sequencer.c

<Linux1.0核心游记>电子书+书后源码+Linux1.0源码

void
sequencer_release (int dev, struct fileinfo *file)
  {
    int             i;
    int             mode = file->mode & O_ACCMODE;

    dev = dev >> 4;

    DEB (printk ("sequencer_release(dev=%d)\n", dev));

    if (dev)			/* Patch manager device */
      {
	dev--;
	pmgr_release (dev);
	pmgr_present[dev] = 0;
	return;
      }

    /*
     * Wait until the queue is empty
     */

    while (!PROCESS_ABORTING (seq_sleeper, seq_sleep_flag) && qlen)
      {
	seq_sync ();
      }

    if (mode != OPEN_READ)
      seq_drain_midi_queues ();	/* Ensure the output queues are empty */
    seq_reset ();
    if (mode != OPEN_READ)
      seq_drain_midi_queues ();	/* Flush the all notes off messages */

    for (i = 0; i < num_midis; i++)
      if (midi_opened[i])
	midi_devs[i]->close (i);

    if (mode == OPEN_WRITE || mode == OPEN_READWRITE)
      for (i = 0; i < num_synths; i++)
	if (synth_open_mask & (1 << i))	/* Actually opened */
	  if (synth_devs[i])
	    synth_devs[i]->close (i);

    for (i = 0; i < num_synths; i++)
      if (pmgr_present[i])
	pmgr_inform (i, PM_E_CLOSED, 0, 0, 0, 0);

    sequencer_busy = 0;
  }

static int
seq_sync (void)
{
  if (qlen && !seq_playing && !PROCESS_ABORTING (seq_sleeper, seq_sleep_flag))
    seq_startplay ();

  if (qlen && !SOMEONE_WAITING (seq_sleeper, seq_sleep_flag))	/* Queue not empty */
    {
      DO_SLEEP (seq_sleeper, seq_sleep_flag, 0);
    }

  return qlen;
}

static void
midi_outc (int dev, unsigned char data)
{
  /*
   * NOTE! Calls sleep(). Don't call this from interrupt.
   */

  int             n;

  /* This routine sends one byte to the Midi channel. */
  /* If the output Fifo is full, it waits until there */
  /* is space in the queue */

  n = 300;			/* Timeout in jiffies */

  while (n && !midi_devs[dev]->putc (dev, data))
    {
      DO_SLEEP (seq_sleeper, seq_sleep_flag, 4);
      n--;
    }
}

static void
seq_reset (void)
{
  /*
   * NOTE! Calls sleep(). Don't call this from interrupt.
   */

  int             i, chn;

  sound_stop_timer ();

  qlen = qhead = qtail = 0;
  iqlen = iqhead = iqtail = 0;

  for (i = 0; i < num_synths; i++)
    if (synth_open_mask & (1 << i))
      if (synth_devs[i])
	synth_devs[i]->reset (i);

  for (i = 0; i < num_midis; i++)
    if (midi_written[i])	/* Midi used. Some notes may still be playing */
      {
	for (chn = 0; chn < 16; chn++)
	  {
	    midi_outc (i, 
		(unsigned char)(0xb0 + (chn & 0xff))); /* Channel msg */
	    midi_outc (i, 0x7b);/* All notes off */
	    midi_outc (i, 0);	/* Dummy parameter */
	  }

	midi_devs[i]->close (i);

	midi_written[i] = 0;
	midi_opened[i] = 0;
      }

  seq_playing = 0;

  if (SOMEONE_WAITING (seq_sleeper, seq_sleep_flag))
    printk ("Sequencer Warning: Unexpected sleeping process\n");

}

int
sequencer_ioctl (int dev, struct fileinfo *file,
		 unsigned int cmd, unsigned int arg)
{
  int             midi_dev, orig_dev;
  int             mode = file->mode & O_ACCMODE;

  orig_dev = dev = dev >> 4;

  switch (cmd)
    {

    case SNDCTL_SEQ_SYNC:
      if (dev)			/* Patch manager */
	return RET_ERROR (EIO);

      if (mode == OPEN_READ)
	return 0;
      while (qlen && !PROCESS_ABORTING (seq_sleeper, seq_sleep_flag))
	seq_sync ();
      return 0;
      break;

    case SNDCTL_SEQ_RESET:
      if (dev)			/* Patch manager */
	return RET_ERROR (EIO);

      seq_reset ();
      return 0;
      break;

    case SNDCTL_SEQ_TESTMIDI:
      if (dev)			/* Patch manager */
	return RET_ERROR (EIO);

      midi_dev = IOCTL_IN (arg);
      if (midi_dev >= num_midis)
	return RET_ERROR (ENXIO);

      if (!midi_opened[midi_dev])
	{
	  int             err, mode;

	  mode = file->mode & O_ACCMODE;
	  if ((err = midi_devs[midi_dev]->open (midi_dev, mode,
						sequencer_midi_input,
						sequencer_midi_output)) < 0)
	    return err;
	}

      midi_opened[midi_dev] = 1;

      return 0;
      break;

    case SNDCTL_SEQ_GETINCOUNT:
      if (dev)			/* Patch manager */
	return RET_ERROR (EIO);

      if (mode == OPEN_WRITE)
	return 0;
      return IOCTL_OUT (arg, iqlen);
      break;

    case SNDCTL_SEQ_GETOUTCOUNT:

      if (mode == OPEN_READ)
	return 0;
      return IOCTL_OUT (arg, SEQ_MAX_QUEUE - qlen);
      break;

    case SNDCTL_SEQ_CTRLRATE:
      if (dev)			/* Patch manager */
	return RET_ERROR (EIO);

      /* If *arg == 0, just return the current rate */
      return IOCTL_OUT (arg, HZ);
      break;

    case SNDCTL_SEQ_RESETSAMPLES:
      dev = IOCTL_IN (arg);
      if (dev < 0 || dev >= num_synths)
	return RET_ERROR (ENXIO);

      if (!(synth_open_mask & (1 << dev)) && !orig_dev)
	return RET_ERROR (EBUSY);

      if (!orig_dev && pmgr_present[dev])
	pmgr_inform (dev, PM_E_PATCH_RESET, 0, 0, 0, 0);

      return synth_devs[dev]->ioctl (dev, cmd, arg);
      break;

    case SNDCTL_SEQ_NRSYNTHS:
      return IOCTL_OUT (arg, num_synths);
      break;

    case SNDCTL_SEQ_NRMIDIS:
      return IOCTL_OUT (arg, num_midis);
      break;

    case SNDCTL_SYNTH_MEMAVL:
      {
	int             dev = IOCTL_IN (arg);

	if (dev < 0 || dev >= num_synths)
	  return RET_ERROR (ENXIO);

	if (!(synth_open_mask & (1 << dev)) && !orig_dev)
	  return RET_ERROR (EBUSY);

	return IOCTL_OUT (arg, synth_devs[dev]->ioctl (dev, cmd, arg));
      }
      break;

    case SNDCTL_FM_4OP_ENABLE:
      {
	int             dev = IOCTL_IN (arg);

	if (dev < 0 || dev >= num_synths)
	  return RET_ERROR (ENXIO);

	if (!(synth_open_mask & (1 << dev)))
	  return RET_ERROR (ENXIO);

	synth_devs[dev]->ioctl (dev, cmd, arg);
	return 0;
      }
      break;

    case SNDCTL_SYNTH_INFO:
      {
	struct synth_info inf;
	int             dev;

	IOCTL_FROM_USER ((char *) &inf, (char *) arg, 0, sizeof (inf));
	dev = inf.device;

	if (dev < 0 || dev >= num_synths)
	  return RET_ERROR (ENXIO);

	if (!(synth_open_mask & (1 << dev)) && !orig_dev)
	  return RET_ERROR (EBUSY);

	return synth_devs[dev]->ioctl (dev, cmd, arg);
      }
      break;

    case SNDCTL_MIDI_INFO:
      {
	struct midi_info inf;
	int             dev;

	IOCTL_FROM_USER ((char *) &inf, (char *) arg, 0, sizeof (inf));
	dev = inf.device;

	if (dev < 0 || dev >= num_midis)
	  return RET_ERROR (ENXIO);

	IOCTL_TO_USER ((char *) arg, 0, (char *) &(midi_devs[dev]->info), sizeof (inf));
	return 0;
      }
      break;

    case SNDCTL_PMGR_IFACE:
      {
	struct patmgr_info *inf;
	int             dev, err;

	inf = (struct patmgr_info *) KERNEL_MALLOC (sizeof (*inf));

	IOCTL_FROM_USER ((char *) inf, (char *) arg, 0, sizeof (*inf));
	dev = inf->device;

	if (dev < 0 || dev >= num_synths)
	  {
	    KERNEL_FREE (inf);
	    return RET_ERROR (ENXIO);
	  }

	if (!synth_devs[dev]->pmgr_interface)
	  {
	    KERNEL_FREE (inf);
	    return RET_ERROR (ENXIO);
	  }

	if ((err = synth_devs[dev]->pmgr_interface (dev, inf)) == -1)
	  {
	    KERNEL_FREE (inf);
	    return err;
	  }

	IOCTL_TO_USER ((char *) arg, 0, (char *) inf, sizeof (*inf));
	KERNEL_FREE (inf);
	return 0;
      }
      break;

    case SNDCTL_PMGR_ACCESS:
      {
	struct patmgr_info *inf;
	int             dev, err;

	inf = (struct patmgr_info *) KERNEL_MALLOC (sizeof (*inf));

	IOCTL_FROM_USER ((char *) inf, (char *) arg, 0, sizeof (*inf));
	dev = inf->device;

	if (dev < 0 || dev >= num_synths)
	  {
	    KERNEL_FREE (inf);
	    return RET_ERROR (ENXIO);
	  }

	if (!pmgr_present[dev])
	  {
	    KERNEL_FREE (inf);
	    return RET_ERROR (ESRCH);
	  }

	if ((err = pmgr_access (dev, inf)) < 0)
	  {
	    KERNEL_FREE (inf);
	    return err;
	  }

	IOCTL_TO_USER ((char *) arg, 0, (char *) inf, sizeof (*inf));
	KERNEL_FREE (inf);
	return 0;
      }
      break;

    case SNDCTL_SEQ_TRESHOLD:
      {
	int             tmp = IOCTL_IN (arg);

	if (dev)		/* Patch manager */
	  return RET_ERROR (EIO);

	if (tmp < 1)
	  tmp = 1;
	if (tmp >= SEQ_MAX_QUEUE)
	  tmp = SEQ_MAX_QUEUE - 1;
	output_treshold = tmp;
	return 0;
      }
      break;

    default:
      if (dev)			/* Patch manager */
	return RET_ERROR (EIO);

      if (mode == OPEN_READ)
	return RET_ERROR (EIO);

      if (!synth_devs[0])
	return RET_ERROR (ENXIO);
      if (!(synth_open_mask & (1 << 0)))
	return RET_ERROR (ENXIO);
      return synth_devs[0]->ioctl (0, cmd, arg);
      break;
    }

  return RET_ERROR (EINVAL);
}

#ifdef ALLOW_SELECT
int
sequencer_select (int dev, struct fileinfo *file, int sel_type, select_table * wait)
{
  dev = dev >> 4;

  switch (sel_type)
    {
    case SEL_IN:
      if (!iqlen)
	{
	  select_wait (&midi_sleeper, wait);
	  return 0;
	}
      return 1;

      break;

    case SEL_OUT:
      if (qlen >= SEQ_MAX_QUEUE)
	{
	  select_wait (&seq_sleeper, wait);
	  return 0;
	}
      return 1;
      break;

    case SEL_EX:
      return 0;
    }

  return 0;
}

#endif

void
sequencer_timer (void)
{
  seq_startplay ();
}

int
note_to_freq (int note_num)
{

  /*
   * This routine converts a midi note to a frequency (multiplied by 1000)
   */

  int             note, octave, note_freq;
  int             notes[] =
  {
    261632, 277189, 293671, 311132, 329632, 349232,
    369998, 391998, 415306, 440000, 466162, 493880
  };				/* Note freq*1000 for octave 5 */

#define BASE_OCTAVE	5

  octave = note_num / 12;
  note = note_num % 12;

  note_freq = notes[note];

  if (octave < BASE_OCTAVE)
    note_freq >>= (BASE_OCTAVE - octave);
  else if (octave > BASE_OCTAVE)
    note_freq <<= (octave - BASE_OCTAVE);

  /* note_freq >>= 1;	 */

  return note_freq;
}

unsigned long
compute_finetune (unsigned long base_freq, int bend, int range)
{
  unsigned long   amount;
  int             negative, semitones, cents;

  if (!bend)
    return base_freq;
  if (!range)
    return base_freq;

  if (!base_freq)
    return base_freq;

  if (range >= 8192)
    range = 8191;

  bend = bend * range / 8192;
  if (!bend)
    return base_freq;

  negative = bend < 0 ? 1 : 0;

  if (bend < 0)
    bend *= -1;
  if (bend > range)
    bend = range;

  if (bend > 2399)
    bend = 2399;

  semitones = bend / 100;
  cents = bend % 100;

  amount = semitone_tuning[semitones] * cent_tuning[cents] / 10000;

  if (negative)
    return (base_freq * 10000) / amount;	/* Bend down */
  else
    return (base_freq * amount) / 10000;	/* Bend up */
}


long
sequencer_init (long mem_start)
{

  sequencer_ok = 1;
  PERMANENT_MALLOC(unsigned char*, queue, SEQ_MAX_QUEUE*EV_SZ, mem_start);
  PERMANENT_MALLOC(unsigned char*, iqueue, SEQ_MAX_QUEUE*IEV_SZ, mem_start);
  return mem_start;
}

#else
/* Stub version */
int
sequencer_read (int dev, struct fileinfo *file, snd_rw_buf * buf, int count)
{
  return RET_ERROR (EIO);
}

int
sequencer_write (int dev, struct fileinfo *file, snd_rw_buf * buf, int count)
{
  return RET_ERROR (EIO);
}

int
sequencer_open (int dev, struct fileinfo *file)
  {
    return RET_ERROR (ENXIO);
  }

void
sequencer_release (int dev, struct fileinfo *file)
  {
  }
int
sequencer_ioctl (int dev, struct fileinfo *file,
		 unsigned int cmd, unsigned int arg)
{
  return RET_ERROR (EIO);
}

int
sequencer_lseek (int dev, struct fileinfo *file, off_t offset, int orig)
{
  return RET_ERROR (EIO);
}

long
sequencer_init (long mem_start)
{
  return mem_start;
}

int
sequencer_select (int dev, struct fileinfo *file, int sel_type, select_table * wait)
{
  return RET_ERROR (EIO);
}

#endif

#endif