp, NULL, 1);
1761
1762 crp = rp;
1763 rp = mfmblkencode(dp, rp + 2, &dcksum, FDSECLWORDS);
1764 dp += FDSECLWORDS;
1765 crp = mfmblkencode(&dcksum, crp, NULL, 1);
1766 if (*(crp - 1) & 0x1)
1767 *crp &= 0x7fffffff; /* clock bit correction */
1768 else if ((*crp & 0x40000000) == 0)
1769 *crp |= 0x80000000;
1770 }
1771 *rp = 0xaaa80000;
1772 if (*(rp - 1) & 0x1)
1773 *rp &= 0x7fffffff;
1774 }
1775
1776 u_long *
1777 fdfindsync(u_long *rp, u_long *ep)
1778 {
1779 u_short *sp;
1780
1781 sp = (u_short *)rp;
1782 while ((u_long *)sp < ep && *sp != FDMFMSYNC)
1783 sp++;
1784 while ((u_long *)sp < ep && *sp == FDMFMSYNC)
1785 sp++;
1786 if ((u_long *)sp < ep)
1787 return((u_long *)sp);
1788 return(NULL);
1789 }
1790
1791 int
1792 amrawtocache(struct fd_softc *sc)
1793 {
1794 u_long mfmnull[4];
1795 u_long *dp, *rp, *erp, *crp, *srp, hcksum, dcksum, info, cktmp;
1796 int cnt, doagain;
1797
1798 doagain = 1;
1799 srp = rp = fdc_dmap;
1800 erp = (u_long *)((u_short *)rp + sc->type->nreadw);
1801 cnt = 0;
1802 again:
1803 if (doagain == 0 || (rp = srp = fdfindsync(srp, erp)) == NULL) {
1804 #ifdef DIAGNOSTIC
1805 aprint_error_dev(sc->sc_dev, "corrupted track (%d) data.\n",
1806 sc->cachetrk);
1807 #endif
1808 return(-1);
1809 }
1810
1811 /*
1812 * process sectors
1813 */
1814 for (; cnt < sc->nsectors; cnt++) {
1815 hcksum = dcksum = 0;
1816 rp = mfmblkdecode(rp, &info, &hcksum, 1);
1817 rp = mfmblkdecode(rp, mfmnull, &hcksum, 4);
1818 rp = mfmblkdecode(rp, &cktmp, NULL, 1);
1819 if (cktmp != hcksum) {
1820 #ifdef FDDEBUG
1821 printf(" info 0x%lx hchksum 0x%lx trkhcksum 0x%lx\n",
1822 info, hcksum, cktmp);
1823 #endif
1824 goto again;
1825 }
1826 if (((info >> 16) & 0xff) != sc->cachetrk) {
1827 #ifdef DEBUG
1828 aprint_debug_dev(sc->sc_dev,
1829 "incorrect track found: 0x%lx %d\n",
1830 info, sc->cachetrk);
1831 #endif
1832 goto again;
1833 }
1834 #ifdef FDDEBUG
1835 printf(" info 0x%lx\n", info);
1836 #endif
1837
1838 rp = mfmblkdecode(rp, &cktmp, NULL, 1);
1839 dp = sc->cachep;
1840 dp += FDSECLWORDS * ((info >> 8) & 0xff);
1841 crp = mfmblkdecode(rp, dp, &dcksum, FDSECLWORDS);
1842 if (cktmp != dcksum) {
1843 #ifdef FDDEBUG
1844 printf(" info 0x%lx dchksum 0x%lx trkdcksum 0x%lx\n",
1845 info, dcksum, cktmp);
1846 #endif
1847 goto again;
1848 }
1849
1850 /*
1851 * if we are at gap then we can no longer be sure
1852 * of correct sync marks
1853 */
1854 if ((info & 0xff) == 1)
1855 doagain = 1;
1856 else
1857 doagain = 0;
1858 srp = rp = fdfindsync(crp, erp);
1859 }
1860 return(0);
1861 }
1862
1863 void
1864 mscachetoraw(struct fd_softc *sc)
1865 {
1866 u_short *rp, *erp, crc;
1867 u_char *cp, tb[5];
1868 int sec, i;
1869
1870 rp = (u_short *)fdc_dmap;
1871 erp = rp + sc->type->nwritew;
1872 cp = sc->cachep;
1873
1874 /*
1875 * initial track filler (828 * GAP1)
1876 */
1877 for (i = 0; i < sc->type->gap; i++) {
1878 *rp++ = FDMFMGAP1;
1879 *rp++ = FDMFMGAP1;
1880 }
1881
1882 for (sec = 0; sec < sc->nsectors; sec++) {
1883
1884 /*
1885 * leading sector gap
1886 * (12 * GAP2) + (3 * SYNC)
1887 */
1888 for (i = 0; i < 12; i++)
1889 *rp++ = FDMFMGAP2;
1890 *rp++ = FDMFMSYNC;
1891 *rp++ = FDMFMSYNC;
1892 *rp++ = FDMFMSYNC;
1893
1894 /*
1895 * sector information
1896 * (ID) + track + side + sector + sector size + CRC16
1897 */
1898 *rp++ = FDMFMID;
1899 tb[0] = sc->cachetrk / FDNHEADS;
1900 tb[1] = sc->cachetrk % FDNHEADS;
1901 tb[2] = sec + 1;
1902 i = sc->bytespersec;
1903 tb[3] = i < 256 ? 0 : (i < 512 ? 1 : (i < 1024 ? 2 : 3));
1904 rp = msblkencode(rp, tb, 4, &crc);
1905 tb[0] = crc >> 8;
1906 tb[1] = crc & 0xff;
1907 tb[2] = 0x4e; /* GAP1 decoded */
1908 rp = msblkencode(rp, tb, 3, 0);
1909
1910 /*
1911 * sector info/data gap
1912 * (22 * GAP1) + (12 * GAP2) + (3 * SYNC)
1913 */
1914 for (i = 0; i < 21; i++)
1915 *rp++ = FDMFMGAP1;
1916 for (i = 0; i < 12; i++)
1917 *rp++ = FDMFMGAP2;
1918 *rp++ = FDMFMSYNC;
1919 *rp++ = FDMFMSYNC;
1920 *rp++ = FDMFMSYNC;
1921
1922 /*
1923 * sector data
1924 * (DATA) + ...data... + CRC16
1925 */
1926 *rp++ = FDMFMDATA;
1927 rp = msblkencode(rp, cp, sc->bytespersec, &crc);
1928 cp += sc->bytespersec;
1929 tb[0] = crc >> 8;
1930 tb[1] = crc & 0xff;
1931 tb[2] = 0x4e; /* GAP3 decoded */
1932 rp = msblkencode(rp, tb, 3, 0);
1933
1934 /*
1935 * trailing sector gap
1936 * (80 * GAP3)
1937 */
1938 for (i = 0; i < 79; i++)
1939 *rp++ = FDMFMGAP3;
1940 }
1941
1942 /*
1943 * fill rest of track with GAP3
1944 */
1945 while (rp != erp)
1946 *rp++ = FDMFMGAP3;
1947
1948 }
1949
1950 int
1951 msrawtocache(struct fd_softc *sc)
1952 {
1953 u_short *rp, *erp;
1954 u_char tb[5], *cp;
1955 int ct, sec, retry;
1956
1957 rp = (u_short *)fdc_dmap;
1958 erp = rp + sc->type->nreadw;
1959 cp = sc->cachep;
1960
1961 for (ct = 0; ct < sc->nsectors; ct++) {
1962 retry = 1;
1963 do {
1964 /*
1965 * skip leading gap to sync
1966 */
1967 if ((rp = (u_short *)fdfindsync((u_long *)rp, (u_long *)erp)) == NULL) {
1968 #ifdef DIAGNOSTIC
1969 aprint_normal_dev(sc->sc_dev,
1970 "corrupted track (%d) data.\n",
1971 sc->cachetrk);
1972 #endif
1973 return(-1);
1974 }
1975
1976 /*
1977 * Grab sector info
1978 */
1979 if (*rp++ != FDMFMID)
1980 continue;
1981 rp = msblkdecode(rp, tb, 4);
1982 #ifdef FDDEBUG
1983 printf("sector id: sector %d, track %d, side %d,"
1984 "bps %d\n", tb[2], tb[0], tb[1], 128 << tb[3]);
1985 #endif
1986 if ((tb[0] * FDNHEADS + tb[1]) != sc->cachetrk ||
1987 tb[2] > sc->nsectors)
1988 continue;
1989
1990 sec = tb[2];
1991 sc->bytespersec = 128 << tb[3];
1992 rp += 2; /* skip CRC-16 */
1993
1994 /*
1995 * skip gap and read in data
1996 */
1997 if ((rp = (u_short *)fdfindsync((u_long *)rp, (u_long *)erp)) == NULL)
1998 return(-1);
1999 if (*rp++ != FDMFMDATA)
2000 continue;
2001 rp = msblkdecode(rp, cp + ((sec-1) * sc->bytespersec),
2002 sc->bytespersec);
2003 rp += 2; /* skip CRC-16 */
2004
2005 retry = 0;
2006 } while (retry);
2007 }
2008 return(0);
2009 }
2010
2011 /*
2012 * encode len longwords of `dp' data in amiga mfm block format (`rp')
2013 * this format specified that the odd bits are at current pos and even
2014 * bits at len + current pos
2015 */
2016 u_long *
2017 mfmblkencode(u_long *dp, u_long *rp, u_long *cp, int len)
2018 {
2019 u_long *sdp, *edp, d, dtmp, correct;
2020
2021 sdp = dp;
2022 edp = dp + len;
2023
2024 if (*(rp - 1) & 0x1)
2025 correct = 1;
2026 else
2027 correct = 0;
2028 /*
2029 * do odd bits
2030 */
2031 while (dp < edp) {
2032 d = (*dp >> 1) & 0x55555555; /* remove clock bits */
2033 dtmp = d ^ 0x55555555;
2034 d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1);
2035 /*
2036 * correct upper clock bit if needed
2037 */
2038 if (correct)
2039 d &= 0x7fffffff;
2040 if (d & 0x1)
2041 correct = 1;
2042 else
2043 correct = 0;
2044 /*
2045 * do checksums and store in raw buffer
2046 */
2047 if (cp)
2048 *cp ^= d;
2049 *rp++ = d;
2050 dp++;
2051 }
2052 /*
2053 * do even bits
2054 */
2055 dp = sdp;
2056 while (dp < edp) {
2057 d = *dp & 0x55555555; /* remove clock bits */
2058 dtmp = d ^ 0x55555555;
2059 d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1);
2060 /*
2061 * correct upper clock bit if needed
2062 */
2063 if (correct)
2064 d &= 0x7fffffff;
2065 if (d & 0x1)
2066 correct = 1;
2067 else
2068 correct = 0;
2069 /*
2070 * do checksums and store in raw buffer
2071 */
2072 if (cp)
2073 *cp ^= d;
2074 *rp++ = d;
2075 dp++;
2076 }
2077 if (cp)
2078 *cp &= 0x55555555;
2079 return(rp);
2080 }
2081
2082 /*
2083 * decode len longwords of `dp' data in amiga mfm block format (`rp')
2084 * this format specified that the odd bits are at current pos and even
2085 * bits at len + current pos
2086 */
2087 u_long *
2088 mfmblkdecode(u_long *rp, u_long *dp, u_long *cp, int len)
2089 {
2090 u_long o, e;
2091 int cnt;
2092
2093 cnt = len;
2094 while (cnt--) {
2095 o = *rp;
2096 e = *(rp + len);
2097 if (cp) {
2098 *cp ^= o;
2099 *cp ^= e;
2100 }
2101 o &= 0x55555555;
2102 e &= 0x55555555;
2103 *dp++ = (o << 1) | e;
2104 rp++;
2105 }
2106 if (cp)
2107 *cp &= 0x55555555;
2108 return(rp + len);
2109 }
2110
2111 /*
2112 * decode len words in standard MFM format to len bytes
2113 * of data.
2114 */
2115 u_short *
2116 msblkdecode(u_short *rp, u_char *cp, int len)
2117 {
2118 while (len--) {
2119 *cp++ = msdecode[*rp & 0x7f] |
2120 (msdecode[(*rp >> 8) & 0x7f] << 4);
2121 rp++;
2122 }
2123
2124 return(rp);
2125 }
2126
2127 /*
2128 * encode len bytes of data into len words in standard MFM format.
2129 * If a pointer is supplied for crc, calculate the CRC-16 of the data
2130 * as well.
2131 */
2132 u_short *
2133 msblkencode(u_short *rp, u_char *cp, int len, u_short *crc)
2134 {
2135 u_short td;
2136 u_short mycrc;
2137
2138 /* preload crc for header (4 bytes)
2139 * or data (anything else)
2140 */
2141 mycrc = (len == 4) ? 0xb230 : 0xe295;
2142
2143 while (len--) {
2144 td = (msencode[*cp >> 4] << 8) | msencode[*cp & 0x0f];
2145
2146 /* Check for zeros in top bit of encode and bottom
2147 * bit of previous encode. if so, slap a one in betweem
2148 * them.
2149 */
2150 if ((td & 0x140) == 0)
2151 td |= 0x80;
2152 if ((td & 0x4000) == 0 && (rp[-1] & 1) == 0)
2153 td |= 0x8000;
2154
2155 *rp++ = td;
2156
2157 /*
2158 * calc crc if requested
2159 */
2160 if (crc)
2161 mycrc = (mycrc << 8) ^ mscrctab[*cp ^ (mycrc >> 8)];
2162
2163 cp++;
2164 }
2165
2166 if (crc)
2167 *crc = mycrc;
2168
2169 return(rp);
2170 }
2171