xref: /netbsd-src/sys/arch/amiga/dev/sci.c (revision 481fca6e59249d8ffcf24fef7cfbe7b131bfb080)
1 /*	$NetBSD: sci.c,v 1.24 2000/06/29 08:44:05 mrg 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 <dev/scsipi/scsi_all.h>
53 #include <dev/scsipi/scsipi_all.h>
54 #include <dev/scsipi/scsiconf.h>
55 #include <uvm/uvm_extern.h>
56 #include <machine/pmap.h>
57 #include <machine/cpu.h>
58 #include <amiga/amiga/device.h>
59 #include <amiga/amiga/custom.h>
60 #include <amiga/amiga/isr.h>
61 #include <amiga/dev/scireg.h>
62 #include <amiga/dev/scivar.h>
63 
64 /*
65  * SCSI delays
66  * In u-seconds, primarily for state changes on the SPC.
67  */
68 #define	SCI_CMD_WAIT	50000	/* wait per step of 'immediate' cmds */
69 #define	SCI_DATA_WAIT	50000	/* wait per data in/out step */
70 #define	SCI_INIT_WAIT	50000	/* wait per step (both) during init */
71 
72 int  sciicmd __P((struct sci_softc *, int, void *, int, void *, int,u_char));
73 int  scigo __P((struct sci_softc *, struct scsipi_xfer *));
74 int  scigetsense __P((struct sci_softc *, struct scsipi_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 scisetdelay __P((int));
79 void sci_scsidone __P((struct sci_softc *, int));
80 void sci_donextcmd __P((struct sci_softc *));
81 int  sci_ixfer_out __P((struct sci_softc *, int, register u_char *, int));
82 void sci_ixfer_in __P((struct sci_softc *, int, register u_char *, int));
83 
84 int sci_cmd_wait = SCI_CMD_WAIT;
85 int sci_data_wait = SCI_DATA_WAIT;
86 int sci_init_wait = SCI_INIT_WAIT;
87 
88 int sci_no_dma = 0;
89 
90 #ifdef DEBUG
91 #define QPRINTF(a) if (sci_debug > 1) printf a
92 int	sci_debug = 0;
93 #else
94 #define QPRINTF(a)
95 #endif
96 
97 /*
98  * default minphys routine for sci based controllers
99  */
100 void
101 sci_minphys(bp)
102 	struct buf *bp;
103 {
104 
105 	/*
106 	 * No max transfer at this level.
107 	 */
108 	minphys(bp);
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_scsipi_cmd().
117  */
118 int
119 sci_scsicmd(xs)
120 	struct scsipi_xfer *xs;
121 {
122 	struct sci_pending *pendp;
123 	struct sci_softc *dev;
124 	struct scsipi_link *slp;
125 	int flags, s;
126 
127 	slp = xs->sc_link;
128 	dev = slp->adapter_softc;
129 	flags = xs->xs_control;
130 
131 	if (flags & XS_CTL_DATA_UIO)
132 		panic("sci: scsi data uio requested");
133 
134 	if (dev->sc_xs && flags & XS_CTL_POLL)
135 		panic("sci_scsicmd: busy");
136 
137 	s = splbio();
138 	pendp = &dev->sc_xsstore[slp->scsipi_scsi.target][slp->scsipi_scsi.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 & XS_CTL_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 scsipi_xfer *xs;
172 	struct scsipi_link *slp;
173 	int flags, phase, stat;
174 
175 	xs = dev->sc_xs;
176 	slp = xs->sc_link;
177 	flags = xs->xs_control;
178 
179 	if (flags & XS_CTL_DATA_IN)
180 		phase = DATA_IN_PHASE;
181 	else if (flags & XS_CTL_DATA_OUT)
182 		phase = DATA_OUT_PHASE;
183 	else
184 		phase = STATUS_PHASE;
185 
186 	if (flags & XS_CTL_RESET)
187 		scireset(dev);
188 
189 	dev->sc_stat[0] = -1;
190 	xs->cmd->bytes[0] |= slp->scsipi_scsi.lun << 5;
191 	if (phase == STATUS_PHASE || flags & XS_CTL_POLL)
192 		stat = sciicmd(dev, slp->scsipi_scsi.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 scsipi_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 	/*
217 	 * is this right?
218 	 */
219 	xs->status = stat;
220 
221 	if (stat == 0)
222 		xs->resid = 0;
223 	else {
224 		switch(stat) {
225 		case SCSI_CHECK:
226 			stat = scigetsense(dev, xs);
227 			if (stat != 0)
228 				goto bad_sense;
229 			xs->error = XS_SENSE;
230 			break;
231 		case SCSI_BUSY:
232 			xs->error = XS_BUSY;
233 			break;
234 		bad_sense:
235 		default:
236 			xs->error = XS_DRIVER_STUFFUP;
237 			QPRINTF(("sci_scsicmd() bad %x\n", stat));
238 			break;
239 		}
240 	}
241 
242 	xs->xs_status |= XS_STS_DONE;
243 
244 	/*
245 	 * grab next command before scsipi_done()
246 	 * this way no single device can hog scsi resources.
247 	 */
248 	s = splbio();
249 	pendp = dev->sc_xslist.tqh_first;
250 	if (pendp == NULL) {
251 		donext = 0;
252 		dev->sc_xs = NULL;
253 	} else {
254 		donext = 1;
255 		TAILQ_REMOVE(&dev->sc_xslist, pendp, link);
256 		dev->sc_xs = pendp->xs;
257 		pendp->xs = NULL;
258 	}
259 	splx(s);
260 	scsipi_done(xs);
261 
262 	if (donext)
263 		sci_donextcmd(dev);
264 }
265 
266 int
267 scigetsense(dev, xs)
268 	struct sci_softc *dev;
269 	struct scsipi_xfer *xs;
270 {
271 	struct scsipi_sense rqs;
272 	struct scsipi_link *slp;
273 
274 	slp = xs->sc_link;
275 
276 	rqs.opcode = REQUEST_SENSE;
277 	rqs.byte2 = slp->scsipi_scsi.lun << 5;
278 #ifdef not_yet
279 	rqs.length = xs->req_sense_length ? xs->req_sense_length :
280 	    sizeof(xs->sense.scsi_sense);
281 #else
282 	rqs.length = sizeof(xs->sense.scsi_sense);
283 #endif
284 
285 	rqs.unused[0] = rqs.unused[1] = rqs.control = 0;
286 
287 	return(sciicmd(dev, slp->scsipi_scsi.target, &rqs, sizeof(rqs),
288 		&xs->sense.scsi_sense,
289 	    rqs.length, DATA_IN_PHASE));
290 }
291 
292 void
293 sciabort(dev, where)
294 	struct sci_softc *dev;
295 	char *where;
296 {
297 	printf ("%s: abort %s: csr = 0x%02x, bus = 0x%02x\n",
298 	  dev->sc_dev.dv_xname, where, *dev->sci_csr, *dev->sci_bus_csr);
299 
300 	if (dev->sc_flags & SCI_SELECTED) {
301 
302 		/* lets just hope it worked.. */
303 		dev->sc_flags &= ~SCI_SELECTED;
304 		/* XXX */
305 		scireset (dev);
306 	}
307 }
308 
309 /*
310  * XXX Set/reset long delays.
311  *
312  * if delay == 0, reset default delays
313  * if delay < 0,  set both delays to default long initialization values
314  * if delay > 0,  set both delays to this value
315  *
316  * Used when a devices is expected to respond slowly (e.g. during
317  * initialization).
318  */
319 void
320 scisetdelay(del)
321 	int del;
322 {
323 	static int saved_cmd_wait, saved_data_wait;
324 
325 	if (del) {
326 		saved_cmd_wait = sci_cmd_wait;
327 		saved_data_wait = sci_data_wait;
328 		if (del > 0)
329 			sci_cmd_wait = sci_data_wait = del;
330 		else
331 			sci_cmd_wait = sci_data_wait = sci_init_wait;
332 	} else {
333 		sci_cmd_wait = saved_cmd_wait;
334 		sci_data_wait = saved_data_wait;
335 	}
336 }
337 
338 void
339 scireset(dev)
340 	struct sci_softc *dev;
341 {
342 	u_int s;
343 	u_char my_id;
344 
345 	dev->sc_flags &= ~SCI_SELECTED;
346 	if (dev->sc_flags & SCI_ALIVE)
347 		sciabort(dev, "reset");
348 
349 	printf("%s: ", dev->sc_dev.dv_xname);
350 
351 	s = splbio();
352 	/* preserve our ID for now */
353 	my_id = 7;
354 
355 	/*
356 	 * Reset the chip
357 	 */
358 	*dev->sci_icmd = SCI_ICMD_TEST;
359 	*dev->sci_icmd = SCI_ICMD_TEST | SCI_ICMD_RST;
360 	delay (25);
361 	*dev->sci_icmd = 0;
362 
363 	/*
364 	 * Set up various chip parameters
365 	 */
366 	*dev->sci_icmd = 0;
367 	*dev->sci_tcmd = 0;
368 	*dev->sci_sel_enb = 0;
369 
370 	/* anything else was zeroed by reset */
371 
372 	splx (s);
373 
374 	printf("sci id %d\n", my_id);
375 	dev->sc_flags |= SCI_ALIVE;
376 }
377 
378 void
379 scierror(dev, csr)
380 	struct sci_softc *dev;
381 	u_char csr;
382 {
383 	struct scsipi_xfer *xs;
384 
385 	xs = dev->sc_xs;
386 
387 #ifdef DIAGNOSTIC
388 	if (xs == NULL)
389 		panic("scierror");
390 #endif
391 	if (xs->xs_control & XS_CTL_SILENT)
392 		return;
393 
394 	printf("%s: ", dev->sc_dev.dv_xname);
395 	printf("csr == 0x%02i\n", csr);	/* XXX */
396 }
397 
398 /*
399  * select the bus, return when selected or error.
400  */
401 int
402 sciselectbus(dev, target, our_addr)
403         struct sci_softc *dev;
404 	u_char target, our_addr;
405 {
406 	register int timeo = 2500;
407 
408 	QPRINTF (("sciselectbus %d\n", target));
409 
410 	/* if we're already selected, return */
411 	if (dev->sc_flags & SCI_SELECTED)	/* XXXX */
412 		return 1;
413 
414 	if ((*dev->sci_bus_csr & (SCI_BUS_BSY|SCI_BUS_SEL)) &&
415 	    (*dev->sci_bus_csr & (SCI_BUS_BSY|SCI_BUS_SEL)) &&
416 	    (*dev->sci_bus_csr & (SCI_BUS_BSY|SCI_BUS_SEL)))
417 		return 1;
418 
419 	*dev->sci_tcmd = 0;
420 	*dev->sci_odata = 0x80 + (1 << target);
421 	*dev->sci_icmd = SCI_ICMD_DATA|SCI_ICMD_SEL;
422 	while ((*dev->sci_bus_csr & SCI_BUS_BSY) == 0) {
423 		if (--timeo > 0) {
424 			delay(100);
425 		} else {
426 			break;
427 		}
428 	}
429 	if (timeo) {
430 		*dev->sci_icmd = 0;
431 		dev->sc_flags |= SCI_SELECTED;
432 		return (0);
433 	}
434 	*dev->sci_icmd = 0;
435 	return (1);
436 }
437 
438 int
439 sci_ixfer_out(dev, len, buf, phase)
440 	register struct sci_softc *dev;
441 	int len;
442 	register u_char *buf;
443 	int phase;
444 {
445 	register int wait = sci_data_wait;
446 	u_char csr;
447 
448 	QPRINTF(("sci_ixfer_out {%d} %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x\n",
449 	  len, buf[0], buf[1], buf[2], buf[3], buf[4], buf[5],
450 	  buf[6], buf[7], buf[8], buf[9]));
451 
452 	*dev->sci_tcmd = phase;
453 	*dev->sci_icmd = SCI_ICMD_DATA;
454 	for (;len > 0; len--) {
455 		csr = *dev->sci_bus_csr;
456 		while (!(csr & SCI_BUS_REQ)) {
457 			if ((csr & SCI_BUS_BSY) == 0 || --wait < 0) {
458 #ifdef DEBUG
459 				if (sci_debug)
460 					printf("sci_ixfer_out fail: l%d i%x w%d\n",
461 					  len, csr, wait);
462 #endif
463 				return (len);
464 			}
465 			delay(1);
466 			csr = *dev->sci_bus_csr;
467 		}
468 
469 		if (!(*dev->sci_csr & SCI_CSR_PHASE_MATCH))
470 			break;
471 		*dev->sci_odata = *buf;
472 		*dev->sci_icmd = SCI_ICMD_DATA|SCI_ICMD_ACK;
473 		buf++;
474 		while (*dev->sci_bus_csr & SCI_BUS_REQ);
475 		*dev->sci_icmd = SCI_ICMD_DATA;
476 	}
477 
478 	QPRINTF(("sci_ixfer_out done\n"));
479 	return (0);
480 }
481 
482 void
483 sci_ixfer_in(dev, len, buf, phase)
484 	struct sci_softc *dev;
485 	int len;
486 	register u_char *buf;
487 	int phase;
488 {
489 	int wait = sci_data_wait;
490 	u_char csr;
491 	volatile register u_char *sci_bus_csr = dev->sci_bus_csr;
492 	volatile register u_char *sci_data = dev->sci_data;
493 	volatile register u_char *sci_icmd = dev->sci_icmd;
494 #ifdef DEBUG
495 	u_char *obp = buf;
496 #endif
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;
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 scsipi_xfer *xs;
642 {
643 	int count, target;
644 	u_char phase, *addr;
645 
646 	target = xs->sc_link->scsipi_scsi.target;
647 	count = xs->datalen;
648 	addr = xs->data;
649 
650 	if (sci_no_dma)	{
651 		sciicmd (dev, target, (u_char *) xs->cmd, xs->cmdlen,
652 		  addr, count,
653 		  xs->xs_control & XS_CTL_DATA_IN ? DATA_IN_PHASE : DATA_OUT_PHASE);
654 
655 		return (1);
656 	}
657 
658 	/* select the SCSI bus (it's an error if bus isn't free) */
659 	if (sciselectbus (dev, target, dev->sc_scsi_addr))
660 		return -1;
661 	/*
662 	 * Wait for a phase change (or error) then let the device
663 	 * sequence us through the various SCSI phases.
664 	 */
665 	dev->sc_stat[0] = 0xff;
666 	dev->sc_msg[0] = 0xff;
667 	phase = CMD_PHASE;
668 	while (1) {
669 		while ((*dev->sci_bus_csr & (SCI_BUS_REQ|SCI_BUS_BSY)) ==
670 		  SCI_BUS_BSY);
671 
672 		QPRINTF((">CSR:%02x<", *dev->sci_bus_csr));
673 		if ((*dev->sci_bus_csr & SCI_BUS_REQ) == 0) {
674 			goto abort;
675 		}
676 		phase = SCI_PHASE(*dev->sci_bus_csr);
677 
678 		switch (phase) {
679 		case CMD_PHASE:
680 			if (sci_ixfer_out (dev, xs->cmdlen, (u_char *) xs->cmd, phase))
681 				goto abort;
682 			phase = xs->xs_control & XS_CTL_DATA_IN ? DATA_IN_PHASE : DATA_OUT_PHASE;
683 			break;
684 
685 		case DATA_IN_PHASE:
686 			if (count <= 0)
687 				goto abort;
688 			/* XXX use psuedo DMA if available */
689 			if (count >= 128 && dev->dma_xfer_in)
690 				(*dev->dma_xfer_in)(dev, count, addr, phase);
691 			else
692 				sci_ixfer_in (dev, count, addr, phase);
693 			phase = STATUS_PHASE;
694 			break;
695 
696 		case DATA_OUT_PHASE:
697 			if (count <= 0)
698 				goto abort;
699 			/* XXX use psuedo DMA if available */
700 			if (count >= 128 && dev->dma_xfer_out)
701 				(*dev->dma_xfer_out)(dev, count, addr, phase);
702 			else
703 				if (sci_ixfer_out (dev, count, addr, phase))
704 					goto abort;
705 			phase = STATUS_PHASE;
706 			break;
707 
708 		case MESG_IN_PHASE:
709 			dev->sc_msg[0] = 0xff;
710 			sci_ixfer_in (dev, 1, dev->sc_msg,phase);
711 			dev->sc_flags &= ~SCI_SELECTED;
712 			while (*dev->sci_bus_csr & SCI_BUS_BSY);
713 			goto out;
714 			break;
715 
716 		case MESG_OUT_PHASE:
717 			phase = STATUS_PHASE;
718 			break;
719 
720 		case STATUS_PHASE:
721 			sci_ixfer_in (dev, 1, dev->sc_stat, phase);
722 			phase = MESG_IN_PHASE;
723 			break;
724 
725 		case BUS_FREE_PHASE:
726 			goto out;
727 
728 		default:
729 		printf("sci: unexpected phase %d in icmd from %d\n",
730 		  phase, target);
731 		goto abort;
732 		}
733 	}
734 
735 abort:
736 	sciabort(dev, "go");
737 out:
738 	QPRINTF(("=STS:%02x=", dev->sc_stat[0]));
739 	return (1);
740 }
741