xref: /openbmc/linux/sound/drivers/dummy.c (revision 1edd0337)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Dummy soundcard
4  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5  */
6 
7 #include <linux/init.h>
8 #include <linux/err.h>
9 #include <linux/platform_device.h>
10 #include <linux/jiffies.h>
11 #include <linux/slab.h>
12 #include <linux/time.h>
13 #include <linux/wait.h>
14 #include <linux/hrtimer.h>
15 #include <linux/math64.h>
16 #include <linux/module.h>
17 #include <sound/core.h>
18 #include <sound/control.h>
19 #include <sound/tlv.h>
20 #include <sound/pcm.h>
21 #include <sound/rawmidi.h>
22 #include <sound/info.h>
23 #include <sound/initval.h>
24 
25 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
26 MODULE_DESCRIPTION("Dummy soundcard (/dev/null)");
27 MODULE_LICENSE("GPL");
28 
29 #define MAX_PCM_DEVICES		4
30 #define MAX_PCM_SUBSTREAMS	128
31 #define MAX_MIDI_DEVICES	2
32 
33 /* defaults */
34 #define MAX_BUFFER_SIZE		(64*1024)
35 #define MIN_PERIOD_SIZE		64
36 #define MAX_PERIOD_SIZE		MAX_BUFFER_SIZE
37 #define USE_FORMATS 		(SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE)
38 #define USE_RATE		SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000
39 #define USE_RATE_MIN		5500
40 #define USE_RATE_MAX		48000
41 #define USE_CHANNELS_MIN 	1
42 #define USE_CHANNELS_MAX 	2
43 #define USE_PERIODS_MIN 	1
44 #define USE_PERIODS_MAX 	1024
45 #define USE_MIXER_VOLUME_LEVEL_MIN	-50
46 #define USE_MIXER_VOLUME_LEVEL_MAX	100
47 
48 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;	/* Index 0-MAX */
49 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* ID for this card */
50 static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
51 static char *model[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = NULL};
52 static int pcm_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1};
53 static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
54 //static int midi_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 2};
55 static int mixer_volume_level_min = USE_MIXER_VOLUME_LEVEL_MIN;
56 static int mixer_volume_level_max = USE_MIXER_VOLUME_LEVEL_MAX;
57 #ifdef CONFIG_HIGH_RES_TIMERS
58 static bool hrtimer = 1;
59 #endif
60 static bool fake_buffer = 1;
61 
62 module_param_array(index, int, NULL, 0444);
63 MODULE_PARM_DESC(index, "Index value for dummy soundcard.");
64 module_param_array(id, charp, NULL, 0444);
65 MODULE_PARM_DESC(id, "ID string for dummy soundcard.");
66 module_param_array(enable, bool, NULL, 0444);
67 MODULE_PARM_DESC(enable, "Enable this dummy soundcard.");
68 module_param_array(model, charp, NULL, 0444);
69 MODULE_PARM_DESC(model, "Soundcard model.");
70 module_param_array(pcm_devs, int, NULL, 0444);
71 MODULE_PARM_DESC(pcm_devs, "PCM devices # (0-4) for dummy driver.");
72 module_param_array(pcm_substreams, int, NULL, 0444);
73 MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-128) for dummy driver.");
74 //module_param_array(midi_devs, int, NULL, 0444);
75 //MODULE_PARM_DESC(midi_devs, "MIDI devices # (0-2) for dummy driver.");
76 module_param(mixer_volume_level_min, int, 0444);
77 MODULE_PARM_DESC(mixer_volume_level_min, "Minimum mixer volume level for dummy driver. Default: -50");
78 module_param(mixer_volume_level_max, int, 0444);
79 MODULE_PARM_DESC(mixer_volume_level_max, "Maximum mixer volume level for dummy driver. Default: 100");
80 module_param(fake_buffer, bool, 0444);
81 MODULE_PARM_DESC(fake_buffer, "Fake buffer allocations.");
82 #ifdef CONFIG_HIGH_RES_TIMERS
83 module_param(hrtimer, bool, 0644);
84 MODULE_PARM_DESC(hrtimer, "Use hrtimer as the timer source.");
85 #endif
86 
87 static struct platform_device *devices[SNDRV_CARDS];
88 
89 #define MIXER_ADDR_MASTER	0
90 #define MIXER_ADDR_LINE		1
91 #define MIXER_ADDR_MIC		2
92 #define MIXER_ADDR_SYNTH	3
93 #define MIXER_ADDR_CD		4
94 #define MIXER_ADDR_LAST		4
95 
96 struct dummy_timer_ops {
97 	int (*create)(struct snd_pcm_substream *);
98 	void (*free)(struct snd_pcm_substream *);
99 	int (*prepare)(struct snd_pcm_substream *);
100 	int (*start)(struct snd_pcm_substream *);
101 	int (*stop)(struct snd_pcm_substream *);
102 	snd_pcm_uframes_t (*pointer)(struct snd_pcm_substream *);
103 };
104 
105 #define get_dummy_ops(substream) \
106 	(*(const struct dummy_timer_ops **)(substream)->runtime->private_data)
107 
108 struct dummy_model {
109 	const char *name;
110 	int (*playback_constraints)(struct snd_pcm_runtime *runtime);
111 	int (*capture_constraints)(struct snd_pcm_runtime *runtime);
112 	u64 formats;
113 	size_t buffer_bytes_max;
114 	size_t period_bytes_min;
115 	size_t period_bytes_max;
116 	unsigned int periods_min;
117 	unsigned int periods_max;
118 	unsigned int rates;
119 	unsigned int rate_min;
120 	unsigned int rate_max;
121 	unsigned int channels_min;
122 	unsigned int channels_max;
123 };
124 
125 struct snd_dummy {
126 	struct snd_card *card;
127 	const struct dummy_model *model;
128 	struct snd_pcm *pcm;
129 	struct snd_pcm_hardware pcm_hw;
130 	spinlock_t mixer_lock;
131 	int mixer_volume[MIXER_ADDR_LAST+1][2];
132 	int capture_source[MIXER_ADDR_LAST+1][2];
133 	int iobox;
134 	struct snd_kcontrol *cd_volume_ctl;
135 	struct snd_kcontrol *cd_switch_ctl;
136 };
137 
138 /*
139  * card models
140  */
141 
142 static int emu10k1_playback_constraints(struct snd_pcm_runtime *runtime)
143 {
144 	int err;
145 	err = snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
146 	if (err < 0)
147 		return err;
148 	err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 256, UINT_MAX);
149 	if (err < 0)
150 		return err;
151 	return 0;
152 }
153 
154 static const struct dummy_model model_emu10k1 = {
155 	.name = "emu10k1",
156 	.playback_constraints = emu10k1_playback_constraints,
157 	.buffer_bytes_max = 128 * 1024,
158 };
159 
160 static const struct dummy_model model_rme9652 = {
161 	.name = "rme9652",
162 	.buffer_bytes_max = 26 * 64 * 1024,
163 	.formats = SNDRV_PCM_FMTBIT_S32_LE,
164 	.channels_min = 26,
165 	.channels_max = 26,
166 	.periods_min = 2,
167 	.periods_max = 2,
168 };
169 
170 static const struct dummy_model model_ice1712 = {
171 	.name = "ice1712",
172 	.buffer_bytes_max = 256 * 1024,
173 	.formats = SNDRV_PCM_FMTBIT_S32_LE,
174 	.channels_min = 10,
175 	.channels_max = 10,
176 	.periods_min = 1,
177 	.periods_max = 1024,
178 };
179 
180 static const struct dummy_model model_uda1341 = {
181 	.name = "uda1341",
182 	.buffer_bytes_max = 16380,
183 	.formats = SNDRV_PCM_FMTBIT_S16_LE,
184 	.channels_min = 2,
185 	.channels_max = 2,
186 	.periods_min = 2,
187 	.periods_max = 255,
188 };
189 
190 static const struct dummy_model model_ac97 = {
191 	.name = "ac97",
192 	.formats = SNDRV_PCM_FMTBIT_S16_LE,
193 	.channels_min = 2,
194 	.channels_max = 2,
195 	.rates = SNDRV_PCM_RATE_48000,
196 	.rate_min = 48000,
197 	.rate_max = 48000,
198 };
199 
200 static const struct dummy_model model_ca0106 = {
201 	.name = "ca0106",
202 	.formats = SNDRV_PCM_FMTBIT_S16_LE,
203 	.buffer_bytes_max = ((65536-64)*8),
204 	.period_bytes_max = (65536-64),
205 	.periods_min = 2,
206 	.periods_max = 8,
207 	.channels_min = 2,
208 	.channels_max = 2,
209 	.rates = SNDRV_PCM_RATE_48000|SNDRV_PCM_RATE_96000|SNDRV_PCM_RATE_192000,
210 	.rate_min = 48000,
211 	.rate_max = 192000,
212 };
213 
214 static const struct dummy_model *dummy_models[] = {
215 	&model_emu10k1,
216 	&model_rme9652,
217 	&model_ice1712,
218 	&model_uda1341,
219 	&model_ac97,
220 	&model_ca0106,
221 	NULL
222 };
223 
224 /*
225  * system timer interface
226  */
227 
228 struct dummy_systimer_pcm {
229 	/* ops must be the first item */
230 	const struct dummy_timer_ops *timer_ops;
231 	spinlock_t lock;
232 	struct timer_list timer;
233 	unsigned long base_time;
234 	unsigned int frac_pos;	/* fractional sample position (based HZ) */
235 	unsigned int frac_period_rest;
236 	unsigned int frac_buffer_size;	/* buffer_size * HZ */
237 	unsigned int frac_period_size;	/* period_size * HZ */
238 	unsigned int rate;
239 	int elapsed;
240 	struct snd_pcm_substream *substream;
241 };
242 
243 static void dummy_systimer_rearm(struct dummy_systimer_pcm *dpcm)
244 {
245 	mod_timer(&dpcm->timer, jiffies +
246 		DIV_ROUND_UP(dpcm->frac_period_rest, dpcm->rate));
247 }
248 
249 static void dummy_systimer_update(struct dummy_systimer_pcm *dpcm)
250 {
251 	unsigned long delta;
252 
253 	delta = jiffies - dpcm->base_time;
254 	if (!delta)
255 		return;
256 	dpcm->base_time += delta;
257 	delta *= dpcm->rate;
258 	dpcm->frac_pos += delta;
259 	while (dpcm->frac_pos >= dpcm->frac_buffer_size)
260 		dpcm->frac_pos -= dpcm->frac_buffer_size;
261 	while (dpcm->frac_period_rest <= delta) {
262 		dpcm->elapsed++;
263 		dpcm->frac_period_rest += dpcm->frac_period_size;
264 	}
265 	dpcm->frac_period_rest -= delta;
266 }
267 
268 static int dummy_systimer_start(struct snd_pcm_substream *substream)
269 {
270 	struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
271 	spin_lock(&dpcm->lock);
272 	dpcm->base_time = jiffies;
273 	dummy_systimer_rearm(dpcm);
274 	spin_unlock(&dpcm->lock);
275 	return 0;
276 }
277 
278 static int dummy_systimer_stop(struct snd_pcm_substream *substream)
279 {
280 	struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
281 	spin_lock(&dpcm->lock);
282 	del_timer(&dpcm->timer);
283 	spin_unlock(&dpcm->lock);
284 	return 0;
285 }
286 
287 static int dummy_systimer_prepare(struct snd_pcm_substream *substream)
288 {
289 	struct snd_pcm_runtime *runtime = substream->runtime;
290 	struct dummy_systimer_pcm *dpcm = runtime->private_data;
291 
292 	dpcm->frac_pos = 0;
293 	dpcm->rate = runtime->rate;
294 	dpcm->frac_buffer_size = runtime->buffer_size * HZ;
295 	dpcm->frac_period_size = runtime->period_size * HZ;
296 	dpcm->frac_period_rest = dpcm->frac_period_size;
297 	dpcm->elapsed = 0;
298 
299 	return 0;
300 }
301 
302 static void dummy_systimer_callback(struct timer_list *t)
303 {
304 	struct dummy_systimer_pcm *dpcm = from_timer(dpcm, t, timer);
305 	unsigned long flags;
306 	int elapsed = 0;
307 
308 	spin_lock_irqsave(&dpcm->lock, flags);
309 	dummy_systimer_update(dpcm);
310 	dummy_systimer_rearm(dpcm);
311 	elapsed = dpcm->elapsed;
312 	dpcm->elapsed = 0;
313 	spin_unlock_irqrestore(&dpcm->lock, flags);
314 	if (elapsed)
315 		snd_pcm_period_elapsed(dpcm->substream);
316 }
317 
318 static snd_pcm_uframes_t
319 dummy_systimer_pointer(struct snd_pcm_substream *substream)
320 {
321 	struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
322 	snd_pcm_uframes_t pos;
323 
324 	spin_lock(&dpcm->lock);
325 	dummy_systimer_update(dpcm);
326 	pos = dpcm->frac_pos / HZ;
327 	spin_unlock(&dpcm->lock);
328 	return pos;
329 }
330 
331 static int dummy_systimer_create(struct snd_pcm_substream *substream)
332 {
333 	struct dummy_systimer_pcm *dpcm;
334 
335 	dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
336 	if (!dpcm)
337 		return -ENOMEM;
338 	substream->runtime->private_data = dpcm;
339 	timer_setup(&dpcm->timer, dummy_systimer_callback, 0);
340 	spin_lock_init(&dpcm->lock);
341 	dpcm->substream = substream;
342 	return 0;
343 }
344 
345 static void dummy_systimer_free(struct snd_pcm_substream *substream)
346 {
347 	kfree(substream->runtime->private_data);
348 }
349 
350 static const struct dummy_timer_ops dummy_systimer_ops = {
351 	.create =	dummy_systimer_create,
352 	.free =		dummy_systimer_free,
353 	.prepare =	dummy_systimer_prepare,
354 	.start =	dummy_systimer_start,
355 	.stop =		dummy_systimer_stop,
356 	.pointer =	dummy_systimer_pointer,
357 };
358 
359 #ifdef CONFIG_HIGH_RES_TIMERS
360 /*
361  * hrtimer interface
362  */
363 
364 struct dummy_hrtimer_pcm {
365 	/* ops must be the first item */
366 	const struct dummy_timer_ops *timer_ops;
367 	ktime_t base_time;
368 	ktime_t period_time;
369 	atomic_t running;
370 	struct hrtimer timer;
371 	struct snd_pcm_substream *substream;
372 };
373 
374 static enum hrtimer_restart dummy_hrtimer_callback(struct hrtimer *timer)
375 {
376 	struct dummy_hrtimer_pcm *dpcm;
377 
378 	dpcm = container_of(timer, struct dummy_hrtimer_pcm, timer);
379 	if (!atomic_read(&dpcm->running))
380 		return HRTIMER_NORESTART;
381 	/*
382 	 * In cases of XRUN and draining, this calls .trigger to stop PCM
383 	 * substream.
384 	 */
385 	snd_pcm_period_elapsed(dpcm->substream);
386 	if (!atomic_read(&dpcm->running))
387 		return HRTIMER_NORESTART;
388 
389 	hrtimer_forward_now(timer, dpcm->period_time);
390 	return HRTIMER_RESTART;
391 }
392 
393 static int dummy_hrtimer_start(struct snd_pcm_substream *substream)
394 {
395 	struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
396 
397 	dpcm->base_time = hrtimer_cb_get_time(&dpcm->timer);
398 	hrtimer_start(&dpcm->timer, dpcm->period_time, HRTIMER_MODE_REL_SOFT);
399 	atomic_set(&dpcm->running, 1);
400 	return 0;
401 }
402 
403 static int dummy_hrtimer_stop(struct snd_pcm_substream *substream)
404 {
405 	struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
406 
407 	atomic_set(&dpcm->running, 0);
408 	if (!hrtimer_callback_running(&dpcm->timer))
409 		hrtimer_cancel(&dpcm->timer);
410 	return 0;
411 }
412 
413 static inline void dummy_hrtimer_sync(struct dummy_hrtimer_pcm *dpcm)
414 {
415 	hrtimer_cancel(&dpcm->timer);
416 }
417 
418 static snd_pcm_uframes_t
419 dummy_hrtimer_pointer(struct snd_pcm_substream *substream)
420 {
421 	struct snd_pcm_runtime *runtime = substream->runtime;
422 	struct dummy_hrtimer_pcm *dpcm = runtime->private_data;
423 	u64 delta;
424 	u32 pos;
425 
426 	delta = ktime_us_delta(hrtimer_cb_get_time(&dpcm->timer),
427 			       dpcm->base_time);
428 	delta = div_u64(delta * runtime->rate + 999999, 1000000);
429 	div_u64_rem(delta, runtime->buffer_size, &pos);
430 	return pos;
431 }
432 
433 static int dummy_hrtimer_prepare(struct snd_pcm_substream *substream)
434 {
435 	struct snd_pcm_runtime *runtime = substream->runtime;
436 	struct dummy_hrtimer_pcm *dpcm = runtime->private_data;
437 	unsigned int period, rate;
438 	long sec;
439 	unsigned long nsecs;
440 
441 	dummy_hrtimer_sync(dpcm);
442 	period = runtime->period_size;
443 	rate = runtime->rate;
444 	sec = period / rate;
445 	period %= rate;
446 	nsecs = div_u64((u64)period * 1000000000UL + rate - 1, rate);
447 	dpcm->period_time = ktime_set(sec, nsecs);
448 
449 	return 0;
450 }
451 
452 static int dummy_hrtimer_create(struct snd_pcm_substream *substream)
453 {
454 	struct dummy_hrtimer_pcm *dpcm;
455 
456 	dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
457 	if (!dpcm)
458 		return -ENOMEM;
459 	substream->runtime->private_data = dpcm;
460 	hrtimer_init(&dpcm->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
461 	dpcm->timer.function = dummy_hrtimer_callback;
462 	dpcm->substream = substream;
463 	atomic_set(&dpcm->running, 0);
464 	return 0;
465 }
466 
467 static void dummy_hrtimer_free(struct snd_pcm_substream *substream)
468 {
469 	struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
470 	dummy_hrtimer_sync(dpcm);
471 	kfree(dpcm);
472 }
473 
474 static const struct dummy_timer_ops dummy_hrtimer_ops = {
475 	.create =	dummy_hrtimer_create,
476 	.free =		dummy_hrtimer_free,
477 	.prepare =	dummy_hrtimer_prepare,
478 	.start =	dummy_hrtimer_start,
479 	.stop =		dummy_hrtimer_stop,
480 	.pointer =	dummy_hrtimer_pointer,
481 };
482 
483 #endif /* CONFIG_HIGH_RES_TIMERS */
484 
485 /*
486  * PCM interface
487  */
488 
489 static int dummy_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
490 {
491 	switch (cmd) {
492 	case SNDRV_PCM_TRIGGER_START:
493 	case SNDRV_PCM_TRIGGER_RESUME:
494 		return get_dummy_ops(substream)->start(substream);
495 	case SNDRV_PCM_TRIGGER_STOP:
496 	case SNDRV_PCM_TRIGGER_SUSPEND:
497 		return get_dummy_ops(substream)->stop(substream);
498 	}
499 	return -EINVAL;
500 }
501 
502 static int dummy_pcm_prepare(struct snd_pcm_substream *substream)
503 {
504 	return get_dummy_ops(substream)->prepare(substream);
505 }
506 
507 static snd_pcm_uframes_t dummy_pcm_pointer(struct snd_pcm_substream *substream)
508 {
509 	return get_dummy_ops(substream)->pointer(substream);
510 }
511 
512 static const struct snd_pcm_hardware dummy_pcm_hardware = {
513 	.info =			(SNDRV_PCM_INFO_MMAP |
514 				 SNDRV_PCM_INFO_INTERLEAVED |
515 				 SNDRV_PCM_INFO_RESUME |
516 				 SNDRV_PCM_INFO_MMAP_VALID),
517 	.formats =		USE_FORMATS,
518 	.rates =		USE_RATE,
519 	.rate_min =		USE_RATE_MIN,
520 	.rate_max =		USE_RATE_MAX,
521 	.channels_min =		USE_CHANNELS_MIN,
522 	.channels_max =		USE_CHANNELS_MAX,
523 	.buffer_bytes_max =	MAX_BUFFER_SIZE,
524 	.period_bytes_min =	MIN_PERIOD_SIZE,
525 	.period_bytes_max =	MAX_PERIOD_SIZE,
526 	.periods_min =		USE_PERIODS_MIN,
527 	.periods_max =		USE_PERIODS_MAX,
528 	.fifo_size =		0,
529 };
530 
531 static int dummy_pcm_hw_params(struct snd_pcm_substream *substream,
532 			       struct snd_pcm_hw_params *hw_params)
533 {
534 	if (fake_buffer) {
535 		/* runtime->dma_bytes has to be set manually to allow mmap */
536 		substream->runtime->dma_bytes = params_buffer_bytes(hw_params);
537 		return 0;
538 	}
539 	return 0;
540 }
541 
542 static int dummy_pcm_open(struct snd_pcm_substream *substream)
543 {
544 	struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
545 	const struct dummy_model *model = dummy->model;
546 	struct snd_pcm_runtime *runtime = substream->runtime;
547 	const struct dummy_timer_ops *ops;
548 	int err;
549 
550 	ops = &dummy_systimer_ops;
551 #ifdef CONFIG_HIGH_RES_TIMERS
552 	if (hrtimer)
553 		ops = &dummy_hrtimer_ops;
554 #endif
555 
556 	err = ops->create(substream);
557 	if (err < 0)
558 		return err;
559 	get_dummy_ops(substream) = ops;
560 
561 	runtime->hw = dummy->pcm_hw;
562 	if (substream->pcm->device & 1) {
563 		runtime->hw.info &= ~SNDRV_PCM_INFO_INTERLEAVED;
564 		runtime->hw.info |= SNDRV_PCM_INFO_NONINTERLEAVED;
565 	}
566 	if (substream->pcm->device & 2)
567 		runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP |
568 				      SNDRV_PCM_INFO_MMAP_VALID);
569 
570 	if (model == NULL)
571 		return 0;
572 
573 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
574 		if (model->playback_constraints)
575 			err = model->playback_constraints(substream->runtime);
576 	} else {
577 		if (model->capture_constraints)
578 			err = model->capture_constraints(substream->runtime);
579 	}
580 	if (err < 0) {
581 		get_dummy_ops(substream)->free(substream);
582 		return err;
583 	}
584 	return 0;
585 }
586 
587 static int dummy_pcm_close(struct snd_pcm_substream *substream)
588 {
589 	get_dummy_ops(substream)->free(substream);
590 	return 0;
591 }
592 
593 /*
594  * dummy buffer handling
595  */
596 
597 static void *dummy_page[2];
598 
599 static void free_fake_buffer(void)
600 {
601 	if (fake_buffer) {
602 		int i;
603 		for (i = 0; i < 2; i++)
604 			if (dummy_page[i]) {
605 				free_page((unsigned long)dummy_page[i]);
606 				dummy_page[i] = NULL;
607 			}
608 	}
609 }
610 
611 static int alloc_fake_buffer(void)
612 {
613 	int i;
614 
615 	if (!fake_buffer)
616 		return 0;
617 	for (i = 0; i < 2; i++) {
618 		dummy_page[i] = (void *)get_zeroed_page(GFP_KERNEL);
619 		if (!dummy_page[i]) {
620 			free_fake_buffer();
621 			return -ENOMEM;
622 		}
623 	}
624 	return 0;
625 }
626 
627 static int dummy_pcm_copy(struct snd_pcm_substream *substream,
628 			  int channel, unsigned long pos,
629 			  void __user *dst, unsigned long bytes)
630 {
631 	return 0; /* do nothing */
632 }
633 
634 static int dummy_pcm_copy_kernel(struct snd_pcm_substream *substream,
635 				 int channel, unsigned long pos,
636 				 void *dst, unsigned long bytes)
637 {
638 	return 0; /* do nothing */
639 }
640 
641 static int dummy_pcm_silence(struct snd_pcm_substream *substream,
642 			     int channel, unsigned long pos,
643 			     unsigned long bytes)
644 {
645 	return 0; /* do nothing */
646 }
647 
648 static struct page *dummy_pcm_page(struct snd_pcm_substream *substream,
649 				   unsigned long offset)
650 {
651 	return virt_to_page(dummy_page[substream->stream]); /* the same page */
652 }
653 
654 static const struct snd_pcm_ops dummy_pcm_ops = {
655 	.open =		dummy_pcm_open,
656 	.close =	dummy_pcm_close,
657 	.hw_params =	dummy_pcm_hw_params,
658 	.prepare =	dummy_pcm_prepare,
659 	.trigger =	dummy_pcm_trigger,
660 	.pointer =	dummy_pcm_pointer,
661 };
662 
663 static const struct snd_pcm_ops dummy_pcm_ops_no_buf = {
664 	.open =		dummy_pcm_open,
665 	.close =	dummy_pcm_close,
666 	.hw_params =	dummy_pcm_hw_params,
667 	.prepare =	dummy_pcm_prepare,
668 	.trigger =	dummy_pcm_trigger,
669 	.pointer =	dummy_pcm_pointer,
670 	.copy_user =	dummy_pcm_copy,
671 	.copy_kernel =	dummy_pcm_copy_kernel,
672 	.fill_silence =	dummy_pcm_silence,
673 	.page =		dummy_pcm_page,
674 };
675 
676 static int snd_card_dummy_pcm(struct snd_dummy *dummy, int device,
677 			      int substreams)
678 {
679 	struct snd_pcm *pcm;
680 	const struct snd_pcm_ops *ops;
681 	int err;
682 
683 	err = snd_pcm_new(dummy->card, "Dummy PCM", device,
684 			       substreams, substreams, &pcm);
685 	if (err < 0)
686 		return err;
687 	dummy->pcm = pcm;
688 	if (fake_buffer)
689 		ops = &dummy_pcm_ops_no_buf;
690 	else
691 		ops = &dummy_pcm_ops;
692 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, ops);
693 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, ops);
694 	pcm->private_data = dummy;
695 	pcm->info_flags = 0;
696 	strcpy(pcm->name, "Dummy PCM");
697 	if (!fake_buffer) {
698 		snd_pcm_set_managed_buffer_all(pcm,
699 			SNDRV_DMA_TYPE_CONTINUOUS,
700 			NULL,
701 			0, 64*1024);
702 	}
703 	return 0;
704 }
705 
706 /*
707  * mixer interface
708  */
709 
710 #define DUMMY_VOLUME(xname, xindex, addr) \
711 { .iface = SNDRV_CTL_ELEM_IFACE_MIXER, \
712   .access = SNDRV_CTL_ELEM_ACCESS_READWRITE | SNDRV_CTL_ELEM_ACCESS_TLV_READ, \
713   .name = xname, .index = xindex, \
714   .info = snd_dummy_volume_info, \
715   .get = snd_dummy_volume_get, .put = snd_dummy_volume_put, \
716   .private_value = addr, \
717   .tlv = { .p = db_scale_dummy } }
718 
719 static int snd_dummy_volume_info(struct snd_kcontrol *kcontrol,
720 				 struct snd_ctl_elem_info *uinfo)
721 {
722 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
723 	uinfo->count = 2;
724 	uinfo->value.integer.min = mixer_volume_level_min;
725 	uinfo->value.integer.max = mixer_volume_level_max;
726 	return 0;
727 }
728 
729 static int snd_dummy_volume_get(struct snd_kcontrol *kcontrol,
730 				struct snd_ctl_elem_value *ucontrol)
731 {
732 	struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
733 	int addr = kcontrol->private_value;
734 
735 	spin_lock_irq(&dummy->mixer_lock);
736 	ucontrol->value.integer.value[0] = dummy->mixer_volume[addr][0];
737 	ucontrol->value.integer.value[1] = dummy->mixer_volume[addr][1];
738 	spin_unlock_irq(&dummy->mixer_lock);
739 	return 0;
740 }
741 
742 static int snd_dummy_volume_put(struct snd_kcontrol *kcontrol,
743 				struct snd_ctl_elem_value *ucontrol)
744 {
745 	struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
746 	int change, addr = kcontrol->private_value;
747 	int left, right;
748 
749 	left = ucontrol->value.integer.value[0];
750 	if (left < mixer_volume_level_min)
751 		left = mixer_volume_level_min;
752 	if (left > mixer_volume_level_max)
753 		left = mixer_volume_level_max;
754 	right = ucontrol->value.integer.value[1];
755 	if (right < mixer_volume_level_min)
756 		right = mixer_volume_level_min;
757 	if (right > mixer_volume_level_max)
758 		right = mixer_volume_level_max;
759 	spin_lock_irq(&dummy->mixer_lock);
760 	change = dummy->mixer_volume[addr][0] != left ||
761 	         dummy->mixer_volume[addr][1] != right;
762 	dummy->mixer_volume[addr][0] = left;
763 	dummy->mixer_volume[addr][1] = right;
764 	spin_unlock_irq(&dummy->mixer_lock);
765 	return change;
766 }
767 
768 static const DECLARE_TLV_DB_SCALE(db_scale_dummy, -4500, 30, 0);
769 
770 #define DUMMY_CAPSRC(xname, xindex, addr) \
771 { .iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = xname, .index = xindex, \
772   .info = snd_dummy_capsrc_info, \
773   .get = snd_dummy_capsrc_get, .put = snd_dummy_capsrc_put, \
774   .private_value = addr }
775 
776 #define snd_dummy_capsrc_info	snd_ctl_boolean_stereo_info
777 
778 static int snd_dummy_capsrc_get(struct snd_kcontrol *kcontrol,
779 				struct snd_ctl_elem_value *ucontrol)
780 {
781 	struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
782 	int addr = kcontrol->private_value;
783 
784 	spin_lock_irq(&dummy->mixer_lock);
785 	ucontrol->value.integer.value[0] = dummy->capture_source[addr][0];
786 	ucontrol->value.integer.value[1] = dummy->capture_source[addr][1];
787 	spin_unlock_irq(&dummy->mixer_lock);
788 	return 0;
789 }
790 
791 static int snd_dummy_capsrc_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
792 {
793 	struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
794 	int change, addr = kcontrol->private_value;
795 	int left, right;
796 
797 	left = ucontrol->value.integer.value[0] & 1;
798 	right = ucontrol->value.integer.value[1] & 1;
799 	spin_lock_irq(&dummy->mixer_lock);
800 	change = dummy->capture_source[addr][0] != left &&
801 	         dummy->capture_source[addr][1] != right;
802 	dummy->capture_source[addr][0] = left;
803 	dummy->capture_source[addr][1] = right;
804 	spin_unlock_irq(&dummy->mixer_lock);
805 	return change;
806 }
807 
808 static int snd_dummy_iobox_info(struct snd_kcontrol *kcontrol,
809 				struct snd_ctl_elem_info *info)
810 {
811 	static const char *const names[] = { "None", "CD Player" };
812 
813 	return snd_ctl_enum_info(info, 1, 2, names);
814 }
815 
816 static int snd_dummy_iobox_get(struct snd_kcontrol *kcontrol,
817 			       struct snd_ctl_elem_value *value)
818 {
819 	struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
820 
821 	value->value.enumerated.item[0] = dummy->iobox;
822 	return 0;
823 }
824 
825 static int snd_dummy_iobox_put(struct snd_kcontrol *kcontrol,
826 			       struct snd_ctl_elem_value *value)
827 {
828 	struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
829 	int changed;
830 
831 	if (value->value.enumerated.item[0] > 1)
832 		return -EINVAL;
833 
834 	changed = value->value.enumerated.item[0] != dummy->iobox;
835 	if (changed) {
836 		dummy->iobox = value->value.enumerated.item[0];
837 
838 		if (dummy->iobox) {
839 			dummy->cd_volume_ctl->vd[0].access &=
840 				~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
841 			dummy->cd_switch_ctl->vd[0].access &=
842 				~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
843 		} else {
844 			dummy->cd_volume_ctl->vd[0].access |=
845 				SNDRV_CTL_ELEM_ACCESS_INACTIVE;
846 			dummy->cd_switch_ctl->vd[0].access |=
847 				SNDRV_CTL_ELEM_ACCESS_INACTIVE;
848 		}
849 
850 		snd_ctl_notify(dummy->card, SNDRV_CTL_EVENT_MASK_INFO,
851 			       &dummy->cd_volume_ctl->id);
852 		snd_ctl_notify(dummy->card, SNDRV_CTL_EVENT_MASK_INFO,
853 			       &dummy->cd_switch_ctl->id);
854 	}
855 
856 	return changed;
857 }
858 
859 static const struct snd_kcontrol_new snd_dummy_controls[] = {
860 DUMMY_VOLUME("Master Volume", 0, MIXER_ADDR_MASTER),
861 DUMMY_CAPSRC("Master Capture Switch", 0, MIXER_ADDR_MASTER),
862 DUMMY_VOLUME("Synth Volume", 0, MIXER_ADDR_SYNTH),
863 DUMMY_CAPSRC("Synth Capture Switch", 0, MIXER_ADDR_SYNTH),
864 DUMMY_VOLUME("Line Volume", 0, MIXER_ADDR_LINE),
865 DUMMY_CAPSRC("Line Capture Switch", 0, MIXER_ADDR_LINE),
866 DUMMY_VOLUME("Mic Volume", 0, MIXER_ADDR_MIC),
867 DUMMY_CAPSRC("Mic Capture Switch", 0, MIXER_ADDR_MIC),
868 DUMMY_VOLUME("CD Volume", 0, MIXER_ADDR_CD),
869 DUMMY_CAPSRC("CD Capture Switch", 0, MIXER_ADDR_CD),
870 {
871 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
872 	.name  = "External I/O Box",
873 	.info  = snd_dummy_iobox_info,
874 	.get   = snd_dummy_iobox_get,
875 	.put   = snd_dummy_iobox_put,
876 },
877 };
878 
879 static int snd_card_dummy_new_mixer(struct snd_dummy *dummy)
880 {
881 	struct snd_card *card = dummy->card;
882 	struct snd_kcontrol *kcontrol;
883 	unsigned int idx;
884 	int err;
885 
886 	spin_lock_init(&dummy->mixer_lock);
887 	strcpy(card->mixername, "Dummy Mixer");
888 	dummy->iobox = 1;
889 
890 	for (idx = 0; idx < ARRAY_SIZE(snd_dummy_controls); idx++) {
891 		kcontrol = snd_ctl_new1(&snd_dummy_controls[idx], dummy);
892 		err = snd_ctl_add(card, kcontrol);
893 		if (err < 0)
894 			return err;
895 		if (!strcmp(kcontrol->id.name, "CD Volume"))
896 			dummy->cd_volume_ctl = kcontrol;
897 		else if (!strcmp(kcontrol->id.name, "CD Capture Switch"))
898 			dummy->cd_switch_ctl = kcontrol;
899 
900 	}
901 	return 0;
902 }
903 
904 #if defined(CONFIG_SND_DEBUG) && defined(CONFIG_SND_PROC_FS)
905 /*
906  * proc interface
907  */
908 static void print_formats(struct snd_dummy *dummy,
909 			  struct snd_info_buffer *buffer)
910 {
911 	snd_pcm_format_t i;
912 
913 	pcm_for_each_format(i) {
914 		if (dummy->pcm_hw.formats & pcm_format_to_bits(i))
915 			snd_iprintf(buffer, " %s", snd_pcm_format_name(i));
916 	}
917 }
918 
919 static void print_rates(struct snd_dummy *dummy,
920 			struct snd_info_buffer *buffer)
921 {
922 	static const int rates[] = {
923 		5512, 8000, 11025, 16000, 22050, 32000, 44100, 48000,
924 		64000, 88200, 96000, 176400, 192000,
925 	};
926 	int i;
927 
928 	if (dummy->pcm_hw.rates & SNDRV_PCM_RATE_CONTINUOUS)
929 		snd_iprintf(buffer, " continuous");
930 	if (dummy->pcm_hw.rates & SNDRV_PCM_RATE_KNOT)
931 		snd_iprintf(buffer, " knot");
932 	for (i = 0; i < ARRAY_SIZE(rates); i++)
933 		if (dummy->pcm_hw.rates & (1 << i))
934 			snd_iprintf(buffer, " %d", rates[i]);
935 }
936 
937 #define get_dummy_int_ptr(dummy, ofs) \
938 	(unsigned int *)((char *)&((dummy)->pcm_hw) + (ofs))
939 #define get_dummy_ll_ptr(dummy, ofs) \
940 	(unsigned long long *)((char *)&((dummy)->pcm_hw) + (ofs))
941 
942 struct dummy_hw_field {
943 	const char *name;
944 	const char *format;
945 	unsigned int offset;
946 	unsigned int size;
947 };
948 #define FIELD_ENTRY(item, fmt) {		   \
949 	.name = #item,				   \
950 	.format = fmt,				   \
951 	.offset = offsetof(struct snd_pcm_hardware, item), \
952 	.size = sizeof(dummy_pcm_hardware.item) }
953 
954 static const struct dummy_hw_field fields[] = {
955 	FIELD_ENTRY(formats, "%#llx"),
956 	FIELD_ENTRY(rates, "%#x"),
957 	FIELD_ENTRY(rate_min, "%d"),
958 	FIELD_ENTRY(rate_max, "%d"),
959 	FIELD_ENTRY(channels_min, "%d"),
960 	FIELD_ENTRY(channels_max, "%d"),
961 	FIELD_ENTRY(buffer_bytes_max, "%ld"),
962 	FIELD_ENTRY(period_bytes_min, "%ld"),
963 	FIELD_ENTRY(period_bytes_max, "%ld"),
964 	FIELD_ENTRY(periods_min, "%d"),
965 	FIELD_ENTRY(periods_max, "%d"),
966 };
967 
968 static void dummy_proc_read(struct snd_info_entry *entry,
969 			    struct snd_info_buffer *buffer)
970 {
971 	struct snd_dummy *dummy = entry->private_data;
972 	int i;
973 
974 	for (i = 0; i < ARRAY_SIZE(fields); i++) {
975 		snd_iprintf(buffer, "%s ", fields[i].name);
976 		if (fields[i].size == sizeof(int))
977 			snd_iprintf(buffer, fields[i].format,
978 				*get_dummy_int_ptr(dummy, fields[i].offset));
979 		else
980 			snd_iprintf(buffer, fields[i].format,
981 				*get_dummy_ll_ptr(dummy, fields[i].offset));
982 		if (!strcmp(fields[i].name, "formats"))
983 			print_formats(dummy, buffer);
984 		else if (!strcmp(fields[i].name, "rates"))
985 			print_rates(dummy, buffer);
986 		snd_iprintf(buffer, "\n");
987 	}
988 }
989 
990 static void dummy_proc_write(struct snd_info_entry *entry,
991 			     struct snd_info_buffer *buffer)
992 {
993 	struct snd_dummy *dummy = entry->private_data;
994 	char line[64];
995 
996 	while (!snd_info_get_line(buffer, line, sizeof(line))) {
997 		char item[20];
998 		const char *ptr;
999 		unsigned long long val;
1000 		int i;
1001 
1002 		ptr = snd_info_get_str(item, line, sizeof(item));
1003 		for (i = 0; i < ARRAY_SIZE(fields); i++) {
1004 			if (!strcmp(item, fields[i].name))
1005 				break;
1006 		}
1007 		if (i >= ARRAY_SIZE(fields))
1008 			continue;
1009 		snd_info_get_str(item, ptr, sizeof(item));
1010 		if (kstrtoull(item, 0, &val))
1011 			continue;
1012 		if (fields[i].size == sizeof(int))
1013 			*get_dummy_int_ptr(dummy, fields[i].offset) = val;
1014 		else
1015 			*get_dummy_ll_ptr(dummy, fields[i].offset) = val;
1016 	}
1017 }
1018 
1019 static void dummy_proc_init(struct snd_dummy *chip)
1020 {
1021 	snd_card_rw_proc_new(chip->card, "dummy_pcm", chip,
1022 			     dummy_proc_read, dummy_proc_write);
1023 }
1024 #else
1025 #define dummy_proc_init(x)
1026 #endif /* CONFIG_SND_DEBUG && CONFIG_SND_PROC_FS */
1027 
1028 static int snd_dummy_probe(struct platform_device *devptr)
1029 {
1030 	struct snd_card *card;
1031 	struct snd_dummy *dummy;
1032 	const struct dummy_model *m = NULL, **mdl;
1033 	int idx, err;
1034 	int dev = devptr->id;
1035 
1036 	err = snd_devm_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
1037 				sizeof(struct snd_dummy), &card);
1038 	if (err < 0)
1039 		return err;
1040 	dummy = card->private_data;
1041 	dummy->card = card;
1042 	for (mdl = dummy_models; *mdl && model[dev]; mdl++) {
1043 		if (strcmp(model[dev], (*mdl)->name) == 0) {
1044 			printk(KERN_INFO
1045 				"snd-dummy: Using model '%s' for card %i\n",
1046 				(*mdl)->name, card->number);
1047 			m = dummy->model = *mdl;
1048 			break;
1049 		}
1050 	}
1051 	for (idx = 0; idx < MAX_PCM_DEVICES && idx < pcm_devs[dev]; idx++) {
1052 		if (pcm_substreams[dev] < 1)
1053 			pcm_substreams[dev] = 1;
1054 		if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1055 			pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1056 		err = snd_card_dummy_pcm(dummy, idx, pcm_substreams[dev]);
1057 		if (err < 0)
1058 			return err;
1059 	}
1060 
1061 	dummy->pcm_hw = dummy_pcm_hardware;
1062 	if (m) {
1063 		if (m->formats)
1064 			dummy->pcm_hw.formats = m->formats;
1065 		if (m->buffer_bytes_max)
1066 			dummy->pcm_hw.buffer_bytes_max = m->buffer_bytes_max;
1067 		if (m->period_bytes_min)
1068 			dummy->pcm_hw.period_bytes_min = m->period_bytes_min;
1069 		if (m->period_bytes_max)
1070 			dummy->pcm_hw.period_bytes_max = m->period_bytes_max;
1071 		if (m->periods_min)
1072 			dummy->pcm_hw.periods_min = m->periods_min;
1073 		if (m->periods_max)
1074 			dummy->pcm_hw.periods_max = m->periods_max;
1075 		if (m->rates)
1076 			dummy->pcm_hw.rates = m->rates;
1077 		if (m->rate_min)
1078 			dummy->pcm_hw.rate_min = m->rate_min;
1079 		if (m->rate_max)
1080 			dummy->pcm_hw.rate_max = m->rate_max;
1081 		if (m->channels_min)
1082 			dummy->pcm_hw.channels_min = m->channels_min;
1083 		if (m->channels_max)
1084 			dummy->pcm_hw.channels_max = m->channels_max;
1085 	}
1086 
1087 	if (mixer_volume_level_min > mixer_volume_level_max) {
1088 		pr_warn("snd-dummy: Invalid mixer volume level: min=%d, max=%d. Fall back to default value.\n",
1089 		mixer_volume_level_min, mixer_volume_level_max);
1090 		mixer_volume_level_min = USE_MIXER_VOLUME_LEVEL_MIN;
1091 		mixer_volume_level_max = USE_MIXER_VOLUME_LEVEL_MAX;
1092 	}
1093 	err = snd_card_dummy_new_mixer(dummy);
1094 	if (err < 0)
1095 		return err;
1096 	strcpy(card->driver, "Dummy");
1097 	strcpy(card->shortname, "Dummy");
1098 	sprintf(card->longname, "Dummy %i", dev + 1);
1099 
1100 	dummy_proc_init(dummy);
1101 
1102 	err = snd_card_register(card);
1103 	if (err < 0)
1104 		return err;
1105 	platform_set_drvdata(devptr, card);
1106 	return 0;
1107 }
1108 
1109 #ifdef CONFIG_PM_SLEEP
1110 static int snd_dummy_suspend(struct device *pdev)
1111 {
1112 	struct snd_card *card = dev_get_drvdata(pdev);
1113 
1114 	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1115 	return 0;
1116 }
1117 
1118 static int snd_dummy_resume(struct device *pdev)
1119 {
1120 	struct snd_card *card = dev_get_drvdata(pdev);
1121 
1122 	snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1123 	return 0;
1124 }
1125 
1126 static SIMPLE_DEV_PM_OPS(snd_dummy_pm, snd_dummy_suspend, snd_dummy_resume);
1127 #define SND_DUMMY_PM_OPS	&snd_dummy_pm
1128 #else
1129 #define SND_DUMMY_PM_OPS	NULL
1130 #endif
1131 
1132 #define SND_DUMMY_DRIVER	"snd_dummy"
1133 
1134 static struct platform_driver snd_dummy_driver = {
1135 	.probe		= snd_dummy_probe,
1136 	.driver		= {
1137 		.name	= SND_DUMMY_DRIVER,
1138 		.pm	= SND_DUMMY_PM_OPS,
1139 	},
1140 };
1141 
1142 static void snd_dummy_unregister_all(void)
1143 {
1144 	int i;
1145 
1146 	for (i = 0; i < ARRAY_SIZE(devices); ++i)
1147 		platform_device_unregister(devices[i]);
1148 	platform_driver_unregister(&snd_dummy_driver);
1149 	free_fake_buffer();
1150 }
1151 
1152 static int __init alsa_card_dummy_init(void)
1153 {
1154 	int i, cards, err;
1155 
1156 	err = platform_driver_register(&snd_dummy_driver);
1157 	if (err < 0)
1158 		return err;
1159 
1160 	err = alloc_fake_buffer();
1161 	if (err < 0) {
1162 		platform_driver_unregister(&snd_dummy_driver);
1163 		return err;
1164 	}
1165 
1166 	cards = 0;
1167 	for (i = 0; i < SNDRV_CARDS; i++) {
1168 		struct platform_device *device;
1169 		if (! enable[i])
1170 			continue;
1171 		device = platform_device_register_simple(SND_DUMMY_DRIVER,
1172 							 i, NULL, 0);
1173 		if (IS_ERR(device))
1174 			continue;
1175 		if (!platform_get_drvdata(device)) {
1176 			platform_device_unregister(device);
1177 			continue;
1178 		}
1179 		devices[i] = device;
1180 		cards++;
1181 	}
1182 	if (!cards) {
1183 #ifdef MODULE
1184 		printk(KERN_ERR "Dummy soundcard not found or device busy\n");
1185 #endif
1186 		snd_dummy_unregister_all();
1187 		return -ENODEV;
1188 	}
1189 	return 0;
1190 }
1191 
1192 static void __exit alsa_card_dummy_exit(void)
1193 {
1194 	snd_dummy_unregister_all();
1195 }
1196 
1197 module_init(alsa_card_dummy_init)
1198 module_exit(alsa_card_dummy_exit)
1199