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