xref: /openbmc/linux/sound/drivers/opl3/opl3_synth.c (revision f42b3800)
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 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
26 #define OPL3_SUPPORT_SYNTH
27 #endif
28 
29 /*
30  *    There is 18 possible 2 OP voices
31  *      (9 in the left and 9 in the right).
32  *      The first OP is the modulator and 2nd is the carrier.
33  *
34  *      The first three voices in the both sides may be connected
35  *      with another voice to a 4 OP voice. For example voice 0
36  *      can be connected with voice 3. The operators of voice 3 are
37  *      used as operators 3 and 4 of the new 4 OP voice.
38  *      In this case the 2 OP voice number 0 is the 'first half' and
39  *      voice 3 is the second.
40  */
41 
42 
43 /*
44  *    Register offset table for OPL2/3 voices,
45  *    OPL2 / one OPL3 register array side only
46  */
47 
48 char snd_opl3_regmap[MAX_OPL2_VOICES][4] =
49 {
50 /*	  OP1   OP2   OP3   OP4		*/
51 /*	 ------------------------	*/
52 	{ 0x00, 0x03, 0x08, 0x0b },
53 	{ 0x01, 0x04, 0x09, 0x0c },
54 	{ 0x02, 0x05, 0x0a, 0x0d },
55 
56 	{ 0x08, 0x0b, 0x00, 0x00 },
57 	{ 0x09, 0x0c, 0x00, 0x00 },
58 	{ 0x0a, 0x0d, 0x00, 0x00 },
59 
60 	{ 0x10, 0x13, 0x00, 0x00 },	/* used by percussive voices */
61 	{ 0x11, 0x14, 0x00, 0x00 },	/* if the percussive mode */
62 	{ 0x12, 0x15, 0x00, 0x00 }	/* is selected (only left reg block) */
63 };
64 
65 EXPORT_SYMBOL(snd_opl3_regmap);
66 
67 /*
68  * prototypes
69  */
70 static int snd_opl3_play_note(struct snd_opl3 * opl3, struct snd_dm_fm_note * note);
71 static int snd_opl3_set_voice(struct snd_opl3 * opl3, struct snd_dm_fm_voice * voice);
72 static int snd_opl3_set_params(struct snd_opl3 * opl3, struct snd_dm_fm_params * params);
73 static int snd_opl3_set_mode(struct snd_opl3 * opl3, int mode);
74 static int snd_opl3_set_connection(struct snd_opl3 * opl3, int connection);
75 
76 /* ------------------------------ */
77 
78 /*
79  * open the device exclusively
80  */
81 int snd_opl3_open(struct snd_hwdep * hw, struct file *file)
82 {
83 	return 0;
84 }
85 
86 /*
87  * ioctl for hwdep device:
88  */
89 int snd_opl3_ioctl(struct snd_hwdep * hw, struct file *file,
90 		   unsigned int cmd, unsigned long arg)
91 {
92 	struct snd_opl3 *opl3 = hw->private_data;
93 	void __user *argp = (void __user *)arg;
94 
95 	snd_assert(opl3 != NULL, return -EINVAL);
96 
97 	switch (cmd) {
98 		/* get information */
99 	case SNDRV_DM_FM_IOCTL_INFO:
100 		{
101 			struct snd_dm_fm_info info;
102 
103 			info.fm_mode = opl3->fm_mode;
104 			info.rhythm = opl3->rhythm;
105 			if (copy_to_user(argp, &info, sizeof(struct snd_dm_fm_info)))
106 				return -EFAULT;
107 			return 0;
108 		}
109 
110 	case SNDRV_DM_FM_IOCTL_RESET:
111 #ifdef CONFIG_SND_OSSEMUL
112 	case SNDRV_DM_FM_OSS_IOCTL_RESET:
113 #endif
114 		snd_opl3_reset(opl3);
115 		return 0;
116 
117 	case SNDRV_DM_FM_IOCTL_PLAY_NOTE:
118 #ifdef CONFIG_SND_OSSEMUL
119 	case SNDRV_DM_FM_OSS_IOCTL_PLAY_NOTE:
120 #endif
121 		{
122 			struct snd_dm_fm_note note;
123 			if (copy_from_user(&note, argp, sizeof(struct snd_dm_fm_note)))
124 				return -EFAULT;
125 			return snd_opl3_play_note(opl3, &note);
126 		}
127 
128 	case SNDRV_DM_FM_IOCTL_SET_VOICE:
129 #ifdef CONFIG_SND_OSSEMUL
130 	case SNDRV_DM_FM_OSS_IOCTL_SET_VOICE:
131 #endif
132 		{
133 			struct snd_dm_fm_voice voice;
134 			if (copy_from_user(&voice, argp, sizeof(struct snd_dm_fm_voice)))
135 				return -EFAULT;
136 			return snd_opl3_set_voice(opl3, &voice);
137 		}
138 
139 	case SNDRV_DM_FM_IOCTL_SET_PARAMS:
140 #ifdef CONFIG_SND_OSSEMUL
141 	case SNDRV_DM_FM_OSS_IOCTL_SET_PARAMS:
142 #endif
143 		{
144 			struct snd_dm_fm_params params;
145 			if (copy_from_user(&params, argp, sizeof(struct snd_dm_fm_params)))
146 				return -EFAULT;
147 			return snd_opl3_set_params(opl3, &params);
148 		}
149 
150 	case SNDRV_DM_FM_IOCTL_SET_MODE:
151 #ifdef CONFIG_SND_OSSEMUL
152 	case SNDRV_DM_FM_OSS_IOCTL_SET_MODE:
153 #endif
154 		return snd_opl3_set_mode(opl3, (int) arg);
155 
156 	case SNDRV_DM_FM_IOCTL_SET_CONNECTION:
157 #ifdef CONFIG_SND_OSSEMUL
158 	case SNDRV_DM_FM_OSS_IOCTL_SET_OPL:
159 #endif
160 		return snd_opl3_set_connection(opl3, (int) arg);
161 
162 #ifdef OPL3_SUPPORT_SYNTH
163 	case SNDRV_DM_FM_IOCTL_CLEAR_PATCHES:
164 		snd_opl3_clear_patches(opl3);
165 		return 0;
166 #endif
167 
168 #ifdef CONFIG_SND_DEBUG
169 	default:
170 		snd_printk("unknown IOCTL: 0x%x\n", cmd);
171 #endif
172 	}
173 	return -ENOTTY;
174 }
175 
176 /*
177  * close the device
178  */
179 int snd_opl3_release(struct snd_hwdep * hw, struct file *file)
180 {
181 	struct snd_opl3 *opl3 = hw->private_data;
182 
183 	snd_opl3_reset(opl3);
184 	return 0;
185 }
186 
187 #ifdef OPL3_SUPPORT_SYNTH
188 /*
189  * write the device - load patches
190  */
191 long snd_opl3_write(struct snd_hwdep *hw, const char __user *buf, long count,
192 		    loff_t *offset)
193 {
194 	struct snd_opl3 *opl3 = hw->private_data;
195 	long result = 0;
196 	int err = 0;
197 	struct sbi_patch inst;
198 
199 	while (count >= sizeof(inst)) {
200 		unsigned char type;
201 		if (copy_from_user(&inst, buf, sizeof(inst)))
202 			return -EFAULT;
203 		if (!memcmp(inst.key, FM_KEY_SBI, 4) ||
204 		    !memcmp(inst.key, FM_KEY_2OP, 4))
205 			type = FM_PATCH_OPL2;
206 		else if (!memcmp(inst.key, FM_KEY_4OP, 4))
207 			type = FM_PATCH_OPL3;
208 		else /* invalid type */
209 			break;
210 		err = snd_opl3_load_patch(opl3, inst.prog, inst.bank, type,
211 					  inst.name, inst.extension,
212 					  inst.data);
213 		if (err < 0)
214 			break;
215 		result += sizeof(inst);
216 		count -= sizeof(inst);
217 	}
218 	return result > 0 ? result : err;
219 }
220 
221 
222 /*
223  * Patch management
224  */
225 
226 /* offsets for SBI params */
227 #define AM_VIB		0
228 #define KSL_LEVEL	2
229 #define ATTACK_DECAY	4
230 #define SUSTAIN_RELEASE	6
231 #define WAVE_SELECT	8
232 
233 /* offset for SBI instrument */
234 #define CONNECTION	10
235 #define OFFSET_4OP	11
236 
237 /*
238  * load a patch, obviously.
239  *
240  * loaded on the given program and bank numbers with the given type
241  * (FM_PATCH_OPLx).
242  * data is the pointer of SBI record _without_ header (key and name).
243  * name is the name string of the patch.
244  * ext is the extension data of 7 bytes long (stored in name of SBI
245  * data up to offset 25), or NULL to skip.
246  * return 0 if successful or a negative error code.
247  */
248 int snd_opl3_load_patch(struct snd_opl3 *opl3,
249 			int prog, int bank, int type,
250 			const char *name,
251 			const unsigned char *ext,
252 			const unsigned char *data)
253 {
254 	struct fm_patch *patch;
255 	int i;
256 
257 	patch = snd_opl3_find_patch(opl3, prog, bank, 1);
258 	if (!patch)
259 		return -ENOMEM;
260 
261 	patch->type = type;
262 
263 	for (i = 0; i < 2; i++) {
264 		patch->inst.op[i].am_vib = data[AM_VIB + i];
265 		patch->inst.op[i].ksl_level = data[KSL_LEVEL + i];
266 		patch->inst.op[i].attack_decay = data[ATTACK_DECAY + i];
267 		patch->inst.op[i].sustain_release = data[SUSTAIN_RELEASE + i];
268 		patch->inst.op[i].wave_select = data[WAVE_SELECT + i];
269 	}
270 	patch->inst.feedback_connection[0] = data[CONNECTION];
271 
272 	if (type == FM_PATCH_OPL3) {
273 		for (i = 0; i < 2; i++) {
274 			patch->inst.op[i+2].am_vib =
275 				data[OFFSET_4OP + AM_VIB + i];
276 			patch->inst.op[i+2].ksl_level =
277 				data[OFFSET_4OP + KSL_LEVEL + i];
278 			patch->inst.op[i+2].attack_decay =
279 				data[OFFSET_4OP + ATTACK_DECAY + i];
280 			patch->inst.op[i+2].sustain_release =
281 				data[OFFSET_4OP + SUSTAIN_RELEASE + i];
282 			patch->inst.op[i+2].wave_select =
283 				data[OFFSET_4OP + WAVE_SELECT + i];
284 		}
285 		patch->inst.feedback_connection[1] =
286 			data[OFFSET_4OP + CONNECTION];
287 	}
288 
289 	if (ext) {
290 		patch->inst.echo_delay = ext[0];
291 		patch->inst.echo_atten = ext[1];
292 		patch->inst.chorus_spread = ext[2];
293 		patch->inst.trnsps = ext[3];
294 		patch->inst.fix_dur = ext[4];
295 		patch->inst.modes = ext[5];
296 		patch->inst.fix_key = ext[6];
297 	}
298 
299 	if (name)
300 		strlcpy(patch->name, name, sizeof(patch->name));
301 
302 	return 0;
303 }
304 EXPORT_SYMBOL(snd_opl3_load_patch);
305 
306 /*
307  * find a patch with the given program and bank numbers, returns its pointer
308  * if no matching patch is found and create_patch is set, it creates a
309  * new patch object.
310  */
311 struct fm_patch *snd_opl3_find_patch(struct snd_opl3 *opl3, int prog, int bank,
312 				     int create_patch)
313 {
314 	/* pretty dumb hash key */
315 	unsigned int key = (prog + bank) % OPL3_PATCH_HASH_SIZE;
316 	struct fm_patch *patch;
317 
318 	for (patch = opl3->patch_table[key]; patch; patch = patch->next) {
319 		if (patch->prog == prog && patch->bank == bank)
320 			return patch;
321 	}
322 	if (!create_patch)
323 		return NULL;
324 
325 	patch = kzalloc(sizeof(*patch), GFP_KERNEL);
326 	if (!patch)
327 		return NULL;
328 	patch->prog = prog;
329 	patch->bank = bank;
330 	patch->next = opl3->patch_table[key];
331 	opl3->patch_table[key] = patch;
332 	return patch;
333 }
334 EXPORT_SYMBOL(snd_opl3_find_patch);
335 
336 /*
337  * Clear all patches of the given OPL3 instance
338  */
339 void snd_opl3_clear_patches(struct snd_opl3 *opl3)
340 {
341 	int i;
342 	for (i = 0; i <  OPL3_PATCH_HASH_SIZE; i++) {
343 		struct fm_patch *patch, *next;
344 		for (patch = opl3->patch_table[i]; patch; patch = next) {
345 			next = patch->next;
346 			kfree(patch);
347 		}
348 	}
349 	memset(opl3->patch_table, 0, sizeof(opl3->patch_table));
350 }
351 #endif /* OPL3_SUPPORT_SYNTH */
352 
353 /* ------------------------------ */
354 
355 void snd_opl3_reset(struct snd_opl3 * opl3)
356 {
357 	unsigned short opl3_reg;
358 
359 	unsigned short reg_side;
360 	unsigned char voice_offset;
361 
362 	int max_voices, i;
363 
364 	max_voices = (opl3->hardware < OPL3_HW_OPL3) ?
365 		MAX_OPL2_VOICES : MAX_OPL3_VOICES;
366 
367 	for (i = 0; i < max_voices; i++) {
368 		/* Get register array side and offset of voice */
369 		if (i < MAX_OPL2_VOICES) {
370 			/* Left register block for voices 0 .. 8 */
371 			reg_side = OPL3_LEFT;
372 			voice_offset = i;
373 		} else {
374 			/* Right register block for voices 9 .. 17 */
375 			reg_side = OPL3_RIGHT;
376 			voice_offset = i - MAX_OPL2_VOICES;
377 		}
378 		opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + snd_opl3_regmap[voice_offset][0]);
379 		opl3->command(opl3, opl3_reg, OPL3_TOTAL_LEVEL_MASK); /* Operator 1 volume */
380 		opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + snd_opl3_regmap[voice_offset][1]);
381 		opl3->command(opl3, opl3_reg, OPL3_TOTAL_LEVEL_MASK); /* Operator 2 volume */
382 
383 		opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
384 		opl3->command(opl3, opl3_reg, 0x00);	/* Note off */
385 	}
386 
387 	opl3->max_voices = MAX_OPL2_VOICES;
388 	opl3->fm_mode = SNDRV_DM_FM_MODE_OPL2;
389 
390 	opl3->command(opl3, OPL3_LEFT | OPL3_REG_TEST, OPL3_ENABLE_WAVE_SELECT);
391 	opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION, 0x00);	/* Melodic mode */
392 	opl3->rhythm = 0;
393 }
394 
395 EXPORT_SYMBOL(snd_opl3_reset);
396 
397 static int snd_opl3_play_note(struct snd_opl3 * opl3, struct snd_dm_fm_note * note)
398 {
399 	unsigned short reg_side;
400 	unsigned char voice_offset;
401 
402 	unsigned short opl3_reg;
403 	unsigned char reg_val;
404 
405 	/* Voices 0 -  8 in OPL2 mode */
406 	/* Voices 0 - 17 in OPL3 mode */
407 	if (note->voice >= ((opl3->fm_mode == SNDRV_DM_FM_MODE_OPL3) ?
408 			    MAX_OPL3_VOICES : MAX_OPL2_VOICES))
409 		return -EINVAL;
410 
411 	/* Get register array side and offset of voice */
412 	if (note->voice < MAX_OPL2_VOICES) {
413 		/* Left register block for voices 0 .. 8 */
414 		reg_side = OPL3_LEFT;
415 		voice_offset = note->voice;
416 	} else {
417 		/* Right register block for voices 9 .. 17 */
418 		reg_side = OPL3_RIGHT;
419 		voice_offset = note->voice - MAX_OPL2_VOICES;
420 	}
421 
422 	/* Set lower 8 bits of note frequency */
423 	reg_val = (unsigned char) note->fnum;
424 	opl3_reg = reg_side | (OPL3_REG_FNUM_LOW + voice_offset);
425 	opl3->command(opl3, opl3_reg, reg_val);
426 
427 	reg_val = 0x00;
428 	/* Set output sound flag */
429 	if (note->key_on)
430 		reg_val |= OPL3_KEYON_BIT;
431 	/* Set octave */
432 	reg_val |= (note->octave << 2) & OPL3_BLOCKNUM_MASK;
433 	/* Set higher 2 bits of note frequency */
434 	reg_val |= (unsigned char) (note->fnum >> 8) & OPL3_FNUM_HIGH_MASK;
435 
436 	/* Set OPL3 KEYON_BLOCK register of requested voice */
437 	opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
438 	opl3->command(opl3, opl3_reg, reg_val);
439 
440 	return 0;
441 }
442 
443 
444 static int snd_opl3_set_voice(struct snd_opl3 * opl3, struct snd_dm_fm_voice * voice)
445 {
446 	unsigned short reg_side;
447 	unsigned char op_offset;
448 	unsigned char voice_offset;
449 
450 	unsigned short opl3_reg;
451 	unsigned char reg_val;
452 
453 	/* Only operators 1 and 2 */
454 	if (voice->op > 1)
455 		return -EINVAL;
456 	/* Voices 0 -  8 in OPL2 mode */
457 	/* Voices 0 - 17 in OPL3 mode */
458 	if (voice->voice >= ((opl3->fm_mode == SNDRV_DM_FM_MODE_OPL3) ?
459 			     MAX_OPL3_VOICES : MAX_OPL2_VOICES))
460 		return -EINVAL;
461 
462 	/* Get register array side and offset of voice */
463 	if (voice->voice < MAX_OPL2_VOICES) {
464 		/* Left register block for voices 0 .. 8 */
465 		reg_side = OPL3_LEFT;
466 		voice_offset = voice->voice;
467 	} else {
468 		/* Right register block for voices 9 .. 17 */
469 		reg_side = OPL3_RIGHT;
470 		voice_offset = voice->voice - MAX_OPL2_VOICES;
471 	}
472 	/* Get register offset of operator */
473 	op_offset = snd_opl3_regmap[voice_offset][voice->op];
474 
475 	reg_val = 0x00;
476 	/* Set amplitude modulation (tremolo) effect */
477 	if (voice->am)
478 		reg_val |= OPL3_TREMOLO_ON;
479 	/* Set vibrato effect */
480 	if (voice->vibrato)
481 		reg_val |= OPL3_VIBRATO_ON;
482 	/* Set sustaining sound phase */
483 	if (voice->do_sustain)
484 		reg_val |= OPL3_SUSTAIN_ON;
485 	/* Set keyboard scaling bit */
486 	if (voice->kbd_scale)
487 		reg_val |= OPL3_KSR;
488 	/* Set harmonic or frequency multiplier */
489 	reg_val |= voice->harmonic & OPL3_MULTIPLE_MASK;
490 
491 	/* Set OPL3 AM_VIB register of requested voice/operator */
492 	opl3_reg = reg_side | (OPL3_REG_AM_VIB + op_offset);
493 	opl3->command(opl3, opl3_reg, reg_val);
494 
495 	/* Set decreasing volume of higher notes */
496 	reg_val = (voice->scale_level << 6) & OPL3_KSL_MASK;
497 	/* Set output volume */
498 	reg_val |= ~voice->volume & OPL3_TOTAL_LEVEL_MASK;
499 
500 	/* Set OPL3 KSL_LEVEL register of requested voice/operator */
501 	opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + op_offset);
502 	opl3->command(opl3, opl3_reg, reg_val);
503 
504 	/* Set attack phase level */
505 	reg_val = (voice->attack << 4) & OPL3_ATTACK_MASK;
506 	/* Set decay phase level */
507 	reg_val |= voice->decay & OPL3_DECAY_MASK;
508 
509 	/* Set OPL3 ATTACK_DECAY register of requested voice/operator */
510 	opl3_reg = reg_side | (OPL3_REG_ATTACK_DECAY + op_offset);
511 	opl3->command(opl3, opl3_reg, reg_val);
512 
513 	/* Set sustain phase level */
514 	reg_val = (voice->sustain << 4) & OPL3_SUSTAIN_MASK;
515 	/* Set release phase level */
516 	reg_val |= voice->release & OPL3_RELEASE_MASK;
517 
518 	/* Set OPL3 SUSTAIN_RELEASE register of requested voice/operator */
519 	opl3_reg = reg_side | (OPL3_REG_SUSTAIN_RELEASE + op_offset);
520 	opl3->command(opl3, opl3_reg, reg_val);
521 
522 	/* Set inter-operator feedback */
523 	reg_val = (voice->feedback << 1) & OPL3_FEEDBACK_MASK;
524 	/* Set inter-operator connection */
525 	if (voice->connection)
526 		reg_val |= OPL3_CONNECTION_BIT;
527 	/* OPL-3 only */
528 	if (opl3->fm_mode == SNDRV_DM_FM_MODE_OPL3) {
529 		if (voice->left)
530 			reg_val |= OPL3_VOICE_TO_LEFT;
531 		if (voice->right)
532 			reg_val |= OPL3_VOICE_TO_RIGHT;
533 	}
534 	/* Feedback/connection bits are applicable to voice */
535 	opl3_reg = reg_side | (OPL3_REG_FEEDBACK_CONNECTION + voice_offset);
536 	opl3->command(opl3, opl3_reg, reg_val);
537 
538 	/* Select waveform */
539 	reg_val = voice->waveform & OPL3_WAVE_SELECT_MASK;
540 	opl3_reg = reg_side | (OPL3_REG_WAVE_SELECT + op_offset);
541 	opl3->command(opl3, opl3_reg, reg_val);
542 
543 	return 0;
544 }
545 
546 static int snd_opl3_set_params(struct snd_opl3 * opl3, struct snd_dm_fm_params * params)
547 {
548 	unsigned char reg_val;
549 
550 	reg_val = 0x00;
551 	/* Set keyboard split method */
552 	if (params->kbd_split)
553 		reg_val |= OPL3_KEYBOARD_SPLIT;
554 	opl3->command(opl3, OPL3_LEFT | OPL3_REG_KBD_SPLIT, reg_val);
555 
556 	reg_val = 0x00;
557 	/* Set amplitude modulation (tremolo) depth */
558 	if (params->am_depth)
559 		reg_val |= OPL3_TREMOLO_DEPTH;
560 	/* Set vibrato depth */
561 	if (params->vib_depth)
562 		reg_val |= OPL3_VIBRATO_DEPTH;
563 	/* Set percussion mode */
564 	if (params->rhythm) {
565 		reg_val |= OPL3_PERCUSSION_ENABLE;
566 		opl3->rhythm = 1;
567 	} else {
568 		opl3->rhythm = 0;
569 	}
570 	/* Play percussion instruments */
571 	if (params->bass)
572 		reg_val |= OPL3_BASSDRUM_ON;
573 	if (params->snare)
574 		reg_val |= OPL3_SNAREDRUM_ON;
575 	if (params->tomtom)
576 		reg_val |= OPL3_TOMTOM_ON;
577 	if (params->cymbal)
578 		reg_val |= OPL3_CYMBAL_ON;
579 	if (params->hihat)
580 		reg_val |= OPL3_HIHAT_ON;
581 
582 	opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION, reg_val);
583 	return 0;
584 }
585 
586 static int snd_opl3_set_mode(struct snd_opl3 * opl3, int mode)
587 {
588 	if ((mode == SNDRV_DM_FM_MODE_OPL3) && (opl3->hardware < OPL3_HW_OPL3))
589 		return -EINVAL;
590 
591 	opl3->fm_mode = mode;
592 	if (opl3->hardware >= OPL3_HW_OPL3)
593 		opl3->command(opl3, OPL3_RIGHT | OPL3_REG_CONNECTION_SELECT, 0x00);	/* Clear 4-op connections */
594 
595 	return 0;
596 }
597 
598 static int snd_opl3_set_connection(struct snd_opl3 * opl3, int connection)
599 {
600 	unsigned char reg_val;
601 
602 	/* OPL-3 only */
603 	if (opl3->fm_mode != SNDRV_DM_FM_MODE_OPL3)
604 		return -EINVAL;
605 
606 	reg_val = connection & (OPL3_RIGHT_4OP_0 | OPL3_RIGHT_4OP_1 | OPL3_RIGHT_4OP_2 |
607 				OPL3_LEFT_4OP_0 | OPL3_LEFT_4OP_1 | OPL3_LEFT_4OP_2);
608 	/* Set 4-op connections */
609 	opl3->command(opl3, OPL3_RIGHT | OPL3_REG_CONNECTION_SELECT, reg_val);
610 
611 	return 0;
612 }
613 
614