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. */
66 static 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. */
75 static 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. */
127 static const char * const subformat_lookup[] = {
128 "STD",
129 };
130
param_is_mask(int p)131 static 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
param_is_interval(int p)137 static 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
param_to_interval(struct snd_pcm_hw_params * p,int n)143 static 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
param_to_mask(struct snd_pcm_hw_params * p,int n)148 static 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
param_set_mask(struct snd_pcm_hw_params * p,int n,unsigned int bit)153 static 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
param_set_min(struct snd_pcm_hw_params * p,int n,unsigned int val)165 static 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
param_get_min(struct snd_pcm_hw_params * p,int n)173 static 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
param_set_max(struct snd_pcm_hw_params * p,int n,unsigned int val)182 static 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
param_get_max(struct snd_pcm_hw_params * p,int n)190 static 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
param_set_int(struct snd_pcm_hw_params * p,int n,unsigned int val)199 static 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
param_get_int(struct snd_pcm_hw_params * p,int n)209 static 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
param_init(struct snd_pcm_hw_params * p)219 static 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
243 struct 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
pcm_get_buffer_size(struct pcm * pcm)262 unsigned int pcm_get_buffer_size(struct pcm *pcm)
263 {
264 return pcm->buffer_size;
265 }
266
pcm_get_error(struct pcm * pcm)267 const char* pcm_get_error(struct pcm *pcm)
268 {
269 return pcm->error;
270 }
271
pcm_get_subdevice(struct pcm * pcm)272 unsigned int pcm_get_subdevice(struct pcm *pcm)
273 {
274 return pcm->subdevice;
275 }
276
oops(struct pcm * pcm,int e,const char * fmt,...)277 static 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
pcm_format_to_alsa(enum pcm_format format)293 static 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
pcm_format_to_bits(enum pcm_format format)310 unsigned 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
pcm_bytes_to_frames(struct pcm * pcm,unsigned int bytes)324 unsigned 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
pcm_frames_to_bytes(struct pcm * pcm,unsigned int frames)330 unsigned 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
pcm_sync_ptr(struct pcm * pcm,int flags)336 static 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
pcm_hw_mmap_status(struct pcm * pcm)345 static 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
374 mmap_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
pcm_hw_munmap_status(struct pcm * pcm)391 static 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
pcm_areas_copy(struct pcm * pcm,unsigned int pcm_offset,char * buf,unsigned int src_offset,unsigned int frames)406 static 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
pcm_mmap_transfer_areas(struct pcm * pcm,char * buf,unsigned int offset,unsigned int size)426 static 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
pcm_get_htimestamp(struct pcm * pcm,unsigned int * avail,struct timespec * tstamp)450 int 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
pcm_mmap_get_hw_ptr(struct pcm * pcm,unsigned int * hw_ptr,struct timespec * tstamp)488 int 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
pcm_write(struct pcm * pcm,const void * data,unsigned int count)519 int 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
pcm_read(struct pcm * pcm,void * data,unsigned int count)558 int 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
590 static struct pcm bad_pcm = {
591 .fd = -1,
592 };
593
pcm_params_get(unsigned int card,unsigned int device,unsigned int flags)594 struct 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
624 err_hw_refine:
625 free(params);
626 err_calloc:
627 close(fd);
628 err_open:
629 return NULL;
630 }
631
pcm_params_free(struct pcm_params * pcm_params)632 void 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
pcm_param_to_alsa(enum pcm_param param)640 static 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
pcm_params_get_mask(struct pcm_params * pcm_params,enum pcm_param param)691 struct 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
pcm_params_get_min(struct pcm_params * pcm_params,enum pcm_param param)708 unsigned 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
pcm_params_set_min(struct pcm_params * pcm_params,enum pcm_param param,unsigned int val)724 void 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
pcm_params_get_max(struct pcm_params * pcm_params,enum pcm_param param)740 unsigned 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
pcm_params_set_max(struct pcm_params * pcm_params,enum pcm_param param,unsigned int val)756 void 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
pcm_mask_test(struct pcm_mask * m,unsigned int index)772 static 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
pcm_mask_to_string(struct pcm_mask * m,char * string,unsigned int size,char * mask_name,const char * const * bit_array_name,size_t bit_array_size)784 static 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
pcm_params_to_string(struct pcm_params * params,char * string,unsigned int size)809 int 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
pcm_params_format_test(struct pcm_params * params,enum pcm_format format)844 int 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
pcm_close(struct pcm * pcm)853 int 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
pcm_open(unsigned int card,unsigned int device,unsigned int flags,struct pcm_config * config)875 struct 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
1034 fail:
1035 if (flags & PCM_MMAP)
1036 munmap(pcm->mmap_buffer, pcm_frames_to_bytes(pcm, pcm->buffer_size));
1037 fail_close:
1038 close(pcm->fd);
1039 pcm->fd = -1;
1040 return pcm;
1041 }
1042
pcm_is_ready(struct pcm * pcm)1043 int pcm_is_ready(struct pcm *pcm)
1044 {
1045 return pcm->fd >= 0;
1046 }
1047
pcm_prepare(struct pcm * pcm)1048 int 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
pcm_start(struct pcm * pcm)1060 int 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
pcm_stop(struct pcm * pcm)1076 int 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
pcm_mmap_playback_avail(struct pcm * pcm)1086 static 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
pcm_mmap_capture_avail(struct pcm * pcm)1100 static 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
pcm_mmap_avail(struct pcm * pcm)1108 int 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
pcm_mmap_appl_forward(struct pcm * pcm,int frames)1117 static 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
pcm_mmap_begin(struct pcm * pcm,void ** areas,unsigned int * offset,unsigned int * frames)1128 int 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
pcm_mmap_commit(struct pcm * pcm,unsigned int offset,unsigned int frames)1155 int 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
pcm_avail_update(struct pcm * pcm)1164 int pcm_avail_update(struct pcm *pcm)
1165 {
1166 pcm_sync_ptr(pcm, 0);
1167 return pcm_mmap_avail(pcm);
1168 }
1169
pcm_state(struct pcm * pcm)1170 int 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
pcm_set_avail_min(struct pcm * pcm,int avail_min)1179 int 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
pcm_wait(struct pcm * pcm,int timeout)1188 int 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
pcm_get_poll_fd(struct pcm * pcm)1229 int pcm_get_poll_fd(struct pcm *pcm)
1230 {
1231 return pcm->fd;
1232 }
1233
pcm_mmap_transfer(struct pcm * pcm,const void * buffer,unsigned int bytes)1234 int 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
pcm_mmap_write(struct pcm * pcm,const void * data,unsigned int count)1322 int 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
pcm_mmap_read(struct pcm * pcm,void * data,unsigned int count)1330 int 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
pcm_ioctl(struct pcm * pcm,int request,...)1338 int 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