1 /*
2  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
3  *  Routines for control of MPU-401 in UART mode
4  *
5  *  MPU-401 supports UART mode which is not capable generate transmit
6  *  interrupts thus output is done via polling. Without interrupt,
7  *  input is done also via polling. Do not expect good performance.
8  *
9  *
10  *   This program is free software; you can redistribute it and/or modify
11  *   it under the terms of the GNU General Public License as published by
12  *   the Free Software Foundation; either version 2 of the License, or
13  *   (at your option) any later version.
14  *
15  *   This program is distributed in the hope that it will be useful,
16  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
17  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  *   GNU General Public License for more details.
19  *
20  *   You should have received a copy of the GNU General Public License
21  *   along with this program; if not, write to the Free Software
22  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
23  *
24  *   13-03-2003:
25  *      Added support for different kind of hardware I/O. Build in choices
26  *      are port and mmio. For other kind of I/O, set mpu->read and
27  *      mpu->write to your own I/O functions.
28  *
29  */
30 
31 #include <asm/io.h>
32 #include <linux/delay.h>
33 #include <linux/init.h>
34 #include <linux/slab.h>
35 #include <linux/ioport.h>
36 #include <linux/module.h>
37 #include <linux/interrupt.h>
38 #include <linux/errno.h>
39 #include <sound/core.h>
40 #include <sound/mpu401.h>
41 
42 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
43 MODULE_DESCRIPTION("Routines for control of MPU-401 in UART mode");
44 MODULE_LICENSE("GPL");
45 
46 static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu);
47 static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu);
48 
49 /*
50 
51  */
52 
53 #define snd_mpu401_input_avail(mpu) \
54 	(!(mpu->read(mpu, MPU401C(mpu)) & MPU401_RX_EMPTY))
55 #define snd_mpu401_output_ready(mpu) \
56 	(!(mpu->read(mpu, MPU401C(mpu)) & MPU401_TX_FULL))
57 
58 /* Build in lowlevel io */
59 static void mpu401_write_port(struct snd_mpu401 *mpu, unsigned char data,
60 			      unsigned long addr)
61 {
62 	outb(data, addr);
63 }
64 
65 static unsigned char mpu401_read_port(struct snd_mpu401 *mpu,
66 				      unsigned long addr)
67 {
68 	return inb(addr);
69 }
70 
71 static void mpu401_write_mmio(struct snd_mpu401 *mpu, unsigned char data,
72 			      unsigned long addr)
73 {
74 	writeb(data, (void __iomem *)addr);
75 }
76 
77 static unsigned char mpu401_read_mmio(struct snd_mpu401 *mpu,
78 				      unsigned long addr)
79 {
80 	return readb((void __iomem *)addr);
81 }
82 /*  */
83 
84 static void snd_mpu401_uart_clear_rx(struct snd_mpu401 *mpu)
85 {
86 	int timeout = 100000;
87 	for (; timeout > 0 && snd_mpu401_input_avail(mpu); timeout--)
88 		mpu->read(mpu, MPU401D(mpu));
89 #ifdef CONFIG_SND_DEBUG
90 	if (timeout <= 0)
91 		snd_printk(KERN_ERR "cmd: clear rx timeout (status = 0x%x)\n",
92 			   mpu->read(mpu, MPU401C(mpu)));
93 #endif
94 }
95 
96 static void uart_interrupt_tx(struct snd_mpu401 *mpu)
97 {
98 	unsigned long flags;
99 
100 	if (test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode) &&
101 	    test_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode)) {
102 		spin_lock_irqsave(&mpu->output_lock, flags);
103 		snd_mpu401_uart_output_write(mpu);
104 		spin_unlock_irqrestore(&mpu->output_lock, flags);
105 	}
106 }
107 
108 static void _snd_mpu401_uart_interrupt(struct snd_mpu401 *mpu)
109 {
110 	unsigned long flags;
111 
112 	if (mpu->info_flags & MPU401_INFO_INPUT) {
113 		spin_lock_irqsave(&mpu->input_lock, flags);
114 		if (test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
115 			snd_mpu401_uart_input_read(mpu);
116 		else
117 			snd_mpu401_uart_clear_rx(mpu);
118 		spin_unlock_irqrestore(&mpu->input_lock, flags);
119 	}
120 	if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
121 		/* ok. for better Tx performance try do some output
122 		   when input is done */
123 		uart_interrupt_tx(mpu);
124 }
125 
126 /**
127  * snd_mpu401_uart_interrupt - generic MPU401-UART interrupt handler
128  * @irq: the irq number
129  * @dev_id: mpu401 instance
130  *
131  * Processes the interrupt for MPU401-UART i/o.
132  *
133  * Return: %IRQ_HANDLED if the interrupt was handled. %IRQ_NONE otherwise.
134  */
135 irqreturn_t snd_mpu401_uart_interrupt(int irq, void *dev_id)
136 {
137 	struct snd_mpu401 *mpu = dev_id;
138 
139 	if (mpu == NULL)
140 		return IRQ_NONE;
141 	_snd_mpu401_uart_interrupt(mpu);
142 	return IRQ_HANDLED;
143 }
144 
145 EXPORT_SYMBOL(snd_mpu401_uart_interrupt);
146 
147 /**
148  * snd_mpu401_uart_interrupt_tx - generic MPU401-UART transmit irq handler
149  * @irq: the irq number
150  * @dev_id: mpu401 instance
151  *
152  * Processes the interrupt for MPU401-UART output.
153  *
154  * Return: %IRQ_HANDLED if the interrupt was handled. %IRQ_NONE otherwise.
155  */
156 irqreturn_t snd_mpu401_uart_interrupt_tx(int irq, void *dev_id)
157 {
158 	struct snd_mpu401 *mpu = dev_id;
159 
160 	if (mpu == NULL)
161 		return IRQ_NONE;
162 	uart_interrupt_tx(mpu);
163 	return IRQ_HANDLED;
164 }
165 
166 EXPORT_SYMBOL(snd_mpu401_uart_interrupt_tx);
167 
168 /*
169  * timer callback
170  * reprogram the timer and call the interrupt job
171  */
172 static void snd_mpu401_uart_timer(unsigned long data)
173 {
174 	struct snd_mpu401 *mpu = (struct snd_mpu401 *)data;
175 	unsigned long flags;
176 
177 	spin_lock_irqsave(&mpu->timer_lock, flags);
178 	/*mpu->mode |= MPU401_MODE_TIMER;*/
179 	mpu->timer.expires = 1 + jiffies;
180 	add_timer(&mpu->timer);
181 	spin_unlock_irqrestore(&mpu->timer_lock, flags);
182 	if (mpu->rmidi)
183 		_snd_mpu401_uart_interrupt(mpu);
184 }
185 
186 /*
187  * initialize the timer callback if not programmed yet
188  */
189 static void snd_mpu401_uart_add_timer (struct snd_mpu401 *mpu, int input)
190 {
191 	unsigned long flags;
192 
193 	spin_lock_irqsave (&mpu->timer_lock, flags);
194 	if (mpu->timer_invoked == 0) {
195 		init_timer(&mpu->timer);
196 		mpu->timer.data = (unsigned long)mpu;
197 		mpu->timer.function = snd_mpu401_uart_timer;
198 		mpu->timer.expires = 1 + jiffies;
199 		add_timer(&mpu->timer);
200 	}
201 	mpu->timer_invoked |= input ? MPU401_MODE_INPUT_TIMER :
202 		MPU401_MODE_OUTPUT_TIMER;
203 	spin_unlock_irqrestore (&mpu->timer_lock, flags);
204 }
205 
206 /*
207  * remove the timer callback if still active
208  */
209 static void snd_mpu401_uart_remove_timer (struct snd_mpu401 *mpu, int input)
210 {
211 	unsigned long flags;
212 
213 	spin_lock_irqsave (&mpu->timer_lock, flags);
214 	if (mpu->timer_invoked) {
215 		mpu->timer_invoked &= input ? ~MPU401_MODE_INPUT_TIMER :
216 			~MPU401_MODE_OUTPUT_TIMER;
217 		if (! mpu->timer_invoked)
218 			del_timer(&mpu->timer);
219 	}
220 	spin_unlock_irqrestore (&mpu->timer_lock, flags);
221 }
222 
223 /*
224  * send a UART command
225  * return zero if successful, non-zero for some errors
226  */
227 
228 static int snd_mpu401_uart_cmd(struct snd_mpu401 * mpu, unsigned char cmd,
229 			       int ack)
230 {
231 	unsigned long flags;
232 	int timeout, ok;
233 
234 	spin_lock_irqsave(&mpu->input_lock, flags);
235 	if (mpu->hardware != MPU401_HW_TRID4DWAVE) {
236 		mpu->write(mpu, 0x00, MPU401D(mpu));
237 		/*snd_mpu401_uart_clear_rx(mpu);*/
238 	}
239 	/* ok. standard MPU-401 initialization */
240 	if (mpu->hardware != MPU401_HW_SB) {
241 		for (timeout = 1000; timeout > 0 &&
242 			     !snd_mpu401_output_ready(mpu); timeout--)
243 			udelay(10);
244 #ifdef CONFIG_SND_DEBUG
245 		if (!timeout)
246 			snd_printk(KERN_ERR "cmd: tx timeout (status = 0x%x)\n",
247 				   mpu->read(mpu, MPU401C(mpu)));
248 #endif
249 	}
250 	mpu->write(mpu, cmd, MPU401C(mpu));
251 	if (ack && !(mpu->info_flags & MPU401_INFO_NO_ACK)) {
252 		ok = 0;
253 		timeout = 10000;
254 		while (!ok && timeout-- > 0) {
255 			if (snd_mpu401_input_avail(mpu)) {
256 				if (mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
257 					ok = 1;
258 			}
259 		}
260 		if (!ok && mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
261 			ok = 1;
262 	} else
263 		ok = 1;
264 	spin_unlock_irqrestore(&mpu->input_lock, flags);
265 	if (!ok) {
266 		snd_printk(KERN_ERR "cmd: 0x%x failed at 0x%lx "
267 			   "(status = 0x%x, data = 0x%x)\n", cmd, mpu->port,
268 			   mpu->read(mpu, MPU401C(mpu)),
269 			   mpu->read(mpu, MPU401D(mpu)));
270 		return 1;
271 	}
272 	return 0;
273 }
274 
275 static int snd_mpu401_do_reset(struct snd_mpu401 *mpu)
276 {
277 	if (snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1))
278 		return -EIO;
279 	if (snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 0))
280 		return -EIO;
281 	return 0;
282 }
283 
284 /*
285  * input/output open/close - protected by open_mutex in rawmidi.c
286  */
287 static int snd_mpu401_uart_input_open(struct snd_rawmidi_substream *substream)
288 {
289 	struct snd_mpu401 *mpu;
290 	int err;
291 
292 	mpu = substream->rmidi->private_data;
293 	if (mpu->open_input && (err = mpu->open_input(mpu)) < 0)
294 		return err;
295 	if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode)) {
296 		if (snd_mpu401_do_reset(mpu) < 0)
297 			goto error_out;
298 	}
299 	mpu->substream_input = substream;
300 	set_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
301 	return 0;
302 
303 error_out:
304 	if (mpu->open_input && mpu->close_input)
305 		mpu->close_input(mpu);
306 	return -EIO;
307 }
308 
309 static int snd_mpu401_uart_output_open(struct snd_rawmidi_substream *substream)
310 {
311 	struct snd_mpu401 *mpu;
312 	int err;
313 
314 	mpu = substream->rmidi->private_data;
315 	if (mpu->open_output && (err = mpu->open_output(mpu)) < 0)
316 		return err;
317 	if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode)) {
318 		if (snd_mpu401_do_reset(mpu) < 0)
319 			goto error_out;
320 	}
321 	mpu->substream_output = substream;
322 	set_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
323 	return 0;
324 
325 error_out:
326 	if (mpu->open_output && mpu->close_output)
327 		mpu->close_output(mpu);
328 	return -EIO;
329 }
330 
331 static int snd_mpu401_uart_input_close(struct snd_rawmidi_substream *substream)
332 {
333 	struct snd_mpu401 *mpu;
334 	int err = 0;
335 
336 	mpu = substream->rmidi->private_data;
337 	clear_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
338 	mpu->substream_input = NULL;
339 	if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode))
340 		err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
341 	if (mpu->close_input)
342 		mpu->close_input(mpu);
343 	if (err)
344 		return -EIO;
345 	return 0;
346 }
347 
348 static int snd_mpu401_uart_output_close(struct snd_rawmidi_substream *substream)
349 {
350 	struct snd_mpu401 *mpu;
351 	int err = 0;
352 
353 	mpu = substream->rmidi->private_data;
354 	clear_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
355 	mpu->substream_output = NULL;
356 	if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
357 		err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
358 	if (mpu->close_output)
359 		mpu->close_output(mpu);
360 	if (err)
361 		return -EIO;
362 	return 0;
363 }
364 
365 /*
366  * trigger input callback
367  */
368 static void
369 snd_mpu401_uart_input_trigger(struct snd_rawmidi_substream *substream, int up)
370 {
371 	unsigned long flags;
372 	struct snd_mpu401 *mpu;
373 	int max = 64;
374 
375 	mpu = substream->rmidi->private_data;
376 	if (up) {
377 		if (! test_and_set_bit(MPU401_MODE_BIT_INPUT_TRIGGER,
378 				       &mpu->mode)) {
379 			/* first time - flush FIFO */
380 			while (max-- > 0)
381 				mpu->read(mpu, MPU401D(mpu));
382 			if (mpu->info_flags & MPU401_INFO_USE_TIMER)
383 				snd_mpu401_uart_add_timer(mpu, 1);
384 		}
385 
386 		/* read data in advance */
387 		spin_lock_irqsave(&mpu->input_lock, flags);
388 		snd_mpu401_uart_input_read(mpu);
389 		spin_unlock_irqrestore(&mpu->input_lock, flags);
390 	} else {
391 		if (mpu->info_flags & MPU401_INFO_USE_TIMER)
392 			snd_mpu401_uart_remove_timer(mpu, 1);
393 		clear_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode);
394 	}
395 
396 }
397 
398 /*
399  * transfer input pending data
400  * call with input_lock spinlock held
401  */
402 static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu)
403 {
404 	int max = 128;
405 	unsigned char byte;
406 
407 	while (max-- > 0) {
408 		if (! snd_mpu401_input_avail(mpu))
409 			break; /* input not available */
410 		byte = mpu->read(mpu, MPU401D(mpu));
411 		if (test_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode))
412 			snd_rawmidi_receive(mpu->substream_input, &byte, 1);
413 	}
414 }
415 
416 /*
417  *  Tx FIFO sizes:
418  *    CS4237B			- 16 bytes
419  *    AudioDrive ES1688         - 12 bytes
420  *    S3 SonicVibes             -  8 bytes
421  *    SoundBlaster AWE 64       -  2 bytes (ugly hardware)
422  */
423 
424 /*
425  * write output pending bytes
426  * call with output_lock spinlock held
427  */
428 static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu)
429 {
430 	unsigned char byte;
431 	int max = 256;
432 
433 	do {
434 		if (snd_rawmidi_transmit_peek(mpu->substream_output,
435 					      &byte, 1) == 1) {
436 			/*
437 			 * Try twice because there is hardware that insists on
438 			 * setting the output busy bit after each write.
439 			 */
440 			if (!snd_mpu401_output_ready(mpu) &&
441 			    !snd_mpu401_output_ready(mpu))
442 				break;	/* Tx FIFO full - try again later */
443 			mpu->write(mpu, byte, MPU401D(mpu));
444 			snd_rawmidi_transmit_ack(mpu->substream_output, 1);
445 		} else {
446 			snd_mpu401_uart_remove_timer (mpu, 0);
447 			break;	/* no other data - leave the tx loop */
448 		}
449 	} while (--max > 0);
450 }
451 
452 /*
453  * output trigger callback
454  */
455 static void
456 snd_mpu401_uart_output_trigger(struct snd_rawmidi_substream *substream, int up)
457 {
458 	unsigned long flags;
459 	struct snd_mpu401 *mpu;
460 
461 	mpu = substream->rmidi->private_data;
462 	if (up) {
463 		set_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);
464 
465 		/* try to add the timer at each output trigger,
466 		 * since the output timer might have been removed in
467 		 * snd_mpu401_uart_output_write().
468 		 */
469 		if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
470 			snd_mpu401_uart_add_timer(mpu, 0);
471 
472 		/* output pending data */
473 		spin_lock_irqsave(&mpu->output_lock, flags);
474 		snd_mpu401_uart_output_write(mpu);
475 		spin_unlock_irqrestore(&mpu->output_lock, flags);
476 	} else {
477 		if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
478 			snd_mpu401_uart_remove_timer(mpu, 0);
479 		clear_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);
480 	}
481 }
482 
483 /*
484 
485  */
486 
487 static struct snd_rawmidi_ops snd_mpu401_uart_output =
488 {
489 	.open =		snd_mpu401_uart_output_open,
490 	.close =	snd_mpu401_uart_output_close,
491 	.trigger =	snd_mpu401_uart_output_trigger,
492 };
493 
494 static struct snd_rawmidi_ops snd_mpu401_uart_input =
495 {
496 	.open =		snd_mpu401_uart_input_open,
497 	.close =	snd_mpu401_uart_input_close,
498 	.trigger =	snd_mpu401_uart_input_trigger,
499 };
500 
501 static void snd_mpu401_uart_free(struct snd_rawmidi *rmidi)
502 {
503 	struct snd_mpu401 *mpu = rmidi->private_data;
504 	if (mpu->irq >= 0)
505 		free_irq(mpu->irq, (void *) mpu);
506 	release_and_free_resource(mpu->res);
507 	kfree(mpu);
508 }
509 
510 /**
511  * snd_mpu401_uart_new - create an MPU401-UART instance
512  * @card: the card instance
513  * @device: the device index, zero-based
514  * @hardware: the hardware type, MPU401_HW_XXXX
515  * @port: the base address of MPU401 port
516  * @info_flags: bitflags MPU401_INFO_XXX
517  * @irq: the ISA irq number, -1 if not to be allocated
518  * @rrawmidi: the pointer to store the new rawmidi instance
519  *
520  * Creates a new MPU-401 instance.
521  *
522  * Note that the rawmidi instance is returned on the rrawmidi argument,
523  * not the mpu401 instance itself.  To access to the mpu401 instance,
524  * cast from rawmidi->private_data (with struct snd_mpu401 magic-cast).
525  *
526  * Return: Zero if successful, or a negative error code.
527  */
528 int snd_mpu401_uart_new(struct snd_card *card, int device,
529 			unsigned short hardware,
530 			unsigned long port,
531 			unsigned int info_flags,
532 			int irq,
533 			struct snd_rawmidi ** rrawmidi)
534 {
535 	struct snd_mpu401 *mpu;
536 	struct snd_rawmidi *rmidi;
537 	int in_enable, out_enable;
538 	int err;
539 
540 	if (rrawmidi)
541 		*rrawmidi = NULL;
542 	if (! (info_flags & (MPU401_INFO_INPUT | MPU401_INFO_OUTPUT)))
543 		info_flags |= MPU401_INFO_INPUT | MPU401_INFO_OUTPUT;
544 	in_enable = (info_flags & MPU401_INFO_INPUT) ? 1 : 0;
545 	out_enable = (info_flags & MPU401_INFO_OUTPUT) ? 1 : 0;
546 	if ((err = snd_rawmidi_new(card, "MPU-401U", device,
547 				   out_enable, in_enable, &rmidi)) < 0)
548 		return err;
549 	mpu = kzalloc(sizeof(*mpu), GFP_KERNEL);
550 	if (mpu == NULL) {
551 		snd_printk(KERN_ERR "mpu401_uart: cannot allocate\n");
552 		snd_device_free(card, rmidi);
553 		return -ENOMEM;
554 	}
555 	rmidi->private_data = mpu;
556 	rmidi->private_free = snd_mpu401_uart_free;
557 	spin_lock_init(&mpu->input_lock);
558 	spin_lock_init(&mpu->output_lock);
559 	spin_lock_init(&mpu->timer_lock);
560 	mpu->hardware = hardware;
561 	mpu->irq = -1;
562 	if (! (info_flags & MPU401_INFO_INTEGRATED)) {
563 		int res_size = hardware == MPU401_HW_PC98II ? 4 : 2;
564 		mpu->res = request_region(port, res_size, "MPU401 UART");
565 		if (mpu->res == NULL) {
566 			snd_printk(KERN_ERR "mpu401_uart: "
567 				   "unable to grab port 0x%lx size %d\n",
568 				   port, res_size);
569 			snd_device_free(card, rmidi);
570 			return -EBUSY;
571 		}
572 	}
573 	if (info_flags & MPU401_INFO_MMIO) {
574 		mpu->write = mpu401_write_mmio;
575 		mpu->read = mpu401_read_mmio;
576 	} else {
577 		mpu->write = mpu401_write_port;
578 		mpu->read = mpu401_read_port;
579 	}
580 	mpu->port = port;
581 	if (hardware == MPU401_HW_PC98II)
582 		mpu->cport = port + 2;
583 	else
584 		mpu->cport = port + 1;
585 	if (irq >= 0) {
586 		if (request_irq(irq, snd_mpu401_uart_interrupt, 0,
587 				"MPU401 UART", (void *) mpu)) {
588 			snd_printk(KERN_ERR "mpu401_uart: "
589 				   "unable to grab IRQ %d\n", irq);
590 			snd_device_free(card, rmidi);
591 			return -EBUSY;
592 		}
593 	}
594 	if (irq < 0 && !(info_flags & MPU401_INFO_IRQ_HOOK))
595 		info_flags |= MPU401_INFO_USE_TIMER;
596 	mpu->info_flags = info_flags;
597 	mpu->irq = irq;
598 	if (card->shortname[0])
599 		snprintf(rmidi->name, sizeof(rmidi->name), "%s MIDI",
600 			 card->shortname);
601 	else
602 		sprintf(rmidi->name, "MPU-401 MIDI %d-%d",card->number, device);
603 	if (out_enable) {
604 		snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
605 				    &snd_mpu401_uart_output);
606 		rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
607 	}
608 	if (in_enable) {
609 		snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
610 				    &snd_mpu401_uart_input);
611 		rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
612 		if (out_enable)
613 			rmidi->info_flags |= SNDRV_RAWMIDI_INFO_DUPLEX;
614 	}
615 	mpu->rmidi = rmidi;
616 	if (rrawmidi)
617 		*rrawmidi = rmidi;
618 	return 0;
619 }
620 
621 EXPORT_SYMBOL(snd_mpu401_uart_new);
622 
623 /*
624  *  INIT part
625  */
626 
627 static int __init alsa_mpu401_uart_init(void)
628 {
629 	return 0;
630 }
631 
632 static void __exit alsa_mpu401_uart_exit(void)
633 {
634 }
635 
636 module_init(alsa_mpu401_uart_init)
637 module_exit(alsa_mpu401_uart_exit)
638