xref: /openbmc/linux/sound/core/compress_offload.c (revision ee89bd6b)
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 	data->stream.ops->free(&data->stream);
143 	kfree(data->stream.runtime->buffer);
144 	kfree(data->stream.runtime);
145 	kfree(data);
146 	return 0;
147 }
148 
149 static int snd_compr_update_tstamp(struct snd_compr_stream *stream,
150 		struct snd_compr_tstamp *tstamp)
151 {
152 	if (!stream->ops->pointer)
153 		return -ENOTSUPP;
154 	stream->ops->pointer(stream, tstamp);
155 	pr_debug("dsp consumed till %d total %d bytes\n",
156 		tstamp->byte_offset, tstamp->copied_total);
157 	if (stream->direction == SND_COMPRESS_PLAYBACK)
158 		stream->runtime->total_bytes_transferred = tstamp->copied_total;
159 	else
160 		stream->runtime->total_bytes_available = tstamp->copied_total;
161 	return 0;
162 }
163 
164 static size_t snd_compr_calc_avail(struct snd_compr_stream *stream,
165 		struct snd_compr_avail *avail)
166 {
167 	memset(avail, 0, sizeof(*avail));
168 	snd_compr_update_tstamp(stream, &avail->tstamp);
169 	/* Still need to return avail even if tstamp can't be filled in */
170 
171 	if (stream->runtime->total_bytes_available == 0 &&
172 			stream->runtime->state == SNDRV_PCM_STATE_SETUP &&
173 			stream->direction == SND_COMPRESS_PLAYBACK) {
174 		pr_debug("detected init and someone forgot to do a write\n");
175 		return stream->runtime->buffer_size;
176 	}
177 	pr_debug("app wrote %lld, DSP consumed %lld\n",
178 			stream->runtime->total_bytes_available,
179 			stream->runtime->total_bytes_transferred);
180 	if (stream->runtime->total_bytes_available ==
181 				stream->runtime->total_bytes_transferred) {
182 		if (stream->direction == SND_COMPRESS_PLAYBACK) {
183 			pr_debug("both pointers are same, returning full avail\n");
184 			return stream->runtime->buffer_size;
185 		} else {
186 			pr_debug("both pointers are same, returning no avail\n");
187 			return 0;
188 		}
189 	}
190 
191 	avail->avail = stream->runtime->total_bytes_available -
192 			stream->runtime->total_bytes_transferred;
193 	if (stream->direction == SND_COMPRESS_PLAYBACK)
194 		avail->avail = stream->runtime->buffer_size - avail->avail;
195 
196 	pr_debug("ret avail as %lld\n", avail->avail);
197 	return avail->avail;
198 }
199 
200 static inline size_t snd_compr_get_avail(struct snd_compr_stream *stream)
201 {
202 	struct snd_compr_avail avail;
203 
204 	return snd_compr_calc_avail(stream, &avail);
205 }
206 
207 static int
208 snd_compr_ioctl_avail(struct snd_compr_stream *stream, unsigned long arg)
209 {
210 	struct snd_compr_avail ioctl_avail;
211 	size_t avail;
212 
213 	avail = snd_compr_calc_avail(stream, &ioctl_avail);
214 	ioctl_avail.avail = avail;
215 
216 	if (copy_to_user((__u64 __user *)arg,
217 				&ioctl_avail, sizeof(ioctl_avail)))
218 		return -EFAULT;
219 	return 0;
220 }
221 
222 static int snd_compr_write_data(struct snd_compr_stream *stream,
223 	       const char __user *buf, size_t count)
224 {
225 	void *dstn;
226 	size_t copy;
227 	struct snd_compr_runtime *runtime = stream->runtime;
228 	/* 64-bit Modulus */
229 	u64 app_pointer = div64_u64(runtime->total_bytes_available,
230 				    runtime->buffer_size);
231 	app_pointer = runtime->total_bytes_available -
232 		      (app_pointer * runtime->buffer_size);
233 
234 	dstn = runtime->buffer + app_pointer;
235 	pr_debug("copying %ld at %lld\n",
236 			(unsigned long)count, app_pointer);
237 	if (count < runtime->buffer_size - app_pointer) {
238 		if (copy_from_user(dstn, buf, count))
239 			return -EFAULT;
240 	} else {
241 		copy = runtime->buffer_size - app_pointer;
242 		if (copy_from_user(dstn, buf, copy))
243 			return -EFAULT;
244 		if (copy_from_user(runtime->buffer, buf + copy, count - copy))
245 			return -EFAULT;
246 	}
247 	/* if DSP cares, let it know data has been written */
248 	if (stream->ops->ack)
249 		stream->ops->ack(stream, count);
250 	return count;
251 }
252 
253 static ssize_t snd_compr_write(struct file *f, const char __user *buf,
254 		size_t count, loff_t *offset)
255 {
256 	struct snd_compr_file *data = f->private_data;
257 	struct snd_compr_stream *stream;
258 	size_t avail;
259 	int retval;
260 
261 	if (snd_BUG_ON(!data))
262 		return -EFAULT;
263 
264 	stream = &data->stream;
265 	mutex_lock(&stream->device->lock);
266 	/* write is allowed when stream is running or has been steup */
267 	if (stream->runtime->state != SNDRV_PCM_STATE_SETUP &&
268 			stream->runtime->state != SNDRV_PCM_STATE_RUNNING) {
269 		mutex_unlock(&stream->device->lock);
270 		return -EBADFD;
271 	}
272 
273 	avail = snd_compr_get_avail(stream);
274 	pr_debug("avail returned %ld\n", (unsigned long)avail);
275 	/* calculate how much we can write to buffer */
276 	if (avail > count)
277 		avail = count;
278 
279 	if (stream->ops->copy) {
280 		char __user* cbuf = (char __user*)buf;
281 		retval = stream->ops->copy(stream, cbuf, avail);
282 	} else {
283 		retval = snd_compr_write_data(stream, buf, avail);
284 	}
285 	if (retval > 0)
286 		stream->runtime->total_bytes_available += retval;
287 
288 	/* while initiating the stream, write should be called before START
289 	 * call, so in setup move state */
290 	if (stream->runtime->state == SNDRV_PCM_STATE_SETUP) {
291 		stream->runtime->state = SNDRV_PCM_STATE_PREPARED;
292 		pr_debug("stream prepared, Houston we are good to go\n");
293 	}
294 
295 	mutex_unlock(&stream->device->lock);
296 	return retval;
297 }
298 
299 
300 static ssize_t snd_compr_read(struct file *f, char __user *buf,
301 		size_t count, loff_t *offset)
302 {
303 	struct snd_compr_file *data = f->private_data;
304 	struct snd_compr_stream *stream;
305 	size_t avail;
306 	int retval;
307 
308 	if (snd_BUG_ON(!data))
309 		return -EFAULT;
310 
311 	stream = &data->stream;
312 	mutex_lock(&stream->device->lock);
313 
314 	/* read is allowed when stream is running, paused, draining and setup
315 	 * (yes setup is state which we transition to after stop, so if user
316 	 * wants to read data after stop we allow that)
317 	 */
318 	switch (stream->runtime->state) {
319 	case SNDRV_PCM_STATE_OPEN:
320 	case SNDRV_PCM_STATE_PREPARED:
321 	case SNDRV_PCM_STATE_XRUN:
322 	case SNDRV_PCM_STATE_SUSPENDED:
323 	case SNDRV_PCM_STATE_DISCONNECTED:
324 		retval = -EBADFD;
325 		goto out;
326 	}
327 
328 	avail = snd_compr_get_avail(stream);
329 	pr_debug("avail returned %ld\n", (unsigned long)avail);
330 	/* calculate how much we can read from buffer */
331 	if (avail > count)
332 		avail = count;
333 
334 	if (stream->ops->copy) {
335 		retval = stream->ops->copy(stream, buf, avail);
336 	} else {
337 		retval = -ENXIO;
338 		goto out;
339 	}
340 	if (retval > 0)
341 		stream->runtime->total_bytes_transferred += retval;
342 
343 out:
344 	mutex_unlock(&stream->device->lock);
345 	return retval;
346 }
347 
348 static int snd_compr_mmap(struct file *f, struct vm_area_struct *vma)
349 {
350 	return -ENXIO;
351 }
352 
353 static inline int snd_compr_get_poll(struct snd_compr_stream *stream)
354 {
355 	if (stream->direction == SND_COMPRESS_PLAYBACK)
356 		return POLLOUT | POLLWRNORM;
357 	else
358 		return POLLIN | POLLRDNORM;
359 }
360 
361 static unsigned int snd_compr_poll(struct file *f, poll_table *wait)
362 {
363 	struct snd_compr_file *data = f->private_data;
364 	struct snd_compr_stream *stream;
365 	size_t avail;
366 	int retval = 0;
367 
368 	if (snd_BUG_ON(!data))
369 		return -EFAULT;
370 	stream = &data->stream;
371 	if (snd_BUG_ON(!stream))
372 		return -EFAULT;
373 
374 	mutex_lock(&stream->device->lock);
375 	if (stream->runtime->state == SNDRV_PCM_STATE_PAUSED ||
376 			stream->runtime->state == SNDRV_PCM_STATE_OPEN) {
377 		retval = -EBADFD;
378 		goto out;
379 	}
380 	poll_wait(f, &stream->runtime->sleep, wait);
381 
382 	avail = snd_compr_get_avail(stream);
383 	pr_debug("avail is %ld\n", (unsigned long)avail);
384 	/* check if we have at least one fragment to fill */
385 	switch (stream->runtime->state) {
386 	case SNDRV_PCM_STATE_DRAINING:
387 		/* stream has been woken up after drain is complete
388 		 * draining done so set stream state to stopped
389 		 */
390 		retval = snd_compr_get_poll(stream);
391 		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
392 		break;
393 	case SNDRV_PCM_STATE_RUNNING:
394 	case SNDRV_PCM_STATE_PREPARED:
395 	case SNDRV_PCM_STATE_PAUSED:
396 		if (avail >= stream->runtime->fragment_size)
397 			retval = snd_compr_get_poll(stream);
398 		break;
399 	default:
400 		if (stream->direction == SND_COMPRESS_PLAYBACK)
401 			retval = POLLOUT | POLLWRNORM | POLLERR;
402 		else
403 			retval = POLLIN | POLLRDNORM | POLLERR;
404 		break;
405 	}
406 out:
407 	mutex_unlock(&stream->device->lock);
408 	return retval;
409 }
410 
411 static int
412 snd_compr_get_caps(struct snd_compr_stream *stream, unsigned long arg)
413 {
414 	int retval;
415 	struct snd_compr_caps caps;
416 
417 	if (!stream->ops->get_caps)
418 		return -ENXIO;
419 
420 	memset(&caps, 0, sizeof(caps));
421 	retval = stream->ops->get_caps(stream, &caps);
422 	if (retval)
423 		goto out;
424 	if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
425 		retval = -EFAULT;
426 out:
427 	return retval;
428 }
429 
430 static int
431 snd_compr_get_codec_caps(struct snd_compr_stream *stream, unsigned long arg)
432 {
433 	int retval;
434 	struct snd_compr_codec_caps *caps;
435 
436 	if (!stream->ops->get_codec_caps)
437 		return -ENXIO;
438 
439 	caps = kzalloc(sizeof(*caps), GFP_KERNEL);
440 	if (!caps)
441 		return -ENOMEM;
442 
443 	retval = stream->ops->get_codec_caps(stream, caps);
444 	if (retval)
445 		goto out;
446 	if (copy_to_user((void __user *)arg, caps, sizeof(*caps)))
447 		retval = -EFAULT;
448 
449 out:
450 	kfree(caps);
451 	return retval;
452 }
453 
454 /* revisit this with snd_pcm_preallocate_xxx */
455 static int snd_compr_allocate_buffer(struct snd_compr_stream *stream,
456 		struct snd_compr_params *params)
457 {
458 	unsigned int buffer_size;
459 	void *buffer;
460 
461 	buffer_size = params->buffer.fragment_size * params->buffer.fragments;
462 	if (stream->ops->copy) {
463 		buffer = NULL;
464 		/* if copy is defined the driver will be required to copy
465 		 * the data from core
466 		 */
467 	} else {
468 		buffer = kmalloc(buffer_size, GFP_KERNEL);
469 		if (!buffer)
470 			return -ENOMEM;
471 	}
472 	stream->runtime->fragment_size = params->buffer.fragment_size;
473 	stream->runtime->fragments = params->buffer.fragments;
474 	stream->runtime->buffer = buffer;
475 	stream->runtime->buffer_size = buffer_size;
476 	return 0;
477 }
478 
479 static int snd_compress_check_input(struct snd_compr_params *params)
480 {
481 	/* first let's check the buffer parameter's */
482 	if (params->buffer.fragment_size == 0 ||
483 			params->buffer.fragments > SIZE_MAX / params->buffer.fragment_size)
484 		return -EINVAL;
485 
486 	/* now codec parameters */
487 	if (params->codec.id == 0 || params->codec.id > SND_AUDIOCODEC_MAX)
488 		return -EINVAL;
489 
490 	if (params->codec.ch_in == 0 || params->codec.ch_out == 0)
491 		return -EINVAL;
492 
493 	if (!(params->codec.sample_rate & SNDRV_PCM_RATE_8000_192000))
494 		return -EINVAL;
495 
496 	return 0;
497 }
498 
499 static int
500 snd_compr_set_params(struct snd_compr_stream *stream, unsigned long arg)
501 {
502 	struct snd_compr_params *params;
503 	int retval;
504 
505 	if (stream->runtime->state == SNDRV_PCM_STATE_OPEN) {
506 		/*
507 		 * we should allow parameter change only when stream has been
508 		 * opened not in other cases
509 		 */
510 		params = kmalloc(sizeof(*params), GFP_KERNEL);
511 		if (!params)
512 			return -ENOMEM;
513 		if (copy_from_user(params, (void __user *)arg, sizeof(*params))) {
514 			retval = -EFAULT;
515 			goto out;
516 		}
517 
518 		retval = snd_compress_check_input(params);
519 		if (retval)
520 			goto out;
521 
522 		retval = snd_compr_allocate_buffer(stream, params);
523 		if (retval) {
524 			retval = -ENOMEM;
525 			goto out;
526 		}
527 
528 		retval = stream->ops->set_params(stream, params);
529 		if (retval)
530 			goto out;
531 
532 		stream->metadata_set = false;
533 		stream->next_track = false;
534 
535 		if (stream->direction == SND_COMPRESS_PLAYBACK)
536 			stream->runtime->state = SNDRV_PCM_STATE_SETUP;
537 		else
538 			stream->runtime->state = SNDRV_PCM_STATE_PREPARED;
539 	} else {
540 		return -EPERM;
541 	}
542 out:
543 	kfree(params);
544 	return retval;
545 }
546 
547 static int
548 snd_compr_get_params(struct snd_compr_stream *stream, unsigned long arg)
549 {
550 	struct snd_codec *params;
551 	int retval;
552 
553 	if (!stream->ops->get_params)
554 		return -EBADFD;
555 
556 	params = kzalloc(sizeof(*params), GFP_KERNEL);
557 	if (!params)
558 		return -ENOMEM;
559 	retval = stream->ops->get_params(stream, params);
560 	if (retval)
561 		goto out;
562 	if (copy_to_user((char __user *)arg, params, sizeof(*params)))
563 		retval = -EFAULT;
564 
565 out:
566 	kfree(params);
567 	return retval;
568 }
569 
570 static int
571 snd_compr_get_metadata(struct snd_compr_stream *stream, unsigned long arg)
572 {
573 	struct snd_compr_metadata metadata;
574 	int retval;
575 
576 	if (!stream->ops->get_metadata)
577 		return -ENXIO;
578 
579 	if (copy_from_user(&metadata, (void __user *)arg, sizeof(metadata)))
580 		return -EFAULT;
581 
582 	retval = stream->ops->get_metadata(stream, &metadata);
583 	if (retval != 0)
584 		return retval;
585 
586 	if (copy_to_user((void __user *)arg, &metadata, sizeof(metadata)))
587 		return -EFAULT;
588 
589 	return 0;
590 }
591 
592 static int
593 snd_compr_set_metadata(struct snd_compr_stream *stream, unsigned long arg)
594 {
595 	struct snd_compr_metadata metadata;
596 	int retval;
597 
598 	if (!stream->ops->set_metadata)
599 		return -ENXIO;
600 	/*
601 	* we should allow parameter change only when stream has been
602 	* opened not in other cases
603 	*/
604 	if (copy_from_user(&metadata, (void __user *)arg, sizeof(metadata)))
605 		return -EFAULT;
606 
607 	retval = stream->ops->set_metadata(stream, &metadata);
608 	stream->metadata_set = true;
609 
610 	return retval;
611 }
612 
613 static inline int
614 snd_compr_tstamp(struct snd_compr_stream *stream, unsigned long arg)
615 {
616 	struct snd_compr_tstamp tstamp = {0};
617 	int ret;
618 
619 	ret = snd_compr_update_tstamp(stream, &tstamp);
620 	if (ret == 0)
621 		ret = copy_to_user((struct snd_compr_tstamp __user *)arg,
622 			&tstamp, sizeof(tstamp)) ? -EFAULT : 0;
623 	return ret;
624 }
625 
626 static int snd_compr_pause(struct snd_compr_stream *stream)
627 {
628 	int retval;
629 
630 	if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING)
631 		return -EPERM;
632 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_PUSH);
633 	if (!retval)
634 		stream->runtime->state = SNDRV_PCM_STATE_PAUSED;
635 	return retval;
636 }
637 
638 static int snd_compr_resume(struct snd_compr_stream *stream)
639 {
640 	int retval;
641 
642 	if (stream->runtime->state != SNDRV_PCM_STATE_PAUSED)
643 		return -EPERM;
644 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_RELEASE);
645 	if (!retval)
646 		stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
647 	return retval;
648 }
649 
650 static int snd_compr_start(struct snd_compr_stream *stream)
651 {
652 	int retval;
653 
654 	if (stream->runtime->state != SNDRV_PCM_STATE_PREPARED)
655 		return -EPERM;
656 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_START);
657 	if (!retval)
658 		stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
659 	return retval;
660 }
661 
662 static int snd_compr_stop(struct snd_compr_stream *stream)
663 {
664 	int retval;
665 
666 	if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
667 			stream->runtime->state == SNDRV_PCM_STATE_SETUP)
668 		return -EPERM;
669 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_STOP);
670 	if (!retval) {
671 		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
672 		wake_up(&stream->runtime->sleep);
673 		stream->runtime->total_bytes_available = 0;
674 		stream->runtime->total_bytes_transferred = 0;
675 	}
676 	return retval;
677 }
678 
679 static int snd_compr_drain(struct snd_compr_stream *stream)
680 {
681 	int retval;
682 
683 	if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
684 			stream->runtime->state == SNDRV_PCM_STATE_SETUP)
685 		return -EPERM;
686 	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_DRAIN);
687 	if (!retval) {
688 		stream->runtime->state = SNDRV_PCM_STATE_DRAINING;
689 		wake_up(&stream->runtime->sleep);
690 	}
691 	return retval;
692 }
693 
694 static int snd_compr_next_track(struct snd_compr_stream *stream)
695 {
696 	int retval;
697 
698 	/* only a running stream can transition to next track */
699 	if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING)
700 		return -EPERM;
701 
702 	/* you can signal next track isf this is intended to be a gapless stream
703 	 * and current track metadata is set
704 	 */
705 	if (stream->metadata_set == false)
706 		return -EPERM;
707 
708 	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_NEXT_TRACK);
709 	if (retval != 0)
710 		return retval;
711 	stream->metadata_set = false;
712 	stream->next_track = true;
713 	return 0;
714 }
715 
716 static int snd_compr_partial_drain(struct snd_compr_stream *stream)
717 {
718 	int retval;
719 	if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
720 			stream->runtime->state == SNDRV_PCM_STATE_SETUP)
721 		return -EPERM;
722 	/* stream can be drained only when next track has been signalled */
723 	if (stream->next_track == false)
724 		return -EPERM;
725 
726 	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_PARTIAL_DRAIN);
727 
728 	stream->next_track = false;
729 	return retval;
730 }
731 
732 static long snd_compr_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
733 {
734 	struct snd_compr_file *data = f->private_data;
735 	struct snd_compr_stream *stream;
736 	int retval = -ENOTTY;
737 
738 	if (snd_BUG_ON(!data))
739 		return -EFAULT;
740 	stream = &data->stream;
741 	if (snd_BUG_ON(!stream))
742 		return -EFAULT;
743 	mutex_lock(&stream->device->lock);
744 	switch (_IOC_NR(cmd)) {
745 	case _IOC_NR(SNDRV_COMPRESS_IOCTL_VERSION):
746 		put_user(SNDRV_COMPRESS_VERSION,
747 				(int __user *)arg) ? -EFAULT : 0;
748 		break;
749 	case _IOC_NR(SNDRV_COMPRESS_GET_CAPS):
750 		retval = snd_compr_get_caps(stream, arg);
751 		break;
752 	case _IOC_NR(SNDRV_COMPRESS_GET_CODEC_CAPS):
753 		retval = snd_compr_get_codec_caps(stream, arg);
754 		break;
755 	case _IOC_NR(SNDRV_COMPRESS_SET_PARAMS):
756 		retval = snd_compr_set_params(stream, arg);
757 		break;
758 	case _IOC_NR(SNDRV_COMPRESS_GET_PARAMS):
759 		retval = snd_compr_get_params(stream, arg);
760 		break;
761 	case _IOC_NR(SNDRV_COMPRESS_SET_METADATA):
762 		retval = snd_compr_set_metadata(stream, arg);
763 		break;
764 	case _IOC_NR(SNDRV_COMPRESS_GET_METADATA):
765 		retval = snd_compr_get_metadata(stream, arg);
766 		break;
767 	case _IOC_NR(SNDRV_COMPRESS_TSTAMP):
768 		retval = snd_compr_tstamp(stream, arg);
769 		break;
770 	case _IOC_NR(SNDRV_COMPRESS_AVAIL):
771 		retval = snd_compr_ioctl_avail(stream, arg);
772 		break;
773 	case _IOC_NR(SNDRV_COMPRESS_PAUSE):
774 		retval = snd_compr_pause(stream);
775 		break;
776 	case _IOC_NR(SNDRV_COMPRESS_RESUME):
777 		retval = snd_compr_resume(stream);
778 		break;
779 	case _IOC_NR(SNDRV_COMPRESS_START):
780 		retval = snd_compr_start(stream);
781 		break;
782 	case _IOC_NR(SNDRV_COMPRESS_STOP):
783 		retval = snd_compr_stop(stream);
784 		break;
785 	case _IOC_NR(SNDRV_COMPRESS_DRAIN):
786 		retval = snd_compr_drain(stream);
787 		break;
788 	case _IOC_NR(SNDRV_COMPRESS_PARTIAL_DRAIN):
789 		retval = snd_compr_partial_drain(stream);
790 		break;
791 	case _IOC_NR(SNDRV_COMPRESS_NEXT_TRACK):
792 		retval = snd_compr_next_track(stream);
793 		break;
794 
795 	}
796 	mutex_unlock(&stream->device->lock);
797 	return retval;
798 }
799 
800 static const struct file_operations snd_compr_file_ops = {
801 		.owner =	THIS_MODULE,
802 		.open =		snd_compr_open,
803 		.release =	snd_compr_free,
804 		.write =	snd_compr_write,
805 		.read =		snd_compr_read,
806 		.unlocked_ioctl = snd_compr_ioctl,
807 		.mmap =		snd_compr_mmap,
808 		.poll =		snd_compr_poll,
809 };
810 
811 static int snd_compress_dev_register(struct snd_device *device)
812 {
813 	int ret = -EINVAL;
814 	char str[16];
815 	struct snd_compr *compr;
816 
817 	if (snd_BUG_ON(!device || !device->device_data))
818 		return -EBADFD;
819 	compr = device->device_data;
820 
821 	sprintf(str, "comprC%iD%i", compr->card->number, compr->device);
822 	pr_debug("reg %s for device %s, direction %d\n", str, compr->name,
823 			compr->direction);
824 	/* register compressed device */
825 	ret = snd_register_device(SNDRV_DEVICE_TYPE_COMPRESS, compr->card,
826 			compr->device, &snd_compr_file_ops, compr, str);
827 	if (ret < 0) {
828 		pr_err("snd_register_device failed\n %d", ret);
829 		return ret;
830 	}
831 	return ret;
832 
833 }
834 
835 static int snd_compress_dev_disconnect(struct snd_device *device)
836 {
837 	struct snd_compr *compr;
838 
839 	compr = device->device_data;
840 	snd_unregister_device(compr->direction, compr->card, compr->device);
841 	return 0;
842 }
843 
844 /*
845  * snd_compress_new: create new compress device
846  * @card: sound card pointer
847  * @device: device number
848  * @dirn: device direction, should be of type enum snd_compr_direction
849  * @compr: compress device pointer
850  */
851 int snd_compress_new(struct snd_card *card, int device,
852 			int dirn, struct snd_compr *compr)
853 {
854 	static struct snd_device_ops ops = {
855 		.dev_free = NULL,
856 		.dev_register = snd_compress_dev_register,
857 		.dev_disconnect = snd_compress_dev_disconnect,
858 	};
859 
860 	compr->card = card;
861 	compr->device = device;
862 	compr->direction = dirn;
863 	return snd_device_new(card, SNDRV_DEV_COMPRESS, compr, &ops);
864 }
865 EXPORT_SYMBOL_GPL(snd_compress_new);
866 
867 static int snd_compress_add_device(struct snd_compr *device)
868 {
869 	int ret;
870 
871 	if (!device->card)
872 		return -EINVAL;
873 
874 	/* register the card */
875 	ret = snd_card_register(device->card);
876 	if (ret)
877 		goto out;
878 	return 0;
879 
880 out:
881 	pr_err("failed with %d\n", ret);
882 	return ret;
883 
884 }
885 
886 static int snd_compress_remove_device(struct snd_compr *device)
887 {
888 	return snd_card_free(device->card);
889 }
890 
891 /**
892  * snd_compress_register - register compressed device
893  *
894  * @device: compressed device to register
895  */
896 int snd_compress_register(struct snd_compr *device)
897 {
898 	int retval;
899 
900 	if (device->name == NULL || device->dev == NULL || device->ops == NULL)
901 		return -EINVAL;
902 
903 	pr_debug("Registering compressed device %s\n", device->name);
904 	if (snd_BUG_ON(!device->ops->open))
905 		return -EINVAL;
906 	if (snd_BUG_ON(!device->ops->free))
907 		return -EINVAL;
908 	if (snd_BUG_ON(!device->ops->set_params))
909 		return -EINVAL;
910 	if (snd_BUG_ON(!device->ops->trigger))
911 		return -EINVAL;
912 
913 	mutex_init(&device->lock);
914 
915 	/* register a compressed card */
916 	mutex_lock(&device_mutex);
917 	retval = snd_compress_add_device(device);
918 	mutex_unlock(&device_mutex);
919 	return retval;
920 }
921 EXPORT_SYMBOL_GPL(snd_compress_register);
922 
923 int snd_compress_deregister(struct snd_compr *device)
924 {
925 	pr_debug("Removing compressed device %s\n", device->name);
926 	mutex_lock(&device_mutex);
927 	snd_compress_remove_device(device);
928 	mutex_unlock(&device_mutex);
929 	return 0;
930 }
931 EXPORT_SYMBOL_GPL(snd_compress_deregister);
932 
933 static int __init snd_compress_init(void)
934 {
935 	return 0;
936 }
937 
938 static void __exit snd_compress_exit(void)
939 {
940 }
941 
942 module_init(snd_compress_init);
943 module_exit(snd_compress_exit);
944 
945 MODULE_DESCRIPTION("ALSA Compressed offload framework");
946 MODULE_AUTHOR("Vinod Koul <vinod.koul@linux.intel.com>");
947 MODULE_LICENSE("GPL v2");
948