/*
 * Copyright 2000, 2001, 2002
 *         Dan Potter. All rights reserved.
 *
 * 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.
 * 3. Neither the name of Cryptic Allusion nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS 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.
 */

/* Modified by Walter van Niftrik <w.f.b.w.v.niftrik@stud.tue.nl> */

#include <string.h>
#include <stdlib.h>

#include <arch/timer.h>
#include <dc/g2bus.h>
#include <dc/spu.h>
#include <dc/sound/sound.h>
#include <stream.h>

#include <../sound/arm/aica_cmd_iface.h>

/*

Here we implement a very simple double-buffering, not the rather complex
circular queueing done in most DMA'd sound architectures. This is done for
simplicity's sake. At some point we may upgrade that the circular queue
system. 

Basically this poll routine checks to see which buffer is playing, and
whether a new one is available or not. If not, we ask the user routine
for more sound data and load it up. That's about it.

*/


/* The last write position in the playing buffer */
static int last_write_pos = 0;

/* the address of the sound ram from the SH4 side */
#define SPU_RAM_BASE            0xa0800000

/* buffer size per channel in bytes */
static int buffer_size;

/* callback chunk size in frames, must be power of 2 */
static int chunk_size;

/* Stream data location in AICA RAM */
static uint32			spu_ram_sch1, spu_ram_sch2;

/* Seperation buffers (for stereo) */
static int16 *sep_buffer[2] = { NULL, NULL };

/* "Get data" callback; we'll call this any time we want to get another
   buffer of output data. */
static void* (*str_get_data)(int requested_cnt, int * received_cnt) = NULL;

/* Stereo/mono flag for stream */
static int stereo;

/* Stream queueing is where we get everything ready to go but don't
   actually start it playing until the signal (for music sync, etc) */
static int snd_stream_queueing;

/* Have we been initialized yet? (and reserved a buffer, etc) */
static int initted = 0;

/* Set "get data" callback */
void snd_stream_set_callback(void *(*func)(int, int*)) {
	str_get_data = func;
}

/* Performs stereo seperation for the two channels; this routine
   has been optimized for the SH-4. */
static void sep_data(void *buffer, int len) {
	register int16	*bufsrc, *bufdst;
	register int	x, y, cnt;

	if (stereo) {
		bufsrc = (int16*)buffer;
		bufdst = sep_buffer[0];
		x = 0; y = 0; cnt = len / 2;
		do {
			*bufdst = *bufsrc;
			bufdst++; bufsrc+=2; cnt--;
		} while (cnt > 0);

		bufsrc = (int16*)buffer; bufsrc++;
		bufdst = sep_buffer[1];
		x = 1; y = 0; cnt = len / 2;
		do {
			*bufdst = *bufsrc;
			bufdst++; bufsrc+=2; cnt--;
			x+=2; y++;
		} while (cnt > 0);
	} else {
		memcpy(sep_buffer[0], buffer, len);
		memcpy(sep_buffer[1], buffer, len);
	}
}

/* Prefill buffers -- do this before calling start() */
void snd_stream_prefill() {
	spu_memset(spu_ram_sch1, 0, buffer_size);
	spu_memset(spu_ram_sch2, 0, buffer_size);

	last_write_pos = 0;
}

/* Initialize stream system */
int snd_stream_init(void* (*callback)(int, int *), int buf_size, int ch_size) {
	/* Start off with queueing disabled */
	snd_stream_queueing = 0;

	/* Setup the callback */
	snd_stream_set_callback(callback);

	if (initted)
		return 0;

	buffer_size = buf_size;

	chunk_size = ch_size;

	/* Create stereo seperation buffers */
	if (!sep_buffer[0]) {
		sep_buffer[0] = memalign(32, (buffer_size >> 1));
		sep_buffer[1] = memalign(32, (buffer_size >> 1));
	}

	/* Finish loading the stream driver */
	if (snd_init() < 0) {
		dbglog(DBG_ERROR, "snd_stream_init(): snd_init() failed, giving up\n");
		return -1;
	}

	spu_ram_sch1 = snd_mem_malloc(buffer_size << 1);
	spu_ram_sch2 = spu_ram_sch1 + (buffer_size);

	initted = 1;

	return 0;
}

/* Shut everything down and free mem */
void snd_stream_shutdown() {
	if (!initted)
		return;

	snd_stream_stop();
	if (sep_buffer[0]) {
		free(sep_buffer[0]);	sep_buffer[0] = NULL;
		free(sep_buffer[1]);	sep_buffer[1] = NULL;
	}
	snd_mem_free(spu_ram_sch1);
	initted = 0;
}

/* Enable / disable stream queueing */
void snd_stream_queue_enable() {
	snd_stream_queueing = 1;
}

void snd_stream_queue_disable() {
	snd_stream_queueing = 0;
}

/* Start streaming (or if queueing is enabled, just get ready) */
void snd_stream_start(uint32 freq, int st) {
	AICA_CMDSTR_CHANNEL(tmp, cmd, chan);
	
	if (!str_get_data) return;

	stereo = st;

	/* Make sure these are sync'd (and/or delayed) */
	snd_sh4_to_aica_stop();
	
	/* Prefill buffers */
	snd_stream_prefill();

	/* Channel 0 */
	cmd->cmd = AICA_CMD_CHAN;
	cmd->timestamp = 0;
	cmd->size = AICA_CMDSTR_CHANNEL_SIZE;
	cmd->cmd_id = 0;
	chan->cmd = AICA_CH_CMD_START;
	chan->base = spu_ram_sch1;
	chan->type = AICA_SM_16BIT;
	chan->length = (buffer_size >> 1);
	chan->loop = 1;
	chan->loopstart = 0;
	chan->loopend = (buffer_size >> 1);
	chan->freq = freq;
	chan->vol = 240;
	chan->pan = 0;
	snd_sh4_to_aica(tmp, cmd->size);

	/* Channel 1 */
	cmd->cmd_id = 1;
	chan->base = spu_ram_sch2;
	chan->pan = 255;
	snd_sh4_to_aica(tmp, cmd->size);

	/* Process the changes */
	if (!snd_stream_queueing)
		snd_sh4_to_aica_start();
}

/* Actually make it go (in queued mode) */
void snd_stream_queue_go() {
	snd_sh4_to_aica_start();
}

/* Stop streaming */
void snd_stream_stop() {
	AICA_CMDSTR_CHANNEL(tmp, cmd, chan);
	
	if (!str_get_data) return;

	/* Stop stream */
	/* Channel 0 */
	cmd->cmd = AICA_CMD_CHAN;
	cmd->timestamp = 0;
	cmd->size = AICA_CMDSTR_CHANNEL_SIZE;
	cmd->cmd_id = 0;
	chan->cmd = AICA_CH_CMD_STOP;
	snd_sh4_to_aica(tmp, cmd->size);

	/* Channel 1 */
	cmd->cmd_id = 1;
	snd_sh4_to_aica(tmp, AICA_CMDSTR_CHANNEL_SIZE);
}

/* Poll streamer to load more data if neccessary */
int snd_stream_poll(int size) {
	uint32		ch0pos, ch1pos;
	int		realbuffer;
	int		current_play_pos;
	int		needed_samples;
	int		got_samples;
	void		*data;

	if (!str_get_data) return -1;

	/* Get "real" buffer */
	ch0pos = g2_read_32(SPU_RAM_BASE + AICA_CHANNEL(0) + offsetof(aica_channel_t, pos));
	ch1pos = g2_read_32(SPU_RAM_BASE + AICA_CHANNEL(1) + offsetof(aica_channel_t, pos));

	if (ch0pos >= (buffer_size >> 1)) {
		dbglog(DBG_ERROR, "snd_stream_poll: chan0.pos = %ld (%08lx)\n", ch0pos, ch0pos);
		return -1;
	}
	
	realbuffer = !((ch0pos < (buffer_size >> 2)) && (ch1pos < (buffer_size >> 2)));

	current_play_pos = (ch0pos < ch1pos)?(ch0pos):(ch1pos);

	/* count just till the end of the buffer, so we don't have to
	   handle buffer wraps */
	if (last_write_pos <= current_play_pos)
		needed_samples = current_play_pos - last_write_pos;
	else
		needed_samples = (buffer_size >> 1) - last_write_pos;

	if (needed_samples >= chunk_size)
		needed_samples = chunk_size;
	else
		needed_samples = 0;
	/* printf("last_write_pos %6i, current_play_pos %6i, needed_samples %6i\n",last_write_pos,current_play_pos,needed_samples); */

	if (needed_samples > 0) {
		if (stereo) {
			data = str_get_data(needed_samples * 4, &got_samples);
			if (got_samples < needed_samples * 4) {
				needed_samples = got_samples / 4;
				if (needed_samples & 3)
					needed_samples = (needed_samples + 4) & ~3;
			}
		} else {
			data = str_get_data(needed_samples * 2, &got_samples);
			if (got_samples < needed_samples * 2) {
				needed_samples = got_samples / 2;
				if (needed_samples & 1)
					needed_samples = (needed_samples + 2) & ~1;
			}
		}
		if (data == NULL) {
			/* Fill the "other" buffer with zeros */
			spu_memset(spu_ram_sch1 + (last_write_pos * 2), 0, needed_samples * 2);
			spu_memset(spu_ram_sch2 + (last_write_pos * 2), 0, needed_samples * 2);
			return -3;
		}

		sep_data(data, needed_samples * 2);
		spu_memload(spu_ram_sch1 + (last_write_pos * 2), (uint8*)sep_buffer[0], needed_samples * 2);
		spu_memload(spu_ram_sch2 + (last_write_pos * 2), (uint8*)sep_buffer[1], needed_samples * 2);

		last_write_pos += needed_samples;
		if (last_write_pos >= (buffer_size >> 1))
			last_write_pos -= (buffer_size >> 1);
	}
	return 0;
}

/* Set the volume on the streaming channels */
void snd_stream_volume(int vol) {
	AICA_CMDSTR_CHANNEL(tmp, cmd, chan);

	cmd->cmd = AICA_CMD_CHAN;
	cmd->timestamp = 0;
	cmd->size = AICA_CMDSTR_CHANNEL_SIZE;
	cmd->cmd_id = 0;
	chan->cmd = AICA_CH_CMD_UPDATE | AICA_CH_UPDATE_SET_VOL;
	chan->vol = vol;
	snd_sh4_to_aica(tmp, cmd->size);

	cmd->cmd_id = 1;
	snd_sh4_to_aica(tmp, cmd->size);
}