xref: /openbmc/linux/sound/drivers/opl3/opl3_synth.c (revision 05c1afe7)
1 /*
2  *  Copyright (c) by Uros Bizjak <uros@kss-loka.si>
3  *
4  *  Routines for OPL2/OPL3/OPL4 control
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  *
16  *   You should have received a copy of the GNU General Public License
17  *   along with this program; if not, write to the Free Software
18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  *
20  */
21 
22 #include <sound/opl3.h>
23 #include <sound/asound_fm.h>
24 
25 /*
26  *    There is 18 possible 2 OP voices
27  *      (9 in the left and 9 in the right).
28  *      The first OP is the modulator and 2nd is the carrier.
29  *
30  *      The first three voices in the both sides may be connected
31  *      with another voice to a 4 OP voice. For example voice 0
32  *      can be connected with voice 3. The operators of voice 3 are
33  *      used as operators 3 and 4 of the new 4 OP voice.
34  *      In this case the 2 OP voice number 0 is the 'first half' and
35  *      voice 3 is the second.
36  */
37 
38 
39 /*
40  *    Register offset table for OPL2/3 voices,
41  *    OPL2 / one OPL3 register array side only
42  */
43 
44 char snd_opl3_regmap[MAX_OPL2_VOICES][4] =
45 {
46 /*	  OP1   OP2   OP3   OP4		*/
47 /*	 ------------------------	*/
48 	{ 0x00, 0x03, 0x08, 0x0b },
49 	{ 0x01, 0x04, 0x09, 0x0c },
50 	{ 0x02, 0x05, 0x0a, 0x0d },
51 
52 	{ 0x08, 0x0b, 0x00, 0x00 },
53 	{ 0x09, 0x0c, 0x00, 0x00 },
54 	{ 0x0a, 0x0d, 0x00, 0x00 },
55 
56 	{ 0x10, 0x13, 0x00, 0x00 },	/* used by percussive voices */
57 	{ 0x11, 0x14, 0x00, 0x00 },	/* if the percussive mode */
58 	{ 0x12, 0x15, 0x00, 0x00 }	/* is selected (only left reg block) */
59 };
60 
61 EXPORT_SYMBOL(snd_opl3_regmap);
62 
63 /*
64  * prototypes
65  */
66 static int snd_opl3_play_note(struct snd_opl3 * opl3, struct snd_dm_fm_note * note);
67 static int snd_opl3_set_voice(struct snd_opl3 * opl3, struct snd_dm_fm_voice * voice);
68 static int snd_opl3_set_params(struct snd_opl3 * opl3, struct snd_dm_fm_params * params);
69 static int snd_opl3_set_mode(struct snd_opl3 * opl3, int mode);
70 static int snd_opl3_set_connection(struct snd_opl3 * opl3, int connection);
71 
72 /* ------------------------------ */
73 
74 /*
75  * open the device exclusively
76  */
77 int snd_opl3_open(struct snd_hwdep * hw, struct file *file)
78 {
79 	return 0;
80 }
81 
82 /*
83  * ioctl for hwdep device:
84  */
85 int snd_opl3_ioctl(struct snd_hwdep * hw, struct file *file,
86 		   unsigned int cmd, unsigned long arg)
87 {
88 	struct snd_opl3 *opl3 = hw->private_data;
89 	void __user *argp = (void __user *)arg;
90 
91 	snd_assert(opl3 != NULL, return -EINVAL);
92 
93 	switch (cmd) {
94 		/* get information */
95 	case SNDRV_DM_FM_IOCTL_INFO:
96 		{
97 			struct snd_dm_fm_info info;
98 
99 			info.fm_mode = opl3->fm_mode;
100 			info.rhythm = opl3->rhythm;
101 			if (copy_to_user(argp, &info, sizeof(struct snd_dm_fm_info)))
102 				return -EFAULT;
103 			return 0;
104 		}
105 
106 	case SNDRV_DM_FM_IOCTL_RESET:
107 #ifdef CONFIG_SND_OSSEMUL
108 	case SNDRV_DM_FM_OSS_IOCTL_RESET:
109 #endif
110 		snd_opl3_reset(opl3);
111 		return 0;
112 
113 	case SNDRV_DM_FM_IOCTL_PLAY_NOTE:
114 #ifdef CONFIG_SND_OSSEMUL
115 	case SNDRV_DM_FM_OSS_IOCTL_PLAY_NOTE:
116 #endif
117 		{
118 			struct snd_dm_fm_note note;
119 			if (copy_from_user(&note, argp, sizeof(struct snd_dm_fm_note)))
120 				return -EFAULT;
121 			return snd_opl3_play_note(opl3, &note);
122 		}
123 
124 	case SNDRV_DM_FM_IOCTL_SET_VOICE:
125 #ifdef CONFIG_SND_OSSEMUL
126 	case SNDRV_DM_FM_OSS_IOCTL_SET_VOICE:
127 #endif
128 		{
129 			struct snd_dm_fm_voice voice;
130 			if (copy_from_user(&voice, argp, sizeof(struct snd_dm_fm_voice)))
131 				return -EFAULT;
132 			return snd_opl3_set_voice(opl3, &voice);
133 		}
134 
135 	case SNDRV_DM_FM_IOCTL_SET_PARAMS:
136 #ifdef CONFIG_SND_OSSEMUL
137 	case SNDRV_DM_FM_OSS_IOCTL_SET_PARAMS:
138 #endif
139 		{
140 			struct snd_dm_fm_params params;
141 			if (copy_from_user(&params, argp, sizeof(struct snd_dm_fm_params)))
142 				return -EFAULT;
143 			return snd_opl3_set_params(opl3, &params);
144 		}
145 
146 	case SNDRV_DM_FM_IOCTL_SET_MODE:
147 #ifdef CONFIG_SND_OSSEMUL
148 	case SNDRV_DM_FM_OSS_IOCTL_SET_MODE:
149 #endif
150 		return snd_opl3_set_mode(opl3, (int) arg);
151 
152 	case SNDRV_DM_FM_IOCTL_SET_CONNECTION:
153 #ifdef CONFIG_SND_OSSEMUL
154 	case SNDRV_DM_FM_OSS_IOCTL_SET_OPL:
155 #endif
156 		return snd_opl3_set_connection(opl3, (int) arg);
157 
158 	case SNDRV_DM_FM_IOCTL_CLEAR_PATCHES:
159 		snd_opl3_clear_patches(opl3);
160 		return 0;
161 
162 #ifdef CONFIG_SND_DEBUG
163 	default:
164 		snd_printk("unknown IOCTL: 0x%x\n", cmd);
165 #endif
166 	}
167 	return -ENOTTY;
168 }
169 
170 /*
171  * close the device
172  */
173 int snd_opl3_release(struct snd_hwdep * hw, struct file *file)
174 {
175 	struct snd_opl3 *opl3 = hw->private_data;
176 
177 	snd_opl3_reset(opl3);
178 	return 0;
179 }
180 
181 /*
182  * write the device - load patches
183  */
184 long snd_opl3_write(struct snd_hwdep *hw, const char __user *buf, long count,
185 		    loff_t *offset)
186 {
187 	struct snd_opl3 *opl3 = hw->private_data;
188 	long result = 0;
189 	int err = 0;
190 	struct sbi_patch inst;
191 
192 	while (count >= sizeof(inst)) {
193 		unsigned char type;
194 		if (copy_from_user(&inst, buf, sizeof(inst)))
195 			return -EFAULT;
196 		if (!memcmp(inst.key, FM_KEY_SBI, 4) ||
197 		    !memcmp(inst.key, FM_KEY_2OP, 4))
198 			type = FM_PATCH_OPL2;
199 		else if (!memcmp(inst.key, FM_KEY_4OP, 4))
200 			type = FM_PATCH_OPL3;
201 		else /* invalid type */
202 			break;
203 		err = snd_opl3_load_patch(opl3, inst.prog, inst.bank, type,
204 					  inst.name, inst.extension,
205 					  inst.data);
206 		if (err < 0)
207 			break;
208 		result += sizeof(inst);
209 		count -= sizeof(inst);
210 	}
211 	return result > 0 ? result : err;
212 }
213 
214 
215 /*
216  * Patch management
217  */
218 
219 /* offsets for SBI params */
220 #define AM_VIB		0
221 #define KSL_LEVEL	2
222 #define ATTACK_DECAY	4
223 #define SUSTAIN_RELEASE	6
224 #define WAVE_SELECT	8
225 
226 /* offset for SBI instrument */
227 #define CONNECTION	10
228 #define OFFSET_4OP	11
229 
230 /*
231  * load a patch, obviously.
232  *
233  * loaded on the given program and bank numbers with the given type
234  * (FM_PATCH_OPLx).
235  * data is the pointer of SBI record _without_ header (key and name).
236  * name is the name string of the patch.
237  * ext is the extension data of 7 bytes long (stored in name of SBI
238  * data up to offset 25), or NULL to skip.
239  * return 0 if successful or a negative error code.
240  */
241 int snd_opl3_load_patch(struct snd_opl3 *opl3,
242 			int prog, int bank, int type,
243 			const char *name,
244 			const unsigned char *ext,
245 			const unsigned char *data)
246 {
247 	struct fm_patch *patch;
248 	int i;
249 
250 	patch = snd_opl3_find_patch(opl3, prog, bank, 1);
251 	if (!patch)
252 		return -ENOMEM;
253 
254 	patch->type = type;
255 
256 	for (i = 0; i < 2; i++) {
257 		patch->inst.op[i].am_vib = data[AM_VIB + i];
258 		patch->inst.op[i].ksl_level = data[KSL_LEVEL + i];
259 		patch->inst.op[i].attack_decay = data[ATTACK_DECAY + i];
260 		patch->inst.op[i].sustain_release = data[SUSTAIN_RELEASE + i];
261 		patch->inst.op[i].wave_select = data[WAVE_SELECT + i];
262 	}
263 	patch->inst.feedback_connection[0] = data[CONNECTION];
264 
265 	if (type == FM_PATCH_OPL3) {
266 		for (i = 0; i < 2; i++) {
267 			patch->inst.op[i+2].am_vib =
268 				data[OFFSET_4OP + AM_VIB + i];
269 			patch->inst.op[i+2].ksl_level =
270 				data[OFFSET_4OP + KSL_LEVEL + i];
271 			patch->inst.op[i+2].attack_decay =
272 				data[OFFSET_4OP + ATTACK_DECAY + i];
273 			patch->inst.op[i+2].sustain_release =
274 				data[OFFSET_4OP + SUSTAIN_RELEASE + i];
275 			patch->inst.op[i+2].wave_select =
276 				data[OFFSET_4OP + WAVE_SELECT + i];
277 		}
278 		patch->inst.feedback_connection[1] =
279 			data[OFFSET_4OP + CONNECTION];
280 	}
281 
282 	if (ext) {
283 		patch->inst.echo_delay = ext[0];
284 		patch->inst.echo_atten = ext[1];
285 		patch->inst.chorus_spread = ext[2];
286 		patch->inst.trnsps = ext[3];
287 		patch->inst.fix_dur = ext[4];
288 		patch->inst.modes = ext[5];
289 		patch->inst.fix_key = ext[6];
290 	}
291 
292 	if (name)
293 		strlcpy(patch->name, name, sizeof(patch->name));
294 
295 	return 0;
296 }
297 EXPORT_SYMBOL(snd_opl3_load_patch);
298 
299 /*
300  * find a patch with the given program and bank numbers, returns its pointer
301  * if no matching patch is found and create_patch is set, it creates a
302  * new patch object.
303  */
304 struct fm_patch *snd_opl3_find_patch(struct snd_opl3 *opl3, int prog, int bank,
305 				     int create_patch)
306 {
307 	/* pretty dumb hash key */
308 	unsigned int key = (prog + bank) % OPL3_PATCH_HASH_SIZE;
309 	struct fm_patch *patch;
310 
311 	for (patch = opl3->patch_table[key]; patch; patch = patch->next) {
312 		if (patch->prog == prog && patch->bank == bank)
313 			return patch;
314 	}
315 	if (!create_patch)
316 		return NULL;
317 
318 	patch = kzalloc(sizeof(*patch), GFP_KERNEL);
319 	if (!patch)
320 		return NULL;
321 	patch->prog = prog;
322 	patch->bank = bank;
323 	patch->next = opl3->patch_table[key];
324 	opl3->patch_table[key] = patch;
325 	return patch;
326 }
327 EXPORT_SYMBOL(snd_opl3_find_patch);
328 
329 /*
330  * Clear all patches of the given OPL3 instance
331  */
332 void snd_opl3_clear_patches(struct snd_opl3 *opl3)
333 {
334 	int i;
335 	for (i = 0; i <  OPL3_PATCH_HASH_SIZE; i++) {
336 		struct fm_patch *patch, *next;
337 		for (patch = opl3->patch_table[i]; patch; patch = next) {
338 			next = patch->next;
339 			kfree(patch);
340 		}
341 	}
342 	memset(opl3->patch_table, 0, sizeof(opl3->patch_table));
343 }
344 
345 /* ------------------------------ */
346 
347 void snd_opl3_reset(struct snd_opl3 * opl3)
348 {
349 	unsigned short opl3_reg;
350 
351 	unsigned short reg_side;
352 	unsigned char voice_offset;
353 
354 	int max_voices, i;
355 
356 	max_voices = (opl3->hardware < OPL3_HW_OPL3) ?
357 		MAX_OPL2_VOICES : MAX_OPL3_VOICES;
358 
359 	for (i = 0; i < max_voices; i++) {
360 		/* Get register array side and offset of voice */
361 		if (i < MAX_OPL2_VOICES) {
362 			/* Left register block for voices 0 .. 8 */
363 			reg_side = OPL3_LEFT;
364 			voice_offset = i;
365 		} else {
366 			/* Right register block for voices 9 .. 17 */
367 			reg_side = OPL3_RIGHT;
368 			voice_offset = i - MAX_OPL2_VOICES;
369 		}
370 		opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + snd_opl3_regmap[voice_offset][0]);
371 		opl3->command(opl3, opl3_reg, OPL3_TOTAL_LEVEL_MASK); /* Operator 1 volume */
372 		opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + snd_opl3_regmap[voice_offset][1]);
373 		opl3->command(opl3, opl3_reg, OPL3_TOTAL_LEVEL_MASK); /* Operator 2 volume */
374 
375 		opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
376 		opl3->command(opl3, opl3_reg, 0x00);	/* Note off */
377 	}
378 
379 	opl3->max_voices = MAX_OPL2_VOICES;
380 	opl3->fm_mode = SNDRV_DM_FM_MODE_OPL2;
381 
382 	opl3->command(opl3, OPL3_LEFT | OPL3_REG_TEST, OPL3_ENABLE_WAVE_SELECT);
383 	opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION, 0x00);	/* Melodic mode */
384 	opl3->rhythm = 0;
385 }
386 
387 EXPORT_SYMBOL(snd_opl3_reset);
388 
389 static int snd_opl3_play_note(struct snd_opl3 * opl3, struct snd_dm_fm_note * note)
390 {
391 	unsigned short reg_side;
392 	unsigned char voice_offset;
393 
394 	unsigned short opl3_reg;
395 	unsigned char reg_val;
396 
397 	/* Voices 0 -  8 in OPL2 mode */
398 	/* Voices 0 - 17 in OPL3 mode */
399 	if (note->voice >= ((opl3->fm_mode == SNDRV_DM_FM_MODE_OPL3) ?
400 			    MAX_OPL3_VOICES : MAX_OPL2_VOICES))
401 		return -EINVAL;
402 
403 	/* Get register array side and offset of voice */
404 	if (note->voice < MAX_OPL2_VOICES) {
405 		/* Left register block for voices 0 .. 8 */
406 		reg_side = OPL3_LEFT;
407 		voice_offset = note->voice;
408 	} else {
409 		/* Right register block for voices 9 .. 17 */
410 		reg_side = OPL3_RIGHT;
411 		voice_offset = note->voice - MAX_OPL2_VOICES;
412 	}
413 
414 	/* Set lower 8 bits of note frequency */
415 	reg_val = (unsigned char) note->fnum;
416 	opl3_reg = reg_side | (OPL3_REG_FNUM_LOW + voice_offset);
417 	opl3->command(opl3, opl3_reg, reg_val);
418 
419 	reg_val = 0x00;
420 	/* Set output sound flag */
421 	if (note->key_on)
422 		reg_val |= OPL3_KEYON_BIT;
423 	/* Set octave */
424 	reg_val |= (note->octave << 2) & OPL3_BLOCKNUM_MASK;
425 	/* Set higher 2 bits of note frequency */
426 	reg_val |= (unsigned char) (note->fnum >> 8) & OPL3_FNUM_HIGH_MASK;
427 
428 	/* Set OPL3 KEYON_BLOCK register of requested voice */
429 	opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
430 	opl3->command(opl3, opl3_reg, reg_val);
431 
432 	return 0;
433 }
434 
435 
436 static int snd_opl3_set_voice(struct snd_opl3 * opl3, struct snd_dm_fm_voice * voice)
437 {
438 	unsigned short reg_side;
439 	unsigned char op_offset;
440 	unsigned char voice_offset;
441 
442 	unsigned short opl3_reg;
443 	unsigned char reg_val;
444 
445 	/* Only operators 1 and 2 */
446 	if (voice->op > 1)
447 		return -EINVAL;
448 	/* Voices 0 -  8 in OPL2 mode */
449 	/* Voices 0 - 17 in OPL3 mode */
450 	if (voice->voice >= ((opl3->fm_mode == SNDRV_DM_FM_MODE_OPL3) ?
451 			     MAX_OPL3_VOICES : MAX_OPL2_VOICES))
452 		return -EINVAL;
453 
454 	/* Get register array side and offset of voice */
455 	if (voice->voice < MAX_OPL2_VOICES) {
456 		/* Left register block for voices 0 .. 8 */
457 		reg_side = OPL3_LEFT;
458 		voice_offset = voice->voice;
459 	} else {
460 		/* Right register block for voices 9 .. 17 */
461 		reg_side = OPL3_RIGHT;
462 		voice_offset = voice->voice - MAX_OPL2_VOICES;
463 	}
464 	/* Get register offset of operator */
465 	op_offset = snd_opl3_regmap[voice_offset][voice->op];
466 
467 	reg_val = 0x00;
468 	/* Set amplitude modulation (tremolo) effect */
469 	if (voice->am)
470 		reg_val |= OPL3_TREMOLO_ON;
471 	/* Set vibrato effect */
472 	if (voice->vibrato)
473 		reg_val |= OPL3_VIBRATO_ON;
474 	/* Set sustaining sound phase */
475 	if (voice->do_sustain)
476 		reg_val |= OPL3_SUSTAIN_ON;
477 	/* Set keyboard scaling bit */
478 	if (voice->kbd_scale)
479 		reg_val |= OPL3_KSR;
480 	/* Set harmonic or frequency multiplier */
481 	reg_val |= voice->harmonic & OPL3_MULTIPLE_MASK;
482 
483 	/* Set OPL3 AM_VIB register of requested voice/operator */
484 	opl3_reg = reg_side | (OPL3_REG_AM_VIB + op_offset);
485 	opl3->command(opl3, opl3_reg, reg_val);
486 
487 	/* Set decreasing volume of higher notes */
488 	reg_val = (voice->scale_level << 6) & OPL3_KSL_MASK;
489 	/* Set output volume */
490 	reg_val |= ~voice->volume & OPL3_TOTAL_LEVEL_MASK;
491 
492 	/* Set OPL3 KSL_LEVEL register of requested voice/operator */
493 	opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + op_offset);
494 	opl3->command(opl3, opl3_reg, reg_val);
495 
496 	/* Set attack phase level */
497 	reg_val = (voice->attack << 4) & OPL3_ATTACK_MASK;
498 	/* Set decay phase level */
499 	reg_val |= voice->decay & OPL3_DECAY_MASK;
500 
501 	/* Set OPL3 ATTACK_DECAY register of requested voice/operator */
502 	opl3_reg = reg_side | (OPL3_REG_ATTACK_DECAY + op_offset);
503 	opl3->command(opl3, opl3_reg, reg_val);
504 
505 	/* Set sustain phase level */
506 	reg_val = (voice->sustain << 4) & OPL3_SUSTAIN_MASK;
507 	/* Set release phase level */
508 	reg_val |= voice->release & OPL3_RELEASE_MASK;
509 
510 	/* Set OPL3 SUSTAIN_RELEASE register of requested voice/operator */
511 	opl3_reg = reg_side | (OPL3_REG_SUSTAIN_RELEASE + op_offset);
512 	opl3->command(opl3, opl3_reg, reg_val);
513 
514 	/* Set inter-operator feedback */
515 	reg_val = (voice->feedback << 1) & OPL3_FEEDBACK_MASK;
516 	/* Set inter-operator connection */
517 	if (voice->connection)
518 		reg_val |= OPL3_CONNECTION_BIT;
519 	/* OPL-3 only */
520 	if (opl3->fm_mode == SNDRV_DM_FM_MODE_OPL3) {
521 		if (voice->left)
522 			reg_val |= OPL3_VOICE_TO_LEFT;
523 		if (voice->right)
524 			reg_val |= OPL3_VOICE_TO_RIGHT;
525 	}
526 	/* Feedback/connection bits are applicable to voice */
527 	opl3_reg = reg_side | (OPL3_REG_FEEDBACK_CONNECTION + voice_offset);
528 	opl3->command(opl3, opl3_reg, reg_val);
529 
530 	/* Select waveform */
531 	reg_val = voice->waveform & OPL3_WAVE_SELECT_MASK;
532 	opl3_reg = reg_side | (OPL3_REG_WAVE_SELECT + op_offset);
533 	opl3->command(opl3, opl3_reg, reg_val);
534 
535 	return 0;
536 }
537 
538 static int snd_opl3_set_params(struct snd_opl3 * opl3, struct snd_dm_fm_params * params)
539 {
540 	unsigned char reg_val;
541 
542 	reg_val = 0x00;
543 	/* Set keyboard split method */
544 	if (params->kbd_split)
545 		reg_val |= OPL3_KEYBOARD_SPLIT;
546 	opl3->command(opl3, OPL3_LEFT | OPL3_REG_KBD_SPLIT, reg_val);
547 
548 	reg_val = 0x00;
549 	/* Set amplitude modulation (tremolo) depth */
550 	if (params->am_depth)
551 		reg_val |= OPL3_TREMOLO_DEPTH;
552 	/* Set vibrato depth */
553 	if (params->vib_depth)
554 		reg_val |= OPL3_VIBRATO_DEPTH;
555 	/* Set percussion mode */
556 	if (params->rhythm) {
557 		reg_val |= OPL3_PERCUSSION_ENABLE;
558 		opl3->rhythm = 1;
559 	} else {
560 		opl3->rhythm = 0;
561 	}
562 	/* Play percussion instruments */
563 	if (params->bass)
564 		reg_val |= OPL3_BASSDRUM_ON;
565 	if (params->snare)
566 		reg_val |= OPL3_SNAREDRUM_ON;
567 	if (params->tomtom)
568 		reg_val |= OPL3_TOMTOM_ON;
569 	if (params->cymbal)
570 		reg_val |= OPL3_CYMBAL_ON;
571 	if (params->hihat)
572 		reg_val |= OPL3_HIHAT_ON;
573 
574 	opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION, reg_val);
575 	return 0;
576 }
577 
578 static int snd_opl3_set_mode(struct snd_opl3 * opl3, int mode)
579 {
580 	if ((mode == SNDRV_DM_FM_MODE_OPL3) && (opl3->hardware < OPL3_HW_OPL3))
581 		return -EINVAL;
582 
583 	opl3->fm_mode = mode;
584 	if (opl3->hardware >= OPL3_HW_OPL3)
585 		opl3->command(opl3, OPL3_RIGHT | OPL3_REG_CONNECTION_SELECT, 0x00);	/* Clear 4-op connections */
586 
587 	return 0;
588 }
589 
590 static int snd_opl3_set_connection(struct snd_opl3 * opl3, int connection)
591 {
592 	unsigned char reg_val;
593 
594 	/* OPL-3 only */
595 	if (opl3->fm_mode != SNDRV_DM_FM_MODE_OPL3)
596 		return -EINVAL;
597 
598 	reg_val = connection & (OPL3_RIGHT_4OP_0 | OPL3_RIGHT_4OP_1 | OPL3_RIGHT_4OP_2 |
599 				OPL3_LEFT_4OP_0 | OPL3_LEFT_4OP_1 | OPL3_LEFT_4OP_2);
600 	/* Set 4-op connections */
601 	opl3->command(opl3, OPL3_RIGHT | OPL3_REG_CONNECTION_SELECT, reg_val);
602 
603 	return 0;
604 }
605 
606