aboutsummaryrefslogtreecommitdiffstats
path: root/Alsa-afb/Alsa-SetGet.c
blob: 71206e66962645f5503df2f23f2168e78ce76377 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
/*
 * AlsaLibMapping -- provide low level interface with ALSA lib (extracted from alsa-json-gateway code)
 * Copyright (C) 2015,2016,2017, Fulup Ar Foll fulup@iot.bzh
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.

   References:
   https://github.com/fulup-bzh/AlsaJsonGateway (original code)
   http://alsa-lib.sourcearchive.com/documentation/1.0.20/modules.html
   http://alsa-lib.sourcearchive.com/documentation/1.0.8/group__Control_gd48d44da8e3bfe150e928267008b8ff5.html
   http://alsa.opensrc.org/HowTo_access_a_mixer_control
   https://github.com/gch1p/alsa-volume-monitor/blob/master/main.c
   https://github.com/DongheonKim/android_hardware_alsa-sound/blob/master/ALSAControl.cpp (ALSA low level API)
   https://www.kernel.org/doc/html/v4.11/sound/index.html

 */

#define _GNU_SOURCE  // needed for vasprintf
#include "Alsa-ApiHat.h"

PUBLIC void NumidsListParse(ActionSetGetT action, queryValuesT *queryValues, ctlRequestT *ctlRequest) {
    int length;

    for (int idx = 0; idx < queryValues->count; idx++) {
        json_object *jId, *valuesJ;
        ctlRequest[idx].used = 0;
        ctlRequest[idx].valuesJ = NULL;

        // when only one NUMID is provided it might not be encapsulated in a JSON array
        if (json_type_array == json_object_get_type(queryValues->numidsJ)) ctlRequest[idx].jToken = json_object_array_get_idx(queryValues->numidsJ, idx);
        else ctlRequest[idx].jToken = queryValues->numidsJ;

        enum json_type jtype = json_object_get_type(ctlRequest[idx].jToken);
        switch (jtype) {

            case json_type_int:
                // if NUMID is not an array then it should be an integer numid with no value
                ctlRequest[idx].numId = json_object_get_int(ctlRequest[idx].jToken);

                // Special SET simple short numid form [numid, [VAL1...VALX]]
                if (action == ACTION_SET && queryValues->count == 2) {
                    ctlRequest[idx].valuesJ = json_object_array_get_idx(queryValues->numidsJ, 1);
                    queryValues->count = 1; //In this form count==2 , when only one numid is to set
                    idx++;
                    continue;
                } else
                    break;

            case json_type_array:
                // NUMID is an array 1st slot should be numid, optionally values may come after
                length = json_object_array_length(ctlRequest[idx].jToken);

                // numid must be in 1st slot of numid json array
                ctlRequest[idx].numId = json_object_get_int(json_object_array_get_idx(ctlRequest[idx].jToken, 0));
                if (action == ACTION_GET) continue;

                // In Write mode second value should be the value
                if (action == ACTION_SET && length == 2) {
                    ctlRequest[idx].valuesJ = json_object_array_get_idx(ctlRequest[idx].jToken, 1);
                    continue;
                }

                // no numid value
                ctlRequest[idx].used = -1;
                break;

            case json_type_object:
                // numid+values formated as {id:xxx, val:[aa,bb...,nn]}
                if (!json_object_object_get_ex(ctlRequest[idx].jToken, "id", &jId) || !json_object_object_get_ex(ctlRequest[idx].jToken, "val", &valuesJ)) {
                    AFB_NOTICE("Invalid Json=%s missing 'id'|'val'", json_object_get_string(ctlRequest[idx].jToken));
                    ctlRequest[idx].used = -1;
                } else {
                    ctlRequest[idx].numId = json_object_get_int(jId);
                    if (action == ACTION_SET) ctlRequest[idx].valuesJ = valuesJ;
                }
                break;

            default:
                ctlRequest[idx].used = -1;
        }
    }
}

STATIC json_object *DB2StringJsonOject(long dB) {
    char label [20];
    if (dB < 0) {
        snprintf(label, sizeof (label), "-%li.%02lidB", -dB / 100, -dB % 100);
    } else {
        snprintf(label, sizeof (label), "%li.%02lidB", dB / 100, dB % 100);
    }

    // json function takes care of string copy
    return (json_object_new_string(label));
}


// Direct port from amixer TLV decode routine. This code is too complex for me.
// I hopefully did not break it when porting it.

STATIC json_object *decodeTlv(unsigned int *tlv, unsigned int tlv_size, int mode) {
    char label[20];
    unsigned int type = tlv[0];
    unsigned int size;
    unsigned int idx = 0;
    const char *chmap_type = NULL;
    json_object * decodeTlvJson = json_object_new_object();

    if (tlv_size < (unsigned int) (2 * sizeof (unsigned int))) {
        printf("TLV size error!\n");
        return NULL;
    }
    type = tlv[idx++];
    size = tlv[idx++];
    tlv_size -= (unsigned int) (2 * sizeof (unsigned int));
    if (size > tlv_size) {
        fprintf(stderr, "TLV size error (%i, %i, %i)!\n", type, size, tlv_size);
        return NULL;
    }
    switch (type) {

        case SND_CTL_TLVT_CONTAINER:
        {
            json_object * containerJson = json_object_new_array();

            size += (unsigned int) (sizeof (unsigned int) - 1);
            size /= (unsigned int) (sizeof (unsigned int));
            while (idx < size) {
                json_object *embedJson;

                if (tlv[idx + 1] > (size - idx) * sizeof (unsigned int)) {
                    fprintf(stderr, "TLV size error in compound!\n");
                    return NULL;
                }
                embedJson = decodeTlv(tlv + idx, tlv[idx + 1] + 8, mode);
                json_object_array_add(containerJson, embedJson);
                idx += (unsigned int) (2 + (tlv[idx + 1] + sizeof (unsigned int) - 1) / sizeof (unsigned int));
            }
            json_object_object_add(decodeTlvJson, "container", containerJson);
            break;
        }

        case SND_CTL_TLVT_DB_SCALE:
        {
            json_object * dbscaleJson = json_object_new_object();

            if (size != 2 * sizeof (unsigned int)) {
                json_object * arrayJson = json_object_new_array();
                while (size > 0) {
                    if (mode >= QUERY_VERBOSE) {
                        snprintf(label, sizeof (label), "0x%08x,", tlv[idx++]);
                        json_object_array_add(arrayJson, json_object_new_string(label));
                    } else {
                        json_object_array_add(arrayJson, json_object_new_int(tlv[idx++]));
                    }
                    size -= (unsigned int) sizeof (unsigned int);
                }
                json_object_object_add(dbscaleJson, "array", arrayJson);
            } else {
                if (mode >= QUERY_VERBOSE) {
                    json_object_object_add(dbscaleJson, "min", DB2StringJsonOject((int) tlv[2]));
                    json_object_object_add(dbscaleJson, "step", DB2StringJsonOject(tlv[3] & 0xffff));
                    json_object_object_add(dbscaleJson, "mute", DB2StringJsonOject((tlv[3] >> 16) & 1));
                } else {
                    json_object_object_add(dbscaleJson, "min", json_object_new_int((int) tlv[2]));
                    json_object_object_add(dbscaleJson, "step", json_object_new_int(tlv[3] & 0xffff));
                    json_object_object_add(dbscaleJson, "mute", json_object_new_int((tlv[3] >> 16) & 1));
                }
            }
            json_object_object_add(decodeTlvJson, "dbscale", dbscaleJson);
            break;
        }

#ifdef SND_CTL_TLVT_DB_LINEAR
        case SND_CTL_TLVT_DB_LINEAR:
        {
            json_object * dbLinearJson = json_object_new_object();

            if (size != 2 * sizeof (unsigned int)) {
                json_object * arrayJson = json_object_new_array();
                while (size > 0) {
                    if (mode >= QUERY_VERBOSE) {
                        snprintf(label, sizeof (label), "0x%08x,", tlv[idx++]);
                        json_object_array_add(arrayJson, json_object_new_string(label));
                    } else {
                        json_object_array_add(arrayJson, json_object_new_int(tlv[idx++]));
                    }
                    size -= (unsigned int) sizeof (unsigned int);
                }
                json_object_object_add(dbLinearJson, "offset", arrayJson);
            } else {
                if (mode >= QUERY_VERBOSE) {
                    json_object_object_add(dbLinearJson, "min", DB2StringJsonOject((int) tlv[2]));
                    json_object_object_add(dbLinearJson, "max", DB2StringJsonOject((int) tlv[3]));
                } else {
                    json_object_object_add(dbLinearJson, "min", json_object_new_int((int) tlv[2]));
                    json_object_object_add(dbLinearJson, "max", json_object_new_int((int) tlv[3]));
                }
            }
            json_object_object_add(decodeTlvJson, "dblinear", dbLinearJson);
            break;
        }
#endif

#ifdef SND_CTL_TLVT_DB_RANGE
        case SND_CTL_TLVT_DB_RANGE:
        {
            json_object *dbRangeJson = json_object_new_object();

            if ((size % (6 * sizeof (unsigned int))) != 0) {
                json_object *arrayJson = json_object_new_array();
                while (size > 0) {
                    if (mode >= QUERY_VERBOSE) {
                        snprintf(label, sizeof (label), "0x%08x,", tlv[idx++]);
                        json_object_array_add(arrayJson, json_object_new_string(label));
                    } else {
                        json_object_array_add(arrayJson, json_object_new_int(tlv[idx++]));
                    }
                    size -= (unsigned int) sizeof (unsigned int);
                }
                json_object_object_add(dbRangeJson, "dbrange", arrayJson);
                break;
            }
            while (size > 0) {
                json_object * embedJson = json_object_new_object();
                json_object_object_add(embedJson, "rangemin", json_object_new_int(tlv[idx++]));
                json_object_object_add(embedJson, "rangemax", json_object_new_int(tlv[idx++]));
                embedJson = decodeTlv(tlv + idx, 4 * sizeof (unsigned int), mode);
                json_object_object_add(embedJson, "tlv", embedJson);
                idx += 4;
                size -= (unsigned int) (6 * sizeof (unsigned int));
                json_object_array_add(dbRangeJson, embedJson);
            }
            json_object_object_add(decodeTlvJson, "dbrange", dbRangeJson);
            break;
        }
#endif
#ifdef SND_CTL_TLVT_DB_MINMAX
        case SND_CTL_TLVT_DB_MINMAX:
        case SND_CTL_TLVT_DB_MINMAX_MUTE:
        {
            json_object * dbMinMaxJson = json_object_new_object();

            if (size != 2 * sizeof (unsigned int)) {
                json_object * arrayJson = json_object_new_array();
                while (size > 0) {
                    if (mode >= QUERY_VERBOSE) {
                        snprintf(label, sizeof (label), "0x%08x,", tlv[idx++]);
                        json_object_array_add(arrayJson, json_object_new_string(label));
                    } else {
                        json_object_array_add(arrayJson, json_object_new_int(tlv[idx++]));
                    }
                    size -= (unsigned int) sizeof (unsigned int);
                }
                json_object_object_add(dbMinMaxJson, "array", arrayJson);

            } else {
                if (mode >= QUERY_VERBOSE) {
                    json_object_object_add(dbMinMaxJson, "min", DB2StringJsonOject((int) tlv[2]));
                    json_object_object_add(dbMinMaxJson, "max", DB2StringJsonOject((int) tlv[3]));
                } else {
                    json_object_object_add(dbMinMaxJson, "min", json_object_new_int((int) tlv[2]));
                    json_object_object_add(dbMinMaxJson, "max", json_object_new_int((int) tlv[3]));
                }
            }

            if (type == SND_CTL_TLVT_DB_MINMAX_MUTE) {
                json_object_object_add(decodeTlvJson, "dbminmaxmute", dbMinMaxJson);
            } else {
                json_object_object_add(decodeTlvJson, "dbminmax", dbMinMaxJson);
            }
            break;
        }
#endif
#ifdef SND_CTL_TLVT_CHMAP_FIXED
        case SND_CTL_TLVT_CHMAP_FIXED:
            chmap_type = "fixed";
            /* Fall through */
        case SND_CTL_TLVT_CHMAP_VAR:
            if (!chmap_type)
                chmap_type = "variable";
            /* Fall through */
        case SND_CTL_TLVT_CHMAP_PAIRED:
            if (!chmap_type)
                chmap_type = "paired";

            json_object * chmapJson = json_object_new_object();
            json_object * arrayJson = json_object_new_array();

            while (size > 0) {
                snprintf(label, sizeof (label), "%s", snd_pcm_chmap_name(tlv[idx++]));
                size -= (unsigned int) sizeof (unsigned int);
                json_object_array_add(arrayJson, json_object_new_string(label));
            }
            json_object_object_add(chmapJson, chmap_type, arrayJson);
            json_object_object_add(decodeTlvJson, "chmap", chmapJson);
            break;
#endif
        default:
        {
            printf("unk-%i-", type);
            json_object * arrayJson = json_object_new_array();

            while (size > 0) {
                snprintf(label, sizeof (label), "0x%08x,", tlv[idx++]);
                size -= (unsigned int) sizeof (unsigned int);
                json_object_array_add(arrayJson, json_object_new_string(label));
            }
            break;
            json_object_object_add(decodeTlvJson, "unknown", arrayJson);
        }
    }

    return (decodeTlvJson);
}


// retreive info for one given card

STATIC json_object* alsaCardProbe(const char *rqtSndId) {
    const char *info, *name;
    const char *devid, *driver;
    json_object *ctlDev;
    snd_ctl_t *handle;
    snd_ctl_card_info_t *cardinfo;
    int err;

    if ((err = snd_ctl_open(&handle, rqtSndId, 0)) < 0) {
        AFB_INFO("alsaCardProbe '%s' Not Found", rqtSndId);
        return NULL;
    }

    snd_ctl_card_info_alloca(&cardinfo);
    if ((err = snd_ctl_card_info(handle, cardinfo)) < 0) {
        snd_ctl_close(handle);
        AFB_WARNING("SndCard '%s' info error: %s", rqtSndId, snd_strerror(err));
        return NULL;
    }

    // start a new json object to store card info
    ctlDev = json_object_new_object();

    devid = snd_ctl_card_info_get_id(cardinfo);
    json_object_object_add(ctlDev, "devid", json_object_new_string(devid));
    name = snd_ctl_card_info_get_name(cardinfo);
    json_object_object_add(ctlDev, "name", json_object_new_string(name));

    if (AFB_GET_VERBOSITY > 1) {
        json_object_object_add(ctlDev, "devid", json_object_new_string(rqtSndId));
        driver = snd_ctl_card_info_get_driver(cardinfo);
        json_object_object_add(ctlDev, "driver", json_object_new_string(driver));
        info = strdup(snd_ctl_card_info_get_longname(cardinfo));
        json_object_object_add(ctlDev, "info", json_object_new_string(info));
        AFB_INFO("AJG: Soundcard Devid=%-5s devid=%-7s Name=%s\n", rqtSndId, devid, info);
    }

    // free card handle and return info
    snd_ctl_close(handle);
    return (ctlDev);
}

// Loop on every potential Sound card and register active one

PUBLIC void alsaGetInfo(afb_req request) {
    int card;
    json_object *ctlDev, *ctlDevs;
    char devid[32];

    const char *rqtSndId = afb_req_value(request, "devid");

    // if no specific card requested loop on all

    if (rqtSndId != NULL) {
        // only one card was requested let's probe it
        ctlDev = alsaCardProbe(rqtSndId);
        if (ctlDev != NULL) afb_req_success(request, ctlDev, NULL);
        else afb_req_fail_f(request, "sndscard-notfound", "SndCard '%s' Not Found", rqtSndId);

    } else {
        // return an array of ctlDev
        ctlDevs = json_object_new_array();

        // loop on potential card number
        for (card = 0; card < MAX_SND_CARD; card++) {

            // build card devid and probe it
            snprintf(devid, sizeof (devid), "hw:%i", card);
            ctlDev = alsaCardProbe(devid);

            // Alsa has hole within card list [ignore them]
            if (ctlDev != NULL) {
                // add current ctlDev to ctlDevs object
                json_object_array_add(ctlDevs, ctlDev);
            }
        }
        afb_req_success(request, ctlDevs, NULL);
    }
}

// pack Alsa element's ACL into a JSON object

STATIC json_object *getControlAcl(snd_ctl_elem_info_t *info) {

    json_object * jsonAclCtl = json_object_new_object();

    json_object_object_add(jsonAclCtl, "read", json_object_new_boolean(snd_ctl_elem_info_is_readable(info)));
    json_object_object_add(jsonAclCtl, "write", json_object_new_boolean(snd_ctl_elem_info_is_writable(info)));
    json_object_object_add(jsonAclCtl, "inact", json_object_new_boolean(snd_ctl_elem_info_is_inactive(info)));
    json_object_object_add(jsonAclCtl, "volat", json_object_new_boolean(snd_ctl_elem_info_is_volatile(info)));
    json_object_object_add(jsonAclCtl, "lock", json_object_new_boolean(snd_ctl_elem_info_is_locked(info)));

    // if TLV is readable we insert its ACL
    if (!snd_ctl_elem_info_is_tlv_readable(info)) {
        json_object * jsonTlv = json_object_new_object();

        json_object_object_add(jsonTlv, "read", json_object_new_boolean(snd_ctl_elem_info_is_tlv_readable(info)));
        json_object_object_add(jsonTlv, "write", json_object_new_boolean(snd_ctl_elem_info_is_tlv_writable(info)));
        json_object_object_add(jsonTlv, "command", json_object_new_boolean(snd_ctl_elem_info_is_tlv_commandable(info)));

        json_object_object_add(jsonAclCtl, "tlv", jsonTlv);
    }
    return (jsonAclCtl);
}

// process ALSA control and store resulting value into ctlRequest

PUBLIC int alsaSetSingleCtl(snd_ctl_t *ctlDev, snd_ctl_elem_id_t *elemId, ctlRequestT *ctlRequest) {
    snd_ctl_elem_value_t *elemData;
    snd_ctl_elem_info_t *elemInfo;
    int count, length, err, valueIsArray = 0;

    // let's make sure we are processing the right control
    if (ctlRequest->numId != snd_ctl_elem_id_get_numid(elemId)) goto OnErrorExit;

    // set info event ID and get value
    snd_ctl_elem_info_alloca(&elemInfo);
    snd_ctl_elem_info_set_id(elemInfo, elemId); // map ctlInfo to ctlId elemInfo is updated !!!
    if (snd_ctl_elem_info(ctlDev, elemInfo) < 0) {
        AFB_NOTICE("Fail to load ALSA NUMID=%d Values='%s'", ctlRequest->numId, json_object_get_string(ctlRequest->valuesJ));
        goto OnErrorExit;
    }

    if (!snd_ctl_elem_info_is_writable(elemInfo)) {
        AFB_NOTICE("Not Writable ALSA NUMID=%d Values='%s'", ctlRequest->numId, json_object_get_string(ctlRequest->valuesJ));
        goto OnErrorExit;
    }

    count = snd_ctl_elem_info_get_count(elemInfo);
    if (count == 0) goto OnErrorExit;

    enum json_type jtype = json_object_get_type(ctlRequest->valuesJ);
    switch (jtype) {
        case json_type_array:
            length = json_object_array_length(ctlRequest->valuesJ);
            valueIsArray = 1;
            break;
        case json_type_int:
            length = 1;
            valueIsArray = 0;
            break;
        default:
            length = 0;
            break;
    }


    if (length == 0) {
        AFB_NOTICE("Invalid values NUMID='%d' Values='%s' count='%d' wanted='%d'", ctlRequest->numId, json_object_get_string(ctlRequest->valuesJ), length, count);
        goto OnErrorExit;
    }

    snd_ctl_elem_value_alloca(&elemData);
    snd_ctl_elem_value_set_id(elemData, elemId); // map ctlInfo to ctlId elemInfo is updated !!!
    if (snd_ctl_elem_read(ctlDev, elemData) < 0) goto OnErrorExit;

    // Loop on every control value and push to sndcard
    for (int index = 0; index < count; index++) {
        json_object *element;
        int value;

        // when not enough value duplicate last provided one
        if (!valueIsArray) element = ctlRequest->valuesJ;
        else {
            if (index < length) element = json_object_array_get_idx(ctlRequest->valuesJ, index);
            else element = json_object_array_get_idx(ctlRequest->valuesJ, length - 1);
        }

        value = json_object_get_int(element);
        snd_ctl_elem_value_set_integer(elemData, index, value);
    }

    err = snd_ctl_elem_write(ctlDev, elemData);
    if (err < 0) {
        AFB_NOTICE("Fail to write ALSA NUMID=%d Values='%s' Error=%s", ctlRequest->numId, json_object_get_string(ctlRequest->valuesJ), snd_strerror(err));
        goto OnErrorExit;
    }

    ctlRequest->used = 1;
    return 0;

OnErrorExit:
    ctlRequest->used = -1;
    return -1;
}

// process ALSA control and store then into ctlRequest

PUBLIC int alsaGetSingleCtl(snd_ctl_t *ctlDev, snd_ctl_elem_id_t *elemId, ctlRequestT *ctlRequest, halQueryMode queryMode) {
    snd_ctl_elem_type_t elemType;
    snd_ctl_elem_value_t *elemData;
    snd_ctl_elem_info_t *elemInfo;
    int count, idx, err;


    // set info event ID and get value

    snd_ctl_elem_info_alloca(&elemInfo);
    snd_ctl_elem_info_set_id(elemInfo, elemId);
    if (snd_ctl_elem_info(ctlDev, elemInfo) < 0) goto OnErrorExit;
    count = snd_ctl_elem_info_get_count(elemInfo);
    if (count == 0) goto OnErrorExit;

    if (!snd_ctl_elem_info_is_readable(elemInfo)) goto OnErrorExit;
    elemType = snd_ctl_elem_info_get_type(elemInfo);

    snd_ctl_elem_value_alloca(&elemData);
    snd_ctl_elem_value_set_id(elemData, elemId);
    if (snd_ctl_elem_read(ctlDev, elemData) < 0) goto OnErrorExit;

    int numid = snd_ctl_elem_info_get_numid(elemInfo);

    ctlRequest->valuesJ = json_object_new_object();
    json_object_object_add(ctlRequest->valuesJ, "id", json_object_new_int(numid));
    if (queryMode >= 1) json_object_object_add(ctlRequest->valuesJ, "name", json_object_new_string(snd_ctl_elem_id_get_name(elemId)));
    if (queryMode >= 2) json_object_object_add(ctlRequest->valuesJ, "iface", json_object_new_string(snd_ctl_elem_iface_name(snd_ctl_elem_id_get_interface(elemId))));
    if (queryMode >= 3) json_object_object_add(ctlRequest->valuesJ, "actif", json_object_new_boolean(!snd_ctl_elem_info_is_inactive(elemInfo)));

    json_object *jsonValuesCtl = json_object_new_array();
    for (idx = 0; idx < count; idx++) { // start from one in amixer.c !!!
        switch (elemType) {
            case SND_CTL_ELEM_TYPE_BOOLEAN:
            {
                json_object_array_add(jsonValuesCtl, json_object_new_boolean(snd_ctl_elem_value_get_boolean(elemData, idx)));
                break;
            }
            case SND_CTL_ELEM_TYPE_INTEGER:
                json_object_array_add(jsonValuesCtl, json_object_new_int((int) snd_ctl_elem_value_get_integer(elemData, idx)));
                break;
            case SND_CTL_ELEM_TYPE_INTEGER64:
                json_object_array_add(jsonValuesCtl, json_object_new_int64(snd_ctl_elem_value_get_integer64(elemData, idx)));
                break;
            case SND_CTL_ELEM_TYPE_ENUMERATED:
                json_object_array_add(jsonValuesCtl, json_object_new_int(snd_ctl_elem_value_get_enumerated(elemData, idx)));
                break;
            case SND_CTL_ELEM_TYPE_BYTES:
                json_object_array_add(jsonValuesCtl, json_object_new_int((int) snd_ctl_elem_value_get_byte(elemData, idx)));
                break;
            case SND_CTL_ELEM_TYPE_IEC958:
            {
                json_object *jsonIec958Ctl = json_object_new_object();
                snd_aes_iec958_t iec958;
                snd_ctl_elem_value_get_iec958(elemData, &iec958);

                json_object_object_add(jsonIec958Ctl, "AES0", json_object_new_int(iec958.status[0]));
                json_object_object_add(jsonIec958Ctl, "AES1", json_object_new_int(iec958.status[1]));
                json_object_object_add(jsonIec958Ctl, "AES2", json_object_new_int(iec958.status[2]));
                json_object_object_add(jsonIec958Ctl, "AES3", json_object_new_int(iec958.status[3]));
                json_object_array_add(jsonValuesCtl, jsonIec958Ctl);
                break;
            }
            default:
                json_object_array_add(jsonValuesCtl, json_object_new_string("?unknown?"));
                break;
        }
    }
    json_object_object_add(ctlRequest->valuesJ, "val", jsonValuesCtl);

    if (queryMode >= 1) { // in simple mode do not print usable values
        json_object *jsonClassCtl = json_object_new_object();
        json_object_object_add(jsonClassCtl, "type", json_object_new_int(elemType));
        json_object_object_add(jsonClassCtl, "count", json_object_new_int(count));

        switch (elemType) {
            case SND_CTL_ELEM_TYPE_INTEGER:
                json_object_object_add(jsonClassCtl, "min", json_object_new_int((int) snd_ctl_elem_info_get_min(elemInfo)));
                json_object_object_add(jsonClassCtl, "max", json_object_new_int((int) snd_ctl_elem_info_get_max(elemInfo)));
                json_object_object_add(jsonClassCtl, "step", json_object_new_int((int) snd_ctl_elem_info_get_step(elemInfo)));
                break;
            case SND_CTL_ELEM_TYPE_INTEGER64:
                json_object_object_add(jsonClassCtl, "min", json_object_new_int64(snd_ctl_elem_info_get_min64(elemInfo)));
                json_object_object_add(jsonClassCtl, "max", json_object_new_int64(snd_ctl_elem_info_get_max64(elemInfo)));
                json_object_object_add(jsonClassCtl, "step", json_object_new_int64(snd_ctl_elem_info_get_step64(elemInfo)));
                break;
            case SND_CTL_ELEM_TYPE_ENUMERATED:
            {
                unsigned int item, items = snd_ctl_elem_info_get_items(elemInfo);
                json_object *jsonEnum = json_object_new_array();

                for (item = 0; item < items; item++) {
                    snd_ctl_elem_info_set_item(elemInfo, item);
                    if ((err = snd_ctl_elem_info(ctlDev, elemInfo)) >= 0) {
                        json_object_array_add(jsonEnum, json_object_new_string(snd_ctl_elem_info_get_item_name(elemInfo)));
                    }
                }
                json_object_object_add(jsonClassCtl, "enums", jsonEnum);
                break;
            }
            default: break; // ignore any unknown type
        }

        // add collected class info with associated ACLs
        json_object_object_add(ctlRequest->valuesJ, "ctl", jsonClassCtl);

        if (queryMode >= QUERY_FULL) json_object_object_add(ctlRequest->valuesJ, "acl", getControlAcl(elemInfo));

        // check for tlv [direct port from amixer.c]
        if (snd_ctl_elem_info_is_tlv_readable(elemInfo)) {
            unsigned int *tlv = alloca(TLV_BYTE_SIZE);
            if ((err = snd_ctl_elem_tlv_read(ctlDev, elemId, tlv, 4096)) < 0) {
                AFB_NOTICE("Control numid=%d err=%s element TLV read error\n", numid, snd_strerror(err));
                goto OnErrorExit;
            } else {
                json_object_object_add(ctlRequest->valuesJ, "tlv", decodeTlv(tlv, TLV_BYTE_SIZE, queryMode));
            }
        }
    }

    ctlRequest->used = 1;
    return 0;

OnErrorExit:
    ctlRequest->used = -1;
    return -1;
}

// assign multiple control to the same value

STATIC void alsaSetGetCtls(ActionSetGetT action, afb_req request) {
    ctlRequestT *ctlRequest;
    const char *warmsg = NULL;
    int err = 0, status = 0, done;
    unsigned int ctlCount;
    snd_ctl_t *ctlDev;
    snd_ctl_elem_list_t *ctlList;
    queryValuesT queryValues;
    json_object *queryJ, *numidsJ, *sndctls;

    queryJ = alsaCheckQuery(request, &queryValues);
    if (!queryJ) goto OnErrorExit;

    // Prase Numids + optional values
    done = json_object_object_get_ex(queryJ, "ctl", &numidsJ);
    if (!done) queryValues.count = 0;
    else {
        enum json_type jtype = json_object_get_type(numidsJ);
        switch (jtype) {
            case json_type_array:
                queryValues.numidsJ = numidsJ;
                queryValues.count = json_object_array_length(numidsJ);
                break;

            case json_type_int:
            case json_type_object:
                queryValues.count = 1;
                queryValues.numidsJ = numidsJ;
                break;

            default:
                afb_req_fail_f(request, "numid-notarray", "NumId=%s NumId not valid JSON array", json_object_get_string(numidsJ));
                goto OnErrorExit;
        }
    }

    if ((err = snd_ctl_open(&ctlDev, queryValues.devid, 0)) < 0) {
        afb_req_fail_f(request, "sndcrl-notfound", "devid='%s' load fail error=%s\n", queryValues.devid, snd_strerror(err));
        goto OnErrorExit;
    }

    snd_ctl_elem_list_alloca(&ctlList);
    if ((err = snd_ctl_elem_list(ctlDev, ctlList)) < 0) {
        afb_req_fail_f(request, "listInit-failed", "devid='%s' load fail error=%s\n", queryValues.devid, snd_strerror(err));
        goto OnErrorExit;
    }

    if ((err = snd_ctl_elem_list_alloc_space(ctlList, snd_ctl_elem_list_get_count(ctlList))) < 0) {
        afb_req_fail_f(request, "listAlloc-failed", "devid='%s' load fail error=%s\n", queryValues.devid, snd_strerror(err));
        goto OnErrorExit;
    }

    if ((err = snd_ctl_elem_list(ctlDev, ctlList)) < 0) {
        afb_req_fail_f(request, "listOpen-failed", "devid='%s' load fail error=%s\n", queryValues.devid, snd_strerror(err));
        goto OnErrorExit;
    }

    // Parse numids string (empty == all)
    ctlCount = snd_ctl_elem_list_get_used(ctlList);
    if (queryValues.count == 0) {
        ctlRequest = alloca(sizeof (ctlRequestT)*(ctlCount));
    } else {
        ctlRequest = alloca(sizeof (ctlRequestT)*(queryValues.count));
        NumidsListParse(action, &queryValues, ctlRequest);
    }

    // if more than one crl requested prepare an array for response
    if (queryValues.count != 1 && action == ACTION_GET) sndctls = json_object_new_array();
    else sndctls = NULL;

    // Loop on all ctlDev controls
    for (int ctlIndex = 0; ctlIndex < ctlCount; ctlIndex++) {
        unsigned int selected = 0;
        int jdx;

        if (queryValues.count == 0 && action == ACTION_GET) {
            selected = 1; // check is this numid is selected within query
            jdx = ctlIndex; // map all existing ctl as requested
        } else {
            int numid = snd_ctl_elem_list_get_numid(ctlList, ctlIndex);
            if (numid < 0) {
                AFB_NOTICE("snd_ctl_elem_list_get_numid index=%d fail", ctlIndex);
                continue;
            }
            // check if current control was requested in query numids list
            for (jdx = 0; jdx < queryValues.count; jdx++) {
                if (numid == ctlRequest[jdx].numId) {
                    selected = 1;
                    break;
                }
            }
        }

        // control is selected open ctlid and get value
        if (selected) {
            snd_ctl_elem_id_t *elemId;
            snd_ctl_elem_id_alloca(&elemId);

            snd_ctl_elem_list_get_id(ctlList, ctlIndex, elemId);
            switch (action) {
                case ACTION_GET:
                    err = alsaGetSingleCtl(ctlDev, elemId, &ctlRequest[jdx], queryValues.mode);
                    break;

                case ACTION_SET:
                    err = alsaSetSingleCtl(ctlDev, elemId, &ctlRequest[jdx]);
                    break;

                default:
                    err = 1;
            }
            if (err) status++;
            else {
                // Do not embed response in an array when only one ctl was requested
                if (action == ACTION_GET) {
                    if (queryValues.count == 1) sndctls = ctlRequest[jdx].valuesJ;
                    else json_object_array_add(sndctls, ctlRequest[jdx].valuesJ);
                }
            }
        }
    }

    // if we had error let's add them into response message info
    json_object *warningsJ = json_object_new_array();
    for (int jdx = 0; jdx < queryValues.count; jdx++) {
        if (ctlRequest[jdx].used <= 0) {
            json_object *failctl = json_object_new_object();
            if (ctlRequest[jdx].numId == -1) json_object_object_add(failctl, "warning", json_object_new_string("Numid Invalid"));
            else {
                if (ctlRequest[jdx].used == 0) json_object_object_add(failctl, "warning", json_object_new_string("Numid Does Not Exist"));
                if (ctlRequest[jdx].used == -1) json_object_object_add(failctl, "warning", json_object_new_string("Value Refused"));
            }

            json_object_object_add(failctl, "ctl", ctlRequest[jdx].jToken);

            json_object_array_add(warningsJ, failctl);
        }
        /* WARNING!!!! Check with Jose why following put free valuesJ
        if (ctlRequest[jdx].jToken) json_object_put(ctlRequest[jdx].jToken);
        if (ctlRequest[jdx].valuesJ) json_object_put(ctlRequest[jdx].valuesJ);
         */
    }

    if (json_object_array_length(warningsJ) > 0) warmsg = json_object_get_string(warningsJ);
    else json_object_put(warningsJ);

    // send response+warning if any
    afb_req_success(request, sndctls, warmsg);
    snd_ctl_elem_list_clear(ctlList);

OnErrorExit:
    return;
}

PUBLIC void alsaGetCtls(afb_req request) {
    alsaSetGetCtls(ACTION_GET, request);
}

PUBLIC void alsaSetCtls(afb_req request) {
    alsaSetGetCtls(ACTION_SET, request);
}