xref: /openbmc/linux/sound/core/compress_offload.c (revision cd5d5810)
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/math64.h>
32 #include <linux/mm.h>
33 #include <linux/mutex.h>
34 #include <linux/poll.h>
35 #include <linux/slab.h>
36 #include <linux/sched.h>
37 #include <linux/types.h>
38 #include <linux/uio.h>
39 #include <linux/uaccess.h>
40 #include <linux/module.h>
41 #include <sound/core.h>
42 #include <sound/initval.h>
43 #include <sound/compress_params.h>
44 #include <sound/compress_offload.h>
45 #include <sound/compress_driver.h>
46 
47 /* TODO:
48  * - add substream support for multiple devices in case of
49  *	SND_DYNAMIC_MINORS is not used
50  * - Multiple node representation
51  *	driver should be able to register multiple nodes
52  */
53 
54 static DEFINE_MUTEX(device_mutex);
55 
56 struct snd_compr_file {
57 	unsigned long caps;
58 	struct snd_compr_stream stream;
59 };
60 
61 /*
62  * a note on stream states used:
63  * we use follwing states in the compressed core
64  * SNDRV_PCM_STATE_OPEN: When stream has been opened.
65  * SNDRV_PCM_STATE_SETUP: When stream has been initialized. This is done by
66  *	calling SNDRV_COMPRESS_SET_PARAMS. running streams will come to this
67  *	state at stop by calling SNDRV_COMPRESS_STOP, or at end of drain.
68  * SNDRV_PCM_STATE_RUNNING: When stream has been started and is
69  *	decoding/encoding and rendering/capturing data.
70  * SNDRV_PCM_STATE_DRAINING: When stream is draining current data. This is done
71  *	by calling SNDRV_COMPRESS_DRAIN.
72  * SNDRV_PCM_STATE_PAUSED: When stream is paused. This is done by calling
73  *	SNDRV_COMPRESS_PAUSE. It can be stopped or resumed by calling
74  *	SNDRV_COMPRESS_STOP or SNDRV_COMPRESS_RESUME respectively.
75  */
76 static int snd_compr_open(struct inode *inode, struct file *f)
77 {
78 	struct snd_compr *compr;
79 	struct snd_compr_file *data;
80 	struct snd_compr_runtime *runtime;
81 	enum snd_compr_direction dirn;
82 	int maj = imajor(inode);
83 	int ret;
84 
85 	if ((f->f_flags & O_ACCMODE) == O_WRONLY)
86 		dirn = SND_COMPRESS_PLAYBACK;
87 	else if ((f->f_flags & O_ACCMODE) == O_RDONLY)
88 		dirn = SND_COMPRESS_CAPTURE;
89 	else
90 		return -EINVAL;
91 
92 	if (maj == snd_major)
93 		compr = snd_lookup_minor_data(iminor(inode),
94 					SNDRV_DEVICE_TYPE_COMPRESS);
95 	else
96 		return -EBADFD;
97 
98 	if (compr == NULL) {
99 		pr_err("no device data!!!\n");
100 		return -ENODEV;
101 	}
102 
103 	if (dirn != compr->direction) {
104 		pr_err("this device doesn't support this direction\n");
105 		snd_card_unref(compr->card);
106 		return -EINVAL;
107 	}
108 
109 	data = kzalloc(sizeof(*data), GFP_KERNEL);
110 	if (!data) {
111 		snd_card_unref(compr->card);
112 		return -ENOMEM;
113 	}
114 	data->stream.ops = compr->ops;
115 	data->stream.direction = dirn;
116 	data->stream.private_data = compr->private_data;
117 	data->stream.device = compr;
118 	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
119 	if (!runtime) {
120 		kfree(data);
121 		snd_card_unref(compr->card);
122 		return -ENOMEM;
123 	}
124 	runtime->state = SNDRV_PCM_STATE_OPEN;
125 	init_waitqueue_head(&runtime->sleep);
126 	data->stream.runtime = runtime;
127 	f->private_data = (void *)data;
128 	mutex_lock(&compr->lock);
129 	ret = compr->ops->open(&data->stream);
130 	mutex_unlock(&compr->lock);
131 	if (ret) {
132 		kfree(runtime);
133 		kfree(data);
134 	}
135 	snd_card_unref(compr->card);
136 	return 0;
137 }
138 
139 static int snd_compr_free(struct inode *inode, struct file *f)
140 {
141 	struct snd_compr_file *data = f->private_data;
142 	struct snd_compr_runtime *runtime = data->stream.runtime;
143 
144 	switch (runtime->state) {
145 	case SNDRV_PCM_STATE_RUNNING:
146 	case SNDRV_PCM_STATE_DRAINING:
147 	case SNDRV_PCM_STATE_PAUSED:
148 		data->stream.ops->trigger(&data->stream, SNDRV_PCM_TRIGGER_STOP);
149 		break;
150 	default:
151 		break;
152 	}
153 
154 	data->stream.ops->free(&data->stream);
155 	kfree(data->stream.runtime->buffer);
156 	kfree(data->stream.runtime);
157 	kfree(data);
158 	return 0;
159 }
160 
161 static int snd_compr_update_tstamp(struct snd_compr_stream *stream,
162 		struct snd_compr_tstamp *tstamp)
163 {
164 	if (!stream->ops->pointer)
165 		return -ENOTSUPP;
166 	stream->ops->pointer(stream, tstamp);
167 	pr_debug("dsp consumed till %d total %d bytes\n",
168 		tstamp->byte_offset, tstamp->copied_total);
169 	if (stream->direction == SND_COMPRESS_PLAYBACK)
170 		stream->runtime->total_bytes_transferred = tstamp->copied_total;
171 	else
172 		stream->runtime->total_bytes_available = tstamp->copied_total;
173 	return 0;
174 }
175 
176 static size_t snd_compr_calc_avail(struct snd_compr_stream *stream,
177 		struct snd_compr_avail *avail)
178 {
179 	memset(avail, 0, sizeof(*avail));
180 	snd_compr_update_tstamp(stream, &avail->tstamp);
181 	/* Still need to return avail even if tstamp can't be filled in */
182 
183 	if (stream->runtime->total_bytes_available == 0 &&
184 			stream->runtime->state == SNDRV_PCM_STATE_SETUP &&
185 			stream->direction == SND_COMPRESS_PLAYBACK) {
186 		pr_debug("detected init and someone forgot to do a write\n");
187 		return stream->runtime->buffer_size;
188 	}
189 	pr_debug("app wrote %lld, DSP consumed %lld\n",
190 			stream->runtime->total_bytes_available,
191 			stream->runtime->total_bytes_transferred);
192 	if (stream->runtime->total_bytes_available ==
193 				stream->runtime->total_bytes_transferred) {
194 		if (stream->direction == SND_COMPRESS_PLAYBACK) {
195 			pr_debug("both pointers are same, returning full avail\n");
196 			return stream->runtime->buffer_size;
197 		} else {
198 			pr_debug("both pointers are same, returning no avail\n");
199 			return 0;
200 		}
201 	}
202 
203 	avail->avail = stream->runtime->total_bytes_available -
204 			stream->runtime->total_bytes_transferred;
205 	if (stream->direction == SND_COMPRESS_PLAYBACK)
206 		avail->avail = stream->runtime->buffer_size - avail->avail;
207 
208 	pr_debug("ret avail as %lld\n", avail->avail);
209 	return avail->avail;
210 }
211 
212 static inline size_t snd_compr_get_avail(struct snd_compr_stream *stream)
213 {
214 	struct snd_compr_avail avail;
215 
216 	return snd_compr_calc_avail(stream, &avail);
217 }
218 
219 static int
220 snd_compr_ioctl_avail(struct snd_compr_stream *stream, unsigned long arg)
221 {
222 	struct snd_compr_avail ioctl_avail;
223 	size_t avail;
224 
225 	avail = snd_compr_calc_avail(stream, &ioctl_avail);
226 	ioctl_avail.avail = avail;
227 
228 	if (copy_to_user((__u64 __user *)arg,
229 				&ioctl_avail, sizeof(ioctl_avail)))
230 		return -EFAULT;
231 	return 0;
232 }
233 
234 static int snd_compr_write_data(struct snd_compr_stream *stream,
235 	       const char __user *buf, size_t count)
236 {
237 	void *dstn;
238 	size_t copy;
239 	struct snd_compr_runtime *runtime = stream->runtime;
240 	/* 64-bit Modulus */
241 	u64 app_pointer = div64_u64(runtime->total_bytes_available,
242 				    runtime->buffer_size);
243 	app_pointer = runtime->total_bytes_available -
244 		      (app_pointer * runtime->buffer_size);
245 
246 	dstn = runtime->buffer + app_pointer;
247 	pr_debug("copying %ld at %lld\n",
248 			(unsigned long)count, app_pointer);
249 	if (count < runtime->buffer_size - app_pointer) {
250 		if (copy_from_user(dstn, buf, count))
251 			return -EFAULT;
252 	} else {
253 		copy = runtime->buffer_size - app_pointer;
254 		if (copy_from_user(dstn, buf, copy))
255 			return -EFAULT;
256 		if (copy_from_user(runtime->buffer, buf + copy, count - copy))
257 			return -EFAULT;
258 	}
259 	/* if DSP cares, let it know data has been written */
260 	if (stream->ops->ack)
261 		stream->ops->ack(stream, count);
262 	return count;
263 }
264 
265 static ssize_t snd_compr_write(struct file *f, const char __user *buf,
266 		size_t count, loff_t *offset)
267 {
268 	struct snd_compr_file *data = f->private_data;
269 	struct snd_compr_stream *stream;
270 	size_t avail;
271 	int retval;
272 
273 	if (snd_BUG_ON(!data))
274 		return -EFAULT;
275 
276 	stream = &data->stream;
277 	mutex_lock(&stream->device->lock);
278 	/* write is allowed when stream is running or has been steup */
279 	if (stream->runtime->state != SNDRV_PCM_STATE_SETUP &&
280 			stream->runtime->state != SNDRV_PCM_STATE_RUNNING) {
281 		mutex_unlock(&stream->device->lock);
282 		return -EBADFD;
283 	}
284 
285 	avail = snd_compr_get_avail(stream);
286 	pr_debug("avail returned %ld\n", (unsigned long)avail);
287 	/* calculate how much we can write to buffer */
288 	if (avail > count)
289 		avail = count;
290 
291 	if (stream->ops->copy) {
292 		char __user* cbuf = (char __user*)buf;
293 		retval = stream->ops->copy(stream, cbuf, avail);
294 	} else {
295 		retval = snd_compr_write_data(stream, buf, avail);
296 	}
297 	if (retval > 0)
298 		stream->runtime->total_bytes_available += retval;
299 
300 	/* while initiating the stream, write should be called before START
301 	 * call, so in setup move state */
302 	if (stream->runtime->state == SNDRV_PCM_STATE_SETUP) {
303 		stream->runtime->state = SNDRV_PCM_STATE_PREPARED;
304 		pr_debug("stream prepared, Houston we are good to go\n");
305 	}
306 
307 	mutex_unlock(&stream->device->lock);
308 	return retval;
309 }
310 
311 
312 static ssize_t snd_compr_read(struct file *f, char __user *buf,
313 		size_t count, loff_t *offset)
314 {
315 	struct snd_compr_file *data = f->private_data;
316 	struct snd_compr_stream *stream;
317 	size_t avail;
318 	int retval;
319 
320 	if (snd_BUG_ON(!data))
321 		return -EFAULT;
322 
323 	stream = &data->stream;
324 	mutex_lock(&stream->device->lock);
325 
326 	/* read is allowed when stream is running, paused, draining and setup
327 	 * (yes setup is state which we transition to after stop, so if user
328 	 * wants to read data after stop we allow that)
329 	 */
330 	switch (stream->runtime->state) {
331 	case SNDRV_PCM_STATE_OPEN:
332 	case SNDRV_PCM_STATE_PREPARED:
333 	case SNDRV_PCM_STATE_XRUN:
334 	case SNDRV_PCM_STATE_SUSPENDED:
335 	case SNDRV_PCM_STATE_DISCONNECTED:
336 		retval = -EBADFD;
337 		goto out;
338 	}
339 
340 	avail = snd_compr_get_avail(stream);
341 	pr_debug("avail returned %ld\n", (unsigned long)avail);
342 	/* calculate how much we can read from buffer */
343 	if (avail > count)
344 		avail = count;
345 
346 	if (stream->ops->copy) {
347 		retval = stream->ops->copy(stream, buf, avail);
348 	} else {
349 		retval = -ENXIO;
350 		goto out;
351 	}
352 	if (retval > 0)
353 		stream->runtime->total_bytes_transferred += retval;
354 
355 out:
356 	mutex_unlock(&stream->device->lock);
357 	return retval;
358 }
359 
360 static int snd_compr_mmap(struct file *f, struct vm_area_struct *vma)
361 {
362 	return -ENXIO;
363 }
364 
365 static inline int snd_compr_get_poll(struct snd_compr_stream *stream)
366 {
367 	if (stream->direction == SND_COMPRESS_PLAYBACK)
368 		return POLLOUT | POLLWRNORM;
369 	else
370 		return POLLIN | POLLRDNORM;
371 }
372 
373 static unsigned int snd_compr_poll(struct file *f, poll_table *wait)
374 {
375 	struct snd_compr_file *data = f->private_data;
376 	struct snd_compr_stream *stream;
377 	size_t avail;
378 	int retval = 0;
379 
380 	if (snd_BUG_ON(!data))
381 		return -EFAULT;
382 	stream = &data->stream;
383 	if (snd_BUG_ON(!stream))
384 		return -EFAULT;
385 
386 	mutex_lock(&stream->device->lock);
387 	if (stream->runtime->state == SNDRV_PCM_STATE_PAUSED ||
388 			stream->runtime->state == SNDRV_PCM_STATE_OPEN) {
389 		retval = -EBADFD;
390 		goto out;
391 	}
392 	poll_wait(f, &stream->runtime->sleep, wait);
393 
394 	avail = snd_compr_get_avail(stream);
395 	pr_debug("avail is %ld\n", (unsigned long)avail);
396 	/* check if we have at least one fragment to fill */
397 	switch (stream->runtime->state) {
398 	case SNDRV_PCM_STATE_DRAINING:
399 		/* stream has been woken up after drain is complete
400 		 * draining done so set stream state to stopped
401 		 */
402 		retval = snd_compr_get_poll(stream);
403 		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
404 		break;
405 	case SNDRV_PCM_STATE_RUNNING:
406 	case SNDRV_PCM_STATE_PREPARED:
407 	case SNDRV_PCM_STATE_PAUSED:
408 		if (avail >= stream->runtime->fragment_size)
409 			retval = snd_compr_get_poll(stream);
410 		break;
411 	default:
412 		if (stream->direction == SND_COMPRESS_PLAYBACK)
413 			retval = POLLOUT | POLLWRNORM | POLLERR;
414 		else
415 			retval = POLLIN | POLLRDNORM | POLLERR;
416 		break;
417 	}
418 out:
419 	mutex_unlock(&stream->device->lock);
420 	return retval;
421 }
422 
423 static int
424 snd_compr_get_caps(struct snd_compr_stream *stream, unsigned long arg)
425 {
426 	int retval;
427 	struct snd_compr_caps caps;
428 
429 	if (!stream->ops->get_caps)
430 		return -ENXIO;
431 
432 	memset(&caps, 0, sizeof(caps));
433 	retval = stream->ops->get_caps(stream, &caps);
434 	if (retval)
435 		goto out;
436 	if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
437 		retval = -EFAULT;
438 out:
439 	return retval;
440 }
441 
442 static int
443 snd_compr_get_codec_caps(struct snd_compr_stream *stream, unsigned long arg)
444 {
445 	int retval;
446 	struct snd_compr_codec_caps *caps;
447 
448 	if (!stream->ops->get_codec_caps)
449 		return -ENXIO;
450 
451 	caps = kzalloc(sizeof(*caps), GFP_KERNEL);
452 	if (!caps)
453 		return -ENOMEM;
454 
455 	retval = stream->ops->get_codec_caps(stream, caps);
456 	if (retval)
457 		goto out;
458 	if (copy_to_user((void __user *)arg, caps, sizeof(*caps)))
459 		retval = -EFAULT;
460 
461 out:
462 	kfree(caps);
463 	return retval;
464 }
465 
466 /* revisit this with snd_pcm_preallocate_xxx */
467 static int snd_compr_allocate_buffer(struct snd_compr_stream *stream,
468 		struct snd_compr_params *params)
469 {
470 	unsigned int buffer_size;
471 	void *buffer;
472 
473 	buffer_size = params->buffer.fragment_size * params->buffer.fragments;
474 	if (stream->ops->copy) {
475 		buffer = NULL;
476 		/* if copy is defined the driver will be required to copy
477 		 * the data from core
478 		 */
479 	} else {
480 		buffer = kmalloc(buffer_size, GFP_KERNEL);
481 		if (!buffer)
482 			return -ENOMEM;
483 	}
484 	stream->runtime->fragment_size = params->buffer.fragment_size;
485 	stream->runtime->fragments = params->buffer.fragments;
486 	stream->runtime->buffer = buffer;
487 	stream->runtime->buffer_size = buffer_size;
488 	return 0;
489 }
490 
491 static int snd_compress_check_input(struct snd_compr_params *params)
492 {
493 	/* first let's check the buffer parameter's */
494 	if (params->buffer.fragment_size == 0 ||
495 			params->buffer.fragments > SIZE_MAX / params->buffer.fragment_size)
496 		return -EINVAL;
497 
498 	/* now codec parameters */
499 	if (params->codec.id == 0 || params->codec.id > SND_AUDIOCODEC_MAX)
500 		return -EINVAL;
501 
502 	if (params->codec.ch_in == 0 || params->codec.ch_out == 0)
503 		return -EINVAL;
504 
505 	if (!(params->codec.sample_rate & SNDRV_PCM_RATE_8000_192000))
506 		return -EINVAL;
507 
508 	return 0;
509 }
510 
511 static int
512 snd_compr_set_params(struct snd_compr_stream *stream, unsigned long arg)
513 {
514 	struct snd_compr_params *params;
515 	int retval;
516 
517 	if (stream->runtime->state == SNDRV_PCM_STATE_OPEN) {
518 		/*
519 		 * we should allow parameter change only when stream has been
520 		 * opened not in other cases
521 		 */
522 		params = kmalloc(sizeof(*params), GFP_KERNEL);
523 		if (!params)
524 			return -ENOMEM;
525 		if (copy_from_user(params, (void __user *)arg, sizeof(*params))) {
526 			retval = -EFAULT;
527 			goto out;
528 		}
529 
530 		retval = snd_compress_check_input(params);
531 		if (retval)
532 			goto out;
533 
534 		retval = snd_compr_allocate_buffer(stream, params);
535 		if (retval) {
536 			retval = -ENOMEM;
537 			goto out;
538 		}
539 
540 		retval = stream->ops->set_params(stream, params);
541 		if (retval)
542 			goto out;
543 
544 		stream->metadata_set = false;
545 		stream->next_track = false;
546 
547 		if (stream->direction == SND_COMPRESS_PLAYBACK)
548 			stream->runtime->state = SNDRV_PCM_STATE_SETUP;
549 		else
550 			stream->runtime->state = SNDRV_PCM_STATE_PREPARED;
551 	} else {
552 		return -EPERM;
553 	}
554 out:
555 	kfree(params);
556 	return retval;
557 }
558 
559 static int
560 snd_compr_get_params(struct snd_compr_stream *stream, unsigned long arg)
561 {
562 	struct snd_codec *params;
563 	int retval;
564 
565 	if (!stream->ops->get_params)
566 		return -EBADFD;
567 
568 	params = kzalloc(sizeof(*params), GFP_KERNEL);
569 	if (!params)
570 		return -ENOMEM;
571 	retval = stream->ops->get_params(stream, params);
572 	if (retval)
573 		goto out;
574 	if (copy_to_user((char __user *)arg, params, sizeof(*params)))
575 		retval = -EFAULT;
576 
577 out:
578 	kfree(params);
579 	return retval;
580 }
581 
582 static int
583 snd_compr_get_metadata(struct snd_compr_stream *stream, unsigned long arg)
584 {
585 	struct snd_compr_metadata metadata;
586 	int retval;
587 
588 	if (!stream->ops->get_metadata)
589 		return -ENXIO;
590 
591 	if (copy_from_user(&metadata, (void __user *)arg, sizeof(metadata)))
592 		return -EFAULT;
593 
594 	retval = stream->ops->get_metadata(stream, &metadata);
595 	if (retval != 0)
596 		return retval;
597 
598 	if (copy_to_user((void __user *)arg, &metadata, sizeof(metadata)))
599 		return -EFAULT;
600 
601 	return 0;
602 }
603 
604 static int
605 snd_compr_set_metadata(struct snd_compr_stream *stream, unsigned long arg)
606 {
607 	struct snd_compr_metadata metadata;
608 	int retval;
609 
610 	if (!stream->ops->set_metadata)
611 		return -ENXIO;
612 	/*
613 	* we should allow parameter change only when stream has been
614 	* opened not in other cases
615 	*/
616 	if (copy_from_user(&metadata, (void __user *)arg, sizeof(metadata)))
617 		return -EFAULT;
618 
619 	retval = stream->ops->set_metadata(stream, &metadata);
620 	stream->metadata_set = true;
621 
622 	return retval;
623 }
624 
625 static inline int
626 snd_compr_tstamp(struct snd_compr_stream *stream, unsigned long arg)
627 {
628 	struct snd_compr_tstamp tstamp = {0};
629 	int ret;
630 
631 	ret = snd_compr_update_tstamp(stream, &tstamp);
632 	if (ret == 0)
633 		ret = copy_to_user((struct snd_compr_tstamp __user *)arg,
634 			&tstamp, sizeof(tstamp)) ? -EFAULT : 0;
635 	return ret;
636 }
637 
638 static int snd_compr_pause(struct snd_compr_stream *stream)
639 {
640 	int retval;
641 
642 	if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING)
643 		return -EPERM;
644 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_PUSH);
645 	if (!retval)
646 		stream->runtime->state = SNDRV_PCM_STATE_PAUSED;
647 	return retval;
648 }
649 
650 static int snd_compr_resume(struct snd_compr_stream *stream)
651 {
652 	int retval;
653 
654 	if (stream->runtime->state != SNDRV_PCM_STATE_PAUSED)
655 		return -EPERM;
656 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_RELEASE);
657 	if (!retval)
658 		stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
659 	return retval;
660 }
661 
662 static int snd_compr_start(struct snd_compr_stream *stream)
663 {
664 	int retval;
665 
666 	if (stream->runtime->state != SNDRV_PCM_STATE_PREPARED)
667 		return -EPERM;
668 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_START);
669 	if (!retval)
670 		stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
671 	return retval;
672 }
673 
674 static int snd_compr_stop(struct snd_compr_stream *stream)
675 {
676 	int retval;
677 
678 	if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
679 			stream->runtime->state == SNDRV_PCM_STATE_SETUP)
680 		return -EPERM;
681 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_STOP);
682 	if (!retval) {
683 		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
684 		wake_up(&stream->runtime->sleep);
685 		stream->runtime->total_bytes_available = 0;
686 		stream->runtime->total_bytes_transferred = 0;
687 	}
688 	return retval;
689 }
690 
691 static int snd_compr_drain(struct snd_compr_stream *stream)
692 {
693 	int retval;
694 
695 	if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
696 			stream->runtime->state == SNDRV_PCM_STATE_SETUP)
697 		return -EPERM;
698 	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_DRAIN);
699 	if (!retval) {
700 		stream->runtime->state = SNDRV_PCM_STATE_DRAINING;
701 		wake_up(&stream->runtime->sleep);
702 	}
703 	return retval;
704 }
705 
706 static int snd_compr_next_track(struct snd_compr_stream *stream)
707 {
708 	int retval;
709 
710 	/* only a running stream can transition to next track */
711 	if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING)
712 		return -EPERM;
713 
714 	/* you can signal next track isf this is intended to be a gapless stream
715 	 * and current track metadata is set
716 	 */
717 	if (stream->metadata_set == false)
718 		return -EPERM;
719 
720 	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_NEXT_TRACK);
721 	if (retval != 0)
722 		return retval;
723 	stream->metadata_set = false;
724 	stream->next_track = true;
725 	return 0;
726 }
727 
728 static int snd_compr_partial_drain(struct snd_compr_stream *stream)
729 {
730 	int retval;
731 	if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
732 			stream->runtime->state == SNDRV_PCM_STATE_SETUP)
733 		return -EPERM;
734 	/* stream can be drained only when next track has been signalled */
735 	if (stream->next_track == false)
736 		return -EPERM;
737 
738 	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_PARTIAL_DRAIN);
739 
740 	stream->next_track = false;
741 	return retval;
742 }
743 
744 static long snd_compr_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
745 {
746 	struct snd_compr_file *data = f->private_data;
747 	struct snd_compr_stream *stream;
748 	int retval = -ENOTTY;
749 
750 	if (snd_BUG_ON(!data))
751 		return -EFAULT;
752 	stream = &data->stream;
753 	if (snd_BUG_ON(!stream))
754 		return -EFAULT;
755 	mutex_lock(&stream->device->lock);
756 	switch (_IOC_NR(cmd)) {
757 	case _IOC_NR(SNDRV_COMPRESS_IOCTL_VERSION):
758 		retval = put_user(SNDRV_COMPRESS_VERSION,
759 				(int __user *)arg) ? -EFAULT : 0;
760 		break;
761 	case _IOC_NR(SNDRV_COMPRESS_GET_CAPS):
762 		retval = snd_compr_get_caps(stream, arg);
763 		break;
764 	case _IOC_NR(SNDRV_COMPRESS_GET_CODEC_CAPS):
765 		retval = snd_compr_get_codec_caps(stream, arg);
766 		break;
767 	case _IOC_NR(SNDRV_COMPRESS_SET_PARAMS):
768 		retval = snd_compr_set_params(stream, arg);
769 		break;
770 	case _IOC_NR(SNDRV_COMPRESS_GET_PARAMS):
771 		retval = snd_compr_get_params(stream, arg);
772 		break;
773 	case _IOC_NR(SNDRV_COMPRESS_SET_METADATA):
774 		retval = snd_compr_set_metadata(stream, arg);
775 		break;
776 	case _IOC_NR(SNDRV_COMPRESS_GET_METADATA):
777 		retval = snd_compr_get_metadata(stream, arg);
778 		break;
779 	case _IOC_NR(SNDRV_COMPRESS_TSTAMP):
780 		retval = snd_compr_tstamp(stream, arg);
781 		break;
782 	case _IOC_NR(SNDRV_COMPRESS_AVAIL):
783 		retval = snd_compr_ioctl_avail(stream, arg);
784 		break;
785 	case _IOC_NR(SNDRV_COMPRESS_PAUSE):
786 		retval = snd_compr_pause(stream);
787 		break;
788 	case _IOC_NR(SNDRV_COMPRESS_RESUME):
789 		retval = snd_compr_resume(stream);
790 		break;
791 	case _IOC_NR(SNDRV_COMPRESS_START):
792 		retval = snd_compr_start(stream);
793 		break;
794 	case _IOC_NR(SNDRV_COMPRESS_STOP):
795 		retval = snd_compr_stop(stream);
796 		break;
797 	case _IOC_NR(SNDRV_COMPRESS_DRAIN):
798 		retval = snd_compr_drain(stream);
799 		break;
800 	case _IOC_NR(SNDRV_COMPRESS_PARTIAL_DRAIN):
801 		retval = snd_compr_partial_drain(stream);
802 		break;
803 	case _IOC_NR(SNDRV_COMPRESS_NEXT_TRACK):
804 		retval = snd_compr_next_track(stream);
805 		break;
806 
807 	}
808 	mutex_unlock(&stream->device->lock);
809 	return retval;
810 }
811 
812 static const struct file_operations snd_compr_file_ops = {
813 		.owner =	THIS_MODULE,
814 		.open =		snd_compr_open,
815 		.release =	snd_compr_free,
816 		.write =	snd_compr_write,
817 		.read =		snd_compr_read,
818 		.unlocked_ioctl = snd_compr_ioctl,
819 		.mmap =		snd_compr_mmap,
820 		.poll =		snd_compr_poll,
821 };
822 
823 static int snd_compress_dev_register(struct snd_device *device)
824 {
825 	int ret = -EINVAL;
826 	char str[16];
827 	struct snd_compr *compr;
828 
829 	if (snd_BUG_ON(!device || !device->device_data))
830 		return -EBADFD;
831 	compr = device->device_data;
832 
833 	sprintf(str, "comprC%iD%i", compr->card->number, compr->device);
834 	pr_debug("reg %s for device %s, direction %d\n", str, compr->name,
835 			compr->direction);
836 	/* register compressed device */
837 	ret = snd_register_device(SNDRV_DEVICE_TYPE_COMPRESS, compr->card,
838 			compr->device, &snd_compr_file_ops, compr, str);
839 	if (ret < 0) {
840 		pr_err("snd_register_device failed\n %d", ret);
841 		return ret;
842 	}
843 	return ret;
844 
845 }
846 
847 static int snd_compress_dev_disconnect(struct snd_device *device)
848 {
849 	struct snd_compr *compr;
850 
851 	compr = device->device_data;
852 	snd_unregister_device(SNDRV_DEVICE_TYPE_COMPRESS, compr->card,
853 		compr->device);
854 	return 0;
855 }
856 
857 /*
858  * snd_compress_new: create new compress device
859  * @card: sound card pointer
860  * @device: device number
861  * @dirn: device direction, should be of type enum snd_compr_direction
862  * @compr: compress device pointer
863  */
864 int snd_compress_new(struct snd_card *card, int device,
865 			int dirn, struct snd_compr *compr)
866 {
867 	static struct snd_device_ops ops = {
868 		.dev_free = NULL,
869 		.dev_register = snd_compress_dev_register,
870 		.dev_disconnect = snd_compress_dev_disconnect,
871 	};
872 
873 	compr->card = card;
874 	compr->device = device;
875 	compr->direction = dirn;
876 	return snd_device_new(card, SNDRV_DEV_COMPRESS, compr, &ops);
877 }
878 EXPORT_SYMBOL_GPL(snd_compress_new);
879 
880 static int snd_compress_add_device(struct snd_compr *device)
881 {
882 	int ret;
883 
884 	if (!device->card)
885 		return -EINVAL;
886 
887 	/* register the card */
888 	ret = snd_card_register(device->card);
889 	if (ret)
890 		goto out;
891 	return 0;
892 
893 out:
894 	pr_err("failed with %d\n", ret);
895 	return ret;
896 
897 }
898 
899 static int snd_compress_remove_device(struct snd_compr *device)
900 {
901 	return snd_card_free(device->card);
902 }
903 
904 /**
905  * snd_compress_register - register compressed device
906  *
907  * @device: compressed device to register
908  */
909 int snd_compress_register(struct snd_compr *device)
910 {
911 	int retval;
912 
913 	if (device->name == NULL || device->dev == NULL || device->ops == NULL)
914 		return -EINVAL;
915 
916 	pr_debug("Registering compressed device %s\n", device->name);
917 	if (snd_BUG_ON(!device->ops->open))
918 		return -EINVAL;
919 	if (snd_BUG_ON(!device->ops->free))
920 		return -EINVAL;
921 	if (snd_BUG_ON(!device->ops->set_params))
922 		return -EINVAL;
923 	if (snd_BUG_ON(!device->ops->trigger))
924 		return -EINVAL;
925 
926 	mutex_init(&device->lock);
927 
928 	/* register a compressed card */
929 	mutex_lock(&device_mutex);
930 	retval = snd_compress_add_device(device);
931 	mutex_unlock(&device_mutex);
932 	return retval;
933 }
934 EXPORT_SYMBOL_GPL(snd_compress_register);
935 
936 int snd_compress_deregister(struct snd_compr *device)
937 {
938 	pr_debug("Removing compressed device %s\n", device->name);
939 	mutex_lock(&device_mutex);
940 	snd_compress_remove_device(device);
941 	mutex_unlock(&device_mutex);
942 	return 0;
943 }
944 EXPORT_SYMBOL_GPL(snd_compress_deregister);
945 
946 static int __init snd_compress_init(void)
947 {
948 	return 0;
949 }
950 
951 static void __exit snd_compress_exit(void)
952 {
953 }
954 
955 module_init(snd_compress_init);
956 module_exit(snd_compress_exit);
957 
958 MODULE_DESCRIPTION("ALSA Compressed offload framework");
959 MODULE_AUTHOR("Vinod Koul <vinod.koul@linux.intel.com>");
960 MODULE_LICENSE("GPL v2");
961