xref: /openbmc/linux/sound/core/compress_offload.c (revision d0b73b48)
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 		snd_card_unref(compr->card);
104 		return -EINVAL;
105 	}
106 
107 	data = kzalloc(sizeof(*data), GFP_KERNEL);
108 	if (!data) {
109 		snd_card_unref(compr->card);
110 		return -ENOMEM;
111 	}
112 	data->stream.ops = compr->ops;
113 	data->stream.direction = dirn;
114 	data->stream.private_data = compr->private_data;
115 	data->stream.device = compr;
116 	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
117 	if (!runtime) {
118 		kfree(data);
119 		snd_card_unref(compr->card);
120 		return -ENOMEM;
121 	}
122 	runtime->state = SNDRV_PCM_STATE_OPEN;
123 	init_waitqueue_head(&runtime->sleep);
124 	data->stream.runtime = runtime;
125 	f->private_data = (void *)data;
126 	mutex_lock(&compr->lock);
127 	ret = compr->ops->open(&data->stream);
128 	mutex_unlock(&compr->lock);
129 	if (ret) {
130 		kfree(runtime);
131 		kfree(data);
132 	}
133 	snd_card_unref(compr->card);
134 	return 0;
135 }
136 
137 static int snd_compr_free(struct inode *inode, struct file *f)
138 {
139 	struct snd_compr_file *data = f->private_data;
140 	data->stream.ops->free(&data->stream);
141 	kfree(data->stream.runtime->buffer);
142 	kfree(data->stream.runtime);
143 	kfree(data);
144 	return 0;
145 }
146 
147 static void snd_compr_update_tstamp(struct snd_compr_stream *stream,
148 		struct snd_compr_tstamp *tstamp)
149 {
150 	if (!stream->ops->pointer)
151 		return;
152 	stream->ops->pointer(stream, tstamp);
153 	pr_debug("dsp consumed till %d total %d bytes\n",
154 		tstamp->byte_offset, tstamp->copied_total);
155 	stream->runtime->hw_pointer = tstamp->byte_offset;
156 	stream->runtime->total_bytes_transferred = tstamp->copied_total;
157 }
158 
159 static size_t snd_compr_calc_avail(struct snd_compr_stream *stream,
160 		struct snd_compr_avail *avail)
161 {
162 	long avail_calc; /*this needs to be signed variable */
163 
164 	snd_compr_update_tstamp(stream, &avail->tstamp);
165 
166 	/* FIXME: This needs to be different for capture stream,
167 	   available is # of compressed data, for playback it's
168 	   remainder of buffer */
169 
170 	if (stream->runtime->total_bytes_available == 0 &&
171 			stream->runtime->state == SNDRV_PCM_STATE_SETUP) {
172 		pr_debug("detected init and someone forgot to do a write\n");
173 		return stream->runtime->buffer_size;
174 	}
175 	pr_debug("app wrote %lld, DSP consumed %lld\n",
176 			stream->runtime->total_bytes_available,
177 			stream->runtime->total_bytes_transferred);
178 	if (stream->runtime->total_bytes_available ==
179 				stream->runtime->total_bytes_transferred) {
180 		pr_debug("both pointers are same, returning full avail\n");
181 		return stream->runtime->buffer_size;
182 	}
183 
184 	/* FIXME: this routine isn't consistent, in one test we use
185 	 * cumulative values and in the other byte offsets. Do we
186 	 * really need the byte offsets if the cumulative values have
187 	 * been updated? In the PCM interface app_ptr and hw_ptr are
188 	 * already cumulative */
189 
190 	avail_calc = stream->runtime->buffer_size -
191 		(stream->runtime->app_pointer - stream->runtime->hw_pointer);
192 	pr_debug("calc avail as %ld, app_ptr %lld, hw+ptr %lld\n", avail_calc,
193 			stream->runtime->app_pointer,
194 			stream->runtime->hw_pointer);
195 	if (avail_calc >= stream->runtime->buffer_size)
196 		avail_calc -= stream->runtime->buffer_size;
197 	pr_debug("ret avail as %ld\n", avail_calc);
198 	avail->avail = avail_calc;
199 	return avail_calc;
200 }
201 
202 static inline size_t snd_compr_get_avail(struct snd_compr_stream *stream)
203 {
204 	struct snd_compr_avail avail;
205 
206 	return snd_compr_calc_avail(stream, &avail);
207 }
208 
209 static int
210 snd_compr_ioctl_avail(struct snd_compr_stream *stream, unsigned long arg)
211 {
212 	struct snd_compr_avail ioctl_avail;
213 	size_t avail;
214 
215 	avail = snd_compr_calc_avail(stream, &ioctl_avail);
216 	ioctl_avail.avail = avail;
217 
218 	if (copy_to_user((__u64 __user *)arg,
219 				&ioctl_avail, sizeof(ioctl_avail)))
220 		return -EFAULT;
221 	return 0;
222 }
223 
224 static int snd_compr_write_data(struct snd_compr_stream *stream,
225 	       const char __user *buf, size_t count)
226 {
227 	void *dstn;
228 	size_t copy;
229 	struct snd_compr_runtime *runtime = stream->runtime;
230 
231 	dstn = runtime->buffer + runtime->app_pointer;
232 	pr_debug("copying %ld at %lld\n",
233 			(unsigned long)count, runtime->app_pointer);
234 	if (count < runtime->buffer_size - runtime->app_pointer) {
235 		if (copy_from_user(dstn, buf, count))
236 			return -EFAULT;
237 		runtime->app_pointer += count;
238 	} else {
239 		copy = runtime->buffer_size - runtime->app_pointer;
240 		if (copy_from_user(dstn, buf, copy))
241 			return -EFAULT;
242 		if (copy_from_user(runtime->buffer, buf + copy, count - copy))
243 			return -EFAULT;
244 		runtime->app_pointer = count - copy;
245 	}
246 	/* if DSP cares, let it know data has been written */
247 	if (stream->ops->ack)
248 		stream->ops->ack(stream, count);
249 	return count;
250 }
251 
252 static ssize_t snd_compr_write(struct file *f, const char __user *buf,
253 		size_t count, loff_t *offset)
254 {
255 	struct snd_compr_file *data = f->private_data;
256 	struct snd_compr_stream *stream;
257 	size_t avail;
258 	int retval;
259 
260 	if (snd_BUG_ON(!data))
261 		return -EFAULT;
262 
263 	stream = &data->stream;
264 	mutex_lock(&stream->device->lock);
265 	/* write is allowed when stream is running or has been steup */
266 	if (stream->runtime->state != SNDRV_PCM_STATE_SETUP &&
267 			stream->runtime->state != SNDRV_PCM_STATE_RUNNING) {
268 		mutex_unlock(&stream->device->lock);
269 		return -EBADFD;
270 	}
271 
272 	avail = snd_compr_get_avail(stream);
273 	pr_debug("avail returned %ld\n", (unsigned long)avail);
274 	/* calculate how much we can write to buffer */
275 	if (avail > count)
276 		avail = count;
277 
278 	if (stream->ops->copy)
279 		retval = stream->ops->copy(stream, buf, avail);
280 	else
281 		retval = snd_compr_write_data(stream, buf, avail);
282 	if (retval > 0)
283 		stream->runtime->total_bytes_available += retval;
284 
285 	/* while initiating the stream, write should be called before START
286 	 * call, so in setup move state */
287 	if (stream->runtime->state == SNDRV_PCM_STATE_SETUP) {
288 		stream->runtime->state = SNDRV_PCM_STATE_PREPARED;
289 		pr_debug("stream prepared, Houston we are good to go\n");
290 	}
291 
292 	mutex_unlock(&stream->device->lock);
293 	return retval;
294 }
295 
296 
297 static ssize_t snd_compr_read(struct file *f, char __user *buf,
298 		size_t count, loff_t *offset)
299 {
300 	return -ENXIO;
301 }
302 
303 static int snd_compr_mmap(struct file *f, struct vm_area_struct *vma)
304 {
305 	return -ENXIO;
306 }
307 
308 static inline int snd_compr_get_poll(struct snd_compr_stream *stream)
309 {
310 	if (stream->direction == SND_COMPRESS_PLAYBACK)
311 		return POLLOUT | POLLWRNORM;
312 	else
313 		return POLLIN | POLLRDNORM;
314 }
315 
316 static unsigned int snd_compr_poll(struct file *f, poll_table *wait)
317 {
318 	struct snd_compr_file *data = f->private_data;
319 	struct snd_compr_stream *stream;
320 	size_t avail;
321 	int retval = 0;
322 
323 	if (snd_BUG_ON(!data))
324 		return -EFAULT;
325 	stream = &data->stream;
326 	if (snd_BUG_ON(!stream))
327 		return -EFAULT;
328 
329 	mutex_lock(&stream->device->lock);
330 	if (stream->runtime->state == SNDRV_PCM_STATE_PAUSED ||
331 			stream->runtime->state == SNDRV_PCM_STATE_OPEN) {
332 		retval = -EBADFD;
333 		goto out;
334 	}
335 	poll_wait(f, &stream->runtime->sleep, wait);
336 
337 	avail = snd_compr_get_avail(stream);
338 	pr_debug("avail is %ld\n", (unsigned long)avail);
339 	/* check if we have at least one fragment to fill */
340 	switch (stream->runtime->state) {
341 	case SNDRV_PCM_STATE_DRAINING:
342 		/* stream has been woken up after drain is complete
343 		 * draining done so set stream state to stopped
344 		 */
345 		retval = snd_compr_get_poll(stream);
346 		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
347 		break;
348 	case SNDRV_PCM_STATE_RUNNING:
349 	case SNDRV_PCM_STATE_PREPARED:
350 	case SNDRV_PCM_STATE_PAUSED:
351 		if (avail >= stream->runtime->fragment_size)
352 			retval = snd_compr_get_poll(stream);
353 		break;
354 	default:
355 		if (stream->direction == SND_COMPRESS_PLAYBACK)
356 			retval = POLLOUT | POLLWRNORM | POLLERR;
357 		else
358 			retval = POLLIN | POLLRDNORM | POLLERR;
359 		break;
360 	}
361 out:
362 	mutex_unlock(&stream->device->lock);
363 	return retval;
364 }
365 
366 static int
367 snd_compr_get_caps(struct snd_compr_stream *stream, unsigned long arg)
368 {
369 	int retval;
370 	struct snd_compr_caps caps;
371 
372 	if (!stream->ops->get_caps)
373 		return -ENXIO;
374 
375 	retval = stream->ops->get_caps(stream, &caps);
376 	if (retval)
377 		goto out;
378 	if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
379 		retval = -EFAULT;
380 out:
381 	return retval;
382 }
383 
384 static int
385 snd_compr_get_codec_caps(struct snd_compr_stream *stream, unsigned long arg)
386 {
387 	int retval;
388 	struct snd_compr_codec_caps *caps;
389 
390 	if (!stream->ops->get_codec_caps)
391 		return -ENXIO;
392 
393 	caps = kmalloc(sizeof(*caps), GFP_KERNEL);
394 	if (!caps)
395 		return -ENOMEM;
396 
397 	retval = stream->ops->get_codec_caps(stream, caps);
398 	if (retval)
399 		goto out;
400 	if (copy_to_user((void __user *)arg, caps, sizeof(*caps)))
401 		retval = -EFAULT;
402 
403 out:
404 	kfree(caps);
405 	return retval;
406 }
407 
408 /* revisit this with snd_pcm_preallocate_xxx */
409 static int snd_compr_allocate_buffer(struct snd_compr_stream *stream,
410 		struct snd_compr_params *params)
411 {
412 	unsigned int buffer_size;
413 	void *buffer;
414 
415 	buffer_size = params->buffer.fragment_size * params->buffer.fragments;
416 	if (stream->ops->copy) {
417 		buffer = NULL;
418 		/* if copy is defined the driver will be required to copy
419 		 * the data from core
420 		 */
421 	} else {
422 		buffer = kmalloc(buffer_size, GFP_KERNEL);
423 		if (!buffer)
424 			return -ENOMEM;
425 	}
426 	stream->runtime->fragment_size = params->buffer.fragment_size;
427 	stream->runtime->fragments = params->buffer.fragments;
428 	stream->runtime->buffer = buffer;
429 	stream->runtime->buffer_size = buffer_size;
430 	return 0;
431 }
432 
433 static int snd_compress_check_input(struct snd_compr_params *params)
434 {
435 	/* first let's check the buffer parameter's */
436 	if (params->buffer.fragment_size == 0 ||
437 			params->buffer.fragments > SIZE_MAX / params->buffer.fragment_size)
438 		return -EINVAL;
439 
440 	/* now codec parameters */
441 	if (params->codec.id == 0 || params->codec.id > SND_AUDIOCODEC_MAX)
442 		return -EINVAL;
443 
444 	if (params->codec.ch_in == 0 || params->codec.ch_out == 0)
445 		return -EINVAL;
446 
447 	if (!(params->codec.sample_rate & SNDRV_PCM_RATE_8000_192000))
448 		return -EINVAL;
449 
450 	return 0;
451 }
452 
453 static int
454 snd_compr_set_params(struct snd_compr_stream *stream, unsigned long arg)
455 {
456 	struct snd_compr_params *params;
457 	int retval;
458 
459 	if (stream->runtime->state == SNDRV_PCM_STATE_OPEN) {
460 		/*
461 		 * we should allow parameter change only when stream has been
462 		 * opened not in other cases
463 		 */
464 		params = kmalloc(sizeof(*params), GFP_KERNEL);
465 		if (!params)
466 			return -ENOMEM;
467 		if (copy_from_user(params, (void __user *)arg, sizeof(*params))) {
468 			retval = -EFAULT;
469 			goto out;
470 		}
471 
472 		retval = snd_compress_check_input(params);
473 		if (retval)
474 			goto out;
475 
476 		retval = snd_compr_allocate_buffer(stream, params);
477 		if (retval) {
478 			retval = -ENOMEM;
479 			goto out;
480 		}
481 
482 		retval = stream->ops->set_params(stream, params);
483 		if (retval)
484 			goto out;
485 		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
486 	} else {
487 		return -EPERM;
488 	}
489 out:
490 	kfree(params);
491 	return retval;
492 }
493 
494 static int
495 snd_compr_get_params(struct snd_compr_stream *stream, unsigned long arg)
496 {
497 	struct snd_codec *params;
498 	int retval;
499 
500 	if (!stream->ops->get_params)
501 		return -EBADFD;
502 
503 	params = kmalloc(sizeof(*params), GFP_KERNEL);
504 	if (!params)
505 		return -ENOMEM;
506 	retval = stream->ops->get_params(stream, params);
507 	if (retval)
508 		goto out;
509 	if (copy_to_user((char __user *)arg, params, sizeof(*params)))
510 		retval = -EFAULT;
511 
512 out:
513 	kfree(params);
514 	return retval;
515 }
516 
517 static inline int
518 snd_compr_tstamp(struct snd_compr_stream *stream, unsigned long arg)
519 {
520 	struct snd_compr_tstamp tstamp;
521 
522 	snd_compr_update_tstamp(stream, &tstamp);
523 	return copy_to_user((struct snd_compr_tstamp __user *)arg,
524 		&tstamp, sizeof(tstamp)) ? -EFAULT : 0;
525 }
526 
527 static int snd_compr_pause(struct snd_compr_stream *stream)
528 {
529 	int retval;
530 
531 	if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING)
532 		return -EPERM;
533 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_PUSH);
534 	if (!retval)
535 		stream->runtime->state = SNDRV_PCM_STATE_PAUSED;
536 	return retval;
537 }
538 
539 static int snd_compr_resume(struct snd_compr_stream *stream)
540 {
541 	int retval;
542 
543 	if (stream->runtime->state != SNDRV_PCM_STATE_PAUSED)
544 		return -EPERM;
545 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_RELEASE);
546 	if (!retval)
547 		stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
548 	return retval;
549 }
550 
551 static int snd_compr_start(struct snd_compr_stream *stream)
552 {
553 	int retval;
554 
555 	if (stream->runtime->state != SNDRV_PCM_STATE_PREPARED)
556 		return -EPERM;
557 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_START);
558 	if (!retval)
559 		stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
560 	return retval;
561 }
562 
563 static int snd_compr_stop(struct snd_compr_stream *stream)
564 {
565 	int retval;
566 
567 	if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
568 			stream->runtime->state == SNDRV_PCM_STATE_SETUP)
569 		return -EPERM;
570 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_STOP);
571 	if (!retval) {
572 		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
573 		wake_up(&stream->runtime->sleep);
574 		stream->runtime->hw_pointer = 0;
575 		stream->runtime->app_pointer = 0;
576 		stream->runtime->total_bytes_available = 0;
577 		stream->runtime->total_bytes_transferred = 0;
578 	}
579 	return retval;
580 }
581 
582 static int snd_compr_drain(struct snd_compr_stream *stream)
583 {
584 	int retval;
585 
586 	if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
587 			stream->runtime->state == SNDRV_PCM_STATE_SETUP)
588 		return -EPERM;
589 	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_DRAIN);
590 	if (!retval) {
591 		stream->runtime->state = SNDRV_PCM_STATE_DRAINING;
592 		wake_up(&stream->runtime->sleep);
593 	}
594 	return retval;
595 }
596 
597 static long snd_compr_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
598 {
599 	struct snd_compr_file *data = f->private_data;
600 	struct snd_compr_stream *stream;
601 	int retval = -ENOTTY;
602 
603 	if (snd_BUG_ON(!data))
604 		return -EFAULT;
605 	stream = &data->stream;
606 	if (snd_BUG_ON(!stream))
607 		return -EFAULT;
608 	mutex_lock(&stream->device->lock);
609 	switch (_IOC_NR(cmd)) {
610 	case _IOC_NR(SNDRV_COMPRESS_IOCTL_VERSION):
611 		put_user(SNDRV_COMPRESS_VERSION,
612 				(int __user *)arg) ? -EFAULT : 0;
613 		break;
614 	case _IOC_NR(SNDRV_COMPRESS_GET_CAPS):
615 		retval = snd_compr_get_caps(stream, arg);
616 		break;
617 	case _IOC_NR(SNDRV_COMPRESS_GET_CODEC_CAPS):
618 		retval = snd_compr_get_codec_caps(stream, arg);
619 		break;
620 	case _IOC_NR(SNDRV_COMPRESS_SET_PARAMS):
621 		retval = snd_compr_set_params(stream, arg);
622 		break;
623 	case _IOC_NR(SNDRV_COMPRESS_GET_PARAMS):
624 		retval = snd_compr_get_params(stream, arg);
625 		break;
626 	case _IOC_NR(SNDRV_COMPRESS_TSTAMP):
627 		retval = snd_compr_tstamp(stream, arg);
628 		break;
629 	case _IOC_NR(SNDRV_COMPRESS_AVAIL):
630 		retval = snd_compr_ioctl_avail(stream, arg);
631 		break;
632 	case _IOC_NR(SNDRV_COMPRESS_PAUSE):
633 		retval = snd_compr_pause(stream);
634 		break;
635 	case _IOC_NR(SNDRV_COMPRESS_RESUME):
636 		retval = snd_compr_resume(stream);
637 		break;
638 	case _IOC_NR(SNDRV_COMPRESS_START):
639 		retval = snd_compr_start(stream);
640 		break;
641 	case _IOC_NR(SNDRV_COMPRESS_STOP):
642 		retval = snd_compr_stop(stream);
643 		break;
644 	case _IOC_NR(SNDRV_COMPRESS_DRAIN):
645 		retval = snd_compr_drain(stream);
646 		break;
647 	}
648 	mutex_unlock(&stream->device->lock);
649 	return retval;
650 }
651 
652 static const struct file_operations snd_compr_file_ops = {
653 		.owner =	THIS_MODULE,
654 		.open =		snd_compr_open,
655 		.release =	snd_compr_free,
656 		.write =	snd_compr_write,
657 		.read =		snd_compr_read,
658 		.unlocked_ioctl = snd_compr_ioctl,
659 		.mmap =		snd_compr_mmap,
660 		.poll =		snd_compr_poll,
661 };
662 
663 static int snd_compress_dev_register(struct snd_device *device)
664 {
665 	int ret = -EINVAL;
666 	char str[16];
667 	struct snd_compr *compr;
668 
669 	if (snd_BUG_ON(!device || !device->device_data))
670 		return -EBADFD;
671 	compr = device->device_data;
672 
673 	sprintf(str, "comprC%iD%i", compr->card->number, compr->device);
674 	pr_debug("reg %s for device %s, direction %d\n", str, compr->name,
675 			compr->direction);
676 	/* register compressed device */
677 	ret = snd_register_device(SNDRV_DEVICE_TYPE_COMPRESS, compr->card,
678 			compr->device, &snd_compr_file_ops, compr, str);
679 	if (ret < 0) {
680 		pr_err("snd_register_device failed\n %d", ret);
681 		return ret;
682 	}
683 	return ret;
684 
685 }
686 
687 static int snd_compress_dev_disconnect(struct snd_device *device)
688 {
689 	struct snd_compr *compr;
690 
691 	compr = device->device_data;
692 	snd_unregister_device(compr->direction, compr->card, compr->device);
693 	return 0;
694 }
695 
696 /*
697  * snd_compress_new: create new compress device
698  * @card: sound card pointer
699  * @device: device number
700  * @dirn: device direction, should be of type enum snd_compr_direction
701  * @compr: compress device pointer
702  */
703 int snd_compress_new(struct snd_card *card, int device,
704 			int dirn, struct snd_compr *compr)
705 {
706 	static struct snd_device_ops ops = {
707 		.dev_free = NULL,
708 		.dev_register = snd_compress_dev_register,
709 		.dev_disconnect = snd_compress_dev_disconnect,
710 	};
711 
712 	compr->card = card;
713 	compr->device = device;
714 	compr->direction = dirn;
715 	return snd_device_new(card, SNDRV_DEV_COMPRESS, compr, &ops);
716 }
717 EXPORT_SYMBOL_GPL(snd_compress_new);
718 
719 static int snd_compress_add_device(struct snd_compr *device)
720 {
721 	int ret;
722 
723 	if (!device->card)
724 		return -EINVAL;
725 
726 	/* register the card */
727 	ret = snd_card_register(device->card);
728 	if (ret)
729 		goto out;
730 	return 0;
731 
732 out:
733 	pr_err("failed with %d\n", ret);
734 	return ret;
735 
736 }
737 
738 static int snd_compress_remove_device(struct snd_compr *device)
739 {
740 	return snd_card_free(device->card);
741 }
742 
743 /**
744  * snd_compress_register - register compressed device
745  *
746  * @device: compressed device to register
747  */
748 int snd_compress_register(struct snd_compr *device)
749 {
750 	int retval;
751 
752 	if (device->name == NULL || device->dev == NULL || device->ops == NULL)
753 		return -EINVAL;
754 
755 	pr_debug("Registering compressed device %s\n", device->name);
756 	if (snd_BUG_ON(!device->ops->open))
757 		return -EINVAL;
758 	if (snd_BUG_ON(!device->ops->free))
759 		return -EINVAL;
760 	if (snd_BUG_ON(!device->ops->set_params))
761 		return -EINVAL;
762 	if (snd_BUG_ON(!device->ops->trigger))
763 		return -EINVAL;
764 
765 	mutex_init(&device->lock);
766 
767 	/* register a compressed card */
768 	mutex_lock(&device_mutex);
769 	retval = snd_compress_add_device(device);
770 	mutex_unlock(&device_mutex);
771 	return retval;
772 }
773 EXPORT_SYMBOL_GPL(snd_compress_register);
774 
775 int snd_compress_deregister(struct snd_compr *device)
776 {
777 	pr_debug("Removing compressed device %s\n", device->name);
778 	mutex_lock(&device_mutex);
779 	snd_compress_remove_device(device);
780 	mutex_unlock(&device_mutex);
781 	return 0;
782 }
783 EXPORT_SYMBOL_GPL(snd_compress_deregister);
784 
785 static int __init snd_compress_init(void)
786 {
787 	return 0;
788 }
789 
790 static void __exit snd_compress_exit(void)
791 {
792 }
793 
794 module_init(snd_compress_init);
795 module_exit(snd_compress_exit);
796 
797 MODULE_DESCRIPTION("ALSA Compressed offload framework");
798 MODULE_AUTHOR("Vinod Koul <vinod.koul@linux.intel.com>");
799 MODULE_LICENSE("GPL v2");
800