seq_midi_emul.c

linux-2.6.15.6

			ops->control(drv, control, chan);
		break;
	}
}


/*
 * initialize the MIDI status
 */
void
snd_midi_channel_set_clear(snd_midi_channel_set_t *chset)
{
	int i;

	chset->midi_mode = SNDRV_MIDI_MODE_GM;
	chset->gs_master_volume = 127;

	for (i = 0; i < chset->max_channels; i++) {
		snd_midi_channel_t *chan = chset->channels + i;
		memset(chan->note, 0, sizeof(chan->note));

		chan->midi_aftertouch = 0;
		chan->midi_pressure = 0;
		chan->midi_program = 0;
		chan->midi_pitchbend = 0;
		snd_midi_reset_controllers(chan);
		chan->gm_rpn_pitch_bend_range = 256; /* 2 semitones */
		chan->gm_rpn_fine_tuning = 0;
		chan->gm_rpn_coarse_tuning = 0;

		if (i == 9)
			chan->drum_channel = 1;
		else
			chan->drum_channel = 0;
	}
}

/*
 * Process a rpn message.
 */
static void
rpn(snd_midi_op_t *ops, void *drv, snd_midi_channel_t *chan,
    snd_midi_channel_set_t *chset)
{
	int type;
	int val;

	if (chset->midi_mode != SNDRV_MIDI_MODE_NONE) {
		type = (chan->control[MIDI_CTL_REGIST_PARM_NUM_MSB] << 8) |
			chan->control[MIDI_CTL_REGIST_PARM_NUM_LSB];
		val = (chan->control[MIDI_CTL_MSB_DATA_ENTRY] << 7) |
			chan->control[MIDI_CTL_LSB_DATA_ENTRY];

		switch (type) {
		case 0x0000: /* Pitch bend sensitivity */
			/* MSB only / 1 semitone per 128 */
			chan->gm_rpn_pitch_bend_range = val;
			break;
					
		case 0x0001: /* fine tuning: */
			/* MSB/LSB, 8192=center, 100/8192 cent step */
			chan->gm_rpn_fine_tuning = val - 8192;
			break;

		case 0x0002: /* coarse tuning */
			/* MSB only / 8192=center, 1 semitone per 128 */
			chan->gm_rpn_coarse_tuning = val - 8192;
			break;

		case 0x7F7F: /* "lock-in" RPN */
			/* ignored */
			break;
		}
	}
	/* should call nrpn or rpn callback here.. */
}

/*
 * Process an nrpn message.
 */
static void
nrpn(snd_midi_op_t *ops, void *drv, snd_midi_channel_t *chan,
     snd_midi_channel_set_t *chset)
{
	/* parse XG NRPNs here if possible */
	if (ops->nrpn)
		ops->nrpn(drv, chan, chset);
}


/*
 * convert channel parameter in GS sysex
 */
static int
get_channel(unsigned char cmd)
{
	int p = cmd & 0x0f;
	if (p == 0)
		p = 9;
	else if (p < 10)
		p--;
	return p;
}


/*
 * Process a sysex message.
 */
static void
sysex(snd_midi_op_t *ops, void *private, unsigned char *buf, int len, snd_midi_channel_set_t *chset)
{
	/* GM on */
	static unsigned char gm_on_macro[] = {
		0x7e,0x7f,0x09,0x01,
	};
	/* XG on */
	static unsigned char xg_on_macro[] = {
		0x43,0x10,0x4c,0x00,0x00,0x7e,0x00,
	};
	/* GS prefix
	 * drum channel: XX=0x1?(channel), YY=0x15, ZZ=on/off
	 * reverb mode: XX=0x01, YY=0x30, ZZ=0-7
	 * chorus mode: XX=0x01, YY=0x38, ZZ=0-7
	 * master vol:  XX=0x00, YY=0x04, ZZ=0-127
	 */
	static unsigned char gs_pfx_macro[] = {
		0x41,0x10,0x42,0x12,0x40,/*XX,YY,ZZ*/
	};

	int parsed = SNDRV_MIDI_SYSEX_NOT_PARSED;

	if (len <= 0 || buf[0] != 0xf0)
		return;
	/* skip first byte */
	buf++;
	len--;

	/* GM on */
	if (len >= (int)sizeof(gm_on_macro) &&
	    memcmp(buf, gm_on_macro, sizeof(gm_on_macro)) == 0) {
		if (chset->midi_mode != SNDRV_MIDI_MODE_GS &&
		    chset->midi_mode != SNDRV_MIDI_MODE_XG) {
			chset->midi_mode = SNDRV_MIDI_MODE_GM;
			reset_all_channels(chset);
			parsed = SNDRV_MIDI_SYSEX_GM_ON;
		}
	}

	/* GS macros */
	else if (len >= 8 &&
		 memcmp(buf, gs_pfx_macro, sizeof(gs_pfx_macro)) == 0) {
		if (chset->midi_mode != SNDRV_MIDI_MODE_GS &&
		    chset->midi_mode != SNDRV_MIDI_MODE_XG)
			chset->midi_mode = SNDRV_MIDI_MODE_GS;

		if (buf[5] == 0x00 && buf[6] == 0x7f && buf[7] == 0x00) {
			/* GS reset */
			parsed = SNDRV_MIDI_SYSEX_GS_RESET;
			reset_all_channels(chset);
		}

		else if ((buf[5] & 0xf0) == 0x10 && buf[6] == 0x15) {
			/* drum pattern */
			int p = get_channel(buf[5]);
			if (p < chset->max_channels) {
				parsed = SNDRV_MIDI_SYSEX_GS_DRUM_CHANNEL;
				if (buf[7])
					chset->channels[p].drum_channel = 1;
				else
					chset->channels[p].drum_channel = 0;
			}

		} else if ((buf[5] & 0xf0) == 0x10 && buf[6] == 0x21) {
			/* program */
			int p = get_channel(buf[5]);
			if (p < chset->max_channels &&
			    ! chset->channels[p].drum_channel) {
				parsed = SNDRV_MIDI_SYSEX_GS_DRUM_CHANNEL;
				chset->channels[p].midi_program = buf[7];
			}

		} else if (buf[5] == 0x01 && buf[6] == 0x30) {
			/* reverb mode */
			parsed = SNDRV_MIDI_SYSEX_GS_REVERB_MODE;
			chset->gs_reverb_mode = buf[7];

		} else if (buf[5] == 0x01 && buf[6] == 0x38) {
			/* chorus mode */
			parsed = SNDRV_MIDI_SYSEX_GS_CHORUS_MODE;
			chset->gs_chorus_mode = buf[7];

		} else if (buf[5] == 0x00 && buf[6] == 0x04) {
			/* master volume */
			parsed = SNDRV_MIDI_SYSEX_GS_MASTER_VOLUME;
			chset->gs_master_volume = buf[7];

		}
	}

	/* XG on */
	else if (len >= (int)sizeof(xg_on_macro) &&
		 memcmp(buf, xg_on_macro, sizeof(xg_on_macro)) == 0) {
		int i;
		chset->midi_mode = SNDRV_MIDI_MODE_XG;
		parsed = SNDRV_MIDI_SYSEX_XG_ON;
		/* reset CC#0 for drums */
		for (i = 0; i < chset->max_channels; i++) {
			if (chset->channels[i].drum_channel)
				chset->channels[i].control[MIDI_CTL_MSB_BANK] = 127;
			else
				chset->channels[i].control[MIDI_CTL_MSB_BANK] = 0;
		}
	}

	if (ops->sysex)
		ops->sysex(private, buf - 1, len + 1, parsed, chset);
}

/*
 * all sound off
 */
static void
all_sounds_off(snd_midi_op_t *ops, void *drv, snd_midi_channel_t *chan)
{
	int n;

	if (! ops->note_terminate)
		return;
	for (n = 0; n < 128; n++) {
		if (chan->note[n]) {
			ops->note_terminate(drv, n, chan);
			chan->note[n] = 0;
		}
	}
}

/*
 * all notes off
 */
static void
all_notes_off(snd_midi_op_t *ops, void *drv, snd_midi_channel_t *chan)
{
	int n;

	if (! ops->note_off)
		return;
	for (n = 0; n < 128; n++) {
		if (chan->note[n] == SNDRV_MIDI_NOTE_ON)
			note_off(ops, drv, chan, n, 0);
	}
}

/*
 * Initialise a single midi channel control block.
 */
static void snd_midi_channel_init(snd_midi_channel_t *p, int n)
{
	if (p == NULL)
		return;

	memset(p, 0, sizeof(snd_midi_channel_t));
	p->private = NULL;
	p->number = n;

	snd_midi_reset_controllers(p);
	p->gm_rpn_pitch_bend_range = 256; /* 2 semitones */
	p->gm_rpn_fine_tuning = 0;
	p->gm_rpn_coarse_tuning = 0;

	if (n == 9)
		p->drum_channel = 1;	/* Default ch 10 as drums */
}

/*
 * Allocate and initialise a set of midi channel control blocks.
 */
static snd_midi_channel_t *snd_midi_channel_init_set(int n)
{
	snd_midi_channel_t *chan;
	int  i;

	chan = kmalloc(n * sizeof(snd_midi_channel_t), GFP_KERNEL);
	if (chan) {
		for (i = 0; i < n; i++)
			snd_midi_channel_init(chan+i, i);
	}

	return chan;
}

/*
 * reset all midi channels
 */
static void
reset_all_channels(snd_midi_channel_set_t *chset)
{
	int ch;
	for (ch = 0; ch < chset->max_channels; ch++) {
		snd_midi_channel_t *chan = chset->channels + ch;
		snd_midi_reset_controllers(chan);
		chan->gm_rpn_pitch_bend_range = 256; /* 2 semitones */
		chan->gm_rpn_fine_tuning = 0;
		chan->gm_rpn_coarse_tuning = 0;

		if (ch == 9)
			chan->drum_channel = 1;
		else
			chan->drum_channel = 0;
	}
}


/*
 * Allocate and initialise a midi channel set.
 */
snd_midi_channel_set_t *snd_midi_channel_alloc_set(int n)
{
	snd_midi_channel_set_t *chset;

	chset = kmalloc(sizeof(*chset), GFP_KERNEL);
	if (chset) {
		chset->channels = snd_midi_channel_init_set(n);
		chset->private_data = NULL;
		chset->max_channels = n;
	}
	return chset;
}

/*
 * Reset the midi controllers on a particular channel to default values.
 */
static void snd_midi_reset_controllers(snd_midi_channel_t *chan)
{
	memset(chan->control, 0, sizeof(chan->control));
	chan->gm_volume = 127;
	chan->gm_expression = 127;
	chan->gm_pan = 64;
}


/*
 * Free a midi channel set.
 */
void snd_midi_channel_free_set(snd_midi_channel_set_t *chset)
{
	if (chset == NULL)
		return;
	kfree(chset->channels);
	kfree(chset);
}

static int __init alsa_seq_midi_emul_init(void)
{
	return 0;
}

static void __exit alsa_seq_midi_emul_exit(void)
{
}

module_init(alsa_seq_midi_emul_init)
module_exit(alsa_seq_midi_emul_exit)

EXPORT_SYMBOL(snd_midi_process_event);
EXPORT_SYMBOL(snd_midi_channel_set_clear);
EXPORT_SYMBOL(snd_midi_channel_alloc_set);
EXPORT_SYMBOL(snd_midi_channel_free_set);