sound/firewire/isight.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Apple iSight audio driver
   4  *
   5  * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
   6  */
   7
   8 #include <asm/byteorder.h>
   9 #include <linux/delay.h>
  10 #include <linux/device.h>
  11 #include <linux/firewire.h>
  12 #include <linux/firewire-constants.h>
  13 #include <linux/module.h>
  14 #include <linux/mod_devicetable.h>
  15 #include <linux/mutex.h>
  16 #include <linux/string.h>
  17 #include <sound/control.h>
  18 #include <sound/core.h>
  19 #include <sound/initval.h>
  20 #include <sound/pcm.h>
  21 #include <sound/tlv.h>
  22 #include "lib.h"
  23 #include "iso-resources.h"
  24 #include "packets-buffer.h"
  25
  26 #define OUI_APPLE               0x000a27
  27 #define MODEL_APPLE_ISIGHT      0x000008
  28 #define SW_ISIGHT_AUDIO         0x000010
  29
  30 #define REG_AUDIO_ENABLE        0x000
  31 #define  AUDIO_ENABLE           0x80000000
  32 #define REG_DEF_AUDIO_GAIN      0x204
  33 #define REG_GAIN_RAW_START      0x210
  34 #define REG_GAIN_RAW_END        0x214
  35 #define REG_GAIN_DB_START       0x218
  36 #define REG_GAIN_DB_END         0x21c
  37 #define REG_SAMPLE_RATE_INQUIRY 0x280
  38 #define REG_ISO_TX_CONFIG       0x300
  39 #define  SPEED_SHIFT            16
  40 #define REG_SAMPLE_RATE         0x400
  41 #define  RATE_48000             0x80000000
  42 #define REG_GAIN                0x500
  43 #define REG_MUTE                0x504
  44
  45 #define MAX_FRAMES_PER_PACKET   475
  46
  47 #define QUEUE_LENGTH            20
  48
  49 struct isight {
  50         struct snd_card *card;
  51         struct fw_unit *unit;
  52         struct fw_device *device;
  53         u64 audio_base;
  54         struct snd_pcm_substream *pcm;
  55         struct mutex mutex;
  56         struct iso_packets_buffer buffer;
  57         struct fw_iso_resources resources;
  58         struct fw_iso_context *context;
  59         bool pcm_active;
  60         bool pcm_running;
  61         bool first_packet;
  62         int packet_index;
  63         u32 total_samples;
  64         unsigned int buffer_pointer;
  65         unsigned int period_counter;
  66         s32 gain_min, gain_max;
  67         unsigned int gain_tlv[4];
  68 };
  69
  70 struct audio_payload {
  71         __be32 sample_count;
  72         __be32 signature;
  73         __be32 sample_total;
  74         __be32 reserved;
  75         __be16 samples[2 * MAX_FRAMES_PER_PACKET];
  76 };
  77
  78 MODULE_DESCRIPTION("iSight audio driver");
  79 MODULE_AUTHOR("Clemens Ladisch <clemens@ladisch.de>");
  80 MODULE_LICENSE("GPL v2");
  81
  82 static struct fw_iso_packet audio_packet = {
  83         .payload_length = sizeof(struct audio_payload),
  84         .interrupt = 1,
  85         .header_length = 4,
  86 };
  87
  88 static void isight_update_pointers(struct isight *isight, unsigned int count)
  89 {
  90         struct snd_pcm_runtime *runtime = isight->pcm->runtime;
  91         unsigned int ptr;
  92
  93         smp_wmb(); /* update buffer data before buffer pointer */
  94
  95         ptr = isight->buffer_pointer;
  96         ptr += count;
  97         if (ptr >= runtime->buffer_size)
  98                 ptr -= runtime->buffer_size;
  99         WRITE_ONCE(isight->buffer_pointer, ptr);
 100
 101         isight->period_counter += count;
 102         if (isight->period_counter >= runtime->period_size) {
 103                 isight->period_counter -= runtime->period_size;
 104                 snd_pcm_period_elapsed(isight->pcm);
 105         }
 106 }
 107
 108 static void isight_samples(struct isight *isight,
 109                            const __be16 *samples, unsigned int count)
 110 {
 111         struct snd_pcm_runtime *runtime;
 112         unsigned int count1;
 113
 114         if (!READ_ONCE(isight->pcm_running))
 115                 return;
 116
 117         runtime = isight->pcm->runtime;
 118         if (isight->buffer_pointer + count <= runtime->buffer_size) {
 119                 memcpy(runtime->dma_area + isight->buffer_pointer * 4,
 120                        samples, count * 4);
 121         } else {
 122                 count1 = runtime->buffer_size - isight->buffer_pointer;
 123                 memcpy(runtime->dma_area + isight->buffer_pointer * 4,
 124                        samples, count1 * 4);
 125                 samples += count1 * 2;
 126                 memcpy(runtime->dma_area, samples, (count - count1) * 4);
 127         }
 128
 129         isight_update_pointers(isight, count);
 130 }
 131
 132 static void isight_pcm_abort(struct isight *isight)
 133 {
 134         if (READ_ONCE(isight->pcm_active))
 135                 snd_pcm_stop_xrun(isight->pcm);
 136 }
 137
 138 static void isight_dropped_samples(struct isight *isight, unsigned int total)
 139 {
 140         struct snd_pcm_runtime *runtime;
 141         u32 dropped;
 142         unsigned int count1;
 143
 144         if (!READ_ONCE(isight->pcm_running))
 145                 return;
 146
 147         runtime = isight->pcm->runtime;
 148         dropped = total - isight->total_samples;
 149         if (dropped < runtime->buffer_size) {
 150                 if (isight->buffer_pointer + dropped <= runtime->buffer_size) {
 151                         memset(runtime->dma_area + isight->buffer_pointer * 4,
 152                                0, dropped * 4);
 153                 } else {
 154                         count1 = runtime->buffer_size - isight->buffer_pointer;
 155                         memset(runtime->dma_area + isight->buffer_pointer * 4,
 156                                0, count1 * 4);
 157                         memset(runtime->dma_area, 0, (dropped - count1) * 4);
 158                 }
 159                 isight_update_pointers(isight, dropped);
 160         } else {
 161                 isight_pcm_abort(isight);
 162         }
 163 }
 164
 165 static void isight_packet(struct fw_iso_context *context, u32 cycle,
 166                           size_t header_length, void *header, void *data)
 167 {
 168         struct isight *isight = data;
 169         const struct audio_payload *payload;
 170         unsigned int index, length, count, total;
 171         int err;
 172
 173         if (isight->packet_index < 0)
 174                 return;
 175         index = isight->packet_index;
 176         payload = isight->buffer.packets[index].buffer;
 177         length = be32_to_cpup(header) >> 16;
 178
 179         if (likely(length >= 16 &&
 180                    payload->signature == cpu_to_be32(0x73676874/*"sght"*/))) {
 181                 count = be32_to_cpu(payload->sample_count);
 182                 if (likely(count <= (length - 16) / 4)) {
 183                         total = be32_to_cpu(payload->sample_total);
 184                         if (unlikely(total != isight->total_samples)) {
 185                                 if (!isight->first_packet)
 186                                         isight_dropped_samples(isight, total);
 187                                 isight->first_packet = false;
 188                                 isight->total_samples = total;
 189                         }
 190
 191                         isight_samples(isight, payload->samples, count);
 192                         isight->total_samples += count;
 193                 }
 194         }
 195
 196         err = fw_iso_context_queue(isight->context, &audio_packet,
 197                                    &isight->buffer.iso_buffer,
 198                                    isight->buffer.packets[index].offset);
 199         if (err < 0) {
 200                 dev_err(&isight->unit->device, "queueing error: %d\n", err);
 201                 isight_pcm_abort(isight);
 202                 isight->packet_index = -1;
 203                 return;
 204         }
 205         fw_iso_context_queue_flush(isight->context);
 206
 207         if (++index >= QUEUE_LENGTH)
 208                 index = 0;
 209         isight->packet_index = index;
 210 }
 211
 212 static int isight_connect(struct isight *isight)
 213 {
 214         int ch, err;
 215         __be32 value;
 216
 217 retry_after_bus_reset:
 218         ch = fw_iso_resources_allocate(&isight->resources,
 219                                        sizeof(struct audio_payload),
 220                                        isight->device->max_speed);
 221         if (ch < 0) {
 222                 err = ch;
 223                 goto error;
 224         }
 225
 226         value = cpu_to_be32(ch | (isight->device->max_speed << SPEED_SHIFT));
 227         err = snd_fw_transaction(isight->unit, TCODE_WRITE_QUADLET_REQUEST,
 228                                  isight->audio_base + REG_ISO_TX_CONFIG,
 229                                  &value, 4, FW_FIXED_GENERATION |
 230                                  isight->resources.generation);
 231         if (err == -EAGAIN) {
 232                 fw_iso_resources_free(&isight->resources);
 233                 goto retry_after_bus_reset;
 234         } else if (err < 0) {
 235                 goto err_resources;
 236         }
 237
 238         return 0;
 239
 240 err_resources:
 241         fw_iso_resources_free(&isight->resources);
 242 error:
 243         return err;
 244 }
 245
 246 static int isight_open(struct snd_pcm_substream *substream)
 247 {
 248         static const struct snd_pcm_hardware hardware = {
 249                 .info = SNDRV_PCM_INFO_MMAP |
 250                         SNDRV_PCM_INFO_MMAP_VALID |
 251                         SNDRV_PCM_INFO_BATCH |
 252                         SNDRV_PCM_INFO_INTERLEAVED |
 253                         SNDRV_PCM_INFO_BLOCK_TRANSFER,
 254                 .formats = SNDRV_PCM_FMTBIT_S16_BE,
 255                 .rates = SNDRV_PCM_RATE_48000,
 256                 .rate_min = 48000,
 257                 .rate_max = 48000,
 258                 .channels_min = 2,
 259                 .channels_max = 2,
 260                 .buffer_bytes_max = 4 * 1024 * 1024,
 261                 .period_bytes_min = MAX_FRAMES_PER_PACKET * 4,
 262                 .period_bytes_max = 1024 * 1024,
 263                 .periods_min = 2,
 264                 .periods_max = UINT_MAX,
 265         };
 266         struct isight *isight = substream->private_data;
 267
 268         substream->runtime->hw = hardware;
 269
 270         return iso_packets_buffer_init(&isight->buffer, isight->unit,
 271                                        QUEUE_LENGTH,
 272                                        sizeof(struct audio_payload),
 273                                        DMA_FROM_DEVICE);
 274 }
 275
 276 static int isight_close(struct snd_pcm_substream *substream)
 277 {
 278         struct isight *isight = substream->private_data;
 279
 280         iso_packets_buffer_destroy(&isight->buffer, isight->unit);
 281
 282         return 0;
 283 }
 284
 285 static int isight_hw_params(struct snd_pcm_substream *substream,
 286                             struct snd_pcm_hw_params *hw_params)
 287 {
 288         struct isight *isight = substream->private_data;
 289
 290         WRITE_ONCE(isight->pcm_active, true);
 291
 292         return 0;
 293 }
 294
 295 static int reg_read(struct isight *isight, int offset, __be32 *value)
 296 {
 297         return snd_fw_transaction(isight->unit, TCODE_READ_QUADLET_REQUEST,
 298                                   isight->audio_base + offset, value, 4, 0);
 299 }
 300
 301 static int reg_write(struct isight *isight, int offset, __be32 value)
 302 {
 303         return snd_fw_transaction(isight->unit, TCODE_WRITE_QUADLET_REQUEST,
 304                                   isight->audio_base + offset, &value, 4, 0);
 305 }
 306
 307 static void isight_stop_streaming(struct isight *isight)
 308 {
 309         __be32 value;
 310
 311         if (!isight->context)
 312                 return;
 313
 314         fw_iso_context_stop(isight->context);
 315         fw_iso_context_destroy(isight->context);
 316         isight->context = NULL;
 317         fw_iso_resources_free(&isight->resources);
 318         value = 0;
 319         snd_fw_transaction(isight->unit, TCODE_WRITE_QUADLET_REQUEST,
 320                            isight->audio_base + REG_AUDIO_ENABLE,
 321                            &value, 4, FW_QUIET);
 322 }
 323
 324 static int isight_hw_free(struct snd_pcm_substream *substream)
 325 {
 326         struct isight *isight = substream->private_data;
 327
 328         WRITE_ONCE(isight->pcm_active, false);
 329
 330         mutex_lock(&isight->mutex);
 331         isight_stop_streaming(isight);
 332         mutex_unlock(&isight->mutex);
 333
 334         return 0;
 335 }
 336
 337 static int isight_start_streaming(struct isight *isight)
 338 {
 339         unsigned int i;
 340         int err;
 341
 342         if (isight->context) {
 343                 if (isight->packet_index < 0)
 344                         isight_stop_streaming(isight);
 345                 else
 346                         return 0;
 347         }
 348
 349         err = reg_write(isight, REG_SAMPLE_RATE, cpu_to_be32(RATE_48000));
 350         if (err < 0)
 351                 goto error;
 352
 353         err = isight_connect(isight);
 354         if (err < 0)
 355                 goto error;
 356
 357         err = reg_write(isight, REG_AUDIO_ENABLE, cpu_to_be32(AUDIO_ENABLE));
 358         if (err < 0)
 359                 goto err_resources;
 360
 361         isight->context = fw_iso_context_create(isight->device->card,
 362                                                 FW_ISO_CONTEXT_RECEIVE,
 363                                                 isight->resources.channel,
 364                                                 isight->device->max_speed,
 365                                                 4, isight_packet, isight);
 366         if (IS_ERR(isight->context)) {
 367                 err = PTR_ERR(isight->context);
 368                 isight->context = NULL;
 369                 goto err_resources;
 370         }
 371
 372         for (i = 0; i < QUEUE_LENGTH; ++i) {
 373                 err = fw_iso_context_queue(isight->context, &audio_packet,
 374                                            &isight->buffer.iso_buffer,
 375                                            isight->buffer.packets[i].offset);
 376                 if (err < 0)
 377                         goto err_context;
 378         }
 379
 380         isight->first_packet = true;
 381         isight->packet_index = 0;
 382
 383         err = fw_iso_context_start(isight->context, -1, 0,
 384                                    FW_ISO_CONTEXT_MATCH_ALL_TAGS/*?*/);
 385         if (err < 0)
 386                 goto err_context;
 387
 388         return 0;
 389
 390 err_context:
 391         fw_iso_context_destroy(isight->context);
 392         isight->context = NULL;
 393 err_resources:
 394         fw_iso_resources_free(&isight->resources);
 395         reg_write(isight, REG_AUDIO_ENABLE, 0);
 396 error:
 397         return err;
 398 }
 399
 400 static int isight_prepare(struct snd_pcm_substream *substream)
 401 {
 402         struct isight *isight = substream->private_data;
 403         int err;
 404
 405         isight->buffer_pointer = 0;
 406         isight->period_counter = 0;
 407
 408         mutex_lock(&isight->mutex);
 409         err = isight_start_streaming(isight);
 410         mutex_unlock(&isight->mutex);
 411
 412         return err;
 413 }
 414
 415 static int isight_trigger(struct snd_pcm_substream *substream, int cmd)
 416 {
 417         struct isight *isight = substream->private_data;
 418
 419         switch (cmd) {
 420         case SNDRV_PCM_TRIGGER_START:
 421                 WRITE_ONCE(isight->pcm_running, true);
 422                 break;
 423         case SNDRV_PCM_TRIGGER_STOP:
 424                 WRITE_ONCE(isight->pcm_running, false);
 425                 break;
 426         default:
 427                 return -EINVAL;
 428         }
 429         return 0;
 430 }
 431
 432 static snd_pcm_uframes_t isight_pointer(struct snd_pcm_substream *substream)
 433 {
 434         struct isight *isight = substream->private_data;
 435
 436         return READ_ONCE(isight->buffer_pointer);
 437 }
 438
 439 static int isight_create_pcm(struct isight *isight)
 440 {
 441         static const struct snd_pcm_ops ops = {
 442                 .open      = isight_open,
 443                 .close     = isight_close,
 444                 .hw_params = isight_hw_params,
 445                 .hw_free   = isight_hw_free,
 446                 .prepare   = isight_prepare,
 447                 .trigger   = isight_trigger,
 448                 .pointer   = isight_pointer,
 449         };
 450         struct snd_pcm *pcm;
 451         int err;
 452
 453         err = snd_pcm_new(isight->card, "iSight", 0, 0, 1, &pcm);
 454         if (err < 0)
 455                 return err;
 456         pcm->private_data = isight;
 457         strcpy(pcm->name, "iSight");
 458         isight->pcm = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;
 459         isight->pcm->ops = &ops;
 460         snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0);
 461
 462         return 0;
 463 }
 464
 465 static int isight_gain_info(struct snd_kcontrol *ctl,
 466                             struct snd_ctl_elem_info *info)
 467 {
 468         struct isight *isight = ctl->private_data;
 469
 470         info->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 471         info->count = 1;
 472         info->value.integer.min = isight->gain_min;
 473         info->value.integer.max = isight->gain_max;
 474
 475         return 0;
 476 }
 477
 478 static int isight_gain_get(struct snd_kcontrol *ctl,
 479                            struct snd_ctl_elem_value *value)
 480 {
 481         struct isight *isight = ctl->private_data;
 482         __be32 gain;
 483         int err;
 484
 485         err = reg_read(isight, REG_GAIN, &gain);
 486         if (err < 0)
 487                 return err;
 488
 489         value->value.integer.value[0] = (s32)be32_to_cpu(gain);
 490
 491         return 0;
 492 }
 493
 494 static int isight_gain_put(struct snd_kcontrol *ctl,
 495                            struct snd_ctl_elem_value *value)
 496 {
 497         struct isight *isight = ctl->private_data;
 498
 499         if (value->value.integer.value[0] < isight->gain_min ||
 500             value->value.integer.value[0] > isight->gain_max)
 501                 return -EINVAL;
 502
 503         return reg_write(isight, REG_GAIN,
 504                          cpu_to_be32(value->value.integer.value[0]));
 505 }
 506
 507 static int isight_mute_get(struct snd_kcontrol *ctl,
 508                            struct snd_ctl_elem_value *value)
 509 {
 510         struct isight *isight = ctl->private_data;
 511         __be32 mute;
 512         int err;
 513
 514         err = reg_read(isight, REG_MUTE, &mute);
 515         if (err < 0)
 516                 return err;
 517
 518         value->value.integer.value[0] = !mute;
 519
 520         return 0;
 521 }
 522
 523 static int isight_mute_put(struct snd_kcontrol *ctl,
 524                            struct snd_ctl_elem_value *value)
 525 {
 526         struct isight *isight = ctl->private_data;
 527
 528         return reg_write(isight, REG_MUTE,
 529                          (__force __be32)!value->value.integer.value[0]);
 530 }
 531
 532 static int isight_create_mixer(struct isight *isight)
 533 {
 534         static const struct snd_kcontrol_new gain_control = {
 535                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 536                 .name = "Mic Capture Volume",
 537                 .access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
 538                           SNDRV_CTL_ELEM_ACCESS_TLV_READ,
 539                 .info = isight_gain_info,
 540                 .get = isight_gain_get,
 541                 .put = isight_gain_put,
 542         };
 543         static const struct snd_kcontrol_new mute_control = {
 544                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 545                 .name = "Mic Capture Switch",
 546                 .info = snd_ctl_boolean_mono_info,
 547                 .get = isight_mute_get,
 548                 .put = isight_mute_put,
 549         };
 550         __be32 value;
 551         struct snd_kcontrol *ctl;
 552         int err;
 553
 554         err = reg_read(isight, REG_GAIN_RAW_START, &value);
 555         if (err < 0)
 556                 return err;
 557         isight->gain_min = be32_to_cpu(value);
 558
 559         err = reg_read(isight, REG_GAIN_RAW_END, &value);
 560         if (err < 0)
 561                 return err;
 562         isight->gain_max = be32_to_cpu(value);
 563
 564         isight->gain_tlv[SNDRV_CTL_TLVO_TYPE] = SNDRV_CTL_TLVT_DB_MINMAX;
 565         isight->gain_tlv[SNDRV_CTL_TLVO_LEN] = 2 * sizeof(unsigned int);
 566
 567         err = reg_read(isight, REG_GAIN_DB_START, &value);
 568         if (err < 0)
 569                 return err;
 570         isight->gain_tlv[SNDRV_CTL_TLVO_DB_MINMAX_MIN] =
 571                                                 (s32)be32_to_cpu(value) * 100;
 572
 573         err = reg_read(isight, REG_GAIN_DB_END, &value);
 574         if (err < 0)
 575                 return err;
 576         isight->gain_tlv[SNDRV_CTL_TLVO_DB_MINMAX_MAX] =
 577                                                 (s32)be32_to_cpu(value) * 100;
 578
 579         ctl = snd_ctl_new1(&gain_control, isight);
 580         if (ctl)
 581                 ctl->tlv.p = isight->gain_tlv;
 582         err = snd_ctl_add(isight->card, ctl);
 583         if (err < 0)
 584                 return err;
 585
 586         err = snd_ctl_add(isight->card, snd_ctl_new1(&mute_control, isight));
 587         if (err < 0)
 588                 return err;
 589
 590         return 0;
 591 }
 592
 593 static void isight_card_free(struct snd_card *card)
 594 {
 595         struct isight *isight = card->private_data;
 596
 597         fw_iso_resources_destroy(&isight->resources);
 598 }
 599
 600 static u64 get_unit_base(struct fw_unit *unit)
 601 {
 602         struct fw_csr_iterator i;
 603         int key, value;
 604
 605         fw_csr_iterator_init(&i, unit->directory);
 606         while (fw_csr_iterator_next(&i, &key, &value))
 607                 if (key == CSR_OFFSET)
 608                         return CSR_REGISTER_BASE + value * 4;
 609         return 0;
 610 }
 611
 612 static int isight_probe(struct fw_unit *unit,
 613                         const struct ieee1394_device_id *id)
 614 {
 615         struct fw_device *fw_dev = fw_parent_device(unit);
 616         struct snd_card *card;
 617         struct isight *isight;
 618         int err;
 619
 620         err = snd_card_new(&unit->device, -1, NULL, THIS_MODULE,
 621                            sizeof(*isight), &card);
 622         if (err < 0)
 623                 return err;
 624
 625         isight = card->private_data;
 626         isight->card = card;
 627         mutex_init(&isight->mutex);
 628         isight->unit = fw_unit_get(unit);
 629         isight->device = fw_dev;
 630         isight->audio_base = get_unit_base(unit);
 631         if (!isight->audio_base) {
 632                 dev_err(&unit->device, "audio unit base not found\n");
 633                 err = -ENXIO;
 634                 goto error;
 635         }
 636         fw_iso_resources_init(&isight->resources, unit);
 637
 638         card->private_free = isight_card_free;
 639
 640         strcpy(card->driver, "iSight");
 641         strcpy(card->shortname, "Apple iSight");
 642         snprintf(card->longname, sizeof(card->longname),
 643                  "Apple iSight (GUID %08x%08x) at %s, S%d",
 644                  fw_dev->config_rom[3], fw_dev->config_rom[4],
 645                  dev_name(&unit->device), 100 << fw_dev->max_speed);
 646         strcpy(card->mixername, "iSight");
 647
 648         err = isight_create_pcm(isight);
 649         if (err < 0)
 650                 goto error;
 651
 652         err = isight_create_mixer(isight);
 653         if (err < 0)
 654                 goto error;
 655
 656         err = snd_card_register(card);
 657         if (err < 0)
 658                 goto error;
 659
 660         dev_set_drvdata(&unit->device, isight);
 661
 662         return 0;
 663 error:
 664         snd_card_free(card);
 665
 666         mutex_destroy(&isight->mutex);
 667         fw_unit_put(isight->unit);
 668
 669         return err;
 670 }
 671
 672 static void isight_bus_reset(struct fw_unit *unit)
 673 {
 674         struct isight *isight = dev_get_drvdata(&unit->device);
 675
 676         if (fw_iso_resources_update(&isight->resources) < 0) {
 677                 isight_pcm_abort(isight);
 678
 679                 mutex_lock(&isight->mutex);
 680                 isight_stop_streaming(isight);
 681                 mutex_unlock(&isight->mutex);
 682         }
 683 }
 684
 685 static void isight_remove(struct fw_unit *unit)
 686 {
 687         struct isight *isight = dev_get_drvdata(&unit->device);
 688
 689         isight_pcm_abort(isight);
 690
 691         snd_card_disconnect(isight->card);
 692
 693         mutex_lock(&isight->mutex);
 694         isight_stop_streaming(isight);
 695         mutex_unlock(&isight->mutex);
 696
 697         // Block till all of ALSA character devices are released.
 698         snd_card_free(isight->card);
 699
 700         mutex_destroy(&isight->mutex);
 701         fw_unit_put(isight->unit);
 702 }
 703
 704 static const struct ieee1394_device_id isight_id_table[] = {
 705         {
 706                 .match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
 707                                 IEEE1394_MATCH_VERSION,
 708                 .specifier_id = OUI_APPLE,
 709                 .version      = SW_ISIGHT_AUDIO,
 710         },
 711         { }
 712 };
 713 MODULE_DEVICE_TABLE(ieee1394, isight_id_table);
 714
 715 static struct fw_driver isight_driver = {
 716         .driver   = {
 717                 .owner  = THIS_MODULE,
 718                 .name   = KBUILD_MODNAME,
 719                 .bus    = &fw_bus_type,
 720         },
 721         .probe    = isight_probe,
 722         .update   = isight_bus_reset,
 723         .remove   = isight_remove,
 724         .id_table = isight_id_table,
 725 };
 726
 727 static int __init alsa_isight_init(void)
 728 {
 729         return driver_register(&isight_driver.driver);
 730 }
 731
 732 static void __exit alsa_isight_exit(void)
 733 {
 734         driver_unregister(&isight_driver.driver);
 735 }
 736
 737 module_init(alsa_isight_init);
 738 module_exit(alsa_isight_exit);