/*

   YMF278B  FM + Wave table Synthesizer (OPL4)

   Timer and PCM YMF278B.  The FM will be shared with the ymf262, eventually.

   This chip roughly splits the difference between the Sega 315-5560 MultiPCM
   (Multi32, Model 1/2) and YMF 292-F SCSP (later Model 2, STV, Saturn, Model 3).

   Features as listed in LSI-4MF2782 data sheet:
    FM Synthesis (same as YMF262)
     1. Sound generation mode
         Two-operater mode
          Generates eighteen voices or fifteen voices plus five rhythm sounds simultaneously
         Four-operator mode
          Generates six voices in four-operator mode plus six voices in two-operator mode simultaneously,
          or generates six voices in four-operator mode plus three voices in two-operator mode plus five
          rhythm sounds simultaneously
     2. Eight selectable waveforms
     3. Stereo output
    Wave Table Synthesis
     1. Generates twenty-four voices simultaneously
     2. 44.1kHz sampling rate for output sound data
     3. Selectable from 8-bit, 12-bit and 16-bit word lengths for wave data
     4. Stereo output (16-stage panpot for each voice)
    Wave Data
     1. Accepts 32M bit external memory at maximum
     2. Up to 512 wave tables
     3. External ROM or SRAM can be connected. With SRAM connected, the CPU can download wave data
     4. Outputs chip select signals for 1Mbit, 4Mbit, 8Mbit or 16Mbit memory
     5. Can be directly connected to the Yamaha YRW801 (Wave data ROM)
        Features of YRW801 as listed in LSI 4RW801A2
          Built-in wave data of tones which comply with GM system Level 1
           Melody tone ....... 128 tones
           Percussion tone ...  47 tones
          16Mbit capacity (2,097,152word x 8)

   By R. Belmont and O. Galibert.

   Copyright (c) 2002-2003 R. Belmont and O. Galibert.

   This software is dual-licensed: it may be used in MAME and properly licensed
   MAME derivatives under the terms of the MAME license.  For use outside of
   MAME and properly licensed derivatives, it is available under the
   terms of the GNU Lesser General Public License (LGPL), version 2.1.
   You may read the LGPL at http://www.gnu.org/licenses/lgpl.html

   Changelog:
   Sep. 8, 2002 - fixed ymf278b_compute_rate when OCT is negative (RB)
   Dec. 11, 2002 - added ability to set non-standard clock rates (RB)
                   fixed envelope target for release (fixes missing
           instruments in hotdebut).
                   Thanks to Team Japump! for MP3s from a real PCB.
           fixed crash if MAME is run with no sound.
   June 4, 2003 -  Changed to dual-license with LGPL for use in OpenMSX.
                   OpenMSX contributed a bugfix where looped samples were
            not being addressed properly, causing pitch fluctuation.
*/

#include <math.h>
#include "sndintrf.h"
#include "streams.h"
#include "cpuintrf.h"
#include "ymf278b.h"

#undef VERBOSE

typedef struct
{
	INT16 wave;		/* wavetable number */
	INT16 FN;		/* f-number */
	INT8 OCT;		/* octave */
	INT8 PRVB;		/* pseudo-reverb */
	INT8 LD;		/* level direct */
	INT8 TL;		/* total level */
	INT8 pan;		/* panpot */
	INT8 lfo;		/* LFO */
	INT8 vib;		/* vibrato */
	INT8 AM;		/* AM level */

	INT8 AR;
	INT8 D1R;
	INT8 DL;
	INT8 D2R;
	INT8 RC;   		/* rate correction */
	INT8 RR;

	UINT32 step;	/* fixed-point frequency step */
	UINT32 stepptr;	/* fixed-point pointer into the sample */

	INT8 active;		/* slot keyed on */
	INT8 bits;		/* width of the samples */
	UINT32 startaddr;
	UINT32 loopaddr;
	UINT32 endaddr;

	int env_step;
	UINT32 env_vol;
	UINT32 env_vol_step;
	UINT32 env_vol_lim;
} YMF278BSlot;

typedef struct
{
	YMF278BSlot slots[24];
	INT8 lsitest0;
	INT8 lsitest1;
	INT8 wavetblhdr;
	INT8 memmode;
	INT32 memadr;

	INT32 fm_l, fm_r;
	INT32 pcm_l, pcm_r;

	UINT8 timer_a_count, timer_b_count, enable, current_irq;
	emu_timer *timer_a, *timer_b;
	int irq_line;

	UINT8 port_A, port_B, port_C;
	void (*irq_callback)(int);

	const UINT8 *rom;
	int clock;

	INT32 volume[256*4];			// precalculated attenuation values with some marging for enveloppe and pan levels
	int pan_left[16], pan_right[16];	// pan volume offsets
	INT32 mix_level[8];

	sound_stream * stream;
	int index;
} YMF278BChip;

static INT32 *mix;

static int ymf278b_compute_rate(YMF278BSlot *slot, int val)
{
	int res, oct;

	if(val == 0)
		return 0;
	if(val == 15)
		return 63;
	if(slot->RC != 15)
	{
		oct = slot->OCT;
		if (oct & 8) oct |= -8;

		res = (oct+slot->RC)*2 + (slot->FN & 0x200 ? 1 : 0) + val*4;
	}
	else
		res = val * 4;
	if(res < 0)
		res = 0;
	else if(res > 63)
		res = 63;
	return res;
}

static UINT32 ymf278_compute_decay_rate(int num)
{
	int samples;

	if (num <= 3)
		samples = 0;
	else if (num >= 60)
		samples = 15 << 4;
	else
	{
		samples = (15 << (21 - num / 4)) / (4 + num % 4);
		if (num % 4 && num / 4 <= 11)
			samples += 2;
		else if (num == 51)
			samples += 2;
	}

	return samples;
}

static void ymf278b_envelope_next(YMF278BSlot *slot)
{
	if(slot->env_step == 0)
	{
		// Attack
		slot->env_vol = (256U << 23) - 1;
		slot->env_vol_lim = 256U<<23;
#ifdef VERBOSE
		logerror("YMF278B: Skipping attack (rate = %d)\n", slot->AR);
#endif
		slot->env_step++;
	}
	if(slot->env_step == 1)
	{
		// Decay 1
		slot->env_vol = 0;
		slot->env_step++;
		if(slot->DL)
		{
			int rate = ymf278b_compute_rate(slot, slot->D1R);
#ifdef VERBOSE
			logerror("YMF278B: Decay step 1, dl=%d, val = %d rate = %d, delay = %g\n", slot->DL, slot->D1R, rate, ymf278_compute_decay_rate(rate)*1000.0);
#endif
			if(rate<4)
				slot->env_vol_step = 0;
			else
				slot->env_vol_step = ((slot->DL*8)<<23) / ymf278_compute_decay_rate(rate);
			slot->env_vol_lim = (slot->DL*8)<<23;
			return;
		}
	}
	if(slot->env_step == 2)
	{
		// Decay 2
		int rate = ymf278b_compute_rate(slot, slot->D2R);
#ifdef VERBOSE
		logerror("YMF278B: Decay step 2, val = %d, rate = %d, delay = %g, current vol = %d\n", slot->D2R, rate, ymf278_compute_decay_rate(rate)*1000.0, slot->env_vol >> 23);
#endif
		if(rate<4)
			slot->env_vol_step = 0;
		else
			slot->env_vol_step = ((256U-slot->DL*8)<<23) / ymf278_compute_decay_rate(rate);
		slot->env_vol_lim = 256U<<23;
		slot->env_step++;
		return;
	}
	if(slot->env_step == 3)
	{
		// Decay 2 reached -96dB
#ifdef VERBOSE
		logerror("YMF278B: Voice cleared because of decay 2\n");
#endif
		slot->env_vol = 256U<<23;
		slot->env_vol_step = 0;
		slot->env_vol_lim = 0;
		slot->active = 0;
		return;
	}
	if(slot->env_step == 4)
	{
		// Release
		int rate = ymf278b_compute_rate(slot, slot->RR);
#ifdef VERBOSE
		logerror("YMF278B: Release, val = %d, rate = %d, delay = %g\n", slot->RR, rate, ymf278_compute_decay_rate(rate)*1000.0);
#endif
		if(rate<4)
			slot->env_vol_step = 0;
		else
			slot->env_vol_step = ((256U<<23)-slot->env_vol) / ymf278_compute_decay_rate(rate);
		slot->env_vol_lim = 256U<<23;
		slot->env_step++;
		return;
	}
	if(slot->env_step == 5)
	{
		// Release reached -96dB
#ifdef VERBOSE
		logerror("YMF278B: Release ends\n");
#endif
		slot->env_vol = 256U<<23;
		slot->env_vol_step = 0;
		slot->env_vol_lim = 0;
		slot->active = 0;
		return;
	}
}

static void ymf278b_pcm_update(void *param, stream_sample_t **inputs, stream_sample_t **outputs, int length)
{
	YMF278BChip *chip = param;
	int i, j;
	YMF278BSlot *slot = NULL;
	INT16 sample = 0;
	const UINT8 *rombase;
	INT32 *mixp;
	INT32 vl, vr;

	memset(mix, 0, sizeof(mix[0])*length*2);

	rombase = chip->rom;

	for (i = 0; i < 24; i++)
	{
		slot = &chip->slots[i];

		if (slot->active)
		{
			mixp = mix;

			for (j = 0; j < length; j++)
			{
				switch (slot->bits)
				{
					case 8: 	// 8 bit
						sample = rombase[slot->startaddr + (slot->stepptr>>16)]<<8;
						break;

					case 12:  	// 12 bit
						if (slot->stepptr & 1)
							sample = rombase[slot->startaddr + (slot->stepptr>>17)*3 + 2]<<8 | ((rombase[slot->startaddr + (slot->stepptr>>17)*3 + 1] << 4) & 0xf0);
						else
							sample = rombase[slot->startaddr + (slot->stepptr>>17)*3]<<8 | (rombase[slot->startaddr + (slot->stepptr>>17)*3 + 1] & 0xf0);
						break;

					case 16:  	// 16 bit
						sample = rombase[slot->startaddr + ((slot->stepptr>>16)*2)]<<8;
						sample |= rombase[slot->startaddr + ((slot->stepptr>>16)*2) + 1];
						break;
				}

				*mixp++ += (sample * chip->volume[slot->TL+chip->pan_left [slot->pan]+(slot->env_vol>>23)])>>17;
				*mixp++ += (sample * chip->volume[slot->TL+chip->pan_right[slot->pan]+(slot->env_vol>>23)])>>17;

				// update frequency
				slot->stepptr += slot->step;
				if(slot->stepptr >= slot->endaddr)
				{
					slot->stepptr = slot->stepptr - slot->endaddr + slot->loopaddr;
					// If the step is bigger than the loop, finish the sample forcibly
					if(slot->stepptr >= slot->endaddr)
					{
						slot->env_vol = 256U<<23;
						slot->env_vol_step = 0;
						slot->env_vol_lim = 0;
						slot->active = 0;
						slot->stepptr = 0;
						slot->step = 0;
					}
				}

				// update envelope
				slot->env_vol += slot->env_vol_step;
				if(((INT32)(slot->env_vol - slot->env_vol_lim)) >= 0)
			 		ymf278b_envelope_next(slot);
			}
		}
	}

	mixp = mix;
	vl = chip->mix_level[chip->pcm_l];
	vr = chip->mix_level[chip->pcm_r];
	for (i = 0; i < length; i++)
	{
		outputs[0][i] = (*mixp++ * vl) >> 16;
		outputs[1][i] = (*mixp++ * vr) >> 16;
	}
}

static void ymf278b_irq_check(YMF278BChip *chip)
{
	int prev_line = chip->irq_line;
	chip->irq_line = chip->current_irq ? ASSERT_LINE : CLEAR_LINE;
	if(chip->irq_line != prev_line && chip->irq_callback)
		chip->irq_callback(chip->irq_line);
}

static TIMER_CALLBACK( ymf278b_timer_a_tick )
{
	YMF278BChip *chip = ptr;
	if(!(chip->enable & 0x40))
	{
		chip->current_irq |= 0x40;
		ymf278b_irq_check(chip);
	}
}

static TIMER_CALLBACK( ymf278b_timer_b_tick )
{
	YMF278BChip *chip = ptr;
	if(!(chip->enable & 0x20))
	{
		chip->current_irq |= 0x20;
		ymf278b_irq_check(chip);
	}
}

static void ymf278b_timer_a_reset(YMF278BChip *chip)
{
	if(chip->enable & 1)
	{
		attotime period = ATTOTIME_IN_NSEC((256-chip->timer_a_count) * 80800);

		if (chip->clock != YMF278B_STD_CLOCK)
			period = attotime_div(attotime_mul(period, chip->clock), YMF278B_STD_CLOCK);

		timer_adjust(chip->timer_a, period, 0, period);
	}
	else
		timer_adjust(chip->timer_a, attotime_never, 0, attotime_zero);
}

static void ymf278b_timer_b_reset(YMF278BChip *chip)
{
	if(chip->enable & 2)
	{
		attotime period = ATTOTIME_IN_NSEC((256-chip->timer_b_count) * 323100);

		if (chip->clock != YMF278B_STD_CLOCK)
			period = attotime_div(attotime_mul(period, chip->clock), YMF278B_STD_CLOCK);

		timer_adjust(chip->timer_a, period, 0, period);
	}
	else
		timer_adjust(chip->timer_b, attotime_never, 0, attotime_zero);
}

static void ymf278b_A_w(YMF278BChip *chip, UINT8 reg, UINT8 data)
{
	switch(reg)
	{
		case 0x02:
			chip->timer_a_count = data;
			ymf278b_timer_a_reset(chip);
			break;
		case 0x03:
			chip->timer_b_count = data;
			ymf278b_timer_b_reset(chip);
			break;
		case 0x04:
			if(data & 0x80)
				chip->current_irq = 0;
			else
			{
				UINT8 old_enable = chip->enable;
				chip->enable = data;
				chip->current_irq &= ~data;
				if((old_enable ^ data) & 1)
					ymf278b_timer_a_reset(chip);
				if((old_enable ^ data) & 2)
					ymf278b_timer_b_reset(chip);
			}
			ymf278b_irq_check(chip);
			break;
		default:
			logerror("YMF278B:  Port A write %02x, %02x\n", reg, data);
	}
}

static void ymf278b_B_w(YMF278BChip *chip, UINT8 reg, UINT8 data)
{
	logerror("YMF278B:  Port B write %02x, %02x\n", reg, data);
}

static void ymf278b_C_w(YMF278BChip *chip, UINT8 reg, UINT8 data)
{
	// Handle slot registers specifically
	if (reg >= 0x08 && reg <= 0xf7)
	{
		YMF278BSlot *slot = NULL;
		int snum;
		snum = (reg-8) % 24;
		slot = &chip->slots[snum];
		switch((reg-8) / 24)
		{
			case 0:
			{
				const UINT8 *p;

				slot->wave &= 0x100;
				slot->wave |= data;

				if(slot->wave < 384 || !chip->wavetblhdr)
					p = chip->rom + (slot->wave * 12);
				else
					p = chip->rom + chip->wavetblhdr*0x80000 + ((slot->wave - 384) * 12);

				switch (p[0]&0xc0)
				{
					case 0:
						slot->bits = 8;
						break;
					case 0x40:
						slot->bits = 12;
						break;
					case 0x80:
						slot->bits = 16;
						break;
				}

				slot->lfo = (p[7] >> 2) & 7;
				slot->vib = p[7] & 7;
				slot->AR = p[8] >> 4;
				slot->D1R = p[8] & 0xf;
				slot->DL = p[9] >> 4;
				slot->D2R = p[9] & 0xf;
				slot->RC = p[10] >> 4;
				slot->RR = p[10] & 0xf;
				slot->AM = p[11] & 7;

				slot->startaddr = (p[2] | (p[1]<<8) | ((p[0]&0x3f)<<16));
				slot->loopaddr = (p[4]<<16) | (p[3]<<24);
				slot->endaddr = (p[6]<<16) | (p[5]<<24);
				slot->endaddr -= 0x00010000U;
				slot->endaddr ^= 0xffff0000U;
				break;
			}
			case 1:
				slot->wave &= 0xff;
				slot->wave |= ((data&0x1)<<8);
				slot->FN &= 0x380;
				slot->FN |= (data>>1);
				break;
			case 2:
				slot->FN &= 0x07f;
				slot->FN |= ((data&0x07)<<7);
				slot->PRVB = ((data&0x4)>>3);
				slot->OCT = ((data&0xf0)>>4);
				break;
			case 3:
				slot->TL = (data>>1);
				slot->LD = data&0x1;
				break;
			case 4:
				slot->pan = data&0xf;
				if (data & 0x80)
				{
					unsigned int step;
					int oct;

					slot->active = 1;

					oct = slot->OCT;
					if(oct & 8)
						oct |= -8;

					slot->env_step = 0;
					slot->env_vol = 256U<<23;
					slot->env_vol_step = 0;
					slot->env_vol_lim = 256U<<23;
					slot->stepptr = 0;
					slot->step = 0;

					step = (slot->FN | 1024) << (oct + 7);
					slot->step = step / 4;

					ymf278b_envelope_next(slot);

#ifdef VERBOSE
					logerror("YMF278B: slot %2d wave %3d lfo=%d vib=%d ar=%d d1r=%d dl=%d d2r=%d rc=%d rr=%d am=%d\n", snum, slot->wave,
							 slot->lfo, slot->vib, slot->AR, slot->D1R, slot->DL, slot->D2R, slot->RC, slot->RR, slot->AM);
					logerror("                  b=%d, start=%x, loop=%x, end=%x, oct=%d, fn=%d, step=%x\n", slot->bits, slot->startaddr, slot->loopaddr>>16, slot->endaddr>>16, oct, slot->FN, slot->step);
#endif
				}
				else
				{
#ifdef VERBOSE
					logerror("YMF278B: slot %2d off\n", snum);
#endif
					if(slot->active)
					{
						slot->env_step = 4;
						ymf278b_envelope_next(slot);
					}
				}
				break;
			case 5:
				slot->vib = data&0x7;
				slot->lfo = (data>>3)&0x7;
		       	break;
			case 6:
				slot->AR = data>>4;
				slot->D1R = data&0xf;
				break;
			case 7:
				slot->DL = data>>4;
				slot->D2R = data&0xf;
				break;
			case 8:
				slot->RC = data>>4;
				slot->RR = data&0xf;
				break;
			case 9:
				slot->AM = data & 0x7;
				break;
		}
	}
	else
	{
		// All non-slot registers
		switch (reg)
		{
			case 0x00:    	// TEST
			case 0x01:
				break;

			case 0x02:
				chip->wavetblhdr = (data>>2)&0x7;
				chip->memmode = data&1;
				break;

			case 0x03:
				chip->memadr &= 0xffff;
				chip->memadr |= (data<<16);
				break;

			case 0x04:
				chip->memadr &= 0xff00ff;
				chip->memadr |= (data<<8);
				break;

			case 0x05:
				chip->memadr &= 0xffff00;
				chip->memadr |= data;
				break;

			case 0x06:  // memory data (ignored, we don't support RAM)
			case 0x07:	// unused
				break;

			case 0xf8:
				chip->fm_l = data & 0x7;
				chip->fm_r = (data>>3)&0x7;
				break;

			case 0xf9:
				chip->pcm_l = data & 0x7;
				chip->pcm_r = (data>>3)&0x7;
				break;
		}
	}
}

static UINT8 ymf278b_status_port_r(int num)
{
	YMF278BChip *chip = sndti_token(SOUND_YMF278B, num);
	return chip->current_irq | (chip->irq_line == ASSERT_LINE ? 0x80 : 0x00);
}

// Not implemented yet
static UINT8 ymf278b_data_port_r(int num)
{
	return 0;
}

static void ymf278b_control_port_A_w(int num, UINT8 data)
{
	YMF278BChip *chip = sndti_token(SOUND_YMF278B, num);
	chip->port_A = data;
}

static void ymf278b_data_port_A_w(int num, UINT8 data)
{
	YMF278BChip *chip = sndti_token(SOUND_YMF278B, num);
	ymf278b_A_w(chip, chip->port_A, data);
}

static void ymf278b_control_port_B_w(int num, UINT8 data)
{
	YMF278BChip *chip = sndti_token(SOUND_YMF278B, num);
	chip->port_B = data;
}

static void ymf278b_data_port_B_w(int num, UINT8 data)
{
	YMF278BChip *chip = sndti_token(SOUND_YMF278B, num);
	ymf278b_B_w(chip, chip->port_B, data);
}

static void ymf278b_control_port_C_w(int num, UINT8 data)
{
	YMF278BChip *chip = sndti_token(SOUND_YMF278B, num);
	chip->port_C = data;
}

static void ymf278b_data_port_C_w(int num, UINT8 data)
{
	YMF278BChip *chip = sndti_token(SOUND_YMF278B, num);
	ymf278b_C_w(chip, chip->port_C, data);
}

static void ymf278b_init(YMF278BChip *chip, UINT8 *rom, void (*cb)(int), int clock)
{
	chip->rom = rom;
	chip->irq_callback = cb;
	chip->timer_a = timer_alloc(ymf278b_timer_a_tick, chip);
	chip->timer_b = timer_alloc(ymf278b_timer_b_tick, chip);
	chip->irq_line = CLEAR_LINE;
	chip->clock = clock;

	mix = auto_malloc(44100*2*sizeof(*mix));
}

static void *ymf278b_start(int sndindex, int clock, const void *config)
{
	const struct YMF278B_interface *intf;
	int i;
	YMF278BChip *chip;

	chip = auto_malloc(sizeof(*chip));
	memset(chip, 0, sizeof(*chip));
	chip->index = sndindex;

	intf = config;

	ymf278b_init(chip, memory_region(intf->region), intf->irq_callback, clock);
	chip->stream = stream_create(0, 2, clock/768, chip, ymf278b_pcm_update);

	// Volume table, 1 = -0.375dB, 8 = -3dB, 256 = -96dB
	for(i = 0; i < 256; i++)
		chip->volume[i] = 65536*pow(2.0, (-0.375/6)*i);
	for(i = 256; i < 256*4; i++)
		chip->volume[i] = 0;

	// Pan values, units are -3dB, i.e. 8.
	for(i = 0; i < 16; i++)
	{
		chip->pan_left[i] = i < 7 ? i*8 : i < 9 ? 256 : 0;
		chip->pan_right[i] = i < 8 ? 0 : i < 10 ? 256 : (16-i)*8;
	}

	// Mixing levels, units are -3dB, and add some marging to avoid clipping
	for(i=0; i<7; i++)
		chip->mix_level[i] = chip->volume[8*i+8];
	chip->mix_level[7] = 0;

	return chip;
}


READ8_HANDLER( YMF278B_status_port_0_r )
{
	return ymf278b_status_port_r(0);
}

READ8_HANDLER( YMF278B_data_port_0_r )
{
	return ymf278b_data_port_r(0);
}

WRITE8_HANDLER( YMF278B_control_port_0_A_w )
{
	ymf278b_control_port_A_w(0, data);
}

WRITE8_HANDLER( YMF278B_data_port_0_A_w )
{
	ymf278b_data_port_A_w(0, data);
}

WRITE8_HANDLER( YMF278B_control_port_0_B_w )
{
	ymf278b_control_port_B_w(0, data);
}

WRITE8_HANDLER( YMF278B_data_port_0_B_w )
{
	ymf278b_data_port_B_w(0, data);
}

WRITE8_HANDLER( YMF278B_control_port_0_C_w )
{
	ymf278b_control_port_C_w(0, data);
}

WRITE8_HANDLER( YMF278B_data_port_0_C_w )
{
	ymf278b_data_port_C_w(0, data);
}


READ8_HANDLER( YMF278B_status_port_1_r )
{
	return ymf278b_status_port_r(1);
}

READ8_HANDLER( YMF278B_data_port_1_r )
{
	return ymf278b_data_port_r(1);
}

WRITE8_HANDLER( YMF278B_control_port_1_A_w )
{
	ymf278b_control_port_A_w(1, data);
}

WRITE8_HANDLER( YMF278B_data_port_1_A_w )
{
	ymf278b_data_port_A_w(1, data);
}

WRITE8_HANDLER( YMF278B_control_port_1_B_w )
{
	ymf278b_control_port_B_w(1, data);
}

WRITE8_HANDLER( YMF278B_data_port_1_B_w )
{
	ymf278b_data_port_B_w(1, data);
}

WRITE8_HANDLER( YMF278B_control_port_1_C_w )
{
	ymf278b_control_port_C_w(1, data);
}

WRITE8_HANDLER( YMF278B_data_port_1_C_w )
{
	ymf278b_data_port_C_w(1, data);
}




/**************************************************************************
 * Generic get_info
 **************************************************************************/

static void ymf278b_set_info(void *token, UINT32 state, sndinfo *info)
{
	switch (state)
	{
		/* no parameters to set */
	}
}


void ymf278b_get_info(void *token, UINT32 state, sndinfo *info)
{
	switch (state)
	{
		/* --- the following bits of info are returned as 64-bit signed integers --- */

		/* --- the following bits of info are returned as pointers to data or functions --- */
		case SNDINFO_PTR_SET_INFO:						info->set_info = ymf278b_set_info;		break;
		case SNDINFO_PTR_START:							info->start = ymf278b_start;			break;
		case SNDINFO_PTR_STOP:							/* Nothing */							break;
		case SNDINFO_PTR_RESET:							/* Nothing */							break;

		/* --- the following bits of info are returned as NULL-terminated strings --- */
		case SNDINFO_STR_NAME:							info->s = "YMF278B";					break;
		case SNDINFO_STR_CORE_FAMILY:					info->s = "Yamaha FM";					break;
		case SNDINFO_STR_CORE_VERSION:					info->s = "1.0";						break;
		case SNDINFO_STR_CORE_FILE:						info->s = __FILE__;						break;
		case SNDINFO_STR_CORE_CREDITS:					info->s = "Copyright (c) 2004, The MAME Team"; break;
	}
}

