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// license:BSD-3-Clause
// copyright-holders:Aaron Giles

#include "emu.h"
#include "ym2151.h"


DEFINE_DEVICE_TYPE(YM2151, ym2151_device, "ym2151", "YM2151 OPM")
DEFINE_DEVICE_TYPE(YM2164, ym2164_device, "ym2164", "YM2164 OPP")
DEFINE_DEVICE_TYPE(YM2414, ym2414_device, "ym2414", "YM2414 OPZ")


//*********************************************************
//  YM2151 DEVICE
//*********************************************************

//-------------------------------------------------
//  ym2151_device - constructor
//-------------------------------------------------

ym2151_device::ym2151_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock, device_type type) :
	device_t(mconfig, type, tag, owner, clock),
	device_sound_interface(mconfig, *this),
	m_fm(*this),
	m_stream(nullptr),
	m_port_w(*this),
	m_busy_duration(m_fm.compute_busy_duration()),
	m_address(0),
	m_reset_state(1)
{
}


//-------------------------------------------------
//  read - handle a read from the device
//-------------------------------------------------

u8 ym2151_device::read(offs_t offset)
{
	u8 result = 0xff;
	switch (offset & 1)
	{
		case 0: // data port (unused)
			logerror("Unexpected read from YM2151 offset %d\n", offset & 3);
			break;

		case 1:	// status port, YM2203 compatible
			result = m_fm.status();
			break;
	}
	return result;
}


//-------------------------------------------------
//  write - handle a write to the register
//  interface
//-------------------------------------------------

void ym2151_device::write(offs_t offset, u8 value)
{
	// ignore writes when the reset is active (low)
	if (m_reset_state == 0)
		return;

	switch (offset & 1)
	{
		case 0: // address port
			m_address = value;
			break;

		case 1: // data port

			// force an update
			m_stream->update();

			// write to FM
			m_fm.write(m_address, value);

			// special cases
			if (m_address == 0x01 && BIT(value, 1))
			{
				// writes to the test register can reset the LFO
				m_fm.reset_lfo();
			}
			else if (m_address == 0x1b)
			{
				// writes to register 0x1B send the upper 2 bits to the output lines
				m_port_w(0, value >> 6, 0xff);
			}

			// mark busy for a bit
			m_fm.set_busy_end(machine().time() + m_busy_duration);
			break;
	}
}


//-------------------------------------------------
//  reset_w - write to the (active low) reset line
//-------------------------------------------------

WRITE_LINE_MEMBER(ym2151_device::reset_w)
{
	// reset the device upon going low
	if (state == 0 && m_reset_state != 0)
		reset();
	m_reset_state = state;
}


//-------------------------------------------------
//  device_start - start of emulation
//-------------------------------------------------

void ym2151_device::device_start()
{
	// create our stream
	m_stream = stream_alloc(0, fm_engine::OUTPUTS, m_fm.sample_rate(clock()));

	// resolve the write callback
	m_port_w.resolve_safe();

	// call this for the variants that need to adjust the rate
	device_clock_changed();

	// initialize the FM engine
	m_fm.init();
}


//-------------------------------------------------
//  device_register_save - register for save state
//-------------------------------------------------

void ym2151_device::device_register_save(save_registrar &save)
{
	// save our data
	save.reg(NAME(m_address))
		.reg(NAME(m_reset_state));

	// save the engines
	m_fm.register_save(save);
}


//-------------------------------------------------
//  device_reset - start of emulation
//-------------------------------------------------

void ym2151_device::device_reset()
{
	// reset the engines
	m_fm.reset();
}


//-------------------------------------------------
//  device_clock_changed - update if clock changes
//-------------------------------------------------

void ym2151_device::device_clock_changed()
{
	m_stream->set_sample_rate(m_fm.sample_rate(clock()));
	m_busy_duration = m_fm.compute_busy_duration();
}


//-------------------------------------------------
//  sound_stream_update - update the sound stream
//-------------------------------------------------

void ym2151_device::sound_stream_update(sound_stream &stream, std::vector<read_stream_view> const &inputs, std::vector<write_stream_view> &outputs)
{
	// iterate over all target samples
	for (int sampindex = 0; sampindex < outputs[0].samples(); sampindex++)
	{
		// clock the system
		m_fm.clock(fm_engine::ALL_CHANNELS);

		// update the FM content; YM2151 is full 14-bit with no intermediate clipping
		s32 sums[fm_engine::OUTPUTS] = { 0 };
		m_fm.output(sums, 0, 32767, fm_engine::ALL_CHANNELS);

		// convert to 10.3 floating point value for the DAC and back
		// YM2151 is stereo
		for (int index = 0; index < fm_engine::OUTPUTS; index++)
			outputs[index].put_int(sampindex, ymfm_roundtrip_fp(sums[index]), 32768);
	}
}


//*********************************************************
//  YM2164 DEVICE
//*********************************************************

//-------------------------------------------------
//  ym2164_device - constructor
//-------------------------------------------------

ym2164_device::ym2164_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
	ym2151_device(mconfig, tag, owner, clock, YM2164)
{
}


//-------------------------------------------------
//  write - handle a write to the register
//  interface
//-------------------------------------------------

void ym2164_device::write(offs_t offset, u8 value)
{
	// ignore writes when the reset is active (low)
	if (m_reset_state == 0)
		return;

	switch (offset & 1)
	{
		case 0: // address port
			m_address = value;
			break;

		case 1: // data port

			// force an update
			m_stream->update();

			// write to FM
			m_fm.write(m_address, value);

			// writes to register 0x1B send the upper 2 bits to the output lines
			if (m_address == 0x1b)
				m_port_w(0, value >> 6, 0xff);

			// mark busy for a bit
			m_fm.set_busy_end(machine().time() + m_busy_duration);
			break;
	}
}



//*********************************************************
//  YM2151 DEVICE
//*********************************************************

//-------------------------------------------------
//  ym2414_device - constructor
//-------------------------------------------------

ym2414_device::ym2414_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
	ym2151_device(mconfig, tag, owner, clock, YM2414)
{
}