/*
 * sound/sb_dsp.c
 *
 * The low level driver for the SoundBlaster DS 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.
 *
 */

#include "sound_config.h"

#if defined(CONFIGURE_SOUNDCARD) && !defined(EXCLUDE_SB) && !defined(EXCLUDE_MIDI)

#include "sb.h"
#undef SB_TEST_IRQ

/*
 * The DSP channel can be used either for input or output. Variable
 * 'sb_irq_mode' will be set when the program calls read or write first time
 * after open. Current version doesn't support mode changes without closing
 * and reopening the device. Support for this feature may be implemented in a
 * future version of this driver.
 */

extern int      sb_dsp_ok;	/* Set to 1 atfer successful initialization */
extern int      sbc_base;

extern int      sb_midi_mode;
extern int      sb_midi_busy;	/*


				 * *  * * 1 if the process has output to MIDI
				 *
				 */
extern int      sb_dsp_busy;
extern int      sb_dsp_highspeed;

extern volatile int sb_irq_mode;
extern int      sb_duplex_midi;
extern int      sb_intr_active;
int             input_opened = 0;
static int      my_dev;

void            (*midi_input_intr) (int dev, unsigned char data);

static int
sb_midi_open (int dev, int mode,
	      void            (*input) (int dev, unsigned char data),
	      void            (*output) (int dev)
)
{
  int             ret;

  if (!sb_dsp_ok)
    {
      printk ("SB Error: MIDI hardware not installed\n");
      return RET_ERROR (ENXIO);
    }

  if (sb_midi_busy)
    return RET_ERROR (EBUSY);

  if (mode != OPEN_WRITE && !sb_duplex_midi)
    {
      if (num_midis == 1)
	printk ("SoundBlaster: Midi input not currently supported\n");
      return RET_ERROR (EPERM);
    }

  sb_midi_mode = NORMAL_MIDI;
  if (mode != OPEN_WRITE)
    {
      if (sb_dsp_busy || sb_intr_active)
	return RET_ERROR (EBUSY);
      sb_midi_mode = UART_MIDI;
    }

  if (sb_dsp_highspeed)
    {
      printk ("SB Error: Midi output not possible during stereo or high speed audio\n");
      return RET_ERROR (EBUSY);
    }

  if (sb_midi_mode == UART_MIDI)
    {
      sb_irq_mode = IMODE_MIDI;

      sb_reset_dsp ();

      if (!sb_dsp_command (0x35))
	return RET_ERROR (EIO);	/*
				 * Enter the UART mode
				 */
      sb_intr_active = 1;

      if ((ret = sb_get_irq ()) < 0)
	{
	  sb_reset_dsp ();
	  return 0;		/*
				 * IRQ not free
				 */
	}
      input_opened = 1;
      midi_input_intr = input;
    }

  sb_midi_busy = 1;

  return 0;
}

static void
sb_midi_close (int dev)
{
  if (sb_midi_mode == UART_MIDI)
    {
      sb_reset_dsp ();		/*
				 * The only way to kill the UART mode
				 */
      sb_free_irq ();
    }
  sb_intr_active = 0;
  sb_midi_busy = 0;
  input_opened = 0;
}

static int
sb_midi_out (int dev, unsigned char midi_byte)
{
  unsigned long   flags;

  if (sb_midi_mode == NORMAL_MIDI)
    {
      DISABLE_INTR (flags);
      if (sb_dsp_command (0x38))
	sb_dsp_command (midi_byte);
      else
	printk ("SB Error: Unable to send a MIDI byte\n");
      RESTORE_INTR (flags);
    }
  else
    sb_dsp_command (midi_byte);	/*
				 * UART write
				 */

  return 1;
}

static int
sb_midi_start_read (int dev)
{
  if (sb_midi_mode != UART_MIDI)
    {
      printk ("SoundBlaster: MIDI input not implemented.\n");
      return RET_ERROR (EPERM);
    }
  return 0;
}

static int
sb_midi_end_read (int dev)
{
  if (sb_midi_mode == UART_MIDI)
    {
      sb_reset_dsp ();
      sb_intr_active = 0;
    }
  return 0;
}

static int
sb_midi_ioctl (int dev, unsigned cmd, unsigned arg)
{
  return RET_ERROR (EPERM);
}

void
sb_midi_interrupt (int dummy)
{
  unsigned long   flags;
  unsigned char   data;

  DISABLE_INTR (flags);

  data = INB (DSP_READ);
  if (input_opened)
    midi_input_intr (my_dev, data);

  RESTORE_INTR (flags);
}

#define MIDI_SYNTH_NAME	"SoundBlaster Midi"
#define MIDI_SYNTH_CAPS	0
#include "midi_synth.h"

static struct midi_operations sb_midi_operations =
{
  {"SoundBlaster", 0, 0, SNDCARD_SB},
  &std_midi_synth,
  {0},
  sb_midi_open,
  sb_midi_close,
  sb_midi_ioctl,
  sb_midi_out,
  sb_midi_start_read,
  sb_midi_end_read,
  NULL,				/*
				 * Kick
				 */
  NULL,				/*
				 * command
				 */
  NULL,				/*
				 * buffer_status
				 */
  NULL
};

void
sb_midi_init (int model)
{
  if (num_midis >= MAX_MIDI_DEV)
    {
      printk ("Sound: Too many midi devices detected\n");
      return;
    }

  std_midi_synth.midi_dev = num_midis;
  my_dev = num_midis;
  midi_devs[num_midis++] = &sb_midi_operations;
}

#endif