xref: /freebsd/sys/dev/sound/pcm/mixer.c (revision acd3428b7d3e94cef0e1881c868cb4b131d4ff41)
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 
27 #include <dev/sound/pcm/sound.h>
28 
29 #include "mixer_if.h"
30 
31 SND_DECLARE_FILE("$FreeBSD$");
32 
33 MALLOC_DEFINE(M_MIXER, "mixer", "mixer");
34 
35 #define MIXER_NAMELEN	16
36 struct snd_mixer {
37 	KOBJ_FIELDS;
38 	const char *type;
39 	void *devinfo;
40 	int busy;
41 	int hwvol_muted;
42 	int hwvol_mixer;
43 	int hwvol_step;
44 	device_t dev;
45 	u_int32_t hwvol_mute_level;
46 	u_int32_t devs;
47 	u_int32_t recdevs;
48 	u_int32_t recsrc;
49 	u_int16_t level[32];
50 	u_int8_t parent[32];
51 	u_int32_t child[32];
52 	u_int8_t realdev[32];
53 	char name[MIXER_NAMELEN];
54 	struct mtx *lock;
55 	oss_mixer_enuminfo enuminfo;
56 	/**
57 	 * Counter is incremented when applications change any of this
58 	 * mixer's controls.  A change in value indicates that persistent
59 	 * mixer applications should update their displays.
60 	 */
61 	int modify_counter;
62 };
63 
64 static u_int16_t snd_mixerdefaults[SOUND_MIXER_NRDEVICES] = {
65 	[SOUND_MIXER_VOLUME]	= 75,
66 	[SOUND_MIXER_BASS]	= 50,
67 	[SOUND_MIXER_TREBLE]	= 50,
68 	[SOUND_MIXER_SYNTH]	= 75,
69 	[SOUND_MIXER_PCM]	= 75,
70 	[SOUND_MIXER_SPEAKER]	= 75,
71 	[SOUND_MIXER_LINE]	= 75,
72 	[SOUND_MIXER_MIC] 	= 0,
73 	[SOUND_MIXER_CD]	= 75,
74 	[SOUND_MIXER_IGAIN]	= 0,
75 	[SOUND_MIXER_LINE1]	= 75,
76 	[SOUND_MIXER_VIDEO]	= 75,
77 	[SOUND_MIXER_RECLEV]	= 0,
78 	[SOUND_MIXER_OGAIN]	= 50,
79 	[SOUND_MIXER_MONITOR]	= 75,
80 };
81 
82 static char* snd_mixernames[SOUND_MIXER_NRDEVICES] = SOUND_DEVICE_NAMES;
83 
84 static d_open_t mixer_open;
85 static d_close_t mixer_close;
86 
87 static struct cdevsw mixer_cdevsw = {
88 	.d_version =	D_VERSION,
89 	.d_flags =	D_TRACKCLOSE | D_NEEDGIANT,
90 	.d_open =	mixer_open,
91 	.d_close =	mixer_close,
92 	.d_ioctl =	mixer_ioctl,
93 	.d_name =	"mixer",
94 };
95 
96 /**
97  * Keeps a count of mixer devices; used only by OSSv4 SNDCTL_SYSINFO ioctl.
98  */
99 int mixer_count = 0;
100 
101 #ifdef USING_DEVFS
102 static eventhandler_tag mixer_ehtag;
103 #endif
104 
105 static struct cdev *
106 mixer_get_devt(device_t dev)
107 {
108 	struct snddev_info *snddev;
109 
110 	snddev = device_get_softc(dev);
111 
112 	return snddev->mixer_dev;
113 }
114 
115 #ifdef SND_DYNSYSCTL
116 static int
117 mixer_lookup(char *devname)
118 {
119 	int i;
120 
121 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++)
122 		if (strncmp(devname, snd_mixernames[i],
123 		    strlen(snd_mixernames[i])) == 0)
124 			return i;
125 	return -1;
126 }
127 #endif
128 
129 static int
130 mixer_set_softpcmvol(struct snd_mixer *mixer, struct snddev_info *d,
131 						unsigned left, unsigned right)
132 {
133 	struct snddev_channel *sce;
134 	struct pcm_channel *ch;
135 #ifdef USING_MUTEX
136 	int locked = (mixer->lock && mtx_owned((struct mtx *)(mixer->lock))) ? 1 : 0;
137 
138 	if (locked)
139 		snd_mtxunlock(mixer->lock);
140 #endif
141 	SLIST_FOREACH(sce, &d->channels, link) {
142 		ch = sce->channel;
143 		CHN_LOCK(ch);
144 		if (ch->direction == PCMDIR_PLAY &&
145 				(ch->feederflags & (1 << FEEDER_VOLUME)))
146 			chn_setvolume(ch, left, right);
147 		CHN_UNLOCK(ch);
148 	}
149 #ifdef USING_MUTEX
150 	if (locked)
151 		snd_mtxlock(mixer->lock);
152 #endif
153 	return 0;
154 }
155 
156 static int
157 mixer_set(struct snd_mixer *m, unsigned dev, unsigned lev)
158 {
159 	struct snddev_info *d;
160 	unsigned l, r, tl, tr;
161 	u_int32_t parent = SOUND_MIXER_NONE, child = 0;
162 	u_int32_t realdev;
163 	int i;
164 
165 	if (m == NULL || dev >= SOUND_MIXER_NRDEVICES ||
166 	    (0 == (m->devs & (1 << dev))))
167 		return -1;
168 
169 	l = min((lev & 0x00ff), 100);
170 	r = min(((lev & 0xff00) >> 8), 100);
171 	realdev = m->realdev[dev];
172 
173 	d = device_get_softc(m->dev);
174 	if (d == NULL)
175 		return -1;
176 
177 	/* TODO: recursive handling */
178 	parent = m->parent[dev];
179 	if (parent >= SOUND_MIXER_NRDEVICES)
180 		parent = SOUND_MIXER_NONE;
181 	if (parent == SOUND_MIXER_NONE)
182 		child = m->child[dev];
183 
184 	if (parent != SOUND_MIXER_NONE) {
185 		tl = (l * (m->level[parent] & 0x00ff)) / 100;
186 		tr = (r * ((m->level[parent] & 0xff00) >> 8)) / 100;
187 		if (dev == SOUND_MIXER_PCM && (d->flags & SD_F_SOFTPCMVOL))
188 			mixer_set_softpcmvol(m, d, tl, tr);
189 		else if (realdev != SOUND_MIXER_NONE &&
190 		    MIXER_SET(m, realdev, tl, tr) < 0)
191 			return -1;
192 	} else if (child != 0) {
193 		for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
194 			if (!(child & (1 << i)) || m->parent[i] != dev)
195 				continue;
196 			realdev = m->realdev[i];
197 			tl = (l * (m->level[i] & 0x00ff)) / 100;
198 			tr = (r * ((m->level[i] & 0xff00) >> 8)) / 100;
199 			if (i == SOUND_MIXER_PCM && (d->flags & SD_F_SOFTPCMVOL))
200 				mixer_set_softpcmvol(m, d, tl, tr);
201 			else if (realdev != SOUND_MIXER_NONE)
202 				MIXER_SET(m, realdev, tl, tr);
203 		}
204 		realdev = m->realdev[dev];
205 		if (realdev != SOUND_MIXER_NONE &&
206 		    MIXER_SET(m, realdev, l, r) < 0)
207 				return -1;
208 	} else {
209 		if (dev == SOUND_MIXER_PCM && (d->flags & SD_F_SOFTPCMVOL))
210 			mixer_set_softpcmvol(m, d, l, r);
211 		else if (realdev != SOUND_MIXER_NONE &&
212 		    MIXER_SET(m, realdev, l, r) < 0)
213 			return -1;
214 	}
215 
216 	m->level[dev] = l | (r << 8);
217 
218 	return 0;
219 }
220 
221 static int
222 mixer_get(struct snd_mixer *mixer, int dev)
223 {
224 	if ((dev < SOUND_MIXER_NRDEVICES) && (mixer->devs & (1 << dev)))
225 		return mixer->level[dev];
226 	else return -1;
227 }
228 
229 static int
230 mixer_setrecsrc(struct snd_mixer *mixer, u_int32_t src)
231 {
232 	src &= mixer->recdevs;
233 	if (src == 0)
234 		src = SOUND_MASK_MIC;
235 	mixer->recsrc = MIXER_SETRECSRC(mixer, src);
236 	return 0;
237 }
238 
239 static int
240 mixer_getrecsrc(struct snd_mixer *mixer)
241 {
242 	return mixer->recsrc;
243 }
244 
245 /**
246  * @brief Retrieve the route number of the current recording device
247  *
248  * OSSv4 assigns routing numbers to recording devices, unlike the previous
249  * API which relied on a fixed table of device numbers and names.  This
250  * function returns the routing number of the device currently selected
251  * for recording.
252  *
253  * For now, this function is kind of a goofy compatibility stub atop the
254  * existing sound system.  (For example, in theory, the old sound system
255  * allows multiple recording devices to be specified via a bitmask.)
256  *
257  * @param m	mixer context container thing
258  *
259  * @retval 0		success
260  * @retval EIDRM	no recording device found (generally not possible)
261  * @todo Ask about error code
262  */
263 static int
264 mixer_get_recroute(struct snd_mixer *m, int *route)
265 {
266 	int i, cnt;
267 
268 	cnt = 0;
269 
270 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
271 		/** @todo can user set a multi-device mask? (== or &?) */
272 		if ((1 << i) == m->recsrc)
273 			break;
274 		if ((1 << i) & m->recdevs)
275 			++cnt;
276 	}
277 
278 	if (i == SOUND_MIXER_NRDEVICES)
279 		return EIDRM;
280 
281 	*route = cnt;
282 	return 0;
283 }
284 
285 /**
286  * @brief Select a device for recording
287  *
288  * This function sets a recording source based on a recording device's
289  * routing number.  Said number is translated to an old school recdev
290  * mask and passed over mixer_setrecsrc.
291  *
292  * @param m	mixer context container thing
293  *
294  * @retval 0		success(?)
295  * @retval EINVAL	User specified an invalid device number
296  * @retval otherwise	error from mixer_setrecsrc
297  */
298 static int
299 mixer_set_recroute(struct snd_mixer *m, int route)
300 {
301 	int i, cnt, ret;
302 
303 	ret = 0;
304 	cnt = 0;
305 
306 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
307 		if ((1 << i) & m->recdevs) {
308 			if (route == cnt)
309 				break;
310 			++cnt;
311 		}
312 	}
313 
314 	if (i == SOUND_MIXER_NRDEVICES)
315 		ret = EINVAL;
316 	else
317 		ret = mixer_setrecsrc(m, (1 << i));
318 
319 	return ret;
320 }
321 
322 void
323 mix_setdevs(struct snd_mixer *m, u_int32_t v)
324 {
325 	struct snddev_info *d;
326 	int i;
327 
328 	if (m == NULL)
329 		return;
330 
331 	d = device_get_softc(m->dev);
332 	if (d != NULL && (d->flags & SD_F_SOFTPCMVOL))
333 		v |= SOUND_MASK_PCM;
334 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
335 		if (m->parent[i] < SOUND_MIXER_NRDEVICES)
336 			v |= 1 << m->parent[i];
337 		v |= m->child[i];
338 	}
339 	m->devs = v;
340 }
341 
342 /**
343  * @brief Record mask of available recording devices
344  *
345  * Calling functions are responsible for defining the mask of available
346  * recording devices.  This function records that value in a structure
347  * used by the rest of the mixer code.
348  *
349  * This function also populates a structure used by the SNDCTL_DSP_*RECSRC*
350  * family of ioctls that are part of OSSV4.  All recording device labels
351  * are concatenated in ascending order corresponding to their routing
352  * numbers.  (Ex:  a system might have 0 => 'vol', 1 => 'cd', 2 => 'line',
353  * etc.)  For now, these labels are just the standard recording device
354  * names (cd, line1, etc.), but will eventually be fully dynamic and user
355  * controlled.
356  *
357  * @param m	mixer device context container thing
358  * @param v	mask of recording devices
359  */
360 void
361 mix_setrecdevs(struct snd_mixer *m, u_int32_t v)
362 {
363 	oss_mixer_enuminfo *ei;
364 	char *loc;
365 	int i, nvalues, nwrote, nleft, ncopied;
366 
367 	ei = &m->enuminfo;
368 
369 	nvalues = 0;
370 	nwrote = 0;
371 	nleft = sizeof(ei->strings);
372 	loc = ei->strings;
373 
374 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
375 		if ((1 << i) & v) {
376 			ei->strindex[nvalues] = nwrote;
377 			ncopied = strlcpy(loc, snd_mixernames[i], nleft) + 1;
378 			    /* strlcpy retval doesn't include terminator */
379 
380 			nwrote += ncopied;
381 			nleft -= ncopied;
382 			nvalues++;
383 
384 			/*
385 			 * XXX I don't think this should ever be possible.
386 			 * Even with a move to dynamic device/channel names,
387 			 * each label is limited to ~16 characters, so that'd
388 			 * take a LOT to fill this buffer.
389 			 */
390 			if ((nleft <= 0) || (nvalues >= OSS_ENUM_MAXVALUE)) {
391 				device_printf(m->dev,
392 				    "mix_setrecdevs:  Not enough room to store device names--please file a bug report.\n");
393 				device_printf(m->dev,
394 				    "mix_setrecdevs:  Please include details about your sound hardware, OS version, etc.\n");
395 				break;
396 			}
397 
398 			loc = &ei->strings[nwrote];
399 		}
400 	}
401 
402 	/*
403 	 * NB:	The SNDCTL_DSP_GET_RECSRC_NAMES ioctl ignores the dev
404 	 * 	and ctrl fields.
405 	 */
406 	ei->nvalues = nvalues;
407 	m->recdevs = v;
408 }
409 
410 void
411 mix_setparentchild(struct snd_mixer *m, u_int32_t parent, u_int32_t childs)
412 {
413 	u_int32_t mask = 0;
414 	int i;
415 
416 	if (m == NULL || parent >= SOUND_MIXER_NRDEVICES)
417 		return;
418 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
419 		if (i == parent)
420 			continue;
421 		if (childs & (1 << i)) {
422 			mask |= 1 << i;
423 			if (m->parent[i] < SOUND_MIXER_NRDEVICES)
424 				m->child[m->parent[i]] &= ~(1 << i);
425 			m->parent[i] = parent;
426 			m->child[i] = 0;
427 		}
428 	}
429 	mask &= ~(1 << parent);
430 	m->child[parent] = mask;
431 }
432 
433 void
434 mix_setrealdev(struct snd_mixer *m, u_int32_t dev, u_int32_t realdev)
435 {
436 	if (m == NULL || dev >= SOUND_MIXER_NRDEVICES ||
437 	    !(realdev == SOUND_MIXER_NONE || realdev < SOUND_MIXER_NRDEVICES))
438 		return;
439 	m->realdev[dev] = realdev;
440 }
441 
442 u_int32_t
443 mix_getparent(struct snd_mixer *m, u_int32_t dev)
444 {
445 	if (m == NULL || dev >= SOUND_MIXER_NRDEVICES)
446 		return SOUND_MIXER_NONE;
447 	return m->parent[dev];
448 }
449 
450 u_int32_t
451 mix_getchild(struct snd_mixer *m, u_int32_t dev)
452 {
453 	if (m == NULL || dev >= SOUND_MIXER_NRDEVICES)
454 		return 0;
455 	return m->child[dev];
456 }
457 
458 u_int32_t
459 mix_getdevs(struct snd_mixer *m)
460 {
461 	return m->devs;
462 }
463 
464 u_int32_t
465 mix_getrecdevs(struct snd_mixer *m)
466 {
467 	return m->recdevs;
468 }
469 
470 void *
471 mix_getdevinfo(struct snd_mixer *m)
472 {
473 	return m->devinfo;
474 }
475 
476 int
477 mixer_init(device_t dev, kobj_class_t cls, void *devinfo)
478 {
479 	struct snddev_info *snddev;
480 	struct snd_mixer *m;
481 	u_int16_t v;
482 	struct cdev *pdev;
483 	int i, unit, val;
484 
485 	m = (struct snd_mixer *)kobj_create(cls, M_MIXER, M_WAITOK | M_ZERO);
486 	snprintf(m->name, MIXER_NAMELEN, "%s:mixer", device_get_nameunit(dev));
487 	m->lock = snd_mtxcreate(m->name, "pcm mixer");
488 	m->type = cls->name;
489 	m->devinfo = devinfo;
490 	m->busy = 0;
491 	m->dev = dev;
492 	for (i = 0; i < 32; i++) {
493 		m->parent[i] = SOUND_MIXER_NONE;
494 		m->child[i] = 0;
495 		m->realdev[i] = i;
496 	}
497 
498 	if (MIXER_INIT(m))
499 		goto bad;
500 
501 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
502 		v = snd_mixerdefaults[i];
503 
504 		if (resource_int_value(device_get_name(dev),
505 		    device_get_unit(dev), snd_mixernames[i], &val) == 0) {
506 			if (val >= 0 && val <= 100) {
507 				v = (u_int16_t) val;
508 			}
509 		}
510 
511 		mixer_set(m, i, v | (v << 8));
512 	}
513 
514 	mixer_setrecsrc(m, SOUND_MASK_MIC);
515 
516 	unit = device_get_unit(dev);
517 	pdev = make_dev(&mixer_cdevsw, PCMMKMINOR(unit, SND_DEV_CTL, 0),
518 		 UID_ROOT, GID_WHEEL, 0666, "mixer%d", unit);
519 	pdev->si_drv1 = m;
520 	snddev = device_get_softc(dev);
521 	snddev->mixer_dev = pdev;
522 
523 	++mixer_count;
524 
525 	if (bootverbose) {
526 		for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
527 			if (!(m->devs & (1 << i)))
528 				continue;
529 			if (m->realdev[i] != i) {
530 				device_printf(dev, "Mixer \"%s\" -> \"%s\":",
531 				    snd_mixernames[i],
532 				    (m->realdev[i] < SOUND_MIXER_NRDEVICES) ?
533 				    snd_mixernames[m->realdev[i]] : "none");
534 			} else {
535 				device_printf(dev, "Mixer \"%s\":",
536 				    snd_mixernames[i]);
537 			}
538 			if (m->parent[i] < SOUND_MIXER_NRDEVICES)
539 				printf(" parent=\"%s\"",
540 				    snd_mixernames[m->parent[i]]);
541 			if (m->child[i] != 0)
542 				printf(" child=0x%08x", m->child[i]);
543 			printf("\n");
544 		}
545 		if (snddev->flags & SD_F_SOFTPCMVOL)
546 			device_printf(dev, "Soft PCM mixer ENABLED\n");
547 	}
548 
549 	return 0;
550 
551 bad:
552 	snd_mtxlock(m->lock);
553 	snd_mtxfree(m->lock);
554 	kobj_delete((kobj_t)m, M_MIXER);
555 	return -1;
556 }
557 
558 int
559 mixer_uninit(device_t dev)
560 {
561 	int i;
562 	struct snddev_info *d;
563 	struct snd_mixer *m;
564 	struct cdev *pdev;
565 
566 	d = device_get_softc(dev);
567 	pdev = mixer_get_devt(dev);
568 	if (d == NULL || pdev == NULL || pdev->si_drv1 == NULL)
569 		return EBADF;
570 	m = pdev->si_drv1;
571 	snd_mtxlock(m->lock);
572 
573 	if (m->busy) {
574 		snd_mtxunlock(m->lock);
575 		return EBUSY;
576 	}
577 
578 	pdev->si_drv1 = NULL;
579 	destroy_dev(pdev);
580 
581 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++)
582 		mixer_set(m, i, 0);
583 
584 	mixer_setrecsrc(m, SOUND_MASK_MIC);
585 
586 	MIXER_UNINIT(m);
587 
588 	snd_mtxfree(m->lock);
589 	kobj_delete((kobj_t)m, M_MIXER);
590 
591 	d->mixer_dev = NULL;
592 
593 	--mixer_count;
594 
595 	return 0;
596 }
597 
598 int
599 mixer_reinit(device_t dev)
600 {
601 	struct snd_mixer *m;
602 	struct cdev *pdev;
603 	int i;
604 
605 	pdev = mixer_get_devt(dev);
606 	m = pdev->si_drv1;
607 	snd_mtxlock(m->lock);
608 
609 	i = MIXER_REINIT(m);
610 	if (i) {
611 		snd_mtxunlock(m->lock);
612 		return i;
613 	}
614 
615 	for (i = 0; i < SOUND_MIXER_NRDEVICES; i++)
616 		mixer_set(m, i, m->level[i]);
617 
618 	mixer_setrecsrc(m, m->recsrc);
619 	snd_mtxunlock(m->lock);
620 
621 	return 0;
622 }
623 
624 #ifdef SND_DYNSYSCTL
625 static int
626 sysctl_hw_snd_hwvol_mixer(SYSCTL_HANDLER_ARGS)
627 {
628 	char devname[32];
629 	int error, dev;
630 	struct snd_mixer *m;
631 
632 	m = oidp->oid_arg1;
633 	snd_mtxlock(m->lock);
634 	strncpy(devname, snd_mixernames[m->hwvol_mixer], sizeof(devname));
635 	snd_mtxunlock(m->lock);
636 	error = sysctl_handle_string(oidp, &devname[0], sizeof(devname), req);
637 	snd_mtxlock(m->lock);
638 	if (error == 0 && req->newptr != NULL) {
639 		dev = mixer_lookup(devname);
640 		if (dev == -1) {
641 			snd_mtxunlock(m->lock);
642 			return EINVAL;
643 		}
644 		else if (dev != m->hwvol_mixer) {
645 			m->hwvol_mixer = dev;
646 			m->hwvol_muted = 0;
647 		}
648 	}
649 	snd_mtxunlock(m->lock);
650 	return error;
651 }
652 #endif
653 
654 int
655 mixer_hwvol_init(device_t dev)
656 {
657 	struct snd_mixer *m;
658 	struct cdev *pdev;
659 
660 	pdev = mixer_get_devt(dev);
661 	m = pdev->si_drv1;
662 
663 	m->hwvol_mixer = SOUND_MIXER_VOLUME;
664 	m->hwvol_step = 5;
665 #ifdef SND_DYNSYSCTL
666 	SYSCTL_ADD_INT(snd_sysctl_tree(dev), SYSCTL_CHILDREN(snd_sysctl_tree_top(dev)),
667             OID_AUTO, "hwvol_step", CTLFLAG_RW, &m->hwvol_step, 0, "");
668 	SYSCTL_ADD_PROC(snd_sysctl_tree(dev), SYSCTL_CHILDREN(snd_sysctl_tree_top(dev)),
669             OID_AUTO, "hwvol_mixer", CTLTYPE_STRING | CTLFLAG_RW, m, 0,
670 	    sysctl_hw_snd_hwvol_mixer, "A", "");
671 #endif
672 	return 0;
673 }
674 
675 void
676 mixer_hwvol_mute(device_t dev)
677 {
678 	struct snd_mixer *m;
679 	struct cdev *pdev;
680 
681 	pdev = mixer_get_devt(dev);
682 	m = pdev->si_drv1;
683 	snd_mtxlock(m->lock);
684 	if (m->hwvol_muted) {
685 		m->hwvol_muted = 0;
686 		mixer_set(m, m->hwvol_mixer, m->hwvol_mute_level);
687 	} else {
688 		m->hwvol_muted++;
689 		m->hwvol_mute_level = mixer_get(m, m->hwvol_mixer);
690 		mixer_set(m, m->hwvol_mixer, 0);
691 	}
692 	snd_mtxunlock(m->lock);
693 }
694 
695 void
696 mixer_hwvol_step(device_t dev, int left_step, int right_step)
697 {
698 	struct snd_mixer *m;
699 	int level, left, right;
700 	struct cdev *pdev;
701 
702 	pdev = mixer_get_devt(dev);
703 	m = pdev->si_drv1;
704 	snd_mtxlock(m->lock);
705 	if (m->hwvol_muted) {
706 		m->hwvol_muted = 0;
707 		level = m->hwvol_mute_level;
708 	} else
709 		level = mixer_get(m, m->hwvol_mixer);
710 	if (level != -1) {
711 		left = level & 0xff;
712 		right = level >> 8;
713 		left += left_step * m->hwvol_step;
714 		if (left < 0)
715 			left = 0;
716 		right += right_step * m->hwvol_step;
717 		if (right < 0)
718 			right = 0;
719 		mixer_set(m, m->hwvol_mixer, left | right << 8);
720 	}
721 	snd_mtxunlock(m->lock);
722 }
723 
724 /* ----------------------------------------------------------------------- */
725 
726 static int
727 mixer_open(struct cdev *i_dev, int flags, int mode, struct thread *td)
728 {
729 	struct snd_mixer *m;
730 
731 	m = i_dev->si_drv1;
732 	snd_mtxlock(m->lock);
733 
734 	m->busy++;
735 
736 	snd_mtxunlock(m->lock);
737 	return 0;
738 }
739 
740 static int
741 mixer_close(struct cdev *i_dev, int flags, int mode, struct thread *td)
742 {
743 	struct snd_mixer *m;
744 
745 	m = i_dev->si_drv1;
746 	snd_mtxlock(m->lock);
747 
748 	if (!m->busy) {
749 		snd_mtxunlock(m->lock);
750 		return EBADF;
751 	}
752 	m->busy--;
753 
754 	snd_mtxunlock(m->lock);
755 	return 0;
756 }
757 
758 int
759 mixer_ioctl(struct cdev *i_dev, u_long cmd, caddr_t arg, int mode, struct thread *td)
760 {
761 	struct snd_mixer *m;
762 	int ret, *arg_i = (int *)arg;
763 	int v = -1, j = cmd & 0xff;
764 
765 	m = i_dev->si_drv1;
766 
767 	if (m == NULL)
768 		return EBADF;
769 
770 	snd_mtxlock(m->lock);
771 	if (mode != -1 && !m->busy) {
772 		snd_mtxunlock(m->lock);
773 		return EBADF;
774 	}
775 
776 	if (cmd == SNDCTL_MIXERINFO) {
777 		snd_mtxunlock(m->lock);
778 		return mixer_oss_mixerinfo(i_dev, (oss_mixerinfo *)arg);
779 	}
780 
781 	if ((cmd & MIXER_WRITE(0)) == MIXER_WRITE(0)) {
782 		if (j == SOUND_MIXER_RECSRC)
783 			ret = mixer_setrecsrc(m, *arg_i);
784 		else
785 			ret = mixer_set(m, j, *arg_i);
786 		snd_mtxunlock(m->lock);
787 		return (ret == 0)? 0 : ENXIO;
788 	}
789 
790     	if ((cmd & MIXER_READ(0)) == MIXER_READ(0)) {
791 		switch (j) {
792     		case SOUND_MIXER_DEVMASK:
793     		case SOUND_MIXER_CAPS:
794     		case SOUND_MIXER_STEREODEVS:
795 			v = mix_getdevs(m);
796 			break;
797 
798     		case SOUND_MIXER_RECMASK:
799 			v = mix_getrecdevs(m);
800 			break;
801 
802     		case SOUND_MIXER_RECSRC:
803 			v = mixer_getrecsrc(m);
804 			break;
805 
806 		default:
807 			v = mixer_get(m, j);
808 		}
809 		*arg_i = v;
810 		snd_mtxunlock(m->lock);
811 		return (v != -1)? 0 : ENXIO;
812 	}
813 
814 	ret = 0;
815 
816 	switch (cmd) {
817  	/** @todo Double check return values, error codes. */
818 	case SNDCTL_SYSINFO:
819 		sound_oss_sysinfo((oss_sysinfo *)arg);
820 		break;
821 	case SNDCTL_AUDIOINFO:
822 		ret = dsp_oss_audioinfo(i_dev, (oss_audioinfo *)arg);
823 		break;
824 	case SNDCTL_DSP_GET_RECSRC_NAMES:
825 		bcopy((void *)&m->enuminfo, arg, sizeof(oss_mixer_enuminfo));
826 		break;
827 	case SNDCTL_DSP_GET_RECSRC:
828 		ret = mixer_get_recroute(m, arg_i);
829 		break;
830 	case SNDCTL_DSP_SET_RECSRC:
831 		ret = mixer_set_recroute(m, *arg_i);
832 		break;
833 	default:
834 		ret = ENXIO;
835 	}
836 
837 	snd_mtxunlock(m->lock);
838 	return ret;
839 }
840 
841 #ifdef USING_DEVFS
842 static void
843 mixer_clone(void *arg, struct ucred *cred, char *name, int namelen,
844     struct cdev **dev)
845 {
846 	struct snddev_info *sd;
847 
848 	if (*dev != NULL)
849 		return;
850 	if (strcmp(name, "mixer") == 0) {
851 		sd = devclass_get_softc(pcm_devclass, snd_unit);
852 		if (sd != NULL && sd->mixer_dev != NULL) {
853 			*dev = sd->mixer_dev;
854 			dev_ref(*dev);
855 		}
856 	}
857 }
858 
859 static void
860 mixer_sysinit(void *p)
861 {
862 	mixer_ehtag = EVENTHANDLER_REGISTER(dev_clone, mixer_clone, 0, 1000);
863 }
864 
865 static void
866 mixer_sysuninit(void *p)
867 {
868 	if (mixer_ehtag != NULL)
869 		EVENTHANDLER_DEREGISTER(dev_clone, mixer_ehtag);
870 }
871 
872 SYSINIT(mixer_sysinit, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, mixer_sysinit, NULL);
873 SYSUNINIT(mixer_sysuninit, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, mixer_sysuninit, NULL);
874 #endif
875 
876 /**
877  * @brief Handler for SNDCTL_MIXERINFO
878  *
879  * This function searches for a mixer based on the numeric ID stored
880  * in oss_miserinfo::dev.  If set to -1, then information about the
881  * current mixer handling the request is provided.  Note, however, that
882  * this ioctl may be made with any sound device (audio, mixer, midi).
883  *
884  * @note Caller must not hold any PCM device, channel, or mixer locks.
885  *
886  * See http://manuals.opensound.com/developer/SNDCTL_MIXERINFO.html for
887  * more information.
888  *
889  * @param i_dev	character device on which the ioctl arrived
890  * @param arg	user argument (oss_mixerinfo *)
891  *
892  * @retval EINVAL	oss_mixerinfo::dev specified a bad value
893  * @retval 0		success
894  */
895 int
896 mixer_oss_mixerinfo(struct cdev *i_dev, oss_mixerinfo *mi)
897 {
898 	struct snddev_info *d;
899 	struct snd_mixer *m;
900 	struct cdev *t_cdev;
901 	int nmix, ret, pcmunit, i;
902 
903 	/*
904 	 * If probing the device handling the ioctl, make sure it's a mixer
905 	 * device.  (This ioctl is valid on audio, mixer, and midi devices.)
906 	 */
907 	if ((mi->dev == -1) && (i_dev->si_devsw != &mixer_cdevsw))
908 		return EINVAL;
909 
910 	d = NULL;
911 	m = NULL;
912 	t_cdev = NULL;
913 	nmix = 0;
914 	ret = 0;
915 	pcmunit = -1; /* pcmX */
916 
917 	/*
918 	 * There's a 1:1 relationship between mixers and PCM devices, so
919 	 * begin by iterating over PCM devices and search for our mixer.
920 	 */
921 	for (i = 0; i < devclass_get_maxunit(pcm_devclass); i++) {
922 		d = devclass_get_softc(pcm_devclass, i);
923 		if (d == NULL)
924 			continue;
925 
926 		/* See the note in function docblock. */
927 		mtx_assert(d->lock, MA_NOTOWNED);
928 		pcm_inprog(d, 1);
929 		pcm_lock(d);
930 
931 		if (d->mixer_dev != NULL) {
932 			if (((mi->dev == -1) && (d->mixer_dev == i_dev)) || (mi->dev == nmix)) {
933 				t_cdev = d->mixer_dev;
934 				pcmunit = i;
935 				break;
936 			}
937 			++nmix;
938 		}
939 
940 		pcm_unlock(d);
941 		pcm_inprog(d, -1);
942 	}
943 
944 	/*
945 	 * If t_cdev is NULL, then search was exhausted and device wasn't
946 	 * found.  No locks are held, so just return.
947 	 */
948 	if (t_cdev == NULL)
949 		return EINVAL;
950 
951 	m = t_cdev->si_drv1;
952 	mtx_lock(m->lock);
953 
954 	/*
955 	 * At this point, the following synchronization stuff has happened:
956 	 *   - a specific PCM device is locked and its "in progress
957 	 *     operations" counter has been incremented, so be sure to unlock
958 	 *     and decrement when exiting;
959 	 *   - a specific mixer device has been locked, so be sure to unlock
960 	 *     when existing.
961 	 */
962 
963 	bzero((void *)mi, sizeof(*mi));
964 
965 	mi->dev = nmix;
966 	snprintf(mi->id, sizeof(mi->id), "mixer%d", dev2unit(t_cdev));
967 	strlcpy(mi->name, m->name, sizeof(mi->name));
968 	mi->modify_counter = m->modify_counter;
969 	mi->card_number = pcmunit;
970 	/*
971 	 * Currently, FreeBSD assumes 1:1 relationship between a pcm and
972 	 * mixer devices, so this is hardcoded to 0.
973 	 */
974 	mi->port_number = 0;
975 
976 	/**
977 	 * @todo Fill in @sa oss_mixerinfo::mixerhandle.
978 	 * @note From 4Front:  "mixerhandle is an arbitrary string that
979 	 * 	 identifies the mixer better than the device number
980 	 * 	 (mixerinfo.dev). Device numbers may change depending on
981 	 * 	 the order the drivers are loaded. However the handle
982 	 * 	 should remain the same provided that the sound card is
983 	 * 	 not moved to another PCI slot."
984 	 */
985 
986 	/**
987 	 * @note
988 	 * @sa oss_mixerinfo::magic is a reserved field.
989 	 *
990 	 * @par
991 	 * From 4Front:  "magic is usually 0. However some devices may have
992 	 * dedicated setup utilities and the magic field may contain an
993 	 * unique driver specific value (managed by [4Front])."
994 	 */
995 
996 	mi->enabled = device_is_attached(m->dev) ? 1 : 0;
997 	/**
998 	 * The only flag for @sa oss_mixerinfo::caps is currently
999 	 * MIXER_CAP_VIRTUAL, which I'm not sure we really worry about.
1000 	 */
1001 	/**
1002 	 * Mixer extensions currently aren't supported, so leave
1003 	 * @sa oss_mixerinfo::nrext blank for now.
1004 	 */
1005 	/**
1006 	 * @todo Fill in @sa oss_mixerinfo::priority (requires touching
1007 	 * 	 drivers?)
1008 	 * @note The priority field is for mixer applets to determine which
1009 	 * mixer should be the default, with 0 being least preferred and 10
1010 	 * being most preferred.  From 4Front:  "OSS drivers like ICH use
1011 	 * higher values (10) because such chips are known to be used only
1012 	 * on motherboards.  Drivers for high end pro devices use 0 because
1013 	 * they will never be the default mixer. Other devices use values 1
1014 	 * to 9 depending on the estimated probability of being the default
1015 	 * device.
1016 	 *
1017 	 * XXX Described by Hannu@4Front, but not found in soundcard.h.
1018 	strlcpy(mi->devnode, t_cdev->si_name, sizeof(mi->devnode));
1019 	mi->legacy_device = pcmunit;
1020 	 */
1021 
1022 	mtx_unlock(m->lock);
1023 	pcm_unlock(d);
1024 	pcm_inprog(d, -1);
1025 
1026 	return ret;
1027 }
1028