1 files changed, 166 insertions, 0 deletions
diff --git a/src/chips/opl_serial_port.cpp b/src/chips/opl_serial_port.cpp
new file mode 100644
index 0000000..0d2e58d
--- /dev/null
+++ b/src/chips/opl_serial_port.cpp
@@ -0,0 +1,166 @@
+/*
+ * Interfaces over Yamaha OPL3 (YMF262) chip emulators
+ *
+ * Copyright (c) 2017-2023 Vitaly Novichkov (Wohlstand)
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+
+#ifdef ENABLE_HW_OPL_SERIAL_PORT
+
+#include "opl_serial_port.h"
+#include "opl_serial_misc.h"
+
+
+static size_t retrowave_protocol_serial_pack(const uint8_t *buf_in, size_t len_in, uint8_t *buf_out)
+{
+    size_t in_cursor = 0;
+    size_t out_cursor = 0;
+
+    buf_out[out_cursor] = 0x00;
+    out_cursor += 1;
+
+    uint8_t shift_count = 0;
+
+    while(in_cursor < len_in)
+    {
+        uint8_t cur_byte_out = buf_in[in_cursor] >> shift_count;
+        if(in_cursor > 0)
+            cur_byte_out |= (buf_in[in_cursor - 1] << (8 - shift_count));
+
+        cur_byte_out |= 0x01;
+        buf_out[out_cursor] = cur_byte_out;
+
+        shift_count += 1;
+        in_cursor += 1;
+        out_cursor += 1;
+        if(shift_count > 7)
+        {
+            shift_count = 0;
+            in_cursor -= 1;
+        }
+    }
+
+    if(shift_count)
+    {
+        buf_out[out_cursor] = buf_in[in_cursor - 1] << (8 - shift_count);
+        buf_out[out_cursor] |= 0x01;
+        out_cursor += 1;
+    }
+
+    buf_out[out_cursor] = 0x02;
+    out_cursor += 1;
+
+    return out_cursor;
+}
+
+OPL_SerialPort::OPL_SerialPort()
+    : m_port(NULL), m_protocol(ProtocolUnknown)
+{}
+
+OPL_SerialPort::~OPL_SerialPort()
+{
+    delete m_port;
+    m_port = NULL;
+}
+
+bool OPL_SerialPort::connectPort(const std::string& name, unsigned baudRate, unsigned protocol)
+{
+    delete m_port;
+    m_port = NULL;
+
+    // ensure audio thread reads protocol atomically and in order,
+    // so chipType() will be correct after the port is live
+    m_protocol = protocol;
+
+    // QSerialPort *port = m_port = new QSerialPort(name);
+    // port->setBaudRate(baudRate);
+    // return port->open(QSerialPort::WriteOnly);
+
+    m_port = new ChipSerialPort;
+    return m_port->open(name, baudRate);
+}
+
+void OPL_SerialPort::writeReg(uint16_t addr, uint8_t data)
+{
+    uint8_t sendBuffer[16];
+    ChipSerialPort *port = m_port;
+
+    if(!port || !port->isOpen())
+        return;
+
+    switch(m_protocol)
+    {
+    default:
+    case ProtocolArduinoOPL2:
+    {
+        if(addr >= 0x100)
+            break;
+        sendBuffer[0] = (uint8_t)addr;
+        sendBuffer[1] = (uint8_t)data;
+        port->write(sendBuffer, 2);
+        break;
+    }
+    case ProtocolNukeYktOPL3:
+    {
+        sendBuffer[0] = (addr >> 6) | 0x80;
+        sendBuffer[1] = ((addr & 0x3f) << 1) | (data >> 7);
+        sendBuffer[2] = (data & 0x7f);
+        port->write(sendBuffer, 3);
+        break;
+    }
+    case ProtocolRetroWaveOPL3:
+    {
+        bool port1 = (addr & 0x100) != 0;
+        uint8_t buf[8] =
+        {
+            static_cast<uint8_t>(0x21 << 1), 0x12,
+            static_cast<uint8_t>(port1 ? 0xe5 : 0xe1), static_cast<uint8_t>(addr & 0xff),
+            static_cast<uint8_t>(port1 ? 0xe7 : 0xe3), static_cast<uint8_t>(data),
+            0xfb, static_cast<uint8_t>(data)
+        };
+        size_t packed_len = retrowave_protocol_serial_pack(buf, sizeof(buf), sendBuffer);
+        port->write(sendBuffer, packed_len);
+        break;
+    }
+    }
+}
+
+void OPL_SerialPort::nativeGenerate(int16_t *frame)
+{
+    frame[0] = 0;
+    frame[1] = 0;
+}
+
+const char *OPL_SerialPort::emulatorName()
+{
+    return "OPL Serial Port Driver";
+}
+
+OPLChipBase::ChipType OPL_SerialPort::chipType()
+{
+    switch(m_protocol)
+    {
+    default:
+    case ProtocolArduinoOPL2:
+        return OPLChipBase::CHIPTYPE_OPL2;
+    case ProtocolNukeYktOPL3:
+    case ProtocolRetroWaveOPL3:
+        return OPLChipBase::CHIPTYPE_OPL3;
+    }
+}
+
+#endif // ENABLE_HW_OPL_SERIAL_PORT