dingusppc/devices/serial/escc.cpp
joevt 941a405cf8 escc: Implement RR8 and WR8.
Normally, the Port_B_Data or Port_A_Data address is used to directly access RR8 or WR8, but setting the register pointer in Port_B_Cmd or Port_A_Cmd to RR8/WR8 is another option.
Update write_regs[WR8] and read_regs[RR8] for possible debugging purposes.
2024-05-06 21:11:36 -07:00

489 lines
14 KiB
C++

/*
DingusPPC - The Experimental PowerPC Macintosh emulator
Copyright (C) 2018-24 divingkatae and maximum
(theweirdo) spatium
(Contact divingkatae#1017 or powermax#2286 on Discord for more info)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
/** @file Enhanced Serial Communications Controller (ESCC) emulation. */
#include <core/timermanager.h>
#include <devices/deviceregistry.h>
#include <devices/serial/chario.h>
#include <devices/serial/escc.h>
#include <devices/serial/z85c30.h>
#include <loguru.hpp>
#include <machines/machineproperties.h>
#include <cinttypes>
#include <memory>
#include <string>
#include <vector>
/** Remap the compatible addressing scheme to MacRISC one. */
const uint8_t compat_to_macrisc[6] = {
EsccReg::Port_B_Cmd, EsccReg::Port_A_Cmd,
EsccReg::Port_B_Data, EsccReg::Port_A_Data,
EsccReg::Enh_Reg_B, EsccReg::Enh_Reg_A
};
EsccController::EsccController()
{
// allocate channels
this->ch_a = std::unique_ptr<EsccChannel> (new EsccChannel("ESCC_A"));
this->ch_b = std::unique_ptr<EsccChannel> (new EsccChannel("ESCC_B"));
// attach backends
std::string backend_name = GET_STR_PROP("serial_backend");
this->ch_a->attach_backend(
(backend_name == "stdio") ? CHARIO_BE_STDIO :
#ifdef _WIN32
#else
(backend_name == "socket") ? CHARIO_BE_SOCKET :
#endif
CHARIO_BE_NULL
);
this->ch_b->attach_backend(CHARIO_BE_NULL);
this->master_int_cntrl = 0;
this->reset();
}
void EsccController::reset()
{
this->master_int_cntrl &= (WR9_NO_VECTOR | WR9_VECTOR_INCLUDES_STATUS);
this->master_int_cntrl |= WR9_FORCE_HARDWARE_RESET;
this->reg_ptr = WR0; // or RR0
this->ch_a->reset(true);
this->ch_b->reset(true);
}
uint8_t EsccController::read(uint8_t reg_offset)
{
uint8_t value;
switch(reg_offset) {
case EsccReg::Port_B_Cmd:
value = this->read_internal(this->ch_b.get());
break;
case EsccReg::Port_A_Cmd:
value = this->read_internal(this->ch_a.get());
break;
case EsccReg::Port_B_Data:
value = this->ch_b->receive_byte();
break;
case EsccReg::Port_A_Data:
value = this->ch_a->receive_byte();
break;
case EsccReg::Enh_Reg_B:
value = this->ch_b->get_enh_reg();
break;
case EsccReg::Enh_Reg_A:
value = this->ch_a->get_enh_reg();
break;
default:
LOG_F(WARNING, "ESCC: reading from unimplemented register 0x%x", reg_offset);
value = 0;
}
return value;
}
void EsccController::write(uint8_t reg_offset, uint8_t value)
{
switch(reg_offset) {
case EsccReg::Port_B_Cmd:
this->write_internal(this->ch_b.get(), value);
break;
case EsccReg::Port_A_Cmd:
this->write_internal(this->ch_a.get(), value);
break;
case EsccReg::Port_B_Data:
this->ch_b->send_byte(value);
break;
case EsccReg::Port_A_Data:
this->ch_a->send_byte(value);
break;
case EsccReg::Enh_Reg_B:
this->ch_b->set_enh_reg(value);
break;
case EsccReg::Enh_Reg_A:
this->ch_a->set_enh_reg(value);
break;
default:
LOG_F(9, "ESCC: writing 0x%X to unimplemented register 0x%x", value, reg_offset);
}
}
uint8_t EsccController::read_internal(EsccChannel *ch)
{
uint8_t value;
switch (this->reg_ptr) {
case RR2:
// TODO: implement interrupt vector modifications
value = this->int_vec;
break;
default:
value = ch->read_reg(this->reg_ptr);
}
this->reg_ptr = RR0; // or WR0
return value;
}
void EsccController::write_internal(EsccChannel *ch, uint8_t value)
{
switch (this->reg_ptr) {
// chip-specific registers
case WR0:
this->reg_ptr = value & WR0_REGISTER_SELECTION_CODE;
switch (value & WR0_COMMAND_CODES) {
case WR0_COMMAND_POINT_HIGH:
this->reg_ptr |= WR8; // or RR8
break;
}
return;
case WR2:
this->int_vec = value;
break;
case WR9:
// see if some reset is requested
switch (value & WR9_RESET_COMMAND_BITS) {
case WR9_CHANNEL_RESET_B:
this->master_int_cntrl &= ~WR9_INTERRUPT_MASKING_WITHOUT_INTACK;
this->ch_b->reset(false);
break;
case WR9_CHANNEL_RESET_A:
this->master_int_cntrl &= ~WR9_INTERRUPT_MASKING_WITHOUT_INTACK;
this->ch_a->reset(false);
break;
case WR9_FORCE_HARDWARE_RESET:
this->reset();
break;
}
this->master_int_cntrl = value & WR9_INTERRUPT_CONTROL_BITS;
break;
default:
// channel-specific registers
ch->write_reg(this->reg_ptr, value);
}
this->reg_ptr = WR0; // or RR0
}
// ======================== ESCC Channel methods ==============================
void EsccChannel::attach_backend(int id)
{
switch(id) {
case CHARIO_BE_NULL:
this->chario = std::unique_ptr<CharIoBackEnd> (new CharIoNull);
break;
case CHARIO_BE_STDIO:
this->chario = std::unique_ptr<CharIoBackEnd> (new CharIoStdin);
break;
#ifdef _WIN32
#else
case CHARIO_BE_SOCKET:
this->chario = std::unique_ptr<CharIoBackEnd> (new CharIoSocket);
break;
#endif
default:
LOG_F(ERROR, "%s: unknown backend ID %d, using NULL instead", this->name.c_str(), id);
this->chario = std::unique_ptr<CharIoBackEnd> (new CharIoNull);
}
}
void EsccChannel::reset(bool hw_reset)
{
this->chario->rcv_disable();
/*
We use hex values here instead of enums to more
easily compare with the z85c30 data sheet.
*/
this->write_regs[WR0] = 0;
this->write_regs[WR1] &= 0x24;
this->write_regs[WR3] &= 0xFE;
this->write_regs[WR4] |= 0x04;
this->write_regs[WR5] &= 0x61;
this->write_regs[WR15] = 0xF8;
this->read_regs[RR0] &= 0x38;
this->read_regs[RR0] |= 0x44;
this->read_regs[RR1] = 0x06 | RR1_ALL_SENT; // HACK: also set ALL_SENT flag.
this->read_regs[RR3] = 0x00;
this->read_regs[RR10] = 0x00;
// initialize DPLL
this->dpll_active = 0;
this->dpll_mode = DpllMode::NRZI;
this->dpll_clock_src = 0;
// initialize Baud Rate Generator (BRG)
this->brg_active = 0;
this->brg_clock_src = 0;
if (hw_reset) {
this->write_regs[WR9] &= 0x03; // clear all except (WR9_NO_VECTOR | WR9_VECTOR_INCLUDES_STATUS)
this->write_regs[WR9] |= 0xC0; // set WR9_FORCE_HARDWARE_RESET
this->write_regs[WR10] = 0;
this->write_regs[WR11] = 8;
this->write_regs[WR14] &= 0xC0;
} else {
this->write_regs[WR9] &= ~0x20; // clear WR9_INTERRUPT_MASKING_WITHOUT_INTACK
this->write_regs[WR10] &= 0x60;
this->write_regs[WR14] &= 0xC3;
}
this->write_regs[WR14] |= 0x20;
}
void EsccChannel::write_reg(int reg_num, uint8_t value)
{
switch (reg_num) {
case WR3:
if ((this->write_regs[WR3] ^ value) & WR3_ENTER_HUNT_MODE) {
this->write_regs[WR3] |= WR3_ENTER_HUNT_MODE;
this->read_regs[RR0] |= RR0_SYNC_HUNT;
LOG_F(9, "%s: Hunt mode entered.", this->name.c_str());
}
if ((this->write_regs[WR3] ^ value) & WR3_RX_ENABLE) {
if (value & WR3_RX_ENABLE) {
this->write_regs[WR3] |= WR3_RX_ENABLE;
this->chario->rcv_enable();
LOG_F(9, "%s: receiver enabled.", this->name.c_str());
} else {
this->write_regs[WR3] ^= WR3_RX_ENABLE;
this->chario->rcv_disable();
LOG_F(9, "%s: receiver disabled.", this->name.c_str());
this->write_regs[WR3] |= WR3_ENTER_HUNT_MODE;
this->read_regs[RR0] |= RR0_SYNC_HUNT;
}
}
this->write_regs[WR3] = (this->write_regs[WR3] & (WR3_RX_ENABLE | WR3_ENTER_HUNT_MODE)) | (value & ~(WR3_RX_ENABLE | WR3_ENTER_HUNT_MODE));
return;
case WR7:
if (this->write_regs[WR15] & WR15_SDLC_HDLC_ENHANCEMENT_ENABLE) {
this->wr7_enh = value;
return;
}
break;
case WR8:
this->send_byte(value);
return;
case WR14:
switch (value & WR14_DPLL_COMMAND_BITS) {
case WR14_DPLL_NULL_COMMAND:
break;
case WR14_DPLL_ENTER_SEARCH_MODE:
this->dpll_active = 1;
this->read_regs[RR10] &= ~(RR10_TWO_CLOCKS_MISSING | RR10_ONE_CLOCK_MISSING);
break;
case WR14_DPLL_RESET_MISSING_CLOCK:
this->read_regs[RR10] &= ~(RR10_TWO_CLOCKS_MISSING | RR10_ONE_CLOCK_MISSING);
break;
case WR14_DPLL_DISABLE_DPLL:
this->dpll_active = 0;
// fallthrough
case WR14_DPLL_SET_SOURCE_BR_GENERATOR:
this->dpll_clock_src = 0;
break;
case WR14_DPLL_SET_SOURCE_RTXC:
this->dpll_clock_src = 1;
break;
case WR14_DPLL_SET_FM_MODE:
this->dpll_mode = DpllMode::FM;
break;
case WR14_DPLL_SET_NRZI_MODE:
this->dpll_mode = DpllMode::NRZI;
break;
}
if (value & (WR14_LOCAL_LOOPBACK | WR14_AUTO_ECHO | WR14_DTR_REQUEST_FUNCTION)) {
LOG_F(WARNING, "%s: unexpected value in WR14 = 0x%X", this->name.c_str(), value);
}
if (this->brg_active ^ (value & WR14_BR_GENERATOR_ENABLE)) {
this->brg_active = value & WR14_BR_GENERATOR_ENABLE;
LOG_F(9, "%s: BRG %s", this->name.c_str(), this->brg_active ? "enabled" : "disabled");
}
return;
}
this->write_regs[reg_num] = value;
}
uint8_t EsccChannel::read_reg(int reg_num)
{
switch (reg_num) {
case RR0:
if (this->chario->rcv_char_available()) {
this->read_regs[RR0] |= RR0_RX_CHARACTER_AVAILABLE;
}
break;
case RR8:
return this->receive_byte();
}
return this->read_regs[reg_num];
}
void EsccChannel::send_byte(uint8_t value)
{
// TODO: put one byte into the Data FIFO
this->write_regs[WR8] = value;
this->chario->xmit_char(value);
}
uint8_t EsccChannel::receive_byte()
{
// TODO: remove one byte from the Receive FIFO
uint8_t c;
if (this->chario->rcv_char_available_now()) {
this->chario->rcv_char(&c);
} else {
c = 0;
}
this->read_regs[RR0] &= ~RR0_RX_CHARACTER_AVAILABLE;
this->read_regs[RR8] = c;
return c;
}
uint8_t EsccChannel::get_enh_reg()
{
return this->enh_reg;
}
void EsccChannel::set_enh_reg(uint8_t value)
{
uint8_t changed_bits = value ^ this->enh_reg;
if (changed_bits & 0x10) {
if (value & 0x10)
LOG_F(ERROR, "%s: CTS connected to GPIO; DCD connected to GND", this->name.c_str());
else
LOG_F(INFO, "%s: CTS connected to TRXC_In_l; DCD connected to GPIO", this->name.c_str());
this->enh_reg = value & 0x10;
} else if (changed_bits & ~0x10) {
if (value & ~0x10)
LOG_F(ERROR, "%s: Ignoring attempt to set Enh_Reg bits 0x%02x", this->name.c_str(), value & ~0x10);
}
}
void EsccChannel::dma_start_tx()
{
}
void EsccChannel::dma_start_rx()
{
}
void EsccChannel::dma_stop_tx()
{
if (this->timer_id_tx) {
TimerManager::get_instance()->cancel_timer(this->timer_id_tx);
this->timer_id_tx = 0;
}
}
void EsccChannel::dma_stop_rx()
{
if (this->timer_id_rx) {
TimerManager::get_instance()->cancel_timer(this->timer_id_rx);
this->timer_id_rx = 0;
}
}
void EsccChannel::dma_in_tx()
{
LOG_F(ERROR, "%s: Unexpected DMA INPUT command for transmit.", this->name.c_str());
}
void EsccChannel::dma_in_rx()
{
if (dma_ch[1]->get_push_data_remaining()) {
this->timer_id_rx = TimerManager::get_instance()->add_oneshot_timer(
0,
[this]() {
this->timer_id_rx = 0;
char c = receive_byte();
int xx = dma_ch[1]->push_data(&c, 1);
this->dma_in_rx();
});
}
}
void EsccChannel::dma_out_tx()
{
this->timer_id_tx = TimerManager::get_instance()->add_oneshot_timer(
10,
[this]() {
this->timer_id_tx = 0;
uint8_t *data;
uint32_t avail_len;
if (dma_ch[1]->pull_data(256, &avail_len, &data) == MoreData) {
while(avail_len) {
this->send_byte(*data++);
avail_len--;
}
this->dma_out_tx();
}
});
}
void EsccChannel::dma_out_rx()
{
LOG_F(ERROR, "%s: Unexpected DMA OUTPUT command for receive.", this->name.c_str());
}
void EsccChannel::dma_flush_tx()
{
this->dma_stop_tx();
this->timer_id_tx = TimerManager::get_instance()->add_oneshot_timer(
10,
[this]() {
this->timer_id_tx = 0;
dma_ch[1]->end_pull_data();
});
}
void EsccChannel::dma_flush_rx()
{
this->dma_stop_rx();
this->timer_id_rx = TimerManager::get_instance()->add_oneshot_timer(
10,
[this]() {
this->timer_id_rx = 0;
dma_ch[1]->end_push_data();
});
}
static const vector<string> CharIoBackends = {"null", "stdio", "socket"};
static const PropMap Escc_Properties = {
{"serial_backend", new StrProperty("null", CharIoBackends)},
};
static const DeviceDescription Escc_Descriptor = {
EsccController::create, {}, Escc_Properties
};
REGISTER_DEVICE(Escc, Escc_Descriptor);