xref: /openbmc/linux/sound/core/compress_offload.c (revision 97da55fc)
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 int snd_compr_update_tstamp(struct snd_compr_stream *stream,
148 		struct snd_compr_tstamp *tstamp)
149 {
150 	if (!stream->ops->pointer)
151 		return -ENOTSUPP;
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 	return 0;
158 }
159 
160 static size_t snd_compr_calc_avail(struct snd_compr_stream *stream,
161 		struct snd_compr_avail *avail)
162 {
163 	long avail_calc; /*this needs to be signed variable */
164 
165 	memset(avail, 0, sizeof(*avail));
166 	snd_compr_update_tstamp(stream, &avail->tstamp);
167 	/* Still need to return avail even if tstamp can't be filled in */
168 
169 	/* FIXME: This needs to be different for capture stream,
170 	   available is # of compressed data, for playback it's
171 	   remainder of buffer */
172 
173 	if (stream->runtime->total_bytes_available == 0 &&
174 			stream->runtime->state == SNDRV_PCM_STATE_SETUP) {
175 		pr_debug("detected init and someone forgot to do a write\n");
176 		return stream->runtime->buffer_size;
177 	}
178 	pr_debug("app wrote %lld, DSP consumed %lld\n",
179 			stream->runtime->total_bytes_available,
180 			stream->runtime->total_bytes_transferred);
181 	if (stream->runtime->total_bytes_available ==
182 				stream->runtime->total_bytes_transferred) {
183 		pr_debug("both pointers are same, returning full avail\n");
184 		return stream->runtime->buffer_size;
185 	}
186 
187 	/* FIXME: this routine isn't consistent, in one test we use
188 	 * cumulative values and in the other byte offsets. Do we
189 	 * really need the byte offsets if the cumulative values have
190 	 * been updated? In the PCM interface app_ptr and hw_ptr are
191 	 * already cumulative */
192 
193 	avail_calc = stream->runtime->buffer_size -
194 		(stream->runtime->app_pointer - stream->runtime->hw_pointer);
195 	pr_debug("calc avail as %ld, app_ptr %lld, hw+ptr %lld\n", avail_calc,
196 			stream->runtime->app_pointer,
197 			stream->runtime->hw_pointer);
198 	if (avail_calc >= stream->runtime->buffer_size)
199 		avail_calc -= stream->runtime->buffer_size;
200 	pr_debug("ret avail as %ld\n", avail_calc);
201 	avail->avail = avail_calc;
202 	return avail_calc;
203 }
204 
205 static inline size_t snd_compr_get_avail(struct snd_compr_stream *stream)
206 {
207 	struct snd_compr_avail avail;
208 
209 	return snd_compr_calc_avail(stream, &avail);
210 }
211 
212 static int
213 snd_compr_ioctl_avail(struct snd_compr_stream *stream, unsigned long arg)
214 {
215 	struct snd_compr_avail ioctl_avail;
216 	size_t avail;
217 
218 	avail = snd_compr_calc_avail(stream, &ioctl_avail);
219 	ioctl_avail.avail = avail;
220 
221 	if (copy_to_user((__u64 __user *)arg,
222 				&ioctl_avail, sizeof(ioctl_avail)))
223 		return -EFAULT;
224 	return 0;
225 }
226 
227 static int snd_compr_write_data(struct snd_compr_stream *stream,
228 	       const char __user *buf, size_t count)
229 {
230 	void *dstn;
231 	size_t copy;
232 	struct snd_compr_runtime *runtime = stream->runtime;
233 
234 	dstn = runtime->buffer + runtime->app_pointer;
235 	pr_debug("copying %ld at %lld\n",
236 			(unsigned long)count, runtime->app_pointer);
237 	if (count < runtime->buffer_size - runtime->app_pointer) {
238 		if (copy_from_user(dstn, buf, count))
239 			return -EFAULT;
240 		runtime->app_pointer += count;
241 	} else {
242 		copy = runtime->buffer_size - runtime->app_pointer;
243 		if (copy_from_user(dstn, buf, copy))
244 			return -EFAULT;
245 		if (copy_from_user(runtime->buffer, buf + copy, count - copy))
246 			return -EFAULT;
247 		runtime->app_pointer = count - copy;
248 	}
249 	/* if DSP cares, let it know data has been written */
250 	if (stream->ops->ack)
251 		stream->ops->ack(stream, count);
252 	return count;
253 }
254 
255 static ssize_t snd_compr_write(struct file *f, const char __user *buf,
256 		size_t count, loff_t *offset)
257 {
258 	struct snd_compr_file *data = f->private_data;
259 	struct snd_compr_stream *stream;
260 	size_t avail;
261 	int retval;
262 
263 	if (snd_BUG_ON(!data))
264 		return -EFAULT;
265 
266 	stream = &data->stream;
267 	mutex_lock(&stream->device->lock);
268 	/* write is allowed when stream is running or has been steup */
269 	if (stream->runtime->state != SNDRV_PCM_STATE_SETUP &&
270 			stream->runtime->state != SNDRV_PCM_STATE_RUNNING) {
271 		mutex_unlock(&stream->device->lock);
272 		return -EBADFD;
273 	}
274 
275 	avail = snd_compr_get_avail(stream);
276 	pr_debug("avail returned %ld\n", (unsigned long)avail);
277 	/* calculate how much we can write to buffer */
278 	if (avail > count)
279 		avail = count;
280 
281 	if (stream->ops->copy)
282 		retval = stream->ops->copy(stream, buf, avail);
283 	else
284 		retval = snd_compr_write_data(stream, buf, avail);
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 	return -ENXIO;
304 }
305 
306 static int snd_compr_mmap(struct file *f, struct vm_area_struct *vma)
307 {
308 	return -ENXIO;
309 }
310 
311 static inline int snd_compr_get_poll(struct snd_compr_stream *stream)
312 {
313 	if (stream->direction == SND_COMPRESS_PLAYBACK)
314 		return POLLOUT | POLLWRNORM;
315 	else
316 		return POLLIN | POLLRDNORM;
317 }
318 
319 static unsigned int snd_compr_poll(struct file *f, poll_table *wait)
320 {
321 	struct snd_compr_file *data = f->private_data;
322 	struct snd_compr_stream *stream;
323 	size_t avail;
324 	int retval = 0;
325 
326 	if (snd_BUG_ON(!data))
327 		return -EFAULT;
328 	stream = &data->stream;
329 	if (snd_BUG_ON(!stream))
330 		return -EFAULT;
331 
332 	mutex_lock(&stream->device->lock);
333 	if (stream->runtime->state == SNDRV_PCM_STATE_PAUSED ||
334 			stream->runtime->state == SNDRV_PCM_STATE_OPEN) {
335 		retval = -EBADFD;
336 		goto out;
337 	}
338 	poll_wait(f, &stream->runtime->sleep, wait);
339 
340 	avail = snd_compr_get_avail(stream);
341 	pr_debug("avail is %ld\n", (unsigned long)avail);
342 	/* check if we have at least one fragment to fill */
343 	switch (stream->runtime->state) {
344 	case SNDRV_PCM_STATE_DRAINING:
345 		/* stream has been woken up after drain is complete
346 		 * draining done so set stream state to stopped
347 		 */
348 		retval = snd_compr_get_poll(stream);
349 		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
350 		break;
351 	case SNDRV_PCM_STATE_RUNNING:
352 	case SNDRV_PCM_STATE_PREPARED:
353 	case SNDRV_PCM_STATE_PAUSED:
354 		if (avail >= stream->runtime->fragment_size)
355 			retval = snd_compr_get_poll(stream);
356 		break;
357 	default:
358 		if (stream->direction == SND_COMPRESS_PLAYBACK)
359 			retval = POLLOUT | POLLWRNORM | POLLERR;
360 		else
361 			retval = POLLIN | POLLRDNORM | POLLERR;
362 		break;
363 	}
364 out:
365 	mutex_unlock(&stream->device->lock);
366 	return retval;
367 }
368 
369 static int
370 snd_compr_get_caps(struct snd_compr_stream *stream, unsigned long arg)
371 {
372 	int retval;
373 	struct snd_compr_caps caps;
374 
375 	if (!stream->ops->get_caps)
376 		return -ENXIO;
377 
378 	retval = stream->ops->get_caps(stream, &caps);
379 	if (retval)
380 		goto out;
381 	if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
382 		retval = -EFAULT;
383 out:
384 	return retval;
385 }
386 
387 static int
388 snd_compr_get_codec_caps(struct snd_compr_stream *stream, unsigned long arg)
389 {
390 	int retval;
391 	struct snd_compr_codec_caps *caps;
392 
393 	if (!stream->ops->get_codec_caps)
394 		return -ENXIO;
395 
396 	caps = kmalloc(sizeof(*caps), GFP_KERNEL);
397 	if (!caps)
398 		return -ENOMEM;
399 
400 	retval = stream->ops->get_codec_caps(stream, caps);
401 	if (retval)
402 		goto out;
403 	if (copy_to_user((void __user *)arg, caps, sizeof(*caps)))
404 		retval = -EFAULT;
405 
406 out:
407 	kfree(caps);
408 	return retval;
409 }
410 
411 /* revisit this with snd_pcm_preallocate_xxx */
412 static int snd_compr_allocate_buffer(struct snd_compr_stream *stream,
413 		struct snd_compr_params *params)
414 {
415 	unsigned int buffer_size;
416 	void *buffer;
417 
418 	buffer_size = params->buffer.fragment_size * params->buffer.fragments;
419 	if (stream->ops->copy) {
420 		buffer = NULL;
421 		/* if copy is defined the driver will be required to copy
422 		 * the data from core
423 		 */
424 	} else {
425 		buffer = kmalloc(buffer_size, GFP_KERNEL);
426 		if (!buffer)
427 			return -ENOMEM;
428 	}
429 	stream->runtime->fragment_size = params->buffer.fragment_size;
430 	stream->runtime->fragments = params->buffer.fragments;
431 	stream->runtime->buffer = buffer;
432 	stream->runtime->buffer_size = buffer_size;
433 	return 0;
434 }
435 
436 static int snd_compress_check_input(struct snd_compr_params *params)
437 {
438 	/* first let's check the buffer parameter's */
439 	if (params->buffer.fragment_size == 0 ||
440 			params->buffer.fragments > SIZE_MAX / params->buffer.fragment_size)
441 		return -EINVAL;
442 
443 	/* now codec parameters */
444 	if (params->codec.id == 0 || params->codec.id > SND_AUDIOCODEC_MAX)
445 		return -EINVAL;
446 
447 	if (params->codec.ch_in == 0 || params->codec.ch_out == 0)
448 		return -EINVAL;
449 
450 	if (!(params->codec.sample_rate & SNDRV_PCM_RATE_8000_192000))
451 		return -EINVAL;
452 
453 	return 0;
454 }
455 
456 static int
457 snd_compr_set_params(struct snd_compr_stream *stream, unsigned long arg)
458 {
459 	struct snd_compr_params *params;
460 	int retval;
461 
462 	if (stream->runtime->state == SNDRV_PCM_STATE_OPEN) {
463 		/*
464 		 * we should allow parameter change only when stream has been
465 		 * opened not in other cases
466 		 */
467 		params = kmalloc(sizeof(*params), GFP_KERNEL);
468 		if (!params)
469 			return -ENOMEM;
470 		if (copy_from_user(params, (void __user *)arg, sizeof(*params))) {
471 			retval = -EFAULT;
472 			goto out;
473 		}
474 
475 		retval = snd_compress_check_input(params);
476 		if (retval)
477 			goto out;
478 
479 		retval = snd_compr_allocate_buffer(stream, params);
480 		if (retval) {
481 			retval = -ENOMEM;
482 			goto out;
483 		}
484 
485 		retval = stream->ops->set_params(stream, params);
486 		if (retval)
487 			goto out;
488 		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
489 		stream->metadata_set = false;
490 		stream->next_track = false;
491 	} else {
492 		return -EPERM;
493 	}
494 out:
495 	kfree(params);
496 	return retval;
497 }
498 
499 static int
500 snd_compr_get_params(struct snd_compr_stream *stream, unsigned long arg)
501 {
502 	struct snd_codec *params;
503 	int retval;
504 
505 	if (!stream->ops->get_params)
506 		return -EBADFD;
507 
508 	params = kmalloc(sizeof(*params), GFP_KERNEL);
509 	if (!params)
510 		return -ENOMEM;
511 	retval = stream->ops->get_params(stream, params);
512 	if (retval)
513 		goto out;
514 	if (copy_to_user((char __user *)arg, params, sizeof(*params)))
515 		retval = -EFAULT;
516 
517 out:
518 	kfree(params);
519 	return retval;
520 }
521 
522 static int
523 snd_compr_get_metadata(struct snd_compr_stream *stream, unsigned long arg)
524 {
525 	struct snd_compr_metadata metadata;
526 	int retval;
527 
528 	if (!stream->ops->get_metadata)
529 		return -ENXIO;
530 
531 	if (copy_from_user(&metadata, (void __user *)arg, sizeof(metadata)))
532 		return -EFAULT;
533 
534 	retval = stream->ops->get_metadata(stream, &metadata);
535 	if (retval != 0)
536 		return retval;
537 
538 	if (copy_to_user((void __user *)arg, &metadata, sizeof(metadata)))
539 		return -EFAULT;
540 
541 	return 0;
542 }
543 
544 static int
545 snd_compr_set_metadata(struct snd_compr_stream *stream, unsigned long arg)
546 {
547 	struct snd_compr_metadata metadata;
548 	int retval;
549 
550 	if (!stream->ops->set_metadata)
551 		return -ENXIO;
552 	/*
553 	* we should allow parameter change only when stream has been
554 	* opened not in other cases
555 	*/
556 	if (copy_from_user(&metadata, (void __user *)arg, sizeof(metadata)))
557 		return -EFAULT;
558 
559 	retval = stream->ops->set_metadata(stream, &metadata);
560 	stream->metadata_set = true;
561 
562 	return retval;
563 }
564 
565 static inline int
566 snd_compr_tstamp(struct snd_compr_stream *stream, unsigned long arg)
567 {
568 	struct snd_compr_tstamp tstamp = {0};
569 	int ret;
570 
571 	ret = snd_compr_update_tstamp(stream, &tstamp);
572 	if (ret == 0)
573 		ret = copy_to_user((struct snd_compr_tstamp __user *)arg,
574 			&tstamp, sizeof(tstamp)) ? -EFAULT : 0;
575 	return ret;
576 }
577 
578 static int snd_compr_pause(struct snd_compr_stream *stream)
579 {
580 	int retval;
581 
582 	if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING)
583 		return -EPERM;
584 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_PUSH);
585 	if (!retval)
586 		stream->runtime->state = SNDRV_PCM_STATE_PAUSED;
587 	return retval;
588 }
589 
590 static int snd_compr_resume(struct snd_compr_stream *stream)
591 {
592 	int retval;
593 
594 	if (stream->runtime->state != SNDRV_PCM_STATE_PAUSED)
595 		return -EPERM;
596 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_RELEASE);
597 	if (!retval)
598 		stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
599 	return retval;
600 }
601 
602 static int snd_compr_start(struct snd_compr_stream *stream)
603 {
604 	int retval;
605 
606 	if (stream->runtime->state != SNDRV_PCM_STATE_PREPARED)
607 		return -EPERM;
608 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_START);
609 	if (!retval)
610 		stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
611 	return retval;
612 }
613 
614 static int snd_compr_stop(struct snd_compr_stream *stream)
615 {
616 	int retval;
617 
618 	if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
619 			stream->runtime->state == SNDRV_PCM_STATE_SETUP)
620 		return -EPERM;
621 	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_STOP);
622 	if (!retval) {
623 		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
624 		wake_up(&stream->runtime->sleep);
625 		stream->runtime->hw_pointer = 0;
626 		stream->runtime->app_pointer = 0;
627 		stream->runtime->total_bytes_available = 0;
628 		stream->runtime->total_bytes_transferred = 0;
629 	}
630 	return retval;
631 }
632 
633 static int snd_compr_drain(struct snd_compr_stream *stream)
634 {
635 	int retval;
636 
637 	if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
638 			stream->runtime->state == SNDRV_PCM_STATE_SETUP)
639 		return -EPERM;
640 	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_DRAIN);
641 	if (!retval) {
642 		stream->runtime->state = SNDRV_PCM_STATE_DRAINING;
643 		wake_up(&stream->runtime->sleep);
644 	}
645 	return retval;
646 }
647 
648 static int snd_compr_next_track(struct snd_compr_stream *stream)
649 {
650 	int retval;
651 
652 	/* only a running stream can transition to next track */
653 	if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING)
654 		return -EPERM;
655 
656 	/* you can signal next track isf this is intended to be a gapless stream
657 	 * and current track metadata is set
658 	 */
659 	if (stream->metadata_set == false)
660 		return -EPERM;
661 
662 	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_NEXT_TRACK);
663 	if (retval != 0)
664 		return retval;
665 	stream->metadata_set = false;
666 	stream->next_track = true;
667 	return 0;
668 }
669 
670 static int snd_compr_partial_drain(struct snd_compr_stream *stream)
671 {
672 	int retval;
673 	if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
674 			stream->runtime->state == SNDRV_PCM_STATE_SETUP)
675 		return -EPERM;
676 	/* stream can be drained only when next track has been signalled */
677 	if (stream->next_track == false)
678 		return -EPERM;
679 
680 	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_PARTIAL_DRAIN);
681 
682 	stream->next_track = false;
683 	return retval;
684 }
685 
686 static long snd_compr_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
687 {
688 	struct snd_compr_file *data = f->private_data;
689 	struct snd_compr_stream *stream;
690 	int retval = -ENOTTY;
691 
692 	if (snd_BUG_ON(!data))
693 		return -EFAULT;
694 	stream = &data->stream;
695 	if (snd_BUG_ON(!stream))
696 		return -EFAULT;
697 	mutex_lock(&stream->device->lock);
698 	switch (_IOC_NR(cmd)) {
699 	case _IOC_NR(SNDRV_COMPRESS_IOCTL_VERSION):
700 		put_user(SNDRV_COMPRESS_VERSION,
701 				(int __user *)arg) ? -EFAULT : 0;
702 		break;
703 	case _IOC_NR(SNDRV_COMPRESS_GET_CAPS):
704 		retval = snd_compr_get_caps(stream, arg);
705 		break;
706 	case _IOC_NR(SNDRV_COMPRESS_GET_CODEC_CAPS):
707 		retval = snd_compr_get_codec_caps(stream, arg);
708 		break;
709 	case _IOC_NR(SNDRV_COMPRESS_SET_PARAMS):
710 		retval = snd_compr_set_params(stream, arg);
711 		break;
712 	case _IOC_NR(SNDRV_COMPRESS_GET_PARAMS):
713 		retval = snd_compr_get_params(stream, arg);
714 		break;
715 	case _IOC_NR(SNDRV_COMPRESS_SET_METADATA):
716 		retval = snd_compr_set_metadata(stream, arg);
717 		break;
718 	case _IOC_NR(SNDRV_COMPRESS_GET_METADATA):
719 		retval = snd_compr_get_metadata(stream, arg);
720 		break;
721 	case _IOC_NR(SNDRV_COMPRESS_TSTAMP):
722 		retval = snd_compr_tstamp(stream, arg);
723 		break;
724 	case _IOC_NR(SNDRV_COMPRESS_AVAIL):
725 		retval = snd_compr_ioctl_avail(stream, arg);
726 		break;
727 	case _IOC_NR(SNDRV_COMPRESS_PAUSE):
728 		retval = snd_compr_pause(stream);
729 		break;
730 	case _IOC_NR(SNDRV_COMPRESS_RESUME):
731 		retval = snd_compr_resume(stream);
732 		break;
733 	case _IOC_NR(SNDRV_COMPRESS_START):
734 		retval = snd_compr_start(stream);
735 		break;
736 	case _IOC_NR(SNDRV_COMPRESS_STOP):
737 		retval = snd_compr_stop(stream);
738 		break;
739 	case _IOC_NR(SNDRV_COMPRESS_DRAIN):
740 		retval = snd_compr_drain(stream);
741 		break;
742 	case _IOC_NR(SNDRV_COMPRESS_PARTIAL_DRAIN):
743 		retval = snd_compr_partial_drain(stream);
744 		break;
745 	case _IOC_NR(SNDRV_COMPRESS_NEXT_TRACK):
746 		retval = snd_compr_next_track(stream);
747 		break;
748 
749 	}
750 	mutex_unlock(&stream->device->lock);
751 	return retval;
752 }
753 
754 static const struct file_operations snd_compr_file_ops = {
755 		.owner =	THIS_MODULE,
756 		.open =		snd_compr_open,
757 		.release =	snd_compr_free,
758 		.write =	snd_compr_write,
759 		.read =		snd_compr_read,
760 		.unlocked_ioctl = snd_compr_ioctl,
761 		.mmap =		snd_compr_mmap,
762 		.poll =		snd_compr_poll,
763 };
764 
765 static int snd_compress_dev_register(struct snd_device *device)
766 {
767 	int ret = -EINVAL;
768 	char str[16];
769 	struct snd_compr *compr;
770 
771 	if (snd_BUG_ON(!device || !device->device_data))
772 		return -EBADFD;
773 	compr = device->device_data;
774 
775 	sprintf(str, "comprC%iD%i", compr->card->number, compr->device);
776 	pr_debug("reg %s for device %s, direction %d\n", str, compr->name,
777 			compr->direction);
778 	/* register compressed device */
779 	ret = snd_register_device(SNDRV_DEVICE_TYPE_COMPRESS, compr->card,
780 			compr->device, &snd_compr_file_ops, compr, str);
781 	if (ret < 0) {
782 		pr_err("snd_register_device failed\n %d", ret);
783 		return ret;
784 	}
785 	return ret;
786 
787 }
788 
789 static int snd_compress_dev_disconnect(struct snd_device *device)
790 {
791 	struct snd_compr *compr;
792 
793 	compr = device->device_data;
794 	snd_unregister_device(compr->direction, compr->card, compr->device);
795 	return 0;
796 }
797 
798 /*
799  * snd_compress_new: create new compress device
800  * @card: sound card pointer
801  * @device: device number
802  * @dirn: device direction, should be of type enum snd_compr_direction
803  * @compr: compress device pointer
804  */
805 int snd_compress_new(struct snd_card *card, int device,
806 			int dirn, struct snd_compr *compr)
807 {
808 	static struct snd_device_ops ops = {
809 		.dev_free = NULL,
810 		.dev_register = snd_compress_dev_register,
811 		.dev_disconnect = snd_compress_dev_disconnect,
812 	};
813 
814 	compr->card = card;
815 	compr->device = device;
816 	compr->direction = dirn;
817 	return snd_device_new(card, SNDRV_DEV_COMPRESS, compr, &ops);
818 }
819 EXPORT_SYMBOL_GPL(snd_compress_new);
820 
821 static int snd_compress_add_device(struct snd_compr *device)
822 {
823 	int ret;
824 
825 	if (!device->card)
826 		return -EINVAL;
827 
828 	/* register the card */
829 	ret = snd_card_register(device->card);
830 	if (ret)
831 		goto out;
832 	return 0;
833 
834 out:
835 	pr_err("failed with %d\n", ret);
836 	return ret;
837 
838 }
839 
840 static int snd_compress_remove_device(struct snd_compr *device)
841 {
842 	return snd_card_free(device->card);
843 }
844 
845 /**
846  * snd_compress_register - register compressed device
847  *
848  * @device: compressed device to register
849  */
850 int snd_compress_register(struct snd_compr *device)
851 {
852 	int retval;
853 
854 	if (device->name == NULL || device->dev == NULL || device->ops == NULL)
855 		return -EINVAL;
856 
857 	pr_debug("Registering compressed device %s\n", device->name);
858 	if (snd_BUG_ON(!device->ops->open))
859 		return -EINVAL;
860 	if (snd_BUG_ON(!device->ops->free))
861 		return -EINVAL;
862 	if (snd_BUG_ON(!device->ops->set_params))
863 		return -EINVAL;
864 	if (snd_BUG_ON(!device->ops->trigger))
865 		return -EINVAL;
866 
867 	mutex_init(&device->lock);
868 
869 	/* register a compressed card */
870 	mutex_lock(&device_mutex);
871 	retval = snd_compress_add_device(device);
872 	mutex_unlock(&device_mutex);
873 	return retval;
874 }
875 EXPORT_SYMBOL_GPL(snd_compress_register);
876 
877 int snd_compress_deregister(struct snd_compr *device)
878 {
879 	pr_debug("Removing compressed device %s\n", device->name);
880 	mutex_lock(&device_mutex);
881 	snd_compress_remove_device(device);
882 	mutex_unlock(&device_mutex);
883 	return 0;
884 }
885 EXPORT_SYMBOL_GPL(snd_compress_deregister);
886 
887 static int __init snd_compress_init(void)
888 {
889 	return 0;
890 }
891 
892 static void __exit snd_compress_exit(void)
893 {
894 }
895 
896 module_init(snd_compress_init);
897 module_exit(snd_compress_exit);
898 
899 MODULE_DESCRIPTION("ALSA Compressed offload framework");
900 MODULE_AUTHOR("Vinod Koul <vinod.koul@linux.intel.com>");
901 MODULE_LICENSE("GPL v2");
902