1/* pcm.c 2** 3** Copyright 2011, The Android Open Source Project 4** 5** Redistribution and use in source and binary forms, with or without 6** modification, are permitted provided that the following conditions are met: 7** * Redistributions of source code must retain the above copyright 8** notice, this list of conditions and the following disclaimer. 9** * Redistributions in binary form must reproduce the above copyright 10** notice, this list of conditions and the following disclaimer in the 11** documentation and/or other materials provided with the distribution. 12** * Neither the name of The Android Open Source Project nor the names of 13** its contributors may be used to endorse or promote products derived 14** from this software without specific prior written permission. 15** 16** THIS SOFTWARE IS PROVIDED BY The Android Open Source Project ``AS IS'' AND 17** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19** ARE DISCLAIMED. IN NO EVENT SHALL The Android Open Source Project BE LIABLE 20** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 22** SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 23** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 26** DAMAGE. 27*/ 28 29#include <stdio.h> 30#include <stdlib.h> 31#include <fcntl.h> 32#include <stdarg.h> 33#include <string.h> 34#include <errno.h> 35#include <unistd.h> 36#include <poll.h> 37 38#include <sys/ioctl.h> 39#include <sys/mman.h> 40#include <sys/time.h> 41#include <limits.h> 42 43#include <linux/ioctl.h> 44#define __force 45#define __bitwise 46#define __user 47#include <sound/asound.h> 48 49#include <tinyalsa/asoundlib.h> 50 51#define PARAM_MAX SNDRV_PCM_HW_PARAM_LAST_INTERVAL 52 53/* Logs information into a string; follows snprintf() in that 54 * offset may be greater than size, and though no characters are copied 55 * into string, characters are still counted into offset. */ 56#define STRLOG(string, offset, size, ...) \ 57 do { int temp, clipoffset = offset > size ? size : offset; \ 58 temp = snprintf(string + clipoffset, size - clipoffset, __VA_ARGS__); \ 59 if (temp > 0) offset += temp; } while (0) 60 61#ifndef ARRAY_SIZE 62#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0])) 63#endif 64 65/* refer to SNDRV_PCM_ACCESS_##index in sound/asound.h. */ 66static const char * const access_lookup[] = { 67 "MMAP_INTERLEAVED", 68 "MMAP_NONINTERLEAVED", 69 "MMAP_COMPLEX", 70 "RW_INTERLEAVED", 71 "RW_NONINTERLEAVED", 72}; 73 74/* refer to SNDRV_PCM_FORMAT_##index in sound/asound.h. */ 75static const char * const format_lookup[] = { 76 /*[0] =*/ "S8", 77 "U8", 78 "S16_LE", 79 "S16_BE", 80 "U16_LE", 81 "U16_BE", 82 "S24_LE", 83 "S24_BE", 84 "U24_LE", 85 "U24_BE", 86 "S32_LE", 87 "S32_BE", 88 "U32_LE", 89 "U32_BE", 90 "FLOAT_LE", 91 "FLOAT_BE", 92 "FLOAT64_LE", 93 "FLOAT64_BE", 94 "IEC958_SUBFRAME_LE", 95 "IEC958_SUBFRAME_BE", 96 "MU_LAW", 97 "A_LAW", 98 "IMA_ADPCM", 99 "MPEG", 100 /*[24] =*/ "GSM", 101 /* gap */ 102 [31] = "SPECIAL", 103 "S24_3LE", 104 "S24_3BE", 105 "U24_3LE", 106 "U24_3BE", 107 "S20_3LE", 108 "S20_3BE", 109 "U20_3LE", 110 "U20_3BE", 111 "S18_3LE", 112 "S18_3BE", 113 "U18_3LE", 114 /*[43] =*/ "U18_3BE", 115#if 0 116 /* recent additions, may not be present on local asound.h */ 117 "G723_24", 118 "G723_24_1B", 119 "G723_40", 120 "G723_40_1B", 121 "DSD_U8", 122 "DSD_U16_LE", 123#endif 124}; 125 126/* refer to SNDRV_PCM_SUBFORMAT_##index in sound/asound.h. */ 127static const char * const subformat_lookup[] = { 128 "STD", 129}; 130 131static inline int param_is_mask(int p) 132{ 133 return (p >= SNDRV_PCM_HW_PARAM_FIRST_MASK) && 134 (p <= SNDRV_PCM_HW_PARAM_LAST_MASK); 135} 136 137static inline int param_is_interval(int p) 138{ 139 return (p >= SNDRV_PCM_HW_PARAM_FIRST_INTERVAL) && 140 (p <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL); 141} 142 143static inline struct snd_interval *param_to_interval(struct snd_pcm_hw_params *p, int n) 144{ 145 return &(p->intervals[n - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL]); 146} 147 148static inline struct snd_mask *param_to_mask(struct snd_pcm_hw_params *p, int n) 149{ 150 return &(p->masks[n - SNDRV_PCM_HW_PARAM_FIRST_MASK]); 151} 152 153static void param_set_mask(struct snd_pcm_hw_params *p, int n, unsigned int bit) 154{ 155 if (bit >= SNDRV_MASK_MAX) 156 return; 157 if (param_is_mask(n)) { 158 struct snd_mask *m = param_to_mask(p, n); 159 m->bits[0] = 0; 160 m->bits[1] = 0; 161 m->bits[bit >> 5] |= (1 << (bit & 31)); 162 } 163} 164 165static void param_set_min(struct snd_pcm_hw_params *p, int n, unsigned int val) 166{ 167 if (param_is_interval(n)) { 168 struct snd_interval *i = param_to_interval(p, n); 169 i->min = val; 170 } 171} 172 173static unsigned int param_get_min(struct snd_pcm_hw_params *p, int n) 174{ 175 if (param_is_interval(n)) { 176 struct snd_interval *i = param_to_interval(p, n); 177 return i->min; 178 } 179 return 0; 180} 181 182static void param_set_max(struct snd_pcm_hw_params *p, int n, unsigned int val) 183{ 184 if (param_is_interval(n)) { 185 struct snd_interval *i = param_to_interval(p, n); 186 i->max = val; 187 } 188} 189 190static unsigned int param_get_max(struct snd_pcm_hw_params *p, int n) 191{ 192 if (param_is_interval(n)) { 193 struct snd_interval *i = param_to_interval(p, n); 194 return i->max; 195 } 196 return 0; 197} 198 199static void param_set_int(struct snd_pcm_hw_params *p, int n, unsigned int val) 200{ 201 if (param_is_interval(n)) { 202 struct snd_interval *i = param_to_interval(p, n); 203 i->min = val; 204 i->max = val; 205 i->integer = 1; 206 } 207} 208 209static unsigned int param_get_int(struct snd_pcm_hw_params *p, int n) 210{ 211 if (param_is_interval(n)) { 212 struct snd_interval *i = param_to_interval(p, n); 213 if (i->integer) 214 return i->max; 215 } 216 return 0; 217} 218 219static void param_init(struct snd_pcm_hw_params *p) 220{ 221 int n; 222 223 memset(p, 0, sizeof(*p)); 224 for (n = SNDRV_PCM_HW_PARAM_FIRST_MASK; 225 n <= SNDRV_PCM_HW_PARAM_LAST_MASK; n++) { 226 struct snd_mask *m = param_to_mask(p, n); 227 m->bits[0] = ~0; 228 m->bits[1] = ~0; 229 } 230 for (n = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; 231 n <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; n++) { 232 struct snd_interval *i = param_to_interval(p, n); 233 i->min = 0; 234 i->max = ~0; 235 } 236 p->rmask = ~0U; 237 p->cmask = 0; 238 p->info = ~0U; 239} 240 241#define PCM_ERROR_MAX 128 242 243struct pcm { 244 int fd; 245 unsigned int flags; 246 int running:1; 247 int prepared:1; 248 int underruns; 249 unsigned int buffer_size; 250 unsigned int boundary; 251 char error[PCM_ERROR_MAX]; 252 struct pcm_config config; 253 struct snd_pcm_mmap_status *mmap_status; 254 struct snd_pcm_mmap_control *mmap_control; 255 struct snd_pcm_sync_ptr *sync_ptr; 256 void *mmap_buffer; 257 unsigned int noirq_frames_per_msec; 258 int wait_for_avail_min; 259 unsigned int subdevice; 260}; 261 262unsigned int pcm_get_buffer_size(struct pcm *pcm) 263{ 264 return pcm->buffer_size; 265} 266 267const char* pcm_get_error(struct pcm *pcm) 268{ 269 return pcm->error; 270} 271 272unsigned int pcm_get_subdevice(struct pcm *pcm) 273{ 274 return pcm->subdevice; 275} 276 277static int oops(struct pcm *pcm, int e, const char *fmt, ...) 278{ 279 va_list ap; 280 int sz; 281 282 va_start(ap, fmt); 283 vsnprintf(pcm->error, PCM_ERROR_MAX, fmt, ap); 284 va_end(ap); 285 sz = strlen(pcm->error); 286 287 if (e) 288 snprintf(pcm->error + sz, PCM_ERROR_MAX - sz, 289 ": %s", strerror(e)); 290 return -1; 291} 292 293static unsigned int pcm_format_to_alsa(enum pcm_format format) 294{ 295 switch (format) { 296 case PCM_FORMAT_S32_LE: 297 return SNDRV_PCM_FORMAT_S32_LE; 298 case PCM_FORMAT_S8: 299 return SNDRV_PCM_FORMAT_S8; 300 case PCM_FORMAT_S24_3LE: 301 return SNDRV_PCM_FORMAT_S24_3LE; 302 case PCM_FORMAT_S24_LE: 303 return SNDRV_PCM_FORMAT_S24_LE; 304 default: 305 case PCM_FORMAT_S16_LE: 306 return SNDRV_PCM_FORMAT_S16_LE; 307 }; 308} 309 310unsigned int pcm_format_to_bits(enum pcm_format format) 311{ 312 switch (format) { 313 case PCM_FORMAT_S32_LE: 314 case PCM_FORMAT_S24_LE: 315 return 32; 316 case PCM_FORMAT_S24_3LE: 317 return 24; 318 default: 319 case PCM_FORMAT_S16_LE: 320 return 16; 321 }; 322} 323 324unsigned int pcm_bytes_to_frames(struct pcm *pcm, unsigned int bytes) 325{ 326 return bytes / (pcm->config.channels * 327 (pcm_format_to_bits(pcm->config.format) >> 3)); 328} 329 330unsigned int pcm_frames_to_bytes(struct pcm *pcm, unsigned int frames) 331{ 332 return frames * pcm->config.channels * 333 (pcm_format_to_bits(pcm->config.format) >> 3); 334} 335 336static int pcm_sync_ptr(struct pcm *pcm, int flags) { 337 if (pcm->sync_ptr) { 338 pcm->sync_ptr->flags = flags; 339 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_SYNC_PTR, pcm->sync_ptr) < 0) 340 return -1; 341 } 342 return 0; 343} 344 345static int pcm_hw_mmap_status(struct pcm *pcm) { 346 347 if (pcm->sync_ptr) 348 return 0; 349 350 int page_size = sysconf(_SC_PAGE_SIZE); 351 pcm->mmap_status = mmap(NULL, page_size, PROT_READ, MAP_FILE | MAP_SHARED, 352 pcm->fd, SNDRV_PCM_MMAP_OFFSET_STATUS); 353 if (pcm->mmap_status == MAP_FAILED) 354 pcm->mmap_status = NULL; 355 if (!pcm->mmap_status) 356 goto mmap_error; 357 358 pcm->mmap_control = mmap(NULL, page_size, PROT_READ | PROT_WRITE, 359 MAP_FILE | MAP_SHARED, pcm->fd, SNDRV_PCM_MMAP_OFFSET_CONTROL); 360 if (pcm->mmap_control == MAP_FAILED) 361 pcm->mmap_control = NULL; 362 if (!pcm->mmap_control) { 363 munmap(pcm->mmap_status, page_size); 364 pcm->mmap_status = NULL; 365 goto mmap_error; 366 } 367 if (pcm->flags & PCM_MMAP) 368 pcm->mmap_control->avail_min = pcm->config.avail_min; 369 else 370 pcm->mmap_control->avail_min = 1; 371 372 return 0; 373 374mmap_error: 375 376 pcm->sync_ptr = calloc(1, sizeof(*pcm->sync_ptr)); 377 if (!pcm->sync_ptr) 378 return -ENOMEM; 379 pcm->mmap_status = &pcm->sync_ptr->s.status; 380 pcm->mmap_control = &pcm->sync_ptr->c.control; 381 if (pcm->flags & PCM_MMAP) 382 pcm->mmap_control->avail_min = pcm->config.avail_min; 383 else 384 pcm->mmap_control->avail_min = 1; 385 386 pcm_sync_ptr(pcm, 0); 387 388 return 0; 389} 390 391static void pcm_hw_munmap_status(struct pcm *pcm) { 392 if (pcm->sync_ptr) { 393 free(pcm->sync_ptr); 394 pcm->sync_ptr = NULL; 395 } else { 396 int page_size = sysconf(_SC_PAGE_SIZE); 397 if (pcm->mmap_status) 398 munmap(pcm->mmap_status, page_size); 399 if (pcm->mmap_control) 400 munmap(pcm->mmap_control, page_size); 401 } 402 pcm->mmap_status = NULL; 403 pcm->mmap_control = NULL; 404} 405 406static int pcm_areas_copy(struct pcm *pcm, unsigned int pcm_offset, 407 char *buf, unsigned int src_offset, 408 unsigned int frames) 409{ 410 int size_bytes = pcm_frames_to_bytes(pcm, frames); 411 int pcm_offset_bytes = pcm_frames_to_bytes(pcm, pcm_offset); 412 int src_offset_bytes = pcm_frames_to_bytes(pcm, src_offset); 413 414 /* interleaved only atm */ 415 if (pcm->flags & PCM_IN) 416 memcpy(buf + src_offset_bytes, 417 (char*)pcm->mmap_buffer + pcm_offset_bytes, 418 size_bytes); 419 else 420 memcpy((char*)pcm->mmap_buffer + pcm_offset_bytes, 421 buf + src_offset_bytes, 422 size_bytes); 423 return 0; 424} 425 426static int pcm_mmap_transfer_areas(struct pcm *pcm, char *buf, 427 unsigned int offset, unsigned int size) 428{ 429 void *pcm_areas; 430 int commit; 431 unsigned int pcm_offset, frames, count = 0; 432 433 while (size > 0) { 434 frames = size; 435 pcm_mmap_begin(pcm, &pcm_areas, &pcm_offset, &frames); 436 pcm_areas_copy(pcm, pcm_offset, buf, offset, frames); 437 commit = pcm_mmap_commit(pcm, pcm_offset, frames); 438 if (commit < 0) { 439 oops(pcm, errno, "failed to commit %d frames\n", frames); 440 return commit; 441 } 442 443 offset += commit; 444 count += commit; 445 size -= commit; 446 } 447 return count; 448} 449 450int pcm_get_htimestamp(struct pcm *pcm, unsigned int *avail, 451 struct timespec *tstamp) 452{ 453 int frames; 454 int rc; 455 snd_pcm_uframes_t hw_ptr; 456 457 if (!pcm_is_ready(pcm)) 458 return -1; 459 460 rc = pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_APPL|SNDRV_PCM_SYNC_PTR_HWSYNC); 461 if (rc < 0) 462 return -1; 463 464 if ((pcm->mmap_status->state != PCM_STATE_RUNNING) && 465 (pcm->mmap_status->state != PCM_STATE_DRAINING)) 466 return -1; 467 468 *tstamp = pcm->mmap_status->tstamp; 469 if (tstamp->tv_sec == 0 && tstamp->tv_nsec == 0) 470 return -1; 471 472 hw_ptr = pcm->mmap_status->hw_ptr; 473 if (pcm->flags & PCM_IN) 474 frames = hw_ptr - pcm->mmap_control->appl_ptr; 475 else 476 frames = hw_ptr + pcm->buffer_size - pcm->mmap_control->appl_ptr; 477 478 if (frames < 0) 479 frames += pcm->boundary; 480 else if (frames > (int)pcm->boundary) 481 frames -= pcm->boundary; 482 483 *avail = (unsigned int)frames; 484 485 return 0; 486} 487 488int pcm_mmap_get_hw_ptr(struct pcm* pcm, unsigned int *hw_ptr, struct timespec *tstamp) 489{ 490 int frames; 491 int rc; 492 493 if (pcm == NULL || hw_ptr == NULL || tstamp == NULL) 494 return oops(pcm, EINVAL, "pcm %p, hw_ptr %p, tstamp %p", pcm, hw_ptr, tstamp); 495 496 if (!pcm_is_ready(pcm)) 497 return oops(pcm, errno, "pcm_is_ready failed"); 498 499 rc = pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_HWSYNC); 500 if (rc < 0) 501 return oops(pcm, errno, "pcm_sync_ptr failed"); 502 503 if (pcm->mmap_status == NULL) 504 return oops(pcm, EINVAL, "pcm %p, mmap_status is NULL", pcm); 505 506 if ((pcm->mmap_status->state != PCM_STATE_RUNNING) && 507 (pcm->mmap_status->state != PCM_STATE_DRAINING)) 508 return oops(pcm, ENOSYS, "invalid stream state %d", pcm->mmap_status->state); 509 510 *tstamp = pcm->mmap_status->tstamp; 511 if (tstamp->tv_sec == 0 && tstamp->tv_nsec == 0) 512 return oops(pcm, errno, "invalid time stamp"); 513 514 *hw_ptr = pcm->mmap_status->hw_ptr; 515 516 return 0; 517} 518 519int pcm_write(struct pcm *pcm, const void *data, unsigned int count) 520{ 521 struct snd_xferi x; 522 523 if (pcm->flags & PCM_IN) 524 return -EINVAL; 525 526 x.buf = (void*)data; 527 x.frames = count / (pcm->config.channels * 528 pcm_format_to_bits(pcm->config.format) / 8); 529 530 for (;;) { 531 if (!pcm->running) { 532 int prepare_error = pcm_prepare(pcm); 533 if (prepare_error) 534 return prepare_error; 535 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_WRITEI_FRAMES, &x)) 536 return oops(pcm, errno, "cannot write initial data"); 537 pcm->running = 1; 538 return 0; 539 } 540 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_WRITEI_FRAMES, &x)) { 541 pcm->prepared = 0; 542 pcm->running = 0; 543 if (errno == EPIPE) { 544 /* we failed to make our window -- try to restart if we are 545 * allowed to do so. Otherwise, simply allow the EPIPE error to 546 * propagate up to the app level */ 547 pcm->underruns++; 548 if (pcm->flags & PCM_NORESTART) 549 return -EPIPE; 550 continue; 551 } 552 return oops(pcm, errno, "cannot write stream data"); 553 } 554 return 0; 555 } 556} 557 558int pcm_read(struct pcm *pcm, void *data, unsigned int count) 559{ 560 struct snd_xferi x; 561 562 if (!(pcm->flags & PCM_IN)) 563 return -EINVAL; 564 565 x.buf = data; 566 x.frames = count / (pcm->config.channels * 567 pcm_format_to_bits(pcm->config.format) / 8); 568 569 for (;;) { 570 if (!pcm->running) { 571 if (pcm_start(pcm) < 0) { 572 fprintf(stderr, "start error"); 573 return -errno; 574 } 575 } 576 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_READI_FRAMES, &x)) { 577 pcm->prepared = 0; 578 pcm->running = 0; 579 if (errno == EPIPE) { 580 /* we failed to make our window -- try to restart */ 581 pcm->underruns++; 582 continue; 583 } 584 return oops(pcm, errno, "cannot read stream data"); 585 } 586 return 0; 587 } 588} 589 590static struct pcm bad_pcm = { 591 .fd = -1, 592}; 593 594struct pcm_params *pcm_params_get(unsigned int card, unsigned int device, 595 unsigned int flags) 596{ 597 struct snd_pcm_hw_params *params; 598 char fn[256]; 599 int fd; 600 601 snprintf(fn, sizeof(fn), "/dev/snd/pcmC%uD%u%c", card, device, 602 flags & PCM_IN ? 'c' : 'p'); 603 604 fd = open(fn, O_RDWR); 605 if (fd < 0) { 606 fprintf(stderr, "cannot open device '%s'\n", fn); 607 goto err_open; 608 } 609 610 params = calloc(1, sizeof(struct snd_pcm_hw_params)); 611 if (!params) 612 goto err_calloc; 613 614 param_init(params); 615 if (ioctl(fd, SNDRV_PCM_IOCTL_HW_REFINE, params)) { 616 fprintf(stderr, "SNDRV_PCM_IOCTL_HW_REFINE error (%d)\n", errno); 617 goto err_hw_refine; 618 } 619 620 close(fd); 621 622 return (struct pcm_params *)params; 623 624err_hw_refine: 625 free(params); 626err_calloc: 627 close(fd); 628err_open: 629 return NULL; 630} 631 632void pcm_params_free(struct pcm_params *pcm_params) 633{ 634 struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params; 635 636 if (params) 637 free(params); 638} 639 640static int pcm_param_to_alsa(enum pcm_param param) 641{ 642 switch (param) { 643 case PCM_PARAM_ACCESS: 644 return SNDRV_PCM_HW_PARAM_ACCESS; 645 case PCM_PARAM_FORMAT: 646 return SNDRV_PCM_HW_PARAM_FORMAT; 647 case PCM_PARAM_SUBFORMAT: 648 return SNDRV_PCM_HW_PARAM_SUBFORMAT; 649 case PCM_PARAM_SAMPLE_BITS: 650 return SNDRV_PCM_HW_PARAM_SAMPLE_BITS; 651 break; 652 case PCM_PARAM_FRAME_BITS: 653 return SNDRV_PCM_HW_PARAM_FRAME_BITS; 654 break; 655 case PCM_PARAM_CHANNELS: 656 return SNDRV_PCM_HW_PARAM_CHANNELS; 657 break; 658 case PCM_PARAM_RATE: 659 return SNDRV_PCM_HW_PARAM_RATE; 660 break; 661 case PCM_PARAM_PERIOD_TIME: 662 return SNDRV_PCM_HW_PARAM_PERIOD_TIME; 663 break; 664 case PCM_PARAM_PERIOD_SIZE: 665 return SNDRV_PCM_HW_PARAM_PERIOD_SIZE; 666 break; 667 case PCM_PARAM_PERIOD_BYTES: 668 return SNDRV_PCM_HW_PARAM_PERIOD_BYTES; 669 break; 670 case PCM_PARAM_PERIODS: 671 return SNDRV_PCM_HW_PARAM_PERIODS; 672 break; 673 case PCM_PARAM_BUFFER_TIME: 674 return SNDRV_PCM_HW_PARAM_BUFFER_TIME; 675 break; 676 case PCM_PARAM_BUFFER_SIZE: 677 return SNDRV_PCM_HW_PARAM_BUFFER_SIZE; 678 break; 679 case PCM_PARAM_BUFFER_BYTES: 680 return SNDRV_PCM_HW_PARAM_BUFFER_BYTES; 681 break; 682 case PCM_PARAM_TICK_TIME: 683 return SNDRV_PCM_HW_PARAM_TICK_TIME; 684 break; 685 686 default: 687 return -1; 688 } 689} 690 691struct pcm_mask *pcm_params_get_mask(struct pcm_params *pcm_params, 692 enum pcm_param param) 693{ 694 int p; 695 struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params; 696 if (params == NULL) { 697 return NULL; 698 } 699 700 p = pcm_param_to_alsa(param); 701 if (p < 0 || !param_is_mask(p)) { 702 return NULL; 703 } 704 705 return (struct pcm_mask *)param_to_mask(params, p); 706} 707 708unsigned int pcm_params_get_min(struct pcm_params *pcm_params, 709 enum pcm_param param) 710{ 711 struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params; 712 int p; 713 714 if (!params) 715 return 0; 716 717 p = pcm_param_to_alsa(param); 718 if (p < 0) 719 return 0; 720 721 return param_get_min(params, p); 722} 723 724void pcm_params_set_min(struct pcm_params *pcm_params, 725 enum pcm_param param, unsigned int val) 726{ 727 struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params; 728 int p; 729 730 if (!params) 731 return; 732 733 p = pcm_param_to_alsa(param); 734 if (p < 0) 735 return; 736 737 param_set_min(params, p, val); 738} 739 740unsigned int pcm_params_get_max(struct pcm_params *pcm_params, 741 enum pcm_param param) 742{ 743 struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params; 744 int p; 745 746 if (!params) 747 return 0; 748 749 p = pcm_param_to_alsa(param); 750 if (p < 0) 751 return 0; 752 753 return param_get_max(params, p); 754} 755 756void pcm_params_set_max(struct pcm_params *pcm_params, 757 enum pcm_param param, unsigned int val) 758{ 759 struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params; 760 int p; 761 762 if (!params) 763 return; 764 765 p = pcm_param_to_alsa(param); 766 if (p < 0) 767 return; 768 769 param_set_max(params, p, val); 770} 771 772static int pcm_mask_test(struct pcm_mask *m, unsigned int index) 773{ 774 const unsigned int bitshift = 5; /* for 32 bit integer */ 775 const unsigned int bitmask = (1 << bitshift) - 1; 776 unsigned int element; 777 778 element = index >> bitshift; 779 if (element >= ARRAY_SIZE(m->bits)) 780 return 0; /* for safety, but should never occur */ 781 return (m->bits[element] >> (index & bitmask)) & 1; 782} 783 784static int pcm_mask_to_string(struct pcm_mask *m, char *string, unsigned int size, 785 char *mask_name, 786 const char * const *bit_array_name, size_t bit_array_size) 787{ 788 unsigned int i; 789 unsigned int offset = 0; 790 791 if (m == NULL) 792 return 0; 793 if (bit_array_size < 32) { 794 STRLOG(string, offset, size, "%12s:\t%#08x\n", mask_name, m->bits[0]); 795 } else { /* spans two or more bitfields, print with an array index */ 796 for (i = 0; i < (bit_array_size + 31) >> 5; ++i) { 797 STRLOG(string, offset, size, "%9s[%d]:\t%#08x\n", 798 mask_name, i, m->bits[i]); 799 } 800 } 801 for (i = 0; i < bit_array_size; ++i) { 802 if (pcm_mask_test(m, i)) { 803 STRLOG(string, offset, size, "%12s \t%s\n", "", bit_array_name[i]); 804 } 805 } 806 return offset; 807} 808 809int pcm_params_to_string(struct pcm_params *params, char *string, unsigned int size) 810{ 811 struct pcm_mask *m; 812 unsigned int min, max; 813 unsigned int clipoffset, offset; 814 815 m = pcm_params_get_mask(params, PCM_PARAM_ACCESS); 816 offset = pcm_mask_to_string(m, string, size, 817 "Access", access_lookup, ARRAY_SIZE(access_lookup)); 818 m = pcm_params_get_mask(params, PCM_PARAM_FORMAT); 819 clipoffset = offset > size ? size : offset; 820 offset += pcm_mask_to_string(m, string + clipoffset, size - clipoffset, 821 "Format", format_lookup, ARRAY_SIZE(format_lookup)); 822 m = pcm_params_get_mask(params, PCM_PARAM_SUBFORMAT); 823 clipoffset = offset > size ? size : offset; 824 offset += pcm_mask_to_string(m, string + clipoffset, size - clipoffset, 825 "Subformat", subformat_lookup, ARRAY_SIZE(subformat_lookup)); 826 min = pcm_params_get_min(params, PCM_PARAM_RATE); 827 max = pcm_params_get_max(params, PCM_PARAM_RATE); 828 STRLOG(string, offset, size, " Rate:\tmin=%uHz\tmax=%uHz\n", min, max); 829 min = pcm_params_get_min(params, PCM_PARAM_CHANNELS); 830 max = pcm_params_get_max(params, PCM_PARAM_CHANNELS); 831 STRLOG(string, offset, size, " Channels:\tmin=%u\t\tmax=%u\n", min, max); 832 min = pcm_params_get_min(params, PCM_PARAM_SAMPLE_BITS); 833 max = pcm_params_get_max(params, PCM_PARAM_SAMPLE_BITS); 834 STRLOG(string, offset, size, " Sample bits:\tmin=%u\t\tmax=%u\n", min, max); 835 min = pcm_params_get_min(params, PCM_PARAM_PERIOD_SIZE); 836 max = pcm_params_get_max(params, PCM_PARAM_PERIOD_SIZE); 837 STRLOG(string, offset, size, " Period size:\tmin=%u\t\tmax=%u\n", min, max); 838 min = pcm_params_get_min(params, PCM_PARAM_PERIODS); 839 max = pcm_params_get_max(params, PCM_PARAM_PERIODS); 840 STRLOG(string, offset, size, "Period count:\tmin=%u\t\tmax=%u\n", min, max); 841 return offset; 842} 843 844int pcm_params_format_test(struct pcm_params *params, enum pcm_format format) 845{ 846 unsigned int alsa_format = pcm_format_to_alsa(format); 847 848 if (alsa_format == SNDRV_PCM_FORMAT_S16_LE && format != PCM_FORMAT_S16_LE) 849 return 0; /* caution: format not recognized is equivalent to S16_LE */ 850 return pcm_mask_test(pcm_params_get_mask(params, PCM_PARAM_FORMAT), alsa_format); 851} 852 853int pcm_close(struct pcm *pcm) 854{ 855 if (pcm == &bad_pcm) 856 return 0; 857 858 pcm_hw_munmap_status(pcm); 859 860 if (pcm->flags & PCM_MMAP) { 861 pcm_stop(pcm); 862 munmap(pcm->mmap_buffer, pcm_frames_to_bytes(pcm, pcm->buffer_size)); 863 } 864 865 if (pcm->fd >= 0) 866 close(pcm->fd); 867 pcm->prepared = 0; 868 pcm->running = 0; 869 pcm->buffer_size = 0; 870 pcm->fd = -1; 871 free(pcm); 872 return 0; 873} 874 875struct pcm *pcm_open(unsigned int card, unsigned int device, 876 unsigned int flags, struct pcm_config *config) 877{ 878 struct pcm *pcm; 879 struct snd_pcm_info info; 880 struct snd_pcm_hw_params params; 881 struct snd_pcm_sw_params sparams; 882 char fn[256]; 883 int rc; 884 885 if (!config) { 886 return &bad_pcm; /* TODO: could support default config here */ 887 } 888 pcm = calloc(1, sizeof(struct pcm)); 889 if (!pcm) 890 return &bad_pcm; /* TODO: could support default config here */ 891 892 pcm->config = *config; 893 894 snprintf(fn, sizeof(fn), "/dev/snd/pcmC%uD%u%c", card, device, 895 flags & PCM_IN ? 'c' : 'p'); 896 897 pcm->flags = flags; 898 pcm->fd = open(fn, O_RDWR|O_NONBLOCK); 899 if (pcm->fd < 0) { 900 oops(pcm, errno, "cannot open device '%s'", fn); 901 return pcm; 902 } 903 904 if (fcntl(pcm->fd, F_SETFL, fcntl(pcm->fd, F_GETFL) & 905 ~O_NONBLOCK) < 0) { 906 oops(pcm, errno, "failed to reset blocking mode '%s'", fn); 907 goto fail_close; 908 } 909 910 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_INFO, &info)) { 911 oops(pcm, errno, "cannot get info"); 912 goto fail_close; 913 } 914 pcm->subdevice = info.subdevice; 915 916 param_init(¶ms); 917 param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_FORMAT, 918 pcm_format_to_alsa(config->format)); 919 param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_SUBFORMAT, 920 SNDRV_PCM_SUBFORMAT_STD); 921 param_set_min(¶ms, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, config->period_size); 922 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_SAMPLE_BITS, 923 pcm_format_to_bits(config->format)); 924 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_FRAME_BITS, 925 pcm_format_to_bits(config->format) * config->channels); 926 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_CHANNELS, 927 config->channels); 928 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_PERIODS, config->period_count); 929 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_RATE, config->rate); 930 931 if (flags & PCM_NOIRQ) { 932 if (!(flags & PCM_MMAP)) { 933 oops(pcm, EINVAL, "noirq only currently supported with mmap()."); 934 goto fail_close; 935 } 936 937 params.flags |= SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP; 938 pcm->noirq_frames_per_msec = config->rate / 1000; 939 } 940 941 if (flags & PCM_MMAP) 942 param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_ACCESS, 943 SNDRV_PCM_ACCESS_MMAP_INTERLEAVED); 944 else 945 param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_ACCESS, 946 SNDRV_PCM_ACCESS_RW_INTERLEAVED); 947 948 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_HW_PARAMS, ¶ms)) { 949 oops(pcm, errno, "cannot set hw params"); 950 goto fail_close; 951 } 952 953 /* get our refined hw_params */ 954 config->period_size = param_get_int(¶ms, SNDRV_PCM_HW_PARAM_PERIOD_SIZE); 955 config->period_count = param_get_int(¶ms, SNDRV_PCM_HW_PARAM_PERIODS); 956 pcm->buffer_size = config->period_count * config->period_size; 957 958 if (flags & PCM_MMAP) { 959 pcm->mmap_buffer = mmap(NULL, pcm_frames_to_bytes(pcm, pcm->buffer_size), 960 PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, pcm->fd, 0); 961 if (pcm->mmap_buffer == MAP_FAILED) { 962 oops(pcm, errno, "failed to mmap buffer %d bytes\n", 963 pcm_frames_to_bytes(pcm, pcm->buffer_size)); 964 goto fail_close; 965 } 966 } 967 968 memset(&sparams, 0, sizeof(sparams)); 969 sparams.tstamp_mode = SNDRV_PCM_TSTAMP_ENABLE; 970 sparams.period_step = 1; 971 972 if (!config->start_threshold) { 973 if (pcm->flags & PCM_IN) 974 pcm->config.start_threshold = sparams.start_threshold = 1; 975 else 976 pcm->config.start_threshold = sparams.start_threshold = 977 config->period_count * config->period_size / 2; 978 } else 979 sparams.start_threshold = config->start_threshold; 980 981 /* pick a high stop threshold - todo: does this need further tuning */ 982 if (!config->stop_threshold) { 983 if (pcm->flags & PCM_IN) 984 pcm->config.stop_threshold = sparams.stop_threshold = 985 config->period_count * config->period_size * 10; 986 else 987 pcm->config.stop_threshold = sparams.stop_threshold = 988 config->period_count * config->period_size; 989 } 990 else 991 sparams.stop_threshold = config->stop_threshold; 992 993 if (!pcm->config.avail_min) { 994 if (pcm->flags & PCM_MMAP) 995 pcm->config.avail_min = sparams.avail_min = pcm->config.period_size; 996 else 997 pcm->config.avail_min = sparams.avail_min = 1; 998 } else 999 sparams.avail_min = config->avail_min; 1000 1001 sparams.xfer_align = config->period_size / 2; /* needed for old kernels */ 1002 sparams.silence_threshold = config->silence_threshold; 1003 sparams.silence_size = config->silence_size; 1004 pcm->boundary = sparams.boundary = pcm->buffer_size; 1005 1006 while (pcm->boundary * 2 <= INT_MAX - pcm->buffer_size) 1007 pcm->boundary *= 2; 1008 1009 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_SW_PARAMS, &sparams)) { 1010 oops(pcm, errno, "cannot set sw params"); 1011 goto fail; 1012 } 1013 1014 rc = pcm_hw_mmap_status(pcm); 1015 if (rc < 0) { 1016 oops(pcm, errno, "mmap status failed"); 1017 goto fail; 1018 } 1019 1020#ifdef SNDRV_PCM_IOCTL_TTSTAMP 1021 if (pcm->flags & PCM_MONOTONIC) { 1022 int arg = SNDRV_PCM_TSTAMP_TYPE_MONOTONIC; 1023 rc = ioctl(pcm->fd, SNDRV_PCM_IOCTL_TTSTAMP, &arg); 1024 if (rc < 0) { 1025 oops(pcm, errno, "cannot set timestamp type"); 1026 goto fail; 1027 } 1028 } 1029#endif 1030 1031 pcm->underruns = 0; 1032 return pcm; 1033 1034fail: 1035 if (flags & PCM_MMAP) 1036 munmap(pcm->mmap_buffer, pcm_frames_to_bytes(pcm, pcm->buffer_size)); 1037fail_close: 1038 close(pcm->fd); 1039 pcm->fd = -1; 1040 return pcm; 1041} 1042 1043int pcm_is_ready(struct pcm *pcm) 1044{ 1045 return pcm->fd >= 0; 1046} 1047 1048int pcm_prepare(struct pcm *pcm) 1049{ 1050 if (pcm->prepared) 1051 return 0; 1052 1053 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_PREPARE) < 0) 1054 return oops(pcm, errno, "cannot prepare channel"); 1055 1056 pcm->prepared = 1; 1057 return 0; 1058} 1059 1060int pcm_start(struct pcm *pcm) 1061{ 1062 int prepare_error = pcm_prepare(pcm); 1063 if (prepare_error) 1064 return prepare_error; 1065 1066 if (pcm->flags & PCM_MMAP) 1067 pcm_sync_ptr(pcm, 0); 1068 1069 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_START) < 0) 1070 return oops(pcm, errno, "cannot start channel"); 1071 1072 pcm->running = 1; 1073 return 0; 1074} 1075 1076int pcm_stop(struct pcm *pcm) 1077{ 1078 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_DROP) < 0) 1079 return oops(pcm, errno, "cannot stop channel"); 1080 1081 pcm->prepared = 0; 1082 pcm->running = 0; 1083 return 0; 1084} 1085 1086static inline int pcm_mmap_playback_avail(struct pcm *pcm) 1087{ 1088 int avail; 1089 1090 avail = pcm->mmap_status->hw_ptr + pcm->buffer_size - pcm->mmap_control->appl_ptr; 1091 1092 if (avail < 0) 1093 avail += pcm->boundary; 1094 else if (avail > (int)pcm->boundary) 1095 avail -= pcm->boundary; 1096 1097 return avail; 1098} 1099 1100static inline int pcm_mmap_capture_avail(struct pcm *pcm) 1101{ 1102 int avail = pcm->mmap_status->hw_ptr - pcm->mmap_control->appl_ptr; 1103 if (avail < 0) 1104 avail += pcm->boundary; 1105 return avail; 1106} 1107 1108int pcm_mmap_avail(struct pcm *pcm) 1109{ 1110 pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_HWSYNC); 1111 if (pcm->flags & PCM_IN) 1112 return pcm_mmap_capture_avail(pcm); 1113 else 1114 return pcm_mmap_playback_avail(pcm); 1115} 1116 1117static void pcm_mmap_appl_forward(struct pcm *pcm, int frames) 1118{ 1119 unsigned int appl_ptr = pcm->mmap_control->appl_ptr; 1120 appl_ptr += frames; 1121 1122 /* check for boundary wrap */ 1123 if (appl_ptr > pcm->boundary) 1124 appl_ptr -= pcm->boundary; 1125 pcm->mmap_control->appl_ptr = appl_ptr; 1126} 1127 1128int pcm_mmap_begin(struct pcm *pcm, void **areas, unsigned int *offset, 1129 unsigned int *frames) 1130{ 1131 unsigned int continuous, copy_frames, avail; 1132 1133 /* return the mmap buffer */ 1134 *areas = pcm->mmap_buffer; 1135 1136 /* and the application offset in frames */ 1137 *offset = pcm->mmap_control->appl_ptr % pcm->buffer_size; 1138 1139 avail = pcm_mmap_avail(pcm); 1140 if (avail > pcm->buffer_size) 1141 avail = pcm->buffer_size; 1142 continuous = pcm->buffer_size - *offset; 1143 1144 /* we can only copy frames if the are availabale and continuos */ 1145 copy_frames = *frames; 1146 if (copy_frames > avail) 1147 copy_frames = avail; 1148 if (copy_frames > continuous) 1149 copy_frames = continuous; 1150 *frames = copy_frames; 1151 1152 return 0; 1153} 1154 1155int pcm_mmap_commit(struct pcm *pcm, unsigned int offset __attribute__((unused)), unsigned int frames) 1156{ 1157 /* update the application pointer in userspace and kernel */ 1158 pcm_mmap_appl_forward(pcm, frames); 1159 pcm_sync_ptr(pcm, 0); 1160 1161 return frames; 1162} 1163 1164int pcm_avail_update(struct pcm *pcm) 1165{ 1166 pcm_sync_ptr(pcm, 0); 1167 return pcm_mmap_avail(pcm); 1168} 1169 1170int pcm_state(struct pcm *pcm) 1171{ 1172 int err = pcm_sync_ptr(pcm, 0); 1173 if (err < 0) 1174 return err; 1175 1176 return pcm->mmap_status->state; 1177} 1178 1179int pcm_set_avail_min(struct pcm *pcm, int avail_min) 1180{ 1181 if ((~pcm->flags) & (PCM_MMAP | PCM_NOIRQ)) 1182 return -ENOSYS; 1183 1184 pcm->config.avail_min = avail_min; 1185 return 0; 1186} 1187 1188int pcm_wait(struct pcm *pcm, int timeout) 1189{ 1190 struct pollfd pfd; 1191 int err; 1192 1193 pfd.fd = pcm->fd; 1194 pfd.events = POLLOUT | POLLERR | POLLNVAL; 1195 1196 do { 1197 /* let's wait for avail or timeout */ 1198 err = poll(&pfd, 1, timeout); 1199 if (err < 0) 1200 return -errno; 1201 1202 /* timeout ? */ 1203 if (err == 0) 1204 return 0; 1205 1206 /* have we been interrupted ? */ 1207 if (errno == -EINTR) 1208 continue; 1209 1210 /* check for any errors */ 1211 if (pfd.revents & (POLLERR | POLLNVAL)) { 1212 switch (pcm_state(pcm)) { 1213 case PCM_STATE_XRUN: 1214 return -EPIPE; 1215 case PCM_STATE_SUSPENDED: 1216 return -ESTRPIPE; 1217 case PCM_STATE_DISCONNECTED: 1218 return -ENODEV; 1219 default: 1220 return -EIO; 1221 } 1222 } 1223 /* poll again if fd not ready for IO */ 1224 } while (!(pfd.revents & (POLLIN | POLLOUT))); 1225 1226 return 1; 1227} 1228 1229int pcm_get_poll_fd(struct pcm *pcm) 1230{ 1231 return pcm->fd; 1232} 1233 1234int pcm_mmap_transfer(struct pcm *pcm, const void *buffer, unsigned int bytes) 1235{ 1236 int err = 0, frames, avail; 1237 unsigned int offset = 0, count; 1238 1239 if (bytes == 0) 1240 return 0; 1241 1242 count = pcm_bytes_to_frames(pcm, bytes); 1243 1244 while (count > 0) { 1245 1246 /* get the available space for writing new frames */ 1247 avail = pcm_avail_update(pcm); 1248 if (avail < 0) { 1249 fprintf(stderr, "cannot determine available mmap frames"); 1250 return err; 1251 } 1252 1253 /* start the audio if we reach the threshold */ 1254 if (!pcm->running && 1255 (pcm->buffer_size - avail) >= pcm->config.start_threshold) { 1256 if (pcm_start(pcm) < 0) { 1257 fprintf(stderr, "start error: hw 0x%x app 0x%x avail 0x%x\n", 1258 (unsigned int)pcm->mmap_status->hw_ptr, 1259 (unsigned int)pcm->mmap_control->appl_ptr, 1260 avail); 1261 return -errno; 1262 } 1263 pcm->wait_for_avail_min = 0; 1264 } 1265 1266 /* sleep until we have space to write new frames */ 1267 if (pcm->running) { 1268 /* enable waiting for avail_min threshold when less frames than we have to write 1269 * are available. */ 1270 if (!pcm->wait_for_avail_min && (count > (unsigned int)avail)) 1271 pcm->wait_for_avail_min = 1; 1272 1273 if (pcm->wait_for_avail_min && (avail < pcm->config.avail_min)) { 1274 int time = -1; 1275 1276 /* disable waiting for avail_min threshold to allow small amounts of data to be 1277 * written without waiting as long as there is enough room in buffer. */ 1278 pcm->wait_for_avail_min = 0; 1279 1280 if (pcm->flags & PCM_NOIRQ) 1281 time = (pcm->config.avail_min - avail) / pcm->noirq_frames_per_msec; 1282 1283 err = pcm_wait(pcm, time); 1284 if (err < 0) { 1285 pcm->prepared = 0; 1286 pcm->running = 0; 1287 oops(pcm, errno, "wait error: hw 0x%x app 0x%x avail 0x%x\n", 1288 (unsigned int)pcm->mmap_status->hw_ptr, 1289 (unsigned int)pcm->mmap_control->appl_ptr, 1290 avail); 1291 pcm->mmap_control->appl_ptr = 0; 1292 return err; 1293 } 1294 continue; 1295 } 1296 } 1297 1298 frames = count; 1299 if (frames > avail) 1300 frames = avail; 1301 1302 if (!frames) 1303 break; 1304 1305 /* copy frames from buffer */ 1306 frames = pcm_mmap_transfer_areas(pcm, (void *)buffer, offset, frames); 1307 if (frames < 0) { 1308 fprintf(stderr, "write error: hw 0x%x app 0x%x avail 0x%x\n", 1309 (unsigned int)pcm->mmap_status->hw_ptr, 1310 (unsigned int)pcm->mmap_control->appl_ptr, 1311 avail); 1312 return frames; 1313 } 1314 1315 offset += frames; 1316 count -= frames; 1317 } 1318 1319 return 0; 1320} 1321 1322int pcm_mmap_write(struct pcm *pcm, const void *data, unsigned int count) 1323{ 1324 if ((~pcm->flags) & (PCM_OUT | PCM_MMAP)) 1325 return -ENOSYS; 1326 1327 return pcm_mmap_transfer(pcm, (void *)data, count); 1328} 1329 1330int pcm_mmap_read(struct pcm *pcm, void *data, unsigned int count) 1331{ 1332 if ((~pcm->flags) & (PCM_IN | PCM_MMAP)) 1333 return -ENOSYS; 1334 1335 return pcm_mmap_transfer(pcm, data, count); 1336} 1337 1338int pcm_ioctl(struct pcm *pcm, int request, ...) 1339{ 1340 va_list ap; 1341 void * arg; 1342 1343 if (!pcm_is_ready(pcm)) 1344 return -1; 1345 1346 va_start(ap, request); 1347 arg = va_arg(ap, void *); 1348 va_end(ap); 1349 1350 return ioctl(pcm->fd, request, arg); 1351} 1352