xref: /openbmc/linux/sound/isa/sb/sb8_main.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /*
2  *  Copyright (c) by Jaroslav Kysela <perex@suse.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 <sound/driver.h>
34 #include <asm/io.h>
35 #include <asm/dma.h>
36 #include <linux/init.h>
37 #include <linux/time.h>
38 #include <sound/core.h>
39 #include <sound/sb.h>
40 
41 MODULE_AUTHOR("Jaroslav Kysela <perex@suse.cz>, Uros Bizjak <uros@kss-loka.si>");
42 MODULE_DESCRIPTION("Routines for control of 8-bit SoundBlaster cards and clones");
43 MODULE_LICENSE("GPL");
44 
45 #define SB8_CLOCK	1000000
46 #define SB8_DEN(v)	((SB8_CLOCK + (v) / 2) / (v))
47 #define SB8_RATE(v)	(SB8_CLOCK / SB8_DEN(v))
48 
49 static ratnum_t clock = {
50 	.num = SB8_CLOCK,
51 	.den_min = 1,
52 	.den_max = 256,
53 	.den_step = 1,
54 };
55 
56 static snd_pcm_hw_constraint_ratnums_t hw_constraints_clock = {
57 	.nrats = 1,
58 	.rats = &clock,
59 };
60 
61 static ratnum_t stereo_clocks[] = {
62 	{
63 		.num = SB8_CLOCK,
64 		.den_min = SB8_DEN(22050),
65 		.den_max = SB8_DEN(22050),
66 		.den_step = 1,
67 	},
68 	{
69 		.num = SB8_CLOCK,
70 		.den_min = SB8_DEN(11025),
71 		.den_max = SB8_DEN(11025),
72 		.den_step = 1,
73 	}
74 };
75 
76 static int snd_sb8_hw_constraint_rate_channels(snd_pcm_hw_params_t *params,
77 					       snd_pcm_hw_rule_t *rule)
78 {
79 	snd_interval_t *c = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
80 	if (c->min > 1) {
81 	  	unsigned int num = 0, den = 0;
82 		int err = snd_interval_ratnum(hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE),
83 					  2, stereo_clocks, &num, &den);
84 		if (err >= 0 && den) {
85 			params->rate_num = num;
86 			params->rate_den = den;
87 		}
88 		return err;
89 	}
90 	return 0;
91 }
92 
93 static int snd_sb8_hw_constraint_channels_rate(snd_pcm_hw_params_t *params,
94 					       snd_pcm_hw_rule_t *rule)
95 {
96 	snd_interval_t *r = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
97 	if (r->min > SB8_RATE(22050) || r->max <= SB8_RATE(11025)) {
98 		snd_interval_t t = { .min = 1, .max = 1 };
99 		return snd_interval_refine(hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS), &t);
100 	}
101 	return 0;
102 }
103 
104 static int snd_sb8_playback_prepare(snd_pcm_substream_t * substream)
105 {
106 	unsigned long flags;
107 	sb_t *chip = snd_pcm_substream_chip(substream);
108 	snd_pcm_runtime_t *runtime = substream->runtime;
109 	unsigned int mixreg, rate, size, count;
110 
111 	rate = runtime->rate;
112 	switch (chip->hardware) {
113 	case SB_HW_PRO:
114 		if (runtime->channels > 1) {
115 			snd_assert(rate == SB8_RATE(11025) || rate == SB8_RATE(22050), return -EINVAL);
116 			chip->playback_format = SB_DSP_HI_OUTPUT_AUTO;
117 			break;
118 		}
119 		/* fallthru */
120 	case SB_HW_201:
121 		if (rate > 23000) {
122 			chip->playback_format = SB_DSP_HI_OUTPUT_AUTO;
123 			break;
124 		}
125 		/* fallthru */
126 	case SB_HW_20:
127 		chip->playback_format = SB_DSP_LO_OUTPUT_AUTO;
128 		break;
129 	case SB_HW_10:
130 		chip->playback_format = SB_DSP_OUTPUT;
131 		break;
132 	default:
133 		return -EINVAL;
134 	}
135 	size = chip->p_dma_size = snd_pcm_lib_buffer_bytes(substream);
136 	count = chip->p_period_size = snd_pcm_lib_period_bytes(substream);
137 	spin_lock_irqsave(&chip->reg_lock, flags);
138 	snd_sbdsp_command(chip, SB_DSP_SPEAKER_ON);
139 	if (runtime->channels > 1) {
140 		/* set playback stereo mode */
141 		spin_lock(&chip->mixer_lock);
142 		mixreg = snd_sbmixer_read(chip, SB_DSP_STEREO_SW);
143 		snd_sbmixer_write(chip, SB_DSP_STEREO_SW, mixreg | 0x02);
144 		spin_unlock(&chip->mixer_lock);
145 
146 		/* Soundblaster hardware programming reference guide, 3-23 */
147 		snd_sbdsp_command(chip, SB_DSP_DMA8_EXIT);
148 		runtime->dma_area[0] = 0x80;
149 		snd_dma_program(chip->dma8, runtime->dma_addr, 1, DMA_MODE_WRITE);
150 		/* force interrupt */
151 		chip->mode = SB_MODE_HALT;
152 		snd_sbdsp_command(chip, SB_DSP_OUTPUT);
153 		snd_sbdsp_command(chip, 0);
154 		snd_sbdsp_command(chip, 0);
155 	}
156 	snd_sbdsp_command(chip, SB_DSP_SAMPLE_RATE);
157 	if (runtime->channels > 1) {
158 		snd_sbdsp_command(chip, 256 - runtime->rate_den / 2);
159 		spin_lock(&chip->mixer_lock);
160 		/* save output filter status and turn it off */
161 		mixreg = snd_sbmixer_read(chip, SB_DSP_PLAYBACK_FILT);
162 		snd_sbmixer_write(chip, SB_DSP_PLAYBACK_FILT, mixreg | 0x20);
163 		spin_unlock(&chip->mixer_lock);
164 		/* just use force_mode16 for temporary storate... */
165 		chip->force_mode16 = mixreg;
166 	} else {
167 		snd_sbdsp_command(chip, 256 - runtime->rate_den);
168 	}
169 	if (chip->playback_format != SB_DSP_OUTPUT) {
170 		count--;
171 		snd_sbdsp_command(chip, SB_DSP_BLOCK_SIZE);
172 		snd_sbdsp_command(chip, count & 0xff);
173 		snd_sbdsp_command(chip, count >> 8);
174 	}
175 	spin_unlock_irqrestore(&chip->reg_lock, flags);
176 	snd_dma_program(chip->dma8, runtime->dma_addr,
177 			size, DMA_MODE_WRITE | DMA_AUTOINIT);
178 	return 0;
179 }
180 
181 static int snd_sb8_playback_trigger(snd_pcm_substream_t * substream,
182 				    int cmd)
183 {
184 	unsigned long flags;
185 	sb_t *chip = snd_pcm_substream_chip(substream);
186 	unsigned int count;
187 
188 	spin_lock_irqsave(&chip->reg_lock, flags);
189 	switch (cmd) {
190 	case SNDRV_PCM_TRIGGER_START:
191 		snd_sbdsp_command(chip, chip->playback_format);
192 		if (chip->playback_format == SB_DSP_OUTPUT) {
193 			count = chip->p_period_size - 1;
194 			snd_sbdsp_command(chip, count & 0xff);
195 			snd_sbdsp_command(chip, count >> 8);
196 		}
197 		break;
198 	case SNDRV_PCM_TRIGGER_STOP:
199 		if (chip->playback_format == SB_DSP_HI_OUTPUT_AUTO) {
200 			snd_pcm_runtime_t *runtime = substream->runtime;
201 			snd_sbdsp_reset(chip);
202 			if (runtime->channels > 1) {
203 				spin_lock(&chip->mixer_lock);
204 				/* restore output filter and set hardware to mono mode */
205 				snd_sbmixer_write(chip, SB_DSP_STEREO_SW, chip->force_mode16 & ~0x02);
206 				spin_unlock(&chip->mixer_lock);
207 			}
208 		} else {
209 			snd_sbdsp_command(chip, SB_DSP_DMA8_OFF);
210 		}
211 		snd_sbdsp_command(chip, SB_DSP_SPEAKER_OFF);
212 	}
213 	spin_unlock_irqrestore(&chip->reg_lock, flags);
214 	chip->mode = (cmd == SNDRV_PCM_TRIGGER_START) ? SB_MODE_PLAYBACK_8 : SB_MODE_HALT;
215 	return 0;
216 }
217 
218 static int snd_sb8_hw_params(snd_pcm_substream_t * substream,
219 			     snd_pcm_hw_params_t * hw_params)
220 {
221 	return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params));
222 }
223 
224 static int snd_sb8_hw_free(snd_pcm_substream_t * substream)
225 {
226 	snd_pcm_lib_free_pages(substream);
227 	return 0;
228 }
229 
230 static int snd_sb8_capture_prepare(snd_pcm_substream_t * substream)
231 {
232 	unsigned long flags;
233 	sb_t *chip = snd_pcm_substream_chip(substream);
234 	snd_pcm_runtime_t *runtime = substream->runtime;
235 	unsigned int mixreg, rate, size, count;
236 
237 	rate = runtime->rate;
238 	switch (chip->hardware) {
239 	case SB_HW_PRO:
240 		if (runtime->channels > 1) {
241 			snd_assert(rate == SB8_RATE(11025) || rate == SB8_RATE(22050), return -EINVAL);
242 			chip->capture_format = SB_DSP_HI_INPUT_AUTO;
243 			break;
244 		}
245 		chip->capture_format = (rate > 23000) ? SB_DSP_HI_INPUT_AUTO : SB_DSP_LO_INPUT_AUTO;
246 		break;
247 	case SB_HW_201:
248 		if (rate > 13000) {
249 			chip->capture_format = SB_DSP_HI_INPUT_AUTO;
250 			break;
251 		}
252 		/* fallthru */
253 	case SB_HW_20:
254 		chip->capture_format = SB_DSP_LO_INPUT_AUTO;
255 		break;
256 	case SB_HW_10:
257 		chip->capture_format = SB_DSP_INPUT;
258 		break;
259 	default:
260 		return -EINVAL;
261 	}
262 	size = chip->c_dma_size = snd_pcm_lib_buffer_bytes(substream);
263 	count = chip->c_period_size = snd_pcm_lib_period_bytes(substream);
264 	spin_lock_irqsave(&chip->reg_lock, flags);
265 	snd_sbdsp_command(chip, SB_DSP_SPEAKER_OFF);
266 	if (runtime->channels > 1)
267 		snd_sbdsp_command(chip, SB_DSP_STEREO_8BIT);
268 	snd_sbdsp_command(chip, SB_DSP_SAMPLE_RATE);
269 	if (runtime->channels > 1) {
270 		snd_sbdsp_command(chip, 256 - runtime->rate_den / 2);
271 		spin_lock(&chip->mixer_lock);
272 		/* save input filter status and turn it off */
273 		mixreg = snd_sbmixer_read(chip, SB_DSP_CAPTURE_FILT);
274 		snd_sbmixer_write(chip, SB_DSP_CAPTURE_FILT, mixreg | 0x20);
275 		spin_unlock(&chip->mixer_lock);
276 		/* just use force_mode16 for temporary storate... */
277 		chip->force_mode16 = mixreg;
278 	} else {
279 		snd_sbdsp_command(chip, 256 - runtime->rate_den);
280 	}
281 	if (chip->capture_format != SB_DSP_OUTPUT) {
282 		count--;
283 		snd_sbdsp_command(chip, SB_DSP_BLOCK_SIZE);
284 		snd_sbdsp_command(chip, count & 0xff);
285 		snd_sbdsp_command(chip, count >> 8);
286 	}
287 	spin_unlock_irqrestore(&chip->reg_lock, flags);
288 	snd_dma_program(chip->dma8, runtime->dma_addr,
289 			size, DMA_MODE_READ | DMA_AUTOINIT);
290 	return 0;
291 }
292 
293 static int snd_sb8_capture_trigger(snd_pcm_substream_t * substream,
294 				   int cmd)
295 {
296 	unsigned long flags;
297 	sb_t *chip = snd_pcm_substream_chip(substream);
298 	unsigned int count;
299 
300 	spin_lock_irqsave(&chip->reg_lock, flags);
301 	switch (cmd) {
302 	case SNDRV_PCM_TRIGGER_START:
303 		snd_sbdsp_command(chip, chip->capture_format);
304 		if (chip->capture_format == SB_DSP_INPUT) {
305 			count = chip->c_period_size - 1;
306 			snd_sbdsp_command(chip, count & 0xff);
307 			snd_sbdsp_command(chip, count >> 8);
308 		}
309 		break;
310 	case SNDRV_PCM_TRIGGER_STOP:
311 		if (chip->capture_format == SB_DSP_HI_INPUT_AUTO) {
312 			snd_pcm_runtime_t *runtime = substream->runtime;
313 			snd_sbdsp_reset(chip);
314 			if (runtime->channels > 1) {
315 				/* restore input filter status */
316 				spin_lock(&chip->mixer_lock);
317 				snd_sbmixer_write(chip, SB_DSP_CAPTURE_FILT, chip->force_mode16);
318 				spin_unlock(&chip->mixer_lock);
319 				/* set hardware to mono mode */
320 				snd_sbdsp_command(chip, SB_DSP_MONO_8BIT);
321 			}
322 		} else {
323 			snd_sbdsp_command(chip, SB_DSP_DMA8_OFF);
324 		}
325 		snd_sbdsp_command(chip, SB_DSP_SPEAKER_OFF);
326 	}
327 	spin_unlock_irqrestore(&chip->reg_lock, flags);
328 	chip->mode = (cmd == SNDRV_PCM_TRIGGER_START) ? SB_MODE_CAPTURE_8 : SB_MODE_HALT;
329 	return 0;
330 }
331 
332 irqreturn_t snd_sb8dsp_interrupt(sb_t *chip)
333 {
334 	snd_pcm_substream_t *substream;
335 	snd_pcm_runtime_t *runtime;
336 
337 #if 0
338 	snd_printk("sb8: interrupt\n");
339 #endif
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(snd_pcm_substream_t * substream)
361 {
362 	sb_t *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(snd_pcm_substream_t * substream)
372 {
373 	sb_t *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 snd_pcm_hardware_t 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 snd_pcm_hardware_t 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(snd_pcm_substream_t *substream)
429 {
430 	sb_t *chip = snd_pcm_substream_chip(substream);
431 	snd_pcm_runtime_t *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(snd_pcm_substream_t *substream)
475 {
476 	unsigned long flags;
477 	sb_t *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 snd_pcm_ops_t 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 snd_pcm_ops_t 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 static void snd_sb8dsp_pcm_free(snd_pcm_t *pcm)
514 {
515 	snd_pcm_lib_preallocate_free_for_all(pcm);
516 }
517 
518 int snd_sb8dsp_pcm(sb_t *chip, int device, snd_pcm_t ** rpcm)
519 {
520 	snd_card_t *card = chip->card;
521 	snd_pcm_t *pcm;
522 	int err;
523 
524 	if (rpcm)
525 		*rpcm = NULL;
526 	if ((err = snd_pcm_new(card, "SB8 DSP", device, 1, 1, &pcm)) < 0)
527 		return err;
528 	sprintf(pcm->name, "DSP v%i.%i", chip->version >> 8, chip->version & 0xff);
529 	pcm->info_flags = SNDRV_PCM_INFO_HALF_DUPLEX;
530 	pcm->private_data = chip;
531 	pcm->private_free = snd_sb8dsp_pcm_free;
532 
533 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sb8_playback_ops);
534 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_sb8_capture_ops);
535 
536 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
537 					      snd_dma_isa_data(),
538 					      64*1024, 64*1024);
539 
540 	if (rpcm)
541 		*rpcm = pcm;
542 	return 0;
543 }
544 
545 EXPORT_SYMBOL(snd_sb8dsp_pcm);
546 EXPORT_SYMBOL(snd_sb8dsp_interrupt);
547   /* sb8_midi.c */
548 EXPORT_SYMBOL(snd_sb8dsp_midi_interrupt);
549 EXPORT_SYMBOL(snd_sb8dsp_midi);
550 
551 /*
552  *  INIT part
553  */
554 
555 static int __init alsa_sb8_init(void)
556 {
557 	return 0;
558 }
559 
560 static void __exit alsa_sb8_exit(void)
561 {
562 }
563 
564 module_init(alsa_sb8_init)
565 module_exit(alsa_sb8_exit)
566