xref: /linux/sound/drivers/opl3/opl3_midi.c (revision 06a130e42a5bfc84795464bff023bff4c16f58c5)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Copyright (c) by Uros Bizjak <uros@kss-loka.si>
4  *
5  *  Midi synth routines for OPL2/OPL3/OPL4 FM
6  */
7 
8 #undef DEBUG_ALLOC
9 #undef DEBUG_MIDI
10 
11 #include "opl3_voice.h"
12 #include <sound/asoundef.h>
13 
14 #ifdef DEBUG_MIDI
15 #define opl3_dbg(opl3, fmt, ...) \
16 	dev_dbg(((struct snd_opl3 *)(opl3))->card->dev, fmt, ##__VA_ARGS__)
17 #else
18 #define opl3_dbg(opl3, fmt, ...) do {} while (0)
19 #endif
20 
21 static void snd_opl3_note_off_unsafe(void *p, int note, int vel,
22 				     struct snd_midi_channel *chan);
23 /*
24  * The next table looks magical, but it certainly is not. Its values have
25  * been calculated as table[i]=8*log(i/64)/log(2) with an obvious exception
26  * for i=0. This log-table converts a linear volume-scaling (0..127) to a
27  * logarithmic scaling as present in the FM-synthesizer chips. so :    Volume
28  * 64 =  0 db = relative volume  0 and:    Volume 32 = -6 db = relative
29  * volume -8 it was implemented as a table because it is only 128 bytes and
30  * it saves a lot of log() calculations. (Rob Hooft <hooft@chem.ruu.nl>)
31  */
32 
33 static const char opl3_volume_table[128] =
34 {
35 	-63, -48, -40, -35, -32, -29, -27, -26,
36 	-24, -23, -21, -20, -19, -18, -18, -17,
37 	-16, -15, -15, -14, -13, -13, -12, -12,
38 	-11, -11, -10, -10, -10, -9, -9, -8,
39 	-8, -8, -7, -7, -7, -6, -6, -6,
40 	-5, -5, -5, -5, -4, -4, -4, -4,
41 	-3, -3, -3, -3, -2, -2, -2, -2,
42 	-2, -1, -1, -1, -1, 0, 0, 0,
43 	0, 0, 0, 1, 1, 1, 1, 1,
44 	1, 2, 2, 2, 2, 2, 2, 2,
45 	3, 3, 3, 3, 3, 3, 3, 4,
46 	4, 4, 4, 4, 4, 4, 4, 5,
47 	5, 5, 5, 5, 5, 5, 5, 5,
48 	6, 6, 6, 6, 6, 6, 6, 6,
49 	6, 7, 7, 7, 7, 7, 7, 7,
50 	7, 7, 7, 8, 8, 8, 8, 8
51 };
52 
53 void snd_opl3_calc_volume(unsigned char *volbyte, int vel,
54 			  struct snd_midi_channel *chan)
55 {
56 	int oldvol, newvol, n;
57 	int volume;
58 
59 	volume = (vel * chan->gm_volume * chan->gm_expression) / (127*127);
60 	if (volume > 127)
61 		volume = 127;
62 
63 	oldvol = OPL3_TOTAL_LEVEL_MASK - (*volbyte & OPL3_TOTAL_LEVEL_MASK);
64 
65 	newvol = opl3_volume_table[volume] + oldvol;
66 	if (newvol > OPL3_TOTAL_LEVEL_MASK)
67 		newvol = OPL3_TOTAL_LEVEL_MASK;
68 	else if (newvol < 0)
69 		newvol = 0;
70 
71 	n = OPL3_TOTAL_LEVEL_MASK - (newvol & OPL3_TOTAL_LEVEL_MASK);
72 
73 	*volbyte = (*volbyte & OPL3_KSL_MASK) | (n & OPL3_TOTAL_LEVEL_MASK);
74 }
75 
76 /*
77  * Converts the note frequency to block and fnum values for the FM chip
78  */
79 static const short opl3_note_table[16] =
80 {
81 	305, 323,	/* for pitch bending, -2 semitones */
82 	343, 363, 385, 408, 432, 458, 485, 514, 544, 577, 611, 647,
83 	686, 726	/* for pitch bending, +2 semitones */
84 };
85 
86 static void snd_opl3_calc_pitch(unsigned char *fnum, unsigned char *blocknum,
87 				int note, struct snd_midi_channel *chan)
88 {
89 	int block = ((note / 12) & 0x07) - 1;
90 	int idx = (note % 12) + 2;
91 	int freq;
92 
93 	if (chan->midi_pitchbend) {
94 		int pitchbend = chan->midi_pitchbend;
95 		int segment;
96 
97 		if (pitchbend < -0x2000)
98 			pitchbend = -0x2000;
99 		if (pitchbend > 0x1FFF)
100 			pitchbend = 0x1FFF;
101 
102 		segment = pitchbend / 0x1000;
103 		freq = opl3_note_table[idx+segment];
104 		freq += ((opl3_note_table[idx+segment+1] - freq) *
105 			 (pitchbend % 0x1000)) / 0x1000;
106 	} else {
107 		freq = opl3_note_table[idx];
108 	}
109 
110 	*fnum = (unsigned char) freq;
111 	*blocknum = ((freq >> 8) & OPL3_FNUM_HIGH_MASK) |
112 		((block << 2) & OPL3_BLOCKNUM_MASK);
113 }
114 
115 
116 #ifdef DEBUG_ALLOC
117 static void debug_alloc(struct snd_opl3 *opl3, char *s, int voice)
118 {
119 	int i;
120 	const char *str = "x.24";
121 	char buf[MAX_OPL3_VOICES + 1];
122 
123 	for (i = 0; i < opl3->max_voices; i++)
124 		buf[i] = str[opl3->voices[i].state + 1];
125 	buf[i] = 0;
126 	dev_dbg(opl3->card->dev, "time %.5i: %s [%.2i]: %s\n",
127 		opl3->use_time, s, voice, buf);
128 }
129 #endif
130 
131 /*
132  * Get a FM voice (channel) to play a note on.
133  */
134 static int opl3_get_voice(struct snd_opl3 *opl3, int instr_4op,
135 			  struct snd_midi_channel *chan) {
136 	int chan_4op_1;		/* first voice for 4op instrument */
137 	int chan_4op_2;		/* second voice for 4op instrument */
138 
139 	struct snd_opl3_voice *vp, *vp2;
140 	unsigned int voice_time;
141 	int i;
142 
143 #ifdef DEBUG_ALLOC
144 	char *alloc_type[3] = { "FREE     ", "CHEAP    ", "EXPENSIVE" };
145 #endif
146 
147 	/* This is our "allocation cost" table */
148 	enum {
149 		FREE = 0, CHEAP, EXPENSIVE, END
150 	};
151 
152 	/* Keeps track of what we are finding */
153 	struct best {
154 		unsigned int time;
155 		int voice;
156 	} best[END];
157 	struct best *bp;
158 
159 	for (i = 0; i < END; i++) {
160 		best[i].time = (unsigned int)(-1); /* XXX MAX_?INT really */
161 		best[i].voice = -1;
162 	}
163 
164 	/* Look through all the channels for the most suitable. */
165 	for (i = 0; i < opl3->max_voices; i++) {
166 		vp = &opl3->voices[i];
167 
168 		if (vp->state == SNDRV_OPL3_ST_NOT_AVAIL)
169 		  /* skip unavailable channels, allocated by
170 		     drum voices or by bounded 4op voices) */
171 			continue;
172 
173 		voice_time = vp->time;
174 		bp = best;
175 
176 		chan_4op_1 = ((i < 3) || (i > 8 && i < 12));
177 		chan_4op_2 = ((i > 2 && i < 6) || (i > 11 && i < 15));
178 		if (instr_4op) {
179 			/* allocate 4op voice */
180 			/* skip channels unavailable to 4op instrument */
181 			if (!chan_4op_1)
182 				continue;
183 
184 			if (vp->state)
185 				/* kill one voice, CHEAP */
186 				bp++;
187 			/* get state of bounded 2op channel
188 			   to be allocated for 4op instrument */
189 			vp2 = &opl3->voices[i + 3];
190 			if (vp2->state == SNDRV_OPL3_ST_ON_2OP) {
191 				/* kill two voices, EXPENSIVE */
192 				bp++;
193 				voice_time = max(voice_time, vp2->time);
194 			}
195 		} else {
196 			/* allocate 2op voice */
197 			if ((chan_4op_1) || (chan_4op_2))
198 				/* use bounded channels for 2op, CHEAP */
199 				bp++;
200 			else if (vp->state)
201 				/* kill one voice on 2op channel, CHEAP */
202 				bp++;
203 			/* raise kill cost to EXPENSIVE for all channels */
204 			if (vp->state)
205 				bp++;
206 		}
207 		if (voice_time < bp->time) {
208 			bp->time = voice_time;
209 			bp->voice = i;
210 		}
211 	}
212 
213 	for (i = 0; i < END; i++) {
214 		if (best[i].voice >= 0) {
215 #ifdef DEBUG_ALLOC
216 			dev_dbg(opl3->card->dev,
217 				"%s %iop allocation on voice %i\n",
218 				alloc_type[i], instr_4op ? 4 : 2,
219 				best[i].voice);
220 #endif
221 			return best[i].voice;
222 		}
223 	}
224 	/* not found */
225 	return -1;
226 }
227 
228 /* ------------------------------ */
229 
230 /*
231  * System timer interrupt function
232  */
233 void snd_opl3_timer_func(struct timer_list *t)
234 {
235 
236 	struct snd_opl3 *opl3 = from_timer(opl3, t, tlist);
237 	unsigned long flags;
238 	int again = 0;
239 	int i;
240 
241 	spin_lock_irqsave(&opl3->voice_lock, flags);
242 	for (i = 0; i < opl3->max_voices; i++) {
243 		struct snd_opl3_voice *vp = &opl3->voices[i];
244 		if (vp->state > 0 && vp->note_off_check) {
245 			if (vp->note_off == jiffies)
246 				snd_opl3_note_off_unsafe(opl3, vp->note, 0,
247 							 vp->chan);
248 			else
249 				again++;
250 		}
251 	}
252 	spin_unlock_irqrestore(&opl3->voice_lock, flags);
253 
254 	spin_lock_irqsave(&opl3->sys_timer_lock, flags);
255 	if (again)
256 		mod_timer(&opl3->tlist, jiffies + 1);	/* invoke again */
257 	else
258 		opl3->sys_timer_status = 0;
259 	spin_unlock_irqrestore(&opl3->sys_timer_lock, flags);
260 }
261 
262 /*
263  * Start system timer
264  */
265 static void snd_opl3_start_timer(struct snd_opl3 *opl3)
266 {
267 	unsigned long flags;
268 	spin_lock_irqsave(&opl3->sys_timer_lock, flags);
269 	if (! opl3->sys_timer_status) {
270 		mod_timer(&opl3->tlist, jiffies + 1);
271 		opl3->sys_timer_status = 1;
272 	}
273 	spin_unlock_irqrestore(&opl3->sys_timer_lock, flags);
274 }
275 
276 /* ------------------------------ */
277 
278 
279 static const int snd_opl3_oss_map[MAX_OPL3_VOICES] = {
280 	0, 1, 2, 9, 10, 11, 6, 7, 8, 15, 16, 17, 3, 4 ,5, 12, 13, 14
281 };
282 
283 /*
284  * Start a note.
285  */
286 void snd_opl3_note_on(void *p, int note, int vel, struct snd_midi_channel *chan)
287 {
288 	struct snd_opl3 *opl3;
289 	int instr_4op;
290 
291 	int voice;
292 	struct snd_opl3_voice *vp, *vp2;
293 	unsigned short connect_mask;
294 	unsigned char connection;
295 	unsigned char vol_op[4];
296 
297 	int extra_prg = 0;
298 
299 	unsigned short reg_side;
300 	unsigned char op_offset;
301 	unsigned char voice_offset;
302 	unsigned short opl3_reg;
303 	unsigned char reg_val;
304 	unsigned char prg, bank;
305 
306 	int key = note;
307 	unsigned char fnum, blocknum;
308 	int i;
309 
310 	struct fm_patch *patch;
311 	struct fm_instrument *fm;
312 	unsigned long flags;
313 
314 	opl3 = p;
315 
316 	opl3_dbg(opl3, "Note on, ch %i, inst %i, note %i, vel %i\n",
317 		 chan->number, chan->midi_program, note, vel);
318 
319 	/* in SYNTH mode, application takes care of voices */
320 	/* in SEQ mode, drum voice numbers are notes on drum channel */
321 	if (opl3->synth_mode == SNDRV_OPL3_MODE_SEQ) {
322 		if (chan->drum_channel) {
323 			/* percussion instruments are located in bank 128 */
324 			bank = 128;
325 			prg = note;
326 		} else {
327 			bank = chan->gm_bank_select;
328 			prg = chan->midi_program;
329 		}
330 	} else {
331 		/* Prepare for OSS mode */
332 		if (chan->number >= MAX_OPL3_VOICES)
333 			return;
334 
335 		/* OSS instruments are located in bank 127 */
336 		bank = 127;
337 		prg = chan->midi_program;
338 	}
339 
340 	spin_lock_irqsave(&opl3->voice_lock, flags);
341 
342 	if (use_internal_drums) {
343 		snd_opl3_drum_switch(opl3, note, vel, 1, chan);
344 		spin_unlock_irqrestore(&opl3->voice_lock, flags);
345 		return;
346 	}
347 
348  __extra_prg:
349 	patch = snd_opl3_find_patch(opl3, prg, bank, 0);
350 	if (!patch) {
351 		spin_unlock_irqrestore(&opl3->voice_lock, flags);
352 		return;
353 	}
354 
355 	fm = &patch->inst;
356 	switch (patch->type) {
357 	case FM_PATCH_OPL2:
358 		instr_4op = 0;
359 		break;
360 	case FM_PATCH_OPL3:
361 		if (opl3->hardware >= OPL3_HW_OPL3) {
362 			instr_4op = 1;
363 			break;
364 		}
365 		fallthrough;
366 	default:
367 		spin_unlock_irqrestore(&opl3->voice_lock, flags);
368 		return;
369 	}
370 	opl3_dbg(opl3, "  --> OPL%i instrument: %s\n",
371 		 instr_4op ? 3 : 2, patch->name);
372 	/* in SYNTH mode, application takes care of voices */
373 	/* in SEQ mode, allocate voice on free OPL3 channel */
374 	if (opl3->synth_mode == SNDRV_OPL3_MODE_SEQ) {
375 		voice = opl3_get_voice(opl3, instr_4op, chan);
376 	} else {
377 		/* remap OSS voice */
378 		voice = snd_opl3_oss_map[chan->number];
379 	}
380 
381 	if (voice < 0) {
382 		spin_unlock_irqrestore(&opl3->voice_lock, flags);
383 		return;
384 	}
385 
386 	if (voice < MAX_OPL2_VOICES) {
387 		/* Left register block for voices 0 .. 8 */
388 		reg_side = OPL3_LEFT;
389 		voice_offset = voice;
390 		connect_mask = (OPL3_LEFT_4OP_0 << voice_offset) & 0x07;
391 	} else {
392 		/* Right register block for voices 9 .. 17 */
393 		reg_side = OPL3_RIGHT;
394 		voice_offset = voice - MAX_OPL2_VOICES;
395 		connect_mask = (OPL3_RIGHT_4OP_0 << voice_offset) & 0x38;
396 	}
397 
398 	/* kill voice on channel */
399 	vp = &opl3->voices[voice];
400 	if (vp->state > 0) {
401 		opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
402 		reg_val = vp->keyon_reg & ~OPL3_KEYON_BIT;
403 		opl3->command(opl3, opl3_reg, reg_val);
404 	}
405 	if (instr_4op) {
406 		vp2 = &opl3->voices[voice + 3];
407 		if (vp2->state > 0) {
408 			opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK +
409 					       voice_offset + 3);
410 			reg_val = vp->keyon_reg & ~OPL3_KEYON_BIT;
411 			opl3->command(opl3, opl3_reg, reg_val);
412 		}
413 	}
414 
415 	/* set connection register */
416 	if (instr_4op) {
417 		if ((opl3->connection_reg ^ connect_mask) & connect_mask) {
418 			opl3->connection_reg |= connect_mask;
419 			/* set connection bit */
420 			opl3_reg = OPL3_RIGHT | OPL3_REG_CONNECTION_SELECT;
421 			opl3->command(opl3, opl3_reg, opl3->connection_reg);
422 		}
423 	} else {
424 		if ((opl3->connection_reg ^ ~connect_mask) & connect_mask) {
425 			opl3->connection_reg &= ~connect_mask;
426 			/* clear connection bit */
427 			opl3_reg = OPL3_RIGHT | OPL3_REG_CONNECTION_SELECT;
428 			opl3->command(opl3, opl3_reg, opl3->connection_reg);
429 		}
430 	}
431 
432 	opl3_dbg(opl3, "  --> setting OPL3 connection: 0x%x\n",
433 		opl3->connection_reg);
434 	/*
435 	 * calculate volume depending on connection
436 	 * between FM operators (see include/opl3.h)
437 	 */
438 	for (i = 0; i < (instr_4op ? 4 : 2); i++)
439 		vol_op[i] = fm->op[i].ksl_level;
440 
441 	connection = fm->feedback_connection[0] & 0x01;
442 	if (instr_4op) {
443 		connection <<= 1;
444 		connection |= fm->feedback_connection[1] & 0x01;
445 
446 		snd_opl3_calc_volume(&vol_op[3], vel, chan);
447 		switch (connection) {
448 		case 0x03:
449 			snd_opl3_calc_volume(&vol_op[2], vel, chan);
450 			fallthrough;
451 		case 0x02:
452 			snd_opl3_calc_volume(&vol_op[0], vel, chan);
453 			break;
454 		case 0x01:
455 			snd_opl3_calc_volume(&vol_op[1], vel, chan);
456 		}
457 	} else {
458 		snd_opl3_calc_volume(&vol_op[1], vel, chan);
459 		if (connection)
460 			snd_opl3_calc_volume(&vol_op[0], vel, chan);
461 	}
462 
463 	/* Program the FM voice characteristics */
464 	for (i = 0; i < (instr_4op ? 4 : 2); i++) {
465 		opl3_dbg(opl3, "  --> programming operator %i\n", i);
466 		op_offset = snd_opl3_regmap[voice_offset][i];
467 
468 		/* Set OPL3 AM_VIB register of requested voice/operator */
469 		reg_val = fm->op[i].am_vib;
470 		opl3_reg = reg_side | (OPL3_REG_AM_VIB + op_offset);
471 		opl3->command(opl3, opl3_reg, reg_val);
472 
473 		/* Set OPL3 KSL_LEVEL register of requested voice/operator */
474 		reg_val = vol_op[i];
475 		opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + op_offset);
476 		opl3->command(opl3, opl3_reg, reg_val);
477 
478 		/* Set OPL3 ATTACK_DECAY register of requested voice/operator */
479 		reg_val = fm->op[i].attack_decay;
480 		opl3_reg = reg_side | (OPL3_REG_ATTACK_DECAY + op_offset);
481 		opl3->command(opl3, opl3_reg, reg_val);
482 
483 		/* Set OPL3 SUSTAIN_RELEASE register of requested voice/operator */
484 		reg_val = fm->op[i].sustain_release;
485 		opl3_reg = reg_side | (OPL3_REG_SUSTAIN_RELEASE + op_offset);
486 		opl3->command(opl3, opl3_reg, reg_val);
487 
488 		/* Select waveform */
489 		reg_val = fm->op[i].wave_select;
490 		opl3_reg = reg_side | (OPL3_REG_WAVE_SELECT + op_offset);
491 		opl3->command(opl3, opl3_reg, reg_val);
492 	}
493 
494 	/* Set operator feedback and 2op inter-operator connection */
495 	reg_val = fm->feedback_connection[0];
496 	/* Set output voice connection */
497 	reg_val |= OPL3_STEREO_BITS;
498 	if (chan->gm_pan < 43)
499 		reg_val &= ~OPL3_VOICE_TO_RIGHT;
500 	if (chan->gm_pan > 85)
501 		reg_val &= ~OPL3_VOICE_TO_LEFT;
502 	opl3_reg = reg_side | (OPL3_REG_FEEDBACK_CONNECTION + voice_offset);
503 	opl3->command(opl3, opl3_reg, reg_val);
504 
505 	if (instr_4op) {
506 		/* Set 4op inter-operator connection */
507 		reg_val = fm->feedback_connection[1] & OPL3_CONNECTION_BIT;
508 		/* Set output voice connection */
509 		reg_val |= OPL3_STEREO_BITS;
510 		if (chan->gm_pan < 43)
511 			reg_val &= ~OPL3_VOICE_TO_RIGHT;
512 		if (chan->gm_pan > 85)
513 			reg_val &= ~OPL3_VOICE_TO_LEFT;
514 		opl3_reg = reg_side | (OPL3_REG_FEEDBACK_CONNECTION +
515 				       voice_offset + 3);
516 		opl3->command(opl3, opl3_reg, reg_val);
517 	}
518 
519 	/*
520 	 * Special treatment of percussion notes for fm:
521 	 * Requested pitch is really program, and pitch for
522 	 * device is whatever was specified in the patch library.
523 	 */
524 	if (fm->fix_key)
525 		note = fm->fix_key;
526 	/*
527 	 * use transpose if defined in patch library
528 	 */
529 	if (fm->trnsps)
530 		note += (fm->trnsps - 64);
531 
532 	snd_opl3_calc_pitch(&fnum, &blocknum, note, chan);
533 
534 	/* Set OPL3 FNUM_LOW register of requested voice */
535 	opl3_reg = reg_side | (OPL3_REG_FNUM_LOW + voice_offset);
536 	opl3->command(opl3, opl3_reg, fnum);
537 
538 	opl3->voices[voice].keyon_reg = blocknum;
539 
540 	/* Set output sound flag */
541 	blocknum |= OPL3_KEYON_BIT;
542 
543 	opl3_dbg(opl3, "  --> trigger voice %i\n", voice);
544 	/* Set OPL3 KEYON_BLOCK register of requested voice */
545 	opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
546 	opl3->command(opl3, opl3_reg, blocknum);
547 
548 	/* kill note after fixed duration (in centiseconds) */
549 	if (fm->fix_dur) {
550 		opl3->voices[voice].note_off = jiffies +
551 			(fm->fix_dur * HZ) / 100;
552 		snd_opl3_start_timer(opl3);
553 		opl3->voices[voice].note_off_check = 1;
554 	} else
555 		opl3->voices[voice].note_off_check = 0;
556 
557 	/* get extra pgm, but avoid possible loops */
558 	extra_prg = (extra_prg) ? 0 : fm->modes;
559 
560 	/* do the bookkeeping */
561 	vp->time = opl3->use_time++;
562 	vp->note = key;
563 	vp->chan = chan;
564 
565 	if (instr_4op) {
566 		vp->state = SNDRV_OPL3_ST_ON_4OP;
567 
568 		vp2 = &opl3->voices[voice + 3];
569 		vp2->time = opl3->use_time++;
570 		vp2->note = key;
571 		vp2->chan = chan;
572 		vp2->state = SNDRV_OPL3_ST_NOT_AVAIL;
573 	} else {
574 		if (vp->state == SNDRV_OPL3_ST_ON_4OP) {
575 			/* 4op killed by 2op, release bounded voice */
576 			vp2 = &opl3->voices[voice + 3];
577 			vp2->time = opl3->use_time++;
578 			vp2->state = SNDRV_OPL3_ST_OFF;
579 		}
580 		vp->state = SNDRV_OPL3_ST_ON_2OP;
581 	}
582 
583 #ifdef DEBUG_ALLOC
584 	debug_alloc(opl3, "note on ", voice);
585 #endif
586 
587 	/* allocate extra program if specified in patch library */
588 	if (extra_prg) {
589 		if (extra_prg > 128) {
590 			bank = 128;
591 			/* percussions start at 35 */
592 			prg = extra_prg - 128 + 35 - 1;
593 		} else {
594 			bank = 0;
595 			prg = extra_prg - 1;
596 		}
597 		opl3_dbg(opl3, " *** allocating extra program\n");
598 		goto __extra_prg;
599 	}
600 	spin_unlock_irqrestore(&opl3->voice_lock, flags);
601 }
602 
603 static void snd_opl3_kill_voice(struct snd_opl3 *opl3, int voice)
604 {
605 	unsigned short reg_side;
606 	unsigned char voice_offset;
607 	unsigned short opl3_reg;
608 
609 	struct snd_opl3_voice *vp, *vp2;
610 
611 	if (snd_BUG_ON(voice >= MAX_OPL3_VOICES))
612 		return;
613 
614 	vp = &opl3->voices[voice];
615 	if (voice < MAX_OPL2_VOICES) {
616 		/* Left register block for voices 0 .. 8 */
617 		reg_side = OPL3_LEFT;
618 		voice_offset = voice;
619 	} else {
620 		/* Right register block for voices 9 .. 17 */
621 		reg_side = OPL3_RIGHT;
622 		voice_offset = voice - MAX_OPL2_VOICES;
623 	}
624 
625 	/* kill voice */
626 	opl3_dbg(opl3, "  --> kill voice %i\n", voice);
627 	opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
628 	/* clear Key ON bit */
629 	opl3->command(opl3, opl3_reg, vp->keyon_reg);
630 
631 	/* do the bookkeeping */
632 	vp->time = opl3->use_time++;
633 
634 	if (vp->state == SNDRV_OPL3_ST_ON_4OP) {
635 		vp2 = &opl3->voices[voice + 3];
636 
637 		vp2->time = opl3->use_time++;
638 		vp2->state = SNDRV_OPL3_ST_OFF;
639 	}
640 	vp->state = SNDRV_OPL3_ST_OFF;
641 #ifdef DEBUG_ALLOC
642 	debug_alloc(opl3, "note off", voice);
643 #endif
644 
645 }
646 
647 /*
648  * Release a note in response to a midi note off.
649  */
650 static void snd_opl3_note_off_unsafe(void *p, int note, int vel,
651 				     struct snd_midi_channel *chan)
652 {
653   	struct snd_opl3 *opl3;
654 
655 	int voice;
656 	struct snd_opl3_voice *vp;
657 
658 	opl3 = p;
659 
660 	opl3_dbg(opl3, "Note off, ch %i, inst %i, note %i\n",
661 		 chan->number, chan->midi_program, note);
662 
663 	if (opl3->synth_mode == SNDRV_OPL3_MODE_SEQ) {
664 		if (chan->drum_channel && use_internal_drums) {
665 			snd_opl3_drum_switch(opl3, note, vel, 0, chan);
666 			return;
667 		}
668 		/* this loop will hopefully kill all extra voices, because
669 		   they are grouped by the same channel and note values */
670 		for (voice = 0; voice < opl3->max_voices; voice++) {
671 			vp = &opl3->voices[voice];
672 			if (vp->state > 0 && vp->chan == chan && vp->note == note) {
673 				snd_opl3_kill_voice(opl3, voice);
674 			}
675 		}
676 	} else {
677 		/* remap OSS voices */
678 		if (chan->number < MAX_OPL3_VOICES) {
679 			voice = snd_opl3_oss_map[chan->number];
680 			snd_opl3_kill_voice(opl3, voice);
681 		}
682 	}
683 }
684 
685 void snd_opl3_note_off(void *p, int note, int vel,
686 		       struct snd_midi_channel *chan)
687 {
688 	struct snd_opl3 *opl3 = p;
689 	unsigned long flags;
690 
691 	spin_lock_irqsave(&opl3->voice_lock, flags);
692 	snd_opl3_note_off_unsafe(p, note, vel, chan);
693 	spin_unlock_irqrestore(&opl3->voice_lock, flags);
694 }
695 
696 /*
697  * key pressure change
698  */
699 void snd_opl3_key_press(void *p, int note, int vel, struct snd_midi_channel *chan)
700 {
701 	opl3_dbg(p, "Key pressure, ch#: %i, inst#: %i\n",
702 		 chan->number, chan->midi_program);
703 }
704 
705 /*
706  * terminate note
707  */
708 void snd_opl3_terminate_note(void *p, int note, struct snd_midi_channel *chan)
709 {
710 	opl3_dbg(p, "Terminate note, ch#: %i, inst#: %i\n",
711 		 chan->number, chan->midi_program);
712 }
713 
714 static void snd_opl3_update_pitch(struct snd_opl3 *opl3, int voice)
715 {
716 	unsigned short reg_side;
717 	unsigned char voice_offset;
718 	unsigned short opl3_reg;
719 
720 	unsigned char fnum, blocknum;
721 
722 	struct snd_opl3_voice *vp;
723 
724 	if (snd_BUG_ON(voice >= MAX_OPL3_VOICES))
725 		return;
726 
727 	vp = &opl3->voices[voice];
728 	if (vp->chan == NULL)
729 		return; /* not allocated? */
730 
731 	if (voice < MAX_OPL2_VOICES) {
732 		/* Left register block for voices 0 .. 8 */
733 		reg_side = OPL3_LEFT;
734 		voice_offset = voice;
735 	} else {
736 		/* Right register block for voices 9 .. 17 */
737 		reg_side = OPL3_RIGHT;
738 		voice_offset = voice - MAX_OPL2_VOICES;
739 	}
740 
741 	snd_opl3_calc_pitch(&fnum, &blocknum, vp->note, vp->chan);
742 
743 	/* Set OPL3 FNUM_LOW register of requested voice */
744 	opl3_reg = reg_side | (OPL3_REG_FNUM_LOW + voice_offset);
745 	opl3->command(opl3, opl3_reg, fnum);
746 
747 	vp->keyon_reg = blocknum;
748 
749 	/* Set output sound flag */
750 	blocknum |= OPL3_KEYON_BIT;
751 
752 	/* Set OPL3 KEYON_BLOCK register of requested voice */
753 	opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
754 	opl3->command(opl3, opl3_reg, blocknum);
755 
756 	vp->time = opl3->use_time++;
757 }
758 
759 /*
760  * Update voice pitch controller
761  */
762 static void snd_opl3_pitch_ctrl(struct snd_opl3 *opl3, struct snd_midi_channel *chan)
763 {
764 	int voice;
765 	struct snd_opl3_voice *vp;
766 
767 	unsigned long flags;
768 
769 	spin_lock_irqsave(&opl3->voice_lock, flags);
770 
771 	if (opl3->synth_mode == SNDRV_OPL3_MODE_SEQ) {
772 		for (voice = 0; voice < opl3->max_voices; voice++) {
773 			vp = &opl3->voices[voice];
774 			if (vp->state > 0 && vp->chan == chan) {
775 				snd_opl3_update_pitch(opl3, voice);
776 			}
777 		}
778 	} else {
779 		/* remap OSS voices */
780 		if (chan->number < MAX_OPL3_VOICES) {
781 			voice = snd_opl3_oss_map[chan->number];
782 			snd_opl3_update_pitch(opl3, voice);
783 		}
784 	}
785 	spin_unlock_irqrestore(&opl3->voice_lock, flags);
786 }
787 
788 /*
789  * Deal with a controller type event.  This includes all types of
790  * control events, not just the midi controllers
791  */
792 void snd_opl3_control(void *p, int type, struct snd_midi_channel *chan)
793 {
794   	struct snd_opl3 *opl3;
795 
796 	opl3 = p;
797 	opl3_dbg(opl3, "Controller, TYPE = %i, ch#: %i, inst#: %i\n",
798 		 type, chan->number, chan->midi_program);
799 
800 	switch (type) {
801 	case MIDI_CTL_MSB_MODWHEEL:
802 		if (chan->control[MIDI_CTL_MSB_MODWHEEL] > 63)
803 			opl3->drum_reg |= OPL3_VIBRATO_DEPTH;
804 		else
805 			opl3->drum_reg &= ~OPL3_VIBRATO_DEPTH;
806 		opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION,
807 				 opl3->drum_reg);
808 		break;
809 	case MIDI_CTL_E2_TREMOLO_DEPTH:
810 		if (chan->control[MIDI_CTL_E2_TREMOLO_DEPTH] > 63)
811 			opl3->drum_reg |= OPL3_TREMOLO_DEPTH;
812 		else
813 			opl3->drum_reg &= ~OPL3_TREMOLO_DEPTH;
814 		opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION,
815 				 opl3->drum_reg);
816 		break;
817 	case MIDI_CTL_PITCHBEND:
818 		snd_opl3_pitch_ctrl(opl3, chan);
819 		break;
820 	}
821 }
822 
823 /*
824  * NRPN events
825  */
826 void snd_opl3_nrpn(void *p, struct snd_midi_channel *chan,
827 		   struct snd_midi_channel_set *chset)
828 {
829 	opl3_dbg(p, "NRPN, ch#: %i, inst#: %i\n",
830 		 chan->number, chan->midi_program);
831 }
832 
833 /*
834  * receive sysex
835  */
836 void snd_opl3_sysex(void *p, unsigned char *buf, int len,
837 		    int parsed, struct snd_midi_channel_set *chset)
838 {
839 	opl3_dbg(p, "SYSEX\n");
840 }
841