1 /* 2 * Loopback soundcard 3 * 4 * Original code: 5 * Copyright (c) by Jaroslav Kysela <perex@perex.cz> 6 * 7 * More accurate positioning and full-duplex support: 8 * Copyright (c) Ahmet İnan <ainan at mathematik.uni-freiburg.de> 9 * 10 * Major (almost complete) rewrite: 11 * Copyright (c) by Takashi Iwai <tiwai@suse.de> 12 * 13 * A next major update in 2010 (separate timers for playback and capture): 14 * Copyright (c) Jaroslav Kysela <perex@perex.cz> 15 * 16 * This program is free software; you can redistribute it and/or modify 17 * it under the terms of the GNU General Public License as published by 18 * the Free Software Foundation; either version 2 of the License, or 19 * (at your option) any later version. 20 * 21 * This program is distributed in the hope that it will be useful, 22 * but WITHOUT ANY WARRANTY; without even the implied warranty of 23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 24 * GNU General Public License for more details. 25 * 26 * You should have received a copy of the GNU General Public License 27 * along with this program; if not, write to the Free Software 28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 29 * 30 */ 31 32 #include <linux/init.h> 33 #include <linux/jiffies.h> 34 #include <linux/slab.h> 35 #include <linux/time.h> 36 #include <linux/wait.h> 37 #include <linux/module.h> 38 #include <linux/platform_device.h> 39 #include <sound/core.h> 40 #include <sound/control.h> 41 #include <sound/pcm.h> 42 #include <sound/pcm_params.h> 43 #include <sound/info.h> 44 #include <sound/initval.h> 45 46 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>"); 47 MODULE_DESCRIPTION("A loopback soundcard"); 48 MODULE_LICENSE("GPL"); 49 MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}"); 50 51 #define MAX_PCM_SUBSTREAMS 8 52 53 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */ 54 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */ 55 static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0}; 56 static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8}; 57 static int pcm_notify[SNDRV_CARDS]; 58 59 module_param_array(index, int, NULL, 0444); 60 MODULE_PARM_DESC(index, "Index value for loopback soundcard."); 61 module_param_array(id, charp, NULL, 0444); 62 MODULE_PARM_DESC(id, "ID string for loopback soundcard."); 63 module_param_array(enable, bool, NULL, 0444); 64 MODULE_PARM_DESC(enable, "Enable this loopback soundcard."); 65 module_param_array(pcm_substreams, int, NULL, 0444); 66 MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver."); 67 module_param_array(pcm_notify, int, NULL, 0444); 68 MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes."); 69 70 #define NO_PITCH 100000 71 72 struct loopback_pcm; 73 74 struct loopback_cable { 75 spinlock_t lock; 76 struct loopback_pcm *streams[2]; 77 struct snd_pcm_hardware hw; 78 /* flags */ 79 unsigned int valid; 80 unsigned int running; 81 unsigned int pause; 82 }; 83 84 struct loopback_setup { 85 unsigned int notify: 1; 86 unsigned int rate_shift; 87 unsigned int format; 88 unsigned int rate; 89 unsigned int channels; 90 struct snd_ctl_elem_id active_id; 91 struct snd_ctl_elem_id format_id; 92 struct snd_ctl_elem_id rate_id; 93 struct snd_ctl_elem_id channels_id; 94 }; 95 96 struct loopback { 97 struct snd_card *card; 98 struct mutex cable_lock; 99 struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2]; 100 struct snd_pcm *pcm[2]; 101 struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2]; 102 }; 103 104 struct loopback_pcm { 105 struct loopback *loopback; 106 struct snd_pcm_substream *substream; 107 struct loopback_cable *cable; 108 unsigned int pcm_buffer_size; 109 unsigned int buf_pos; /* position in buffer */ 110 unsigned int silent_size; 111 /* PCM parameters */ 112 unsigned int pcm_period_size; 113 unsigned int pcm_bps; /* bytes per second */ 114 unsigned int pcm_salign; /* bytes per sample * channels */ 115 unsigned int pcm_rate_shift; /* rate shift value */ 116 /* flags */ 117 unsigned int period_update_pending :1; 118 /* timer stuff */ 119 unsigned int irq_pos; /* fractional IRQ position */ 120 unsigned int period_size_frac; 121 unsigned int last_drift; 122 unsigned long last_jiffies; 123 struct timer_list timer; 124 }; 125 126 static struct platform_device *devices[SNDRV_CARDS]; 127 128 static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x) 129 { 130 if (dpcm->pcm_rate_shift == NO_PITCH) { 131 x /= HZ; 132 } else { 133 x = div_u64(NO_PITCH * (unsigned long long)x, 134 HZ * (unsigned long long)dpcm->pcm_rate_shift); 135 } 136 return x - (x % dpcm->pcm_salign); 137 } 138 139 static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x) 140 { 141 if (dpcm->pcm_rate_shift == NO_PITCH) { /* no pitch */ 142 return x * HZ; 143 } else { 144 x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ, 145 NO_PITCH); 146 } 147 return x; 148 } 149 150 static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm) 151 { 152 int device = dpcm->substream->pstr->pcm->device; 153 154 if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK) 155 device ^= 1; 156 return &dpcm->loopback->setup[dpcm->substream->number][device]; 157 } 158 159 static inline unsigned int get_notify(struct loopback_pcm *dpcm) 160 { 161 return get_setup(dpcm)->notify; 162 } 163 164 static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm) 165 { 166 return get_setup(dpcm)->rate_shift; 167 } 168 169 /* call in cable->lock */ 170 static void loopback_timer_start(struct loopback_pcm *dpcm) 171 { 172 unsigned long tick; 173 unsigned int rate_shift = get_rate_shift(dpcm); 174 175 if (rate_shift != dpcm->pcm_rate_shift) { 176 dpcm->pcm_rate_shift = rate_shift; 177 dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size); 178 } 179 if (dpcm->period_size_frac <= dpcm->irq_pos) { 180 dpcm->irq_pos %= dpcm->period_size_frac; 181 dpcm->period_update_pending = 1; 182 } 183 tick = dpcm->period_size_frac - dpcm->irq_pos; 184 tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps; 185 mod_timer(&dpcm->timer, jiffies + tick); 186 } 187 188 /* call in cable->lock */ 189 static inline void loopback_timer_stop(struct loopback_pcm *dpcm) 190 { 191 del_timer(&dpcm->timer); 192 dpcm->timer.expires = 0; 193 } 194 195 static inline void loopback_timer_stop_sync(struct loopback_pcm *dpcm) 196 { 197 del_timer_sync(&dpcm->timer); 198 } 199 200 #define CABLE_VALID_PLAYBACK (1 << SNDRV_PCM_STREAM_PLAYBACK) 201 #define CABLE_VALID_CAPTURE (1 << SNDRV_PCM_STREAM_CAPTURE) 202 #define CABLE_VALID_BOTH (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE) 203 204 static int loopback_check_format(struct loopback_cable *cable, int stream) 205 { 206 struct snd_pcm_runtime *runtime, *cruntime; 207 struct loopback_setup *setup; 208 struct snd_card *card; 209 int check; 210 211 if (cable->valid != CABLE_VALID_BOTH) { 212 if (stream == SNDRV_PCM_STREAM_PLAYBACK) 213 goto __notify; 214 return 0; 215 } 216 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]-> 217 substream->runtime; 218 cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]-> 219 substream->runtime; 220 check = runtime->format != cruntime->format || 221 runtime->rate != cruntime->rate || 222 runtime->channels != cruntime->channels; 223 if (!check) 224 return 0; 225 if (stream == SNDRV_PCM_STREAM_CAPTURE) { 226 return -EIO; 227 } else { 228 snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]-> 229 substream, SNDRV_PCM_STATE_DRAINING); 230 __notify: 231 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]-> 232 substream->runtime; 233 setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]); 234 card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card; 235 if (setup->format != runtime->format) { 236 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, 237 &setup->format_id); 238 setup->format = runtime->format; 239 } 240 if (setup->rate != runtime->rate) { 241 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, 242 &setup->rate_id); 243 setup->rate = runtime->rate; 244 } 245 if (setup->channels != runtime->channels) { 246 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, 247 &setup->channels_id); 248 setup->channels = runtime->channels; 249 } 250 } 251 return 0; 252 } 253 254 static void loopback_active_notify(struct loopback_pcm *dpcm) 255 { 256 snd_ctl_notify(dpcm->loopback->card, 257 SNDRV_CTL_EVENT_MASK_VALUE, 258 &get_setup(dpcm)->active_id); 259 } 260 261 static int loopback_trigger(struct snd_pcm_substream *substream, int cmd) 262 { 263 struct snd_pcm_runtime *runtime = substream->runtime; 264 struct loopback_pcm *dpcm = runtime->private_data; 265 struct loopback_cable *cable = dpcm->cable; 266 int err, stream = 1 << substream->stream; 267 268 switch (cmd) { 269 case SNDRV_PCM_TRIGGER_START: 270 err = loopback_check_format(cable, substream->stream); 271 if (err < 0) 272 return err; 273 dpcm->last_jiffies = jiffies; 274 dpcm->pcm_rate_shift = 0; 275 dpcm->last_drift = 0; 276 spin_lock(&cable->lock); 277 cable->running |= stream; 278 cable->pause &= ~stream; 279 loopback_timer_start(dpcm); 280 spin_unlock(&cable->lock); 281 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) 282 loopback_active_notify(dpcm); 283 break; 284 case SNDRV_PCM_TRIGGER_STOP: 285 spin_lock(&cable->lock); 286 cable->running &= ~stream; 287 cable->pause &= ~stream; 288 loopback_timer_stop(dpcm); 289 spin_unlock(&cable->lock); 290 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) 291 loopback_active_notify(dpcm); 292 break; 293 case SNDRV_PCM_TRIGGER_PAUSE_PUSH: 294 case SNDRV_PCM_TRIGGER_SUSPEND: 295 spin_lock(&cable->lock); 296 cable->pause |= stream; 297 loopback_timer_stop(dpcm); 298 spin_unlock(&cable->lock); 299 break; 300 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: 301 case SNDRV_PCM_TRIGGER_RESUME: 302 spin_lock(&cable->lock); 303 dpcm->last_jiffies = jiffies; 304 cable->pause &= ~stream; 305 loopback_timer_start(dpcm); 306 spin_unlock(&cable->lock); 307 break; 308 default: 309 return -EINVAL; 310 } 311 return 0; 312 } 313 314 static void params_change(struct snd_pcm_substream *substream) 315 { 316 struct snd_pcm_runtime *runtime = substream->runtime; 317 struct loopback_pcm *dpcm = runtime->private_data; 318 struct loopback_cable *cable = dpcm->cable; 319 320 cable->hw.formats = pcm_format_to_bits(runtime->format); 321 cable->hw.rate_min = runtime->rate; 322 cable->hw.rate_max = runtime->rate; 323 cable->hw.channels_min = runtime->channels; 324 cable->hw.channels_max = runtime->channels; 325 } 326 327 static int loopback_prepare(struct snd_pcm_substream *substream) 328 { 329 struct snd_pcm_runtime *runtime = substream->runtime; 330 struct loopback_pcm *dpcm = runtime->private_data; 331 struct loopback_cable *cable = dpcm->cable; 332 int bps, salign; 333 334 loopback_timer_stop_sync(dpcm); 335 336 salign = (snd_pcm_format_width(runtime->format) * 337 runtime->channels) / 8; 338 bps = salign * runtime->rate; 339 if (bps <= 0 || salign <= 0) 340 return -EINVAL; 341 342 dpcm->buf_pos = 0; 343 dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size); 344 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) { 345 /* clear capture buffer */ 346 dpcm->silent_size = dpcm->pcm_buffer_size; 347 snd_pcm_format_set_silence(runtime->format, runtime->dma_area, 348 runtime->buffer_size * runtime->channels); 349 } 350 351 dpcm->irq_pos = 0; 352 dpcm->period_update_pending = 0; 353 dpcm->pcm_bps = bps; 354 dpcm->pcm_salign = salign; 355 dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size); 356 357 mutex_lock(&dpcm->loopback->cable_lock); 358 if (!(cable->valid & ~(1 << substream->stream)) || 359 (get_setup(dpcm)->notify && 360 substream->stream == SNDRV_PCM_STREAM_PLAYBACK)) 361 params_change(substream); 362 cable->valid |= 1 << substream->stream; 363 mutex_unlock(&dpcm->loopback->cable_lock); 364 365 return 0; 366 } 367 368 static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes) 369 { 370 struct snd_pcm_runtime *runtime = dpcm->substream->runtime; 371 char *dst = runtime->dma_area; 372 unsigned int dst_off = dpcm->buf_pos; 373 374 if (dpcm->silent_size >= dpcm->pcm_buffer_size) 375 return; 376 if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size) 377 bytes = dpcm->pcm_buffer_size - dpcm->silent_size; 378 379 for (;;) { 380 unsigned int size = bytes; 381 if (dst_off + size > dpcm->pcm_buffer_size) 382 size = dpcm->pcm_buffer_size - dst_off; 383 snd_pcm_format_set_silence(runtime->format, dst + dst_off, 384 bytes_to_frames(runtime, size) * 385 runtime->channels); 386 dpcm->silent_size += size; 387 bytes -= size; 388 if (!bytes) 389 break; 390 dst_off = 0; 391 } 392 } 393 394 static void copy_play_buf(struct loopback_pcm *play, 395 struct loopback_pcm *capt, 396 unsigned int bytes) 397 { 398 struct snd_pcm_runtime *runtime = play->substream->runtime; 399 char *src = runtime->dma_area; 400 char *dst = capt->substream->runtime->dma_area; 401 unsigned int src_off = play->buf_pos; 402 unsigned int dst_off = capt->buf_pos; 403 unsigned int clear_bytes = 0; 404 405 /* check if playback is draining, trim the capture copy size 406 * when our pointer is at the end of playback ring buffer */ 407 if (runtime->status->state == SNDRV_PCM_STATE_DRAINING && 408 snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) { 409 snd_pcm_uframes_t appl_ptr, appl_ptr1, diff; 410 appl_ptr = appl_ptr1 = runtime->control->appl_ptr; 411 appl_ptr1 -= appl_ptr1 % runtime->buffer_size; 412 appl_ptr1 += play->buf_pos / play->pcm_salign; 413 if (appl_ptr < appl_ptr1) 414 appl_ptr1 -= runtime->buffer_size; 415 diff = (appl_ptr - appl_ptr1) * play->pcm_salign; 416 if (diff < bytes) { 417 clear_bytes = bytes - diff; 418 bytes = diff; 419 } 420 } 421 422 for (;;) { 423 unsigned int size = bytes; 424 if (src_off + size > play->pcm_buffer_size) 425 size = play->pcm_buffer_size - src_off; 426 if (dst_off + size > capt->pcm_buffer_size) 427 size = capt->pcm_buffer_size - dst_off; 428 memcpy(dst + dst_off, src + src_off, size); 429 capt->silent_size = 0; 430 bytes -= size; 431 if (!bytes) 432 break; 433 src_off = (src_off + size) % play->pcm_buffer_size; 434 dst_off = (dst_off + size) % capt->pcm_buffer_size; 435 } 436 437 if (clear_bytes > 0) { 438 clear_capture_buf(capt, clear_bytes); 439 capt->silent_size = 0; 440 } 441 } 442 443 static inline unsigned int bytepos_delta(struct loopback_pcm *dpcm, 444 unsigned int jiffies_delta) 445 { 446 unsigned long last_pos; 447 unsigned int delta; 448 449 last_pos = byte_pos(dpcm, dpcm->irq_pos); 450 dpcm->irq_pos += jiffies_delta * dpcm->pcm_bps; 451 delta = byte_pos(dpcm, dpcm->irq_pos) - last_pos; 452 if (delta >= dpcm->last_drift) 453 delta -= dpcm->last_drift; 454 dpcm->last_drift = 0; 455 if (dpcm->irq_pos >= dpcm->period_size_frac) { 456 dpcm->irq_pos %= dpcm->period_size_frac; 457 dpcm->period_update_pending = 1; 458 } 459 return delta; 460 } 461 462 static inline void bytepos_finish(struct loopback_pcm *dpcm, 463 unsigned int delta) 464 { 465 dpcm->buf_pos += delta; 466 dpcm->buf_pos %= dpcm->pcm_buffer_size; 467 } 468 469 /* call in cable->lock */ 470 static unsigned int loopback_pos_update(struct loopback_cable *cable) 471 { 472 struct loopback_pcm *dpcm_play = 473 cable->streams[SNDRV_PCM_STREAM_PLAYBACK]; 474 struct loopback_pcm *dpcm_capt = 475 cable->streams[SNDRV_PCM_STREAM_CAPTURE]; 476 unsigned long delta_play = 0, delta_capt = 0; 477 unsigned int running, count1, count2; 478 479 running = cable->running ^ cable->pause; 480 if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) { 481 delta_play = jiffies - dpcm_play->last_jiffies; 482 dpcm_play->last_jiffies += delta_play; 483 } 484 485 if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) { 486 delta_capt = jiffies - dpcm_capt->last_jiffies; 487 dpcm_capt->last_jiffies += delta_capt; 488 } 489 490 if (delta_play == 0 && delta_capt == 0) 491 goto unlock; 492 493 if (delta_play > delta_capt) { 494 count1 = bytepos_delta(dpcm_play, delta_play - delta_capt); 495 bytepos_finish(dpcm_play, count1); 496 delta_play = delta_capt; 497 } else if (delta_play < delta_capt) { 498 count1 = bytepos_delta(dpcm_capt, delta_capt - delta_play); 499 clear_capture_buf(dpcm_capt, count1); 500 bytepos_finish(dpcm_capt, count1); 501 delta_capt = delta_play; 502 } 503 504 if (delta_play == 0 && delta_capt == 0) 505 goto unlock; 506 507 /* note delta_capt == delta_play at this moment */ 508 count1 = bytepos_delta(dpcm_play, delta_play); 509 count2 = bytepos_delta(dpcm_capt, delta_capt); 510 if (count1 < count2) { 511 dpcm_capt->last_drift = count2 - count1; 512 count1 = count2; 513 } else if (count1 > count2) { 514 dpcm_play->last_drift = count1 - count2; 515 } 516 copy_play_buf(dpcm_play, dpcm_capt, count1); 517 bytepos_finish(dpcm_play, count1); 518 bytepos_finish(dpcm_capt, count1); 519 unlock: 520 return running; 521 } 522 523 static void loopback_timer_function(struct timer_list *t) 524 { 525 struct loopback_pcm *dpcm = from_timer(dpcm, t, timer); 526 unsigned long flags; 527 528 spin_lock_irqsave(&dpcm->cable->lock, flags); 529 if (loopback_pos_update(dpcm->cable) & (1 << dpcm->substream->stream)) { 530 loopback_timer_start(dpcm); 531 if (dpcm->period_update_pending) { 532 dpcm->period_update_pending = 0; 533 spin_unlock_irqrestore(&dpcm->cable->lock, flags); 534 /* need to unlock before calling below */ 535 snd_pcm_period_elapsed(dpcm->substream); 536 return; 537 } 538 } 539 spin_unlock_irqrestore(&dpcm->cable->lock, flags); 540 } 541 542 static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream) 543 { 544 struct snd_pcm_runtime *runtime = substream->runtime; 545 struct loopback_pcm *dpcm = runtime->private_data; 546 snd_pcm_uframes_t pos; 547 548 spin_lock(&dpcm->cable->lock); 549 loopback_pos_update(dpcm->cable); 550 pos = dpcm->buf_pos; 551 spin_unlock(&dpcm->cable->lock); 552 return bytes_to_frames(runtime, pos); 553 } 554 555 static const struct snd_pcm_hardware loopback_pcm_hardware = 556 { 557 .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP | 558 SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE | 559 SNDRV_PCM_INFO_RESUME), 560 .formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE | 561 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE | 562 SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE), 563 .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000, 564 .rate_min = 8000, 565 .rate_max = 192000, 566 .channels_min = 1, 567 .channels_max = 32, 568 .buffer_bytes_max = 2 * 1024 * 1024, 569 .period_bytes_min = 64, 570 /* note check overflow in frac_pos() using pcm_rate_shift before 571 changing period_bytes_max value */ 572 .period_bytes_max = 1024 * 1024, 573 .periods_min = 1, 574 .periods_max = 1024, 575 .fifo_size = 0, 576 }; 577 578 static void loopback_runtime_free(struct snd_pcm_runtime *runtime) 579 { 580 struct loopback_pcm *dpcm = runtime->private_data; 581 kfree(dpcm); 582 } 583 584 static int loopback_hw_params(struct snd_pcm_substream *substream, 585 struct snd_pcm_hw_params *params) 586 { 587 return snd_pcm_lib_alloc_vmalloc_buffer(substream, 588 params_buffer_bytes(params)); 589 } 590 591 static int loopback_hw_free(struct snd_pcm_substream *substream) 592 { 593 struct snd_pcm_runtime *runtime = substream->runtime; 594 struct loopback_pcm *dpcm = runtime->private_data; 595 struct loopback_cable *cable = dpcm->cable; 596 597 mutex_lock(&dpcm->loopback->cable_lock); 598 cable->valid &= ~(1 << substream->stream); 599 mutex_unlock(&dpcm->loopback->cable_lock); 600 return snd_pcm_lib_free_vmalloc_buffer(substream); 601 } 602 603 static unsigned int get_cable_index(struct snd_pcm_substream *substream) 604 { 605 if (!substream->pcm->device) 606 return substream->stream; 607 else 608 return !substream->stream; 609 } 610 611 static int rule_format(struct snd_pcm_hw_params *params, 612 struct snd_pcm_hw_rule *rule) 613 { 614 struct loopback_pcm *dpcm = rule->private; 615 struct loopback_cable *cable = dpcm->cable; 616 struct snd_mask m; 617 618 snd_mask_none(&m); 619 mutex_lock(&dpcm->loopback->cable_lock); 620 m.bits[0] = (u_int32_t)cable->hw.formats; 621 m.bits[1] = (u_int32_t)(cable->hw.formats >> 32); 622 mutex_unlock(&dpcm->loopback->cable_lock); 623 return snd_mask_refine(hw_param_mask(params, rule->var), &m); 624 } 625 626 static int rule_rate(struct snd_pcm_hw_params *params, 627 struct snd_pcm_hw_rule *rule) 628 { 629 struct loopback_pcm *dpcm = rule->private; 630 struct loopback_cable *cable = dpcm->cable; 631 struct snd_interval t; 632 633 mutex_lock(&dpcm->loopback->cable_lock); 634 t.min = cable->hw.rate_min; 635 t.max = cable->hw.rate_max; 636 mutex_unlock(&dpcm->loopback->cable_lock); 637 t.openmin = t.openmax = 0; 638 t.integer = 0; 639 return snd_interval_refine(hw_param_interval(params, rule->var), &t); 640 } 641 642 static int rule_channels(struct snd_pcm_hw_params *params, 643 struct snd_pcm_hw_rule *rule) 644 { 645 struct loopback_pcm *dpcm = rule->private; 646 struct loopback_cable *cable = dpcm->cable; 647 struct snd_interval t; 648 649 mutex_lock(&dpcm->loopback->cable_lock); 650 t.min = cable->hw.channels_min; 651 t.max = cable->hw.channels_max; 652 mutex_unlock(&dpcm->loopback->cable_lock); 653 t.openmin = t.openmax = 0; 654 t.integer = 0; 655 return snd_interval_refine(hw_param_interval(params, rule->var), &t); 656 } 657 658 static void free_cable(struct snd_pcm_substream *substream) 659 { 660 struct loopback *loopback = substream->private_data; 661 int dev = get_cable_index(substream); 662 struct loopback_cable *cable; 663 664 cable = loopback->cables[substream->number][dev]; 665 if (!cable) 666 return; 667 if (cable->streams[!substream->stream]) { 668 /* other stream is still alive */ 669 spin_lock_irq(&cable->lock); 670 cable->streams[substream->stream] = NULL; 671 spin_unlock_irq(&cable->lock); 672 } else { 673 /* free the cable */ 674 loopback->cables[substream->number][dev] = NULL; 675 kfree(cable); 676 } 677 } 678 679 static int loopback_open(struct snd_pcm_substream *substream) 680 { 681 struct snd_pcm_runtime *runtime = substream->runtime; 682 struct loopback *loopback = substream->private_data; 683 struct loopback_pcm *dpcm; 684 struct loopback_cable *cable = NULL; 685 int err = 0; 686 int dev = get_cable_index(substream); 687 688 mutex_lock(&loopback->cable_lock); 689 dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL); 690 if (!dpcm) { 691 err = -ENOMEM; 692 goto unlock; 693 } 694 dpcm->loopback = loopback; 695 dpcm->substream = substream; 696 timer_setup(&dpcm->timer, loopback_timer_function, 0); 697 698 cable = loopback->cables[substream->number][dev]; 699 if (!cable) { 700 cable = kzalloc(sizeof(*cable), GFP_KERNEL); 701 if (!cable) { 702 err = -ENOMEM; 703 goto unlock; 704 } 705 spin_lock_init(&cable->lock); 706 cable->hw = loopback_pcm_hardware; 707 loopback->cables[substream->number][dev] = cable; 708 } 709 dpcm->cable = cable; 710 711 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS); 712 713 /* use dynamic rules based on actual runtime->hw values */ 714 /* note that the default rules created in the PCM midlevel code */ 715 /* are cached -> they do not reflect the actual state */ 716 err = snd_pcm_hw_rule_add(runtime, 0, 717 SNDRV_PCM_HW_PARAM_FORMAT, 718 rule_format, dpcm, 719 SNDRV_PCM_HW_PARAM_FORMAT, -1); 720 if (err < 0) 721 goto unlock; 722 err = snd_pcm_hw_rule_add(runtime, 0, 723 SNDRV_PCM_HW_PARAM_RATE, 724 rule_rate, dpcm, 725 SNDRV_PCM_HW_PARAM_RATE, -1); 726 if (err < 0) 727 goto unlock; 728 err = snd_pcm_hw_rule_add(runtime, 0, 729 SNDRV_PCM_HW_PARAM_CHANNELS, 730 rule_channels, dpcm, 731 SNDRV_PCM_HW_PARAM_CHANNELS, -1); 732 if (err < 0) 733 goto unlock; 734 735 runtime->private_data = dpcm; 736 runtime->private_free = loopback_runtime_free; 737 if (get_notify(dpcm)) 738 runtime->hw = loopback_pcm_hardware; 739 else 740 runtime->hw = cable->hw; 741 742 spin_lock_irq(&cable->lock); 743 cable->streams[substream->stream] = dpcm; 744 spin_unlock_irq(&cable->lock); 745 746 unlock: 747 if (err < 0) { 748 free_cable(substream); 749 kfree(dpcm); 750 } 751 mutex_unlock(&loopback->cable_lock); 752 return err; 753 } 754 755 static int loopback_close(struct snd_pcm_substream *substream) 756 { 757 struct loopback *loopback = substream->private_data; 758 struct loopback_pcm *dpcm = substream->runtime->private_data; 759 760 loopback_timer_stop_sync(dpcm); 761 mutex_lock(&loopback->cable_lock); 762 free_cable(substream); 763 mutex_unlock(&loopback->cable_lock); 764 return 0; 765 } 766 767 static const struct snd_pcm_ops loopback_playback_ops = { 768 .open = loopback_open, 769 .close = loopback_close, 770 .ioctl = snd_pcm_lib_ioctl, 771 .hw_params = loopback_hw_params, 772 .hw_free = loopback_hw_free, 773 .prepare = loopback_prepare, 774 .trigger = loopback_trigger, 775 .pointer = loopback_pointer, 776 .page = snd_pcm_lib_get_vmalloc_page, 777 .mmap = snd_pcm_lib_mmap_vmalloc, 778 }; 779 780 static const struct snd_pcm_ops loopback_capture_ops = { 781 .open = loopback_open, 782 .close = loopback_close, 783 .ioctl = snd_pcm_lib_ioctl, 784 .hw_params = loopback_hw_params, 785 .hw_free = loopback_hw_free, 786 .prepare = loopback_prepare, 787 .trigger = loopback_trigger, 788 .pointer = loopback_pointer, 789 .page = snd_pcm_lib_get_vmalloc_page, 790 .mmap = snd_pcm_lib_mmap_vmalloc, 791 }; 792 793 static int loopback_pcm_new(struct loopback *loopback, 794 int device, int substreams) 795 { 796 struct snd_pcm *pcm; 797 int err; 798 799 err = snd_pcm_new(loopback->card, "Loopback PCM", device, 800 substreams, substreams, &pcm); 801 if (err < 0) 802 return err; 803 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops); 804 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops); 805 806 pcm->private_data = loopback; 807 pcm->info_flags = 0; 808 strcpy(pcm->name, "Loopback PCM"); 809 810 loopback->pcm[device] = pcm; 811 return 0; 812 } 813 814 static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol, 815 struct snd_ctl_elem_info *uinfo) 816 { 817 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; 818 uinfo->count = 1; 819 uinfo->value.integer.min = 80000; 820 uinfo->value.integer.max = 120000; 821 uinfo->value.integer.step = 1; 822 return 0; 823 } 824 825 static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol, 826 struct snd_ctl_elem_value *ucontrol) 827 { 828 struct loopback *loopback = snd_kcontrol_chip(kcontrol); 829 830 ucontrol->value.integer.value[0] = 831 loopback->setup[kcontrol->id.subdevice] 832 [kcontrol->id.device].rate_shift; 833 return 0; 834 } 835 836 static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol, 837 struct snd_ctl_elem_value *ucontrol) 838 { 839 struct loopback *loopback = snd_kcontrol_chip(kcontrol); 840 unsigned int val; 841 int change = 0; 842 843 val = ucontrol->value.integer.value[0]; 844 if (val < 80000) 845 val = 80000; 846 if (val > 120000) 847 val = 120000; 848 mutex_lock(&loopback->cable_lock); 849 if (val != loopback->setup[kcontrol->id.subdevice] 850 [kcontrol->id.device].rate_shift) { 851 loopback->setup[kcontrol->id.subdevice] 852 [kcontrol->id.device].rate_shift = val; 853 change = 1; 854 } 855 mutex_unlock(&loopback->cable_lock); 856 return change; 857 } 858 859 static int loopback_notify_get(struct snd_kcontrol *kcontrol, 860 struct snd_ctl_elem_value *ucontrol) 861 { 862 struct loopback *loopback = snd_kcontrol_chip(kcontrol); 863 864 ucontrol->value.integer.value[0] = 865 loopback->setup[kcontrol->id.subdevice] 866 [kcontrol->id.device].notify; 867 return 0; 868 } 869 870 static int loopback_notify_put(struct snd_kcontrol *kcontrol, 871 struct snd_ctl_elem_value *ucontrol) 872 { 873 struct loopback *loopback = snd_kcontrol_chip(kcontrol); 874 unsigned int val; 875 int change = 0; 876 877 val = ucontrol->value.integer.value[0] ? 1 : 0; 878 if (val != loopback->setup[kcontrol->id.subdevice] 879 [kcontrol->id.device].notify) { 880 loopback->setup[kcontrol->id.subdevice] 881 [kcontrol->id.device].notify = val; 882 change = 1; 883 } 884 return change; 885 } 886 887 static int loopback_active_get(struct snd_kcontrol *kcontrol, 888 struct snd_ctl_elem_value *ucontrol) 889 { 890 struct loopback *loopback = snd_kcontrol_chip(kcontrol); 891 struct loopback_cable *cable = loopback->cables 892 [kcontrol->id.subdevice][kcontrol->id.device ^ 1]; 893 unsigned int val = 0; 894 895 if (cable != NULL) 896 val = (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ? 897 1 : 0; 898 ucontrol->value.integer.value[0] = val; 899 return 0; 900 } 901 902 static int loopback_format_info(struct snd_kcontrol *kcontrol, 903 struct snd_ctl_elem_info *uinfo) 904 { 905 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; 906 uinfo->count = 1; 907 uinfo->value.integer.min = 0; 908 uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST; 909 uinfo->value.integer.step = 1; 910 return 0; 911 } 912 913 static int loopback_format_get(struct snd_kcontrol *kcontrol, 914 struct snd_ctl_elem_value *ucontrol) 915 { 916 struct loopback *loopback = snd_kcontrol_chip(kcontrol); 917 918 ucontrol->value.integer.value[0] = 919 loopback->setup[kcontrol->id.subdevice] 920 [kcontrol->id.device].format; 921 return 0; 922 } 923 924 static int loopback_rate_info(struct snd_kcontrol *kcontrol, 925 struct snd_ctl_elem_info *uinfo) 926 { 927 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; 928 uinfo->count = 1; 929 uinfo->value.integer.min = 0; 930 uinfo->value.integer.max = 192000; 931 uinfo->value.integer.step = 1; 932 return 0; 933 } 934 935 static int loopback_rate_get(struct snd_kcontrol *kcontrol, 936 struct snd_ctl_elem_value *ucontrol) 937 { 938 struct loopback *loopback = snd_kcontrol_chip(kcontrol); 939 940 ucontrol->value.integer.value[0] = 941 loopback->setup[kcontrol->id.subdevice] 942 [kcontrol->id.device].rate; 943 return 0; 944 } 945 946 static int loopback_channels_info(struct snd_kcontrol *kcontrol, 947 struct snd_ctl_elem_info *uinfo) 948 { 949 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; 950 uinfo->count = 1; 951 uinfo->value.integer.min = 1; 952 uinfo->value.integer.max = 1024; 953 uinfo->value.integer.step = 1; 954 return 0; 955 } 956 957 static int loopback_channels_get(struct snd_kcontrol *kcontrol, 958 struct snd_ctl_elem_value *ucontrol) 959 { 960 struct loopback *loopback = snd_kcontrol_chip(kcontrol); 961 962 ucontrol->value.integer.value[0] = 963 loopback->setup[kcontrol->id.subdevice] 964 [kcontrol->id.device].channels; 965 return 0; 966 } 967 968 static struct snd_kcontrol_new loopback_controls[] = { 969 { 970 .iface = SNDRV_CTL_ELEM_IFACE_PCM, 971 .name = "PCM Rate Shift 100000", 972 .info = loopback_rate_shift_info, 973 .get = loopback_rate_shift_get, 974 .put = loopback_rate_shift_put, 975 }, 976 { 977 .iface = SNDRV_CTL_ELEM_IFACE_PCM, 978 .name = "PCM Notify", 979 .info = snd_ctl_boolean_mono_info, 980 .get = loopback_notify_get, 981 .put = loopback_notify_put, 982 }, 983 #define ACTIVE_IDX 2 984 { 985 .access = SNDRV_CTL_ELEM_ACCESS_READ, 986 .iface = SNDRV_CTL_ELEM_IFACE_PCM, 987 .name = "PCM Slave Active", 988 .info = snd_ctl_boolean_mono_info, 989 .get = loopback_active_get, 990 }, 991 #define FORMAT_IDX 3 992 { 993 .access = SNDRV_CTL_ELEM_ACCESS_READ, 994 .iface = SNDRV_CTL_ELEM_IFACE_PCM, 995 .name = "PCM Slave Format", 996 .info = loopback_format_info, 997 .get = loopback_format_get 998 }, 999 #define RATE_IDX 4 1000 { 1001 .access = SNDRV_CTL_ELEM_ACCESS_READ, 1002 .iface = SNDRV_CTL_ELEM_IFACE_PCM, 1003 .name = "PCM Slave Rate", 1004 .info = loopback_rate_info, 1005 .get = loopback_rate_get 1006 }, 1007 #define CHANNELS_IDX 5 1008 { 1009 .access = SNDRV_CTL_ELEM_ACCESS_READ, 1010 .iface = SNDRV_CTL_ELEM_IFACE_PCM, 1011 .name = "PCM Slave Channels", 1012 .info = loopback_channels_info, 1013 .get = loopback_channels_get 1014 } 1015 }; 1016 1017 static int loopback_mixer_new(struct loopback *loopback, int notify) 1018 { 1019 struct snd_card *card = loopback->card; 1020 struct snd_pcm *pcm; 1021 struct snd_kcontrol *kctl; 1022 struct loopback_setup *setup; 1023 int err, dev, substr, substr_count, idx; 1024 1025 strcpy(card->mixername, "Loopback Mixer"); 1026 for (dev = 0; dev < 2; dev++) { 1027 pcm = loopback->pcm[dev]; 1028 substr_count = 1029 pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count; 1030 for (substr = 0; substr < substr_count; substr++) { 1031 setup = &loopback->setup[substr][dev]; 1032 setup->notify = notify; 1033 setup->rate_shift = NO_PITCH; 1034 setup->format = SNDRV_PCM_FORMAT_S16_LE; 1035 setup->rate = 48000; 1036 setup->channels = 2; 1037 for (idx = 0; idx < ARRAY_SIZE(loopback_controls); 1038 idx++) { 1039 kctl = snd_ctl_new1(&loopback_controls[idx], 1040 loopback); 1041 if (!kctl) 1042 return -ENOMEM; 1043 kctl->id.device = dev; 1044 kctl->id.subdevice = substr; 1045 switch (idx) { 1046 case ACTIVE_IDX: 1047 setup->active_id = kctl->id; 1048 break; 1049 case FORMAT_IDX: 1050 setup->format_id = kctl->id; 1051 break; 1052 case RATE_IDX: 1053 setup->rate_id = kctl->id; 1054 break; 1055 case CHANNELS_IDX: 1056 setup->channels_id = kctl->id; 1057 break; 1058 default: 1059 break; 1060 } 1061 err = snd_ctl_add(card, kctl); 1062 if (err < 0) 1063 return err; 1064 } 1065 } 1066 } 1067 return 0; 1068 } 1069 1070 static void print_dpcm_info(struct snd_info_buffer *buffer, 1071 struct loopback_pcm *dpcm, 1072 const char *id) 1073 { 1074 snd_iprintf(buffer, " %s\n", id); 1075 if (dpcm == NULL) { 1076 snd_iprintf(buffer, " inactive\n"); 1077 return; 1078 } 1079 snd_iprintf(buffer, " buffer_size:\t%u\n", dpcm->pcm_buffer_size); 1080 snd_iprintf(buffer, " buffer_pos:\t\t%u\n", dpcm->buf_pos); 1081 snd_iprintf(buffer, " silent_size:\t%u\n", dpcm->silent_size); 1082 snd_iprintf(buffer, " period_size:\t%u\n", dpcm->pcm_period_size); 1083 snd_iprintf(buffer, " bytes_per_sec:\t%u\n", dpcm->pcm_bps); 1084 snd_iprintf(buffer, " sample_align:\t%u\n", dpcm->pcm_salign); 1085 snd_iprintf(buffer, " rate_shift:\t\t%u\n", dpcm->pcm_rate_shift); 1086 snd_iprintf(buffer, " update_pending:\t%u\n", 1087 dpcm->period_update_pending); 1088 snd_iprintf(buffer, " irq_pos:\t\t%u\n", dpcm->irq_pos); 1089 snd_iprintf(buffer, " period_frac:\t%u\n", dpcm->period_size_frac); 1090 snd_iprintf(buffer, " last_jiffies:\t%lu (%lu)\n", 1091 dpcm->last_jiffies, jiffies); 1092 snd_iprintf(buffer, " timer_expires:\t%lu\n", dpcm->timer.expires); 1093 } 1094 1095 static void print_substream_info(struct snd_info_buffer *buffer, 1096 struct loopback *loopback, 1097 int sub, 1098 int num) 1099 { 1100 struct loopback_cable *cable = loopback->cables[sub][num]; 1101 1102 snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub); 1103 if (cable == NULL) { 1104 snd_iprintf(buffer, " inactive\n"); 1105 return; 1106 } 1107 snd_iprintf(buffer, " valid: %u\n", cable->valid); 1108 snd_iprintf(buffer, " running: %u\n", cable->running); 1109 snd_iprintf(buffer, " pause: %u\n", cable->pause); 1110 print_dpcm_info(buffer, cable->streams[0], "Playback"); 1111 print_dpcm_info(buffer, cable->streams[1], "Capture"); 1112 } 1113 1114 static void print_cable_info(struct snd_info_entry *entry, 1115 struct snd_info_buffer *buffer) 1116 { 1117 struct loopback *loopback = entry->private_data; 1118 int sub, num; 1119 1120 mutex_lock(&loopback->cable_lock); 1121 num = entry->name[strlen(entry->name)-1]; 1122 num = num == '0' ? 0 : 1; 1123 for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++) 1124 print_substream_info(buffer, loopback, sub, num); 1125 mutex_unlock(&loopback->cable_lock); 1126 } 1127 1128 static int loopback_proc_new(struct loopback *loopback, int cidx) 1129 { 1130 char name[32]; 1131 struct snd_info_entry *entry; 1132 int err; 1133 1134 snprintf(name, sizeof(name), "cable#%d", cidx); 1135 err = snd_card_proc_new(loopback->card, name, &entry); 1136 if (err < 0) 1137 return err; 1138 1139 snd_info_set_text_ops(entry, loopback, print_cable_info); 1140 return 0; 1141 } 1142 1143 static int loopback_probe(struct platform_device *devptr) 1144 { 1145 struct snd_card *card; 1146 struct loopback *loopback; 1147 int dev = devptr->id; 1148 int err; 1149 1150 err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE, 1151 sizeof(struct loopback), &card); 1152 if (err < 0) 1153 return err; 1154 loopback = card->private_data; 1155 1156 if (pcm_substreams[dev] < 1) 1157 pcm_substreams[dev] = 1; 1158 if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS) 1159 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS; 1160 1161 loopback->card = card; 1162 mutex_init(&loopback->cable_lock); 1163 1164 err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]); 1165 if (err < 0) 1166 goto __nodev; 1167 err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]); 1168 if (err < 0) 1169 goto __nodev; 1170 err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0); 1171 if (err < 0) 1172 goto __nodev; 1173 loopback_proc_new(loopback, 0); 1174 loopback_proc_new(loopback, 1); 1175 strcpy(card->driver, "Loopback"); 1176 strcpy(card->shortname, "Loopback"); 1177 sprintf(card->longname, "Loopback %i", dev + 1); 1178 err = snd_card_register(card); 1179 if (!err) { 1180 platform_set_drvdata(devptr, card); 1181 return 0; 1182 } 1183 __nodev: 1184 snd_card_free(card); 1185 return err; 1186 } 1187 1188 static int loopback_remove(struct platform_device *devptr) 1189 { 1190 snd_card_free(platform_get_drvdata(devptr)); 1191 return 0; 1192 } 1193 1194 #ifdef CONFIG_PM_SLEEP 1195 static int loopback_suspend(struct device *pdev) 1196 { 1197 struct snd_card *card = dev_get_drvdata(pdev); 1198 struct loopback *loopback = card->private_data; 1199 1200 snd_power_change_state(card, SNDRV_CTL_POWER_D3hot); 1201 1202 snd_pcm_suspend_all(loopback->pcm[0]); 1203 snd_pcm_suspend_all(loopback->pcm[1]); 1204 return 0; 1205 } 1206 1207 static int loopback_resume(struct device *pdev) 1208 { 1209 struct snd_card *card = dev_get_drvdata(pdev); 1210 1211 snd_power_change_state(card, SNDRV_CTL_POWER_D0); 1212 return 0; 1213 } 1214 1215 static SIMPLE_DEV_PM_OPS(loopback_pm, loopback_suspend, loopback_resume); 1216 #define LOOPBACK_PM_OPS &loopback_pm 1217 #else 1218 #define LOOPBACK_PM_OPS NULL 1219 #endif 1220 1221 #define SND_LOOPBACK_DRIVER "snd_aloop" 1222 1223 static struct platform_driver loopback_driver = { 1224 .probe = loopback_probe, 1225 .remove = loopback_remove, 1226 .driver = { 1227 .name = SND_LOOPBACK_DRIVER, 1228 .pm = LOOPBACK_PM_OPS, 1229 }, 1230 }; 1231 1232 static void loopback_unregister_all(void) 1233 { 1234 int i; 1235 1236 for (i = 0; i < ARRAY_SIZE(devices); ++i) 1237 platform_device_unregister(devices[i]); 1238 platform_driver_unregister(&loopback_driver); 1239 } 1240 1241 static int __init alsa_card_loopback_init(void) 1242 { 1243 int i, err, cards; 1244 1245 err = platform_driver_register(&loopback_driver); 1246 if (err < 0) 1247 return err; 1248 1249 1250 cards = 0; 1251 for (i = 0; i < SNDRV_CARDS; i++) { 1252 struct platform_device *device; 1253 if (!enable[i]) 1254 continue; 1255 device = platform_device_register_simple(SND_LOOPBACK_DRIVER, 1256 i, NULL, 0); 1257 if (IS_ERR(device)) 1258 continue; 1259 if (!platform_get_drvdata(device)) { 1260 platform_device_unregister(device); 1261 continue; 1262 } 1263 devices[i] = device; 1264 cards++; 1265 } 1266 if (!cards) { 1267 #ifdef MODULE 1268 printk(KERN_ERR "aloop: No loopback enabled\n"); 1269 #endif 1270 loopback_unregister_all(); 1271 return -ENODEV; 1272 } 1273 return 0; 1274 } 1275 1276 static void __exit alsa_card_loopback_exit(void) 1277 { 1278 loopback_unregister_all(); 1279 } 1280 1281 module_init(alsa_card_loopback_init) 1282 module_exit(alsa_card_loopback_exit) 1283