1 /* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
2 * Use of this source code is governed by a BSD-style license that can be
3 * found in the LICENSE file.
4 */
5
6 #ifndef _GNU_SOURCE
7 #define _GNU_SOURCE /* For asprintf */
8 #endif
9
10 #include <alsa/asoundlib.h>
11 #include <syslog.h>
12
13 #include "cras_alsa_card.h"
14 #include "cras_alsa_io.h"
15 #include "cras_alsa_mixer.h"
16 #include "cras_alsa_ucm.h"
17 #include "cras_device_blocklist.h"
18 #include "cras_card_config.h"
19 #include "cras_config.h"
20 #include "cras_iodev.h"
21 #include "cras_iodev_list.h"
22 #include "cras_system_state.h"
23 #include "cras_types.h"
24 #include "cras_util.h"
25 #include "utlist.h"
26
27 #define MAX_ALSA_CARDS 32 /* Alsa limit on number of cards. */
28 #define MAX_ALSA_CARD_NAME_LENGTH 6 /* Alsa card name "hw:XX" + 1 for null. */
29 #define MAX_ALSA_PCM_NAME_LENGTH 9 /* Alsa pcm name "hw:XX,YY" + 1 for null. */
30 #define MAX_COUPLED_OUTPUT_SIZE 4
31
32 struct iodev_list_node {
33 struct cras_iodev *iodev;
34 enum CRAS_STREAM_DIRECTION direction;
35 struct iodev_list_node *prev, *next;
36 };
37
38 /* Keeps an fd that is registered with system state. A list of fds must be
39 * kept so that they can be removed when the card is destroyed. */
40 struct hctl_poll_fd {
41 int fd;
42 struct hctl_poll_fd *prev, *next;
43 };
44
45 /* Holds information about each sound card on the system.
46 * name - of the form hw:XX.
47 * card_index - 0 based index, value of "XX" in the name.
48 * iodevs - Input and output devices for this card.
49 * mixer - Controls the mixer controls for this card.
50 * ucm - CRAS use case manager if available.
51 * hctl - ALSA high-level control interface.
52 * hctl_poll_fds - List of fds registered with cras_system_state.
53 * config - Config info for this card, can be NULL if none found.
54 */
55 struct cras_alsa_card {
56 char name[MAX_ALSA_CARD_NAME_LENGTH];
57 size_t card_index;
58 struct iodev_list_node *iodevs;
59 struct cras_alsa_mixer *mixer;
60 struct cras_use_case_mgr *ucm;
61 snd_hctl_t *hctl;
62 struct hctl_poll_fd *hctl_poll_fds;
63 struct cras_card_config *config;
64 };
65
66 /* Creates an iodev for the given device.
67 * Args:
68 * alsa_card - the alsa_card the device will be added to.
69 * info - Information about the card type and priority.
70 * card_name - The name of the card.
71 * dev_name - The name of the device.
72 * dev_id - The id string of the device.
73 * device_index - 0 based index, value of "YY" in "hw:XX,YY".
74 * direction - Input or output.
75 * Returns:
76 * Pointer to the created iodev, or NULL on error.
77 * other negative error code otherwise.
78 */
create_iodev_for_device(struct cras_alsa_card * alsa_card,struct cras_alsa_card_info * info,const char * card_name,const char * dev_name,const char * dev_id,unsigned device_index,enum CRAS_STREAM_DIRECTION direction)79 struct cras_iodev *create_iodev_for_device(
80 struct cras_alsa_card *alsa_card, struct cras_alsa_card_info *info,
81 const char *card_name, const char *dev_name, const char *dev_id,
82 unsigned device_index, enum CRAS_STREAM_DIRECTION direction)
83 {
84 struct iodev_list_node *new_dev;
85 struct iodev_list_node *node;
86 int first = 1;
87 char pcm_name[MAX_ALSA_PCM_NAME_LENGTH];
88
89 /* Find whether this is the first device in this direction, and
90 * avoid duplicate device indexes. */
91 DL_FOREACH (alsa_card->iodevs, node) {
92 if (node->direction != direction)
93 continue;
94 first = 0;
95 if (alsa_iodev_index(node->iodev) == device_index) {
96 syslog(LOG_DEBUG,
97 "Skipping duplicate device for %s:%s:%s [%u]",
98 card_name, dev_name, dev_id, device_index);
99 return node->iodev;
100 }
101 }
102
103 new_dev = calloc(1, sizeof(*new_dev));
104 if (new_dev == NULL)
105 return NULL;
106
107 /* Append device index to card namem, ex: 'hw:0', for the PCM name of
108 * target iodev. */
109 snprintf(pcm_name, MAX_ALSA_PCM_NAME_LENGTH, "%s,%u", alsa_card->name,
110 device_index);
111
112 new_dev->direction = direction;
113 new_dev->iodev =
114 alsa_iodev_create(info->card_index, card_name, device_index,
115 pcm_name, dev_name, dev_id, info->card_type,
116 first, alsa_card->mixer, alsa_card->config,
117 alsa_card->ucm, alsa_card->hctl, direction,
118 info->usb_vendor_id, info->usb_product_id,
119 info->usb_serial_number);
120 if (new_dev->iodev == NULL) {
121 syslog(LOG_ERR, "Couldn't create alsa_iodev for %s", pcm_name);
122 free(new_dev);
123 return NULL;
124 }
125
126 syslog(LOG_DEBUG, "New %s device %s",
127 direction == CRAS_STREAM_OUTPUT ? "playback" : "capture",
128 pcm_name);
129
130 DL_APPEND(alsa_card->iodevs, new_dev);
131 return new_dev->iodev;
132 }
133
134 /* Returns non-zero if this card has hctl jacks.
135 */
card_has_hctl_jack(struct cras_alsa_card * alsa_card)136 static int card_has_hctl_jack(struct cras_alsa_card *alsa_card)
137 {
138 struct iodev_list_node *node;
139
140 /* Find the first device that has an hctl jack. */
141 DL_FOREACH (alsa_card->iodevs, node) {
142 if (alsa_iodev_has_hctl_jacks(node->iodev))
143 return 1;
144 }
145 return 0;
146 }
147
148 /* Check if a device should be ignored for this card. Returns non-zero if the
149 * device is in the blocklist and should be ignored.
150 */
should_ignore_dev(struct cras_alsa_card_info * info,struct cras_device_blocklist * blocklist,size_t device_index)151 static int should_ignore_dev(struct cras_alsa_card_info *info,
152 struct cras_device_blocklist *blocklist,
153 size_t device_index)
154 {
155 if (info->card_type == ALSA_CARD_TYPE_USB)
156 return cras_device_blocklist_check(
157 blocklist, info->usb_vendor_id, info->usb_product_id,
158 info->usb_desc_checksum, device_index);
159 return 0;
160 }
161
162 /* Filters an array of mixer control names. Keep a name if it is
163 * specified in the ucm config. */
filter_controls(struct cras_use_case_mgr * ucm,struct mixer_name * controls)164 static struct mixer_name *filter_controls(struct cras_use_case_mgr *ucm,
165 struct mixer_name *controls)
166 {
167 struct mixer_name *control;
168 DL_FOREACH (controls, control) {
169 char *dev = ucm_get_dev_for_mixer(ucm, control->name,
170 CRAS_STREAM_OUTPUT);
171 if (!dev)
172 DL_DELETE(controls, control);
173 else
174 free(dev);
175 }
176 return controls;
177 }
178
179 /* Handles notifications from alsa controls. Called by main thread when a poll
180 * fd provided by alsa signals there is an event available. */
alsa_control_event_pending(void * arg,int revent)181 static void alsa_control_event_pending(void *arg, int revent)
182 {
183 struct cras_alsa_card *card;
184
185 card = (struct cras_alsa_card *)arg;
186 if (card == NULL) {
187 syslog(LOG_ERR, "Invalid card from control event.");
188 return;
189 }
190
191 /* handle_events will trigger the callback registered with each control
192 * that has changed. */
193 snd_hctl_handle_events(card->hctl);
194 }
195
196 static int
add_controls_and_iodevs_by_matching(struct cras_alsa_card_info * info,struct cras_device_blocklist * blocklist,struct cras_alsa_card * alsa_card,const char * card_name,snd_ctl_t * handle)197 add_controls_and_iodevs_by_matching(struct cras_alsa_card_info *info,
198 struct cras_device_blocklist *blocklist,
199 struct cras_alsa_card *alsa_card,
200 const char *card_name, snd_ctl_t *handle)
201 {
202 struct mixer_name *coupled_controls = NULL;
203 int dev_idx;
204 snd_pcm_info_t *dev_info;
205 struct mixer_name *extra_controls = NULL;
206 int rc = 0;
207
208 snd_pcm_info_alloca(&dev_info);
209
210 if (alsa_card->ucm) {
211 char *extra_main_volume;
212
213 /* Filter the extra output mixer names */
214 extra_controls = filter_controls(
215 alsa_card->ucm,
216 mixer_name_add(extra_controls, "IEC958",
217 CRAS_STREAM_OUTPUT, MIXER_NAME_VOLUME));
218
219 /* Get the extra main volume control. */
220 extra_main_volume =
221 ucm_get_flag(alsa_card->ucm, "ExtraMainVolume");
222 if (extra_main_volume) {
223 extra_controls = mixer_name_add(extra_controls,
224 extra_main_volume,
225 CRAS_STREAM_OUTPUT,
226 MIXER_NAME_MAIN_VOLUME);
227 free(extra_main_volume);
228 }
229 mixer_name_dump(extra_controls, "extra controls");
230
231 /* Check if coupled controls has been specified for speaker. */
232 coupled_controls =
233 ucm_get_coupled_mixer_names(alsa_card->ucm, "Speaker");
234 mixer_name_dump(coupled_controls, "coupled controls");
235 }
236
237 /* Add controls to mixer by name matching. */
238 rc = cras_alsa_mixer_add_controls_by_name_matching(
239 alsa_card->mixer, extra_controls, coupled_controls);
240 if (rc) {
241 syslog(LOG_ERR, "Fail adding controls to mixer for %s.",
242 alsa_card->name);
243 goto error;
244 }
245
246 /* Go through every device. */
247 dev_idx = -1;
248 while (1) {
249 rc = snd_ctl_pcm_next_device(handle, &dev_idx);
250 if (rc < 0)
251 goto error;
252 if (dev_idx < 0)
253 break;
254
255 snd_pcm_info_set_device(dev_info, dev_idx);
256 snd_pcm_info_set_subdevice(dev_info, 0);
257
258 /* Check for playback devices. */
259 snd_pcm_info_set_stream(dev_info, SND_PCM_STREAM_PLAYBACK);
260 if (snd_ctl_pcm_info(handle, dev_info) == 0 &&
261 !should_ignore_dev(info, blocklist, dev_idx)) {
262 struct cras_iodev *iodev = create_iodev_for_device(
263 alsa_card, info, card_name,
264 snd_pcm_info_get_name(dev_info),
265 snd_pcm_info_get_id(dev_info), dev_idx,
266 CRAS_STREAM_OUTPUT);
267 if (iodev) {
268 rc = alsa_iodev_legacy_complete_init(iodev);
269 if (rc < 0)
270 goto error;
271 }
272 }
273
274 /* Check for capture devices. */
275 snd_pcm_info_set_stream(dev_info, SND_PCM_STREAM_CAPTURE);
276 if (snd_ctl_pcm_info(handle, dev_info) == 0) {
277 struct cras_iodev *iodev = create_iodev_for_device(
278 alsa_card, info, card_name,
279 snd_pcm_info_get_name(dev_info),
280 snd_pcm_info_get_id(dev_info), dev_idx,
281 CRAS_STREAM_INPUT);
282 if (iodev) {
283 rc = alsa_iodev_legacy_complete_init(iodev);
284 if (rc < 0)
285 goto error;
286 }
287 }
288 }
289 error:
290 mixer_name_free(coupled_controls);
291 mixer_name_free(extra_controls);
292 return rc;
293 }
294
add_controls_and_iodevs_with_ucm(struct cras_alsa_card_info * info,struct cras_alsa_card * alsa_card,const char * card_name,snd_ctl_t * handle)295 static int add_controls_and_iodevs_with_ucm(struct cras_alsa_card_info *info,
296 struct cras_alsa_card *alsa_card,
297 const char *card_name,
298 snd_ctl_t *handle)
299 {
300 snd_pcm_info_t *dev_info;
301 struct mixer_name *main_volume_control_names;
302 struct iodev_list_node *node;
303 int rc = 0;
304 struct ucm_section *section;
305 struct ucm_section *ucm_sections;
306
307 snd_pcm_info_alloca(&dev_info);
308
309 main_volume_control_names = ucm_get_main_volume_names(alsa_card->ucm);
310 if (main_volume_control_names) {
311 rc = cras_alsa_mixer_add_main_volume_control_by_name(
312 alsa_card->mixer, main_volume_control_names);
313 if (rc) {
314 syslog(LOG_ERR,
315 "Failed adding main volume controls to"
316 " mixer for '%s'.'",
317 card_name);
318 goto cleanup_names;
319 }
320 }
321
322 /* Get info on the devices specified in the UCM config. */
323 ucm_sections = ucm_get_sections(alsa_card->ucm);
324 if (!ucm_sections) {
325 syslog(LOG_ERR,
326 "Could not retrieve any UCM SectionDevice"
327 " info for '%s'.",
328 card_name);
329 rc = -ENOENT;
330 goto cleanup_names;
331 }
332
333 /* Create all of the controls first. */
334 DL_FOREACH (ucm_sections, section) {
335 rc = cras_alsa_mixer_add_controls_in_section(alsa_card->mixer,
336 section);
337 if (rc) {
338 syslog(LOG_ERR,
339 "Failed adding controls to"
340 " mixer for '%s:%s'",
341 card_name, section->name);
342 goto cleanup;
343 }
344 }
345
346 /* Create all of the devices. */
347 DL_FOREACH (ucm_sections, section) {
348 /* If a UCM section specifies certain device as dependency
349 * then don't create an alsa iodev for it, just append it
350 * as node later. */
351 if (section->dependent_dev_idx != -1)
352 continue;
353 snd_pcm_info_set_device(dev_info, section->dev_idx);
354 snd_pcm_info_set_subdevice(dev_info, 0);
355 if (section->dir == CRAS_STREAM_OUTPUT)
356 snd_pcm_info_set_stream(dev_info,
357 SND_PCM_STREAM_PLAYBACK);
358 else if (section->dir == CRAS_STREAM_INPUT)
359 snd_pcm_info_set_stream(dev_info,
360 SND_PCM_STREAM_CAPTURE);
361 else {
362 syslog(LOG_ERR, "Unexpected direction: %d",
363 section->dir);
364 rc = -EINVAL;
365 goto cleanup;
366 }
367
368 if (snd_ctl_pcm_info(handle, dev_info)) {
369 syslog(LOG_ERR, "Could not get info for device: %s",
370 section->name);
371 continue;
372 }
373
374 create_iodev_for_device(alsa_card, info, card_name,
375 snd_pcm_info_get_name(dev_info),
376 snd_pcm_info_get_id(dev_info),
377 section->dev_idx, section->dir);
378 }
379
380 /* Setup jacks and controls for the devices. If a SectionDevice is
381 * dependent on another SectionDevice, it'll be added as a node to
382 * a existing ALSA iodev. */
383 DL_FOREACH (ucm_sections, section) {
384 DL_FOREACH (alsa_card->iodevs, node) {
385 if (node->direction != section->dir)
386 continue;
387 if (alsa_iodev_index(node->iodev) == section->dev_idx)
388 break;
389 if (alsa_iodev_index(node->iodev) ==
390 section->dependent_dev_idx)
391 break;
392 }
393 if (node) {
394 rc = alsa_iodev_ucm_add_nodes_and_jacks(node->iodev,
395 section);
396 if (rc < 0)
397 goto cleanup;
398 }
399 }
400
401 DL_FOREACH (alsa_card->iodevs, node) {
402 alsa_iodev_ucm_complete_init(node->iodev);
403 }
404
405 cleanup:
406 ucm_section_free_list(ucm_sections);
407 cleanup_names:
408 mixer_name_free(main_volume_control_names);
409 return rc;
410 }
411
configure_echo_reference_dev(struct cras_alsa_card * alsa_card)412 static void configure_echo_reference_dev(struct cras_alsa_card *alsa_card)
413 {
414 struct iodev_list_node *dev_node, *echo_ref_node;
415 const char *echo_ref_name;
416
417 if (!alsa_card->ucm)
418 return;
419
420 DL_FOREACH (alsa_card->iodevs, dev_node) {
421 if (!dev_node->iodev->nodes)
422 continue;
423
424 echo_ref_name = ucm_get_echo_reference_dev_name_for_dev(
425 alsa_card->ucm, dev_node->iodev->nodes->name);
426 if (!echo_ref_name)
427 continue;
428 DL_FOREACH (alsa_card->iodevs, echo_ref_node) {
429 if (echo_ref_node->iodev->nodes == NULL)
430 continue;
431 if (!strcmp(echo_ref_name,
432 echo_ref_node->iodev->nodes->name))
433 break;
434 }
435 if (echo_ref_node)
436 dev_node->iodev->echo_reference_dev =
437 echo_ref_node->iodev;
438 else
439 syslog(LOG_ERR,
440 "Echo ref dev %s doesn't exist on card %s",
441 echo_ref_name, alsa_card->name);
442 free((void *)echo_ref_name);
443 }
444 }
445
446 /*
447 * Exported Interface.
448 */
449
cras_alsa_card_create(struct cras_alsa_card_info * info,const char * device_config_dir,struct cras_device_blocklist * blocklist,const char * ucm_suffix)450 struct cras_alsa_card *cras_alsa_card_create(
451 struct cras_alsa_card_info *info, const char *device_config_dir,
452 struct cras_device_blocklist *blocklist, const char *ucm_suffix)
453 {
454 snd_ctl_t *handle = NULL;
455 int rc, n;
456 snd_ctl_card_info_t *card_info;
457 const char *card_name;
458 struct cras_alsa_card *alsa_card;
459
460 if (info->card_index >= MAX_ALSA_CARDS) {
461 syslog(LOG_ERR, "Invalid alsa card index %u", info->card_index);
462 return NULL;
463 }
464
465 snd_ctl_card_info_alloca(&card_info);
466
467 alsa_card = calloc(1, sizeof(*alsa_card));
468 if (alsa_card == NULL)
469 return NULL;
470 alsa_card->card_index = info->card_index;
471
472 snprintf(alsa_card->name, MAX_ALSA_CARD_NAME_LENGTH, "hw:%u",
473 info->card_index);
474
475 rc = snd_ctl_open(&handle, alsa_card->name, 0);
476 if (rc < 0) {
477 syslog(LOG_ERR, "Fail opening control %s.", alsa_card->name);
478 goto error_bail;
479 }
480
481 rc = snd_ctl_card_info(handle, card_info);
482 if (rc < 0) {
483 syslog(LOG_ERR, "Error getting card info.");
484 goto error_bail;
485 }
486
487 card_name = snd_ctl_card_info_get_name(card_info);
488 if (card_name == NULL) {
489 syslog(LOG_ERR, "Error getting card name.");
490 goto error_bail;
491 }
492
493 if (info->card_type != ALSA_CARD_TYPE_INTERNAL ||
494 cras_system_check_ignore_ucm_suffix(card_name))
495 ucm_suffix = NULL;
496
497 /* Read config file for this card if it exists. */
498 alsa_card->config =
499 cras_card_config_create(device_config_dir, card_name);
500 if (alsa_card->config == NULL)
501 syslog(LOG_DEBUG, "No config file for %s", alsa_card->name);
502
503 /* Create a use case manager if a configuration is available. */
504 if (ucm_suffix) {
505 char *ucm_name;
506 if (asprintf(&ucm_name, "%s.%s", card_name, ucm_suffix) == -1) {
507 syslog(LOG_ERR, "Error creating ucm name");
508 goto error_bail;
509 }
510 alsa_card->ucm = ucm_create(ucm_name);
511 syslog(LOG_INFO, "Card %s (%s) has UCM: %s", alsa_card->name,
512 ucm_name, alsa_card->ucm ? "yes" : "no");
513 free(ucm_name);
514 } else {
515 alsa_card->ucm = ucm_create(card_name);
516 syslog(LOG_INFO, "Card %s (%s) has UCM: %s", alsa_card->name,
517 card_name, alsa_card->ucm ? "yes" : "no");
518 }
519
520 if (info->card_type == ALSA_CARD_TYPE_INTERNAL && !alsa_card->ucm)
521 syslog(LOG_ERR, "No ucm config on internal card %s", card_name);
522
523 rc = snd_hctl_open(&alsa_card->hctl, alsa_card->name, SND_CTL_NONBLOCK);
524 if (rc < 0) {
525 syslog(LOG_DEBUG, "failed to get hctl for %s", alsa_card->name);
526 alsa_card->hctl = NULL;
527 } else {
528 rc = snd_hctl_nonblock(alsa_card->hctl, 1);
529 if (rc < 0) {
530 syslog(LOG_ERR, "failed to nonblock hctl for %s",
531 alsa_card->name);
532 goto error_bail;
533 }
534
535 rc = snd_hctl_load(alsa_card->hctl);
536 if (rc < 0) {
537 syslog(LOG_ERR, "failed to load hctl for %s",
538 alsa_card->name);
539 goto error_bail;
540 }
541 }
542
543 /* Create one mixer per card. */
544 alsa_card->mixer = cras_alsa_mixer_create(alsa_card->name);
545
546 if (alsa_card->mixer == NULL) {
547 syslog(LOG_ERR, "Fail opening mixer for %s.", alsa_card->name);
548 goto error_bail;
549 }
550
551 if (alsa_card->ucm && ucm_has_fully_specified_ucm_flag(alsa_card->ucm))
552 rc = add_controls_and_iodevs_with_ucm(info, alsa_card,
553 card_name, handle);
554 else
555 rc = add_controls_and_iodevs_by_matching(
556 info, blocklist, alsa_card, card_name, handle);
557 if (rc)
558 goto error_bail;
559
560 configure_echo_reference_dev(alsa_card);
561
562 n = alsa_card->hctl ? snd_hctl_poll_descriptors_count(alsa_card->hctl) :
563 0;
564 if (n != 0 && card_has_hctl_jack(alsa_card)) {
565 struct hctl_poll_fd *registered_fd;
566 struct pollfd *pollfds;
567 int i;
568
569 pollfds = malloc(n * sizeof(*pollfds));
570 if (pollfds == NULL) {
571 rc = -ENOMEM;
572 goto error_bail;
573 }
574
575 n = snd_hctl_poll_descriptors(alsa_card->hctl, pollfds, n);
576 for (i = 0; i < n; i++) {
577 registered_fd = calloc(1, sizeof(*registered_fd));
578 if (registered_fd == NULL) {
579 free(pollfds);
580 rc = -ENOMEM;
581 goto error_bail;
582 }
583 registered_fd->fd = pollfds[i].fd;
584 DL_APPEND(alsa_card->hctl_poll_fds, registered_fd);
585 rc = cras_system_add_select_fd(
586 registered_fd->fd, alsa_control_event_pending,
587 alsa_card, POLLIN);
588 if (rc < 0) {
589 DL_DELETE(alsa_card->hctl_poll_fds,
590 registered_fd);
591 free(pollfds);
592 goto error_bail;
593 }
594 }
595 free(pollfds);
596 }
597
598 snd_ctl_close(handle);
599 return alsa_card;
600
601 error_bail:
602 if (handle != NULL)
603 snd_ctl_close(handle);
604 cras_alsa_card_destroy(alsa_card);
605 return NULL;
606 }
607
cras_alsa_card_destroy(struct cras_alsa_card * alsa_card)608 void cras_alsa_card_destroy(struct cras_alsa_card *alsa_card)
609 {
610 struct iodev_list_node *curr;
611 struct hctl_poll_fd *poll_fd;
612
613 if (alsa_card == NULL)
614 return;
615
616 DL_FOREACH (alsa_card->iodevs, curr) {
617 alsa_iodev_destroy(curr->iodev);
618 DL_DELETE(alsa_card->iodevs, curr);
619 free(curr);
620 }
621 DL_FOREACH (alsa_card->hctl_poll_fds, poll_fd) {
622 cras_system_rm_select_fd(poll_fd->fd);
623 DL_DELETE(alsa_card->hctl_poll_fds, poll_fd);
624 free(poll_fd);
625 }
626 if (alsa_card->hctl)
627 snd_hctl_close(alsa_card->hctl);
628 if (alsa_card->ucm)
629 ucm_destroy(alsa_card->ucm);
630 if (alsa_card->mixer)
631 cras_alsa_mixer_destroy(alsa_card->mixer);
632 if (alsa_card->config)
633 cras_card_config_destroy(alsa_card->config);
634 free(alsa_card);
635 }
636
cras_alsa_card_get_index(const struct cras_alsa_card * alsa_card)637 size_t cras_alsa_card_get_index(const struct cras_alsa_card *alsa_card)
638 {
639 assert(alsa_card);
640 return alsa_card->card_index;
641 }
642