xref: /linux/sound/core/compress_offload.c (revision 9429ec96c2718c0d1e3317cf60a87a0405223814)
1 /*
2  *  compress_core.c - compress offload core
3  *
4  *  Copyright (C) 2011 Intel Corporation
5  *  Authors:	Vinod Koul <vinod.koul@linux.intel.com>
6  *		Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
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; version 2 of the License.
12  *
13  *  This program is distributed in the hope that it will be useful, but
14  *  WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  *  General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License along
19  *  with this program; if not, write to the Free Software Foundation, Inc.,
20  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
21  *
22  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
23  *
24  */
25 #define FORMAT(fmt) "%s: %d: " fmt, __func__, __LINE__
26 #define pr_fmt(fmt) KBUILD_MODNAME ": " FORMAT(fmt)
27 
28 #include <linux/file.h>
29 #include <linux/fs.h>
30 #include <linux/list.h>
31 #include <linux/mm.h>
32 #include <linux/mutex.h>
33 #include <linux/poll.h>
34 #include <linux/slab.h>
35 #include <linux/sched.h>
36 #include <linux/uio.h>
37 #include <linux/uaccess.h>
38 #include <linux/module.h>
39 #include <sound/core.h>
40 #include <sound/initval.h>
41 #include <sound/compress_params.h>
42 #include <sound/compress_offload.h>
43 #include <sound/compress_driver.h>
44 
45 /* TODO:
46  * - add substream support for multiple devices in case of
47  *	SND_DYNAMIC_MINORS is not used
48  * - Multiple node representation
49  *	driver should be able to register multiple nodes
50  */
51 
52 static DEFINE_MUTEX(device_mutex);
53 
54 struct snd_compr_file {
55 	unsigned long caps;
56 	struct snd_compr_stream stream;
57 };
58 
59 /*
60  * a note on stream states used:
61  * we use follwing states in the compressed core
62  * SNDRV_PCM_STATE_OPEN: When stream has been opened.
63  * SNDRV_PCM_STATE_SETUP: When stream has been initialized. This is done by
64  *	calling SNDRV_COMPRESS_SET_PARAMS. running streams will come to this
65  *	state at stop by calling SNDRV_COMPRESS_STOP, or at end of drain.
66  * SNDRV_PCM_STATE_RUNNING: When stream has been started and is
67  *	decoding/encoding and rendering/capturing data.
68  * SNDRV_PCM_STATE_DRAINING: When stream is draining current data. This is done
69  *	by calling SNDRV_COMPRESS_DRAIN.
70  * SNDRV_PCM_STATE_PAUSED: When stream is paused. This is done by calling
71  *	SNDRV_COMPRESS_PAUSE. It can be stopped or resumed by calling
72  *	SNDRV_COMPRESS_STOP or SNDRV_COMPRESS_RESUME respectively.
73  */
74 static int snd_compr_open(struct inode *inode, struct file *f)
75 {
76 	struct snd_compr *compr;
77 	struct snd_compr_file *data;
78 	struct snd_compr_runtime *runtime;
79 	enum snd_compr_direction dirn;
80 	int maj = imajor(inode);
81 	int ret;
82 
83 	if ((f->f_flags & O_ACCMODE) == O_WRONLY)
84 		dirn = SND_COMPRESS_PLAYBACK;
85 	else if ((f->f_flags & O_ACCMODE) == O_RDONLY)
86 		dirn = SND_COMPRESS_CAPTURE;
87 	else
88 		return -EINVAL;
89 
90 	if (maj == snd_major)
91 		compr = snd_lookup_minor_data(iminor(inode),
92 					SNDRV_DEVICE_TYPE_COMPRESS);
93 	else
94 		return -EBADFD;
95 
96 	if (compr == NULL) {
97 		pr_err("no device data!!!\n");
98 		return -ENODEV;
99 	}
100 
101 	if (dirn != compr->direction) {
102 		pr_err("this device doesn't support this direction\n");
103 		return -EINVAL;
104 	}
105 
106 	data = kzalloc(sizeof(*data), GFP_KERNEL);
107 	if (!data)
108 		return -ENOMEM;
109 	data->stream.ops = compr->ops;
110 	data->stream.direction = dirn;
111 	data->stream.private_data = compr->private_data;
112 	data->stream.device = compr;
113 	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
114 	if (!runtime) {
115 		kfree(data);
116 		return -ENOMEM;
117 	}
118 	runtime->state = SNDRV_PCM_STATE_OPEN;
119 	init_waitqueue_head(&runtime->sleep);
120 	data->stream.runtime = runtime;
121 	f->private_data = (void *)data;
122 	mutex_lock(&compr->lock);
123 	ret = compr->ops->open(&data->stream);
124 	mutex_unlock(&compr->lock);
125 	if (ret) {
126 		kfree(runtime);
127 		kfree(data);
128 	}
129 	return ret;
130 }
131 
132 static int snd_compr_free(struct inode *inode, struct file *f)
133 {
134 	struct snd_compr_file *data = f->private_data;
135 	data->stream.ops->free(&data->stream);
136 	kfree(data->stream.runtime->buffer);
137 	kfree(data->stream.runtime);
138 	kfree(data);
139 	return 0;
140 }
141 
142 static void snd_compr_update_tstamp(struct snd_compr_stream *stream,
143 		struct snd_compr_tstamp *tstamp)
144 {
145 	if (!stream->ops->pointer)
146 		return;
147 	stream->ops->pointer(stream, tstamp);
148 	pr_debug("dsp consumed till %d total %d bytes\n",
149 		tstamp->byte_offset, tstamp->copied_total);
150 	stream->runtime->hw_pointer = tstamp->byte_offset;
151 	stream->runtime->total_bytes_transferred = tstamp->copied_total;
152 }
153 
154 static size_t snd_compr_calc_avail(struct snd_compr_stream *stream,
155 		struct snd_compr_avail *avail)
156 {
157 	long avail_calc; /*this needs to be signed variable */
158 
159 	snd_compr_update_tstamp(stream, &avail->tstamp);
160 
161 	/* FIXME: This needs to be different for capture stream,
162 	   available is # of compressed data, for playback it's
163 	   remainder of buffer */
164 
165 	if (stream->runtime->total_bytes_available == 0 &&
166 			stream->runtime->state == SNDRV_PCM_STATE_SETUP) {
167 		pr_debug("detected init and someone forgot to do a write\n");
168 		return stream->runtime->buffer_size;
169 	}
170 	pr_debug("app wrote %lld, DSP consumed %lld\n",
171 			stream->runtime->total_bytes_available,
172 			stream->runtime->total_bytes_transferred);
173 	if (stream->runtime->total_bytes_available ==
174 				stream->runtime->total_bytes_transferred) {
175 		pr_debug("both pointers are same, returning full avail\n");
176 		return stream->runtime->buffer_size;
177 	}
178 
179 	/* FIXME: this routine isn't consistent, in one test we use
180 	 * cumulative values and in the other byte offsets. Do we
181 	 * really need the byte offsets if the cumulative values have
182 	 * been updated? In the PCM interface app_ptr and hw_ptr are
183 	 * already cumulative */
184 
185 	avail_calc = stream->runtime->buffer_size -
186 		(stream->runtime->app_pointer - stream->runtime->hw_pointer);
187 	pr_debug("calc avail as %ld, app_ptr %lld, hw+ptr %lld\n", avail_calc,
188 			stream->runtime->app_pointer,
189 			stream->runtime->hw_pointer);
190 	if (avail_calc >= stream->runtime->buffer_size)
191 		avail_calc -= stream->runtime->buffer_size;
192 	pr_debug("ret avail as %ld\n", avail_calc);
193 	avail->avail = avail_calc;
194 	return avail_calc;
195 }
196 
197 static inline size_t snd_compr_get_avail(struct snd_compr_stream *stream)
198 {
199 	struct snd_compr_avail avail;
200 
201 	return snd_compr_calc_avail(stream, &avail);
202 }
203 
204 static int
205 snd_compr_ioctl_avail(struct snd_compr_stream *stream, unsigned long arg)
206 {
207 	struct snd_compr_avail ioctl_avail;
208 	size_t avail;
209 
210 	avail = snd_compr_calc_avail(stream, &ioctl_avail);
211 	ioctl_avail.avail = avail;
212 
213 	if (copy_to_user((__u64 __user *)arg,
214 				&ioctl_avail, sizeof(ioctl_avail)))
215 		return -EFAULT;
216 	return 0;
217 }
218 
219 static int snd_compr_write_data(struct snd_compr_stream *stream,
220 	       const char __user *buf, size_t count)
221 {
222 	void *dstn;
223 	size_t copy;
224 	struct snd_compr_runtime *runtime = stream->runtime;
225 
226 	dstn = runtime->buffer + runtime->app_pointer;
227 	pr_debug("copying %ld at %lld\n",
228 			(unsigned long)count, runtime->app_pointer);
229 	if (count < runtime->buffer_size - runtime->app_pointer) {
230 		if (copy_from_user(dstn, buf, count))
231 			return -EFAULT;
232 		runtime->app_pointer += count;
233 	} else {
234 		copy = runtime->buffer_size - runtime->app_pointer;
235 		if (copy_from_user(dstn, buf, copy))
236 			return -EFAULT;
237 		if (copy_from_user(runtime->buffer, buf + copy, count - copy))
238 			return -EFAULT;
239 		runtime->app_pointer = count - copy;
240 	}
241 	/* if DSP cares, let it know data has been written */
242 	if (stream->ops->ack)
243 		stream->ops->ack(stream, count);
244 	return count;
245 }
246 
247 static ssize_t snd_compr_write(struct file *f, const char __user *buf,
248 		size_t count, loff_t *offset)
249 {
250 	struct snd_compr_file *data = f->private_data;
251 	struct snd_compr_stream *stream;
252 	size_t avail;
253 	int retval;
254 
255 	if (snd_BUG_ON(!data))
256 		return -EFAULT;
257 
258 	stream = &data->stream;
259 	mutex_lock(&stream->device->lock);
260 	/* write is allowed when stream is running or has been steup */
261 	if (stream->runtime->state != SNDRV_PCM_STATE_SETUP &&
262 			stream->runtime->state != SNDRV_PCM_STATE_RUNNING) {
263 		mutex_unlock(&stream->device->lock);
264 		return -EBADFD;
265 	}
266 
267 	avail = snd_compr_get_avail(stream);
268 	pr_debug("avail returned %ld\n", (unsigned long)avail);
269 	/* calculate how much we can write to buffer */
270 	if (avail > count)
271 		avail = count;
272 
273 	if (stream->ops->copy)
274 		retval = stream->ops->copy(stream, buf, avail);
275 	else
276 		retval = snd_compr_write_data(stream, buf, avail);
277 	if (retval > 0)
278 		stream->runtime->total_bytes_available += retval;
279 
280 	/* while initiating the stream, write should be called before START
281 	 * call, so in setup move state */
282 	if (stream->runtime->state == SNDRV_PCM_STATE_SETUP) {
283 		stream->runtime->state = SNDRV_PCM_STATE_PREPARED;
284 		pr_debug("stream prepared, Houston we are good to go\n");
285 	}
286 
287 	mutex_unlock(&stream->device->lock);
288 	return retval;
289 }
290 
291 
292 static ssize_t snd_compr_read(struct file *f, char __user *buf,
293 		size_t count, loff_t *offset)
294 {
295 	return -ENXIO;
296 }
297 
298 static int snd_compr_mmap(struct file *f, struct vm_area_struct *vma)
299 {
300 	return -ENXIO;
301 }
302 
303 static inline int snd_compr_get_poll(struct snd_compr_stream *stream)
304 {
305 	if (stream->direction == SND_COMPRESS_PLAYBACK)
306 		return POLLOUT | POLLWRNORM;
307 	else
308 		return POLLIN | POLLRDNORM;
309 }
310 
311 static unsigned int snd_compr_poll(struct file *f, poll_table *wait)
312 {
313 	struct snd_compr_file *data = f->private_data;
314 	struct snd_compr_stream *stream;
315 	size_t avail;
316 	int retval = 0;
317 
318 	if (snd_BUG_ON(!data))
319 		return -EFAULT;
320 	stream = &data->stream;
321 	if (snd_BUG_ON(!stream))
322 		return -EFAULT;
323 
324 	mutex_lock(&stream->device->lock);
325 	if (stream->runtime->state == SNDRV_PCM_STATE_PAUSED ||
326 			stream->runtime->state == SNDRV_PCM_STATE_OPEN) {
327 		retval = -EBADFD;
328 		goto out;
329 	}
330 	poll_wait(f, &stream->runtime->sleep, wait);
331 
332 	avail = snd_compr_get_avail(stream);
333 	pr_debug("avail is %ld\n", (unsigned long)avail);
334 	/* check if we have at least one fragment to fill */
335 	switch (stream->runtime->state) {
336 	case SNDRV_PCM_STATE_DRAINING:
337 		/* stream has been woken up after drain is complete
338 		 * draining done so set stream state to stopped
339 		 */
340 		retval = snd_compr_get_poll(stream);
341 		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
342 		break;
343 	case SNDRV_PCM_STATE_RUNNING:
344 	case SNDRV_PCM_STATE_PREPARED:
345 	case SNDRV_PCM_STATE_PAUSED:
346 		if (avail >= stream->runtime->fragment_size)
347 			retval = snd_compr_get_poll(stream);
348 		break;
349 	default:
350 		if (stream->direction == SND_COMPRESS_PLAYBACK)
351 			retval = POLLOUT | POLLWRNORM | POLLERR;
352 		else
353 			retval = POLLIN | POLLRDNORM | POLLERR;
354 		break;
355 	}
356 out:
357 	mutex_unlock(&stream->device->lock);
358 	return retval;
359 }
360 
361 static int
362 snd_compr_get_caps(struct snd_compr_stream *stream, unsigned long arg)
363 {
364 	int retval;
365 	struct snd_compr_caps caps;
366 
367 	if (!stream->ops->get_caps)
368 		return -ENXIO;
369 
370 	retval = stream->ops->get_caps(stream, &caps);
371 	if (retval)
372 		goto out;
373 	if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
374 		retval = -EFAULT;
375 out:
376 	return retval;
377 }
378 
379 static int
380 snd_compr_get_codec_caps(struct snd_compr_stream *stream, unsigned long arg)
381 {
382 	int retval;
383 	struct snd_compr_codec_caps *caps;
384 
385 	if (!stream->ops->get_codec_caps)
386 		return -ENXIO;
387 
388 	caps = kmalloc(sizeof(*caps), GFP_KERNEL);
389 	if (!caps)
390 		return -ENOMEM;
391 
392 	retval = stream->ops->get_codec_caps(stream, caps);
393 	if (retval)
394 		goto out;
395 	if (copy_to_user((void __user *)arg, caps, sizeof(*caps)))
396 		retval = -EFAULT;
397 
398 out:
399 	kfree(caps);
400 	return retval;
401 }
402 
403 /* revisit this with snd_pcm_preallocate_xxx */
404 static int snd_compr_allocate_buffer(struct snd_compr_stream *stream,
405 		struct snd_compr_params *params)
406 {
407 	unsigned int buffer_size;
408 	void *buffer;
409 
410 	buffer_size = params->buffer.fragment_size * params->buffer.fragments;
411 	if (stream->ops->copy) {
412 		buffer = NULL;
413 		/* if copy is defined the driver will be required to copy
414 		 * the data from core
415 		 */
416 	} else {
417 		buffer = kmalloc(buffer_size, GFP_KERNEL);
418 		if (!buffer)
419 			return -ENOMEM;
420 	}
421 	stream->runtime->fragment_size = params->buffer.fragment_size;
422 	stream->runtime->fragments = params->buffer.fragments;
423 	stream->runtime->buffer = buffer;
424 	stream->runtime->buffer_size = buffer_size;
425 	return 0;
426 }
427 
428 static int
429 snd_compr_set_params(struct snd_compr_stream *stream, unsigned long arg)
430 {
431 	struct snd_compr_params *params;
432 	int retval;
433 
434 	if (stream->runtime->state == SNDRV_PCM_STATE_OPEN) {
435 		/*
436 		 * we should allow parameter change only when stream has been
437 		 * opened not in other cases
438 		 */
439 		params = kmalloc(sizeof(*params), GFP_KERNEL);
440 		if (!params)
441 			return -ENOMEM;
442 		if (copy_from_user(params, (void __user *)arg, sizeof(*params))) {
443 			retval = -EFAULT;
444 			goto out;
445 		}
446 		retval = snd_compr_allocate_buffer(stream, params);
447 		if (retval) {
448 			retval = -ENOMEM;
449 			goto out;
450 		}
451 		retval = stream->ops->set_params(stream, params);
452 		if (retval)
453 			goto out;
454 		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
455 	} else {
456 		return -EPERM;
457 	}
458 out:
459 	kfree(params);
460 	return retval;
461 }
462 
463 static int
464 snd_compr_get_params(struct snd_compr_stream *stream, unsigned long arg)
465 {
466 	struct snd_codec *params;
467 	int retval;
468 
469 	if (!stream->ops->get_params)
470 		return -EBADFD;
471 
472 	params = kmalloc(sizeof(*params), GFP_KERNEL);
473 	if (!params)
474 		return -ENOMEM;
475 	retval = stream->ops->get_params(stream, params);
476 	if (retval)
477 		goto out;
478 	if (copy_to_user((char __user *)arg, params, sizeof(*params)))
479 		retval = -EFAULT;
480 
481 out:
482 	kfree(params);
483 	return retval;
484 }
485 
486 static inline int
487 snd_compr_tstamp(struct snd_compr_stream *stream, unsigned long arg)
488 {
489 	struct snd_compr_tstamp tstamp;
490 
491 	snd_compr_update_tstamp(stream, &tstamp);
492 	return copy_to_user((struct snd_compr_tstamp __user *)arg,
493 		&tstamp, sizeof(tstamp)) ? -EFAULT : 0;
494 }
495 
496 static int snd_compr_pause(struct snd_compr_stream *stream)
497 {
498 	int retval;
499 
500 	if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING)
501 		return -EPERM;
502 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_PUSH);
503 	if (!retval)
504 		stream->runtime->state = SNDRV_PCM_STATE_PAUSED;
505 	return retval;
506 }
507 
508 static int snd_compr_resume(struct snd_compr_stream *stream)
509 {
510 	int retval;
511 
512 	if (stream->runtime->state != SNDRV_PCM_STATE_PAUSED)
513 		return -EPERM;
514 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_RELEASE);
515 	if (!retval)
516 		stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
517 	return retval;
518 }
519 
520 static int snd_compr_start(struct snd_compr_stream *stream)
521 {
522 	int retval;
523 
524 	if (stream->runtime->state != SNDRV_PCM_STATE_PREPARED)
525 		return -EPERM;
526 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_START);
527 	if (!retval)
528 		stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
529 	return retval;
530 }
531 
532 static int snd_compr_stop(struct snd_compr_stream *stream)
533 {
534 	int retval;
535 
536 	if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
537 			stream->runtime->state == SNDRV_PCM_STATE_SETUP)
538 		return -EPERM;
539 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_STOP);
540 	if (!retval) {
541 		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
542 		wake_up(&stream->runtime->sleep);
543 		stream->runtime->hw_pointer = 0;
544 		stream->runtime->app_pointer = 0;
545 		stream->runtime->total_bytes_available = 0;
546 		stream->runtime->total_bytes_transferred = 0;
547 	}
548 	return retval;
549 }
550 
551 static int snd_compr_drain(struct snd_compr_stream *stream)
552 {
553 	int retval;
554 
555 	if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
556 			stream->runtime->state == SNDRV_PCM_STATE_SETUP)
557 		return -EPERM;
558 	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_DRAIN);
559 	if (!retval) {
560 		stream->runtime->state = SNDRV_PCM_STATE_DRAINING;
561 		wake_up(&stream->runtime->sleep);
562 	}
563 	return retval;
564 }
565 
566 static long snd_compr_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
567 {
568 	struct snd_compr_file *data = f->private_data;
569 	struct snd_compr_stream *stream;
570 	int retval = -ENOTTY;
571 
572 	if (snd_BUG_ON(!data))
573 		return -EFAULT;
574 	stream = &data->stream;
575 	if (snd_BUG_ON(!stream))
576 		return -EFAULT;
577 	mutex_lock(&stream->device->lock);
578 	switch (_IOC_NR(cmd)) {
579 	case _IOC_NR(SNDRV_COMPRESS_IOCTL_VERSION):
580 		put_user(SNDRV_COMPRESS_VERSION,
581 				(int __user *)arg) ? -EFAULT : 0;
582 		break;
583 	case _IOC_NR(SNDRV_COMPRESS_GET_CAPS):
584 		retval = snd_compr_get_caps(stream, arg);
585 		break;
586 	case _IOC_NR(SNDRV_COMPRESS_GET_CODEC_CAPS):
587 		retval = snd_compr_get_codec_caps(stream, arg);
588 		break;
589 	case _IOC_NR(SNDRV_COMPRESS_SET_PARAMS):
590 		retval = snd_compr_set_params(stream, arg);
591 		break;
592 	case _IOC_NR(SNDRV_COMPRESS_GET_PARAMS):
593 		retval = snd_compr_get_params(stream, arg);
594 		break;
595 	case _IOC_NR(SNDRV_COMPRESS_TSTAMP):
596 		retval = snd_compr_tstamp(stream, arg);
597 		break;
598 	case _IOC_NR(SNDRV_COMPRESS_AVAIL):
599 		retval = snd_compr_ioctl_avail(stream, arg);
600 		break;
601 	case _IOC_NR(SNDRV_COMPRESS_PAUSE):
602 		retval = snd_compr_pause(stream);
603 		break;
604 	case _IOC_NR(SNDRV_COMPRESS_RESUME):
605 		retval = snd_compr_resume(stream);
606 		break;
607 	case _IOC_NR(SNDRV_COMPRESS_START):
608 		retval = snd_compr_start(stream);
609 		break;
610 	case _IOC_NR(SNDRV_COMPRESS_STOP):
611 		retval = snd_compr_stop(stream);
612 		break;
613 	case _IOC_NR(SNDRV_COMPRESS_DRAIN):
614 		retval = snd_compr_drain(stream);
615 		break;
616 	}
617 	mutex_unlock(&stream->device->lock);
618 	return retval;
619 }
620 
621 static const struct file_operations snd_compr_file_ops = {
622 		.owner =	THIS_MODULE,
623 		.open =		snd_compr_open,
624 		.release =	snd_compr_free,
625 		.write =	snd_compr_write,
626 		.read =		snd_compr_read,
627 		.unlocked_ioctl = snd_compr_ioctl,
628 		.mmap =		snd_compr_mmap,
629 		.poll =		snd_compr_poll,
630 };
631 
632 static int snd_compress_dev_register(struct snd_device *device)
633 {
634 	int ret = -EINVAL;
635 	char str[16];
636 	struct snd_compr *compr;
637 
638 	if (snd_BUG_ON(!device || !device->device_data))
639 		return -EBADFD;
640 	compr = device->device_data;
641 
642 	sprintf(str, "comprC%iD%i", compr->card->number, compr->device);
643 	pr_debug("reg %s for device %s, direction %d\n", str, compr->name,
644 			compr->direction);
645 	/* register compressed device */
646 	ret = snd_register_device(SNDRV_DEVICE_TYPE_COMPRESS, compr->card,
647 			compr->device, &snd_compr_file_ops, compr, str);
648 	if (ret < 0) {
649 		pr_err("snd_register_device failed\n %d", ret);
650 		return ret;
651 	}
652 	return ret;
653 
654 }
655 
656 static int snd_compress_dev_disconnect(struct snd_device *device)
657 {
658 	struct snd_compr *compr;
659 
660 	compr = device->device_data;
661 	snd_unregister_device(compr->direction, compr->card, compr->device);
662 	return 0;
663 }
664 
665 /*
666  * snd_compress_new: create new compress device
667  * @card: sound card pointer
668  * @device: device number
669  * @dirn: device direction, should be of type enum snd_compr_direction
670  * @compr: compress device pointer
671  */
672 int snd_compress_new(struct snd_card *card, int device,
673 			int dirn, struct snd_compr *compr)
674 {
675 	static struct snd_device_ops ops = {
676 		.dev_free = NULL,
677 		.dev_register = snd_compress_dev_register,
678 		.dev_disconnect = snd_compress_dev_disconnect,
679 	};
680 
681 	compr->card = card;
682 	compr->device = device;
683 	compr->direction = dirn;
684 	return snd_device_new(card, SNDRV_DEV_COMPRESS, compr, &ops);
685 }
686 EXPORT_SYMBOL_GPL(snd_compress_new);
687 
688 static int snd_compress_add_device(struct snd_compr *device)
689 {
690 	int ret;
691 
692 	if (!device->card)
693 		return -EINVAL;
694 
695 	/* register the card */
696 	ret = snd_card_register(device->card);
697 	if (ret)
698 		goto out;
699 	return 0;
700 
701 out:
702 	pr_err("failed with %d\n", ret);
703 	return ret;
704 
705 }
706 
707 static int snd_compress_remove_device(struct snd_compr *device)
708 {
709 	return snd_card_free(device->card);
710 }
711 
712 /**
713  * snd_compress_register - register compressed device
714  *
715  * @device: compressed device to register
716  */
717 int snd_compress_register(struct snd_compr *device)
718 {
719 	int retval;
720 
721 	if (device->name == NULL || device->dev == NULL || device->ops == NULL)
722 		return -EINVAL;
723 
724 	pr_debug("Registering compressed device %s\n", device->name);
725 	if (snd_BUG_ON(!device->ops->open))
726 		return -EINVAL;
727 	if (snd_BUG_ON(!device->ops->free))
728 		return -EINVAL;
729 	if (snd_BUG_ON(!device->ops->set_params))
730 		return -EINVAL;
731 	if (snd_BUG_ON(!device->ops->trigger))
732 		return -EINVAL;
733 
734 	mutex_init(&device->lock);
735 
736 	/* register a compressed card */
737 	mutex_lock(&device_mutex);
738 	retval = snd_compress_add_device(device);
739 	mutex_unlock(&device_mutex);
740 	return retval;
741 }
742 EXPORT_SYMBOL_GPL(snd_compress_register);
743 
744 int snd_compress_deregister(struct snd_compr *device)
745 {
746 	pr_debug("Removing compressed device %s\n", device->name);
747 	mutex_lock(&device_mutex);
748 	snd_compress_remove_device(device);
749 	mutex_unlock(&device_mutex);
750 	return 0;
751 }
752 EXPORT_SYMBOL_GPL(snd_compress_deregister);
753 
754 static int __init snd_compress_init(void)
755 {
756 	return 0;
757 }
758 
759 static void __exit snd_compress_exit(void)
760 {
761 }
762 
763 module_init(snd_compress_init);
764 module_exit(snd_compress_exit);
765 
766 MODULE_DESCRIPTION("ALSA Compressed offload framework");
767 MODULE_AUTHOR("Vinod Koul <vinod.koul@linux.intel.com>");
768 MODULE_LICENSE("GPL v2");
769