/*
 *  Copyright (c) by Uros Bizjak <uros@kss-loka.si>
 *                   
 *  Routines for OPL2/OPL3/OPL4 control
 *
 *   This program is free software; you can redistribute it and/or modify 
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <linux/slab.h>
#include <linux/export.h>
#include <linux/nospec.h>
#include <sound/opl3.h>
#include <sound/asound_fm.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;

                        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)
                strlcpy(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;
}