xref: /openbmc/linux/sound/drivers/opl3/opl3_midi.c (revision 9a29f5fc)
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 static void snd_opl3_note_off_unsafe(void *p, int note, int vel,
15 				     struct snd_midi_channel *chan);
16 /*
17  * The next table looks magical, but it certainly is not. Its values have
18  * been calculated as table[i]=8*log(i/64)/log(2) with an obvious exception
19  * for i=0. This log-table converts a linear volume-scaling (0..127) to a
20  * logarithmic scaling as present in the FM-synthesizer chips. so :    Volume
21  * 64 =  0 db = relative volume  0 and:    Volume 32 = -6 db = relative
22  * volume -8 it was implemented as a table because it is only 128 bytes and
23  * it saves a lot of log() calculations. (Rob Hooft <hooft@chem.ruu.nl>)
24  */
25 
26 static const char opl3_volume_table[128] =
27 {
28 	-63, -48, -40, -35, -32, -29, -27, -26,
29 	-24, -23, -21, -20, -19, -18, -18, -17,
30 	-16, -15, -15, -14, -13, -13, -12, -12,
31 	-11, -11, -10, -10, -10, -9, -9, -8,
32 	-8, -8, -7, -7, -7, -6, -6, -6,
33 	-5, -5, -5, -5, -4, -4, -4, -4,
34 	-3, -3, -3, -3, -2, -2, -2, -2,
35 	-2, -1, -1, -1, -1, 0, 0, 0,
36 	0, 0, 0, 1, 1, 1, 1, 1,
37 	1, 2, 2, 2, 2, 2, 2, 2,
38 	3, 3, 3, 3, 3, 3, 3, 4,
39 	4, 4, 4, 4, 4, 4, 4, 5,
40 	5, 5, 5, 5, 5, 5, 5, 5,
41 	6, 6, 6, 6, 6, 6, 6, 6,
42 	6, 7, 7, 7, 7, 7, 7, 7,
43 	7, 7, 7, 8, 8, 8, 8, 8
44 };
45 
46 void snd_opl3_calc_volume(unsigned char *volbyte, int vel,
47 			  struct snd_midi_channel *chan)
48 {
49 	int oldvol, newvol, n;
50 	int volume;
51 
52 	volume = (vel * chan->gm_volume * chan->gm_expression) / (127*127);
53 	if (volume > 127)
54 		volume = 127;
55 
56 	oldvol = OPL3_TOTAL_LEVEL_MASK - (*volbyte & OPL3_TOTAL_LEVEL_MASK);
57 
58 	newvol = opl3_volume_table[volume] + oldvol;
59 	if (newvol > OPL3_TOTAL_LEVEL_MASK)
60 		newvol = OPL3_TOTAL_LEVEL_MASK;
61 	else if (newvol < 0)
62 		newvol = 0;
63 
64 	n = OPL3_TOTAL_LEVEL_MASK - (newvol & OPL3_TOTAL_LEVEL_MASK);
65 
66 	*volbyte = (*volbyte & OPL3_KSL_MASK) | (n & OPL3_TOTAL_LEVEL_MASK);
67 }
68 
69 /*
70  * Converts the note frequency to block and fnum values for the FM chip
71  */
72 static const short opl3_note_table[16] =
73 {
74 	305, 323,	/* for pitch bending, -2 semitones */
75 	343, 363, 385, 408, 432, 458, 485, 514, 544, 577, 611, 647,
76 	686, 726	/* for pitch bending, +2 semitones */
77 };
78 
79 static void snd_opl3_calc_pitch(unsigned char *fnum, unsigned char *blocknum,
80 				int note, struct snd_midi_channel *chan)
81 {
82 	int block = ((note / 12) & 0x07) - 1;
83 	int idx = (note % 12) + 2;
84 	int freq;
85 
86 	if (chan->midi_pitchbend) {
87 		int pitchbend = chan->midi_pitchbend;
88 		int segment;
89 
90 		if (pitchbend < -0x2000)
91 			pitchbend = -0x2000;
92 		if (pitchbend > 0x1FFF)
93 			pitchbend = 0x1FFF;
94 
95 		segment = pitchbend / 0x1000;
96 		freq = opl3_note_table[idx+segment];
97 		freq += ((opl3_note_table[idx+segment+1] - freq) *
98 			 (pitchbend % 0x1000)) / 0x1000;
99 	} else {
100 		freq = opl3_note_table[idx];
101 	}
102 
103 	*fnum = (unsigned char) freq;
104 	*blocknum = ((freq >> 8) & OPL3_FNUM_HIGH_MASK) |
105 		((block << 2) & OPL3_BLOCKNUM_MASK);
106 }
107 
108 
109 #ifdef DEBUG_ALLOC
110 static void debug_alloc(struct snd_opl3 *opl3, char *s, int voice) {
111 	int i;
112 	char *str = "x.24";
113 
114 	printk(KERN_DEBUG "time %.5i: %s [%.2i]: ", opl3->use_time, s, voice);
115 	for (i = 0; i < opl3->max_voices; i++)
116 		printk(KERN_CONT "%c", *(str + opl3->voices[i].state + 1));
117 	printk(KERN_CONT "\n");
118 }
119 #endif
120 
121 /*
122  * Get a FM voice (channel) to play a note on.
123  */
124 static int opl3_get_voice(struct snd_opl3 *opl3, int instr_4op,
125 			  struct snd_midi_channel *chan) {
126 	int chan_4op_1;		/* first voice for 4op instrument */
127 	int chan_4op_2;		/* second voice for 4op instrument */
128 
129 	struct snd_opl3_voice *vp, *vp2;
130 	unsigned int voice_time;
131 	int i;
132 
133 #ifdef DEBUG_ALLOC
134 	char *alloc_type[3] = { "FREE     ", "CHEAP    ", "EXPENSIVE" };
135 #endif
136 
137 	/* This is our "allocation cost" table */
138 	enum {
139 		FREE = 0, CHEAP, EXPENSIVE, END
140 	};
141 
142 	/* Keeps track of what we are finding */
143 	struct best {
144 		unsigned int time;
145 		int voice;
146 	} best[END];
147 	struct best *bp;
148 
149 	for (i = 0; i < END; i++) {
150 		best[i].time = (unsigned int)(-1); /* XXX MAX_?INT really */
151 		best[i].voice = -1;
152 	}
153 
154 	/* Look through all the channels for the most suitable. */
155 	for (i = 0; i < opl3->max_voices; i++) {
156 		vp = &opl3->voices[i];
157 
158 		if (vp->state == SNDRV_OPL3_ST_NOT_AVAIL)
159 		  /* skip unavailable channels, allocated by
160 		     drum voices or by bounded 4op voices) */
161 			continue;
162 
163 		voice_time = vp->time;
164 		bp = best;
165 
166 		chan_4op_1 = ((i < 3) || (i > 8 && i < 12));
167 		chan_4op_2 = ((i > 2 && i < 6) || (i > 11 && i < 15));
168 		if (instr_4op) {
169 			/* allocate 4op voice */
170 			/* skip channels unavailable to 4op instrument */
171 			if (!chan_4op_1)
172 				continue;
173 
174 			if (vp->state)
175 				/* kill one voice, CHEAP */
176 				bp++;
177 			/* get state of bounded 2op channel
178 			   to be allocated for 4op instrument */
179 			vp2 = &opl3->voices[i + 3];
180 			if (vp2->state == SNDRV_OPL3_ST_ON_2OP) {
181 				/* kill two voices, EXPENSIVE */
182 				bp++;
183 				voice_time = max(voice_time, vp2->time);
184 			}
185 		} else {
186 			/* allocate 2op voice */
187 			if ((chan_4op_1) || (chan_4op_2))
188 				/* use bounded channels for 2op, CHEAP */
189 				bp++;
190 			else if (vp->state)
191 				/* kill one voice on 2op channel, CHEAP */
192 				bp++;
193 			/* raise kill cost to EXPENSIVE for all channels */
194 			if (vp->state)
195 				bp++;
196 		}
197 		if (voice_time < bp->time) {
198 			bp->time = voice_time;
199 			bp->voice = i;
200 		}
201 	}
202 
203 	for (i = 0; i < END; i++) {
204 		if (best[i].voice >= 0) {
205 #ifdef DEBUG_ALLOC
206 			printk(KERN_DEBUG "%s %iop allocation on voice %i\n",
207 			       alloc_type[i], instr_4op ? 4 : 2,
208 			       best[i].voice);
209 #endif
210 			return best[i].voice;
211 		}
212 	}
213 	/* not found */
214 	return -1;
215 }
216 
217 /* ------------------------------ */
218 
219 /*
220  * System timer interrupt function
221  */
222 void snd_opl3_timer_func(struct timer_list *t)
223 {
224 
225 	struct snd_opl3 *opl3 = from_timer(opl3, t, tlist);
226 	unsigned long flags;
227 	int again = 0;
228 	int i;
229 
230 	spin_lock_irqsave(&opl3->voice_lock, flags);
231 	for (i = 0; i < opl3->max_voices; i++) {
232 		struct snd_opl3_voice *vp = &opl3->voices[i];
233 		if (vp->state > 0 && vp->note_off_check) {
234 			if (vp->note_off == jiffies)
235 				snd_opl3_note_off_unsafe(opl3, vp->note, 0,
236 							 vp->chan);
237 			else
238 				again++;
239 		}
240 	}
241 	spin_unlock_irqrestore(&opl3->voice_lock, flags);
242 
243 	spin_lock_irqsave(&opl3->sys_timer_lock, flags);
244 	if (again)
245 		mod_timer(&opl3->tlist, jiffies + 1);	/* invoke again */
246 	else
247 		opl3->sys_timer_status = 0;
248 	spin_unlock_irqrestore(&opl3->sys_timer_lock, flags);
249 }
250 
251 /*
252  * Start system timer
253  */
254 static void snd_opl3_start_timer(struct snd_opl3 *opl3)
255 {
256 	unsigned long flags;
257 	spin_lock_irqsave(&opl3->sys_timer_lock, flags);
258 	if (! opl3->sys_timer_status) {
259 		mod_timer(&opl3->tlist, jiffies + 1);
260 		opl3->sys_timer_status = 1;
261 	}
262 	spin_unlock_irqrestore(&opl3->sys_timer_lock, flags);
263 }
264 
265 /* ------------------------------ */
266 
267 
268 static const int snd_opl3_oss_map[MAX_OPL3_VOICES] = {
269 	0, 1, 2, 9, 10, 11, 6, 7, 8, 15, 16, 17, 3, 4 ,5, 12, 13, 14
270 };
271 
272 /*
273  * Start a note.
274  */
275 void snd_opl3_note_on(void *p, int note, int vel, struct snd_midi_channel *chan)
276 {
277 	struct snd_opl3 *opl3;
278 	int instr_4op;
279 
280 	int voice;
281 	struct snd_opl3_voice *vp, *vp2;
282 	unsigned short connect_mask;
283 	unsigned char connection;
284 	unsigned char vol_op[4];
285 
286 	int extra_prg = 0;
287 
288 	unsigned short reg_side;
289 	unsigned char op_offset;
290 	unsigned char voice_offset;
291 	unsigned short opl3_reg;
292 	unsigned char reg_val;
293 	unsigned char prg, bank;
294 
295 	int key = note;
296 	unsigned char fnum, blocknum;
297 	int i;
298 
299 	struct fm_patch *patch;
300 	struct fm_instrument *fm;
301 	unsigned long flags;
302 
303 	opl3 = p;
304 
305 #ifdef DEBUG_MIDI
306 	snd_printk(KERN_DEBUG "Note on, ch %i, inst %i, note %i, vel %i\n",
307 		   chan->number, chan->midi_program, note, vel);
308 #endif
309 
310 	/* in SYNTH mode, application takes care of voices */
311 	/* in SEQ mode, drum voice numbers are notes on drum channel */
312 	if (opl3->synth_mode == SNDRV_OPL3_MODE_SEQ) {
313 		if (chan->drum_channel) {
314 			/* percussion instruments are located in bank 128 */
315 			bank = 128;
316 			prg = note;
317 		} else {
318 			bank = chan->gm_bank_select;
319 			prg = chan->midi_program;
320 		}
321 	} else {
322 		/* Prepare for OSS mode */
323 		if (chan->number >= MAX_OPL3_VOICES)
324 			return;
325 
326 		/* OSS instruments are located in bank 127 */
327 		bank = 127;
328 		prg = chan->midi_program;
329 	}
330 
331 	spin_lock_irqsave(&opl3->voice_lock, flags);
332 
333 	if (use_internal_drums) {
334 		snd_opl3_drum_switch(opl3, note, vel, 1, chan);
335 		spin_unlock_irqrestore(&opl3->voice_lock, flags);
336 		return;
337 	}
338 
339  __extra_prg:
340 	patch = snd_opl3_find_patch(opl3, prg, bank, 0);
341 	if (!patch) {
342 		spin_unlock_irqrestore(&opl3->voice_lock, flags);
343 		return;
344 	}
345 
346 	fm = &patch->inst;
347 	switch (patch->type) {
348 	case FM_PATCH_OPL2:
349 		instr_4op = 0;
350 		break;
351 	case FM_PATCH_OPL3:
352 		if (opl3->hardware >= OPL3_HW_OPL3) {
353 			instr_4op = 1;
354 			break;
355 		}
356 		fallthrough;
357 	default:
358 		spin_unlock_irqrestore(&opl3->voice_lock, flags);
359 		return;
360 	}
361 #ifdef DEBUG_MIDI
362 	snd_printk(KERN_DEBUG "  --> OPL%i instrument: %s\n",
363 		   instr_4op ? 3 : 2, patch->name);
364 #endif
365 	/* in SYNTH mode, application takes care of voices */
366 	/* in SEQ mode, allocate voice on free OPL3 channel */
367 	if (opl3->synth_mode == SNDRV_OPL3_MODE_SEQ) {
368 		voice = opl3_get_voice(opl3, instr_4op, chan);
369 	} else {
370 		/* remap OSS voice */
371 		voice = snd_opl3_oss_map[chan->number];
372 	}
373 
374 	if (voice < 0) {
375 		spin_unlock_irqrestore(&opl3->voice_lock, flags);
376 		return;
377 	}
378 
379 	if (voice < MAX_OPL2_VOICES) {
380 		/* Left register block for voices 0 .. 8 */
381 		reg_side = OPL3_LEFT;
382 		voice_offset = voice;
383 		connect_mask = (OPL3_LEFT_4OP_0 << voice_offset) & 0x07;
384 	} else {
385 		/* Right register block for voices 9 .. 17 */
386 		reg_side = OPL3_RIGHT;
387 		voice_offset = voice - MAX_OPL2_VOICES;
388 		connect_mask = (OPL3_RIGHT_4OP_0 << voice_offset) & 0x38;
389 	}
390 
391 	/* kill voice on channel */
392 	vp = &opl3->voices[voice];
393 	if (vp->state > 0) {
394 		opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
395 		reg_val = vp->keyon_reg & ~OPL3_KEYON_BIT;
396 		opl3->command(opl3, opl3_reg, reg_val);
397 	}
398 	if (instr_4op) {
399 		vp2 = &opl3->voices[voice + 3];
400 		if (vp2->state > 0) {
401 			opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK +
402 					       voice_offset + 3);
403 			reg_val = vp->keyon_reg & ~OPL3_KEYON_BIT;
404 			opl3->command(opl3, opl3_reg, reg_val);
405 		}
406 	}
407 
408 	/* set connection register */
409 	if (instr_4op) {
410 		if ((opl3->connection_reg ^ connect_mask) & connect_mask) {
411 			opl3->connection_reg |= connect_mask;
412 			/* set connection bit */
413 			opl3_reg = OPL3_RIGHT | OPL3_REG_CONNECTION_SELECT;
414 			opl3->command(opl3, opl3_reg, opl3->connection_reg);
415 		}
416 	} else {
417 		if ((opl3->connection_reg ^ ~connect_mask) & connect_mask) {
418 			opl3->connection_reg &= ~connect_mask;
419 			/* clear connection bit */
420 			opl3_reg = OPL3_RIGHT | OPL3_REG_CONNECTION_SELECT;
421 			opl3->command(opl3, opl3_reg, opl3->connection_reg);
422 		}
423 	}
424 
425 #ifdef DEBUG_MIDI
426 	snd_printk(KERN_DEBUG "  --> setting OPL3 connection: 0x%x\n",
427 		   opl3->connection_reg);
428 #endif
429 	/*
430 	 * calculate volume depending on connection
431 	 * between FM operators (see include/opl3.h)
432 	 */
433 	for (i = 0; i < (instr_4op ? 4 : 2); i++)
434 		vol_op[i] = fm->op[i].ksl_level;
435 
436 	connection = fm->feedback_connection[0] & 0x01;
437 	if (instr_4op) {
438 		connection <<= 1;
439 		connection |= fm->feedback_connection[1] & 0x01;
440 
441 		snd_opl3_calc_volume(&vol_op[3], vel, chan);
442 		switch (connection) {
443 		case 0x03:
444 			snd_opl3_calc_volume(&vol_op[2], vel, chan);
445 			fallthrough;
446 		case 0x02:
447 			snd_opl3_calc_volume(&vol_op[0], vel, chan);
448 			break;
449 		case 0x01:
450 			snd_opl3_calc_volume(&vol_op[1], vel, chan);
451 		}
452 	} else {
453 		snd_opl3_calc_volume(&vol_op[1], vel, chan);
454 		if (connection)
455 			snd_opl3_calc_volume(&vol_op[0], vel, chan);
456 	}
457 
458 	/* Program the FM voice characteristics */
459 	for (i = 0; i < (instr_4op ? 4 : 2); i++) {
460 #ifdef DEBUG_MIDI
461 		snd_printk(KERN_DEBUG "  --> programming operator %i\n", i);
462 #endif
463 		op_offset = snd_opl3_regmap[voice_offset][i];
464 
465 		/* Set OPL3 AM_VIB register of requested voice/operator */
466 		reg_val = fm->op[i].am_vib;
467 		opl3_reg = reg_side | (OPL3_REG_AM_VIB + op_offset);
468 		opl3->command(opl3, opl3_reg, reg_val);
469 
470 		/* Set OPL3 KSL_LEVEL register of requested voice/operator */
471 		reg_val = vol_op[i];
472 		opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + op_offset);
473 		opl3->command(opl3, opl3_reg, reg_val);
474 
475 		/* Set OPL3 ATTACK_DECAY register of requested voice/operator */
476 		reg_val = fm->op[i].attack_decay;
477 		opl3_reg = reg_side | (OPL3_REG_ATTACK_DECAY + op_offset);
478 		opl3->command(opl3, opl3_reg, reg_val);
479 
480 		/* Set OPL3 SUSTAIN_RELEASE register of requested voice/operator */
481 		reg_val = fm->op[i].sustain_release;
482 		opl3_reg = reg_side | (OPL3_REG_SUSTAIN_RELEASE + op_offset);
483 		opl3->command(opl3, opl3_reg, reg_val);
484 
485 		/* Select waveform */
486 		reg_val = fm->op[i].wave_select;
487 		opl3_reg = reg_side | (OPL3_REG_WAVE_SELECT + op_offset);
488 		opl3->command(opl3, opl3_reg, reg_val);
489 	}
490 
491 	/* Set operator feedback and 2op inter-operator connection */
492 	reg_val = fm->feedback_connection[0];
493 	/* Set output voice connection */
494 	reg_val |= OPL3_STEREO_BITS;
495 	if (chan->gm_pan < 43)
496 		reg_val &= ~OPL3_VOICE_TO_RIGHT;
497 	if (chan->gm_pan > 85)
498 		reg_val &= ~OPL3_VOICE_TO_LEFT;
499 	opl3_reg = reg_side | (OPL3_REG_FEEDBACK_CONNECTION + voice_offset);
500 	opl3->command(opl3, opl3_reg, reg_val);
501 
502 	if (instr_4op) {
503 		/* Set 4op inter-operator connection */
504 		reg_val = fm->feedback_connection[1] & OPL3_CONNECTION_BIT;
505 		/* Set output voice connection */
506 		reg_val |= OPL3_STEREO_BITS;
507 		if (chan->gm_pan < 43)
508 			reg_val &= ~OPL3_VOICE_TO_RIGHT;
509 		if (chan->gm_pan > 85)
510 			reg_val &= ~OPL3_VOICE_TO_LEFT;
511 		opl3_reg = reg_side | (OPL3_REG_FEEDBACK_CONNECTION +
512 				       voice_offset + 3);
513 		opl3->command(opl3, opl3_reg, reg_val);
514 	}
515 
516 	/*
517 	 * Special treatment of percussion notes for fm:
518 	 * Requested pitch is really program, and pitch for
519 	 * device is whatever was specified in the patch library.
520 	 */
521 	if (fm->fix_key)
522 		note = fm->fix_key;
523 	/*
524 	 * use transpose if defined in patch library
525 	 */
526 	if (fm->trnsps)
527 		note += (fm->trnsps - 64);
528 
529 	snd_opl3_calc_pitch(&fnum, &blocknum, note, chan);
530 
531 	/* Set OPL3 FNUM_LOW register of requested voice */
532 	opl3_reg = reg_side | (OPL3_REG_FNUM_LOW + voice_offset);
533 	opl3->command(opl3, opl3_reg, fnum);
534 
535 	opl3->voices[voice].keyon_reg = blocknum;
536 
537 	/* Set output sound flag */
538 	blocknum |= OPL3_KEYON_BIT;
539 
540 #ifdef DEBUG_MIDI
541 	snd_printk(KERN_DEBUG "  --> trigger voice %i\n", voice);
542 #endif
543 	/* Set OPL3 KEYON_BLOCK register of requested voice */
544 	opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
545 	opl3->command(opl3, opl3_reg, blocknum);
546 
547 	/* kill note after fixed duration (in centiseconds) */
548 	if (fm->fix_dur) {
549 		opl3->voices[voice].note_off = jiffies +
550 			(fm->fix_dur * HZ) / 100;
551 		snd_opl3_start_timer(opl3);
552 		opl3->voices[voice].note_off_check = 1;
553 	} else
554 		opl3->voices[voice].note_off_check = 0;
555 
556 	/* get extra pgm, but avoid possible loops */
557 	extra_prg = (extra_prg) ? 0 : fm->modes;
558 
559 	/* do the bookkeeping */
560 	vp->time = opl3->use_time++;
561 	vp->note = key;
562 	vp->chan = chan;
563 
564 	if (instr_4op) {
565 		vp->state = SNDRV_OPL3_ST_ON_4OP;
566 
567 		vp2 = &opl3->voices[voice + 3];
568 		vp2->time = opl3->use_time++;
569 		vp2->note = key;
570 		vp2->chan = chan;
571 		vp2->state = SNDRV_OPL3_ST_NOT_AVAIL;
572 	} else {
573 		if (vp->state == SNDRV_OPL3_ST_ON_4OP) {
574 			/* 4op killed by 2op, release bounded voice */
575 			vp2 = &opl3->voices[voice + 3];
576 			vp2->time = opl3->use_time++;
577 			vp2->state = SNDRV_OPL3_ST_OFF;
578 		}
579 		vp->state = SNDRV_OPL3_ST_ON_2OP;
580 	}
581 
582 #ifdef DEBUG_ALLOC
583 	debug_alloc(opl3, "note on ", voice);
584 #endif
585 
586 	/* allocate extra program if specified in patch library */
587 	if (extra_prg) {
588 		if (extra_prg > 128) {
589 			bank = 128;
590 			/* percussions start at 35 */
591 			prg = extra_prg - 128 + 35 - 1;
592 		} else {
593 			bank = 0;
594 			prg = extra_prg - 1;
595 		}
596 #ifdef DEBUG_MIDI
597 		snd_printk(KERN_DEBUG " *** allocating extra program\n");
598 #endif
599 		goto __extra_prg;
600 	}
601 	spin_unlock_irqrestore(&opl3->voice_lock, flags);
602 }
603 
604 static void snd_opl3_kill_voice(struct snd_opl3 *opl3, int voice)
605 {
606 	unsigned short reg_side;
607 	unsigned char voice_offset;
608 	unsigned short opl3_reg;
609 
610 	struct snd_opl3_voice *vp, *vp2;
611 
612 	if (snd_BUG_ON(voice >= MAX_OPL3_VOICES))
613 		return;
614 
615 	vp = &opl3->voices[voice];
616 	if (voice < MAX_OPL2_VOICES) {
617 		/* Left register block for voices 0 .. 8 */
618 		reg_side = OPL3_LEFT;
619 		voice_offset = voice;
620 	} else {
621 		/* Right register block for voices 9 .. 17 */
622 		reg_side = OPL3_RIGHT;
623 		voice_offset = voice - MAX_OPL2_VOICES;
624 	}
625 
626 	/* kill voice */
627 #ifdef DEBUG_MIDI
628 	snd_printk(KERN_DEBUG "  --> kill voice %i\n", voice);
629 #endif
630 	opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
631 	/* clear Key ON bit */
632 	opl3->command(opl3, opl3_reg, vp->keyon_reg);
633 
634 	/* do the bookkeeping */
635 	vp->time = opl3->use_time++;
636 
637 	if (vp->state == SNDRV_OPL3_ST_ON_4OP) {
638 		vp2 = &opl3->voices[voice + 3];
639 
640 		vp2->time = opl3->use_time++;
641 		vp2->state = SNDRV_OPL3_ST_OFF;
642 	}
643 	vp->state = SNDRV_OPL3_ST_OFF;
644 #ifdef DEBUG_ALLOC
645 	debug_alloc(opl3, "note off", voice);
646 #endif
647 
648 }
649 
650 /*
651  * Release a note in response to a midi note off.
652  */
653 static void snd_opl3_note_off_unsafe(void *p, int note, int vel,
654 				     struct snd_midi_channel *chan)
655 {
656   	struct snd_opl3 *opl3;
657 
658 	int voice;
659 	struct snd_opl3_voice *vp;
660 
661 	opl3 = p;
662 
663 #ifdef DEBUG_MIDI
664 	snd_printk(KERN_DEBUG "Note off, ch %i, inst %i, note %i\n",
665 		   chan->number, chan->midi_program, note);
666 #endif
667 
668 	if (opl3->synth_mode == SNDRV_OPL3_MODE_SEQ) {
669 		if (chan->drum_channel && use_internal_drums) {
670 			snd_opl3_drum_switch(opl3, note, vel, 0, chan);
671 			return;
672 		}
673 		/* this loop will hopefully kill all extra voices, because
674 		   they are grouped by the same channel and note values */
675 		for (voice = 0; voice < opl3->max_voices; voice++) {
676 			vp = &opl3->voices[voice];
677 			if (vp->state > 0 && vp->chan == chan && vp->note == note) {
678 				snd_opl3_kill_voice(opl3, voice);
679 			}
680 		}
681 	} else {
682 		/* remap OSS voices */
683 		if (chan->number < MAX_OPL3_VOICES) {
684 			voice = snd_opl3_oss_map[chan->number];
685 			snd_opl3_kill_voice(opl3, voice);
686 		}
687 	}
688 }
689 
690 void snd_opl3_note_off(void *p, int note, int vel,
691 		       struct snd_midi_channel *chan)
692 {
693 	struct snd_opl3 *opl3 = p;
694 	unsigned long flags;
695 
696 	spin_lock_irqsave(&opl3->voice_lock, flags);
697 	snd_opl3_note_off_unsafe(p, note, vel, chan);
698 	spin_unlock_irqrestore(&opl3->voice_lock, flags);
699 }
700 
701 /*
702  * key pressure change
703  */
704 void snd_opl3_key_press(void *p, int note, int vel, struct snd_midi_channel *chan)
705 {
706 #ifdef DEBUG_MIDI
707 	snd_printk(KERN_DEBUG "Key pressure, ch#: %i, inst#: %i\n",
708 		   chan->number, chan->midi_program);
709 #endif
710 }
711 
712 /*
713  * terminate note
714  */
715 void snd_opl3_terminate_note(void *p, int note, struct snd_midi_channel *chan)
716 {
717 #ifdef DEBUG_MIDI
718 	snd_printk(KERN_DEBUG "Terminate note, ch#: %i, inst#: %i\n",
719 		   chan->number, chan->midi_program);
720 #endif
721 }
722 
723 static void snd_opl3_update_pitch(struct snd_opl3 *opl3, int voice)
724 {
725 	unsigned short reg_side;
726 	unsigned char voice_offset;
727 	unsigned short opl3_reg;
728 
729 	unsigned char fnum, blocknum;
730 
731 	struct snd_opl3_voice *vp;
732 
733 	if (snd_BUG_ON(voice >= MAX_OPL3_VOICES))
734 		return;
735 
736 	vp = &opl3->voices[voice];
737 	if (vp->chan == NULL)
738 		return; /* not allocated? */
739 
740 	if (voice < MAX_OPL2_VOICES) {
741 		/* Left register block for voices 0 .. 8 */
742 		reg_side = OPL3_LEFT;
743 		voice_offset = voice;
744 	} else {
745 		/* Right register block for voices 9 .. 17 */
746 		reg_side = OPL3_RIGHT;
747 		voice_offset = voice - MAX_OPL2_VOICES;
748 	}
749 
750 	snd_opl3_calc_pitch(&fnum, &blocknum, vp->note, vp->chan);
751 
752 	/* Set OPL3 FNUM_LOW register of requested voice */
753 	opl3_reg = reg_side | (OPL3_REG_FNUM_LOW + voice_offset);
754 	opl3->command(opl3, opl3_reg, fnum);
755 
756 	vp->keyon_reg = blocknum;
757 
758 	/* Set output sound flag */
759 	blocknum |= OPL3_KEYON_BIT;
760 
761 	/* Set OPL3 KEYON_BLOCK register of requested voice */
762 	opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
763 	opl3->command(opl3, opl3_reg, blocknum);
764 
765 	vp->time = opl3->use_time++;
766 }
767 
768 /*
769  * Update voice pitch controller
770  */
771 static void snd_opl3_pitch_ctrl(struct snd_opl3 *opl3, struct snd_midi_channel *chan)
772 {
773 	int voice;
774 	struct snd_opl3_voice *vp;
775 
776 	unsigned long flags;
777 
778 	spin_lock_irqsave(&opl3->voice_lock, flags);
779 
780 	if (opl3->synth_mode == SNDRV_OPL3_MODE_SEQ) {
781 		for (voice = 0; voice < opl3->max_voices; voice++) {
782 			vp = &opl3->voices[voice];
783 			if (vp->state > 0 && vp->chan == chan) {
784 				snd_opl3_update_pitch(opl3, voice);
785 			}
786 		}
787 	} else {
788 		/* remap OSS voices */
789 		if (chan->number < MAX_OPL3_VOICES) {
790 			voice = snd_opl3_oss_map[chan->number];
791 			snd_opl3_update_pitch(opl3, voice);
792 		}
793 	}
794 	spin_unlock_irqrestore(&opl3->voice_lock, flags);
795 }
796 
797 /*
798  * Deal with a controller type event.  This includes all types of
799  * control events, not just the midi controllers
800  */
801 void snd_opl3_control(void *p, int type, struct snd_midi_channel *chan)
802 {
803   	struct snd_opl3 *opl3;
804 
805 	opl3 = p;
806 #ifdef DEBUG_MIDI
807 	snd_printk(KERN_DEBUG "Controller, TYPE = %i, ch#: %i, inst#: %i\n",
808 		   type, chan->number, chan->midi_program);
809 #endif
810 
811 	switch (type) {
812 	case MIDI_CTL_MSB_MODWHEEL:
813 		if (chan->control[MIDI_CTL_MSB_MODWHEEL] > 63)
814 			opl3->drum_reg |= OPL3_VIBRATO_DEPTH;
815 		else
816 			opl3->drum_reg &= ~OPL3_VIBRATO_DEPTH;
817 		opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION,
818 				 opl3->drum_reg);
819 		break;
820 	case MIDI_CTL_E2_TREMOLO_DEPTH:
821 		if (chan->control[MIDI_CTL_E2_TREMOLO_DEPTH] > 63)
822 			opl3->drum_reg |= OPL3_TREMOLO_DEPTH;
823 		else
824 			opl3->drum_reg &= ~OPL3_TREMOLO_DEPTH;
825 		opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION,
826 				 opl3->drum_reg);
827 		break;
828 	case MIDI_CTL_PITCHBEND:
829 		snd_opl3_pitch_ctrl(opl3, chan);
830 		break;
831 	}
832 }
833 
834 /*
835  * NRPN events
836  */
837 void snd_opl3_nrpn(void *p, struct snd_midi_channel *chan,
838 		   struct snd_midi_channel_set *chset)
839 {
840 #ifdef DEBUG_MIDI
841 	snd_printk(KERN_DEBUG "NRPN, ch#: %i, inst#: %i\n",
842 		   chan->number, chan->midi_program);
843 #endif
844 }
845 
846 /*
847  * receive sysex
848  */
849 void snd_opl3_sysex(void *p, unsigned char *buf, int len,
850 		    int parsed, struct snd_midi_channel_set *chset)
851 {
852 #ifdef DEBUG_MIDI
853 	snd_printk(KERN_DEBUG "SYSEX\n");
854 #endif
855 }
856