AUDIO: Move ALSA OPL 'driver' out of softsynth

Might eventually be worth moving to backends/

1 files changed, 349 insertions, 0 deletions

diff --git a/audio/alsa_opl.cpp b/audio/alsa_opl.cpp
new file mode 100644
index 0000000000..6b9e48e987
--- /dev/null
+++ b/audio/alsa_opl.cpp
@@ -0,0 +1,349 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * 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 2
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+/* OPL implementation for hardware OPL using ALSA Direct FM API.
+ *
+ * Caveats and limitations:
+ * - Pretends to be a softsynth (emitting silence).
+ * - Dual OPL2 mode requires OPL3 hardware.
+ * - Every register write leads to a series of register writes on the hardware,
+ *   due to the lack of direct register access in the ALSA Direct FM API.
+ * - No timers
+ */
+
+#define FORBIDDEN_SYMBOL_ALLOW_ALL
+#include "common/scummsys.h"
+
+#include "common/debug.h"
+#include "common/str.h"
+#include "audio/fmopl.h"
+
+#include <sys/ioctl.h>
+#include <alsa/asoundlib.h>
+#include <sound/asound_fm.h>
+
+namespace OPL {
+namespace ALSA {
+
+class OPL : public ::OPL::RealOPL {
+private:
+	enum {
+		kOpl2Voices = 9,
+		kVoices = 18,
+		kOpl2Operators = 18,
+		kOperators = 36
+	};
+
+	Config::OplType _type;
+	int _iface;
+	snd_hwdep_t *_opl;
+	snd_dm_fm_voice _oper[kOperators];
+	snd_dm_fm_note _voice[kVoices];
+	snd_dm_fm_params _params;
+	int index[2];
+	static const int voiceToOper0[kVoices];
+	static const int regOffsetToOper[0x20];
+
+	void writeOplReg(int c, int r, int v);
+	void clear();
+
+public:
+	OPL(Config::OplType type);
+	~OPL();
+
+	bool init();
+	void reset();
+
+	void write(int a, int v);
+	byte read(int a);
+
+	void writeReg(int r, int v);
+};
+
+const int OPL::voiceToOper0[OPL::kVoices] =
+	{ 0, 1, 2, 6, 7, 8, 12, 13, 14, 18, 19, 20, 24, 25, 26, 30, 31, 32 };
+
+const int OPL::regOffsetToOper[0x20] =
+	{ 0,  1,  2,  3,  4,  5, -1, -1, 6, 7, 8, 9, 10, 11, -1, -1,
+	 12, 13, 14, 15, 16, 17, -1, -1, -1, -1, -1, -1, -1, -1, -1 };
+
+OPL::OPL(Config::OplType type) : _type(type), _opl(nullptr), _iface(0) {
+}
+
+OPL::~OPL() {
+	stop();
+
+	if (_opl) {
+		snd_hwdep_ioctl(_opl, SNDRV_DM_FM_IOCTL_RESET, nullptr);
+		snd_hwdep_close(_opl);
+	}
+}
+
+void OPL::clear() {
+	index[0] = index[1] = 0;
+
+	memset(_oper, 0, sizeof(_oper));
+	memset(_voice, 0, sizeof(_voice));
+	memset(&_params, 0, sizeof(_params));
+
+	for (int i = 0; i < kOperators; ++i) {
+		_oper[i].op = (i / 3) % 2;
+		_oper[i].voice = (i / 6) * 3 + (i % 3);
+	}
+
+	for (int i = 0; i < kVoices; ++i)
+		_voice[i].voice = i;
+
+	// For OPL3 hardware we need to set up the panning in OPL2 modes
+	if (_iface == SND_HWDEP_IFACE_OPL3) {
+		if (_type == Config::kDualOpl2) {
+			for (int i = 0; i < kOpl2Operators; ++i)
+				_oper[i].left = 1; // FIXME below
+			for (int i = kOpl2Operators; i < kOperators; ++i)
+				_oper[i].right = 1;
+		} else if (_type == Config::kOpl2) {
+			for (int i = 0; i < kOpl2Operators; ++i) {
+				_oper[i].left = 1;
+				_oper[i].right = 1;			
+			}
+		}
+	}
+}
+
+bool OPL::init() {
+	clear();
+
+	int card = -1;
+	snd_ctl_t *ctl;
+	snd_hwdep_info_t *info;
+	snd_hwdep_info_alloca(&info);
+
+	int iface = SND_HWDEP_IFACE_OPL3;
+	if (_type == Config::kOpl2)
+		iface = SND_HWDEP_IFACE_OPL2;
+
+	// Look for OPL hwdep interface
+	while (!snd_card_next(&card) && card >= 0) {
+		int dev = -1;
+		Common::String name = Common::String::format("hw:%d", card);
+
+		if (snd_ctl_open(&ctl, name.c_str(), 0) < 0)
+			continue;
+
+		while (!snd_ctl_hwdep_next_device(ctl, &dev) && dev >= 0) {
+			name = Common::String::format("hw:%d,%d", card, dev);
+
+			if (snd_hwdep_open(&_opl, name.c_str(), SND_HWDEP_OPEN_WRITE) < 0) 
+				continue;
+
+			if (!snd_hwdep_info(_opl, info)) {
+				int found = snd_hwdep_info_get_iface(info);
+				// OPL3 can be used for (Dual) OPL2 mode
+				if (found == iface || found == SND_HWDEP_IFACE_OPL3) {
+					snd_ctl_close(ctl);
+					_iface = found;
+					reset();
+					return true;
+				}
+			}
+
+			// Wrong interface, try next device
+			snd_hwdep_close(_opl);
+			_opl = nullptr;
+		}
+
+		snd_ctl_close(ctl);
+	}
+
+	return false;
+}
+
+void OPL::reset() {
+	snd_hwdep_ioctl(_opl, SNDRV_DM_FM_IOCTL_RESET, nullptr);
+	if (_iface == SND_HWDEP_IFACE_OPL3)
+		snd_hwdep_ioctl(_opl, SNDRV_DM_FM_IOCTL_SET_MODE, (void *)SNDRV_DM_FM_MODE_OPL3);
+
+	clear();
+
+	// Sync up with the hardware
+	snd_hwdep_ioctl(_opl, SNDRV_DM_FM_IOCTL_SET_PARAMS, (void *)&_params);
+	for (uint i = 0; i < (_iface == SND_HWDEP_IFACE_OPL3 ? kVoices : kOpl2Voices); ++i)
+		snd_hwdep_ioctl(_opl, SNDRV_DM_FM_IOCTL_PLAY_NOTE, (void *)&_voice[i]);
+	for (uint i = 0; i < (_iface == SND_HWDEP_IFACE_OPL3 ? kOperators : kOpl2Operators); ++i)
+		snd_hwdep_ioctl(_opl, SNDRV_DM_FM_IOCTL_SET_VOICE, (void *)&_oper[i]);
+}
+
+void OPL::write(int port, int val) {
+	val &= 0xff;
+	int chip = (port & 2) >> 1;
+
+	if (port & 1) {
+		switch(_type) {
+		case Config::kOpl2:
+			writeOplReg(0, index[0], val);
+			break;
+		case Config::kDualOpl2:
+			if (port & 8) {
+				writeOplReg(0, index[0], val);
+				writeOplReg(1, index[1], val);
+			} else
+				writeOplReg(chip, index[chip], val);
+			break;
+		case Config::kOpl3:
+			writeOplReg(chip, index[chip], val);
+		}
+	} else {
+		switch(_type) {
+		case Config::kOpl2:
+			index[0] = val;
+			break;
+		case Config::kDualOpl2:
+			if (port & 8) {
+				index[0] = val;
+				index[1] = val;
+			} else
+				index[chip] = val;
+			break;
+		case Config::kOpl3:
+			index[chip] = val;
+		}
+	}
+}
+
+byte OPL::read(int port) {
+	return 0;
+}
+
+void OPL::writeReg(int r, int v) {
+	switch (_type) {
+	case Config::kOpl2:
+		writeOplReg(0, r, v);
+		break;
+	case Config::kDualOpl2:
+		writeOplReg(0, r, v);
+		writeOplReg(1, r, v);
+		break;
+	case Config::kOpl3:
+		writeOplReg(r >= 0x100, r & 0xff, v);
+	}
+}
+
+void OPL::writeOplReg(int c, int r, int v) {
+	if (r == 0x04 && c == 1 && _type == Config::kOpl3) {
+		snd_hwdep_ioctl(_opl, SNDRV_DM_FM_IOCTL_SET_CONNECTION, reinterpret_cast<void *>(v & 0x3f));
+	} else if (r == 0x08 && c == 0) {
+		_params.kbd_split = (v >> 6) & 0x1;
+		snd_hwdep_ioctl(_opl, SNDRV_DM_FM_IOCTL_SET_PARAMS, (void *)&_params);
+	} else if (r == 0xbd && c == 0) {
+		_params.hihat = v & 0x1;
+		_params.cymbal = (v >> 1) & 0x1;
+		_params.tomtom = (v >> 2) & 0x1;
+		_params.snare = (v >> 3) & 0x1;
+		_params.bass = (v >> 4) & 0x1;
+		_params.rhythm = (v >> 5) & 0x1;
+		_params.vib_depth = (v >> 6) & 0x1;
+		_params.am_depth = (v >> 7) & 0x1;
+		snd_hwdep_ioctl(_opl, SNDRV_DM_FM_IOCTL_SET_PARAMS, (void *)&_params);
+	} else if (r < 0xa0 || r >= 0xe0) {
+		// Operator
+		int idx = regOffsetToOper[r & 0x1f];
+
+		if (idx == -1)
+			return;
+
+		if (c == 1)
+			idx += kOpl2Operators;
+
+		switch (r & 0xf0) {
+		case 0x20:
+		case 0x30:
+			_oper[idx].harmonic = v & 0xf;
+			_oper[idx].kbd_scale = (v >> 4) & 0x1;
+			_oper[idx].do_sustain = (v >> 5) & 0x1;
+			_oper[idx].vibrato = (v >> 6) & 0x1;
+			_oper[idx].am = (v >> 7) & 0x1;
+			snd_hwdep_ioctl(_opl, SNDRV_DM_FM_IOCTL_SET_VOICE, (void *)&_oper[idx]);
+			break;
+		case 0x40:
+		case 0x50:
+			_oper[idx].volume = ~v & 0x3f;
+			_oper[idx].scale_level = (v >> 6) & 0x3;
+			snd_hwdep_ioctl(_opl, SNDRV_DM_FM_IOCTL_SET_VOICE, (void *)&_oper[idx]);
+			break;
+		case 0x60:
+		case 0x70:
+			_oper[idx].decay = v & 0xf;
+			_oper[idx].attack = (v >> 4) & 0xf;
+			snd_hwdep_ioctl(_opl, SNDRV_DM_FM_IOCTL_SET_VOICE, (void *)&_oper[idx]);
+			break;
+		case 0x80:
+		case 0x90:
+			_oper[idx].release = v & 0xf;
+			_oper[idx].sustain = (v >> 4) & 0xf;
+			snd_hwdep_ioctl(_opl, SNDRV_DM_FM_IOCTL_SET_VOICE, (void *)&_oper[idx]);
+			break;
+		case 0xe0:
+		case 0xf0:
+			_oper[idx].waveform = v & (_type == Config::kOpl3 ? 0x7 : 0x3);
+			snd_hwdep_ioctl(_opl, SNDRV_DM_FM_IOCTL_SET_VOICE, (void *)&_oper[idx]);
+		}
+	} else {
+		// Voice
+		int idx = r & 0xf;
+
+		if (idx >= kOpl2Voices)
+			return;
+
+		if (c == 1)
+			idx += kOpl2Voices;
+
+		int opIdx = voiceToOper0[idx];
+
+		switch (r & 0xf0) {
+		case 0xa0:
+			_voice[idx].fnum = (_voice[idx].fnum & 0x300) | (v & 0xff);
+			snd_hwdep_ioctl(_opl, SNDRV_DM_FM_IOCTL_PLAY_NOTE, (void *)&_voice[idx]);
+			break;
+		case 0xb0:
+			_voice[idx].fnum = ((v << 8) & 0x300) | (_voice[idx].fnum & 0xff);
+			_voice[idx].octave = (v >> 2) & 0x7;
+			_voice[idx].key_on = (v >> 5) & 0x1;
+			snd_hwdep_ioctl(_opl, SNDRV_DM_FM_IOCTL_PLAY_NOTE, (void *)&_voice[idx]);
+			break;
+		case 0xc0:
+			_oper[opIdx].connection = _oper[opIdx + 3].connection = v & 0x1;
+			_oper[opIdx].feedback = _oper[opIdx + 3].feedback = (v >> 1) & 0x7;
+			if (_type == Config::kOpl3) {
+				_oper[opIdx].left = _oper[opIdx + 3].left = (v >> 4) & 0x1;
+				_oper[opIdx].right = _oper[opIdx + 3].right = (v >> 5) & 0x1;
+			}
+			snd_hwdep_ioctl(_opl, SNDRV_DM_FM_IOCTL_SET_VOICE, (void *)&_oper[opIdx]);
+		}
+	}
+}
+
+OPL *create(Config::OplType type) {
+	return new OPL(type);
+}
+
+} // End of namespace ALSA
+} // End of namespace OPL