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