xref: /netbsd-src/sys/dev/gpib/mt.c (revision 0f521138e36fe4a533e2d8f4a346045d8e8b234d)
1 /*	$NetBSD: mt.c,v 1.27 2014/03/23 02:57:20 christos Exp $ */
2 
3 /*-
4  * Copyright (c) 1996-2003 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 1988 University of Utah.
34  * Copyright (c) 1982, 1990, 1993
35  *	The Regents of the University of California.  All rights reserved.
36  *
37  * This code is derived from software contributed to Berkeley by
38  * the Systems Programming Group of the University of Utah Computer
39  * Science Department.
40  *
41  * Redistribution and use in source and binary forms, with or without
42  * modification, are permitted provided that the following conditions
43  * are met:
44  * 1. Redistributions of source code must retain the above copyright
45  *    notice, this list of conditions and the following disclaimer.
46  * 2. Redistributions in binary form must reproduce the above copyright
47  *    notice, this list of conditions and the following disclaimer in the
48  *    documentation and/or other materials provided with the distribution.
49  * 3. Neither the name of the University nor the names of its contributors
50  *    may be used to endorse or promote products derived from this software
51  *    without specific prior written permission.
52  *
53  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63  * SUCH DAMAGE.
64  *
65  * from: Utah $Hdr: rd.c 1.44 92/12/26$
66  *
67  *	@(#)rd.c	8.2 (Berkeley) 5/19/94
68  */
69 
70 /*
71  * Magnetic tape driver (HP7974a, HP7978a/b, HP7979a, HP7980a, HP7980xc)
72  * Original version contributed by Mt. Xinu.
73  * Modified for 4.4BSD by Mark Davies and Andrew Vignaux, Department of
74  * Computer Science, Victoria University of Wellington
75  */
76 
77 #include <sys/cdefs.h>
78 __KERNEL_RCSID(0, "$NetBSD: mt.c,v 1.27 2014/03/23 02:57:20 christos Exp $");
79 
80 #include <sys/param.h>
81 #include <sys/systm.h>
82 #include <sys/callout.h>
83 #include <sys/buf.h>
84 #include <sys/bufq.h>
85 #include <sys/ioctl.h>
86 #include <sys/mtio.h>
87 #include <sys/file.h>
88 #include <sys/proc.h>
89 #include <sys/tty.h>
90 #include <sys/kernel.h>
91 #include <sys/tprintf.h>
92 #include <sys/device.h>
93 #include <sys/conf.h>
94 
95 #include <dev/gpib/gpibvar.h>
96 #include <dev/gpib/cs80busvar.h>
97 
98 #include <dev/gpib/mtreg.h>
99 
100 #ifdef DEBUG
101 int	mtdebug = 0;
102 #define MDB_ANY		0xff
103 #define MDB_FOLLOW	0x01
104 #define	DPRINTF(mask, str)	if (mtdebug & (mask)) printf str
105 #else
106 #define	DPRINTF(mask, str)	/* nothing */
107 #endif
108 
109 struct	mt_softc {
110 	device_t sc_dev;
111 
112 	gpib_chipset_tag_t sc_ic;
113 	gpib_handle_t sc_hdl;
114 
115 	int	sc_slave;	/* GPIB slave address (0-6) */
116 	short	sc_flags;	/* see below */
117 	u_char	sc_lastdsj;	/* place for DSJ in mtreaddsj() */
118 	u_char	sc_lastecmd;	/* place for End Command in mtreaddsj() */
119 	short	sc_recvtimeo;	/* count of gpibsend timeouts to prevent hang */
120 	short	sc_statindex;	/* index for next sc_stat when MTF_STATTIMEO */
121 	struct	mt_stat sc_stat;/* status bytes last read from device */
122 	short	sc_density;	/* current density of tape (mtio.h format) */
123 	short	sc_type;	/* tape drive model (hardware IDs) */
124 	tpr_t	sc_ttyp;
125 	struct bufq_state *sc_tab;/* buf queue */
126 	int	sc_active;
127 	struct buf sc_bufstore;	/* XXX buffer storage */
128 
129 	struct	callout sc_start_ch;
130 	struct	callout sc_intr_ch;
131 };
132 
133 #define	MTUNIT(x)	(minor(x) & 0x03)
134 
135 #define B_CMD		B_DEVPRIVATE	/* command buf instead of data */
136 #define	b_cmd		b_blkno		/* blkno holds cmd when B_CMD */
137 
138 int	mtmatch(device_t, cfdata_t, void *);
139 void	mtattach(device_t, device_t, void *);
140 
141 CFATTACH_DECL_NEW(mt, sizeof(struct mt_softc),
142 	mtmatch, mtattach, NULL, NULL);
143 
144 int	mtlookup(int, int, int);
145 void	mtustart(struct mt_softc *);
146 int	mtreaddsj(struct mt_softc *, int);
147 int	mtcommand(dev_t, int, int);
148 
149 void	mtintr_callout(void *);
150 void	mtstart_callout(void *);
151 
152 void	mtcallback(void *, int);
153 void	mtstart(struct mt_softc *);
154 void	mtintr(struct mt_softc  *);
155 
156 dev_type_open(mtopen);
157 dev_type_close(mtclose);
158 dev_type_read(mtread);
159 dev_type_write(mtwrite);
160 dev_type_ioctl(mtioctl);
161 dev_type_strategy(mtstrategy);
162 
163 const struct bdevsw mt_bdevsw = {
164 	.d_open = mtopen,
165 	.d_close = mtclose,
166 	.d_strategy = mtstrategy,
167 	.d_ioctl = mtioctl,
168 	.d_dump = nodump,
169 	.d_psize = nosize,
170 	.d_flag = D_TAPE
171 };
172 
173 const struct cdevsw mt_cdevsw = {
174 	.d_open = mtopen,
175 	.d_close = mtclose,
176 	.d_read = mtread,
177 	.d_write = mtwrite,
178 	.d_ioctl = mtioctl,
179 	.d_stop = nostop,
180 	.d_tty = notty,
181 	.d_poll = nopoll,
182 	.d_mmap = nommap,
183 	.d_kqfilter = nokqfilter,
184 	.d_flag = D_TAPE
185 };
186 
187 
188 extern struct cfdriver mt_cd;
189 
190 struct	mtinfo {
191 	u_short	hwid;
192 	const char	*desc;
193 } mtinfo[] = {
194 	{ MT7978ID,	"7978"	},
195 	{ MT7979AID,	"7979A"	},
196 	{ MT7980ID,	"7980"	},
197 	{ MT7974AID,	"7974A"	},
198 };
199 int	nmtinfo = sizeof(mtinfo) / sizeof(mtinfo[0]);
200 
201 
202 int
203 mtlookup(int id, int slave, int punit)
204 {
205 	int i;
206 
207 	for (i = 0; i < nmtinfo; i++)
208 		if (mtinfo[i].hwid == id)
209 			break;
210 	if (i == nmtinfo)
211 		return (-1);
212 	return (0);
213 }
214 
215 int
216 mtmatch(device_t parent, cfdata_t match, void *aux)
217 {
218 	struct cs80bus_attach_args *ca = aux;
219 
220 	ca->ca_punit = 0;
221 	return (mtlookup(ca->ca_id, ca->ca_slave, ca->ca_punit) == 0);
222 }
223 
224 void
225 mtattach(device_t parent, device_t self, void *aux)
226 {
227 	struct mt_softc *sc = device_private(self);
228 	struct cs80bus_attach_args *ca = aux;
229 	int type;
230 
231 	sc->sc_ic = ca->ca_ic;
232 	sc->sc_slave = ca->ca_slave;
233 
234 	if ((type = mtlookup(ca->ca_id, ca->ca_slave, ca->ca_punit)) < 0)
235 		return;
236 
237 	printf(": %s tape\n", mtinfo[type].desc);
238 
239 	sc->sc_type = type;
240 	sc->sc_flags = MTF_EXISTS;
241 
242 	bufq_alloc(&sc->sc_tab, "fcfs", 0);
243 	callout_init(&sc->sc_start_ch, 0);
244 	callout_init(&sc->sc_intr_ch, 0);
245 
246 	if (gpibregister(sc->sc_ic, sc->sc_slave, mtcallback, sc,
247 	    &sc->sc_hdl)) {
248 		aprint_error_dev(sc->sc_dev, "can't register callback\n");
249 		return;
250 	}
251 }
252 
253 /*
254  * Perform a read of "Device Status Jump" register and update the
255  * status if necessary.  If status is read, the given "ecmd" is also
256  * performed, unless "ecmd" is zero.  Returns DSJ value, -1 on failure
257  * and -2 on "temporary" failure.
258  */
259 int
260 mtreaddsj(struct mt_softc *sc, int ecmd)
261 {
262 	int retval;
263 
264 	if (sc->sc_flags & MTF_STATTIMEO)
265 		goto getstats;
266 	retval = gpibrecv(sc->sc_ic,
267 	    (sc->sc_flags & MTF_DSJTIMEO) ? -1 : sc->sc_slave,
268 	    MTT_DSJ, &(sc->sc_lastdsj), 1);
269 	sc->sc_flags &= ~MTF_DSJTIMEO;
270 	if (retval != 1) {
271 		DPRINTF(MDB_ANY, ("%s can't gpibrecv DSJ",
272 		    device_xname(sc->sc_dev)));
273 		if (sc->sc_recvtimeo == 0)
274 			sc->sc_recvtimeo = hz;
275 		if (--sc->sc_recvtimeo == 0)
276 			return (-1);
277 		if (retval == 0)
278 			sc->sc_flags |= MTF_DSJTIMEO;
279 		return (-2);
280 	}
281 	sc->sc_recvtimeo = 0;
282 	sc->sc_statindex = 0;
283 	DPRINTF(MDB_ANY, ("%s readdsj: 0x%x", device_xname(sc->sc_dev),
284 	    sc->sc_lastdsj));
285 	sc->sc_lastecmd = ecmd;
286 	switch (sc->sc_lastdsj) {
287 	    case 0:
288 		if (ecmd & MTE_DSJ_FORCE)
289 			break;
290 		return (0);
291 
292 	    case 2:
293 		sc->sc_lastecmd = MTE_COMPLETE;
294 	    case 1:
295 		break;
296 
297 	    default:
298 		printf("%s readdsj: DSJ 0x%x\n", device_xname(sc->sc_dev),
299 		    sc->sc_lastdsj);
300 		return (-1);
301 	}
302 
303 getstats:
304 	retval = gpibrecv(sc->sc_ic,
305 	    (sc->sc_flags & MTF_STATCONT) ? -1 : sc->sc_slave, MTT_STAT,
306 	     ((char *)&(sc->sc_stat)) + sc->sc_statindex,
307 	    sizeof(sc->sc_stat) - sc->sc_statindex);
308 	sc->sc_flags &= ~(MTF_STATTIMEO | MTF_STATCONT);
309 	if (retval != sizeof(sc->sc_stat) - sc->sc_statindex) {
310 		if (sc->sc_recvtimeo == 0)
311 			sc->sc_recvtimeo = hz;
312 		if (--sc->sc_recvtimeo != 0) {
313 			if (retval >= 0) {
314 				sc->sc_statindex += retval;
315 				sc->sc_flags |= MTF_STATCONT;
316 			}
317 			sc->sc_flags |= MTF_STATTIMEO;
318 			return (-2);
319 		}
320 		printf("%s readdsj: can't read status", device_xname(sc->sc_dev));
321 		return (-1);
322 	}
323 	sc->sc_recvtimeo = 0;
324 	sc->sc_statindex = 0;
325 	DPRINTF(MDB_ANY, ("%s readdsj: status is %x %x %x %x %x %x",
326 	    device_xname(sc->sc_dev),
327 	    sc->sc_stat1, sc->sc_stat2, sc->sc_stat3,
328 	    sc->sc_stat4, sc->sc_stat5, sc->sc_stat6));
329 	if (sc->sc_lastecmd)
330 		(void) gpibsend(sc->sc_ic, sc->sc_slave,
331 		    MTL_ECMD, &(sc->sc_lastecmd), 1);
332 	return ((int) sc->sc_lastdsj);
333 }
334 
335 int
336 mtopen(dev_t dev, int flag, int mode, struct lwp *l)
337 {
338 	struct mt_softc *sc;
339 	int req_den;
340 	int error;
341 
342 	sc = device_lookup_private(&mt_cd, MTUNIT(dev));
343 	if (sc == NULL || (sc->sc_flags & MTF_EXISTS) == 0)
344 		return (ENXIO);
345 
346 	if (sc->sc_flags & MTF_OPEN)
347 		return (EBUSY);
348 
349 	DPRINTF(MDB_ANY, ("%s open: flags 0x%x", device_xname(sc->sc_dev),
350 	    sc->sc_flags));
351 
352 	sc->sc_flags |= MTF_OPEN;
353 	sc->sc_ttyp = tprintf_open(l->l_proc);
354 	if ((sc->sc_flags & MTF_ALIVE) == 0) {
355 		error = mtcommand(dev, MTRESET, 0);
356 		if (error != 0 || (sc->sc_flags & MTF_ALIVE) == 0)
357 			goto errout;
358 		if ((sc->sc_stat1 & (SR1_BOT | SR1_ONLINE)) == SR1_ONLINE)
359 			(void) mtcommand(dev, MTREW, 0);
360 	}
361 	for (;;) {
362 		if ((error = mtcommand(dev, MTNOP, 0)) != 0)
363 			goto errout;
364 		if (!(sc->sc_flags & MTF_REW))
365 			break;
366 		error = kpause("mt", true, hz, NULL);
367 		if (error != 0 && error != EWOULDBLOCK) {
368 			error = EINTR;
369 			goto errout;
370 		}
371 	}
372 	if ((flag & FWRITE) && (sc->sc_stat1 & SR1_RO)) {
373 		error = EROFS;
374 		goto errout;
375 	}
376 	if (!(sc->sc_stat1 & SR1_ONLINE)) {
377 		uprintf("%s: not online\n", device_xname(sc->sc_dev));
378 		error = EIO;
379 		goto errout;
380 	}
381 	/*
382 	 * Select density:
383 	 *  - find out what density the drive is set to
384 	 *	(i.e. the density of the current tape)
385 	 *  - if we are going to write
386 	 *    - if we're not at the beginning of the tape
387 	 *      - complain if we want to change densities
388 	 *    - otherwise, select the mtcommand to set the density
389 	 *
390 	 * If the drive doesn't support it then don't change the recorded
391 	 * density.
392 	 *
393 	 * The original MOREbsd code had these additional conditions
394 	 * for the mid-tape change
395 	 *
396 	 *	req_den != T_BADBPI &&
397 	 *	sc->sc_density != T_6250BPI
398 	 *
399 	 * which suggests that it would be possible to write multiple
400 	 * densities if req_den == T_BAD_BPI or the current tape
401 	 * density was 6250.  Testing of our 7980 suggests that the
402 	 * device cannot change densities mid-tape.
403 	 *
404 	 * ajv@comp.vuw.ac.nz
405 	 */
406 	sc->sc_density = (sc->sc_stat2 & SR2_6250) ? T_6250BPI : (
407 			 (sc->sc_stat3 & SR3_1600) ? T_1600BPI : (
408 			 (sc->sc_stat3 & SR3_800) ? T_800BPI : -1));
409 	req_den = (dev & T_DENSEL);
410 
411 	if (flag & FWRITE) {
412 		if (!(sc->sc_stat1 & SR1_BOT)) {
413 			if (sc->sc_density != req_den) {
414 				uprintf("%s: can't change density mid-tape\n",
415 				    device_xname(sc->sc_dev));
416 				error = EIO;
417 				goto errout;
418 			}
419 		}
420 		else {
421 			int mtset_density =
422 			    (req_den == T_800BPI  ? MTSET800BPI : (
423 			     req_den == T_1600BPI ? MTSET1600BPI : (
424 			     req_den == T_6250BPI ? MTSET6250BPI : (
425 			     sc->sc_type == MT7980ID
426 						  ? MTSET6250DC
427 						  : MTSET6250BPI))));
428 			if (mtcommand(dev, mtset_density, 0) == 0)
429 				sc->sc_density = req_den;
430 		}
431 	}
432 	return (0);
433 errout:
434 	sc->sc_flags &= ~MTF_OPEN;
435 	return (error);
436 }
437 
438 int
439 mtclose(dev_t dev, int flag, int fmt, struct lwp *l)
440 {
441 	struct mt_softc *sc;
442 
443 	sc = device_lookup_private(&mt_cd, MTUNIT(dev));
444 	if (sc == NULL)
445 		return (ENXIO);
446 
447 	if (sc->sc_flags & MTF_WRT) {
448 		(void) mtcommand(dev, MTWEOF, 2);
449 		(void) mtcommand(dev, MTBSF, 0);
450 	}
451 	if ((minor(dev) & T_NOREWIND) == 0)
452 		(void) mtcommand(dev, MTREW, 0);
453 	sc->sc_flags &= ~MTF_OPEN;
454 	tprintf_close(sc->sc_ttyp);
455 	return (0);
456 }
457 
458 int
459 mtcommand(dev_t dev, int cmd, int cnt)
460 {
461 	struct mt_softc *sc;
462 	struct buf *bp;
463 	int error = 0;
464 
465 	sc = device_lookup_private(&mt_cd, MTUNIT(dev));
466 	bp = &sc->sc_bufstore;
467 
468 	if (bp->b_cflags & BC_BUSY)
469 		return (EBUSY);
470 
471 	bp->b_cmd = cmd;
472 	bp->b_dev = dev;
473 	bp->b_objlock = &buffer_lock;
474 	do {
475 		bp->b_cflags = BC_BUSY;
476 		bp->b_flags = B_CMD;
477 		bp->b_oflags = 0;
478 		mtstrategy(bp);
479 		biowait(bp);
480 		if (bp->b_error != 0) {
481 			error = (int) (unsigned) bp->b_error;
482 			break;
483 		}
484 	} while (--cnt > 0);
485 #if 0
486 	bp->b_cflags = 0 /*&= ~BC_BUSY*/;
487 #else
488 	bp->b_cflags &= ~BC_BUSY;
489 #endif
490 	return (error);
491 }
492 
493 /*
494  * Only thing to check here is for legal record lengths (writes only).
495  */
496 void
497 mtstrategy(struct buf *bp)
498 {
499 	struct mt_softc *sc;
500 	int s;
501 
502 	sc = device_lookup_private(&mt_cd, MTUNIT(bp->b_dev));
503 
504 	DPRINTF(MDB_ANY, ("%s strategy", device_xname(sc->sc_dev)));
505 
506 	if ((bp->b_flags & (B_CMD | B_READ)) == 0) {
507 #define WRITE_BITS_IGNORED	8
508 #if 0
509 		if (bp->b_bcount & ((1 << WRITE_BITS_IGNORED) - 1)) {
510 			tprintf(sc->sc_ttyp,
511 				"%s: write record must be multiple of %d\n",
512 				device_xname(sc->sc_dev), 1 << WRITE_BITS_IGNORED);
513 			goto error;
514 		}
515 #endif
516 		s = 16 * 1024;
517 		if (sc->sc_stat2 & SR2_LONGREC) {
518 			switch (sc->sc_density) {
519 			    case T_1600BPI:
520 				s = 32 * 1024;
521 				break;
522 
523 			    case T_6250BPI:
524 			    case T_BADBPI:
525 				s = 60 * 1024;
526 				break;
527 			}
528 		}
529 		if (bp->b_bcount > s) {
530 			tprintf(sc->sc_ttyp,
531 				"%s: write record (%d) too big: limit (%d)\n",
532 				device_xname(sc->sc_dev), bp->b_bcount, s);
533 #if 0 /* XXX see above */
534 	    error:
535 #endif
536 			bp->b_error = EIO;
537 			biodone(bp);
538 			return;
539 		}
540 	}
541 	s = splbio();
542 	bufq_put(sc->sc_tab, bp);
543 	if (sc->sc_active == 0) {
544 		sc->sc_active = 1;
545 		mtustart(sc);
546 	}
547 	splx(s);
548 }
549 
550 void
551 mtustart(struct mt_softc *sc)
552 {
553 
554 	DPRINTF(MDB_ANY, ("%s ustart", device_xname(sc->sc_dev)));
555 	if (gpibrequest(sc->sc_ic, sc->sc_hdl))
556 		mtstart(sc);
557 }
558 
559 void
560 mtcallback(void *v, int action)
561 {
562 	struct mt_softc *sc = v;
563 
564 	DPRINTF(MDB_FOLLOW, ("mtcallback: v=%p, action=%d\n", v, action));
565 
566 	switch (action) {
567 	case GPIBCBF_START:
568 		mtstart(sc);
569 		break;
570 	case GPIBCBF_INTR:
571 		mtintr(sc);
572 		break;
573 #ifdef DEBUG
574 	default:
575 		printf("mtcallback: unknown action %d\n", action);
576 		break;
577 #endif
578 	}
579 }
580 
581 void
582 mtintr_callout(void *arg)
583 {
584 	struct mt_softc *sc = arg;
585 	int s = splbio();
586 
587 	gpibppclear(sc->sc_ic);
588 	mtintr(sc);
589 	splx(s);
590 }
591 
592 void
593 mtstart_callout(void *arg)
594 {
595 	int s = splbio();
596 
597 	mtstart((struct mt_softc *)arg);
598 	splx(s);
599 }
600 
601 void
602 mtstart(struct mt_softc *sc)
603 {
604 	struct buf *bp;
605 	short	cmdcount = 1;
606 	u_char	cmdbuf[2];
607 
608 	DPRINTF(MDB_ANY, ("%s start", device_xname(sc->sc_dev)));
609 	sc->sc_flags &= ~MTF_WRT;
610 	bp = bufq_peek(sc->sc_tab);
611 	if ((sc->sc_flags & MTF_ALIVE) == 0 &&
612 	    ((bp->b_flags & B_CMD) == 0 || bp->b_cmd != MTRESET))
613 		goto fatalerror;
614 
615 	if (sc->sc_flags & MTF_REW) {
616 		if (!gpibpptest(sc->sc_ic, sc->sc_slave))
617 			goto stillrew;
618 		switch (mtreaddsj(sc, MTE_DSJ_FORCE|MTE_COMPLETE|MTE_IDLE)) {
619 		    case 0:
620 		    case 1:
621 		stillrew:
622 			if ((sc->sc_stat1 & SR1_BOT) ||
623 			    !(sc->sc_stat1 & SR1_ONLINE)) {
624 				sc->sc_flags &= ~MTF_REW;
625 				break;
626 			}
627 		    case -2:
628 			/*
629 			 * -2 means "timeout" reading DSJ, which is probably
630 			 * temporary.  This is considered OK when doing a NOP,
631 			 * but not otherwise.
632 			 */
633 			if (sc->sc_flags & (MTF_DSJTIMEO | MTF_STATTIMEO)) {
634 				callout_reset(&sc->sc_start_ch, hz >> 5,
635 				    mtstart_callout, sc);
636 				return;
637 			}
638 		    case 2:
639 			if (bp->b_cmd != MTNOP || !(bp->b_flags & B_CMD)) {
640 				bp->b_error = EBUSY;
641 				goto done;
642 			}
643 			goto done;
644 
645 		    default:
646 			goto fatalerror;
647 		}
648 	}
649 	if (bp->b_flags & B_CMD) {
650 		if (sc->sc_flags & MTF_PASTEOT) {
651 			switch(bp->b_cmd) {
652 			    case MTFSF:
653 			    case MTWEOF:
654 			    case MTFSR:
655 				bp->b_error = ENOSPC;
656 				goto done;
657 
658 			    case MTBSF:
659 			    case MTOFFL:
660 			    case MTBSR:
661 			    case MTREW:
662 				sc->sc_flags &= ~(MTF_PASTEOT | MTF_ATEOT);
663 				break;
664 			}
665 		}
666 		switch(bp->b_cmd) {
667 		    case MTFSF:
668 			if (sc->sc_flags & MTF_HITEOF)
669 				goto done;
670 			cmdbuf[0] = MTTC_FSF;
671 			break;
672 
673 		    case MTBSF:
674 			if (sc->sc_flags & MTF_HITBOF)
675 				goto done;
676 			cmdbuf[0] = MTTC_BSF;
677 			break;
678 
679 		    case MTOFFL:
680 			sc->sc_flags |= MTF_REW;
681 			cmdbuf[0] = MTTC_REWOFF;
682 			break;
683 
684 		    case MTWEOF:
685 			cmdbuf[0] = MTTC_WFM;
686 			break;
687 
688 		    case MTBSR:
689 			cmdbuf[0] = MTTC_BSR;
690 			break;
691 
692 		    case MTFSR:
693 			cmdbuf[0] = MTTC_FSR;
694 			break;
695 
696 		    case MTREW:
697 			sc->sc_flags |= MTF_REW;
698 			cmdbuf[0] = MTTC_REW;
699 			break;
700 
701 		    case MTNOP:
702 			/*
703 			 * NOP is supposed to set status bits.
704 			 * Force readdsj to do it.
705 			 */
706 			switch (mtreaddsj(sc,
707 			  MTE_DSJ_FORCE | MTE_COMPLETE | MTE_IDLE)) {
708 			    default:
709 				goto done;
710 
711 			    case -1:
712 				/*
713 				 * If this fails, perform a device clear
714 				 * to fix any protocol problems and (most
715 				 * likely) get the status.
716 				 */
717 				bp->b_cmd = MTRESET;
718 				break;
719 
720 			    case -2:
721 				callout_reset(&sc->sc_start_ch, hz >> 5,
722 				    mtstart_callout, sc);
723 				return;
724 			}
725 
726 		    case MTRESET:
727 			/*
728 			 * 1) selected device clear (send with "-2" secondary)
729 			 * 2) set timeout, then wait for "service request"
730 			 * 3) interrupt will read DSJ (and END COMPLETE-IDLE)
731 			 */
732 			if (gpibsend(sc->sc_ic, sc->sc_slave, -2, NULL, 0)){
733 				aprint_error_dev(sc->sc_dev, "can't reset");
734 				goto fatalerror;
735 			}
736 			callout_reset(&sc->sc_intr_ch, 4*hz, mtintr_callout,
737 			    sc);
738 			gpibawait(sc->sc_ic);
739 			return;
740 
741 		    case MTSET800BPI:
742 			cmdbuf[0] = MTTC_800;
743 			break;
744 
745 		    case MTSET1600BPI:
746 			cmdbuf[0] = MTTC_1600;
747 			break;
748 
749 		    case MTSET6250BPI:
750 			cmdbuf[0] = MTTC_6250;
751 			break;
752 
753 		    case MTSET6250DC:
754 			cmdbuf[0] = MTTC_DC6250;
755 			break;
756 		}
757 	} else {
758 		if (sc->sc_flags & MTF_PASTEOT) {
759 			bp->b_error = ENOSPC;
760 			goto done;
761 		}
762 		if (bp->b_flags & B_READ) {
763 			sc->sc_flags |= MTF_IO;
764 			cmdbuf[0] = MTTC_READ;
765 		} else {
766 			sc->sc_flags |= MTF_WRT | MTF_IO;
767 			cmdbuf[0] = MTTC_WRITE;
768 			cmdbuf[1] = (bp->b_bcount +((1 << WRITE_BITS_IGNORED) - 1)) >> WRITE_BITS_IGNORED;
769 			cmdcount = 2;
770 		}
771 	}
772 	if (gpibsend(sc->sc_ic, sc->sc_slave, MTL_TCMD, cmdbuf, cmdcount)
773 	    == cmdcount) {
774 		if (sc->sc_flags & MTF_REW)
775 			goto done;
776 		gpibawait(sc->sc_ic);
777 		return;
778 	}
779 fatalerror:
780 	/*
781 	 * If anything fails, the drive is probably hosed, so mark it not
782 	 * "ALIVE" (but it EXISTS and is OPEN or we wouldn't be here, and
783 	 * if, last we heard, it was REWinding, remember that).
784 	 */
785 	sc->sc_flags &= MTF_EXISTS | MTF_OPEN | MTF_REW;
786 	bp->b_error = EIO;
787 done:
788 	sc->sc_flags &= ~(MTF_HITEOF | MTF_HITBOF);
789 	(void)bufq_get(sc->sc_tab);
790 	biodone(bp);
791 	gpibrelease(sc->sc_ic, sc->sc_hdl);
792 	if ((bp = bufq_peek(sc->sc_tab)) == NULL)
793 		sc->sc_active = 0;
794 	else
795 		mtustart(sc);
796 }
797 
798 void
799 mtintr(struct mt_softc *sc)
800 {
801 	struct buf *bp;
802 	int slave, dir, i;
803 	u_char cmdbuf[4];
804 
805 	slave = sc->sc_slave;
806 
807 	bp = bufq_peek(sc->sc_tab);
808 	if (bp == NULL) {
809 		printf("%s intr: bp == NULL", device_xname(sc->sc_dev));
810 		return;
811 	}
812 
813 	DPRINTF(MDB_ANY, ("%s intr", device_xname(sc->sc_dev)));
814 
815 	/*
816 	 * Some operation completed.  Read status bytes and report errors.
817 	 * Clear EOF flags here `cause they're set once on specific conditions
818 	 * below when a command succeeds.
819 	 * A DSJ of 2 always means keep waiting.  If the command was READ
820 	 * (and we're in data DMA phase) stop data transfer first.
821 	 */
822 	sc->sc_flags &= ~(MTF_HITEOF | MTF_HITBOF);
823 	if ((bp->b_flags & (B_CMD|B_READ)) == B_READ &&
824 	    !(sc->sc_flags & (MTF_IO | MTF_STATTIMEO | MTF_DSJTIMEO))){
825 		cmdbuf[0] = MTE_STOP;
826 		(void) gpibsend(sc->sc_ic, slave, MTL_ECMD,cmdbuf,1);
827 	}
828 	switch (mtreaddsj(sc, 0)) {
829 	    case 0:
830 		break;
831 
832 	    case 1:
833 		/*
834 		 * If we're in the middle of a READ/WRITE and have yet to
835 		 * start the data transfer, a DSJ of one should terminate it.
836 		 */
837 		sc->sc_flags &= ~MTF_IO;
838 		break;
839 
840 	    case 2:
841 		(void) gpibawait(sc->sc_ic);
842 		return;
843 
844 	    case -2:
845 		/*
846 		 * -2 means that the drive failed to respond quickly enough
847 		 * to the request for DSJ.  It's probably just "busy" figuring
848 		 * it out and will know in a little bit...
849 		 */
850 		callout_reset(&sc->sc_intr_ch, hz >> 5, mtintr_callout, sc);
851 		return;
852 
853 	    default:
854 		printf("%s intr: can't get drive stat", device_xname(sc->sc_dev));
855 		goto error;
856 	}
857 	if (sc->sc_stat1 & (SR1_ERR | SR1_REJECT)) {
858 		i = sc->sc_stat4 & SR4_ERCLMASK;
859 		printf("%s: %s error, retry %d, SR2/3 %x/%x, code %d",
860 			device_xname(sc->sc_dev), i == SR4_DEVICE ? "device" :
861 			(i == SR4_PROTOCOL ? "protocol" :
862 			(i == SR4_SELFTEST ? "selftest" : "unknown")),
863 			sc->sc_stat4 & SR4_RETRYMASK, sc->sc_stat2,
864 			sc->sc_stat3, sc->sc_stat5);
865 
866 		if ((bp->b_flags & B_CMD) && bp->b_cmd == MTRESET)
867 			callout_stop(&sc->sc_intr_ch);
868 		if (sc->sc_stat3 & SR3_POWERUP)
869 			sc->sc_flags &= MTF_OPEN | MTF_EXISTS;
870 		goto error;
871 	}
872 	/*
873 	 * Report and clear any soft errors.
874 	 */
875 	if (sc->sc_stat1 & SR1_SOFTERR) {
876 		printf("%s: soft error, retry %d\n", device_xname(sc->sc_dev),
877 		    sc->sc_stat4 & SR4_RETRYMASK);
878 		sc->sc_stat1 &= ~SR1_SOFTERR;
879 	}
880 	/*
881 	 * We've initiated a read or write, but haven't actually started to
882 	 * DMA the data yet.  At this point, the drive's ready.
883 	 */
884 	if (sc->sc_flags & MTF_IO) {
885 		sc->sc_flags &= ~MTF_IO;
886 		dir = (bp->b_flags & B_READ ? GPIB_READ : GPIB_WRITE);
887 		gpibxfer(sc->sc_ic, slave,
888 		    dir == GPIB_READ ? MTT_READ : MTL_WRITE,
889 		    bp->b_data, bp->b_bcount, dir, dir == GPIB_READ);
890 		return;
891 	}
892 	/*
893 	 * Check for End Of Tape - we're allowed to hit EOT and then write (or
894 	 * read) one more record.  If we get here and have not already hit EOT,
895 	 * return ENOSPC to inform the process that it's hit it.  If we get
896 	 * here and HAVE already hit EOT, don't allow any more operations that
897 	 * move the tape forward.
898 	 */
899 	if (sc->sc_stat1 & SR1_EOT) {
900 		if (sc->sc_flags & MTF_ATEOT)
901 			sc->sc_flags |= MTF_PASTEOT;
902 		else {
903 			bp->b_error = ENOSPC;
904 			sc->sc_flags |= MTF_ATEOT;
905 		}
906 	}
907 	/*
908 	 * If a motion command was being executed, check for Tape Marks.
909 	 * If we were doing data, make sure we got the right amount, and
910 	 * check for hitting tape marks on reads.
911 	 */
912 	if (bp->b_flags & B_CMD) {
913 		if (sc->sc_stat1 & SR1_EOF) {
914 			if (bp->b_cmd == MTFSR)
915 				sc->sc_flags |= MTF_HITEOF;
916 			if (bp->b_cmd == MTBSR)
917 				sc->sc_flags |= MTF_HITBOF;
918 		}
919 		if (bp->b_cmd == MTRESET) {
920 			callout_stop(&sc->sc_intr_ch);
921 			sc->sc_flags |= MTF_ALIVE;
922 		}
923 	} else {
924 		i = gpibrecv(sc->sc_ic, slave, MTT_BCNT, cmdbuf, 2);
925 		if (i != 2) {
926 			aprint_error_dev(sc->sc_dev, "intr: can't get xfer length\n");
927 			goto error;
928 		}
929 		i = (int) *((u_short *) cmdbuf);
930 		if (i <= bp->b_bcount) {
931 			if (i == 0)
932 				sc->sc_flags |= MTF_HITEOF;
933 			bp->b_resid = bp->b_bcount - i;
934 			DPRINTF(MDB_ANY, ("%s intr: bcount %d, resid %d",
935 			    device_xname(sc->sc_dev),
936 			    bp->b_bcount, bp->b_resid));
937 		} else {
938 			tprintf(sc->sc_ttyp,
939 				"%s: record (%d) larger than wanted (%d)\n",
940 				device_xname(sc->sc_dev), i, bp->b_bcount);
941 error:
942 			sc->sc_flags &= ~MTF_IO;
943 			bp->b_error = EIO;
944 		}
945 	}
946 	/*
947 	 * The operation is completely done.
948 	 * Let the drive know with an END command.
949 	 */
950 	cmdbuf[0] = MTE_COMPLETE | MTE_IDLE;
951 	(void) gpibsend(sc->sc_ic, slave, MTL_ECMD, cmdbuf, 1);
952 	bp->b_flags &= ~B_CMD;
953 	(void)bufq_get(sc->sc_tab);
954 	biodone(bp);
955 	gpibrelease(sc->sc_ic, sc->sc_hdl);
956 	if (bufq_peek(sc->sc_tab) == NULL)
957 		sc->sc_active = 0;
958 	else
959 		mtustart(sc);
960 }
961 
962 int
963 mtread(dev_t dev, struct uio *uio, int flags)
964 {
965 	return (physio(mtstrategy, NULL, dev, B_READ, minphys, uio));
966 }
967 
968 int
969 mtwrite(dev_t dev, struct uio *uio, int flags)
970 {
971 	return (physio(mtstrategy, NULL, dev, B_WRITE, minphys, uio));
972 }
973 
974 int
975 mtioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
976 {
977 	struct mtop *op;
978 	int cnt;
979 
980 	switch (cmd) {
981 	    case MTIOCTOP:
982 		op = (struct mtop *)data;
983 		switch(op->mt_op) {
984 		    case MTWEOF:
985 		    case MTFSF:
986 		    case MTBSR:
987 		    case MTBSF:
988 		    case MTFSR:
989 			cnt = op->mt_count;
990 			break;
991 
992 		    case MTOFFL:
993 		    case MTREW:
994 		    case MTNOP:
995 			cnt = 0;
996 			break;
997 
998 		    default:
999 			return (EINVAL);
1000 		}
1001 		return (mtcommand(dev, op->mt_op, cnt));
1002 
1003 	    case MTIOCGET:
1004 		break;
1005 
1006 	    default:
1007 		return (EINVAL);
1008 	}
1009 	return (0);
1010 }
1011