// license:BSD-3-Clause
// copyright-holders:Curt Coder
/**********************************************************************

    Commodore 8280 Dual 8" Disk Drive emulation

**********************************************************************/

#include "emu.h"
#include "c8280.h"

#include "cpu/m6502/m6502.h"
#include "imagedev/floppy.h"
#include "machine/mos6530.h"
#include "machine/wd_fdc.h"

#include "formats/c8280_dsk.h"



namespace {

//**************************************************************************
//  MACROS / CONSTANTS
//**************************************************************************

#define M6502_DOS_TAG   "5c"
#define M6502_FDC_TAG   "9e"
#define WD1797_TAG      "5e"


enum
{
	LED_POWER = 0,
	LED_ACT0,
	LED_ACT1,
	LED_ERR
};



//**************************************************************************
//  TYPE DEFINITIONS
//**************************************************************************

// ======================> c8280_device

class c8280_device : public device_t, public device_ieee488_interface
{
public:
	// construction/destruction
	c8280_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);

protected:
	// device_t implementation
	virtual void device_start() override ATTR_COLD;
	virtual void device_reset() override ATTR_COLD;
	virtual const tiny_rom_entry *device_rom_region() const override ATTR_COLD;
	virtual void device_add_mconfig(machine_config &config) override ATTR_COLD;
	virtual ioport_constructor device_input_ports() const override ATTR_COLD;

	// device_ieee488_interface implementation
	void ieee488_atn(int state) override;
	void ieee488_ifc(int state) override;

private:
	inline void update_ieee_signals();

	uint8_t dio_r();
	void dio_w(uint8_t data);
	uint8_t riot1_pa_r();
	void riot1_pa_w(uint8_t data);
	uint8_t riot1_pb_r();
	void riot1_pb_w(uint8_t data);
	uint8_t fk5_r();
	void fk5_w(uint8_t data);

	void c8280_fdc_mem(address_map &map) ATTR_COLD;
	void c8280_main_mem(address_map &map) ATTR_COLD;

	static void floppy_formats(format_registration &fr);

	required_device<cpu_device> m_maincpu;
	required_device<cpu_device> m_fdccpu;
	required_device<mos6532_device> m_riot0;
	required_device<mos6532_device> m_riot1;
	required_device<fd1797_device> m_fdc;
	required_device_array<floppy_connector, 2> m_floppy;
	required_ioport m_address;
	floppy_image_device *m_selected_floppy;
	output_finder<4> m_leds;

	// IEEE-488 bus
	int m_rfdo;                         // not ready for data output
	int m_daco;                         // not data accepted output
	int m_atna;                         // attention acknowledge
	int m_ifc;

	uint8_t m_fk5;
};


//-------------------------------------------------
//  ROM( c8280 )
//-------------------------------------------------

ROM_START( c8280 )
	ROM_DEFAULT_BIOS("r2")
	ROM_SYSTEM_BIOS( 0, "r1", "Revision 1" )
	ROM_SYSTEM_BIOS( 1, "r2", "Revision 2" )

	ROM_REGION( 0x4000, M6502_DOS_TAG, 0 )
	ROMX_LOAD( "300542-001.10c", 0x0000, 0x2000, CRC(3c6eee1e) SHA1(0726f6ab4de4fc9c18707fe87780ffd9f5ed72ab), ROM_BIOS(0) )
	ROMX_LOAD( "300543-001.10d", 0x2000, 0x2000, CRC(f58e665e) SHA1(9e58b47c686c91efc6ef1a27f72dbb5e26c485ec), ROM_BIOS(0) )
	ROMX_LOAD( "300542-reva.10c", 0x0000, 0x2000, CRC(6f32ccfb) SHA1(6926c049f1635e6769ec69891de8c92941ff880e), ROM_BIOS(1) )
	ROMX_LOAD( "300543-reva.10d", 0x2000, 0x2000, CRC(1af93f2c) SHA1(ad197b1d5dfa273487b33f473403ebd20dd15b2b), ROM_BIOS(1) )

	ROM_REGION( 0x800, M6502_FDC_TAG, 0 )
	ROMX_LOAD( "300541-001.3c", 0x000, 0x800, BAD_DUMP CRC(cb07b2db) SHA1(a1f9c5a7bd3798f5a97dc0b465c3bf5e3513e148), ROM_BIOS(0) )
	ROMX_LOAD( "300541-revb.3c", 0x000, 0x800, CRC(403e632c) SHA1(a0994c80025240d2b49ffd209dbfe8a4de3975b0), ROM_BIOS(1) )
ROM_END


//-------------------------------------------------
//  rom_region - device-specific ROM region
//-------------------------------------------------

const tiny_rom_entry *c8280_device::device_rom_region() const
{
	return ROM_NAME( c8280 );
}


//-------------------------------------------------
//  ADDRESS_MAP( c8280_main_mem )
//-------------------------------------------------

void c8280_device::c8280_main_mem(address_map &map)
{
	map(0x0000, 0x007f).mirror(0x100).m(m_riot0, FUNC(mos6532_device::ram_map));
	map(0x0080, 0x00ff).mirror(0x100).m(m_riot1, FUNC(mos6532_device::ram_map));
	map(0x0200, 0x021f).mirror(0xd60).m(m_riot0, FUNC(mos6532_device::io_map));
	map(0x0280, 0x029f).mirror(0xd60).m(m_riot1, FUNC(mos6532_device::io_map));
	map(0x1000, 0x13ff).mirror(0xc00).ram().share("share1");
	map(0x2000, 0x23ff).mirror(0xc00).ram().share("share2");
	map(0x3000, 0x33ff).mirror(0xc00).ram().share("share3");
	map(0x4000, 0x43ff).mirror(0xc00).ram().share("share4");
	map(0xc000, 0xffff).rom().region(M6502_DOS_TAG, 0);
}


//-------------------------------------------------
//  ADDRESS_MAP( c8280_fdc_mem )
//-------------------------------------------------

void c8280_device::c8280_fdc_mem(address_map &map)
{
	map.global_mask(0x1fff);
	map(0x0000, 0x007f).mirror(0x300).ram();
	map(0x0080, 0x0083).mirror(0x37c).rw(m_fdc, FUNC(fd1797_device::read), FUNC(fd1797_device::write));
	map(0x0400, 0x07ff).ram().share("share1");
	map(0x0800, 0x0bff).ram().share("share2");
	map(0x0c00, 0x0fff).ram().share("share3");
	map(0x1000, 0x13ff).ram().share("share4");
	map(0x1400, 0x1400).mirror(0x3ff).rw(FUNC(c8280_device::fk5_r), FUNC(c8280_device::fk5_w));
	map(0x1800, 0x1fff).rom().region(M6502_FDC_TAG, 0);
}


//-------------------------------------------------
//  riot6532 0
//-------------------------------------------------

uint8_t c8280_device::dio_r()
{
	/*

	    bit     description

	    PA0     DI0
	    PA1     DI1
	    PA2     DI2
	    PA3     DI3
	    PA4     DI4
	    PA5     DI5
	    PA6     DI6
	    PA7     DI7

	*/

	return m_bus->dio_r();
}

void c8280_device::dio_w(uint8_t data)
{
	/*

	    bit     description

	    PB0     DO0
	    PB1     DO1
	    PB2     DO2
	    PB3     DO3
	    PB4     DO4
	    PB5     DO5
	    PB6     DO6
	    PB7     DO7

	*/

	m_bus->dio_w(this, data);
}


//-------------------------------------------------
//  riot6532 1
//-------------------------------------------------

uint8_t c8280_device::riot1_pa_r()
{
	/*

	    bit     description

	    PA0
	    PA1
	    PA2
	    PA3
	    PA4
	    PA5     EOII
	    PA6     DAVI
	    PA7     _ATN

	*/

	uint8_t data = 0;

	// end or identify in
	data |= m_bus->eoi_r() << 5;

	// data valid in
	data |= m_bus->dav_r() << 6;

	// attention
	data |= !m_bus->atn_r() << 7;

	return data;
}

void c8280_device::riot1_pa_w(uint8_t data)
{
	/*

	    bit     description

	    PA0     ATNA
	    PA1     DACO
	    PA2     RFDO
	    PA3     EOIO
	    PA4     DAVO
	    PA5
	    PA6
	    PA7

	*/

	// attention acknowledge
	m_atna = BIT(data, 0);

	// data accepted out
	m_daco = BIT(data, 1);

	// not ready for data out
	m_rfdo = BIT(data, 2);

	// end or identify out
	m_bus->eoi_w(this, BIT(data, 3));

	// data valid out
	m_bus->dav_w(this, BIT(data, 4));

	update_ieee_signals();
}

uint8_t c8280_device::riot1_pb_r()
{
	/*

	    bit     description

	    PB0     DEVICE NUMBER SELECTION
	    PB1     DEVICE NUMBER SELECTION
	    PB2     DEVICE NUMBER SELECTION
	    PB3
	    PB4
	    PB5
	    PB6     DACI
	    PB7     RFDI

	*/

	uint8_t data = 0;

	// device number selection
	data |= m_slot->get_address() - 8;

	// data accepted in
	data |= m_bus->ndac_r() << 6;

	// ready for data in
	data |= m_bus->nrfd_r() << 7;

	return data;
}

void c8280_device::riot1_pb_w(uint8_t data)
{
	/*

	    bit     description

	    PB0
	    PB1
	    PB2
	    PB3     ACT LED 1
	    PB4     ACT LED 0
	    PB5     ERR LED
	    PB6
	    PB7

	*/

	// activity led 1
	m_leds[LED_ACT1] = BIT(data, 3);

	// activity led 0
	m_leds[LED_ACT0] = BIT(data, 4);

	// error led
	m_leds[LED_ERR] = BIT(data, 5);
}

static void c8280_floppies(device_slot_interface &device)
{
	device.option_add("8dsdd", FLOPPY_8_DSDD);
}

void c8280_device::floppy_formats(format_registration &fr)
{
	fr.add_mfm_containers();
	fr.add(FLOPPY_C8280_FORMAT);
}


//-------------------------------------------------
//  device_add_mconfig - add device configuration
//-------------------------------------------------

void c8280_device::device_add_mconfig(machine_config &config)
{
	M6502(config, m_maincpu, XTAL(12'000'000)/8);
	m_maincpu->set_addrmap(AS_PROGRAM, &c8280_device::c8280_main_mem);

	MOS6532(config, m_riot0, XTAL(12'000'000)/8);
	m_riot0->pa_rd_callback().set(FUNC(c8280_device::dio_r));
	m_riot0->pb_wr_callback().set(FUNC(c8280_device::dio_w));

	MOS6532(config, m_riot1, XTAL(12'000'000)/8);
	m_riot1->pa_rd_callback().set(FUNC(c8280_device::riot1_pa_r));
	m_riot1->pa_wr_callback().set(FUNC(c8280_device::riot1_pa_w));
	m_riot1->pb_rd_callback().set(FUNC(c8280_device::riot1_pb_r));
	m_riot1->pb_wr_callback().set(FUNC(c8280_device::riot1_pb_w));
	m_riot1->irq_wr_callback().set_inputline(m_maincpu, INPUT_LINE_IRQ0);

	M6502(config, m_fdccpu, XTAL(12'000'000)/8);
	m_fdccpu->set_addrmap(AS_PROGRAM, &c8280_device::c8280_fdc_mem);

	FD1797(config, m_fdc, XTAL(12'000'000)/6);
	m_fdc->intrq_wr_callback().set_inputline(m_fdccpu, M6502_IRQ_LINE);
	m_fdc->drq_wr_callback().set_inputline(m_fdccpu, M6502_SET_OVERFLOW);

	for (auto &floppy : m_floppy)
		FLOPPY_CONNECTOR(config, floppy, c8280_floppies, "8dsdd", c8280_device::floppy_formats);
}


//-------------------------------------------------
//  INPUT_PORTS( c8280 )
//-------------------------------------------------

static INPUT_PORTS_START( c8280 )
	PORT_START("ADDRESS")
	PORT_DIPNAME( 0x07, 0x00, "Device Address" )
	PORT_DIPSETTING(    0x00, "8" )
	PORT_DIPSETTING(    0x01, "9" )
	PORT_DIPSETTING(    0x02, "10" )
	PORT_DIPSETTING(    0x03, "11" )
	PORT_DIPSETTING(    0x04, "12" )
	PORT_DIPSETTING(    0x05, "13" )
	PORT_DIPSETTING(    0x06, "14" )
	PORT_DIPSETTING(    0x07, "15" )
INPUT_PORTS_END


//-------------------------------------------------
//  input_ports - device-specific input ports
//-------------------------------------------------

ioport_constructor c8280_device::device_input_ports() const
{
	return INPUT_PORTS_NAME( c8280 );
}



//**************************************************************************
//  INLINE HELPERS
//**************************************************************************

//-------------------------------------------------
//  update_ieee_signals -
//-------------------------------------------------

inline void c8280_device::update_ieee_signals()
{
	int atn = m_bus->atn_r();
	int nrfd = !(!(!(atn && m_atna) && m_rfdo) || !(atn || m_atna));
	int ndac = !(m_daco || !(atn || m_atna));

	m_bus->nrfd_w(this, nrfd);
	m_bus->ndac_w(this, ndac);
}



//**************************************************************************
//  LIVE DEVICE
//**************************************************************************

//-------------------------------------------------
//  c8280_device - constructor
//-------------------------------------------------

c8280_device::c8280_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
	device_t(mconfig, GPIB_C8280, tag, owner, clock),
	device_ieee488_interface(mconfig, *this),
	m_maincpu(*this, M6502_DOS_TAG),
	m_fdccpu(*this, M6502_FDC_TAG),
	m_riot0(*this, "9f"),
	m_riot1(*this, "9g"),
	m_fdc(*this, WD1797_TAG),
	m_floppy(*this, WD1797_TAG ":%u", 0U),
	m_address(*this, "ADDRESS"),
	m_selected_floppy(nullptr),
	m_leds(*this, "led%u", 0U),
	m_rfdo(1),
	m_daco(1),
	m_atna(1), m_ifc(0), m_fk5(0)
{
}


//-------------------------------------------------
//  device_start - device-specific startup
//-------------------------------------------------

void c8280_device::device_start()
{
	// state saving
	save_item(NAME(m_rfdo));
	save_item(NAME(m_daco));
	save_item(NAME(m_atna));
	save_item(NAME(m_ifc));
	save_item(NAME(m_fk5));
}


//-------------------------------------------------
//  device_reset - device-specific reset
//-------------------------------------------------

void c8280_device::device_reset()
{
	m_maincpu->reset();

	// toggle M6502 SO
	m_maincpu->set_input_line(M6502_SET_OVERFLOW, ASSERT_LINE);
	m_maincpu->set_input_line(M6502_SET_OVERFLOW, CLEAR_LINE);

	m_fdccpu->reset();

	m_riot0->reset();
	m_riot1->reset();
	m_fdc->reset();

	m_riot1->pa_bit_w<7>(1);

	m_fk5 = 0;
	m_selected_floppy = nullptr;
	m_fdc->set_floppy(m_selected_floppy);
	m_fdc->dden_w(0);
}


//-------------------------------------------------
//  ieee488_atn -
//-------------------------------------------------

void c8280_device::ieee488_atn(int state)
{
	update_ieee_signals();

	m_riot1->pa_bit_w<7>(state);
}


//-------------------------------------------------
//  ieee488_ifc -
//-------------------------------------------------

void c8280_device::ieee488_ifc(int state)
{
	if (!m_ifc && state)
	{
		device_reset();
	}

	m_ifc = state;
}

uint8_t c8280_device::fk5_r()
{
	/*

	    bit     description

	    0
	    1
	    2
	    3       DCHG
	    4       TSID
	    5
	    6       0
	    7       0

	*/

	uint8_t data = m_fk5;

	data |= (m_selected_floppy ? m_selected_floppy->dskchg_r() : 1) << 3;
	data |= (m_selected_floppy ? m_selected_floppy->twosid_r() : 1) << 4;

	return data;
}

void c8280_device::fk5_w(uint8_t data)
{
	/*

	    bit     description

	    0       DS1
	    1       DS2
	    2       _DDEN
	    3
	    4
	    5       MOTOR ENABLE
	    6
	    7

	*/

	m_fk5 = data & 0x27;

	// drive select
	m_selected_floppy = nullptr;
	for (int n = 0; n < 2; n++)
	{
		if (BIT(data, n))
			m_selected_floppy = m_floppy[n]->get_device();
	}

	m_fdc->set_floppy(m_selected_floppy);

	if (m_selected_floppy)
		m_selected_floppy->mon_w(!BIT(data, 5));

	// density select
	m_fdc->dden_w(BIT(data, 2));
}

} // anonymous namespace


//**************************************************************************
//  DEVICE DEFINITIONS
//**************************************************************************

DEFINE_DEVICE_TYPE_PRIVATE(GPIB_C8280, device_ieee488_interface, c8280_device, "c8280", "Commodore 8280 dual 8\" disk drive")
