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
|
/*
* 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 <systemd/sd-event.h>
#include "Alsa-ApiHat.h"
#include <sys/ioctl.h>
typedef struct _snd_ctl_ops {
int (*close)(snd_ctl_t *handle);
int (*nonblock)(snd_ctl_t *handle, int nonblock);
int (*async)(snd_ctl_t *handle, int sig, pid_t pid);
int (*subscribe_events)(snd_ctl_t *handle, int subscribe);
int (*card_info)(snd_ctl_t *handle, snd_ctl_card_info_t *info);
int (*element_list)(snd_ctl_t *handle, snd_ctl_elem_list_t *list);
int (*element_info)(snd_ctl_t *handle, snd_ctl_elem_info_t *info);
int (*element_add)(snd_ctl_t *handle, snd_ctl_elem_info_t *info);
int (*element_replace)(snd_ctl_t *handle, snd_ctl_elem_info_t *info);
int (*element_remove)(snd_ctl_t *handle, snd_ctl_elem_id_t *id);
int (*element_read)(snd_ctl_t *handle, snd_ctl_elem_value_t *control);
int (*element_write)(snd_ctl_t *handle, snd_ctl_elem_value_t *control);
int (*element_lock)(snd_ctl_t *handle, snd_ctl_elem_id_t *lock);
int (*element_unlock)(snd_ctl_t *handle, snd_ctl_elem_id_t *unlock);
int (*element_tlv)(snd_ctl_t *handle, int op_flag, unsigned int numid,
unsigned int *tlv, unsigned int tlv_size);
int (*hwdep_next_device)(snd_ctl_t *handle, int *device);
int (*hwdep_info)(snd_ctl_t *handle, snd_hwdep_info_t * info);
int (*pcm_next_device)(snd_ctl_t *handle, int *device);
int (*pcm_info)(snd_ctl_t *handle, snd_pcm_info_t * info);
int (*pcm_prefer_subdevice)(snd_ctl_t *handle, int subdev);
int (*rawmidi_next_device)(snd_ctl_t *handle, int *device);
int (*rawmidi_info)(snd_ctl_t *handle, snd_rawmidi_info_t * info);
int (*rawmidi_prefer_subdevice)(snd_ctl_t *handle, int subdev);
int (*set_power_state)(snd_ctl_t *handle, unsigned int state);
int (*get_power_state)(snd_ctl_t *handle, unsigned int *state);
int (*read)(snd_ctl_t *handle, snd_ctl_event_t *event);
int (*poll_descriptors_count)(snd_ctl_t *handle);
int (*poll_descriptors)(snd_ctl_t *handle, struct pollfd *pfds, unsigned int space);
int (*poll_revents)(snd_ctl_t *handle, struct pollfd *pfds, unsigned int nfds, unsigned short *revents);
} snd_ctl_ops_t;
typedef struct private_snd_ctl {
void *open_func;
char *name;
snd_ctl_type_t type;
const snd_ctl_ops_t *ops;
void *private_data;
int nonblock;
int poll_fd;
void *async_handlers;
} private_snd_ctl_t;
typedef struct {
int card;
int fd;
unsigned int protocol;
} snd_ctl_hw_t;
static int snd_ctl_hw_elem_replace(snd_ctl_t *ctlDev, snd_ctl_elem_info_t *info, snd_ctl_elem_id_t *elemId) {
size_t len=snd_ctl_elem_info_sizeof();
private_snd_ctl_t *handle= (private_snd_ctl_t*) ctlDev;
snd_ctl_hw_t *hw = handle->private_data;
NOTICE ("count=%d ITEMNAME=%s writable=%d owner=%d", snd_ctl_elem_info_get_count(info), snd_ctl_elem_info_get_name(info)
, snd_ctl_elem_info_is_writable(info), snd_ctl_elem_info_get_owner(info));
snd_ctl_elem_lock(ctlDev, elemId);
int err= handle->ops->element_replace (ctlDev, info);
NOTICE ("count=%d ITEMNAME=%s writable=%d isowner=%d islocked=%d innactiv=%d", snd_ctl_elem_info_get_count(info), snd_ctl_elem_info_get_name(info)
, snd_ctl_elem_info_is_writable(info), snd_ctl_elem_info_is_owner(info), snd_ctl_elem_info_is_locked(info), snd_ctl_elem_info_is_inactive(info));
return err;
}
STATIC int addOneSndCtl(afb_req request, snd_ctl_t *ctlDev, json_object *ctlJ) {
int err, ctlExist;
json_object *jTmp;
const char *ctlName;
int ctlNumid, ctlMax, ctlMin, ctlStep, ctlCount, ctlSubDev, ctlSndDev;
snd_ctl_elem_type_t ctlType;
snd_ctl_elem_id_t *elemId;
snd_ctl_elem_info_t *elemInfo;
snd_ctl_elem_value_t *elemValue;
// parse json ctl object
json_object_object_get_ex (ctlJ, "name" , &jTmp);
if (!jTmp) {
afb_req_fail_f (request, "ctl-invalid", "crl=%s name missing", json_object_get_string(ctlJ));
goto OnErrorExit;
}
ctlName = json_object_get_string(jTmp);
// default value when not present => 0
json_object_object_get_ex (ctlJ, "numid" , &jTmp);
ctlNumid = json_object_get_int(jTmp);
// default for json_object_get_int is zero
json_object_object_get_ex (ctlJ, "min" , &jTmp);
ctlMin = json_object_get_int(jTmp);
json_object_object_get_ex (ctlJ, "max" , &jTmp);
if (!jTmp) ctlMax=1;
else ctlMax = json_object_get_int(jTmp);
json_object_object_get_ex (ctlJ, "step" , &jTmp);
if (!jTmp) ctlStep=1;
else ctlStep = json_object_get_int(jTmp);
json_object_object_get_ex (ctlJ, "count" , &jTmp);
if (!jTmp) ctlCount=2;
else ctlCount = json_object_get_int(jTmp);
json_object_object_get_ex (ctlJ, "snddev" , &jTmp);
ctlSndDev = json_object_get_int(jTmp);
json_object_object_get_ex (ctlJ, "subdev" , &jTmp);
ctlSubDev = json_object_get_int(jTmp);
json_object_object_get_ex (ctlJ, "type" , &jTmp);
if (!jTmp) ctlType=SND_CTL_ELEM_TYPE_BOOLEAN;
else ctlType = json_object_get_int(jTmp);
// Add requested ID into elemInfo
snd_ctl_elem_info_alloca(&elemInfo);
snd_ctl_elem_id_alloca(&elemId);
snd_ctl_elem_id_set_numid (elemId, ctlNumid);
snd_ctl_elem_id_set_name (elemId, ctlName);
snd_ctl_elem_id_set_interface(elemId, SND_CTL_ELEM_IFACE_HWDEP);
snd_ctl_elem_id_set_device(elemId, ctlSndDev);
snd_ctl_elem_id_set_subdevice(elemId, ctlSubDev);
// Assert that this ctls is not used
snd_ctl_elem_info_set_id (elemInfo, elemId);
ctlExist= !snd_ctl_elem_info(ctlDev, elemInfo);
if (ctlExist) {
NOTICE ("1:ctl exist ctlName=%s NUMID=%d NAME=%s", ctlName, snd_ctl_elem_info_get_numid(elemInfo), snd_ctl_elem_info_get_name(elemInfo));
snd_ctl_elem_id_set_name (elemId, ctlName);
snd_ctl_elem_info_set_name (elemInfo, ctlName);
err= snd_ctl_hw_elem_replace (ctlDev, elemInfo, elemId);
if (err) {
NOTICE ("Fail changing ctlname error=%s", snd_strerror(err));
}
NOTICE ("2:ctl exist ctlName=%s NUMID=%d NAME=%s", ctlName, snd_ctl_elem_info_get_numid(elemInfo), snd_ctl_elem_info_get_name(elemInfo));
}
// try to normalise ctl name
snd_ctl_elem_value_alloca(&elemValue);
snd_ctl_elem_id_set_name (elemId, ctlName);
snd_ctl_elem_value_set_id(elemValue, elemId);
if (!ctlExist) switch (ctlType) {
case SND_CTL_ELEM_TYPE_BOOLEAN:
err = snd_ctl_add_boolean_elem_set(ctlDev, elemInfo, 1, ctlCount);
if (err) {
afb_req_fail_f (request, "ctl-invalid-bool", "devid=%s crl=%s invalid boolean data", snd_ctl_name(ctlDev), json_object_get_string(ctlJ));
goto OnErrorExit;
}
// Provide FALSE as default value
for (int idx=0; idx < ctlCount; idx ++) {
snd_ctl_elem_value_set_boolean (elemValue, idx, 0);
}
break;
case SND_CTL_ELEM_TYPE_INTEGER:
break;
case SND_CTL_ELEM_TYPE_INTEGER64:
break;
case SND_CTL_ELEM_TYPE_ENUMERATED:
break;
case SND_CTL_ELEM_TYPE_BYTES:
break;
default:
afb_req_fail_f (request, "ctl-invalid-type", "crl=%s invalid/unknown type", json_object_get_string(ctlJ));
goto OnErrorExit;
}
err = snd_ctl_elem_write (ctlDev, elemValue);
if (err < 0) {
afb_req_fail_f (request, "ctl-write-fail", "crl=%s fail to write data data", json_object_get_string(ctlJ));
goto OnErrorExit;
}
return 0;
OnErrorExit:
return -1;
}
PUBLIC void alsaAddCustomCtls(afb_req request) {
int err;
json_object *ctlsJ;
enum json_type;
snd_ctl_t *ctlDev=NULL;
const char *devid;
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;
}
// extract sound controls and parse json
ctlsJ = json_tokener_parse (afb_req_value(request, "ctls"));
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:
addOneSndCtl(request, ctlDev, ctlsJ);
break;
case json_type_array:
for (int idx= 0; idx < json_object_array_length (ctlsJ); idx++) {
json_object *ctlJ = json_object_array_get_idx (ctlsJ, idx);
addOneSndCtl(request, ctlDev, ctlJ) ;
}
break;
default:
afb_req_fail_f (request, "ctls-invalid","ctls=%s not valid JSON array", json_object_get_string(ctlsJ));
goto OnErrorExit;
}
OnErrorExit:
if (ctlDev) snd_ctl_close(ctlDev);
return;
}
|
