xref: /freebsd/sys/dev/sound/pcm/sound.c (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2005-2009 Ariff Abdullah <ariff@FreeBSD.org>
5  * Portions Copyright (c) Ryan Beasley <ryan.beasley@gmail.com> - GSoC 2006
6  * Copyright (c) 1999 Cameron Grant <cg@FreeBSD.org>
7  * Copyright (c) 1997 Luigi Rizzo
8  * All rights reserved.
9  * Copyright (c) 2024 The FreeBSD Foundation
10  *
11  * Portions of this software were developed by Christos Margiolis
12  * <christos@FreeBSD.org> under sponsorship from the FreeBSD Foundation.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #ifdef HAVE_KERNEL_OPTION_HEADERS
37 #include "opt_snd.h"
38 #endif
39 
40 #include <dev/sound/pcm/sound.h>
41 #include <dev/sound/pcm/ac97.h>
42 #include <dev/sound/pcm/vchan.h>
43 #include <dev/sound/pcm/dsp.h>
44 #include <sys/limits.h>
45 #include <sys/sysctl.h>
46 
47 #include "feeder_if.h"
48 
49 devclass_t pcm_devclass;
50 
51 int snd_unit = -1;
52 
53 static int snd_unit_auto = -1;
54 SYSCTL_INT(_hw_snd, OID_AUTO, default_auto, CTLFLAG_RWTUN,
55     &snd_unit_auto, 0, "assign default unit to a newly attached device");
56 
57 SYSCTL_NODE(_hw, OID_AUTO, snd, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
58     "Sound driver");
59 
60 static void pcm_sysinit(device_t);
61 
62 /**
63  * @brief Unit number allocator for syncgroup IDs
64  */
65 struct unrhdr *pcmsg_unrhdr = NULL;
66 
67 void *
68 snd_mtxcreate(const char *desc, const char *type)
69 {
70 	struct mtx *m;
71 
72 	m = malloc(sizeof(*m), M_DEVBUF, M_WAITOK | M_ZERO);
73 	mtx_init(m, desc, type, MTX_DEF);
74 	return m;
75 }
76 
77 void
78 snd_mtxfree(void *m)
79 {
80 	struct mtx *mtx = m;
81 
82 	mtx_destroy(mtx);
83 	free(mtx, M_DEVBUF);
84 }
85 
86 void
87 snd_mtxassert(void *m)
88 {
89 #ifdef INVARIANTS
90 	struct mtx *mtx = m;
91 
92 	mtx_assert(mtx, MA_OWNED);
93 #endif
94 }
95 
96 int
97 snd_setup_intr(device_t dev, struct resource *res, int flags, driver_intr_t hand, void *param, void **cookiep)
98 {
99 	struct snddev_info *d;
100 
101 	flags &= INTR_MPSAFE;
102 	flags |= INTR_TYPE_AV;
103 	d = device_get_softc(dev);
104 	if (d != NULL && (flags & INTR_MPSAFE))
105 		d->flags |= SD_F_MPSAFE;
106 
107 	return bus_setup_intr(dev, res, flags, NULL, hand, param, cookiep);
108 }
109 
110 int
111 pcm_chnalloc(struct snddev_info *d, struct pcm_channel **ch, int direction,
112     pid_t pid, char *comm)
113 {
114 	struct pcm_channel *c;
115 	int err, vchancount;
116 	bool retry;
117 
118 	KASSERT(d != NULL && ch != NULL &&
119 	    (direction == PCMDIR_PLAY || direction == PCMDIR_REC),
120 	    ("%s(): invalid d=%p ch=%p direction=%d pid=%d",
121 	    __func__, d, ch, direction, pid));
122 	PCM_BUSYASSERT(d);
123 
124 	*ch = NULL;
125 	vchancount = (direction == PCMDIR_PLAY) ? d->pvchancount :
126 	    d->rvchancount;
127 	retry = false;
128 
129 retry_chnalloc:
130 	/* Scan for a free channel. */
131 	CHN_FOREACH(c, d, channels.pcm) {
132 		CHN_LOCK(c);
133 		if (c->direction != direction) {
134 			CHN_UNLOCK(c);
135 			continue;
136 		}
137 		if (!(c->flags & CHN_F_BUSY)) {
138 			c->flags |= CHN_F_BUSY;
139 			c->pid = pid;
140 			strlcpy(c->comm, (comm != NULL) ? comm :
141 			    CHN_COMM_UNKNOWN, sizeof(c->comm));
142 			*ch = c;
143 
144 			return (0);
145 		}
146 		CHN_UNLOCK(c);
147 	}
148 	/* Maybe next time... */
149 	if (retry)
150 		return (EBUSY);
151 
152 	/* No channel available. We also cannot create more VCHANs. */
153 	if (!(vchancount > 0 && vchancount < snd_maxautovchans))
154 		return (ENOTSUP);
155 
156 	/* Increase the VCHAN count and try to get the new channel. */
157 	err = vchan_setnew(d, direction, vchancount + 1);
158 	if (err == 0) {
159 		retry = true;
160 		goto retry_chnalloc;
161 	}
162 
163 	return (err);
164 }
165 
166 static int
167 sysctl_hw_snd_default_unit(SYSCTL_HANDLER_ARGS)
168 {
169 	struct snddev_info *d;
170 	int error, unit;
171 
172 	unit = snd_unit;
173 	error = sysctl_handle_int(oidp, &unit, 0, req);
174 	if (error == 0 && req->newptr != NULL) {
175 		d = devclass_get_softc(pcm_devclass, unit);
176 		if (!PCM_REGISTERED(d) || CHN_EMPTY(d, channels.pcm))
177 			return EINVAL;
178 		snd_unit = unit;
179 		snd_unit_auto = 0;
180 	}
181 	return (error);
182 }
183 /* XXX: do we need a way to let the user change the default unit? */
184 SYSCTL_PROC(_hw_snd, OID_AUTO, default_unit,
185     CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_ANYBODY | CTLFLAG_NEEDGIANT, 0,
186     sizeof(int), sysctl_hw_snd_default_unit, "I",
187     "default sound device");
188 
189 int
190 pcm_addchan(device_t dev, int dir, kobj_class_t cls, void *devinfo)
191 {
192 	struct snddev_info *d = device_get_softc(dev);
193 	struct pcm_channel *ch;
194 
195 	PCM_BUSYASSERT(d);
196 
197 	PCM_LOCK(d);
198 	ch = chn_init(d, NULL, cls, dir, devinfo);
199 	if (!ch) {
200 		device_printf(d->dev, "chn_init(%s, %d, %p) failed\n",
201 		    cls->name, dir, devinfo);
202 		PCM_UNLOCK(d);
203 		return (ENODEV);
204 	}
205 	PCM_UNLOCK(d);
206 
207 	return (0);
208 }
209 
210 static void
211 pcm_killchans(struct snddev_info *d)
212 {
213 	struct pcm_channel *ch;
214 	bool again;
215 
216 	PCM_BUSYASSERT(d);
217 	KASSERT(!PCM_REGISTERED(d), ("%s(): still registered\n", __func__));
218 
219 	for (;;) {
220 		again = false;
221 		/* Make sure all channels are stopped. */
222 		CHN_FOREACH(ch, d, channels.pcm) {
223 			CHN_LOCK(ch);
224 			if (ch->inprog == 0 && ch->sleeping == 0 &&
225 			    CHN_STOPPED(ch)) {
226 				CHN_UNLOCK(ch);
227 				continue;
228 			}
229 			chn_shutdown(ch);
230 			if (ch->direction == PCMDIR_PLAY)
231 				chn_flush(ch);
232 			else
233 				chn_abort(ch);
234 			CHN_UNLOCK(ch);
235 			again = true;
236 		}
237 		/*
238 		 * Some channels are still active. Sleep for a bit and try
239 		 * again.
240 		 */
241 		if (again)
242 			pause_sbt("pcmkillchans", mstosbt(5), 0, 0);
243 		else
244 			break;
245 	}
246 
247 	/* All channels are finally dead. */
248 	while (!CHN_EMPTY(d, channels.pcm)) {
249 		ch = CHN_FIRST(d, channels.pcm);
250 		chn_kill(ch);
251 	}
252 
253 	if (d->p_unr != NULL)
254 		delete_unrhdr(d->p_unr);
255 	if (d->vp_unr != NULL)
256 		delete_unrhdr(d->vp_unr);
257 	if (d->r_unr != NULL)
258 		delete_unrhdr(d->r_unr);
259 	if (d->vr_unr != NULL)
260 		delete_unrhdr(d->vr_unr);
261 }
262 
263 static int
264 pcm_best_unit(int old)
265 {
266 	struct snddev_info *d;
267 	int i, best, bestprio, prio;
268 
269 	best = -1;
270 	bestprio = -100;
271 	for (i = 0; pcm_devclass != NULL &&
272 	    i < devclass_get_maxunit(pcm_devclass); i++) {
273 		d = devclass_get_softc(pcm_devclass, i);
274 		if (!PCM_REGISTERED(d))
275 			continue;
276 		prio = 0;
277 		if (d->playcount == 0)
278 			prio -= 10;
279 		if (d->reccount == 0)
280 			prio -= 2;
281 		if (prio > bestprio || (prio == bestprio && i == old)) {
282 			best = i;
283 			bestprio = prio;
284 		}
285 	}
286 	return (best);
287 }
288 
289 uint32_t
290 pcm_getflags(device_t dev)
291 {
292 	struct snddev_info *d = device_get_softc(dev);
293 
294 	return d->flags;
295 }
296 
297 void
298 pcm_setflags(device_t dev, uint32_t val)
299 {
300 	struct snddev_info *d = device_get_softc(dev);
301 
302 	d->flags = val;
303 }
304 
305 void *
306 pcm_getdevinfo(device_t dev)
307 {
308 	struct snddev_info *d = device_get_softc(dev);
309 
310 	return d->devinfo;
311 }
312 
313 unsigned int
314 pcm_getbuffersize(device_t dev, unsigned int minbufsz, unsigned int deflt, unsigned int maxbufsz)
315 {
316 	struct snddev_info *d = device_get_softc(dev);
317 	int sz, x;
318 
319 	sz = 0;
320 	if (resource_int_value(device_get_name(dev), device_get_unit(dev), "buffersize", &sz) == 0) {
321 		x = sz;
322 		RANGE(sz, minbufsz, maxbufsz);
323 		if (x != sz)
324 			device_printf(dev, "'buffersize=%d' hint is out of range (%d-%d), using %d\n", x, minbufsz, maxbufsz, sz);
325 		x = minbufsz;
326 		while (x < sz)
327 			x <<= 1;
328 		if (x > sz)
329 			x >>= 1;
330 		if (x != sz) {
331 			device_printf(dev, "'buffersize=%d' hint is not a power of 2, using %d\n", sz, x);
332 			sz = x;
333 		}
334 	} else {
335 		sz = deflt;
336 	}
337 
338 	d->bufsz = sz;
339 
340 	return sz;
341 }
342 
343 static int
344 sysctl_dev_pcm_bitperfect(SYSCTL_HANDLER_ARGS)
345 {
346 	struct snddev_info *d;
347 	int err, val;
348 
349 	d = oidp->oid_arg1;
350 	if (!PCM_REGISTERED(d))
351 		return (ENODEV);
352 
353 	PCM_LOCK(d);
354 	PCM_WAIT(d);
355 	val = (d->flags & SD_F_BITPERFECT) ? 1 : 0;
356 	PCM_ACQUIRE(d);
357 	PCM_UNLOCK(d);
358 
359 	err = sysctl_handle_int(oidp, &val, 0, req);
360 
361 	if (err == 0 && req->newptr != NULL) {
362 		if (!(val == 0 || val == 1)) {
363 			PCM_RELEASE_QUICK(d);
364 			return (EINVAL);
365 		}
366 
367 		PCM_LOCK(d);
368 
369 		d->flags &= ~SD_F_BITPERFECT;
370 		d->flags |= (val != 0) ? SD_F_BITPERFECT : 0;
371 
372 		PCM_RELEASE(d);
373 		PCM_UNLOCK(d);
374 	} else
375 		PCM_RELEASE_QUICK(d);
376 
377 	return (err);
378 }
379 
380 static u_int8_t
381 pcm_mode_init(struct snddev_info *d)
382 {
383 	u_int8_t mode = 0;
384 
385 	if (d->playcount > 0)
386 		mode |= PCM_MODE_PLAY;
387 	if (d->reccount > 0)
388 		mode |= PCM_MODE_REC;
389 	if (d->mixer_dev != NULL)
390 		mode |= PCM_MODE_MIXER;
391 
392 	return (mode);
393 }
394 
395 static void
396 pcm_sysinit(device_t dev)
397 {
398   	struct snddev_info *d = device_get_softc(dev);
399 	u_int8_t mode;
400 
401 	mode = pcm_mode_init(d);
402 
403 	sysctl_ctx_init(&d->play_sysctl_ctx);
404 	d->play_sysctl_tree = SYSCTL_ADD_NODE(&d->play_sysctl_ctx,
405 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO, "play",
406 	    CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "playback channels node");
407 	sysctl_ctx_init(&d->rec_sysctl_ctx);
408 	d->rec_sysctl_tree = SYSCTL_ADD_NODE(&d->rec_sysctl_ctx,
409 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO, "rec",
410 	    CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "recording channels node");
411 
412 	/* XXX: a user should be able to set this with a control tool, the
413 	   sysadmin then needs min+max sysctls for this */
414 	SYSCTL_ADD_UINT(device_get_sysctl_ctx(dev),
415 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
416             OID_AUTO, "buffersize", CTLFLAG_RD, &d->bufsz, 0, "allocated buffer size");
417 	SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
418 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO,
419 	    "bitperfect", CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, d,
420 	    sizeof(d), sysctl_dev_pcm_bitperfect, "I",
421 	    "bit-perfect playback/recording (0=disable, 1=enable)");
422 	SYSCTL_ADD_UINT(device_get_sysctl_ctx(dev),
423 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
424 	    OID_AUTO, "mode", CTLFLAG_RD, NULL, mode,
425 	    "mode (1=mixer, 2=play, 4=rec. The values are OR'ed if more than "
426 	    "one mode is supported)");
427 	if (d->flags & SD_F_AUTOVCHAN)
428 		vchan_initsys(dev);
429 	if (d->flags & SD_F_EQ)
430 		feeder_eq_initsys(dev);
431 }
432 
433 /*
434  * Basic initialization so that drivers can use pcm_addchan() before
435  * pcm_register().
436  */
437 void
438 pcm_init(device_t dev, void *devinfo)
439 {
440 	struct snddev_info *d;
441 	int i;
442 
443 	d = device_get_softc(dev);
444 	d->dev = dev;
445 	d->lock = snd_mtxcreate(device_get_nameunit(dev), "sound cdev");
446 	cv_init(&d->cv, device_get_nameunit(dev));
447 	PCM_ACQUIRE_QUICK(d);
448 
449 	i = 0;
450 	if (resource_int_value(device_get_name(dev), device_get_unit(dev),
451 	    "vpc", &i) != 0 || i != 0)
452 		d->flags |= SD_F_VPC;
453 
454 	if (resource_int_value(device_get_name(dev), device_get_unit(dev),
455 	    "bitperfect", &i) == 0 && i != 0)
456 		d->flags |= SD_F_BITPERFECT;
457 
458 	d->devinfo = devinfo;
459 	d->reccount = 0;
460 	d->playcount = 0;
461 	d->pvchancount = 0;
462 	d->rvchancount = 0;
463 	d->pvchanrate = 0;
464 	d->pvchanformat = 0;
465 	d->rvchanrate = 0;
466 	d->rvchanformat = 0;
467 	d->p_unr = new_unrhdr(0, INT_MAX, NULL);
468 	d->vp_unr = new_unrhdr(0, INT_MAX, NULL);
469 	d->r_unr = new_unrhdr(0, INT_MAX, NULL);
470 	d->vr_unr = new_unrhdr(0, INT_MAX, NULL);
471 
472 	CHN_INIT(d, channels.pcm);
473 	CHN_INIT(d, channels.pcm.busy);
474 	CHN_INIT(d, channels.pcm.opened);
475 }
476 
477 int
478 pcm_register(device_t dev, char *str)
479 {
480 	struct snddev_info *d = device_get_softc(dev);
481 
482 	/* should only be called once */
483 	if (d->flags & SD_F_REGISTERED)
484 		return (EINVAL);
485 
486 	PCM_BUSYASSERT(d);
487 
488 	if (d->playcount == 0 || d->reccount == 0)
489 		d->flags |= SD_F_SIMPLEX;
490 
491 	if (d->playcount > 0 || d->reccount > 0)
492 		d->flags |= SD_F_AUTOVCHAN;
493 
494 	vchan_setmaxauto(d, snd_maxautovchans);
495 
496 	strlcpy(d->status, str, SND_STATUSLEN);
497 	sndstat_register(dev, d->status);
498 
499 	PCM_LOCK(d);
500 
501 	/* Done, we're ready.. */
502 	d->flags |= SD_F_REGISTERED;
503 
504 	PCM_RELEASE(d);
505 
506 	PCM_UNLOCK(d);
507 
508 	/*
509 	 * Create all sysctls once SD_F_REGISTERED is set else
510 	 * tunable sysctls won't work:
511 	 */
512 	pcm_sysinit(dev);
513 
514 	if (snd_unit_auto < 0)
515 		snd_unit_auto = (snd_unit < 0) ? 1 : 0;
516 	if (snd_unit < 0 || snd_unit_auto > 1)
517 		snd_unit = device_get_unit(dev);
518 	else if (snd_unit_auto == 1)
519 		snd_unit = pcm_best_unit(snd_unit);
520 
521 	return (dsp_make_dev(dev));
522 }
523 
524 int
525 pcm_unregister(device_t dev)
526 {
527 	struct snddev_info *d;
528 
529 	d = device_get_softc(dev);
530 
531 	if (!PCM_ALIVE(d)) {
532 		device_printf(dev, "unregister: device not configured\n");
533 		return (0);
534 	}
535 
536 	PCM_LOCK(d);
537 	PCM_WAIT(d);
538 
539 	d->flags &= ~SD_F_REGISTERED;
540 
541 	PCM_ACQUIRE(d);
542 	PCM_UNLOCK(d);
543 
544 	pcm_killchans(d);
545 
546 	PCM_RELEASE_QUICK(d);
547 
548 	if (d->play_sysctl_tree != NULL) {
549 		sysctl_ctx_free(&d->play_sysctl_ctx);
550 		d->play_sysctl_tree = NULL;
551 	}
552 	if (d->rec_sysctl_tree != NULL) {
553 		sysctl_ctx_free(&d->rec_sysctl_ctx);
554 		d->rec_sysctl_tree = NULL;
555 	}
556 
557 	sndstat_unregister(dev);
558 	mixer_uninit(dev);
559 	dsp_destroy_dev(dev);
560 
561 	cv_destroy(&d->cv);
562 	snd_mtxfree(d->lock);
563 
564 	if (snd_unit == device_get_unit(dev)) {
565 		snd_unit = pcm_best_unit(-1);
566 		if (snd_unit_auto == 0)
567 			snd_unit_auto = 1;
568 	}
569 
570 	return (0);
571 }
572 
573 /************************************************************************/
574 
575 /**
576  * @brief	Handle OSSv4 SNDCTL_SYSINFO ioctl.
577  *
578  * @param si	Pointer to oss_sysinfo struct where information about the
579  * 		sound subsystem will be written/copied.
580  *
581  * This routine returns information about the sound system, such as the
582  * current OSS version, number of audio, MIDI, and mixer drivers, etc.
583  * Also includes a bitmask showing which of the above types of devices
584  * are open (busy).
585  *
586  * @note
587  * Calling threads must not hold any snddev_info or pcm_channel locks.
588  *
589  * @author	Ryan Beasley <ryanb@FreeBSD.org>
590  */
591 void
592 sound_oss_sysinfo(oss_sysinfo *si)
593 {
594 	static char si_product[] = "FreeBSD native OSS ABI";
595 	static char si_version[] = __XSTRING(__FreeBSD_version);
596 	static char si_license[] = "BSD";
597 	static int intnbits = sizeof(int) * 8;	/* Better suited as macro?
598 						   Must pester a C guru. */
599 
600 	struct snddev_info *d;
601 	struct pcm_channel *c;
602 	int j;
603 	size_t i;
604 
605 	strlcpy(si->product, si_product, sizeof(si->product));
606 	strlcpy(si->version, si_version, sizeof(si->version));
607 	si->versionnum = SOUND_VERSION;
608 	strlcpy(si->license, si_license, sizeof(si->license));
609 
610 	/*
611 	 * Iterate over PCM devices and their channels, gathering up data
612 	 * for the numaudioengines and openedaudio fields.
613 	 */
614 	si->numaudioengines = 0;
615 	bzero((void *)&si->openedaudio, sizeof(si->openedaudio));
616 
617 	j = 0;
618 
619 	for (i = 0; pcm_devclass != NULL &&
620 	    i < devclass_get_maxunit(pcm_devclass); i++) {
621 		d = devclass_get_softc(pcm_devclass, i);
622 		if (!PCM_REGISTERED(d))
623 			continue;
624 
625 		/* XXX Need Giant magic entry ??? */
626 
627 		/* See note in function's docblock */
628 		PCM_UNLOCKASSERT(d);
629 		PCM_LOCK(d);
630 
631 		si->numaudioengines += PCM_CHANCOUNT(d);
632 
633 		CHN_FOREACH(c, d, channels.pcm) {
634 			CHN_UNLOCKASSERT(c);
635 			CHN_LOCK(c);
636 			if (c->flags & CHN_F_BUSY)
637 				si->openedaudio[j / intnbits] |=
638 				    (1 << (j % intnbits));
639 			CHN_UNLOCK(c);
640 			j++;
641 		}
642 
643 		PCM_UNLOCK(d);
644 	}
645 
646 	si->numsynths = 0;	/* OSSv4 docs:  this field is obsolete */
647 	/**
648 	 * @todo	Collect num{midis,timers}.
649 	 *
650 	 * Need access to sound/midi/midi.c::midistat_lock in order
651 	 * to safely touch midi_devices and get a head count of, well,
652 	 * MIDI devices.  midistat_lock is a global static (i.e., local to
653 	 * midi.c), but midi_devices is a regular global; should the mutex
654 	 * be publicized, or is there another way to get this information?
655 	 *
656 	 * NB:	MIDI/sequencer stuff is currently on hold.
657 	 */
658 	si->nummidis = 0;
659 	si->numtimers = 0;
660 	/*
661 	 * Set this to the maximum unit number so that applications will not
662 	 * break if they try to loop through all mixers and some of them are
663 	 * not available.
664 	 */
665 	si->nummixers = devclass_get_maxunit(pcm_devclass);
666 	si->numcards = devclass_get_maxunit(pcm_devclass);
667 	si->numaudios = devclass_get_maxunit(pcm_devclass);
668 		/* OSSv4 docs:	Intended only for test apps; API doesn't
669 		   really have much of a concept of cards.  Shouldn't be
670 		   used by applications. */
671 
672 	/**
673 	 * @todo	Fill in "busy devices" fields.
674 	 *
675 	 *  si->openedmidi = " MIDI devices
676 	 */
677 	bzero((void *)&si->openedmidi, sizeof(si->openedmidi));
678 
679 	/*
680 	 * Si->filler is a reserved array, but according to docs each
681 	 * element should be set to -1.
682 	 */
683 	for (i = 0; i < nitems(si->filler); i++)
684 		si->filler[i] = -1;
685 }
686 
687 int
688 sound_oss_card_info(oss_card_info *si)
689 {
690 	struct snddev_info *d;
691 	int i;
692 
693 	for (i = 0; pcm_devclass != NULL &&
694 	    i < devclass_get_maxunit(pcm_devclass); i++) {
695 		d = devclass_get_softc(pcm_devclass, i);
696 		if (i != si->card)
697 			continue;
698 
699 		if (!PCM_REGISTERED(d)) {
700 			snprintf(si->shortname, sizeof(si->shortname),
701 			    "pcm%d (n/a)", i);
702 			strlcpy(si->longname, "Device unavailable",
703 			    sizeof(si->longname));
704 			si->hw_info[0] = '\0';
705 			si->intr_count = si->ack_count = 0;
706 		} else {
707 			PCM_UNLOCKASSERT(d);
708 			PCM_LOCK(d);
709 
710 			strlcpy(si->shortname, device_get_nameunit(d->dev),
711 			    sizeof(si->shortname));
712 			strlcpy(si->longname, device_get_desc(d->dev),
713 			    sizeof(si->longname));
714 			strlcpy(si->hw_info, d->status, sizeof(si->hw_info));
715 			si->intr_count = si->ack_count = 0;
716 
717 			PCM_UNLOCK(d);
718 		}
719 
720 		return (0);
721 	}
722 	return (ENXIO);
723 }
724 
725 /************************************************************************/
726 
727 static void
728 sound_global_init(void)
729 {
730 	if (snd_verbose < 0 || snd_verbose > 4)
731 		snd_verbose = 1;
732 
733 	if (snd_unit < 0)
734 		snd_unit = -1;
735 
736 	if (snd_maxautovchans < 0 ||
737 	    snd_maxautovchans > SND_MAXVCHANS)
738 		snd_maxautovchans = 0;
739 
740 	if (chn_latency < CHN_LATENCY_MIN ||
741 	    chn_latency > CHN_LATENCY_MAX)
742 		chn_latency = CHN_LATENCY_DEFAULT;
743 
744 	if (chn_latency_profile < CHN_LATENCY_PROFILE_MIN ||
745 	    chn_latency_profile > CHN_LATENCY_PROFILE_MAX)
746 		chn_latency_profile = CHN_LATENCY_PROFILE_DEFAULT;
747 
748 	if (feeder_rate_min < FEEDRATE_MIN ||
749 		    feeder_rate_max < FEEDRATE_MIN ||
750 		    feeder_rate_min > FEEDRATE_MAX ||
751 		    feeder_rate_max > FEEDRATE_MAX ||
752 		    !(feeder_rate_min < feeder_rate_max)) {
753 		feeder_rate_min = FEEDRATE_RATEMIN;
754 		feeder_rate_max = FEEDRATE_RATEMAX;
755 	}
756 
757 	if (feeder_rate_round < FEEDRATE_ROUNDHZ_MIN ||
758 		    feeder_rate_round > FEEDRATE_ROUNDHZ_MAX)
759 		feeder_rate_round = FEEDRATE_ROUNDHZ;
760 
761 	if (bootverbose)
762 		printf("%s: snd_unit=%d snd_maxautovchans=%d "
763 		    "latency=%d "
764 		    "feeder_rate_min=%d feeder_rate_max=%d "
765 		    "feeder_rate_round=%d\n",
766 		    __func__, snd_unit, snd_maxautovchans,
767 		    chn_latency,
768 		    feeder_rate_min, feeder_rate_max,
769 		    feeder_rate_round);
770 }
771 
772 static int
773 sound_modevent(module_t mod, int type, void *data)
774 {
775 	int ret;
776 
777 	ret = 0;
778 	switch (type) {
779 	case MOD_LOAD:
780 		pcm_devclass = devclass_create("pcm");
781 		pcmsg_unrhdr = new_unrhdr(1, INT_MAX, NULL);
782 		sound_global_init();
783 		break;
784 	case MOD_UNLOAD:
785 		if (pcmsg_unrhdr != NULL) {
786 			delete_unrhdr(pcmsg_unrhdr);
787 			pcmsg_unrhdr = NULL;
788 		}
789 		break;
790 	case MOD_SHUTDOWN:
791 		break;
792 	default:
793 		ret = ENOTSUP;
794 	}
795 
796 	return ret;
797 }
798 
799 DEV_MODULE(sound, sound_modevent, NULL);
800 MODULE_VERSION(sound, SOUND_MODVER);
801