aboutsummaryrefslogtreecommitdiffstats
path: root/alsa-binding/Alsa-RegEvt.c
blob: 41db2075e9c32bc3b95cdfcf91f484e530d69b48 (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
/*
 * 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.

 */

#define _GNU_SOURCE  // needed for vasprintf

#include "Alsa-ApiHat.h"

// generic sndctrl event handle hook to event callback when pooling

typedef struct {
    struct pollfd pfds;
    sd_event_source *src;
    snd_ctl_t *ctlDev;
    int mode;
    struct afb_event afbevt;
} evtHandleT;

typedef struct {
    int ucount;
    int cardId;
    evtHandleT *evtHandle;
} sndHandleT;

typedef struct {
    char *devid;
    char *apiprefix;
    char *shortname;
    char *longname;
} cardRegistryT;

cardRegistryT *cardRegistry[MAX_SND_CARD + 1];

PUBLIC json_object *alsaCheckQuery(afb_req request, queryValuesT *queryValues) {

    json_object *tmpJ;
    int done;

    // get query from request
    json_object *queryInJ = afb_req_json(request);

    done = json_object_object_get_ex(queryInJ, "devid", &tmpJ);
    if (!done) {
        afb_req_fail_f(request, "devid-missing", "Invalid query='%s'", json_object_get_string(queryInJ));
        goto OnErrorExit;
    }
    queryValues->devid = json_object_get_string(tmpJ);

    done = json_object_object_get_ex(queryInJ, "mode", &tmpJ);
    if (!done) queryValues->mode = QUERY_QUIET; // default quiet
    else queryValues->mode = json_object_get_int(tmpJ);

    return queryInJ;

OnErrorExit:
    return NULL;
}

// This routine is called when ALSA event are fired

STATIC int sndCtlEventCB(sd_event_source* src, int fd, uint32_t revents, void* userData) {
    int err, ctlNumid;
    evtHandleT *evtHandle = (evtHandleT*) userData;
    snd_ctl_event_t *eventId;
    json_object *ctlEventJ;
    unsigned int mask;
    int iface;
    int device;
    int subdev;
    const char*ctlName;
    ctlRequestT ctlRequest;
    snd_ctl_elem_id_t *elemId;

    if ((revents & EPOLLHUP) != 0) {
        AFB_NOTICE("SndCtl hanghup [car disconnected]");
        goto ExitOnSucess;
    }

    if ((revents & EPOLLIN) != 0) {

        // initialise event structure on stack
        snd_ctl_event_alloca(&eventId);
        snd_ctl_elem_id_alloca(&elemId);

        err = snd_ctl_read(evtHandle->ctlDev, eventId);
        if (err < 0) goto OnErrorExit;

        // we only process sndctrl element
        if (snd_ctl_event_get_type(eventId) != SND_CTL_EVENT_ELEM) goto ExitOnSucess;

        // we only process value changed events
        mask = snd_ctl_event_elem_get_mask(eventId);
        if (!(mask & SND_CTL_EVENT_MASK_VALUE)) goto ExitOnSucess;

        snd_ctl_event_elem_get_id(eventId, elemId);

        err = alsaGetSingleCtl(evtHandle->ctlDev, elemId, &ctlRequest, evtHandle->mode);
        if (err) goto OnErrorExit;

        // If CTL as a value use it as container for response
        if (ctlRequest.valuesJ) ctlEventJ = ctlRequest.valuesJ;
        else {
            ctlEventJ = json_object_new_object();
            ctlNumid = snd_ctl_event_elem_get_numid(eventId);
            json_object_object_add(ctlEventJ, "id", json_object_new_int(ctlNumid));
        }

        if (evtHandle->mode >= QUERY_COMPACT) {
            ctlName = snd_ctl_event_elem_get_name(eventId);
            json_object_object_add(ctlEventJ, "name", json_object_new_string(ctlName));
        }

        if (evtHandle->mode >= QUERY_VERBOSE) {
            iface = snd_ctl_event_elem_get_interface(eventId);
            device = snd_ctl_event_elem_get_device(eventId);
            subdev = snd_ctl_event_elem_get_subdevice(eventId);
            json_object_object_add(ctlEventJ, "ifc", json_object_new_int(iface));
            json_object_object_add(ctlEventJ, "dev", json_object_new_int(device));
            json_object_object_add(ctlEventJ, "sub", json_object_new_int(subdev));
        }


        AFB_DEBUG("sndCtlEventCB=%s", json_object_get_string(ctlEventJ));
        afb_event_push(evtHandle->afbevt, ctlEventJ);
    }

ExitOnSucess:
    return 0;

OnErrorExit:
    AFB_WARNING("sndCtlEventCB: ignored unsupported event type");
    return (0);
}

// Subscribe to every Alsa CtlEvent send by a given board

PUBLIC void alsaEvtSubcribe(afb_req request) {
    static sndHandleT sndHandles[MAX_SND_CARD];
    evtHandleT *evtHandle = NULL;
    snd_ctl_t *ctlDev = NULL;
    int err, idx, cardId, idxFree = -1;
    snd_ctl_card_info_t *cardinfo;
    queryValuesT queryValues;

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

    // open control interface for devid
    err = snd_ctl_open(&ctlDev, queryValues.devid, SND_CTL_READONLY);
    if (err < 0) {
        afb_req_fail_f(request, "devid-unknown", "SndCard devid=%s Not Found err=%s", queryValues.devid, snd_strerror(err));
        goto OnErrorExit;
    }

    snd_ctl_card_info_alloca(&cardinfo);
    if ((err = snd_ctl_card_info(ctlDev, cardinfo)) < 0) {
        afb_req_fail_f(request, "devid-invalid", "SndCard devid=%s Not Found err=%s", queryValues.devid, snd_strerror(err));
        goto OnErrorExit;
    }

    cardId = snd_ctl_card_info_get_card(cardinfo);

    // search for an existing subscription and mark 1st free slot
    for (idx = 0; idx < MAX_SND_CARD; idx++) {
        if (sndHandles[idx].ucount > 0 && cardId == sndHandles[idx].cardId) {
            evtHandle = sndHandles[idx].evtHandle;
            break;
        } else if (idxFree == -1) idxFree = idx;
    };

    // if not subscription exist for the event let's create one
    if (idx == MAX_SND_CARD) {

        // reach MAX_SND_CARD event registration
        if (idxFree == -1) {
            afb_req_fail_f(request, "register-toomany", "Cannot register new event Maxcard==%d", idx);
            goto OnErrorExit;
        }

        evtHandle = malloc(sizeof (evtHandleT));
        evtHandle->ctlDev = ctlDev;
        evtHandle->mode = queryValues.mode;
        sndHandles[idxFree].ucount = 0;
        sndHandles[idxFree].cardId = cardId;
        sndHandles[idxFree].evtHandle = evtHandle;

        // subscribe for sndctl events attached to devid
        err = snd_ctl_subscribe_events(evtHandle->ctlDev, 1);
        if (err < 0) {
            afb_req_fail_f(request, "subscribe-fail", "Cannot subscribe events from devid=%s err=%d", queryValues.devid, err);
            goto OnErrorExit;
        }

        // get pollfd attach to this sound board
        snd_ctl_poll_descriptors(evtHandle->ctlDev, &evtHandle->pfds, 1);

        // register sound event to binder main loop
        err = sd_event_add_io(afb_daemon_get_event_loop(), &evtHandle->src, evtHandle->pfds.fd, EPOLLIN, sndCtlEventCB, evtHandle);
        if (err < 0) {
            afb_req_fail_f(request, "register-mainloop", "Cannot hook events to mainloop devid=%s err=%d", queryValues.devid, err);
            goto OnErrorExit;
        }

        // create binder event attached to devid name
        evtHandle->afbevt = afb_daemon_make_event(queryValues.devid);
        if (!afb_event_is_valid(evtHandle->afbevt)) {
            afb_req_fail_f(request, "register-event", "Cannot register new binder event name=%s", queryValues.devid);
            goto OnErrorExit;
        }

        // everything looks OK let's move forward
        idx = idxFree;
    }

    // subscribe to binder event
    err = afb_req_subscribe(request, evtHandle->afbevt);
    if (err != 0) {
        afb_req_fail_f(request, "register-eventname", "Cannot subscribe binder event name=%s [invalid channel]", queryValues.devid);
        goto OnErrorExit;
    }

    // increase usage count and return success
    sndHandles[idx].ucount++;
    afb_req_success(request, NULL, NULL);
    return;

OnErrorExit:
    if (ctlDev) snd_ctl_close(ctlDev);
    return;
}

// Subscribe to every Alsa CtlEvent send by a given board

STATIC json_object *alsaProbeCardId(afb_req request) {
    char devid [10];
    const char *ctlName, *shortname, *longname;
    int card, err, index, idx;
    json_object *responseJ;
    snd_ctl_t *ctlDev;
    snd_ctl_card_info_t *cardinfo;

    const char *sndname = afb_req_value(request, "sndname");
    if (sndname == NULL) {
        afb_req_fail_f(request, "argument-missing", "sndname=SndCardName missing");
        goto OnErrorExit;
    }

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

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

        // open control interface for devid
        err = snd_ctl_open(&ctlDev, devid, SND_CTL_READONLY);
        if (err < 0) continue;

        // extract sound card information
        snd_ctl_card_info(ctlDev, cardinfo);
        index = snd_ctl_card_info_get_card(cardinfo);
        ctlName = snd_ctl_card_info_get_id(cardinfo);
        shortname = snd_ctl_card_info_get_name(cardinfo);
        longname = snd_ctl_card_info_get_longname(cardinfo);

        // check if short|long name match
        if (!strcmp(sndname, ctlName)) break;
        if (!strcmp(sndname, shortname)) break;
        if (!strcmp(sndname, longname)) break;
    }

    if (card == MAX_SND_CARD) {
        afb_req_fail_f(request, "ctlDev-notfound", "Fail to find card with name=%s", sndname);
        goto OnErrorExit;
    }

    // proxy ctlevent as a binder event
    responseJ = json_object_new_object();
    json_object_object_add(responseJ, "index", json_object_new_int(index));
    json_object_object_add(responseJ, "devid", json_object_new_string(devid));
    json_object_object_add(responseJ, "shortname", json_object_new_string(shortname));
    json_object_object_add(responseJ, "longname", json_object_new_string(longname));

    // search for a HAL binder card mapping name to api prefix
    for (idx = 0; (idx < MAX_SND_CARD && cardRegistry[idx]); idx++) {
        if (!strcmp(cardRegistry[idx]->shortname, shortname)) {
            json_object_object_add(responseJ, "halapi", json_object_new_string(cardRegistry[idx]->apiprefix));
            break;
        }
    }

    return responseJ;

OnErrorExit:
    return NULL;
}

// Make alsaProbeCardId compatible with AFB request

PUBLIC void alsaGetCardId(afb_req request) {

    json_object *responseJ = alsaProbeCardId(request);
    if (responseJ) afb_req_success(request, responseJ, NULL);
}

// Return list of active resgistrated HAL with corresponding sndcard

PUBLIC void alsaActiveHal(afb_req request) {
    json_object *responseJ = json_object_new_array();

    for (int idx = 0; idx < MAX_SND_CARD; idx++) {
        if (!cardRegistry[idx]) break;

        json_object *haldevJ = json_object_new_object();
        json_object_object_add(haldevJ, "api", json_object_new_string(cardRegistry[idx]->apiprefix));
        if (cardRegistry[idx]->devid) json_object_object_add(haldevJ, "devid", json_object_new_string(cardRegistry[idx]->devid));
        if (cardRegistry[idx]->shortname)json_object_object_add(haldevJ, "shortname", json_object_new_string(cardRegistry[idx]->shortname));
        if (cardRegistry[idx]->longname) json_object_object_add(haldevJ, "longname", json_object_new_string(cardRegistry[idx]->longname));
        json_object_array_add(responseJ, haldevJ);
    }

    afb_req_success(request, responseJ, NULL);
}


// Register loaded HAL with board Name and API prefix

PUBLIC void alsaRegisterHal(afb_req request) {
    static int index = 0;
    json_object *responseJ;
    const char *shortname, *apiPrefix;

    apiPrefix = afb_req_value(request, "prefix");
    if (apiPrefix == NULL) {
        afb_req_fail_f(request, "argument-missing", "prefix=BindingApiPrefix missing");
        goto OnErrorExit;
    }

    shortname = afb_req_value(request, "sndname");
    if (shortname == NULL) {
        afb_req_fail_f(request, "argument-missing", "sndname=SndCardName missing");
        goto OnErrorExit;
    }

    if (index == MAX_SND_CARD) {
        afb_req_fail_f(request, "alsahal-toomany", "Fail to register sndname=[%s]", shortname);
        goto OnErrorExit;
    }

    // alsaGetCardId should be check to register only valid card
    responseJ = alsaProbeCardId(request);
    if (responseJ) {
        json_object *tmpJ;
        int done;

        cardRegistry[index] = malloc(sizeof (cardRegistry));
        cardRegistry[index]->apiprefix = strdup(apiPrefix);
        cardRegistry[index]->shortname = strdup(shortname);

        done = json_object_object_get_ex(responseJ, "devid", &tmpJ);
        if (done) cardRegistry[index]->devid = strdup(json_object_get_string(tmpJ));
        else cardRegistry[index]->devid = NULL;

        done = json_object_object_get_ex(responseJ, "longname", &tmpJ);
        if (done) cardRegistry[index]->longname = strdup(json_object_get_string(tmpJ));
        else cardRegistry[index]->longname = NULL;

        // make sure register close with a null value
        index++;
        cardRegistry[index] = NULL;

        afb_req_success(request, responseJ, NULL);
    }

    // If OK return sound card Alsa ID+Info
    return;

OnErrorExit:
    return;
}