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