xref: /btstack/src/classic/hfp_ag.c (revision d84719b14b724e9967aeab5d871d19d77c4c56ef)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "hfp_ag.c"
39 
40 // *****************************************************************************
41 //
42 // HFP Audio Gateway (AG) unit
43 //
44 // *****************************************************************************
45 
46 #include "btstack_config.h"
47 
48 #include <stdint.h>
49 #include <stdio.h>
50 #include <string.h>
51 
52 #include "hci_cmd.h"
53 #include "btstack_run_loop.h"
54 
55 #include "bluetooth_sdp.h"
56 #include "hci.h"
57 #include "btstack_memory.h"
58 #include "hci_dump.h"
59 #include "l2cap.h"
60 #include "btstack_debug.h"
61 #include "btstack_event.h"
62 #include "classic/core.h"
63 #include "classic/hfp.h"
64 #include "classic/hfp_ag.h"
65 #include "classic/hfp_gsm_model.h"
66 #include "classic/sdp_client_rfcomm.h"
67 #include "classic/sdp_server.h"
68 #include "classic/sdp_util.h"
69 
70 // private prototypes
71 static void hfp_ag_run_for_context(hfp_connection_t *hfp_connection);
72 static void hfp_ag_hf_start_ringing(hfp_connection_t * hfp_connection);
73 static uint8_t hfp_ag_setup_audio_connection(hfp_connection_t * hfp_connection);
74 
75 // public prototypes
76 hfp_generic_status_indicator_t * get_hfp_generic_status_indicators(void);
77 int get_hfp_generic_status_indicators_nr(void);
78 void set_hfp_generic_status_indicators(hfp_generic_status_indicator_t * indicators, int indicator_nr);
79 void set_hfp_ag_indicators(hfp_ag_indicator_t * indicators, int indicator_nr);
80 int get_hfp_ag_indicators_nr(hfp_connection_t * context);
81 hfp_ag_indicator_t * get_hfp_ag_indicators(hfp_connection_t * context);
82 
83 
84 // const
85 static const char default_hfp_ag_service_name[] = "Voice gateway";
86 
87 // globals
88 static btstack_packet_callback_registration_t hfp_ag_hci_event_callback_registration;
89 
90 static uint16_t hfp_supported_features;
91 
92 static uint8_t hfp_codecs_nr;
93 static uint8_t hfp_codecs[HFP_MAX_NUM_CODECS];
94 
95 static int  hfp_ag_indicators_nr;
96 static hfp_ag_indicator_t hfp_ag_indicators[HFP_MAX_NUM_INDICATORS];
97 
98 static int hfp_generic_status_indicators_nr;
99 static hfp_generic_status_indicator_t hfp_generic_status_indicators[HFP_MAX_NUM_INDICATORS];
100 
101 static int  hfp_ag_call_hold_services_nr;
102 static char *hfp_ag_call_hold_services[6];
103 static btstack_packet_handler_t hfp_ag_callback;
104 
105 static hfp_response_and_hold_state_t hfp_ag_response_and_hold_state;
106 static int hfp_ag_response_and_hold_active;
107 
108 // Subscriber information entries
109 static hfp_phone_number_t * subscriber_numbers;
110 static int subscriber_numbers_count;
111 
112 // code
113 static int hfp_ag_get_ag_indicators_nr(hfp_connection_t * hfp_connection){
114     if (hfp_connection->ag_indicators_nr != hfp_ag_indicators_nr){
115         hfp_connection->ag_indicators_nr = hfp_ag_indicators_nr;
116         (void)memcpy(hfp_connection->ag_indicators, hfp_ag_indicators,
117                      hfp_ag_indicators_nr * sizeof(hfp_ag_indicator_t));
118     }
119     return hfp_connection->ag_indicators_nr;
120 }
121 
122 hfp_ag_indicator_t * hfp_ag_get_ag_indicators(hfp_connection_t * hfp_connection){
123     // TODO: save only value, and value changed in the hfp_connection?
124     if (hfp_connection->ag_indicators_nr != hfp_ag_indicators_nr){
125         hfp_connection->ag_indicators_nr = hfp_ag_indicators_nr;
126         (void)memcpy(hfp_connection->ag_indicators, hfp_ag_indicators,
127                      hfp_ag_indicators_nr * sizeof(hfp_ag_indicator_t));
128     }
129     return (hfp_ag_indicator_t *)&(hfp_connection->ag_indicators);
130 }
131 
132 static hfp_ag_indicator_t * get_ag_indicator_for_name(const char * name){
133     int i;
134     for (i = 0; i < hfp_ag_indicators_nr; i++){
135         if (strcmp(hfp_ag_indicators[i].name, name) == 0){
136             return &hfp_ag_indicators[i];
137         }
138     }
139     return NULL;
140 }
141 
142 static int get_ag_indicator_index_for_name(const char * name){
143     int i;
144     for (i = 0; i < hfp_ag_indicators_nr; i++){
145         if (strcmp(hfp_ag_indicators[i].name, name) == 0){
146             return i;
147         }
148     }
149     return -1;
150 }
151 
152 static hfp_connection_t * get_hfp_ag_connection_context_for_acl_handle(uint16_t handle){
153     btstack_linked_list_iterator_t it;
154     btstack_linked_list_iterator_init(&it, hfp_get_connections());
155     while (btstack_linked_list_iterator_has_next(&it)){
156         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
157         if (hfp_connection->acl_handle != handle)      continue;
158         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
159         return hfp_connection;
160     }
161     return NULL;
162 }
163 
164 static int use_in_band_tone(void){
165     return get_bit(hfp_supported_features, HFP_AGSF_IN_BAND_RING_TONE);
166 }
167 
168 static int has_codec_negotiation_feature(hfp_connection_t * hfp_connection){
169     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_CODEC_NEGOTIATION);
170     int ag = get_bit(hfp_supported_features, HFP_AGSF_CODEC_NEGOTIATION);
171     return hf && ag;
172 }
173 
174 static int has_call_waiting_and_3way_calling_feature(hfp_connection_t * hfp_connection){
175     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_THREE_WAY_CALLING);
176     int ag = get_bit(hfp_supported_features, HFP_AGSF_THREE_WAY_CALLING);
177     return hf && ag;
178 }
179 
180 static int has_hf_indicators_feature(hfp_connection_t * hfp_connection){
181     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_HF_INDICATORS);
182     int ag = get_bit(hfp_supported_features, HFP_AGSF_HF_INDICATORS);
183     return hf && ag;
184 }
185 
186 /* unsolicited responses */
187 
188 static int hfp_ag_send_change_in_band_ring_tone_setting_cmd(uint16_t cid){
189     char buffer[20];
190     snprintf(buffer, sizeof(buffer), "\r\n%s: %d\r\n",
191              HFP_CHANGE_IN_BAND_RING_TONE_SETTING, use_in_band_tone());
192     buffer[sizeof(buffer) - 1] = 0;
193     return send_str_over_rfcomm(cid, buffer);
194 }
195 
196 static int hfp_ag_exchange_supported_features_cmd(uint16_t cid){
197     char buffer[40];
198     snprintf(buffer, sizeof(buffer), "\r\n%s:%d\r\n\r\nOK\r\n",
199              HFP_SUPPORTED_FEATURES, hfp_supported_features);
200     buffer[sizeof(buffer) - 1] = 0;
201     return send_str_over_rfcomm(cid, buffer);
202 }
203 
204 static int hfp_ag_send_ok(uint16_t cid){
205     char buffer[10];
206     snprintf(buffer, sizeof(buffer), "\r\nOK\r\n");
207     buffer[sizeof(buffer) - 1] = 0;
208     return send_str_over_rfcomm(cid, buffer);
209 }
210 
211 static int hfp_ag_send_ring(uint16_t cid){
212     return send_str_over_rfcomm(cid, (char *) "\r\nRING\r\n");
213 }
214 
215 static int hfp_ag_send_no_carrier(uint16_t cid){
216     char buffer[15];
217     snprintf(buffer, sizeof(buffer), "\r\nNO CARRIER\r\n");
218     buffer[sizeof(buffer) - 1] = 0;
219     return send_str_over_rfcomm(cid, buffer);
220 }
221 
222 static int hfp_ag_send_clip(uint16_t cid){
223     char buffer[50];
224     snprintf(buffer, sizeof(buffer), "\r\n%s: \"%s\",%u\r\n", HFP_ENABLE_CLIP,
225              hfp_gsm_clip_number(), hfp_gsm_clip_type());
226     buffer[sizeof(buffer) - 1] = 0;
227     return send_str_over_rfcomm(cid, buffer);
228 }
229 
230 static int hfp_send_subscriber_number_cmd(uint16_t cid, uint8_t type, const char * number){
231     char buffer[50];
232     snprintf(buffer, sizeof(buffer), "\r\n%s: ,\"%s\",%u, , \r\n",
233              HFP_SUBSCRIBER_NUMBER_INFORMATION, number, type);
234     buffer[sizeof(buffer) - 1] = 0;
235     return send_str_over_rfcomm(cid, buffer);
236 }
237 
238 static int hfp_ag_send_phone_number_for_voice_tag_cmd(uint16_t cid){
239     char buffer[50];
240     snprintf(buffer, sizeof(buffer), "\r\n%s: %s\r\n",
241              HFP_PHONE_NUMBER_FOR_VOICE_TAG, hfp_gsm_clip_number());
242     buffer[sizeof(buffer) - 1] = 0;
243     return send_str_over_rfcomm(cid, buffer);
244 }
245 
246 static int hfp_ag_send_call_waiting_notification(uint16_t cid){
247     char buffer[50];
248     snprintf(buffer, sizeof(buffer), "\r\n%s: \"%s\",%u\r\n",
249              HFP_ENABLE_CALL_WAITING_NOTIFICATION, hfp_gsm_clip_number(),
250              hfp_gsm_clip_type());
251     buffer[sizeof(buffer) - 1] = 0;
252     return send_str_over_rfcomm(cid, buffer);
253 }
254 
255 static int hfp_ag_send_error(uint16_t cid){
256     char buffer[10];
257     snprintf(buffer, sizeof(buffer), "\r\nERROR\r\n");
258     buffer[sizeof(buffer) - 1] = 0;
259     return send_str_over_rfcomm(cid, buffer);
260 }
261 
262 static int hfp_ag_send_report_extended_audio_gateway_error(uint16_t cid, uint8_t error){
263     char buffer[20];
264     snprintf(buffer, sizeof(buffer), "\r\n%s=%d\r\n",
265              HFP_EXTENDED_AUDIO_GATEWAY_ERROR, error);
266     buffer[sizeof(buffer) - 1] = 0;
267     return send_str_over_rfcomm(cid, buffer);
268 }
269 
270 // get size for indicator string
271 static int hfp_ag_indicators_string_size(hfp_connection_t * hfp_connection, int i){
272     // template: ("$NAME",($MIN,$MAX))
273     return 8 + (int) strlen(hfp_ag_get_ag_indicators(hfp_connection)[i].name)
274          + string_len_for_uint32(hfp_ag_get_ag_indicators(hfp_connection)[i].min_range)
275          + string_len_for_uint32(hfp_ag_get_ag_indicators(hfp_connection)[i].min_range);
276 }
277 
278 // store indicator
279 static void hfp_ag_indicators_string_store(hfp_connection_t * hfp_connection, int i, uint8_t * buffer, uint16_t buffer_size){
280     snprintf((char *)buffer, buffer_size, "(\"%s\",(%d,%d)),",
281              hfp_ag_get_ag_indicators(hfp_connection)[i].name,
282              hfp_ag_get_ag_indicators(hfp_connection)[i].min_range,
283              hfp_ag_get_ag_indicators(hfp_connection)[i].max_range);
284     ((char *)buffer)[buffer_size - 1] = 0;
285 }
286 
287 // structure: header [indicator [comma indicator]] footer
288 static int hfp_ag_indicators_cmd_generator_num_segments(hfp_connection_t * hfp_connection){
289     int num_indicators = hfp_ag_get_ag_indicators_nr(hfp_connection);
290     if (!num_indicators) return 2;
291     return 3 + ((num_indicators-1) * 2);
292 }
293 
294 // get size of individual segment for hfp_ag_retrieve_indicators_cmd
295 static int hfp_ag_indicators_cmd_generator_get_segment_len(hfp_connection_t * hfp_connection, int index){
296     if (index == 0) {
297         return strlen(HFP_INDICATOR) + 3;   // "\n\r%s:""
298     }
299     index--;
300     int num_indicators = hfp_ag_get_ag_indicators_nr(hfp_connection);
301     int indicator_index = index >> 1;
302     if ((index & 1) == 0){
303         return hfp_ag_indicators_string_size(hfp_connection, indicator_index);
304     }
305     if (indicator_index == (num_indicators - 1)){
306         return 8; // "\r\n\r\nOK\r\n"
307     }
308     return 1; // comma
309 }
310 
311 static void hfp_ag_indicators_cmd_generator_store_segment(hfp_connection_t * hfp_connection, int index, uint8_t * buffer, uint16_t buffer_size){
312     if (index == 0){
313         *buffer++ = '\r';
314         *buffer++ = '\n';
315         int len = strlen(HFP_INDICATOR);
316         (void)memcpy(buffer, HFP_INDICATOR, len);
317         buffer += len;
318         *buffer++ = ':';
319         return;
320     }
321     index--;
322     int num_indicators = hfp_ag_get_ag_indicators_nr(hfp_connection);
323     int indicator_index = index >> 1;
324     if ((index & 1) == 0){
325         hfp_ag_indicators_string_store(hfp_connection, indicator_index, buffer, buffer_size);
326         return;
327     }
328     if (indicator_index == (num_indicators-1)){
329         (void)memcpy(buffer, "\r\n\r\nOK\r\n", 8);
330         return;
331     }
332     *buffer = ',';
333 }
334 
335 static int hfp_hf_indicators_join(char * buffer, int buffer_size){
336     if (buffer_size < (hfp_ag_indicators_nr * 3)) return 0;
337     int i;
338     int offset = 0;
339     for (i = 0; i < (hfp_generic_status_indicators_nr-1); i++) {
340         offset += snprintf(buffer+offset, buffer_size-offset, "%d,", hfp_generic_status_indicators[i].uuid);
341     }
342     if (i < hfp_generic_status_indicators_nr){
343         offset += snprintf(buffer+offset, buffer_size-offset, "%d", hfp_generic_status_indicators[i].uuid);
344     }
345     return offset;
346 }
347 
348 static int hfp_hf_indicators_initial_status_join(char * buffer, int buffer_size){
349     if (buffer_size < (hfp_generic_status_indicators_nr * 3)) return 0;
350     int i;
351     int offset = 0;
352     for (i = 0; i < hfp_generic_status_indicators_nr; i++) {
353         offset += snprintf(buffer+offset, buffer_size-offset, "\r\n%s:%d,%d\r\n", HFP_GENERIC_STATUS_INDICATOR, hfp_generic_status_indicators[i].uuid, hfp_generic_status_indicators[i].state);
354     }
355     return offset;
356 }
357 
358 static int hfp_ag_indicators_status_join(char * buffer, int buffer_size){
359     if (buffer_size < (hfp_ag_indicators_nr * 3)) return 0;
360     int i;
361     int offset = 0;
362     for (i = 0; i < (hfp_ag_indicators_nr-1); i++) {
363         offset += snprintf(buffer+offset, buffer_size-offset, "%d,", hfp_ag_indicators[i].status);
364     }
365     if (i<hfp_ag_indicators_nr){
366         offset += snprintf(buffer+offset, buffer_size-offset, "%d", hfp_ag_indicators[i].status);
367     }
368     return offset;
369 }
370 
371 static int hfp_ag_call_services_join(char * buffer, int buffer_size){
372     if (buffer_size < (hfp_ag_call_hold_services_nr * 3)) return 0;
373     int i;
374     int offset = snprintf(buffer, buffer_size, "(");
375     for (i = 0; i < (hfp_ag_call_hold_services_nr-1); i++) {
376         offset += snprintf(buffer+offset, buffer_size-offset, "%s,", hfp_ag_call_hold_services[i]);
377     }
378     if (i<hfp_ag_call_hold_services_nr){
379         offset += snprintf(buffer+offset, buffer_size-offset, "%s)", hfp_ag_call_hold_services[i]);
380     }
381     return offset;
382 }
383 
384 static int hfp_ag_send_cmd_via_generator(uint16_t cid, hfp_connection_t * hfp_connection,
385     int start_segment, int num_segments,
386     int (*get_segment_len)(hfp_connection_t * hfp_connection, int segment),
387     void (*store_segment) (hfp_connection_t * hfp_connection, int segment, uint8_t * buffer, uint16_t buffer_size)){
388 
389     // assumes: can send now == true
390     // assumes: num segments > 0
391     // assumes: individual segments are smaller than MTU
392     rfcomm_reserve_packet_buffer();
393     int mtu = rfcomm_get_max_frame_size(cid);
394     uint8_t * data = rfcomm_get_outgoing_buffer();
395     int offset = 0;
396     int segment = start_segment;
397     while (segment < num_segments){
398         int segment_len = get_segment_len(hfp_connection, segment);
399         if ((offset + segment_len + 1) > mtu) break;
400         // append segment. As it appends a '\0', we provide a buffer one byte larger
401         store_segment(hfp_connection, segment, data+offset, segment_len + 1);
402         offset += segment_len;
403         segment++;
404     }
405     rfcomm_send_prepared(cid, offset);
406 #ifdef ENABLE_HFP_AT_MESSAGES
407     hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_AT_MESSAGE_SENT, (char *) data);
408 #endif
409     return segment;
410 }
411 
412 // returns next segment to store
413 static int hfp_ag_send_retrieve_indicators_cmd_via_generator(uint16_t cid, hfp_connection_t * hfp_connection, int start_segment){
414     int num_segments = hfp_ag_indicators_cmd_generator_num_segments(hfp_connection);
415     return hfp_ag_send_cmd_via_generator(cid, hfp_connection, start_segment, num_segments,
416                                          hfp_ag_indicators_cmd_generator_get_segment_len,
417                                          hfp_ag_indicators_cmd_generator_store_segment);
418 }
419 
420 static int hfp_ag_send_retrieve_indicators_status_cmd(uint16_t cid){
421     char buffer[40];
422     const int size = sizeof(buffer);
423     int offset = snprintf(buffer, size, "\r\n%s:", HFP_INDICATOR);
424     offset += hfp_ag_indicators_status_join(buffer+offset, size-offset-9);
425     offset += snprintf(buffer+offset, size-offset, "\r\n\r\nOK\r\n");
426     return send_str_over_rfcomm(cid, buffer);
427 }
428 
429 static int hfp_ag_send_retrieve_can_hold_call_cmd(uint16_t cid){
430     char buffer[40];
431     const int size = sizeof(buffer);
432     int offset = snprintf(buffer, size, "\r\n%s:", HFP_SUPPORT_CALL_HOLD_AND_MULTIPARTY_SERVICES);
433     offset += hfp_ag_call_services_join(buffer+offset, size-offset-9);
434     offset += snprintf(buffer+offset, size-offset, "\r\n\r\nOK\r\n");
435     return send_str_over_rfcomm(cid, buffer);
436 }
437 
438 
439 static int hfp_ag_send_list_supported_generic_status_indicators_cmd(uint16_t cid){
440     return hfp_ag_send_ok(cid);
441 }
442 
443 static int hfp_ag_send_retrieve_supported_generic_status_indicators_cmd(uint16_t cid){
444     char buffer[40];
445     const int size = sizeof(buffer);
446     int offset = snprintf(buffer, size, "\r\n%s:(", HFP_GENERIC_STATUS_INDICATOR);
447     offset += hfp_hf_indicators_join(buffer+offset, size-offset-10);
448     offset += snprintf(buffer+offset, size-offset, ")\r\n\r\nOK\r\n");
449     return send_str_over_rfcomm(cid, buffer);
450 }
451 
452 static int hfp_ag_send_retrieve_initital_supported_generic_status_indicators_cmd(uint16_t cid){
453     char buffer[40];
454     int offset = hfp_hf_indicators_initial_status_join(buffer, sizeof(buffer) - 7);
455     snprintf(buffer+offset, sizeof(buffer)-offset, "\r\nOK\r\n");
456     return send_str_over_rfcomm(cid, buffer);
457 }
458 
459 static int hfp_ag_send_transfer_ag_indicators_status_cmd(uint16_t cid, hfp_ag_indicator_t * indicator){
460     char buffer[20];
461     snprintf(buffer, sizeof(buffer), "\r\n%s:%d,%d\r\n",
462              HFP_TRANSFER_AG_INDICATOR_STATUS, indicator->index,
463              indicator->status);
464     buffer[sizeof(buffer) - 1] = 0;
465     return send_str_over_rfcomm(cid, buffer);
466 }
467 
468 static int hfp_ag_send_report_network_operator_name_cmd(uint16_t cid, hfp_network_opearator_t op){
469     char buffer[41];
470     if (strlen(op.name) == 0){
471         snprintf(buffer, sizeof(buffer), "\r\n%s:%d,,\r\n\r\nOK\r\n", HFP_QUERY_OPERATOR_SELECTION, op.mode);
472     } else {
473         int offset = snprintf(buffer,  sizeof(buffer), "\r\n%s:%d,%d,", HFP_QUERY_OPERATOR_SELECTION, op.mode, op.format);
474         offset += snprintf(buffer+offset, 16, "%s", op.name);
475         snprintf(buffer+offset, sizeof(buffer)-offset, "\r\n\r\nOK\r\n");
476     }
477     return send_str_over_rfcomm(cid, buffer);
478 }
479 
480 static inline int hfp_ag_send_cmd_with_space_and_int(uint16_t cid, const char * cmd, uint8_t value){
481     char buffer[30];
482     snprintf(buffer, sizeof(buffer), "\r\n%s: %d\r\n", cmd, value);
483     return send_str_over_rfcomm(cid, buffer);
484 }
485 
486 
487 static inline int hfp_ag_send_cmd_with_int(uint16_t cid, const char * cmd, uint8_t value){
488     char buffer[30];
489     snprintf(buffer, sizeof(buffer), "\r\n%s:%d\r\n", cmd, value);
490     return send_str_over_rfcomm(cid, buffer);
491 }
492 
493 static int hfp_ag_send_suggest_codec_cmd(uint16_t cid, uint8_t codec){
494     return hfp_ag_send_cmd_with_int(cid, HFP_CONFIRM_COMMON_CODEC, codec);
495 }
496 
497 static int hfp_ag_send_activate_voice_recognition_cmd(uint16_t cid, uint8_t activate_voice_recognition){
498     return hfp_ag_send_cmd_with_space_and_int(cid, HFP_ACTIVATE_VOICE_RECOGNITION, activate_voice_recognition);
499 }
500 
501 static int hfp_ag_send_set_speaker_gain_cmd(uint16_t cid, uint8_t gain){
502     return hfp_ag_send_cmd_with_int(cid, HFP_SET_SPEAKER_GAIN, gain);
503 }
504 
505 static int hfp_ag_send_set_microphone_gain_cmd(uint16_t cid, uint8_t gain){
506     return hfp_ag_send_cmd_with_int(cid, HFP_SET_MICROPHONE_GAIN, gain);
507 }
508 
509 static int hfp_ag_send_set_response_and_hold(uint16_t cid, int state){
510     return hfp_ag_send_cmd_with_space_and_int(cid, HFP_RESPONSE_AND_HOLD, state);
511 }
512 
513 static int hfp_ag_send_enhanced_voice_recognition_cmd(uint16_t cid, uint8_t status, uint8_t state){
514     char buffer[30];
515     snprintf(buffer, sizeof(buffer), "\r\n%s: %d,%d\r\n", HFP_ACTIVATE_VOICE_RECOGNITION, status, state);
516     return send_str_over_rfcomm(cid, buffer);
517 }
518 
519 static int hfp_ag_send_enhanced_voice_recognition_msg_cmd(hfp_connection_t *hfp_connection){
520     char buffer[100];
521     snprintf(buffer, sizeof(buffer), "\r\n%s: 1,%d,%X,%d,%d,\"%s\"\r\n", HFP_ACTIVATE_VOICE_RECOGNITION,
522         hfp_connection->ag_vra_state,
523         hfp_connection->ag_msg.text_id,
524         hfp_connection->ag_msg.text_type,
525         hfp_connection->ag_msg.text_operation,
526         hfp_connection->ag_msg.text);
527     return send_str_over_rfcomm(hfp_connection->rfcomm_cid, buffer);
528 }
529 
530 static uint8_t hfp_ag_suggest_codec(hfp_connection_t *hfp_connection){
531     if (hfp_connection->sco_for_msbc_failed) return HFP_CODEC_CVSD;
532 
533     if (hfp_supports_codec(HFP_CODEC_MSBC, hfp_codecs_nr, hfp_codecs)){
534         if (hfp_supports_codec(HFP_CODEC_MSBC, hfp_connection->remote_codecs_nr, hfp_connection->remote_codecs)){
535             return HFP_CODEC_MSBC;
536         }
537     }
538     return HFP_CODEC_CVSD;
539 }
540 
541 /* state machines */
542 
543 static uint8_t hfp_ag_esco_s4_supported(hfp_connection_t * hfp_connection){
544     return (hfp_connection->remote_supported_features & (1<<HFP_HFSF_ESCO_S4)) &&  (hfp_supported_features  & (1<<HFP_AGSF_ESCO_S4));
545 }
546 
547 static int codecs_exchange_state_machine(hfp_connection_t * hfp_connection){
548     /* events ( == commands):
549         HFP_CMD_AVAILABLE_CODECS == received AT+BAC with list of codecs
550         HFP_CMD_TRIGGER_CODEC_CONNECTION_SETUP:
551             hf_trigger_codec_connection_setup == received BCC
552             ag_trigger_codec_connection_setup == received from AG to send BCS
553         HFP_CMD_HF_CONFIRMED_CODEC == received AT+BCS
554     */
555     switch (hfp_connection->codecs_state){
556         case HFP_CODECS_EXCHANGED:
557             if (hfp_connection->command == HFP_CMD_AVAILABLE_CODECS){
558                 hfp_ag_send_ok(hfp_connection->rfcomm_cid);
559                 return 1;
560             }
561             break;
562 
563         case HFP_CODECS_RECEIVED_TRIGGER_CODEC_EXCHANGE:
564             hfp_connection->command = HFP_CMD_AG_SEND_COMMON_CODEC;
565             break;
566         case HFP_CODECS_AG_RESEND_COMMON_CODEC:
567             hfp_connection->command = HFP_CMD_AG_SEND_COMMON_CODEC;
568             break;
569         default:
570             break;
571     }
572 
573     switch (hfp_connection->command){
574         case HFP_CMD_AVAILABLE_CODECS:
575             if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED){
576                 hfp_connection->codecs_state = HFP_CODECS_RECEIVED_LIST;
577                 hfp_ag_send_ok(hfp_connection->rfcomm_cid);
578                 return 1;
579             }
580 
581             switch (hfp_connection->codecs_state){
582                 case HFP_CODECS_AG_SENT_COMMON_CODEC:
583                     hfp_connection->codecs_state = HFP_CODECS_AG_RESEND_COMMON_CODEC;
584                     break;
585                 default:
586                     break;
587             }
588             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
589             return 1;
590 
591         case HFP_CMD_TRIGGER_CODEC_CONNECTION_SETUP:
592             hfp_connection->codecs_state = HFP_CODECS_RECEIVED_TRIGGER_CODEC_EXCHANGE;
593             hfp_connection->establish_audio_connection = 1;
594             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
595             return 1;
596 
597         case HFP_CMD_AG_SEND_COMMON_CODEC:
598             hfp_connection->codecs_state = HFP_CODECS_AG_SENT_COMMON_CODEC;
599             hfp_connection->suggested_codec = hfp_ag_suggest_codec(hfp_connection);
600             hfp_ag_send_suggest_codec_cmd(hfp_connection->rfcomm_cid, hfp_connection->suggested_codec);
601             return 1;
602 
603         case HFP_CMD_HF_CONFIRMED_CODEC:
604             if (hfp_connection->codec_confirmed != hfp_connection->suggested_codec){
605                 hfp_connection->codecs_state = HFP_CODECS_ERROR;
606                 hfp_ag_send_error(hfp_connection->rfcomm_cid);
607                 return 1;
608             }
609             hfp_connection->negotiated_codec = hfp_connection->codec_confirmed;
610             hfp_connection->codecs_state = HFP_CODECS_EXCHANGED;
611             log_info("hfp: codec confirmed: %s", (hfp_connection->negotiated_codec == HFP_CODEC_MSBC) ? "mSBC" : "CVSD");
612             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
613             // now, pick link settings
614             hfp_init_link_settings(hfp_connection, hfp_ag_esco_s4_supported(hfp_connection));
615 #ifdef ENABLE_CC256X_ASSISTED_HFP
616             hfp_cc256x_prepare_for_sco(hfp_connection);
617 #endif
618             return 1;
619         default:
620             break;
621     }
622     return 0;
623 }
624 
625 static void hfp_ag_slc_established(hfp_connection_t * hfp_connection){
626     hfp_connection->state = HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED;
627     hfp_emit_slc_connection_event(hfp_connection, 0, hfp_connection->acl_handle, hfp_connection->remote_addr);
628 
629     // if active call exist, set per-hfp_connection state active, too (when audio is on)
630     if (hfp_gsm_call_status() == HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT){
631         hfp_connection->call_state = HFP_CALL_W4_AUDIO_CONNECTION_FOR_ACTIVE;
632     }
633     // if AG is ringing, also start ringing on the HF
634     if ((hfp_gsm_call_status() == HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS) &&
635         (hfp_gsm_callsetup_status() == HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS)){
636         hfp_ag_hf_start_ringing(hfp_connection);
637     }
638 }
639 
640 static int hfp_ag_run_for_context_service_level_connection(hfp_connection_t * hfp_connection){
641     // log_info("hfp_ag_run_for_context_service_level_connection state %u, command %u", hfp_connection->state, hfp_connection->command);
642     if (hfp_connection->state >= HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED) return 0;
643     int sent = 0;
644     switch(hfp_connection->command){
645         case HFP_CMD_SUPPORTED_FEATURES:
646             switch(hfp_connection->state){
647                 case HFP_W4_EXCHANGE_SUPPORTED_FEATURES:
648                 case HFP_EXCHANGE_SUPPORTED_FEATURES:
649                     hfp_hf_drop_mSBC_if_eSCO_not_supported(hfp_codecs, &hfp_codecs_nr);
650                     if (has_codec_negotiation_feature(hfp_connection)){
651                         hfp_connection->state = HFP_W4_NOTIFY_ON_CODECS;
652                     } else {
653                         hfp_connection->state = HFP_W4_RETRIEVE_INDICATORS;
654                     }
655                     hfp_ag_exchange_supported_features_cmd(hfp_connection->rfcomm_cid);
656                     return 1;
657                 default:
658                     break;
659             }
660             break;
661         case HFP_CMD_AVAILABLE_CODECS:
662             sent = codecs_exchange_state_machine(hfp_connection);
663             if (hfp_connection->codecs_state == HFP_CODECS_RECEIVED_LIST){
664                 hfp_connection->state = HFP_W4_RETRIEVE_INDICATORS;
665             }
666             return sent;
667 
668         case HFP_CMD_RETRIEVE_AG_INDICATORS:
669             if (hfp_connection->state == HFP_W4_RETRIEVE_INDICATORS) {
670                 // HF requested AG Indicators and we did expect it
671                 hfp_connection->send_ag_indicators_segment = 0;
672                 hfp_connection->state = HFP_RETRIEVE_INDICATORS;
673                 // continue below in state switch
674             }
675             break;
676 
677         case HFP_CMD_RETRIEVE_AG_INDICATORS_STATUS:
678             if (hfp_connection->state != HFP_W4_RETRIEVE_INDICATORS_STATUS) break;
679             hfp_connection->state = HFP_W4_ENABLE_INDICATORS_STATUS_UPDATE;
680             hfp_ag_send_retrieve_indicators_status_cmd(hfp_connection->rfcomm_cid);
681             return 1;
682 
683         case HFP_CMD_ENABLE_INDICATOR_STATUS_UPDATE:
684             if (hfp_connection->state != HFP_W4_ENABLE_INDICATORS_STATUS_UPDATE) break;
685             if (has_call_waiting_and_3way_calling_feature(hfp_connection)){
686                 hfp_connection->state = HFP_W4_RETRIEVE_CAN_HOLD_CALL;
687             } else if (has_hf_indicators_feature(hfp_connection)){
688                 hfp_connection->state = HFP_W4_LIST_GENERIC_STATUS_INDICATORS;
689             } else {
690                 hfp_ag_slc_established(hfp_connection);
691             }
692             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
693             return 1;
694 
695         case HFP_CMD_SUPPORT_CALL_HOLD_AND_MULTIPARTY_SERVICES:
696             if (hfp_connection->state != HFP_W4_RETRIEVE_CAN_HOLD_CALL) break;
697             if (has_hf_indicators_feature(hfp_connection)){
698                 hfp_connection->state = HFP_W4_LIST_GENERIC_STATUS_INDICATORS;
699             }
700             hfp_ag_send_retrieve_can_hold_call_cmd(hfp_connection->rfcomm_cid);
701             if (!has_hf_indicators_feature(hfp_connection)){
702                 hfp_ag_slc_established(hfp_connection);
703             }
704             return 1;
705 
706         case HFP_CMD_LIST_GENERIC_STATUS_INDICATORS:
707             if (hfp_connection->state != HFP_W4_LIST_GENERIC_STATUS_INDICATORS) break;
708             hfp_connection->state = HFP_W4_RETRIEVE_GENERIC_STATUS_INDICATORS;
709             hfp_ag_send_list_supported_generic_status_indicators_cmd(hfp_connection->rfcomm_cid);
710             return 1;
711 
712         case HFP_CMD_RETRIEVE_GENERIC_STATUS_INDICATORS:
713             if (hfp_connection->state != HFP_W4_RETRIEVE_GENERIC_STATUS_INDICATORS) break;
714             hfp_connection->state = HFP_W4_RETRIEVE_INITITAL_STATE_GENERIC_STATUS_INDICATORS;
715             hfp_ag_send_retrieve_supported_generic_status_indicators_cmd(hfp_connection->rfcomm_cid);
716             return 1;
717 
718         case HFP_CMD_RETRIEVE_GENERIC_STATUS_INDICATORS_STATE:
719             if (hfp_connection->state != HFP_W4_RETRIEVE_INITITAL_STATE_GENERIC_STATUS_INDICATORS) break;
720             hfp_ag_slc_established(hfp_connection);
721             hfp_ag_send_retrieve_initital_supported_generic_status_indicators_cmd(hfp_connection->rfcomm_cid);
722             return 1;
723         default:
724             break;
725     }
726 
727     switch (hfp_connection->state){
728         case HFP_RETRIEVE_INDICATORS: {
729             int next_segment = hfp_ag_send_retrieve_indicators_cmd_via_generator(hfp_connection->rfcomm_cid, hfp_connection, hfp_connection->send_ag_indicators_segment);
730             int num_segments = hfp_ag_indicators_cmd_generator_num_segments(hfp_connection);
731             log_info("HFP_CMD_RETRIEVE_AG_INDICATORS next segment %u, num_segments %u", next_segment, num_segments);
732             if (next_segment < num_segments){
733                 // prepare sending of next segment
734                 hfp_connection->send_ag_indicators_segment = next_segment;
735                 log_info("HFP_CMD_RETRIEVE_AG_INDICATORS more. command %u, next seg %u", hfp_connection->command, next_segment);
736             } else {
737                 // done, go to next state
738                 hfp_connection->send_ag_indicators_segment = 0;
739                 hfp_connection->state = HFP_W4_RETRIEVE_INDICATORS_STATUS;
740             }
741             return 1;
742         }
743         default:
744             break;
745     }
746     return 0;
747 }
748 
749 static bool hfp_ag_voice_recognition_supported(hfp_connection_t * hfp_connection){
750     int ag = get_bit(hfp_supported_features, HFP_AGSF_VOICE_RECOGNITION_FUNCTION);
751     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_VOICE_RECOGNITION_FUNCTION);
752     return hf && ag;
753 }
754 
755 static uint8_t hfp_ag_activate_voice_recognition_for_connection(hfp_connection_t * hfp_connection){
756     if (!hfp_ag_voice_recognition_supported(hfp_connection)){
757         return ERROR_CODE_COMMAND_DISALLOWED;
758     }
759     if (hfp_connection->vra_status != HFP_VRA_VOICE_RECOGNITION_OFF){
760         return ERROR_CODE_COMMAND_DISALLOWED;
761     }
762 
763     hfp_connection->command = HFP_CMD_AG_ACTIVATE_VOICE_RECOGNITION;
764     hfp_connection->vra_status = HFP_VRA_W4_VOICE_RECOGNITION_ACTIVATED;
765     return ERROR_CODE_SUCCESS;
766 }
767 
768 static uint8_t hfp_ag_deactivate_voice_recognition_for_connection(hfp_connection_t * hfp_connection){
769     if (!hfp_ag_voice_recognition_supported(hfp_connection)){
770         return ERROR_CODE_COMMAND_DISALLOWED;
771     }
772     if (hfp_connection->vra_status != HFP_VRA_VOICE_RECOGNITION_ACTIVATED){
773         return ERROR_CODE_COMMAND_DISALLOWED;
774     }
775     hfp_connection->command = HFP_CMD_AG_ACTIVATE_VOICE_RECOGNITION;
776     hfp_connection->vra_status = HFP_VRA_W4_VOICE_RECOGNITION_OFF;
777     return ERROR_CODE_SUCCESS;
778 }
779 static int hfp_ag_run_for_context_service_level_connection_queries(hfp_connection_t * hfp_connection){
780     int sent = codecs_exchange_state_machine(hfp_connection);
781     if (sent) return 1;
782 
783     switch(hfp_connection->command){
784 
785         case HFP_CMD_AG_ACTIVATE_ENHANCED_VOICE_RECOGNITION:
786             switch (hfp_connection->ag_vra_status){
787                 case HFP_VRA_W4_ENHANCED_VOICE_RECOGNITION_ACTIVATED:
788                     hfp_connection->ag_vra_status = HFP_VRA_ENHANCED_VOICE_RECOGNITION_ACTIVATED;
789                     hfp_ag_send_enhanced_voice_recognition_cmd(hfp_connection->rfcomm_cid, 1, hfp_connection->ag_vra_state);
790                     hfp_ag_setup_audio_connection(hfp_connection);
791                     break;
792                 case HFP_VRA_W4_ENHANCED_VOICE_RECOGNITION_STATUS:
793                     hfp_connection->ag_vra_status = HFP_VRA_ENHANCED_VOICE_RECOGNITION_ACTIVATED;
794                     hfp_ag_send_enhanced_voice_recognition_cmd(hfp_connection->rfcomm_cid, 1, hfp_connection->ag_vra_state);
795                     break;
796                 case HFP_VRA_W4_ENHANCED_VOICE_RECOGNITION_OFF:
797                     hfp_connection->ag_vra_status = HFP_VRA_VOICE_RECOGNITION_OFF;
798                     hfp_ag_send_enhanced_voice_recognition_cmd(hfp_connection->rfcomm_cid, 0, hfp_connection->ag_vra_state);
799                     hfp_trigger_release_audio_connection(hfp_connection);
800                     break;
801                 case HFP_VRA_W4_ENHANCED_VOICE_RECOGNITION_MSG:
802                     hfp_connection->ag_vra_status = HFP_VRA_ENHANCED_VOICE_RECOGNITION_ACTIVATED;
803                     hfp_ag_send_enhanced_voice_recognition_msg_cmd(hfp_connection);
804                     break;
805                 default:
806                     return 0;
807             }
808             return 1;
809 
810         case HFP_CMD_HF_ACTIVATE_VOICE_RECOGNITION:
811 
812             if (get_bit(hfp_supported_features, HFP_AGSF_VOICE_RECOGNITION_FUNCTION)){
813                 hfp_ag_send_ok(hfp_connection->rfcomm_cid);
814             } else {
815                 switch (hfp_connection->ag_vra_status){
816                     case HFP_VRA_ENHANCED_VOICE_RECOGNITION_ACTIVATED:
817                         hfp_ag_send_ok(hfp_connection->rfcomm_cid);
818                         break;
819                     default:
820                         hfp_ag_send_error(hfp_connection->rfcomm_cid);
821                         break;
822                 }
823             }
824             return 1;
825         case HFP_CMD_CHANGE_IN_BAND_RING_TONE_SETTING:
826             hfp_ag_send_change_in_band_ring_tone_setting_cmd(hfp_connection->rfcomm_cid);
827             return 1;
828         case HFP_CMD_QUERY_OPERATOR_SELECTION_NAME:
829             hfp_ag_send_report_network_operator_name_cmd(hfp_connection->rfcomm_cid, hfp_connection->network_operator);
830             return 1;
831         case HFP_CMD_QUERY_OPERATOR_SELECTION_NAME_FORMAT:
832             if (hfp_connection->network_operator.format != 0){
833                 hfp_ag_send_error(hfp_connection->rfcomm_cid);
834             } else {
835                 hfp_ag_send_ok(hfp_connection->rfcomm_cid);
836             }
837             return 1;
838         case HFP_CMD_ENABLE_INDIVIDUAL_AG_INDICATOR_STATUS_UPDATE:
839             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
840             return 1;
841         case HFP_CMD_ENABLE_EXTENDED_AUDIO_GATEWAY_ERROR:
842             if (hfp_connection->extended_audio_gateway_error){
843                 hfp_connection->extended_audio_gateway_error = 0;
844                 hfp_ag_send_report_extended_audio_gateway_error(hfp_connection->rfcomm_cid, hfp_connection->extended_audio_gateway_error_value);
845                 return 1;
846             }
847             break;
848         case HFP_CMD_ENABLE_INDICATOR_STATUS_UPDATE:
849             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
850             return 1;
851         default:
852             break;
853     }
854     return 0;
855 }
856 
857 static int hfp_ag_run_for_audio_connection(hfp_connection_t * hfp_connection){
858     if ((hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED) ||
859         (hfp_connection->state > HFP_W2_DISCONNECT_SCO)) return 0;
860 
861     if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED) return 0;
862 
863     // accept incoming audio connection (codec negotiation is not used)
864     if (hfp_connection->accept_sco){
865         // notify about codec selection if not done already
866         if (hfp_connection->negotiated_codec == 0){
867             hfp_connection->negotiated_codec = HFP_CODEC_CVSD;
868         }
869         //
870         bool incoming_eSCO = hfp_connection->accept_sco == 2;
871         hfp_connection->accept_sco = 0;
872         hfp_connection->state = HFP_W4_SCO_CONNECTED;
873         hfp_accept_synchronous_connection(hfp_connection, incoming_eSCO);
874         return 1;
875     }
876 
877     // run codecs exchange
878     int sent = codecs_exchange_state_machine(hfp_connection);
879     if (sent) return 1;
880 
881     if (hfp_connection->codecs_state != HFP_CODECS_EXCHANGED) return 0;
882     if (hfp_connection->establish_audio_connection){
883         hfp_connection->state = HFP_W4_SCO_CONNECTED;
884         hfp_connection->establish_audio_connection = 0;
885         hfp_setup_synchronous_connection(hfp_connection);
886         return 1;
887     }
888     return 0;
889 }
890 
891 static hfp_connection_t * hfp_ag_context_for_timer(btstack_timer_source_t * ts){
892     btstack_linked_list_iterator_t it;
893     btstack_linked_list_iterator_init(&it, hfp_get_connections());
894 
895     while (btstack_linked_list_iterator_has_next(&it)){
896         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
897         if ( & hfp_connection->hfp_timeout == ts) {
898             return hfp_connection;
899         }
900     }
901     return NULL;
902 }
903 
904 static void hfp_timeout_handler(btstack_timer_source_t * timer){
905     hfp_connection_t * hfp_connection = hfp_ag_context_for_timer(timer);
906     if (!hfp_connection) return;
907 
908     log_info("HFP start ring timeout, con handle 0x%02x", hfp_connection->acl_handle);
909     hfp_connection->ag_ring = 1;
910     hfp_connection->ag_send_clip = hfp_gsm_clip_type() && hfp_connection->clip_enabled;
911 
912     btstack_run_loop_set_timer(& hfp_connection->hfp_timeout, 2000); // 2 seconds timeout
913     btstack_run_loop_add_timer(& hfp_connection->hfp_timeout);
914 
915     hfp_ag_run_for_context(hfp_connection);
916 }
917 
918 static void hfp_timeout_start(hfp_connection_t * hfp_connection){
919     btstack_run_loop_remove_timer(& hfp_connection->hfp_timeout);
920     btstack_run_loop_set_timer_handler(& hfp_connection->hfp_timeout, hfp_timeout_handler);
921     btstack_run_loop_set_timer(& hfp_connection->hfp_timeout, 2000); // 2 seconds timeout
922     btstack_run_loop_add_timer(& hfp_connection->hfp_timeout);
923 }
924 
925 static void hfp_timeout_stop(hfp_connection_t * hfp_connection){
926     log_info("HFP stop ring timeout, con handle 0x%02x", hfp_connection->acl_handle);
927     btstack_run_loop_remove_timer(& hfp_connection->hfp_timeout);
928 }
929 
930 static void hfp_ag_set_callsetup_indicator(void){
931     hfp_ag_indicator_t * indicator = get_ag_indicator_for_name("callsetup");
932     if (!indicator){
933         log_error("hfp_ag_set_callsetup_indicator: callsetup indicator is missing");
934         return;
935     };
936     indicator->status = hfp_gsm_callsetup_status();
937 }
938 
939 static void hfp_ag_set_callheld_indicator(void){
940     hfp_ag_indicator_t * indicator = get_ag_indicator_for_name("callheld");
941     if (!indicator){
942         log_error("hfp_ag_set_callheld_state: callheld indicator is missing");
943         return;
944     };
945     indicator->status = hfp_gsm_callheld_status();
946 }
947 
948 //
949 // transitition implementations for hfp_ag_call_state_machine
950 //
951 
952 static void hfp_ag_hf_start_ringing(hfp_connection_t * hfp_connection){
953     if (use_in_band_tone()){
954         hfp_connection->call_state = HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING;
955         hfp_ag_establish_audio_connection(hfp_connection->acl_handle);
956     } else {
957         hfp_timeout_start(hfp_connection);
958         hfp_connection->ag_ring = 1;
959         hfp_connection->ag_send_clip = hfp_gsm_clip_type() && hfp_connection->clip_enabled;
960         hfp_connection->call_state = HFP_CALL_RINGING;
961         hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_START_RINGINIG);
962     }
963 }
964 
965 static void hfp_ag_hf_stop_ringing(hfp_connection_t * hfp_connection){
966     hfp_connection->ag_ring = 0;
967     hfp_connection->ag_send_clip = 0;
968     hfp_timeout_stop(hfp_connection);
969     hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_STOP_RINGINIG);
970 }
971 
972 static void hfp_ag_trigger_incoming_call(void){
973     int indicator_index = get_ag_indicator_index_for_name("callsetup");
974     if (indicator_index < 0) return;
975 
976     btstack_linked_list_iterator_t it;
977     btstack_linked_list_iterator_init(&it, hfp_get_connections());
978     while (btstack_linked_list_iterator_has_next(&it)){
979         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
980         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
981         hfp_ag_establish_service_level_connection(hfp_connection->remote_addr);
982         if (hfp_connection->call_state == HFP_CALL_IDLE){
983             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
984             hfp_ag_hf_start_ringing(hfp_connection);
985         }
986         if (hfp_connection->call_state == HFP_CALL_ACTIVE){
987             hfp_connection->call_state = HFP_CALL_W2_SEND_CALL_WAITING;
988         }
989         hfp_ag_run_for_context(hfp_connection);
990     }
991 }
992 
993 static void hfp_ag_trigger_outgoing_call(void){
994     btstack_linked_list_iterator_t it;
995     btstack_linked_list_iterator_init(&it, hfp_get_connections());
996     while (btstack_linked_list_iterator_has_next(&it)){
997         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
998         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
999         hfp_ag_establish_service_level_connection(hfp_connection->remote_addr);
1000         if (hfp_connection->call_state == HFP_CALL_IDLE){
1001             hfp_connection->call_state = HFP_CALL_OUTGOING_INITIATED;
1002         }
1003     }
1004 }
1005 
1006 static void hfp_ag_handle_outgoing_call_accepted(hfp_connection_t * hfp_connection){
1007     hfp_connection->call_state = HFP_CALL_OUTGOING_DIALING;
1008 
1009     // trigger callsetup to be
1010     int put_call_on_hold = hfp_gsm_call_status() == HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT;
1011     hfp_gsm_handler(HFP_AG_OUTGOING_CALL_ACCEPTED, 0, 0, NULL);
1012 
1013     int indicator_index ;
1014 
1015     hfp_ag_set_callsetup_indicator();
1016     indicator_index = get_ag_indicator_index_for_name("callsetup");
1017     hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
1018 
1019     // put current call on hold if active
1020     if (put_call_on_hold){
1021         log_info("AG putting current call on hold for new outgoing call");
1022         hfp_ag_set_callheld_indicator();
1023         indicator_index = get_ag_indicator_index_for_name("callheld");
1024         hfp_ag_send_transfer_ag_indicators_status_cmd(hfp_connection->rfcomm_cid, &hfp_ag_indicators[indicator_index]);
1025     }
1026 
1027     // start audio if needed
1028     hfp_ag_establish_audio_connection(hfp_connection->acl_handle);
1029 }
1030 
1031 static void hfp_ag_transfer_indicator(const char * name){
1032     int indicator_index = get_ag_indicator_index_for_name(name);
1033     if (indicator_index < 0) return;
1034 
1035     btstack_linked_list_iterator_t it;
1036     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1037     while (btstack_linked_list_iterator_has_next(&it)){
1038         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1039         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1040         hfp_ag_establish_service_level_connection(hfp_connection->remote_addr);
1041         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
1042         hfp_ag_run_for_context(hfp_connection);
1043     }
1044 }
1045 
1046 static void hfp_ag_transfer_callsetup_state(void){
1047     hfp_ag_transfer_indicator("callsetup");
1048 }
1049 
1050 static void hfp_ag_transfer_call_state(void){
1051     hfp_ag_transfer_indicator("call");
1052 }
1053 
1054 static void hfp_ag_transfer_callheld_state(void){
1055     hfp_ag_transfer_indicator("callheld");
1056 }
1057 
1058 static void hfp_ag_hf_accept_call(hfp_connection_t * source){
1059     int call_indicator_index = get_ag_indicator_index_for_name("call");
1060     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
1061 
1062     btstack_linked_list_iterator_t it;
1063     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1064     while (btstack_linked_list_iterator_has_next(&it)){
1065         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1066         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1067         if ((hfp_connection->call_state != HFP_CALL_RINGING) &&
1068             (hfp_connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING)) continue;
1069 
1070         hfp_ag_hf_stop_ringing(hfp_connection);
1071         if (hfp_connection == source){
1072 
1073             if (use_in_band_tone()){
1074                 hfp_connection->call_state = HFP_CALL_ACTIVE;
1075             } else {
1076                 hfp_connection->call_state = HFP_CALL_W4_AUDIO_CONNECTION_FOR_ACTIVE;
1077                 hfp_ag_establish_audio_connection(hfp_connection->acl_handle);
1078             }
1079 
1080             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
1081             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1082 
1083         } else {
1084             hfp_connection->call_state = HFP_CALL_IDLE;
1085         }
1086         hfp_ag_run_for_context(hfp_connection);
1087     }
1088 }
1089 
1090 static void hfp_ag_ag_accept_call(void){
1091     int call_indicator_index = get_ag_indicator_index_for_name("call");
1092     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
1093 
1094     btstack_linked_list_iterator_t it;
1095     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1096     while (btstack_linked_list_iterator_has_next(&it)){
1097         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1098         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1099         if (hfp_connection->call_state != HFP_CALL_RINGING) continue;
1100 
1101         hfp_ag_hf_stop_ringing(hfp_connection);
1102         hfp_connection->call_state = HFP_CALL_TRIGGER_AUDIO_CONNECTION;
1103 
1104         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
1105         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1106 
1107         hfp_ag_run_for_context(hfp_connection);
1108         break;  // only single
1109     }
1110 }
1111 
1112 static void hfp_ag_trigger_reject_call(void){
1113     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
1114     btstack_linked_list_iterator_t it;
1115     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1116     while (btstack_linked_list_iterator_has_next(&it)){
1117         hfp_connection_t * connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1118         if (connection->local_role != HFP_ROLE_AG) continue;
1119         if ((connection->call_state != HFP_CALL_RINGING) &&
1120             (connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING)) continue;
1121         hfp_ag_hf_stop_ringing(connection);
1122         connection->ag_indicators_status_update_bitmap = store_bit(connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1123         connection->call_state = HFP_CALL_IDLE;
1124         hfp_ag_run_for_context(connection);
1125     }
1126 }
1127 
1128 static void hfp_ag_trigger_terminate_call(void){
1129     int call_indicator_index = get_ag_indicator_index_for_name("call");
1130 
1131     btstack_linked_list_iterator_t it;
1132     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1133     while (btstack_linked_list_iterator_has_next(&it)){
1134         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1135         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1136         hfp_ag_establish_service_level_connection(hfp_connection->remote_addr);
1137         if (hfp_connection->call_state == HFP_CALL_IDLE) continue;
1138         hfp_connection->call_state = HFP_CALL_IDLE;
1139         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
1140         if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED){
1141             hfp_connection->release_audio_connection = 1;
1142         }
1143         hfp_ag_run_for_context(hfp_connection);
1144     }
1145     hfp_emit_simple_event(NULL, HFP_SUBEVENT_CALL_TERMINATED);
1146 }
1147 
1148 static void hfp_ag_set_call_indicator(void){
1149     hfp_ag_indicator_t * indicator = get_ag_indicator_for_name("call");
1150     if (!indicator){
1151         log_error("hfp_ag_set_call_state: call indicator is missing");
1152         return;
1153     };
1154     indicator->status = hfp_gsm_call_status();
1155 }
1156 
1157 static void hfp_ag_stop_ringing(void){
1158     btstack_linked_list_iterator_t it;
1159     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1160     while (btstack_linked_list_iterator_has_next(&it)){
1161         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1162         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1163         if ((hfp_connection->call_state != HFP_CALL_RINGING) &&
1164             (hfp_connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING)) continue;
1165         hfp_ag_hf_stop_ringing(hfp_connection);
1166     }
1167 }
1168 
1169 static hfp_connection_t * hfp_ag_connection_for_call_state(hfp_call_state_t call_state){
1170     btstack_linked_list_iterator_t it;
1171     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1172     while (btstack_linked_list_iterator_has_next(&it)){
1173         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1174         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1175         if (hfp_connection->call_state == call_state) return hfp_connection;
1176     }
1177     return NULL;
1178 }
1179 
1180 static void hfp_ag_send_response_and_hold_state(hfp_response_and_hold_state_t state){
1181     btstack_linked_list_iterator_t it;
1182     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1183     while (btstack_linked_list_iterator_has_next(&it)){
1184         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1185         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1186         hfp_connection->send_response_and_hold_status = state + 1;
1187     }
1188 }
1189 
1190 static int call_setup_state_machine(hfp_connection_t * hfp_connection){
1191     int indicator_index;
1192     switch (hfp_connection->call_state){
1193         case HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING:
1194             if (hfp_connection->state != HFP_AUDIO_CONNECTION_ESTABLISHED) return 0;
1195             // we got event: audio hfp_connection established
1196             hfp_timeout_start(hfp_connection);
1197             hfp_connection->ag_ring = 1;
1198             hfp_connection->ag_send_clip = hfp_gsm_clip_type() && hfp_connection->clip_enabled;
1199             hfp_connection->call_state = HFP_CALL_RINGING;
1200             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_START_RINGINIG);
1201             break;
1202         case HFP_CALL_W4_AUDIO_CONNECTION_FOR_ACTIVE:
1203             if (hfp_connection->state != HFP_AUDIO_CONNECTION_ESTABLISHED) return 0;
1204             // we got event: audio hfp_connection established
1205             hfp_connection->call_state = HFP_CALL_ACTIVE;
1206             break;
1207         case HFP_CALL_W2_SEND_CALL_WAITING:
1208             hfp_connection->call_state = HFP_CALL_W4_CHLD;
1209             hfp_ag_send_call_waiting_notification(hfp_connection->rfcomm_cid);
1210             indicator_index = get_ag_indicator_index_for_name("callsetup");
1211             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
1212             break;
1213         default:
1214             break;
1215     }
1216     return 0;
1217 }
1218 
1219 // functions extracted from hfp_ag_call_sm below
1220 static void hfp_ag_handle_reject_outgoing_call(void){
1221     hfp_connection_t * hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_INITIATED);
1222     if (!hfp_connection){
1223         log_info("hfp_ag_call_sm: did not find outgoing hfp_connection in initiated state");
1224         return;
1225     }
1226 
1227     hfp_gsm_handler(HFP_AG_OUTGOING_CALL_REJECTED, 0, 0, NULL);
1228     hfp_connection->call_state = HFP_CALL_IDLE;
1229     hfp_connection->send_error = 1;
1230     hfp_ag_run_for_context(hfp_connection);
1231 }
1232 
1233 // hfp_connection is used to identify originating HF
1234 static void hfp_ag_call_sm(hfp_ag_call_event_t event, hfp_connection_t * hfp_connection){
1235     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
1236     int callheld_indicator_index = get_ag_indicator_index_for_name("callheld");
1237     int call_indicator_index = get_ag_indicator_index_for_name("call");
1238 
1239     switch (event){
1240         case HFP_AG_INCOMING_CALL:
1241             switch (hfp_gsm_call_status()){
1242                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1243                     switch (hfp_gsm_callsetup_status()){
1244                         case HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS:
1245                             hfp_gsm_handler(HFP_AG_INCOMING_CALL, 0, 0, NULL);
1246                             hfp_ag_set_callsetup_indicator();
1247                             hfp_ag_trigger_incoming_call();
1248                             log_info("AG rings");
1249                             break;
1250                         default:
1251                             break;
1252                     }
1253                     break;
1254                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1255                     switch (hfp_gsm_callsetup_status()){
1256                         case HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS:
1257                             hfp_gsm_handler(HFP_AG_INCOMING_CALL, 0, 0, NULL);
1258                             hfp_ag_set_callsetup_indicator();
1259                             hfp_ag_trigger_incoming_call();
1260                             log_info("AG call waiting");
1261                             break;
1262                         default:
1263                             break;
1264                     }
1265                     break;
1266                 default:
1267                     break;
1268             }
1269             break;
1270         case HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG:
1271             switch (hfp_gsm_call_status()){
1272                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1273                     switch (hfp_gsm_callsetup_status()){
1274                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1275                             hfp_gsm_handler(HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG, 0, 0, NULL);
1276                             hfp_ag_set_call_indicator();
1277                             hfp_ag_set_callsetup_indicator();
1278                             hfp_ag_ag_accept_call();
1279                             log_info("AG answers call, accept call by GSM");
1280                             break;
1281                         default:
1282                             break;
1283                     }
1284                     break;
1285                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1286                     switch (hfp_gsm_callsetup_status()){
1287                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1288                             log_info("AG: current call is placed on hold, incoming call gets active");
1289                             hfp_gsm_handler(HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG, 0, 0, NULL);
1290                             hfp_ag_set_callsetup_indicator();
1291                             hfp_ag_set_callheld_indicator();
1292                             hfp_ag_transfer_callsetup_state();
1293                             hfp_ag_transfer_callheld_state();
1294                             break;
1295                         default:
1296                             break;
1297                     }
1298                     break;
1299                 default:
1300                     break;
1301             }
1302             break;
1303 
1304         case HFP_AG_HELD_CALL_JOINED_BY_AG:
1305             switch (hfp_gsm_call_status()){
1306                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1307                     switch (hfp_gsm_callheld_status()){
1308                         case HFP_CALLHELD_STATUS_CALL_ON_HOLD_OR_SWAPPED:
1309                             log_info("AG: joining held call with active call");
1310                             hfp_gsm_handler(HFP_AG_HELD_CALL_JOINED_BY_AG, 0, 0, NULL);
1311                             hfp_ag_set_callheld_indicator();
1312                             hfp_ag_transfer_callheld_state();
1313                             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CONFERENCE_CALL);
1314                             break;
1315                         default:
1316                             break;
1317                     }
1318                     break;
1319                 default:
1320                     break;
1321             }
1322             break;
1323 
1324         case HFP_AG_INCOMING_CALL_ACCEPTED_BY_HF:
1325             switch (hfp_gsm_call_status()){
1326                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1327                     switch (hfp_gsm_callsetup_status()){
1328                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1329                             hfp_gsm_handler(HFP_AG_INCOMING_CALL_ACCEPTED_BY_HF, 0, 0, NULL);
1330                             hfp_ag_set_callsetup_indicator();
1331                             hfp_ag_set_call_indicator();
1332                             hfp_ag_hf_accept_call(hfp_connection);
1333                             hfp_connection->ok_pending = 1;
1334                             log_info("HF answers call, accept call by GSM");
1335                             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CALL_ANSWERED);
1336                             break;
1337                         default:
1338                             break;
1339                     }
1340                     break;
1341                 default:
1342                     break;
1343             }
1344             break;
1345 
1346         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_AG:
1347             switch (hfp_gsm_call_status()){
1348                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1349                     switch (hfp_gsm_callsetup_status()){
1350                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1351                             hfp_gsm_handler(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_AG, 0, 0, NULL);
1352                             hfp_ag_response_and_hold_active = 1;
1353                             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD;
1354                             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1355                             // as with regular call
1356                             hfp_ag_set_call_indicator();
1357                             hfp_ag_set_callsetup_indicator();
1358                             hfp_ag_ag_accept_call();
1359                             log_info("AG response and hold - hold by AG");
1360                             break;
1361                         default:
1362                             break;
1363                     }
1364                     break;
1365                 default:
1366                     break;
1367             }
1368             break;
1369 
1370         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_HF:
1371             switch (hfp_gsm_call_status()){
1372                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1373                     switch (hfp_gsm_callsetup_status()){
1374                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1375                             hfp_gsm_handler(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_HF, 0, 0, NULL);
1376                             hfp_ag_response_and_hold_active = 1;
1377                             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD;
1378                             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1379                             // as with regular call
1380                             hfp_ag_set_call_indicator();
1381                             hfp_ag_set_callsetup_indicator();
1382                             hfp_ag_hf_accept_call(hfp_connection);
1383                             log_info("AG response and hold - hold by HF");
1384                             break;
1385                         default:
1386                             break;
1387                     }
1388                     break;
1389                 default:
1390                     break;
1391             }
1392             break;
1393 
1394         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_AG:
1395         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_HF:
1396             if (!hfp_ag_response_and_hold_active) break;
1397             if (hfp_ag_response_and_hold_state != HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD) break;
1398             hfp_gsm_handler(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_AG, 0, 0, NULL);
1399             hfp_ag_response_and_hold_active = 0;
1400             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_HELD_INCOMING_ACCEPTED;
1401             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1402             log_info("Held Call accepted and active");
1403             break;
1404 
1405         case HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_AG:
1406         case HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_HF:
1407             if (!hfp_ag_response_and_hold_active) break;
1408             if (hfp_ag_response_and_hold_state != HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD) break;
1409             hfp_gsm_handler(HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_AG, 0, 0, NULL);
1410             hfp_ag_response_and_hold_active = 0;
1411             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_HELD_INCOMING_REJECTED;
1412             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1413             // from terminate by ag
1414             hfp_ag_set_call_indicator();
1415             hfp_ag_trigger_terminate_call();
1416             break;
1417 
1418         case HFP_AG_TERMINATE_CALL_BY_HF:
1419             switch (hfp_gsm_call_status()){
1420                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1421                     switch (hfp_gsm_callsetup_status()){
1422                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1423                             hfp_gsm_handler(HFP_AG_TERMINATE_CALL_BY_HF, 0, 0, NULL);
1424                             hfp_ag_set_callsetup_indicator();
1425                             hfp_ag_transfer_callsetup_state();
1426                             hfp_ag_trigger_reject_call();
1427                             log_info("HF Rejected Incoming call, AG terminate call");
1428                             break;
1429                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_DIALING_STATE:
1430                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_ALERTING_STATE:
1431                             hfp_gsm_handler(HFP_AG_TERMINATE_CALL_BY_HF, 0, 0, NULL);
1432                             hfp_ag_set_callsetup_indicator();
1433                             hfp_ag_transfer_callsetup_state();
1434                             log_info("AG terminate outgoing call process");
1435                             break;
1436                         default:
1437                             break;
1438                     }
1439                     break;
1440                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1441                     hfp_gsm_handler(HFP_AG_TERMINATE_CALL_BY_HF, 0, 0, NULL);
1442                     hfp_ag_set_callsetup_indicator();
1443                     hfp_ag_set_call_indicator();
1444                     hfp_ag_trigger_terminate_call();
1445                     log_info("AG terminate call");
1446                     break;
1447                 default:
1448                     break;
1449             }
1450             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CALL_TERMINATED);
1451             break;
1452 
1453         case HFP_AG_TERMINATE_CALL_BY_AG:
1454             switch (hfp_gsm_call_status()){
1455                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1456                     switch (hfp_gsm_callsetup_status()){
1457                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1458                             hfp_gsm_handler(HFP_AG_TERMINATE_CALL_BY_AG, 0, 0, NULL);
1459                             hfp_ag_set_callsetup_indicator();
1460                             hfp_ag_trigger_reject_call();
1461                             log_info("AG Rejected Incoming call, AG terminate call");
1462                             break;
1463                         default:
1464                             break;
1465                     }
1466                     break;
1467                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1468                     hfp_gsm_handler(HFP_AG_TERMINATE_CALL_BY_AG, 0, 0, NULL);
1469                     hfp_ag_set_callsetup_indicator();
1470                     hfp_ag_set_call_indicator();
1471                     hfp_ag_trigger_terminate_call();
1472                     log_info("AG terminate call");
1473                     break;
1474                 default:
1475                     break;
1476             }
1477             break;
1478         case HFP_AG_CALL_DROPPED:
1479             switch (hfp_gsm_call_status()){
1480                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1481                     switch (hfp_gsm_callsetup_status()){
1482                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1483                             hfp_ag_stop_ringing();
1484                             log_info("Incoming call interrupted");
1485                             break;
1486                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_DIALING_STATE:
1487                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_ALERTING_STATE:
1488                             log_info("Outgoing call interrupted\n");
1489                             log_info("AG notify call dropped\n");
1490                             break;
1491                         default:
1492                             break;
1493                     }
1494                     hfp_gsm_handler(HFP_AG_CALL_DROPPED, 0, 0, NULL);
1495                     hfp_ag_set_callsetup_indicator();
1496                     hfp_ag_transfer_callsetup_state();
1497                     hfp_ag_trigger_terminate_call();
1498                     break;
1499                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1500                     if (hfp_ag_response_and_hold_active) {
1501                         hfp_gsm_handler(HFP_AG_CALL_DROPPED, 0, 0, NULL);
1502                         hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_HELD_INCOMING_REJECTED;
1503                         hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1504                     }
1505                     hfp_gsm_handler(HFP_AG_CALL_DROPPED, 0, 0, NULL);
1506                     hfp_ag_set_callsetup_indicator();
1507                     hfp_ag_set_call_indicator();
1508                     hfp_ag_trigger_terminate_call();
1509                     log_info("AG notify call dropped");
1510                     break;
1511                 default:
1512                     break;
1513             }
1514             break;
1515 
1516         case HFP_AG_OUTGOING_CALL_INITIATED_BY_HF:
1517             // directly reject call if number of free slots is exceeded
1518             if (!hfp_gsm_call_possible()){
1519                 hfp_connection->send_error = 1;
1520                 hfp_ag_run_for_context(hfp_connection);
1521                 break;
1522             }
1523 
1524             // note: number not used currently
1525             hfp_gsm_handler(HFP_AG_OUTGOING_CALL_INITIATED_BY_HF, 0, 0, (const char *) &hfp_connection->line_buffer[3]);
1526 
1527             hfp_connection->call_state = HFP_CALL_OUTGOING_INITIATED;
1528 
1529             hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_PLACE_CALL_WITH_NUMBER, (const char *) &hfp_connection->line_buffer[3]);
1530             break;
1531 
1532         case HFP_AG_OUTGOING_CALL_INITIATED_BY_AG:
1533             // directly reject call if number of free slots is exceeded
1534             if (!hfp_gsm_call_possible()) {
1535                 // TODO: no error for user
1536                 break;
1537             }
1538             switch (hfp_gsm_call_status()) {
1539                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1540                     switch (hfp_gsm_callsetup_status()) {
1541                         case HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS:
1542                             // note: number not used currently
1543                             hfp_gsm_handler(HFP_AG_OUTGOING_CALL_INITIATED_BY_AG, 0, 0, "1234567");
1544                             // init call state for all connections
1545                             hfp_ag_trigger_outgoing_call();
1546                             // get first one and accept call
1547                             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_INITIATED);
1548                             if (hfp_connection) {
1549                                 hfp_ag_handle_outgoing_call_accepted(hfp_connection);
1550                             }
1551                             break;
1552                         default:
1553                             // TODO: no error for user
1554                             break;
1555                     }
1556                     break;
1557                 default:
1558                     // TODO: no error for user
1559                     break;
1560             }
1561             break;
1562         case HFP_AG_OUTGOING_REDIAL_INITIATED:{
1563             // directly reject call if number of free slots is exceeded
1564             if (!hfp_gsm_call_possible()){
1565                 hfp_connection->send_error = 1;
1566                 hfp_ag_run_for_context(hfp_connection);
1567                 break;
1568             }
1569 
1570             hfp_gsm_handler(HFP_AG_OUTGOING_REDIAL_INITIATED, 0, 0, NULL);
1571             hfp_connection->call_state = HFP_CALL_OUTGOING_INITIATED;
1572 
1573             log_info("Redial last number");
1574             char * last_dialed_number = hfp_gsm_last_dialed_number();
1575 
1576             if (strlen(last_dialed_number) > 0){
1577                 log_info("Last number exists: accept call");
1578                 hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_PLACE_CALL_WITH_NUMBER, last_dialed_number);
1579             } else {
1580                 log_info("log_infoLast number missing: reject call");
1581                 hfp_ag_handle_reject_outgoing_call();
1582             }
1583             break;
1584         }
1585         case HFP_AG_OUTGOING_CALL_REJECTED:
1586             hfp_ag_handle_reject_outgoing_call();
1587             break;
1588 
1589         case HFP_AG_OUTGOING_CALL_ACCEPTED:{
1590             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_INITIATED);
1591             if (!hfp_connection){
1592                 log_info("hfp_ag_call_sm: did not find outgoing hfp_connection in initiated state");
1593                 break;
1594             }
1595 
1596             hfp_connection->ok_pending = 1;
1597             hfp_ag_handle_outgoing_call_accepted(hfp_connection);
1598             break;
1599         }
1600         case HFP_AG_OUTGOING_CALL_RINGING:
1601             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_DIALING);
1602             if (!hfp_connection){
1603                 log_info("hfp_ag_call_sm: did not find outgoing hfp_connection in dialing state");
1604                 break;
1605             }
1606 
1607             hfp_gsm_handler(HFP_AG_OUTGOING_CALL_RINGING, 0, 0, NULL);
1608             hfp_connection->call_state = HFP_CALL_OUTGOING_RINGING;
1609             hfp_ag_set_callsetup_indicator();
1610             hfp_ag_transfer_callsetup_state();
1611             break;
1612 
1613         case HFP_AG_OUTGOING_CALL_ESTABLISHED:{
1614             // get outgoing call
1615             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_RINGING);
1616             if (!hfp_connection){
1617                 hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_DIALING);
1618             }
1619             if (!hfp_connection){
1620                 log_info("hfp_ag_call_sm: did not find outgoing hfp_connection");
1621                 break;
1622             }
1623 
1624             int CALLHELD_STATUS_CALL_ON_HOLD_AND_NO_ACTIVE_CALLS = hfp_gsm_callheld_status() == HFP_CALLHELD_STATUS_CALL_ON_HOLD_AND_NO_ACTIVE_CALLS;
1625             hfp_gsm_handler(HFP_AG_OUTGOING_CALL_ESTABLISHED, 0, 0, NULL);
1626             hfp_connection->call_state = HFP_CALL_ACTIVE;
1627             hfp_ag_set_callsetup_indicator();
1628             hfp_ag_set_call_indicator();
1629             hfp_ag_transfer_call_state();
1630             hfp_ag_transfer_callsetup_state();
1631             if (CALLHELD_STATUS_CALL_ON_HOLD_AND_NO_ACTIVE_CALLS){
1632                 hfp_ag_set_callheld_indicator();
1633                 hfp_ag_transfer_callheld_state();
1634             }
1635             break;
1636         }
1637 
1638         case HFP_AG_CALL_HOLD_USER_BUSY:
1639             hfp_gsm_handler(HFP_AG_CALL_HOLD_USER_BUSY, 0, 0, NULL);
1640             hfp_ag_set_callsetup_indicator();
1641             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1642             hfp_connection->call_state = HFP_CALL_ACTIVE;
1643             log_info("AG: Call Waiting, User Busy");
1644             break;
1645 
1646         case HFP_AG_CALL_HOLD_RELEASE_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL:{
1647             int call_setup_in_progress = hfp_gsm_callsetup_status() != HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS;
1648             int call_held = hfp_gsm_callheld_status() != HFP_CALLHELD_STATUS_NO_CALLS_HELD;
1649 
1650             // Releases all active calls (if any exist) and accepts the other (held or waiting) call.
1651             if (call_held || call_setup_in_progress){
1652                 hfp_gsm_handler(HFP_AG_CALL_HOLD_RELEASE_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection->call_index,
1653                                 0, NULL);
1654 
1655             }
1656 
1657             if (call_setup_in_progress){
1658                 log_info("AG: Call Dropped, Accept new call");
1659                 hfp_ag_set_callsetup_indicator();
1660                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1661             } else {
1662                 log_info("AG: Call Dropped, Resume held call");
1663             }
1664             if (call_held){
1665                 hfp_ag_set_callheld_indicator();
1666                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
1667             }
1668 
1669             hfp_connection->call_state = HFP_CALL_ACTIVE;
1670             break;
1671         }
1672 
1673         case HFP_AG_CALL_HOLD_PARK_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL:{
1674             // Places all active calls (if any exist) on hold and accepts the other (held or waiting) call.
1675             // only update if callsetup changed
1676             int call_setup_in_progress = hfp_gsm_callsetup_status() != HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS;
1677             hfp_gsm_handler(HFP_AG_CALL_HOLD_PARK_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection->call_index, 0,
1678                             NULL);
1679 
1680             if (call_setup_in_progress){
1681                 log_info("AG: Call on Hold, Accept new call");
1682                 hfp_ag_set_callsetup_indicator();
1683                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1684             } else {
1685                 log_info("AG: Swap calls");
1686             }
1687 
1688             hfp_ag_set_callheld_indicator();
1689             // hfp_ag_set_callheld_state(HFP_CALLHELD_STATUS_CALL_ON_HOLD_OR_SWAPPED);
1690             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
1691             hfp_connection->call_state = HFP_CALL_ACTIVE;
1692             break;
1693         }
1694 
1695         case HFP_AG_CALL_HOLD_ADD_HELD_CALL:
1696             // Adds a held call to the conversation.
1697             if (hfp_gsm_callheld_status() != HFP_CALLHELD_STATUS_NO_CALLS_HELD){
1698                 log_info("AG: Join 3-way-call");
1699                 hfp_gsm_handler(HFP_AG_CALL_HOLD_ADD_HELD_CALL, 0, 0, NULL);
1700                 hfp_ag_set_callheld_indicator();
1701                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
1702                 hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CONFERENCE_CALL);
1703             }
1704             hfp_connection->call_state = HFP_CALL_ACTIVE;
1705             break;
1706         case HFP_AG_CALL_HOLD_EXIT_AND_JOIN_CALLS:
1707             // Connects the two calls and disconnects the subscriber from both calls (Explicit Call Transfer)
1708             hfp_gsm_handler(HFP_AG_CALL_HOLD_EXIT_AND_JOIN_CALLS, 0, 0, NULL);
1709             log_info("AG: Transfer call -> Connect two calls and disconnect");
1710             hfp_ag_set_call_indicator();
1711             hfp_ag_set_callheld_indicator();
1712             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
1713             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
1714             hfp_connection->call_state = HFP_CALL_IDLE;
1715             break;
1716 
1717         default:
1718             break;
1719     }
1720 
1721 
1722 }
1723 
1724 
1725 static void hfp_ag_send_call_status(hfp_connection_t * hfp_connection, int call_index){
1726     hfp_gsm_call_t * active_call = hfp_gsm_call(call_index);
1727     if (!active_call) return;
1728 
1729     int idx = active_call->index;
1730     hfp_enhanced_call_dir_t dir = active_call->direction;
1731     hfp_enhanced_call_status_t status = active_call->enhanced_status;
1732     hfp_enhanced_call_mode_t mode = active_call->mode;
1733     hfp_enhanced_call_mpty_t mpty = active_call->mpty;
1734     uint8_t type = active_call->clip_type;
1735     char * number = active_call->clip_number;
1736 
1737     char buffer[100];
1738     // TODO: check length of a buffer, to fit the MTU
1739     int offset = snprintf(buffer, sizeof(buffer), "\r\n%s: %d,%d,%d,%d,%d", HFP_LIST_CURRENT_CALLS, idx, dir, status, mode, mpty);
1740     if (number){
1741         offset += snprintf(buffer+offset, sizeof(buffer)-offset-3, ", \"%s\",%u", number, type);
1742     }
1743     snprintf(buffer+offset, sizeof(buffer)-offset, "\r\n");
1744     log_info("hfp_ag_send_current_call_status 000 index %d, dir %d, status %d, mode %d, mpty %d, type %d, number %s", idx, dir, status,
1745        mode, mpty, type, number);
1746     send_str_over_rfcomm(hfp_connection->rfcomm_cid, buffer);
1747 }
1748 
1749 
1750 // sends pending command, returns if command was sent
1751 static int hfp_ag_send_commands(hfp_connection_t *hfp_connection){
1752 
1753     if (hfp_connection->send_status_of_current_calls){
1754         hfp_connection->ok_pending = 0;
1755         if (hfp_connection->next_call_index < hfp_gsm_get_number_of_calls()){
1756             hfp_connection->next_call_index++;
1757             hfp_ag_send_call_status(hfp_connection, hfp_connection->next_call_index);
1758             return 1;
1759         } else {
1760             // TODO: this code should be removed. check a) before setting send_status_of_current_calls, or b) right before hfp_ag_send_call_status above
1761             hfp_connection->next_call_index = 0;
1762             hfp_connection->ok_pending = 1;
1763             hfp_connection->send_status_of_current_calls = 0;
1764         }
1765     }
1766 
1767     if (hfp_connection->ag_notify_incoming_call_waiting){
1768         hfp_connection->ag_notify_incoming_call_waiting = 0;
1769         hfp_ag_send_call_waiting_notification(hfp_connection->rfcomm_cid);
1770         return 1;
1771     }
1772 
1773     if (hfp_connection->command == HFP_CMD_UNKNOWN){
1774         hfp_connection->ok_pending = 0;
1775         hfp_connection->send_error = 0;
1776         hfp_connection->command = HFP_CMD_NONE;
1777         hfp_ag_send_error(hfp_connection->rfcomm_cid);
1778         return 1;
1779     }
1780 
1781     if (hfp_connection->send_error){
1782         hfp_connection->send_error = 0;
1783         hfp_connection->command = HFP_CMD_NONE;
1784         hfp_ag_send_error(hfp_connection->rfcomm_cid);
1785         return 1;
1786     }
1787 
1788     // note: before update AG indicators and ok_pending
1789     if (hfp_connection->send_response_and_hold_status){
1790         int status = hfp_connection->send_response_and_hold_status - 1;
1791         hfp_connection->send_response_and_hold_status = 0;
1792         hfp_ag_send_set_response_and_hold(hfp_connection->rfcomm_cid, status);
1793         return 1;
1794     }
1795 
1796     if (hfp_connection->ok_pending){
1797         hfp_connection->ok_pending = 0;
1798         hfp_connection->command = HFP_CMD_NONE;
1799         hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1800         return 1;
1801     }
1802 
1803     // update AG indicators
1804     if (hfp_connection->ag_indicators_status_update_bitmap){
1805         int i;
1806         for (i=0;i<hfp_connection->ag_indicators_nr;i++){
1807             if (get_bit(hfp_connection->ag_indicators_status_update_bitmap, i)){
1808                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, i, 0);
1809                 if (!hfp_connection->enable_status_update_for_ag_indicators) {
1810                     log_info("+CMER:3,0,0,0 - not sending update for '%s'", hfp_ag_indicators[i].name);
1811                     break;
1812                 }
1813                 hfp_ag_send_transfer_ag_indicators_status_cmd(hfp_connection->rfcomm_cid, &hfp_ag_indicators[i]);
1814                 return 1;
1815             }
1816         }
1817     }
1818 
1819     if (hfp_connection->ag_send_no_carrier){
1820         hfp_connection->ag_send_no_carrier = false;
1821         hfp_ag_send_no_carrier(hfp_connection->rfcomm_cid);
1822         return 1;
1823     }
1824 
1825     if (hfp_connection->ag_ring){
1826         hfp_connection->ag_ring = 0;
1827         hfp_connection->command = HFP_CMD_NONE;
1828         hfp_ag_send_ring(hfp_connection->rfcomm_cid);
1829         return 1;
1830     }
1831 
1832     if (hfp_connection->ag_send_clip){
1833         hfp_connection->ag_send_clip = 0;
1834         hfp_connection->command = HFP_CMD_NONE;
1835         hfp_ag_send_clip(hfp_connection->rfcomm_cid);
1836         return 1;
1837     }
1838 
1839     if (hfp_connection->send_phone_number_for_voice_tag){
1840         hfp_connection->send_phone_number_for_voice_tag = 0;
1841         hfp_connection->command = HFP_CMD_NONE;
1842         hfp_connection->ok_pending = 1;
1843         hfp_ag_send_phone_number_for_voice_tag_cmd(hfp_connection->rfcomm_cid);
1844         return 1;
1845     }
1846 
1847     if (hfp_connection->send_subscriber_number){
1848         if (hfp_connection->next_subscriber_number_to_send < subscriber_numbers_count){
1849             hfp_phone_number_t phone = subscriber_numbers[hfp_connection->next_subscriber_number_to_send++];
1850             hfp_send_subscriber_number_cmd(hfp_connection->rfcomm_cid, phone.type, phone.number);
1851         } else {
1852             hfp_connection->send_subscriber_number = 0;
1853             hfp_connection->next_subscriber_number_to_send = 0;
1854             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1855         }
1856         hfp_connection->command = HFP_CMD_NONE;
1857         return 1;
1858     }
1859 
1860     if (hfp_connection->send_microphone_gain){
1861         hfp_connection->send_microphone_gain = 0;
1862         hfp_connection->command = HFP_CMD_NONE;
1863         hfp_ag_send_set_microphone_gain_cmd(hfp_connection->rfcomm_cid, hfp_connection->microphone_gain);
1864         return 1;
1865     }
1866 
1867     if (hfp_connection->send_speaker_gain){
1868         hfp_connection->send_speaker_gain = 0;
1869         hfp_connection->command = HFP_CMD_NONE;
1870         hfp_ag_send_set_speaker_gain_cmd(hfp_connection->rfcomm_cid, hfp_connection->speaker_gain);
1871         return 1;
1872     }
1873 
1874     if (hfp_connection->send_ag_status_indicators){
1875         hfp_connection->send_ag_status_indicators = 0;
1876         hfp_ag_send_retrieve_indicators_status_cmd(hfp_connection->rfcomm_cid);
1877         return 1;
1878     }
1879 
1880     return 0;
1881 }
1882 
1883 static void hfp_ag_run_for_context(hfp_connection_t *hfp_connection){
1884 
1885 	btstack_assert(hfp_connection != NULL);
1886 	btstack_assert(hfp_connection->local_role == HFP_ROLE_AG);
1887 
1888 	// during SDP query, RFCOMM CID is not set
1889 	if (hfp_connection->rfcomm_cid == 0) return;
1890 
1891     // assert command could be sent
1892     if (hci_can_send_command_packet_now() == 0) return;
1893 
1894     if ((hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED) && hfp_connection->release_audio_connection){
1895         hfp_connection->state = HFP_W4_SCO_DISCONNECTED;
1896         hfp_connection->release_audio_connection = 0;
1897         gap_disconnect(hfp_connection->sco_handle);
1898         return;
1899     }
1900 
1901 #ifdef ENABLE_CC256X_ASSISTED_HFP
1902     // WBS Disassociate
1903     if (hfp_connection->cc256x_send_wbs_disassociate){
1904         hfp_connection->cc256x_send_wbs_disassociate = false;
1905         hci_send_cmd(&hci_ti_wbs_disassociate);
1906         return;
1907     }
1908     // Write Codec Config
1909     if (hfp_connection->cc256x_send_write_codec_config){
1910         hfp_connection->cc256x_send_write_codec_config = false;
1911         hfp_cc256x_write_codec_config(hfp_connection);
1912         return;
1913     }
1914     // WBS Associate
1915     if (hfp_connection->cc256x_send_wbs_associate){
1916         hfp_connection->cc256x_send_wbs_associate = false;
1917         hci_send_cmd(&hci_ti_wbs_associate, hfp_connection->acl_handle);
1918         return;
1919     }
1920 #endif
1921 #ifdef ENABLE_BCM_PCM_WBS
1922     // Enable WBS
1923     if (hfp_connection->bcm_send_enable_wbs){
1924         hfp_connection->bcm_send_enable_wbs = false;
1925         hci_send_cmd(&hci_bcm_enable_wbs, 1, 2);
1926         return;
1927     }
1928     // Write I2S/PCM params
1929     if (hfp_connection->bcm_send_write_i2spcm_interface_param){
1930         hfp_connection->bcm_send_write_i2spcm_interface_param = false;
1931         hfp_bcm_write_i2spcm_interface_param(hfp_connection);
1932         return;
1933     }
1934     // Disable WBS
1935     if (hfp_connection->bcm_send_disable_wbs){
1936         hfp_connection->bcm_send_disable_wbs = false;
1937         hci_send_cmd(&hci_bcm_enable_wbs, 0, 2);
1938         return;
1939     }
1940 #endif
1941 #if defined (ENABLE_CC256X_ASSISTED_HFP) || defined (ENABLE_BCM_PCM_WBS)
1942     if (hfp_connection->state == HFP_W4_WBS_SHUTDOWN){
1943         hfp_finalize_connection_context(hfp_connection);
1944         return;
1945     }
1946 #endif
1947 
1948     if (!rfcomm_can_send_packet_now(hfp_connection->rfcomm_cid)) {
1949         log_info("hfp_ag_run_for_context: request can send for 0x%02x", hfp_connection->rfcomm_cid);
1950         rfcomm_request_can_send_now_event(hfp_connection->rfcomm_cid);
1951         return;
1952     }
1953 
1954     int cmd_sent = hfp_ag_send_commands(hfp_connection);
1955 
1956     if (!cmd_sent){
1957         cmd_sent = hfp_ag_run_for_context_service_level_connection(hfp_connection);
1958     }
1959 
1960     if (!cmd_sent){
1961         cmd_sent = hfp_ag_run_for_context_service_level_connection_queries(hfp_connection);
1962     }
1963 
1964     if (!cmd_sent){
1965         cmd_sent = hfp_ag_voice_recognition_state_machine(hfp_connection);
1966     }
1967 
1968     if (!cmd_sent){
1969         cmd_sent = call_setup_state_machine(hfp_connection);
1970     }
1971 
1972     // trigger codec exchange (must be before hfp_ag_run_for_audio_connection)
1973     if (!cmd_sent && (hfp_connection->command == HFP_CMD_NONE) && hfp_connection->trigger_codec_exchange){
1974         switch (hfp_connection->codecs_state){
1975             case HFP_CODECS_IDLE:
1976             case HFP_CODECS_RECEIVED_LIST:
1977             case HFP_CODECS_AG_RESEND_COMMON_CODEC:
1978             case HFP_CODECS_ERROR:
1979                 hfp_connection->trigger_codec_exchange = 0;
1980                 hfp_connection->command = HFP_CMD_AG_SEND_COMMON_CODEC;
1981                 break;
1982             default:
1983                 break;
1984         }
1985     }
1986 
1987     if (!cmd_sent){
1988         cmd_sent = hfp_ag_run_for_audio_connection(hfp_connection);
1989     }
1990 
1991 
1992     // disconnect
1993     if (!cmd_sent && (hfp_connection->command == HFP_CMD_NONE) && (hfp_connection->state == HFP_W2_DISCONNECT_RFCOMM)){
1994         hfp_connection->state = HFP_W4_RFCOMM_DISCONNECTED;
1995         rfcomm_disconnect(hfp_connection->rfcomm_cid);
1996     }
1997 
1998     if (cmd_sent){
1999         hfp_connection->command = HFP_CMD_NONE;
2000         rfcomm_request_can_send_now_event(hfp_connection->rfcomm_cid);
2001     }
2002 }
2003 
2004 static int hfp_parser_is_end_of_line(uint8_t byte){
2005     return (byte == '\n') || (byte == '\r');
2006 }
2007 
2008 static void hfp_ag_handle_rfcomm_data(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
2009     UNUSED(packet_type);    // ok: only called with RFCOMM_DATA_PACKET
2010 
2011     // assertion: size >= 1 as rfcomm.c does not deliver empty packets
2012     if (size < 1) return;
2013 
2014     hfp_connection_t * hfp_connection = get_hfp_connection_context_for_rfcomm_cid(channel);
2015     if (!hfp_connection) return;
2016 
2017     hfp_log_rfcomm_message("HFP_AG_RX", packet, size);
2018 #ifdef ENABLE_HFP_AT_MESSAGES
2019     hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_AT_MESSAGE_RECEIVED, (char *) packet);
2020 #endif
2021 
2022     // process messages byte-wise
2023     int pos;
2024     for (pos = 0; pos < size ; pos++){
2025         hfp_parse(hfp_connection, packet[pos], 0);
2026 
2027         // parse until end of line
2028         if (!hfp_parser_is_end_of_line(packet[pos])) continue;
2029 
2030         hfp_generic_status_indicator_t * indicator;
2031         switch(hfp_connection->command){
2032             case HFP_CMD_HF_ACTIVATE_VOICE_RECOGNITION:
2033                 if (hfp_connection->ag_activate_voice_recognition == 0){
2034                     hfp_trigger_release_audio_connection(hfp_connection);
2035                 }
2036                 break;
2037             case HFP_CMD_RESPONSE_AND_HOLD_QUERY:
2038                 if (hfp_ag_response_and_hold_active){
2039                     hfp_connection->send_response_and_hold_status = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD + 1;
2040                 }
2041                 hfp_connection->ok_pending = 1;
2042                 break;
2043             case HFP_CMD_RESPONSE_AND_HOLD_COMMAND:
2044                 switch(hfp_connection->ag_response_and_hold_action){
2045                     case HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD:
2046                         hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_HF, hfp_connection);
2047                         break;
2048                     case HFP_RESPONSE_AND_HOLD_HELD_INCOMING_ACCEPTED:
2049                         hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_HF, hfp_connection);
2050                         break;
2051                     case HFP_RESPONSE_AND_HOLD_HELD_INCOMING_REJECTED:
2052                         hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_HF, hfp_connection);
2053                         break;
2054                     default:
2055                         break;
2056                 }
2057                 hfp_connection->ok_pending = 1;
2058                 break;
2059             case HFP_CMD_HF_INDICATOR_STATUS:
2060                 hfp_connection->command = HFP_CMD_NONE;
2061                 if (hfp_connection->parser_indicator_index < hfp_generic_status_indicators_nr){
2062                     indicator = &hfp_generic_status_indicators[hfp_connection->parser_indicator_index];
2063                 } else {
2064                     hfp_connection->send_error = 1;
2065                     break;
2066                 }
2067                 switch (indicator->uuid){
2068                     case 1: // enhanced security
2069                         if (hfp_connection->parser_indicator_value > 1) {
2070                             hfp_connection->send_error = 1;
2071                             return;
2072                         }
2073                         log_info("HF Indicator 'enhanced security' set to %u", (unsigned int) hfp_connection->parser_indicator_value);
2074                         break;
2075                     case 2: // battery level
2076                         if (hfp_connection->parser_indicator_value > 100){
2077                             hfp_connection->send_error = 1;
2078                             return;
2079                         }
2080                         log_info("HF Indicator 'battery' set to %u", (unsigned int) hfp_connection->parser_indicator_value);
2081                         break;
2082                     default:
2083                         log_info("HF Indicator unknown set to %u", (unsigned int) hfp_connection->parser_indicator_value);
2084                         break;
2085                 }
2086                 hfp_connection->ok_pending = 1;
2087                 break;
2088             case HFP_CMD_RETRIEVE_AG_INDICATORS_STATUS:
2089                 // expected by SLC state machine
2090                 if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED) break;
2091                 hfp_connection->send_ag_indicators_segment = 0;
2092                 hfp_connection->send_ag_status_indicators = 1;
2093                 break;
2094             case HFP_CMD_LIST_CURRENT_CALLS:
2095                 hfp_connection->command = HFP_CMD_NONE;
2096                 hfp_connection->next_call_index = 0;
2097                 hfp_connection->send_status_of_current_calls = 1;
2098                 break;
2099             case HFP_CMD_GET_SUBSCRIBER_NUMBER_INFORMATION:
2100                 if (subscriber_numbers_count == 0){
2101                     hfp_ag_send_ok(hfp_connection->rfcomm_cid);
2102                     break;
2103                 }
2104                 hfp_connection->next_subscriber_number_to_send = 0;
2105                 hfp_connection->send_subscriber_number = 1;
2106                 break;
2107             case HFP_CMD_TRANSMIT_DTMF_CODES:
2108             {
2109                 hfp_connection->command = HFP_CMD_NONE;
2110                 char buffer[2];
2111                 buffer[0] = (char) hfp_connection->ag_dtmf_code;
2112                 buffer[1] = 0;
2113                 hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_TRANSMIT_DTMF_CODES, buffer);
2114                 break;
2115             }
2116             case HFP_CMD_HF_REQUEST_PHONE_NUMBER:
2117                 hfp_connection->command = HFP_CMD_NONE;
2118                 hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_ATTACH_NUMBER_TO_VOICE_TAG);
2119                 break;
2120             case HFP_CMD_TURN_OFF_EC_AND_NR:
2121                 hfp_connection->command = HFP_CMD_NONE;
2122                 if (get_bit(hfp_supported_features, HFP_AGSF_EC_NR_FUNCTION)){
2123                     hfp_connection->ok_pending = 1;
2124                     hfp_supported_features = store_bit(hfp_supported_features, HFP_AGSF_EC_NR_FUNCTION, hfp_connection->ag_echo_and_noise_reduction);
2125                     log_info("AG: EC/NR = %u", hfp_connection->ag_echo_and_noise_reduction);
2126                 } else {
2127                     hfp_connection->send_error = 1;
2128                 }
2129                 break;
2130             case HFP_CMD_CALL_ANSWERED:
2131                 hfp_connection->command = HFP_CMD_NONE;
2132                 log_info("HFP: ATA");
2133                 hfp_ag_call_sm(HFP_AG_INCOMING_CALL_ACCEPTED_BY_HF, hfp_connection);
2134                 break;
2135             case HFP_CMD_HANG_UP_CALL:
2136                 hfp_connection->command = HFP_CMD_NONE;
2137                 hfp_connection->ok_pending = 1;
2138                 hfp_ag_call_sm(HFP_AG_TERMINATE_CALL_BY_HF, hfp_connection);
2139                 break;
2140             case HFP_CMD_CALL_HOLD: {
2141                 hfp_connection->command = HFP_CMD_NONE;
2142                 hfp_connection->ok_pending = 1;
2143 
2144                 switch (hfp_connection->ag_call_hold_action){
2145                     case 0:
2146                         // Releases all held calls or sets User Determined User Busy (UDUB) for a waiting call.
2147                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_USER_BUSY, hfp_connection);
2148                         break;
2149                     case 1:
2150                         // Releases all active calls (if any exist) and accepts the other (held or waiting) call.
2151                         // Where both a held and a waiting call exist, the above procedures shall apply to the
2152                         // waiting call (i.e., not to the held call) in conflicting situation.
2153                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_RELEASE_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection);
2154                         break;
2155                     case 2:
2156                         // Places all active calls (if any exist) on hold and accepts the other (held or waiting) call.
2157                         // Where both a held and a waiting call exist, the above procedures shall apply to the
2158                         // waiting call (i.e., not to the held call) in conflicting situation.
2159                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_PARK_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection);
2160                         break;
2161                     case 3:
2162                         // Adds a held call to the conversation.
2163                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_ADD_HELD_CALL, hfp_connection);
2164                         break;
2165                     case 4:
2166                         // Connects the two calls and disconnects the subscriber from both calls (Explicit Call Transfer).
2167                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_EXIT_AND_JOIN_CALLS, hfp_connection);
2168                         break;
2169                     default:
2170                         break;
2171                 }
2172 				hfp_connection->call_index = 0;
2173                 break;
2174             }
2175             case HFP_CMD_CALL_PHONE_NUMBER:
2176                 hfp_connection->command = HFP_CMD_NONE;
2177                 hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_INITIATED_BY_HF, hfp_connection);
2178                 break;
2179             case HFP_CMD_REDIAL_LAST_NUMBER:
2180                 hfp_connection->command = HFP_CMD_NONE;
2181                 hfp_ag_call_sm(HFP_AG_OUTGOING_REDIAL_INITIATED, hfp_connection);
2182                 break;
2183             case HFP_CMD_ENABLE_CLIP:
2184                 hfp_connection->command = HFP_CMD_NONE;
2185                 log_info("hfp: clip set, now: %u", hfp_connection->clip_enabled);
2186                 hfp_connection->ok_pending = 1;
2187                 break;
2188             case HFP_CMD_ENABLE_CALL_WAITING_NOTIFICATION:
2189                 hfp_connection->command = HFP_CMD_NONE;
2190                 log_info("hfp: call waiting notification set, now: %u", hfp_connection->call_waiting_notification_enabled);
2191                 hfp_connection->ok_pending = 1;
2192                 break;
2193             case HFP_CMD_SET_SPEAKER_GAIN:
2194                 hfp_connection->command = HFP_CMD_NONE;
2195                 hfp_connection->ok_pending = 1;
2196                 log_info("HF speaker gain = %u", hfp_connection->speaker_gain);
2197                 hfp_emit_event(hfp_connection, HFP_SUBEVENT_SPEAKER_VOLUME, hfp_connection->speaker_gain);
2198                 break;
2199             case HFP_CMD_SET_MICROPHONE_GAIN:
2200                 hfp_connection->command = HFP_CMD_NONE;
2201                 hfp_connection->ok_pending = 1;
2202                 log_info("HF microphone gain = %u", hfp_connection->microphone_gain);
2203                 hfp_emit_event(hfp_connection, HFP_SUBEVENT_MICROPHONE_VOLUME, hfp_connection->microphone_gain);
2204                 break;
2205             default:
2206                 break;
2207         }
2208     }
2209 }
2210 
2211 static void hfp_ag_run(void){
2212     btstack_linked_list_iterator_t it;
2213     btstack_linked_list_iterator_init(&it, hfp_get_connections());
2214     while (btstack_linked_list_iterator_has_next(&it)){
2215         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2216         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
2217         hfp_ag_run_for_context(hfp_connection);
2218     }
2219 }
2220 
2221 static void hfp_ag_rfcomm_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
2222     switch (packet_type){
2223         case RFCOMM_DATA_PACKET:
2224             hfp_ag_handle_rfcomm_data(packet_type, channel, packet, size);
2225             break;
2226         case HCI_EVENT_PACKET:
2227             if (packet[0] == RFCOMM_EVENT_CAN_SEND_NOW){
2228                 uint16_t rfcomm_cid = rfcomm_event_can_send_now_get_rfcomm_cid(packet);
2229                 hfp_ag_run_for_context(get_hfp_connection_context_for_rfcomm_cid(rfcomm_cid));
2230                 return;
2231             }
2232             hfp_handle_rfcomm_event(packet_type, channel, packet, size, HFP_ROLE_AG);
2233             break;
2234         default:
2235             break;
2236     }
2237 
2238     hfp_ag_run();
2239 }
2240 
2241 static void hfp_ag_hci_event_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
2242     hfp_handle_hci_event(packet_type, channel, packet, size, HFP_ROLE_AG);
2243     hfp_ag_run();
2244 }
2245 
2246 void hfp_ag_init_codecs(int codecs_nr, const uint8_t * codecs){
2247     if (codecs_nr > HFP_MAX_NUM_CODECS){
2248         log_error("hfp_init: codecs_nr (%d) > HFP_MAX_NUM_CODECS (%d)", codecs_nr, HFP_MAX_NUM_CODECS);
2249         return;
2250     }
2251     int i;
2252     hfp_codecs_nr = codecs_nr;
2253     for (i=0; i < codecs_nr; i++){
2254         hfp_codecs[i] = codecs[i];
2255     }
2256 }
2257 
2258 void hfp_ag_init_supported_features(uint32_t supported_features){
2259     hfp_supported_features = supported_features;
2260 }
2261 
2262 void hfp_ag_init_ag_indicators(int ag_indicators_nr, const hfp_ag_indicator_t * ag_indicators){
2263     hfp_ag_indicators_nr = ag_indicators_nr;
2264     (void)memcpy(hfp_ag_indicators, ag_indicators,
2265                  ag_indicators_nr * sizeof(hfp_ag_indicator_t));
2266 }
2267 
2268 void hfp_ag_init_hf_indicators(int hf_indicators_nr, const hfp_generic_status_indicator_t * hf_indicators){
2269     if (hf_indicators_nr > HFP_MAX_NUM_INDICATORS) return;
2270     hfp_generic_status_indicators_nr = hf_indicators_nr;
2271     (void)memcpy(hfp_generic_status_indicators, hf_indicators,
2272                  hf_indicators_nr * sizeof(hfp_generic_status_indicator_t));
2273 }
2274 
2275 void hfp_ag_init_call_hold_services(int call_hold_services_nr, const char * call_hold_services[]){
2276     hfp_ag_call_hold_services_nr = call_hold_services_nr;
2277     (void)memcpy(hfp_ag_call_hold_services, call_hold_services,
2278                  call_hold_services_nr * sizeof(char *));
2279 }
2280 
2281 
2282 void hfp_ag_init(uint16_t rfcomm_channel_nr){
2283 
2284     hfp_init();
2285     hfp_ag_call_hold_services_nr = 0;
2286     hfp_ag_response_and_hold_active = 0;
2287     hfp_ag_indicators_nr = 0;
2288     hfp_codecs_nr = 0;
2289     hfp_supported_features = HFP_DEFAULT_AG_SUPPORTED_FEATURES;
2290     subscriber_numbers = NULL;
2291     subscriber_numbers_count = 0;
2292 
2293     hfp_ag_hci_event_callback_registration.callback = &hfp_ag_hci_event_packet_handler;
2294     hci_add_event_handler(&hfp_ag_hci_event_callback_registration);
2295 
2296     rfcomm_register_service(&hfp_ag_rfcomm_packet_handler, rfcomm_channel_nr, 0xffff);
2297 
2298     // used to set packet handler for outgoing rfcomm connections - could be handled by emitting an event to us
2299     hfp_set_ag_rfcomm_packet_handler(&hfp_ag_rfcomm_packet_handler);
2300 
2301     hfp_gsm_init();
2302 }
2303 
2304 void hfp_ag_deinit(void){
2305     hfp_deinit();
2306     hfp_gsm_deinit();
2307     (void) memset(&hfp_ag_hci_event_callback_registration, 0, sizeof(btstack_packet_callback_registration_t));
2308     (void) memset(&hfp_ag_callback, 0, sizeof(btstack_packet_handler_t));
2309     (void) memset(&hfp_ag_call_hold_services, 0, sizeof(hfp_ag_call_hold_services));
2310     (void) memset(&hfp_ag_response_and_hold_state, 0, sizeof(hfp_response_and_hold_state_t));
2311 }
2312 
2313 uint8_t hfp_ag_establish_service_level_connection(bd_addr_t bd_addr){
2314     return hfp_establish_service_level_connection(bd_addr, BLUETOOTH_SERVICE_CLASS_HANDSFREE, HFP_ROLE_AG);
2315 }
2316 
2317 uint8_t hfp_ag_release_service_level_connection(hci_con_handle_t acl_handle){
2318     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2319     if (!hfp_connection){
2320         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2321     }
2322 
2323     hfp_trigger_release_service_level_connection(hfp_connection);
2324     hfp_ag_run_for_context(hfp_connection);
2325     return ERROR_CODE_SUCCESS;
2326 }
2327 
2328 uint8_t hfp_ag_report_extended_audio_gateway_error_result_code(hci_con_handle_t acl_handle, hfp_cme_error_t error){
2329     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2330     if (!hfp_connection){
2331         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2332     }
2333 
2334     hfp_connection->extended_audio_gateway_error = 0;
2335     if (!hfp_connection->enable_extended_audio_gateway_error_report){
2336         return ERROR_CODE_COMMAND_DISALLOWED;
2337     }
2338 
2339     hfp_connection->extended_audio_gateway_error = error;
2340     hfp_ag_run_for_context(hfp_connection);
2341     return ERROR_CODE_SUCCESS;
2342 }
2343 
2344 static uint8_t hfp_ag_setup_audio_connection(hfp_connection_t * hfp_connection){
2345     if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED){
2346         return ERROR_CODE_COMMAND_DISALLOWED;
2347     }
2348     if (hfp_connection->state >= HFP_W2_DISCONNECT_SCO){
2349         return ERROR_CODE_COMMAND_DISALLOWED;
2350     }
2351 
2352     hfp_connection->establish_audio_connection = 1;
2353     if (!has_codec_negotiation_feature(hfp_connection)){
2354         log_info("hfp_ag_establish_audio_connection - no codec negotiation feature, using CVSD");
2355         hfp_connection->negotiated_codec = HFP_CODEC_CVSD;
2356         hfp_connection->codecs_state = HFP_CODECS_EXCHANGED;
2357         // now, pick link settings
2358         hfp_init_link_settings(hfp_connection, hfp_ag_esco_s4_supported(hfp_connection));
2359 #ifdef ENABLE_CC256X_ASSISTED_HFP
2360         hfp_cc256x_prepare_for_sco(hfp_connection);
2361 #endif
2362         return ERROR_CODE_SUCCESS;
2363     }
2364 
2365     uint8_t i;
2366     bool codec_was_in_use = false;
2367     bool better_codec_can_be_used = false;
2368 
2369     for (i = 0; i<hfp_connection->remote_codecs_nr; i++){
2370         if (hfp_connection->negotiated_codec == hfp_connection->remote_codecs[i]){
2371             codec_was_in_use = true;
2372         } else if (hfp_connection->negotiated_codec < hfp_connection->remote_codecs[i]){
2373             better_codec_can_be_used = true;
2374         }
2375     }
2376 
2377     if (!codec_was_in_use || better_codec_can_be_used){
2378         hfp_connection->trigger_codec_exchange = 1;
2379         hfp_connection->codecs_state = HFP_CODECS_IDLE;
2380     }
2381     return ERROR_CODE_SUCCESS;
2382 }
2383 
2384 uint8_t hfp_ag_establish_audio_connection(hci_con_handle_t acl_handle){
2385     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2386     if (!hfp_connection){
2387         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2388     }
2389 
2390     uint8_t status = hfp_ag_setup_audio_connection(hfp_connection);
2391     if (status != ERROR_CODE_SUCCESS){
2392         return status;
2393     }
2394     hfp_ag_run_for_context(hfp_connection);
2395     return ERROR_CODE_SUCCESS;
2396 }
2397 
2398 uint8_t hfp_ag_release_audio_connection(hci_con_handle_t acl_handle){
2399     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2400     if (!hfp_connection){
2401         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2402     }
2403 
2404     hfp_trigger_release_audio_connection(hfp_connection);
2405     hfp_ag_run_for_context(hfp_connection);
2406     return ERROR_CODE_SUCCESS;
2407 }
2408 
2409 /**
2410  * @brief Enable in-band ring tone
2411  */
2412 void hfp_ag_set_use_in_band_ring_tone(int use_in_band_ring_tone){
2413     if (get_bit(hfp_supported_features, HFP_AGSF_IN_BAND_RING_TONE) == use_in_band_ring_tone){
2414         return;
2415     }
2416 
2417     hfp_supported_features = store_bit(hfp_supported_features, HFP_AGSF_IN_BAND_RING_TONE, use_in_band_ring_tone);
2418 
2419     btstack_linked_list_iterator_t it;
2420     btstack_linked_list_iterator_init(&it, hfp_get_connections());
2421     while (btstack_linked_list_iterator_has_next(&it)){
2422         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2423         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
2424         hfp_connection->command = HFP_CMD_CHANGE_IN_BAND_RING_TONE_SETTING;
2425         hfp_ag_run_for_context(hfp_connection);
2426     }
2427 }
2428 
2429 /**
2430  * @brief Called from GSM
2431  */
2432 void hfp_ag_incoming_call(void){
2433     hfp_ag_call_sm(HFP_AG_INCOMING_CALL, NULL);
2434 }
2435 
2436 void hfp_ag_outgoing_call_initiated(const char * number) {
2437     UNUSED(number);
2438     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_INITIATED_BY_AG, NULL);
2439 }
2440 
2441 /**
2442  * @brief number is stored.
2443  */
2444 void hfp_ag_set_clip(uint8_t type, const char * number){
2445     hfp_gsm_handler(HFP_AG_SET_CLIP, 0, type, number);
2446 }
2447 
2448 void hfp_ag_call_dropped(void){
2449     hfp_ag_call_sm(HFP_AG_CALL_DROPPED, NULL);
2450 }
2451 
2452 // call from AG UI
2453 void hfp_ag_answer_incoming_call(void){
2454     hfp_ag_call_sm(HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG, NULL);
2455 }
2456 
2457 void hfp_ag_join_held_call(void){
2458     hfp_ag_call_sm(HFP_AG_HELD_CALL_JOINED_BY_AG, NULL);
2459 }
2460 
2461 void hfp_ag_terminate_call(void){
2462     hfp_ag_call_sm(HFP_AG_TERMINATE_CALL_BY_AG, NULL);
2463 }
2464 
2465 void hfp_ag_outgoing_call_ringing(void){
2466     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_RINGING, NULL);
2467 }
2468 
2469 void hfp_ag_outgoing_call_established(void){
2470     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_ESTABLISHED, NULL);
2471 }
2472 
2473 void hfp_ag_outgoing_call_rejected(void){
2474     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_REJECTED, NULL);
2475 }
2476 
2477 void hfp_ag_outgoing_call_accepted(void){
2478     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_ACCEPTED, NULL);
2479 }
2480 
2481 void hfp_ag_hold_incoming_call(void){
2482     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_AG, NULL);
2483 }
2484 
2485 void hfp_ag_accept_held_incoming_call(void) {
2486     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_AG, NULL);
2487 }
2488 
2489 void hfp_ag_reject_held_incoming_call(void){
2490     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_AG, NULL);
2491 }
2492 
2493 static void hfp_ag_set_ag_indicator(const char * name, int value){
2494     int indicator_index = get_ag_indicator_index_for_name(name);
2495     if (indicator_index < 0) return;
2496     hfp_ag_indicators[indicator_index].status = value;
2497 
2498     btstack_linked_list_iterator_t it;
2499     btstack_linked_list_iterator_init(&it, hfp_get_connections());
2500     while (btstack_linked_list_iterator_has_next(&it)){
2501         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2502         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
2503         if (!hfp_connection->ag_indicators[indicator_index].enabled) {
2504             log_info("Requested AG indicator '%s' update to %u, but it is not enabled", hfp_ag_indicators[indicator_index].name, value);
2505             continue;
2506         }
2507         log_info("AG indicator '%s' changed to %u, request transfer status", hfp_ag_indicators[indicator_index].name, value);
2508         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
2509         hfp_ag_run_for_context(hfp_connection);
2510     }
2511 }
2512 
2513 uint8_t hfp_ag_set_registration_status(int registration_status){
2514     if ((registration_status < 0) || (registration_status > 1)){
2515         return ERROR_CODE_COMMAND_DISALLOWED;
2516     }
2517 
2518     if ( (registration_status == 0) && (hfp_gsm_call_status() == HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT)){
2519 
2520         // if network goes away wihle a call is active:
2521         // - the  call gets dropped
2522         // - we send NO CARRIER
2523         // NOTE: the CALL=0 has to be sent before NO CARRIER
2524 
2525         hfp_ag_call_sm(HFP_AG_CALL_DROPPED, NULL);
2526 
2527         btstack_linked_list_iterator_t it;
2528         btstack_linked_list_iterator_init(&it, hfp_get_connections());
2529         while (btstack_linked_list_iterator_has_next(&it)){
2530             hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2531             hfp_connection->ag_send_no_carrier = true;
2532         }
2533     }
2534     hfp_ag_set_ag_indicator("service", registration_status);
2535     return ERROR_CODE_SUCCESS;
2536 }
2537 
2538 uint8_t hfp_ag_set_signal_strength(int signal_strength){
2539     if ((signal_strength < 0) || (signal_strength > 5)){
2540         return ERROR_CODE_COMMAND_DISALLOWED;
2541     }
2542 
2543     hfp_ag_set_ag_indicator("signal", signal_strength);
2544     return ERROR_CODE_SUCCESS;
2545 }
2546 
2547 uint8_t hfp_ag_set_roaming_status(int roaming_status){
2548     if ((roaming_status < 0) || (roaming_status > 1)){
2549         return ERROR_CODE_COMMAND_DISALLOWED;
2550     }
2551 
2552     hfp_ag_set_ag_indicator("roam", roaming_status);
2553     return ERROR_CODE_SUCCESS;
2554 }
2555 
2556 uint8_t hfp_ag_set_battery_level(int battery_level){
2557     if ((battery_level < 0) || (battery_level > 5)){
2558         return ERROR_CODE_COMMAND_DISALLOWED;
2559     }
2560     hfp_ag_set_ag_indicator("battchg", battery_level);
2561     return ERROR_CODE_SUCCESS;
2562 }
2563 
2564 uint8_t hfp_ag_activate_voice_recognition(hci_con_handle_t acl_handle){
2565     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2566     if (!hfp_connection){
2567         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2568     }
2569     uint8_t status = hfp_ag_activate_voice_recognition_for_connection(hfp_connection);
2570     if (status == ERROR_CODE_SUCCESS){
2571         hfp_ag_run_for_context(hfp_connection);
2572     }
2573     return status;
2574 }
2575 
2576 uint8_t hfp_ag_deactivate_voice_recognition(hci_con_handle_t acl_handle){
2577     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2578     if (!hfp_connection){
2579         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2580     }
2581     uint8_t status = hfp_ag_deactivate_voice_recognition_for_connection(hfp_connection);
2582     if (status == ERROR_CODE_SUCCESS){
2583         hfp_ag_run_for_context(hfp_connection);
2584     }
2585     return status;
2586 }
2587 
2588 
2589 uint8_t hfp_ag_enhanced_voice_recognition_activate(hci_con_handle_t acl_handle){
2590     if (!get_bit(hfp_supported_features, HFP_AGSF_VOICE_RECOGNITION_FUNCTION)){
2591         return ERROR_CODE_COMMAND_DISALLOWED;
2592     }
2593 
2594     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2595     if (!hfp_connection){
2596         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2597     }
2598 
2599     if (!get_bit(hfp_connection->remote_supported_features, HFP_HFSF_VOICE_RECOGNITION_FUNCTION)){
2600         return ERROR_CODE_COMMAND_DISALLOWED;
2601     }
2602 
2603     hfp_connection->command = HFP_CMD_AG_ACTIVATE_ENHANCED_VOICE_RECOGNITION;
2604     hfp_connection->ag_vra_state = HFP_VOICE_RECOGNITION_STATE_AG_READY;
2605     hfp_connection->ag_vra_status = HFP_VRA_W4_ENHANCED_VOICE_RECOGNITION_ACTIVATED;
2606     hfp_ag_run_for_context(hfp_connection);
2607     return ERROR_CODE_SUCCESS;
2608 }
2609 
2610 uint8_t hfp_ag_enhanced_voice_recognition_deactivate(hci_con_handle_t acl_handle){
2611     if (!get_bit(hfp_supported_features, HFP_AGSF_VOICE_RECOGNITION_FUNCTION)){
2612         return ERROR_CODE_COMMAND_DISALLOWED;
2613     }
2614 
2615     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2616     if (!hfp_connection){
2617         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2618     }
2619 
2620     if (!get_bit(hfp_connection->remote_supported_features, HFP_HFSF_VOICE_RECOGNITION_FUNCTION)){
2621         return ERROR_CODE_COMMAND_DISALLOWED;
2622     }
2623 
2624     hfp_connection->command = HFP_CMD_AG_ACTIVATE_ENHANCED_VOICE_RECOGNITION;
2625     hfp_connection->ag_vra_state = HFP_VOICE_RECOGNITION_STATE_AG_READY;
2626     hfp_connection->ag_vra_status = HFP_VRA_W4_ENHANCED_VOICE_RECOGNITION_OFF;
2627     hfp_ag_run_for_context(hfp_connection);
2628     return ERROR_CODE_SUCCESS;
2629 }
2630 
2631 uint8_t hfp_ag_enhanced_voice_recognition_state(hci_con_handle_t acl_handle, hfp_voice_recognition_state_t state){
2632     if (!get_bit(hfp_supported_features, HFP_AGSF_VOICE_RECOGNITION_FUNCTION)){
2633         return ERROR_CODE_COMMAND_DISALLOWED;
2634     }
2635 
2636     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2637     if (!hfp_connection){
2638         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2639     }
2640 
2641     if (!get_bit(hfp_connection->remote_supported_features, HFP_HFSF_VOICE_RECOGNITION_FUNCTION)){
2642         return ERROR_CODE_COMMAND_DISALLOWED;
2643     }
2644 
2645     hfp_connection->command = HFP_CMD_AG_ACTIVATE_ENHANCED_VOICE_RECOGNITION;
2646     hfp_connection->ag_vra_state = state;
2647     hfp_connection->ag_vra_status = HFP_VRA_W4_ENHANCED_VOICE_RECOGNITION_STATUS;
2648     hfp_ag_run_for_context(hfp_connection);
2649     return ERROR_CODE_SUCCESS;
2650 }
2651 
2652 uint8_t hfp_ag_enhanced_voice_recognition_starting_sound(hci_con_handle_t acl_handle){
2653     return hfp_ag_enhanced_voice_recognition_state(acl_handle, HFP_VOICE_RECOGNITION_STATE_AG_IS_SENDING_AUDIO_TO_HF);
2654 }
2655 uint8_t hfp_ag_enhanced_voice_recognition_ready_for_input(hci_con_handle_t acl_handle){
2656     return hfp_ag_enhanced_voice_recognition_state(acl_handle, HFP_VOICE_RECOGNITION_STATE_AG_READY_TO_ACCEPT_AUDIO_INPUT);
2657 }
2658 uint8_t hfp_ag_enhanced_voice_recognition_processing_input(hci_con_handle_t acl_handle){
2659     return hfp_ag_enhanced_voice_recognition_state(acl_handle, HFP_VOICE_RECOGNITION_STATE_AG_IS_PROCESSING_AUDIO_INPUT);
2660 }
2661 
2662 uint8_t hfp_ag_enhanced_voice_recognition_message(hci_con_handle_t acl_handle, hfp_voice_recognition_state_t state, hfp_voice_recognition_message_t msg){
2663     if (!get_bit(hfp_supported_features, HFP_AGSF_VOICE_RECOGNITION_FUNCTION)){
2664         return ERROR_CODE_COMMAND_DISALLOWED;
2665     }
2666 
2667     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2668     if (!hfp_connection){
2669         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2670     }
2671 
2672     if (!get_bit(hfp_connection->remote_supported_features, HFP_HFSF_VOICE_RECOGNITION_FUNCTION)){
2673         return ERROR_CODE_COMMAND_DISALLOWED;
2674     }
2675 
2676     hfp_connection->command = HFP_CMD_AG_ACTIVATE_ENHANCED_VOICE_RECOGNITION;
2677     hfp_connection->ag_vra_state = state;
2678     hfp_connection->ag_vra_status = HFP_VRA_W4_ENHANCED_VOICE_RECOGNITION_MSG;
2679     hfp_connection->ag_msg = msg;
2680     hfp_ag_run_for_context(hfp_connection);
2681     return ERROR_CODE_SUCCESS;
2682 }
2683 
2684 uint8_t hfp_ag_set_microphone_gain(hci_con_handle_t acl_handle, int gain){
2685     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2686     if (!hfp_connection){
2687         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2688     }
2689 
2690     if ((gain < 0) || (gain > 15)){
2691         log_info("Valid range for a gain is [0..15]. Currently sent: %d", gain);
2692         return ERROR_CODE_COMMAND_DISALLOWED;
2693     }
2694 
2695     if (hfp_connection->microphone_gain != gain){
2696         hfp_connection->command = HFP_CMD_SET_MICROPHONE_GAIN;
2697         hfp_connection->microphone_gain = gain;
2698         hfp_connection->send_microphone_gain = 1;
2699     }
2700     hfp_ag_run_for_context(hfp_connection);
2701     return ERROR_CODE_SUCCESS;
2702 }
2703 
2704 uint8_t hfp_ag_set_speaker_gain(hci_con_handle_t acl_handle, int gain){
2705     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2706     if (!hfp_connection){
2707         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2708     }
2709 
2710     if ((gain < 0) || (gain > 15)){
2711         log_info("Valid range for a gain is [0..15]. Currently sent: %d", gain);
2712         return ERROR_CODE_COMMAND_DISALLOWED;
2713     }
2714 
2715     if (hfp_connection->speaker_gain != gain){
2716         hfp_connection->speaker_gain = gain;
2717         hfp_connection->send_speaker_gain = 1;
2718     }
2719     hfp_ag_run_for_context(hfp_connection);
2720     return ERROR_CODE_SUCCESS;
2721 }
2722 
2723 uint8_t hfp_ag_send_phone_number_for_voice_tag(hci_con_handle_t acl_handle, const char * number){
2724     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2725     if (!hfp_connection){
2726         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2727     }
2728 
2729     hfp_ag_set_clip(0, number);
2730     hfp_connection->send_phone_number_for_voice_tag = 1;
2731     return ERROR_CODE_SUCCESS;
2732 }
2733 
2734 uint8_t hfp_ag_reject_phone_number_for_voice_tag(hci_con_handle_t acl_handle){
2735     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2736     if (!hfp_connection){
2737         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2738     }
2739 
2740     hfp_connection->send_error = 1;
2741     return ERROR_CODE_SUCCESS;
2742 }
2743 
2744 uint8_t hfp_ag_send_dtmf_code_done(hci_con_handle_t acl_handle){
2745     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2746     if (!hfp_connection){
2747         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2748     }
2749 
2750     hfp_connection->ok_pending = 1;
2751     return ERROR_CODE_SUCCESS;
2752 }
2753 
2754 void hfp_ag_set_subcriber_number_information(hfp_phone_number_t * numbers, int numbers_count){
2755     subscriber_numbers = numbers;
2756     subscriber_numbers_count = numbers_count;
2757 }
2758 
2759 void hfp_ag_clear_last_dialed_number(void){
2760     hfp_gsm_clear_last_dialed_number();
2761 }
2762 
2763 void hfp_ag_set_last_dialed_number(const char * number){
2764     hfp_gsm_set_last_dialed_number(number);
2765 }
2766 
2767 uint8_t hfp_ag_notify_incoming_call_waiting(hci_con_handle_t acl_handle){
2768     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2769     if (!hfp_connection){
2770         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2771     }
2772 
2773     if (!hfp_connection->call_waiting_notification_enabled){
2774         return ERROR_CODE_COMMAND_DISALLOWED;
2775     }
2776 
2777     hfp_connection->ag_notify_incoming_call_waiting = 1;
2778     hfp_ag_run_for_context(hfp_connection);
2779     return ERROR_CODE_SUCCESS;
2780 }
2781 
2782 void hfp_ag_create_sdp_record(uint8_t * service, uint32_t service_record_handle, int rfcomm_channel_nr, const char * name, uint8_t ability_to_reject_call, uint16_t supported_features, int wide_band_speech){
2783 	if (!name){
2784 		name = default_hfp_ag_service_name;
2785 	}
2786 	hfp_create_sdp_record(service, service_record_handle, BLUETOOTH_SERVICE_CLASS_HANDSFREE_AUDIO_GATEWAY, rfcomm_channel_nr, name);
2787 
2788 	/*
2789 	 * 0x01 – Ability to reject a call
2790 	 * 0x00 – No ability to reject a call
2791 	 */
2792 	de_add_number(service, DE_UINT, DE_SIZE_16, 0x0301);    // Hands-Free Profile - Network
2793 	de_add_number(service, DE_UINT, DE_SIZE_8, ability_to_reject_call);
2794 
2795 	// Construct SupportedFeatures for SDP bitmap:
2796 	//
2797 	// "The values of the “SupportedFeatures” bitmap given in Table 5.4 shall be the same as the values
2798 	//  of the Bits 0 to 4 of the unsolicited result code +BRSF"
2799 	//
2800 	// Wide band speech (bit 5) requires Codec negotiation
2801 	//
2802 	uint16_t sdp_features = supported_features & 0x1f;
2803 	if ( (wide_band_speech == 1) && (supported_features & (1 << HFP_AGSF_CODEC_NEGOTIATION))){
2804 		sdp_features |= 1 << 5;
2805 	}
2806 
2807     if (supported_features & (1 << HFP_AGSF_ENHANCED_VOICE_RECOGNITION_STATUS)){
2808         sdp_features |= 1 << 6;
2809     }
2810 
2811     if (supported_features & (1 << HFP_AGSF_VOICE_RECOGNITION_TEXT)){
2812         sdp_features |= 1 << 7;
2813     }
2814 
2815 	de_add_number(service, DE_UINT, DE_SIZE_16, 0x0311);    // Hands-Free Profile - SupportedFeatures
2816 	de_add_number(service, DE_UINT, DE_SIZE_16, sdp_features);
2817 }
2818 
2819 void hfp_ag_register_packet_handler(btstack_packet_handler_t callback){
2820 	btstack_assert(callback != NULL);
2821 
2822 	hfp_ag_callback = callback;
2823 	hfp_set_ag_callback(callback);
2824 }
2825