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 };
260
pcm_get_buffer_size(struct pcm * pcm)261 unsigned int pcm_get_buffer_size(struct pcm *pcm)
262 {
263 return pcm->buffer_size;
264 }
265
pcm_get_error(struct pcm * pcm)266 const char* pcm_get_error(struct pcm *pcm)
267 {
268 return pcm->error;
269 }
270
oops(struct pcm * pcm,int e,const char * fmt,...)271 static int oops(struct pcm *pcm, int e, const char *fmt, ...)
272 {
273 va_list ap;
274 int sz;
275
276 va_start(ap, fmt);
277 vsnprintf(pcm->error, PCM_ERROR_MAX, fmt, ap);
278 va_end(ap);
279 sz = strlen(pcm->error);
280
281 if (errno)
282 snprintf(pcm->error + sz, PCM_ERROR_MAX - sz,
283 ": %s", strerror(e));
284 return -1;
285 }
286
pcm_format_to_alsa(enum pcm_format format)287 static unsigned int pcm_format_to_alsa(enum pcm_format format)
288 {
289 switch (format) {
290 case PCM_FORMAT_S32_LE:
291 return SNDRV_PCM_FORMAT_S32_LE;
292 case PCM_FORMAT_S8:
293 return SNDRV_PCM_FORMAT_S8;
294 case PCM_FORMAT_S24_3LE:
295 return SNDRV_PCM_FORMAT_S24_3LE;
296 case PCM_FORMAT_S24_LE:
297 return SNDRV_PCM_FORMAT_S24_LE;
298 default:
299 case PCM_FORMAT_S16_LE:
300 return SNDRV_PCM_FORMAT_S16_LE;
301 };
302 }
303
pcm_format_to_bits(enum pcm_format format)304 unsigned int pcm_format_to_bits(enum pcm_format format)
305 {
306 switch (format) {
307 case PCM_FORMAT_S32_LE:
308 case PCM_FORMAT_S24_LE:
309 return 32;
310 case PCM_FORMAT_S24_3LE:
311 return 24;
312 default:
313 case PCM_FORMAT_S16_LE:
314 return 16;
315 };
316 }
317
pcm_bytes_to_frames(struct pcm * pcm,unsigned int bytes)318 unsigned int pcm_bytes_to_frames(struct pcm *pcm, unsigned int bytes)
319 {
320 return bytes / (pcm->config.channels *
321 (pcm_format_to_bits(pcm->config.format) >> 3));
322 }
323
pcm_frames_to_bytes(struct pcm * pcm,unsigned int frames)324 unsigned int pcm_frames_to_bytes(struct pcm *pcm, unsigned int frames)
325 {
326 return frames * pcm->config.channels *
327 (pcm_format_to_bits(pcm->config.format) >> 3);
328 }
329
pcm_sync_ptr(struct pcm * pcm,int flags)330 static int pcm_sync_ptr(struct pcm *pcm, int flags) {
331 if (pcm->sync_ptr) {
332 pcm->sync_ptr->flags = flags;
333 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_SYNC_PTR, pcm->sync_ptr) < 0)
334 return -1;
335 }
336 return 0;
337 }
338
pcm_hw_mmap_status(struct pcm * pcm)339 static int pcm_hw_mmap_status(struct pcm *pcm) {
340
341 if (pcm->sync_ptr)
342 return 0;
343
344 int page_size = sysconf(_SC_PAGE_SIZE);
345 pcm->mmap_status = mmap(NULL, page_size, PROT_READ, MAP_FILE | MAP_SHARED,
346 pcm->fd, SNDRV_PCM_MMAP_OFFSET_STATUS);
347 if (pcm->mmap_status == MAP_FAILED)
348 pcm->mmap_status = NULL;
349 if (!pcm->mmap_status)
350 goto mmap_error;
351
352 pcm->mmap_control = mmap(NULL, page_size, PROT_READ | PROT_WRITE,
353 MAP_FILE | MAP_SHARED, pcm->fd, SNDRV_PCM_MMAP_OFFSET_CONTROL);
354 if (pcm->mmap_control == MAP_FAILED)
355 pcm->mmap_control = NULL;
356 if (!pcm->mmap_control) {
357 munmap(pcm->mmap_status, page_size);
358 pcm->mmap_status = NULL;
359 goto mmap_error;
360 }
361 if (pcm->flags & PCM_MMAP)
362 pcm->mmap_control->avail_min = pcm->config.avail_min;
363 else
364 pcm->mmap_control->avail_min = 1;
365
366 return 0;
367
368 mmap_error:
369
370 pcm->sync_ptr = calloc(1, sizeof(*pcm->sync_ptr));
371 if (!pcm->sync_ptr)
372 return -ENOMEM;
373 pcm->mmap_status = &pcm->sync_ptr->s.status;
374 pcm->mmap_control = &pcm->sync_ptr->c.control;
375 if (pcm->flags & PCM_MMAP)
376 pcm->mmap_control->avail_min = pcm->config.avail_min;
377 else
378 pcm->mmap_control->avail_min = 1;
379
380 pcm_sync_ptr(pcm, 0);
381
382 return 0;
383 }
384
pcm_hw_munmap_status(struct pcm * pcm)385 static void pcm_hw_munmap_status(struct pcm *pcm) {
386 if (pcm->sync_ptr) {
387 free(pcm->sync_ptr);
388 pcm->sync_ptr = NULL;
389 } else {
390 int page_size = sysconf(_SC_PAGE_SIZE);
391 if (pcm->mmap_status)
392 munmap(pcm->mmap_status, page_size);
393 if (pcm->mmap_control)
394 munmap(pcm->mmap_control, page_size);
395 }
396 pcm->mmap_status = NULL;
397 pcm->mmap_control = NULL;
398 }
399
pcm_areas_copy(struct pcm * pcm,unsigned int pcm_offset,char * buf,unsigned int src_offset,unsigned int frames)400 static int pcm_areas_copy(struct pcm *pcm, unsigned int pcm_offset,
401 char *buf, unsigned int src_offset,
402 unsigned int frames)
403 {
404 int size_bytes = pcm_frames_to_bytes(pcm, frames);
405 int pcm_offset_bytes = pcm_frames_to_bytes(pcm, pcm_offset);
406 int src_offset_bytes = pcm_frames_to_bytes(pcm, src_offset);
407
408 /* interleaved only atm */
409 if (pcm->flags & PCM_IN)
410 memcpy(buf + src_offset_bytes,
411 (char*)pcm->mmap_buffer + pcm_offset_bytes,
412 size_bytes);
413 else
414 memcpy((char*)pcm->mmap_buffer + pcm_offset_bytes,
415 buf + src_offset_bytes,
416 size_bytes);
417 return 0;
418 }
419
pcm_mmap_transfer_areas(struct pcm * pcm,char * buf,unsigned int offset,unsigned int size)420 static int pcm_mmap_transfer_areas(struct pcm *pcm, char *buf,
421 unsigned int offset, unsigned int size)
422 {
423 void *pcm_areas;
424 int commit;
425 unsigned int pcm_offset, frames, count = 0;
426
427 while (size > 0) {
428 frames = size;
429 pcm_mmap_begin(pcm, &pcm_areas, &pcm_offset, &frames);
430 pcm_areas_copy(pcm, pcm_offset, buf, offset, frames);
431 commit = pcm_mmap_commit(pcm, pcm_offset, frames);
432 if (commit < 0) {
433 oops(pcm, commit, "failed to commit %d frames\n", frames);
434 return commit;
435 }
436
437 offset += commit;
438 count += commit;
439 size -= commit;
440 }
441 return count;
442 }
443
pcm_get_htimestamp(struct pcm * pcm,unsigned int * avail,struct timespec * tstamp)444 int pcm_get_htimestamp(struct pcm *pcm, unsigned int *avail,
445 struct timespec *tstamp)
446 {
447 int frames;
448 int rc;
449 snd_pcm_uframes_t hw_ptr;
450
451 if (!pcm_is_ready(pcm))
452 return -1;
453
454 rc = pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_APPL|SNDRV_PCM_SYNC_PTR_HWSYNC);
455 if (rc < 0)
456 return -1;
457
458 if ((pcm->mmap_status->state != PCM_STATE_RUNNING) &&
459 (pcm->mmap_status->state != PCM_STATE_DRAINING))
460 return -1;
461
462 *tstamp = pcm->mmap_status->tstamp;
463 if (tstamp->tv_sec == 0 && tstamp->tv_nsec == 0)
464 return -1;
465
466 hw_ptr = pcm->mmap_status->hw_ptr;
467 if (pcm->flags & PCM_IN)
468 frames = hw_ptr - pcm->mmap_control->appl_ptr;
469 else
470 frames = hw_ptr + pcm->buffer_size - pcm->mmap_control->appl_ptr;
471
472 if (frames < 0)
473 frames += pcm->boundary;
474 else if (frames > (int)pcm->boundary)
475 frames -= pcm->boundary;
476
477 *avail = (unsigned int)frames;
478
479 return 0;
480 }
481
pcm_write(struct pcm * pcm,const void * data,unsigned int count)482 int pcm_write(struct pcm *pcm, const void *data, unsigned int count)
483 {
484 struct snd_xferi x;
485
486 if (pcm->flags & PCM_IN)
487 return -EINVAL;
488
489 x.buf = (void*)data;
490 x.frames = count / (pcm->config.channels *
491 pcm_format_to_bits(pcm->config.format) / 8);
492
493 for (;;) {
494 if (!pcm->running) {
495 int prepare_error = pcm_prepare(pcm);
496 if (prepare_error)
497 return prepare_error;
498 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_WRITEI_FRAMES, &x))
499 return oops(pcm, errno, "cannot write initial data");
500 pcm->running = 1;
501 return 0;
502 }
503 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_WRITEI_FRAMES, &x)) {
504 pcm->prepared = 0;
505 pcm->running = 0;
506 if (errno == EPIPE) {
507 /* we failed to make our window -- try to restart if we are
508 * allowed to do so. Otherwise, simply allow the EPIPE error to
509 * propagate up to the app level */
510 pcm->underruns++;
511 if (pcm->flags & PCM_NORESTART)
512 return -EPIPE;
513 continue;
514 }
515 return oops(pcm, errno, "cannot write stream data");
516 }
517 return 0;
518 }
519 }
520
pcm_read(struct pcm * pcm,void * data,unsigned int count)521 int pcm_read(struct pcm *pcm, void *data, unsigned int count)
522 {
523 struct snd_xferi x;
524
525 if (!(pcm->flags & PCM_IN))
526 return -EINVAL;
527
528 x.buf = data;
529 x.frames = count / (pcm->config.channels *
530 pcm_format_to_bits(pcm->config.format) / 8);
531
532 for (;;) {
533 if (!pcm->running) {
534 if (pcm_start(pcm) < 0) {
535 fprintf(stderr, "start error");
536 return -errno;
537 }
538 }
539 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_READI_FRAMES, &x)) {
540 pcm->prepared = 0;
541 pcm->running = 0;
542 if (errno == EPIPE) {
543 /* we failed to make our window -- try to restart */
544 pcm->underruns++;
545 continue;
546 }
547 return oops(pcm, errno, "cannot read stream data");
548 }
549 return 0;
550 }
551 }
552
553 static struct pcm bad_pcm = {
554 .fd = -1,
555 };
556
pcm_params_get(unsigned int card,unsigned int device,unsigned int flags)557 struct pcm_params *pcm_params_get(unsigned int card, unsigned int device,
558 unsigned int flags)
559 {
560 struct snd_pcm_hw_params *params;
561 char fn[256];
562 int fd;
563
564 snprintf(fn, sizeof(fn), "/dev/snd/pcmC%uD%u%c", card, device,
565 flags & PCM_IN ? 'c' : 'p');
566
567 fd = open(fn, O_RDWR);
568 if (fd < 0) {
569 fprintf(stderr, "cannot open device '%s'\n", fn);
570 goto err_open;
571 }
572
573 params = calloc(1, sizeof(struct snd_pcm_hw_params));
574 if (!params)
575 goto err_calloc;
576
577 param_init(params);
578 if (ioctl(fd, SNDRV_PCM_IOCTL_HW_REFINE, params)) {
579 fprintf(stderr, "SNDRV_PCM_IOCTL_HW_REFINE error (%d)\n", errno);
580 goto err_hw_refine;
581 }
582
583 close(fd);
584
585 return (struct pcm_params *)params;
586
587 err_hw_refine:
588 free(params);
589 err_calloc:
590 close(fd);
591 err_open:
592 return NULL;
593 }
594
pcm_params_free(struct pcm_params * pcm_params)595 void pcm_params_free(struct pcm_params *pcm_params)
596 {
597 struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params;
598
599 if (params)
600 free(params);
601 }
602
pcm_param_to_alsa(enum pcm_param param)603 static int pcm_param_to_alsa(enum pcm_param param)
604 {
605 switch (param) {
606 case PCM_PARAM_ACCESS:
607 return SNDRV_PCM_HW_PARAM_ACCESS;
608 case PCM_PARAM_FORMAT:
609 return SNDRV_PCM_HW_PARAM_FORMAT;
610 case PCM_PARAM_SUBFORMAT:
611 return SNDRV_PCM_HW_PARAM_SUBFORMAT;
612 case PCM_PARAM_SAMPLE_BITS:
613 return SNDRV_PCM_HW_PARAM_SAMPLE_BITS;
614 break;
615 case PCM_PARAM_FRAME_BITS:
616 return SNDRV_PCM_HW_PARAM_FRAME_BITS;
617 break;
618 case PCM_PARAM_CHANNELS:
619 return SNDRV_PCM_HW_PARAM_CHANNELS;
620 break;
621 case PCM_PARAM_RATE:
622 return SNDRV_PCM_HW_PARAM_RATE;
623 break;
624 case PCM_PARAM_PERIOD_TIME:
625 return SNDRV_PCM_HW_PARAM_PERIOD_TIME;
626 break;
627 case PCM_PARAM_PERIOD_SIZE:
628 return SNDRV_PCM_HW_PARAM_PERIOD_SIZE;
629 break;
630 case PCM_PARAM_PERIOD_BYTES:
631 return SNDRV_PCM_HW_PARAM_PERIOD_BYTES;
632 break;
633 case PCM_PARAM_PERIODS:
634 return SNDRV_PCM_HW_PARAM_PERIODS;
635 break;
636 case PCM_PARAM_BUFFER_TIME:
637 return SNDRV_PCM_HW_PARAM_BUFFER_TIME;
638 break;
639 case PCM_PARAM_BUFFER_SIZE:
640 return SNDRV_PCM_HW_PARAM_BUFFER_SIZE;
641 break;
642 case PCM_PARAM_BUFFER_BYTES:
643 return SNDRV_PCM_HW_PARAM_BUFFER_BYTES;
644 break;
645 case PCM_PARAM_TICK_TIME:
646 return SNDRV_PCM_HW_PARAM_TICK_TIME;
647 break;
648
649 default:
650 return -1;
651 }
652 }
653
pcm_params_get_mask(struct pcm_params * pcm_params,enum pcm_param param)654 struct pcm_mask *pcm_params_get_mask(struct pcm_params *pcm_params,
655 enum pcm_param param)
656 {
657 int p;
658 struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params;
659 if (params == NULL) {
660 return NULL;
661 }
662
663 p = pcm_param_to_alsa(param);
664 if (p < 0 || !param_is_mask(p)) {
665 return NULL;
666 }
667
668 return (struct pcm_mask *)param_to_mask(params, p);
669 }
670
pcm_params_get_min(struct pcm_params * pcm_params,enum pcm_param param)671 unsigned int pcm_params_get_min(struct pcm_params *pcm_params,
672 enum pcm_param param)
673 {
674 struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params;
675 int p;
676
677 if (!params)
678 return 0;
679
680 p = pcm_param_to_alsa(param);
681 if (p < 0)
682 return 0;
683
684 return param_get_min(params, p);
685 }
686
pcm_params_set_min(struct pcm_params * pcm_params,enum pcm_param param,unsigned int val)687 void pcm_params_set_min(struct pcm_params *pcm_params,
688 enum pcm_param param, unsigned int val)
689 {
690 struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params;
691 int p;
692
693 if (!params)
694 return;
695
696 p = pcm_param_to_alsa(param);
697 if (p < 0)
698 return;
699
700 param_set_min(params, p, val);
701 }
702
pcm_params_get_max(struct pcm_params * pcm_params,enum pcm_param param)703 unsigned int pcm_params_get_max(struct pcm_params *pcm_params,
704 enum pcm_param param)
705 {
706 struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params;
707 int p;
708
709 if (!params)
710 return 0;
711
712 p = pcm_param_to_alsa(param);
713 if (p < 0)
714 return 0;
715
716 return param_get_max(params, p);
717 }
718
pcm_params_set_max(struct pcm_params * pcm_params,enum pcm_param param,unsigned int val)719 void pcm_params_set_max(struct pcm_params *pcm_params,
720 enum pcm_param param, unsigned int val)
721 {
722 struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params;
723 int p;
724
725 if (!params)
726 return;
727
728 p = pcm_param_to_alsa(param);
729 if (p < 0)
730 return;
731
732 param_set_max(params, p, val);
733 }
734
pcm_mask_test(struct pcm_mask * m,unsigned int index)735 static int pcm_mask_test(struct pcm_mask *m, unsigned int index)
736 {
737 const unsigned int bitshift = 5; /* for 32 bit integer */
738 const unsigned int bitmask = (1 << bitshift) - 1;
739 unsigned int element;
740
741 element = index >> bitshift;
742 if (element >= ARRAY_SIZE(m->bits))
743 return 0; /* for safety, but should never occur */
744 return (m->bits[element] >> (index & bitmask)) & 1;
745 }
746
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)747 static int pcm_mask_to_string(struct pcm_mask *m, char *string, unsigned int size,
748 char *mask_name,
749 const char * const *bit_array_name, size_t bit_array_size)
750 {
751 unsigned int i;
752 unsigned int offset = 0;
753
754 if (m == NULL)
755 return 0;
756 if (bit_array_size < 32) {
757 STRLOG(string, offset, size, "%12s:\t%#08x\n", mask_name, m->bits[0]);
758 } else { /* spans two or more bitfields, print with an array index */
759 for (i = 0; i < (bit_array_size + 31) >> 5; ++i) {
760 STRLOG(string, offset, size, "%9s[%d]:\t%#08x\n",
761 mask_name, i, m->bits[i]);
762 }
763 }
764 for (i = 0; i < bit_array_size; ++i) {
765 if (pcm_mask_test(m, i)) {
766 STRLOG(string, offset, size, "%12s \t%s\n", "", bit_array_name[i]);
767 }
768 }
769 return offset;
770 }
771
pcm_params_to_string(struct pcm_params * params,char * string,unsigned int size)772 int pcm_params_to_string(struct pcm_params *params, char *string, unsigned int size)
773 {
774 struct pcm_mask *m;
775 unsigned int min, max;
776 unsigned int clipoffset, offset;
777
778 m = pcm_params_get_mask(params, PCM_PARAM_ACCESS);
779 offset = pcm_mask_to_string(m, string, size,
780 "Access", access_lookup, ARRAY_SIZE(access_lookup));
781 m = pcm_params_get_mask(params, PCM_PARAM_FORMAT);
782 clipoffset = offset > size ? size : offset;
783 offset += pcm_mask_to_string(m, string + clipoffset, size - clipoffset,
784 "Format", format_lookup, ARRAY_SIZE(format_lookup));
785 m = pcm_params_get_mask(params, PCM_PARAM_SUBFORMAT);
786 clipoffset = offset > size ? size : offset;
787 offset += pcm_mask_to_string(m, string + clipoffset, size - clipoffset,
788 "Subformat", subformat_lookup, ARRAY_SIZE(subformat_lookup));
789 min = pcm_params_get_min(params, PCM_PARAM_RATE);
790 max = pcm_params_get_max(params, PCM_PARAM_RATE);
791 STRLOG(string, offset, size, " Rate:\tmin=%uHz\tmax=%uHz\n", min, max);
792 min = pcm_params_get_min(params, PCM_PARAM_CHANNELS);
793 max = pcm_params_get_max(params, PCM_PARAM_CHANNELS);
794 STRLOG(string, offset, size, " Channels:\tmin=%u\t\tmax=%u\n", min, max);
795 min = pcm_params_get_min(params, PCM_PARAM_SAMPLE_BITS);
796 max = pcm_params_get_max(params, PCM_PARAM_SAMPLE_BITS);
797 STRLOG(string, offset, size, " Sample bits:\tmin=%u\t\tmax=%u\n", min, max);
798 min = pcm_params_get_min(params, PCM_PARAM_PERIOD_SIZE);
799 max = pcm_params_get_max(params, PCM_PARAM_PERIOD_SIZE);
800 STRLOG(string, offset, size, " Period size:\tmin=%u\t\tmax=%u\n", min, max);
801 min = pcm_params_get_min(params, PCM_PARAM_PERIODS);
802 max = pcm_params_get_max(params, PCM_PARAM_PERIODS);
803 STRLOG(string, offset, size, "Period count:\tmin=%u\t\tmax=%u\n", min, max);
804 return offset;
805 }
806
pcm_params_format_test(struct pcm_params * params,enum pcm_format format)807 int pcm_params_format_test(struct pcm_params *params, enum pcm_format format)
808 {
809 unsigned int alsa_format = pcm_format_to_alsa(format);
810
811 if (alsa_format == SNDRV_PCM_FORMAT_S16_LE && format != PCM_FORMAT_S16_LE)
812 return 0; /* caution: format not recognized is equivalent to S16_LE */
813 return pcm_mask_test(pcm_params_get_mask(params, PCM_PARAM_FORMAT), alsa_format);
814 }
815
pcm_close(struct pcm * pcm)816 int pcm_close(struct pcm *pcm)
817 {
818 if (pcm == &bad_pcm)
819 return 0;
820
821 pcm_hw_munmap_status(pcm);
822
823 if (pcm->flags & PCM_MMAP) {
824 pcm_stop(pcm);
825 munmap(pcm->mmap_buffer, pcm_frames_to_bytes(pcm, pcm->buffer_size));
826 }
827
828 if (pcm->fd >= 0)
829 close(pcm->fd);
830 pcm->prepared = 0;
831 pcm->running = 0;
832 pcm->buffer_size = 0;
833 pcm->fd = -1;
834 free(pcm);
835 return 0;
836 }
837
pcm_open(unsigned int card,unsigned int device,unsigned int flags,struct pcm_config * config)838 struct pcm *pcm_open(unsigned int card, unsigned int device,
839 unsigned int flags, struct pcm_config *config)
840 {
841 struct pcm *pcm;
842 struct snd_pcm_info info;
843 struct snd_pcm_hw_params params;
844 struct snd_pcm_sw_params sparams;
845 char fn[256];
846 int rc;
847
848 pcm = calloc(1, sizeof(struct pcm));
849 if (!pcm || !config)
850 return &bad_pcm; /* TODO: could support default config here */
851
852 pcm->config = *config;
853
854 snprintf(fn, sizeof(fn), "/dev/snd/pcmC%uD%u%c", card, device,
855 flags & PCM_IN ? 'c' : 'p');
856
857 pcm->flags = flags;
858 pcm->fd = open(fn, O_RDWR|O_NONBLOCK);
859 if (pcm->fd < 0) {
860 oops(pcm, errno, "cannot open device '%s'", fn);
861 return pcm;
862 }
863
864 if (fcntl(pcm->fd, F_SETFL, fcntl(pcm->fd, F_GETFL) &
865 ~O_NONBLOCK) < 0) {
866 oops(pcm, errno, "failed to reset blocking mode '%s'", fn);
867 goto fail_close;
868 }
869
870 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_INFO, &info)) {
871 oops(pcm, errno, "cannot get info");
872 goto fail_close;
873 }
874
875 param_init(¶ms);
876 param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_FORMAT,
877 pcm_format_to_alsa(config->format));
878 param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_SUBFORMAT,
879 SNDRV_PCM_SUBFORMAT_STD);
880 param_set_min(¶ms, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, config->period_size);
881 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_SAMPLE_BITS,
882 pcm_format_to_bits(config->format));
883 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_FRAME_BITS,
884 pcm_format_to_bits(config->format) * config->channels);
885 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_CHANNELS,
886 config->channels);
887 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_PERIODS, config->period_count);
888 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_RATE, config->rate);
889
890 if (flags & PCM_NOIRQ) {
891 if (!(flags & PCM_MMAP)) {
892 oops(pcm, -EINVAL, "noirq only currently supported with mmap().");
893 goto fail_close;
894 }
895
896 params.flags |= SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP;
897 pcm->noirq_frames_per_msec = config->rate / 1000;
898 }
899
900 if (flags & PCM_MMAP)
901 param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_ACCESS,
902 SNDRV_PCM_ACCESS_MMAP_INTERLEAVED);
903 else
904 param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_ACCESS,
905 SNDRV_PCM_ACCESS_RW_INTERLEAVED);
906
907 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_HW_PARAMS, ¶ms)) {
908 oops(pcm, errno, "cannot set hw params");
909 goto fail_close;
910 }
911
912 /* get our refined hw_params */
913 config->period_size = param_get_int(¶ms, SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
914 config->period_count = param_get_int(¶ms, SNDRV_PCM_HW_PARAM_PERIODS);
915 pcm->buffer_size = config->period_count * config->period_size;
916
917 if (flags & PCM_MMAP) {
918 pcm->mmap_buffer = mmap(NULL, pcm_frames_to_bytes(pcm, pcm->buffer_size),
919 PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, pcm->fd, 0);
920 if (pcm->mmap_buffer == MAP_FAILED) {
921 oops(pcm, -errno, "failed to mmap buffer %d bytes\n",
922 pcm_frames_to_bytes(pcm, pcm->buffer_size));
923 goto fail_close;
924 }
925 }
926
927 memset(&sparams, 0, sizeof(sparams));
928 sparams.tstamp_mode = SNDRV_PCM_TSTAMP_ENABLE;
929 sparams.period_step = 1;
930
931 if (!config->start_threshold) {
932 if (pcm->flags & PCM_IN)
933 pcm->config.start_threshold = sparams.start_threshold = 1;
934 else
935 pcm->config.start_threshold = sparams.start_threshold =
936 config->period_count * config->period_size / 2;
937 } else
938 sparams.start_threshold = config->start_threshold;
939
940 /* pick a high stop threshold - todo: does this need further tuning */
941 if (!config->stop_threshold) {
942 if (pcm->flags & PCM_IN)
943 pcm->config.stop_threshold = sparams.stop_threshold =
944 config->period_count * config->period_size * 10;
945 else
946 pcm->config.stop_threshold = sparams.stop_threshold =
947 config->period_count * config->period_size;
948 }
949 else
950 sparams.stop_threshold = config->stop_threshold;
951
952 if (!pcm->config.avail_min) {
953 if (pcm->flags & PCM_MMAP)
954 pcm->config.avail_min = sparams.avail_min = pcm->config.period_size;
955 else
956 pcm->config.avail_min = sparams.avail_min = 1;
957 } else
958 sparams.avail_min = config->avail_min;
959
960 sparams.xfer_align = config->period_size / 2; /* needed for old kernels */
961 sparams.silence_threshold = config->silence_threshold;
962 sparams.silence_size = config->silence_size;
963 pcm->boundary = sparams.boundary = pcm->buffer_size;
964
965 while (pcm->boundary * 2 <= INT_MAX - pcm->buffer_size)
966 pcm->boundary *= 2;
967
968 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_SW_PARAMS, &sparams)) {
969 oops(pcm, errno, "cannot set sw params");
970 goto fail;
971 }
972
973 rc = pcm_hw_mmap_status(pcm);
974 if (rc < 0) {
975 oops(pcm, rc, "mmap status failed");
976 goto fail;
977 }
978
979 #ifdef SNDRV_PCM_IOCTL_TTSTAMP
980 if (pcm->flags & PCM_MONOTONIC) {
981 int arg = SNDRV_PCM_TSTAMP_TYPE_MONOTONIC;
982 rc = ioctl(pcm->fd, SNDRV_PCM_IOCTL_TTSTAMP, &arg);
983 if (rc < 0) {
984 oops(pcm, rc, "cannot set timestamp type");
985 goto fail;
986 }
987 }
988 #endif
989
990 pcm->underruns = 0;
991 return pcm;
992
993 fail:
994 if (flags & PCM_MMAP)
995 munmap(pcm->mmap_buffer, pcm_frames_to_bytes(pcm, pcm->buffer_size));
996 fail_close:
997 close(pcm->fd);
998 pcm->fd = -1;
999 return pcm;
1000 }
1001
pcm_is_ready(struct pcm * pcm)1002 int pcm_is_ready(struct pcm *pcm)
1003 {
1004 return pcm->fd >= 0;
1005 }
1006
pcm_prepare(struct pcm * pcm)1007 int pcm_prepare(struct pcm *pcm)
1008 {
1009 if (pcm->prepared)
1010 return 0;
1011
1012 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_PREPARE) < 0)
1013 return oops(pcm, errno, "cannot prepare channel");
1014
1015 pcm->prepared = 1;
1016 return 0;
1017 }
1018
pcm_start(struct pcm * pcm)1019 int pcm_start(struct pcm *pcm)
1020 {
1021 int prepare_error = pcm_prepare(pcm);
1022 if (prepare_error)
1023 return prepare_error;
1024
1025 if (pcm->flags & PCM_MMAP)
1026 pcm_sync_ptr(pcm, 0);
1027
1028 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_START) < 0)
1029 return oops(pcm, errno, "cannot start channel");
1030
1031 pcm->running = 1;
1032 return 0;
1033 }
1034
pcm_stop(struct pcm * pcm)1035 int pcm_stop(struct pcm *pcm)
1036 {
1037 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_DROP) < 0)
1038 return oops(pcm, errno, "cannot stop channel");
1039
1040 pcm->prepared = 0;
1041 pcm->running = 0;
1042 return 0;
1043 }
1044
pcm_mmap_playback_avail(struct pcm * pcm)1045 static inline int pcm_mmap_playback_avail(struct pcm *pcm)
1046 {
1047 int avail;
1048
1049 avail = pcm->mmap_status->hw_ptr + pcm->buffer_size - pcm->mmap_control->appl_ptr;
1050
1051 if (avail < 0)
1052 avail += pcm->boundary;
1053 else if (avail > (int)pcm->boundary)
1054 avail -= pcm->boundary;
1055
1056 return avail;
1057 }
1058
pcm_mmap_capture_avail(struct pcm * pcm)1059 static inline int pcm_mmap_capture_avail(struct pcm *pcm)
1060 {
1061 int avail = pcm->mmap_status->hw_ptr - pcm->mmap_control->appl_ptr;
1062 if (avail < 0)
1063 avail += pcm->boundary;
1064 return avail;
1065 }
1066
pcm_mmap_avail(struct pcm * pcm)1067 int pcm_mmap_avail(struct pcm *pcm)
1068 {
1069 pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_HWSYNC);
1070 if (pcm->flags & PCM_IN)
1071 return pcm_mmap_capture_avail(pcm);
1072 else
1073 return pcm_mmap_playback_avail(pcm);
1074 }
1075
pcm_mmap_appl_forward(struct pcm * pcm,int frames)1076 static void pcm_mmap_appl_forward(struct pcm *pcm, int frames)
1077 {
1078 unsigned int appl_ptr = pcm->mmap_control->appl_ptr;
1079 appl_ptr += frames;
1080
1081 /* check for boundary wrap */
1082 if (appl_ptr > pcm->boundary)
1083 appl_ptr -= pcm->boundary;
1084 pcm->mmap_control->appl_ptr = appl_ptr;
1085 }
1086
pcm_mmap_begin(struct pcm * pcm,void ** areas,unsigned int * offset,unsigned int * frames)1087 int pcm_mmap_begin(struct pcm *pcm, void **areas, unsigned int *offset,
1088 unsigned int *frames)
1089 {
1090 unsigned int continuous, copy_frames, avail;
1091
1092 /* return the mmap buffer */
1093 *areas = pcm->mmap_buffer;
1094
1095 /* and the application offset in frames */
1096 *offset = pcm->mmap_control->appl_ptr % pcm->buffer_size;
1097
1098 avail = pcm_mmap_avail(pcm);
1099 if (avail > pcm->buffer_size)
1100 avail = pcm->buffer_size;
1101 continuous = pcm->buffer_size - *offset;
1102
1103 /* we can only copy frames if the are availabale and continuos */
1104 copy_frames = *frames;
1105 if (copy_frames > avail)
1106 copy_frames = avail;
1107 if (copy_frames > continuous)
1108 copy_frames = continuous;
1109 *frames = copy_frames;
1110
1111 return 0;
1112 }
1113
pcm_mmap_commit(struct pcm * pcm,unsigned int offset,unsigned int frames)1114 int pcm_mmap_commit(struct pcm *pcm, unsigned int offset __attribute__((unused)), unsigned int frames)
1115 {
1116 /* update the application pointer in userspace and kernel */
1117 pcm_mmap_appl_forward(pcm, frames);
1118 pcm_sync_ptr(pcm, 0);
1119
1120 return frames;
1121 }
1122
pcm_avail_update(struct pcm * pcm)1123 int pcm_avail_update(struct pcm *pcm)
1124 {
1125 pcm_sync_ptr(pcm, 0);
1126 return pcm_mmap_avail(pcm);
1127 }
1128
pcm_state(struct pcm * pcm)1129 int pcm_state(struct pcm *pcm)
1130 {
1131 int err = pcm_sync_ptr(pcm, 0);
1132 if (err < 0)
1133 return err;
1134
1135 return pcm->mmap_status->state;
1136 }
1137
pcm_set_avail_min(struct pcm * pcm,int avail_min)1138 int pcm_set_avail_min(struct pcm *pcm, int avail_min)
1139 {
1140 if ((~pcm->flags) & (PCM_MMAP | PCM_NOIRQ))
1141 return -ENOSYS;
1142
1143 pcm->config.avail_min = avail_min;
1144 return 0;
1145 }
1146
pcm_wait(struct pcm * pcm,int timeout)1147 int pcm_wait(struct pcm *pcm, int timeout)
1148 {
1149 struct pollfd pfd;
1150 int err;
1151
1152 pfd.fd = pcm->fd;
1153 pfd.events = POLLOUT | POLLERR | POLLNVAL;
1154
1155 do {
1156 /* let's wait for avail or timeout */
1157 err = poll(&pfd, 1, timeout);
1158 if (err < 0)
1159 return -errno;
1160
1161 /* timeout ? */
1162 if (err == 0)
1163 return 0;
1164
1165 /* have we been interrupted ? */
1166 if (errno == -EINTR)
1167 continue;
1168
1169 /* check for any errors */
1170 if (pfd.revents & (POLLERR | POLLNVAL)) {
1171 switch (pcm_state(pcm)) {
1172 case PCM_STATE_XRUN:
1173 return -EPIPE;
1174 case PCM_STATE_SUSPENDED:
1175 return -ESTRPIPE;
1176 case PCM_STATE_DISCONNECTED:
1177 return -ENODEV;
1178 default:
1179 return -EIO;
1180 }
1181 }
1182 /* poll again if fd not ready for IO */
1183 } while (!(pfd.revents & (POLLIN | POLLOUT)));
1184
1185 return 1;
1186 }
1187
pcm_get_poll_fd(struct pcm * pcm)1188 int pcm_get_poll_fd(struct pcm *pcm)
1189 {
1190 return pcm->fd;
1191 }
1192
pcm_mmap_transfer(struct pcm * pcm,const void * buffer,unsigned int bytes)1193 int pcm_mmap_transfer(struct pcm *pcm, const void *buffer, unsigned int bytes)
1194 {
1195 int err = 0, frames, avail;
1196 unsigned int offset = 0, count;
1197
1198 if (bytes == 0)
1199 return 0;
1200
1201 count = pcm_bytes_to_frames(pcm, bytes);
1202
1203 while (count > 0) {
1204
1205 /* get the available space for writing new frames */
1206 avail = pcm_avail_update(pcm);
1207 if (avail < 0) {
1208 fprintf(stderr, "cannot determine available mmap frames");
1209 return err;
1210 }
1211
1212 /* start the audio if we reach the threshold */
1213 if (!pcm->running &&
1214 (pcm->buffer_size - avail) >= pcm->config.start_threshold) {
1215 if (pcm_start(pcm) < 0) {
1216 fprintf(stderr, "start error: hw 0x%x app 0x%x avail 0x%x\n",
1217 (unsigned int)pcm->mmap_status->hw_ptr,
1218 (unsigned int)pcm->mmap_control->appl_ptr,
1219 avail);
1220 return -errno;
1221 }
1222 pcm->wait_for_avail_min = 0;
1223 }
1224
1225 /* sleep until we have space to write new frames */
1226 if (pcm->running) {
1227 /* enable waiting for avail_min threshold when less frames than we have to write
1228 * are available. */
1229 if (!pcm->wait_for_avail_min && (count > (unsigned int)avail))
1230 pcm->wait_for_avail_min = 1;
1231
1232 if (pcm->wait_for_avail_min && (avail < pcm->config.avail_min)) {
1233 int time = -1;
1234
1235 /* disable waiting for avail_min threshold to allow small amounts of data to be
1236 * written without waiting as long as there is enough room in buffer. */
1237 pcm->wait_for_avail_min = 0;
1238
1239 if (pcm->flags & PCM_NOIRQ)
1240 time = (pcm->config.avail_min - avail) / pcm->noirq_frames_per_msec;
1241
1242 err = pcm_wait(pcm, time);
1243 if (err < 0) {
1244 pcm->prepared = 0;
1245 pcm->running = 0;
1246 oops(pcm, err, "wait error: hw 0x%x app 0x%x avail 0x%x\n",
1247 (unsigned int)pcm->mmap_status->hw_ptr,
1248 (unsigned int)pcm->mmap_control->appl_ptr,
1249 avail);
1250 pcm->mmap_control->appl_ptr = 0;
1251 return err;
1252 }
1253 continue;
1254 }
1255 }
1256
1257 frames = count;
1258 if (frames > avail)
1259 frames = avail;
1260
1261 if (!frames)
1262 break;
1263
1264 /* copy frames from buffer */
1265 frames = pcm_mmap_transfer_areas(pcm, (void *)buffer, offset, frames);
1266 if (frames < 0) {
1267 fprintf(stderr, "write error: hw 0x%x app 0x%x avail 0x%x\n",
1268 (unsigned int)pcm->mmap_status->hw_ptr,
1269 (unsigned int)pcm->mmap_control->appl_ptr,
1270 avail);
1271 return frames;
1272 }
1273
1274 offset += frames;
1275 count -= frames;
1276 }
1277
1278 return 0;
1279 }
1280
pcm_mmap_write(struct pcm * pcm,const void * data,unsigned int count)1281 int pcm_mmap_write(struct pcm *pcm, const void *data, unsigned int count)
1282 {
1283 if ((~pcm->flags) & (PCM_OUT | PCM_MMAP))
1284 return -ENOSYS;
1285
1286 return pcm_mmap_transfer(pcm, (void *)data, count);
1287 }
1288
pcm_mmap_read(struct pcm * pcm,void * data,unsigned int count)1289 int pcm_mmap_read(struct pcm *pcm, void *data, unsigned int count)
1290 {
1291 if ((~pcm->flags) & (PCM_IN | PCM_MMAP))
1292 return -ENOSYS;
1293
1294 return pcm_mmap_transfer(pcm, data, count);
1295 }
1296
pcm_ioctl(struct pcm * pcm,int request,...)1297 int pcm_ioctl(struct pcm *pcm, int request, ...)
1298 {
1299 va_list ap;
1300 void * arg;
1301
1302 if (!pcm_is_ready(pcm))
1303 return -1;
1304
1305 va_start(ap, request);
1306 arg = va_arg(ap, void *);
1307 va_end(ap);
1308
1309 return ioctl(pcm->fd, request, arg);
1310 }
1311