midi_synth.c

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/*
 * sound/oss/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]); */
		  ;
	  }
}
EXPORT_SYMBOL(do_midi_msg);

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, void __user *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;
	}
}
EXPORT_SYMBOL(midi_synth_ioctl);

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;
}
EXPORT_SYMBOL(midi_synth_kill_note);

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;