/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * 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.
 */

#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 <dev/sound/pcm/vchan.h>
#include "feeder_if.h"

#define SND_USE_FXDIV
#include "snd_fxdiv_gen.h"

SND_DECLARE_FILE("$FreeBSD$");
#endif

#undef SND_FEEDER_MULTIFORMAT
#define SND_FEEDER_MULTIFORMAT	1

typedef void (*feed_mixer_t)(uint8_t *, uint8_t *, uint32_t);

#define FEEDMIXER_DECLARE(SIGN, BIT, ENDIAN)				\
static void								\
feed_mixer_##SIGN##BIT##ENDIAN(uint8_t *src, uint8_t *dst,		\
    uint32_t count)							\
{									\
	intpcm##BIT##_t z;						\
	intpcm_t x, y;							\
									\
	src += count;							\
	dst += count;							\
									\
	do {								\
		src -= PCM_##BIT##_BPS;					\
		dst -= PCM_##BIT##_BPS;					\
		count -= PCM_##BIT##_BPS;				\
		x = PCM_READ_##SIGN##BIT##_##ENDIAN(src);		\
		y = PCM_READ_##SIGN##BIT##_##ENDIAN(dst);		\
		z = INTPCM##BIT##_T(x) + y;				\
		x = PCM_CLAMP_##SIGN##BIT(z);				\
		_PCM_WRITE_##SIGN##BIT##_##ENDIAN(dst, x);		\
	} while (count != 0);						\
}

#if BYTE_ORDER == LITTLE_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
FEEDMIXER_DECLARE(S, 16, LE)
FEEDMIXER_DECLARE(S, 32, LE)
#endif
#if BYTE_ORDER == BIG_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
FEEDMIXER_DECLARE(S, 16, BE)
FEEDMIXER_DECLARE(S, 32, BE)
#endif
#ifdef SND_FEEDER_MULTIFORMAT
FEEDMIXER_DECLARE(S,  8, NE)
FEEDMIXER_DECLARE(S, 24, LE)
FEEDMIXER_DECLARE(S, 24, BE)
FEEDMIXER_DECLARE(U,  8, NE)
FEEDMIXER_DECLARE(U, 16, LE)
FEEDMIXER_DECLARE(U, 24, LE)
FEEDMIXER_DECLARE(U, 32, LE)
FEEDMIXER_DECLARE(U, 16, BE)
FEEDMIXER_DECLARE(U, 24, BE)
FEEDMIXER_DECLARE(U, 32, BE)
#endif

struct feed_mixer_info {
	uint32_t format;
	int bps;
	feed_mixer_t mix;
};

#define FEEDMIXER_ENTRY(SIGN, BIT, ENDIAN)				\
	{								\
		AFMT_##SIGN##BIT##_##ENDIAN, PCM_##BIT##_BPS,		\
		feed_mixer_##SIGN##BIT##ENDIAN				\
	}

static struct feed_mixer_info feed_mixer_info_tab[] = {
	FEEDMIXER_ENTRY(S,  8, NE),
#if BYTE_ORDER == LITTLE_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
	FEEDMIXER_ENTRY(S, 16, LE),
	FEEDMIXER_ENTRY(S, 32, LE),
#endif
#if BYTE_ORDER == BIG_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
	FEEDMIXER_ENTRY(S, 16, BE),
	FEEDMIXER_ENTRY(S, 32, BE),
#endif
#ifdef SND_FEEDER_MULTIFORMAT
	FEEDMIXER_ENTRY(S, 24, LE),
	FEEDMIXER_ENTRY(S, 24, BE),
	FEEDMIXER_ENTRY(U,  8, NE),
	FEEDMIXER_ENTRY(U, 16, LE),
	FEEDMIXER_ENTRY(U, 24, LE),
	FEEDMIXER_ENTRY(U, 32, LE),
	FEEDMIXER_ENTRY(U, 16, BE),
	FEEDMIXER_ENTRY(U, 24, BE),
	FEEDMIXER_ENTRY(U, 32, BE),
#endif
	{    AFMT_AC3, PCM_16_BPS, NULL },
	{ AFMT_MU_LAW,  PCM_8_BPS, feed_mixer_U8NE },	/* dummy */
	{  AFMT_A_LAW,  PCM_8_BPS, feed_mixer_U8NE }	/* dummy */
};

#define FEEDMIXER_TAB_SIZE	((int32_t)				\
				 (sizeof(feed_mixer_info_tab) /		\
				  sizeof(feed_mixer_info_tab[0])))

#define FEEDMIXER_DATA(i, c)	((void *)				\
				 ((uintptr_t)((((i) & 0x1f) << 7) |	\
				 ((c) & 0x7f))))
#define FEEDMIXER_INFOIDX(d)	((uint32_t)((uintptr_t)(d) >> 7) & 0x1f)
#define FEEDMIXER_CHANNELS(d)	((uint32_t)((uintptr_t)(d)) & 0x7f)

static int
feed_mixer_init(struct pcm_feeder *f)
{
	int i;

	if (f->desc->in != f->desc->out)
		return (EINVAL);

	for (i = 0; i < FEEDMIXER_TAB_SIZE; i++) {
		if (AFMT_ENCODING(f->desc->in) ==
		    feed_mixer_info_tab[i].format) {
		    	f->data =
			    FEEDMIXER_DATA(i, AFMT_CHANNEL(f->desc->in));
			return (0);
		}
	}

	return (EINVAL);
}

static int
feed_mixer_set(struct pcm_feeder *f, int what, int value)
{

	switch (what) {
	case FEEDMIXER_CHANNELS:
		if (value < SND_CHN_MIN || value > SND_CHN_MAX)
			return (EINVAL);
		f->data = FEEDMIXER_DATA(FEEDMIXER_INFOIDX(f->data), value);
		break;
	default:
		return (EINVAL);
		break;
	}

	return (0);
}

static __inline int
feed_mixer_rec(struct pcm_channel *c)
{
	struct pcm_channel *ch;
	struct snd_dbuf *b, *bs;
	uint32_t cnt, maxfeed;
	int rdy;

	/*
	 * Reset ready and moving pointer. We're not using bufsoft
	 * anywhere since its sole purpose is to become the primary
	 * distributor for the recorded buffer and also as an interrupt
	 * threshold progress indicator.
	 */
	b = c->bufsoft;
	b->rp = 0;
	b->rl = 0;
	cnt = sndbuf_getsize(b);
	maxfeed = SND_FXROUND(SND_FXDIV_MAX, sndbuf_getalign(b));

	do {
		cnt = FEEDER_FEED(c->feeder->source, c, b->tmpbuf,
		    min(cnt, maxfeed), c->bufhard);
		if (cnt != 0) {
			sndbuf_acquire(b, b->tmpbuf, cnt);
			cnt = sndbuf_getfree(b);
		}
	} while (cnt != 0);

	/* Not enough data */
	if (b->rl < sndbuf_getalign(b)) {
		b->rl = 0;
		return (0);
	}

	/*
	 * Keep track of ready and moving pointer since we will use
	 * bufsoft over and over again, pretending nothing has happened.
	 */
	rdy = b->rl;

	CHN_FOREACH(ch, c, children.busy) {
		CHN_LOCK(ch);
		if (CHN_STOPPED(ch) || (ch->flags & CHN_F_DIRTY)) {
			CHN_UNLOCK(ch);
			continue;
		}
#ifdef SND_DEBUG
		if ((c->flags & CHN_F_DIRTY) && VCHAN_SYNC_REQUIRED(ch)) {
			if (vchan_sync(ch) != 0) {
				CHN_UNLOCK(ch);
				continue;
			}
		}
#endif
		bs = ch->bufsoft;
		if (ch->flags & CHN_F_MMAP)
			sndbuf_dispose(bs, NULL, sndbuf_getready(bs));
		cnt = sndbuf_getfree(bs);
		if (cnt < sndbuf_getalign(bs)) {
			CHN_UNLOCK(ch);
			continue;
		}
		maxfeed = SND_FXROUND(SND_FXDIV_MAX, sndbuf_getalign(bs));
		do {
			cnt = FEEDER_FEED(ch->feeder, ch, bs->tmpbuf,
			    min(cnt, maxfeed), b);
			if (cnt != 0) {
				sndbuf_acquire(bs, bs->tmpbuf, cnt);
				cnt = sndbuf_getfree(bs);
			}
		} while (cnt != 0);
		/*
		 * Not entirely flushed out...
		 */
		if (b->rl != 0)
			ch->xruns++;
		CHN_UNLOCK(ch);
		/*
		 * Rewind buffer position for next virtual channel.
		 */
		b->rp = 0;
		b->rl = rdy;
	}

	/*
	 * Set ready pointer to indicate that our children are ready
	 * to be woken up, also as an interrupt threshold progress
	 * indicator.
	 */
	b->rl = 1;

	c->flags &= ~CHN_F_DIRTY;

	/*
	 * Return 0 to bail out early from sndbuf_feed() loop.
	 * No need to increase feedcount counter since part of this
	 * feeder chains already include feed_root().
	 */
	return (0);
}

static int
feed_mixer_feed(struct pcm_feeder *f, struct pcm_channel *c, uint8_t *b,
    uint32_t count, void *source)
{
	struct feed_mixer_info *info;
	struct snd_dbuf *src = source;
	struct pcm_channel *ch;
	uint32_t cnt, mcnt, rcnt, sz;
	int passthrough;
	uint8_t *tmp;

	if (c->direction == PCMDIR_REC)
		return (feed_mixer_rec(c));

	sz = sndbuf_getsize(src);
	if (sz < count)
		count = sz;

	info = &feed_mixer_info_tab[FEEDMIXER_INFOIDX(f->data)];
	sz = info->bps * FEEDMIXER_CHANNELS(f->data);
	count = SND_FXROUND(count, sz);
	if (count < sz)
		return (0);

	/*
	 * We are going to use our source as a temporary buffer since it's
	 * got no other purpose.  We obtain our data by traversing the channel
	 * list of children and calling mixer function to mix count bytes from
	 * each into our destination buffer, b.
	 */
	tmp = sndbuf_getbuf(src);
	rcnt = 0;
	mcnt = 0;
	passthrough = 0;	/* 'passthrough' / 'exclusive' marker */

	CHN_FOREACH(ch, c, children.busy) {
		CHN_LOCK(ch);
		if (CHN_STOPPED(ch) || (ch->flags & CHN_F_DIRTY)) {
			CHN_UNLOCK(ch);
			continue;
		}
#ifdef SND_DEBUG
		if ((c->flags & CHN_F_DIRTY) && VCHAN_SYNC_REQUIRED(ch)) {
			if (vchan_sync(ch) != 0) {
				CHN_UNLOCK(ch);
				continue;
			}
		}
#endif
		if ((ch->flags & CHN_F_MMAP) && !(ch->flags & CHN_F_CLOSING))
			sndbuf_acquire(ch->bufsoft, NULL,
			    sndbuf_getfree(ch->bufsoft));
		if (info->mix == NULL) {
			/*
			 * Passthrough. Dump the first digital/passthrough
			 * channel into destination buffer, and the rest into
			 * nothingness (mute effect).
			 */
			if (passthrough == 0 &&
			    (ch->format & AFMT_PASSTHROUGH)) {
				rcnt = SND_FXROUND(FEEDER_FEED(ch->feeder, ch,
				    b, count, ch->bufsoft), sz);
				passthrough = 1;
			} else
				FEEDER_FEED(ch->feeder, ch, tmp, count,
				    ch->bufsoft);
		} else if (c->flags & CHN_F_EXCLUSIVE) {
			/*
			 * Exclusive. Dump the first 'exclusive' channel into
			 * destination buffer, and the rest into nothingness
			 * (mute effect).
			 */
			if (passthrough == 0 && (ch->flags & CHN_F_EXCLUSIVE)) {
				rcnt = SND_FXROUND(FEEDER_FEED(ch->feeder, ch,
				    b, count, ch->bufsoft), sz);
				passthrough = 1;
			} else
				FEEDER_FEED(ch->feeder, ch, tmp, count,
				    ch->bufsoft);
		} else {
			if (rcnt == 0) {
				rcnt = SND_FXROUND(FEEDER_FEED(ch->feeder, ch,
				    b, count, ch->bufsoft), sz);
				mcnt = count - rcnt;
			} else {
				cnt = SND_FXROUND(FEEDER_FEED(ch->feeder, ch,
				    tmp, count, ch->bufsoft), sz);
				if (cnt != 0) {
					if (mcnt != 0) {
						memset(b + rcnt,
						    sndbuf_zerodata(
						    f->desc->out), mcnt);
						mcnt = 0;
					}
					info->mix(tmp, b, cnt);
					if (cnt > rcnt)
						rcnt = cnt;
				}
			}
		}
		CHN_UNLOCK(ch);
	}

	if (++c->feedcount == 0)
		c->feedcount = 2;

	c->flags &= ~CHN_F_DIRTY;

	return (rcnt);
}

static struct pcm_feederdesc feeder_mixer_desc[] = {
	{ FEEDER_MIXER, 0, 0, 0, 0 },
	{ 0, 0, 0, 0, 0 }
};

static kobj_method_t feeder_mixer_methods[] = {
	KOBJMETHOD(feeder_init,		feed_mixer_init),
	KOBJMETHOD(feeder_set,		feed_mixer_set),
	KOBJMETHOD(feeder_feed,		feed_mixer_feed),
	KOBJMETHOD_END
};

FEEDER_DECLARE(feeder_mixer, NULL);