PCM sound, refactored code940

[picodrive.git] / platform / gp2x / code940 / 940.c

#include "940shared.h"\r
\r
static _940_data_t *shared_data = (_940_data_t *)   0x00100000;\r
static _940_ctl_t  *shared_ctl  = (_940_ctl_t *)    0x00200000;\r
static unsigned char *mp3_data  = (unsigned char *) 0x01000000;\r
YM2612 *ym2612_940;\r
int *mix_buffer;\r
\r
// from init.s\r
void wait_irq(void);\r
void spend_cycles(int c);\r
void cache_clean(void);\r
void cache_clean_flush(void);\r
// this should help to resolve race confition where shared var\r
// is changed by other core just before we update it\r
void set_if_not_changed(int *val, int oldval, int newval);\r
\r
//	asm volatile ("mov r0, #0" ::: "r0");\r
//	asm volatile ("mcr p15, 0, r0, c7, c6,  0" ::: "r0"); /* flush dcache */\r
//	asm volatile ("mcr p15, 0, r0, c7, c10, 4" ::: "r0"); /* drain write buffer */\r
\r
\r
static void mp3_decode(void)\r
{\r
	int mp3_offs = shared_ctl->mp3_offs;\r
	unsigned char *readPtr = mp3_data + mp3_offs;\r
	int bytesLeft = shared_ctl->mp3_len - mp3_offs;\r
	int offset; // frame offset from readPtr\r
	int err;\r
\r
	if (bytesLeft <= 0) return; // EOF, nothing to do\r
\r
	offset = MP3FindSyncWord(readPtr, bytesLeft);\r
	if (offset < 0) {\r
		set_if_not_changed(&shared_ctl->mp3_offs, mp3_offs, shared_ctl->mp3_len);\r
		return; // EOF\r
	}\r
	readPtr += offset;\r
	bytesLeft -= offset;\r
\r
	err = MP3Decode(shared_data->mp3dec, &readPtr, &bytesLeft,\r
			shared_data->mp3_buffer[shared_ctl->mp3_buffsel], 0);\r
	if (err) {\r
		if (err == ERR_MP3_INDATA_UNDERFLOW) {\r
			shared_ctl->mp3_offs = shared_ctl->mp3_len; // EOF\r
			set_if_not_changed(&shared_ctl->mp3_offs, mp3_offs, shared_ctl->mp3_len);\r
			return;\r
		} else if (err <= -6 && err >= -12) {\r
			// ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_*\r
			// just try to skip the offending frame..\r
			readPtr++;\r
		}\r
		shared_ctl->mp3_errors++;\r
		shared_ctl->mp3_lasterr = err;\r
	}\r
	set_if_not_changed(&shared_ctl->mp3_offs, mp3_offs, readPtr - mp3_data);\r
}\r
\r
\r
void Main940(int startvector, int pc_at_irq)\r
{\r
	ym2612_940 = &shared_data->ym2612;\r
	mix_buffer = shared_data->mix_buffer;\r
\r
	// debug\r
	shared_ctl->vstarts[startvector]++;\r
	shared_ctl->last_irq_pc = pc_at_irq;\r
	// asm volatile ("mcr p15, 0, r0, c7, c10, 4" ::: "r0");\r
\r
\r
//	for (;;)\r
	{\r
		int job_num = 0;\r
/*\r
		while (!shared_ctl->busy)\r
		{\r
			//shared_ctl->waitc++;\r
			spend_cycles(8*1024);\r
		}\r
*/\r
/*\r
		if (!shared_ctl->busy)\r
		{\r
			wait_irq();\r
		}\r
		shared_ctl->lastbusy = shared_ctl->busy;\r
*/\r
\r
		for (job_num = 0; job_num < MAX_940JOBS; job_num++)\r
		{\r
			shared_ctl->lastjob = (job_num << 8) | shared_ctl->jobs[job_num];\r
\r
			switch (shared_ctl->jobs[job_num])\r
			{\r
				case JOB940_INITALL:\r
					/* ym2612 */\r
					shared_ctl->writebuff0[0] = shared_ctl->writebuff1[0] = 0xffff;\r
					YM2612Init_(shared_ctl->baseclock, shared_ctl->rate);\r
					/* Helix mp3 decoder */\r
					shared_data->mp3dec = MP3InitDecoder();\r
					break;\r
\r
				case JOB940_YM2612RESETCHIP:\r
					YM2612ResetChip_();\r
					break;\r
\r
				case JOB940_PICOSTATELOAD:\r
					YM2612PicoStateLoad_();\r
					break;\r
\r
				case JOB940_YM2612UPDATEONE: {\r
					int i, dw, *wbuff;\r
					if (shared_ctl->writebuffsel == 1) {\r
						wbuff = (int *) shared_ctl->writebuff1;\r
					} else {\r
						wbuff = (int *) shared_ctl->writebuff0;\r
					}\r
\r
					/* playback all writes */\r
					for (i = 2048/2; i > 0; i--) {\r
						UINT16 d;\r
						dw = *wbuff++;\r
						d = dw;\r
						if (d == 0xffff) break;\r
						YM2612Write_(d >> 8, d);\r
						d = (dw>>16);\r
						if (d == 0xffff) break;\r
						YM2612Write_(d >> 8, d);\r
					}\r
\r
					YM2612UpdateOne_(mix_buffer, shared_ctl->length, shared_ctl->stereo, 1);\r
					break;\r
				}\r
\r
				case JOB940_MP3DECODE:\r
					mp3_decode();\r
					break;\r
			}\r
		}\r
\r
		cache_clean();\r
//		asm volatile ("mov r0, #0" ::: "r0");\r
//		asm volatile ("mcr p15, 0, r0, c7, c10, 4" ::: "r0"); /* drain write buffer, should be done on nonbuffered write */\r
//		cache_clean_flush();\r
\r
		shared_ctl->loopc++;\r
\r
//		// shared_ctl->busy = 0; // shared mem is not reliable?\r
\r
		wait_irq();\r
	}\r
}\r
\r