// license:BSD-3-Clause
// copyright-holders:Barry Rodewald
/*
*
* Implementation of Fujitsu FMR-50, FMR-60 and FM-Towns SCSI hardware
*
*
info from Toshiya Takeda's e-FMR50 source (the Towns uses the same controller?)
0xc30 = Data register
0xc32 = Status register (read)
bit 7 = REQ
bit 6 = I/O
bit 5 = MSG
bit 4 = C/D
bit 3 = BUSY
bit 1 = INT
bit 0 = PERR
0xc32 = Control register (write)
bit 7 = WEN
bit 6 = IMSK
bit 4 = ATN
bit 2 = SEL
bit 1 = DMAE
bit 0 = RST
*/
#include "emu.h"
#include "fm_scsi.h"
#include "debugger.h"
// SCSI input lines (from target)
#define FMSCSI_LINE_REQ 0x80
#define FMSCSI_LINE_IO 0x40
#define FMSCSI_LINE_MSG 0x20
#define FMSCSI_LINE_CD 0x10
#define FMSCSI_LINE_BSY 0x08
#define FMSCSI_LINE_EX 0x04
#define FMSCSI_LINE_INT 0x02
#define FMSCSI_LINE_PERR 0x01
// SCSI output lines (to target)
#define FMSCSI_LINE_WEN 0x80
#define FMSCSI_LINE_IMSK 0x40
#define FMSCSI_LINE_RMSK 0x20
#define FMSCSI_LINE_ATN 0x10
#define FMSCSI_LINE_WRD 0x08
#define FMSCSI_LINE_SEL 0x04
#define FMSCSI_LINE_DMAE 0x02
#define FMSCSI_LINE_RST 0x01
/*
* Device config
*/
DEFINE_DEVICE_TYPE(FMSCSI, fmscsi_device, "fmscsi", "FM-SCSI")
/*
* Device
*/
fmscsi_device::fmscsi_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
: legacy_scsi_host_adapter(mconfig, FMSCSI, tag, owner, clock),
m_irq_handler(*this),
m_drq_handler(*this)
{
}
void fmscsi_device::device_start()
{
m_input_lines = 0;
m_output_lines = 0;
m_data = 0;
m_command_index = 0;
m_last_id = 0;
m_target = 0;
m_phase = SCSI_PHASE_BUS_FREE;
m_irq_handler.resolve_safe();
m_drq_handler.resolve_safe();
// allocate read timer
m_transfer_timer = timer_alloc(TIMER_TRANSFER);
m_phase_timer = timer_alloc(TIMER_PHASE);
}
void fmscsi_device::device_reset()
{
m_input_lines = 0;
m_output_lines = 0;
m_data = 0;
m_command_index = 0;
m_last_id = 0;
m_target = 0;
m_result_length = 0;
m_result_index = 0;
stop_transfer();
set_input_line(FMSCSI_LINE_INT,0);
m_irq_handler(0);
m_phase = SCSI_PHASE_BUS_FREE;
}
// get the length of a SCSI command based on it's command byte type
int fmscsi_device::get_scsi_cmd_len(uint8_t cbyte)
{
int group;
group = (cbyte>>5) & 7;
if (group == 0) return 6;
if (group == 1 || group == 2) return 10;
if (group == 5) return 12;
fatalerror("fmscsi: Unknown SCSI command group %d\n", group);
// never executed
//return 6;
}
void fmscsi_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
{
switch(id)
{
case TIMER_TRANSFER:
set_input_line(FMSCSI_LINE_REQ,1);
//logerror("FMSCSI: timer triggered: %i/%i\n",m_result_index,m_result_length);
if(m_output_lines & FMSCSI_LINE_DMAE)
{
m_drq_handler(1);
}
break;
case TIMER_PHASE:
set_phase(param);
break;
}
}
void fmscsi_device::stop_transfer()
{
m_transfer_timer->adjust(attotime::never); // stop timer
m_phase_timer->adjust(attotime::from_usec(800),SCSI_PHASE_STATUS);
if(m_output_lines & FMSCSI_LINE_DMAE)
{
m_drq_handler(0);
}
logerror("FMSCSI: Stopping transfer : (%i/%i)\n",m_result_index,m_result_length);
}
uint8_t fmscsi_device::fmscsi_data_r(void)
{
// read from data bus
// ACK is automatic on accessing the data bus, so REQ will go low.
set_input_line(FMSCSI_LINE_REQ,0);
if(m_phase == SCSI_PHASE_DATAIN)
{
m_data = m_buffer[m_result_index % 512];
//logerror("FMSCSI: DATAIN phase read data %02x\n",m_data);
m_result_index++;
if(m_result_index % 512 == 0)
read_data(m_buffer,512); // read next sector
if(m_result_index >= m_result_length)
{
// end of data transfer
stop_transfer();
}
return m_data;
}
if(m_phase == SCSI_PHASE_MESSAGE_IN)
{
m_data = 0; // command complete message
m_phase_timer->adjust(attotime::from_usec(800),SCSI_PHASE_BUS_FREE);
m_command_index = 0;
return m_data;
}
if(m_phase == SCSI_PHASE_STATUS)
{
m_data = get_status();
// no command complete message?
m_phase_timer->adjust(attotime::from_usec(800),SCSI_PHASE_MESSAGE_IN);
m_command_index = 0;
//set_input_line(FMSCSI_LINE_REQ,1); // raise REQ yet again
return m_data;
}
return m_data;
}
void fmscsi_device::fmscsi_data_w(uint8_t data)
{
int phase;
// write to data bus
m_data = data;
//logerror("FMSCSI: data write %02x\n",data);
// ACK is automatic on accessing the data bus, so REQ will go low.
set_input_line(FMSCSI_LINE_REQ,0);
if(m_phase == SCSI_PHASE_BUS_FREE)
{
// select target
switch(data & 0x7f)
{
case 0x01: m_target = 0; break;
case 0x02: m_target = 1; break;
case 0x04: m_target = 2; break;
case 0x08: m_target = 3; break;
case 0x10: m_target = 4; break;
}
}
if(m_phase == SCSI_PHASE_DATAOUT)
{
m_buffer[m_result_index % 512] = m_data;
m_result_index++;
if(m_result_index % 512 == 0)
write_data(m_buffer,512); // write buffer to disc
if(m_result_index >= m_result_length)
{
// end of data transfer
m_transfer_timer->adjust(attotime::never); // stop timer
m_phase_timer->adjust(attotime::from_usec(800),SCSI_PHASE_STATUS);
if(m_output_lines & FMSCSI_LINE_DMAE)
{
m_drq_handler(0);
}
logerror("FMSCSI: Stopping transfer : (%i/%i)\n",m_result_index,m_result_length);
}
}
if(m_phase == SCSI_PHASE_COMMAND)
{
m_command[m_command_index] = data;
logerror("FMSCSI: writing command byte %02x [%i]\n",data,m_command_index);
m_command_index++;
if(m_command_index >= get_scsi_cmd_len(m_command[0]))
{
// command complete
send_command(m_command,m_command_index);
m_result_length = get_length();
phase = legacy_scsi_host_adapter::get_phase();
m_phase_timer->adjust(attotime::from_usec(800),phase);
logerror("FMSCSI: Command %02x sent, result length = %i\n",m_command[0],m_result_length);
}
else
{
m_phase_timer->adjust(attotime::from_usec(800),SCSI_PHASE_COMMAND);
}
}
if(m_phase == SCSI_PHASE_MESSAGE_OUT)
{
m_phase_timer->adjust(attotime::from_usec(800),SCSI_PHASE_STATUS);
}
}
void fmscsi_device::set_phase(int phase)
{
m_phase = phase;
logerror("FMSCSI: phase set to %i\n",m_phase);
// set input lines accordingly
switch(phase)
{
case SCSI_PHASE_BUS_FREE:
set_input_line(FMSCSI_LINE_BSY,0);
set_input_line(FMSCSI_LINE_CD,0);
set_input_line(FMSCSI_LINE_MSG,0);
set_input_line(FMSCSI_LINE_IO,0);
//set_input_line(FMSCSI_LINE_REQ,0);
break;
case SCSI_PHASE_COMMAND:
set_input_line(FMSCSI_LINE_BSY,1);
set_input_line(FMSCSI_LINE_CD,1);
set_input_line(FMSCSI_LINE_MSG,0);
set_input_line(FMSCSI_LINE_IO,0);
set_input_line(FMSCSI_LINE_REQ,1);
break;
case SCSI_PHASE_STATUS:
set_input_line(FMSCSI_LINE_CD,1);
set_input_line(FMSCSI_LINE_MSG,0);
set_input_line(FMSCSI_LINE_IO,1);
set_input_line(FMSCSI_LINE_REQ,1);
break;
case SCSI_PHASE_DATAIN:
set_input_line(FMSCSI_LINE_CD,0);
set_input_line(FMSCSI_LINE_MSG,0);
set_input_line(FMSCSI_LINE_IO,1);
set_input_line(FMSCSI_LINE_REQ,1);
// start transfer timer
m_transfer_timer->adjust(attotime::zero,0,attotime::from_hz(3000000)); // arbitrary value for now
read_data(m_buffer,512);
m_result_index = 0;
logerror("FMSCSI: Starting transfer in (%i)\n",m_result_length);
break;
case SCSI_PHASE_DATAOUT:
set_input_line(FMSCSI_LINE_CD,0);
set_input_line(FMSCSI_LINE_MSG,0);
set_input_line(FMSCSI_LINE_IO,0);
set_input_line(FMSCSI_LINE_REQ,1);
// start transfer timer
m_transfer_timer->adjust(attotime::zero,0,attotime::from_hz(3000000)); // arbitrary value for now
m_result_index = 0;
logerror("FMSCSI: Starting transfer out (%i)\n",m_result_length);
break;
case SCSI_PHASE_MESSAGE_IN:
set_input_line(FMSCSI_LINE_CD,1);
set_input_line(FMSCSI_LINE_MSG,1);
set_input_line(FMSCSI_LINE_IO,1);
set_input_line(FMSCSI_LINE_REQ,1);
break;
case SCSI_PHASE_MESSAGE_OUT:
set_input_line(FMSCSI_LINE_CD,1);
set_input_line(FMSCSI_LINE_MSG,1);
set_input_line(FMSCSI_LINE_IO,0);
set_input_line(FMSCSI_LINE_REQ,1);
break;
}
}
int fmscsi_device::get_phase(void)
{
return m_phase;
}
void fmscsi_device::set_input_line(uint8_t line, uint8_t state)
{
if(line == FMSCSI_LINE_REQ)
{
if(state != 0 && !(m_input_lines & FMSCSI_LINE_REQ)) // low to high
{
if(m_output_lines & FMSCSI_LINE_IMSK && m_phase != SCSI_PHASE_DATAIN && m_phase != SCSI_PHASE_DATAOUT)
{
set_input_line(FMSCSI_LINE_INT,1);
m_irq_handler(1);
logerror("FMSCSI: IRQ high\n");
}
}
if(state == 0 && (m_input_lines & FMSCSI_LINE_REQ)) // high to low
{
if(m_output_lines & FMSCSI_LINE_IMSK && m_phase != SCSI_PHASE_DATAIN && m_phase != SCSI_PHASE_DATAOUT)
{
set_input_line(FMSCSI_LINE_INT,0);
m_irq_handler(0);
logerror("FMSCSI: IRQ low\n");
}
}
}
if(state != 0)
m_input_lines |= line;
else
m_input_lines &= ~line;
// logerror("FMSCSI: input line %02x set to %i\n",line,state);
}
uint8_t fmscsi_device::get_input_line(uint8_t line)
{
return m_input_lines & line;
}
void fmscsi_device::set_output_line(uint8_t line, uint8_t state)
{
if(line == FMSCSI_LINE_RST && state != 0)
{
device_reset();
logerror("FMSCSI: reset\n");
}
if(line == FMSCSI_LINE_SEL)
{
if(state != 0 && !(m_output_lines & FMSCSI_LINE_SEL)) // low to high transition
{
if (select(m_target))
{
m_phase_timer->adjust(attotime::from_usec(800),SCSI_PHASE_COMMAND);
m_data = 0x08;
}
}
}
if(line == FMSCSI_LINE_ATN)
{
if(state != 0)
m_phase_timer->adjust(attotime::from_usec(800),SCSI_PHASE_MESSAGE_OUT);
}
if(state != 0)
m_output_lines |= line;
else
m_output_lines &= ~line;
// logerror("FMSCSI: output line %02x set to %i\n",line,state);
}
uint8_t fmscsi_device::get_output_line(uint8_t line)
{
return m_output_lines & line;
}
uint8_t fmscsi_device::fmscsi_status_r(void)
{
// status inputs
return m_input_lines;
}
void fmscsi_device::fmscsi_control_w(uint8_t data)
{
// control outputs
set_output_line(FMSCSI_LINE_RST,data & FMSCSI_LINE_RST);
set_output_line(FMSCSI_LINE_DMAE,data & FMSCSI_LINE_DMAE);
set_output_line(FMSCSI_LINE_IMSK,data & FMSCSI_LINE_IMSK);
set_output_line(FMSCSI_LINE_ATN,data & FMSCSI_LINE_ATN);
set_output_line(FMSCSI_LINE_WEN,data & FMSCSI_LINE_WEN);
set_output_line(FMSCSI_LINE_SEL,data & FMSCSI_LINE_SEL);
logerror("FMSCSI: control write %02x\n",data);
}
READ8_MEMBER( fmscsi_device::fmscsi_r )
{
switch(offset & 0x03)
{
case 0x00:
return fmscsi_data_r();
case 0x01:
return fmscsi_status_r();
case 0x02:
return 0x80; // Linux uses this port to detect the ability to do word transfers. We'll tell it that it doesn't for now.
default:
logerror("FMSCSI: Unknown read at offset %i\n",offset);
}
return 0;
}
WRITE8_MEMBER( fmscsi_device::fmscsi_w )
{
switch(offset & 0x03)
{
case 0x00:
fmscsi_data_w(data);
break;
case 0x01:
fmscsi_control_w(data);
break;
default:
logerror("FMSCSI: Unknown write 0x%02x at offset %i\n",data,offset);
}
}