summaryrefslogtreecommitdiff
path: root/sound/drivers/mpu401/mpu401_uart.c
blob: 3e745f47dd2fd6b6f0334accd289d5bfbdc7687b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
/*
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 *  Routines for control of MPU-401 in UART mode
 *
 *  MPU-401 supports UART mode which is not capable generate transmit
 *  interrupts thus output is done via polling. Without interrupt,
 *  input is done also via polling. Do not expect good performance.
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 *   13-03-2003:
 *      Added support for different kind of hardware I/O. Build in choices
 *      are port and mmio. For other kind of I/O, set mpu->read and
 *      mpu->write to your own I/O functions.
 *
 */

#include <linux/io.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <sound/core.h>
#include <sound/mpu401.h>

MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
MODULE_DESCRIPTION("Routines for control of MPU-401 in UART mode");
MODULE_LICENSE("GPL");

static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu);
static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu);

/*

 */

#define snd_mpu401_input_avail(mpu) \
	(!(mpu->read(mpu, MPU401C(mpu)) & MPU401_RX_EMPTY))
#define snd_mpu401_output_ready(mpu) \
	(!(mpu->read(mpu, MPU401C(mpu)) & MPU401_TX_FULL))

/* Build in lowlevel io */
static void mpu401_write_port(struct snd_mpu401 *mpu, unsigned char data,
			      unsigned long addr)
{
	outb(data, addr);
}

static unsigned char mpu401_read_port(struct snd_mpu401 *mpu,
				      unsigned long addr)
{
	return inb(addr);
}

static void mpu401_write_mmio(struct snd_mpu401 *mpu, unsigned char data,
			      unsigned long addr)
{
	writeb(data, (void __iomem *)addr);
}

static unsigned char mpu401_read_mmio(struct snd_mpu401 *mpu,
				      unsigned long addr)
{
	return readb((void __iomem *)addr);
}
/*  */

static void snd_mpu401_uart_clear_rx(struct snd_mpu401 *mpu)
{
	int timeout = 100000;
	for (; timeout > 0 && snd_mpu401_input_avail(mpu); timeout--)
		mpu->read(mpu, MPU401D(mpu));
#ifdef CONFIG_SND_DEBUG
	if (timeout <= 0)
		snd_printk(KERN_ERR "cmd: clear rx timeout (status = 0x%x)\n",
			   mpu->read(mpu, MPU401C(mpu)));
#endif
}

static void uart_interrupt_tx(struct snd_mpu401 *mpu)
{
	unsigned long flags;

	if (test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode) &&
	    test_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode)) {
		spin_lock_irqsave(&mpu->output_lock, flags);
		snd_mpu401_uart_output_write(mpu);
		spin_unlock_irqrestore(&mpu->output_lock, flags);
	}
}

static void _snd_mpu401_uart_interrupt(struct snd_mpu401 *mpu)
{
	unsigned long flags;

	if (mpu->info_flags & MPU401_INFO_INPUT) {
		spin_lock_irqsave(&mpu->input_lock, flags);
		if (test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
			snd_mpu401_uart_input_read(mpu);
		else
			snd_mpu401_uart_clear_rx(mpu);
		spin_unlock_irqrestore(&mpu->input_lock, flags);
	}
	if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
		/* ok. for better Tx performance try do some output
		   when input is done */
		uart_interrupt_tx(mpu);
}

/**
 * snd_mpu401_uart_interrupt - generic MPU401-UART interrupt handler
 * @irq: the irq number
 * @dev_id: mpu401 instance
 *
 * Processes the interrupt for MPU401-UART i/o.
 *
 * Return: %IRQ_HANDLED if the interrupt was handled. %IRQ_NONE otherwise.
 */
irqreturn_t snd_mpu401_uart_interrupt(int irq, void *dev_id)
{
	struct snd_mpu401 *mpu = dev_id;
	
	if (!mpu)
		return IRQ_NONE;
	_snd_mpu401_uart_interrupt(mpu);
	return IRQ_HANDLED;
}

EXPORT_SYMBOL(snd_mpu401_uart_interrupt);

/**
 * snd_mpu401_uart_interrupt_tx - generic MPU401-UART transmit irq handler
 * @irq: the irq number
 * @dev_id: mpu401 instance
 *
 * Processes the interrupt for MPU401-UART output.
 *
 * Return: %IRQ_HANDLED if the interrupt was handled. %IRQ_NONE otherwise.
 */
irqreturn_t snd_mpu401_uart_interrupt_tx(int irq, void *dev_id)
{
	struct snd_mpu401 *mpu = dev_id;
	
	if (!mpu)
		return IRQ_NONE;
	uart_interrupt_tx(mpu);
	return IRQ_HANDLED;
}

EXPORT_SYMBOL(snd_mpu401_uart_interrupt_tx);

/*
 * timer callback
 * reprogram the timer and call the interrupt job
 */
static void snd_mpu401_uart_timer(struct timer_list *t)
{
	struct snd_mpu401 *mpu = from_timer(mpu, t, timer);
	unsigned long flags;

	spin_lock_irqsave(&mpu->timer_lock, flags);
	/*mpu->mode |= MPU401_MODE_TIMER;*/
	mod_timer(&mpu->timer,  1 + jiffies);
	spin_unlock_irqrestore(&mpu->timer_lock, flags);
	if (mpu->rmidi)
		_snd_mpu401_uart_interrupt(mpu);
}

/*
 * initialize the timer callback if not programmed yet
 */
static void snd_mpu401_uart_add_timer (struct snd_mpu401 *mpu, int input)
{
	unsigned long flags;

	spin_lock_irqsave (&mpu->timer_lock, flags);
	if (mpu->timer_invoked == 0) {
		timer_setup(&mpu->timer, snd_mpu401_uart_timer, 0);
		mod_timer(&mpu->timer, 1 + jiffies);
	} 
	mpu->timer_invoked |= input ? MPU401_MODE_INPUT_TIMER :
		MPU401_MODE_OUTPUT_TIMER;
	spin_unlock_irqrestore (&mpu->timer_lock, flags);
}

/*
 * remove the timer callback if still active
 */
static void snd_mpu401_uart_remove_timer (struct snd_mpu401 *mpu, int input)
{
	unsigned long flags;

	spin_lock_irqsave (&mpu->timer_lock, flags);
	if (mpu->timer_invoked) {
		mpu->timer_invoked &= input ? ~MPU401_MODE_INPUT_TIMER :
			~MPU401_MODE_OUTPUT_TIMER;
		if (! mpu->timer_invoked)
			del_timer(&mpu->timer);
	}
	spin_unlock_irqrestore (&mpu->timer_lock, flags);
}

/*
 * send a UART command
 * return zero if successful, non-zero for some errors
 */

static int snd_mpu401_uart_cmd(struct snd_mpu401 * mpu, unsigned char cmd,
			       int ack)
{
	unsigned long flags;
	int timeout, ok;

	spin_lock_irqsave(&mpu->input_lock, flags);
	if (mpu->hardware != MPU401_HW_TRID4DWAVE) {
		mpu->write(mpu, 0x00, MPU401D(mpu));
		/*snd_mpu401_uart_clear_rx(mpu);*/
	}
	/* ok. standard MPU-401 initialization */
	if (mpu->hardware != MPU401_HW_SB) {
		for (timeout = 1000; timeout > 0 &&
			     !snd_mpu401_output_ready(mpu); timeout--)
			udelay(10);
#ifdef CONFIG_SND_DEBUG
		if (!timeout)
			snd_printk(KERN_ERR "cmd: tx timeout (status = 0x%x)\n",
				   mpu->read(mpu, MPU401C(mpu)));
#endif
	}
	mpu->write(mpu, cmd, MPU401C(mpu));
	if (ack && !(mpu->info_flags & MPU401_INFO_NO_ACK)) {
		ok = 0;
		timeout = 10000;
		while (!ok && timeout-- > 0) {
			if (snd_mpu401_input_avail(mpu)) {
				if (mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
					ok = 1;
			}
		}
		if (!ok && mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
			ok = 1;
	} else
		ok = 1;
	spin_unlock_irqrestore(&mpu->input_lock, flags);
	if (!ok) {
		snd_printk(KERN_ERR "cmd: 0x%x failed at 0x%lx "
			   "(status = 0x%x, data = 0x%x)\n", cmd, mpu->port,
			   mpu->read(mpu, MPU401C(mpu)),
			   mpu->read(mpu, MPU401D(mpu)));
		return 1;
	}
	return 0;
}

static int snd_mpu401_do_reset(struct snd_mpu401 *mpu)
{
	if (snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1))
		return -EIO;
	if (snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 0))
		return -EIO;
	return 0;
}

/*
 * input/output open/close - protected by open_mutex in rawmidi.c
 */
static int snd_mpu401_uart_input_open(struct snd_rawmidi_substream *substream)
{
	struct snd_mpu401 *mpu;
	int err;

	mpu = substream->rmidi->private_data;
	if (mpu->open_input && (err = mpu->open_input(mpu)) < 0)
		return err;
	if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode)) {
		if (snd_mpu401_do_reset(mpu) < 0)
			goto error_out;
	}
	mpu->substream_input = substream;
	set_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
	return 0;

error_out:
	if (mpu->open_input && mpu->close_input)
		mpu->close_input(mpu);
	return -EIO;
}

static int snd_mpu401_uart_output_open(struct snd_rawmidi_substream *substream)
{
	struct snd_mpu401 *mpu;
	int err;

	mpu = substream->rmidi->private_data;
	if (mpu->open_output && (err = mpu->open_output(mpu)) < 0)
		return err;
	if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode)) {
		if (snd_mpu401_do_reset(mpu) < 0)
			goto error_out;
	}
	mpu->substream_output = substream;
	set_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
	return 0;

error_out:
	if (mpu->open_output && mpu->close_output)
		mpu->close_output(mpu);
	return -EIO;
}

static int snd_mpu401_uart_input_close(struct snd_rawmidi_substream *substream)
{
	struct snd_mpu401 *mpu;
	int err = 0;

	mpu = substream->rmidi->private_data;
	clear_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
	mpu->substream_input = NULL;
	if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode))
		err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
	if (mpu->close_input)
		mpu->close_input(mpu);
	if (err)
		return -EIO;
	return 0;
}

static int snd_mpu401_uart_output_close(struct snd_rawmidi_substream *substream)
{
	struct snd_mpu401 *mpu;
	int err = 0;

	mpu = substream->rmidi->private_data;
	clear_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
	mpu->substream_output = NULL;
	if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
		err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
	if (mpu->close_output)
		mpu->close_output(mpu);
	if (err)
		return -EIO;
	return 0;
}

/*
 * trigger input callback
 */
static void
snd_mpu401_uart_input_trigger(struct snd_rawmidi_substream *substream, int up)
{
	unsigned long flags;
	struct snd_mpu401 *mpu;
	int max = 64;

	mpu = substream->rmidi->private_data;
	if (up) {
		if (! test_and_set_bit(MPU401_MODE_BIT_INPUT_TRIGGER,
				       &mpu->mode)) {
			/* first time - flush FIFO */
			while (max-- > 0)
				mpu->read(mpu, MPU401D(mpu));
			if (mpu->info_flags & MPU401_INFO_USE_TIMER)
				snd_mpu401_uart_add_timer(mpu, 1);
		}
		
		/* read data in advance */
		spin_lock_irqsave(&mpu->input_lock, flags);
		snd_mpu401_uart_input_read(mpu);
		spin_unlock_irqrestore(&mpu->input_lock, flags);
	} else {
		if (mpu->info_flags & MPU401_INFO_USE_TIMER)
			snd_mpu401_uart_remove_timer(mpu, 1);
		clear_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode);
	}

}

/*
 * transfer input pending data
 * call with input_lock spinlock held
 */
static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu)
{
	int max = 128;
	unsigned char byte;

	while (max-- > 0) {
		if (! snd_mpu401_input_avail(mpu))
			break; /* input not available */
		byte = mpu->read(mpu, MPU401D(mpu));
		if (test_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode))
			snd_rawmidi_receive(mpu->substream_input, &byte, 1);
	}
}

/*
 *  Tx FIFO sizes:
 *    CS4237B			- 16 bytes
 *    AudioDrive ES1688         - 12 bytes
 *    S3 SonicVibes             -  8 bytes
 *    SoundBlaster AWE 64       -  2 bytes (ugly hardware)
 */

/*
 * write output pending bytes
 * call with output_lock spinlock held
 */
static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu)
{
	unsigned char byte;
	int max = 256;

	do {
		if (snd_rawmidi_transmit_peek(mpu->substream_output,
					      &byte, 1) == 1) {
			/*
			 * Try twice because there is hardware that insists on
			 * setting the output busy bit after each write.
			 */
			if (!snd_mpu401_output_ready(mpu) &&
			    !snd_mpu401_output_ready(mpu))
				break;	/* Tx FIFO full - try again later */
			mpu->write(mpu, byte, MPU401D(mpu));
			snd_rawmidi_transmit_ack(mpu->substream_output, 1);
		} else {
			snd_mpu401_uart_remove_timer (mpu, 0);
			break;	/* no other data - leave the tx loop */
		}
	} while (--max > 0);
}

/*
 * output trigger callback
 */
static void
snd_mpu401_uart_output_trigger(struct snd_rawmidi_substream *substream, int up)
{
	unsigned long flags;
	struct snd_mpu401 *mpu;

	mpu = substream->rmidi->private_data;
	if (up) {
		set_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);

		/* try to add the timer at each output trigger,
		 * since the output timer might have been removed in
		 * snd_mpu401_uart_output_write().
		 */
		if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
			snd_mpu401_uart_add_timer(mpu, 0);

		/* output pending data */
		spin_lock_irqsave(&mpu->output_lock, flags);
		snd_mpu401_uart_output_write(mpu);
		spin_unlock_irqrestore(&mpu->output_lock, flags);
	} else {
		if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
			snd_mpu401_uart_remove_timer(mpu, 0);
		clear_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);
	}
}

/*

 */

static const struct snd_rawmidi_ops snd_mpu401_uart_output =
{
	.open =		snd_mpu401_uart_output_open,
	.close =	snd_mpu401_uart_output_close,
	.trigger =	snd_mpu401_uart_output_trigger,
};

static const struct snd_rawmidi_ops snd_mpu401_uart_input =
{
	.open =		snd_mpu401_uart_input_open,
	.close =	snd_mpu401_uart_input_close,
	.trigger =	snd_mpu401_uart_input_trigger,
};

static void snd_mpu401_uart_free(struct snd_rawmidi *rmidi)
{
	struct snd_mpu401 *mpu = rmidi->private_data;
	if (mpu->irq >= 0)
		free_irq(mpu->irq, (void *) mpu);
	release_and_free_resource(mpu->res);
	kfree(mpu);
}

/**
 * snd_mpu401_uart_new - create an MPU401-UART instance
 * @card: the card instance
 * @device: the device index, zero-based
 * @hardware: the hardware type, MPU401_HW_XXXX
 * @port: the base address of MPU401 port
 * @info_flags: bitflags MPU401_INFO_XXX
 * @irq: the ISA irq number, -1 if not to be allocated
 * @rrawmidi: the pointer to store the new rawmidi instance
 *
 * Creates a new MPU-401 instance.
 *
 * Note that the rawmidi instance is returned on the rrawmidi argument,
 * not the mpu401 instance itself.  To access to the mpu401 instance,
 * cast from rawmidi->private_data (with struct snd_mpu401 magic-cast).
 *
 * Return: Zero if successful, or a negative error code.
 */
int snd_mpu401_uart_new(struct snd_card *card, int device,
			unsigned short hardware,
			unsigned long port,
			unsigned int info_flags,
			int irq,
			struct snd_rawmidi ** rrawmidi)
{
	struct snd_mpu401 *mpu;
	struct snd_rawmidi *rmidi;
	int in_enable, out_enable;
	int err;

	if (rrawmidi)
		*rrawmidi = NULL;
	if (! (info_flags & (MPU401_INFO_INPUT | MPU401_INFO_OUTPUT)))
		info_flags |= MPU401_INFO_INPUT | MPU401_INFO_OUTPUT;
	in_enable = (info_flags & MPU401_INFO_INPUT) ? 1 : 0;
	out_enable = (info_flags & MPU401_INFO_OUTPUT) ? 1 : 0;
	if ((err = snd_rawmidi_new(card, "MPU-401U", device,
				   out_enable, in_enable, &rmidi)) < 0)
		return err;
	mpu = kzalloc(sizeof(*mpu), GFP_KERNEL);
	if (!mpu) {
		err = -ENOMEM;
		goto free_device;
	}
	rmidi->private_data = mpu;
	rmidi->private_free = snd_mpu401_uart_free;
	spin_lock_init(&mpu->input_lock);
	spin_lock_init(&mpu->output_lock);
	spin_lock_init(&mpu->timer_lock);
	mpu->hardware = hardware;
	mpu->irq = -1;
	if (! (info_flags & MPU401_INFO_INTEGRATED)) {
		int res_size = hardware == MPU401_HW_PC98II ? 4 : 2;
		mpu->res = request_region(port, res_size, "MPU401 UART");
		if (!mpu->res) {
			snd_printk(KERN_ERR "mpu401_uart: "
				   "unable to grab port 0x%lx size %d\n",
				   port, res_size);
			err = -EBUSY;
			goto free_device;
		}
	}
	if (info_flags & MPU401_INFO_MMIO) {
		mpu->write = mpu401_write_mmio;
		mpu->read = mpu401_read_mmio;
	} else {
		mpu->write = mpu401_write_port;
		mpu->read = mpu401_read_port;
	}
	mpu->port = port;
	if (hardware == MPU401_HW_PC98II)
		mpu->cport = port + 2;
	else
		mpu->cport = port + 1;
	if (irq >= 0) {
		if (request_irq(irq, snd_mpu401_uart_interrupt, 0,
				"MPU401 UART", (void *) mpu)) {
			snd_printk(KERN_ERR "mpu401_uart: "
				   "unable to grab IRQ %d\n", irq);
			err = -EBUSY;
			goto free_device;
		}
	}
	if (irq < 0 && !(info_flags & MPU401_INFO_IRQ_HOOK))
		info_flags |= MPU401_INFO_USE_TIMER;
	mpu->info_flags = info_flags;
	mpu->irq = irq;
	if (card->shortname[0])
		snprintf(rmidi->name, sizeof(rmidi->name), "%s MIDI",
			 card->shortname);
	else
		sprintf(rmidi->name, "MPU-401 MIDI %d-%d",card->number, device);
	if (out_enable) {
		snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
				    &snd_mpu401_uart_output);
		rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
	}
	if (in_enable) {
		snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
				    &snd_mpu401_uart_input);
		rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
		if (out_enable)
			rmidi->info_flags |= SNDRV_RAWMIDI_INFO_DUPLEX;
	}
	mpu->rmidi = rmidi;
	if (rrawmidi)
		*rrawmidi = rmidi;
	return 0;
free_device:
	snd_device_free(card, rmidi);
	return err;
}

EXPORT_SYMBOL(snd_mpu401_uart_new);

/*
 *  INIT part
 */

static int __init alsa_mpu401_uart_init(void)
{
	return 0;
}

static void __exit alsa_mpu401_uart_exit(void)
{
}

module_init(alsa_mpu401_uart_init)
module_exit(alsa_mpu401_uart_exit)