xref: /freebsd/sys/dev/sound/pcm/mixer.c (revision a3d65cde7775818fb78afe935a4616a31f137c3d)
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  * All rights reserved.
8  * Copyright (c) 2026 The FreeBSD Foundation
9  *
10  * Portions of this software were developed by Christos Margiolis
11  * <christos@FreeBSD.org> under sponsorship from the FreeBSD Foundation.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #ifdef HAVE_KERNEL_OPTION_HEADERS
36 #include "opt_snd.h"
37 #endif
38 
39 #include <dev/sound/pcm/sound.h>
40 
41 #include "feeder_if.h"
42 #include "mixer_if.h"
43 
44 static u_int16_t snd_mixerdefaults[SOUND_MIXER_NRDEVICES] = {
45 	[SOUND_MIXER_VOLUME]	= 75,
46 	[SOUND_MIXER_BASS]	= 50,
47 	[SOUND_MIXER_TREBLE]	= 50,
48 	[SOUND_MIXER_SYNTH]	= 75,
49 	[SOUND_MIXER_PCM]	= 75,
50 	[SOUND_MIXER_SPEAKER]	= 75,
51 	[SOUND_MIXER_LINE]	= 75,
52 	[SOUND_MIXER_MIC] 	= 25,
53 	[SOUND_MIXER_CD]	= 75,
54 	[SOUND_MIXER_IGAIN]	= 0,
55 	[SOUND_MIXER_LINE1]	= 75,
56 	[SOUND_MIXER_VIDEO]	= 75,
57 	[SOUND_MIXER_RECLEV]	= 75,
58 	[SOUND_MIXER_OGAIN]	= 50,
59 	[SOUND_MIXER_MONITOR]	= 75,
60 };
61 
62 static char* snd_mixernames[SOUND_MIXER_NRDEVICES] = SOUND_DEVICE_NAMES;
63 
64 static d_open_t mixer_open;
65 static d_close_t mixer_close;
66 static d_ioctl_t mixer_ioctl;
67 
68 static struct cdevsw mixer_cdevsw = {
69 	.d_version =	D_VERSION,
70 	.d_open =	mixer_open,
71 	.d_close =	mixer_close,
72 	.d_ioctl =	mixer_ioctl,
73 	.d_name =	"mixer",
74 };
75 
76 static eventhandler_tag mixer_ehtag = NULL;
77 
78 static struct cdev *
79 mixer_get_devt(device_t dev)
80 {
81 	struct snddev_info *snddev;
82 
83 	snddev = device_get_softc(dev);
84 
85 	return snddev->mixer_dev;
86 }
87 
88 static int
89 mixer_lookup(char *devname)
90 {
91 	int i;
92 
93 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++)
94 		if (strncmp(devname, snd_mixernames[i],
95 		    strlen(snd_mixernames[i])) == 0)
96 			return i;
97 	return -1;
98 }
99 
100 #define MIXER_SET_UNLOCK(x, y)		do {				\
101 	if ((y) != 0)							\
102 		mtx_unlock(&(x)->lock);					\
103 } while (0)
104 
105 #define MIXER_SET_LOCK(x, y)		do {				\
106 	if ((y) != 0)							\
107 		mtx_lock(&(x)->lock);					\
108 } while (0)
109 
110 static int
111 mixer_set_softpcmvol(struct snd_mixer *m, struct snddev_info *d,
112     u_int left, u_int right)
113 {
114 	struct pcm_channel *c;
115 	int dropmtx, acquiremtx;
116 
117 	if (!PCM_REGISTERED(d))
118 		return (EINVAL);
119 
120 	if (mtx_owned(&m->lock))
121 		dropmtx = 1;
122 	else
123 		dropmtx = 0;
124 
125 	if (!(d->flags & SD_F_MPSAFE) || mtx_owned(&d->lock) != 0)
126 		acquiremtx = 0;
127 	else
128 		acquiremtx = 1;
129 
130 	/*
131 	 * Be careful here. If we're coming from cdev ioctl, it is OK to
132 	 * not doing locking AT ALL (except on individual channel) since
133 	 * we've been heavily guarded by pcm cv, or if we're still
134 	 * under Giant influence. Since we also have mix_* calls, we cannot
135 	 * assume such protection and just do the lock as usuall.
136 	 */
137 	MIXER_SET_UNLOCK(m, dropmtx);
138 	MIXER_SET_LOCK(d, acquiremtx);
139 
140 	CHN_FOREACH(c, d, channels.pcm.busy) {
141 		CHN_LOCK(c);
142 		if (c->direction == PCMDIR_PLAY &&
143 		    (c->feederflags & (1 << FEEDER_VOLUME)))
144 			chn_setvolume_multi(c, SND_VOL_C_MASTER, left, right,
145 			    (left + right) >> 1);
146 		CHN_UNLOCK(c);
147 	}
148 
149 	MIXER_SET_UNLOCK(d, acquiremtx);
150 	MIXER_SET_LOCK(m, dropmtx);
151 
152 	return (0);
153 }
154 
155 static int
156 mixer_set_eq(struct snd_mixer *m, struct snddev_info *d,
157     u_int dev, u_int level)
158 {
159 	struct pcm_channel *c;
160 	struct pcm_feeder *f;
161 	int tone, dropmtx, acquiremtx;
162 
163 	if (dev == SOUND_MIXER_TREBLE)
164 		tone = FEEDEQ_TREBLE;
165 	else if (dev == SOUND_MIXER_BASS)
166 		tone = FEEDEQ_BASS;
167 	else
168 		return (EINVAL);
169 
170 	if (!PCM_REGISTERED(d))
171 		return (EINVAL);
172 
173 	if (mtx_owned(&m->lock))
174 		dropmtx = 1;
175 	else
176 		dropmtx = 0;
177 
178 	if (!(d->flags & SD_F_MPSAFE) || mtx_owned(&d->lock) != 0)
179 		acquiremtx = 0;
180 	else
181 		acquiremtx = 1;
182 
183 	/*
184 	 * Be careful here. If we're coming from cdev ioctl, it is OK to
185 	 * not doing locking AT ALL (except on individual channel) since
186 	 * we've been heavily guarded by pcm cv, or if we're still
187 	 * under Giant influence. Since we also have mix_* calls, we cannot
188 	 * assume such protection and just do the lock as usuall.
189 	 */
190 	MIXER_SET_UNLOCK(m, dropmtx);
191 	MIXER_SET_LOCK(d, acquiremtx);
192 
193 	CHN_FOREACH(c, d, channels.pcm.busy) {
194 		CHN_LOCK(c);
195 		f = feeder_find(c, FEEDER_EQ);
196 		if (f != NULL)
197 			(void)FEEDER_SET(f, tone, level);
198 		CHN_UNLOCK(c);
199 	}
200 
201 	MIXER_SET_UNLOCK(d, acquiremtx);
202 	MIXER_SET_LOCK(m, dropmtx);
203 
204 	return (0);
205 }
206 
207 static int
208 mixer_set(struct snd_mixer *m, u_int dev, u_int32_t muted, u_int lev)
209 {
210 	struct snddev_info *d;
211 	u_int l, r, tl, tr;
212 	u_int32_t parent = SOUND_MIXER_NONE, child = 0;
213 	u_int32_t realdev;
214 	int i, dropmtx;
215 
216 	if (m == NULL || dev >= SOUND_MIXER_NRDEVICES ||
217 	    (0 == (m->devs & (1 << dev))))
218 		return (-1);
219 
220 	l = min((lev & 0x00ff), 100);
221 	r = min(((lev & 0xff00) >> 8), 100);
222 	realdev = m->realdev[dev];
223 
224 	d = device_get_softc(m->dev);
225 	if (d == NULL)
226 		return (-1);
227 
228 	/* It is safe to drop this mutex due to Giant. */
229 	if (!(d->flags & SD_F_MPSAFE) && mtx_owned(&m->lock) != 0)
230 		dropmtx = 1;
231 	else
232 		dropmtx = 0;
233 
234 	/* Allow the volume to be "changed" while muted. */
235 	if (muted & (1 << dev)) {
236 		m->level_muted[dev] = l | (r << 8);
237 		return (0);
238 	}
239 	MIXER_SET_UNLOCK(m, dropmtx);
240 
241 	/* TODO: recursive handling */
242 	parent = m->parent[dev];
243 	if (parent >= SOUND_MIXER_NRDEVICES)
244 		parent = SOUND_MIXER_NONE;
245 	if (parent == SOUND_MIXER_NONE)
246 		child = m->child[dev];
247 
248 	if (parent != SOUND_MIXER_NONE) {
249 		tl = (l * (m->level[parent] & 0x00ff)) / 100;
250 		tr = (r * ((m->level[parent] & 0xff00) >> 8)) / 100;
251 		if (dev == SOUND_MIXER_PCM && (d->flags & SD_F_SOFTPCMVOL))
252 			(void)mixer_set_softpcmvol(m, d, tl, tr);
253 		else if (realdev != SOUND_MIXER_NONE &&
254 		    MIXER_SET(m, realdev, tl, tr) < 0) {
255 			MIXER_SET_LOCK(m, dropmtx);
256 			return (-1);
257 		}
258 	} else if (child != 0) {
259 		for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
260 			if (!(child & (1 << i)) || m->parent[i] != dev)
261 				continue;
262 			realdev = m->realdev[i];
263 			tl = (l * (m->level[i] & 0x00ff)) / 100;
264 			tr = (r * ((m->level[i] & 0xff00) >> 8)) / 100;
265 			if (i == SOUND_MIXER_PCM &&
266 			    (d->flags & SD_F_SOFTPCMVOL))
267 				(void)mixer_set_softpcmvol(m, d, tl, tr);
268 			else if (realdev != SOUND_MIXER_NONE)
269 				MIXER_SET(m, realdev, tl, tr);
270 		}
271 		realdev = m->realdev[dev];
272 		if (realdev != SOUND_MIXER_NONE &&
273 		    MIXER_SET(m, realdev, l, r) < 0) {
274 			MIXER_SET_LOCK(m, dropmtx);
275 			return (-1);
276 		}
277 	} else {
278 		if (dev == SOUND_MIXER_PCM && (d->flags & SD_F_SOFTPCMVOL))
279 			(void)mixer_set_softpcmvol(m, d, l, r);
280 		else if ((dev == SOUND_MIXER_TREBLE ||
281 		    dev == SOUND_MIXER_BASS) && (d->flags & SD_F_EQ))
282 			(void)mixer_set_eq(m, d, dev, (l + r) >> 1);
283 		else if (realdev != SOUND_MIXER_NONE &&
284 		    MIXER_SET(m, realdev, l, r) < 0) {
285 			MIXER_SET_LOCK(m, dropmtx);
286 			return (-1);
287 		}
288 	}
289 
290 	MIXER_SET_LOCK(m, dropmtx);
291 
292 	m->level[dev] = l | (r << 8);
293 	m->modify_counter++;
294 
295 	return (0);
296 }
297 
298 static int
299 mixer_get(struct snd_mixer *mixer, int dev)
300 {
301 	if ((dev < SOUND_MIXER_NRDEVICES) && (mixer->devs & (1 << dev))) {
302 		if (mixer->mutedevs & (1 << dev))
303 			return (mixer->level_muted[dev]);
304 		else
305 			return (mixer->level[dev]);
306 	} else {
307 		return (-1);
308 	}
309 }
310 
311 void
312 mix_setmutedevs(struct snd_mixer *mixer, u_int32_t mutedevs)
313 {
314 	u_int32_t delta;
315 
316 	/* Filter out invalid values. */
317 	mutedevs &= mixer->devs;
318 	delta = (mixer->mutedevs ^ mutedevs) & mixer->devs;
319 	mixer->mutedevs = mutedevs;
320 
321 	for (int i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
322 		if (!(delta & (1 << i)))
323 			continue;
324 		if (mutedevs & (1 << i)) {
325 			mixer->level_muted[i] = mixer->level[i];
326 			mixer_set(mixer, i, 0, 0);
327 		} else {
328 			mixer_set(mixer, i, 0, mixer->level_muted[i]);
329 		}
330 	}
331 }
332 
333 static int
334 mixer_setrecsrc(struct snd_mixer *mixer, u_int32_t src)
335 {
336 	struct snddev_info *d;
337 	u_int32_t recsrc;
338 	int dropmtx;
339 
340 	d = device_get_softc(mixer->dev);
341 	if (d == NULL)
342 		return -1;
343 	if (!(d->flags & SD_F_MPSAFE) && mtx_owned(&mixer->lock) != 0)
344 		dropmtx = 1;
345 	else
346 		dropmtx = 0;
347 	src &= mixer->recdevs;
348 	if (src == 0)
349 		src = mixer->recdevs & SOUND_MASK_MIC;
350 	if (src == 0)
351 		src = mixer->recdevs & SOUND_MASK_MONITOR;
352 	if (src == 0)
353 		src = mixer->recdevs & SOUND_MASK_LINE;
354 	if (src == 0 && mixer->recdevs != 0)
355 		src = (1 << (ffs(mixer->recdevs) - 1));
356 	/* It is safe to drop this mutex due to Giant. */
357 	MIXER_SET_UNLOCK(mixer, dropmtx);
358 	recsrc = MIXER_SETRECSRC(mixer, src);
359 	MIXER_SET_LOCK(mixer, dropmtx);
360 
361 	mixer->recsrc = recsrc;
362 
363 	return 0;
364 }
365 
366 static int
367 mixer_getrecsrc(struct snd_mixer *mixer)
368 {
369 	return mixer->recsrc;
370 }
371 
372 /**
373  * @brief Retrieve the route number of the current recording device
374  *
375  * OSSv4 assigns routing numbers to recording devices, unlike the previous
376  * API which relied on a fixed table of device numbers and names.  This
377  * function returns the routing number of the device currently selected
378  * for recording.
379  *
380  * For now, this function is kind of a goofy compatibility stub atop the
381  * existing sound system.  (For example, in theory, the old sound system
382  * allows multiple recording devices to be specified via a bitmask.)
383  *
384  * @param m	mixer context container thing
385  *
386  * @retval 0		success
387  * @retval EIDRM	no recording device found (generally not possible)
388  * @todo Ask about error code
389  */
390 static int
391 mixer_get_recroute(struct snd_mixer *m, int *route)
392 {
393 	int i, cnt;
394 
395 	cnt = 0;
396 
397 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
398 		/** @todo can user set a multi-device mask? (== or &?) */
399 		if ((1 << i) == m->recsrc)
400 			break;
401 		if ((1 << i) & m->recdevs)
402 			++cnt;
403 	}
404 
405 	if (i == SOUND_MIXER_NRDEVICES)
406 		return EIDRM;
407 
408 	*route = cnt;
409 	return 0;
410 }
411 
412 /**
413  * @brief Select a device for recording
414  *
415  * This function sets a recording source based on a recording device's
416  * routing number.  Said number is translated to an old school recdev
417  * mask and passed over mixer_setrecsrc.
418  *
419  * @param m	mixer context container thing
420  *
421  * @retval 0		success(?)
422  * @retval EINVAL	User specified an invalid device number
423  * @retval otherwise	error from mixer_setrecsrc
424  */
425 static int
426 mixer_set_recroute(struct snd_mixer *m, int route)
427 {
428 	int i, cnt, ret;
429 
430 	ret = 0;
431 	cnt = 0;
432 
433 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
434 		if ((1 << i) & m->recdevs) {
435 			if (route == cnt)
436 				break;
437 			++cnt;
438 		}
439 	}
440 
441 	if (i == SOUND_MIXER_NRDEVICES)
442 		ret = EINVAL;
443 	else
444 		ret = mixer_setrecsrc(m, (1 << i));
445 
446 	return ret;
447 }
448 
449 void
450 mix_setdevs(struct snd_mixer *m, u_int32_t v)
451 {
452 	struct snddev_info *d;
453 	int i;
454 
455 	if (m == NULL)
456 		return;
457 
458 	d = device_get_softc(m->dev);
459 	if (d != NULL && (d->flags & SD_F_SOFTPCMVOL))
460 		v |= SOUND_MASK_PCM;
461 	v |= SOUND_MASK_TREBLE | SOUND_MASK_BASS;
462 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
463 		if (m->parent[i] < SOUND_MIXER_NRDEVICES)
464 			v |= 1 << m->parent[i];
465 		v |= m->child[i];
466 	}
467 	m->devs = v;
468 }
469 
470 /**
471  * @brief Record mask of available recording devices
472  *
473  * Calling functions are responsible for defining the mask of available
474  * recording devices.  This function records that value in a structure
475  * used by the rest of the mixer code.
476  *
477  * @param m	mixer device context container thing
478  * @param v	mask of recording devices
479  */
480 void
481 mix_setrecdevs(struct snd_mixer *m, u_int32_t v)
482 {
483 	m->recdevs = v;
484 }
485 
486 void
487 mix_setparentchild(struct snd_mixer *m, u_int32_t parent, u_int32_t childs)
488 {
489 	u_int32_t mask = 0;
490 	int i;
491 
492 	if (m == NULL || parent >= SOUND_MIXER_NRDEVICES)
493 		return;
494 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
495 		if (i == parent)
496 			continue;
497 		if (childs & (1 << i)) {
498 			mask |= 1 << i;
499 			if (m->parent[i] < SOUND_MIXER_NRDEVICES)
500 				m->child[m->parent[i]] &= ~(1 << i);
501 			m->parent[i] = parent;
502 			m->child[i] = 0;
503 		}
504 	}
505 	mask &= ~(1 << parent);
506 	m->child[parent] = mask;
507 }
508 
509 void
510 mix_setrealdev(struct snd_mixer *m, u_int32_t dev, u_int32_t realdev)
511 {
512 	if (m == NULL || dev >= SOUND_MIXER_NRDEVICES ||
513 	    !(realdev == SOUND_MIXER_NONE || realdev < SOUND_MIXER_NRDEVICES))
514 		return;
515 	m->realdev[dev] = realdev;
516 }
517 
518 u_int32_t
519 mix_getparent(struct snd_mixer *m, u_int32_t dev)
520 {
521 	if (m == NULL || dev >= SOUND_MIXER_NRDEVICES)
522 		return SOUND_MIXER_NONE;
523 	return m->parent[dev];
524 }
525 
526 u_int32_t
527 mix_getdevs(struct snd_mixer *m)
528 {
529 	return m->devs;
530 }
531 
532 u_int32_t
533 mix_getmutedevs(struct snd_mixer *m)
534 {
535 	return m->mutedevs;
536 }
537 
538 u_int32_t
539 mix_getrecdevs(struct snd_mixer *m)
540 {
541 	return m->recdevs;
542 }
543 
544 void *
545 mix_getdevinfo(struct snd_mixer *m)
546 {
547 	return m->devinfo;
548 }
549 
550 static struct snd_mixer *
551 mixer_obj_create(device_t dev, kobj_class_t cls, void *devinfo,
552     int type, const char *desc)
553 {
554 	struct snd_mixer *m;
555 	size_t i;
556 
557 	KASSERT(dev != NULL && cls != NULL && devinfo != NULL,
558 	    ("%s(): NULL data dev=%p cls=%p devinfo=%p",
559 	    __func__, dev, cls, devinfo));
560 	KASSERT(type == MIXER_TYPE_PRIMARY || type == MIXER_TYPE_SECONDARY,
561 	    ("invalid mixer type=%d", type));
562 
563 	m = (struct snd_mixer *)kobj_create(cls, M_DEVBUF, M_WAITOK | M_ZERO);
564 	snprintf(m->name, sizeof(m->name), "%s:mixer",
565 	    device_get_nameunit(dev));
566 	if (desc != NULL) {
567 		strlcat(m->name, ":", sizeof(m->name));
568 		strlcat(m->name, desc, sizeof(m->name));
569 	}
570 	mtx_init(&m->lock, m->name, (type == MIXER_TYPE_PRIMARY) ?
571 	    "primary pcm mixer" : "secondary pcm mixer", MTX_DEF);
572 	m->type = type;
573 	m->devinfo = devinfo;
574 	m->dev = dev;
575 	for (i = 0; i < nitems(m->parent); i++) {
576 		m->parent[i] = SOUND_MIXER_NONE;
577 		m->child[i] = 0;
578 		m->realdev[i] = i;
579 	}
580 
581 	if (MIXER_INIT(m)) {
582 		mtx_destroy(&m->lock);
583 		kobj_delete((kobj_t)m, M_DEVBUF);
584 		return (NULL);
585 	}
586 
587 	return (m);
588 }
589 
590 int
591 mixer_delete(struct snd_mixer *m)
592 {
593 	KASSERT(m != NULL, ("NULL snd_mixer"));
594 	KASSERT(m->type == MIXER_TYPE_SECONDARY,
595 	    ("%s(): illegal mixer type=%d", __func__, m->type));
596 
597 	/* mixer uninit can sleep --hps */
598 
599 	MIXER_UNINIT(m);
600 
601 	mtx_destroy(&m->lock);
602 	kobj_delete((kobj_t)m, M_DEVBUF);
603 
604 	return (0);
605 }
606 
607 struct snd_mixer *
608 mixer_create(device_t dev, kobj_class_t cls, void *devinfo, const char *desc)
609 {
610 	return (mixer_obj_create(dev, cls, devinfo, MIXER_TYPE_SECONDARY, desc));
611 }
612 
613 int
614 mixer_init(device_t dev, kobj_class_t cls, void *devinfo)
615 {
616 	struct snddev_info *snddev;
617 	struct snd_mixer *m;
618 	u_int16_t v;
619 	struct cdev *pdev;
620 	const char *name;
621 	int i, unit, val;
622 
623 	snddev = device_get_softc(dev);
624 	if (snddev == NULL)
625 		return (-1);
626 
627 	name = device_get_name(dev);
628 	unit = device_get_unit(dev);
629 
630 	m = mixer_obj_create(dev, cls, devinfo, MIXER_TYPE_PRIMARY, NULL);
631 	if (m == NULL)
632 		return (-1);
633 
634 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
635 		v = snd_mixerdefaults[i];
636 
637 		if (resource_int_value(name, unit, snd_mixernames[i],
638 		    &val) == 0) {
639 			if (val >= 0 && val <= 100) {
640 				v = (u_int16_t) val;
641 			}
642 		}
643 
644 		mixer_set(m, i, 0, v | (v << 8));
645 	}
646 
647 	mixer_setrecsrc(m, 0); /* Set default input. */
648 
649 	pdev = make_dev(&mixer_cdevsw, 0, UID_ROOT, GID_AUDIO, 0660, "mixer%d",
650 	    unit);
651 	pdev->si_drv1 = m;
652 	snddev->mixer_dev = pdev;
653 
654 	if (bootverbose) {
655 		for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
656 			if (!(m->devs & (1 << i)))
657 				continue;
658 			if (m->realdev[i] != i) {
659 				device_printf(dev, "Mixer \"%s\" -> \"%s\":",
660 				    snd_mixernames[i],
661 				    (m->realdev[i] < SOUND_MIXER_NRDEVICES) ?
662 				    snd_mixernames[m->realdev[i]] : "none");
663 			} else {
664 				device_printf(dev, "Mixer \"%s\":",
665 				    snd_mixernames[i]);
666 			}
667 			if (m->parent[i] < SOUND_MIXER_NRDEVICES)
668 				printf(" parent=\"%s\"",
669 				    snd_mixernames[m->parent[i]]);
670 			if (m->child[i] != 0)
671 				printf(" child=0x%08x", m->child[i]);
672 			printf("\n");
673 		}
674 		if (snddev->flags & SD_F_SOFTPCMVOL)
675 			device_printf(dev, "Soft PCM mixer ENABLED\n");
676 		device_printf(dev, "EQ Treble/Bass ENABLED\n");
677 	}
678 
679 	return (0);
680 }
681 
682 int
683 mixer_uninit(device_t dev)
684 {
685 	int i;
686 	struct snddev_info *d;
687 	struct snd_mixer *m;
688 	struct cdev *pdev;
689 
690 	d = device_get_softc(dev);
691 	pdev = mixer_get_devt(dev);
692 	if (d == NULL || pdev == NULL || pdev->si_drv1 == NULL)
693 		return EBADF;
694 
695 	m = pdev->si_drv1;
696 	KASSERT(m != NULL, ("NULL snd_mixer"));
697 	KASSERT(m->type == MIXER_TYPE_PRIMARY,
698 	    ("%s(): illegal mixer type=%d", __func__, m->type));
699 
700 	pdev->si_drv1 = NULL;
701 	destroy_dev(pdev);
702 
703 	mtx_lock(&m->lock);
704 
705 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++)
706 		mixer_set(m, i, 0, 0);
707 
708 	mixer_setrecsrc(m, SOUND_MASK_MIC);
709 
710 	mtx_unlock(&m->lock);
711 
712 	/* mixer uninit can sleep --hps */
713 
714 	MIXER_UNINIT(m);
715 
716 	mtx_destroy(&m->lock);
717 	kobj_delete((kobj_t)m, M_DEVBUF);
718 
719 	d->mixer_dev = NULL;
720 
721 	return 0;
722 }
723 
724 int
725 mixer_reinit(device_t dev)
726 {
727 	struct snd_mixer *m;
728 	struct cdev *pdev;
729 	int i;
730 
731 	pdev = mixer_get_devt(dev);
732 	m = pdev->si_drv1;
733 	mtx_lock(&m->lock);
734 
735 	i = MIXER_REINIT(m);
736 	if (i) {
737 		mtx_unlock(&m->lock);
738 		return i;
739 	}
740 
741 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
742 		if (m->mutedevs & (1 << i))
743 			mixer_set(m, i, 0, 0);
744 		else
745 			mixer_set(m, i, 0, m->level[i]);
746 	}
747 
748 	mixer_setrecsrc(m, m->recsrc);
749 	mtx_unlock(&m->lock);
750 
751 	return 0;
752 }
753 
754 static int
755 sysctl_hw_snd_hwvol_mixer(SYSCTL_HANDLER_ARGS)
756 {
757 	char devname[32];
758 	int error, dev;
759 	struct snd_mixer *m;
760 
761 	m = oidp->oid_arg1;
762 	mtx_lock(&m->lock);
763 	strlcpy(devname, snd_mixernames[m->hwvol_mixer], sizeof(devname));
764 	mtx_unlock(&m->lock);
765 	error = sysctl_handle_string(oidp, &devname[0], sizeof(devname), req);
766 	mtx_lock(&m->lock);
767 	if (error == 0 && req->newptr != NULL) {
768 		dev = mixer_lookup(devname);
769 		if (dev == -1) {
770 			mtx_unlock(&m->lock);
771 			return EINVAL;
772 		} else {
773 			m->hwvol_mixer = dev;
774 		}
775 	}
776 	mtx_unlock(&m->lock);
777 	return error;
778 }
779 
780 int
781 mixer_hwvol_init(device_t dev)
782 {
783 	struct snd_mixer *m;
784 	struct cdev *pdev;
785 
786 	pdev = mixer_get_devt(dev);
787 	m = pdev->si_drv1;
788 
789 	m->hwvol_mixer = SOUND_MIXER_VOLUME;
790 	m->hwvol_step = 5;
791 	SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
792 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
793             OID_AUTO, "hwvol_step", CTLFLAG_RWTUN, &m->hwvol_step, 0, "");
794 	SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
795 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO,
796 	    "hwvol_mixer", CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_MPSAFE,
797 	    m, 0, sysctl_hw_snd_hwvol_mixer, "A", "");
798 	return 0;
799 }
800 
801 void
802 mixer_hwvol_mute_locked(struct snd_mixer *m)
803 {
804 	mix_setmutedevs(m, m->mutedevs ^ (1 << m->hwvol_mixer));
805 }
806 
807 void
808 mixer_hwvol_mute(device_t dev)
809 {
810 	struct snd_mixer *m;
811 	struct cdev *pdev;
812 
813 	pdev = mixer_get_devt(dev);
814 	m = pdev->si_drv1;
815 	mtx_lock(&m->lock);
816 	mixer_hwvol_mute_locked(m);
817 	mtx_unlock(&m->lock);
818 }
819 
820 void
821 mixer_hwvol_step_locked(struct snd_mixer *m, int left_step, int right_step)
822 {
823 	int level, left, right;
824 
825 	level = mixer_get(m, m->hwvol_mixer);
826 
827 	if (level != -1) {
828 		left = level & 0xff;
829 		right = (level >> 8) & 0xff;
830 		left += left_step * m->hwvol_step;
831 		if (left < 0)
832 			left = 0;
833 		else if (left > 100)
834 			left = 100;
835 		right += right_step * m->hwvol_step;
836 		if (right < 0)
837 			right = 0;
838 		else if (right > 100)
839 			right = 100;
840 
841 		mixer_set(m, m->hwvol_mixer, m->mutedevs, left | right << 8);
842 	}
843 }
844 
845 void
846 mixer_hwvol_step(device_t dev, int left_step, int right_step)
847 {
848 	struct snd_mixer *m;
849 	struct cdev *pdev;
850 
851 	pdev = mixer_get_devt(dev);
852 	m = pdev->si_drv1;
853 	mtx_lock(&m->lock);
854 	mixer_hwvol_step_locked(m, left_step, right_step);
855 	mtx_unlock(&m->lock);
856 }
857 
858 int
859 mix_set(struct snd_mixer *m, u_int dev, u_int left, u_int right)
860 {
861 	int ret;
862 
863 	KASSERT(m != NULL, ("NULL snd_mixer"));
864 
865 	mtx_lock(&m->lock);
866 	ret = mixer_set(m, dev, m->mutedevs, left | (right << 8));
867 	mtx_unlock(&m->lock);
868 
869 	return ((ret != 0) ? ENXIO : 0);
870 }
871 
872 int
873 mix_get(struct snd_mixer *m, u_int dev)
874 {
875 	int ret;
876 
877 	KASSERT(m != NULL, ("NULL snd_mixer"));
878 
879 	mtx_lock(&m->lock);
880 	ret = mixer_get(m, dev);
881 	mtx_unlock(&m->lock);
882 
883 	return (ret);
884 }
885 
886 int
887 mix_setrecsrc(struct snd_mixer *m, u_int32_t src)
888 {
889 	int ret;
890 
891 	KASSERT(m != NULL, ("NULL snd_mixer"));
892 
893 	mtx_lock(&m->lock);
894 	ret = mixer_setrecsrc(m, src);
895 	mtx_unlock(&m->lock);
896 
897 	return ((ret != 0) ? ENXIO : 0);
898 }
899 
900 u_int32_t
901 mix_getrecsrc(struct snd_mixer *m)
902 {
903 	u_int32_t ret;
904 
905 	KASSERT(m != NULL, ("NULL snd_mixer"));
906 
907 	mtx_lock(&m->lock);
908 	ret = mixer_getrecsrc(m);
909 	mtx_unlock(&m->lock);
910 
911 	return (ret);
912 }
913 
914 device_t
915 mix_get_dev(struct snd_mixer *m)
916 {
917 	KASSERT(m != NULL, ("NULL snd_mixer"));
918 
919 	return (m->dev);
920 }
921 
922 /* ----------------------------------------------------------------------- */
923 
924 static int
925 mixer_open(struct cdev *i_dev, int flags, int mode, struct thread *td)
926 {
927 	struct snddev_info *d;
928 	struct snd_mixer *m;
929 
930 	if (i_dev == NULL || i_dev->si_drv1 == NULL)
931 		return (EBADF);
932 
933 	m = i_dev->si_drv1;
934 	d = device_get_softc(m->dev);
935 	if (!PCM_REGISTERED(d))
936 		return (EBADF);
937 
938 	return (0);
939 }
940 
941 static int
942 mixer_close(struct cdev *i_dev, int flags, int mode, struct thread *td)
943 {
944 	struct snddev_info *d;
945 	struct snd_mixer *m;
946 
947 	if (i_dev == NULL || i_dev->si_drv1 == NULL)
948 		return (EBADF);
949 
950 	m = i_dev->si_drv1;
951 	d = device_get_softc(m->dev);
952 	if (!PCM_REGISTERED(d))
953 		return (EBADF);
954 
955 	return (0);
956 }
957 
958 static int
959 mixer_ioctl(struct cdev *i_dev, u_long cmd, caddr_t arg, int mode,
960     struct thread *td)
961 {
962 	struct snddev_info *d;
963 	int ret;
964 
965 	if (i_dev == NULL || i_dev->si_drv1 == NULL)
966 		return (EBADF);
967 
968 	d = device_get_softc(((struct snd_mixer *)i_dev->si_drv1)->dev);
969 	if (!PCM_REGISTERED(d))
970 		return (EBADF);
971 
972 	PCM_GIANT_ENTER(d);
973 	PCM_ACQUIRE_QUICK(d);
974 
975 	ret = mixer_ioctl_cmd(i_dev, cmd, arg, mode, td);
976 
977 	PCM_RELEASE_QUICK(d);
978 	PCM_GIANT_LEAVE(d);
979 
980 	return (ret);
981 }
982 
983 static void
984 mixer_mixerinfo(struct snd_mixer *m, mixer_info *mi)
985 {
986 	bzero((void *)mi, sizeof(*mi));
987 	strlcpy(mi->id, m->name, sizeof(mi->id));
988 	strlcpy(mi->name, device_get_desc(m->dev), sizeof(mi->name));
989 	mi->modify_counter = m->modify_counter;
990 }
991 
992 /*
993  * XXX Make sure you can guarantee concurrency safety before calling this
994  *     function, be it through Giant, PCM_*, etc !
995  */
996 int
997 mixer_ioctl_cmd(struct cdev *i_dev, u_long cmd, caddr_t arg, int mode,
998     struct thread *td)
999 {
1000 	struct snd_mixer *m;
1001 	int ret = EINVAL, *arg_i = (int *)arg;
1002 	int v = -1, j = cmd & 0xff;
1003 
1004 	/*
1005 	 * Certain ioctls may be made on any type of device (audio, mixer,
1006 	 * and MIDI).  Handle those special cases here.
1007 	 */
1008 	if (IOCGROUP(cmd) == 'X') {
1009 		switch (cmd) {
1010 		case SNDCTL_SYSINFO:
1011 			sound_oss_sysinfo((oss_sysinfo *)arg);
1012 			return (0);
1013 		case SNDCTL_CARDINFO:
1014 			return (sound_oss_card_info((oss_card_info *)arg));
1015 	    	case SNDCTL_AUDIOINFO:
1016 			return (dsp_oss_audioinfo(i_dev, (oss_audioinfo *)arg,
1017 			    false));
1018 	    	case SNDCTL_AUDIOINFO_EX:
1019 			return (dsp_oss_audioinfo(i_dev, (oss_audioinfo *)arg,
1020 			    true));
1021 		case SNDCTL_ENGINEINFO:
1022 			return (dsp_oss_engineinfo(i_dev, (oss_audioinfo *)arg));
1023 		case SNDCTL_MIXERINFO:
1024 			return (mixer_oss_mixerinfo(i_dev, (oss_mixerinfo *)arg));
1025 		}
1026 		return (EINVAL);
1027 	}
1028 
1029 	m = i_dev->si_drv1;
1030 
1031 	if (m == NULL)
1032 		return (EBADF);
1033 
1034 	mtx_lock(&m->lock);
1035 	switch (cmd) {
1036 	case SNDCTL_DSP_GET_RECSRC_NAMES: {
1037 		oss_mixer_enuminfo *ei = (oss_mixer_enuminfo *)arg;
1038 		char *loc;
1039 		int i, nvalues, nwrote, nleft, ncopied;
1040 
1041 		nvalues = 0;
1042 		nwrote = 0;
1043 		nleft = sizeof(ei->strings);
1044 		loc = ei->strings;
1045 
1046 		for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
1047 			if (!((1 << i) & m->recdevs))
1048 				continue;
1049 			ei->strindex[nvalues] = nwrote;
1050 			ncopied = strlcpy(loc, snd_mixernames[i], nleft) + 1;
1051 			nwrote += ncopied;
1052 			nleft -= ncopied;
1053 			nvalues++;
1054 			loc = &ei->strings[nwrote];
1055 		}
1056 		ei->nvalues = nvalues;
1057 
1058 		ret = 0;
1059 		goto done;
1060 	}
1061 	case SNDCTL_DSP_GET_RECSRC:
1062 		ret = mixer_get_recroute(m, arg_i);
1063 		goto done;
1064 	case SNDCTL_DSP_SET_RECSRC:
1065 		ret = mixer_set_recroute(m, *arg_i);
1066 		goto done;
1067 	case OSS_GETVERSION:
1068 		*arg_i = SOUND_VERSION;
1069 		ret = 0;
1070 		goto done;
1071 	case SOUND_MIXER_INFO:
1072 		mixer_mixerinfo(m, (mixer_info *)arg);
1073 		ret = 0;
1074 		goto done;
1075 	}
1076 	if ((cmd & ~0xff) == MIXER_WRITE(0)) {
1077 		switch (j) {
1078 		case SOUND_MIXER_RECSRC:
1079 			ret = mixer_setrecsrc(m, *arg_i);
1080 			break;
1081 		case SOUND_MIXER_MUTE:
1082 			mix_setmutedevs(m, *arg_i);
1083 			ret = 0;
1084 			break;
1085 		default:
1086 			ret = mixer_set(m, j, m->mutedevs, *arg_i);
1087 			break;
1088 		}
1089 		mtx_unlock(&m->lock);
1090 		return ((ret == 0) ? 0 : ENXIO);
1091 	}
1092 	if ((cmd & ~0xff) == MIXER_READ(0)) {
1093 		switch (j) {
1094 		case SOUND_MIXER_DEVMASK:
1095 		case SOUND_MIXER_CAPS:
1096 		case SOUND_MIXER_STEREODEVS:
1097 			v = mix_getdevs(m);
1098 			break;
1099 		case SOUND_MIXER_MUTE:
1100 			v = mix_getmutedevs(m);
1101 			break;
1102 		case SOUND_MIXER_RECMASK:
1103 			v = mix_getrecdevs(m);
1104 			break;
1105 		case SOUND_MIXER_RECSRC:
1106 			v = mixer_getrecsrc(m);
1107 			break;
1108 		default:
1109 			v = mixer_get(m, j);
1110 			break;
1111 		}
1112 		*arg_i = v;
1113 		mtx_unlock(&m->lock);
1114 		return ((v != -1) ? 0 : ENXIO);
1115 	}
1116 done:
1117 	mtx_unlock(&m->lock);
1118 	return (ret);
1119 }
1120 
1121 static void
1122 mixer_clone(void *arg,
1123     struct ucred *cred,
1124     char *name, int namelen, struct cdev **dev)
1125 {
1126 	struct snddev_info *d;
1127 
1128 	if (*dev != NULL)
1129 		return;
1130 	if (strcmp(name, "mixer") == 0) {
1131 		bus_topo_lock();
1132 		d = devclass_get_softc(pcm_devclass, snd_unit);
1133 		/* See related comment in dsp_clone(). */
1134 		if (PCM_REGISTERED(d) && d->mixer_dev != NULL) {
1135 			*dev = d->mixer_dev;
1136 			dev_ref(*dev);
1137 		}
1138 		bus_topo_unlock();
1139 	}
1140 }
1141 
1142 static void
1143 mixer_sysinit(void *p)
1144 {
1145 	if (mixer_ehtag != NULL)
1146 		return;
1147 	mixer_ehtag = EVENTHANDLER_REGISTER(dev_clone, mixer_clone, 0, 1000);
1148 }
1149 
1150 static void
1151 mixer_sysuninit(void *p)
1152 {
1153 	if (mixer_ehtag == NULL)
1154 		return;
1155 	EVENTHANDLER_DEREGISTER(dev_clone, mixer_ehtag);
1156 	mixer_ehtag = NULL;
1157 }
1158 
1159 SYSINIT(mixer_sysinit, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, mixer_sysinit, NULL);
1160 SYSUNINIT(mixer_sysuninit, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, mixer_sysuninit, NULL);
1161 
1162 static void
1163 mixer_oss_mixerinfo_unavail(oss_mixerinfo *mi, int unit)
1164 {
1165 	bzero(mi, sizeof(*mi));
1166 	mi->dev = unit;
1167 	snprintf(mi->id, sizeof(mi->id), "mixer%d (n/a)", unit);
1168 	snprintf(mi->name, sizeof(mi->name), "pcm%d:mixer (unavailable)", unit);
1169 	mi->card_number = unit;
1170 	mi->legacy_device = unit;
1171 }
1172 
1173 /**
1174  * @brief Handler for SNDCTL_MIXERINFO
1175  *
1176  * This function searches for a mixer based on the numeric ID stored
1177  * in oss_miserinfo::dev.  If set to -1, then information about the
1178  * current mixer handling the request is provided.  Note, however, that
1179  * this ioctl may be made with any sound device (audio, mixer, midi).
1180  *
1181  * @note Caller must not hold any PCM device, channel, or mixer locks.
1182  *
1183  * See http://manuals.opensound.com/developer/SNDCTL_MIXERINFO.html for
1184  * more information.
1185  *
1186  * @param i_dev	character device on which the ioctl arrived
1187  * @param arg	user argument (oss_mixerinfo *)
1188  *
1189  * @retval EINVAL	oss_mixerinfo::dev specified a bad value
1190  * @retval 0		success
1191  */
1192 int
1193 mixer_oss_mixerinfo(struct cdev *i_dev, oss_mixerinfo *mi)
1194 {
1195 	struct snddev_info *d;
1196 	struct snd_mixer *m;
1197 	int i;
1198 
1199 	/*
1200 	 * If probing the device handling the ioctl, make sure it's a mixer
1201 	 * device.  (This ioctl is valid on audio, mixer, and midi devices.)
1202 	 */
1203 	if (mi->dev == -1 && i_dev->si_devsw != &mixer_cdevsw)
1204 		return (EINVAL);
1205 
1206 	d = NULL;
1207 	m = NULL;
1208 
1209 	/*
1210 	 * There's a 1:1 relationship between mixers and PCM devices, so
1211 	 * begin by iterating over PCM devices and search for our mixer.
1212 	 */
1213 	bus_topo_lock();
1214 	for (i = 0; pcm_devclass != NULL &&
1215 	    i < devclass_get_maxunit(pcm_devclass); i++) {
1216 		d = devclass_get_softc(pcm_devclass, i);
1217 		if (!PCM_REGISTERED(d)) {
1218 			if ((mi->dev == -1 && i == snd_unit) || mi->dev == i) {
1219 				mixer_oss_mixerinfo_unavail(mi, i);
1220 				bus_topo_unlock();
1221 				return (0);
1222 			} else
1223 				continue;
1224 		}
1225 
1226 		/* XXX Need Giant magic entry */
1227 
1228 		/* See the note in function docblock. */
1229 		PCM_UNLOCKASSERT(d);
1230 		PCM_LOCK(d);
1231 
1232 		if (!((d->mixer_dev == i_dev && mi->dev == -1) ||
1233 		    mi->dev == i)) {
1234 			PCM_UNLOCK(d);
1235 			continue;
1236 		}
1237 
1238 		if (d->mixer_dev->si_drv1 == NULL) {
1239 			mixer_oss_mixerinfo_unavail(mi, i);
1240 			PCM_UNLOCK(d);
1241 			bus_topo_unlock();
1242 			return (0);
1243 		}
1244 
1245 		m = d->mixer_dev->si_drv1;
1246 		mtx_lock(&m->lock);
1247 
1248 		/*
1249 		 * At this point, the following synchronization stuff
1250 		 * has happened:
1251 		 * - a specific PCM device is locked.
1252 		 * - a specific mixer device has been locked, so be
1253 		 *   sure to unlock when existing.
1254 		 */
1255 		bzero((void *)mi, sizeof(*mi));
1256 		mi->dev = i;
1257 		snprintf(mi->id, sizeof(mi->id), "mixer%d", i);
1258 		strlcpy(mi->name, m->name, sizeof(mi->name));
1259 		/**
1260 		 * Counter is incremented when applications change any of this
1261 		 * mixer's controls.  A change in value indicates that
1262 		 * persistent mixer applications should update their displays.
1263 		 */
1264 		mi->modify_counter = m->modify_counter;
1265 		mi->card_number = i;
1266 		/*
1267 		 * Currently, FreeBSD assumes 1:1 relationship between
1268 		 * a pcm and mixer devices, so this is hardcoded to 0.
1269 		 */
1270 		mi->port_number = 0;
1271 
1272 		/**
1273 		 * @todo Fill in @sa oss_mixerinfo::mixerhandle.
1274 		 * @note From 4Front:  "mixerhandle is an arbitrary
1275 		 *       string that identifies the mixer better than
1276 		 *       the device number (mixerinfo.dev).  Device
1277 		 *       numbers may change depending on the order the
1278 		 *       drivers are loaded. However the handle should
1279 		 *       remain the same provided that the sound card
1280 		 *       is not moved to another PCI slot."
1281 		 */
1282 
1283 		/**
1284 		 * @note
1285 		 * @sa oss_mixerinfo::magic is a reserved field.
1286 		 *
1287 		 * @par
1288 		 * From 4Front:  "magic is usually 0. However some
1289 		 * devices may have dedicated setup utilities and the
1290 		 * magic field may contain an unique driver specific
1291 		 * value (managed by [4Front])."
1292 		 */
1293 
1294 		mi->enabled = device_is_attached(m->dev) ? 1 : 0;
1295 		/**
1296 		 * The only flag for @sa oss_mixerinfo::caps is
1297 		 * currently MIXER_CAP_VIRTUAL, which I'm not sure we
1298 		 * really worry about.
1299 		 */
1300 		/**
1301 		 * Mixer extensions currently aren't supported, so
1302 		 * leave @sa oss_mixerinfo::nrext blank for now.
1303 		 */
1304 
1305 		/**
1306 		 * @todo Fill in @sa oss_mixerinfo::priority (requires
1307 		 *       touching drivers?)
1308 		 * @note The priority field is for mixer applets to
1309 		 * determine which mixer should be the default, with 0
1310 		 * being least preferred and 10 being most preferred.
1311 		 * From 4Front:  "OSS drivers like ICH use higher
1312 		 * values (10) because such chips are known to be used
1313 		 * only on motherboards.  Drivers for high end pro
1314 		 * devices use 0 because they will never be the
1315 		 * default mixer. Other devices use values 1 to 9
1316 		 * depending on the estimated probability of being the
1317 		 * default device.
1318 		 */
1319 
1320 		snprintf(mi->devnode, sizeof(mi->devnode), "/dev/mixer%d", i);
1321 		mi->legacy_device = i;
1322 
1323 		mtx_unlock(&m->lock);
1324 
1325 		PCM_UNLOCK(d);
1326 
1327 		bus_topo_unlock();
1328 		return (0);
1329 	}
1330 	bus_topo_unlock();
1331 
1332 	return (EINVAL);
1333 }
1334