Current Path : /usr/src/sys/dev/sound/pcm/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
Current File : //usr/src/sys/dev/sound/pcm/feeder_eq.c |
/*- * Copyright (c) 2008-2009 Ariff Abdullah <ariff@FreeBSD.org> * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * feeder_eq: Parametric (compile time) Software Equalizer. Though accidental, * it proves good enough for educational and general consumption. * * "Cookbook formulae for audio EQ biquad filter coefficients" * by Robert Bristow-Johnson <rbj@audioimagination.com> * - http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt */ #ifdef _KERNEL #ifdef HAVE_KERNEL_OPTION_HEADERS #include "opt_snd.h" #endif #include <dev/sound/pcm/sound.h> #include <dev/sound/pcm/pcm.h> #include "feeder_if.h" #define SND_USE_FXDIV #include "snd_fxdiv_gen.h" SND_DECLARE_FILE("$FreeBSD: release/9.1.0/sys/dev/sound/pcm/feeder_eq.c 209193 2010-06-15 07:06:54Z avg $"); #endif #include "feeder_eq_gen.h" #define FEEDEQ_LEVELS \ (((FEEDEQ_GAIN_MAX - FEEDEQ_GAIN_MIN) * \ (FEEDEQ_GAIN_DIV / FEEDEQ_GAIN_STEP)) + 1) #define FEEDEQ_L2GAIN(v) \ ((int)min(((v) * FEEDEQ_LEVELS) / 100, FEEDEQ_LEVELS - 1)) #define FEEDEQ_PREAMP_IPART(x) (abs(x) >> FEEDEQ_GAIN_SHIFT) #define FEEDEQ_PREAMP_FPART(x) (abs(x) & FEEDEQ_GAIN_FMASK) #define FEEDEQ_PREAMP_SIGNVAL(x) ((x) < 0 ? -1 : 1) #define FEEDEQ_PREAMP_SIGNMARK(x) (((x) < 0) ? '-' : '+') #define FEEDEQ_PREAMP_IMIN -192 #define FEEDEQ_PREAMP_IMAX 192 #define FEEDEQ_PREAMP_FMIN 0 #define FEEDEQ_PREAMP_FMAX 9 #define FEEDEQ_PREAMP_INVALID INT_MAX #define FEEDEQ_IF2PREAMP(i, f) \ ((abs(i) << FEEDEQ_GAIN_SHIFT) | \ (((abs(f) / FEEDEQ_GAIN_STEP) * FEEDEQ_GAIN_STEP) & \ FEEDEQ_GAIN_FMASK)) #define FEEDEQ_PREAMP_MIN \ (FEEDEQ_PREAMP_SIGNVAL(FEEDEQ_GAIN_MIN) * \ FEEDEQ_IF2PREAMP(FEEDEQ_GAIN_MIN, 0)) #define FEEDEQ_PREAMP_MAX \ (FEEDEQ_PREAMP_SIGNVAL(FEEDEQ_GAIN_MAX) * \ FEEDEQ_IF2PREAMP(FEEDEQ_GAIN_MAX, 0)) #define FEEDEQ_PREAMP_DEFAULT FEEDEQ_IF2PREAMP(0, 0) #define FEEDEQ_PREAMP2IDX(v) \ ((int32_t)((FEEDEQ_GAIN_MAX * (FEEDEQ_GAIN_DIV / \ FEEDEQ_GAIN_STEP)) + (FEEDEQ_PREAMP_SIGNVAL(v) * \ FEEDEQ_PREAMP_IPART(v) * (FEEDEQ_GAIN_DIV / \ FEEDEQ_GAIN_STEP)) + (FEEDEQ_PREAMP_SIGNVAL(v) * \ (FEEDEQ_PREAMP_FPART(v) / FEEDEQ_GAIN_STEP)))) static int feeder_eq_exact_rate = 0; #ifdef _KERNEL static char feeder_eq_presets[] = FEEDER_EQ_PRESETS; SYSCTL_STRING(_hw_snd, OID_AUTO, feeder_eq_presets, CTLFLAG_RD, &feeder_eq_presets, 0, "compile-time eq presets"); TUNABLE_INT("hw.snd.feeder_eq_exact_rate", &feeder_eq_exact_rate); SYSCTL_INT(_hw_snd, OID_AUTO, feeder_eq_exact_rate, CTLFLAG_RW, &feeder_eq_exact_rate, 0, "force exact rate validation"); #endif struct feed_eq_info; typedef void (*feed_eq_t)(struct feed_eq_info *, uint8_t *, uint32_t); struct feed_eq_tone { intpcm_t o1[SND_CHN_MAX]; intpcm_t o2[SND_CHN_MAX]; intpcm_t i1[SND_CHN_MAX]; intpcm_t i2[SND_CHN_MAX]; int gain; }; struct feed_eq_info { struct feed_eq_tone treble; struct feed_eq_tone bass; struct feed_eq_coeff *coeff; feed_eq_t biquad; uint32_t channels; uint32_t rate; uint32_t align; int32_t preamp; int state; }; #if !defined(_KERNEL) && defined(FEEDEQ_ERR_CLIP) #define FEEDEQ_ERR_CLIP_CHECK(t, v) do { \ if ((v) < PCM_S32_MIN || (v) > PCM_S32_MAX) \ errx(1, "\n\n%s(): ["#t"] Sample clipping: %jd\n", \ __func__, (intmax_t)(v)); \ } while (0) #else #define FEEDEQ_ERR_CLIP_CHECK(...) #endif #define FEEDEQ_CLAMP(v) (((v) > PCM_S32_MAX) ? PCM_S32_MAX : \ (((v) < PCM_S32_MIN) ? PCM_S32_MIN : \ (v))) #define FEEDEQ_DECLARE(SIGN, BIT, ENDIAN) \ static void \ feed_eq_biquad_##SIGN##BIT##ENDIAN(struct feed_eq_info *info, \ uint8_t *dst, uint32_t count) \ { \ struct feed_eq_coeff_tone *treble, *bass; \ intpcm64_t w; \ intpcm_t v; \ uint32_t i, j; \ int32_t pmul, pshift; \ \ pmul = feed_eq_preamp[info->preamp].mul; \ pshift = feed_eq_preamp[info->preamp].shift; \ \ if (info->state == FEEDEQ_DISABLE) { \ j = count * info->channels; \ dst += j * PCM_##BIT##_BPS; \ do { \ dst -= PCM_##BIT##_BPS; \ v = _PCM_READ_##SIGN##BIT##_##ENDIAN(dst); \ v = ((intpcm64_t)pmul * v) >> pshift; \ _PCM_WRITE_##SIGN##BIT##_##ENDIAN(dst, v); \ } while (--j != 0); \ \ return; \ } \ \ treble = &(info->coeff[info->treble.gain].treble); \ bass = &(info->coeff[info->bass.gain].bass); \ \ do { \ i = 0; \ j = info->channels; \ do { \ v = _PCM_READ_##SIGN##BIT##_##ENDIAN(dst); \ v <<= 32 - BIT; \ v = ((intpcm64_t)pmul * v) >> pshift; \ \ w = (intpcm64_t)v * treble->b0; \ w += (intpcm64_t)info->treble.i1[i] * treble->b1; \ w += (intpcm64_t)info->treble.i2[i] * treble->b2; \ w -= (intpcm64_t)info->treble.o1[i] * treble->a1; \ w -= (intpcm64_t)info->treble.o2[i] * treble->a2; \ info->treble.i2[i] = info->treble.i1[i]; \ info->treble.i1[i] = v; \ info->treble.o2[i] = info->treble.o1[i]; \ w >>= FEEDEQ_COEFF_SHIFT; \ FEEDEQ_ERR_CLIP_CHECK(treble, w); \ v = FEEDEQ_CLAMP(w); \ info->treble.o1[i] = v; \ \ w = (intpcm64_t)v * bass->b0; \ w += (intpcm64_t)info->bass.i1[i] * bass->b1; \ w += (intpcm64_t)info->bass.i2[i] * bass->b2; \ w -= (intpcm64_t)info->bass.o1[i] * bass->a1; \ w -= (intpcm64_t)info->bass.o2[i] * bass->a2; \ info->bass.i2[i] = info->bass.i1[i]; \ info->bass.i1[i] = v; \ info->bass.o2[i] = info->bass.o1[i]; \ w >>= FEEDEQ_COEFF_SHIFT; \ FEEDEQ_ERR_CLIP_CHECK(bass, w); \ v = FEEDEQ_CLAMP(w); \ info->bass.o1[i] = v; \ \ v >>= 32 - BIT; \ _PCM_WRITE_##SIGN##BIT##_##ENDIAN(dst, v); \ dst += PCM_##BIT##_BPS; \ i++; \ } while (--j != 0); \ } while (--count != 0); \ } #if BYTE_ORDER == LITTLE_ENDIAN || defined(SND_FEEDER_MULTIFORMAT) FEEDEQ_DECLARE(S, 16, LE) FEEDEQ_DECLARE(S, 32, LE) #endif #if BYTE_ORDER == BIG_ENDIAN || defined(SND_FEEDER_MULTIFORMAT) FEEDEQ_DECLARE(S, 16, BE) FEEDEQ_DECLARE(S, 32, BE) #endif #ifdef SND_FEEDER_MULTIFORMAT FEEDEQ_DECLARE(S, 8, NE) FEEDEQ_DECLARE(S, 24, LE) FEEDEQ_DECLARE(S, 24, BE) FEEDEQ_DECLARE(U, 8, NE) FEEDEQ_DECLARE(U, 16, LE) FEEDEQ_DECLARE(U, 24, LE) FEEDEQ_DECLARE(U, 32, LE) FEEDEQ_DECLARE(U, 16, BE) FEEDEQ_DECLARE(U, 24, BE) FEEDEQ_DECLARE(U, 32, BE) #endif #define FEEDEQ_ENTRY(SIGN, BIT, ENDIAN) \ { \ AFMT_##SIGN##BIT##_##ENDIAN, \ feed_eq_biquad_##SIGN##BIT##ENDIAN \ } static const struct { uint32_t format; feed_eq_t biquad; } feed_eq_biquad_tab[] = { #if BYTE_ORDER == LITTLE_ENDIAN || defined(SND_FEEDER_MULTIFORMAT) FEEDEQ_ENTRY(S, 16, LE), FEEDEQ_ENTRY(S, 32, LE), #endif #if BYTE_ORDER == BIG_ENDIAN || defined(SND_FEEDER_MULTIFORMAT) FEEDEQ_ENTRY(S, 16, BE), FEEDEQ_ENTRY(S, 32, BE), #endif #ifdef SND_FEEDER_MULTIFORMAT FEEDEQ_ENTRY(S, 8, NE), FEEDEQ_ENTRY(S, 24, LE), FEEDEQ_ENTRY(S, 24, BE), FEEDEQ_ENTRY(U, 8, NE), FEEDEQ_ENTRY(U, 16, LE), FEEDEQ_ENTRY(U, 24, LE), FEEDEQ_ENTRY(U, 32, LE), FEEDEQ_ENTRY(U, 16, BE), FEEDEQ_ENTRY(U, 24, BE), FEEDEQ_ENTRY(U, 32, BE) #endif }; #define FEEDEQ_BIQUAD_TAB_SIZE \ ((int32_t)(sizeof(feed_eq_biquad_tab) / sizeof(feed_eq_biquad_tab[0]))) static struct feed_eq_coeff * feed_eq_coeff_rate(uint32_t rate) { uint32_t spd, threshold; int i; if (rate < FEEDEQ_RATE_MIN || rate > FEEDEQ_RATE_MAX) return (NULL); /* * Not all rates are supported. Choose the best rate that we can to * allow 'sloppy' conversion. Good enough for naive listeners. */ for (i = 0; i < FEEDEQ_TAB_SIZE; i++) { spd = feed_eq_tab[i].rate; threshold = spd + ((i < (FEEDEQ_TAB_SIZE - 1) && feed_eq_tab[i + 1].rate > spd) ? ((feed_eq_tab[i + 1].rate - spd) >> 1) : 0); if (rate == spd || (feeder_eq_exact_rate == 0 && rate <= threshold)) return (feed_eq_tab[i].coeff); } return (NULL); } int feeder_eq_validrate(uint32_t rate) { if (feed_eq_coeff_rate(rate) != NULL) return (1); return (0); } static void feed_eq_reset(struct feed_eq_info *info) { uint32_t i; for (i = 0; i < info->channels; i++) { info->treble.i1[i] = 0; info->treble.i2[i] = 0; info->treble.o1[i] = 0; info->treble.o2[i] = 0; info->bass.i1[i] = 0; info->bass.i2[i] = 0; info->bass.o1[i] = 0; info->bass.o2[i] = 0; } } static int feed_eq_setup(struct feed_eq_info *info) { info->coeff = feed_eq_coeff_rate(info->rate); if (info->coeff == NULL) return (EINVAL); feed_eq_reset(info); return (0); } static int feed_eq_init(struct pcm_feeder *f) { struct feed_eq_info *info; feed_eq_t biquad_op; int i; if (f->desc->in != f->desc->out) return (EINVAL); biquad_op = NULL; for (i = 0; i < FEEDEQ_BIQUAD_TAB_SIZE && biquad_op == NULL; i++) { if (AFMT_ENCODING(f->desc->in) == feed_eq_biquad_tab[i].format) biquad_op = feed_eq_biquad_tab[i].biquad; } if (biquad_op == NULL) return (EINVAL); info = malloc(sizeof(*info), M_DEVBUF, M_NOWAIT | M_ZERO); if (info == NULL) return (ENOMEM); info->channels = AFMT_CHANNEL(f->desc->in); info->align = info->channels * AFMT_BPS(f->desc->in); info->rate = FEEDEQ_RATE_MIN; info->treble.gain = FEEDEQ_L2GAIN(50); info->bass.gain = FEEDEQ_L2GAIN(50); info->preamp = FEEDEQ_PREAMP2IDX(FEEDEQ_PREAMP_DEFAULT); info->state = FEEDEQ_UNKNOWN; info->biquad = biquad_op; f->data = info; return (feed_eq_setup(info)); } static int feed_eq_set(struct pcm_feeder *f, int what, int value) { struct feed_eq_info *info; info = f->data; switch (what) { case FEEDEQ_CHANNELS: if (value < SND_CHN_MIN || value > SND_CHN_MAX) return (EINVAL); info->channels = (uint32_t)value; info->align = info->channels * AFMT_BPS(f->desc->in); feed_eq_reset(info); break; case FEEDEQ_RATE: if (feeder_eq_validrate(value) == 0) return (EINVAL); info->rate = (uint32_t)value; if (info->state == FEEDEQ_UNKNOWN) info->state = FEEDEQ_ENABLE; return (feed_eq_setup(info)); break; case FEEDEQ_TREBLE: case FEEDEQ_BASS: if (value < 0 || value > 100) return (EINVAL); if (what == FEEDEQ_TREBLE) info->treble.gain = FEEDEQ_L2GAIN(value); else info->bass.gain = FEEDEQ_L2GAIN(value); break; case FEEDEQ_PREAMP: if (value < FEEDEQ_PREAMP_MIN || value > FEEDEQ_PREAMP_MAX) return (EINVAL); info->preamp = FEEDEQ_PREAMP2IDX(value); break; case FEEDEQ_STATE: if (!(value == FEEDEQ_BYPASS || value == FEEDEQ_ENABLE || value == FEEDEQ_DISABLE)) return (EINVAL); info->state = value; feed_eq_reset(info); break; default: return (EINVAL); break; } return (0); } static int feed_eq_free(struct pcm_feeder *f) { struct feed_eq_info *info; info = f->data; if (info != NULL) free(info, M_DEVBUF); f->data = NULL; return (0); } static int feed_eq_feed(struct pcm_feeder *f, struct pcm_channel *c, uint8_t *b, uint32_t count, void *source) { struct feed_eq_info *info; uint32_t j; uint8_t *dst; info = f->data; /* * 3 major states: * FEEDEQ_BYPASS - Bypass entirely, nothing happened. * FEEDEQ_ENABLE - Preamp+biquad filtering. * FEEDEQ_DISABLE - Preamp only. */ if (info->state == FEEDEQ_BYPASS) return (FEEDER_FEED(f->source, c, b, count, source)); dst = b; count = SND_FXROUND(count, info->align); do { if (count < info->align) break; j = SND_FXDIV(FEEDER_FEED(f->source, c, dst, count, source), info->align); if (j == 0) break; info->biquad(info, dst, j); j *= info->align; dst += j; count -= j; } while (count != 0); return (dst - b); } static struct pcm_feederdesc feeder_eq_desc[] = { { FEEDER_EQ, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 } }; static kobj_method_t feeder_eq_methods[] = { KOBJMETHOD(feeder_init, feed_eq_init), KOBJMETHOD(feeder_free, feed_eq_free), KOBJMETHOD(feeder_set, feed_eq_set), KOBJMETHOD(feeder_feed, feed_eq_feed), KOBJMETHOD_END }; FEEDER_DECLARE(feeder_eq, NULL); static int32_t feed_eq_scan_preamp_arg(const char *s) { int r, i, f; size_t len; char buf[32]; bzero(buf, sizeof(buf)); /* XXX kind of ugly, but works for now.. */ r = sscanf(s, "%d.%d", &i, &f); if (r == 1 && !(i < FEEDEQ_PREAMP_IMIN || i > FEEDEQ_PREAMP_IMAX)) { snprintf(buf, sizeof(buf), "%c%d", FEEDEQ_PREAMP_SIGNMARK(i), abs(i)); f = 0; } else if (r == 2 && !(i < FEEDEQ_PREAMP_IMIN || i > FEEDEQ_PREAMP_IMAX || f < FEEDEQ_PREAMP_FMIN || f > FEEDEQ_PREAMP_FMAX)) snprintf(buf, sizeof(buf), "%c%d.%d", FEEDEQ_PREAMP_SIGNMARK(i), abs(i), f); else return (FEEDEQ_PREAMP_INVALID); len = strlen(s); if (len > 2 && strcasecmp(s + len - 2, "dB") == 0) strlcat(buf, "dB", sizeof(buf)); if (i == 0 && *s == '-') *buf = '-'; if (strcasecmp(buf + ((*s >= '0' && *s <= '9') ? 1 : 0), s) != 0) return (FEEDEQ_PREAMP_INVALID); while ((f / FEEDEQ_GAIN_DIV) > 0) f /= FEEDEQ_GAIN_DIV; return (((i < 0 || *buf == '-') ? -1 : 1) * FEEDEQ_IF2PREAMP(i, f)); } #ifdef _KERNEL static int sysctl_dev_pcm_eq(SYSCTL_HANDLER_ARGS) { struct snddev_info *d; struct pcm_channel *c; struct pcm_feeder *f; int err, val, oval; d = oidp->oid_arg1; if (!PCM_REGISTERED(d)) return (ENODEV); PCM_LOCK(d); PCM_WAIT(d); if (d->flags & SD_F_EQ_BYPASSED) val = 2; else if (d->flags & SD_F_EQ_ENABLED) val = 1; else val = 0; PCM_ACQUIRE(d); PCM_UNLOCK(d); oval = val; err = sysctl_handle_int(oidp, &val, 0, req); if (err == 0 && req->newptr != NULL && val != oval) { if (!(val == 0 || val == 1 || val == 2)) { PCM_RELEASE_QUICK(d); return (EINVAL); } PCM_LOCK(d); d->flags &= ~(SD_F_EQ_ENABLED | SD_F_EQ_BYPASSED); if (val == 2) { val = FEEDEQ_BYPASS; d->flags |= SD_F_EQ_BYPASSED; } else if (val == 1) { val = FEEDEQ_ENABLE; d->flags |= SD_F_EQ_ENABLED; } else val = FEEDEQ_DISABLE; CHN_FOREACH(c, d, channels.pcm.busy) { CHN_LOCK(c); f = chn_findfeeder(c, FEEDER_EQ); if (f != NULL) (void)FEEDER_SET(f, FEEDEQ_STATE, val); CHN_UNLOCK(c); } PCM_RELEASE(d); PCM_UNLOCK(d); } else PCM_RELEASE_QUICK(d); return (err); } static int sysctl_dev_pcm_eq_preamp(SYSCTL_HANDLER_ARGS) { struct snddev_info *d; struct pcm_channel *c; struct pcm_feeder *f; int err, val, oval; char buf[32]; d = oidp->oid_arg1; if (!PCM_REGISTERED(d)) return (ENODEV); PCM_LOCK(d); PCM_WAIT(d); val = d->eqpreamp; bzero(buf, sizeof(buf)); (void)snprintf(buf, sizeof(buf), "%c%d.%ddB", FEEDEQ_PREAMP_SIGNMARK(val), FEEDEQ_PREAMP_IPART(val), FEEDEQ_PREAMP_FPART(val)); PCM_ACQUIRE(d); PCM_UNLOCK(d); oval = val; err = sysctl_handle_string(oidp, buf, sizeof(buf), req); if (err == 0 && req->newptr != NULL) { val = feed_eq_scan_preamp_arg(buf); if (val == FEEDEQ_PREAMP_INVALID) { PCM_RELEASE_QUICK(d); return (EINVAL); } PCM_LOCK(d); if (val != oval) { if (val < FEEDEQ_PREAMP_MIN) val = FEEDEQ_PREAMP_MIN; else if (val > FEEDEQ_PREAMP_MAX) val = FEEDEQ_PREAMP_MAX; d->eqpreamp = val; CHN_FOREACH(c, d, channels.pcm.busy) { CHN_LOCK(c); f = chn_findfeeder(c, FEEDER_EQ); if (f != NULL) (void)FEEDER_SET(f, FEEDEQ_PREAMP, val); CHN_UNLOCK(c); } } PCM_RELEASE(d); PCM_UNLOCK(d); } else PCM_RELEASE_QUICK(d); return (err); } void feeder_eq_initsys(device_t dev) { struct snddev_info *d; const char *preamp; char buf[64]; d = device_get_softc(dev); if (!(resource_string_value(device_get_name(dev), device_get_unit(dev), "eq_preamp", &preamp) == 0 && (d->eqpreamp = feed_eq_scan_preamp_arg(preamp)) != FEEDEQ_PREAMP_INVALID)) d->eqpreamp = FEEDEQ_PREAMP_DEFAULT; if (d->eqpreamp < FEEDEQ_PREAMP_MIN) d->eqpreamp = FEEDEQ_PREAMP_MIN; else if (d->eqpreamp > FEEDEQ_PREAMP_MAX) d->eqpreamp = FEEDEQ_PREAMP_MAX; SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev), SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO, "eq", CTLTYPE_INT | CTLFLAG_RW, d, sizeof(d), sysctl_dev_pcm_eq, "I", "Bass/Treble Equalizer (0=disable, 1=enable, 2=bypass)"); bzero(buf, sizeof(buf)); (void)snprintf(buf, sizeof(buf), "Bass/Treble Equalizer Preamp " "(-/+ %d.0dB , %d.%ddB step)", FEEDEQ_GAIN_MAX, FEEDEQ_GAIN_STEP / FEEDEQ_GAIN_DIV, FEEDEQ_GAIN_STEP - ((FEEDEQ_GAIN_STEP / FEEDEQ_GAIN_DIV) * FEEDEQ_GAIN_DIV)); SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev), SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO, "eq_preamp", CTLTYPE_STRING | CTLFLAG_RW, d, sizeof(d), sysctl_dev_pcm_eq_preamp, "A", buf); } #endif