xref: /linux/sound/isa/sb/sb8_main.c (revision 18f90d372cf35b387663f1567de701e5393f6eb5)
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 <linux/io.h>
34 #include <asm/dma.h>
35 #include <linux/init.h>
36 #include <linux/time.h>
37 #include <linux/module.h>
38 #include <sound/core.h>
39 #include <sound/sb.h>
40 
41 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.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 const struct snd_ratnum clock = {
50 	.num = SB8_CLOCK,
51 	.den_min = 1,
52 	.den_max = 256,
53 	.den_step = 1,
54 };
55 
56 static const struct snd_pcm_hw_constraint_ratnums hw_constraints_clock = {
57 	.nrats = 1,
58 	.rats = &clock,
59 };
60 
61 static const struct snd_ratnum 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(struct snd_pcm_hw_params *params,
77 					       struct snd_pcm_hw_rule *rule)
78 {
79 	struct snd_interval *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(struct snd_pcm_hw_params *params,
94 					       struct snd_pcm_hw_rule *rule)
95 {
96 	struct snd_interval *r = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
97 	if (r->min > SB8_RATE(22050) || r->max <= SB8_RATE(11025)) {
98 		struct snd_interval 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(struct snd_pcm_substream *substream)
105 {
106 	unsigned long flags;
107 	struct snd_sb *chip = snd_pcm_substream_chip(substream);
108 	struct snd_pcm_runtime *runtime = substream->runtime;
109 	unsigned int mixreg, rate, size, count;
110 	unsigned char format;
111 	unsigned char stereo = runtime->channels > 1;
112 	int dma;
113 
114 	rate = runtime->rate;
115 	switch (chip->hardware) {
116 	case SB_HW_JAZZ16:
117 		if (runtime->format == SNDRV_PCM_FORMAT_S16_LE) {
118 			if (chip->mode & SB_MODE_CAPTURE_16)
119 				return -EBUSY;
120 			else
121 				chip->mode |= SB_MODE_PLAYBACK_16;
122 		}
123 		chip->playback_format = SB_DSP_LO_OUTPUT_AUTO;
124 		break;
125 	case SB_HW_PRO:
126 		if (runtime->channels > 1) {
127 			if (snd_BUG_ON(rate != SB8_RATE(11025) &&
128 				       rate != SB8_RATE(22050)))
129 				return -EINVAL;
130 			chip->playback_format = SB_DSP_HI_OUTPUT_AUTO;
131 			break;
132 		}
133 		/* fall through */
134 	case SB_HW_201:
135 		if (rate > 23000) {
136 			chip->playback_format = SB_DSP_HI_OUTPUT_AUTO;
137 			break;
138 		}
139 		/* fall through */
140 	case SB_HW_20:
141 		chip->playback_format = SB_DSP_LO_OUTPUT_AUTO;
142 		break;
143 	case SB_HW_10:
144 		chip->playback_format = SB_DSP_OUTPUT;
145 		break;
146 	default:
147 		return -EINVAL;
148 	}
149 	if (chip->mode & SB_MODE_PLAYBACK_16) {
150 		format = stereo ? SB_DSP_STEREO_16BIT : SB_DSP_MONO_16BIT;
151 		dma = chip->dma16;
152 	} else {
153 		format = stereo ? SB_DSP_STEREO_8BIT : SB_DSP_MONO_8BIT;
154 		chip->mode |= SB_MODE_PLAYBACK_8;
155 		dma = chip->dma8;
156 	}
157 	size = chip->p_dma_size = snd_pcm_lib_buffer_bytes(substream);
158 	count = chip->p_period_size = snd_pcm_lib_period_bytes(substream);
159 	spin_lock_irqsave(&chip->reg_lock, flags);
160 	snd_sbdsp_command(chip, SB_DSP_SPEAKER_ON);
161 	if (chip->hardware == SB_HW_JAZZ16)
162 		snd_sbdsp_command(chip, format);
163 	else if (stereo) {
164 		/* set playback stereo mode */
165 		spin_lock(&chip->mixer_lock);
166 		mixreg = snd_sbmixer_read(chip, SB_DSP_STEREO_SW);
167 		snd_sbmixer_write(chip, SB_DSP_STEREO_SW, mixreg | 0x02);
168 		spin_unlock(&chip->mixer_lock);
169 
170 		/* Soundblaster hardware programming reference guide, 3-23 */
171 		snd_sbdsp_command(chip, SB_DSP_DMA8_EXIT);
172 		runtime->dma_area[0] = 0x80;
173 		snd_dma_program(dma, runtime->dma_addr, 1, DMA_MODE_WRITE);
174 		/* force interrupt */
175 		snd_sbdsp_command(chip, SB_DSP_OUTPUT);
176 		snd_sbdsp_command(chip, 0);
177 		snd_sbdsp_command(chip, 0);
178 	}
179 	snd_sbdsp_command(chip, SB_DSP_SAMPLE_RATE);
180 	if (stereo) {
181 		snd_sbdsp_command(chip, 256 - runtime->rate_den / 2);
182 		spin_lock(&chip->mixer_lock);
183 		/* save output filter status and turn it off */
184 		mixreg = snd_sbmixer_read(chip, SB_DSP_PLAYBACK_FILT);
185 		snd_sbmixer_write(chip, SB_DSP_PLAYBACK_FILT, mixreg | 0x20);
186 		spin_unlock(&chip->mixer_lock);
187 		/* just use force_mode16 for temporary storate... */
188 		chip->force_mode16 = mixreg;
189 	} else {
190 		snd_sbdsp_command(chip, 256 - runtime->rate_den);
191 	}
192 	if (chip->playback_format != SB_DSP_OUTPUT) {
193 		if (chip->mode & SB_MODE_PLAYBACK_16)
194 			count /= 2;
195 		count--;
196 		snd_sbdsp_command(chip, SB_DSP_BLOCK_SIZE);
197 		snd_sbdsp_command(chip, count & 0xff);
198 		snd_sbdsp_command(chip, count >> 8);
199 	}
200 	spin_unlock_irqrestore(&chip->reg_lock, flags);
201 	snd_dma_program(dma, runtime->dma_addr,
202 			size, DMA_MODE_WRITE | DMA_AUTOINIT);
203 	return 0;
204 }
205 
206 static int snd_sb8_playback_trigger(struct snd_pcm_substream *substream,
207 				    int cmd)
208 {
209 	unsigned long flags;
210 	struct snd_sb *chip = snd_pcm_substream_chip(substream);
211 	unsigned int count;
212 
213 	spin_lock_irqsave(&chip->reg_lock, flags);
214 	switch (cmd) {
215 	case SNDRV_PCM_TRIGGER_START:
216 		snd_sbdsp_command(chip, chip->playback_format);
217 		if (chip->playback_format == SB_DSP_OUTPUT) {
218 			count = chip->p_period_size - 1;
219 			snd_sbdsp_command(chip, count & 0xff);
220 			snd_sbdsp_command(chip, count >> 8);
221 		}
222 		break;
223 	case SNDRV_PCM_TRIGGER_STOP:
224 		if (chip->playback_format == SB_DSP_HI_OUTPUT_AUTO) {
225 			struct snd_pcm_runtime *runtime = substream->runtime;
226 			snd_sbdsp_reset(chip);
227 			if (runtime->channels > 1) {
228 				spin_lock(&chip->mixer_lock);
229 				/* restore output filter and set hardware to mono mode */
230 				snd_sbmixer_write(chip, SB_DSP_STEREO_SW, chip->force_mode16 & ~0x02);
231 				spin_unlock(&chip->mixer_lock);
232 			}
233 		} else {
234 			snd_sbdsp_command(chip, SB_DSP_DMA8_OFF);
235 		}
236 		snd_sbdsp_command(chip, SB_DSP_SPEAKER_OFF);
237 	}
238 	spin_unlock_irqrestore(&chip->reg_lock, flags);
239 	return 0;
240 }
241 
242 static int snd_sb8_hw_params(struct snd_pcm_substream *substream,
243 			     struct snd_pcm_hw_params *hw_params)
244 {
245 	return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params));
246 }
247 
248 static int snd_sb8_hw_free(struct snd_pcm_substream *substream)
249 {
250 	snd_pcm_lib_free_pages(substream);
251 	return 0;
252 }
253 
254 static int snd_sb8_capture_prepare(struct snd_pcm_substream *substream)
255 {
256 	unsigned long flags;
257 	struct snd_sb *chip = snd_pcm_substream_chip(substream);
258 	struct snd_pcm_runtime *runtime = substream->runtime;
259 	unsigned int mixreg, rate, size, count;
260 	unsigned char format;
261 	unsigned char stereo = runtime->channels > 1;
262 	int dma;
263 
264 	rate = runtime->rate;
265 	switch (chip->hardware) {
266 	case SB_HW_JAZZ16:
267 		if (runtime->format == SNDRV_PCM_FORMAT_S16_LE) {
268 			if (chip->mode & SB_MODE_PLAYBACK_16)
269 				return -EBUSY;
270 			else
271 				chip->mode |= SB_MODE_CAPTURE_16;
272 		}
273 		chip->capture_format = SB_DSP_LO_INPUT_AUTO;
274 		break;
275 	case SB_HW_PRO:
276 		if (runtime->channels > 1) {
277 			if (snd_BUG_ON(rate != SB8_RATE(11025) &&
278 				       rate != SB8_RATE(22050)))
279 				return -EINVAL;
280 			chip->capture_format = SB_DSP_HI_INPUT_AUTO;
281 			break;
282 		}
283 		chip->capture_format = (rate > 23000) ? SB_DSP_HI_INPUT_AUTO : SB_DSP_LO_INPUT_AUTO;
284 		break;
285 	case SB_HW_201:
286 		if (rate > 13000) {
287 			chip->capture_format = SB_DSP_HI_INPUT_AUTO;
288 			break;
289 		}
290 		/* fall through */
291 	case SB_HW_20:
292 		chip->capture_format = SB_DSP_LO_INPUT_AUTO;
293 		break;
294 	case SB_HW_10:
295 		chip->capture_format = SB_DSP_INPUT;
296 		break;
297 	default:
298 		return -EINVAL;
299 	}
300 	if (chip->mode & SB_MODE_CAPTURE_16) {
301 		format = stereo ? SB_DSP_STEREO_16BIT : SB_DSP_MONO_16BIT;
302 		dma = chip->dma16;
303 	} else {
304 		format = stereo ? SB_DSP_STEREO_8BIT : SB_DSP_MONO_8BIT;
305 		chip->mode |= SB_MODE_CAPTURE_8;
306 		dma = chip->dma8;
307 	}
308 	size = chip->c_dma_size = snd_pcm_lib_buffer_bytes(substream);
309 	count = chip->c_period_size = snd_pcm_lib_period_bytes(substream);
310 	spin_lock_irqsave(&chip->reg_lock, flags);
311 	snd_sbdsp_command(chip, SB_DSP_SPEAKER_OFF);
312 	if (chip->hardware == SB_HW_JAZZ16)
313 		snd_sbdsp_command(chip, format);
314 	else if (stereo)
315 		snd_sbdsp_command(chip, SB_DSP_STEREO_8BIT);
316 	snd_sbdsp_command(chip, SB_DSP_SAMPLE_RATE);
317 	if (stereo) {
318 		snd_sbdsp_command(chip, 256 - runtime->rate_den / 2);
319 		spin_lock(&chip->mixer_lock);
320 		/* save input filter status and turn it off */
321 		mixreg = snd_sbmixer_read(chip, SB_DSP_CAPTURE_FILT);
322 		snd_sbmixer_write(chip, SB_DSP_CAPTURE_FILT, mixreg | 0x20);
323 		spin_unlock(&chip->mixer_lock);
324 		/* just use force_mode16 for temporary storate... */
325 		chip->force_mode16 = mixreg;
326 	} else {
327 		snd_sbdsp_command(chip, 256 - runtime->rate_den);
328 	}
329 	if (chip->capture_format != SB_DSP_INPUT) {
330 		if (chip->mode & SB_MODE_PLAYBACK_16)
331 			count /= 2;
332 		count--;
333 		snd_sbdsp_command(chip, SB_DSP_BLOCK_SIZE);
334 		snd_sbdsp_command(chip, count & 0xff);
335 		snd_sbdsp_command(chip, count >> 8);
336 	}
337 	spin_unlock_irqrestore(&chip->reg_lock, flags);
338 	snd_dma_program(dma, runtime->dma_addr,
339 			size, DMA_MODE_READ | DMA_AUTOINIT);
340 	return 0;
341 }
342 
343 static int snd_sb8_capture_trigger(struct snd_pcm_substream *substream,
344 				   int cmd)
345 {
346 	unsigned long flags;
347 	struct snd_sb *chip = snd_pcm_substream_chip(substream);
348 	unsigned int count;
349 
350 	spin_lock_irqsave(&chip->reg_lock, flags);
351 	switch (cmd) {
352 	case SNDRV_PCM_TRIGGER_START:
353 		snd_sbdsp_command(chip, chip->capture_format);
354 		if (chip->capture_format == SB_DSP_INPUT) {
355 			count = chip->c_period_size - 1;
356 			snd_sbdsp_command(chip, count & 0xff);
357 			snd_sbdsp_command(chip, count >> 8);
358 		}
359 		break;
360 	case SNDRV_PCM_TRIGGER_STOP:
361 		if (chip->capture_format == SB_DSP_HI_INPUT_AUTO) {
362 			struct snd_pcm_runtime *runtime = substream->runtime;
363 			snd_sbdsp_reset(chip);
364 			if (runtime->channels > 1) {
365 				/* restore input filter status */
366 				spin_lock(&chip->mixer_lock);
367 				snd_sbmixer_write(chip, SB_DSP_CAPTURE_FILT, chip->force_mode16);
368 				spin_unlock(&chip->mixer_lock);
369 				/* set hardware to mono mode */
370 				snd_sbdsp_command(chip, SB_DSP_MONO_8BIT);
371 			}
372 		} else {
373 			snd_sbdsp_command(chip, SB_DSP_DMA8_OFF);
374 		}
375 		snd_sbdsp_command(chip, SB_DSP_SPEAKER_OFF);
376 	}
377 	spin_unlock_irqrestore(&chip->reg_lock, flags);
378 	return 0;
379 }
380 
381 irqreturn_t snd_sb8dsp_interrupt(struct snd_sb *chip)
382 {
383 	struct snd_pcm_substream *substream;
384 
385 	snd_sb_ack_8bit(chip);
386 	switch (chip->mode) {
387 	case SB_MODE_PLAYBACK_16:	/* ok.. playback is active */
388 		if (chip->hardware != SB_HW_JAZZ16)
389 			break;
390 		/* fall through */
391 	case SB_MODE_PLAYBACK_8:
392 		substream = chip->playback_substream;
393 		if (chip->playback_format == SB_DSP_OUTPUT)
394 		    	snd_sb8_playback_trigger(substream, SNDRV_PCM_TRIGGER_START);
395 		snd_pcm_period_elapsed(substream);
396 		break;
397 	case SB_MODE_CAPTURE_16:
398 		if (chip->hardware != SB_HW_JAZZ16)
399 			break;
400 		/* fall through */
401 	case SB_MODE_CAPTURE_8:
402 		substream = chip->capture_substream;
403 		if (chip->capture_format == SB_DSP_INPUT)
404 		    	snd_sb8_capture_trigger(substream, SNDRV_PCM_TRIGGER_START);
405 		snd_pcm_period_elapsed(substream);
406 		break;
407 	}
408 	return IRQ_HANDLED;
409 }
410 
411 static snd_pcm_uframes_t snd_sb8_playback_pointer(struct snd_pcm_substream *substream)
412 {
413 	struct snd_sb *chip = snd_pcm_substream_chip(substream);
414 	size_t ptr;
415 	int dma;
416 
417 	if (chip->mode & SB_MODE_PLAYBACK_8)
418 		dma = chip->dma8;
419 	else if (chip->mode & SB_MODE_PLAYBACK_16)
420 		dma = chip->dma16;
421 	else
422 		return 0;
423 	ptr = snd_dma_pointer(dma, chip->p_dma_size);
424 	return bytes_to_frames(substream->runtime, ptr);
425 }
426 
427 static snd_pcm_uframes_t snd_sb8_capture_pointer(struct snd_pcm_substream *substream)
428 {
429 	struct snd_sb *chip = snd_pcm_substream_chip(substream);
430 	size_t ptr;
431 	int dma;
432 
433 	if (chip->mode & SB_MODE_CAPTURE_8)
434 		dma = chip->dma8;
435 	else if (chip->mode & SB_MODE_CAPTURE_16)
436 		dma = chip->dma16;
437 	else
438 		return 0;
439 	ptr = snd_dma_pointer(dma, chip->c_dma_size);
440 	return bytes_to_frames(substream->runtime, ptr);
441 }
442 
443 /*
444 
445  */
446 
447 static const struct snd_pcm_hardware snd_sb8_playback =
448 {
449 	.info =			(SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
450 				 SNDRV_PCM_INFO_MMAP_VALID),
451 	.formats =		 SNDRV_PCM_FMTBIT_U8,
452 	.rates =		(SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000 |
453 				 SNDRV_PCM_RATE_11025 | SNDRV_PCM_RATE_22050),
454 	.rate_min =		4000,
455 	.rate_max =		23000,
456 	.channels_min =		1,
457 	.channels_max =		1,
458 	.buffer_bytes_max =	65536,
459 	.period_bytes_min =	64,
460 	.period_bytes_max =	65536,
461 	.periods_min =		1,
462 	.periods_max =		1024,
463 	.fifo_size =		0,
464 };
465 
466 static const struct snd_pcm_hardware snd_sb8_capture =
467 {
468 	.info =			(SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
469 				 SNDRV_PCM_INFO_MMAP_VALID),
470 	.formats =		SNDRV_PCM_FMTBIT_U8,
471 	.rates =		(SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000 |
472 				 SNDRV_PCM_RATE_11025),
473 	.rate_min =		4000,
474 	.rate_max =		13000,
475 	.channels_min =		1,
476 	.channels_max =		1,
477 	.buffer_bytes_max =	65536,
478 	.period_bytes_min =	64,
479 	.period_bytes_max =	65536,
480 	.periods_min =		1,
481 	.periods_max =		1024,
482 	.fifo_size =		0,
483 };
484 
485 /*
486  *
487  */
488 
489 static int snd_sb8_open(struct snd_pcm_substream *substream)
490 {
491 	struct snd_sb *chip = snd_pcm_substream_chip(substream);
492 	struct snd_pcm_runtime *runtime = substream->runtime;
493 	unsigned long flags;
494 
495 	spin_lock_irqsave(&chip->open_lock, flags);
496 	if (chip->open) {
497 		spin_unlock_irqrestore(&chip->open_lock, flags);
498 		return -EAGAIN;
499 	}
500 	chip->open |= SB_OPEN_PCM;
501 	spin_unlock_irqrestore(&chip->open_lock, flags);
502 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
503 		chip->playback_substream = substream;
504 		runtime->hw = snd_sb8_playback;
505 	} else {
506 		chip->capture_substream = substream;
507 		runtime->hw = snd_sb8_capture;
508 	}
509 	switch (chip->hardware) {
510 	case SB_HW_JAZZ16:
511 		if (chip->dma16 == 5 || chip->dma16 == 7)
512 			runtime->hw.formats |= SNDRV_PCM_FMTBIT_S16_LE;
513 		runtime->hw.rates |= SNDRV_PCM_RATE_8000_48000;
514 		runtime->hw.rate_min = 4000;
515 		runtime->hw.rate_max = 50000;
516 		runtime->hw.channels_max = 2;
517 		break;
518 	case SB_HW_PRO:
519 		runtime->hw.rate_max = 44100;
520 		runtime->hw.channels_max = 2;
521 		snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
522 				    snd_sb8_hw_constraint_rate_channels, NULL,
523 				    SNDRV_PCM_HW_PARAM_CHANNELS,
524 				    SNDRV_PCM_HW_PARAM_RATE, -1);
525 		snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
526 				     snd_sb8_hw_constraint_channels_rate, NULL,
527 				     SNDRV_PCM_HW_PARAM_RATE, -1);
528 		break;
529 	case SB_HW_201:
530 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
531 			runtime->hw.rate_max = 44100;
532 		} else {
533 			runtime->hw.rate_max = 15000;
534 		}
535 	default:
536 		break;
537 	}
538 	snd_pcm_hw_constraint_ratnums(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
539 				      &hw_constraints_clock);
540 	if (chip->dma8 > 3 || chip->dma16 >= 0) {
541 		snd_pcm_hw_constraint_step(runtime, 0,
542 					   SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 2);
543 		snd_pcm_hw_constraint_step(runtime, 0,
544 					   SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 2);
545 		runtime->hw.buffer_bytes_max = 128 * 1024 * 1024;
546 		runtime->hw.period_bytes_max = 128 * 1024 * 1024;
547 	}
548 	return 0;
549 }
550 
551 static int snd_sb8_close(struct snd_pcm_substream *substream)
552 {
553 	unsigned long flags;
554 	struct snd_sb *chip = snd_pcm_substream_chip(substream);
555 
556 	chip->playback_substream = NULL;
557 	chip->capture_substream = NULL;
558 	spin_lock_irqsave(&chip->open_lock, flags);
559 	chip->open &= ~SB_OPEN_PCM;
560 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
561 		chip->mode &= ~SB_MODE_PLAYBACK;
562 	else
563 		chip->mode &= ~SB_MODE_CAPTURE;
564 	spin_unlock_irqrestore(&chip->open_lock, flags);
565 	return 0;
566 }
567 
568 /*
569  *  Initialization part
570  */
571 
572 static const struct snd_pcm_ops snd_sb8_playback_ops = {
573 	.open =			snd_sb8_open,
574 	.close =		snd_sb8_close,
575 	.ioctl =		snd_pcm_lib_ioctl,
576 	.hw_params =		snd_sb8_hw_params,
577 	.hw_free =		snd_sb8_hw_free,
578 	.prepare =		snd_sb8_playback_prepare,
579 	.trigger =		snd_sb8_playback_trigger,
580 	.pointer =		snd_sb8_playback_pointer,
581 };
582 
583 static const struct snd_pcm_ops snd_sb8_capture_ops = {
584 	.open =			snd_sb8_open,
585 	.close =		snd_sb8_close,
586 	.ioctl =		snd_pcm_lib_ioctl,
587 	.hw_params =		snd_sb8_hw_params,
588 	.hw_free =		snd_sb8_hw_free,
589 	.prepare =		snd_sb8_capture_prepare,
590 	.trigger =		snd_sb8_capture_trigger,
591 	.pointer =		snd_sb8_capture_pointer,
592 };
593 
594 int snd_sb8dsp_pcm(struct snd_sb *chip, int device)
595 {
596 	struct snd_card *card = chip->card;
597 	struct snd_pcm *pcm;
598 	int err;
599 	size_t max_prealloc = 64 * 1024;
600 
601 	if ((err = snd_pcm_new(card, "SB8 DSP", device, 1, 1, &pcm)) < 0)
602 		return err;
603 	sprintf(pcm->name, "DSP v%i.%i", chip->version >> 8, chip->version & 0xff);
604 	pcm->info_flags = SNDRV_PCM_INFO_HALF_DUPLEX;
605 	pcm->private_data = chip;
606 
607 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sb8_playback_ops);
608 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_sb8_capture_ops);
609 
610 	if (chip->dma8 > 3 || chip->dma16 >= 0)
611 		max_prealloc = 128 * 1024;
612 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
613 					      card->dev,
614 					      64*1024, max_prealloc);
615 
616 	return 0;
617 }
618 
619 EXPORT_SYMBOL(snd_sb8dsp_pcm);
620 EXPORT_SYMBOL(snd_sb8dsp_interrupt);
621   /* sb8_midi.c */
622 EXPORT_SYMBOL(snd_sb8dsp_midi_interrupt);
623 EXPORT_SYMBOL(snd_sb8dsp_midi);
624