aboutsummaryrefslogtreecommitdiffstats
path: root/Alsa-afb/Alsa-AddCtl.c
blob: 44de782766516c315a171845d6f8eded4a74041f (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
/*
 * AlsaUseCase -- 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://kernel.readthedocs.io/en/sphinx-samples/writing-an-alsa-driver.html#control-names
 *  https://01.org/linuxgraphics/gfx-docs/drm/sound/designs/control-names.html

 */
#define _GNU_SOURCE  // needed for vasprintf

#include <alsa/asoundlib.h>
#include <alsa/sound/tlv.h>
#include <systemd/sd-event.h>
#include <sys/ioctl.h>

#include "Alsa-ApiHat.h"

// Performs like a toggle switch for attenuation, because they're bool (ref:user-ctl-element-set.c)

static const unsigned int *allocate_bool_fake_tlv(void) {
    static const SNDRV_CTL_TLVD_DECLARE_DB_MINMAX(range, -10000, 0);
    unsigned int *tlv = malloc(sizeof (range));
    if (tlv == NULL) return NULL;
    memcpy(tlv, range, sizeof (range));
    return tlv;
}

static const unsigned int *allocate_int_dbscale_tlv(int min, int step, int mute) {
    // SNDRV_CTL_TLVD_DECLARE_DB_SCALE(range, min, step, mute);
    size_t tlvSize = sizeof (4 * sizeof (unsigned int));
    unsigned int *tlv = malloc(tlvSize);
    tlv[0] = SNDRV_CTL_TLVT_DB_LINEAR;
    tlv[1] = (int) tlvSize;
    tlv[2] = min * 100;
    tlv[3] = ((step * 100) & SNDRV_CTL_TLVD_DB_SCALE_MASK) | ((mute * 100) ? SNDRV_CTL_TLVD_DB_SCALE_MUTE : 0);
    return tlv;
}

static const unsigned int *allocate_int_linear_tlv(int max, int min) {
    // SNDRV_CTL_TLVD_DECLARE_DB_LINEAR (range, min, max);
    size_t tlvSize = sizeof (4 * sizeof (unsigned int));
    unsigned int *tlv = malloc(tlvSize);
    tlv[0] = SNDRV_CTL_TLVT_DB_LINEAR;
    tlv[1] = (int) tlvSize;
    tlv[2] = -min * 100;
    tlv[3] = max * 100;
    return tlv;
}

STATIC json_object * addOneSndCtl(afb_req request, snd_ctl_t *ctlDev, json_object *ctlJ, halQueryMode queryMode) {
    int err, done, ctlNumid, ctlValue, shouldCreate;
    json_object *tmpJ;
    const char *ctlName;
    ctlRequestT ctlRequest;
    int ctlMax, ctlMin, ctlStep, ctlCount, ctlSubDev, ctlSndDev;
    snd_ctl_elem_type_t ctlType;
    snd_ctl_elem_info_t *elemInfo;
    snd_ctl_elem_id_t *elemId;
    snd_ctl_elem_value_t *elemValue;
    const unsigned int *elemTlv = NULL;

    // parse json ctl object
    json_object_object_get_ex(ctlJ, "name", &tmpJ);
    ctlName = json_object_get_string(tmpJ);

    json_object_object_get_ex(ctlJ, "ctl", &tmpJ);
    ctlNumid = json_object_get_int(tmpJ);

    if (!ctlNumid && !ctlName) {
        afb_req_fail_f(request, "ctl-invalid", "crl=%s name or numid missing", json_object_get_string(ctlJ));
        goto OnErrorExit;
    }


    // We are facing a software ctl
    if (ctlNumid == CTL_AUTO) {
        done = json_object_object_get_ex(ctlJ, "type", &tmpJ);
        if (done) ctlType = json_object_get_int(tmpJ);
        else ctlType = SND_CTL_ELEM_TYPE_INTEGER;

        json_object_object_get_ex(ctlJ, "value", &tmpJ);
        ctlValue = json_object_get_int(tmpJ);

        // default for json_object_get_int is zero
        json_object_object_get_ex(ctlJ, "min", &tmpJ);
        ctlMin = json_object_get_int(tmpJ);

        done = json_object_object_get_ex(ctlJ, "max", &tmpJ);
        if (done) ctlMax = json_object_get_int(tmpJ);
        else {
            if (ctlType == SND_CTL_ELEM_TYPE_BOOLEAN) ctlMax = 1;
            else ctlMax = 100;
        }

        done = json_object_object_get_ex(ctlJ, "step", &tmpJ);
        if (!done) ctlStep = 1;
        else ctlStep = json_object_get_int(tmpJ);

        done = json_object_object_get_ex(ctlJ, "count", &tmpJ);
        if (!done) ctlCount = 1;
        else ctlCount = json_object_get_int(tmpJ);

        json_object_object_get_ex(ctlJ, "snddev", &tmpJ);
        ctlSndDev = json_object_get_int(tmpJ);

        json_object_object_get_ex(ctlJ, "subdev", &tmpJ);
        ctlSubDev = json_object_get_int(tmpJ);
    }

    // Assert that this ctls is not used
    snd_ctl_elem_info_alloca(&elemInfo);
    if (ctlName) snd_ctl_elem_info_set_name(elemInfo, ctlName);
    if (ctlNumid > 0)snd_ctl_elem_info_set_numid(elemInfo, ctlNumid);
    snd_ctl_elem_info_set_interface(elemInfo, SND_CTL_ELEM_IFACE_MIXER);

    // If control exist try to reuse it
    err = snd_ctl_elem_info(ctlDev, elemInfo);
    if (err) {
        shouldCreate = 1;
    } else {
        int count, min, max, sndDev, subDev;
        snd_ctl_elem_type_t type;

        // ctl exit let's get associated elemID
        snd_ctl_elem_id_alloca(&elemId);
        snd_ctl_elem_info_get_id(elemInfo, elemId);

        // If this is a hardware ctl only update value
        if (ctlNumid != CTL_AUTO) goto UpdateDefaultVal;

        count = snd_ctl_elem_info_get_count(elemInfo);
        min = (int) snd_ctl_elem_info_get_min(elemInfo);
        max = (int) snd_ctl_elem_info_get_max(elemInfo);
        type = snd_ctl_elem_info_get_type(elemInfo);
        sndDev = (int) snd_ctl_elem_info_get_device(elemInfo);
        subDev = (int) snd_ctl_elem_info_get_subdevice(elemInfo);

        if (count == ctlCount && min == ctlMin && max == ctlMax && type == ctlType && sndDev == ctlSndDev && subDev == ctlSubDev) {
            // Adjust value to best fit request
            shouldCreate = 0;
        } else {
            err = snd_ctl_elem_remove(ctlDev, elemId);
            shouldCreate = 1;
            if (err < 0) {
                AFB_ERROR("addOneSndCtl: ctlName=%s numid=%d fail to reset", snd_ctl_elem_info_get_name(elemInfo), snd_ctl_elem_info_get_numid(elemInfo));
                goto DoNotUpdate;
            };

            // Control was deleted need to refresh elemInfo
            snd_ctl_elem_info_alloca(&elemInfo);
            if (ctlName) snd_ctl_elem_info_set_name(elemInfo, ctlName);
            snd_ctl_elem_info_set_interface(elemInfo, SND_CTL_ELEM_IFACE_MIXER);
            snd_ctl_elem_info(ctlDev, elemInfo);
        }
    }

    // Add requested ID into elemInfo
    snd_ctl_elem_info_set_device(elemInfo, ctlSndDev);
    snd_ctl_elem_info_set_subdevice(elemInfo, ctlSubDev);

    switch (ctlType) {
        case SND_CTL_ELEM_TYPE_BOOLEAN:
            if (shouldCreate) {
                err = snd_ctl_add_boolean_elem_set(ctlDev, elemInfo, 1, ctlCount);
                if (err) {
                    AFB_ERROR("AddOntSndCtl Boolean: devid='%s' name='%s' count=%d", snd_ctl_name(ctlDev), ctlName, ctlCount);
                    afb_req_fail_f(request, "ctl-invalid-bool", "devid='%s' name='%s' count=%d", snd_ctl_name(ctlDev), ctlName, ctlCount);
                    goto OnErrorExit;
                }
            }

            // Create a dummy TLV
            elemTlv = allocate_bool_fake_tlv();

            break;

        case SND_CTL_ELEM_TYPE_INTEGER:
            if (shouldCreate) {
                err = snd_ctl_add_integer_elem_set(ctlDev, elemInfo, 1, ctlCount, ctlMin, ctlMax, ctlStep);
                if (err) {
                    AFB_ERROR("AddOntSndCtl Integer: devid='%s' name='%s' count=%d min=%d max=%d step=%d", snd_ctl_name(ctlDev), ctlName, ctlCount, ctlMin, ctlMax, ctlStep);
                    afb_req_fail_f(request, "ctl-invalid-bool", "devid='%s' name='%s' count=%d min=%d max=%d step=%d", snd_ctl_name(ctlDev), ctlName, ctlCount, ctlMin, ctlMax, ctlStep);
                    goto OnErrorExit;
                }
            }

            // Fulup needed to be tested with some dB expert !!!
            json_object *dbscaleJ;
            if (json_object_object_get_ex(ctlJ, "dbscale", &dbscaleJ)) {
                int min, max;

                if (json_object_get_type(dbscaleJ) != json_type_object) {
                    afb_req_fail_f(request, "ctl-invalid-dbscale", "devid=%s crl=%s invalid json in integer control", snd_ctl_name(ctlDev), json_object_get_string(ctlJ));
                    goto OnErrorExit;

                    json_object_object_get_ex(ctlJ, "min", &tmpJ);
                    min = json_object_get_int(tmpJ);
                    if (min >= 0) {
                        afb_req_fail_f(request, "ctl-invalid-dbscale", "devid=%s crl=%s min should be a negative number", snd_ctl_name(ctlDev), json_object_get_string(ctlJ));
                        goto OnErrorExit;
                    }

                    // default value 0=mute
                    json_object_object_get_ex(ctlJ, "max", &tmpJ);
                    max = json_object_get_int(tmpJ);

                    // default value 1dB
                    json_object_object_get_ex(ctlJ, "step", &tmpJ);
                    int step = json_object_get_int(tmpJ);
                    if (step <= 0) step = 1;

                    elemTlv = allocate_int_dbscale_tlv(min, max, step);

                }
            } else {
                // provide a fake linear TLV
                elemTlv = allocate_int_linear_tlv(ctlMin, ctlMax);
            }
            break;

        case SND_CTL_ELEM_TYPE_ENUMERATED:

            if (shouldCreate) {
                json_object *enumsJ;
                json_object_object_get_ex(ctlJ, "enums", &enumsJ);
                if (json_object_get_type(enumsJ) != json_type_array) {
                    afb_req_fail_f(request, "ctl-missing-enums", "devid=%s crl=%s mandatory enum=xxx missing in enumerated control", snd_ctl_name(ctlDev), json_object_get_string(ctlJ));
                    goto OnErrorExit;
                }

                int length = json_object_array_length(enumsJ);
                const char **enumlabels = malloc(length * sizeof (char*));

                for (int jdx = 0; jdx < length; jdx++) {
                    tmpJ = json_object_array_get_idx(enumsJ, jdx);
                    enumlabels[jdx] = json_object_get_string(tmpJ);
                }

                err = snd_ctl_add_enumerated_elem_set(ctlDev, elemInfo, 1, ctlCount, length, enumlabels);
                if (err) {
                    afb_req_fail_f(request, "ctl-invalid-bool", "devid=%s crl=%s invalid enumerated control", snd_ctl_name(ctlDev), json_object_get_string(ctlJ));
                    goto OnErrorExit;
                }

                // Fulup should be an empty container
                elemTlv = allocate_bool_fake_tlv();
            }
            break;

            // Long Term Waiting ToDoList
        case SND_CTL_ELEM_TYPE_INTEGER64:
        case SND_CTL_ELEM_TYPE_BYTES:
        default:
            afb_req_fail_f(request, "ctl-invalid-type", "crl=%s unsupported type type=%d numid=%d", json_object_get_string(ctlJ), ctlType, ctlNumid);
            goto OnErrorExit;
    }

UpdateDefaultVal:

    // Set Value to default
    snd_ctl_elem_value_alloca(&elemValue);
    for (int idx = 0; idx < snd_ctl_elem_info_get_count(elemInfo); idx++) {
        snd_ctl_elem_value_set_integer(elemValue, idx, ctlValue);
    }

    // write default values in newly created control
    snd_ctl_elem_id_alloca(&elemId);
    snd_ctl_elem_info(ctlDev, elemInfo);
    snd_ctl_elem_info_get_id(elemInfo, elemId);
    snd_ctl_elem_value_set_id(elemValue, elemId);
    err = snd_ctl_elem_write(ctlDev, elemValue);
    if (err < 0) {
        AFB_WARNING("addOneSndCtl: crl=%s numid=%d fail to write Values error=%s", json_object_get_string(ctlJ), snd_ctl_elem_info_get_numid(elemInfo), snd_strerror(err));
        goto DoNotUpdate;
    }

    // write a default null TLV (if usefull should be implemented for every ctl type)
    if (elemTlv) {
        err = snd_ctl_elem_tlv_write(ctlDev, elemId, elemTlv);
        if (err < 0) {
            AFB_WARNING("addOneSndCtl: crl=%s numid=%d fail to write TLV error=%s", json_object_get_string(ctlJ), snd_ctl_elem_info_get_numid(elemInfo), snd_strerror(err));
            goto DoNotUpdate;
        }
    }

DoNotUpdate:
    // return newly created as a JSON object
    alsaGetSingleCtl(ctlDev, elemId, &ctlRequest, queryMode);
    if (ctlRequest.used < 0) {
        AFB_WARNING("addOneSndCtl: crl=%s numid=%d Fail to get value", json_object_get_string(ctlJ), snd_ctl_elem_info_get_numid(elemInfo));
    }
    return ctlRequest.valuesJ;

OnErrorExit:
    return NULL;
}

PUBLIC void alsaAddCustomCtls(afb_req request) {
    int err;
    json_object *ctlsJ, *ctlsValues, *ctlValues;
    enum json_type;
    snd_ctl_t *ctlDev = NULL;
    const char *devid, *mode;

    devid = afb_req_value(request, "devid");
    if (devid == NULL) {
        afb_req_fail_f(request, "devid-missing", "devid MUST be defined for alsaAddCustomCtls");
        goto OnErrorExit;
    }

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

    // get verbosity level
    halQueryMode queryMode = QUERY_QUIET;
    mode = afb_req_value(request, "mode");
    if (mode != NULL) {
        sscanf(mode, "%i", (int*) &queryMode);
    }

    // extract sound controls and parse json
    ctlsJ = json_tokener_parse(afb_req_value(request, "ctl"));
    if (!ctlsJ) {
        afb_req_fail_f(request, "ctls-missing", "ctls MUST be defined as a JSON array for alsaAddCustomCtls");
        goto OnErrorExit;
    }

    switch (json_object_get_type(ctlsJ)) {
        case json_type_object:
            ctlsValues = addOneSndCtl(request, ctlDev, ctlsJ, queryMode);
            if (!ctlsValues) goto OnErrorExit;
            break;

        case json_type_array:
            ctlsValues = json_object_new_array();
            for (int idx = 0; idx < json_object_array_length(ctlsJ); idx++) {
                json_object *ctlJ = json_object_array_get_idx(ctlsJ, idx);
                ctlValues = addOneSndCtl(request, ctlDev, ctlJ, queryMode);
                if (ctlValues) json_object_array_add(ctlsValues, ctlValues);
                else goto OnErrorExit;
            }
            break;

        default:
            afb_req_fail_f(request, "ctls-invalid", "ctls=%s not valid JSON array", json_object_get_string(ctlsJ));
            goto OnErrorExit;
    }

    // get ctl as a json response
    afb_req_success(request, ctlsValues, NULL);

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