xref: /netbsd-src/sys/arch/amiga/dev/sci.c (revision ae9172d6cd9432a6a1a56760d86b32c57a66c39c)
1 /*	$NetBSD: sci.c,v 1.8 1994/10/26 02:04:44 cgd 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/buf.h>
50 #include <scsi/scsi_all.h>
51 #include <scsi/scsiconf.h>
52 #include <vm/vm.h>
53 #include <vm/vm_kern.h>
54 #include <vm/vm_page.h>
55 #include <machine/pmap.h>
56 #include <machine/cpu.h>
57 #include <amiga/amiga/device.h>
58 #include <amiga/amiga/custom.h>
59 #include <amiga/dev/scireg.h>
60 #include <amiga/dev/scivar.h>
61 
62 /*
63  * SCSI delays
64  * In u-seconds, primarily for state changes on the SPC.
65  */
66 #define	SCI_CMD_WAIT	50000	/* wait per step of 'immediate' cmds */
67 #define	SCI_DATA_WAIT	50000	/* wait per data in/out step */
68 #define	SCI_INIT_WAIT	50000	/* wait per step (both) during init */
69 
70 #define	b_cylin		b_resid
71 
72 int  sciicmd __P((struct sci_softc *, int, void *, int, void *, int,u_char));
73 int  scigo __P((struct sci_softc *, struct scsi_xfer *));
74 int  scigetsense __P((struct sci_softc *, struct scsi_xfer *));
75 int  sciselectbus __P((struct sci_softc *, u_char, u_char));
76 void sciabort __P((struct sci_softc *, char *));
77 void scierror __P((struct sci_softc *, u_char));
78 void scireset __P((struct sci_softc *));
79 void scisetdelay __P((int));
80 void sci_scsidone __P((struct sci_softc *, int));
81 void sci_donextcmd __P((struct sci_softc *));
82 
83 int sci_cmd_wait = SCI_CMD_WAIT;
84 int sci_data_wait = SCI_DATA_WAIT;
85 int sci_init_wait = SCI_INIT_WAIT;
86 
87 int sci_no_dma = 0;
88 
89 #ifdef DEBUG
90 #define QPRINTF(a) if (sci_debug > 1) printf a
91 int	sci_debug = 0;
92 #else
93 #define QPRINTF
94 #endif
95 
96 /*
97  * default minphys routine for sci based controllers
98  */
99 void
100 sci_minphys(bp)
101 	struct buf *bp;
102 {
103 	/*
104 	 * no max transfer at this level
105 	 */
106 }
107 
108 /*
109  * must be used
110  */
111 u_int
112 sci_adinfo()
113 {
114 	/*
115 	 * one request at a time please
116 	 */
117 	return(1);
118 }
119 
120 /*
121  * used by specific sci controller
122  *
123  * it appears that the higher level code does nothing with LUN's
124  * so I will too.  I could plug it in, however so could they
125  * in scsi_scsi_cmd().
126  */
127 int
128 sci_scsicmd(xs)
129 	struct scsi_xfer *xs;
130 {
131 	struct sci_pending *pendp;
132 	struct sci_softc *dev;
133 	struct scsi_link *slp;
134 	int flags, s;
135 
136 	slp = xs->sc_link;
137 	dev = slp->adapter_softc;
138 	flags = xs->flags;
139 
140 	if (flags & SCSI_DATA_UIO)
141 		panic("sci: scsi data uio requested");
142 
143 	if (dev->sc_xs && flags & SCSI_NOMASK)
144 		panic("sci_scsicmd: busy");
145 
146 	s = splbio();
147 	pendp = &dev->sc_xsstore[slp->target][slp->lun];
148 	if (pendp->xs) {
149 		splx(s);
150 		return(TRY_AGAIN_LATER);
151 	}
152 
153 	if (dev->sc_xs) {
154 		pendp->xs = xs;
155 		TAILQ_INSERT_TAIL(&dev->sc_xslist, pendp, link);
156 		splx(s);
157 		return(SUCCESSFULLY_QUEUED);
158 	}
159 	pendp->xs = NULL;
160 	dev->sc_xs = xs;
161 	splx(s);
162 
163 	/*
164 	 * nothing is pending do it now.
165 	 */
166 	sci_donextcmd(dev);
167 
168 	if (flags & SCSI_NOMASK)
169 		return(COMPLETE);
170 	return(SUCCESSFULLY_QUEUED);
171 }
172 
173 /*
174  * entered with dev->sc_xs pointing to the next xfer to perform
175  */
176 void
177 sci_donextcmd(dev)
178 	struct sci_softc *dev;
179 {
180 	struct scsi_xfer *xs;
181 	struct scsi_link *slp;
182 	int flags, phase, stat;
183 
184 	xs = dev->sc_xs;
185 	slp = xs->sc_link;
186 	flags = xs->flags;
187 
188 	if (flags & SCSI_DATA_IN)
189 		phase = DATA_IN_PHASE;
190 	else if (flags & SCSI_DATA_OUT)
191 		phase = DATA_OUT_PHASE;
192 	else
193 		phase = STATUS_PHASE;
194 
195 	if (flags & SCSI_RESET)
196 		scireset(dev);
197 
198 	dev->sc_stat[0] = -1;
199 	if (phase == STATUS_PHASE || flags & SCSI_NOMASK)
200 		stat = sciicmd(dev, slp->target, xs->cmd, xs->cmdlen,
201 		    xs->data, xs->datalen, phase);
202 	else if (scigo(dev, xs) == 0)
203 		return;
204 	else
205 		stat = dev->sc_stat[0];
206 
207 	sci_scsidone(dev, stat);
208 }
209 
210 void
211 sci_scsidone(dev, stat)
212 	struct sci_softc *dev;
213 	int stat;
214 {
215 	struct sci_pending *pendp;
216 	struct scsi_xfer *xs;
217 	int s, donext;
218 
219 	xs = dev->sc_xs;
220 #ifdef DIAGNOSTIC
221 	if (xs == NULL)
222 		panic("sci_scsidone");
223 #endif
224 	/*
225 	 * is this right?
226 	 */
227 	xs->status = stat;
228 
229 	if (stat == 0 || xs->flags & SCSI_ERR_OK)
230 		xs->resid = 0;
231 	else {
232 		switch(stat) {
233 		case SCSI_CHECK:
234 			if (stat = scigetsense(dev, xs))
235 				goto bad_sense;
236 			xs->error = XS_SENSE;
237 			break;
238 		case SCSI_BUSY:
239 			xs->error = XS_BUSY;
240 			break;
241 		bad_sense:
242 		default:
243 			xs->error = XS_DRIVER_STUFFUP;
244 			QPRINTF(("sci_scsicmd() bad %x\n", stat));
245 			break;
246 		}
247 	}
248 	xs->flags |= ITSDONE;
249 
250 	/*
251 	 * grab next command before scsi_done()
252 	 * this way no single device can hog scsi resources.
253 	 */
254 	s = splbio();
255 	pendp = dev->sc_xslist.tqh_first;
256 	if (pendp == NULL) {
257 		donext = 0;
258 		dev->sc_xs = NULL;
259 	} else {
260 		donext = 1;
261 		TAILQ_REMOVE(&dev->sc_xslist, pendp, link);
262 		dev->sc_xs = pendp->xs;
263 		pendp->xs = NULL;
264 	}
265 	splx(s);
266 	scsi_done(xs);
267 
268 	if (donext)
269 		sci_donextcmd(dev);
270 }
271 
272 int
273 scigetsense(dev, xs)
274 	struct sci_softc *dev;
275 	struct scsi_xfer *xs;
276 {
277 	struct scsi_sense rqs;
278 	struct scsi_link *slp;
279 	int stat;
280 
281 	slp = xs->sc_link;
282 
283 	rqs.op_code = REQUEST_SENSE;
284 	rqs.byte2 = slp->lun << 5;
285 #ifdef not_yet
286 	rqs.length = xs->req_sense_length ? xs->req_sense_length :
287 	    sizeof(xs->sense);
288 #else
289 	rqs.length = sizeof(xs->sense);
290 #endif
291 
292 	rqs.unused[0] = rqs.unused[1] = rqs.control = 0;
293 
294 	return(sciicmd(dev, slp->target, &rqs, sizeof(rqs), &xs->sense,
295 	    rqs.length, DATA_IN_PHASE));
296 }
297 
298 void
299 sciabort(dev, where)
300 	struct sci_softc *dev;
301 	char *where;
302 {
303 	printf ("%s: abort %s: csr = 0x%02x, bus = 0x%02x\n",
304 	  dev->sc_dev.dv_xname, where, *dev->sci_csr, *dev->sci_bus_csr);
305 
306 	if (dev->sc_flags & SCI_SELECTED) {
307 
308 		/* lets just hope it worked.. */
309 		dev->sc_flags &= ~SCI_SELECTED;
310 		/* XXX */
311 		scireset (dev);
312 	}
313 }
314 
315 /*
316  * XXX Set/reset long delays.
317  *
318  * if delay == 0, reset default delays
319  * if delay < 0,  set both delays to default long initialization values
320  * if delay > 0,  set both delays to this value
321  *
322  * Used when a devices is expected to respond slowly (e.g. during
323  * initialization).
324  */
325 void
326 scisetdelay(del)
327 	int del;
328 {
329 	static int saved_cmd_wait, saved_data_wait;
330 
331 	if (del) {
332 		saved_cmd_wait = sci_cmd_wait;
333 		saved_data_wait = sci_data_wait;
334 		if (del > 0)
335 			sci_cmd_wait = sci_data_wait = del;
336 		else
337 			sci_cmd_wait = sci_data_wait = sci_init_wait;
338 	} else {
339 		sci_cmd_wait = saved_cmd_wait;
340 		sci_data_wait = saved_data_wait;
341 	}
342 }
343 
344 void
345 scireset(dev)
346 	struct sci_softc *dev;
347 {
348 	u_int i, s;
349 	u_char my_id, csr;
350 
351 	dev->sc_flags &= ~SCI_SELECTED;
352 	if (dev->sc_flags & SCI_ALIVE)
353 		sciabort(dev, "reset");
354 
355 	printf("%s: ", dev->sc_dev.dv_xname);
356 
357 	s = splbio();
358 	/* preserve our ID for now */
359 	my_id = 7;
360 
361 	/*
362 	 * Reset the chip
363 	 */
364 	*dev->sci_icmd = SCI_ICMD_TEST;
365 	*dev->sci_icmd = SCI_ICMD_TEST | SCI_ICMD_RST;
366 	delay (25);
367 	*dev->sci_icmd = 0;
368 
369 	/*
370 	 * Set up various chip parameters
371 	 */
372 	*dev->sci_icmd = 0;
373 	*dev->sci_tcmd = 0;
374 	*dev->sci_sel_enb = 0;
375 
376 	/* anything else was zeroed by reset */
377 
378 	splx (s);
379 
380 	printf("sci id %d\n", my_id);
381 	dev->sc_flags |= SCI_ALIVE;
382 }
383 
384 void
385 scierror(dev, csr)
386 	struct sci_softc *dev;
387 	u_char csr;
388 {
389 	struct scsi_xfer *xs;
390 
391 	xs = dev->sc_xs;
392 
393 #ifdef DIAGNOSTIC
394 	if (xs == NULL)
395 		panic("scierror");
396 #endif
397 	if (xs->flags & SCSI_SILENT)
398 		return;
399 
400 	printf("%s: ", dev->sc_dev.dv_xname);
401 	printf("csr == 0x%02i\n", csr);	/* XXX */
402 }
403 
404 /*
405  * select the bus, return when selected or error.
406  */
407 int
408 sciselectbus(dev, target, our_addr)
409         struct sci_softc *dev;
410 	u_char target, our_addr;
411 {
412 	register int timeo = 2500;
413 
414 	QPRINTF (("sciselectbus %d\n", target));
415 
416 	/* if we're already selected, return */
417 	if (dev->sc_flags & SCI_SELECTED)	/* XXXX */
418 		return 1;
419 
420 	if ((*dev->sci_bus_csr & (SCI_BUS_BSY|SCI_BUS_SEL)) &&
421 	    (*dev->sci_bus_csr & (SCI_BUS_BSY|SCI_BUS_SEL)) &&
422 	    (*dev->sci_bus_csr & (SCI_BUS_BSY|SCI_BUS_SEL)))
423 		return 1;
424 
425 	*dev->sci_tcmd = 0;
426 	*dev->sci_odata = 0x80 + (1 << target);
427 	*dev->sci_icmd = SCI_ICMD_DATA|SCI_ICMD_SEL;
428 	while ((*dev->sci_bus_csr & SCI_BUS_BSY) == 0) {
429 		if (--timeo > 0) {
430 			delay(100);
431 		} else {
432 			break;
433 		}
434 	}
435 	if (timeo) {
436 		*dev->sci_icmd = 0;
437 		dev->sc_flags |= SCI_SELECTED;
438 		return (0);
439 	}
440 	*dev->sci_icmd = 0;
441 	return (1);
442 }
443 
444 int
445 sci_ixfer_out(dev, len, buf, phase)
446 	register struct sci_softc *dev;
447 	int len;
448 	register u_char *buf;
449 	int phase;
450 {
451 	register int wait = sci_data_wait;
452 	u_char csr;
453 
454 	QPRINTF(("sci_ixfer_out {%d} %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x\n",
455 	  len, buf[0], buf[1], buf[2], buf[3], buf[4], buf[5],
456 	  buf[6], buf[7], buf[8], buf[9]));
457 
458 	*dev->sci_tcmd = phase;
459 	*dev->sci_icmd = SCI_ICMD_DATA;
460 	for (;len > 0; len--) {
461 		csr = *dev->sci_bus_csr;
462 		while (!(csr & SCI_BUS_REQ)) {
463 			if ((csr & SCI_BUS_BSY) == 0 || --wait < 0) {
464 #ifdef DEBUG
465 				if (sci_debug)
466 					printf("sci_ixfer_out fail: l%d i%x w%d\n",
467 					  len, csr, wait);
468 #endif
469 				return (len);
470 			}
471 			delay(1);
472 			csr = *dev->sci_bus_csr;
473 		}
474 
475 		if (!(*dev->sci_csr & SCI_CSR_PHASE_MATCH))
476 			break;
477 		*dev->sci_odata = *buf;
478 		*dev->sci_icmd = SCI_ICMD_DATA|SCI_ICMD_ACK;
479 		buf++;
480 		while (*dev->sci_bus_csr & SCI_BUS_REQ);
481 		*dev->sci_icmd = SCI_ICMD_DATA;
482 	}
483 
484 	QPRINTF(("sci_ixfer_out done\n"));
485 	return (0);
486 }
487 
488 void
489 sci_ixfer_in(dev, len, buf, phase)
490 	struct sci_softc *dev;
491 	int len;
492 	register u_char *buf;
493 	int phase;
494 {
495 	int wait = sci_data_wait;
496 	u_char *obp = buf;
497 	u_char csr;
498 	volatile register u_char *sci_bus_csr = dev->sci_bus_csr;
499 	volatile register u_char *sci_data = dev->sci_data;
500 	volatile register u_char *sci_icmd = dev->sci_icmd;
501 
502 	csr = *sci_bus_csr;
503 
504 	QPRINTF(("sci_ixfer_in %d, csr=%02x\n", len, csr));
505 
506 	*dev->sci_tcmd = phase;
507 	*sci_icmd = 0;
508 	for (;len > 0; len--) {
509 		csr = *sci_bus_csr;
510 		while (!(csr & SCI_BUS_REQ)) {
511 			if (!(csr & SCI_BUS_BSY) || --wait < 0) {
512 #ifdef DEBUG
513 				if (sci_debug)
514 					printf("sci_ixfer_in fail: l%d i%x w%d\n",
515 					len, csr, wait);
516 #endif
517 				return;
518 			}
519 
520 			delay(1);
521 			csr = *sci_bus_csr;
522 		}
523 
524 		if (!(*dev->sci_csr & SCI_CSR_PHASE_MATCH))
525 			break;
526 		*buf = *sci_data;
527 		*sci_icmd = SCI_ICMD_ACK;
528 		buf++;
529 		while (*sci_bus_csr & SCI_BUS_REQ);
530 		*sci_icmd = 0;
531 	}
532 
533 	QPRINTF(("sci_ixfer_in {%d} %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x\n",
534 	  len, obp[0], obp[1], obp[2], obp[3], obp[4], obp[5],
535 	  obp[6], obp[7], obp[8], obp[9]));
536 }
537 
538 /*
539  * SCSI 'immediate' command:  issue a command to some SCSI device
540  * and get back an 'immediate' response (i.e., do programmed xfer
541  * to get the response data).  'cbuf' is a buffer containing a scsi
542  * command of length clen bytes.  'buf' is a buffer of length 'len'
543  * bytes for data.  The transfer direction is determined by the device
544  * (i.e., by the scsi bus data xfer phase).  If 'len' is zero, the
545  * command must supply no data.  'xferphase' is the bus phase the
546  * caller expects to happen after the command is issued.  It should
547  * be one of DATA_IN_PHASE, DATA_OUT_PHASE or STATUS_PHASE.
548  */
549 int
550 sciicmd(dev, target, cbuf, clen, buf, len, xferphase)
551 	struct sci_softc *dev;
552 	void *cbuf, *buf;
553 	int clen, len;
554 	u_char xferphase;
555 {
556 	u_char phase, csr, asr;
557 	register int wait;
558 
559 	/* select the SCSI bus (it's an error if bus isn't free) */
560 	if (sciselectbus (dev, target, dev->sc_scsi_addr))
561 		return -1;
562 	/*
563 	 * Wait for a phase change (or error) then let the device
564 	 * sequence us through the various SCSI phases.
565 	 */
566 	dev->sc_stat[0] = 0xff;
567 	dev->sc_msg[0] = 0xff;
568 	phase = CMD_PHASE;
569 	while (1) {
570 		wait = sci_cmd_wait;
571 
572 		while ((*dev->sci_bus_csr & (SCI_BUS_REQ|SCI_BUS_BSY)) == SCI_BUS_BSY);
573 
574 		QPRINTF((">CSR:%02x<", *dev->sci_bus_csr));
575 		if ((*dev->sci_bus_csr & SCI_BUS_REQ) == 0) {
576 			return -1;
577 		}
578 		phase = SCI_PHASE(*dev->sci_bus_csr);
579 
580 		switch (phase) {
581 		case CMD_PHASE:
582 			if (sci_ixfer_out (dev, clen, cbuf, phase))
583 				goto abort;
584 			phase = xferphase;
585 			break;
586 
587 		case DATA_IN_PHASE:
588 			if (len <= 0)
589 				goto abort;
590 			wait = sci_data_wait;
591 			sci_ixfer_in (dev, len, buf, phase);
592 			phase = STATUS_PHASE;
593 			break;
594 
595 		case DATA_OUT_PHASE:
596 			if (len <= 0)
597 				goto abort;
598 			wait = sci_data_wait;
599 			if (sci_ixfer_out (dev, len, buf, phase))
600 				goto abort;
601 			phase = STATUS_PHASE;
602 			break;
603 
604 		case MESG_IN_PHASE:
605 			dev->sc_msg[0] = 0xff;
606 			sci_ixfer_in (dev, 1, dev->sc_msg,phase);
607 			dev->sc_flags &= ~SCI_SELECTED;
608 			while (*dev->sci_bus_csr & SCI_BUS_BSY);
609 			goto out;
610 			break;
611 
612 		case MESG_OUT_PHASE:
613 			phase = STATUS_PHASE;
614 			break;
615 
616 		case STATUS_PHASE:
617 			sci_ixfer_in (dev, 1, dev->sc_stat, phase);
618 			phase = MESG_IN_PHASE;
619 			break;
620 
621 		case BUS_FREE_PHASE:
622 			goto out;
623 
624 		default:
625 		printf("sci: unexpected phase %d in icmd from %d\n",
626 		  phase, target);
627 		goto abort;
628 		}
629 #if 0
630 		if (wait <= 0)
631 			goto abort;
632 #endif
633 	}
634 
635 abort:
636 	sciabort(dev, "icmd");
637 out:
638 	QPRINTF(("=STS:%02x=", dev->sc_stat[0]));
639 	return (dev->sc_stat[0]);
640 }
641 
642 int
643 scigo(dev, xs)
644 	struct sci_softc *dev;
645 	struct scsi_xfer *xs;
646 {
647 	int i, count, target;
648 	u_char phase, csr, asr, cmd, *addr;
649 	int wait;
650 
651 	target = xs->sc_link->target;
652 	count = xs->datalen;
653 	addr = xs->data;
654 
655 	if (sci_no_dma)	{
656 		sciicmd (dev, target, (u_char *) xs->cmd, xs->cmdlen,
657 		  addr, count,
658 		  xs->flags & SCSI_DATA_IN ? DATA_IN_PHASE : DATA_OUT_PHASE);
659 
660 		return (1);
661 	}
662 
663 	/* select the SCSI bus (it's an error if bus isn't free) */
664 	if (sciselectbus (dev, target, dev->sc_scsi_addr))
665 		return -1;
666 	/*
667 	 * Wait for a phase change (or error) then let the device
668 	 * sequence us through the various SCSI phases.
669 	 */
670 	dev->sc_stat[0] = 0xff;
671 	dev->sc_msg[0] = 0xff;
672 	phase = CMD_PHASE;
673 	while (1) {
674 		while ((*dev->sci_bus_csr & (SCI_BUS_REQ|SCI_BUS_BSY)) ==
675 		  SCI_BUS_BSY);
676 
677 		QPRINTF((">CSR:%02x<", *dev->sci_bus_csr));
678 		if ((*dev->sci_bus_csr & SCI_BUS_REQ) == 0) {
679 			goto abort;
680 		}
681 		phase = SCI_PHASE(*dev->sci_bus_csr);
682 
683 		switch (phase) {
684 		case CMD_PHASE:
685 			if (sci_ixfer_out (dev, xs->cmdlen, xs->cmd, phase))
686 				goto abort;
687 			phase = xs->flags & SCSI_DATA_IN ? DATA_IN_PHASE : DATA_OUT_PHASE;
688 			break;
689 
690 		case DATA_IN_PHASE:
691 			if (count <= 0)
692 				goto abort;
693 			/* XXX use psuedo DMA if available */
694 			if (count >= 128 && dev->dma_xfer_in)
695 				(*dev->dma_xfer_in)(dev, count, addr, phase);
696 			else
697 				sci_ixfer_in (dev, count, addr, phase);
698 			phase = STATUS_PHASE;
699 			break;
700 
701 		case DATA_OUT_PHASE:
702 			if (count <= 0)
703 				goto abort;
704 			/* XXX use psuedo DMA if available */
705 			if (count >= 128 && dev->dma_xfer_out)
706 				(*dev->dma_xfer_out)(dev, count, addr, phase);
707 			else
708 				if (sci_ixfer_out (dev, count, addr, phase))
709 					goto abort;
710 			phase = STATUS_PHASE;
711 			break;
712 
713 		case MESG_IN_PHASE:
714 			dev->sc_msg[0] = 0xff;
715 			sci_ixfer_in (dev, 1, dev->sc_msg,phase);
716 			dev->sc_flags &= ~SCI_SELECTED;
717 			while (*dev->sci_bus_csr & SCI_BUS_BSY);
718 			goto out;
719 			break;
720 
721 		case MESG_OUT_PHASE:
722 			phase = STATUS_PHASE;
723 			break;
724 
725 		case STATUS_PHASE:
726 			sci_ixfer_in (dev, 1, dev->sc_stat, phase);
727 			phase = MESG_IN_PHASE;
728 			break;
729 
730 		case BUS_FREE_PHASE:
731 			goto out;
732 
733 		default:
734 		printf("sci: unexpected phase %d in icmd from %d\n",
735 		  phase, target);
736 		goto abort;
737 		}
738 	}
739 
740 abort:
741 	sciabort(dev, "go");
742 out:
743 	QPRINTF(("=STS:%02x=", dev->sc_stat[0]));
744 	return (1);
745 }
746