xref: /linux/sound/drivers/dummy.c (revision d4b996f9ef1fe83d9ce9ad5c1ca0bd8231638ce5)
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 
46 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;	/* Index 0-MAX */
47 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* ID for this card */
48 static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
49 static char *model[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = NULL};
50 static int pcm_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1};
51 static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
52 //static int midi_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 2};
53 #ifdef CONFIG_HIGH_RES_TIMERS
54 static bool hrtimer = 1;
55 #endif
56 static bool fake_buffer = 1;
57 
58 module_param_array(index, int, NULL, 0444);
59 MODULE_PARM_DESC(index, "Index value for dummy soundcard.");
60 module_param_array(id, charp, NULL, 0444);
61 MODULE_PARM_DESC(id, "ID string for dummy soundcard.");
62 module_param_array(enable, bool, NULL, 0444);
63 MODULE_PARM_DESC(enable, "Enable this dummy soundcard.");
64 module_param_array(model, charp, NULL, 0444);
65 MODULE_PARM_DESC(model, "Soundcard model.");
66 module_param_array(pcm_devs, int, NULL, 0444);
67 MODULE_PARM_DESC(pcm_devs, "PCM devices # (0-4) for dummy driver.");
68 module_param_array(pcm_substreams, int, NULL, 0444);
69 MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-128) for dummy driver.");
70 //module_param_array(midi_devs, int, NULL, 0444);
71 //MODULE_PARM_DESC(midi_devs, "MIDI devices # (0-2) for dummy driver.");
72 module_param(fake_buffer, bool, 0444);
73 MODULE_PARM_DESC(fake_buffer, "Fake buffer allocations.");
74 #ifdef CONFIG_HIGH_RES_TIMERS
75 module_param(hrtimer, bool, 0644);
76 MODULE_PARM_DESC(hrtimer, "Use hrtimer as the timer source.");
77 #endif
78 
79 static struct platform_device *devices[SNDRV_CARDS];
80 
81 #define MIXER_ADDR_MASTER	0
82 #define MIXER_ADDR_LINE		1
83 #define MIXER_ADDR_MIC		2
84 #define MIXER_ADDR_SYNTH	3
85 #define MIXER_ADDR_CD		4
86 #define MIXER_ADDR_LAST		4
87 
88 struct dummy_timer_ops {
89 	int (*create)(struct snd_pcm_substream *);
90 	void (*free)(struct snd_pcm_substream *);
91 	int (*prepare)(struct snd_pcm_substream *);
92 	int (*start)(struct snd_pcm_substream *);
93 	int (*stop)(struct snd_pcm_substream *);
94 	snd_pcm_uframes_t (*pointer)(struct snd_pcm_substream *);
95 };
96 
97 #define get_dummy_ops(substream) \
98 	(*(const struct dummy_timer_ops **)(substream)->runtime->private_data)
99 
100 struct dummy_model {
101 	const char *name;
102 	int (*playback_constraints)(struct snd_pcm_runtime *runtime);
103 	int (*capture_constraints)(struct snd_pcm_runtime *runtime);
104 	u64 formats;
105 	size_t buffer_bytes_max;
106 	size_t period_bytes_min;
107 	size_t period_bytes_max;
108 	unsigned int periods_min;
109 	unsigned int periods_max;
110 	unsigned int rates;
111 	unsigned int rate_min;
112 	unsigned int rate_max;
113 	unsigned int channels_min;
114 	unsigned int channels_max;
115 };
116 
117 struct snd_dummy {
118 	struct snd_card *card;
119 	const struct dummy_model *model;
120 	struct snd_pcm *pcm;
121 	struct snd_pcm_hardware pcm_hw;
122 	spinlock_t mixer_lock;
123 	int mixer_volume[MIXER_ADDR_LAST+1][2];
124 	int capture_source[MIXER_ADDR_LAST+1][2];
125 	int iobox;
126 	struct snd_kcontrol *cd_volume_ctl;
127 	struct snd_kcontrol *cd_switch_ctl;
128 };
129 
130 /*
131  * card models
132  */
133 
134 static int emu10k1_playback_constraints(struct snd_pcm_runtime *runtime)
135 {
136 	int err;
137 	err = snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
138 	if (err < 0)
139 		return err;
140 	err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 256, UINT_MAX);
141 	if (err < 0)
142 		return err;
143 	return 0;
144 }
145 
146 static const struct dummy_model model_emu10k1 = {
147 	.name = "emu10k1",
148 	.playback_constraints = emu10k1_playback_constraints,
149 	.buffer_bytes_max = 128 * 1024,
150 };
151 
152 static const struct dummy_model model_rme9652 = {
153 	.name = "rme9652",
154 	.buffer_bytes_max = 26 * 64 * 1024,
155 	.formats = SNDRV_PCM_FMTBIT_S32_LE,
156 	.channels_min = 26,
157 	.channels_max = 26,
158 	.periods_min = 2,
159 	.periods_max = 2,
160 };
161 
162 static const struct dummy_model model_ice1712 = {
163 	.name = "ice1712",
164 	.buffer_bytes_max = 256 * 1024,
165 	.formats = SNDRV_PCM_FMTBIT_S32_LE,
166 	.channels_min = 10,
167 	.channels_max = 10,
168 	.periods_min = 1,
169 	.periods_max = 1024,
170 };
171 
172 static const struct dummy_model model_uda1341 = {
173 	.name = "uda1341",
174 	.buffer_bytes_max = 16380,
175 	.formats = SNDRV_PCM_FMTBIT_S16_LE,
176 	.channels_min = 2,
177 	.channels_max = 2,
178 	.periods_min = 2,
179 	.periods_max = 255,
180 };
181 
182 static const struct dummy_model model_ac97 = {
183 	.name = "ac97",
184 	.formats = SNDRV_PCM_FMTBIT_S16_LE,
185 	.channels_min = 2,
186 	.channels_max = 2,
187 	.rates = SNDRV_PCM_RATE_48000,
188 	.rate_min = 48000,
189 	.rate_max = 48000,
190 };
191 
192 static const struct dummy_model model_ca0106 = {
193 	.name = "ca0106",
194 	.formats = SNDRV_PCM_FMTBIT_S16_LE,
195 	.buffer_bytes_max = ((65536-64)*8),
196 	.period_bytes_max = (65536-64),
197 	.periods_min = 2,
198 	.periods_max = 8,
199 	.channels_min = 2,
200 	.channels_max = 2,
201 	.rates = SNDRV_PCM_RATE_48000|SNDRV_PCM_RATE_96000|SNDRV_PCM_RATE_192000,
202 	.rate_min = 48000,
203 	.rate_max = 192000,
204 };
205 
206 static const struct dummy_model *dummy_models[] = {
207 	&model_emu10k1,
208 	&model_rme9652,
209 	&model_ice1712,
210 	&model_uda1341,
211 	&model_ac97,
212 	&model_ca0106,
213 	NULL
214 };
215 
216 /*
217  * system timer interface
218  */
219 
220 struct dummy_systimer_pcm {
221 	/* ops must be the first item */
222 	const struct dummy_timer_ops *timer_ops;
223 	spinlock_t lock;
224 	struct timer_list timer;
225 	unsigned long base_time;
226 	unsigned int frac_pos;	/* fractional sample position (based HZ) */
227 	unsigned int frac_period_rest;
228 	unsigned int frac_buffer_size;	/* buffer_size * HZ */
229 	unsigned int frac_period_size;	/* period_size * HZ */
230 	unsigned int rate;
231 	int elapsed;
232 	struct snd_pcm_substream *substream;
233 };
234 
235 static void dummy_systimer_rearm(struct dummy_systimer_pcm *dpcm)
236 {
237 	mod_timer(&dpcm->timer, jiffies +
238 		DIV_ROUND_UP(dpcm->frac_period_rest, dpcm->rate));
239 }
240 
241 static void dummy_systimer_update(struct dummy_systimer_pcm *dpcm)
242 {
243 	unsigned long delta;
244 
245 	delta = jiffies - dpcm->base_time;
246 	if (!delta)
247 		return;
248 	dpcm->base_time += delta;
249 	delta *= dpcm->rate;
250 	dpcm->frac_pos += delta;
251 	while (dpcm->frac_pos >= dpcm->frac_buffer_size)
252 		dpcm->frac_pos -= dpcm->frac_buffer_size;
253 	while (dpcm->frac_period_rest <= delta) {
254 		dpcm->elapsed++;
255 		dpcm->frac_period_rest += dpcm->frac_period_size;
256 	}
257 	dpcm->frac_period_rest -= delta;
258 }
259 
260 static int dummy_systimer_start(struct snd_pcm_substream *substream)
261 {
262 	struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
263 	spin_lock(&dpcm->lock);
264 	dpcm->base_time = jiffies;
265 	dummy_systimer_rearm(dpcm);
266 	spin_unlock(&dpcm->lock);
267 	return 0;
268 }
269 
270 static int dummy_systimer_stop(struct snd_pcm_substream *substream)
271 {
272 	struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
273 	spin_lock(&dpcm->lock);
274 	del_timer(&dpcm->timer);
275 	spin_unlock(&dpcm->lock);
276 	return 0;
277 }
278 
279 static int dummy_systimer_prepare(struct snd_pcm_substream *substream)
280 {
281 	struct snd_pcm_runtime *runtime = substream->runtime;
282 	struct dummy_systimer_pcm *dpcm = runtime->private_data;
283 
284 	dpcm->frac_pos = 0;
285 	dpcm->rate = runtime->rate;
286 	dpcm->frac_buffer_size = runtime->buffer_size * HZ;
287 	dpcm->frac_period_size = runtime->period_size * HZ;
288 	dpcm->frac_period_rest = dpcm->frac_period_size;
289 	dpcm->elapsed = 0;
290 
291 	return 0;
292 }
293 
294 static void dummy_systimer_callback(struct timer_list *t)
295 {
296 	struct dummy_systimer_pcm *dpcm = from_timer(dpcm, t, timer);
297 	unsigned long flags;
298 	int elapsed = 0;
299 
300 	spin_lock_irqsave(&dpcm->lock, flags);
301 	dummy_systimer_update(dpcm);
302 	dummy_systimer_rearm(dpcm);
303 	elapsed = dpcm->elapsed;
304 	dpcm->elapsed = 0;
305 	spin_unlock_irqrestore(&dpcm->lock, flags);
306 	if (elapsed)
307 		snd_pcm_period_elapsed(dpcm->substream);
308 }
309 
310 static snd_pcm_uframes_t
311 dummy_systimer_pointer(struct snd_pcm_substream *substream)
312 {
313 	struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
314 	snd_pcm_uframes_t pos;
315 
316 	spin_lock(&dpcm->lock);
317 	dummy_systimer_update(dpcm);
318 	pos = dpcm->frac_pos / HZ;
319 	spin_unlock(&dpcm->lock);
320 	return pos;
321 }
322 
323 static int dummy_systimer_create(struct snd_pcm_substream *substream)
324 {
325 	struct dummy_systimer_pcm *dpcm;
326 
327 	dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
328 	if (!dpcm)
329 		return -ENOMEM;
330 	substream->runtime->private_data = dpcm;
331 	timer_setup(&dpcm->timer, dummy_systimer_callback, 0);
332 	spin_lock_init(&dpcm->lock);
333 	dpcm->substream = substream;
334 	return 0;
335 }
336 
337 static void dummy_systimer_free(struct snd_pcm_substream *substream)
338 {
339 	kfree(substream->runtime->private_data);
340 }
341 
342 static const struct dummy_timer_ops dummy_systimer_ops = {
343 	.create =	dummy_systimer_create,
344 	.free =		dummy_systimer_free,
345 	.prepare =	dummy_systimer_prepare,
346 	.start =	dummy_systimer_start,
347 	.stop =		dummy_systimer_stop,
348 	.pointer =	dummy_systimer_pointer,
349 };
350 
351 #ifdef CONFIG_HIGH_RES_TIMERS
352 /*
353  * hrtimer interface
354  */
355 
356 struct dummy_hrtimer_pcm {
357 	/* ops must be the first item */
358 	const struct dummy_timer_ops *timer_ops;
359 	ktime_t base_time;
360 	ktime_t period_time;
361 	atomic_t running;
362 	struct hrtimer timer;
363 	struct snd_pcm_substream *substream;
364 };
365 
366 static enum hrtimer_restart dummy_hrtimer_callback(struct hrtimer *timer)
367 {
368 	struct dummy_hrtimer_pcm *dpcm;
369 
370 	dpcm = container_of(timer, struct dummy_hrtimer_pcm, timer);
371 	if (!atomic_read(&dpcm->running))
372 		return HRTIMER_NORESTART;
373 	/*
374 	 * In cases of XRUN and draining, this calls .trigger to stop PCM
375 	 * substream.
376 	 */
377 	snd_pcm_period_elapsed(dpcm->substream);
378 	if (!atomic_read(&dpcm->running))
379 		return HRTIMER_NORESTART;
380 
381 	hrtimer_forward_now(timer, dpcm->period_time);
382 	return HRTIMER_RESTART;
383 }
384 
385 static int dummy_hrtimer_start(struct snd_pcm_substream *substream)
386 {
387 	struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
388 
389 	dpcm->base_time = hrtimer_cb_get_time(&dpcm->timer);
390 	hrtimer_start(&dpcm->timer, dpcm->period_time, HRTIMER_MODE_REL_SOFT);
391 	atomic_set(&dpcm->running, 1);
392 	return 0;
393 }
394 
395 static int dummy_hrtimer_stop(struct snd_pcm_substream *substream)
396 {
397 	struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
398 
399 	atomic_set(&dpcm->running, 0);
400 	if (!hrtimer_callback_running(&dpcm->timer))
401 		hrtimer_cancel(&dpcm->timer);
402 	return 0;
403 }
404 
405 static inline void dummy_hrtimer_sync(struct dummy_hrtimer_pcm *dpcm)
406 {
407 	hrtimer_cancel(&dpcm->timer);
408 }
409 
410 static snd_pcm_uframes_t
411 dummy_hrtimer_pointer(struct snd_pcm_substream *substream)
412 {
413 	struct snd_pcm_runtime *runtime = substream->runtime;
414 	struct dummy_hrtimer_pcm *dpcm = runtime->private_data;
415 	u64 delta;
416 	u32 pos;
417 
418 	delta = ktime_us_delta(hrtimer_cb_get_time(&dpcm->timer),
419 			       dpcm->base_time);
420 	delta = div_u64(delta * runtime->rate + 999999, 1000000);
421 	div_u64_rem(delta, runtime->buffer_size, &pos);
422 	return pos;
423 }
424 
425 static int dummy_hrtimer_prepare(struct snd_pcm_substream *substream)
426 {
427 	struct snd_pcm_runtime *runtime = substream->runtime;
428 	struct dummy_hrtimer_pcm *dpcm = runtime->private_data;
429 	unsigned int period, rate;
430 	long sec;
431 	unsigned long nsecs;
432 
433 	dummy_hrtimer_sync(dpcm);
434 	period = runtime->period_size;
435 	rate = runtime->rate;
436 	sec = period / rate;
437 	period %= rate;
438 	nsecs = div_u64((u64)period * 1000000000UL + rate - 1, rate);
439 	dpcm->period_time = ktime_set(sec, nsecs);
440 
441 	return 0;
442 }
443 
444 static int dummy_hrtimer_create(struct snd_pcm_substream *substream)
445 {
446 	struct dummy_hrtimer_pcm *dpcm;
447 
448 	dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
449 	if (!dpcm)
450 		return -ENOMEM;
451 	substream->runtime->private_data = dpcm;
452 	hrtimer_init(&dpcm->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
453 	dpcm->timer.function = dummy_hrtimer_callback;
454 	dpcm->substream = substream;
455 	atomic_set(&dpcm->running, 0);
456 	return 0;
457 }
458 
459 static void dummy_hrtimer_free(struct snd_pcm_substream *substream)
460 {
461 	struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
462 	dummy_hrtimer_sync(dpcm);
463 	kfree(dpcm);
464 }
465 
466 static const struct dummy_timer_ops dummy_hrtimer_ops = {
467 	.create =	dummy_hrtimer_create,
468 	.free =		dummy_hrtimer_free,
469 	.prepare =	dummy_hrtimer_prepare,
470 	.start =	dummy_hrtimer_start,
471 	.stop =		dummy_hrtimer_stop,
472 	.pointer =	dummy_hrtimer_pointer,
473 };
474 
475 #endif /* CONFIG_HIGH_RES_TIMERS */
476 
477 /*
478  * PCM interface
479  */
480 
481 static int dummy_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
482 {
483 	switch (cmd) {
484 	case SNDRV_PCM_TRIGGER_START:
485 	case SNDRV_PCM_TRIGGER_RESUME:
486 		return get_dummy_ops(substream)->start(substream);
487 	case SNDRV_PCM_TRIGGER_STOP:
488 	case SNDRV_PCM_TRIGGER_SUSPEND:
489 		return get_dummy_ops(substream)->stop(substream);
490 	}
491 	return -EINVAL;
492 }
493 
494 static int dummy_pcm_prepare(struct snd_pcm_substream *substream)
495 {
496 	return get_dummy_ops(substream)->prepare(substream);
497 }
498 
499 static snd_pcm_uframes_t dummy_pcm_pointer(struct snd_pcm_substream *substream)
500 {
501 	return get_dummy_ops(substream)->pointer(substream);
502 }
503 
504 static const struct snd_pcm_hardware dummy_pcm_hardware = {
505 	.info =			(SNDRV_PCM_INFO_MMAP |
506 				 SNDRV_PCM_INFO_INTERLEAVED |
507 				 SNDRV_PCM_INFO_RESUME |
508 				 SNDRV_PCM_INFO_MMAP_VALID),
509 	.formats =		USE_FORMATS,
510 	.rates =		USE_RATE,
511 	.rate_min =		USE_RATE_MIN,
512 	.rate_max =		USE_RATE_MAX,
513 	.channels_min =		USE_CHANNELS_MIN,
514 	.channels_max =		USE_CHANNELS_MAX,
515 	.buffer_bytes_max =	MAX_BUFFER_SIZE,
516 	.period_bytes_min =	MIN_PERIOD_SIZE,
517 	.period_bytes_max =	MAX_PERIOD_SIZE,
518 	.periods_min =		USE_PERIODS_MIN,
519 	.periods_max =		USE_PERIODS_MAX,
520 	.fifo_size =		0,
521 };
522 
523 static int dummy_pcm_hw_params(struct snd_pcm_substream *substream,
524 			       struct snd_pcm_hw_params *hw_params)
525 {
526 	if (fake_buffer) {
527 		/* runtime->dma_bytes has to be set manually to allow mmap */
528 		substream->runtime->dma_bytes = params_buffer_bytes(hw_params);
529 		return 0;
530 	}
531 	return 0;
532 }
533 
534 static int dummy_pcm_open(struct snd_pcm_substream *substream)
535 {
536 	struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
537 	const struct dummy_model *model = dummy->model;
538 	struct snd_pcm_runtime *runtime = substream->runtime;
539 	const struct dummy_timer_ops *ops;
540 	int err;
541 
542 	ops = &dummy_systimer_ops;
543 #ifdef CONFIG_HIGH_RES_TIMERS
544 	if (hrtimer)
545 		ops = &dummy_hrtimer_ops;
546 #endif
547 
548 	err = ops->create(substream);
549 	if (err < 0)
550 		return err;
551 	get_dummy_ops(substream) = ops;
552 
553 	runtime->hw = dummy->pcm_hw;
554 	if (substream->pcm->device & 1) {
555 		runtime->hw.info &= ~SNDRV_PCM_INFO_INTERLEAVED;
556 		runtime->hw.info |= SNDRV_PCM_INFO_NONINTERLEAVED;
557 	}
558 	if (substream->pcm->device & 2)
559 		runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP |
560 				      SNDRV_PCM_INFO_MMAP_VALID);
561 
562 	if (model == NULL)
563 		return 0;
564 
565 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
566 		if (model->playback_constraints)
567 			err = model->playback_constraints(substream->runtime);
568 	} else {
569 		if (model->capture_constraints)
570 			err = model->capture_constraints(substream->runtime);
571 	}
572 	if (err < 0) {
573 		get_dummy_ops(substream)->free(substream);
574 		return err;
575 	}
576 	return 0;
577 }
578 
579 static int dummy_pcm_close(struct snd_pcm_substream *substream)
580 {
581 	get_dummy_ops(substream)->free(substream);
582 	return 0;
583 }
584 
585 /*
586  * dummy buffer handling
587  */
588 
589 static void *dummy_page[2];
590 
591 static void free_fake_buffer(void)
592 {
593 	if (fake_buffer) {
594 		int i;
595 		for (i = 0; i < 2; i++)
596 			if (dummy_page[i]) {
597 				free_page((unsigned long)dummy_page[i]);
598 				dummy_page[i] = NULL;
599 			}
600 	}
601 }
602 
603 static int alloc_fake_buffer(void)
604 {
605 	int i;
606 
607 	if (!fake_buffer)
608 		return 0;
609 	for (i = 0; i < 2; i++) {
610 		dummy_page[i] = (void *)get_zeroed_page(GFP_KERNEL);
611 		if (!dummy_page[i]) {
612 			free_fake_buffer();
613 			return -ENOMEM;
614 		}
615 	}
616 	return 0;
617 }
618 
619 static int dummy_pcm_copy(struct snd_pcm_substream *substream,
620 			  int channel, unsigned long pos,
621 			  void __user *dst, unsigned long bytes)
622 {
623 	return 0; /* do nothing */
624 }
625 
626 static int dummy_pcm_copy_kernel(struct snd_pcm_substream *substream,
627 				 int channel, unsigned long pos,
628 				 void *dst, unsigned long bytes)
629 {
630 	return 0; /* do nothing */
631 }
632 
633 static int dummy_pcm_silence(struct snd_pcm_substream *substream,
634 			     int channel, unsigned long pos,
635 			     unsigned long bytes)
636 {
637 	return 0; /* do nothing */
638 }
639 
640 static struct page *dummy_pcm_page(struct snd_pcm_substream *substream,
641 				   unsigned long offset)
642 {
643 	return virt_to_page(dummy_page[substream->stream]); /* the same page */
644 }
645 
646 static const struct snd_pcm_ops dummy_pcm_ops = {
647 	.open =		dummy_pcm_open,
648 	.close =	dummy_pcm_close,
649 	.hw_params =	dummy_pcm_hw_params,
650 	.prepare =	dummy_pcm_prepare,
651 	.trigger =	dummy_pcm_trigger,
652 	.pointer =	dummy_pcm_pointer,
653 };
654 
655 static const struct snd_pcm_ops dummy_pcm_ops_no_buf = {
656 	.open =		dummy_pcm_open,
657 	.close =	dummy_pcm_close,
658 	.hw_params =	dummy_pcm_hw_params,
659 	.prepare =	dummy_pcm_prepare,
660 	.trigger =	dummy_pcm_trigger,
661 	.pointer =	dummy_pcm_pointer,
662 	.copy_user =	dummy_pcm_copy,
663 	.copy_kernel =	dummy_pcm_copy_kernel,
664 	.fill_silence =	dummy_pcm_silence,
665 	.page =		dummy_pcm_page,
666 };
667 
668 static int snd_card_dummy_pcm(struct snd_dummy *dummy, int device,
669 			      int substreams)
670 {
671 	struct snd_pcm *pcm;
672 	const struct snd_pcm_ops *ops;
673 	int err;
674 
675 	err = snd_pcm_new(dummy->card, "Dummy PCM", device,
676 			       substreams, substreams, &pcm);
677 	if (err < 0)
678 		return err;
679 	dummy->pcm = pcm;
680 	if (fake_buffer)
681 		ops = &dummy_pcm_ops_no_buf;
682 	else
683 		ops = &dummy_pcm_ops;
684 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, ops);
685 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, ops);
686 	pcm->private_data = dummy;
687 	pcm->info_flags = 0;
688 	strcpy(pcm->name, "Dummy PCM");
689 	if (!fake_buffer) {
690 		snd_pcm_set_managed_buffer_all(pcm,
691 			SNDRV_DMA_TYPE_CONTINUOUS,
692 			NULL,
693 			0, 64*1024);
694 	}
695 	return 0;
696 }
697 
698 /*
699  * mixer interface
700  */
701 
702 #define DUMMY_VOLUME(xname, xindex, addr) \
703 { .iface = SNDRV_CTL_ELEM_IFACE_MIXER, \
704   .access = SNDRV_CTL_ELEM_ACCESS_READWRITE | SNDRV_CTL_ELEM_ACCESS_TLV_READ, \
705   .name = xname, .index = xindex, \
706   .info = snd_dummy_volume_info, \
707   .get = snd_dummy_volume_get, .put = snd_dummy_volume_put, \
708   .private_value = addr, \
709   .tlv = { .p = db_scale_dummy } }
710 
711 static int snd_dummy_volume_info(struct snd_kcontrol *kcontrol,
712 				 struct snd_ctl_elem_info *uinfo)
713 {
714 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
715 	uinfo->count = 2;
716 	uinfo->value.integer.min = -50;
717 	uinfo->value.integer.max = 100;
718 	return 0;
719 }
720 
721 static int snd_dummy_volume_get(struct snd_kcontrol *kcontrol,
722 				struct snd_ctl_elem_value *ucontrol)
723 {
724 	struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
725 	int addr = kcontrol->private_value;
726 
727 	spin_lock_irq(&dummy->mixer_lock);
728 	ucontrol->value.integer.value[0] = dummy->mixer_volume[addr][0];
729 	ucontrol->value.integer.value[1] = dummy->mixer_volume[addr][1];
730 	spin_unlock_irq(&dummy->mixer_lock);
731 	return 0;
732 }
733 
734 static int snd_dummy_volume_put(struct snd_kcontrol *kcontrol,
735 				struct snd_ctl_elem_value *ucontrol)
736 {
737 	struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
738 	int change, addr = kcontrol->private_value;
739 	int left, right;
740 
741 	left = ucontrol->value.integer.value[0];
742 	if (left < -50)
743 		left = -50;
744 	if (left > 100)
745 		left = 100;
746 	right = ucontrol->value.integer.value[1];
747 	if (right < -50)
748 		right = -50;
749 	if (right > 100)
750 		right = 100;
751 	spin_lock_irq(&dummy->mixer_lock);
752 	change = dummy->mixer_volume[addr][0] != left ||
753 	         dummy->mixer_volume[addr][1] != right;
754 	dummy->mixer_volume[addr][0] = left;
755 	dummy->mixer_volume[addr][1] = right;
756 	spin_unlock_irq(&dummy->mixer_lock);
757 	return change;
758 }
759 
760 static const DECLARE_TLV_DB_SCALE(db_scale_dummy, -4500, 30, 0);
761 
762 #define DUMMY_CAPSRC(xname, xindex, addr) \
763 { .iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = xname, .index = xindex, \
764   .info = snd_dummy_capsrc_info, \
765   .get = snd_dummy_capsrc_get, .put = snd_dummy_capsrc_put, \
766   .private_value = addr }
767 
768 #define snd_dummy_capsrc_info	snd_ctl_boolean_stereo_info
769 
770 static int snd_dummy_capsrc_get(struct snd_kcontrol *kcontrol,
771 				struct snd_ctl_elem_value *ucontrol)
772 {
773 	struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
774 	int addr = kcontrol->private_value;
775 
776 	spin_lock_irq(&dummy->mixer_lock);
777 	ucontrol->value.integer.value[0] = dummy->capture_source[addr][0];
778 	ucontrol->value.integer.value[1] = dummy->capture_source[addr][1];
779 	spin_unlock_irq(&dummy->mixer_lock);
780 	return 0;
781 }
782 
783 static int snd_dummy_capsrc_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
784 {
785 	struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
786 	int change, addr = kcontrol->private_value;
787 	int left, right;
788 
789 	left = ucontrol->value.integer.value[0] & 1;
790 	right = ucontrol->value.integer.value[1] & 1;
791 	spin_lock_irq(&dummy->mixer_lock);
792 	change = dummy->capture_source[addr][0] != left &&
793 	         dummy->capture_source[addr][1] != right;
794 	dummy->capture_source[addr][0] = left;
795 	dummy->capture_source[addr][1] = right;
796 	spin_unlock_irq(&dummy->mixer_lock);
797 	return change;
798 }
799 
800 static int snd_dummy_iobox_info(struct snd_kcontrol *kcontrol,
801 				struct snd_ctl_elem_info *info)
802 {
803 	static const char *const names[] = { "None", "CD Player" };
804 
805 	return snd_ctl_enum_info(info, 1, 2, names);
806 }
807 
808 static int snd_dummy_iobox_get(struct snd_kcontrol *kcontrol,
809 			       struct snd_ctl_elem_value *value)
810 {
811 	struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
812 
813 	value->value.enumerated.item[0] = dummy->iobox;
814 	return 0;
815 }
816 
817 static int snd_dummy_iobox_put(struct snd_kcontrol *kcontrol,
818 			       struct snd_ctl_elem_value *value)
819 {
820 	struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
821 	int changed;
822 
823 	if (value->value.enumerated.item[0] > 1)
824 		return -EINVAL;
825 
826 	changed = value->value.enumerated.item[0] != dummy->iobox;
827 	if (changed) {
828 		dummy->iobox = value->value.enumerated.item[0];
829 
830 		if (dummy->iobox) {
831 			dummy->cd_volume_ctl->vd[0].access &=
832 				~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
833 			dummy->cd_switch_ctl->vd[0].access &=
834 				~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
835 		} else {
836 			dummy->cd_volume_ctl->vd[0].access |=
837 				SNDRV_CTL_ELEM_ACCESS_INACTIVE;
838 			dummy->cd_switch_ctl->vd[0].access |=
839 				SNDRV_CTL_ELEM_ACCESS_INACTIVE;
840 		}
841 
842 		snd_ctl_notify(dummy->card, SNDRV_CTL_EVENT_MASK_INFO,
843 			       &dummy->cd_volume_ctl->id);
844 		snd_ctl_notify(dummy->card, SNDRV_CTL_EVENT_MASK_INFO,
845 			       &dummy->cd_switch_ctl->id);
846 	}
847 
848 	return changed;
849 }
850 
851 static const struct snd_kcontrol_new snd_dummy_controls[] = {
852 DUMMY_VOLUME("Master Volume", 0, MIXER_ADDR_MASTER),
853 DUMMY_CAPSRC("Master Capture Switch", 0, MIXER_ADDR_MASTER),
854 DUMMY_VOLUME("Synth Volume", 0, MIXER_ADDR_SYNTH),
855 DUMMY_CAPSRC("Synth Capture Switch", 0, MIXER_ADDR_SYNTH),
856 DUMMY_VOLUME("Line Volume", 0, MIXER_ADDR_LINE),
857 DUMMY_CAPSRC("Line Capture Switch", 0, MIXER_ADDR_LINE),
858 DUMMY_VOLUME("Mic Volume", 0, MIXER_ADDR_MIC),
859 DUMMY_CAPSRC("Mic Capture Switch", 0, MIXER_ADDR_MIC),
860 DUMMY_VOLUME("CD Volume", 0, MIXER_ADDR_CD),
861 DUMMY_CAPSRC("CD Capture Switch", 0, MIXER_ADDR_CD),
862 {
863 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
864 	.name  = "External I/O Box",
865 	.info  = snd_dummy_iobox_info,
866 	.get   = snd_dummy_iobox_get,
867 	.put   = snd_dummy_iobox_put,
868 },
869 };
870 
871 static int snd_card_dummy_new_mixer(struct snd_dummy *dummy)
872 {
873 	struct snd_card *card = dummy->card;
874 	struct snd_kcontrol *kcontrol;
875 	unsigned int idx;
876 	int err;
877 
878 	spin_lock_init(&dummy->mixer_lock);
879 	strcpy(card->mixername, "Dummy Mixer");
880 	dummy->iobox = 1;
881 
882 	for (idx = 0; idx < ARRAY_SIZE(snd_dummy_controls); idx++) {
883 		kcontrol = snd_ctl_new1(&snd_dummy_controls[idx], dummy);
884 		err = snd_ctl_add(card, kcontrol);
885 		if (err < 0)
886 			return err;
887 		if (!strcmp(kcontrol->id.name, "CD Volume"))
888 			dummy->cd_volume_ctl = kcontrol;
889 		else if (!strcmp(kcontrol->id.name, "CD Capture Switch"))
890 			dummy->cd_switch_ctl = kcontrol;
891 
892 	}
893 	return 0;
894 }
895 
896 #if defined(CONFIG_SND_DEBUG) && defined(CONFIG_SND_PROC_FS)
897 /*
898  * proc interface
899  */
900 static void print_formats(struct snd_dummy *dummy,
901 			  struct snd_info_buffer *buffer)
902 {
903 	snd_pcm_format_t i;
904 
905 	pcm_for_each_format(i) {
906 		if (dummy->pcm_hw.formats & pcm_format_to_bits(i))
907 			snd_iprintf(buffer, " %s", snd_pcm_format_name(i));
908 	}
909 }
910 
911 static void print_rates(struct snd_dummy *dummy,
912 			struct snd_info_buffer *buffer)
913 {
914 	static const int rates[] = {
915 		5512, 8000, 11025, 16000, 22050, 32000, 44100, 48000,
916 		64000, 88200, 96000, 176400, 192000,
917 	};
918 	int i;
919 
920 	if (dummy->pcm_hw.rates & SNDRV_PCM_RATE_CONTINUOUS)
921 		snd_iprintf(buffer, " continuous");
922 	if (dummy->pcm_hw.rates & SNDRV_PCM_RATE_KNOT)
923 		snd_iprintf(buffer, " knot");
924 	for (i = 0; i < ARRAY_SIZE(rates); i++)
925 		if (dummy->pcm_hw.rates & (1 << i))
926 			snd_iprintf(buffer, " %d", rates[i]);
927 }
928 
929 #define get_dummy_int_ptr(dummy, ofs) \
930 	(unsigned int *)((char *)&((dummy)->pcm_hw) + (ofs))
931 #define get_dummy_ll_ptr(dummy, ofs) \
932 	(unsigned long long *)((char *)&((dummy)->pcm_hw) + (ofs))
933 
934 struct dummy_hw_field {
935 	const char *name;
936 	const char *format;
937 	unsigned int offset;
938 	unsigned int size;
939 };
940 #define FIELD_ENTRY(item, fmt) {		   \
941 	.name = #item,				   \
942 	.format = fmt,				   \
943 	.offset = offsetof(struct snd_pcm_hardware, item), \
944 	.size = sizeof(dummy_pcm_hardware.item) }
945 
946 static const struct dummy_hw_field fields[] = {
947 	FIELD_ENTRY(formats, "%#llx"),
948 	FIELD_ENTRY(rates, "%#x"),
949 	FIELD_ENTRY(rate_min, "%d"),
950 	FIELD_ENTRY(rate_max, "%d"),
951 	FIELD_ENTRY(channels_min, "%d"),
952 	FIELD_ENTRY(channels_max, "%d"),
953 	FIELD_ENTRY(buffer_bytes_max, "%ld"),
954 	FIELD_ENTRY(period_bytes_min, "%ld"),
955 	FIELD_ENTRY(period_bytes_max, "%ld"),
956 	FIELD_ENTRY(periods_min, "%d"),
957 	FIELD_ENTRY(periods_max, "%d"),
958 };
959 
960 static void dummy_proc_read(struct snd_info_entry *entry,
961 			    struct snd_info_buffer *buffer)
962 {
963 	struct snd_dummy *dummy = entry->private_data;
964 	int i;
965 
966 	for (i = 0; i < ARRAY_SIZE(fields); i++) {
967 		snd_iprintf(buffer, "%s ", fields[i].name);
968 		if (fields[i].size == sizeof(int))
969 			snd_iprintf(buffer, fields[i].format,
970 				*get_dummy_int_ptr(dummy, fields[i].offset));
971 		else
972 			snd_iprintf(buffer, fields[i].format,
973 				*get_dummy_ll_ptr(dummy, fields[i].offset));
974 		if (!strcmp(fields[i].name, "formats"))
975 			print_formats(dummy, buffer);
976 		else if (!strcmp(fields[i].name, "rates"))
977 			print_rates(dummy, buffer);
978 		snd_iprintf(buffer, "\n");
979 	}
980 }
981 
982 static void dummy_proc_write(struct snd_info_entry *entry,
983 			     struct snd_info_buffer *buffer)
984 {
985 	struct snd_dummy *dummy = entry->private_data;
986 	char line[64];
987 
988 	while (!snd_info_get_line(buffer, line, sizeof(line))) {
989 		char item[20];
990 		const char *ptr;
991 		unsigned long long val;
992 		int i;
993 
994 		ptr = snd_info_get_str(item, line, sizeof(item));
995 		for (i = 0; i < ARRAY_SIZE(fields); i++) {
996 			if (!strcmp(item, fields[i].name))
997 				break;
998 		}
999 		if (i >= ARRAY_SIZE(fields))
1000 			continue;
1001 		snd_info_get_str(item, ptr, sizeof(item));
1002 		if (kstrtoull(item, 0, &val))
1003 			continue;
1004 		if (fields[i].size == sizeof(int))
1005 			*get_dummy_int_ptr(dummy, fields[i].offset) = val;
1006 		else
1007 			*get_dummy_ll_ptr(dummy, fields[i].offset) = val;
1008 	}
1009 }
1010 
1011 static void dummy_proc_init(struct snd_dummy *chip)
1012 {
1013 	snd_card_rw_proc_new(chip->card, "dummy_pcm", chip,
1014 			     dummy_proc_read, dummy_proc_write);
1015 }
1016 #else
1017 #define dummy_proc_init(x)
1018 #endif /* CONFIG_SND_DEBUG && CONFIG_SND_PROC_FS */
1019 
1020 static int snd_dummy_probe(struct platform_device *devptr)
1021 {
1022 	struct snd_card *card;
1023 	struct snd_dummy *dummy;
1024 	const struct dummy_model *m = NULL, **mdl;
1025 	int idx, err;
1026 	int dev = devptr->id;
1027 
1028 	err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
1029 			   sizeof(struct snd_dummy), &card);
1030 	if (err < 0)
1031 		return err;
1032 	dummy = card->private_data;
1033 	dummy->card = card;
1034 	for (mdl = dummy_models; *mdl && model[dev]; mdl++) {
1035 		if (strcmp(model[dev], (*mdl)->name) == 0) {
1036 			printk(KERN_INFO
1037 				"snd-dummy: Using model '%s' for card %i\n",
1038 				(*mdl)->name, card->number);
1039 			m = dummy->model = *mdl;
1040 			break;
1041 		}
1042 	}
1043 	for (idx = 0; idx < MAX_PCM_DEVICES && idx < pcm_devs[dev]; idx++) {
1044 		if (pcm_substreams[dev] < 1)
1045 			pcm_substreams[dev] = 1;
1046 		if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1047 			pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1048 		err = snd_card_dummy_pcm(dummy, idx, pcm_substreams[dev]);
1049 		if (err < 0)
1050 			goto __nodev;
1051 	}
1052 
1053 	dummy->pcm_hw = dummy_pcm_hardware;
1054 	if (m) {
1055 		if (m->formats)
1056 			dummy->pcm_hw.formats = m->formats;
1057 		if (m->buffer_bytes_max)
1058 			dummy->pcm_hw.buffer_bytes_max = m->buffer_bytes_max;
1059 		if (m->period_bytes_min)
1060 			dummy->pcm_hw.period_bytes_min = m->period_bytes_min;
1061 		if (m->period_bytes_max)
1062 			dummy->pcm_hw.period_bytes_max = m->period_bytes_max;
1063 		if (m->periods_min)
1064 			dummy->pcm_hw.periods_min = m->periods_min;
1065 		if (m->periods_max)
1066 			dummy->pcm_hw.periods_max = m->periods_max;
1067 		if (m->rates)
1068 			dummy->pcm_hw.rates = m->rates;
1069 		if (m->rate_min)
1070 			dummy->pcm_hw.rate_min = m->rate_min;
1071 		if (m->rate_max)
1072 			dummy->pcm_hw.rate_max = m->rate_max;
1073 		if (m->channels_min)
1074 			dummy->pcm_hw.channels_min = m->channels_min;
1075 		if (m->channels_max)
1076 			dummy->pcm_hw.channels_max = m->channels_max;
1077 	}
1078 
1079 	err = snd_card_dummy_new_mixer(dummy);
1080 	if (err < 0)
1081 		goto __nodev;
1082 	strcpy(card->driver, "Dummy");
1083 	strcpy(card->shortname, "Dummy");
1084 	sprintf(card->longname, "Dummy %i", dev + 1);
1085 
1086 	dummy_proc_init(dummy);
1087 
1088 	err = snd_card_register(card);
1089 	if (err == 0) {
1090 		platform_set_drvdata(devptr, card);
1091 		return 0;
1092 	}
1093       __nodev:
1094 	snd_card_free(card);
1095 	return err;
1096 }
1097 
1098 static int snd_dummy_remove(struct platform_device *devptr)
1099 {
1100 	snd_card_free(platform_get_drvdata(devptr));
1101 	return 0;
1102 }
1103 
1104 #ifdef CONFIG_PM_SLEEP
1105 static int snd_dummy_suspend(struct device *pdev)
1106 {
1107 	struct snd_card *card = dev_get_drvdata(pdev);
1108 
1109 	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1110 	return 0;
1111 }
1112 
1113 static int snd_dummy_resume(struct device *pdev)
1114 {
1115 	struct snd_card *card = dev_get_drvdata(pdev);
1116 
1117 	snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1118 	return 0;
1119 }
1120 
1121 static SIMPLE_DEV_PM_OPS(snd_dummy_pm, snd_dummy_suspend, snd_dummy_resume);
1122 #define SND_DUMMY_PM_OPS	&snd_dummy_pm
1123 #else
1124 #define SND_DUMMY_PM_OPS	NULL
1125 #endif
1126 
1127 #define SND_DUMMY_DRIVER	"snd_dummy"
1128 
1129 static struct platform_driver snd_dummy_driver = {
1130 	.probe		= snd_dummy_probe,
1131 	.remove		= snd_dummy_remove,
1132 	.driver		= {
1133 		.name	= SND_DUMMY_DRIVER,
1134 		.pm	= SND_DUMMY_PM_OPS,
1135 	},
1136 };
1137 
1138 static void snd_dummy_unregister_all(void)
1139 {
1140 	int i;
1141 
1142 	for (i = 0; i < ARRAY_SIZE(devices); ++i)
1143 		platform_device_unregister(devices[i]);
1144 	platform_driver_unregister(&snd_dummy_driver);
1145 	free_fake_buffer();
1146 }
1147 
1148 static int __init alsa_card_dummy_init(void)
1149 {
1150 	int i, cards, err;
1151 
1152 	err = platform_driver_register(&snd_dummy_driver);
1153 	if (err < 0)
1154 		return err;
1155 
1156 	err = alloc_fake_buffer();
1157 	if (err < 0) {
1158 		platform_driver_unregister(&snd_dummy_driver);
1159 		return err;
1160 	}
1161 
1162 	cards = 0;
1163 	for (i = 0; i < SNDRV_CARDS; i++) {
1164 		struct platform_device *device;
1165 		if (! enable[i])
1166 			continue;
1167 		device = platform_device_register_simple(SND_DUMMY_DRIVER,
1168 							 i, NULL, 0);
1169 		if (IS_ERR(device))
1170 			continue;
1171 		if (!platform_get_drvdata(device)) {
1172 			platform_device_unregister(device);
1173 			continue;
1174 		}
1175 		devices[i] = device;
1176 		cards++;
1177 	}
1178 	if (!cards) {
1179 #ifdef MODULE
1180 		printk(KERN_ERR "Dummy soundcard not found or device busy\n");
1181 #endif
1182 		snd_dummy_unregister_all();
1183 		return -ENODEV;
1184 	}
1185 	return 0;
1186 }
1187 
1188 static void __exit alsa_card_dummy_exit(void)
1189 {
1190 	snd_dummy_unregister_all();
1191 }
1192 
1193 module_init(alsa_card_dummy_init)
1194 module_exit(alsa_card_dummy_exit)
1195