xref: /freebsd/sys/dev/sound/pcm/feeder_eq.c (revision f4b37ed0f8b307b1f3f0f630ca725d68f1dff30d)
1 /*-
2  * Copyright (c) 2008-2009 Ariff Abdullah <ariff@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 /*
28  * feeder_eq: Parametric (compile time) Software Equalizer. Though accidental,
29  *            it proves good enough for educational and general consumption.
30  *
31  * "Cookbook formulae for audio EQ biquad filter coefficients"
32  *    by Robert Bristow-Johnson  <rbj@audioimagination.com>
33  *    -  http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt
34  */
35 
36 #ifdef _KERNEL
37 #ifdef HAVE_KERNEL_OPTION_HEADERS
38 #include "opt_snd.h"
39 #endif
40 #include <dev/sound/pcm/sound.h>
41 #include <dev/sound/pcm/pcm.h>
42 #include "feeder_if.h"
43 
44 #define SND_USE_FXDIV
45 #include "snd_fxdiv_gen.h"
46 
47 SND_DECLARE_FILE("$FreeBSD$");
48 #endif
49 
50 #include "feeder_eq_gen.h"
51 
52 #define FEEDEQ_LEVELS							\
53 	(((FEEDEQ_GAIN_MAX - FEEDEQ_GAIN_MIN) *				\
54 	(FEEDEQ_GAIN_DIV / FEEDEQ_GAIN_STEP)) + 1)
55 
56 #define FEEDEQ_L2GAIN(v)						\
57 	((int)min(((v) * FEEDEQ_LEVELS) / 100, FEEDEQ_LEVELS - 1))
58 
59 #define FEEDEQ_PREAMP_IPART(x)		(abs(x) >> FEEDEQ_GAIN_SHIFT)
60 #define FEEDEQ_PREAMP_FPART(x)		(abs(x) & FEEDEQ_GAIN_FMASK)
61 #define FEEDEQ_PREAMP_SIGNVAL(x)	((x) < 0 ? -1 : 1)
62 #define FEEDEQ_PREAMP_SIGNMARK(x)	(((x) < 0) ? '-' : '+')
63 
64 #define FEEDEQ_PREAMP_IMIN	-192
65 #define FEEDEQ_PREAMP_IMAX	192
66 #define FEEDEQ_PREAMP_FMIN	0
67 #define FEEDEQ_PREAMP_FMAX	9
68 
69 #define FEEDEQ_PREAMP_INVALID	INT_MAX
70 
71 #define FEEDEQ_IF2PREAMP(i, f)						\
72 	((abs(i) << FEEDEQ_GAIN_SHIFT) |				\
73 	(((abs(f) / FEEDEQ_GAIN_STEP) * FEEDEQ_GAIN_STEP) &		\
74 	FEEDEQ_GAIN_FMASK))
75 
76 #define FEEDEQ_PREAMP_MIN						\
77 	(FEEDEQ_PREAMP_SIGNVAL(FEEDEQ_GAIN_MIN) *			\
78 	FEEDEQ_IF2PREAMP(FEEDEQ_GAIN_MIN, 0))
79 
80 #define FEEDEQ_PREAMP_MAX						\
81 	(FEEDEQ_PREAMP_SIGNVAL(FEEDEQ_GAIN_MAX) *			\
82 	FEEDEQ_IF2PREAMP(FEEDEQ_GAIN_MAX, 0))
83 
84 #define FEEDEQ_PREAMP_DEFAULT	FEEDEQ_IF2PREAMP(0, 0)
85 
86 #define FEEDEQ_PREAMP2IDX(v)						\
87 	((int32_t)((FEEDEQ_GAIN_MAX * (FEEDEQ_GAIN_DIV /		\
88 	FEEDEQ_GAIN_STEP)) + (FEEDEQ_PREAMP_SIGNVAL(v) *		\
89 	FEEDEQ_PREAMP_IPART(v) * (FEEDEQ_GAIN_DIV /			\
90 	FEEDEQ_GAIN_STEP)) + (FEEDEQ_PREAMP_SIGNVAL(v) *		\
91 	(FEEDEQ_PREAMP_FPART(v) / FEEDEQ_GAIN_STEP))))
92 
93 static int feeder_eq_exact_rate = 0;
94 
95 #ifdef _KERNEL
96 static char feeder_eq_presets[] = FEEDER_EQ_PRESETS;
97 SYSCTL_STRING(_hw_snd, OID_AUTO, feeder_eq_presets, CTLFLAG_RD,
98     &feeder_eq_presets, 0, "compile-time eq presets");
99 
100 SYSCTL_INT(_hw_snd, OID_AUTO, feeder_eq_exact_rate, CTLFLAG_RWTUN,
101     &feeder_eq_exact_rate, 0, "force exact rate validation");
102 #endif
103 
104 struct feed_eq_info;
105 
106 typedef void (*feed_eq_t)(struct feed_eq_info *, uint8_t *, uint32_t);
107 
108 struct feed_eq_tone {
109 	intpcm_t o1[SND_CHN_MAX];
110 	intpcm_t o2[SND_CHN_MAX];
111 	intpcm_t i1[SND_CHN_MAX];
112 	intpcm_t i2[SND_CHN_MAX];
113 	int gain;
114 };
115 
116 struct feed_eq_info {
117 	struct feed_eq_tone treble;
118 	struct feed_eq_tone bass;
119 	struct feed_eq_coeff *coeff;
120 	feed_eq_t biquad;
121 	uint32_t channels;
122 	uint32_t rate;
123 	uint32_t align;
124 	int32_t preamp;
125 	int state;
126 };
127 
128 #if !defined(_KERNEL) && defined(FEEDEQ_ERR_CLIP)
129 #define FEEDEQ_ERR_CLIP_CHECK(t, v)	do {				\
130 	if ((v) < PCM_S32_MIN || (v) > PCM_S32_MAX)			\
131 		errx(1, "\n\n%s(): ["#t"] Sample clipping: %jd\n",	\
132 		    __func__, (intmax_t)(v));				\
133 } while (0)
134 #else
135 #define FEEDEQ_ERR_CLIP_CHECK(...)
136 #endif
137 
138 #define FEEDEQ_CLAMP(v)		(((v) > PCM_S32_MAX) ? PCM_S32_MAX :	\
139 				(((v) < PCM_S32_MIN) ? PCM_S32_MIN :	\
140 				  (v)))
141 
142 #define FEEDEQ_DECLARE(SIGN, BIT, ENDIAN)					\
143 static void									\
144 feed_eq_biquad_##SIGN##BIT##ENDIAN(struct feed_eq_info *info,			\
145     uint8_t *dst, uint32_t count)						\
146 {										\
147 	struct feed_eq_coeff_tone *treble, *bass;				\
148 	intpcm64_t w;								\
149 	intpcm_t v;								\
150 	uint32_t i, j;								\
151 	int32_t pmul, pshift;							\
152 										\
153 	pmul = feed_eq_preamp[info->preamp].mul;				\
154 	pshift = feed_eq_preamp[info->preamp].shift;				\
155 										\
156 	if (info->state == FEEDEQ_DISABLE) {					\
157 		j = count * info->channels;					\
158 		dst += j * PCM_##BIT##_BPS;					\
159 		do {								\
160 			dst -= PCM_##BIT##_BPS;					\
161 			v = _PCM_READ_##SIGN##BIT##_##ENDIAN(dst);		\
162 			v = ((intpcm64_t)pmul * v) >> pshift;			\
163 			_PCM_WRITE_##SIGN##BIT##_##ENDIAN(dst, v);		\
164 		} while (--j != 0);						\
165 										\
166 		return;								\
167 	}									\
168 										\
169 	treble = &(info->coeff[info->treble.gain].treble);			\
170 	bass   = &(info->coeff[info->bass.gain].bass);				\
171 										\
172 	do {									\
173 		i = 0;								\
174 		j = info->channels;						\
175 		do {								\
176 			v = _PCM_READ_##SIGN##BIT##_##ENDIAN(dst);		\
177 			v <<= 32 - BIT;						\
178 			v = ((intpcm64_t)pmul * v) >> pshift;			\
179 										\
180 			w  = (intpcm64_t)v * treble->b0;			\
181 			w += (intpcm64_t)info->treble.i1[i] * treble->b1;	\
182 			w += (intpcm64_t)info->treble.i2[i] * treble->b2;	\
183 			w -= (intpcm64_t)info->treble.o1[i] * treble->a1;	\
184 			w -= (intpcm64_t)info->treble.o2[i] * treble->a2;	\
185 			info->treble.i2[i] = info->treble.i1[i];		\
186 			info->treble.i1[i] = v;					\
187 			info->treble.o2[i] = info->treble.o1[i];		\
188 			w >>= FEEDEQ_COEFF_SHIFT;				\
189 			FEEDEQ_ERR_CLIP_CHECK(treble, w);			\
190 			v = FEEDEQ_CLAMP(w);					\
191 			info->treble.o1[i] = v;					\
192 										\
193 			w  = (intpcm64_t)v * bass->b0;				\
194 			w += (intpcm64_t)info->bass.i1[i] * bass->b1;		\
195 			w += (intpcm64_t)info->bass.i2[i] * bass->b2;		\
196 			w -= (intpcm64_t)info->bass.o1[i] * bass->a1;		\
197 			w -= (intpcm64_t)info->bass.o2[i] * bass->a2;		\
198 			info->bass.i2[i] = info->bass.i1[i];			\
199 			info->bass.i1[i] = v;					\
200 			info->bass.o2[i] = info->bass.o1[i];			\
201 			w >>= FEEDEQ_COEFF_SHIFT;				\
202 			FEEDEQ_ERR_CLIP_CHECK(bass, w);				\
203 			v = FEEDEQ_CLAMP(w);					\
204 			info->bass.o1[i] = v;					\
205 										\
206 			v >>= 32 - BIT;						\
207 			_PCM_WRITE_##SIGN##BIT##_##ENDIAN(dst, v);		\
208 			dst += PCM_##BIT##_BPS;					\
209 			i++;							\
210 		} while (--j != 0);						\
211 	} while (--count != 0);							\
212 }
213 
214 #if BYTE_ORDER == LITTLE_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
215 FEEDEQ_DECLARE(S, 16, LE)
216 FEEDEQ_DECLARE(S, 32, LE)
217 #endif
218 #if BYTE_ORDER == BIG_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
219 FEEDEQ_DECLARE(S, 16, BE)
220 FEEDEQ_DECLARE(S, 32, BE)
221 #endif
222 #ifdef SND_FEEDER_MULTIFORMAT
223 FEEDEQ_DECLARE(S,  8, NE)
224 FEEDEQ_DECLARE(S, 24, LE)
225 FEEDEQ_DECLARE(S, 24, BE)
226 FEEDEQ_DECLARE(U,  8, NE)
227 FEEDEQ_DECLARE(U, 16, LE)
228 FEEDEQ_DECLARE(U, 24, LE)
229 FEEDEQ_DECLARE(U, 32, LE)
230 FEEDEQ_DECLARE(U, 16, BE)
231 FEEDEQ_DECLARE(U, 24, BE)
232 FEEDEQ_DECLARE(U, 32, BE)
233 #endif
234 
235 #define FEEDEQ_ENTRY(SIGN, BIT, ENDIAN)					\
236 	{								\
237 		AFMT_##SIGN##BIT##_##ENDIAN,				\
238 		feed_eq_biquad_##SIGN##BIT##ENDIAN			\
239 	}
240 
241 
242 static const struct {
243 	uint32_t format;
244 	feed_eq_t biquad;
245 } feed_eq_biquad_tab[] = {
246 #if BYTE_ORDER == LITTLE_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
247 	FEEDEQ_ENTRY(S, 16, LE),
248 	FEEDEQ_ENTRY(S, 32, LE),
249 #endif
250 #if BYTE_ORDER == BIG_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
251 	FEEDEQ_ENTRY(S, 16, BE),
252 	FEEDEQ_ENTRY(S, 32, BE),
253 #endif
254 #ifdef SND_FEEDER_MULTIFORMAT
255 	FEEDEQ_ENTRY(S,  8, NE),
256 	FEEDEQ_ENTRY(S, 24, LE),
257 	FEEDEQ_ENTRY(S, 24, BE),
258 	FEEDEQ_ENTRY(U,  8, NE),
259 	FEEDEQ_ENTRY(U, 16, LE),
260 	FEEDEQ_ENTRY(U, 24, LE),
261 	FEEDEQ_ENTRY(U, 32, LE),
262 	FEEDEQ_ENTRY(U, 16, BE),
263 	FEEDEQ_ENTRY(U, 24, BE),
264 	FEEDEQ_ENTRY(U, 32, BE)
265 #endif
266 };
267 
268 #define FEEDEQ_BIQUAD_TAB_SIZE						\
269 	((int32_t)(sizeof(feed_eq_biquad_tab) / sizeof(feed_eq_biquad_tab[0])))
270 
271 static struct feed_eq_coeff *
272 feed_eq_coeff_rate(uint32_t rate)
273 {
274 	uint32_t spd, threshold;
275 	int i;
276 
277 	if (rate < FEEDEQ_RATE_MIN || rate > FEEDEQ_RATE_MAX)
278 		return (NULL);
279 
280 	/*
281 	 * Not all rates are supported. Choose the best rate that we can to
282 	 * allow 'sloppy' conversion. Good enough for naive listeners.
283 	 */
284 	for (i = 0; i < FEEDEQ_TAB_SIZE; i++) {
285 		spd = feed_eq_tab[i].rate;
286 		threshold = spd + ((i < (FEEDEQ_TAB_SIZE - 1) &&
287 		    feed_eq_tab[i + 1].rate > spd) ?
288 		    ((feed_eq_tab[i + 1].rate - spd) >> 1) : 0);
289 		if (rate == spd ||
290 		    (feeder_eq_exact_rate == 0 && rate <= threshold))
291 			return (feed_eq_tab[i].coeff);
292 	}
293 
294 	return (NULL);
295 }
296 
297 int
298 feeder_eq_validrate(uint32_t rate)
299 {
300 
301 	if (feed_eq_coeff_rate(rate) != NULL)
302 		return (1);
303 
304 	return (0);
305 }
306 
307 static void
308 feed_eq_reset(struct feed_eq_info *info)
309 {
310 	uint32_t i;
311 
312 	for (i = 0; i < info->channels; i++) {
313 		info->treble.i1[i] = 0;
314 		info->treble.i2[i] = 0;
315 		info->treble.o1[i] = 0;
316 		info->treble.o2[i] = 0;
317 		info->bass.i1[i] = 0;
318 		info->bass.i2[i] = 0;
319 		info->bass.o1[i] = 0;
320 		info->bass.o2[i] = 0;
321 	}
322 }
323 
324 static int
325 feed_eq_setup(struct feed_eq_info *info)
326 {
327 
328 	info->coeff = feed_eq_coeff_rate(info->rate);
329 	if (info->coeff == NULL)
330 		return (EINVAL);
331 
332 	feed_eq_reset(info);
333 
334 	return (0);
335 }
336 
337 static int
338 feed_eq_init(struct pcm_feeder *f)
339 {
340 	struct feed_eq_info *info;
341 	feed_eq_t biquad_op;
342 	int i;
343 
344 	if (f->desc->in != f->desc->out)
345 		return (EINVAL);
346 
347 	biquad_op = NULL;
348 
349 	for (i = 0; i < FEEDEQ_BIQUAD_TAB_SIZE && biquad_op == NULL; i++) {
350 		if (AFMT_ENCODING(f->desc->in) == feed_eq_biquad_tab[i].format)
351 			biquad_op = feed_eq_biquad_tab[i].biquad;
352 	}
353 
354 	if (biquad_op == NULL)
355 		return (EINVAL);
356 
357 	info = malloc(sizeof(*info), M_DEVBUF, M_NOWAIT | M_ZERO);
358 	if (info == NULL)
359 		return (ENOMEM);
360 
361 	info->channels = AFMT_CHANNEL(f->desc->in);
362 	info->align = info->channels * AFMT_BPS(f->desc->in);
363 
364 	info->rate = FEEDEQ_RATE_MIN;
365 	info->treble.gain = FEEDEQ_L2GAIN(50);
366 	info->bass.gain = FEEDEQ_L2GAIN(50);
367 	info->preamp = FEEDEQ_PREAMP2IDX(FEEDEQ_PREAMP_DEFAULT);
368 	info->state = FEEDEQ_UNKNOWN;
369 
370 	info->biquad = biquad_op;
371 
372 	f->data = info;
373 
374 	return (feed_eq_setup(info));
375 }
376 
377 static int
378 feed_eq_set(struct pcm_feeder *f, int what, int value)
379 {
380 	struct feed_eq_info *info;
381 
382 	info = f->data;
383 
384 	switch (what) {
385 	case FEEDEQ_CHANNELS:
386 		if (value < SND_CHN_MIN || value > SND_CHN_MAX)
387 			return (EINVAL);
388 		info->channels = (uint32_t)value;
389 		info->align = info->channels * AFMT_BPS(f->desc->in);
390 		feed_eq_reset(info);
391 		break;
392 	case FEEDEQ_RATE:
393 		if (feeder_eq_validrate(value) == 0)
394 			return (EINVAL);
395 		info->rate = (uint32_t)value;
396 		if (info->state == FEEDEQ_UNKNOWN)
397 			info->state = FEEDEQ_ENABLE;
398 		return (feed_eq_setup(info));
399 		break;
400 	case FEEDEQ_TREBLE:
401 	case FEEDEQ_BASS:
402 		if (value < 0 || value > 100)
403 			return (EINVAL);
404 		if (what == FEEDEQ_TREBLE)
405 			info->treble.gain = FEEDEQ_L2GAIN(value);
406 		else
407 			info->bass.gain = FEEDEQ_L2GAIN(value);
408 		break;
409 	case FEEDEQ_PREAMP:
410 		if (value < FEEDEQ_PREAMP_MIN || value > FEEDEQ_PREAMP_MAX)
411 			return (EINVAL);
412 		info->preamp = FEEDEQ_PREAMP2IDX(value);
413 		break;
414 	case FEEDEQ_STATE:
415 		if (!(value == FEEDEQ_BYPASS || value == FEEDEQ_ENABLE ||
416 		    value == FEEDEQ_DISABLE))
417 			return (EINVAL);
418 		info->state = value;
419 		feed_eq_reset(info);
420 		break;
421 	default:
422 		return (EINVAL);
423 		break;
424 	}
425 
426 	return (0);
427 }
428 
429 static int
430 feed_eq_free(struct pcm_feeder *f)
431 {
432 	struct feed_eq_info *info;
433 
434 	info = f->data;
435 	if (info != NULL)
436 		free(info, M_DEVBUF);
437 
438 	f->data = NULL;
439 
440 	return (0);
441 }
442 
443 static int
444 feed_eq_feed(struct pcm_feeder *f, struct pcm_channel *c, uint8_t *b,
445     uint32_t count, void *source)
446 {
447 	struct feed_eq_info *info;
448 	uint32_t j;
449 	uint8_t *dst;
450 
451 	info = f->data;
452 
453 	/*
454 	 * 3 major states:
455 	 * 	FEEDEQ_BYPASS  - Bypass entirely, nothing happened.
456 	 *      FEEDEQ_ENABLE  - Preamp+biquad filtering.
457 	 *      FEEDEQ_DISABLE - Preamp only.
458 	 */
459 	if (info->state == FEEDEQ_BYPASS)
460 		return (FEEDER_FEED(f->source, c, b, count, source));
461 
462 	dst = b;
463 	count = SND_FXROUND(count, info->align);
464 
465 	do {
466 		if (count < info->align)
467 			break;
468 
469 		j = SND_FXDIV(FEEDER_FEED(f->source, c, dst, count, source),
470 		    info->align);
471 		if (j == 0)
472 			break;
473 
474 		info->biquad(info, dst, j);
475 
476 		j *= info->align;
477 		dst += j;
478 		count -= j;
479 
480 	} while (count != 0);
481 
482 	return (dst - b);
483 }
484 
485 static struct pcm_feederdesc feeder_eq_desc[] = {
486 	{ FEEDER_EQ, 0, 0, 0, 0 },
487 	{ 0, 0, 0, 0, 0 }
488 };
489 
490 static kobj_method_t feeder_eq_methods[] = {
491 	KOBJMETHOD(feeder_init,		feed_eq_init),
492 	KOBJMETHOD(feeder_free,		feed_eq_free),
493 	KOBJMETHOD(feeder_set,		feed_eq_set),
494 	KOBJMETHOD(feeder_feed,		feed_eq_feed),
495 	KOBJMETHOD_END
496 };
497 
498 FEEDER_DECLARE(feeder_eq, NULL);
499 
500 static int32_t
501 feed_eq_scan_preamp_arg(const char *s)
502 {
503 	int r, i, f;
504 	size_t len;
505 	char buf[32];
506 
507 	bzero(buf, sizeof(buf));
508 
509 	/* XXX kind of ugly, but works for now.. */
510 
511 	r = sscanf(s, "%d.%d", &i, &f);
512 
513 	if (r == 1 && !(i < FEEDEQ_PREAMP_IMIN || i > FEEDEQ_PREAMP_IMAX)) {
514 		snprintf(buf, sizeof(buf), "%c%d",
515 		    FEEDEQ_PREAMP_SIGNMARK(i), abs(i));
516 		f = 0;
517 	} else if (r == 2 &&
518 	    !(i < FEEDEQ_PREAMP_IMIN || i > FEEDEQ_PREAMP_IMAX ||
519 	    f < FEEDEQ_PREAMP_FMIN || f > FEEDEQ_PREAMP_FMAX))
520 		snprintf(buf, sizeof(buf), "%c%d.%d",
521 		    FEEDEQ_PREAMP_SIGNMARK(i), abs(i), f);
522 	else
523 		return (FEEDEQ_PREAMP_INVALID);
524 
525 	len = strlen(s);
526 	if (len > 2 && strcasecmp(s + len - 2, "dB") == 0)
527 		strlcat(buf, "dB", sizeof(buf));
528 
529 	if (i == 0 && *s == '-')
530 		*buf = '-';
531 
532 	if (strcasecmp(buf + ((*s >= '0' && *s <= '9') ? 1 : 0), s) != 0)
533 		return (FEEDEQ_PREAMP_INVALID);
534 
535 	while ((f / FEEDEQ_GAIN_DIV) > 0)
536 		f /= FEEDEQ_GAIN_DIV;
537 
538 	return (((i < 0 || *buf == '-') ? -1 : 1) * FEEDEQ_IF2PREAMP(i, f));
539 }
540 
541 #ifdef _KERNEL
542 static int
543 sysctl_dev_pcm_eq(SYSCTL_HANDLER_ARGS)
544 {
545 	struct snddev_info *d;
546 	struct pcm_channel *c;
547 	struct pcm_feeder *f;
548 	int err, val, oval;
549 
550 	d = oidp->oid_arg1;
551 	if (!PCM_REGISTERED(d))
552 		return (ENODEV);
553 
554 	PCM_LOCK(d);
555 	PCM_WAIT(d);
556 	if (d->flags & SD_F_EQ_BYPASSED)
557 		val = 2;
558 	else if (d->flags & SD_F_EQ_ENABLED)
559 		val = 1;
560 	else
561 		val = 0;
562 	PCM_ACQUIRE(d);
563 	PCM_UNLOCK(d);
564 
565 	oval = val;
566 	err = sysctl_handle_int(oidp, &val, 0, req);
567 
568 	if (err == 0 && req->newptr != NULL && val != oval) {
569 		if (!(val == 0 || val == 1 || val == 2)) {
570 			PCM_RELEASE_QUICK(d);
571 			return (EINVAL);
572 		}
573 
574 		PCM_LOCK(d);
575 
576 		d->flags &= ~(SD_F_EQ_ENABLED | SD_F_EQ_BYPASSED);
577 		if (val == 2) {
578 			val = FEEDEQ_BYPASS;
579 			d->flags |= SD_F_EQ_BYPASSED;
580 		} else if (val == 1) {
581 			val = FEEDEQ_ENABLE;
582 			d->flags |= SD_F_EQ_ENABLED;
583 		} else
584 			val = FEEDEQ_DISABLE;
585 
586 		CHN_FOREACH(c, d, channels.pcm.busy) {
587 			CHN_LOCK(c);
588 			f = chn_findfeeder(c, FEEDER_EQ);
589 			if (f != NULL)
590 				(void)FEEDER_SET(f, FEEDEQ_STATE, val);
591 			CHN_UNLOCK(c);
592 		}
593 
594 		PCM_RELEASE(d);
595 		PCM_UNLOCK(d);
596 	} else
597 		PCM_RELEASE_QUICK(d);
598 
599 	return (err);
600 }
601 
602 static int
603 sysctl_dev_pcm_eq_preamp(SYSCTL_HANDLER_ARGS)
604 {
605 	struct snddev_info *d;
606 	struct pcm_channel *c;
607 	struct pcm_feeder *f;
608 	int err, val, oval;
609 	char buf[32];
610 
611 	d = oidp->oid_arg1;
612 	if (!PCM_REGISTERED(d))
613 		return (ENODEV);
614 
615 	PCM_LOCK(d);
616 	PCM_WAIT(d);
617 	val = d->eqpreamp;
618 	bzero(buf, sizeof(buf));
619 	(void)snprintf(buf, sizeof(buf), "%c%d.%ddB",
620 	    FEEDEQ_PREAMP_SIGNMARK(val), FEEDEQ_PREAMP_IPART(val),
621 	    FEEDEQ_PREAMP_FPART(val));
622 	PCM_ACQUIRE(d);
623 	PCM_UNLOCK(d);
624 
625 	oval = val;
626 	err = sysctl_handle_string(oidp, buf, sizeof(buf), req);
627 
628 	if (err == 0 && req->newptr != NULL) {
629 		val = feed_eq_scan_preamp_arg(buf);
630 		if (val == FEEDEQ_PREAMP_INVALID) {
631 			PCM_RELEASE_QUICK(d);
632 			return (EINVAL);
633 		}
634 
635 		PCM_LOCK(d);
636 
637 		if (val != oval) {
638 			if (val < FEEDEQ_PREAMP_MIN)
639 				val = FEEDEQ_PREAMP_MIN;
640 			else if (val > FEEDEQ_PREAMP_MAX)
641 				val = FEEDEQ_PREAMP_MAX;
642 
643 			d->eqpreamp = val;
644 
645 			CHN_FOREACH(c, d, channels.pcm.busy) {
646 				CHN_LOCK(c);
647 				f = chn_findfeeder(c, FEEDER_EQ);
648 				if (f != NULL)
649 					(void)FEEDER_SET(f, FEEDEQ_PREAMP, val);
650 				CHN_UNLOCK(c);
651 			}
652 
653 		}
654 
655 		PCM_RELEASE(d);
656 		PCM_UNLOCK(d);
657 	} else
658 		PCM_RELEASE_QUICK(d);
659 
660 	return (err);
661 }
662 
663 void
664 feeder_eq_initsys(device_t dev)
665 {
666 	struct snddev_info *d;
667 	const char *preamp;
668 	char buf[64];
669 
670 	d = device_get_softc(dev);
671 
672 	if (!(resource_string_value(device_get_name(dev), device_get_unit(dev),
673 	    "eq_preamp", &preamp) == 0 &&
674 	    (d->eqpreamp = feed_eq_scan_preamp_arg(preamp)) !=
675 	    FEEDEQ_PREAMP_INVALID))
676 		d->eqpreamp = FEEDEQ_PREAMP_DEFAULT;
677 
678 	if (d->eqpreamp < FEEDEQ_PREAMP_MIN)
679 		d->eqpreamp = FEEDEQ_PREAMP_MIN;
680 	else if (d->eqpreamp > FEEDEQ_PREAMP_MAX)
681 		d->eqpreamp = FEEDEQ_PREAMP_MAX;
682 
683 	SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
684 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO,
685 	    "eq", CTLTYPE_INT | CTLFLAG_RWTUN, d, sizeof(d),
686 	    sysctl_dev_pcm_eq, "I",
687 	    "Bass/Treble Equalizer (0=disable, 1=enable, 2=bypass)");
688 
689 	(void)snprintf(buf, sizeof(buf), "Bass/Treble Equalizer Preamp "
690 	    "(-/+ %d.0dB , %d.%ddB step)",
691 	    FEEDEQ_GAIN_MAX, FEEDEQ_GAIN_STEP / FEEDEQ_GAIN_DIV,
692 	    FEEDEQ_GAIN_STEP - ((FEEDEQ_GAIN_STEP / FEEDEQ_GAIN_DIV) *
693 	    FEEDEQ_GAIN_DIV));
694 
695 	SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
696 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO,
697 	    "eq_preamp", CTLTYPE_STRING | CTLFLAG_RWTUN, d, sizeof(d),
698 	    sysctl_dev_pcm_eq_preamp, "A", buf);
699 }
700 #endif
701