xref: /openbmc/linux/sound/isa/sb/sb8_main.c (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
1 /*
2  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
3  *                   Uros Bizjak <uros@kss-loka.si>
4  *
5  *  Routines for control of 8-bit SoundBlaster cards and clones
6  *  Please note: I don't have access to old SB8 soundcards.
7  *
8  *
9  *   This program is free software; you can redistribute it and/or modify
10  *   it under the terms of the GNU General Public License as published by
11  *   the Free Software Foundation; either version 2 of the License, or
12  *   (at your option) any later version.
13  *
14  *   This program is distributed in the hope that it will be useful,
15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  *   GNU General Public License for more details.
18  *
19  *   You should have received a copy of the GNU General Public License
20  *   along with this program; if not, write to the Free Software
21  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
22  *
23  * --
24  *
25  * Thu Apr 29 20:36:17 BST 1999 George David Morrison <gdm@gedamo.demon.co.uk>
26  *   DSP can't respond to commands whilst in "high speed" mode. Caused
27  *   glitching during playback. Fixed.
28  *
29  * Wed Jul 12 22:02:55 CEST 2000 Uros Bizjak <uros@kss-loka.si>
30  *   Cleaned up and rewrote lowlevel routines.
31  */
32 
33 #include <asm/io.h>
34 #include <asm/dma.h>
35 #include <linux/init.h>
36 #include <linux/time.h>
37 #include <sound/core.h>
38 #include <sound/sb.h>
39 
40 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Uros Bizjak <uros@kss-loka.si>");
41 MODULE_DESCRIPTION("Routines for control of 8-bit SoundBlaster cards and clones");
42 MODULE_LICENSE("GPL");
43 
44 #define SB8_CLOCK	1000000
45 #define SB8_DEN(v)	((SB8_CLOCK + (v) / 2) / (v))
46 #define SB8_RATE(v)	(SB8_CLOCK / SB8_DEN(v))
47 
48 static struct snd_ratnum clock = {
49 	.num = SB8_CLOCK,
50 	.den_min = 1,
51 	.den_max = 256,
52 	.den_step = 1,
53 };
54 
55 static struct snd_pcm_hw_constraint_ratnums hw_constraints_clock = {
56 	.nrats = 1,
57 	.rats = &clock,
58 };
59 
60 static struct snd_ratnum stereo_clocks[] = {
61 	{
62 		.num = SB8_CLOCK,
63 		.den_min = SB8_DEN(22050),
64 		.den_max = SB8_DEN(22050),
65 		.den_step = 1,
66 	},
67 	{
68 		.num = SB8_CLOCK,
69 		.den_min = SB8_DEN(11025),
70 		.den_max = SB8_DEN(11025),
71 		.den_step = 1,
72 	}
73 };
74 
75 static int snd_sb8_hw_constraint_rate_channels(struct snd_pcm_hw_params *params,
76 					       struct snd_pcm_hw_rule *rule)
77 {
78 	struct snd_interval *c = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
79 	if (c->min > 1) {
80 	  	unsigned int num = 0, den = 0;
81 		int err = snd_interval_ratnum(hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE),
82 					  2, stereo_clocks, &num, &den);
83 		if (err >= 0 && den) {
84 			params->rate_num = num;
85 			params->rate_den = den;
86 		}
87 		return err;
88 	}
89 	return 0;
90 }
91 
92 static int snd_sb8_hw_constraint_channels_rate(struct snd_pcm_hw_params *params,
93 					       struct snd_pcm_hw_rule *rule)
94 {
95 	struct snd_interval *r = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
96 	if (r->min > SB8_RATE(22050) || r->max <= SB8_RATE(11025)) {
97 		struct snd_interval t = { .min = 1, .max = 1 };
98 		return snd_interval_refine(hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS), &t);
99 	}
100 	return 0;
101 }
102 
103 static int snd_sb8_playback_prepare(struct snd_pcm_substream *substream)
104 {
105 	unsigned long flags;
106 	struct snd_sb *chip = snd_pcm_substream_chip(substream);
107 	struct snd_pcm_runtime *runtime = substream->runtime;
108 	unsigned int mixreg, rate, size, count;
109 
110 	rate = runtime->rate;
111 	switch (chip->hardware) {
112 	case SB_HW_PRO:
113 		if (runtime->channels > 1) {
114 			if (snd_BUG_ON(rate != SB8_RATE(11025) &&
115 				       rate != SB8_RATE(22050)))
116 				return -EINVAL;
117 			chip->playback_format = SB_DSP_HI_OUTPUT_AUTO;
118 			break;
119 		}
120 		/* fallthru */
121 	case SB_HW_201:
122 		if (rate > 23000) {
123 			chip->playback_format = SB_DSP_HI_OUTPUT_AUTO;
124 			break;
125 		}
126 		/* fallthru */
127 	case SB_HW_20:
128 		chip->playback_format = SB_DSP_LO_OUTPUT_AUTO;
129 		break;
130 	case SB_HW_10:
131 		chip->playback_format = SB_DSP_OUTPUT;
132 		break;
133 	default:
134 		return -EINVAL;
135 	}
136 	size = chip->p_dma_size = snd_pcm_lib_buffer_bytes(substream);
137 	count = chip->p_period_size = snd_pcm_lib_period_bytes(substream);
138 	spin_lock_irqsave(&chip->reg_lock, flags);
139 	snd_sbdsp_command(chip, SB_DSP_SPEAKER_ON);
140 	if (runtime->channels > 1) {
141 		/* set playback stereo mode */
142 		spin_lock(&chip->mixer_lock);
143 		mixreg = snd_sbmixer_read(chip, SB_DSP_STEREO_SW);
144 		snd_sbmixer_write(chip, SB_DSP_STEREO_SW, mixreg | 0x02);
145 		spin_unlock(&chip->mixer_lock);
146 
147 		/* Soundblaster hardware programming reference guide, 3-23 */
148 		snd_sbdsp_command(chip, SB_DSP_DMA8_EXIT);
149 		runtime->dma_area[0] = 0x80;
150 		snd_dma_program(chip->dma8, runtime->dma_addr, 1, DMA_MODE_WRITE);
151 		/* force interrupt */
152 		chip->mode = SB_MODE_HALT;
153 		snd_sbdsp_command(chip, SB_DSP_OUTPUT);
154 		snd_sbdsp_command(chip, 0);
155 		snd_sbdsp_command(chip, 0);
156 	}
157 	snd_sbdsp_command(chip, SB_DSP_SAMPLE_RATE);
158 	if (runtime->channels > 1) {
159 		snd_sbdsp_command(chip, 256 - runtime->rate_den / 2);
160 		spin_lock(&chip->mixer_lock);
161 		/* save output filter status and turn it off */
162 		mixreg = snd_sbmixer_read(chip, SB_DSP_PLAYBACK_FILT);
163 		snd_sbmixer_write(chip, SB_DSP_PLAYBACK_FILT, mixreg | 0x20);
164 		spin_unlock(&chip->mixer_lock);
165 		/* just use force_mode16 for temporary storate... */
166 		chip->force_mode16 = mixreg;
167 	} else {
168 		snd_sbdsp_command(chip, 256 - runtime->rate_den);
169 	}
170 	if (chip->playback_format != SB_DSP_OUTPUT) {
171 		count--;
172 		snd_sbdsp_command(chip, SB_DSP_BLOCK_SIZE);
173 		snd_sbdsp_command(chip, count & 0xff);
174 		snd_sbdsp_command(chip, count >> 8);
175 	}
176 	spin_unlock_irqrestore(&chip->reg_lock, flags);
177 	snd_dma_program(chip->dma8, runtime->dma_addr,
178 			size, DMA_MODE_WRITE | DMA_AUTOINIT);
179 	return 0;
180 }
181 
182 static int snd_sb8_playback_trigger(struct snd_pcm_substream *substream,
183 				    int cmd)
184 {
185 	unsigned long flags;
186 	struct snd_sb *chip = snd_pcm_substream_chip(substream);
187 	unsigned int count;
188 
189 	spin_lock_irqsave(&chip->reg_lock, flags);
190 	switch (cmd) {
191 	case SNDRV_PCM_TRIGGER_START:
192 		snd_sbdsp_command(chip, chip->playback_format);
193 		if (chip->playback_format == SB_DSP_OUTPUT) {
194 			count = chip->p_period_size - 1;
195 			snd_sbdsp_command(chip, count & 0xff);
196 			snd_sbdsp_command(chip, count >> 8);
197 		}
198 		break;
199 	case SNDRV_PCM_TRIGGER_STOP:
200 		if (chip->playback_format == SB_DSP_HI_OUTPUT_AUTO) {
201 			struct snd_pcm_runtime *runtime = substream->runtime;
202 			snd_sbdsp_reset(chip);
203 			if (runtime->channels > 1) {
204 				spin_lock(&chip->mixer_lock);
205 				/* restore output filter and set hardware to mono mode */
206 				snd_sbmixer_write(chip, SB_DSP_STEREO_SW, chip->force_mode16 & ~0x02);
207 				spin_unlock(&chip->mixer_lock);
208 			}
209 		} else {
210 			snd_sbdsp_command(chip, SB_DSP_DMA8_OFF);
211 		}
212 		snd_sbdsp_command(chip, SB_DSP_SPEAKER_OFF);
213 	}
214 	spin_unlock_irqrestore(&chip->reg_lock, flags);
215 	chip->mode = (cmd == SNDRV_PCM_TRIGGER_START) ? SB_MODE_PLAYBACK_8 : SB_MODE_HALT;
216 	return 0;
217 }
218 
219 static int snd_sb8_hw_params(struct snd_pcm_substream *substream,
220 			     struct snd_pcm_hw_params *hw_params)
221 {
222 	return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params));
223 }
224 
225 static int snd_sb8_hw_free(struct snd_pcm_substream *substream)
226 {
227 	snd_pcm_lib_free_pages(substream);
228 	return 0;
229 }
230 
231 static int snd_sb8_capture_prepare(struct snd_pcm_substream *substream)
232 {
233 	unsigned long flags;
234 	struct snd_sb *chip = snd_pcm_substream_chip(substream);
235 	struct snd_pcm_runtime *runtime = substream->runtime;
236 	unsigned int mixreg, rate, size, count;
237 
238 	rate = runtime->rate;
239 	switch (chip->hardware) {
240 	case SB_HW_PRO:
241 		if (runtime->channels > 1) {
242 			if (snd_BUG_ON(rate != SB8_RATE(11025) &&
243 				       rate != SB8_RATE(22050)))
244 				return -EINVAL;
245 			chip->capture_format = SB_DSP_HI_INPUT_AUTO;
246 			break;
247 		}
248 		chip->capture_format = (rate > 23000) ? SB_DSP_HI_INPUT_AUTO : SB_DSP_LO_INPUT_AUTO;
249 		break;
250 	case SB_HW_201:
251 		if (rate > 13000) {
252 			chip->capture_format = SB_DSP_HI_INPUT_AUTO;
253 			break;
254 		}
255 		/* fallthru */
256 	case SB_HW_20:
257 		chip->capture_format = SB_DSP_LO_INPUT_AUTO;
258 		break;
259 	case SB_HW_10:
260 		chip->capture_format = SB_DSP_INPUT;
261 		break;
262 	default:
263 		return -EINVAL;
264 	}
265 	size = chip->c_dma_size = snd_pcm_lib_buffer_bytes(substream);
266 	count = chip->c_period_size = snd_pcm_lib_period_bytes(substream);
267 	spin_lock_irqsave(&chip->reg_lock, flags);
268 	snd_sbdsp_command(chip, SB_DSP_SPEAKER_OFF);
269 	if (runtime->channels > 1)
270 		snd_sbdsp_command(chip, SB_DSP_STEREO_8BIT);
271 	snd_sbdsp_command(chip, SB_DSP_SAMPLE_RATE);
272 	if (runtime->channels > 1) {
273 		snd_sbdsp_command(chip, 256 - runtime->rate_den / 2);
274 		spin_lock(&chip->mixer_lock);
275 		/* save input filter status and turn it off */
276 		mixreg = snd_sbmixer_read(chip, SB_DSP_CAPTURE_FILT);
277 		snd_sbmixer_write(chip, SB_DSP_CAPTURE_FILT, mixreg | 0x20);
278 		spin_unlock(&chip->mixer_lock);
279 		/* just use force_mode16 for temporary storate... */
280 		chip->force_mode16 = mixreg;
281 	} else {
282 		snd_sbdsp_command(chip, 256 - runtime->rate_den);
283 	}
284 	if (chip->capture_format != SB_DSP_INPUT) {
285 		count--;
286 		snd_sbdsp_command(chip, SB_DSP_BLOCK_SIZE);
287 		snd_sbdsp_command(chip, count & 0xff);
288 		snd_sbdsp_command(chip, count >> 8);
289 	}
290 	spin_unlock_irqrestore(&chip->reg_lock, flags);
291 	snd_dma_program(chip->dma8, runtime->dma_addr,
292 			size, DMA_MODE_READ | DMA_AUTOINIT);
293 	return 0;
294 }
295 
296 static int snd_sb8_capture_trigger(struct snd_pcm_substream *substream,
297 				   int cmd)
298 {
299 	unsigned long flags;
300 	struct snd_sb *chip = snd_pcm_substream_chip(substream);
301 	unsigned int count;
302 
303 	spin_lock_irqsave(&chip->reg_lock, flags);
304 	switch (cmd) {
305 	case SNDRV_PCM_TRIGGER_START:
306 		snd_sbdsp_command(chip, chip->capture_format);
307 		if (chip->capture_format == SB_DSP_INPUT) {
308 			count = chip->c_period_size - 1;
309 			snd_sbdsp_command(chip, count & 0xff);
310 			snd_sbdsp_command(chip, count >> 8);
311 		}
312 		break;
313 	case SNDRV_PCM_TRIGGER_STOP:
314 		if (chip->capture_format == SB_DSP_HI_INPUT_AUTO) {
315 			struct snd_pcm_runtime *runtime = substream->runtime;
316 			snd_sbdsp_reset(chip);
317 			if (runtime->channels > 1) {
318 				/* restore input filter status */
319 				spin_lock(&chip->mixer_lock);
320 				snd_sbmixer_write(chip, SB_DSP_CAPTURE_FILT, chip->force_mode16);
321 				spin_unlock(&chip->mixer_lock);
322 				/* set hardware to mono mode */
323 				snd_sbdsp_command(chip, SB_DSP_MONO_8BIT);
324 			}
325 		} else {
326 			snd_sbdsp_command(chip, SB_DSP_DMA8_OFF);
327 		}
328 		snd_sbdsp_command(chip, SB_DSP_SPEAKER_OFF);
329 	}
330 	spin_unlock_irqrestore(&chip->reg_lock, flags);
331 	chip->mode = (cmd == SNDRV_PCM_TRIGGER_START) ? SB_MODE_CAPTURE_8 : SB_MODE_HALT;
332 	return 0;
333 }
334 
335 irqreturn_t snd_sb8dsp_interrupt(struct snd_sb *chip)
336 {
337 	struct snd_pcm_substream *substream;
338 	struct snd_pcm_runtime *runtime;
339 
340 	snd_sb_ack_8bit(chip);
341 	switch (chip->mode) {
342 	case SB_MODE_PLAYBACK_8:	/* ok.. playback is active */
343 		substream = chip->playback_substream;
344 		runtime = substream->runtime;
345 		if (chip->playback_format == SB_DSP_OUTPUT)
346 		    	snd_sb8_playback_trigger(substream, SNDRV_PCM_TRIGGER_START);
347 		snd_pcm_period_elapsed(substream);
348 		break;
349 	case SB_MODE_CAPTURE_8:
350 		substream = chip->capture_substream;
351 		runtime = substream->runtime;
352 		if (chip->capture_format == SB_DSP_INPUT)
353 		    	snd_sb8_capture_trigger(substream, SNDRV_PCM_TRIGGER_START);
354 		snd_pcm_period_elapsed(substream);
355 		break;
356 	}
357 	return IRQ_HANDLED;
358 }
359 
360 static snd_pcm_uframes_t snd_sb8_playback_pointer(struct snd_pcm_substream *substream)
361 {
362 	struct snd_sb *chip = snd_pcm_substream_chip(substream);
363 	size_t ptr;
364 
365 	if (chip->mode != SB_MODE_PLAYBACK_8)
366 		return 0;
367 	ptr = snd_dma_pointer(chip->dma8, chip->p_dma_size);
368 	return bytes_to_frames(substream->runtime, ptr);
369 }
370 
371 static snd_pcm_uframes_t snd_sb8_capture_pointer(struct snd_pcm_substream *substream)
372 {
373 	struct snd_sb *chip = snd_pcm_substream_chip(substream);
374 	size_t ptr;
375 
376 	if (chip->mode != SB_MODE_CAPTURE_8)
377 		return 0;
378 	ptr = snd_dma_pointer(chip->dma8, chip->c_dma_size);
379 	return bytes_to_frames(substream->runtime, ptr);
380 }
381 
382 /*
383 
384  */
385 
386 static struct snd_pcm_hardware snd_sb8_playback =
387 {
388 	.info =			(SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
389 				 SNDRV_PCM_INFO_MMAP_VALID),
390 	.formats =		 SNDRV_PCM_FMTBIT_U8,
391 	.rates =		(SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000 |
392 				 SNDRV_PCM_RATE_11025 | SNDRV_PCM_RATE_22050),
393 	.rate_min =		4000,
394 	.rate_max =		23000,
395 	.channels_min =		1,
396 	.channels_max =		1,
397 	.buffer_bytes_max =	65536,
398 	.period_bytes_min =	64,
399 	.period_bytes_max =	65536,
400 	.periods_min =		1,
401 	.periods_max =		1024,
402 	.fifo_size =		0,
403 };
404 
405 static struct snd_pcm_hardware snd_sb8_capture =
406 {
407 	.info =			(SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
408 				 SNDRV_PCM_INFO_MMAP_VALID),
409 	.formats =		SNDRV_PCM_FMTBIT_U8,
410 	.rates =		(SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000 |
411 				 SNDRV_PCM_RATE_11025),
412 	.rate_min =		4000,
413 	.rate_max =		13000,
414 	.channels_min =		1,
415 	.channels_max =		1,
416 	.buffer_bytes_max =	65536,
417 	.period_bytes_min =	64,
418 	.period_bytes_max =	65536,
419 	.periods_min =		1,
420 	.periods_max =		1024,
421 	.fifo_size =		0,
422 };
423 
424 /*
425  *
426  */
427 
428 static int snd_sb8_open(struct snd_pcm_substream *substream)
429 {
430 	struct snd_sb *chip = snd_pcm_substream_chip(substream);
431 	struct snd_pcm_runtime *runtime = substream->runtime;
432 	unsigned long flags;
433 
434 	spin_lock_irqsave(&chip->open_lock, flags);
435 	if (chip->open) {
436 		spin_unlock_irqrestore(&chip->open_lock, flags);
437 		return -EAGAIN;
438 	}
439 	chip->open |= SB_OPEN_PCM;
440 	spin_unlock_irqrestore(&chip->open_lock, flags);
441 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
442 		chip->playback_substream = substream;
443 		runtime->hw = snd_sb8_playback;
444 	} else {
445 		chip->capture_substream = substream;
446 		runtime->hw = snd_sb8_capture;
447 	}
448 	switch (chip->hardware) {
449 	case SB_HW_PRO:
450 		runtime->hw.rate_max = 44100;
451 		runtime->hw.channels_max = 2;
452 		snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
453 				    snd_sb8_hw_constraint_rate_channels, NULL,
454 				    SNDRV_PCM_HW_PARAM_CHANNELS,
455 				    SNDRV_PCM_HW_PARAM_RATE, -1);
456 		snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
457 				     snd_sb8_hw_constraint_channels_rate, NULL,
458 				     SNDRV_PCM_HW_PARAM_RATE, -1);
459 		break;
460 	case SB_HW_201:
461 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
462 			runtime->hw.rate_max = 44100;
463 		} else {
464 			runtime->hw.rate_max = 15000;
465 		}
466 	default:
467 		break;
468 	}
469 	snd_pcm_hw_constraint_ratnums(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
470 				      &hw_constraints_clock);
471 	return 0;
472 }
473 
474 static int snd_sb8_close(struct snd_pcm_substream *substream)
475 {
476 	unsigned long flags;
477 	struct snd_sb *chip = snd_pcm_substream_chip(substream);
478 
479 	chip->playback_substream = NULL;
480 	chip->capture_substream = NULL;
481 	spin_lock_irqsave(&chip->open_lock, flags);
482 	chip->open &= ~SB_OPEN_PCM;
483 	spin_unlock_irqrestore(&chip->open_lock, flags);
484 	return 0;
485 }
486 
487 /*
488  *  Initialization part
489  */
490 
491 static struct snd_pcm_ops snd_sb8_playback_ops = {
492 	.open =			snd_sb8_open,
493 	.close =		snd_sb8_close,
494 	.ioctl =		snd_pcm_lib_ioctl,
495 	.hw_params =		snd_sb8_hw_params,
496 	.hw_free =		snd_sb8_hw_free,
497 	.prepare =		snd_sb8_playback_prepare,
498 	.trigger =		snd_sb8_playback_trigger,
499 	.pointer =		snd_sb8_playback_pointer,
500 };
501 
502 static struct snd_pcm_ops snd_sb8_capture_ops = {
503 	.open =			snd_sb8_open,
504 	.close =		snd_sb8_close,
505 	.ioctl =		snd_pcm_lib_ioctl,
506 	.hw_params =		snd_sb8_hw_params,
507 	.hw_free =		snd_sb8_hw_free,
508 	.prepare =		snd_sb8_capture_prepare,
509 	.trigger =		snd_sb8_capture_trigger,
510 	.pointer =		snd_sb8_capture_pointer,
511 };
512 
513 int snd_sb8dsp_pcm(struct snd_sb *chip, int device, struct snd_pcm ** rpcm)
514 {
515 	struct snd_card *card = chip->card;
516 	struct snd_pcm *pcm;
517 	int err;
518 
519 	if (rpcm)
520 		*rpcm = NULL;
521 	if ((err = snd_pcm_new(card, "SB8 DSP", device, 1, 1, &pcm)) < 0)
522 		return err;
523 	sprintf(pcm->name, "DSP v%i.%i", chip->version >> 8, chip->version & 0xff);
524 	pcm->info_flags = SNDRV_PCM_INFO_HALF_DUPLEX;
525 	pcm->private_data = chip;
526 
527 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sb8_playback_ops);
528 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_sb8_capture_ops);
529 
530 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
531 					      snd_dma_isa_data(),
532 					      64*1024, 64*1024);
533 
534 	if (rpcm)
535 		*rpcm = pcm;
536 	return 0;
537 }
538 
539 EXPORT_SYMBOL(snd_sb8dsp_pcm);
540 EXPORT_SYMBOL(snd_sb8dsp_interrupt);
541   /* sb8_midi.c */
542 EXPORT_SYMBOL(snd_sb8dsp_midi_interrupt);
543 EXPORT_SYMBOL(snd_sb8dsp_midi);
544 
545 /*
546  *  INIT part
547  */
548 
549 static int __init alsa_sb8_init(void)
550 {
551 	return 0;
552 }
553 
554 static void __exit alsa_sb8_exit(void)
555 {
556 }
557 
558 module_init(alsa_sb8_init)
559 module_exit(alsa_sb8_exit)
560