sound/core/compress_offload.c

   1 /*
   2  *  compress_core.c - compress offload core
   3  *
   4  *  Copyright (C) 2011 Intel Corporation
   5  *  Authors:    Vinod Koul <vinod.koul@linux.intel.com>
   6  *              Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
   7  *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; version 2 of the License.
  12  *
  13  *  This program is distributed in the hope that it will be useful, but
  14  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  *  General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License along
  19  *  with this program; if not, write to the Free Software Foundation, Inc.,
  20  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  21  *
  22  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  23  *
  24  */
  25 #define FORMAT(fmt) "%s: %d: " fmt, __func__, __LINE__
  26 #define pr_fmt(fmt) KBUILD_MODNAME ": " FORMAT(fmt)
  27
  28 #include <linux/file.h>
  29 #include <linux/fs.h>
  30 #include <linux/list.h>
  31 #include <linux/mm.h>
  32 #include <linux/mutex.h>
  33 #include <linux/poll.h>
  34 #include <linux/slab.h>
  35 #include <linux/sched.h>
  36 #include <linux/uio.h>
  37 #include <linux/uaccess.h>
  38 #include <linux/module.h>
  39 #include <sound/core.h>
  40 #include <sound/initval.h>
  41 #include <sound/compress_params.h>
  42 #include <sound/compress_offload.h>
  43 #include <sound/compress_driver.h>
  44
  45 /* TODO:
  46  * - add substream support for multiple devices in case of
  47  *      SND_DYNAMIC_MINORS is not used
  48  * - Multiple node representation
  49  *      driver should be able to register multiple nodes
  50  */
  51
  52 static DEFINE_MUTEX(device_mutex);
  53
  54 struct snd_compr_file {
  55         unsigned long caps;
  56         struct snd_compr_stream stream;
  57 };
  58
  59 /*
  60  * a note on stream states used:
  61  * we use follwing states in the compressed core
  62  * SNDRV_PCM_STATE_OPEN: When stream has been opened.
  63  * SNDRV_PCM_STATE_SETUP: When stream has been initialized. This is done by
  64  *      calling SNDRV_COMPRESS_SET_PARAMS. running streams will come to this
  65  *      state at stop by calling SNDRV_COMPRESS_STOP, or at end of drain.
  66  * SNDRV_PCM_STATE_RUNNING: When stream has been started and is
  67  *      decoding/encoding and rendering/capturing data.
  68  * SNDRV_PCM_STATE_DRAINING: When stream is draining current data. This is done
  69  *      by calling SNDRV_COMPRESS_DRAIN.
  70  * SNDRV_PCM_STATE_PAUSED: When stream is paused. This is done by calling
  71  *      SNDRV_COMPRESS_PAUSE. It can be stopped or resumed by calling
  72  *      SNDRV_COMPRESS_STOP or SNDRV_COMPRESS_RESUME respectively.
  73  */
  74 static int snd_compr_open(struct inode *inode, struct file *f)
  75 {
  76         struct snd_compr *compr;
  77         struct snd_compr_file *data;
  78         struct snd_compr_runtime *runtime;
  79         enum snd_compr_direction dirn;
  80         int maj = imajor(inode);
  81         int ret;
  82
  83         if ((f->f_flags & O_ACCMODE) == O_WRONLY)
  84                 dirn = SND_COMPRESS_PLAYBACK;
  85         else if ((f->f_flags & O_ACCMODE) == O_RDONLY)
  86                 dirn = SND_COMPRESS_CAPTURE;
  87         else
  88                 return -EINVAL;
  89
  90         if (maj == snd_major)
  91                 compr = snd_lookup_minor_data(iminor(inode),
  92                                         SNDRV_DEVICE_TYPE_COMPRESS);
  93         else
  94                 return -EBADFD;
  95
  96         if (compr == NULL) {
  97                 pr_err("no device data!!!\n");
  98                 return -ENODEV;
  99         }
 100
 101         if (dirn != compr->direction) {
 102                 pr_err("this device doesn't support this direction\n");
 103                 return -EINVAL;
 104         }
 105
 106         data = kzalloc(sizeof(*data), GFP_KERNEL);
 107         if (!data)
 108                 return -ENOMEM;
 109         data->stream.ops = compr->ops;
 110         data->stream.direction = dirn;
 111         data->stream.private_data = compr->private_data;
 112         data->stream.device = compr;
 113         runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
 114         if (!runtime) {
 115                 kfree(data);
 116                 return -ENOMEM;
 117         }
 118         runtime->state = SNDRV_PCM_STATE_OPEN;
 119         init_waitqueue_head(&runtime->sleep);
 120         data->stream.runtime = runtime;
 121         f->private_data = (void *)data;
 122         mutex_lock(&compr->lock);
 123         ret = compr->ops->open(&data->stream);
 124         mutex_unlock(&compr->lock);
 125         if (ret) {
 126                 kfree(runtime);
 127                 kfree(data);
 128         }
 129         return ret;
 130 }
 131
 132 static int snd_compr_free(struct inode *inode, struct file *f)
 133 {
 134         struct snd_compr_file *data = f->private_data;
 135         data->stream.ops->free(&data->stream);
 136         kfree(data->stream.runtime->buffer);
 137         kfree(data->stream.runtime);
 138         kfree(data);
 139         return 0;
 140 }
 141
 142 static void snd_compr_update_tstamp(struct snd_compr_stream *stream,
 143                 struct snd_compr_tstamp *tstamp)
 144 {
 145         if (!stream->ops->pointer)
 146                 return;
 147         stream->ops->pointer(stream, tstamp);
 148         pr_debug("dsp consumed till %d total %d bytes\n",
 149                 tstamp->byte_offset, tstamp->copied_total);
 150         stream->runtime->hw_pointer = tstamp->byte_offset;
 151         stream->runtime->total_bytes_transferred = tstamp->copied_total;
 152 }
 153
 154 static size_t snd_compr_calc_avail(struct snd_compr_stream *stream,
 155                 struct snd_compr_avail *avail)
 156 {
 157         long avail_calc; /*this needs to be signed variable */
 158
 159         snd_compr_update_tstamp(stream, &avail->tstamp);
 160
 161         /* FIXME: This needs to be different for capture stream,
 162            available is # of compressed data, for playback it's
 163            remainder of buffer */
 164
 165         if (stream->runtime->total_bytes_available == 0 &&
 166                         stream->runtime->state == SNDRV_PCM_STATE_SETUP) {
 167                 pr_debug("detected init and someone forgot to do a write\n");
 168                 return stream->runtime->buffer_size;
 169         }
 170         pr_debug("app wrote %lld, DSP consumed %lld\n",
 171                         stream->runtime->total_bytes_available,
 172                         stream->runtime->total_bytes_transferred);
 173         if (stream->runtime->total_bytes_available ==
 174                                 stream->runtime->total_bytes_transferred) {
 175                 pr_debug("both pointers are same, returning full avail\n");
 176                 return stream->runtime->buffer_size;
 177         }
 178
 179         /* FIXME: this routine isn't consistent, in one test we use
 180          * cumulative values and in the other byte offsets. Do we
 181          * really need the byte offsets if the cumulative values have
 182          * been updated? In the PCM interface app_ptr and hw_ptr are
 183          * already cumulative */
 184
 185         avail_calc = stream->runtime->buffer_size -
 186                 (stream->runtime->app_pointer - stream->runtime->hw_pointer);
 187         pr_debug("calc avail as %ld, app_ptr %lld, hw+ptr %lld\n", avail_calc,
 188                         stream->runtime->app_pointer,
 189                         stream->runtime->hw_pointer);
 190         if (avail_calc >= stream->runtime->buffer_size)
 191                 avail_calc -= stream->runtime->buffer_size;
 192         pr_debug("ret avail as %ld\n", avail_calc);
 193         avail->avail = avail_calc;
 194         return avail_calc;
 195 }
 196
 197 static inline size_t snd_compr_get_avail(struct snd_compr_stream *stream)
 198 {
 199         struct snd_compr_avail avail;
 200
 201         return snd_compr_calc_avail(stream, &avail);
 202 }
 203
 204 static int
 205 snd_compr_ioctl_avail(struct snd_compr_stream *stream, unsigned long arg)
 206 {
 207         struct snd_compr_avail ioctl_avail;
 208         size_t avail;
 209
 210         avail = snd_compr_calc_avail(stream, &ioctl_avail);
 211         ioctl_avail.avail = avail;
 212
 213         if (copy_to_user((__u64 __user *)arg,
 214                                 &ioctl_avail, sizeof(ioctl_avail)))
 215                 return -EFAULT;
 216         return 0;
 217 }
 218
 219 static int snd_compr_write_data(struct snd_compr_stream *stream,
 220                const char __user *buf, size_t count)
 221 {
 222         void *dstn;
 223         size_t copy;
 224         struct snd_compr_runtime *runtime = stream->runtime;
 225
 226         dstn = runtime->buffer + runtime->app_pointer;
 227         pr_debug("copying %ld at %lld\n",
 228                         (unsigned long)count, runtime->app_pointer);
 229         if (count < runtime->buffer_size - runtime->app_pointer) {
 230                 if (copy_from_user(dstn, buf, count))
 231                         return -EFAULT;
 232                 runtime->app_pointer += count;
 233         } else {
 234                 copy = runtime->buffer_size - runtime->app_pointer;
 235                 if (copy_from_user(dstn, buf, copy))
 236                         return -EFAULT;
 237                 if (copy_from_user(runtime->buffer, buf + copy, count - copy))
 238                         return -EFAULT;
 239                 runtime->app_pointer = count - copy;
 240         }
 241         /* if DSP cares, let it know data has been written */
 242         if (stream->ops->ack)
 243                 stream->ops->ack(stream, count);
 244         return count;
 245 }
 246
 247 static ssize_t snd_compr_write(struct file *f, const char __user *buf,
 248                 size_t count, loff_t *offset)
 249 {
 250         struct snd_compr_file *data = f->private_data;
 251         struct snd_compr_stream *stream;
 252         size_t avail;
 253         int retval;
 254
 255         if (snd_BUG_ON(!data))
 256                 return -EFAULT;
 257
 258         stream = &data->stream;
 259         mutex_lock(&stream->device->lock);
 260         /* write is allowed when stream is running or has been steup */
 261         if (stream->runtime->state != SNDRV_PCM_STATE_SETUP &&
 262                         stream->runtime->state != SNDRV_PCM_STATE_RUNNING) {
 263                 mutex_unlock(&stream->device->lock);
 264                 return -EBADFD;
 265         }
 266
 267         avail = snd_compr_get_avail(stream);
 268         pr_debug("avail returned %ld\n", (unsigned long)avail);
 269         /* calculate how much we can write to buffer */
 270         if (avail > count)
 271                 avail = count;
 272
 273         if (stream->ops->copy)
 274                 retval = stream->ops->copy(stream, buf, avail);
 275         else
 276                 retval = snd_compr_write_data(stream, buf, avail);
 277         if (retval > 0)
 278                 stream->runtime->total_bytes_available += retval;
 279
 280         /* while initiating the stream, write should be called before START
 281          * call, so in setup move state */
 282         if (stream->runtime->state == SNDRV_PCM_STATE_SETUP) {
 283                 stream->runtime->state = SNDRV_PCM_STATE_PREPARED;
 284                 pr_debug("stream prepared, Houston we are good to go\n");
 285         }
 286
 287         mutex_unlock(&stream->device->lock);
 288         return retval;
 289 }
 290
 291
 292 static ssize_t snd_compr_read(struct file *f, char __user *buf,
 293                 size_t count, loff_t *offset)
 294 {
 295         return -ENXIO;
 296 }
 297
 298 static int snd_compr_mmap(struct file *f, struct vm_area_struct *vma)
 299 {
 300         return -ENXIO;
 301 }
 302
 303 static inline int snd_compr_get_poll(struct snd_compr_stream *stream)
 304 {
 305         if (stream->direction == SND_COMPRESS_PLAYBACK)
 306                 return POLLOUT | POLLWRNORM;
 307         else
 308                 return POLLIN | POLLRDNORM;
 309 }
 310
 311 static unsigned int snd_compr_poll(struct file *f, poll_table *wait)
 312 {
 313         struct snd_compr_file *data = f->private_data;
 314         struct snd_compr_stream *stream;
 315         size_t avail;
 316         int retval = 0;
 317
 318         if (snd_BUG_ON(!data))
 319                 return -EFAULT;
 320         stream = &data->stream;
 321         if (snd_BUG_ON(!stream))
 322                 return -EFAULT;
 323
 324         mutex_lock(&stream->device->lock);
 325         if (stream->runtime->state == SNDRV_PCM_STATE_PAUSED ||
 326                         stream->runtime->state == SNDRV_PCM_STATE_OPEN) {
 327                 retval = -EBADFD;
 328                 goto out;
 329         }
 330         poll_wait(f, &stream->runtime->sleep, wait);
 331
 332         avail = snd_compr_get_avail(stream);
 333         pr_debug("avail is %ld\n", (unsigned long)avail);
 334         /* check if we have at least one fragment to fill */
 335         switch (stream->runtime->state) {
 336         case SNDRV_PCM_STATE_DRAINING:
 337                 /* stream has been woken up after drain is complete
 338                  * draining done so set stream state to stopped
 339                  */
 340                 retval = snd_compr_get_poll(stream);
 341                 stream->runtime->state = SNDRV_PCM_STATE_SETUP;
 342                 break;
 343         case SNDRV_PCM_STATE_RUNNING:
 344         case SNDRV_PCM_STATE_PREPARED:
 345         case SNDRV_PCM_STATE_PAUSED:
 346                 if (avail >= stream->runtime->fragment_size)
 347                         retval = snd_compr_get_poll(stream);
 348                 break;
 349         default:
 350                 if (stream->direction == SND_COMPRESS_PLAYBACK)
 351                         retval = POLLOUT | POLLWRNORM | POLLERR;
 352                 else
 353                         retval = POLLIN | POLLRDNORM | POLLERR;
 354                 break;
 355         }
 356 out:
 357         mutex_unlock(&stream->device->lock);
 358         return retval;
 359 }
 360
 361 static int
 362 snd_compr_get_caps(struct snd_compr_stream *stream, unsigned long arg)
 363 {
 364         int retval;
 365         struct snd_compr_caps caps;
 366
 367         if (!stream->ops->get_caps)
 368                 return -ENXIO;
 369
 370         retval = stream->ops->get_caps(stream, &caps);
 371         if (retval)
 372                 goto out;
 373         if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
 374                 retval = -EFAULT;
 375 out:
 376         return retval;
 377 }
 378
 379 static int
 380 snd_compr_get_codec_caps(struct snd_compr_stream *stream, unsigned long arg)
 381 {
 382         int retval;
 383         struct snd_compr_codec_caps *caps;
 384
 385         if (!stream->ops->get_codec_caps)
 386                 return -ENXIO;
 387
 388         caps = kmalloc(sizeof(*caps), GFP_KERNEL);
 389         if (!caps)
 390                 return -ENOMEM;
 391
 392         retval = stream->ops->get_codec_caps(stream, caps);
 393         if (retval)
 394                 goto out;
 395         if (copy_to_user((void __user *)arg, caps, sizeof(*caps)))
 396                 retval = -EFAULT;
 397
 398 out:
 399         kfree(caps);
 400         return retval;
 401 }
 402
 403 /* revisit this with snd_pcm_preallocate_xxx */
 404 static int snd_compr_allocate_buffer(struct snd_compr_stream *stream,
 405                 struct snd_compr_params *params)
 406 {
 407         unsigned int buffer_size;
 408         void *buffer;
 409
 410         buffer_size = params->buffer.fragment_size * params->buffer.fragments;
 411         if (stream->ops->copy) {
 412                 buffer = NULL;
 413                 /* if copy is defined the driver will be required to copy
 414                  * the data from core
 415                  */
 416         } else {
 417                 buffer = kmalloc(buffer_size, GFP_KERNEL);
 418                 if (!buffer)
 419                         return -ENOMEM;
 420         }
 421         stream->runtime->fragment_size = params->buffer.fragment_size;
 422         stream->runtime->fragments = params->buffer.fragments;
 423         stream->runtime->buffer = buffer;
 424         stream->runtime->buffer_size = buffer_size;
 425         return 0;
 426 }
 427
 428 static int
 429 snd_compr_set_params(struct snd_compr_stream *stream, unsigned long arg)
 430 {
 431         struct snd_compr_params *params;
 432         int retval;
 433
 434         if (stream->runtime->state == SNDRV_PCM_STATE_OPEN) {
 435                 /*
 436                  * we should allow parameter change only when stream has been
 437                  * opened not in other cases
 438                  */
 439                 params = kmalloc(sizeof(*params), GFP_KERNEL);
 440                 if (!params)
 441                         return -ENOMEM;
 442                 if (copy_from_user(params, (void __user *)arg, sizeof(*params))) {
 443                         retval = -EFAULT;
 444                         goto out;
 445                 }
 446                 retval = snd_compr_allocate_buffer(stream, params);
 447                 if (retval) {
 448                         retval = -ENOMEM;
 449                         goto out;
 450                 }
 451                 retval = stream->ops->set_params(stream, params);
 452                 if (retval)
 453                         goto out;
 454                 stream->runtime->state = SNDRV_PCM_STATE_SETUP;
 455         } else {
 456                 return -EPERM;
 457         }
 458 out:
 459         kfree(params);
 460         return retval;
 461 }
 462
 463 static int
 464 snd_compr_get_params(struct snd_compr_stream *stream, unsigned long arg)
 465 {
 466         struct snd_codec *params;
 467         int retval;
 468
 469         if (!stream->ops->get_params)
 470                 return -EBADFD;
 471
 472         params = kmalloc(sizeof(*params), GFP_KERNEL);
 473         if (!params)
 474                 return -ENOMEM;
 475         retval = stream->ops->get_params(stream, params);
 476         if (retval)
 477                 goto out;
 478         if (copy_to_user((char __user *)arg, params, sizeof(*params)))
 479                 retval = -EFAULT;
 480
 481 out:
 482         kfree(params);
 483         return retval;
 484 }
 485
 486 static inline int
 487 snd_compr_tstamp(struct snd_compr_stream *stream, unsigned long arg)
 488 {
 489         struct snd_compr_tstamp tstamp;
 490
 491         snd_compr_update_tstamp(stream, &tstamp);
 492         return copy_to_user((struct snd_compr_tstamp __user *)arg,
 493                 &tstamp, sizeof(tstamp)) ? -EFAULT : 0;
 494 }
 495
 496 static int snd_compr_pause(struct snd_compr_stream *stream)
 497 {
 498         int retval;
 499
 500         if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING)
 501                 return -EPERM;
 502         retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_PUSH);
 503         if (!retval)
 504                 stream->runtime->state = SNDRV_PCM_STATE_PAUSED;
 505         return retval;
 506 }
 507
 508 static int snd_compr_resume(struct snd_compr_stream *stream)
 509 {
 510         int retval;
 511
 512         if (stream->runtime->state != SNDRV_PCM_STATE_PAUSED)
 513                 return -EPERM;
 514         retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_RELEASE);
 515         if (!retval)
 516                 stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
 517         return retval;
 518 }
 519
 520 static int snd_compr_start(struct snd_compr_stream *stream)
 521 {
 522         int retval;
 523
 524         if (stream->runtime->state != SNDRV_PCM_STATE_PREPARED)
 525                 return -EPERM;
 526         retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_START);
 527         if (!retval)
 528                 stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
 529         return retval;
 530 }
 531
 532 static int snd_compr_stop(struct snd_compr_stream *stream)
 533 {
 534         int retval;
 535
 536         if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
 537                         stream->runtime->state == SNDRV_PCM_STATE_SETUP)
 538                 return -EPERM;
 539         retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_STOP);
 540         if (!retval) {
 541                 stream->runtime->state = SNDRV_PCM_STATE_SETUP;
 542                 wake_up(&stream->runtime->sleep);
 543                 stream->runtime->hw_pointer = 0;
 544                 stream->runtime->app_pointer = 0;
 545                 stream->runtime->total_bytes_available = 0;
 546                 stream->runtime->total_bytes_transferred = 0;
 547         }
 548         return retval;
 549 }
 550
 551 static int snd_compr_drain(struct snd_compr_stream *stream)
 552 {
 553         int retval;
 554
 555         if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
 556                         stream->runtime->state == SNDRV_PCM_STATE_SETUP)
 557                 return -EPERM;
 558         retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_DRAIN);
 559         if (!retval) {
 560                 stream->runtime->state = SNDRV_PCM_STATE_DRAINING;
 561                 wake_up(&stream->runtime->sleep);
 562         }
 563         return retval;
 564 }
 565
 566 static long snd_compr_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
 567 {
 568         struct snd_compr_file *data = f->private_data;
 569         struct snd_compr_stream *stream;
 570         int retval = -ENOTTY;
 571
 572         if (snd_BUG_ON(!data))
 573                 return -EFAULT;
 574         stream = &data->stream;
 575         if (snd_BUG_ON(!stream))
 576                 return -EFAULT;
 577         mutex_lock(&stream->device->lock);
 578         switch (_IOC_NR(cmd)) {
 579         case _IOC_NR(SNDRV_COMPRESS_IOCTL_VERSION):
 580                 put_user(SNDRV_COMPRESS_VERSION,
 581                                 (int __user *)arg) ? -EFAULT : 0;
 582                 break;
 583         case _IOC_NR(SNDRV_COMPRESS_GET_CAPS):
 584                 retval = snd_compr_get_caps(stream, arg);
 585                 break;
 586         case _IOC_NR(SNDRV_COMPRESS_GET_CODEC_CAPS):
 587                 retval = snd_compr_get_codec_caps(stream, arg);
 588                 break;
 589         case _IOC_NR(SNDRV_COMPRESS_SET_PARAMS):
 590                 retval = snd_compr_set_params(stream, arg);
 591                 break;
 592         case _IOC_NR(SNDRV_COMPRESS_GET_PARAMS):
 593                 retval = snd_compr_get_params(stream, arg);
 594                 break;
 595         case _IOC_NR(SNDRV_COMPRESS_TSTAMP):
 596                 retval = snd_compr_tstamp(stream, arg);
 597                 break;
 598         case _IOC_NR(SNDRV_COMPRESS_AVAIL):
 599                 retval = snd_compr_ioctl_avail(stream, arg);
 600                 break;
 601         case _IOC_NR(SNDRV_COMPRESS_PAUSE):
 602                 retval = snd_compr_pause(stream);
 603                 break;
 604         case _IOC_NR(SNDRV_COMPRESS_RESUME):
 605                 retval = snd_compr_resume(stream);
 606                 break;
 607         case _IOC_NR(SNDRV_COMPRESS_START):
 608                 retval = snd_compr_start(stream);
 609                 break;
 610         case _IOC_NR(SNDRV_COMPRESS_STOP):
 611                 retval = snd_compr_stop(stream);
 612                 break;
 613         case _IOC_NR(SNDRV_COMPRESS_DRAIN):
 614                 retval = snd_compr_drain(stream);
 615                 break;
 616         }
 617         mutex_unlock(&stream->device->lock);
 618         return retval;
 619 }
 620
 621 static const struct file_operations snd_compr_file_ops = {
 622                 .owner =        THIS_MODULE,
 623                 .open =         snd_compr_open,
 624                 .release =      snd_compr_free,
 625                 .write =        snd_compr_write,
 626                 .read =         snd_compr_read,
 627                 .unlocked_ioctl = snd_compr_ioctl,
 628                 .mmap =         snd_compr_mmap,
 629                 .poll =         snd_compr_poll,
 630 };
 631
 632 static int snd_compress_dev_register(struct snd_device *device)
 633 {
 634         int ret = -EINVAL;
 635         char str[16];
 636         struct snd_compr *compr;
 637
 638         if (snd_BUG_ON(!device || !device->device_data))
 639                 return -EBADFD;
 640         compr = device->device_data;
 641
 642         sprintf(str, "comprC%iD%i", compr->card->number, compr->device);
 643         pr_debug("reg %s for device %s, direction %d\n", str, compr->name,
 644                         compr->direction);
 645         /* register compressed device */
 646         ret = snd_register_device(SNDRV_DEVICE_TYPE_COMPRESS, compr->card,
 647                         compr->device, &snd_compr_file_ops, compr, str);
 648         if (ret < 0) {
 649                 pr_err("snd_register_device failed\n %d", ret);
 650                 return ret;
 651         }
 652         return ret;
 653
 654 }
 655
 656 static int snd_compress_dev_disconnect(struct snd_device *device)
 657 {
 658         struct snd_compr *compr;
 659
 660         compr = device->device_data;
 661         snd_unregister_device(compr->direction, compr->card, compr->device);
 662         return 0;
 663 }
 664
 665 /*
 666  * snd_compress_new: create new compress device
 667  * @card: sound card pointer
 668  * @device: device number
 669  * @dirn: device direction, should be of type enum snd_compr_direction
 670  * @compr: compress device pointer
 671  */
 672 int snd_compress_new(struct snd_card *card, int device,
 673                         int dirn, struct snd_compr *compr)
 674 {
 675         static struct snd_device_ops ops = {
 676                 .dev_free = NULL,
 677                 .dev_register = snd_compress_dev_register,
 678                 .dev_disconnect = snd_compress_dev_disconnect,
 679         };
 680
 681         compr->card = card;
 682         compr->device = device;
 683         compr->direction = dirn;
 684         return snd_device_new(card, SNDRV_DEV_COMPRESS, compr, &ops);
 685 }
 686 EXPORT_SYMBOL_GPL(snd_compress_new);
 687
 688 static int snd_compress_add_device(struct snd_compr *device)
 689 {
 690         int ret;
 691
 692         if (!device->card)
 693                 return -EINVAL;
 694
 695         /* register the card */
 696         ret = snd_card_register(device->card);
 697         if (ret)
 698                 goto out;
 699         return 0;
 700
 701 out:
 702         pr_err("failed with %d\n", ret);
 703         return ret;
 704
 705 }
 706
 707 static int snd_compress_remove_device(struct snd_compr *device)
 708 {
 709         return snd_card_free(device->card);
 710 }
 711
 712 /**
 713  * snd_compress_register - register compressed device
 714  *
 715  * @device: compressed device to register
 716  */
 717 int snd_compress_register(struct snd_compr *device)
 718 {
 719         int retval;
 720
 721         if (device->name == NULL || device->dev == NULL || device->ops == NULL)
 722                 return -EINVAL;
 723
 724         pr_debug("Registering compressed device %s\n", device->name);
 725         if (snd_BUG_ON(!device->ops->open))
 726                 return -EINVAL;
 727         if (snd_BUG_ON(!device->ops->free))
 728                 return -EINVAL;
 729         if (snd_BUG_ON(!device->ops->set_params))
 730                 return -EINVAL;
 731         if (snd_BUG_ON(!device->ops->trigger))
 732                 return -EINVAL;
 733
 734         mutex_init(&device->lock);
 735
 736         /* register a compressed card */
 737         mutex_lock(&device_mutex);
 738         retval = snd_compress_add_device(device);
 739         mutex_unlock(&device_mutex);
 740         return retval;
 741 }
 742 EXPORT_SYMBOL_GPL(snd_compress_register);
 743
 744 int snd_compress_deregister(struct snd_compr *device)
 745 {
 746         pr_debug("Removing compressed device %s\n", device->name);
 747         mutex_lock(&device_mutex);
 748         snd_compress_remove_device(device);
 749         mutex_unlock(&device_mutex);
 750         return 0;
 751 }
 752 EXPORT_SYMBOL_GPL(snd_compress_deregister);
 753
 754 static int __init snd_compress_init(void)
 755 {
 756         return 0;
 757 }
 758
 759 static void __exit snd_compress_exit(void)
 760 {
 761 }
 762
 763 module_init(snd_compress_init);
 764 module_exit(snd_compress_exit);
 765
 766 MODULE_DESCRIPTION("ALSA Compressed offload framework");
 767 MODULE_AUTHOR("Vinod Koul <vinod.koul@linux.intel.com>");
 768 MODULE_LICENSE("GPL v2");