linux/sound/drivers/opl3/opl3_synth.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  Copyright (c) by Uros Bizjak <uros@kss-loka.si>
   4 *                   
   5 *  Routines for OPL2/OPL3/OPL4 control
   6 */
   7
   8#include <linux/slab.h>
   9#include <linux/export.h>
  10#include <linux/nospec.h>
  11#include <sound/opl3.h>
  12#include <sound/asound_fm.h>
  13#include "opl3_voice.h"
  14
  15#if IS_ENABLED(CONFIG_SND_SEQUENCER)
  16#define OPL3_SUPPORT_SYNTH
  17#endif
  18
  19/*
  20 *    There is 18 possible 2 OP voices
  21 *      (9 in the left and 9 in the right).
  22 *      The first OP is the modulator and 2nd is the carrier.
  23 *
  24 *      The first three voices in the both sides may be connected
  25 *      with another voice to a 4 OP voice. For example voice 0
  26 *      can be connected with voice 3. The operators of voice 3 are
  27 *      used as operators 3 and 4 of the new 4 OP voice.
  28 *      In this case the 2 OP voice number 0 is the 'first half' and
  29 *      voice 3 is the second.
  30 */
  31
  32
  33/*
  34 *    Register offset table for OPL2/3 voices,
  35 *    OPL2 / one OPL3 register array side only
  36 */
  37
  38char snd_opl3_regmap[MAX_OPL2_VOICES][4] =
  39{
  40/*        OP1   OP2   OP3   OP4         */
  41/*       ------------------------       */
  42        { 0x00, 0x03, 0x08, 0x0b },
  43        { 0x01, 0x04, 0x09, 0x0c },
  44        { 0x02, 0x05, 0x0a, 0x0d },
  45
  46        { 0x08, 0x0b, 0x00, 0x00 },
  47        { 0x09, 0x0c, 0x00, 0x00 },
  48        { 0x0a, 0x0d, 0x00, 0x00 },
  49
  50        { 0x10, 0x13, 0x00, 0x00 },     /* used by percussive voices */
  51        { 0x11, 0x14, 0x00, 0x00 },     /* if the percussive mode */
  52        { 0x12, 0x15, 0x00, 0x00 }      /* is selected (only left reg block) */
  53};
  54
  55EXPORT_SYMBOL(snd_opl3_regmap);
  56
  57/*
  58 * prototypes
  59 */
  60static int snd_opl3_play_note(struct snd_opl3 * opl3, struct snd_dm_fm_note * note);
  61static int snd_opl3_set_voice(struct snd_opl3 * opl3, struct snd_dm_fm_voice * voice);
  62static int snd_opl3_set_params(struct snd_opl3 * opl3, struct snd_dm_fm_params * params);
  63static int snd_opl3_set_mode(struct snd_opl3 * opl3, int mode);
  64static int snd_opl3_set_connection(struct snd_opl3 * opl3, int connection);
  65
  66/* ------------------------------ */
  67
  68/*
  69 * open the device exclusively
  70 */
  71int snd_opl3_open(struct snd_hwdep * hw, struct file *file)
  72{
  73        return 0;
  74}
  75
  76/*
  77 * ioctl for hwdep device:
  78 */
  79int snd_opl3_ioctl(struct snd_hwdep * hw, struct file *file,
  80                   unsigned int cmd, unsigned long arg)
  81{
  82        struct snd_opl3 *opl3 = hw->private_data;
  83        void __user *argp = (void __user *)arg;
  84
  85        if (snd_BUG_ON(!opl3))
  86                return -EINVAL;
  87
  88        switch (cmd) {
  89                /* get information */
  90        case SNDRV_DM_FM_IOCTL_INFO:
  91                {
  92                        struct snd_dm_fm_info info;
  93
  94                        memset(&info, 0, sizeof(info));
  95
  96                        info.fm_mode = opl3->fm_mode;
  97                        info.rhythm = opl3->rhythm;
  98                        if (copy_to_user(argp, &info, sizeof(struct snd_dm_fm_info)))
  99                                return -EFAULT;
 100                        return 0;
 101                }
 102
 103        case SNDRV_DM_FM_IOCTL_RESET:
 104#ifdef CONFIG_SND_OSSEMUL
 105        case SNDRV_DM_FM_OSS_IOCTL_RESET:
 106#endif
 107                snd_opl3_reset(opl3);
 108                return 0;
 109
 110        case SNDRV_DM_FM_IOCTL_PLAY_NOTE:
 111#ifdef CONFIG_SND_OSSEMUL
 112        case SNDRV_DM_FM_OSS_IOCTL_PLAY_NOTE:
 113#endif
 114                {
 115                        struct snd_dm_fm_note note;
 116                        if (copy_from_user(&note, argp, sizeof(struct snd_dm_fm_note)))
 117                                return -EFAULT;
 118                        return snd_opl3_play_note(opl3, &note);
 119                }
 120
 121        case SNDRV_DM_FM_IOCTL_SET_VOICE:
 122#ifdef CONFIG_SND_OSSEMUL
 123        case SNDRV_DM_FM_OSS_IOCTL_SET_VOICE:
 124#endif
 125                {
 126                        struct snd_dm_fm_voice voice;
 127                        if (copy_from_user(&voice, argp, sizeof(struct snd_dm_fm_voice)))
 128                                return -EFAULT;
 129                        return snd_opl3_set_voice(opl3, &voice);
 130                }
 131
 132        case SNDRV_DM_FM_IOCTL_SET_PARAMS:
 133#ifdef CONFIG_SND_OSSEMUL
 134        case SNDRV_DM_FM_OSS_IOCTL_SET_PARAMS:
 135#endif
 136                {
 137                        struct snd_dm_fm_params params;
 138                        if (copy_from_user(&params, argp, sizeof(struct snd_dm_fm_params)))
 139                                return -EFAULT;
 140                        return snd_opl3_set_params(opl3, &params);
 141                }
 142
 143        case SNDRV_DM_FM_IOCTL_SET_MODE:
 144#ifdef CONFIG_SND_OSSEMUL
 145        case SNDRV_DM_FM_OSS_IOCTL_SET_MODE:
 146#endif
 147                return snd_opl3_set_mode(opl3, (int) arg);
 148
 149        case SNDRV_DM_FM_IOCTL_SET_CONNECTION:
 150#ifdef CONFIG_SND_OSSEMUL
 151        case SNDRV_DM_FM_OSS_IOCTL_SET_OPL:
 152#endif
 153                return snd_opl3_set_connection(opl3, (int) arg);
 154
 155#ifdef OPL3_SUPPORT_SYNTH
 156        case SNDRV_DM_FM_IOCTL_CLEAR_PATCHES:
 157                snd_opl3_clear_patches(opl3);
 158                return 0;
 159#endif
 160
 161#ifdef CONFIG_SND_DEBUG
 162        default:
 163                snd_printk(KERN_WARNING "unknown IOCTL: 0x%x\n", cmd);
 164#endif
 165        }
 166        return -ENOTTY;
 167}
 168
 169/*
 170 * close the device
 171 */
 172int snd_opl3_release(struct snd_hwdep * hw, struct file *file)
 173{
 174        struct snd_opl3 *opl3 = hw->private_data;
 175
 176        snd_opl3_reset(opl3);
 177        return 0;
 178}
 179
 180#ifdef OPL3_SUPPORT_SYNTH
 181/*
 182 * write the device - load patches
 183 */
 184long 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 */
 241int 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}
 297EXPORT_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 */
 304struct 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}
 327EXPORT_SYMBOL(snd_opl3_find_patch);
 328
 329/*
 330 * Clear all patches of the given OPL3 instance
 331 */
 332void 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#endif /* OPL3_SUPPORT_SYNTH */
 345
 346/* ------------------------------ */
 347
 348void snd_opl3_reset(struct snd_opl3 * opl3)
 349{
 350        unsigned short opl3_reg;
 351
 352        unsigned short reg_side;
 353        unsigned char voice_offset;
 354
 355        int max_voices, i;
 356
 357        max_voices = (opl3->hardware < OPL3_HW_OPL3) ?
 358                MAX_OPL2_VOICES : MAX_OPL3_VOICES;
 359
 360        for (i = 0; i < max_voices; i++) {
 361                /* Get register array side and offset of voice */
 362                if (i < MAX_OPL2_VOICES) {
 363                        /* Left register block for voices 0 .. 8 */
 364                        reg_side = OPL3_LEFT;
 365                        voice_offset = i;
 366                } else {
 367                        /* Right register block for voices 9 .. 17 */
 368                        reg_side = OPL3_RIGHT;
 369                        voice_offset = i - MAX_OPL2_VOICES;
 370                }
 371                opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + snd_opl3_regmap[voice_offset][0]);
 372                opl3->command(opl3, opl3_reg, OPL3_TOTAL_LEVEL_MASK); /* Operator 1 volume */
 373                opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + snd_opl3_regmap[voice_offset][1]);
 374                opl3->command(opl3, opl3_reg, OPL3_TOTAL_LEVEL_MASK); /* Operator 2 volume */
 375
 376                opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
 377                opl3->command(opl3, opl3_reg, 0x00);    /* Note off */
 378        }
 379
 380        opl3->max_voices = MAX_OPL2_VOICES;
 381        opl3->fm_mode = SNDRV_DM_FM_MODE_OPL2;
 382
 383        opl3->command(opl3, OPL3_LEFT | OPL3_REG_TEST, OPL3_ENABLE_WAVE_SELECT);
 384        opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION, 0x00);     /* Melodic mode */
 385        opl3->rhythm = 0;
 386}
 387
 388EXPORT_SYMBOL(snd_opl3_reset);
 389
 390static int snd_opl3_play_note(struct snd_opl3 * opl3, struct snd_dm_fm_note * note)
 391{
 392        unsigned short reg_side;
 393        unsigned char voice_offset;
 394
 395        unsigned short opl3_reg;
 396        unsigned char reg_val;
 397
 398        /* Voices 0 -  8 in OPL2 mode */
 399        /* Voices 0 - 17 in OPL3 mode */
 400        if (note->voice >= ((opl3->fm_mode == SNDRV_DM_FM_MODE_OPL3) ?
 401                            MAX_OPL3_VOICES : MAX_OPL2_VOICES))
 402                return -EINVAL;
 403
 404        /* Get register array side and offset of voice */
 405        if (note->voice < MAX_OPL2_VOICES) {
 406                /* Left register block for voices 0 .. 8 */
 407                reg_side = OPL3_LEFT;
 408                voice_offset = note->voice;
 409        } else {
 410                /* Right register block for voices 9 .. 17 */
 411                reg_side = OPL3_RIGHT;
 412                voice_offset = note->voice - MAX_OPL2_VOICES;
 413        }
 414
 415        /* Set lower 8 bits of note frequency */
 416        reg_val = (unsigned char) note->fnum;
 417        opl3_reg = reg_side | (OPL3_REG_FNUM_LOW + voice_offset);
 418        opl3->command(opl3, opl3_reg, reg_val);
 419        
 420        reg_val = 0x00;
 421        /* Set output sound flag */
 422        if (note->key_on)
 423                reg_val |= OPL3_KEYON_BIT;
 424        /* Set octave */
 425        reg_val |= (note->octave << 2) & OPL3_BLOCKNUM_MASK;
 426        /* Set higher 2 bits of note frequency */
 427        reg_val |= (unsigned char) (note->fnum >> 8) & OPL3_FNUM_HIGH_MASK;
 428
 429        /* Set OPL3 KEYON_BLOCK register of requested voice */ 
 430        opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
 431        opl3->command(opl3, opl3_reg, reg_val);
 432
 433        return 0;
 434}
 435
 436
 437static int snd_opl3_set_voice(struct snd_opl3 * opl3, struct snd_dm_fm_voice * voice)
 438{
 439        unsigned short reg_side;
 440        unsigned char op_offset;
 441        unsigned char voice_offset, voice_op;
 442
 443        unsigned short opl3_reg;
 444        unsigned char reg_val;
 445
 446        /* Only operators 1 and 2 */
 447        if (voice->op > 1)
 448                return -EINVAL;
 449        /* Voices 0 -  8 in OPL2 mode */
 450        /* Voices 0 - 17 in OPL3 mode */
 451        if (voice->voice >= ((opl3->fm_mode == SNDRV_DM_FM_MODE_OPL3) ?
 452                             MAX_OPL3_VOICES : MAX_OPL2_VOICES))
 453                return -EINVAL;
 454
 455        /* Get register array side and offset of voice */
 456        if (voice->voice < MAX_OPL2_VOICES) {
 457                /* Left register block for voices 0 .. 8 */
 458                reg_side = OPL3_LEFT;
 459                voice_offset = voice->voice;
 460        } else {
 461                /* Right register block for voices 9 .. 17 */
 462                reg_side = OPL3_RIGHT;
 463                voice_offset = voice->voice - MAX_OPL2_VOICES;
 464        }
 465        /* Get register offset of operator */
 466        voice_offset = array_index_nospec(voice_offset, MAX_OPL2_VOICES);
 467        voice_op = array_index_nospec(voice->op, 4);
 468        op_offset = snd_opl3_regmap[voice_offset][voice_op];
 469
 470        reg_val = 0x00;
 471        /* Set amplitude modulation (tremolo) effect */
 472        if (voice->am)
 473                reg_val |= OPL3_TREMOLO_ON;
 474        /* Set vibrato effect */
 475        if (voice->vibrato)
 476                reg_val |= OPL3_VIBRATO_ON;
 477        /* Set sustaining sound phase */
 478        if (voice->do_sustain)
 479                reg_val |= OPL3_SUSTAIN_ON;
 480        /* Set keyboard scaling bit */ 
 481        if (voice->kbd_scale)
 482                reg_val |= OPL3_KSR;
 483        /* Set harmonic or frequency multiplier */
 484        reg_val |= voice->harmonic & OPL3_MULTIPLE_MASK;
 485
 486        /* Set OPL3 AM_VIB register of requested voice/operator */ 
 487        opl3_reg = reg_side | (OPL3_REG_AM_VIB + op_offset);
 488        opl3->command(opl3, opl3_reg, reg_val);
 489
 490        /* Set decreasing volume of higher notes */
 491        reg_val = (voice->scale_level << 6) & OPL3_KSL_MASK;
 492        /* Set output volume */
 493        reg_val |= ~voice->volume & OPL3_TOTAL_LEVEL_MASK;
 494
 495        /* Set OPL3 KSL_LEVEL register of requested voice/operator */ 
 496        opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + op_offset);
 497        opl3->command(opl3, opl3_reg, reg_val);
 498
 499        /* Set attack phase level */
 500        reg_val = (voice->attack << 4) & OPL3_ATTACK_MASK;
 501        /* Set decay phase level */
 502        reg_val |= voice->decay & OPL3_DECAY_MASK;
 503
 504        /* Set OPL3 ATTACK_DECAY register of requested voice/operator */ 
 505        opl3_reg = reg_side | (OPL3_REG_ATTACK_DECAY + op_offset);
 506        opl3->command(opl3, opl3_reg, reg_val);
 507
 508        /* Set sustain phase level */
 509        reg_val = (voice->sustain << 4) & OPL3_SUSTAIN_MASK;
 510        /* Set release phase level */
 511        reg_val |= voice->release & OPL3_RELEASE_MASK;
 512
 513        /* Set OPL3 SUSTAIN_RELEASE register of requested voice/operator */ 
 514        opl3_reg = reg_side | (OPL3_REG_SUSTAIN_RELEASE + op_offset);
 515        opl3->command(opl3, opl3_reg, reg_val);
 516
 517        /* Set inter-operator feedback */
 518        reg_val = (voice->feedback << 1) & OPL3_FEEDBACK_MASK;
 519        /* Set inter-operator connection */
 520        if (voice->connection)
 521                reg_val |= OPL3_CONNECTION_BIT;
 522        /* OPL-3 only */
 523        if (opl3->fm_mode == SNDRV_DM_FM_MODE_OPL3) {
 524                if (voice->left)
 525                        reg_val |= OPL3_VOICE_TO_LEFT;
 526                if (voice->right)
 527                        reg_val |= OPL3_VOICE_TO_RIGHT;
 528        }
 529        /* Feedback/connection bits are applicable to voice */
 530        opl3_reg = reg_side | (OPL3_REG_FEEDBACK_CONNECTION + voice_offset);
 531        opl3->command(opl3, opl3_reg, reg_val);
 532
 533        /* Select waveform */
 534        reg_val = voice->waveform & OPL3_WAVE_SELECT_MASK;
 535        opl3_reg = reg_side | (OPL3_REG_WAVE_SELECT + op_offset);
 536        opl3->command(opl3, opl3_reg, reg_val);
 537
 538        return 0;
 539}
 540
 541static int snd_opl3_set_params(struct snd_opl3 * opl3, struct snd_dm_fm_params * params)
 542{
 543        unsigned char reg_val;
 544
 545        reg_val = 0x00;
 546        /* Set keyboard split method */
 547        if (params->kbd_split)
 548                reg_val |= OPL3_KEYBOARD_SPLIT;
 549        opl3->command(opl3, OPL3_LEFT | OPL3_REG_KBD_SPLIT, reg_val);
 550
 551        reg_val = 0x00;
 552        /* Set amplitude modulation (tremolo) depth */
 553        if (params->am_depth)
 554                reg_val |= OPL3_TREMOLO_DEPTH;
 555        /* Set vibrato depth */
 556        if (params->vib_depth)
 557                reg_val |= OPL3_VIBRATO_DEPTH;
 558        /* Set percussion mode */
 559        if (params->rhythm) {
 560                reg_val |= OPL3_PERCUSSION_ENABLE;
 561                opl3->rhythm = 1;
 562        } else {
 563                opl3->rhythm = 0;
 564        }
 565        /* Play percussion instruments */
 566        if (params->bass)
 567                reg_val |= OPL3_BASSDRUM_ON;
 568        if (params->snare)
 569                reg_val |= OPL3_SNAREDRUM_ON;
 570        if (params->tomtom)
 571                reg_val |= OPL3_TOMTOM_ON;
 572        if (params->cymbal)
 573                reg_val |= OPL3_CYMBAL_ON;
 574        if (params->hihat)
 575                reg_val |= OPL3_HIHAT_ON;
 576
 577        opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION, reg_val);
 578        return 0;
 579}
 580
 581static int snd_opl3_set_mode(struct snd_opl3 * opl3, int mode)
 582{
 583        if ((mode == SNDRV_DM_FM_MODE_OPL3) && (opl3->hardware < OPL3_HW_OPL3))
 584                return -EINVAL;
 585
 586        opl3->fm_mode = mode;
 587        if (opl3->hardware >= OPL3_HW_OPL3)
 588                opl3->command(opl3, OPL3_RIGHT | OPL3_REG_CONNECTION_SELECT, 0x00);     /* Clear 4-op connections */
 589
 590        return 0;
 591}
 592
 593static int snd_opl3_set_connection(struct snd_opl3 * opl3, int connection)
 594{
 595        unsigned char reg_val;
 596
 597        /* OPL-3 only */
 598        if (opl3->fm_mode != SNDRV_DM_FM_MODE_OPL3)
 599                return -EINVAL;
 600
 601        reg_val = connection & (OPL3_RIGHT_4OP_0 | OPL3_RIGHT_4OP_1 | OPL3_RIGHT_4OP_2 |
 602                                OPL3_LEFT_4OP_0 | OPL3_LEFT_4OP_1 | OPL3_LEFT_4OP_2);
 603        /* Set 4-op connections */
 604        opl3->command(opl3, OPL3_RIGHT | OPL3_REG_CONNECTION_SELECT, reg_val);
 605
 606        return 0;
 607}
 608
 609