xref: /openbsd-src/lib/libsndio/sio_sun.c (revision e5157e49389faebcb42b7237d55fbf096d9c2523)
1 /*	$OpenBSD: sio_sun.c,v 1.12 2014/08/15 03:51:40 guenther Exp $	*/
2 /*
3  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 /*
18  * TODO:
19  *
20  * remove filling code from sio_sun_write() and create sio_sun_fill()
21  *
22  * allow block size to be set
23  *
24  * call hdl->cb_pos() from sio_sun_read() and sio_sun_write(), or better:
25  * implement generic blocking sio_read() and sio_write() with poll(2)
26  * and use non-blocking sio_ops only
27  */
28 
29 #include <sys/types.h>
30 #include <sys/ioctl.h>
31 #include <sys/audioio.h>
32 #include <sys/stat.h>
33 
34 #include <errno.h>
35 #include <fcntl.h>
36 #include <limits.h>
37 #include <poll.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
42 
43 #include "debug.h"
44 #include "sio_priv.h"
45 
46 struct sio_sun_hdl {
47 	struct sio_hdl sio;
48 	int fd;
49 	int filling;
50 	unsigned int ibpf, obpf;	/* bytes per frame */
51 	unsigned int ibytes, obytes;	/* bytes the hw transferred */
52 	unsigned int ierr, oerr;	/* frames the hw dropped */
53 	int idelta, odelta;		/* position reported to client */
54 };
55 
56 static void sio_sun_close(struct sio_hdl *);
57 static int sio_sun_start(struct sio_hdl *);
58 static int sio_sun_stop(struct sio_hdl *);
59 static int sio_sun_setpar(struct sio_hdl *, struct sio_par *);
60 static int sio_sun_getpar(struct sio_hdl *, struct sio_par *);
61 static int sio_sun_getcap(struct sio_hdl *, struct sio_cap *);
62 static size_t sio_sun_read(struct sio_hdl *, void *, size_t);
63 static size_t sio_sun_write(struct sio_hdl *, const void *, size_t);
64 static int sio_sun_nfds(struct sio_hdl *);
65 static int sio_sun_pollfd(struct sio_hdl *, struct pollfd *, int);
66 static int sio_sun_revents(struct sio_hdl *, struct pollfd *);
67 
68 static struct sio_ops sio_sun_ops = {
69 	sio_sun_close,
70 	sio_sun_setpar,
71 	sio_sun_getpar,
72 	sio_sun_getcap,
73 	sio_sun_write,
74 	sio_sun_read,
75 	sio_sun_start,
76 	sio_sun_stop,
77 	sio_sun_nfds,
78 	sio_sun_pollfd,
79 	sio_sun_revents,
80 	NULL, /* setvol */
81 	NULL, /* getvol */
82 };
83 
84 /*
85  * convert sun encoding to sio_par encoding
86  */
87 static int
88 sio_sun_infotoenc(struct sio_sun_hdl *hdl, struct audio_prinfo *ai,
89     struct sio_par *par)
90 {
91 	par->msb = ai->msb;
92 	par->bits = ai->precision;
93 	par->bps = ai->bps;
94 	switch (ai->encoding) {
95 	case AUDIO_ENCODING_SLINEAR_LE:
96 		par->le = 1;
97 		par->sig = 1;
98 		break;
99 	case AUDIO_ENCODING_SLINEAR_BE:
100 		par->le = 0;
101 		par->sig = 1;
102 		break;
103 	case AUDIO_ENCODING_ULINEAR_LE:
104 		par->le = 1;
105 		par->sig = 0;
106 		break;
107 	case AUDIO_ENCODING_ULINEAR_BE:
108 		par->le = 0;
109 		par->sig = 0;
110 		break;
111 	case AUDIO_ENCODING_SLINEAR:
112 		par->le = SIO_LE_NATIVE;
113 		par->sig = 1;
114 		break;
115 	case AUDIO_ENCODING_ULINEAR:
116 		par->le = SIO_LE_NATIVE;
117 		par->sig = 0;
118 		break;
119 	default:
120 		DPRINTF("sio_sun_infotoenc: unsupported encoding\n");
121 		hdl->sio.eof = 1;
122 		return 0;
123 	}
124 	return 1;
125 }
126 
127 /*
128  * convert sio_par encoding to sun encoding
129  */
130 static void
131 sio_sun_enctoinfo(struct sio_sun_hdl *hdl,
132     unsigned int *renc, struct sio_par *par)
133 {
134 	if (par->le == ~0U && par->sig == ~0U) {
135 		*renc = ~0U;
136 	} else if (par->le == ~0U || par->sig == ~0U) {
137 		*renc = AUDIO_ENCODING_SLINEAR;
138 	} else if (par->le && par->sig) {
139 		*renc = AUDIO_ENCODING_SLINEAR_LE;
140 	} else if (!par->le && par->sig) {
141 		*renc = AUDIO_ENCODING_SLINEAR_BE;
142 	} else if (par->le && !par->sig) {
143 		*renc = AUDIO_ENCODING_ULINEAR_LE;
144 	} else {
145 		*renc = AUDIO_ENCODING_ULINEAR_BE;
146 	}
147 }
148 
149 /*
150  * try to set the device to the given parameters and check that the
151  * device can use them; return 1 on success, 0 on failure or error
152  */
153 static int
154 sio_sun_tryinfo(struct sio_sun_hdl *hdl, struct sio_enc *enc,
155     unsigned int pchan, unsigned int rchan, unsigned int rate)
156 {
157 	struct audio_info aui;
158 	struct audio_prinfo *pr;
159 
160 	pr = (hdl->sio.mode & SIO_PLAY) ? &aui.play : &aui.record;
161 
162 	AUDIO_INITINFO(&aui);
163 	if (enc) {
164 		if (enc->le && enc->sig) {
165 			pr->encoding = AUDIO_ENCODING_SLINEAR_LE;
166 		} else if (!enc->le && enc->sig) {
167 			pr->encoding = AUDIO_ENCODING_SLINEAR_BE;
168 		} else if (enc->le && !enc->sig) {
169 			pr->encoding = AUDIO_ENCODING_ULINEAR_LE;
170 		} else {
171 			pr->encoding = AUDIO_ENCODING_ULINEAR_BE;
172 		}
173 		pr->precision = enc->bits;
174 	}
175 	if (rate)
176 		pr->sample_rate = rate;
177 	if ((hdl->sio.mode & (SIO_PLAY | SIO_REC)) == (SIO_PLAY | SIO_REC))
178 		aui.record = aui.play;
179 	if (pchan && (hdl->sio.mode & SIO_PLAY))
180 		aui.play.channels = pchan;
181 	if (rchan && (hdl->sio.mode & SIO_REC))
182 		aui.record.channels = rchan;
183 	if (ioctl(hdl->fd, AUDIO_SETINFO, &aui) < 0) {
184 		if (errno == EINVAL)
185 			return 0;
186 		DPERROR("sio_sun_tryinfo: setinfo");
187 		hdl->sio.eof = 1;
188 		return 0;
189 	}
190 	if (ioctl(hdl->fd, AUDIO_GETINFO, &aui) < 0) {
191 		DPERROR("sio_sun_tryinfo: getinfo");
192 		hdl->sio.eof = 1;
193 		return 0;
194 	}
195 	if (pchan && aui.play.channels != pchan)
196 		return 0;
197 	if (rchan && aui.record.channels != rchan)
198 		return 0;
199 	if (rate) {
200 		if ((hdl->sio.mode & SIO_PLAY) &&
201 		    (aui.play.sample_rate != rate))
202 			return 0;
203 		if ((hdl->sio.mode & SIO_REC) &&
204 		    (aui.record.sample_rate != rate))
205 			return 0;
206 	}
207 	return 1;
208 }
209 
210 /*
211  * guess device capabilities
212  */
213 static int
214 sio_sun_getcap(struct sio_hdl *sh, struct sio_cap *cap)
215 {
216 #define NCHANS (sizeof(chans) / sizeof(chans[0]))
217 #define NRATES (sizeof(rates) / sizeof(rates[0]))
218 	static unsigned int chans[] = {
219 		1, 2, 4, 6, 8, 10, 12
220 	};
221 	static unsigned int rates[] = {
222 		8000, 11025, 12000, 16000, 22050, 24000,
223 		32000, 44100, 48000, 64000, 88200, 96000
224 	};
225 	struct sio_sun_hdl *hdl = (struct sio_sun_hdl *)sh;
226 	struct sio_par savepar;
227 	struct audio_encoding ae;
228 	unsigned int nenc = 0, nconf = 0;
229 	unsigned int enc_map = 0, rchan_map = 0, pchan_map = 0, rate_map;
230 	unsigned int i, j, conf;
231 
232 	if (!sio_sun_getpar(&hdl->sio, &savepar))
233 		return 0;
234 
235 	/*
236 	 * fill encoding list
237 	 */
238 	for (ae.index = 0; nenc < SIO_NENC; ae.index++) {
239 		if (ioctl(hdl->fd, AUDIO_GETENC, &ae) < 0) {
240 			if (errno == EINVAL)
241 				break;
242 			DPERROR("sio_sun_getcap: getenc");
243 			hdl->sio.eof = 1;
244 			return 0;
245 		}
246 		if (ae.flags & AUDIO_ENCODINGFLAG_EMULATED)
247 			continue;
248 		if (ae.encoding == AUDIO_ENCODING_SLINEAR_LE) {
249 			cap->enc[nenc].le = 1;
250 			cap->enc[nenc].sig = 1;
251 		} else if (ae.encoding == AUDIO_ENCODING_SLINEAR_BE) {
252 			cap->enc[nenc].le = 0;
253 			cap->enc[nenc].sig = 1;
254 		} else if (ae.encoding == AUDIO_ENCODING_ULINEAR_LE) {
255 			cap->enc[nenc].le = 1;
256 			cap->enc[nenc].sig = 0;
257 		} else if (ae.encoding == AUDIO_ENCODING_ULINEAR_BE) {
258 			cap->enc[nenc].le = 0;
259 			cap->enc[nenc].sig = 0;
260 		} else if (ae.encoding == AUDIO_ENCODING_SLINEAR) {
261 			cap->enc[nenc].le = SIO_LE_NATIVE;
262 			cap->enc[nenc].sig = 1;
263 		} else if (ae.encoding == AUDIO_ENCODING_ULINEAR) {
264 			cap->enc[nenc].le = SIO_LE_NATIVE;
265 			cap->enc[nenc].sig = 0;
266 		} else {
267 			/* unsipported encoding */
268 			continue;
269 		}
270 		cap->enc[nenc].bits = ae.precision;
271 		cap->enc[nenc].bps = ae.bps;
272 		cap->enc[nenc].msb = ae.msb;
273 		enc_map |= (1 << nenc);
274 		nenc++;
275 	}
276 
277 	/*
278 	 * fill channels
279 	 *
280 	 * for now we're lucky: all kernel devices assume that the
281 	 * number of channels and the encoding are independent so we can
282 	 * use the current encoding and try various channels.
283 	 */
284 	if (hdl->sio.mode & SIO_PLAY) {
285 		memcpy(&cap->pchan, chans, NCHANS * sizeof(unsigned int));
286 		for (i = 0; i < NCHANS; i++) {
287 			if (sio_sun_tryinfo(hdl, NULL, chans[i], 0, 0))
288 				pchan_map |= (1 << i);
289 		}
290 	}
291 	if (hdl->sio.mode & SIO_REC) {
292 		memcpy(&cap->rchan, chans, NCHANS * sizeof(unsigned int));
293 		for (i = 0; i < NCHANS; i++) {
294 			if (sio_sun_tryinfo(hdl, NULL, 0, chans[i], 0))
295 				rchan_map |= (1 << i);
296 		}
297 	}
298 
299 	/*
300 	 * fill rates
301 	 *
302 	 * rates are not independent from other parameters (eg. on
303 	 * uaudio devices), so certain rates may not be allowed with
304 	 * certain encodings. We have to check rates for all encodings
305 	 */
306 	memcpy(&cap->rate, rates, NRATES * sizeof(unsigned int));
307 	for (j = 0; j < nenc; j++) {
308 		rate_map = 0;
309 		for (i = 0; i < NRATES; i++) {
310 			if (sio_sun_tryinfo(hdl, &cap->enc[j], 0, 0, rates[i]))
311 				rate_map |= (1 << i);
312 		}
313 		for (conf = 0; conf < nconf; conf++) {
314 			if (cap->confs[conf].rate == rate_map) {
315 				cap->confs[conf].enc |= (1 << j);
316 				break;
317 			}
318 		}
319 		if (conf == nconf) {
320 			if (nconf == SIO_NCONF)
321 				break;
322 			cap->confs[nconf].enc = (1 << j);
323 			cap->confs[nconf].pchan = pchan_map;
324 			cap->confs[nconf].rchan = rchan_map;
325 			cap->confs[nconf].rate = rate_map;
326 			nconf++;
327 		}
328 	}
329 	cap->nconf = nconf;
330 	if (!sio_sun_setpar(&hdl->sio, &savepar))
331 		return 0;
332 	return 1;
333 #undef NCHANS
334 #undef NRATES
335 }
336 
337 struct sio_hdl *
338 _sio_sun_open(const char *str, unsigned int mode, int nbio)
339 {
340 	int fd, flags, fullduplex;
341 	struct audio_info aui;
342 	struct sio_sun_hdl *hdl;
343 	struct sio_par par;
344 	char path[PATH_MAX];
345 
346 	switch (*str) {
347 	case '/':
348 	case ':': /* XXX: for backward compat */
349 		str++;
350 		break;
351 	default:
352 		DPRINTF("_sio_sun_open: %s: '/<devnum>' expected\n", str);
353 		return NULL;
354 	}
355 	hdl = malloc(sizeof(struct sio_sun_hdl));
356 	if (hdl == NULL)
357 		return NULL;
358 	_sio_create(&hdl->sio, &sio_sun_ops, mode, nbio);
359 
360 	snprintf(path, sizeof(path), "/dev/audio%s", str);
361 	if (mode == (SIO_PLAY | SIO_REC))
362 		flags = O_RDWR;
363 	else
364 		flags = (mode & SIO_PLAY) ? O_WRONLY : O_RDONLY;
365 
366 	while ((fd = open(path, flags | O_NONBLOCK | O_CLOEXEC)) < 0) {
367 		if (errno == EINTR)
368 			continue;
369 		DPERROR(path);
370 		goto bad_free;
371 	}
372 
373 	/*
374 	 * pause the device
375 	 */
376 	AUDIO_INITINFO(&aui);
377 	if (mode & SIO_PLAY)
378 		aui.play.pause = 1;
379 	if (mode & SIO_REC)
380 		aui.record.pause = 1;
381 	if (ioctl(fd, AUDIO_SETINFO, &aui) < 0) {
382 		DPERROR("sio_open_sun: setinfo");
383 		goto bad_close;
384 	}
385 	/*
386 	 * If both play and record are requested then
387 	 * set full duplex mode.
388 	 */
389 	if (mode == (SIO_PLAY | SIO_REC)) {
390 		fullduplex = 1;
391 		if (ioctl(fd, AUDIO_SETFD, &fullduplex) < 0) {
392 			DPRINTF("sio_open_sun: %s: can't set full-duplex\n", path);
393 			goto bad_close;
394 		}
395 	}
396 	hdl->fd = fd;
397 
398 	/*
399 	 * Default parameters may not be compatible with libsndio (eg. mulaw
400 	 * encodings, different playback and recording parameters, etc...), so
401 	 * set parameters to a random value. If the requested parameters are
402 	 * not supported by the device, then sio_setpar() will pick supported
403 	 * ones.
404 	 */
405 	sio_initpar(&par);
406 	par.rate = 48000;
407 	par.le = SIO_LE_NATIVE;
408 	par.sig = 1;
409 	par.bits = 16;
410 	par.appbufsz = 1200;
411 	if (!sio_setpar(&hdl->sio, &par))
412 		goto bad_close;
413 	return (struct sio_hdl *)hdl;
414  bad_close:
415 	while (close(fd) < 0 && errno == EINTR)
416 		; /* retry */
417  bad_free:
418 	free(hdl);
419 	return NULL;
420 }
421 
422 static void
423 sio_sun_close(struct sio_hdl *sh)
424 {
425 	struct sio_sun_hdl *hdl = (struct sio_sun_hdl *)sh;
426 
427 	while (close(hdl->fd) < 0 && errno == EINTR)
428 		; /* retry */
429 	free(hdl);
430 }
431 
432 static int
433 sio_sun_start(struct sio_hdl *sh)
434 {
435 	struct sio_sun_hdl *hdl = (struct sio_sun_hdl *)sh;
436 	struct audio_info aui;
437 
438 	hdl->obpf = hdl->sio.par.pchan * hdl->sio.par.bps;
439 	hdl->ibpf = hdl->sio.par.rchan * hdl->sio.par.bps;
440 	hdl->ibytes = 0;
441 	hdl->obytes = 0;
442 	hdl->ierr = 0;
443 	hdl->oerr = 0;
444 	hdl->idelta = 0;
445 	hdl->odelta = 0;
446 
447 	if (hdl->sio.mode & SIO_PLAY) {
448 		/*
449 		 * keep the device paused and let sio_sun_write() trigger the
450 		 * start later, to avoid buffer underruns
451 		 */
452 		hdl->filling = 1;
453 	} else {
454 		/*
455 		 * no play buffers to fill, start now!
456 		 */
457 		AUDIO_INITINFO(&aui);
458 		if (hdl->sio.mode & SIO_REC)
459 			aui.record.pause = 0;
460 		if (ioctl(hdl->fd, AUDIO_SETINFO, &aui) < 0) {
461 			DPERROR("sio_sun_start: setinfo");
462 			hdl->sio.eof = 1;
463 			return 0;
464 		}
465 		hdl->filling = 0;
466 		_sio_onmove_cb(&hdl->sio, 0);
467 	}
468 	return 1;
469 }
470 
471 static int
472 sio_sun_stop(struct sio_hdl *sh)
473 {
474 	struct sio_sun_hdl *hdl = (struct sio_sun_hdl *)sh;
475 	struct audio_info aui;
476 	int mode;
477 
478 	if (ioctl(hdl->fd, AUDIO_GETINFO, &aui) < 0) {
479 		DPERROR("sio_sun_stop: getinfo");
480 		hdl->sio.eof = 1;
481 		return 0;
482 	}
483 	mode = aui.mode;
484 
485 	/*
486 	 * there's no way to drain the device without blocking, so just
487 	 * stop it until the kernel driver get fixed
488 	 */
489 	AUDIO_INITINFO(&aui);
490 	aui.mode = 0;
491 	if (hdl->sio.mode & SIO_PLAY)
492 		aui.play.pause = 1;
493 	if (hdl->sio.mode & SIO_REC)
494 		aui.record.pause = 1;
495 	if (ioctl(hdl->fd, AUDIO_SETINFO, &aui) < 0) {
496 		DPERROR("sio_sun_stop: setinfo1");
497 		hdl->sio.eof = 1;
498 		return 0;
499 	}
500 	AUDIO_INITINFO(&aui);
501 	aui.mode = mode;
502 	if (ioctl(hdl->fd, AUDIO_SETINFO, &aui) < 0) {
503 		DPERROR("sio_sun_stop: setinfo2");
504 		hdl->sio.eof = 1;
505 		return 0;
506 	}
507 	return 1;
508 }
509 
510 static int
511 sio_sun_setpar(struct sio_hdl *sh, struct sio_par *par)
512 {
513 #define NRETRIES 8
514 	struct sio_sun_hdl *hdl = (struct sio_sun_hdl *)sh;
515 	struct audio_info aui;
516 	unsigned int i, infr, ibpf, onfr, obpf;
517 	unsigned int bufsz, round;
518 	unsigned int rate, req_rate, prec, enc;
519 
520 	/*
521 	 * try to set parameters until the device accepts
522 	 * a common encoding and rate for play and record
523 	 */
524 	rate = par->rate;
525 	prec = par->bits;
526 	sio_sun_enctoinfo(hdl, &enc, par);
527 	for (i = 0;; i++) {
528 		if (i == NRETRIES) {
529 			DPRINTF("sio_sun_setpar: couldn't set parameters\n");
530 			hdl->sio.eof = 1;
531 			return 0;
532 		}
533 		AUDIO_INITINFO(&aui);
534 		if (hdl->sio.mode & SIO_PLAY) {
535 			aui.play.sample_rate = rate;
536 			aui.play.precision = prec;
537 			aui.play.encoding = enc;
538 			aui.play.channels = par->pchan;
539 		}
540 		if (hdl->sio.mode & SIO_REC) {
541 			aui.record.sample_rate = rate;
542 			aui.record.precision = prec;
543 			aui.record.encoding = enc;
544 			aui.record.channels = par->rchan;
545 		}
546 		DPRINTFN(2, "sio_sun_setpar: %i: trying pars = %u/%u/%u\n",
547 		    i, rate, prec, enc);
548 		if (ioctl(hdl->fd, AUDIO_SETINFO, &aui) < 0 && errno != EINVAL) {
549 			DPERROR("sio_sun_setpar: setinfo(pars)");
550 			hdl->sio.eof = 1;
551 			return 0;
552 		}
553 		if (ioctl(hdl->fd, AUDIO_GETINFO, &aui) < 0) {
554 			DPERROR("sio_sun_setpar: getinfo(pars)");
555 			hdl->sio.eof = 1;
556 			return 0;
557 		}
558 		enc = (hdl->sio.mode & SIO_REC) ?
559 		    aui.record.encoding : aui.play.encoding;
560 		switch (enc) {
561 		case AUDIO_ENCODING_SLINEAR_LE:
562 		case AUDIO_ENCODING_SLINEAR_BE:
563 		case AUDIO_ENCODING_ULINEAR_LE:
564 		case AUDIO_ENCODING_ULINEAR_BE:
565 		case AUDIO_ENCODING_SLINEAR:
566 		case AUDIO_ENCODING_ULINEAR:
567 			break;
568 		default:
569 			DPRINTF("sio_sun_setpar: couldn't set linear encoding\n");
570 			hdl->sio.eof = 1;
571 			return 0;
572 		}
573 		if (hdl->sio.mode != (SIO_REC | SIO_PLAY))
574 			break;
575 		if (aui.play.sample_rate == aui.record.sample_rate &&
576 		    aui.play.precision == aui.record.precision &&
577 		    aui.play.encoding == aui.record.encoding)
578 			break;
579 		if (i < NRETRIES / 2) {
580 			rate = aui.play.sample_rate;
581 			prec = aui.play.precision;
582 			enc = aui.play.encoding;
583 		} else {
584 			rate = aui.record.sample_rate;
585 			prec = aui.record.precision;
586 			enc = aui.record.encoding;
587 		}
588 	}
589 
590 	/*
591 	 * If the rate that the hardware is using is different than
592 	 * the requested rate, scale buffer sizes so they will be the
593 	 * same time duration as what was requested.  This just gets
594 	 * the rates to use for scaling, that actual scaling is done
595 	 * later.
596 	 */
597 	rate = (hdl->sio.mode & SIO_REC) ? aui.record.sample_rate :
598 	    aui.play.sample_rate;
599 	req_rate = rate;
600 	if (par->rate && par->rate != ~0U)
601 		req_rate = par->rate;
602 
603 	/*
604 	 * if block size and buffer size are not both set then
605 	 * set the blocksize to half the buffer size
606 	 */
607 	bufsz = par->appbufsz;
608 	round = par->round;
609 	if (bufsz != ~0U) {
610 		bufsz = bufsz * rate / req_rate;
611 		if (round == ~0U)
612 			round = (bufsz + 1) / 2;
613 		else
614 			round = round * rate / req_rate;
615 	} else if (round != ~0U) {
616 		round = round * rate / req_rate;
617 		bufsz = round * 2;
618 	} else
619 		return 1;
620 
621 	/*
622 	 * get the play/record frame size in bytes
623 	 */
624 	if (ioctl(hdl->fd, AUDIO_GETINFO, &aui) < 0) {
625 		DPERROR("sio_sun_setpar: GETINFO");
626 		hdl->sio.eof = 1;
627 		return 0;
628 	}
629 	ibpf = (hdl->sio.mode & SIO_REC) ?
630 	    aui.record.channels * aui.record.bps : 1;
631 	obpf = (hdl->sio.mode & SIO_PLAY) ?
632 	    aui.play.channels * aui.play.bps : 1;
633 
634 	DPRINTFN(2, "sio_sun_setpar: bpf = (%u, %u)\n", ibpf, obpf);
635 
636 	/*
637 	 * try to set parameters until the device accepts
638 	 * a common block size for play and record
639 	 */
640 	for (i = 0; i < NRETRIES; i++) {
641 		AUDIO_INITINFO(&aui);
642 		aui.hiwat = (bufsz + round - 1) / round;
643 		aui.lowat = aui.hiwat;
644 		if (hdl->sio.mode & SIO_REC)
645 			aui.record.block_size = round * ibpf;
646 		if (hdl->sio.mode & SIO_PLAY)
647 			aui.play.block_size = round * obpf;
648 		if (ioctl(hdl->fd, AUDIO_SETINFO, &aui) < 0) {
649 			DPERROR("sio_sun_setpar2: SETINFO");
650 			hdl->sio.eof = 1;
651 			return 0;
652 		}
653 		if (ioctl(hdl->fd, AUDIO_GETINFO, &aui) < 0) {
654 			DPERROR("sio_sun_setpar2: GETINFO");
655 			hdl->sio.eof = 1;
656 			return 0;
657 		}
658 		infr = aui.record.block_size / ibpf;
659 		onfr = aui.play.block_size / obpf;
660 		DPRINTFN(2, "sio_sun_setpar: %i: trying round = %u -> (%u, %u)\n",
661 		    i, round, infr, onfr);
662 
663 		/*
664 		 * if half-duplex or both block sizes match, we're done
665 		 */
666 		if (hdl->sio.mode != (SIO_REC | SIO_PLAY) || infr == onfr) {
667 			DPRINTFN(2, "sio_sun_setpar: blocksize ok\n");
668 			return 1;
669 		}
670 
671 		/*
672 		 * half of the retries, retry with the smaller value,
673 		 * then with the larger returned value
674 		 */
675 		if (i < NRETRIES / 2)
676 			round = infr < onfr ? infr : onfr;
677 		else
678 			round = infr < onfr ? onfr : infr;
679 	}
680 	DPRINTFN(2, "sio_sun_setpar: couldn't find a working blocksize\n");
681 	hdl->sio.eof = 1;
682 	return 0;
683 #undef NRETRIES
684 }
685 
686 static int
687 sio_sun_getpar(struct sio_hdl *sh, struct sio_par *par)
688 {
689 	struct sio_sun_hdl *hdl = (struct sio_sun_hdl *)sh;
690 	struct audio_info aui;
691 
692 	if (ioctl(hdl->fd, AUDIO_GETINFO, &aui) < 0) {
693 		DPERROR("sio_sun_getpar: getinfo");
694 		hdl->sio.eof = 1;
695 		return 0;
696 	}
697 	if (hdl->sio.mode & SIO_PLAY) {
698 		par->rate = aui.play.sample_rate;
699 		if (!sio_sun_infotoenc(hdl, &aui.play, par))
700 			return 0;
701 	} else if (hdl->sio.mode & SIO_REC) {
702 		par->rate = aui.record.sample_rate;
703 		if (!sio_sun_infotoenc(hdl, &aui.record, par))
704 			return 0;
705 	} else
706 		return 0;
707 	par->pchan = (hdl->sio.mode & SIO_PLAY) ?
708 	    aui.play.channels : 0;
709 	par->rchan = (hdl->sio.mode & SIO_REC) ?
710 	    aui.record.channels : 0;
711 	par->round = (hdl->sio.mode & SIO_REC) ?
712 	    aui.record.block_size / (par->bps * par->rchan) :
713 	    aui.play.block_size / (par->bps * par->pchan);
714 	par->appbufsz = aui.hiwat * par->round;
715 	par->bufsz = par->appbufsz;
716 	return 1;
717 }
718 
719 static size_t
720 sio_sun_read(struct sio_hdl *sh, void *buf, size_t len)
721 {
722 	struct sio_sun_hdl *hdl = (struct sio_sun_hdl *)sh;
723 	ssize_t n;
724 
725 	while ((n = read(hdl->fd, buf, len)) < 0) {
726 		if (errno == EINTR)
727 			continue;
728 		if (errno != EAGAIN) {
729 			DPERROR("sio_sun_read: read");
730 			hdl->sio.eof = 1;
731 		}
732 		return 0;
733 	}
734 	if (n == 0) {
735 		DPRINTF("sio_sun_read: eof\n");
736 		hdl->sio.eof = 1;
737 		return 0;
738 	}
739 	return n;
740 }
741 
742 static size_t
743 sio_sun_autostart(struct sio_sun_hdl *hdl)
744 {
745 	struct audio_info aui;
746 	struct pollfd pfd;
747 
748 	pfd.fd = hdl->fd;
749 	pfd.events = POLLOUT;
750 	while (poll(&pfd, 1, 0) < 0) {
751 		if (errno == EINTR)
752 			continue;
753 		DPERROR("sio_sun_autostart: poll");
754 		hdl->sio.eof = 1;
755 		return 0;
756 	}
757 	if (!(pfd.revents & POLLOUT)) {
758 		hdl->filling = 0;
759 		AUDIO_INITINFO(&aui);
760 		if (hdl->sio.mode & SIO_PLAY)
761 			aui.play.pause = 0;
762 		if (hdl->sio.mode & SIO_REC)
763 			aui.record.pause = 0;
764 		if (ioctl(hdl->fd, AUDIO_SETINFO, &aui) < 0) {
765 			DPERROR("sio_sun_autostart: setinfo");
766 			hdl->sio.eof = 1;
767 			return 0;
768 		}
769 		_sio_onmove_cb(&hdl->sio, 0);
770 	}
771 	return 1;
772 }
773 
774 static size_t
775 sio_sun_write(struct sio_hdl *sh, const void *buf, size_t len)
776 {
777 	struct sio_sun_hdl *hdl = (struct sio_sun_hdl *)sh;
778 	const unsigned char *data = buf;
779 	ssize_t n, todo;
780 
781 	todo = len;
782 	while ((n = write(hdl->fd, data, todo)) < 0) {
783 		if (errno == EINTR)
784 			continue;
785 		if (errno != EAGAIN) {
786 			DPERROR("sio_sun_write: write");
787 			hdl->sio.eof = 1;
788 		}
789  		return 0;
790 	}
791 	if (hdl->filling) {
792 		if (!sio_sun_autostart(hdl))
793 			return 0;
794 	}
795 	return n;
796 }
797 
798 static int
799 sio_sun_nfds(struct sio_hdl *hdl)
800 {
801 	return 1;
802 }
803 
804 static int
805 sio_sun_pollfd(struct sio_hdl *sh, struct pollfd *pfd, int events)
806 {
807 	struct sio_sun_hdl *hdl = (struct sio_sun_hdl *)sh;
808 
809 	pfd->fd = hdl->fd;
810 	pfd->events = events;
811 	return 1;
812 }
813 
814 int
815 sio_sun_revents(struct sio_hdl *sh, struct pollfd *pfd)
816 {
817 	struct sio_sun_hdl *hdl = (struct sio_sun_hdl *)sh;
818 	struct audio_offset ao;
819 	int xrun, dierr = 0, doerr = 0, offset, delta;
820 	int revents = pfd->revents;
821 
822 	if (!hdl->sio.started)
823 		return pfd->revents;
824 	if (hdl->sio.mode & SIO_PLAY) {
825 		if (ioctl(hdl->fd, AUDIO_GETOOFFS, &ao) < 0) {
826 			DPERROR("sio_sun_revents: GETOOFFS");
827 			hdl->sio.eof = 1;
828 			return POLLHUP;
829 		}
830 		delta = (ao.samples - hdl->obytes) / hdl->obpf;
831 		hdl->obytes = ao.samples;
832 		hdl->odelta += delta;
833 		if (!(hdl->sio.mode & SIO_REC))
834 			hdl->idelta += delta;
835 	}
836 	if (hdl->sio.mode & SIO_REC) {
837 		if (ioctl(hdl->fd, AUDIO_GETIOFFS, &ao) < 0) {
838 			DPERROR("sio_sun_revents: GETIOFFS");
839 			hdl->sio.eof = 1;
840 			return POLLHUP;
841 		}
842 		delta = (ao.samples - hdl->ibytes) / hdl->ibpf;
843 		hdl->ibytes = ao.samples;
844 		hdl->idelta += delta;
845 		if (!(hdl->sio.mode & SIO_PLAY))
846 			hdl->odelta += delta;
847 	}
848 	if (hdl->sio.mode & SIO_PLAY) {
849 		if (ioctl(hdl->fd, AUDIO_PERROR, &xrun) < 0) {
850 			DPERROR("sio_sun_revents: PERROR");
851 			hdl->sio.eof = 1;
852 			return POLLHUP;
853 		}
854 		doerr = xrun - hdl->oerr;
855 		hdl->oerr = xrun;
856 		if (!(hdl->sio.mode & SIO_REC))
857 			dierr = doerr;
858 		if (doerr > 0)
859 			DPRINTFN(2, "play xrun %d\n", doerr);
860 	}
861 	if (hdl->sio.mode & SIO_REC) {
862 		if (ioctl(hdl->fd, AUDIO_RERROR, &xrun) < 0) {
863 			DPERROR("sio_sun_revents: RERROR");
864 			hdl->sio.eof = 1;
865 			return POLLHUP;
866 		}
867 		dierr = xrun - hdl->ierr;
868 		hdl->ierr = xrun;
869 		if (!(hdl->sio.mode & SIO_PLAY))
870 			doerr = dierr;
871 		if (dierr > 0)
872 			DPRINTFN(2, "rec xrun %d\n", dierr);
873 	}
874 
875 	/*
876 	 * GET{I,O}OFFS report positions including xruns,
877 	 * so we have to substract to get the real position
878 	 */
879 	hdl->idelta -= dierr;
880 	hdl->odelta -= doerr;
881 
882 	offset = doerr - dierr;
883 	if (offset > 0) {
884 		hdl->sio.rdrop += offset * hdl->ibpf;
885 		hdl->idelta -= offset;
886 		DPRINTFN(2, "will drop %d and pause %d\n", offset, doerr);
887 	} else if (offset < 0) {
888 		hdl->sio.wsil += -offset * hdl->obpf;
889 		hdl->odelta -= offset;
890 		DPRINTFN(2, "will insert %d and pause %d\n", -offset, dierr);
891 	}
892 
893 	delta = (hdl->idelta > hdl->odelta) ? hdl->idelta : hdl->odelta;
894 	if (delta > 0) {
895 		_sio_onmove_cb(&hdl->sio, delta);
896 		hdl->idelta -= delta;
897 		hdl->odelta -= delta;
898 	}
899 
900 	if (hdl->filling)
901 		revents |= POLLOUT; /* XXX: is this necessary ? */
902 	return revents;
903 }
904