xref: /netbsd-src/sys/dev/isa/wt.c (revision ce0bb6e8d2e560ecacbe865a848624f94498063b)
1 /*	$NetBSD: wt.c,v 1.24 1995/04/17 12:09:37 cgd Exp $	*/
2 
3 /*
4  * Streamer tape driver.
5  * Supports Archive and Wangtek compatible QIC-02/QIC-36 boards.
6  *
7  * Copyright (C) 1993 by:
8  *	Sergey Ryzhkov <sir@kiae.su>
9  *	Serge Vakulenko <vak@zebub.msk.su>
10  *
11  * This software is distributed with NO WARRANTIES, not even the implied
12  * warranties for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
13  *
14  * Authors grant any other persons or organisations permission to use
15  * or modify this software as long as this message is kept with the software,
16  * all derivative works or modified versions.
17  *
18  * This driver is derived from the old 386bsd Wangtek streamer tape driver,
19  * made by Robert Baron at CMU, based on Intel sources.
20  */
21 
22 /*
23  * Copyright (c) 1989 Carnegie-Mellon University.
24  * All rights reserved.
25  *
26  * Authors: Robert Baron
27  *
28  * Permission to use, copy, modify and distribute this software and
29  * its documentation is hereby granted, provided that both the copyright
30  * notice and this permission notice appear in all copies of the
31  * software, derivative works or modified versions, and any portions
32  * thereof, and that both notices appear in supporting documentation.
33  *
34  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
35  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
36  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
37  *
38  * Carnegie Mellon requests users of this software to return to
39  *
40  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
41  *  School of Computer Science
42  *  Carnegie Mellon University
43  *  Pittsburgh PA 15213-3890
44  *
45  * any improvements or extensions that they make and grant Carnegie the
46  * rights to redistribute these changes.
47  */
48 
49 /*
50  *  Copyright 1988, 1989 by Intel Corporation
51  */
52 
53 #include <sys/param.h>
54 #include <sys/systm.h>
55 #include <sys/kernel.h>
56 #include <sys/buf.h>
57 #include <sys/fcntl.h>
58 #include <sys/malloc.h>
59 #include <sys/ioctl.h>
60 #include <sys/mtio.h>
61 #include <sys/device.h>
62 
63 #include <vm/vm_param.h>
64 
65 #include <machine/pio.h>
66 
67 #include <dev/isa/isavar.h>
68 #include <dev/isa/isadmavar.h>
69 #include <dev/isa/wtreg.h>
70 
71 /*
72  * Uncomment this to enable internal device tracing.
73  */
74 #define DEBUG(x)		/* printf x */
75 
76 #define WTPRI			(PZERO+10)	/* sleep priority */
77 
78 /*
79  * Wangtek controller ports
80  */
81 #define WT_CTLPORT(base)	((base)+0)	/* control, write only */
82 #define WT_STATPORT(base)	((base)+0)	/* status, read only */
83 #define WT_CMDPORT(base)	((base)+1)	/* command, write only */
84 #define WT_DATAPORT(base)	((base)+1)	/* data, read only */
85 #define WT_NPORT		2		/* 2 i/o ports */
86 
87 /* status port bits */
88 #define WT_BUSY			0x01		/* not ready bit define */
89 #define WT_NOEXCEP		0x02		/* no exception bit define */
90 #define WT_RESETMASK		0x07		/* to check after reset */
91 #define WT_RESETVAL		0x05		/* state after reset */
92 
93 /* control port bits */
94 #define WT_ONLINE		0x01		/* device selected */
95 #define WT_RESET		0x02		/* reset command */
96 #define WT_REQUEST		0x04		/* request command */
97 #define WT_IEN			0x08		/* enable dma */
98 
99 /*
100  * Archive controller ports
101  */
102 #define AV_DATAPORT(base)	((base)+0)	/* data, read only */
103 #define AV_CMDPORT(base)	((base)+0)	/* command, write only */
104 #define AV_STATPORT(base)	((base)+1)	/* status, read only */
105 #define AV_CTLPORT(base)	((base)+1)	/* control, write only */
106 #define AV_SDMAPORT(base)	((base)+2)	/* start dma */
107 #define AV_RDMAPORT(base)	((base)+3)	/* reset dma */
108 #define AV_NPORT		4		/* 4 i/o ports */
109 
110 /* status port bits */
111 #define AV_BUSY			0x40		/* not ready bit define */
112 #define AV_NOEXCEP		0x20		/* no exception bit define */
113 #define AV_RESETMASK		0xf8		/* to check after reset */
114 #define AV_RESETVAL		0x50		/* state after reset */
115 
116 /* control port bits */
117 #define AV_RESET		0x80		/* reset command */
118 #define AV_REQUEST		0x40		/* request command */
119 #define AV_IEN			0x20		/* enable interrupts */
120 
121 enum wttype {
122 	UNKNOWN = 0,	/* unknown type, driver disabled */
123 	ARCHIVE,	/* Archive Viper SC499, SC402 etc */
124 	WANGTEK,	/* Wangtek */
125 };
126 
127 struct wt_softc {
128 	struct device sc_dev;
129 	void *sc_ih;
130 
131 	enum wttype type;	/* type of controller */
132 	int sc_iobase;		/* base i/o port */
133 	int chan;		/* dma channel number, 1..3 */
134 	int flags;		/* state of tape drive */
135 	unsigned dens;		/* tape density */
136 	int bsize;		/* tape block size */
137 	void *buf;		/* internal i/o buffer */
138 
139 	void *dmavaddr;		/* virtual address of dma i/o buffer */
140 	size_t dmatotal;	/* size of i/o buffer */
141 	int dmaflags;		/* i/o direction, B_READ or B_WRITE */
142 	size_t dmacount;	/* resulting length of dma i/o */
143 
144 	u_short error;		/* code for error encountered */
145 	u_short ercnt;		/* number of error blocks */
146 	u_short urcnt;		/* number of underruns */
147 
148 	int DATAPORT, CMDPORT, STATPORT, CTLPORT, SDMAPORT, RDMAPORT;
149 	u_char BUSY, NOEXCEP, RESETMASK, RESETVAL, ONLINE, RESET, REQUEST, IEN;
150 };
151 
152 int wtwait __P((struct wt_softc *sc, int catch, char *msg));
153 int wtcmd __P((struct wt_softc *sc, int cmd));
154 int wtstart __P((struct wt_softc *sc, int flag, void *vaddr, size_t len));
155 void wtdma __P((struct wt_softc *sc));
156 void wttimer __P((void *arg));
157 void wtclock __P((struct wt_softc *sc));
158 int wtreset __P((struct wt_softc *sc));
159 int wtsense __P((struct wt_softc *sc, int verbose, int ignore));
160 int wtstatus __P((struct wt_softc *sc));
161 void wtrewind __P((struct wt_softc *sc));
162 int wtreadfm __P((struct wt_softc *sc));
163 int wtwritefm __P((struct wt_softc *sc));
164 u_char wtpoll __P((struct wt_softc *sc, int mask, int bits));
165 
166 int wtprobe __P((struct device *, void *, void *));
167 void wtattach __P((struct device *, struct device *, void *));
168 int wtintr __P((void *sc));
169 
170 struct cfdriver wtcd = {
171 	NULL, "wt", wtprobe, wtattach, DV_TAPE, sizeof(struct wt_softc)
172 };
173 
174 /*
175  * Probe for the presence of the device.
176  */
177 int
178 wtprobe(parent, match, aux)
179 	struct device *parent;
180 	void *match, *aux;
181 {
182 	struct wt_softc *sc = match;
183 	struct isa_attach_args *ia = aux;
184 	int iobase;
185 
186 	sc->chan = ia->ia_drq;
187 	sc->sc_iobase = iobase = ia->ia_iobase;
188 	if (sc->chan < 1 || sc->chan > 3) {
189 		printf("%s: Bad drq=%d, should be 1..3\n", sc->sc_dev.dv_xname,
190 		    sc->chan);
191 		return 0;
192 	}
193 
194 	/* Try Wangtek. */
195 	sc->type = WANGTEK;
196 	sc->CTLPORT = WT_CTLPORT(iobase);
197 	sc->STATPORT = WT_STATPORT(iobase);
198 	sc->CMDPORT = WT_CMDPORT(iobase);
199 	sc->DATAPORT = WT_DATAPORT(iobase);
200 	sc->SDMAPORT = sc->RDMAPORT = 0;
201 	sc->BUSY = WT_BUSY;		sc->NOEXCEP = WT_NOEXCEP;
202 	sc->RESETMASK = WT_RESETMASK;	sc->RESETVAL = WT_RESETVAL;
203 	sc->ONLINE = WT_ONLINE;		sc->RESET = WT_RESET;
204 	sc->REQUEST = WT_REQUEST;	sc->IEN = WT_IEN;
205 	if (wtreset(sc)) {
206 		ia->ia_iosize = WT_NPORT;
207 		return 1;
208 	}
209 
210 	/* Try Archive. */
211 	sc->type = ARCHIVE;
212 	sc->CTLPORT = AV_CTLPORT(iobase);
213 	sc->STATPORT = AV_STATPORT(iobase);
214 	sc->CMDPORT = AV_CMDPORT(iobase);
215 	sc->DATAPORT = AV_DATAPORT(iobase);
216 	sc->SDMAPORT = AV_SDMAPORT(iobase);
217 	sc->RDMAPORT = AV_RDMAPORT(iobase);
218 	sc->BUSY = AV_BUSY;		sc->NOEXCEP = AV_NOEXCEP;
219 	sc->RESETMASK = AV_RESETMASK;	sc->RESETVAL = AV_RESETVAL;
220 	sc->ONLINE = 0;			sc->RESET = AV_RESET;
221 	sc->REQUEST = AV_REQUEST;	sc->IEN = AV_IEN;
222 	if (wtreset(sc)) {
223 		ia->ia_iosize = AV_NPORT;
224 		return 1;
225 	}
226 
227 	/* Tape controller not found. */
228 	sc->type = UNKNOWN;
229 	return 0;
230 }
231 
232 /*
233  * Device is found, configure it.
234  */
235 void
236 wtattach(parent, self, aux)
237 	struct device *parent, *self;
238 	void *aux;
239 {
240 	struct wt_softc *sc = (void *)self;
241 	struct isa_attach_args *ia = aux;
242 
243 	if (sc->type == ARCHIVE) {
244 		printf(": type <Archive>\n");
245 		/* Reset DMA. */
246 		outb(sc->RDMAPORT, 0);
247 	} else
248 		printf(": type <Wangtek>\n");
249 	sc->flags = TPSTART;		/* tape is rewound */
250 	sc->dens = -1;			/* unknown density */
251 
252 	sc->sc_ih = isa_intr_establish(ia->ia_irq, ISA_IST_EDGE, ISA_IPL_BIO,
253 	    wtintr, sc);
254 }
255 
256 int
257 wtdump(dev)
258 	dev_t dev;
259 {
260 
261 	/* Not implemented. */
262 	return EINVAL;
263 }
264 
265 int
266 wtsize(dev)
267 	dev_t dev;
268 {
269 
270 	/* Not implemented. */
271 	return -1;
272 }
273 
274 /*
275  * Open routine, called on every device open.
276  */
277 int
278 wtopen(dev, flag)
279 	dev_t dev;
280 	int flag;
281 {
282 	int unit = minor(dev) & T_UNIT;
283 	struct wt_softc *sc;
284 	int error;
285 
286 	if (unit >= wtcd.cd_ndevs)
287 		return ENXIO;
288 	sc = wtcd.cd_devs[unit];
289 	if (!sc)
290 		return ENXIO;
291 
292 	/* Check that device is not in use */
293 	if (sc->flags & TPINUSE)
294 		return EBUSY;
295 
296 	/* If the tape is in rewound state, check the status and set density. */
297 	if (sc->flags & TPSTART) {
298 		/* If rewind is going on, wait */
299 		if (error = wtwait(sc, PCATCH, "wtrew"))
300 			return error;
301 
302 		/* Check the controller status */
303 		if (!wtsense(sc, 0, (flag & FWRITE) ? 0 : TP_WRP)) {
304 			/* Bad status, reset the controller. */
305 			if (!wtreset(sc))
306 				return EIO;
307 			if (!wtsense(sc, 1, (flag & FWRITE) ? 0 : TP_WRP))
308 				return EIO;
309 		}
310 
311 		/* Set up tape density. */
312 		if (sc->dens != (minor(dev) & WT_DENSEL)) {
313 			int d = 0;
314 
315 			switch (minor(dev) & WT_DENSEL) {
316 			case WT_DENSDFLT:
317 			default:
318 				break;			/* default density */
319 			case WT_QIC11:
320 				d = QIC_FMT11;  break;	/* minor 010 */
321 			case WT_QIC24:
322 				d = QIC_FMT24;  break;	/* minor 020 */
323 			case WT_QIC120:
324 				d = QIC_FMT120; break;	/* minor 030 */
325 			case WT_QIC150:
326 				d = QIC_FMT150; break;	/* minor 040 */
327 			case WT_QIC300:
328 				d = QIC_FMT300; break;	/* minor 050 */
329 			case WT_QIC600:
330 				d = QIC_FMT600; break;	/* minor 060 */
331 			}
332 			if (d) {
333 				/* Change tape density. */
334 				if (!wtcmd(sc, d))
335 					return EIO;
336 				if (!wtsense(sc, 1, TP_WRP | TP_ILL))
337 					return EIO;
338 
339 				/* Check the status of the controller. */
340 				if (sc->error & TP_ILL) {
341 					printf("%s: invalid tape density\n",
342 					    sc->sc_dev.dv_xname);
343 					return ENODEV;
344 				}
345 			}
346 			sc->dens = minor(dev) & WT_DENSEL;
347 		}
348 		sc->flags &= ~TPSTART;
349 	} else if (sc->dens != (minor(dev) & WT_DENSEL))
350 		return ENXIO;
351 
352 	sc->bsize = (minor(dev) & WT_BSIZE) ? 1024 : 512;
353 	sc->buf = malloc(sc->bsize, M_TEMP, M_WAITOK);
354 
355 	sc->flags = TPINUSE;
356 	if (flag & FREAD)
357 		sc->flags |= TPREAD;
358 	if (flag & FWRITE)
359 		sc->flags |= TPWRITE;
360 	return 0;
361 }
362 
363 /*
364  * Close routine, called on last device close.
365  */
366 int
367 wtclose(dev)
368 	dev_t dev;
369 {
370 	int unit = minor(dev) & T_UNIT;
371 	struct wt_softc *sc = wtcd.cd_devs[unit];
372 
373 	/* If rewind is pending, do nothing */
374 	if (sc->flags & TPREW)
375 		goto done;
376 
377 	/* If seek forward is pending and no rewind on close, do nothing */
378 	if (sc->flags & TPRMARK) {
379 		if (minor(dev) & T_NOREWIND)
380 			goto done;
381 
382 		/* If read file mark is going on, wait */
383 		wtwait(sc, 0, "wtrfm");
384 	}
385 
386 	if (sc->flags & TPWANY) {
387 		/* Tape was written.  Write file mark. */
388 		wtwritefm(sc);
389 	}
390 
391 	if ((minor(dev) & T_NOREWIND) == 0) {
392 		/* Rewind to beginning of tape. */
393 		/* Don't wait until rewind, though. */
394 		wtrewind(sc);
395 		goto done;
396 	}
397 	if ((sc->flags & TPRANY) && (sc->flags & (TPVOL | TPWANY)) == 0) {
398 		/* Space forward to after next file mark if no writing done. */
399 		/* Don't wait for completion. */
400 		wtreadfm(sc);
401 	}
402 
403 done:
404 	sc->flags &= TPREW | TPRMARK | TPSTART | TPTIMER;
405 	free(sc->buf, M_TEMP);
406 	return 0;
407 }
408 
409 /*
410  * Ioctl routine.  Compatible with BSD ioctls.
411  * Direct QIC-02 commands ERASE and RETENSION added.
412  * There are three possible ioctls:
413  * ioctl(int fd, MTIOCGET, struct mtget *buf)	-- get status
414  * ioctl(int fd, MTIOCTOP, struct mtop *buf)	-- do BSD-like op
415  * ioctl(int fd, WTQICMD, int qicop)		-- do QIC op
416  */
417 int
418 wtioctl(dev, cmd, addr, flag)
419 	dev_t dev;
420 	u_long cmd;
421 	void *addr;
422 	int flag;
423 {
424 	int unit = minor(dev) & T_UNIT;
425 	struct wt_softc *sc = wtcd.cd_devs[unit];
426 	int error, count, op;
427 
428 	switch (cmd) {
429 	default:
430 		return EINVAL;
431 	case WTQICMD:	/* direct QIC command */
432 		op = *(int *)addr;
433 		switch (op) {
434 		default:
435 			return EINVAL;
436 		case QIC_ERASE:		/* erase the whole tape */
437 			if ((sc->flags & TPWRITE) == 0 || (sc->flags & TPWP))
438 				return EACCES;
439 			if (error = wtwait(sc, PCATCH, "wterase"))
440 				return error;
441 			break;
442 		case QIC_RETENS:	/* retension the tape */
443 			if (error = wtwait(sc, PCATCH, "wtretens"))
444 				return error;
445 			break;
446 		}
447 		/* Both ERASE and RETENS operations work like REWIND. */
448 		/* Simulate the rewind operation here. */
449 		sc->flags &= ~(TPRO | TPWO | TPVOL);
450 		if (!wtcmd(sc, op))
451 			return EIO;
452 		sc->flags |= TPSTART | TPREW;
453 		if (op == QIC_ERASE)
454 			sc->flags |= TPWANY;
455 		wtclock(sc);
456 		return 0;
457 	case MTIOCIEOT:	/* ignore EOT errors */
458 	case MTIOCEEOT:	/* enable EOT errors */
459 		return 0;
460 	case MTIOCGET:
461 		((struct mtget*)addr)->mt_type =
462 			sc->type == ARCHIVE ? MT_ISVIPER1 : 0x11;
463 		((struct mtget*)addr)->mt_dsreg = sc->flags;	/* status */
464 		((struct mtget*)addr)->mt_erreg = sc->error;	/* errors */
465 		((struct mtget*)addr)->mt_resid = 0;
466 		((struct mtget*)addr)->mt_fileno = 0;		/* file */
467 		((struct mtget*)addr)->mt_blkno = 0;		/* block */
468 		return 0;
469 	case MTIOCTOP:
470 		break;
471 	}
472 
473 	switch ((short)((struct mtop*)addr)->mt_op) {
474 	default:
475 #if 0
476 	case MTFSR:	/* forward space record */
477 	case MTBSR:	/* backward space record */
478 	case MTBSF:	/* backward space file */
479 #endif
480 		return EINVAL;
481 	case MTNOP:	/* no operation, sets status only */
482 	case MTCACHE:	/* enable controller cache */
483 	case MTNOCACHE:	/* disable controller cache */
484 		return 0;
485 	case MTREW:	/* rewind */
486 	case MTOFFL:	/* rewind and put the drive offline */
487 		if (sc->flags & TPREW)   /* rewind is running */
488 			return 0;
489 		if (error = wtwait(sc, PCATCH, "wtorew"))
490 			return error;
491 		wtrewind(sc);
492 		return 0;
493 	case MTFSF:	/* forward space file */
494 		for (count = ((struct mtop*)addr)->mt_count; count > 0;
495 		    --count) {
496 			if (error = wtwait(sc, PCATCH, "wtorfm"))
497 				return error;
498 			if (error = wtreadfm(sc))
499 				return error;
500 		}
501 		return 0;
502 	case MTWEOF:	/* write an end-of-file record */
503 		if ((sc->flags & TPWRITE) == 0 || (sc->flags & TPWP))
504 			return EACCES;
505 		if (error = wtwait(sc, PCATCH, "wtowfm"))
506 			return error;
507 		if (error = wtwritefm(sc))
508 			return error;
509 		return 0;
510 	}
511 
512 #ifdef DIAGNOSTIC
513 	panic("wtioctl: impossible");
514 #endif
515 }
516 
517 /*
518  * Strategy routine.
519  */
520 void
521 wtstrategy(bp)
522 	struct buf *bp;
523 {
524 	int unit = minor(bp->b_dev) & T_UNIT;
525 	struct wt_softc *sc = wtcd.cd_devs[unit];
526 	int s;
527 
528 	bp->b_resid = bp->b_bcount;
529 
530 	/* at file marks and end of tape, we just return '0 bytes available' */
531 	if (sc->flags & TPVOL)
532 		goto xit;
533 
534 	if (bp->b_flags & B_READ) {
535 		/* Check read access and no previous write to this tape. */
536 		if ((sc->flags & TPREAD) == 0 || (sc->flags & TPWANY))
537 			goto errxit;
538 
539 		/* For now, we assume that all data will be copied out */
540 		/* If read command outstanding, just skip down */
541 		if ((sc->flags & TPRO) == 0) {
542 			if (!wtsense(sc, 1, TP_WRP)) {
543 				/* Clear status. */
544 				goto errxit;
545 			}
546 			if (!wtcmd(sc, QIC_RDDATA)) {
547 				/* Set read mode. */
548 				wtsense(sc, 1, TP_WRP);
549 				goto errxit;
550 			}
551 			sc->flags |= TPRO | TPRANY;
552 		}
553 	} else {
554 		/* Check write access and write protection. */
555 		/* No previous read from this tape allowed. */
556 		if ((sc->flags & TPWRITE) == 0 || (sc->flags & (TPWP | TPRANY)))
557 			goto errxit;
558 
559 		/* If write command outstanding, just skip down */
560 		if ((sc->flags & TPWO) == 0) {
561 			if (!wtsense(sc, 1, 0)) {
562 				/* Clear status. */
563 				goto errxit;
564 			}
565 			if (!wtcmd(sc, QIC_WRTDATA)) {
566 				/* Set write mode. */
567 				wtsense(sc, 1, 0);
568 				goto errxit;
569 			}
570 			sc->flags |= TPWO | TPWANY;
571 		}
572 	}
573 
574 	if (bp->b_bcount == 0)
575 		goto xit;
576 
577 	sc->flags &= ~TPEXCEP;
578 	s = splbio();
579 	if (wtstart(sc, bp->b_flags, bp->b_data, bp->b_bcount)) {
580 		wtwait(sc, 0, (bp->b_flags & B_READ) ? "wtread" : "wtwrite");
581 		bp->b_resid -= sc->dmacount;
582 	}
583 	splx(s);
584 
585 	if (sc->flags & TPEXCEP) {
586 errxit:
587 		bp->b_flags |= B_ERROR;
588 		bp->b_error = EIO;
589 	}
590 xit:
591 	biodone(bp);
592 	return;
593 }
594 
595 /*
596  * Interrupt routine.
597  */
598 int
599 wtintr(arg)
600 	void *arg;
601 {
602 	struct wt_softc *sc = arg;
603 	u_char x;
604 
605 	x = inb(sc->STATPORT);			/* get status */
606 	DEBUG(("wtintr() status=0x%x -- ", x));
607 	if ((x & (sc->BUSY | sc->NOEXCEP)) == (sc->BUSY | sc->NOEXCEP)) {
608 		DEBUG(("busy\n"));
609 		return 0;			/* device is busy */
610 	}
611 
612 	/*
613 	 * Check if rewind finished.
614 	 */
615 	if (sc->flags & TPREW) {
616 		DEBUG(((x & (sc->BUSY | sc->NOEXCEP)) == (sc->BUSY | sc->NOEXCEP) ?
617 		    "rewind busy?\n" : "rewind finished\n"));
618 		sc->flags &= ~TPREW;		/* rewind finished */
619 		wtsense(sc, 1, TP_WRP);
620 		wakeup((caddr_t)sc);
621 		return 1;
622 	}
623 
624 	/*
625 	 * Check if writing/reading of file mark finished.
626 	 */
627 	if (sc->flags & (TPRMARK | TPWMARK)) {
628 		DEBUG(((x & (sc->BUSY | sc->NOEXCEP)) == (sc->BUSY | sc->NOEXCEP) ?
629 		    "marker r/w busy?\n" : "marker r/w finished\n"));
630 		if ((x & sc->NOEXCEP) == 0)	/* operation failed */
631 			wtsense(sc, 1, (sc->flags & TPRMARK) ? TP_WRP : 0);
632 		sc->flags &= ~(TPRMARK | TPWMARK); /* operation finished */
633 		wakeup((caddr_t)sc);
634 		return 1;
635 	}
636 
637 	/*
638 	 * Do we started any i/o?  If no, just return.
639 	 */
640 	if ((sc->flags & TPACTIVE) == 0) {
641 		DEBUG(("unexpected interrupt\n"));
642 		return 0;
643 	}
644 	sc->flags &= ~TPACTIVE;
645 	sc->dmacount += sc->bsize;		/* increment counter */
646 
647 	/*
648 	 * Clean up dma.
649 	 */
650 	if ((sc->dmaflags & B_READ) &&
651 	    (sc->dmatotal - sc->dmacount) < sc->bsize) {
652 		/* If reading short block, copy the internal buffer
653 		 * to the user memory. */
654 		isa_dmadone(sc->dmaflags, sc->buf, sc->bsize, sc->chan);
655 		bcopy(sc->buf, sc->dmavaddr, sc->dmatotal - sc->dmacount);
656 	} else
657 		isa_dmadone(sc->dmaflags, sc->dmavaddr, sc->bsize, sc->chan);
658 
659 	/*
660 	 * On exception, check for end of file and end of volume.
661 	 */
662 	if ((x & sc->NOEXCEP) == 0) {
663 		DEBUG(("i/o exception\n"));
664 		wtsense(sc, 1, (sc->dmaflags & B_READ) ? TP_WRP : 0);
665 		if (sc->error & (TP_EOM | TP_FIL))
666 			sc->flags |= TPVOL;	/* end of file */
667 		else
668 			sc->flags |= TPEXCEP;	/* i/o error */
669 		wakeup((caddr_t)sc);
670 		return 1;
671 	}
672 
673 	if (sc->dmacount < sc->dmatotal) {
674 		/* Continue I/O. */
675 		sc->dmavaddr += sc->bsize;
676 		wtdma(sc);
677 		DEBUG(("continue i/o, %d\n", sc->dmacount));
678 		return 1;
679 	}
680 	if (sc->dmacount > sc->dmatotal)	/* short last block */
681 		sc->dmacount = sc->dmatotal;
682 	/* Wake up user level. */
683 	wakeup((caddr_t)sc);
684 	DEBUG(("i/o finished, %d\n", sc->dmacount));
685 	return 1;
686 }
687 
688 /* start the rewind operation */
689 void
690 wtrewind(sc)
691 	struct wt_softc *sc;
692 {
693 	int rwmode = sc->flags & (TPRO | TPWO);
694 
695 	sc->flags &= ~(TPRO | TPWO | TPVOL);
696 	/*
697 	 * Wangtek strictly follows QIC-02 standard:
698 	 * clearing ONLINE in read/write modes causes rewind.
699 	 * REWIND command is not allowed in read/write mode
700 	 * and gives `illegal command' error.
701 	 */
702 	if (sc->type == WANGTEK && rwmode) {
703 		outb(sc->CTLPORT, 0);
704 	} else if (!wtcmd(sc, QIC_REWIND))
705 		return;
706 	sc->flags |= TPSTART | TPREW;
707 	wtclock(sc);
708 }
709 
710 /*
711  * Start the `read marker' operation.
712  */
713 int
714 wtreadfm(sc)
715 	struct wt_softc *sc;
716 {
717 
718 	sc->flags &= ~(TPRO | TPWO | TPVOL);
719 	if (!wtcmd(sc, QIC_READFM)) {
720 		wtsense(sc, 1, TP_WRP);
721 		return EIO;
722 	}
723 	sc->flags |= TPRMARK | TPRANY;
724 	wtclock(sc);
725 	/* Don't wait for completion here. */
726 	return 0;
727 }
728 
729 /*
730  * Write marker to the tape.
731  */
732 int
733 wtwritefm(sc)
734 	struct wt_softc *sc;
735 {
736 
737 	tsleep((caddr_t)wtwritefm, WTPRI, "wtwfm", hz);
738 	sc->flags &= ~(TPRO | TPWO);
739 	if (!wtcmd(sc, QIC_WRITEFM)) {
740 		wtsense(sc, 1, 0);
741 		return EIO;
742 	}
743 	sc->flags |= TPWMARK | TPWANY;
744 	wtclock(sc);
745 	return wtwait(sc, 0, "wtwfm");
746 }
747 
748 /*
749  * While controller status & mask == bits continue waiting.
750  */
751 u_char
752 wtpoll(sc, mask, bits)
753 	struct wt_softc *sc;
754 	int mask, bits;
755 {
756 	u_char x;
757 	int i;
758 
759 	/* Poll status port, waiting for specified bits. */
760 	for (i = 0; i < 1000; ++i) {	/* up to 1 msec */
761 		x = inb(sc->STATPORT);
762 		if ((x & mask) != bits)
763 			return x;
764 		delay(1);
765 	}
766 	for (i = 0; i < 100; ++i) {	/* up to 10 msec */
767 		x = inb(sc->STATPORT);
768 		if ((x & mask) != bits)
769 			return x;
770 		delay(100);
771 	}
772 	for (;;) {			/* forever */
773 		x = inb(sc->STATPORT);
774 		if ((x & mask) != bits)
775 			return x;
776 		tsleep((caddr_t)wtpoll, WTPRI, "wtpoll", 1);
777 	}
778 }
779 
780 /*
781  * Execute QIC command.
782  */
783 int
784 wtcmd(sc, cmd)
785 	struct wt_softc *sc;
786 	int cmd;
787 {
788 	u_char x;
789 	int s;
790 
791 	DEBUG(("wtcmd() cmd=0x%x\n", cmd));
792 	s = splbio();
793 	x = wtpoll(sc, sc->BUSY | sc->NOEXCEP, sc->BUSY | sc->NOEXCEP); /* ready? */
794 	if ((x & sc->NOEXCEP) == 0) {			/* error */
795 		splx(s);
796 		return 0;
797 	}
798 
799 	outb(sc->CMDPORT, cmd);				/* output the command */
800 
801 	outb(sc->CTLPORT, sc->REQUEST | sc->ONLINE);	/* set request */
802 	wtpoll(sc, sc->BUSY, sc->BUSY);			/* wait for ready */
803 	outb(sc->CTLPORT, sc->IEN | sc->ONLINE);	/* reset request */
804 	wtpoll(sc, sc->BUSY, 0);			/* wait for not ready */
805 	splx(s);
806 	return 1;
807 }
808 
809 /* wait for the end of i/o, seeking marker or rewind operation */
810 int
811 wtwait(sc, catch, msg)
812 	struct wt_softc *sc;
813 	int catch;
814 	char *msg;
815 {
816 	int error;
817 
818 	DEBUG(("wtwait() `%s'\n", msg));
819 	while (sc->flags & (TPACTIVE | TPREW | TPRMARK | TPWMARK))
820 		if (error = tsleep((caddr_t)sc, WTPRI | catch, msg, 0))
821 			return error;
822 	return 0;
823 }
824 
825 /* initialize dma for the i/o operation */
826 void
827 wtdma(sc)
828 	struct wt_softc *sc;
829 {
830 
831 	sc->flags |= TPACTIVE;
832 	wtclock(sc);
833 
834 	if (sc->type == ARCHIVE) {
835 		/* Set DMA. */
836 		outb(sc->SDMAPORT, 0);
837 	}
838 
839 	if ((sc->dmaflags & B_READ) &&
840 	    (sc->dmatotal - sc->dmacount) < sc->bsize) {
841 		/* Reading short block; do it through the internal buffer. */
842 		isa_dmastart(sc->dmaflags, sc->buf, sc->bsize, sc->chan);
843 	} else
844 		isa_dmastart(sc->dmaflags, sc->dmavaddr, sc->bsize, sc->chan);
845 }
846 
847 /* start i/o operation */
848 int
849 wtstart(sc, flag, vaddr, len)
850 	struct wt_softc *sc;
851 	int flag;
852 	void *vaddr;
853 	size_t len;
854 {
855 	u_char x;
856 
857 	DEBUG(("wtstart()\n"));
858 	x = wtpoll(sc, sc->BUSY | sc->NOEXCEP, sc->BUSY | sc->NOEXCEP); /* ready? */
859 	if ((x & sc->NOEXCEP) == 0) {
860 		sc->flags |= TPEXCEP;	/* error */
861 		return 0;
862 	}
863 	sc->flags &= ~TPEXCEP;		/* clear exception flag */
864 	sc->dmavaddr = vaddr;
865 	sc->dmatotal = len;
866 	sc->dmacount = 0;
867 	sc->dmaflags = flag;
868 	wtdma(sc);
869 	return 1;
870 }
871 
872 /*
873  * Start timer.
874  */
875 void
876 wtclock(sc)
877 	struct wt_softc *sc;
878 {
879 
880 	if (sc->flags & TPTIMER)
881 		return;
882 	sc->flags |= TPTIMER;
883 	/*
884 	 * Some controllers seem to lose dma interrupts too often.  To make the
885 	 * tape stream we need 1 tick timeout.
886 	 */
887 	timeout(wttimer, sc, (sc->flags & TPACTIVE) ? 1 : hz);
888 }
889 
890 /*
891  * Simulate an interrupt periodically while i/o is going.
892  * This is necessary in case interrupts get eaten due to
893  * multiple devices on a single IRQ line.
894  */
895 void
896 wttimer(arg)
897 	void *arg;
898 {
899 	struct wt_softc *sc = (struct wt_softc *)arg;
900 	int s;
901 
902 	sc->flags &= ~TPTIMER;
903 	if ((sc->flags & (TPACTIVE | TPREW | TPRMARK | TPWMARK)) == 0)
904 		return;
905 
906 	/* If i/o going, simulate interrupt. */
907 	s = splbio();
908 	if ((inb(sc->STATPORT) & (sc->BUSY | sc->NOEXCEP)) != (sc->BUSY | sc->NOEXCEP)) {
909 		DEBUG(("wttimer() -- "));
910 		wtintr(sc);
911 	}
912 	splx(s);
913 
914 	/* Restart timer if i/o pending. */
915 	if (sc->flags & (TPACTIVE | TPREW | TPRMARK | TPWMARK))
916 		wtclock(sc);
917 }
918 
919 /*
920  * Perform QIC-02 and QIC-36 compatible reset sequence.
921  */
922 int
923 wtreset(sc)
924 	struct wt_softc *sc;
925 {
926 	u_char x;
927 	int i;
928 
929 	outb(sc->CTLPORT, sc->RESET | sc->ONLINE); /* send reset */
930 	delay(30);
931 	outb(sc->CTLPORT, sc->ONLINE);	/* turn off reset */
932 	delay(30);
933 
934 	/* Read the controller status. */
935 	x = inb(sc->STATPORT);
936 	if (x == 0xff)			/* no port at this address? */
937 		return 0;
938 
939 	/* Wait 3 sec for reset to complete. Needed for QIC-36 boards? */
940 	for (i = 0; i < 3000; ++i) {
941 		if ((x & sc->BUSY) == 0 || (x & sc->NOEXCEP) == 0)
942 			break;
943 		delay(1000);
944 		x = inb(sc->STATPORT);
945 	}
946 	return (x & sc->RESETMASK) == sc->RESETVAL;
947 }
948 
949 /*
950  * Get controller status information.  Return 0 if user i/o request should
951  * receive an i/o error code.
952  */
953 int
954 wtsense(sc, verbose, ignore)
955 	struct wt_softc *sc;
956 	int verbose, ignore;
957 {
958 	char *msg = 0;
959 	int error;
960 
961 	DEBUG(("wtsense() ignore=0x%x\n", ignore));
962 	sc->flags &= ~(TPRO | TPWO);
963 	if (!wtstatus(sc))
964 		return 0;
965 	if ((sc->error & TP_ST0) == 0)
966 		sc->error &= ~TP_ST0MASK;
967 	if ((sc->error & TP_ST1) == 0)
968 		sc->error &= ~TP_ST1MASK;
969 	sc->error &= ~ignore;	/* ignore certain errors */
970 	error = sc->error & (TP_FIL | TP_BNL | TP_UDA | TP_EOM | TP_WRP |
971 	    TP_USL | TP_CNI | TP_MBD | TP_NDT | TP_ILL);
972 	if (!error)
973 		return 1;
974 	if (!verbose)
975 		return 0;
976 
977 	/* lifted from tdriver.c from Wangtek */
978 	if (error & TP_USL)
979 		msg = "Drive not online";
980 	else if (error & TP_CNI)
981 		msg = "No cartridge";
982 	else if ((error & TP_WRP) && (sc->flags & TPWP) == 0) {
983 		msg = "Tape is write protected";
984 		sc->flags |= TPWP;
985 	} else if (error & TP_FIL)
986 		msg = 0 /*"Filemark detected"*/;
987 	else if (error & TP_EOM)
988 		msg = 0 /*"End of tape"*/;
989 	else if (error & TP_BNL)
990 		msg = "Block not located";
991 	else if (error & TP_UDA)
992 		msg = "Unrecoverable data error";
993 	else if (error & TP_NDT)
994 		msg = "No data detected";
995 	else if (error & TP_ILL)
996 		msg = "Illegal command";
997 	if (msg)
998 		printf("%s: %s\n", sc->sc_dev.dv_xname, msg);
999 	return 0;
1000 }
1001 
1002 /*
1003  * Get controller status information.
1004  */
1005 int
1006 wtstatus(sc)
1007 	struct wt_softc *sc;
1008 {
1009 	char *p;
1010 	int s;
1011 
1012 	s = splbio();
1013 	wtpoll(sc, sc->BUSY | sc->NOEXCEP, sc->BUSY | sc->NOEXCEP); /* ready? */
1014 	outb(sc->CMDPORT, QIC_RDSTAT);	/* send `read status' command */
1015 
1016 	outb(sc->CTLPORT, sc->REQUEST | sc->ONLINE);	/* set request */
1017 	wtpoll(sc, sc->BUSY, sc->BUSY);			/* wait for ready */
1018 	outb(sc->CTLPORT, sc->ONLINE);			/* reset request */
1019 	wtpoll(sc, sc->BUSY, 0);			/* wait for not ready */
1020 
1021 	p = (char *)&sc->error;
1022 	while (p < (char *)&sc->error + 6) {
1023 		u_char x = wtpoll(sc, sc->BUSY | sc->NOEXCEP, sc->BUSY | sc->NOEXCEP);
1024 		if ((x & sc->NOEXCEP) == 0) {	/* error */
1025 			splx(s);
1026 			return 0;
1027 		}
1028 
1029 		*p++ = inb(sc->DATAPORT);	/* read status byte */
1030 
1031 		outb(sc->CTLPORT, sc->REQUEST | sc->ONLINE); /* set request */
1032 		wtpoll(sc, sc->BUSY, 0);	/* wait for not ready */
1033 		outb(sc->CTLPORT, sc->ONLINE);	/* unset request */
1034 	}
1035 	splx(s);
1036 	return 1;
1037 }
1038