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
param_is_mask(int p)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
param_is_interval(int p)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
param_to_interval(struct snd_pcm_hw_params * p,int n)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
param_to_mask(struct snd_pcm_hw_params * p,int n)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
param_set_mask(struct snd_pcm_hw_params * p,int n,unsigned int bit)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
param_set_min(struct snd_pcm_hw_params * p,int n,unsigned int val)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
param_get_min(struct snd_pcm_hw_params * p,int n)96 static unsigned int param_get_min(struct snd_pcm_hw_params *p, int n)
97 {
98 if (param_is_interval(n)) {
99 struct snd_interval *i = param_to_interval(p, n);
100 return i->min;
101 }
102 return 0;
103 }
104
param_get_max(struct snd_pcm_hw_params * p,int n)105 static unsigned int param_get_max(struct snd_pcm_hw_params *p, int n)
106 {
107 if (param_is_interval(n)) {
108 struct snd_interval *i = param_to_interval(p, n);
109 return i->max;
110 }
111 return 0;
112 }
113
param_set_int(struct snd_pcm_hw_params * p,int n,unsigned int val)114 static void param_set_int(struct snd_pcm_hw_params *p, int n, unsigned int val)
115 {
116 if (param_is_interval(n)) {
117 struct snd_interval *i = param_to_interval(p, n);
118 i->min = val;
119 i->max = val;
120 i->integer = 1;
121 }
122 }
123
param_get_int(struct snd_pcm_hw_params * p,int n)124 static unsigned int param_get_int(struct snd_pcm_hw_params *p, int n)
125 {
126 if (param_is_interval(n)) {
127 struct snd_interval *i = param_to_interval(p, n);
128 if (i->integer)
129 return i->max;
130 }
131 return 0;
132 }
133
param_init(struct snd_pcm_hw_params * p)134 static void param_init(struct snd_pcm_hw_params *p)
135 {
136 int n;
137
138 memset(p, 0, sizeof(*p));
139 for (n = SNDRV_PCM_HW_PARAM_FIRST_MASK;
140 n <= SNDRV_PCM_HW_PARAM_LAST_MASK; n++) {
141 struct snd_mask *m = param_to_mask(p, n);
142 m->bits[0] = ~0;
143 m->bits[1] = ~0;
144 }
145 for (n = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL;
146 n <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; n++) {
147 struct snd_interval *i = param_to_interval(p, n);
148 i->min = 0;
149 i->max = ~0;
150 }
151 p->rmask = ~0U;
152 p->cmask = 0;
153 p->info = ~0U;
154 }
155
156 #define PCM_ERROR_MAX 128
157
158 struct pcm {
159 int fd;
160 unsigned int flags;
161 int running:1;
162 int underruns;
163 unsigned int buffer_size;
164 unsigned int boundary;
165 char error[PCM_ERROR_MAX];
166 struct pcm_config config;
167 struct snd_pcm_mmap_status *mmap_status;
168 struct snd_pcm_mmap_control *mmap_control;
169 struct snd_pcm_sync_ptr *sync_ptr;
170 void *mmap_buffer;
171 unsigned int noirq_frames_per_msec;
172 int wait_for_avail_min;
173 };
174
pcm_get_buffer_size(struct pcm * pcm)175 unsigned int pcm_get_buffer_size(struct pcm *pcm)
176 {
177 return pcm->buffer_size;
178 }
179
pcm_get_error(struct pcm * pcm)180 const char* pcm_get_error(struct pcm *pcm)
181 {
182 return pcm->error;
183 }
184
oops(struct pcm * pcm,int e,const char * fmt,...)185 static int oops(struct pcm *pcm, int e, const char *fmt, ...)
186 {
187 va_list ap;
188 int sz;
189
190 va_start(ap, fmt);
191 vsnprintf(pcm->error, PCM_ERROR_MAX, fmt, ap);
192 va_end(ap);
193 sz = strlen(pcm->error);
194
195 if (errno)
196 snprintf(pcm->error + sz, PCM_ERROR_MAX - sz,
197 ": %s", strerror(e));
198 return -1;
199 }
200
pcm_format_to_alsa(enum pcm_format format)201 static unsigned int pcm_format_to_alsa(enum pcm_format format)
202 {
203 switch (format) {
204 case PCM_FORMAT_S32_LE:
205 return SNDRV_PCM_FORMAT_S32_LE;
206 case PCM_FORMAT_S8:
207 return SNDRV_PCM_FORMAT_S8;
208 case PCM_FORMAT_S24_LE:
209 return SNDRV_PCM_FORMAT_S24_LE;
210 default:
211 case PCM_FORMAT_S16_LE:
212 return SNDRV_PCM_FORMAT_S16_LE;
213 };
214 }
215
pcm_format_to_bits(enum pcm_format format)216 unsigned int pcm_format_to_bits(enum pcm_format format)
217 {
218 switch (format) {
219 case PCM_FORMAT_S32_LE:
220 case PCM_FORMAT_S24_LE:
221 return 32;
222 default:
223 case PCM_FORMAT_S16_LE:
224 return 16;
225 };
226 }
227
pcm_bytes_to_frames(struct pcm * pcm,unsigned int bytes)228 unsigned int pcm_bytes_to_frames(struct pcm *pcm, unsigned int bytes)
229 {
230 return bytes / (pcm->config.channels *
231 (pcm_format_to_bits(pcm->config.format) >> 3));
232 }
233
pcm_frames_to_bytes(struct pcm * pcm,unsigned int frames)234 unsigned int pcm_frames_to_bytes(struct pcm *pcm, unsigned int frames)
235 {
236 return frames * pcm->config.channels *
237 (pcm_format_to_bits(pcm->config.format) >> 3);
238 }
239
pcm_sync_ptr(struct pcm * pcm,int flags)240 static int pcm_sync_ptr(struct pcm *pcm, int flags) {
241 if (pcm->sync_ptr) {
242 pcm->sync_ptr->flags = flags;
243 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_SYNC_PTR, pcm->sync_ptr) < 0)
244 return -1;
245 }
246 return 0;
247 }
248
pcm_hw_mmap_status(struct pcm * pcm)249 static int pcm_hw_mmap_status(struct pcm *pcm) {
250
251 if (pcm->sync_ptr)
252 return 0;
253
254 int page_size = sysconf(_SC_PAGE_SIZE);
255 pcm->mmap_status = mmap(NULL, page_size, PROT_READ, MAP_FILE | MAP_SHARED,
256 pcm->fd, SNDRV_PCM_MMAP_OFFSET_STATUS);
257 if (pcm->mmap_status == MAP_FAILED)
258 pcm->mmap_status = NULL;
259 if (!pcm->mmap_status)
260 goto mmap_error;
261
262 pcm->mmap_control = mmap(NULL, page_size, PROT_READ | PROT_WRITE,
263 MAP_FILE | MAP_SHARED, pcm->fd, SNDRV_PCM_MMAP_OFFSET_CONTROL);
264 if (pcm->mmap_control == MAP_FAILED)
265 pcm->mmap_control = NULL;
266 if (!pcm->mmap_control) {
267 munmap(pcm->mmap_status, page_size);
268 pcm->mmap_status = NULL;
269 goto mmap_error;
270 }
271 if (pcm->flags & PCM_MMAP)
272 pcm->mmap_control->avail_min = pcm->config.avail_min;
273 else
274 pcm->mmap_control->avail_min = 1;
275
276 return 0;
277
278 mmap_error:
279
280 pcm->sync_ptr = calloc(1, sizeof(*pcm->sync_ptr));
281 if (!pcm->sync_ptr)
282 return -ENOMEM;
283 pcm->mmap_status = &pcm->sync_ptr->s.status;
284 pcm->mmap_control = &pcm->sync_ptr->c.control;
285 if (pcm->flags & PCM_MMAP)
286 pcm->mmap_control->avail_min = pcm->config.avail_min;
287 else
288 pcm->mmap_control->avail_min = 1;
289
290 pcm_sync_ptr(pcm, 0);
291
292 return 0;
293 }
294
pcm_hw_munmap_status(struct pcm * pcm)295 static void pcm_hw_munmap_status(struct pcm *pcm) {
296 if (pcm->sync_ptr) {
297 free(pcm->sync_ptr);
298 pcm->sync_ptr = NULL;
299 } else {
300 int page_size = sysconf(_SC_PAGE_SIZE);
301 if (pcm->mmap_status)
302 munmap(pcm->mmap_status, page_size);
303 if (pcm->mmap_control)
304 munmap(pcm->mmap_control, page_size);
305 }
306 pcm->mmap_status = NULL;
307 pcm->mmap_control = NULL;
308 }
309
pcm_areas_copy(struct pcm * pcm,unsigned int pcm_offset,char * buf,unsigned int src_offset,unsigned int frames)310 static int pcm_areas_copy(struct pcm *pcm, unsigned int pcm_offset,
311 char *buf, unsigned int src_offset,
312 unsigned int frames)
313 {
314 int size_bytes = pcm_frames_to_bytes(pcm, frames);
315 int pcm_offset_bytes = pcm_frames_to_bytes(pcm, pcm_offset);
316 int src_offset_bytes = pcm_frames_to_bytes(pcm, src_offset);
317
318 /* interleaved only atm */
319 if (pcm->flags & PCM_IN)
320 memcpy(buf + src_offset_bytes,
321 (char*)pcm->mmap_buffer + pcm_offset_bytes,
322 size_bytes);
323 else
324 memcpy((char*)pcm->mmap_buffer + pcm_offset_bytes,
325 buf + src_offset_bytes,
326 size_bytes);
327 return 0;
328 }
329
pcm_mmap_transfer_areas(struct pcm * pcm,char * buf,unsigned int offset,unsigned int size)330 static int pcm_mmap_transfer_areas(struct pcm *pcm, char *buf,
331 unsigned int offset, unsigned int size)
332 {
333 void *pcm_areas;
334 int commit;
335 unsigned int pcm_offset, frames, count = 0;
336
337 while (size > 0) {
338 frames = size;
339 pcm_mmap_begin(pcm, &pcm_areas, &pcm_offset, &frames);
340 pcm_areas_copy(pcm, pcm_offset, buf, offset, frames);
341 commit = pcm_mmap_commit(pcm, pcm_offset, frames);
342 if (commit < 0) {
343 oops(pcm, commit, "failed to commit %d frames\n", frames);
344 return commit;
345 }
346
347 offset += commit;
348 count += commit;
349 size -= commit;
350 }
351 return count;
352 }
353
pcm_get_htimestamp(struct pcm * pcm,unsigned int * avail,struct timespec * tstamp)354 int pcm_get_htimestamp(struct pcm *pcm, unsigned int *avail,
355 struct timespec *tstamp)
356 {
357 int frames;
358 int rc;
359 snd_pcm_uframes_t hw_ptr;
360
361 if (!pcm_is_ready(pcm))
362 return -1;
363
364 rc = pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_APPL|SNDRV_PCM_SYNC_PTR_HWSYNC);
365 if (rc < 0)
366 return -1;
367
368 if ((pcm->mmap_status->state != PCM_STATE_RUNNING) &&
369 (pcm->mmap_status->state != PCM_STATE_DRAINING))
370 return -1;
371
372 *tstamp = pcm->mmap_status->tstamp;
373 if (tstamp->tv_sec == 0 && tstamp->tv_nsec == 0)
374 return -1;
375
376 hw_ptr = pcm->mmap_status->hw_ptr;
377 if (pcm->flags & PCM_IN)
378 frames = hw_ptr - pcm->mmap_control->appl_ptr;
379 else
380 frames = hw_ptr + pcm->buffer_size - pcm->mmap_control->appl_ptr;
381
382 if (frames < 0)
383 frames += pcm->boundary;
384 else if (frames > (int)pcm->boundary)
385 frames -= pcm->boundary;
386
387 *avail = (unsigned int)frames;
388
389 return 0;
390 }
391
pcm_write(struct pcm * pcm,const void * data,unsigned int count)392 int pcm_write(struct pcm *pcm, const void *data, unsigned int count)
393 {
394 struct snd_xferi x;
395
396 if (pcm->flags & PCM_IN)
397 return -EINVAL;
398
399 x.buf = (void*)data;
400 x.frames = count / (pcm->config.channels *
401 pcm_format_to_bits(pcm->config.format) / 8);
402
403 for (;;) {
404 if (!pcm->running) {
405 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_PREPARE))
406 return oops(pcm, errno, "cannot prepare channel");
407 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_WRITEI_FRAMES, &x))
408 return oops(pcm, errno, "cannot write initial data");
409 pcm->running = 1;
410 return 0;
411 }
412 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_WRITEI_FRAMES, &x)) {
413 pcm->running = 0;
414 if (errno == EPIPE) {
415 /* we failed to make our window -- try to restart if we are
416 * allowed to do so. Otherwise, simply allow the EPIPE error to
417 * propagate up to the app level */
418 pcm->underruns++;
419 if (pcm->flags & PCM_NORESTART)
420 return -EPIPE;
421 continue;
422 }
423 return oops(pcm, errno, "cannot write stream data");
424 }
425 return 0;
426 }
427 }
428
pcm_read(struct pcm * pcm,void * data,unsigned int count)429 int pcm_read(struct pcm *pcm, void *data, unsigned int count)
430 {
431 struct snd_xferi x;
432
433 if (!(pcm->flags & PCM_IN))
434 return -EINVAL;
435
436 x.buf = data;
437 x.frames = count / (pcm->config.channels *
438 pcm_format_to_bits(pcm->config.format) / 8);
439
440 for (;;) {
441 if (!pcm->running) {
442 if (pcm_start(pcm) < 0) {
443 fprintf(stderr, "start error");
444 return -errno;
445 }
446 }
447 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_READI_FRAMES, &x)) {
448 pcm->running = 0;
449 if (errno == EPIPE) {
450 /* we failed to make our window -- try to restart */
451 pcm->underruns++;
452 continue;
453 }
454 return oops(pcm, errno, "cannot read stream data");
455 }
456 return 0;
457 }
458 }
459
460 static struct pcm bad_pcm = {
461 .fd = -1,
462 };
463
pcm_params_get(unsigned int card,unsigned int device,unsigned int flags)464 struct pcm_params *pcm_params_get(unsigned int card, unsigned int device,
465 unsigned int flags)
466 {
467 struct snd_pcm_hw_params *params;
468 char fn[256];
469 int fd;
470
471 snprintf(fn, sizeof(fn), "/dev/snd/pcmC%uD%u%c", card, device,
472 flags & PCM_IN ? 'c' : 'p');
473
474 fd = open(fn, O_RDWR);
475 if (fd < 0) {
476 fprintf(stderr, "cannot open device '%s'\n", fn);
477 goto err_open;
478 }
479
480 params = calloc(1, sizeof(struct snd_pcm_hw_params));
481 if (!params)
482 goto err_calloc;
483
484 param_init(params);
485 if (ioctl(fd, SNDRV_PCM_IOCTL_HW_REFINE, params)) {
486 fprintf(stderr, "SNDRV_PCM_IOCTL_HW_REFINE error (%d)\n", errno);
487 goto err_hw_refine;
488 }
489
490 close(fd);
491
492 return (struct pcm_params *)params;
493
494 err_hw_refine:
495 free(params);
496 err_calloc:
497 close(fd);
498 err_open:
499 return NULL;
500 }
501
pcm_params_free(struct pcm_params * pcm_params)502 void pcm_params_free(struct pcm_params *pcm_params)
503 {
504 struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params;
505
506 if (params)
507 free(params);
508 }
509
pcm_param_to_alsa(enum pcm_param param)510 static int pcm_param_to_alsa(enum pcm_param param)
511 {
512 switch (param) {
513 case PCM_PARAM_SAMPLE_BITS:
514 return SNDRV_PCM_HW_PARAM_SAMPLE_BITS;
515 break;
516 case PCM_PARAM_FRAME_BITS:
517 return SNDRV_PCM_HW_PARAM_FRAME_BITS;
518 break;
519 case PCM_PARAM_CHANNELS:
520 return SNDRV_PCM_HW_PARAM_CHANNELS;
521 break;
522 case PCM_PARAM_RATE:
523 return SNDRV_PCM_HW_PARAM_RATE;
524 break;
525 case PCM_PARAM_PERIOD_TIME:
526 return SNDRV_PCM_HW_PARAM_PERIOD_TIME;
527 break;
528 case PCM_PARAM_PERIOD_SIZE:
529 return SNDRV_PCM_HW_PARAM_PERIOD_SIZE;
530 break;
531 case PCM_PARAM_PERIOD_BYTES:
532 return SNDRV_PCM_HW_PARAM_PERIOD_BYTES;
533 break;
534 case PCM_PARAM_PERIODS:
535 return SNDRV_PCM_HW_PARAM_PERIODS;
536 break;
537 case PCM_PARAM_BUFFER_TIME:
538 return SNDRV_PCM_HW_PARAM_BUFFER_TIME;
539 break;
540 case PCM_PARAM_BUFFER_SIZE:
541 return SNDRV_PCM_HW_PARAM_BUFFER_SIZE;
542 break;
543 case PCM_PARAM_BUFFER_BYTES:
544 return SNDRV_PCM_HW_PARAM_BUFFER_BYTES;
545 break;
546 case PCM_PARAM_TICK_TIME:
547 return SNDRV_PCM_HW_PARAM_TICK_TIME;
548 break;
549
550 default:
551 return -1;
552 }
553 }
554
pcm_params_get_min(struct pcm_params * pcm_params,enum pcm_param param)555 unsigned int pcm_params_get_min(struct pcm_params *pcm_params,
556 enum pcm_param param)
557 {
558 struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params;
559 int p;
560
561 if (!params)
562 return 0;
563
564 p = pcm_param_to_alsa(param);
565 if (p < 0)
566 return 0;
567
568 return param_get_min(params, p);
569 }
570
pcm_params_get_max(struct pcm_params * pcm_params,enum pcm_param param)571 unsigned int pcm_params_get_max(struct pcm_params *pcm_params,
572 enum pcm_param param)
573 {
574 struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params;
575 int p;
576
577 if (!params)
578 return 0;
579
580 p = pcm_param_to_alsa(param);
581 if (p < 0)
582 return 0;
583
584 return param_get_max(params, p);
585 }
586
pcm_close(struct pcm * pcm)587 int pcm_close(struct pcm *pcm)
588 {
589 if (pcm == &bad_pcm)
590 return 0;
591
592 pcm_hw_munmap_status(pcm);
593
594 if (pcm->flags & PCM_MMAP) {
595 pcm_stop(pcm);
596 munmap(pcm->mmap_buffer, pcm_frames_to_bytes(pcm, pcm->buffer_size));
597 }
598
599 if (pcm->fd >= 0)
600 close(pcm->fd);
601 pcm->running = 0;
602 pcm->buffer_size = 0;
603 pcm->fd = -1;
604 free(pcm);
605 return 0;
606 }
607
pcm_open(unsigned int card,unsigned int device,unsigned int flags,struct pcm_config * config)608 struct pcm *pcm_open(unsigned int card, unsigned int device,
609 unsigned int flags, struct pcm_config *config)
610 {
611 struct pcm *pcm;
612 struct snd_pcm_info info;
613 struct snd_pcm_hw_params params;
614 struct snd_pcm_sw_params sparams;
615 char fn[256];
616 int rc;
617
618 pcm = calloc(1, sizeof(struct pcm));
619 if (!pcm || !config)
620 return &bad_pcm; /* TODO: could support default config here */
621
622 pcm->config = *config;
623
624 snprintf(fn, sizeof(fn), "/dev/snd/pcmC%uD%u%c", card, device,
625 flags & PCM_IN ? 'c' : 'p');
626
627 pcm->flags = flags;
628 pcm->fd = open(fn, O_RDWR);
629 if (pcm->fd < 0) {
630 oops(pcm, errno, "cannot open device '%s'", fn);
631 return pcm;
632 }
633
634 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_INFO, &info)) {
635 oops(pcm, errno, "cannot get info");
636 goto fail_close;
637 }
638
639 param_init(¶ms);
640 param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_FORMAT,
641 pcm_format_to_alsa(config->format));
642 param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_SUBFORMAT,
643 SNDRV_PCM_SUBFORMAT_STD);
644 param_set_min(¶ms, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, config->period_size);
645 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_SAMPLE_BITS,
646 pcm_format_to_bits(config->format));
647 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_FRAME_BITS,
648 pcm_format_to_bits(config->format) * config->channels);
649 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_CHANNELS,
650 config->channels);
651 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_PERIODS, config->period_count);
652 param_set_int(¶ms, SNDRV_PCM_HW_PARAM_RATE, config->rate);
653
654 if (flags & PCM_NOIRQ) {
655
656 if (!(flags & PCM_MMAP)) {
657 oops(pcm, -EINVAL, "noirq only currently supported with mmap().");
658 goto fail;
659 }
660
661 params.flags |= SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP;
662 pcm->noirq_frames_per_msec = config->rate / 1000;
663 }
664
665 if (flags & PCM_MMAP)
666 param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_ACCESS,
667 SNDRV_PCM_ACCESS_MMAP_INTERLEAVED);
668 else
669 param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_ACCESS,
670 SNDRV_PCM_ACCESS_RW_INTERLEAVED);
671
672 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_HW_PARAMS, ¶ms)) {
673 oops(pcm, errno, "cannot set hw params");
674 goto fail_close;
675 }
676
677 /* get our refined hw_params */
678 config->period_size = param_get_int(¶ms, SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
679 config->period_count = param_get_int(¶ms, SNDRV_PCM_HW_PARAM_PERIODS);
680 pcm->buffer_size = config->period_count * config->period_size;
681
682 if (flags & PCM_MMAP) {
683 pcm->mmap_buffer = mmap(NULL, pcm_frames_to_bytes(pcm, pcm->buffer_size),
684 PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, pcm->fd, 0);
685 if (pcm->mmap_buffer == MAP_FAILED) {
686 oops(pcm, -errno, "failed to mmap buffer %d bytes\n",
687 pcm_frames_to_bytes(pcm, pcm->buffer_size));
688 goto fail_close;
689 }
690 }
691
692
693 memset(&sparams, 0, sizeof(sparams));
694 sparams.tstamp_mode = SNDRV_PCM_TSTAMP_ENABLE;
695 sparams.period_step = 1;
696
697 if (!config->start_threshold) {
698 if (pcm->flags & PCM_IN)
699 pcm->config.start_threshold = sparams.start_threshold = 1;
700 else
701 pcm->config.start_threshold = sparams.start_threshold =
702 config->period_count * config->period_size / 2;
703 } else
704 sparams.start_threshold = config->start_threshold;
705
706 /* pick a high stop threshold - todo: does this need further tuning */
707 if (!config->stop_threshold) {
708 if (pcm->flags & PCM_IN)
709 pcm->config.stop_threshold = sparams.stop_threshold =
710 config->period_count * config->period_size * 10;
711 else
712 pcm->config.stop_threshold = sparams.stop_threshold =
713 config->period_count * config->period_size;
714 }
715 else
716 sparams.stop_threshold = config->stop_threshold;
717
718 if (!pcm->config.avail_min) {
719 if (pcm->flags & PCM_MMAP)
720 pcm->config.avail_min = sparams.avail_min = pcm->config.period_size;
721 else
722 pcm->config.avail_min = sparams.avail_min = 1;
723 } else
724 sparams.avail_min = config->avail_min;
725
726 sparams.xfer_align = config->period_size / 2; /* needed for old kernels */
727 sparams.silence_size = 0;
728 sparams.silence_threshold = config->silence_threshold;
729 pcm->boundary = sparams.boundary = pcm->buffer_size;
730
731 while (pcm->boundary * 2 <= INT_MAX - pcm->buffer_size)
732 pcm->boundary *= 2;
733
734 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_SW_PARAMS, &sparams)) {
735 oops(pcm, errno, "cannot set sw params");
736 goto fail;
737 }
738
739 rc = pcm_hw_mmap_status(pcm);
740 if (rc < 0) {
741 oops(pcm, rc, "mmap status failed");
742 goto fail;
743 }
744
745 #ifdef SNDRV_PCM_IOCTL_TTSTAMP
746 if (pcm->flags & PCM_MONOTONIC) {
747 int arg = SNDRV_PCM_TSTAMP_TYPE_MONOTONIC;
748 rc = ioctl(pcm->fd, SNDRV_PCM_IOCTL_TTSTAMP, &arg);
749 if (rc < 0) {
750 oops(pcm, rc, "cannot set timestamp type");
751 goto fail;
752 }
753 }
754 #endif
755
756 pcm->underruns = 0;
757 return pcm;
758
759 fail:
760 if (flags & PCM_MMAP)
761 munmap(pcm->mmap_buffer, pcm_frames_to_bytes(pcm, pcm->buffer_size));
762 fail_close:
763 close(pcm->fd);
764 pcm->fd = -1;
765 return pcm;
766 }
767
pcm_is_ready(struct pcm * pcm)768 int pcm_is_ready(struct pcm *pcm)
769 {
770 return pcm->fd >= 0;
771 }
772
pcm_start(struct pcm * pcm)773 int pcm_start(struct pcm *pcm)
774 {
775 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_PREPARE) < 0)
776 return oops(pcm, errno, "cannot prepare channel");
777
778 if (pcm->flags & PCM_MMAP)
779 pcm_sync_ptr(pcm, 0);
780
781 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_START) < 0)
782 return oops(pcm, errno, "cannot start channel");
783
784 pcm->running = 1;
785 return 0;
786 }
787
pcm_stop(struct pcm * pcm)788 int pcm_stop(struct pcm *pcm)
789 {
790 if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_DROP) < 0)
791 return oops(pcm, errno, "cannot stop channel");
792
793 pcm->running = 0;
794 return 0;
795 }
796
pcm_mmap_playback_avail(struct pcm * pcm)797 static inline int pcm_mmap_playback_avail(struct pcm *pcm)
798 {
799 int avail;
800
801 avail = pcm->mmap_status->hw_ptr + pcm->buffer_size - pcm->mmap_control->appl_ptr;
802
803 if (avail < 0)
804 avail += pcm->boundary;
805 else if (avail > (int)pcm->boundary)
806 avail -= pcm->boundary;
807
808 return avail;
809 }
810
pcm_mmap_capture_avail(struct pcm * pcm)811 static inline int pcm_mmap_capture_avail(struct pcm *pcm)
812 {
813 int avail = pcm->mmap_status->hw_ptr - pcm->mmap_control->appl_ptr;
814 if (avail < 0)
815 avail += pcm->boundary;
816 return avail;
817 }
818
pcm_mmap_avail(struct pcm * pcm)819 static inline int pcm_mmap_avail(struct pcm *pcm)
820 {
821 pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_HWSYNC);
822 if (pcm->flags & PCM_IN)
823 return pcm_mmap_capture_avail(pcm);
824 else
825 return pcm_mmap_playback_avail(pcm);
826 }
827
pcm_mmap_appl_forward(struct pcm * pcm,int frames)828 static void pcm_mmap_appl_forward(struct pcm *pcm, int frames)
829 {
830 unsigned int appl_ptr = pcm->mmap_control->appl_ptr;
831 appl_ptr += frames;
832
833 /* check for boundary wrap */
834 if (appl_ptr > pcm->boundary)
835 appl_ptr -= pcm->boundary;
836 pcm->mmap_control->appl_ptr = appl_ptr;
837 }
838
pcm_mmap_begin(struct pcm * pcm,void ** areas,unsigned int * offset,unsigned int * frames)839 int pcm_mmap_begin(struct pcm *pcm, void **areas, unsigned int *offset,
840 unsigned int *frames)
841 {
842 unsigned int continuous, copy_frames, avail;
843
844 /* return the mmap buffer */
845 *areas = pcm->mmap_buffer;
846
847 /* and the application offset in frames */
848 *offset = pcm->mmap_control->appl_ptr % pcm->buffer_size;
849
850 avail = pcm_mmap_avail(pcm);
851 if (avail > pcm->buffer_size)
852 avail = pcm->buffer_size;
853 continuous = pcm->buffer_size - *offset;
854
855 /* we can only copy frames if the are availabale and continuos */
856 copy_frames = *frames;
857 if (copy_frames > avail)
858 copy_frames = avail;
859 if (copy_frames > continuous)
860 copy_frames = continuous;
861 *frames = copy_frames;
862
863 return 0;
864 }
865
pcm_mmap_commit(struct pcm * pcm,unsigned int offset,unsigned int frames)866 int pcm_mmap_commit(struct pcm *pcm, unsigned int offset, unsigned int frames)
867 {
868 /* update the application pointer in userspace and kernel */
869 pcm_mmap_appl_forward(pcm, frames);
870 pcm_sync_ptr(pcm, 0);
871
872 return frames;
873 }
874
pcm_avail_update(struct pcm * pcm)875 int pcm_avail_update(struct pcm *pcm)
876 {
877 pcm_sync_ptr(pcm, 0);
878 return pcm_mmap_avail(pcm);
879 }
880
pcm_state(struct pcm * pcm)881 int pcm_state(struct pcm *pcm)
882 {
883 int err = pcm_sync_ptr(pcm, 0);
884 if (err < 0)
885 return err;
886
887 return pcm->mmap_status->state;
888 }
889
pcm_set_avail_min(struct pcm * pcm,int avail_min)890 int pcm_set_avail_min(struct pcm *pcm, int avail_min)
891 {
892 if ((~pcm->flags) & (PCM_MMAP | PCM_NOIRQ))
893 return -ENOSYS;
894
895 pcm->config.avail_min = avail_min;
896 return 0;
897 }
898
pcm_wait(struct pcm * pcm,int timeout)899 int pcm_wait(struct pcm *pcm, int timeout)
900 {
901 struct pollfd pfd;
902 int err;
903
904 pfd.fd = pcm->fd;
905 pfd.events = POLLOUT | POLLERR | POLLNVAL;
906
907 do {
908 /* let's wait for avail or timeout */
909 err = poll(&pfd, 1, timeout);
910 if (err < 0)
911 return -errno;
912
913 /* timeout ? */
914 if (err == 0)
915 return 0;
916
917 /* have we been interrupted ? */
918 if (errno == -EINTR)
919 continue;
920
921 /* check for any errors */
922 if (pfd.revents & (POLLERR | POLLNVAL)) {
923 switch (pcm_state(pcm)) {
924 case PCM_STATE_XRUN:
925 return -EPIPE;
926 case PCM_STATE_SUSPENDED:
927 return -ESTRPIPE;
928 case PCM_STATE_DISCONNECTED:
929 return -ENODEV;
930 default:
931 return -EIO;
932 }
933 }
934 /* poll again if fd not ready for IO */
935 } while (!(pfd.revents & (POLLIN | POLLOUT)));
936
937 return 1;
938 }
939
pcm_mmap_transfer(struct pcm * pcm,const void * buffer,unsigned int bytes)940 int pcm_mmap_transfer(struct pcm *pcm, const void *buffer, unsigned int bytes)
941 {
942 int err = 0, frames, avail;
943 unsigned int offset = 0, count;
944
945 if (bytes == 0)
946 return 0;
947
948 count = pcm_bytes_to_frames(pcm, bytes);
949
950 while (count > 0) {
951
952 /* get the available space for writing new frames */
953 avail = pcm_avail_update(pcm);
954 if (avail < 0) {
955 fprintf(stderr, "cannot determine available mmap frames");
956 return err;
957 }
958
959 /* start the audio if we reach the threshold */
960 if (!pcm->running &&
961 (pcm->buffer_size - avail) >= pcm->config.start_threshold) {
962 if (pcm_start(pcm) < 0) {
963 fprintf(stderr, "start error: hw 0x%x app 0x%x avail 0x%x\n",
964 (unsigned int)pcm->mmap_status->hw_ptr,
965 (unsigned int)pcm->mmap_control->appl_ptr,
966 avail);
967 return -errno;
968 }
969 pcm->wait_for_avail_min = 0;
970 }
971
972 /* sleep until we have space to write new frames */
973 if (pcm->running) {
974 /* enable waiting for avail_min threshold when less frames than we have to write
975 * are available. */
976 if (!pcm->wait_for_avail_min && (count > (unsigned int)avail))
977 pcm->wait_for_avail_min = 1;
978
979 if (pcm->wait_for_avail_min && (avail < pcm->config.avail_min)) {
980 int time = -1;
981
982 /* disable waiting for avail_min threshold to allow small amounts of data to be
983 * written without waiting as long as there is enough room in buffer. */
984 pcm->wait_for_avail_min = 0;
985
986 if (pcm->flags & PCM_NOIRQ)
987 time = (pcm->config.avail_min - avail) / pcm->noirq_frames_per_msec;
988
989 err = pcm_wait(pcm, time);
990 if (err < 0) {
991 pcm->running = 0;
992 oops(pcm, err, "wait error: hw 0x%x app 0x%x avail 0x%x\n",
993 (unsigned int)pcm->mmap_status->hw_ptr,
994 (unsigned int)pcm->mmap_control->appl_ptr,
995 avail);
996 pcm->mmap_control->appl_ptr = 0;
997 return err;
998 }
999 continue;
1000 }
1001 }
1002
1003 frames = count;
1004 if (frames > avail)
1005 frames = avail;
1006
1007 if (!frames)
1008 break;
1009
1010 /* copy frames from buffer */
1011 frames = pcm_mmap_transfer_areas(pcm, (void *)buffer, offset, frames);
1012 if (frames < 0) {
1013 fprintf(stderr, "write error: hw 0x%x app 0x%x avail 0x%x\n",
1014 (unsigned int)pcm->mmap_status->hw_ptr,
1015 (unsigned int)pcm->mmap_control->appl_ptr,
1016 avail);
1017 return frames;
1018 }
1019
1020 offset += frames;
1021 count -= frames;
1022 }
1023
1024 return 0;
1025 }
1026
pcm_mmap_write(struct pcm * pcm,const void * data,unsigned int count)1027 int pcm_mmap_write(struct pcm *pcm, const void *data, unsigned int count)
1028 {
1029 if ((~pcm->flags) & (PCM_OUT | PCM_MMAP))
1030 return -ENOSYS;
1031
1032 return pcm_mmap_transfer(pcm, (void *)data, count);
1033 }
1034
pcm_mmap_read(struct pcm * pcm,void * data,unsigned int count)1035 int pcm_mmap_read(struct pcm *pcm, void *data, unsigned int count)
1036 {
1037 if ((~pcm->flags) & (PCM_IN | PCM_MMAP))
1038 return -ENOSYS;
1039
1040 return pcm_mmap_transfer(pcm, data, count);
1041 }
1042