/*
 * sound/midi_synth.c
 *
 * High level midi sequencer manager for dumb MIDI interfaces.
 */
/*
 * Copyright (C) by Hannu Savolainen 1993-1997
 *
 * OSS/Free 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.
 */
/*
 * Thomas Sailer   : ioctl code reworked (vmalloc/vfree removed)
 * Andrew Veliath  : fixed running status in MIDI input state machine
 */
#define USE_SEQ_MACROS
#define USE_SIMPLE_MACROS

#include "sound_config.h"

#define _MIDI_SYNTH_C_

#include "midi_synth.h"

static int      midi2synth[MAX_MIDI_DEV];
static int      sysex_state[MAX_MIDI_DEV] =
{0};
static unsigned char prev_out_status[MAX_MIDI_DEV];

#define STORE(cmd) \
{ \
  int len; \
  unsigned char obuf[8]; \
  cmd; \
  seq_input_event(obuf, len); \
}

#define _seqbuf obuf
#define _seqbufptr 0
#define _SEQ_ADVBUF(x) len=x

void
do_midi_msg(int synthno, unsigned char *msg, int mlen)
{
	switch (msg[0] & 0xf0)
	  {
	  case 0x90:
		  if (msg[2] != 0)
		    {
			    STORE(SEQ_START_NOTE(synthno, msg[0] & 0x0f, msg[1], msg[2]));
			    break;
		    }
		  msg[2] = 64;

	  case 0x80:
		  STORE(SEQ_STOP_NOTE(synthno, msg[0] & 0x0f, msg[1], msg[2]));
		  break;

	  case 0xA0:
		  STORE(SEQ_KEY_PRESSURE(synthno, msg[0] & 0x0f, msg[1], msg[2]));
		  break;

	  case 0xB0:
		  STORE(SEQ_CONTROL(synthno, msg[0] & 0x0f,
				    msg[1], msg[2]));
		  break;

	  case 0xC0:
		  STORE(SEQ_SET_PATCH(synthno, msg[0] & 0x0f, msg[1]));
		  break;

	  case 0xD0:
		  STORE(SEQ_CHN_PRESSURE(synthno, msg[0] & 0x0f, msg[1]));
		  break;

	  case 0xE0:
		  STORE(SEQ_BENDER(synthno, msg[0] & 0x0f,
			      (msg[1] & 0x7f) | ((msg[2] & 0x7f) << 7)));
		  break;

	  default:
		  /* printk( "MPU: Unknown midi channel message %02x\n",  msg[0]); */
		  ;
	  }
}

static void
midi_outc(int midi_dev, int data)
{
	int             timeout;

	for (timeout = 0; timeout < 3200; timeout++)
		if (midi_devs[midi_dev]->outputc(midi_dev, (unsigned char) (data & 0xff)))
		  {
			  if (data & 0x80)	/*
						 * Status byte
						 */
				  prev_out_status[midi_dev] =
				      (unsigned char) (data & 0xff);	/*
									 * Store for running status
									 */
			  return;	/*
					 * Mission complete
					 */
		  }
	/*
	 * Sorry! No space on buffers.
	 */
	printk("Midi send timed out\n");
}

static int
prefix_cmd(int midi_dev, unsigned char status)
{
	if ((char *) midi_devs[midi_dev]->prefix_cmd == NULL)
		return 1;

	return midi_devs[midi_dev]->prefix_cmd(midi_dev, status);
}

static void
midi_synth_input(int orig_dev, unsigned char data)
{
	int             dev;
	struct midi_input_info *inc;

	static unsigned char len_tab[] =	/* # of data bytes following a status
						 */
	{
		2,		/* 8x */
		2,		/* 9x */
		2,		/* Ax */
		2,		/* Bx */
		1,		/* Cx */
		1,		/* Dx */
		2,		/* Ex */
		0		/* Fx */
	};

	if (orig_dev < 0 || orig_dev > num_midis || midi_devs[orig_dev] == NULL)
		return;

	if (data == 0xfe)	/* Ignore active sensing */
		return;

	dev = midi2synth[orig_dev];
	inc = &midi_devs[orig_dev]->in_info;

	switch (inc->m_state)
	  {
	  case MST_INIT:
		  if (data & 0x80)	/* MIDI status byte */
		    {
			    if ((data & 0xf0) == 0xf0)	/* Common message */
			      {
				      switch (data)
					{
					case 0xf0:	/* Sysex */
						inc->m_state = MST_SYSEX;
						break;	/* Sysex */

					case 0xf1:	/* MTC quarter frame */
					case 0xf3:	/* Song select */
						inc->m_state = MST_DATA;
						inc->m_ptr = 1;
						inc->m_left = 1;
						inc->m_buf[0] = data;
						break;

					case 0xf2:	/* Song position pointer */
						inc->m_state = MST_DATA;
						inc->m_ptr = 1;
						inc->m_left = 2;
						inc->m_buf[0] = data;
						break;

					default:
						inc->m_buf[0] = data;
						inc->m_ptr = 1;
						do_midi_msg(dev, inc->m_buf, inc->m_ptr);
						inc->m_ptr = 0;
						inc->m_left = 0;
					}
			    } else
			      {
				      inc->m_state = MST_DATA;
				      inc->m_ptr = 1;
				      inc->m_left = len_tab[(data >> 4) - 8];
				      inc->m_buf[0] = inc->m_prev_status = data;
			      }
		    } else if (inc->m_prev_status & 0x80) {
			    /* Data byte (use running status) */
			    inc->m_ptr = 2;
			    inc->m_buf[1] = data;
			    inc->m_buf[0] = inc->m_prev_status;
			    inc->m_left = len_tab[(inc->m_buf[0] >> 4) - 8] - 1;
			    if (inc->m_left > 0)
				    inc->m_state = MST_DATA; /* Not done yet */
			    else {
				    inc->m_state = MST_INIT;
				    do_midi_msg(dev, inc->m_buf, inc->m_ptr);
				    inc->m_ptr = 0;
			    }
		    }
		  break;	/* MST_INIT */

	  case MST_DATA:
		  inc->m_buf[inc->m_ptr++] = data;
		  if (--inc->m_left <= 0)
		    {
			    inc->m_state = MST_INIT;
			    do_midi_msg(dev, inc->m_buf, inc->m_ptr);
			    inc->m_ptr = 0;
		    }
		  break;	/* MST_DATA */

	  case MST_SYSEX:
		  if (data == 0xf7)	/* Sysex end */
		    {
			    inc->m_state = MST_INIT;
			    inc->m_left = 0;
			    inc->m_ptr = 0;
		    }
		  break;	/* MST_SYSEX */

	  default:
		  printk("MIDI%d: Unexpected state %d (%02x)\n", orig_dev, inc->m_state, (int) data);
		  inc->m_state = MST_INIT;
	  }
}

static void
leave_sysex(int dev)
{
	int             orig_dev = synth_devs[dev]->midi_dev;
	int             timeout = 0;

	if (!sysex_state[dev])
		return;

	sysex_state[dev] = 0;

	while (!midi_devs[orig_dev]->outputc(orig_dev, 0xf7) &&
	       timeout < 1000)
		timeout++;

	sysex_state[dev] = 0;
}

static void
midi_synth_output(int dev)
{
	/*
	 * Currently NOP
	 */
}

int midi_synth_ioctl(int dev, unsigned int cmd, caddr_t arg)
{
	/*
	 * int orig_dev = synth_devs[dev]->midi_dev;
	 */

	switch (cmd) {

	case SNDCTL_SYNTH_INFO:
		if (__copy_to_user(arg, synth_devs[dev]->info, sizeof(struct synth_info)))
			return -EFAULT;
		return 0;
		
	case SNDCTL_SYNTH_MEMAVL:
		return 0x7fffffff;

	default:
		return -EINVAL;
	}
}

int
midi_synth_kill_note(int dev, int channel, int note, int velocity)
{
	int             orig_dev = synth_devs[dev]->midi_dev;
	int             msg, chn;

	if (note < 0 || note > 127)
		return 0;
	if (channel < 0 || channel > 15)
		return 0;
	if (velocity < 0)
		velocity = 0;
	if (velocity > 127)
		velocity = 127;

	leave_sysex(dev);

	msg = prev_out_status[orig_dev] & 0xf0;
	chn = prev_out_status[orig_dev] & 0x0f;

	if (chn == channel && ((msg == 0x90 && velocity == 64) || msg == 0x80))
	  {			/*
				 * Use running status
				 */
		  if (!prefix_cmd(orig_dev, note))
			  return 0;

		  midi_outc(orig_dev, note);

		  if (msg == 0x90)	/*
					 * Running status = Note on
					 */
			  midi_outc(orig_dev, 0);	/*
							   * Note on with velocity 0 == note
							   * off
							 */
		  else
			  midi_outc(orig_dev, velocity);
	} else
	  {
		  if (velocity == 64)
		    {
			    if (!prefix_cmd(orig_dev, 0x90 | (channel & 0x0f)))
				    return 0;
			    midi_outc(orig_dev, 0x90 | (channel & 0x0f));	/*
										 * Note on
										 */
			    midi_outc(orig_dev, note);
			    midi_outc(orig_dev, 0);	/*
							 * Zero G
							 */
		  } else
		    {
			    if (!prefix_cmd(orig_dev, 0x80 | (channel & 0x0f)))
				    return 0;
			    midi_outc(orig_dev, 0x80 | (channel & 0x0f));	/*
										 * Note off
										 */
			    midi_outc(orig_dev, note);
			    midi_outc(orig_dev, velocity);
		    }
	  }

	return 0;
}

int
midi_synth_set_instr(int dev, int channel, int instr_no)
{
	int             orig_dev = synth_devs[dev]->midi_dev;

	if (instr_no < 0 || instr_no > 127)
		instr_no = 0;
	if (channel < 0 || channel > 15)
		return 0;

	leave_sysex(dev);

	if (!prefix_cmd(orig_dev, 0xc0 | (channel & 0x0f)))
		return 0;
	midi_outc(orig_dev, 0xc0 | (channel & 0x0f));	/*
							 * Program change
							 */
	midi_outc(orig_dev, instr_no);

	return 0;
}

int
midi_synth_start_note(int dev, int channel, int note, int velocity)
{
	int             orig_dev = synth_devs[dev]->midi_dev;
	int             msg, chn;

	if (note < 0 || note > 127)
		return 0;
	if (channel < 0 || channel > 15)
		return 0;
	if (velocity < 0)
		velocity = 0;
	if (velocity > 127)
		velocity = 127;

	leave_sysex(dev);

	msg = prev_out_status[orig_dev] & 0xf0;
	chn = prev_out_status[orig_dev] & 0x0f;

	if (chn == channel && msg == 0x90)
	  {			/*
				 * Use running status
				 */
		  if (!prefix_cmd(orig_dev, note))
			  return 0;
		  midi_outc(orig_dev, note);
		  midi_outc(orig_dev, velocity);
	} else
	  {
		  if (!prefix_cmd(orig_dev, 0x90 | (channel & 0x0f)))
			  return 0;
		  midi_outc(orig_dev, 0x90 | (channel & 0x0f));		/*
									 * Note on
									 */
		  midi_outc(orig_dev, note);
		  midi_outc(orig_dev, velocity);
	  }
	return 0;
}

void
midi_synth_reset(int dev)
{

	leave_sysex(dev);
}

int
midi_synth_open(int dev, int mode)
{
	int             orig_dev = synth_devs[dev]->midi_dev;
	int             err;
	unsigned long   flags;
	struct midi_input_info *inc;

	if (orig_dev < 0 || orig_dev > num_midis || midi_devs[orig_dev] == NULL)
		return -ENXIO;

	midi2synth[orig_dev] = dev;
	sysex_state[dev] = 0;
	prev_out_status[orig_dev] = 0;

	if ((err = midi_devs[orig_dev]->open(orig_dev, mode,
			       midi_synth_input, midi_synth_output)) < 0)
		return err;
#ifdef MODULE
	MOD_INC_USE_COUNT;
#endif
	inc = &midi_devs[orig_dev]->in_info;

	save_flags(flags);
	cli();
	inc->m_busy = 0;
	inc->m_state = MST_INIT;
	inc->m_ptr = 0;
	inc->m_left = 0;
	inc->m_prev_status = 0x00;
	restore_flags(flags);

	return 1;
}

void
midi_synth_close(int dev)
{
	int             orig_dev = synth_devs[dev]->midi_dev;

	leave_sysex(dev);

	/*
	 * Shut up the synths by sending just single active sensing message.
	 */
	midi_devs[orig_dev]->outputc(orig_dev, 0xfe);

	midi_devs[orig_dev]->close(orig_dev);
#ifdef MODULE
	MOD_DEC_USE_COUNT;
#endif
}

void
midi_synth_hw_control(int dev, unsigned char *event)
{
}

int
midi_synth_load_patch(int dev, int format, const char *addr,
		      int offs, int count, int pmgr_flag)
{
	int             orig_dev = synth_devs[dev]->midi_dev;

	struct sysex_info sysex;
	int             i;
	unsigned long   left, src_offs, eox_seen = 0;
	int             first_byte = 1;
	int             hdr_size = (unsigned long) &sysex.data[0] - (unsigned long) &sysex;

	leave_sysex(dev);

	if (!prefix_cmd(orig_dev, 0xf0))
		return 0;

	if (format != SYSEX_PATCH)
	{
/*		  printk("MIDI Error: Invalid patch format (key) 0x%x\n", format);*/
		  return -EINVAL;
	}
	if (count < hdr_size)
	{
/*		printk("MIDI Error: Patch header too short\n");*/
		return -EINVAL;
	}
	count -= hdr_size;

	/*
	 * Copy the header from user space but ignore the first bytes which have
	 * been transferred already.
	 */

	if(copy_from_user(&((char *) &sysex)[offs], &(addr)[offs], hdr_size - offs))
		return -EFAULT;
 
 	if (count < sysex.len)
	{
/*		printk(KERN_WARNING "MIDI Warning: Sysex record too short (%d<%d)\n", count, (int) sysex.len);*/
		sysex.len = count;
	}
  	left = sysex.len;
  	src_offs = 0;

	for (i = 0; i < left && !signal_pending(current); i++)
	{
		unsigned char   data;

		get_user(*(unsigned char *) &data, (unsigned char *) &((addr)[hdr_size + i]));

		eox_seen = (i > 0 && data & 0x80);	/* End of sysex */

		if (eox_seen && data != 0xf7)
			data = 0xf7;

		if (i == 0)
		{
			if (data != 0xf0)
			{
				printk(KERN_WARNING "midi_synth: Sysex start missing\n");
				return -EINVAL;
			}
		}
		while (!midi_devs[orig_dev]->outputc(orig_dev, (unsigned char) (data & 0xff)) &&
			!signal_pending(current))
			schedule();

		if (!first_byte && data & 0x80)
			return 0;
		first_byte = 0;
	}

	if (!eox_seen)
		midi_outc(orig_dev, 0xf7);
	return 0;
}
  
void midi_synth_panning(int dev, int channel, int pressure)
{
}
  
void midi_synth_aftertouch(int dev, int channel, int pressure)
{
	int             orig_dev = synth_devs[dev]->midi_dev;
	int             msg, chn;

	if (pressure < 0 || pressure > 127)
		return;
	if (channel < 0 || channel > 15)
		return;

	leave_sysex(dev);

	msg = prev_out_status[orig_dev] & 0xf0;
	chn = prev_out_status[orig_dev] & 0x0f;

	if (msg != 0xd0 || chn != channel)	/*
						 * Test for running status
						 */
	  {
		  if (!prefix_cmd(orig_dev, 0xd0 | (channel & 0x0f)))
			  return;
		  midi_outc(orig_dev, 0xd0 | (channel & 0x0f));		/*
									 * Channel pressure
									 */
	} else if (!prefix_cmd(orig_dev, pressure))
		return;

	midi_outc(orig_dev, pressure);
}

void
midi_synth_controller(int dev, int channel, int ctrl_num, int value)
{
	int             orig_dev = synth_devs[dev]->midi_dev;
	int             chn, msg;

	if (ctrl_num < 0 || ctrl_num > 127)
		return;
	if (channel < 0 || channel > 15)
		return;

	leave_sysex(dev);

	msg = prev_out_status[orig_dev] & 0xf0;
	chn = prev_out_status[orig_dev] & 0x0f;

	if (msg != 0xb0 || chn != channel)
	  {
		  if (!prefix_cmd(orig_dev, 0xb0 | (channel & 0x0f)))
			  return;
		  midi_outc(orig_dev, 0xb0 | (channel & 0x0f));
	} else if (!prefix_cmd(orig_dev, ctrl_num))
		return;

	midi_outc(orig_dev, ctrl_num);
	midi_outc(orig_dev, value & 0x7f);
}

void
midi_synth_bender(int dev, int channel, int value)
{
	int             orig_dev = synth_devs[dev]->midi_dev;
	int             msg, prev_chn;

	if (channel < 0 || channel > 15)
		return;

	if (value < 0 || value > 16383)
		return;

	leave_sysex(dev);

	msg = prev_out_status[orig_dev] & 0xf0;
	prev_chn = prev_out_status[orig_dev] & 0x0f;

	if (msg != 0xd0 || prev_chn != channel)		/*
							 * Test for running status
							 */
	  {
		  if (!prefix_cmd(orig_dev, 0xe0 | (channel & 0x0f)))
			  return;
		  midi_outc(orig_dev, 0xe0 | (channel & 0x0f));
	} else if (!prefix_cmd(orig_dev, value & 0x7f))
		return;

	midi_outc(orig_dev, value & 0x7f);
	midi_outc(orig_dev, (value >> 7) & 0x7f);
}

void
midi_synth_setup_voice(int dev, int voice, int channel)
{
}

int
midi_synth_send_sysex(int dev, unsigned char *bytes, int len)
{
	int             orig_dev = synth_devs[dev]->midi_dev;
	int             i;

	for (i = 0; i < len; i++)
	  {
		  switch (bytes[i])
		    {
		    case 0xf0:	/* Start sysex */
			    if (!prefix_cmd(orig_dev, 0xf0))
				    return 0;
			    sysex_state[dev] = 1;
			    break;

		    case 0xf7:	/* End sysex */
			    if (!sysex_state[dev])	/* Orphan sysex end */
				    return 0;
			    sysex_state[dev] = 0;
			    break;

		    default:
			    if (!sysex_state[dev])
				    return 0;

			    if (bytes[i] & 0x80)	/* Error. Another message before sysex end */
			      {
				      bytes[i] = 0xf7;	/* Sysex end */
				      sysex_state[dev] = 0;
			      }
		    }

		  if (!midi_devs[orig_dev]->outputc(orig_dev, bytes[i]))
		    {
/*
 * Hardware level buffer is full. Abort the sysex message.
 */

			    int             timeout = 0;

			    bytes[i] = 0xf7;
			    sysex_state[dev] = 0;

			    while (!midi_devs[orig_dev]->outputc(orig_dev, bytes[i]) &&
				   timeout < 1000)
				    timeout++;
		    }
		  if (!sysex_state[dev])
			  return 0;
	  }

	return 0;
}
