xref: /netbsd-src/sys/arch/amiga/dev/sci.c (revision 1f2744e6e4915c9da2a3f980279398c4cf7d5e6d)
1 /*	$NetBSD: sci.c,v 1.11 1995/02/12 19:19:23 chopps Exp $	*/
2 
3 /*
4  * Copyright (c) 1994 Michael L. Hitch
5  * Copyright (c) 1990 The Regents of the University of California.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Van Jacobson of Lawrence Berkeley Laboratory.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by the University of
22  *	California, Berkeley and its contributors.
23  * 4. Neither the name of the University nor the names of its contributors
24  *    may be used to endorse or promote products derived from this software
25  *    without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  *
39  *	@(#)scsi.c	7.5 (Berkeley) 5/4/91
40  */
41 
42 /*
43  * AMIGA NCR 5380 scsi adaptor driver
44  */
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/device.h>
49 #include <sys/disklabel.h>
50 #include <sys/dkstat.h>
51 #include <sys/buf.h>
52 #include <scsi/scsi_all.h>
53 #include <scsi/scsiconf.h>
54 #include <vm/vm.h>
55 #include <vm/vm_kern.h>
56 #include <vm/vm_page.h>
57 #include <machine/pmap.h>
58 #include <machine/cpu.h>
59 #include <amiga/amiga/device.h>
60 #include <amiga/amiga/custom.h>
61 #include <amiga/amiga/isr.h>
62 #include <amiga/dev/scireg.h>
63 #include <amiga/dev/scivar.h>
64 
65 /*
66  * SCSI delays
67  * In u-seconds, primarily for state changes on the SPC.
68  */
69 #define	SCI_CMD_WAIT	50000	/* wait per step of 'immediate' cmds */
70 #define	SCI_DATA_WAIT	50000	/* wait per data in/out step */
71 #define	SCI_INIT_WAIT	50000	/* wait per step (both) during init */
72 
73 #define	b_cylin		b_resid
74 
75 int  sciicmd __P((struct sci_softc *, int, void *, int, void *, int,u_char));
76 int  scigo __P((struct sci_softc *, struct scsi_xfer *));
77 int  scigetsense __P((struct sci_softc *, struct scsi_xfer *));
78 int  sciselectbus __P((struct sci_softc *, u_char, u_char));
79 void sciabort __P((struct sci_softc *, char *));
80 void scierror __P((struct sci_softc *, u_char));
81 void scireset __P((struct sci_softc *));
82 void scisetdelay __P((int));
83 void sci_scsidone __P((struct sci_softc *, int));
84 void sci_donextcmd __P((struct sci_softc *));
85 
86 int sci_cmd_wait = SCI_CMD_WAIT;
87 int sci_data_wait = SCI_DATA_WAIT;
88 int sci_init_wait = SCI_INIT_WAIT;
89 
90 int sci_no_dma = 0;
91 
92 #ifdef DEBUG
93 #define QPRINTF(a) if (sci_debug > 1) printf a
94 int	sci_debug = 0;
95 #else
96 #define QPRINTF
97 #endif
98 
99 /*
100  * default minphys routine for sci based controllers
101  */
102 void
103 sci_minphys(bp)
104 	struct buf *bp;
105 {
106 	/*
107 	 * no max transfer at this level
108 	 */
109 }
110 
111 /*
112  * used by specific sci controller
113  *
114  * it appears that the higher level code does nothing with LUN's
115  * so I will too.  I could plug it in, however so could they
116  * in scsi_scsi_cmd().
117  */
118 int
119 sci_scsicmd(xs)
120 	struct scsi_xfer *xs;
121 {
122 	struct sci_pending *pendp;
123 	struct sci_softc *dev;
124 	struct scsi_link *slp;
125 	int flags, s;
126 
127 	slp = xs->sc_link;
128 	dev = slp->adapter_softc;
129 	flags = xs->flags;
130 
131 	if (flags & SCSI_DATA_UIO)
132 		panic("sci: scsi data uio requested");
133 
134 	if (dev->sc_xs && flags & SCSI_POLL)
135 		panic("sci_scsicmd: busy");
136 
137 	s = splbio();
138 	pendp = &dev->sc_xsstore[slp->target][slp->lun];
139 	if (pendp->xs) {
140 		splx(s);
141 		return(TRY_AGAIN_LATER);
142 	}
143 
144 	if (dev->sc_xs) {
145 		pendp->xs = xs;
146 		TAILQ_INSERT_TAIL(&dev->sc_xslist, pendp, link);
147 		splx(s);
148 		return(SUCCESSFULLY_QUEUED);
149 	}
150 	pendp->xs = NULL;
151 	dev->sc_xs = xs;
152 	splx(s);
153 
154 	/*
155 	 * nothing is pending do it now.
156 	 */
157 	sci_donextcmd(dev);
158 
159 	if (flags & SCSI_POLL)
160 		return(COMPLETE);
161 	return(SUCCESSFULLY_QUEUED);
162 }
163 
164 /*
165  * entered with dev->sc_xs pointing to the next xfer to perform
166  */
167 void
168 sci_donextcmd(dev)
169 	struct sci_softc *dev;
170 {
171 	struct scsi_xfer *xs;
172 	struct scsi_link *slp;
173 	int flags, phase, stat;
174 
175 	xs = dev->sc_xs;
176 	slp = xs->sc_link;
177 	flags = xs->flags;
178 
179 	if (flags & SCSI_DATA_IN)
180 		phase = DATA_IN_PHASE;
181 	else if (flags & SCSI_DATA_OUT)
182 		phase = DATA_OUT_PHASE;
183 	else
184 		phase = STATUS_PHASE;
185 
186 	if (flags & SCSI_RESET)
187 		scireset(dev);
188 
189 	dev->sc_stat[0] = -1;
190 	xs->cmd->bytes[0] |= slp->lun << 5;
191 	if (phase == STATUS_PHASE || flags & SCSI_POLL)
192 		stat = sciicmd(dev, slp->target, xs->cmd, xs->cmdlen,
193 		    xs->data, xs->datalen, phase);
194 	else if (scigo(dev, xs) == 0)
195 		return;
196 	else
197 		stat = dev->sc_stat[0];
198 
199 	sci_scsidone(dev, stat);
200 }
201 
202 void
203 sci_scsidone(dev, stat)
204 	struct sci_softc *dev;
205 	int stat;
206 {
207 	struct sci_pending *pendp;
208 	struct scsi_xfer *xs;
209 	int s, donext;
210 
211 	xs = dev->sc_xs;
212 #ifdef DIAGNOSTIC
213 	if (xs == NULL)
214 		panic("sci_scsidone");
215 #endif
216 #if 1
217 	if (((struct device *)(xs->sc_link->device_softc))->dv_unit < dk_ndrive)
218 		++dk_xfer[((struct device *)(xs->sc_link->device_softc))->dv_unit];
219 #endif
220 	/*
221 	 * is this right?
222 	 */
223 	xs->status = stat;
224 
225 	if (stat == 0)
226 		xs->resid = 0;
227 	else {
228 		switch(stat) {
229 		case SCSI_CHECK:
230 			if (stat = scigetsense(dev, xs))
231 				goto bad_sense;
232 			xs->error = XS_SENSE;
233 			break;
234 		case SCSI_BUSY:
235 			xs->error = XS_BUSY;
236 			break;
237 		bad_sense:
238 		default:
239 			xs->error = XS_DRIVER_STUFFUP;
240 			QPRINTF(("sci_scsicmd() bad %x\n", stat));
241 			break;
242 		}
243 	}
244 	xs->flags |= ITSDONE;
245 
246 	/*
247 	 * grab next command before scsi_done()
248 	 * this way no single device can hog scsi resources.
249 	 */
250 	s = splbio();
251 	pendp = dev->sc_xslist.tqh_first;
252 	if (pendp == NULL) {
253 		donext = 0;
254 		dev->sc_xs = NULL;
255 	} else {
256 		donext = 1;
257 		TAILQ_REMOVE(&dev->sc_xslist, pendp, link);
258 		dev->sc_xs = pendp->xs;
259 		pendp->xs = NULL;
260 	}
261 	splx(s);
262 	scsi_done(xs);
263 
264 	if (donext)
265 		sci_donextcmd(dev);
266 }
267 
268 int
269 scigetsense(dev, xs)
270 	struct sci_softc *dev;
271 	struct scsi_xfer *xs;
272 {
273 	struct scsi_sense rqs;
274 	struct scsi_link *slp;
275 	int stat;
276 
277 	slp = xs->sc_link;
278 
279 	rqs.opcode = REQUEST_SENSE;
280 	rqs.byte2 = slp->lun << 5;
281 #ifdef not_yet
282 	rqs.length = xs->req_sense_length ? xs->req_sense_length :
283 	    sizeof(xs->sense);
284 #else
285 	rqs.length = sizeof(xs->sense);
286 #endif
287 
288 	rqs.unused[0] = rqs.unused[1] = rqs.control = 0;
289 
290 	return(sciicmd(dev, slp->target, &rqs, sizeof(rqs), &xs->sense,
291 	    rqs.length, DATA_IN_PHASE));
292 }
293 
294 void
295 sciabort(dev, where)
296 	struct sci_softc *dev;
297 	char *where;
298 {
299 	printf ("%s: abort %s: csr = 0x%02x, bus = 0x%02x\n",
300 	  dev->sc_dev.dv_xname, where, *dev->sci_csr, *dev->sci_bus_csr);
301 
302 	if (dev->sc_flags & SCI_SELECTED) {
303 
304 		/* lets just hope it worked.. */
305 		dev->sc_flags &= ~SCI_SELECTED;
306 		/* XXX */
307 		scireset (dev);
308 	}
309 }
310 
311 /*
312  * XXX Set/reset long delays.
313  *
314  * if delay == 0, reset default delays
315  * if delay < 0,  set both delays to default long initialization values
316  * if delay > 0,  set both delays to this value
317  *
318  * Used when a devices is expected to respond slowly (e.g. during
319  * initialization).
320  */
321 void
322 scisetdelay(del)
323 	int del;
324 {
325 	static int saved_cmd_wait, saved_data_wait;
326 
327 	if (del) {
328 		saved_cmd_wait = sci_cmd_wait;
329 		saved_data_wait = sci_data_wait;
330 		if (del > 0)
331 			sci_cmd_wait = sci_data_wait = del;
332 		else
333 			sci_cmd_wait = sci_data_wait = sci_init_wait;
334 	} else {
335 		sci_cmd_wait = saved_cmd_wait;
336 		sci_data_wait = saved_data_wait;
337 	}
338 }
339 
340 void
341 scireset(dev)
342 	struct sci_softc *dev;
343 {
344 	u_int i, s;
345 	u_char my_id, csr;
346 
347 	dev->sc_flags &= ~SCI_SELECTED;
348 	if (dev->sc_flags & SCI_ALIVE)
349 		sciabort(dev, "reset");
350 
351 	printf("%s: ", dev->sc_dev.dv_xname);
352 
353 	s = splbio();
354 	/* preserve our ID for now */
355 	my_id = 7;
356 
357 	/*
358 	 * Reset the chip
359 	 */
360 	*dev->sci_icmd = SCI_ICMD_TEST;
361 	*dev->sci_icmd = SCI_ICMD_TEST | SCI_ICMD_RST;
362 	delay (25);
363 	*dev->sci_icmd = 0;
364 
365 	/*
366 	 * Set up various chip parameters
367 	 */
368 	*dev->sci_icmd = 0;
369 	*dev->sci_tcmd = 0;
370 	*dev->sci_sel_enb = 0;
371 
372 	/* anything else was zeroed by reset */
373 
374 	splx (s);
375 
376 	printf("sci id %d\n", my_id);
377 	dev->sc_flags |= SCI_ALIVE;
378 }
379 
380 void
381 scierror(dev, csr)
382 	struct sci_softc *dev;
383 	u_char csr;
384 {
385 	struct scsi_xfer *xs;
386 
387 	xs = dev->sc_xs;
388 
389 #ifdef DIAGNOSTIC
390 	if (xs == NULL)
391 		panic("scierror");
392 #endif
393 	if (xs->flags & SCSI_SILENT)
394 		return;
395 
396 	printf("%s: ", dev->sc_dev.dv_xname);
397 	printf("csr == 0x%02i\n", csr);	/* XXX */
398 }
399 
400 /*
401  * select the bus, return when selected or error.
402  */
403 int
404 sciselectbus(dev, target, our_addr)
405         struct sci_softc *dev;
406 	u_char target, our_addr;
407 {
408 	register int timeo = 2500;
409 
410 	QPRINTF (("sciselectbus %d\n", target));
411 
412 	/* if we're already selected, return */
413 	if (dev->sc_flags & SCI_SELECTED)	/* XXXX */
414 		return 1;
415 
416 	if ((*dev->sci_bus_csr & (SCI_BUS_BSY|SCI_BUS_SEL)) &&
417 	    (*dev->sci_bus_csr & (SCI_BUS_BSY|SCI_BUS_SEL)) &&
418 	    (*dev->sci_bus_csr & (SCI_BUS_BSY|SCI_BUS_SEL)))
419 		return 1;
420 
421 	*dev->sci_tcmd = 0;
422 	*dev->sci_odata = 0x80 + (1 << target);
423 	*dev->sci_icmd = SCI_ICMD_DATA|SCI_ICMD_SEL;
424 	while ((*dev->sci_bus_csr & SCI_BUS_BSY) == 0) {
425 		if (--timeo > 0) {
426 			delay(100);
427 		} else {
428 			break;
429 		}
430 	}
431 	if (timeo) {
432 		*dev->sci_icmd = 0;
433 		dev->sc_flags |= SCI_SELECTED;
434 		return (0);
435 	}
436 	*dev->sci_icmd = 0;
437 	return (1);
438 }
439 
440 int
441 sci_ixfer_out(dev, len, buf, phase)
442 	register struct sci_softc *dev;
443 	int len;
444 	register u_char *buf;
445 	int phase;
446 {
447 	register int wait = sci_data_wait;
448 	u_char csr;
449 
450 	QPRINTF(("sci_ixfer_out {%d} %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x\n",
451 	  len, buf[0], buf[1], buf[2], buf[3], buf[4], buf[5],
452 	  buf[6], buf[7], buf[8], buf[9]));
453 
454 	*dev->sci_tcmd = phase;
455 	*dev->sci_icmd = SCI_ICMD_DATA;
456 	for (;len > 0; len--) {
457 		csr = *dev->sci_bus_csr;
458 		while (!(csr & SCI_BUS_REQ)) {
459 			if ((csr & SCI_BUS_BSY) == 0 || --wait < 0) {
460 #ifdef DEBUG
461 				if (sci_debug)
462 					printf("sci_ixfer_out fail: l%d i%x w%d\n",
463 					  len, csr, wait);
464 #endif
465 				return (len);
466 			}
467 			delay(1);
468 			csr = *dev->sci_bus_csr;
469 		}
470 
471 		if (!(*dev->sci_csr & SCI_CSR_PHASE_MATCH))
472 			break;
473 		*dev->sci_odata = *buf;
474 		*dev->sci_icmd = SCI_ICMD_DATA|SCI_ICMD_ACK;
475 		buf++;
476 		while (*dev->sci_bus_csr & SCI_BUS_REQ);
477 		*dev->sci_icmd = SCI_ICMD_DATA;
478 	}
479 
480 	QPRINTF(("sci_ixfer_out done\n"));
481 	return (0);
482 }
483 
484 void
485 sci_ixfer_in(dev, len, buf, phase)
486 	struct sci_softc *dev;
487 	int len;
488 	register u_char *buf;
489 	int phase;
490 {
491 	int wait = sci_data_wait;
492 	u_char *obp = buf;
493 	u_char csr;
494 	volatile register u_char *sci_bus_csr = dev->sci_bus_csr;
495 	volatile register u_char *sci_data = dev->sci_data;
496 	volatile register u_char *sci_icmd = dev->sci_icmd;
497 
498 	csr = *sci_bus_csr;
499 
500 	QPRINTF(("sci_ixfer_in %d, csr=%02x\n", len, csr));
501 
502 	*dev->sci_tcmd = phase;
503 	*sci_icmd = 0;
504 	for (;len > 0; len--) {
505 		csr = *sci_bus_csr;
506 		while (!(csr & SCI_BUS_REQ)) {
507 			if (!(csr & SCI_BUS_BSY) || --wait < 0) {
508 #ifdef DEBUG
509 				if (sci_debug)
510 					printf("sci_ixfer_in fail: l%d i%x w%d\n",
511 					len, csr, wait);
512 #endif
513 				return;
514 			}
515 
516 			delay(1);
517 			csr = *sci_bus_csr;
518 		}
519 
520 		if (!(*dev->sci_csr & SCI_CSR_PHASE_MATCH))
521 			break;
522 		*buf = *sci_data;
523 		*sci_icmd = SCI_ICMD_ACK;
524 		buf++;
525 		while (*sci_bus_csr & SCI_BUS_REQ);
526 		*sci_icmd = 0;
527 	}
528 
529 	QPRINTF(("sci_ixfer_in {%d} %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x\n",
530 	  len, obp[0], obp[1], obp[2], obp[3], obp[4], obp[5],
531 	  obp[6], obp[7], obp[8], obp[9]));
532 }
533 
534 /*
535  * SCSI 'immediate' command:  issue a command to some SCSI device
536  * and get back an 'immediate' response (i.e., do programmed xfer
537  * to get the response data).  'cbuf' is a buffer containing a scsi
538  * command of length clen bytes.  'buf' is a buffer of length 'len'
539  * bytes for data.  The transfer direction is determined by the device
540  * (i.e., by the scsi bus data xfer phase).  If 'len' is zero, the
541  * command must supply no data.  'xferphase' is the bus phase the
542  * caller expects to happen after the command is issued.  It should
543  * be one of DATA_IN_PHASE, DATA_OUT_PHASE or STATUS_PHASE.
544  */
545 int
546 sciicmd(dev, target, cbuf, clen, buf, len, xferphase)
547 	struct sci_softc *dev;
548 	void *cbuf, *buf;
549 	int clen, len;
550 	u_char xferphase;
551 {
552 	u_char phase, csr, asr;
553 	register int wait;
554 
555 	/* select the SCSI bus (it's an error if bus isn't free) */
556 	if (sciselectbus (dev, target, dev->sc_scsi_addr))
557 		return -1;
558 	/*
559 	 * Wait for a phase change (or error) then let the device
560 	 * sequence us through the various SCSI phases.
561 	 */
562 	dev->sc_stat[0] = 0xff;
563 	dev->sc_msg[0] = 0xff;
564 	phase = CMD_PHASE;
565 	while (1) {
566 		wait = sci_cmd_wait;
567 
568 		while ((*dev->sci_bus_csr & (SCI_BUS_REQ|SCI_BUS_BSY)) == SCI_BUS_BSY);
569 
570 		QPRINTF((">CSR:%02x<", *dev->sci_bus_csr));
571 		if ((*dev->sci_bus_csr & SCI_BUS_REQ) == 0) {
572 			return -1;
573 		}
574 		phase = SCI_PHASE(*dev->sci_bus_csr);
575 
576 		switch (phase) {
577 		case CMD_PHASE:
578 			if (sci_ixfer_out (dev, clen, cbuf, phase))
579 				goto abort;
580 			phase = xferphase;
581 			break;
582 
583 		case DATA_IN_PHASE:
584 			if (len <= 0)
585 				goto abort;
586 			wait = sci_data_wait;
587 			sci_ixfer_in (dev, len, buf, phase);
588 			phase = STATUS_PHASE;
589 			break;
590 
591 		case DATA_OUT_PHASE:
592 			if (len <= 0)
593 				goto abort;
594 			wait = sci_data_wait;
595 			if (sci_ixfer_out (dev, len, buf, phase))
596 				goto abort;
597 			phase = STATUS_PHASE;
598 			break;
599 
600 		case MESG_IN_PHASE:
601 			dev->sc_msg[0] = 0xff;
602 			sci_ixfer_in (dev, 1, dev->sc_msg,phase);
603 			dev->sc_flags &= ~SCI_SELECTED;
604 			while (*dev->sci_bus_csr & SCI_BUS_BSY);
605 			goto out;
606 			break;
607 
608 		case MESG_OUT_PHASE:
609 			phase = STATUS_PHASE;
610 			break;
611 
612 		case STATUS_PHASE:
613 			sci_ixfer_in (dev, 1, dev->sc_stat, phase);
614 			phase = MESG_IN_PHASE;
615 			break;
616 
617 		case BUS_FREE_PHASE:
618 			goto out;
619 
620 		default:
621 		printf("sci: unexpected phase %d in icmd from %d\n",
622 		  phase, target);
623 		goto abort;
624 		}
625 #if 0
626 		if (wait <= 0)
627 			goto abort;
628 #endif
629 	}
630 
631 abort:
632 	sciabort(dev, "icmd");
633 out:
634 	QPRINTF(("=STS:%02x=", dev->sc_stat[0]));
635 	return (dev->sc_stat[0]);
636 }
637 
638 int
639 scigo(dev, xs)
640 	struct sci_softc *dev;
641 	struct scsi_xfer *xs;
642 {
643 	int i, count, target;
644 	u_char phase, csr, asr, cmd, *addr;
645 	int wait;
646 
647 	target = xs->sc_link->target;
648 	count = xs->datalen;
649 	addr = xs->data;
650 
651 	if (sci_no_dma)	{
652 		sciicmd (dev, target, (u_char *) xs->cmd, xs->cmdlen,
653 		  addr, count,
654 		  xs->flags & SCSI_DATA_IN ? DATA_IN_PHASE : DATA_OUT_PHASE);
655 
656 		return (1);
657 	}
658 
659 	/* select the SCSI bus (it's an error if bus isn't free) */
660 	if (sciselectbus (dev, target, dev->sc_scsi_addr))
661 		return -1;
662 	/*
663 	 * Wait for a phase change (or error) then let the device
664 	 * sequence us through the various SCSI phases.
665 	 */
666 	dev->sc_stat[0] = 0xff;
667 	dev->sc_msg[0] = 0xff;
668 	phase = CMD_PHASE;
669 	while (1) {
670 		while ((*dev->sci_bus_csr & (SCI_BUS_REQ|SCI_BUS_BSY)) ==
671 		  SCI_BUS_BSY);
672 
673 		QPRINTF((">CSR:%02x<", *dev->sci_bus_csr));
674 		if ((*dev->sci_bus_csr & SCI_BUS_REQ) == 0) {
675 			goto abort;
676 		}
677 		phase = SCI_PHASE(*dev->sci_bus_csr);
678 
679 		switch (phase) {
680 		case CMD_PHASE:
681 			if (sci_ixfer_out (dev, xs->cmdlen, xs->cmd, phase))
682 				goto abort;
683 			phase = xs->flags & SCSI_DATA_IN ? DATA_IN_PHASE : DATA_OUT_PHASE;
684 			break;
685 
686 		case DATA_IN_PHASE:
687 			if (count <= 0)
688 				goto abort;
689 			/* XXX use psuedo DMA if available */
690 			if (count >= 128 && dev->dma_xfer_in)
691 				(*dev->dma_xfer_in)(dev, count, addr, phase);
692 			else
693 				sci_ixfer_in (dev, count, addr, phase);
694 			phase = STATUS_PHASE;
695 			break;
696 
697 		case DATA_OUT_PHASE:
698 			if (count <= 0)
699 				goto abort;
700 			/* XXX use psuedo DMA if available */
701 			if (count >= 128 && dev->dma_xfer_out)
702 				(*dev->dma_xfer_out)(dev, count, addr, phase);
703 			else
704 				if (sci_ixfer_out (dev, count, addr, phase))
705 					goto abort;
706 			phase = STATUS_PHASE;
707 			break;
708 
709 		case MESG_IN_PHASE:
710 			dev->sc_msg[0] = 0xff;
711 			sci_ixfer_in (dev, 1, dev->sc_msg,phase);
712 			dev->sc_flags &= ~SCI_SELECTED;
713 			while (*dev->sci_bus_csr & SCI_BUS_BSY);
714 			goto out;
715 			break;
716 
717 		case MESG_OUT_PHASE:
718 			phase = STATUS_PHASE;
719 			break;
720 
721 		case STATUS_PHASE:
722 			sci_ixfer_in (dev, 1, dev->sc_stat, phase);
723 			phase = MESG_IN_PHASE;
724 			break;
725 
726 		case BUS_FREE_PHASE:
727 			goto out;
728 
729 		default:
730 		printf("sci: unexpected phase %d in icmd from %d\n",
731 		  phase, target);
732 		goto abort;
733 		}
734 	}
735 
736 abort:
737 	sciabort(dev, "go");
738 out:
739 	QPRINTF(("=STS:%02x=", dev->sc_stat[0]));
740 	return (1);
741 }
742