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 #define SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP (1<<2) 53 54 static inline int param_is_mask(int p) 55 { 56 return (p >= SNDRV_PCM_HW_PARAM_FIRST_MASK) && 57 (p <= SNDRV_PCM_HW_PARAM_LAST_MASK); 58 } 59 60 static inline int param_is_interval(int p) 61 { 62 return (p >= SNDRV_PCM_HW_PARAM_FIRST_INTERVAL) && 63 (p <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL); 64 } 65 66 static inline struct snd_interval *param_to_interval(struct snd_pcm_hw_params *p, int n) 67 { 68 return &(p->intervals[n - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL]); 69 } 70 71 static inline struct snd_mask *param_to_mask(struct snd_pcm_hw_params *p, int n) 72 { 73 return &(p->masks[n - SNDRV_PCM_HW_PARAM_FIRST_MASK]); 74 } 75 76 static void param_set_mask(struct snd_pcm_hw_params *p, int n, unsigned int bit) 77 { 78 if (bit >= SNDRV_MASK_MAX) 79 return; 80 if (param_is_mask(n)) { 81 struct snd_mask *m = param_to_mask(p, n); 82 m->bits[0] = 0; 83 m->bits[1] = 0; 84 m->bits[bit >> 5] |= (1 << (bit & 31)); 85 } 86 } 87 88 static void param_set_min(struct snd_pcm_hw_params *p, int n, unsigned int val) 89 { 90 if (param_is_interval(n)) { 91 struct snd_interval *i = param_to_interval(p, n); 92 i->min = val; 93 } 94 } 95 96 static void param_set_max(struct snd_pcm_hw_params *p, int n, unsigned int val) 97 { 98 if (param_is_interval(n)) { 99 struct snd_interval *i = param_to_interval(p, n); 100 i->max = val; 101 } 102 } 103 104 static void param_set_int(struct snd_pcm_hw_params *p, int n, unsigned int val) 105 { 106 if (param_is_interval(n)) { 107 struct snd_interval *i = param_to_interval(p, n); 108 i->min = val; 109 i->max = val; 110 i->integer = 1; 111 } 112 } 113 114 static unsigned int param_get_int(struct snd_pcm_hw_params *p, int n) 115 { 116 if (param_is_interval(n)) { 117 struct snd_interval *i = param_to_interval(p, n); 118 if (i->integer) 119 return i->max; 120 } 121 return 0; 122 } 123 124 static void param_init(struct snd_pcm_hw_params *p) 125 { 126 int n; 127 128 memset(p, 0, sizeof(*p)); 129 for (n = SNDRV_PCM_HW_PARAM_FIRST_MASK; 130 n <= SNDRV_PCM_HW_PARAM_LAST_MASK; n++) { 131 struct snd_mask *m = param_to_mask(p, n); 132 m->bits[0] = ~0; 133 m->bits[1] = ~0; 134 } 135 for (n = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; 136 n <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; n++) { 137 struct snd_interval *i = param_to_interval(p, n); 138 i->min = 0; 139 i->max = ~0; 140 } 141 } 142 143 #define PCM_ERROR_MAX 128 144 145 struct pcm { 146 int fd; 147 unsigned int flags; 148 int running:1; 149 int underruns; 150 unsigned int buffer_size; 151 unsigned int boundary; 152 char error[PCM_ERROR_MAX]; 153 struct pcm_config config; 154 struct snd_pcm_mmap_status *mmap_status; 155 struct snd_pcm_mmap_control *mmap_control; 156 struct snd_pcm_sync_ptr *sync_ptr; 157 void *mmap_buffer; 158 unsigned int noirq_frames_per_msec; 159 int wait_for_avail_min; 160 }; 161 162 unsigned int pcm_get_buffer_size(struct pcm *pcm) 163 { 164 return pcm->buffer_size; 165 } 166 167 const char* pcm_get_error(struct pcm *pcm) 168 { 169 return pcm->error; 170 } 171 172 static int oops(struct pcm *pcm, int e, const char *fmt, ...) 173 { 174 va_list ap; 175 int sz; 176 177 va_start(ap, fmt); 178 vsnprintf(pcm->error, PCM_ERROR_MAX, fmt, ap); 179 va_end(ap); 180 sz = strlen(pcm->error); 181 182 if (errno) 183 snprintf(pcm->error + sz, PCM_ERROR_MAX - sz, 184 ": %s", strerror(e)); 185 return -1; 186 } 187 188 static unsigned int pcm_format_to_alsa(enum pcm_format format) 189 { 190 switch (format) { 191 case PCM_FORMAT_S32_LE: 192 return SNDRV_PCM_FORMAT_S32_LE; 193 default: 194 case PCM_FORMAT_S16_LE: 195 return SNDRV_PCM_FORMAT_S16_LE; 196 }; 197 } 198 199 static unsigned int pcm_format_to_bits(enum pcm_format format) 200 { 201 switch (format) { 202 case PCM_FORMAT_S32_LE: 203 return 32; 204 default: 205 case PCM_FORMAT_S16_LE: 206 return 16; 207 }; 208 } 209 210 unsigned int pcm_bytes_to_frames(struct pcm *pcm, unsigned int bytes) 211 { 212 return bytes / (pcm->config.channels * 213 (pcm_format_to_bits(pcm->config.format) >> 3)); 214 } 215 216 unsigned int pcm_frames_to_bytes(struct pcm *pcm, unsigned int frames) 217 { 218 return frames * pcm->config.channels * 219 (pcm_format_to_bits(pcm->config.format) >> 3); 220 } 221 222 static int pcm_sync_ptr(struct pcm *pcm, int flags) { 223 if (pcm->sync_ptr) { 224 pcm->sync_ptr->flags = flags; 225 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_SYNC_PTR, pcm->sync_ptr) < 0) 226 return -1; 227 } 228 return 0; 229 } 230 231 static int pcm_hw_mmap_status(struct pcm *pcm) { 232 233 if (pcm->sync_ptr) 234 return 0; 235 236 int page_size = sysconf(_SC_PAGE_SIZE); 237 pcm->mmap_status = mmap(NULL, page_size, PROT_READ, MAP_FILE | MAP_SHARED, 238 pcm->fd, SNDRV_PCM_MMAP_OFFSET_STATUS); 239 if (pcm->mmap_status == MAP_FAILED) 240 pcm->mmap_status = NULL; 241 if (!pcm->mmap_status) 242 goto mmap_error; 243 244 pcm->mmap_control = mmap(NULL, page_size, PROT_READ | PROT_WRITE, 245 MAP_FILE | MAP_SHARED, pcm->fd, SNDRV_PCM_MMAP_OFFSET_CONTROL); 246 if (pcm->mmap_control == MAP_FAILED) 247 pcm->mmap_control = NULL; 248 if (!pcm->mmap_control) { 249 munmap(pcm->mmap_status, page_size); 250 pcm->mmap_status = NULL; 251 goto mmap_error; 252 } 253 if (pcm->flags & PCM_MMAP) 254 pcm->mmap_control->avail_min = pcm->config.avail_min; 255 else 256 pcm->mmap_control->avail_min = 1; 257 258 return 0; 259 260 mmap_error: 261 262 pcm->sync_ptr = calloc(1, sizeof(*pcm->sync_ptr)); 263 if (!pcm->sync_ptr) 264 return -ENOMEM; 265 pcm->mmap_status = &pcm->sync_ptr->s.status; 266 pcm->mmap_control = &pcm->sync_ptr->c.control; 267 if (pcm->flags & PCM_MMAP) 268 pcm->mmap_control->avail_min = pcm->config.avail_min; 269 else 270 pcm->mmap_control->avail_min = 1; 271 272 pcm_sync_ptr(pcm, 0); 273 274 return 0; 275 } 276 277 static void pcm_hw_munmap_status(struct pcm *pcm) { 278 if (pcm->sync_ptr) { 279 free(pcm->sync_ptr); 280 pcm->sync_ptr = NULL; 281 } else { 282 int page_size = sysconf(_SC_PAGE_SIZE); 283 if (pcm->mmap_status) 284 munmap(pcm->mmap_status, page_size); 285 if (pcm->mmap_control) 286 munmap(pcm->mmap_control, page_size); 287 } 288 pcm->mmap_status = NULL; 289 pcm->mmap_control = NULL; 290 } 291 292 static int pcm_areas_copy(struct pcm *pcm, unsigned int pcm_offset, 293 const char *src, unsigned int src_offset, 294 unsigned int frames) 295 { 296 int size_bytes = pcm_frames_to_bytes(pcm, frames); 297 int pcm_offset_bytes = pcm_frames_to_bytes(pcm, pcm_offset); 298 int src_offset_bytes = pcm_frames_to_bytes(pcm, src_offset); 299 300 /* interleaved only atm */ 301 memcpy((char*)pcm->mmap_buffer + pcm_offset_bytes, 302 src + src_offset_bytes, size_bytes); 303 return 0; 304 } 305 306 static int pcm_mmap_write_areas(struct pcm *pcm, char *src, 307 unsigned int offset, unsigned int size) 308 { 309 void *pcm_areas; 310 int commit; 311 unsigned int pcm_offset, frames, count = 0; 312 313 while (size > 0) { 314 frames = size; 315 pcm_mmap_begin(pcm, &pcm_areas, &pcm_offset, &frames); 316 pcm_areas_copy(pcm, pcm_offset, src, offset, frames); 317 commit = pcm_mmap_commit(pcm, pcm_offset, frames); 318 if (commit < 0) { 319 oops(pcm, commit, "failed to commit %d frames\n", frames); 320 return commit; 321 } 322 323 offset += commit; 324 count += commit; 325 size -= commit; 326 } 327 return count; 328 } 329 330 int pcm_get_htimestamp(struct pcm *pcm, unsigned int *avail, 331 struct timespec *tstamp) 332 { 333 int frames; 334 int rc; 335 snd_pcm_uframes_t hw_ptr; 336 337 if (!pcm_is_ready(pcm)) 338 return -1; 339 340 rc = pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_APPL|SNDRV_PCM_SYNC_PTR_HWSYNC); 341 if (rc < 0) 342 return -1; 343 344 *tstamp = pcm->mmap_status->tstamp; 345 if (tstamp->tv_sec == 0 && tstamp->tv_nsec == 0) 346 return -1; 347 348 hw_ptr = pcm->mmap_status->hw_ptr; 349 if (pcm->flags & PCM_IN) 350 frames = hw_ptr - pcm->mmap_control->appl_ptr; 351 else 352 frames = hw_ptr + pcm->buffer_size - pcm->mmap_control->appl_ptr; 353 354 if (frames < 0) 355 frames += pcm->boundary; 356 else if (frames > (int)pcm->boundary) 357 frames -= pcm->boundary; 358 359 *avail = (unsigned int)frames; 360 361 return 0; 362 } 363 364 int pcm_write(struct pcm *pcm, void *data, unsigned int count) 365 { 366 struct snd_xferi x; 367 368 if (pcm->flags & PCM_IN) 369 return -EINVAL; 370 371 x.buf = data; 372 x.frames = count / (pcm->config.channels * 373 pcm_format_to_bits(pcm->config.format) / 8); 374 375 for (;;) { 376 if (!pcm->running) { 377 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_PREPARE)) 378 return oops(pcm, errno, "cannot prepare channel"); 379 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_WRITEI_FRAMES, &x)) 380 return oops(pcm, errno, "cannot write initial data"); 381 pcm->running = 1; 382 return 0; 383 } 384 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_WRITEI_FRAMES, &x)) { 385 pcm->running = 0; 386 if (errno == EPIPE) { 387 /* we failed to make our window -- try to restart */ 388 pcm->underruns++; 389 continue; 390 } 391 return oops(pcm, errno, "cannot write stream data"); 392 } 393 return 0; 394 } 395 } 396 397 int pcm_read(struct pcm *pcm, void *data, unsigned int count) 398 { 399 struct snd_xferi x; 400 401 if (!(pcm->flags & PCM_IN)) 402 return -EINVAL; 403 404 x.buf = data; 405 x.frames = count / (pcm->config.channels * 406 pcm_format_to_bits(pcm->config.format) / 8); 407 408 for (;;) { 409 if (!pcm->running) { 410 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_PREPARE)) 411 return oops(pcm, errno, "cannot prepare channel"); 412 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_START)) 413 return oops(pcm, errno, "cannot start channel"); 414 pcm->running = 1; 415 } 416 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_READI_FRAMES, &x)) { 417 pcm->running = 0; 418 if (errno == EPIPE) { 419 /* we failed to make our window -- try to restart */ 420 pcm->underruns++; 421 continue; 422 } 423 return oops(pcm, errno, "cannot read stream data"); 424 } 425 return 0; 426 } 427 } 428 429 static struct pcm bad_pcm = { 430 .fd = -1, 431 }; 432 433 int pcm_close(struct pcm *pcm) 434 { 435 if (pcm == &bad_pcm) 436 return 0; 437 438 pcm_hw_munmap_status(pcm); 439 440 if (pcm->flags & PCM_MMAP) { 441 pcm_stop(pcm); 442 munmap(pcm->mmap_buffer, pcm_frames_to_bytes(pcm, pcm->buffer_size)); 443 } 444 445 if (pcm->fd >= 0) 446 close(pcm->fd); 447 pcm->running = 0; 448 pcm->buffer_size = 0; 449 pcm->fd = -1; 450 free(pcm); 451 return 0; 452 } 453 454 struct pcm *pcm_open(unsigned int card, unsigned int device, 455 unsigned int flags, struct pcm_config *config) 456 { 457 struct pcm *pcm; 458 struct snd_pcm_info info; 459 struct snd_pcm_hw_params params; 460 struct snd_pcm_sw_params sparams; 461 char fn[256]; 462 int rc; 463 464 pcm = calloc(1, sizeof(struct pcm)); 465 if (!pcm || !config) 466 return &bad_pcm; /* TODO: could support default config here */ 467 468 pcm->config = *config; 469 470 snprintf(fn, sizeof(fn), "/dev/snd/pcmC%uD%u%c", card, device, 471 flags & PCM_IN ? 'c' : 'p'); 472 473 pcm->flags = flags; 474 pcm->fd = open(fn, O_RDWR); 475 if (pcm->fd < 0) { 476 oops(pcm, errno, "cannot open device '%s'", fn); 477 return pcm; 478 } 479 480 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_INFO, &info)) { 481 oops(pcm, errno, "cannot get info"); 482 goto fail_close; 483 } 484 485 param_init(¶ms); 486 param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_FORMAT, 487 pcm_format_to_alsa(config->format)); 488 param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_SUBFORMAT, 489 SNDRV_PCM_SUBFORMAT_STD); 490 param_set_min(¶ms, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, config->period_size); 491 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_SAMPLE_BITS, 492 pcm_format_to_bits(config->format)); 493 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_FRAME_BITS, 494 pcm_format_to_bits(config->format) * config->channels); 495 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_CHANNELS, 496 config->channels); 497 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_PERIODS, config->period_count); 498 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_RATE, config->rate); 499 500 if (flags & PCM_NOIRQ) { 501 502 if (!(flags & PCM_MMAP)) { 503 oops(pcm, -EINVAL, "noirq only currently supported with mmap()."); 504 goto fail; 505 } 506 507 params.flags |= SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP; 508 pcm->noirq_frames_per_msec = config->rate / 1000; 509 } 510 511 if (flags & PCM_MMAP) 512 param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_ACCESS, 513 SNDRV_PCM_ACCESS_MMAP_INTERLEAVED); 514 else 515 param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_ACCESS, 516 SNDRV_PCM_ACCESS_RW_INTERLEAVED); 517 518 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_HW_PARAMS, ¶ms)) { 519 oops(pcm, errno, "cannot set hw params"); 520 goto fail_close; 521 } 522 523 /* get our refined hw_params */ 524 config->period_size = param_get_int(¶ms, SNDRV_PCM_HW_PARAM_PERIOD_SIZE); 525 config->period_count = param_get_int(¶ms, SNDRV_PCM_HW_PARAM_PERIODS); 526 pcm->buffer_size = config->period_count * config->period_size; 527 528 if (flags & PCM_MMAP) { 529 pcm->mmap_buffer = mmap(NULL, pcm_frames_to_bytes(pcm, pcm->buffer_size), 530 PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, pcm->fd, 0); 531 if (pcm->mmap_buffer == MAP_FAILED) { 532 oops(pcm, -errno, "failed to mmap buffer %d bytes\n", 533 pcm_frames_to_bytes(pcm, pcm->buffer_size)); 534 goto fail_close; 535 } 536 } 537 538 539 memset(&sparams, 0, sizeof(sparams)); 540 sparams.tstamp_mode = SNDRV_PCM_TSTAMP_ENABLE; 541 sparams.period_step = 1; 542 543 if (!config->start_threshold) 544 pcm->config.start_threshold = sparams.start_threshold = 545 config->period_count * config->period_size / 2; 546 else 547 sparams.start_threshold = config->start_threshold; 548 549 /* pick a high stop threshold - todo: does this need further tuning */ 550 if (!config->stop_threshold) 551 pcm->config.stop_threshold = sparams.stop_threshold = 552 config->period_count * config->period_size * 10; 553 else 554 sparams.stop_threshold = config->stop_threshold; 555 556 if (!pcm->config.avail_min) { 557 if (pcm->flags & PCM_MMAP) 558 pcm->config.avail_min = sparams.avail_min = pcm->config.period_size; 559 else 560 pcm->config.avail_min = sparams.avail_min = 1; 561 } else 562 sparams.avail_min = config->avail_min; 563 564 sparams.xfer_align = config->period_size / 2; /* needed for old kernels */ 565 sparams.silence_size = 0; 566 sparams.silence_threshold = config->silence_threshold; 567 pcm->boundary = sparams.boundary = pcm->buffer_size; 568 569 while (pcm->boundary * 2 <= LONG_MAX - pcm->buffer_size) 570 pcm->boundary *= 2; 571 572 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_SW_PARAMS, &sparams)) { 573 oops(pcm, errno, "cannot set sw params"); 574 goto fail; 575 } 576 577 rc = pcm_hw_mmap_status(pcm); 578 if (rc < 0) { 579 oops(pcm, rc, "mmap status failed"); 580 goto fail; 581 } 582 583 pcm->underruns = 0; 584 return pcm; 585 586 fail: 587 if (flags & PCM_MMAP) 588 munmap(pcm->mmap_buffer, pcm_frames_to_bytes(pcm, pcm->buffer_size)); 589 fail_close: 590 close(pcm->fd); 591 pcm->fd = -1; 592 return pcm; 593 } 594 595 int pcm_is_ready(struct pcm *pcm) 596 { 597 return pcm->fd >= 0; 598 } 599 600 int pcm_start(struct pcm *pcm) 601 { 602 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_PREPARE) < 0) 603 return oops(pcm, errno, "cannot prepare channel"); 604 605 if (pcm->flags & PCM_MMAP) 606 pcm_sync_ptr(pcm, 0); 607 608 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_START) < 0) 609 return oops(pcm, errno, "cannot start channel"); 610 611 pcm->running = 1; 612 return 0; 613 } 614 615 int pcm_stop(struct pcm *pcm) 616 { 617 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_DROP) < 0) 618 return oops(pcm, errno, "cannot stop channel"); 619 620 pcm->running = 0; 621 return 0; 622 } 623 624 static inline int pcm_mmap_playback_avail(struct pcm *pcm) 625 { 626 int avail; 627 628 avail = pcm->mmap_status->hw_ptr + pcm->buffer_size - pcm->mmap_control->appl_ptr; 629 630 if (avail < 0) 631 avail += pcm->boundary; 632 else if (avail > (int)pcm->boundary) 633 avail -= pcm->boundary; 634 635 return avail; 636 } 637 638 static inline int pcm_mmap_capture_avail(struct pcm *pcm) 639 { 640 int avail = pcm->mmap_status->hw_ptr - pcm->mmap_control->appl_ptr; 641 if (avail < 0) 642 avail += pcm->boundary; 643 return avail; 644 } 645 646 static inline int pcm_mmap_avail(struct pcm *pcm) 647 { 648 pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_HWSYNC); 649 if (pcm->flags & PCM_IN) 650 return pcm_mmap_capture_avail(pcm); 651 else 652 return pcm_mmap_playback_avail(pcm); 653 } 654 655 static void pcm_mmap_appl_forward(struct pcm *pcm, int frames) 656 { 657 unsigned int appl_ptr = pcm->mmap_control->appl_ptr; 658 appl_ptr += frames; 659 660 /* check for boundary wrap */ 661 if (appl_ptr > pcm->boundary) 662 appl_ptr -= pcm->boundary; 663 pcm->mmap_control->appl_ptr = appl_ptr; 664 } 665 666 int pcm_mmap_begin(struct pcm *pcm, void **areas, unsigned int *offset, 667 unsigned int *frames) 668 { 669 unsigned int continuous, copy_frames, avail; 670 671 /* return the mmap buffer */ 672 *areas = pcm->mmap_buffer; 673 674 /* and the application offset in frames */ 675 *offset = pcm->mmap_control->appl_ptr % pcm->buffer_size; 676 677 avail = pcm_mmap_avail(pcm); 678 if (avail > pcm->buffer_size) 679 avail = pcm->buffer_size; 680 continuous = pcm->buffer_size - *offset; 681 682 /* we can only copy frames if the are availabale and continuos */ 683 copy_frames = *frames; 684 if (copy_frames > avail) 685 copy_frames = avail; 686 if (copy_frames > continuous) 687 copy_frames = continuous; 688 *frames = copy_frames; 689 690 return 0; 691 } 692 693 int pcm_mmap_commit(struct pcm *pcm, unsigned int offset, unsigned int frames) 694 { 695 /* update the application pointer in userspace and kernel */ 696 pcm_mmap_appl_forward(pcm, frames); 697 pcm_sync_ptr(pcm, 0); 698 699 return frames; 700 } 701 702 int pcm_avail_update(struct pcm *pcm) 703 { 704 pcm_sync_ptr(pcm, 0); 705 return pcm_mmap_avail(pcm); 706 } 707 708 int pcm_state(struct pcm *pcm) 709 { 710 int err = pcm_sync_ptr(pcm, 0); 711 if (err < 0) 712 return err; 713 714 return pcm->mmap_status->state; 715 } 716 717 int pcm_set_avail_min(struct pcm *pcm, int avail_min) 718 { 719 if ((~pcm->flags) & (PCM_MMAP | PCM_NOIRQ)) 720 return -ENOSYS; 721 722 pcm->config.avail_min = avail_min; 723 return 0; 724 } 725 726 int pcm_wait(struct pcm *pcm, int timeout) 727 { 728 struct pollfd pfd; 729 unsigned short revents = 0; 730 int err; 731 732 pfd.fd = pcm->fd; 733 pfd.events = POLLOUT | POLLERR | POLLNVAL; 734 735 do { 736 /* let's wait for avail or timeout */ 737 err = poll(&pfd, 1, timeout); 738 if (err < 0) 739 return -errno; 740 741 /* timeout ? */ 742 if (err == 0) 743 return 0; 744 745 /* have we been interrupted ? */ 746 if (errno == -EINTR) 747 continue; 748 749 /* check for any errors */ 750 if (pfd.revents & (POLLERR | POLLNVAL)) { 751 switch (pcm_state(pcm)) { 752 case PCM_STATE_XRUN: 753 return -EPIPE; 754 case PCM_STATE_SUSPENDED: 755 return -ESTRPIPE; 756 case PCM_STATE_DISCONNECTED: 757 return -ENODEV; 758 default: 759 return -EIO; 760 } 761 } 762 /* poll again if fd not ready for IO */ 763 } while (!(pfd.revents & (POLLIN | POLLOUT))); 764 765 return 1; 766 } 767 768 int pcm_mmap_write(struct pcm *pcm, void *buffer, unsigned int bytes) 769 { 770 int err = 0, frames, avail; 771 unsigned int offset = 0, count; 772 773 if (bytes == 0) 774 return 0; 775 776 count = pcm_bytes_to_frames(pcm, bytes); 777 778 while (count > 0) { 779 780 /* get the available space for writing new frames */ 781 avail = pcm_avail_update(pcm); 782 if (avail < 0) { 783 fprintf(stderr, "cannot determine available mmap frames"); 784 return err; 785 } 786 787 /* start the audio if we reach the threshold */ 788 if (!pcm->running && 789 (pcm->buffer_size - avail) >= pcm->config.start_threshold) { 790 if (pcm_start(pcm) < 0) { 791 fprintf(stderr, "start error: hw 0x%x app 0x%x avail 0x%x\n", 792 (unsigned int)pcm->mmap_status->hw_ptr, 793 (unsigned int)pcm->mmap_control->appl_ptr, 794 avail); 795 return -errno; 796 } 797 pcm->wait_for_avail_min = 0; 798 } 799 800 /* sleep until we have space to write new frames */ 801 if (pcm->running) { 802 /* enable waiting for avail_min threshold when less frames than we have to write 803 * are available. */ 804 if (!pcm->wait_for_avail_min && (count > (unsigned int)avail)) 805 pcm->wait_for_avail_min = 1; 806 807 if (pcm->wait_for_avail_min && (avail < pcm->config.avail_min)) { 808 int time = -1; 809 810 /* disable waiting for avail_min threshold to allow small amounts of data to be 811 * written without waiting as long as there is enough room in buffer. */ 812 pcm->wait_for_avail_min = 0; 813 814 if (pcm->flags & PCM_NOIRQ) 815 time = (pcm->config.avail_min - avail) / pcm->noirq_frames_per_msec; 816 817 err = pcm_wait(pcm, time); 818 if (err < 0) { 819 pcm->running = 0; 820 oops(pcm, err, "wait error: hw 0x%x app 0x%x avail 0x%x\n", 821 (unsigned int)pcm->mmap_status->hw_ptr, 822 (unsigned int)pcm->mmap_control->appl_ptr, 823 avail); 824 pcm->mmap_control->appl_ptr = 0; 825 return err; 826 } 827 continue; 828 } 829 } 830 831 frames = count; 832 if (frames > avail) 833 frames = avail; 834 835 if (!frames) 836 break; 837 838 /* copy frames from buffer */ 839 frames = pcm_mmap_write_areas(pcm, buffer, offset, frames); 840 if (frames < 0) { 841 fprintf(stderr, "write error: hw 0x%x app 0x%x avail 0x%x\n", 842 (unsigned int)pcm->mmap_status->hw_ptr, 843 (unsigned int)pcm->mmap_control->appl_ptr, 844 avail); 845 return frames; 846 } 847 848 offset += frames; 849 count -= frames; 850 } 851 852 _end: 853 return 0; 854 } 855
