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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /sound/drivers/opl3/opl3_synth.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'sound/drivers/opl3/opl3_synth.c')
-rw-r--r--sound/drivers/opl3/opl3_synth.c608
1 files changed, 608 insertions, 0 deletions
diff --git a/sound/drivers/opl3/opl3_synth.c b/sound/drivers/opl3/opl3_synth.c
new file mode 100644
index 0000000000..97d30a833a
--- /dev/null
+++ b/sound/drivers/opl3/opl3_synth.c
@@ -0,0 +1,608 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) by Uros Bizjak <uros@kss-loka.si>
+ *
+ * Routines for OPL2/OPL3/OPL4 control
+ */
+
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/nospec.h>
+#include <sound/opl3.h>
+#include <sound/asound_fm.h>
+#include "opl3_voice.h"
+
+#if IS_ENABLED(CONFIG_SND_SEQUENCER)
+#define OPL3_SUPPORT_SYNTH
+#endif
+
+/*
+ * There is 18 possible 2 OP voices
+ * (9 in the left and 9 in the right).
+ * The first OP is the modulator and 2nd is the carrier.
+ *
+ * The first three voices in the both sides may be connected
+ * with another voice to a 4 OP voice. For example voice 0
+ * can be connected with voice 3. The operators of voice 3 are
+ * used as operators 3 and 4 of the new 4 OP voice.
+ * In this case the 2 OP voice number 0 is the 'first half' and
+ * voice 3 is the second.
+ */
+
+
+/*
+ * Register offset table for OPL2/3 voices,
+ * OPL2 / one OPL3 register array side only
+ */
+
+char snd_opl3_regmap[MAX_OPL2_VOICES][4] =
+{
+/* OP1 OP2 OP3 OP4 */
+/* ------------------------ */
+ { 0x00, 0x03, 0x08, 0x0b },
+ { 0x01, 0x04, 0x09, 0x0c },
+ { 0x02, 0x05, 0x0a, 0x0d },
+
+ { 0x08, 0x0b, 0x00, 0x00 },
+ { 0x09, 0x0c, 0x00, 0x00 },
+ { 0x0a, 0x0d, 0x00, 0x00 },
+
+ { 0x10, 0x13, 0x00, 0x00 }, /* used by percussive voices */
+ { 0x11, 0x14, 0x00, 0x00 }, /* if the percussive mode */
+ { 0x12, 0x15, 0x00, 0x00 } /* is selected (only left reg block) */
+};
+
+EXPORT_SYMBOL(snd_opl3_regmap);
+
+/*
+ * prototypes
+ */
+static int snd_opl3_play_note(struct snd_opl3 * opl3, struct snd_dm_fm_note * note);
+static int snd_opl3_set_voice(struct snd_opl3 * opl3, struct snd_dm_fm_voice * voice);
+static int snd_opl3_set_params(struct snd_opl3 * opl3, struct snd_dm_fm_params * params);
+static int snd_opl3_set_mode(struct snd_opl3 * opl3, int mode);
+static int snd_opl3_set_connection(struct snd_opl3 * opl3, int connection);
+
+/* ------------------------------ */
+
+/*
+ * open the device exclusively
+ */
+int snd_opl3_open(struct snd_hwdep * hw, struct file *file)
+{
+ return 0;
+}
+
+/*
+ * ioctl for hwdep device:
+ */
+int snd_opl3_ioctl(struct snd_hwdep * hw, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct snd_opl3 *opl3 = hw->private_data;
+ void __user *argp = (void __user *)arg;
+
+ if (snd_BUG_ON(!opl3))
+ return -EINVAL;
+
+ switch (cmd) {
+ /* get information */
+ case SNDRV_DM_FM_IOCTL_INFO:
+ {
+ struct snd_dm_fm_info info;
+
+ memset(&info, 0, sizeof(info));
+
+ info.fm_mode = opl3->fm_mode;
+ info.rhythm = opl3->rhythm;
+ if (copy_to_user(argp, &info, sizeof(struct snd_dm_fm_info)))
+ return -EFAULT;
+ return 0;
+ }
+
+ case SNDRV_DM_FM_IOCTL_RESET:
+#ifdef CONFIG_SND_OSSEMUL
+ case SNDRV_DM_FM_OSS_IOCTL_RESET:
+#endif
+ snd_opl3_reset(opl3);
+ return 0;
+
+ case SNDRV_DM_FM_IOCTL_PLAY_NOTE:
+#ifdef CONFIG_SND_OSSEMUL
+ case SNDRV_DM_FM_OSS_IOCTL_PLAY_NOTE:
+#endif
+ {
+ struct snd_dm_fm_note note;
+ if (copy_from_user(&note, argp, sizeof(struct snd_dm_fm_note)))
+ return -EFAULT;
+ return snd_opl3_play_note(opl3, &note);
+ }
+
+ case SNDRV_DM_FM_IOCTL_SET_VOICE:
+#ifdef CONFIG_SND_OSSEMUL
+ case SNDRV_DM_FM_OSS_IOCTL_SET_VOICE:
+#endif
+ {
+ struct snd_dm_fm_voice voice;
+ if (copy_from_user(&voice, argp, sizeof(struct snd_dm_fm_voice)))
+ return -EFAULT;
+ return snd_opl3_set_voice(opl3, &voice);
+ }
+
+ case SNDRV_DM_FM_IOCTL_SET_PARAMS:
+#ifdef CONFIG_SND_OSSEMUL
+ case SNDRV_DM_FM_OSS_IOCTL_SET_PARAMS:
+#endif
+ {
+ struct snd_dm_fm_params params;
+ if (copy_from_user(&params, argp, sizeof(struct snd_dm_fm_params)))
+ return -EFAULT;
+ return snd_opl3_set_params(opl3, &params);
+ }
+
+ case SNDRV_DM_FM_IOCTL_SET_MODE:
+#ifdef CONFIG_SND_OSSEMUL
+ case SNDRV_DM_FM_OSS_IOCTL_SET_MODE:
+#endif
+ return snd_opl3_set_mode(opl3, (int) arg);
+
+ case SNDRV_DM_FM_IOCTL_SET_CONNECTION:
+#ifdef CONFIG_SND_OSSEMUL
+ case SNDRV_DM_FM_OSS_IOCTL_SET_OPL:
+#endif
+ return snd_opl3_set_connection(opl3, (int) arg);
+
+#ifdef OPL3_SUPPORT_SYNTH
+ case SNDRV_DM_FM_IOCTL_CLEAR_PATCHES:
+ snd_opl3_clear_patches(opl3);
+ return 0;
+#endif
+
+#ifdef CONFIG_SND_DEBUG
+ default:
+ snd_printk(KERN_WARNING "unknown IOCTL: 0x%x\n", cmd);
+#endif
+ }
+ return -ENOTTY;
+}
+
+/*
+ * close the device
+ */
+int snd_opl3_release(struct snd_hwdep * hw, struct file *file)
+{
+ struct snd_opl3 *opl3 = hw->private_data;
+
+ snd_opl3_reset(opl3);
+ return 0;
+}
+
+#ifdef OPL3_SUPPORT_SYNTH
+/*
+ * write the device - load patches
+ */
+long snd_opl3_write(struct snd_hwdep *hw, const char __user *buf, long count,
+ loff_t *offset)
+{
+ struct snd_opl3 *opl3 = hw->private_data;
+ long result = 0;
+ int err = 0;
+ struct sbi_patch inst;
+
+ while (count >= sizeof(inst)) {
+ unsigned char type;
+ if (copy_from_user(&inst, buf, sizeof(inst)))
+ return -EFAULT;
+ if (!memcmp(inst.key, FM_KEY_SBI, 4) ||
+ !memcmp(inst.key, FM_KEY_2OP, 4))
+ type = FM_PATCH_OPL2;
+ else if (!memcmp(inst.key, FM_KEY_4OP, 4))
+ type = FM_PATCH_OPL3;
+ else /* invalid type */
+ break;
+ err = snd_opl3_load_patch(opl3, inst.prog, inst.bank, type,
+ inst.name, inst.extension,
+ inst.data);
+ if (err < 0)
+ break;
+ result += sizeof(inst);
+ count -= sizeof(inst);
+ }
+ return result > 0 ? result : err;
+}
+
+
+/*
+ * Patch management
+ */
+
+/* offsets for SBI params */
+#define AM_VIB 0
+#define KSL_LEVEL 2
+#define ATTACK_DECAY 4
+#define SUSTAIN_RELEASE 6
+#define WAVE_SELECT 8
+
+/* offset for SBI instrument */
+#define CONNECTION 10
+#define OFFSET_4OP 11
+
+/*
+ * load a patch, obviously.
+ *
+ * loaded on the given program and bank numbers with the given type
+ * (FM_PATCH_OPLx).
+ * data is the pointer of SBI record _without_ header (key and name).
+ * name is the name string of the patch.
+ * ext is the extension data of 7 bytes long (stored in name of SBI
+ * data up to offset 25), or NULL to skip.
+ * return 0 if successful or a negative error code.
+ */
+int snd_opl3_load_patch(struct snd_opl3 *opl3,
+ int prog, int bank, int type,
+ const char *name,
+ const unsigned char *ext,
+ const unsigned char *data)
+{
+ struct fm_patch *patch;
+ int i;
+
+ patch = snd_opl3_find_patch(opl3, prog, bank, 1);
+ if (!patch)
+ return -ENOMEM;
+
+ patch->type = type;
+
+ for (i = 0; i < 2; i++) {
+ patch->inst.op[i].am_vib = data[AM_VIB + i];
+ patch->inst.op[i].ksl_level = data[KSL_LEVEL + i];
+ patch->inst.op[i].attack_decay = data[ATTACK_DECAY + i];
+ patch->inst.op[i].sustain_release = data[SUSTAIN_RELEASE + i];
+ patch->inst.op[i].wave_select = data[WAVE_SELECT + i];
+ }
+ patch->inst.feedback_connection[0] = data[CONNECTION];
+
+ if (type == FM_PATCH_OPL3) {
+ for (i = 0; i < 2; i++) {
+ patch->inst.op[i+2].am_vib =
+ data[OFFSET_4OP + AM_VIB + i];
+ patch->inst.op[i+2].ksl_level =
+ data[OFFSET_4OP + KSL_LEVEL + i];
+ patch->inst.op[i+2].attack_decay =
+ data[OFFSET_4OP + ATTACK_DECAY + i];
+ patch->inst.op[i+2].sustain_release =
+ data[OFFSET_4OP + SUSTAIN_RELEASE + i];
+ patch->inst.op[i+2].wave_select =
+ data[OFFSET_4OP + WAVE_SELECT + i];
+ }
+ patch->inst.feedback_connection[1] =
+ data[OFFSET_4OP + CONNECTION];
+ }
+
+ if (ext) {
+ patch->inst.echo_delay = ext[0];
+ patch->inst.echo_atten = ext[1];
+ patch->inst.chorus_spread = ext[2];
+ patch->inst.trnsps = ext[3];
+ patch->inst.fix_dur = ext[4];
+ patch->inst.modes = ext[5];
+ patch->inst.fix_key = ext[6];
+ }
+
+ if (name)
+ strscpy(patch->name, name, sizeof(patch->name));
+
+ return 0;
+}
+EXPORT_SYMBOL(snd_opl3_load_patch);
+
+/*
+ * find a patch with the given program and bank numbers, returns its pointer
+ * if no matching patch is found and create_patch is set, it creates a
+ * new patch object.
+ */
+struct fm_patch *snd_opl3_find_patch(struct snd_opl3 *opl3, int prog, int bank,
+ int create_patch)
+{
+ /* pretty dumb hash key */
+ unsigned int key = (prog + bank) % OPL3_PATCH_HASH_SIZE;
+ struct fm_patch *patch;
+
+ for (patch = opl3->patch_table[key]; patch; patch = patch->next) {
+ if (patch->prog == prog && patch->bank == bank)
+ return patch;
+ }
+ if (!create_patch)
+ return NULL;
+
+ patch = kzalloc(sizeof(*patch), GFP_KERNEL);
+ if (!patch)
+ return NULL;
+ patch->prog = prog;
+ patch->bank = bank;
+ patch->next = opl3->patch_table[key];
+ opl3->patch_table[key] = patch;
+ return patch;
+}
+EXPORT_SYMBOL(snd_opl3_find_patch);
+
+/*
+ * Clear all patches of the given OPL3 instance
+ */
+void snd_opl3_clear_patches(struct snd_opl3 *opl3)
+{
+ int i;
+ for (i = 0; i < OPL3_PATCH_HASH_SIZE; i++) {
+ struct fm_patch *patch, *next;
+ for (patch = opl3->patch_table[i]; patch; patch = next) {
+ next = patch->next;
+ kfree(patch);
+ }
+ }
+ memset(opl3->patch_table, 0, sizeof(opl3->patch_table));
+}
+#endif /* OPL3_SUPPORT_SYNTH */
+
+/* ------------------------------ */
+
+void snd_opl3_reset(struct snd_opl3 * opl3)
+{
+ unsigned short opl3_reg;
+
+ unsigned short reg_side;
+ unsigned char voice_offset;
+
+ int max_voices, i;
+
+ max_voices = (opl3->hardware < OPL3_HW_OPL3) ?
+ MAX_OPL2_VOICES : MAX_OPL3_VOICES;
+
+ for (i = 0; i < max_voices; i++) {
+ /* Get register array side and offset of voice */
+ if (i < MAX_OPL2_VOICES) {
+ /* Left register block for voices 0 .. 8 */
+ reg_side = OPL3_LEFT;
+ voice_offset = i;
+ } else {
+ /* Right register block for voices 9 .. 17 */
+ reg_side = OPL3_RIGHT;
+ voice_offset = i - MAX_OPL2_VOICES;
+ }
+ opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + snd_opl3_regmap[voice_offset][0]);
+ opl3->command(opl3, opl3_reg, OPL3_TOTAL_LEVEL_MASK); /* Operator 1 volume */
+ opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + snd_opl3_regmap[voice_offset][1]);
+ opl3->command(opl3, opl3_reg, OPL3_TOTAL_LEVEL_MASK); /* Operator 2 volume */
+
+ opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
+ opl3->command(opl3, opl3_reg, 0x00); /* Note off */
+ }
+
+ opl3->max_voices = MAX_OPL2_VOICES;
+ opl3->fm_mode = SNDRV_DM_FM_MODE_OPL2;
+
+ opl3->command(opl3, OPL3_LEFT | OPL3_REG_TEST, OPL3_ENABLE_WAVE_SELECT);
+ opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION, 0x00); /* Melodic mode */
+ opl3->rhythm = 0;
+}
+
+EXPORT_SYMBOL(snd_opl3_reset);
+
+static int snd_opl3_play_note(struct snd_opl3 * opl3, struct snd_dm_fm_note * note)
+{
+ unsigned short reg_side;
+ unsigned char voice_offset;
+
+ unsigned short opl3_reg;
+ unsigned char reg_val;
+
+ /* Voices 0 - 8 in OPL2 mode */
+ /* Voices 0 - 17 in OPL3 mode */
+ if (note->voice >= ((opl3->fm_mode == SNDRV_DM_FM_MODE_OPL3) ?
+ MAX_OPL3_VOICES : MAX_OPL2_VOICES))
+ return -EINVAL;
+
+ /* Get register array side and offset of voice */
+ if (note->voice < MAX_OPL2_VOICES) {
+ /* Left register block for voices 0 .. 8 */
+ reg_side = OPL3_LEFT;
+ voice_offset = note->voice;
+ } else {
+ /* Right register block for voices 9 .. 17 */
+ reg_side = OPL3_RIGHT;
+ voice_offset = note->voice - MAX_OPL2_VOICES;
+ }
+
+ /* Set lower 8 bits of note frequency */
+ reg_val = (unsigned char) note->fnum;
+ opl3_reg = reg_side | (OPL3_REG_FNUM_LOW + voice_offset);
+ opl3->command(opl3, opl3_reg, reg_val);
+
+ reg_val = 0x00;
+ /* Set output sound flag */
+ if (note->key_on)
+ reg_val |= OPL3_KEYON_BIT;
+ /* Set octave */
+ reg_val |= (note->octave << 2) & OPL3_BLOCKNUM_MASK;
+ /* Set higher 2 bits of note frequency */
+ reg_val |= (unsigned char) (note->fnum >> 8) & OPL3_FNUM_HIGH_MASK;
+
+ /* Set OPL3 KEYON_BLOCK register of requested voice */
+ opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
+ opl3->command(opl3, opl3_reg, reg_val);
+
+ return 0;
+}
+
+
+static int snd_opl3_set_voice(struct snd_opl3 * opl3, struct snd_dm_fm_voice * voice)
+{
+ unsigned short reg_side;
+ unsigned char op_offset;
+ unsigned char voice_offset, voice_op;
+
+ unsigned short opl3_reg;
+ unsigned char reg_val;
+
+ /* Only operators 1 and 2 */
+ if (voice->op > 1)
+ return -EINVAL;
+ /* Voices 0 - 8 in OPL2 mode */
+ /* Voices 0 - 17 in OPL3 mode */
+ if (voice->voice >= ((opl3->fm_mode == SNDRV_DM_FM_MODE_OPL3) ?
+ MAX_OPL3_VOICES : MAX_OPL2_VOICES))
+ return -EINVAL;
+
+ /* Get register array side and offset of voice */
+ if (voice->voice < MAX_OPL2_VOICES) {
+ /* Left register block for voices 0 .. 8 */
+ reg_side = OPL3_LEFT;
+ voice_offset = voice->voice;
+ } else {
+ /* Right register block for voices 9 .. 17 */
+ reg_side = OPL3_RIGHT;
+ voice_offset = voice->voice - MAX_OPL2_VOICES;
+ }
+ /* Get register offset of operator */
+ voice_offset = array_index_nospec(voice_offset, MAX_OPL2_VOICES);
+ voice_op = array_index_nospec(voice->op, 4);
+ op_offset = snd_opl3_regmap[voice_offset][voice_op];
+
+ reg_val = 0x00;
+ /* Set amplitude modulation (tremolo) effect */
+ if (voice->am)
+ reg_val |= OPL3_TREMOLO_ON;
+ /* Set vibrato effect */
+ if (voice->vibrato)
+ reg_val |= OPL3_VIBRATO_ON;
+ /* Set sustaining sound phase */
+ if (voice->do_sustain)
+ reg_val |= OPL3_SUSTAIN_ON;
+ /* Set keyboard scaling bit */
+ if (voice->kbd_scale)
+ reg_val |= OPL3_KSR;
+ /* Set harmonic or frequency multiplier */
+ reg_val |= voice->harmonic & OPL3_MULTIPLE_MASK;
+
+ /* Set OPL3 AM_VIB register of requested voice/operator */
+ opl3_reg = reg_side | (OPL3_REG_AM_VIB + op_offset);
+ opl3->command(opl3, opl3_reg, reg_val);
+
+ /* Set decreasing volume of higher notes */
+ reg_val = (voice->scale_level << 6) & OPL3_KSL_MASK;
+ /* Set output volume */
+ reg_val |= ~voice->volume & OPL3_TOTAL_LEVEL_MASK;
+
+ /* Set OPL3 KSL_LEVEL register of requested voice/operator */
+ opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + op_offset);
+ opl3->command(opl3, opl3_reg, reg_val);
+
+ /* Set attack phase level */
+ reg_val = (voice->attack << 4) & OPL3_ATTACK_MASK;
+ /* Set decay phase level */
+ reg_val |= voice->decay & OPL3_DECAY_MASK;
+
+ /* Set OPL3 ATTACK_DECAY register of requested voice/operator */
+ opl3_reg = reg_side | (OPL3_REG_ATTACK_DECAY + op_offset);
+ opl3->command(opl3, opl3_reg, reg_val);
+
+ /* Set sustain phase level */
+ reg_val = (voice->sustain << 4) & OPL3_SUSTAIN_MASK;
+ /* Set release phase level */
+ reg_val |= voice->release & OPL3_RELEASE_MASK;
+
+ /* Set OPL3 SUSTAIN_RELEASE register of requested voice/operator */
+ opl3_reg = reg_side | (OPL3_REG_SUSTAIN_RELEASE + op_offset);
+ opl3->command(opl3, opl3_reg, reg_val);
+
+ /* Set inter-operator feedback */
+ reg_val = (voice->feedback << 1) & OPL3_FEEDBACK_MASK;
+ /* Set inter-operator connection */
+ if (voice->connection)
+ reg_val |= OPL3_CONNECTION_BIT;
+ /* OPL-3 only */
+ if (opl3->fm_mode == SNDRV_DM_FM_MODE_OPL3) {
+ if (voice->left)
+ reg_val |= OPL3_VOICE_TO_LEFT;
+ if (voice->right)
+ reg_val |= OPL3_VOICE_TO_RIGHT;
+ }
+ /* Feedback/connection bits are applicable to voice */
+ opl3_reg = reg_side | (OPL3_REG_FEEDBACK_CONNECTION + voice_offset);
+ opl3->command(opl3, opl3_reg, reg_val);
+
+ /* Select waveform */
+ reg_val = voice->waveform & OPL3_WAVE_SELECT_MASK;
+ opl3_reg = reg_side | (OPL3_REG_WAVE_SELECT + op_offset);
+ opl3->command(opl3, opl3_reg, reg_val);
+
+ return 0;
+}
+
+static int snd_opl3_set_params(struct snd_opl3 * opl3, struct snd_dm_fm_params * params)
+{
+ unsigned char reg_val;
+
+ reg_val = 0x00;
+ /* Set keyboard split method */
+ if (params->kbd_split)
+ reg_val |= OPL3_KEYBOARD_SPLIT;
+ opl3->command(opl3, OPL3_LEFT | OPL3_REG_KBD_SPLIT, reg_val);
+
+ reg_val = 0x00;
+ /* Set amplitude modulation (tremolo) depth */
+ if (params->am_depth)
+ reg_val |= OPL3_TREMOLO_DEPTH;
+ /* Set vibrato depth */
+ if (params->vib_depth)
+ reg_val |= OPL3_VIBRATO_DEPTH;
+ /* Set percussion mode */
+ if (params->rhythm) {
+ reg_val |= OPL3_PERCUSSION_ENABLE;
+ opl3->rhythm = 1;
+ } else {
+ opl3->rhythm = 0;
+ }
+ /* Play percussion instruments */
+ if (params->bass)
+ reg_val |= OPL3_BASSDRUM_ON;
+ if (params->snare)
+ reg_val |= OPL3_SNAREDRUM_ON;
+ if (params->tomtom)
+ reg_val |= OPL3_TOMTOM_ON;
+ if (params->cymbal)
+ reg_val |= OPL3_CYMBAL_ON;
+ if (params->hihat)
+ reg_val |= OPL3_HIHAT_ON;
+
+ opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION, reg_val);
+ return 0;
+}
+
+static int snd_opl3_set_mode(struct snd_opl3 * opl3, int mode)
+{
+ if ((mode == SNDRV_DM_FM_MODE_OPL3) && (opl3->hardware < OPL3_HW_OPL3))
+ return -EINVAL;
+
+ opl3->fm_mode = mode;
+ if (opl3->hardware >= OPL3_HW_OPL3)
+ opl3->command(opl3, OPL3_RIGHT | OPL3_REG_CONNECTION_SELECT, 0x00); /* Clear 4-op connections */
+
+ return 0;
+}
+
+static int snd_opl3_set_connection(struct snd_opl3 * opl3, int connection)
+{
+ unsigned char reg_val;
+
+ /* OPL-3 only */
+ if (opl3->fm_mode != SNDRV_DM_FM_MODE_OPL3)
+ return -EINVAL;
+
+ reg_val = connection & (OPL3_RIGHT_4OP_0 | OPL3_RIGHT_4OP_1 | OPL3_RIGHT_4OP_2 |
+ OPL3_LEFT_4OP_0 | OPL3_LEFT_4OP_1 | OPL3_LEFT_4OP_2);
+ /* Set 4-op connections */
+ opl3->command(opl3, OPL3_RIGHT | OPL3_REG_CONNECTION_SELECT, reg_val);
+
+ return 0;
+}
+