/*
 * sound/opl3.c
 * 
 * A low level driver for Yamaha YM3812 and OPL-3 -chips
 * 
 * Copyright by Hannu Savolainen 1993
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer. 2.
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 */

/* Major improvements to the FM handling 30AUG92 by Rob Hooft, */
/* hooft@chem.ruu.nl */

#include "sound_config.h"

#if defined(CONFIGURE_SOUNDCARD) && !defined(EXCLUDE_YM3812)

#include "opl3.h"

#define MAX_VOICE	18
#define OFFS_4OP	11	/* Definitions for the operators OP3 and OP4
				 * begin here */

static int      opl3_enabled = 0;
static int      left_address = 0x388, right_address = 0x388, both_address = 0;

static int      nr_voices = 9;
static int      logical_voices[MAX_VOICE] =
{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17};

struct voice_info
  {
    unsigned char   keyon_byte;
    long            bender;
    long            bender_range;
    unsigned long   orig_freq;
    unsigned long   current_freq;
    int             mode;
  };

static struct voice_info voices[MAX_VOICE];

static struct sbi_instrument *instrmap;
static struct sbi_instrument *active_instrument[MAX_VOICE] =
{NULL};

static struct synth_info fm_info =
{"AdLib", 0, SYNTH_TYPE_FM, FM_TYPE_ADLIB, 0, 9, 0, SBFM_MAXINSTR, 0};

static int      already_initialized = 0;

static int      opl3_ok = 0;
static int      opl3_busy = 0;
static int      fm_model = 0;	/* 0=no fm, 1=mono, 2=SB Pro 1, 3=SB Pro 2	 */

static int      store_instr (int instr_no, struct sbi_instrument *instr);
static void     freq_to_fnum (int freq, int *block, int *fnum);
static void     opl3_command (int io_addr, unsigned int addr, unsigned int val);
static int      opl3_kill_note (int dev, int voice, int velocity);
static unsigned char connection_mask = 0x00;

void
enable_opl3_mode (int left, int right, int both)
{
  opl3_enabled = 1;
  left_address = left;
  right_address = right;
  both_address = both;
  fm_info.capabilities = SYNTH_CAP_OPL3;
  fm_info.synth_subtype = FM_TYPE_OPL3;
}

static void
enter_4op_mode (void)
{
  int             i;
  static int      voices_4op[MAX_VOICE] =
  {0, 1, 2, 9, 10, 11, 6, 7, 8, 15, 16, 17};

  connection_mask = 0x3f;
  opl3_command (right_address, CONNECTION_SELECT_REGISTER, 0x3f);	/* Select all 4-OP
									 * voices */
  for (i = 0; i < 3; i++)
    physical_voices[i].voice_mode = 4;
  for (i = 3; i < 6; i++)
    physical_voices[i].voice_mode = 0;

  for (i = 9; i < 12; i++)
    physical_voices[i].voice_mode = 4;
  for (i = 12; i < 15; i++)
    physical_voices[i].voice_mode = 0;

  for (i = 0; i < 12; i++)
    logical_voices[i] = voices_4op[i];
  nr_voices = 12;
}

static int
opl3_ioctl (int dev,
	    unsigned int cmd, unsigned int arg)
{
  switch (cmd)
    {

    case SNDCTL_FM_LOAD_INSTR:
      {
	struct sbi_instrument ins;

	IOCTL_FROM_USER ((char *) &ins, (char *) arg, 0, sizeof (ins));

	if (ins.channel < 0 || ins.channel >= SBFM_MAXINSTR)
	  {
	    printk ("FM Error: Invalid instrument number %d\n", ins.channel);
	    return RET_ERROR (EINVAL);
	  }

	pmgr_inform (dev, PM_E_PATCH_LOADED, ins.channel, 0, 0, 0);
	return store_instr (ins.channel, &ins);
      }
      break;

    case SNDCTL_SYNTH_INFO:
      fm_info.nr_voices = (nr_voices == 12) ? 6 : nr_voices;

      IOCTL_TO_USER ((char *) arg, 0, &fm_info, sizeof (fm_info));
      return 0;
      break;

    case SNDCTL_SYNTH_MEMAVL:
      return 0x7fffffff;
      break;

    case SNDCTL_FM_4OP_ENABLE:
      if (opl3_enabled)
	enter_4op_mode ();
      return 0;
      break;

    default:
      return RET_ERROR (EINVAL);
    }

}

int
opl3_detect (int ioaddr)
{
  /*
   * This function returns 1 if the FM chicp is present at the given I/O port
   * The detection algorithm plays with the timer built in the FM chip and
   * looks for a change in the status register.
   * 
   * Note! The timers of the FM chip are not connected to AdLib (and compatible)
   * boards.
   * 
   * Note2! The chip is initialized if detected.
   */

  unsigned char   stat1, stat2;
  int             i;

  if (already_initialized)
    {
      return 0;			/* Do avoid duplicate initializations */
    }

  if (opl3_enabled)
    ioaddr = left_address;

  opl3_command (ioaddr, TIMER_CONTROL_REGISTER, TIMER1_MASK | TIMER2_MASK);	/* Reset timers 1 and 2 */
  opl3_command (ioaddr, TIMER_CONTROL_REGISTER, IRQ_RESET);	/* Reset the IRQ of FM
								 * chicp */

  stat1 = INB (ioaddr);		/* Read status register */

  if ((stat1 & 0xE0) != 0x00)
    {
      return 0;			/* Should be 0x00	 */
    }

  opl3_command (ioaddr, TIMER1_REGISTER, 0xff);	/* Set timer 1 to 0xff */
  opl3_command (ioaddr, TIMER_CONTROL_REGISTER,
		TIMER2_MASK | TIMER1_START);	/* Unmask and start timer 1 */

  /*
   * Now we have to delay at least 80 msec
   */

  for (i = 0; i < 50; i++)
    tenmicrosec ();		/* To be sure */

  stat2 = INB (ioaddr);		/* Read status after timers have expired */

  /* Stop the timers */

  opl3_command (ioaddr, TIMER_CONTROL_REGISTER, TIMER1_MASK | TIMER2_MASK);	/* Reset timers 1 and 2 */
  opl3_command (ioaddr, TIMER_CONTROL_REGISTER, IRQ_RESET);	/* Reset the IRQ of FM
								 * chicp */

  if ((stat2 & 0xE0) != 0xc0)
    {
      return 0;			/* There is no YM3812 */
    }

  /* There is a FM chicp in this address. Now set some default values. */

  for (i = 0; i < 9; i++)
    opl3_command (ioaddr, KEYON_BLOCK + i, 0);	/* Note off */

  opl3_command (ioaddr, TEST_REGISTER, ENABLE_WAVE_SELECT);
  opl3_command (ioaddr, PERCUSSION_REGISTER, 0x00);	/* Melodic mode. */

  return 1;
}

static int
opl3_kill_note (int dev, int voice, int velocity)
{
  struct physical_voice_info *map;

  if (voice < 0 || voice >= nr_voices)
    return 0;

  map = &physical_voices[logical_voices[voice]];

  DEB (printk ("Kill note %d\n", voice));

  if (map->voice_mode == 0)
    return 0;

  opl3_command (map->ioaddr, KEYON_BLOCK + map->voice_num, voices[voice].keyon_byte & ~0x20);

  voices[voice].keyon_byte = 0;
  voices[voice].bender = 0;
  voices[voice].bender_range = 200;	/* 200 cents = 2 semitones */
  voices[voice].orig_freq = 0;
  voices[voice].current_freq = 0;
  voices[voice].mode = 0;

  return 0;
}

#define HIHAT			0
#define CYMBAL			1
#define TOMTOM			2
#define SNARE			3
#define BDRUM			4
#define UNDEFINED		TOMTOM
#define DEFAULT			TOMTOM

static int
store_instr (int instr_no, struct sbi_instrument *instr)
{

  if (instr->key != FM_PATCH && (instr->key != OPL3_PATCH || !opl3_enabled))
    printk ("FM warning: Invalid patch format field (key) 0x%x\n", instr->key);
  memcpy ((char *) &(instrmap[instr_no]), (char *) instr, sizeof (*instr));

  return 0;
}

static int
opl3_set_instr (int dev, int voice, int instr_no)
{
  if (voice < 0 || voice >= nr_voices)
    return 0;

  if (instr_no < 0 || instr_no >= SBFM_MAXINSTR)
    return 0;

  active_instrument[voice] = &instrmap[instr_no];
  return 0;
}

/*
 * The next table looks magical, but it certainly is not. Its values have
 * been calculated as table[i]=8*log(i/64)/log(2) with an obvious exception
 * for i=0. This log-table converts a linear volume-scaling (0..127) to a
 * logarithmic scaling as present in the FM-synthesizer chips. so :    Volume
 * 64 =  0 db = relative volume  0 and:    Volume 32 = -6 db = relative
 * volume -8 it was implemented as a table because it is only 128 bytes and
 * it saves a lot of log() calculations. (RH)
 */
char            fm_volume_table[128] =
{-64, -48, -40, -35, -32, -29, -27, -26,	/* 0 -   7 */
 -24, -23, -21, -20, -19, -18, -18, -17,	/* 8 -  15 */
 -16, -15, -15, -14, -13, -13, -12, -12,	/* 16 -  23 */
 -11, -11, -10, -10, -10, -9, -9, -8,	/* 24 -  31 */
 -8, -8, -7, -7, -7, -6, -6, -6,/* 32 -  39 */
 -5, -5, -5, -5, -4, -4, -4, -4,/* 40 -  47 */
 -3, -3, -3, -3, -2, -2, -2, -2,/* 48 -  55 */
 -2, -1, -1, -1, -1, 0, 0, 0,	/* 56 -  63 */
 0, 0, 0, 1, 1, 1, 1, 1,	/* 64 -  71 */
 1, 2, 2, 2, 2, 2, 2, 2,	/* 72 -  79 */
 3, 3, 3, 3, 3, 3, 3, 4,	/* 80 -  87 */
 4, 4, 4, 4, 4, 4, 4, 5,	/* 88 -  95 */
 5, 5, 5, 5, 5, 5, 5, 5,	/* 96 - 103 */
 6, 6, 6, 6, 6, 6, 6, 6,	/* 104 - 111 */
 6, 7, 7, 7, 7, 7, 7, 7,	/* 112 - 119 */
 7, 7, 7, 8, 8, 8, 8, 8};	/* 120 - 127 */

static void
calc_vol (unsigned char *regbyte, int volume)
{
  int             level = (~*regbyte & 0x3f);

  if (level)
    level += fm_volume_table[volume];

  if (level > 0x3f)
    level = 0x3f;
  if (level < 0)
    level = 0;

  *regbyte = (*regbyte & 0xc0) | (~level & 0x3f);
}

static void
set_voice_volume (int voice, int volume)
{
  unsigned char   vol1, vol2, vol3, vol4;
  struct sbi_instrument *instr;
  struct physical_voice_info *map;

  if (voice < 0 || voice >= nr_voices)
    return;

  map = &physical_voices[logical_voices[voice]];

  instr = active_instrument[voice];

  if (!instr)
    instr = &instrmap[0];

  if (instr->channel < 0)
    return;

  if (voices[voice].mode == 0)
    return;

  if (voices[voice].mode == 2)
    {				/* 2 OP voice */

      vol1 = instr->operators[2];
      vol2 = instr->operators[3];

      if ((instr->operators[10] & 0x01))
	{			/* Additive synthesis	 */
	  calc_vol (&vol1, volume);
	  calc_vol (&vol2, volume);
	}
      else
	{			/* FM synthesis */
	  calc_vol (&vol2, volume);
	}

      opl3_command (map->ioaddr, KSL_LEVEL + map->op[0], vol1);	/* Modulator volume */
      opl3_command (map->ioaddr, KSL_LEVEL + map->op[1], vol2);	/* Carrier volume */
    }
  else
    {				/* 4 OP voice */
      int             connection;

      vol1 = instr->operators[2];
      vol2 = instr->operators[3];
      vol3 = instr->operators[OFFS_4OP + 2];
      vol4 = instr->operators[OFFS_4OP + 3];

      /*
       * The connection method for 4 OP voices is defined by the rightmost
       * bits at the offsets 10 and 10+OFFS_4OP
       */

      connection = ((instr->operators[10] & 0x01) << 1) | (instr->operators[10 + OFFS_4OP] & 0x01);

      switch (connection)
	{
	case 0:
	  calc_vol (&vol4, volume);	/* Just the OP 4 is carrier */
	  break;

	case 1:
	  calc_vol (&vol2, volume);
	  calc_vol (&vol4, volume);
	  break;

	case 2:
	  calc_vol (&vol1, volume);
	  calc_vol (&vol4, volume);
	  break;

	case 3:
	  calc_vol (&vol1, volume);
	  calc_vol (&vol3, volume);
	  calc_vol (&vol4, volume);
	  break;

	default:/* Why ?? */ ;
	}

      opl3_command (map->ioaddr, KSL_LEVEL + map->op[0], vol1);
      opl3_command (map->ioaddr, KSL_LEVEL + map->op[1], vol2);
      opl3_command (map->ioaddr, KSL_LEVEL + map->op[2], vol3);
      opl3_command (map->ioaddr, KSL_LEVEL + map->op[3], vol4);
    }
}

static int
opl3_start_note (int dev, int voice, int note, int volume)
{
  unsigned char   data, fpc;
  int             block, fnum, freq, voice_mode;
  struct sbi_instrument *instr;
  struct physical_voice_info *map;

  if (voice < 0 || voice >= nr_voices)
    return 0;

  map = &physical_voices[logical_voices[voice]];

  if (map->voice_mode == 0)
    return 0;

  if (note == 255)		/* Just change the volume */
    {
      set_voice_volume (voice, volume);
      return 0;
    }

  /* Kill previous note before playing */
  opl3_command (map->ioaddr, KSL_LEVEL + map->op[1], 0xff);	/* Carrier volume to min */
  opl3_command (map->ioaddr, KSL_LEVEL + map->op[0], 0xff);	/* Modulator volume to */

  if (map->voice_mode == 4)
    {
      opl3_command (map->ioaddr, KSL_LEVEL + map->op[2], 0xff);
      opl3_command (map->ioaddr, KSL_LEVEL + map->op[3], 0xff);
    }

  opl3_command (map->ioaddr, KEYON_BLOCK + map->voice_num, 0x00);	/* Note off */

  instr = active_instrument[voice];

  if (!instr)
    instr = &instrmap[0];

  if (instr->channel < 0)
    {
      printk (
	       "OPL3: Initializing voice %d with undefined instrument\n",
	       voice);
      return 0;
    }