/*
   * sound/oss/v_midi.c
   *
   * The low level driver for the Sound Blaster DS chips.
   *
   *
   * Copyright (C) by Hannu Savolainen 1993-1996
   *
   * USS/Lite for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
   * Version 2 (June 1991). See the "COPYING" file distributed with this software
   * for more info.
   * ??
   *
   * Changes
   *	Alan Cox		Modularisation, changed memory allocations
   *	Christoph Hellwig	Adapted to module_init/module_exit
   *
   * Status
   *	Untested
   */
  
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/spinlock.h>
  #include "sound_config.h"
  
  #include "v_midi.h"
  
  static vmidi_devc *v_devc[2] = { NULL, NULL};
  static int midi1,midi2;
  static void *midi_mem = NULL;
  
  /*
   * 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.
   */
  
  
  static int v_midi_open (int dev, int mode,
  	      void            (*input) (int dev, unsigned char data),
  	      void            (*output) (int dev)
  )
  {
  	vmidi_devc *devc = midi_devs[dev]->devc;
  	unsigned long flags;
  
  	if (devc == NULL)
  		return -(ENXIO);
  
  	spin_lock_irqsave(&devc->lock,flags);
  	if (devc->opened)
  	{
  		spin_unlock_irqrestore(&devc->lock,flags);
  		return -(EBUSY);
  	}
  	devc->opened = 1;
  	spin_unlock_irqrestore(&devc->lock,flags);
  
  	devc->intr_active = 1;
  
  	if (mode & OPEN_READ)
  	{
  		devc->input_opened = 1;
  		devc->midi_input_intr = input;
  	}
  
  	return 0;
  }
  
  static void v_midi_close (int dev)
  {
  	vmidi_devc *devc = midi_devs[dev]->devc;
  	unsigned long flags;
  
  	if (devc == NULL)
  		return;
  
  	spin_lock_irqsave(&devc->lock,flags);
  	devc->intr_active = 0;
  	devc->input_opened = 0;
  	devc->opened = 0;
  	spin_unlock_irqrestore(&devc->lock,flags);
  }
  
  static int v_midi_out (int dev, unsigned char midi_byte)
  {
  	vmidi_devc *devc = midi_devs[dev]->devc;
  	vmidi_devc *pdevc;
  
  	if (devc == NULL)
  		return -ENXIO;
  
  	pdevc = midi_devs[devc->pair_mididev]->devc;
  	if (pdevc->input_opened > 0){
  		if (MIDIbuf_avail(pdevc->my_mididev) > 500)
  			return 0;
  		pdevc->midi_input_intr (pdevc->my_mididev, midi_byte);
  	}
  	return 1;
  }
  
  static inline int v_midi_start_read (int dev)
  {
  	return 0;
  }
  
  static int v_midi_end_read (int dev)
  {
  	vmidi_devc *devc = midi_devs[dev]->devc;
  	if (devc == NULL)
  		return -ENXIO;
  
  	devc->intr_active = 0;
  	return 0;
  }
  
  /* why -EPERM and not -EINVAL?? */
  
  static inline int v_midi_ioctl (int dev, unsigned cmd, void __user *arg)
  {
  	return -EPERM;
  }
  
  
  #define MIDI_SYNTH_NAME	"Loopback MIDI"
  #define MIDI_SYNTH_CAPS	SYNTH_CAP_INPUT
  
  #include "midi_synth.h"
  
  static struct midi_operations v_midi_operations =
  {
  	.owner		= THIS_MODULE,
  	.info		= {"Loopback MIDI Port 1", 0, 0, SNDCARD_VMIDI},
  	.converter	= &std_midi_synth,
  	.in_info	= {0},
  	.open		= v_midi_open,
  	.close		= v_midi_close,
  	.ioctl		= v_midi_ioctl,
  	.outputc	= v_midi_out,
  	.start_read	= v_midi_start_read,
  	.end_read	= v_midi_end_read,
  };
  
  static struct midi_operations v_midi_operations2 =
  {
  	.owner		= THIS_MODULE,
  	.info		= {"Loopback MIDI Port 2", 0, 0, SNDCARD_VMIDI},
  	.converter	= &std_midi_synth,
  	.in_info	= {0},
  	.open		= v_midi_open,
  	.close		= v_midi_close,
  	.ioctl		= v_midi_ioctl,
  	.outputc	= v_midi_out,
  	.start_read	= v_midi_start_read,
  	.end_read	= v_midi_end_read,
  };
  
  /*
   *	We kmalloc just one of these - it makes life simpler and the code
   *	cleaner and the memory handling far more efficient
   */
   
  struct vmidi_memory
  {
  	/* Must be first */
  	struct midi_operations m_ops[2];
  	struct synth_operations s_ops[2];
  	struct vmidi_devc v_ops[2];
  };
  
  static void __init attach_v_midi (struct address_info *hw_config)
  {
  	struct vmidi_memory *m;
  	/* printk("Attaching v_midi device.....
  "); */
  
  	midi1 = sound_alloc_mididev();
  	if (midi1 == -1)
  	{
  		printk(KERN_ERR "v_midi: Too many midi devices detected
  ");
  		return;
  	}
  	
  	m = kmalloc(sizeof(struct vmidi_memory), GFP_KERNEL);
  	if (m == NULL)
  	{
  		printk(KERN_WARNING "Loopback MIDI: Failed to allocate memory
  ");
  		sound_unload_mididev(midi1);
  		return;
  	}
  	
  	midi_mem = m;
  	
  	midi_devs[midi1] = &m->m_ops[0];
  	
  
  	midi2 = sound_alloc_mididev();
  	if (midi2 == -1)
  	{
  		printk (KERN_ERR "v_midi: Too many midi devices detected
  ");
  		kfree(m);
  		sound_unload_mididev(midi1);
  		return;
  	}
  
  	midi_devs[midi2] = &m->m_ops[1];
  
  	/* printk("VMIDI1: %d   VMIDI2: %d
  ",midi1,midi2); */
  
  	/* for MIDI-1 */
  	v_devc[0] = &m->v_ops[0];
  	memcpy ((char *) midi_devs[midi1], (char *) &v_midi_operations,
  		sizeof (struct midi_operations));
  
  	v_devc[0]->my_mididev = midi1;
  	v_devc[0]->pair_mididev = midi2;
  	v_devc[0]->opened = v_devc[0]->input_opened = 0;
  	v_devc[0]->intr_active = 0;
  	v_devc[0]->midi_input_intr = NULL;
  	spin_lock_init(&v_devc[0]->lock);
  
  	midi_devs[midi1]->devc = v_devc[0];
  
  	midi_devs[midi1]->converter = &m->s_ops[0];
  	std_midi_synth.midi_dev = midi1;
  	memcpy ((char *) midi_devs[midi1]->converter, (char *) &std_midi_synth,
  		sizeof (struct synth_operations));
  	midi_devs[midi1]->converter->id = "V_MIDI 1";
  
  	/* for MIDI-2 */
  	v_devc[1] = &m->v_ops[1];
  
  	memcpy ((char *) midi_devs[midi2], (char *) &v_midi_operations2,
  		sizeof (struct midi_operations));
  
  	v_devc[1]->my_mididev = midi2;
  	v_devc[1]->pair_mididev = midi1;
  	v_devc[1]->opened = v_devc[1]->input_opened = 0;
  	v_devc[1]->intr_active = 0;
  	v_devc[1]->midi_input_intr = NULL;
  	spin_lock_init(&v_devc[1]->lock);
  
  	midi_devs[midi2]->devc = v_devc[1];
  	midi_devs[midi2]->converter = &m->s_ops[1];
  
  	std_midi_synth.midi_dev = midi2;
  	memcpy ((char *) midi_devs[midi2]->converter, (char *) &std_midi_synth,
  		sizeof (struct synth_operations));
  	midi_devs[midi2]->converter->id = "V_MIDI 2";
  
  	sequencer_init();
  	/* printk("Attached v_midi device
  "); */
  }
  
  static inline int __init probe_v_midi(struct address_info *hw_config)
  {
  	return(1);	/* always OK */
  }
  
  
  static void __exit unload_v_midi(struct address_info *hw_config)
  {
  	sound_unload_mididev(midi1);
  	sound_unload_mididev(midi2);
  	kfree(midi_mem);
  }
  
  static struct address_info cfg; /* dummy */
  
  static int __init init_vmidi(void)
  {
  	printk("MIDI Loopback device driver
  ");
  	if (!probe_v_midi(&cfg))
  		return -ENODEV;
  	attach_v_midi(&cfg);
  
  	return 0;
  }
  
  static void __exit cleanup_vmidi(void)
  {
  	unload_v_midi(&cfg);
  }
  
  module_init(init_vmidi);
  module_exit(cleanup_vmidi);
  MODULE_LICENSE("GPL");