xref: /freebsd/sys/dev/sound/pcm/feeder_eq.c (revision b9f654b163bce26de79705e77b872427c9f2afa1)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2008-2009 Ariff Abdullah <ariff@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*
30  * feeder_eq: Parametric (compile time) Software Equalizer. Though accidental,
31  *            it proves good enough for educational and general consumption.
32  *
33  * "Cookbook formulae for audio EQ biquad filter coefficients"
34  *    by Robert Bristow-Johnson  <rbj@audioimagination.com>
35  *    -  http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt
36  */
37 
38 #ifdef _KERNEL
39 #ifdef HAVE_KERNEL_OPTION_HEADERS
40 #include "opt_snd.h"
41 #endif
42 #include <dev/sound/pcm/sound.h>
43 #include <dev/sound/pcm/pcm.h>
44 #include "feeder_if.h"
45 
46 #define SND_USE_FXDIV
47 #include "snd_fxdiv_gen.h"
48 
49 SND_DECLARE_FILE("$FreeBSD$");
50 #endif
51 
52 #include "feeder_eq_gen.h"
53 
54 #define FEEDEQ_LEVELS							\
55 	(((FEEDEQ_GAIN_MAX - FEEDEQ_GAIN_MIN) *				\
56 	(FEEDEQ_GAIN_DIV / FEEDEQ_GAIN_STEP)) + 1)
57 
58 #define FEEDEQ_L2GAIN(v)						\
59 	((int)min(((v) * FEEDEQ_LEVELS) / 100, FEEDEQ_LEVELS - 1))
60 
61 #define FEEDEQ_PREAMP_IPART(x)		(abs(x) >> FEEDEQ_GAIN_SHIFT)
62 #define FEEDEQ_PREAMP_FPART(x)		(abs(x) & FEEDEQ_GAIN_FMASK)
63 #define FEEDEQ_PREAMP_SIGNVAL(x)	((x) < 0 ? -1 : 1)
64 #define FEEDEQ_PREAMP_SIGNMARK(x)	(((x) < 0) ? '-' : '+')
65 
66 #define FEEDEQ_PREAMP_IMIN	-192
67 #define FEEDEQ_PREAMP_IMAX	192
68 #define FEEDEQ_PREAMP_FMIN	0
69 #define FEEDEQ_PREAMP_FMAX	9
70 
71 #define FEEDEQ_PREAMP_INVALID	INT_MAX
72 
73 #define FEEDEQ_IF2PREAMP(i, f)						\
74 	((abs(i) << FEEDEQ_GAIN_SHIFT) |				\
75 	(((abs(f) / FEEDEQ_GAIN_STEP) * FEEDEQ_GAIN_STEP) &		\
76 	FEEDEQ_GAIN_FMASK))
77 
78 #define FEEDEQ_PREAMP_MIN						\
79 	(FEEDEQ_PREAMP_SIGNVAL(FEEDEQ_GAIN_MIN) *			\
80 	FEEDEQ_IF2PREAMP(FEEDEQ_GAIN_MIN, 0))
81 
82 #define FEEDEQ_PREAMP_MAX						\
83 	(FEEDEQ_PREAMP_SIGNVAL(FEEDEQ_GAIN_MAX) *			\
84 	FEEDEQ_IF2PREAMP(FEEDEQ_GAIN_MAX, 0))
85 
86 #define FEEDEQ_PREAMP_DEFAULT	FEEDEQ_IF2PREAMP(0, 0)
87 
88 #define FEEDEQ_PREAMP2IDX(v)						\
89 	((int32_t)((FEEDEQ_GAIN_MAX * (FEEDEQ_GAIN_DIV /		\
90 	FEEDEQ_GAIN_STEP)) + (FEEDEQ_PREAMP_SIGNVAL(v) *		\
91 	FEEDEQ_PREAMP_IPART(v) * (FEEDEQ_GAIN_DIV /			\
92 	FEEDEQ_GAIN_STEP)) + (FEEDEQ_PREAMP_SIGNVAL(v) *		\
93 	(FEEDEQ_PREAMP_FPART(v) / FEEDEQ_GAIN_STEP))))
94 
95 static int feeder_eq_exact_rate = 0;
96 
97 #ifdef _KERNEL
98 static char feeder_eq_presets[] = FEEDER_EQ_PRESETS;
99 SYSCTL_STRING(_hw_snd, OID_AUTO, feeder_eq_presets, CTLFLAG_RD,
100     &feeder_eq_presets, 0, "compile-time eq presets");
101 
102 SYSCTL_INT(_hw_snd, OID_AUTO, feeder_eq_exact_rate, CTLFLAG_RWTUN,
103     &feeder_eq_exact_rate, 0, "force exact rate validation");
104 #endif
105 
106 struct feed_eq_info;
107 
108 typedef void (*feed_eq_t)(struct feed_eq_info *, uint8_t *, uint32_t);
109 
110 struct feed_eq_tone {
111 	intpcm_t o1[SND_CHN_MAX];
112 	intpcm_t o2[SND_CHN_MAX];
113 	intpcm_t i1[SND_CHN_MAX];
114 	intpcm_t i2[SND_CHN_MAX];
115 	int gain;
116 };
117 
118 struct feed_eq_info {
119 	struct feed_eq_tone treble;
120 	struct feed_eq_tone bass;
121 	struct feed_eq_coeff *coeff;
122 	feed_eq_t biquad;
123 	uint32_t channels;
124 	uint32_t rate;
125 	uint32_t align;
126 	int32_t preamp;
127 	int state;
128 };
129 
130 #if !defined(_KERNEL) && defined(FEEDEQ_ERR_CLIP)
131 #define FEEDEQ_ERR_CLIP_CHECK(t, v)	do {				\
132 	if ((v) < PCM_S32_MIN || (v) > PCM_S32_MAX)			\
133 		errx(1, "\n\n%s(): ["#t"] Sample clipping: %jd\n",	\
134 		    __func__, (intmax_t)(v));				\
135 } while (0)
136 #else
137 #define FEEDEQ_ERR_CLIP_CHECK(...)
138 #endif
139 
140 #define FEEDEQ_CLAMP(v)		(((v) > PCM_S32_MAX) ? PCM_S32_MAX :	\
141 				(((v) < PCM_S32_MIN) ? PCM_S32_MIN :	\
142 				  (v)))
143 
144 #define FEEDEQ_DECLARE(SIGN, BIT, ENDIAN)					\
145 static void									\
146 feed_eq_biquad_##SIGN##BIT##ENDIAN(struct feed_eq_info *info,			\
147     uint8_t *dst, uint32_t count)						\
148 {										\
149 	struct feed_eq_coeff_tone *treble, *bass;				\
150 	intpcm64_t w;								\
151 	intpcm_t v;								\
152 	uint32_t i, j;								\
153 	int32_t pmul, pshift;							\
154 										\
155 	pmul = feed_eq_preamp[info->preamp].mul;				\
156 	pshift = feed_eq_preamp[info->preamp].shift;				\
157 										\
158 	if (info->state == FEEDEQ_DISABLE) {					\
159 		j = count * info->channels;					\
160 		dst += j * PCM_##BIT##_BPS;					\
161 		do {								\
162 			dst -= PCM_##BIT##_BPS;					\
163 			v = _PCM_READ_##SIGN##BIT##_##ENDIAN(dst);		\
164 			v = ((intpcm64_t)pmul * v) >> pshift;			\
165 			_PCM_WRITE_##SIGN##BIT##_##ENDIAN(dst, v);		\
166 		} while (--j != 0);						\
167 										\
168 		return;								\
169 	}									\
170 										\
171 	treble = &(info->coeff[info->treble.gain].treble);			\
172 	bass   = &(info->coeff[info->bass.gain].bass);				\
173 										\
174 	do {									\
175 		i = 0;								\
176 		j = info->channels;						\
177 		do {								\
178 			v = _PCM_READ_##SIGN##BIT##_##ENDIAN(dst);		\
179 			v <<= 32 - BIT;						\
180 			v = ((intpcm64_t)pmul * v) >> pshift;			\
181 										\
182 			w  = (intpcm64_t)v * treble->b0;			\
183 			w += (intpcm64_t)info->treble.i1[i] * treble->b1;	\
184 			w += (intpcm64_t)info->treble.i2[i] * treble->b2;	\
185 			w -= (intpcm64_t)info->treble.o1[i] * treble->a1;	\
186 			w -= (intpcm64_t)info->treble.o2[i] * treble->a2;	\
187 			info->treble.i2[i] = info->treble.i1[i];		\
188 			info->treble.i1[i] = v;					\
189 			info->treble.o2[i] = info->treble.o1[i];		\
190 			w >>= FEEDEQ_COEFF_SHIFT;				\
191 			FEEDEQ_ERR_CLIP_CHECK(treble, w);			\
192 			v = FEEDEQ_CLAMP(w);					\
193 			info->treble.o1[i] = v;					\
194 										\
195 			w  = (intpcm64_t)v * bass->b0;				\
196 			w += (intpcm64_t)info->bass.i1[i] * bass->b1;		\
197 			w += (intpcm64_t)info->bass.i2[i] * bass->b2;		\
198 			w -= (intpcm64_t)info->bass.o1[i] * bass->a1;		\
199 			w -= (intpcm64_t)info->bass.o2[i] * bass->a2;		\
200 			info->bass.i2[i] = info->bass.i1[i];			\
201 			info->bass.i1[i] = v;					\
202 			info->bass.o2[i] = info->bass.o1[i];			\
203 			w >>= FEEDEQ_COEFF_SHIFT;				\
204 			FEEDEQ_ERR_CLIP_CHECK(bass, w);				\
205 			v = FEEDEQ_CLAMP(w);					\
206 			info->bass.o1[i] = v;					\
207 										\
208 			v >>= 32 - BIT;						\
209 			_PCM_WRITE_##SIGN##BIT##_##ENDIAN(dst, v);		\
210 			dst += PCM_##BIT##_BPS;					\
211 			i++;							\
212 		} while (--j != 0);						\
213 	} while (--count != 0);							\
214 }
215 
216 #if BYTE_ORDER == LITTLE_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
217 FEEDEQ_DECLARE(S, 16, LE)
218 FEEDEQ_DECLARE(S, 32, LE)
219 #endif
220 #if BYTE_ORDER == BIG_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
221 FEEDEQ_DECLARE(S, 16, BE)
222 FEEDEQ_DECLARE(S, 32, BE)
223 #endif
224 #ifdef SND_FEEDER_MULTIFORMAT
225 FEEDEQ_DECLARE(S,  8, NE)
226 FEEDEQ_DECLARE(S, 24, LE)
227 FEEDEQ_DECLARE(S, 24, BE)
228 FEEDEQ_DECLARE(U,  8, NE)
229 FEEDEQ_DECLARE(U, 16, LE)
230 FEEDEQ_DECLARE(U, 24, LE)
231 FEEDEQ_DECLARE(U, 32, LE)
232 FEEDEQ_DECLARE(U, 16, BE)
233 FEEDEQ_DECLARE(U, 24, BE)
234 FEEDEQ_DECLARE(U, 32, BE)
235 #endif
236 
237 #define FEEDEQ_ENTRY(SIGN, BIT, ENDIAN)					\
238 	{								\
239 		AFMT_##SIGN##BIT##_##ENDIAN,				\
240 		feed_eq_biquad_##SIGN##BIT##ENDIAN			\
241 	}
242 
243 
244 static const struct {
245 	uint32_t format;
246 	feed_eq_t biquad;
247 } feed_eq_biquad_tab[] = {
248 #if BYTE_ORDER == LITTLE_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
249 	FEEDEQ_ENTRY(S, 16, LE),
250 	FEEDEQ_ENTRY(S, 32, LE),
251 #endif
252 #if BYTE_ORDER == BIG_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
253 	FEEDEQ_ENTRY(S, 16, BE),
254 	FEEDEQ_ENTRY(S, 32, BE),
255 #endif
256 #ifdef SND_FEEDER_MULTIFORMAT
257 	FEEDEQ_ENTRY(S,  8, NE),
258 	FEEDEQ_ENTRY(S, 24, LE),
259 	FEEDEQ_ENTRY(S, 24, BE),
260 	FEEDEQ_ENTRY(U,  8, NE),
261 	FEEDEQ_ENTRY(U, 16, LE),
262 	FEEDEQ_ENTRY(U, 24, LE),
263 	FEEDEQ_ENTRY(U, 32, LE),
264 	FEEDEQ_ENTRY(U, 16, BE),
265 	FEEDEQ_ENTRY(U, 24, BE),
266 	FEEDEQ_ENTRY(U, 32, BE)
267 #endif
268 };
269 
270 #define FEEDEQ_BIQUAD_TAB_SIZE						\
271 	((int32_t)(sizeof(feed_eq_biquad_tab) / sizeof(feed_eq_biquad_tab[0])))
272 
273 static struct feed_eq_coeff *
274 feed_eq_coeff_rate(uint32_t rate)
275 {
276 	uint32_t spd, threshold;
277 	int i;
278 
279 	if (rate < FEEDEQ_RATE_MIN || rate > FEEDEQ_RATE_MAX)
280 		return (NULL);
281 
282 	/*
283 	 * Not all rates are supported. Choose the best rate that we can to
284 	 * allow 'sloppy' conversion. Good enough for naive listeners.
285 	 */
286 	for (i = 0; i < FEEDEQ_TAB_SIZE; i++) {
287 		spd = feed_eq_tab[i].rate;
288 		threshold = spd + ((i < (FEEDEQ_TAB_SIZE - 1) &&
289 		    feed_eq_tab[i + 1].rate > spd) ?
290 		    ((feed_eq_tab[i + 1].rate - spd) >> 1) : 0);
291 		if (rate == spd ||
292 		    (feeder_eq_exact_rate == 0 && rate <= threshold))
293 			return (feed_eq_tab[i].coeff);
294 	}
295 
296 	return (NULL);
297 }
298 
299 int
300 feeder_eq_validrate(uint32_t rate)
301 {
302 
303 	if (feed_eq_coeff_rate(rate) != NULL)
304 		return (1);
305 
306 	return (0);
307 }
308 
309 static void
310 feed_eq_reset(struct feed_eq_info *info)
311 {
312 	uint32_t i;
313 
314 	for (i = 0; i < info->channels; i++) {
315 		info->treble.i1[i] = 0;
316 		info->treble.i2[i] = 0;
317 		info->treble.o1[i] = 0;
318 		info->treble.o2[i] = 0;
319 		info->bass.i1[i] = 0;
320 		info->bass.i2[i] = 0;
321 		info->bass.o1[i] = 0;
322 		info->bass.o2[i] = 0;
323 	}
324 }
325 
326 static int
327 feed_eq_setup(struct feed_eq_info *info)
328 {
329 
330 	info->coeff = feed_eq_coeff_rate(info->rate);
331 	if (info->coeff == NULL)
332 		return (EINVAL);
333 
334 	feed_eq_reset(info);
335 
336 	return (0);
337 }
338 
339 static int
340 feed_eq_init(struct pcm_feeder *f)
341 {
342 	struct feed_eq_info *info;
343 	feed_eq_t biquad_op;
344 	int i;
345 
346 	if (f->desc->in != f->desc->out)
347 		return (EINVAL);
348 
349 	biquad_op = NULL;
350 
351 	for (i = 0; i < FEEDEQ_BIQUAD_TAB_SIZE && biquad_op == NULL; i++) {
352 		if (AFMT_ENCODING(f->desc->in) == feed_eq_biquad_tab[i].format)
353 			biquad_op = feed_eq_biquad_tab[i].biquad;
354 	}
355 
356 	if (biquad_op == NULL)
357 		return (EINVAL);
358 
359 	info = malloc(sizeof(*info), M_DEVBUF, M_NOWAIT | M_ZERO);
360 	if (info == NULL)
361 		return (ENOMEM);
362 
363 	info->channels = AFMT_CHANNEL(f->desc->in);
364 	info->align = info->channels * AFMT_BPS(f->desc->in);
365 
366 	info->rate = FEEDEQ_RATE_MIN;
367 	info->treble.gain = FEEDEQ_L2GAIN(50);
368 	info->bass.gain = FEEDEQ_L2GAIN(50);
369 	info->preamp = FEEDEQ_PREAMP2IDX(FEEDEQ_PREAMP_DEFAULT);
370 	info->state = FEEDEQ_UNKNOWN;
371 
372 	info->biquad = biquad_op;
373 
374 	f->data = info;
375 
376 	return (feed_eq_setup(info));
377 }
378 
379 static int
380 feed_eq_set(struct pcm_feeder *f, int what, int value)
381 {
382 	struct feed_eq_info *info;
383 
384 	info = f->data;
385 
386 	switch (what) {
387 	case FEEDEQ_CHANNELS:
388 		if (value < SND_CHN_MIN || value > SND_CHN_MAX)
389 			return (EINVAL);
390 		info->channels = (uint32_t)value;
391 		info->align = info->channels * AFMT_BPS(f->desc->in);
392 		feed_eq_reset(info);
393 		break;
394 	case FEEDEQ_RATE:
395 		if (feeder_eq_validrate(value) == 0)
396 			return (EINVAL);
397 		info->rate = (uint32_t)value;
398 		if (info->state == FEEDEQ_UNKNOWN)
399 			info->state = FEEDEQ_ENABLE;
400 		return (feed_eq_setup(info));
401 		break;
402 	case FEEDEQ_TREBLE:
403 	case FEEDEQ_BASS:
404 		if (value < 0 || value > 100)
405 			return (EINVAL);
406 		if (what == FEEDEQ_TREBLE)
407 			info->treble.gain = FEEDEQ_L2GAIN(value);
408 		else
409 			info->bass.gain = FEEDEQ_L2GAIN(value);
410 		break;
411 	case FEEDEQ_PREAMP:
412 		if (value < FEEDEQ_PREAMP_MIN || value > FEEDEQ_PREAMP_MAX)
413 			return (EINVAL);
414 		info->preamp = FEEDEQ_PREAMP2IDX(value);
415 		break;
416 	case FEEDEQ_STATE:
417 		if (!(value == FEEDEQ_BYPASS || value == FEEDEQ_ENABLE ||
418 		    value == FEEDEQ_DISABLE))
419 			return (EINVAL);
420 		info->state = value;
421 		feed_eq_reset(info);
422 		break;
423 	default:
424 		return (EINVAL);
425 		break;
426 	}
427 
428 	return (0);
429 }
430 
431 static int
432 feed_eq_free(struct pcm_feeder *f)
433 {
434 	struct feed_eq_info *info;
435 
436 	info = f->data;
437 	if (info != NULL)
438 		free(info, M_DEVBUF);
439 
440 	f->data = NULL;
441 
442 	return (0);
443 }
444 
445 static int
446 feed_eq_feed(struct pcm_feeder *f, struct pcm_channel *c, uint8_t *b,
447     uint32_t count, void *source)
448 {
449 	struct feed_eq_info *info;
450 	uint32_t j;
451 	uint8_t *dst;
452 
453 	info = f->data;
454 
455 	/*
456 	 * 3 major states:
457 	 * 	FEEDEQ_BYPASS  - Bypass entirely, nothing happened.
458 	 *      FEEDEQ_ENABLE  - Preamp+biquad filtering.
459 	 *      FEEDEQ_DISABLE - Preamp only.
460 	 */
461 	if (info->state == FEEDEQ_BYPASS)
462 		return (FEEDER_FEED(f->source, c, b, count, source));
463 
464 	dst = b;
465 	count = SND_FXROUND(count, info->align);
466 
467 	do {
468 		if (count < info->align)
469 			break;
470 
471 		j = SND_FXDIV(FEEDER_FEED(f->source, c, dst, count, source),
472 		    info->align);
473 		if (j == 0)
474 			break;
475 
476 		info->biquad(info, dst, j);
477 
478 		j *= info->align;
479 		dst += j;
480 		count -= j;
481 
482 	} while (count != 0);
483 
484 	return (dst - b);
485 }
486 
487 static struct pcm_feederdesc feeder_eq_desc[] = {
488 	{ FEEDER_EQ, 0, 0, 0, 0 },
489 	{ 0, 0, 0, 0, 0 }
490 };
491 
492 static kobj_method_t feeder_eq_methods[] = {
493 	KOBJMETHOD(feeder_init,		feed_eq_init),
494 	KOBJMETHOD(feeder_free,		feed_eq_free),
495 	KOBJMETHOD(feeder_set,		feed_eq_set),
496 	KOBJMETHOD(feeder_feed,		feed_eq_feed),
497 	KOBJMETHOD_END
498 };
499 
500 FEEDER_DECLARE(feeder_eq, NULL);
501 
502 static int32_t
503 feed_eq_scan_preamp_arg(const char *s)
504 {
505 	int r, i, f;
506 	size_t len;
507 	char buf[32];
508 
509 	bzero(buf, sizeof(buf));
510 
511 	/* XXX kind of ugly, but works for now.. */
512 
513 	r = sscanf(s, "%d.%d", &i, &f);
514 
515 	if (r == 1 && !(i < FEEDEQ_PREAMP_IMIN || i > FEEDEQ_PREAMP_IMAX)) {
516 		snprintf(buf, sizeof(buf), "%c%d",
517 		    FEEDEQ_PREAMP_SIGNMARK(i), abs(i));
518 		f = 0;
519 	} else if (r == 2 &&
520 	    !(i < FEEDEQ_PREAMP_IMIN || i > FEEDEQ_PREAMP_IMAX ||
521 	    f < FEEDEQ_PREAMP_FMIN || f > FEEDEQ_PREAMP_FMAX))
522 		snprintf(buf, sizeof(buf), "%c%d.%d",
523 		    FEEDEQ_PREAMP_SIGNMARK(i), abs(i), f);
524 	else
525 		return (FEEDEQ_PREAMP_INVALID);
526 
527 	len = strlen(s);
528 	if (len > 2 && strcasecmp(s + len - 2, "dB") == 0)
529 		strlcat(buf, "dB", sizeof(buf));
530 
531 	if (i == 0 && *s == '-')
532 		*buf = '-';
533 
534 	if (strcasecmp(buf + ((*s >= '0' && *s <= '9') ? 1 : 0), s) != 0)
535 		return (FEEDEQ_PREAMP_INVALID);
536 
537 	while ((f / FEEDEQ_GAIN_DIV) > 0)
538 		f /= FEEDEQ_GAIN_DIV;
539 
540 	return (((i < 0 || *buf == '-') ? -1 : 1) * FEEDEQ_IF2PREAMP(i, f));
541 }
542 
543 #ifdef _KERNEL
544 static int
545 sysctl_dev_pcm_eq(SYSCTL_HANDLER_ARGS)
546 {
547 	struct snddev_info *d;
548 	struct pcm_channel *c;
549 	struct pcm_feeder *f;
550 	int err, val, oval;
551 
552 	d = oidp->oid_arg1;
553 	if (!PCM_REGISTERED(d))
554 		return (ENODEV);
555 
556 	PCM_LOCK(d);
557 	PCM_WAIT(d);
558 	if (d->flags & SD_F_EQ_BYPASSED)
559 		val = 2;
560 	else if (d->flags & SD_F_EQ_ENABLED)
561 		val = 1;
562 	else
563 		val = 0;
564 	PCM_ACQUIRE(d);
565 	PCM_UNLOCK(d);
566 
567 	oval = val;
568 	err = sysctl_handle_int(oidp, &val, 0, req);
569 
570 	if (err == 0 && req->newptr != NULL && val != oval) {
571 		if (!(val == 0 || val == 1 || val == 2)) {
572 			PCM_RELEASE_QUICK(d);
573 			return (EINVAL);
574 		}
575 
576 		PCM_LOCK(d);
577 
578 		d->flags &= ~(SD_F_EQ_ENABLED | SD_F_EQ_BYPASSED);
579 		if (val == 2) {
580 			val = FEEDEQ_BYPASS;
581 			d->flags |= SD_F_EQ_BYPASSED;
582 		} else if (val == 1) {
583 			val = FEEDEQ_ENABLE;
584 			d->flags |= SD_F_EQ_ENABLED;
585 		} else
586 			val = FEEDEQ_DISABLE;
587 
588 		CHN_FOREACH(c, d, channels.pcm.busy) {
589 			CHN_LOCK(c);
590 			f = chn_findfeeder(c, FEEDER_EQ);
591 			if (f != NULL)
592 				(void)FEEDER_SET(f, FEEDEQ_STATE, val);
593 			CHN_UNLOCK(c);
594 		}
595 
596 		PCM_RELEASE(d);
597 		PCM_UNLOCK(d);
598 	} else
599 		PCM_RELEASE_QUICK(d);
600 
601 	return (err);
602 }
603 
604 static int
605 sysctl_dev_pcm_eq_preamp(SYSCTL_HANDLER_ARGS)
606 {
607 	struct snddev_info *d;
608 	struct pcm_channel *c;
609 	struct pcm_feeder *f;
610 	int err, val, oval;
611 	char buf[32];
612 
613 	d = oidp->oid_arg1;
614 	if (!PCM_REGISTERED(d))
615 		return (ENODEV);
616 
617 	PCM_LOCK(d);
618 	PCM_WAIT(d);
619 	val = d->eqpreamp;
620 	bzero(buf, sizeof(buf));
621 	(void)snprintf(buf, sizeof(buf), "%c%d.%ddB",
622 	    FEEDEQ_PREAMP_SIGNMARK(val), FEEDEQ_PREAMP_IPART(val),
623 	    FEEDEQ_PREAMP_FPART(val));
624 	PCM_ACQUIRE(d);
625 	PCM_UNLOCK(d);
626 
627 	oval = val;
628 	err = sysctl_handle_string(oidp, buf, sizeof(buf), req);
629 
630 	if (err == 0 && req->newptr != NULL) {
631 		val = feed_eq_scan_preamp_arg(buf);
632 		if (val == FEEDEQ_PREAMP_INVALID) {
633 			PCM_RELEASE_QUICK(d);
634 			return (EINVAL);
635 		}
636 
637 		PCM_LOCK(d);
638 
639 		if (val != oval) {
640 			if (val < FEEDEQ_PREAMP_MIN)
641 				val = FEEDEQ_PREAMP_MIN;
642 			else if (val > FEEDEQ_PREAMP_MAX)
643 				val = FEEDEQ_PREAMP_MAX;
644 
645 			d->eqpreamp = val;
646 
647 			CHN_FOREACH(c, d, channels.pcm.busy) {
648 				CHN_LOCK(c);
649 				f = chn_findfeeder(c, FEEDER_EQ);
650 				if (f != NULL)
651 					(void)FEEDER_SET(f, FEEDEQ_PREAMP, val);
652 				CHN_UNLOCK(c);
653 			}
654 
655 		}
656 
657 		PCM_RELEASE(d);
658 		PCM_UNLOCK(d);
659 	} else
660 		PCM_RELEASE_QUICK(d);
661 
662 	return (err);
663 }
664 
665 void
666 feeder_eq_initsys(device_t dev)
667 {
668 	struct snddev_info *d;
669 	const char *preamp;
670 	char buf[64];
671 
672 	d = device_get_softc(dev);
673 
674 	if (!(resource_string_value(device_get_name(dev), device_get_unit(dev),
675 	    "eq_preamp", &preamp) == 0 &&
676 	    (d->eqpreamp = feed_eq_scan_preamp_arg(preamp)) !=
677 	    FEEDEQ_PREAMP_INVALID))
678 		d->eqpreamp = FEEDEQ_PREAMP_DEFAULT;
679 
680 	if (d->eqpreamp < FEEDEQ_PREAMP_MIN)
681 		d->eqpreamp = FEEDEQ_PREAMP_MIN;
682 	else if (d->eqpreamp > FEEDEQ_PREAMP_MAX)
683 		d->eqpreamp = FEEDEQ_PREAMP_MAX;
684 
685 	SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
686 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO,
687 	    "eq", CTLTYPE_INT | CTLFLAG_RWTUN, d, sizeof(d),
688 	    sysctl_dev_pcm_eq, "I",
689 	    "Bass/Treble Equalizer (0=disable, 1=enable, 2=bypass)");
690 
691 	(void)snprintf(buf, sizeof(buf), "Bass/Treble Equalizer Preamp "
692 	    "(-/+ %d.0dB , %d.%ddB step)",
693 	    FEEDEQ_GAIN_MAX, FEEDEQ_GAIN_STEP / FEEDEQ_GAIN_DIV,
694 	    FEEDEQ_GAIN_STEP - ((FEEDEQ_GAIN_STEP / FEEDEQ_GAIN_DIV) *
695 	    FEEDEQ_GAIN_DIV));
696 
697 	SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
698 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO,
699 	    "eq_preamp", CTLTYPE_STRING | CTLFLAG_RWTUN, d, sizeof(d),
700 	    sysctl_dev_pcm_eq_preamp, "A", buf);
701 }
702 #endif
703