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 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) 300 loopback_active_notify(dpcm); 301 break; 302 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: 303 case SNDRV_PCM_TRIGGER_RESUME: 304 spin_lock(&cable->lock); 305 dpcm->last_jiffies = jiffies; 306 cable->pause &= ~stream; 307 loopback_timer_start(dpcm); 308 spin_unlock(&cable->lock); 309 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) 310 loopback_active_notify(dpcm); 311 break; 312 default: 313 return -EINVAL; 314 } 315 return 0; 316 } 317 318 static void params_change(struct snd_pcm_substream *substream) 319 { 320 struct snd_pcm_runtime *runtime = substream->runtime; 321 struct loopback_pcm *dpcm = runtime->private_data; 322 struct loopback_cable *cable = dpcm->cable; 323 324 cable->hw.formats = pcm_format_to_bits(runtime->format); 325 cable->hw.rate_min = runtime->rate; 326 cable->hw.rate_max = runtime->rate; 327 cable->hw.channels_min = runtime->channels; 328 cable->hw.channels_max = runtime->channels; 329 } 330 331 static int loopback_prepare(struct snd_pcm_substream *substream) 332 { 333 struct snd_pcm_runtime *runtime = substream->runtime; 334 struct loopback_pcm *dpcm = runtime->private_data; 335 struct loopback_cable *cable = dpcm->cable; 336 int bps, salign; 337 338 loopback_timer_stop_sync(dpcm); 339 340 salign = (snd_pcm_format_physical_width(runtime->format) * 341 runtime->channels) / 8; 342 bps = salign * runtime->rate; 343 if (bps <= 0 || salign <= 0) 344 return -EINVAL; 345 346 dpcm->buf_pos = 0; 347 dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size); 348 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) { 349 /* clear capture buffer */ 350 dpcm->silent_size = dpcm->pcm_buffer_size; 351 snd_pcm_format_set_silence(runtime->format, runtime->dma_area, 352 runtime->buffer_size * runtime->channels); 353 } 354 355 dpcm->irq_pos = 0; 356 dpcm->period_update_pending = 0; 357 dpcm->pcm_bps = bps; 358 dpcm->pcm_salign = salign; 359 dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size); 360 361 mutex_lock(&dpcm->loopback->cable_lock); 362 if (!(cable->valid & ~(1 << substream->stream)) || 363 (get_setup(dpcm)->notify && 364 substream->stream == SNDRV_PCM_STREAM_PLAYBACK)) 365 params_change(substream); 366 cable->valid |= 1 << substream->stream; 367 mutex_unlock(&dpcm->loopback->cable_lock); 368 369 return 0; 370 } 371 372 static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes) 373 { 374 struct snd_pcm_runtime *runtime = dpcm->substream->runtime; 375 char *dst = runtime->dma_area; 376 unsigned int dst_off = dpcm->buf_pos; 377 378 if (dpcm->silent_size >= dpcm->pcm_buffer_size) 379 return; 380 if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size) 381 bytes = dpcm->pcm_buffer_size - dpcm->silent_size; 382 383 for (;;) { 384 unsigned int size = bytes; 385 if (dst_off + size > dpcm->pcm_buffer_size) 386 size = dpcm->pcm_buffer_size - dst_off; 387 snd_pcm_format_set_silence(runtime->format, dst + dst_off, 388 bytes_to_frames(runtime, size) * 389 runtime->channels); 390 dpcm->silent_size += size; 391 bytes -= size; 392 if (!bytes) 393 break; 394 dst_off = 0; 395 } 396 } 397 398 static void copy_play_buf(struct loopback_pcm *play, 399 struct loopback_pcm *capt, 400 unsigned int bytes) 401 { 402 struct snd_pcm_runtime *runtime = play->substream->runtime; 403 char *src = runtime->dma_area; 404 char *dst = capt->substream->runtime->dma_area; 405 unsigned int src_off = play->buf_pos; 406 unsigned int dst_off = capt->buf_pos; 407 unsigned int clear_bytes = 0; 408 409 /* check if playback is draining, trim the capture copy size 410 * when our pointer is at the end of playback ring buffer */ 411 if (runtime->status->state == SNDRV_PCM_STATE_DRAINING && 412 snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) { 413 snd_pcm_uframes_t appl_ptr, appl_ptr1, diff; 414 appl_ptr = appl_ptr1 = runtime->control->appl_ptr; 415 appl_ptr1 -= appl_ptr1 % runtime->buffer_size; 416 appl_ptr1 += play->buf_pos / play->pcm_salign; 417 if (appl_ptr < appl_ptr1) 418 appl_ptr1 -= runtime->buffer_size; 419 diff = (appl_ptr - appl_ptr1) * play->pcm_salign; 420 if (diff < bytes) { 421 clear_bytes = bytes - diff; 422 bytes = diff; 423 } 424 } 425 426 for (;;) { 427 unsigned int size = bytes; 428 if (src_off + size > play->pcm_buffer_size) 429 size = play->pcm_buffer_size - src_off; 430 if (dst_off + size > capt->pcm_buffer_size) 431 size = capt->pcm_buffer_size - dst_off; 432 memcpy(dst + dst_off, src + src_off, size); 433 capt->silent_size = 0; 434 bytes -= size; 435 if (!bytes) 436 break; 437 src_off = (src_off + size) % play->pcm_buffer_size; 438 dst_off = (dst_off + size) % capt->pcm_buffer_size; 439 } 440 441 if (clear_bytes > 0) { 442 clear_capture_buf(capt, clear_bytes); 443 capt->silent_size = 0; 444 } 445 } 446 447 static inline unsigned int bytepos_delta(struct loopback_pcm *dpcm, 448 unsigned int jiffies_delta) 449 { 450 unsigned long last_pos; 451 unsigned int delta; 452 453 last_pos = byte_pos(dpcm, dpcm->irq_pos); 454 dpcm->irq_pos += jiffies_delta * dpcm->pcm_bps; 455 delta = byte_pos(dpcm, dpcm->irq_pos) - last_pos; 456 if (delta >= dpcm->last_drift) 457 delta -= dpcm->last_drift; 458 dpcm->last_drift = 0; 459 if (dpcm->irq_pos >= dpcm->period_size_frac) { 460 dpcm->irq_pos %= dpcm->period_size_frac; 461 dpcm->period_update_pending = 1; 462 } 463 return delta; 464 } 465 466 static inline void bytepos_finish(struct loopback_pcm *dpcm, 467 unsigned int delta) 468 { 469 dpcm->buf_pos += delta; 470 dpcm->buf_pos %= dpcm->pcm_buffer_size; 471 } 472 473 /* call in cable->lock */ 474 static unsigned int loopback_pos_update(struct loopback_cable *cable) 475 { 476 struct loopback_pcm *dpcm_play = 477 cable->streams[SNDRV_PCM_STREAM_PLAYBACK]; 478 struct loopback_pcm *dpcm_capt = 479 cable->streams[SNDRV_PCM_STREAM_CAPTURE]; 480 unsigned long delta_play = 0, delta_capt = 0; 481 unsigned int running, count1, count2; 482 483 running = cable->running ^ cable->pause; 484 if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) { 485 delta_play = jiffies - dpcm_play->last_jiffies; 486 dpcm_play->last_jiffies += delta_play; 487 } 488 489 if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) { 490 delta_capt = jiffies - dpcm_capt->last_jiffies; 491 dpcm_capt->last_jiffies += delta_capt; 492 } 493 494 if (delta_play == 0 && delta_capt == 0) 495 goto unlock; 496 497 if (delta_play > delta_capt) { 498 count1 = bytepos_delta(dpcm_play, delta_play - delta_capt); 499 bytepos_finish(dpcm_play, count1); 500 delta_play = delta_capt; 501 } else if (delta_play < delta_capt) { 502 count1 = bytepos_delta(dpcm_capt, delta_capt - delta_play); 503 clear_capture_buf(dpcm_capt, count1); 504 bytepos_finish(dpcm_capt, count1); 505 delta_capt = delta_play; 506 } 507 508 if (delta_play == 0 && delta_capt == 0) 509 goto unlock; 510 511 /* note delta_capt == delta_play at this moment */ 512 count1 = bytepos_delta(dpcm_play, delta_play); 513 count2 = bytepos_delta(dpcm_capt, delta_capt); 514 if (count1 < count2) { 515 dpcm_capt->last_drift = count2 - count1; 516 count1 = count2; 517 } else if (count1 > count2) { 518 dpcm_play->last_drift = count1 - count2; 519 } 520 copy_play_buf(dpcm_play, dpcm_capt, count1); 521 bytepos_finish(dpcm_play, count1); 522 bytepos_finish(dpcm_capt, count1); 523 unlock: 524 return running; 525 } 526 527 static void loopback_timer_function(struct timer_list *t) 528 { 529 struct loopback_pcm *dpcm = from_timer(dpcm, t, timer); 530 unsigned long flags; 531 532 spin_lock_irqsave(&dpcm->cable->lock, flags); 533 if (loopback_pos_update(dpcm->cable) & (1 << dpcm->substream->stream)) { 534 loopback_timer_start(dpcm); 535 if (dpcm->period_update_pending) { 536 dpcm->period_update_pending = 0; 537 spin_unlock_irqrestore(&dpcm->cable->lock, flags); 538 /* need to unlock before calling below */ 539 snd_pcm_period_elapsed(dpcm->substream); 540 return; 541 } 542 } 543 spin_unlock_irqrestore(&dpcm->cable->lock, flags); 544 } 545 546 static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream) 547 { 548 struct snd_pcm_runtime *runtime = substream->runtime; 549 struct loopback_pcm *dpcm = runtime->private_data; 550 snd_pcm_uframes_t pos; 551 552 spin_lock(&dpcm->cable->lock); 553 loopback_pos_update(dpcm->cable); 554 pos = dpcm->buf_pos; 555 spin_unlock(&dpcm->cable->lock); 556 return bytes_to_frames(runtime, pos); 557 } 558 559 static const struct snd_pcm_hardware loopback_pcm_hardware = 560 { 561 .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP | 562 SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE | 563 SNDRV_PCM_INFO_RESUME), 564 .formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE | 565 SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S24_BE | 566 SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE | 567 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE | 568 SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE), 569 .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000, 570 .rate_min = 8000, 571 .rate_max = 192000, 572 .channels_min = 1, 573 .channels_max = 32, 574 .buffer_bytes_max = 2 * 1024 * 1024, 575 .period_bytes_min = 64, 576 /* note check overflow in frac_pos() using pcm_rate_shift before 577 changing period_bytes_max value */ 578 .period_bytes_max = 1024 * 1024, 579 .periods_min = 1, 580 .periods_max = 1024, 581 .fifo_size = 0, 582 }; 583 584 static void loopback_runtime_free(struct snd_pcm_runtime *runtime) 585 { 586 struct loopback_pcm *dpcm = runtime->private_data; 587 kfree(dpcm); 588 } 589 590 static int loopback_hw_params(struct snd_pcm_substream *substream, 591 struct snd_pcm_hw_params *params) 592 { 593 return snd_pcm_lib_alloc_vmalloc_buffer(substream, 594 params_buffer_bytes(params)); 595 } 596 597 static int loopback_hw_free(struct snd_pcm_substream *substream) 598 { 599 struct snd_pcm_runtime *runtime = substream->runtime; 600 struct loopback_pcm *dpcm = runtime->private_data; 601 struct loopback_cable *cable = dpcm->cable; 602 603 mutex_lock(&dpcm->loopback->cable_lock); 604 cable->valid &= ~(1 << substream->stream); 605 mutex_unlock(&dpcm->loopback->cable_lock); 606 return snd_pcm_lib_free_vmalloc_buffer(substream); 607 } 608 609 static unsigned int get_cable_index(struct snd_pcm_substream *substream) 610 { 611 if (!substream->pcm->device) 612 return substream->stream; 613 else 614 return !substream->stream; 615 } 616 617 static int rule_format(struct snd_pcm_hw_params *params, 618 struct snd_pcm_hw_rule *rule) 619 { 620 struct loopback_pcm *dpcm = rule->private; 621 struct loopback_cable *cable = dpcm->cable; 622 struct snd_mask m; 623 624 snd_mask_none(&m); 625 mutex_lock(&dpcm->loopback->cable_lock); 626 m.bits[0] = (u_int32_t)cable->hw.formats; 627 m.bits[1] = (u_int32_t)(cable->hw.formats >> 32); 628 mutex_unlock(&dpcm->loopback->cable_lock); 629 return snd_mask_refine(hw_param_mask(params, rule->var), &m); 630 } 631 632 static int rule_rate(struct snd_pcm_hw_params *params, 633 struct snd_pcm_hw_rule *rule) 634 { 635 struct loopback_pcm *dpcm = rule->private; 636 struct loopback_cable *cable = dpcm->cable; 637 struct snd_interval t; 638 639 mutex_lock(&dpcm->loopback->cable_lock); 640 t.min = cable->hw.rate_min; 641 t.max = cable->hw.rate_max; 642 mutex_unlock(&dpcm->loopback->cable_lock); 643 t.openmin = t.openmax = 0; 644 t.integer = 0; 645 return snd_interval_refine(hw_param_interval(params, rule->var), &t); 646 } 647 648 static int rule_channels(struct snd_pcm_hw_params *params, 649 struct snd_pcm_hw_rule *rule) 650 { 651 struct loopback_pcm *dpcm = rule->private; 652 struct loopback_cable *cable = dpcm->cable; 653 struct snd_interval t; 654 655 mutex_lock(&dpcm->loopback->cable_lock); 656 t.min = cable->hw.channels_min; 657 t.max = cable->hw.channels_max; 658 mutex_unlock(&dpcm->loopback->cable_lock); 659 t.openmin = t.openmax = 0; 660 t.integer = 0; 661 return snd_interval_refine(hw_param_interval(params, rule->var), &t); 662 } 663 664 static void free_cable(struct snd_pcm_substream *substream) 665 { 666 struct loopback *loopback = substream->private_data; 667 int dev = get_cable_index(substream); 668 struct loopback_cable *cable; 669 670 cable = loopback->cables[substream->number][dev]; 671 if (!cable) 672 return; 673 if (cable->streams[!substream->stream]) { 674 /* other stream is still alive */ 675 spin_lock_irq(&cable->lock); 676 cable->streams[substream->stream] = NULL; 677 spin_unlock_irq(&cable->lock); 678 } else { 679 /* free the cable */ 680 loopback->cables[substream->number][dev] = NULL; 681 kfree(cable); 682 } 683 } 684 685 static int loopback_open(struct snd_pcm_substream *substream) 686 { 687 struct snd_pcm_runtime *runtime = substream->runtime; 688 struct loopback *loopback = substream->private_data; 689 struct loopback_pcm *dpcm; 690 struct loopback_cable *cable = NULL; 691 int err = 0; 692 int dev = get_cable_index(substream); 693 694 mutex_lock(&loopback->cable_lock); 695 dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL); 696 if (!dpcm) { 697 err = -ENOMEM; 698 goto unlock; 699 } 700 dpcm->loopback = loopback; 701 dpcm->substream = substream; 702 timer_setup(&dpcm->timer, loopback_timer_function, 0); 703 704 cable = loopback->cables[substream->number][dev]; 705 if (!cable) { 706 cable = kzalloc(sizeof(*cable), GFP_KERNEL); 707 if (!cable) { 708 err = -ENOMEM; 709 goto unlock; 710 } 711 spin_lock_init(&cable->lock); 712 cable->hw = loopback_pcm_hardware; 713 loopback->cables[substream->number][dev] = cable; 714 } 715 dpcm->cable = cable; 716 717 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS); 718 719 /* use dynamic rules based on actual runtime->hw values */ 720 /* note that the default rules created in the PCM midlevel code */ 721 /* are cached -> they do not reflect the actual state */ 722 err = snd_pcm_hw_rule_add(runtime, 0, 723 SNDRV_PCM_HW_PARAM_FORMAT, 724 rule_format, dpcm, 725 SNDRV_PCM_HW_PARAM_FORMAT, -1); 726 if (err < 0) 727 goto unlock; 728 err = snd_pcm_hw_rule_add(runtime, 0, 729 SNDRV_PCM_HW_PARAM_RATE, 730 rule_rate, dpcm, 731 SNDRV_PCM_HW_PARAM_RATE, -1); 732 if (err < 0) 733 goto unlock; 734 err = snd_pcm_hw_rule_add(runtime, 0, 735 SNDRV_PCM_HW_PARAM_CHANNELS, 736 rule_channels, dpcm, 737 SNDRV_PCM_HW_PARAM_CHANNELS, -1); 738 if (err < 0) 739 goto unlock; 740 741 runtime->private_data = dpcm; 742 runtime->private_free = loopback_runtime_free; 743 if (get_notify(dpcm)) 744 runtime->hw = loopback_pcm_hardware; 745 else 746 runtime->hw = cable->hw; 747 748 spin_lock_irq(&cable->lock); 749 cable->streams[substream->stream] = dpcm; 750 spin_unlock_irq(&cable->lock); 751 752 unlock: 753 if (err < 0) { 754 free_cable(substream); 755 kfree(dpcm); 756 } 757 mutex_unlock(&loopback->cable_lock); 758 return err; 759 } 760 761 static int loopback_close(struct snd_pcm_substream *substream) 762 { 763 struct loopback *loopback = substream->private_data; 764 struct loopback_pcm *dpcm = substream->runtime->private_data; 765 766 loopback_timer_stop_sync(dpcm); 767 mutex_lock(&loopback->cable_lock); 768 free_cable(substream); 769 mutex_unlock(&loopback->cable_lock); 770 return 0; 771 } 772 773 static const struct snd_pcm_ops loopback_pcm_ops = { 774 .open = loopback_open, 775 .close = loopback_close, 776 .ioctl = snd_pcm_lib_ioctl, 777 .hw_params = loopback_hw_params, 778 .hw_free = loopback_hw_free, 779 .prepare = loopback_prepare, 780 .trigger = loopback_trigger, 781 .pointer = loopback_pointer, 782 .page = snd_pcm_lib_get_vmalloc_page, 783 }; 784 785 static int loopback_pcm_new(struct loopback *loopback, 786 int device, int substreams) 787 { 788 struct snd_pcm *pcm; 789 int err; 790 791 err = snd_pcm_new(loopback->card, "Loopback PCM", device, 792 substreams, substreams, &pcm); 793 if (err < 0) 794 return err; 795 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_pcm_ops); 796 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_pcm_ops); 797 798 pcm->private_data = loopback; 799 pcm->info_flags = 0; 800 strcpy(pcm->name, "Loopback PCM"); 801 802 loopback->pcm[device] = pcm; 803 return 0; 804 } 805 806 static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol, 807 struct snd_ctl_elem_info *uinfo) 808 { 809 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; 810 uinfo->count = 1; 811 uinfo->value.integer.min = 80000; 812 uinfo->value.integer.max = 120000; 813 uinfo->value.integer.step = 1; 814 return 0; 815 } 816 817 static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol, 818 struct snd_ctl_elem_value *ucontrol) 819 { 820 struct loopback *loopback = snd_kcontrol_chip(kcontrol); 821 822 mutex_lock(&loopback->cable_lock); 823 ucontrol->value.integer.value[0] = 824 loopback->setup[kcontrol->id.subdevice] 825 [kcontrol->id.device].rate_shift; 826 mutex_unlock(&loopback->cable_lock); 827 return 0; 828 } 829 830 static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol, 831 struct snd_ctl_elem_value *ucontrol) 832 { 833 struct loopback *loopback = snd_kcontrol_chip(kcontrol); 834 unsigned int val; 835 int change = 0; 836 837 val = ucontrol->value.integer.value[0]; 838 if (val < 80000) 839 val = 80000; 840 if (val > 120000) 841 val = 120000; 842 mutex_lock(&loopback->cable_lock); 843 if (val != loopback->setup[kcontrol->id.subdevice] 844 [kcontrol->id.device].rate_shift) { 845 loopback->setup[kcontrol->id.subdevice] 846 [kcontrol->id.device].rate_shift = val; 847 change = 1; 848 } 849 mutex_unlock(&loopback->cable_lock); 850 return change; 851 } 852 853 static int loopback_notify_get(struct snd_kcontrol *kcontrol, 854 struct snd_ctl_elem_value *ucontrol) 855 { 856 struct loopback *loopback = snd_kcontrol_chip(kcontrol); 857 858 mutex_lock(&loopback->cable_lock); 859 ucontrol->value.integer.value[0] = 860 loopback->setup[kcontrol->id.subdevice] 861 [kcontrol->id.device].notify; 862 mutex_unlock(&loopback->cable_lock); 863 return 0; 864 } 865 866 static int loopback_notify_put(struct snd_kcontrol *kcontrol, 867 struct snd_ctl_elem_value *ucontrol) 868 { 869 struct loopback *loopback = snd_kcontrol_chip(kcontrol); 870 unsigned int val; 871 int change = 0; 872 873 val = ucontrol->value.integer.value[0] ? 1 : 0; 874 mutex_lock(&loopback->cable_lock); 875 if (val != loopback->setup[kcontrol->id.subdevice] 876 [kcontrol->id.device].notify) { 877 loopback->setup[kcontrol->id.subdevice] 878 [kcontrol->id.device].notify = val; 879 change = 1; 880 } 881 mutex_unlock(&loopback->cable_lock); 882 return change; 883 } 884 885 static int loopback_active_get(struct snd_kcontrol *kcontrol, 886 struct snd_ctl_elem_value *ucontrol) 887 { 888 struct loopback *loopback = snd_kcontrol_chip(kcontrol); 889 struct loopback_cable *cable; 890 891 unsigned int val = 0; 892 893 mutex_lock(&loopback->cable_lock); 894 cable = loopback->cables[kcontrol->id.subdevice][kcontrol->id.device ^ 1]; 895 if (cable != NULL) { 896 unsigned int running = cable->running ^ cable->pause; 897 898 val = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ? 1 : 0; 899 } 900 mutex_unlock(&loopback->cable_lock); 901 ucontrol->value.integer.value[0] = val; 902 return 0; 903 } 904 905 static int loopback_format_info(struct snd_kcontrol *kcontrol, 906 struct snd_ctl_elem_info *uinfo) 907 { 908 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; 909 uinfo->count = 1; 910 uinfo->value.integer.min = 0; 911 uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST; 912 uinfo->value.integer.step = 1; 913 return 0; 914 } 915 916 static int loopback_format_get(struct snd_kcontrol *kcontrol, 917 struct snd_ctl_elem_value *ucontrol) 918 { 919 struct loopback *loopback = snd_kcontrol_chip(kcontrol); 920 921 ucontrol->value.integer.value[0] = 922 loopback->setup[kcontrol->id.subdevice] 923 [kcontrol->id.device].format; 924 return 0; 925 } 926 927 static int loopback_rate_info(struct snd_kcontrol *kcontrol, 928 struct snd_ctl_elem_info *uinfo) 929 { 930 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; 931 uinfo->count = 1; 932 uinfo->value.integer.min = 0; 933 uinfo->value.integer.max = 192000; 934 uinfo->value.integer.step = 1; 935 return 0; 936 } 937 938 static int loopback_rate_get(struct snd_kcontrol *kcontrol, 939 struct snd_ctl_elem_value *ucontrol) 940 { 941 struct loopback *loopback = snd_kcontrol_chip(kcontrol); 942 943 mutex_lock(&loopback->cable_lock); 944 ucontrol->value.integer.value[0] = 945 loopback->setup[kcontrol->id.subdevice] 946 [kcontrol->id.device].rate; 947 mutex_unlock(&loopback->cable_lock); 948 return 0; 949 } 950 951 static int loopback_channels_info(struct snd_kcontrol *kcontrol, 952 struct snd_ctl_elem_info *uinfo) 953 { 954 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; 955 uinfo->count = 1; 956 uinfo->value.integer.min = 1; 957 uinfo->value.integer.max = 1024; 958 uinfo->value.integer.step = 1; 959 return 0; 960 } 961 962 static int loopback_channels_get(struct snd_kcontrol *kcontrol, 963 struct snd_ctl_elem_value *ucontrol) 964 { 965 struct loopback *loopback = snd_kcontrol_chip(kcontrol); 966 967 mutex_lock(&loopback->cable_lock); 968 ucontrol->value.integer.value[0] = 969 loopback->setup[kcontrol->id.subdevice] 970 [kcontrol->id.device].channels; 971 mutex_unlock(&loopback->cable_lock); 972 return 0; 973 } 974 975 static struct snd_kcontrol_new loopback_controls[] = { 976 { 977 .iface = SNDRV_CTL_ELEM_IFACE_PCM, 978 .name = "PCM Rate Shift 100000", 979 .info = loopback_rate_shift_info, 980 .get = loopback_rate_shift_get, 981 .put = loopback_rate_shift_put, 982 }, 983 { 984 .iface = SNDRV_CTL_ELEM_IFACE_PCM, 985 .name = "PCM Notify", 986 .info = snd_ctl_boolean_mono_info, 987 .get = loopback_notify_get, 988 .put = loopback_notify_put, 989 }, 990 #define ACTIVE_IDX 2 991 { 992 .access = SNDRV_CTL_ELEM_ACCESS_READ, 993 .iface = SNDRV_CTL_ELEM_IFACE_PCM, 994 .name = "PCM Slave Active", 995 .info = snd_ctl_boolean_mono_info, 996 .get = loopback_active_get, 997 }, 998 #define FORMAT_IDX 3 999 { 1000 .access = SNDRV_CTL_ELEM_ACCESS_READ, 1001 .iface = SNDRV_CTL_ELEM_IFACE_PCM, 1002 .name = "PCM Slave Format", 1003 .info = loopback_format_info, 1004 .get = loopback_format_get 1005 }, 1006 #define RATE_IDX 4 1007 { 1008 .access = SNDRV_CTL_ELEM_ACCESS_READ, 1009 .iface = SNDRV_CTL_ELEM_IFACE_PCM, 1010 .name = "PCM Slave Rate", 1011 .info = loopback_rate_info, 1012 .get = loopback_rate_get 1013 }, 1014 #define CHANNELS_IDX 5 1015 { 1016 .access = SNDRV_CTL_ELEM_ACCESS_READ, 1017 .iface = SNDRV_CTL_ELEM_IFACE_PCM, 1018 .name = "PCM Slave Channels", 1019 .info = loopback_channels_info, 1020 .get = loopback_channels_get 1021 } 1022 }; 1023 1024 static int loopback_mixer_new(struct loopback *loopback, int notify) 1025 { 1026 struct snd_card *card = loopback->card; 1027 struct snd_pcm *pcm; 1028 struct snd_kcontrol *kctl; 1029 struct loopback_setup *setup; 1030 int err, dev, substr, substr_count, idx; 1031 1032 strcpy(card->mixername, "Loopback Mixer"); 1033 for (dev = 0; dev < 2; dev++) { 1034 pcm = loopback->pcm[dev]; 1035 substr_count = 1036 pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count; 1037 for (substr = 0; substr < substr_count; substr++) { 1038 setup = &loopback->setup[substr][dev]; 1039 setup->notify = notify; 1040 setup->rate_shift = NO_PITCH; 1041 setup->format = SNDRV_PCM_FORMAT_S16_LE; 1042 setup->rate = 48000; 1043 setup->channels = 2; 1044 for (idx = 0; idx < ARRAY_SIZE(loopback_controls); 1045 idx++) { 1046 kctl = snd_ctl_new1(&loopback_controls[idx], 1047 loopback); 1048 if (!kctl) 1049 return -ENOMEM; 1050 kctl->id.device = dev; 1051 kctl->id.subdevice = substr; 1052 switch (idx) { 1053 case ACTIVE_IDX: 1054 setup->active_id = kctl->id; 1055 break; 1056 case FORMAT_IDX: 1057 setup->format_id = kctl->id; 1058 break; 1059 case RATE_IDX: 1060 setup->rate_id = kctl->id; 1061 break; 1062 case CHANNELS_IDX: 1063 setup->channels_id = kctl->id; 1064 break; 1065 default: 1066 break; 1067 } 1068 err = snd_ctl_add(card, kctl); 1069 if (err < 0) 1070 return err; 1071 } 1072 } 1073 } 1074 return 0; 1075 } 1076 1077 static void print_dpcm_info(struct snd_info_buffer *buffer, 1078 struct loopback_pcm *dpcm, 1079 const char *id) 1080 { 1081 snd_iprintf(buffer, " %s\n", id); 1082 if (dpcm == NULL) { 1083 snd_iprintf(buffer, " inactive\n"); 1084 return; 1085 } 1086 snd_iprintf(buffer, " buffer_size:\t%u\n", dpcm->pcm_buffer_size); 1087 snd_iprintf(buffer, " buffer_pos:\t\t%u\n", dpcm->buf_pos); 1088 snd_iprintf(buffer, " silent_size:\t%u\n", dpcm->silent_size); 1089 snd_iprintf(buffer, " period_size:\t%u\n", dpcm->pcm_period_size); 1090 snd_iprintf(buffer, " bytes_per_sec:\t%u\n", dpcm->pcm_bps); 1091 snd_iprintf(buffer, " sample_align:\t%u\n", dpcm->pcm_salign); 1092 snd_iprintf(buffer, " rate_shift:\t\t%u\n", dpcm->pcm_rate_shift); 1093 snd_iprintf(buffer, " update_pending:\t%u\n", 1094 dpcm->period_update_pending); 1095 snd_iprintf(buffer, " irq_pos:\t\t%u\n", dpcm->irq_pos); 1096 snd_iprintf(buffer, " period_frac:\t%u\n", dpcm->period_size_frac); 1097 snd_iprintf(buffer, " last_jiffies:\t%lu (%lu)\n", 1098 dpcm->last_jiffies, jiffies); 1099 snd_iprintf(buffer, " timer_expires:\t%lu\n", dpcm->timer.expires); 1100 } 1101 1102 static void print_substream_info(struct snd_info_buffer *buffer, 1103 struct loopback *loopback, 1104 int sub, 1105 int num) 1106 { 1107 struct loopback_cable *cable = loopback->cables[sub][num]; 1108 1109 snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub); 1110 if (cable == NULL) { 1111 snd_iprintf(buffer, " inactive\n"); 1112 return; 1113 } 1114 snd_iprintf(buffer, " valid: %u\n", cable->valid); 1115 snd_iprintf(buffer, " running: %u\n", cable->running); 1116 snd_iprintf(buffer, " pause: %u\n", cable->pause); 1117 print_dpcm_info(buffer, cable->streams[0], "Playback"); 1118 print_dpcm_info(buffer, cable->streams[1], "Capture"); 1119 } 1120 1121 static void print_cable_info(struct snd_info_entry *entry, 1122 struct snd_info_buffer *buffer) 1123 { 1124 struct loopback *loopback = entry->private_data; 1125 int sub, num; 1126 1127 mutex_lock(&loopback->cable_lock); 1128 num = entry->name[strlen(entry->name)-1]; 1129 num = num == '0' ? 0 : 1; 1130 for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++) 1131 print_substream_info(buffer, loopback, sub, num); 1132 mutex_unlock(&loopback->cable_lock); 1133 } 1134 1135 static int loopback_proc_new(struct loopback *loopback, int cidx) 1136 { 1137 char name[32]; 1138 1139 snprintf(name, sizeof(name), "cable#%d", cidx); 1140 return snd_card_ro_proc_new(loopback->card, name, loopback, 1141 print_cable_info); 1142 } 1143 1144 static int loopback_probe(struct platform_device *devptr) 1145 { 1146 struct snd_card *card; 1147 struct loopback *loopback; 1148 int dev = devptr->id; 1149 int err; 1150 1151 err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE, 1152 sizeof(struct loopback), &card); 1153 if (err < 0) 1154 return err; 1155 loopback = card->private_data; 1156 1157 if (pcm_substreams[dev] < 1) 1158 pcm_substreams[dev] = 1; 1159 if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS) 1160 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS; 1161 1162 loopback->card = card; 1163 mutex_init(&loopback->cable_lock); 1164 1165 err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]); 1166 if (err < 0) 1167 goto __nodev; 1168 err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]); 1169 if (err < 0) 1170 goto __nodev; 1171 err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0); 1172 if (err < 0) 1173 goto __nodev; 1174 loopback_proc_new(loopback, 0); 1175 loopback_proc_new(loopback, 1); 1176 strcpy(card->driver, "Loopback"); 1177 strcpy(card->shortname, "Loopback"); 1178 sprintf(card->longname, "Loopback %i", dev + 1); 1179 err = snd_card_register(card); 1180 if (!err) { 1181 platform_set_drvdata(devptr, card); 1182 return 0; 1183 } 1184 __nodev: 1185 snd_card_free(card); 1186 return err; 1187 } 1188 1189 static int loopback_remove(struct platform_device *devptr) 1190 { 1191 snd_card_free(platform_get_drvdata(devptr)); 1192 return 0; 1193 } 1194 1195 #ifdef CONFIG_PM_SLEEP 1196 static int loopback_suspend(struct device *pdev) 1197 { 1198 struct snd_card *card = dev_get_drvdata(pdev); 1199 1200 snd_power_change_state(card, SNDRV_CTL_POWER_D3hot); 1201 return 0; 1202 } 1203 1204 static int loopback_resume(struct device *pdev) 1205 { 1206 struct snd_card *card = dev_get_drvdata(pdev); 1207 1208 snd_power_change_state(card, SNDRV_CTL_POWER_D0); 1209 return 0; 1210 } 1211 1212 static SIMPLE_DEV_PM_OPS(loopback_pm, loopback_suspend, loopback_resume); 1213 #define LOOPBACK_PM_OPS &loopback_pm 1214 #else 1215 #define LOOPBACK_PM_OPS NULL 1216 #endif 1217 1218 #define SND_LOOPBACK_DRIVER "snd_aloop" 1219 1220 static struct platform_driver loopback_driver = { 1221 .probe = loopback_probe, 1222 .remove = loopback_remove, 1223 .driver = { 1224 .name = SND_LOOPBACK_DRIVER, 1225 .pm = LOOPBACK_PM_OPS, 1226 }, 1227 }; 1228 1229 static void loopback_unregister_all(void) 1230 { 1231 int i; 1232 1233 for (i = 0; i < ARRAY_SIZE(devices); ++i) 1234 platform_device_unregister(devices[i]); 1235 platform_driver_unregister(&loopback_driver); 1236 } 1237 1238 static int __init alsa_card_loopback_init(void) 1239 { 1240 int i, err, cards; 1241 1242 err = platform_driver_register(&loopback_driver); 1243 if (err < 0) 1244 return err; 1245 1246 1247 cards = 0; 1248 for (i = 0; i < SNDRV_CARDS; i++) { 1249 struct platform_device *device; 1250 if (!enable[i]) 1251 continue; 1252 device = platform_device_register_simple(SND_LOOPBACK_DRIVER, 1253 i, NULL, 0); 1254 if (IS_ERR(device)) 1255 continue; 1256 if (!platform_get_drvdata(device)) { 1257 platform_device_unregister(device); 1258 continue; 1259 } 1260 devices[i] = device; 1261 cards++; 1262 } 1263 if (!cards) { 1264 #ifdef MODULE 1265 printk(KERN_ERR "aloop: No loopback enabled\n"); 1266 #endif 1267 loopback_unregister_all(); 1268 return -ENODEV; 1269 } 1270 return 0; 1271 } 1272 1273 static void __exit alsa_card_loopback_exit(void) 1274 { 1275 loopback_unregister_all(); 1276 } 1277 1278 module_init(alsa_card_loopback_init) 1279 module_exit(alsa_card_loopback_exit) 1280