xref: /dragonfly/sys/dev/sound/pcm/mixer.c (revision 16fb0422)
1 /*-
2  * Copyright (c) 1999 Cameron Grant <cg@freebsd.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD: src/sys/dev/sound/pcm/mixer.c,v 1.43.2.5 2007/05/13 20:53:39 ariff Exp $
27  */
28 
29 #include <dev/sound/pcm/sound.h>
30 #include <dev/sound/pcm/dsp.h>
31 
32 #include "mixer_if.h"
33 
34 
35 MALLOC_DEFINE(M_MIXER, "mixer", "mixer");
36 
37 #define MIXER_NAMELEN	16
38 struct snd_mixer {
39 	KOBJ_FIELDS;
40 	const char *type;
41 	void *devinfo;
42 	int busy;
43 	int hwvol_muted;
44 	int hwvol_mixer;
45 	int hwvol_step;
46 	device_t dev;
47 	u_int32_t hwvol_mute_level;
48 	u_int32_t devs;
49 	u_int32_t recdevs;
50 	u_int32_t recsrc;
51 	u_int16_t level[32];
52 	u_int8_t parent[32];
53 	u_int32_t child[32];
54 	u_int8_t realdev[32];
55 	char name[MIXER_NAMELEN];
56 	sndlock_t	lock;
57 };
58 
59 static u_int16_t snd_mixerdefaults[SOUND_MIXER_NRDEVICES] = {
60 	[SOUND_MIXER_VOLUME]	= 75,
61 	[SOUND_MIXER_BASS]	= 50,
62 	[SOUND_MIXER_TREBLE]	= 50,
63 	[SOUND_MIXER_SYNTH]	= 75,
64 	[SOUND_MIXER_PCM]	= 75,
65 	[SOUND_MIXER_SPEAKER]	= 75,
66 	[SOUND_MIXER_LINE]	= 75,
67 	[SOUND_MIXER_MIC] 	= 0,
68 	[SOUND_MIXER_CD]	= 75,
69 	[SOUND_MIXER_IGAIN]	= 0,
70 	[SOUND_MIXER_LINE1]	= 75,
71 	[SOUND_MIXER_VIDEO]	= 75,
72 	[SOUND_MIXER_RECLEV]	= 0,
73 	[SOUND_MIXER_OGAIN]	= 50,
74 	[SOUND_MIXER_MONITOR]	= 75,
75 };
76 
77 static char* snd_mixernames[SOUND_MIXER_NRDEVICES] = SOUND_DEVICE_NAMES;
78 
79 static d_open_t mixer_open;
80 static d_close_t mixer_close;
81 
82 static struct dev_ops mixer_cdevsw = {
83 	{ "mixer", 0, D_TRACKCLOSE },
84 	/* .d_flags =	D_TRACKCLOSE | D_NEEDGIANT, */
85 	.d_open =	mixer_open,
86 	.d_close =	mixer_close,
87 	.d_ioctl =	mixer_ioctl,
88 };
89 
90 #ifdef USING_DEVFS
91 static eventhandler_tag mixer_ehtag;
92 #endif
93 
94 static struct cdev *
95 mixer_get_devt(device_t dev)
96 {
97 	struct snddev_info *snddev;
98 
99 	snddev = device_get_softc(dev);
100 
101 	return snddev->mixer_dev;
102 }
103 
104 #ifdef SND_DYNSYSCTL
105 static int
106 mixer_lookup(char *devname)
107 {
108 	int i;
109 
110 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++)
111 		if (strncmp(devname, snd_mixernames[i],
112 		    strlen(snd_mixernames[i])) == 0)
113 			return i;
114 	return -1;
115 }
116 #endif
117 
118 /*
119  * Always called with mixer->lock held.
120  */
121 static int
122 mixer_set_softpcmvol(struct snd_mixer *mixer, struct snddev_info *d,
123 						unsigned left, unsigned right)
124 {
125 	struct snddev_channel *sce;
126 	struct pcm_channel *ch;
127 
128 	snd_mtxunlock(mixer->lock);
129 	SLIST_FOREACH(sce, &d->channels, link) {
130 		ch = sce->channel;
131 		CHN_LOCK(ch);
132 		if (ch->direction == PCMDIR_PLAY &&
133 				(ch->feederflags & (1 << FEEDER_VOLUME)))
134 			chn_setvolume(ch, left, right);
135 		CHN_UNLOCK(ch);
136 	}
137         snd_mtxlock(mixer->lock);
138 	return 0;
139 }
140 
141 static int
142 mixer_set(struct snd_mixer *m, unsigned dev, unsigned lev)
143 {
144 	struct snddev_info *d;
145 	unsigned l, r, tl, tr;
146 	u_int32_t parent = SOUND_MIXER_NONE, child = 0;
147 	u_int32_t realdev;
148 	int i;
149 
150 	if (m == NULL || dev >= SOUND_MIXER_NRDEVICES ||
151 	    (0 == (m->devs & (1 << dev))))
152 		return -1;
153 
154 	l = min((lev & 0x00ff), 100);
155 	r = min(((lev & 0xff00) >> 8), 100);
156 	realdev = m->realdev[dev];
157 
158 	d = device_get_softc(m->dev);
159 	if (d == NULL)
160 		return -1;
161 
162 	/* TODO: recursive handling */
163 	parent = m->parent[dev];
164 	if (parent >= SOUND_MIXER_NRDEVICES)
165 		parent = SOUND_MIXER_NONE;
166 	if (parent == SOUND_MIXER_NONE)
167 		child = m->child[dev];
168 
169 	if (parent != SOUND_MIXER_NONE) {
170 		tl = (l * (m->level[parent] & 0x00ff)) / 100;
171 		tr = (r * ((m->level[parent] & 0xff00) >> 8)) / 100;
172 		if (dev == SOUND_MIXER_PCM && (d->flags & SD_F_SOFTPCMVOL))
173 			mixer_set_softpcmvol(m, d, tl, tr);
174 		else if (realdev != SOUND_MIXER_NONE &&
175 		    MIXER_SET(m, realdev, tl, tr) < 0)
176 			return -1;
177 	} else if (child != 0) {
178 		for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
179 			if (!(child & (1 << i)) || m->parent[i] != dev)
180 				continue;
181 			realdev = m->realdev[i];
182 			tl = (l * (m->level[i] & 0x00ff)) / 100;
183 			tr = (r * ((m->level[i] & 0xff00) >> 8)) / 100;
184 			if (i == SOUND_MIXER_PCM && (d->flags & SD_F_SOFTPCMVOL))
185 				mixer_set_softpcmvol(m, d, tl, tr);
186 			else if (realdev != SOUND_MIXER_NONE)
187 				MIXER_SET(m, realdev, tl, tr);
188 		}
189 		realdev = m->realdev[dev];
190 		if (realdev != SOUND_MIXER_NONE &&
191 		    MIXER_SET(m, realdev, l, r) < 0)
192 			return -1;
193 	} else {
194 		if (dev == SOUND_MIXER_PCM && (d->flags & SD_F_SOFTPCMVOL))
195 			mixer_set_softpcmvol(m, d, l, r);
196 		else if (realdev != SOUND_MIXER_NONE &&
197 		    MIXER_SET(m, realdev, l, r) < 0)
198 			return -1;
199 	}
200 
201 	m->level[dev] = l | (r << 8);
202 
203 	return 0;
204 }
205 
206 static int
207 mixer_get(struct snd_mixer *mixer, int dev)
208 {
209 	if ((dev < SOUND_MIXER_NRDEVICES) && (mixer->devs & (1 << dev)))
210 		return mixer->level[dev];
211 	else return -1;
212 }
213 
214 static int
215 mixer_setrecsrc(struct snd_mixer *mixer, u_int32_t src)
216 {
217 	src &= mixer->recdevs;
218 	if (src == 0)
219 		src = SOUND_MASK_MIC;
220 	mixer->recsrc = MIXER_SETRECSRC(mixer, src);
221 	return 0;
222 }
223 
224 static int
225 mixer_getrecsrc(struct snd_mixer *mixer)
226 {
227 	return mixer->recsrc;
228 }
229 
230 void
231 mix_setdevs(struct snd_mixer *m, u_int32_t v)
232 {
233 	struct snddev_info *d;
234 	int i;
235 
236 	if (m == NULL)
237 		return;
238 
239 	d = device_get_softc(m->dev);
240 	if (d != NULL && (d->flags & SD_F_SOFTPCMVOL))
241 		v |= SOUND_MASK_PCM;
242 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
243 		if (m->parent[i] < SOUND_MIXER_NRDEVICES)
244 			v |= 1 << m->parent[i];
245 		v |= m->child[i];
246 	}
247 	m->devs = v;
248 }
249 
250 void
251 mix_setrecdevs(struct snd_mixer *m, u_int32_t v)
252 {
253 	m->recdevs = v;
254 }
255 
256 void
257 mix_setparentchild(struct snd_mixer *m, u_int32_t parent, u_int32_t childs)
258 {
259 	u_int32_t mask = 0;
260 	int i;
261 
262 	if (m == NULL || parent >= SOUND_MIXER_NRDEVICES)
263 		return;
264 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
265 		if (i == parent)
266 			continue;
267 		if (childs & (1 << i)) {
268 			mask |= 1 << i;
269 			if (m->parent[i] < SOUND_MIXER_NRDEVICES)
270 				m->child[m->parent[i]] &= ~(1 << i);
271 			m->parent[i] = parent;
272 			m->child[i] = 0;
273 		}
274 	}
275 	mask &= ~(1 << parent);
276 	m->child[parent] = mask;
277 }
278 
279 void
280 mix_setrealdev(struct snd_mixer *m, u_int32_t dev, u_int32_t realdev)
281 {
282 	if (m == NULL || dev >= SOUND_MIXER_NRDEVICES ||
283 	    !(realdev == SOUND_MIXER_NONE || realdev < SOUND_MIXER_NRDEVICES))
284 		return;
285 	m->realdev[dev] = realdev;
286 }
287 
288 u_int32_t
289 mix_getparent(struct snd_mixer *m, u_int32_t dev)
290 {
291 	if (m == NULL || dev >= SOUND_MIXER_NRDEVICES)
292 		return SOUND_MIXER_NONE;
293 	return m->parent[dev];
294 }
295 
296 u_int32_t
297 mix_getchild(struct snd_mixer *m, u_int32_t dev)
298 {
299 	if (m == NULL || dev >= SOUND_MIXER_NRDEVICES)
300 		return 0;
301 	return m->child[dev];
302 }
303 
304 u_int32_t
305 mix_getdevs(struct snd_mixer *m)
306 {
307 	return m->devs;
308 }
309 
310 u_int32_t
311 mix_getrecdevs(struct snd_mixer *m)
312 {
313 	return m->recdevs;
314 }
315 
316 void *
317 mix_getdevinfo(struct snd_mixer *m)
318 {
319 	return m->devinfo;
320 }
321 
322 int
323 mixer_init(device_t dev, kobj_class_t cls, void *devinfo)
324 {
325 	struct snddev_info *snddev;
326 	struct snd_mixer *m;
327 	u_int16_t v;
328 	struct cdev *pdev;
329 	int i, unit, val;
330 
331 	m = (struct snd_mixer *)kobj_create(cls, M_MIXER, M_WAITOK | M_ZERO);
332 	ksnprintf(m->name, MIXER_NAMELEN, "%s:mixer", device_get_nameunit(dev));
333 	m->lock = snd_mtxcreate(m->name, "pcm mixer");
334 	m->type = cls->name;
335 	m->devinfo = devinfo;
336 	m->busy = 0;
337 	m->dev = dev;
338 	for (i = 0; i < 32; i++) {
339 		m->parent[i] = SOUND_MIXER_NONE;
340 		m->child[i] = 0;
341 		m->realdev[i] = i;
342 	}
343 
344 	if (MIXER_INIT(m))
345 		goto bad;
346 
347 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
348 		v = snd_mixerdefaults[i];
349 
350 		if (resource_int_value(device_get_name(dev),
351 		    device_get_unit(dev), snd_mixernames[i], &val) == 0) {
352 			if (val >= 0 && val <= 100) {
353 				v = (u_int16_t) val;
354 			}
355 		}
356 
357 		snd_mtxlock(m->lock);
358 		mixer_set(m, i, v | (v << 8));
359 		snd_mtxunlock(m->lock);
360 	}
361 
362 	mixer_setrecsrc(m, SOUND_MASK_MIC);
363 
364 	unit = device_get_unit(dev);
365 	pdev = make_dev(&mixer_cdevsw, PCMMKMINOR(unit, 0),
366 			UID_ROOT, GID_WHEEL, 0666, "mixer%d", unit);
367 	reference_dev(pdev);
368 	pdev->si_drv1 = m;
369 	snddev = device_get_softc(dev);
370 	snddev->mixer_dev = pdev;
371 
372 	if (bootverbose) {
373 		for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
374 			if (!(m->devs & (1 << i)))
375 				continue;
376 			if (m->realdev[i] != i) {
377 				device_printf(dev, "Mixer \"%s\" -> \"%s\":",
378 				    snd_mixernames[i],
379 				    (m->realdev[i] < SOUND_MIXER_NRDEVICES) ?
380 				    snd_mixernames[m->realdev[i]] : "none");
381 			} else {
382 				device_printf(dev, "Mixer \"%s\":",
383 				    snd_mixernames[i]);
384 			}
385 			if (m->parent[i] < SOUND_MIXER_NRDEVICES)
386 				kprintf(" parent=\"%s\"",
387 				    snd_mixernames[m->parent[i]]);
388 			if (m->child[i] != 0)
389 				kprintf(" child=0x%08x", m->child[i]);
390 			kprintf("\n");
391 		}
392 		if (snddev->flags & SD_F_SOFTPCMVOL)
393 			device_printf(dev, "Soft PCM mixer ENABLED\n");
394 	}
395 
396 	return 0;
397 
398 bad:
399 	snd_mtxfree(m->lock);
400 	kobj_delete((kobj_t)m, M_MIXER);
401 	return -1;
402 }
403 
404 int
405 mixer_uninit(device_t dev)
406 {
407 	int i;
408 	int unit;
409 	struct snddev_info *d;
410 	struct snd_mixer *m;
411 	struct cdev *pdev;
412 
413 	d = device_get_softc(dev);
414 	pdev = mixer_get_devt(dev);
415 	if (d == NULL || pdev == NULL || pdev->si_drv1 == NULL)
416 		return EBADF;
417 	m = pdev->si_drv1;
418 	snd_mtxlock(m->lock);
419 
420 	if (m->busy) {
421 		snd_mtxunlock(m->lock);
422 		return EBUSY;
423 	}
424 
425 	pdev->si_drv1 = NULL;
426 	release_dev(pdev);
427 	unit = device_get_unit(dev);
428 	dev_ops_remove_minor(&mixer_cdevsw, /*-1, */PCMMKMINOR(unit, 0));
429 
430 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++)
431 		mixer_set(m, i, 0);
432 
433 	mixer_setrecsrc(m, SOUND_MASK_MIC);
434 
435 	MIXER_UNINIT(m);
436 
437 	snd_mtxunlock(m->lock);
438 	snd_mtxfree(m->lock);
439 	kobj_delete((kobj_t)m, M_MIXER);
440 
441 	d->mixer_dev = NULL;
442 
443 	return 0;
444 }
445 
446 int
447 mixer_reinit(device_t dev)
448 {
449 	struct snd_mixer *m;
450 	struct cdev *pdev;
451 	int i;
452 
453 	pdev = mixer_get_devt(dev);
454 	m = pdev->si_drv1;
455 	snd_mtxlock(m->lock);
456 
457 	i = MIXER_REINIT(m);
458 	if (i) {
459 		snd_mtxunlock(m->lock);
460 		return i;
461 	}
462 
463 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++)
464 		mixer_set(m, i, m->level[i]);
465 
466 	mixer_setrecsrc(m, m->recsrc);
467 	snd_mtxunlock(m->lock);
468 
469 	return 0;
470 }
471 
472 #ifdef SND_DYNSYSCTL
473 static int
474 sysctl_hw_snd_hwvol_mixer(SYSCTL_HANDLER_ARGS)
475 {
476 	char devname[32];
477 	int error, dev;
478 	struct snd_mixer *m;
479 
480 	m = oidp->oid_arg1;
481 	snd_mtxlock(m->lock);
482 	strncpy(devname, snd_mixernames[m->hwvol_mixer], sizeof(devname));
483 	snd_mtxunlock(m->lock);
484 	error = sysctl_handle_string(oidp, &devname[0], sizeof(devname), req);
485 	snd_mtxlock(m->lock);
486 	if (error == 0 && req->newptr != NULL) {
487 		dev = mixer_lookup(devname);
488 		if (dev == -1) {
489 			snd_mtxunlock(m->lock);
490 			return EINVAL;
491 		}
492 		else if (dev != m->hwvol_mixer) {
493 			m->hwvol_mixer = dev;
494 			m->hwvol_muted = 0;
495 		}
496 	}
497 	snd_mtxunlock(m->lock);
498 	return error;
499 }
500 #endif
501 
502 int
503 mixer_hwvol_init(device_t dev)
504 {
505 	struct snd_mixer *m;
506 	struct cdev *pdev;
507 
508 	pdev = mixer_get_devt(dev);
509 	m = pdev->si_drv1;
510 
511 	m->hwvol_mixer = SOUND_MIXER_VOLUME;
512 	m->hwvol_step = 5;
513 #ifdef SND_DYNSYSCTL
514 	SYSCTL_ADD_INT(snd_sysctl_tree(dev), SYSCTL_CHILDREN(snd_sysctl_tree_top(dev)),
515             OID_AUTO, "hwvol_step", CTLFLAG_RW, &m->hwvol_step, 0, "");
516 	SYSCTL_ADD_PROC(snd_sysctl_tree(dev), SYSCTL_CHILDREN(snd_sysctl_tree_top(dev)),
517             OID_AUTO, "hwvol_mixer", CTLTYPE_STRING | CTLFLAG_RW, m, 0,
518 	    sysctl_hw_snd_hwvol_mixer, "A", "");
519 #endif
520 	return 0;
521 }
522 
523 void
524 mixer_hwvol_mute(device_t dev)
525 {
526 	struct snd_mixer *m;
527 	struct cdev *pdev;
528 
529 	pdev = mixer_get_devt(dev);
530 	m = pdev->si_drv1;
531 	snd_mtxlock(m->lock);
532 	if (m->hwvol_muted) {
533 		m->hwvol_muted = 0;
534 		mixer_set(m, m->hwvol_mixer, m->hwvol_mute_level);
535 	} else {
536 		m->hwvol_muted++;
537 		m->hwvol_mute_level = mixer_get(m, m->hwvol_mixer);
538 		mixer_set(m, m->hwvol_mixer, 0);
539 	}
540 	snd_mtxunlock(m->lock);
541 }
542 
543 void
544 mixer_hwvol_step(device_t dev, int left_step, int right_step)
545 {
546 	struct snd_mixer *m;
547 	int level, left, right;
548 	struct cdev *pdev;
549 
550 	pdev = mixer_get_devt(dev);
551 	m = pdev->si_drv1;
552 	snd_mtxlock(m->lock);
553 	if (m->hwvol_muted) {
554 		m->hwvol_muted = 0;
555 		level = m->hwvol_mute_level;
556 	} else
557 		level = mixer_get(m, m->hwvol_mixer);
558 	if (level != -1) {
559 		left = level & 0xff;
560 		right = level >> 8;
561 		left += left_step * m->hwvol_step;
562 		if (left < 0)
563 			left = 0;
564 		right += right_step * m->hwvol_step;
565 		if (right < 0)
566 			right = 0;
567 		mixer_set(m, m->hwvol_mixer, left | right << 8);
568 	}
569 	snd_mtxunlock(m->lock);
570 }
571 
572 /* ----------------------------------------------------------------------- */
573 
574 static int
575 vchanvolume(cdev_t i_dev, int write, int *volume, int *ret,
576 		struct thread *td)
577 {
578 	struct snddev_info *d;
579 	void *cookie;
580 	struct pcm_channel *ch;
581 	int vol_left, vol_right;
582 
583 	crit_enter();
584 	d = dsp_get_info(i_dev);
585 	if (d == NULL) {
586 		crit_exit();
587 		return 0;
588 	}
589 	/*
590 	 * We search for a vchan which is owned by the current process.
591 	 */
592 	for (cookie = NULL; (ch = pcm_chn_iterate(d, &cookie)) != NULL;)
593 		if (ch->flags & CHN_F_VIRTUAL &&
594 		    ch->pid == td->td_proc->p_pid)
595 			break;
596 
597 	if (ch == NULL) {
598 		crit_exit();
599 		return 0;
600 	}
601 
602 	if (write) {
603 		vol_left = min(*volume & 0x00ff, 100);
604 		vol_right = min((*volume & 0xff00) >> 8, 100);
605 		*ret = chn_setvolume(ch, vol_left, vol_right);
606 	} else {
607 		*volume = ch->volume;
608 		*ret = 0;
609 	}
610 	crit_exit();
611 	return 1;
612 }
613 
614 /* ----------------------------------------------------------------------- */
615 
616 static int
617 mixer_open(struct dev_open_args *ap)
618 {
619 	struct cdev *i_dev = ap->a_head.a_dev;
620 	struct snd_mixer *m;
621 
622 	m = i_dev->si_drv1;
623 	snd_mtxlock(m->lock);
624 
625 	m->busy++;
626 
627 	snd_mtxunlock(m->lock);
628 	return 0;
629 }
630 
631 static int
632 mixer_close(struct dev_close_args *ap)
633 {
634 	struct cdev *i_dev = ap->a_head.a_dev;
635 	struct snd_mixer *m;
636 
637 	m = i_dev->si_drv1;
638 	snd_mtxlock(m->lock);
639 
640 	if (!m->busy) {
641 		snd_mtxunlock(m->lock);
642 		return EBADF;
643 	}
644 	m->busy--;
645 
646 	snd_mtxunlock(m->lock);
647 	return 0;
648 }
649 
650 int
651 mixer_ioctl(struct dev_ioctl_args *ap)
652 {
653 	struct cdev *i_dev = ap->a_head.a_dev;
654 	u_long cmd = ap->a_cmd;
655 	caddr_t arg = ap->a_data;
656 	int mode = ap->a_fflag;
657 	struct snd_mixer *m;
658 	int ret, *arg_i = (int *)arg;
659 	int v = -1, j = cmd & 0xff;
660 
661 	m = i_dev->si_drv1;
662 
663 	if (m == NULL)
664 		return EBADF;
665 
666 	/*
667 	 * If we are handling PCM, maybe the app really wants to
668 	 * set its vchan, and fails to use the correct fd.
669 	 */
670 	if (j == SOUND_MIXER_PCM && curthread->td_proc) {
671 		if (vchanvolume(i_dev,
672 			    (cmd & MIXER_WRITE(0)) == MIXER_WRITE(0),
673 			    (int *)arg, &ret, curthread))
674 			return ret;
675 		/* else proceed as usual */
676 	}
677 
678 	snd_mtxlock(m->lock);
679 	if (mode != -1 && !m->busy) {
680 		snd_mtxunlock(m->lock);
681 		return EBADF;
682 	}
683 
684 	if (cmd == OSS_GETVERSION) {
685 		*arg_i = SOUND_VERSION;
686 		snd_mtxunlock(m->lock);
687 		return 0;
688 	}
689 
690 	if ((cmd & MIXER_WRITE(0)) == MIXER_WRITE(0)) {
691 		if (j == SOUND_MIXER_RECSRC)
692 			ret = mixer_setrecsrc(m, *arg_i);
693 		else
694 			ret = mixer_set(m, j, *arg_i);
695 		snd_mtxunlock(m->lock);
696 		return (ret == 0)? 0 : ENXIO;
697 	}
698 
699     	if ((cmd & MIXER_READ(0)) == MIXER_READ(0)) {
700 		switch (j) {
701     		case SOUND_MIXER_DEVMASK:
702     		case SOUND_MIXER_CAPS:
703     		case SOUND_MIXER_STEREODEVS:
704 			v = mix_getdevs(m);
705 			break;
706 
707     		case SOUND_MIXER_RECMASK:
708 			v = mix_getrecdevs(m);
709 			break;
710 
711     		case SOUND_MIXER_RECSRC:
712 			v = mixer_getrecsrc(m);
713 			break;
714 
715 		default:
716 			v = mixer_get(m, j);
717 		}
718 		*arg_i = v;
719 		snd_mtxunlock(m->lock);
720 		return (v != -1)? 0 : ENXIO;
721 	}
722 	snd_mtxunlock(m->lock);
723 	return ENXIO;
724 }
725 
726 #ifdef USING_DEVFS
727 static void
728 mixer_clone(void *arg, struct ucred *cred, char *name, int namelen,
729     struct cdev **dev)
730 {
731 	struct snddev_info *sd;
732 
733 	if (*dev != NULL)
734 		return;
735 	if (strcmp(name, "mixer") == 0) {
736 		sd = devclass_get_softc(pcm_devclass, snd_unit);
737 		if (sd != NULL && sd->mixer_dev != NULL) {
738 			*dev = sd->mixer_dev;
739 			dev_ref(*dev);
740 		}
741 	}
742 }
743 
744 static void
745 mixer_sysinit(void *p)
746 {
747 	mixer_ehtag = EVENTHANDLER_REGISTER(dev_clone, mixer_clone, 0, 1000);
748 }
749 
750 static void
751 mixer_sysuninit(void *p)
752 {
753 	if (mixer_ehtag != NULL)
754 		EVENTHANDLER_DEREGISTER(dev_clone, mixer_ehtag);
755 }
756 
757 SYSINIT(mixer_sysinit, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, mixer_sysinit, NULL);
758 SYSUNINIT(mixer_sysuninit, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, mixer_sysuninit, NULL);
759 #endif
760 
761 
762