xref: /btstack/src/classic/hfp_ag.c (revision 6a580d1772276b965c7f6ed4aba86036f102ce2f)
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 <stdlib.h>
51 #include <string.h>
52 
53 #include "hci_cmd.h"
54 #include "btstack_run_loop.h"
55 
56 #include "bluetooth_sdp.h"
57 #include "hci.h"
58 #include "btstack_memory.h"
59 #include "hci_dump.h"
60 #include "l2cap.h"
61 #include "btstack_debug.h"
62 #include "btstack_event.h"
63 #include "classic/core.h"
64 #include "classic/hfp.h"
65 #include "classic/hfp_ag.h"
66 #include "classic/hfp_gsm_model.h"
67 #include "classic/sdp_client_rfcomm.h"
68 #include "classic/sdp_server.h"
69 #include "classic/sdp_util.h"
70 
71 // private prototypes
72 static void hfp_run_for_context(hfp_connection_t *hfp_connection);
73 static void hfp_ag_hf_start_ringing(hfp_connection_t * hfp_connection);
74 static void hfp_ag_setup_audio_connection(hfp_connection_t * hfp_connection);
75 
76 // public prototypes
77 hfp_generic_status_indicator_t * get_hfp_generic_status_indicators(void);
78 int get_hfp_generic_status_indicators_nr(void);
79 void set_hfp_generic_status_indicators(hfp_generic_status_indicator_t * indicators, int indicator_nr);
80 void set_hfp_ag_indicators(hfp_ag_indicator_t * indicators, int indicator_nr);
81 int get_hfp_ag_indicators_nr(hfp_connection_t * context);
82 hfp_ag_indicator_t * get_hfp_ag_indicators(hfp_connection_t * context);
83 
84 static btstack_packet_callback_registration_t hci_event_callback_registration;
85 
86 // gobals
87 static const char default_hfp_ag_service_name[] = "Voice gateway";
88 
89 static uint16_t hfp_supported_features = HFP_DEFAULT_AG_SUPPORTED_FEATURES;
90 
91 static uint8_t hfp_codecs_nr = 0;
92 static uint8_t hfp_codecs[HFP_MAX_NUM_CODECS];
93 
94 static int  hfp_ag_indicators_nr = 0;
95 static hfp_ag_indicator_t hfp_ag_indicators[HFP_MAX_NUM_AG_INDICATORS];
96 
97 static int hfp_generic_status_indicators_nr = 0;
98 static hfp_generic_status_indicator_t hfp_generic_status_indicators[HFP_MAX_NUM_HF_INDICATORS];
99 
100 static int  hfp_ag_call_hold_services_nr = 0;
101 static char *hfp_ag_call_hold_services[6];
102 static btstack_packet_handler_t hfp_ag_callback;
103 
104 static hfp_response_and_hold_state_t hfp_ag_response_and_hold_state;
105 static int hfp_ag_response_and_hold_active = 0;
106 
107 // Subcriber information entries
108 static hfp_phone_number_t * subscriber_numbers = NULL;
109 static int subscriber_numbers_count = 0;
110 
111 hfp_ag_indicator_t * hfp_ag_get_ag_indicators(hfp_connection_t * hfp_connection);
112 
113 
114 static int hfp_ag_get_ag_indicators_nr(hfp_connection_t * hfp_connection){
115     if (hfp_connection->ag_indicators_nr != hfp_ag_indicators_nr){
116         hfp_connection->ag_indicators_nr = hfp_ag_indicators_nr;
117         memcpy(hfp_connection->ag_indicators, hfp_ag_indicators, 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         memcpy(hfp_connection->ag_indicators, hfp_ag_indicators, hfp_ag_indicators_nr * sizeof(hfp_ag_indicator_t));
127     }
128     return (hfp_ag_indicator_t *)&(hfp_connection->ag_indicators);
129 }
130 
131 static hfp_ag_indicator_t * get_ag_indicator_for_name(const char * name){
132     int i;
133     for (i = 0; i < hfp_ag_indicators_nr; i++){
134         if (strcmp(hfp_ag_indicators[i].name, name) == 0){
135             return &hfp_ag_indicators[i];
136         }
137     }
138     return NULL;
139 }
140 
141 static int get_ag_indicator_index_for_name(const char * name){
142     int i;
143     for (i = 0; i < hfp_ag_indicators_nr; i++){
144         if (strcmp(hfp_ag_indicators[i].name, name) == 0){
145             return i;
146         }
147     }
148     return -1;
149 }
150 
151 static hfp_connection_t * get_hfp_ag_connection_context_for_acl_handle(uint16_t handle){
152     btstack_linked_list_iterator_t it;
153     btstack_linked_list_iterator_init(&it, hfp_get_connections());
154     while (btstack_linked_list_iterator_has_next(&it)){
155         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
156         if (hfp_connection->acl_handle != handle)      continue;
157         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
158         return hfp_connection;
159     }
160     return NULL;
161 }
162 
163 void hfp_ag_register_packet_handler(btstack_packet_handler_t callback){
164     if (callback == NULL){
165         log_error("hfp_ag_register_packet_handler called with NULL callback");
166         return;
167     }
168     hfp_ag_callback = callback;
169     hfp_set_ag_callback(callback);
170 }
171 
172 static int use_in_band_tone(void){
173     return get_bit(hfp_supported_features, HFP_AGSF_IN_BAND_RING_TONE);
174 }
175 
176 static int has_codec_negotiation_feature(hfp_connection_t * hfp_connection){
177     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_CODEC_NEGOTIATION);
178     int ag = get_bit(hfp_supported_features, HFP_AGSF_CODEC_NEGOTIATION);
179     return hf && ag;
180 }
181 
182 static int has_call_waiting_and_3way_calling_feature(hfp_connection_t * hfp_connection){
183     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_THREE_WAY_CALLING);
184     int ag = get_bit(hfp_supported_features, HFP_AGSF_THREE_WAY_CALLING);
185     return hf && ag;
186 }
187 
188 static int has_hf_indicators_feature(hfp_connection_t * hfp_connection){
189     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_HF_INDICATORS);
190     int ag = get_bit(hfp_supported_features, HFP_AGSF_HF_INDICATORS);
191     return hf && ag;
192 }
193 
194 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){
195     if (!name){
196         name = default_hfp_ag_service_name;
197     }
198     hfp_create_sdp_record(service, service_record_handle, BLUETOOTH_SERVICE_CLASS_HANDSFREE_AUDIO_GATEWAY, rfcomm_channel_nr, name);
199 
200     /*
201      * 0x01 – Ability to reject a call
202      * 0x00 – No ability to reject a call
203      */
204     de_add_number(service, DE_UINT, DE_SIZE_16, 0x0301);    // Hands-Free Profile - Network
205     de_add_number(service, DE_UINT, DE_SIZE_8, ability_to_reject_call);
206 
207     // Construct SupportedFeatures for SDP bitmap:
208     //
209     // "The values of the “SupportedFeatures” bitmap given in Table 5.4 shall be the same as the values
210     //  of the Bits 0 to 4 of the unsolicited result code +BRSF"
211     //
212     uint16_t sdp_features = supported_features &0x1f;
213     if (supported_features & wide_band_speech){
214         sdp_features |= 1 << 5; // Wide band speech bit
215     }
216     de_add_number(service, DE_UINT, DE_SIZE_16, 0x0311);    // Hands-Free Profile - SupportedFeatures
217     de_add_number(service, DE_UINT, DE_SIZE_16, sdp_features);
218 }
219 
220 static int hfp_ag_send_change_in_band_ring_tone_setting_cmd(uint16_t cid){
221     char buffer[20];
222     sprintf(buffer, "\r\n%s:%d\r\n", HFP_CHANGE_IN_BAND_RING_TONE_SETTING, use_in_band_tone());
223     return send_str_over_rfcomm(cid, buffer);
224 }
225 
226 static int hfp_ag_exchange_supported_features_cmd(uint16_t cid){
227     char buffer[40];
228     sprintf(buffer, "\r\n%s:%d\r\n\r\nOK\r\n", HFP_SUPPORTED_FEATURES, hfp_supported_features);
229     return send_str_over_rfcomm(cid, buffer);
230 }
231 
232 static int hfp_ag_send_ok(uint16_t cid){
233     char buffer[10];
234     sprintf(buffer, "\r\nOK\r\n");
235     return send_str_over_rfcomm(cid, buffer);
236 }
237 
238 static int hfp_ag_send_ring(uint16_t cid){
239     return send_str_over_rfcomm(cid, (char *) "\r\nRING\r\n");
240 }
241 
242 static int hfp_ag_send_clip(uint16_t cid){
243     char buffer[50];
244     sprintf(buffer, "\r\n%s: \"%s\",%u\r\n", HFP_ENABLE_CLIP, hfp_gsm_clip_number(), hfp_gsm_clip_type());
245     return send_str_over_rfcomm(cid, buffer);
246 }
247 
248 static int hfp_send_subscriber_number_cmd(uint16_t cid, uint8_t type, const char * number){
249     char buffer[50];
250     sprintf(buffer, "\r\n%s: ,\"%s\",%u, , \r\n", HFP_SUBSCRIBER_NUMBER_INFORMATION, number, type);
251     return send_str_over_rfcomm(cid, buffer);
252 }
253 
254 static int hfp_ag_send_phone_number_for_voice_tag_cmd(uint16_t cid){
255     char buffer[50];
256     sprintf(buffer, "\r\n%s: %s\r\n", HFP_PHONE_NUMBER_FOR_VOICE_TAG, hfp_gsm_clip_number());
257     return send_str_over_rfcomm(cid, buffer);
258 }
259 
260 static int hfp_ag_send_call_waiting_notification(uint16_t cid){
261     char buffer[50];
262     sprintf(buffer, "\r\n%s: \"%s\",%u\r\n", HFP_ENABLE_CALL_WAITING_NOTIFICATION, hfp_gsm_clip_number(), hfp_gsm_clip_type());
263     return send_str_over_rfcomm(cid, buffer);
264 }
265 
266 static int hfp_ag_send_error(uint16_t cid){
267     char buffer[10];
268     sprintf(buffer, "\r\nERROR\r\n");
269     return send_str_over_rfcomm(cid, buffer);
270 }
271 
272 static int hfp_ag_send_report_extended_audio_gateway_error(uint16_t cid, uint8_t error){
273     char buffer[20];
274     sprintf(buffer, "\r\n%s=%d\r\n", HFP_EXTENDED_AUDIO_GATEWAY_ERROR, error);
275     return send_str_over_rfcomm(cid, buffer);
276 }
277 
278 // get size for indicator string
279 static int hfp_ag_indicators_string_size(hfp_connection_t * hfp_connection, int i){
280     // template: ("$NAME",($MIN,$MAX))
281     return 8 + (int) strlen(hfp_ag_get_ag_indicators(hfp_connection)[i].name)
282          + string_len_for_uint32(hfp_ag_get_ag_indicators(hfp_connection)[i].min_range)
283          + string_len_for_uint32(hfp_ag_get_ag_indicators(hfp_connection)[i].min_range);
284 }
285 
286 // store indicator
287 static void hfp_ag_indicators_string_store(hfp_connection_t * hfp_connection, int i, uint8_t * buffer){
288     sprintf((char *) buffer, "(\"%s\",(%d,%d)),",
289             hfp_ag_get_ag_indicators(hfp_connection)[i].name,
290             hfp_ag_get_ag_indicators(hfp_connection)[i].min_range,
291             hfp_ag_get_ag_indicators(hfp_connection)[i].max_range);
292 }
293 
294 // structure: header [indicator [comma indicator]] footer
295 static int hfp_ag_indicators_cmd_generator_num_segments(hfp_connection_t * hfp_connection){
296     int num_indicators = hfp_ag_get_ag_indicators_nr(hfp_connection);
297     if (!num_indicators) return 2;
298     return 3 + (num_indicators-1) * 2;
299 }
300 
301 // get size of individual segment for hfp_ag_retrieve_indicators_cmd
302 static int hfp_ag_indicators_cmd_generator_get_segment_len(hfp_connection_t * hfp_connection, int index){
303     if (index == 0) {
304         return strlen(HFP_INDICATOR) + 3;   // "\n\r%s:""
305     }
306     index--;
307     int num_indicators = hfp_ag_get_ag_indicators_nr(hfp_connection);
308     int indicator_index = index >> 1;
309     if ((index & 1) == 0){
310         return hfp_ag_indicators_string_size(hfp_connection, indicator_index);
311     }
312     if (indicator_index == num_indicators - 1){
313         return 8; // "\r\n\r\nOK\r\n"
314     }
315     return 1; // comma
316 }
317 
318 static void hgp_ag_indicators_cmd_generator_store_segment(hfp_connection_t * hfp_connection, int index, uint8_t * buffer){
319     if (index == 0){
320         *buffer++ = '\r';
321         *buffer++ = '\n';
322         int len = strlen(HFP_INDICATOR);
323         memcpy(buffer, HFP_INDICATOR, len);
324         buffer += len;
325         *buffer++ = ':';
326         return;
327     }
328     index--;
329     int num_indicators = hfp_ag_get_ag_indicators_nr(hfp_connection);
330     int indicator_index = index >> 1;
331     if ((index & 1) == 0){
332         hfp_ag_indicators_string_store(hfp_connection, indicator_index, buffer);
333         return;
334     }
335     if (indicator_index == num_indicators-1){
336         memcpy(buffer, "\r\n\r\nOK\r\n", 8);
337         return;
338     }
339     *buffer = ',';
340 }
341 
342 static int hfp_hf_indicators_join(char * buffer, int buffer_size){
343     if (buffer_size < hfp_ag_indicators_nr * 3) return 0;
344     int i;
345     int offset = 0;
346     for (i = 0; i < hfp_generic_status_indicators_nr-1; i++) {
347         offset += snprintf(buffer+offset, buffer_size-offset, "%d,", hfp_generic_status_indicators[i].uuid);
348     }
349     if (i < hfp_generic_status_indicators_nr){
350         offset += snprintf(buffer+offset, buffer_size-offset, "%d,", hfp_generic_status_indicators[i].uuid);
351     }
352     return offset;
353 }
354 
355 static int hfp_hf_indicators_initial_status_join(char * buffer, int buffer_size){
356     if (buffer_size < hfp_generic_status_indicators_nr * 3) return 0;
357     int i;
358     int offset = 0;
359     for (i = 0; i < hfp_generic_status_indicators_nr; i++) {
360         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);
361     }
362     return offset;
363 }
364 
365 static int hfp_ag_indicators_status_join(char * buffer, int buffer_size){
366     if (buffer_size < hfp_ag_indicators_nr * 3) return 0;
367     int i;
368     int offset = 0;
369     for (i = 0; i < hfp_ag_indicators_nr-1; i++) {
370         offset += snprintf(buffer+offset, buffer_size-offset, "%d,", hfp_ag_indicators[i].status);
371     }
372     if (i<hfp_ag_indicators_nr){
373         offset += snprintf(buffer+offset, buffer_size-offset, "%d", hfp_ag_indicators[i].status);
374     }
375     return offset;
376 }
377 
378 static int hfp_ag_call_services_join(char * buffer, int buffer_size){
379     if (buffer_size < hfp_ag_call_hold_services_nr * 3) return 0;
380     int i;
381     int offset = snprintf(buffer, buffer_size, "(");
382     for (i = 0; i < hfp_ag_call_hold_services_nr-1; i++) {
383         offset += snprintf(buffer+offset, buffer_size-offset, "%s,", hfp_ag_call_hold_services[i]);
384     }
385     if (i<hfp_ag_call_hold_services_nr){
386         offset += snprintf(buffer+offset, buffer_size-offset, "%s)", hfp_ag_call_hold_services[i]);
387     }
388     return offset;
389 }
390 
391 static int hfp_ag_send_cmd_via_generator(uint16_t cid, hfp_connection_t * hfp_connection,
392     int start_segment, int num_segments,
393     int (*get_segment_len)(hfp_connection_t * hfp_connection, int segment),
394     void (*store_segment) (hfp_connection_t * hfp_connection, int segment, uint8_t * buffer)){
395 
396     // assumes: can send now == true
397     // assumes: num segments > 0
398     // assumes: individual segments are smaller than MTU
399     rfcomm_reserve_packet_buffer();
400     int mtu = rfcomm_get_max_frame_size(cid);
401     uint8_t * data = rfcomm_get_outgoing_buffer();
402     int offset = 0;
403     int segment = start_segment;
404     while (segment < num_segments){
405         int segment_len = get_segment_len(hfp_connection, segment);
406         if (offset + segment_len > mtu) break;
407         // append segement
408         store_segment(hfp_connection, segment, data+offset);
409         offset += segment_len;
410         segment++;
411     }
412     rfcomm_send_prepared(cid, offset);
413     return segment;
414 }
415 
416 // returns next segment to store
417 static int hfp_ag_send_retrieve_indicators_cmd_via_generator(uint16_t cid, hfp_connection_t * hfp_connection, int start_segment){
418     int num_segments = hfp_ag_indicators_cmd_generator_num_segments(hfp_connection);
419     return hfp_ag_send_cmd_via_generator(cid, hfp_connection, start_segment, num_segments,
420         hfp_ag_indicators_cmd_generator_get_segment_len, hgp_ag_indicators_cmd_generator_store_segment);
421 }
422 
423 static int hfp_ag_send_retrieve_indicators_status_cmd(uint16_t cid){
424     char buffer[40];
425     const int size = sizeof(buffer);
426     int offset = snprintf(buffer, size, "\r\n%s:", HFP_INDICATOR);
427     offset += hfp_ag_indicators_status_join(buffer+offset, size-offset-9);
428     offset += snprintf(buffer+offset, size-offset, "\r\n\r\nOK\r\n");
429     return send_str_over_rfcomm(cid, buffer);
430 }
431 
432 static int hfp_ag_send_retrieve_can_hold_call_cmd(uint16_t cid){
433     char buffer[40];
434     const int size = sizeof(buffer);
435     int offset = snprintf(buffer, size, "\r\n%s:", HFP_SUPPORT_CALL_HOLD_AND_MULTIPARTY_SERVICES);
436     offset += hfp_ag_call_services_join(buffer+offset, size-offset-9);
437     offset += snprintf(buffer+offset, size-offset, "\r\n\r\nOK\r\n");
438     return send_str_over_rfcomm(cid, buffer);
439 }
440 
441 
442 static int hfp_ag_send_list_supported_generic_status_indicators_cmd(uint16_t cid){
443     return hfp_ag_send_ok(cid);
444 }
445 
446 static int hfp_ag_send_retrieve_supported_generic_status_indicators_cmd(uint16_t cid){
447     char buffer[40];
448     const int size = sizeof(buffer);
449     int offset = snprintf(buffer, size, "\r\n%s:(", HFP_GENERIC_STATUS_INDICATOR);
450     offset += hfp_hf_indicators_join(buffer+offset, size-offset-10);
451     offset += snprintf(buffer+offset, size-offset, ")\r\n\r\nOK\r\n");
452     return send_str_over_rfcomm(cid, buffer);
453 }
454 
455 static int hfp_ag_send_retrieve_initital_supported_generic_status_indicators_cmd(uint16_t cid){
456     char buffer[40];
457     int offset = hfp_hf_indicators_initial_status_join(buffer, sizeof(buffer) - 7);
458     snprintf(buffer+offset, sizeof(buffer)-offset, "\r\nOK\r\n");
459     return send_str_over_rfcomm(cid, buffer);
460 }
461 
462 static int hfp_ag_send_transfer_ag_indicators_status_cmd(uint16_t cid, hfp_ag_indicator_t * indicator){
463     char buffer[20];
464     sprintf(buffer, "\r\n%s:%d,%d\r\n", HFP_TRANSFER_AG_INDICATOR_STATUS, indicator->index, indicator->status);
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_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 static int hfp_ag_send_suggest_codec_cmd(uint16_t cid, uint8_t codec){
487     return hfp_ag_send_cmd_with_int(cid, HFP_CONFIRM_COMMON_CODEC, codec);
488 }
489 
490 static int hfp_ag_send_activate_voice_recognition_cmd(uint16_t cid, uint8_t activate_voice_recognition){
491     return hfp_ag_send_cmd_with_int(cid, HFP_ACTIVATE_VOICE_RECOGNITION, activate_voice_recognition);
492 }
493 
494 static int hfp_ag_send_set_speaker_gain_cmd(uint16_t cid, uint8_t gain){
495     return hfp_ag_send_cmd_with_int(cid, HFP_SET_SPEAKER_GAIN, gain);
496 }
497 
498 static int hfp_ag_send_set_microphone_gain_cmd(uint16_t cid, uint8_t gain){
499     return hfp_ag_send_cmd_with_int(cid, HFP_SET_MICROPHONE_GAIN, gain);
500 }
501 
502 static int hfp_ag_send_set_response_and_hold(uint16_t cid, int state){
503     return hfp_ag_send_cmd_with_int(cid, HFP_RESPONSE_AND_HOLD, state);
504 }
505 
506 static uint8_t hfp_ag_suggest_codec(hfp_connection_t *hfp_connection){
507     if (hfp_connection->sco_for_msbc_failed) return HFP_CODEC_CVSD;
508 
509     if (hfp_supports_codec(HFP_CODEC_MSBC, hfp_codecs_nr, hfp_codecs)){
510         if (hfp_supports_codec(HFP_CODEC_MSBC, hfp_connection->remote_codecs_nr, hfp_connection->remote_codecs)){
511             return HFP_CODEC_MSBC;
512         }
513     }
514     return HFP_CODEC_CVSD;
515 }
516 
517 static void hfp_init_link_settings(hfp_connection_t * hfp_connection){
518     // determine highest possible link setting
519     hfp_connection->link_setting = HFP_LINK_SETTINGS_D1;
520     // anything else requires eSCO support on both sides
521     if (hci_extended_sco_link_supported() && hci_remote_esco_supported(hfp_connection->acl_handle)){
522         switch (hfp_connection->negotiated_codec){
523             case HFP_CODEC_CVSD:
524                 hfp_connection->link_setting = HFP_LINK_SETTINGS_S3;
525                 if ((hfp_connection->remote_supported_features & (1<<HFP_HFSF_ESCO_S4))
526                 &&  (hfp_supported_features                    & (1<<HFP_AGSF_ESCO_S4))){
527                     hfp_connection->link_setting = HFP_LINK_SETTINGS_S4;
528                 }
529                 break;
530             case HFP_CODEC_MSBC:
531                 hfp_connection->link_setting = HFP_LINK_SETTINGS_T2;
532                 break;
533             default:
534                 break;
535         }
536     }
537     log_info("hfp_init_link_settings: %u", hfp_connection->link_setting);
538 }
539 
540 static int codecs_exchange_state_machine(hfp_connection_t * hfp_connection){
541     /* events ( == commands):
542         HFP_CMD_AVAILABLE_CODECS == received AT+BAC with list of codecs
543         HFP_CMD_TRIGGER_CODEC_CONNECTION_SETUP:
544             hf_trigger_codec_connection_setup == received BCC
545             ag_trigger_codec_connection_setup == received from AG to send BCS
546         HFP_CMD_HF_CONFIRMED_CODEC == received AT+BCS
547     */
548 
549      switch (hfp_connection->codecs_state){
550         case HFP_CODECS_RECEIVED_TRIGGER_CODEC_EXCHANGE:
551             hfp_connection->command = HFP_CMD_AG_SEND_COMMON_CODEC;
552             break;
553         case HFP_CODECS_AG_RESEND_COMMON_CODEC:
554             hfp_connection->command = HFP_CMD_AG_SEND_COMMON_CODEC;
555             break;
556         default:
557             break;
558     }
559 
560     // printf(" -> State machine: CC\n");
561 
562     switch (hfp_connection->command){
563         case HFP_CMD_AVAILABLE_CODECS:
564             if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED){
565                 hfp_connection->codecs_state = HFP_CODECS_RECEIVED_LIST;
566                 hfp_ag_send_ok(hfp_connection->rfcomm_cid);
567                 return 1;
568             }
569 
570             switch (hfp_connection->codecs_state){
571                 case HFP_CODECS_AG_SENT_COMMON_CODEC:
572                 case HFP_CODECS_EXCHANGED:
573                     hfp_connection->codecs_state = HFP_CODECS_AG_RESEND_COMMON_CODEC;
574                     break;
575                 default:
576                     break;
577             }
578             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
579             return 1;
580 
581         case HFP_CMD_TRIGGER_CODEC_CONNECTION_SETUP:
582             hfp_connection->codecs_state = HFP_CODECS_RECEIVED_TRIGGER_CODEC_EXCHANGE;
583             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
584             return 1;
585 
586         case HFP_CMD_AG_SEND_COMMON_CODEC:
587             hfp_connection->codecs_state = HFP_CODECS_AG_SENT_COMMON_CODEC;
588             hfp_connection->suggested_codec = hfp_ag_suggest_codec(hfp_connection);
589             hfp_ag_send_suggest_codec_cmd(hfp_connection->rfcomm_cid, hfp_connection->suggested_codec);
590             return 1;
591 
592         case HFP_CMD_HF_CONFIRMED_CODEC:
593             if (hfp_connection->codec_confirmed != hfp_connection->suggested_codec){
594                 hfp_connection->codecs_state = HFP_CODECS_ERROR;
595                 hfp_ag_send_error(hfp_connection->rfcomm_cid);
596                 return 1;
597             }
598             hfp_connection->negotiated_codec = hfp_connection->codec_confirmed;
599             hfp_connection->codecs_state = HFP_CODECS_EXCHANGED;
600             log_info("hfp: codec confirmed: %s", hfp_connection->negotiated_codec == HFP_CODEC_MSBC ? "mSBC" : "CVSD");
601             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
602             // now, pick link settings
603             hfp_init_link_settings(hfp_connection);
604             return 1;
605         default:
606             break;
607     }
608     return 0;
609 }
610 
611 static void hfp_ag_slc_established(hfp_connection_t * hfp_connection){
612     hfp_connection->state = HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED;
613     hfp_emit_slc_connection_event(hfp_connection, 0, hfp_connection->acl_handle, hfp_connection->remote_addr);
614 
615     // if active call exist, set per-hfp_connection state active, too (when audio is on)
616     if (hfp_gsm_call_status() == HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT){
617         hfp_connection->call_state = HFP_CALL_W4_AUDIO_CONNECTION_FOR_ACTIVE;
618     }
619     // if AG is ringing, also start ringing on the HF
620     if (hfp_gsm_call_status() == HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS &&
621         hfp_gsm_callsetup_status() == HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS){
622         hfp_ag_hf_start_ringing(hfp_connection);
623     }
624 }
625 
626 static int hfp_ag_run_for_context_service_level_connection(hfp_connection_t * hfp_connection){
627     // log_info("hfp_ag_run_for_context_service_level_connection state %u, command %u", hfp_connection->state, hfp_connection->command);
628     if (hfp_connection->state >= HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED) return 0;
629     int sent = 0;
630     switch(hfp_connection->command){
631         case HFP_CMD_SUPPORTED_FEATURES:
632             switch(hfp_connection->state){
633                 case HFP_W4_EXCHANGE_SUPPORTED_FEATURES:
634                 case HFP_EXCHANGE_SUPPORTED_FEATURES:
635                     hfp_hf_drop_mSBC_if_eSCO_not_supported(hfp_codecs, &hfp_codecs_nr);
636                     if (has_codec_negotiation_feature(hfp_connection)){
637                         hfp_connection->state = HFP_W4_NOTIFY_ON_CODECS;
638                     } else {
639                         hfp_connection->state = HFP_W4_RETRIEVE_INDICATORS;
640                     }
641                     hfp_ag_exchange_supported_features_cmd(hfp_connection->rfcomm_cid);
642                     return 1;
643                 default:
644                     break;
645             }
646             break;
647         case HFP_CMD_AVAILABLE_CODECS:
648             sent = codecs_exchange_state_machine(hfp_connection);
649             if (hfp_connection->codecs_state == HFP_CODECS_RECEIVED_LIST){
650                 hfp_connection->state = HFP_W4_RETRIEVE_INDICATORS;
651             }
652             return sent;
653 
654         case HFP_CMD_RETRIEVE_AG_INDICATORS:
655             if (hfp_connection->state == HFP_W4_RETRIEVE_INDICATORS) {
656                 // HF requested AG Indicators and we did expect it
657                 hfp_connection->state = HFP_RETRIEVE_INDICATORS;
658                 // continue below in state switch
659             }
660             break;
661 
662         case HFP_CMD_RETRIEVE_AG_INDICATORS_STATUS:
663             if (hfp_connection->state != HFP_W4_RETRIEVE_INDICATORS_STATUS) break;
664             hfp_connection->state = HFP_W4_ENABLE_INDICATORS_STATUS_UPDATE;
665             hfp_ag_send_retrieve_indicators_status_cmd(hfp_connection->rfcomm_cid);
666             return 1;
667 
668         case HFP_CMD_ENABLE_INDICATOR_STATUS_UPDATE:
669             if (hfp_connection->state != HFP_W4_ENABLE_INDICATORS_STATUS_UPDATE) break;
670             if (has_call_waiting_and_3way_calling_feature(hfp_connection)){
671                 hfp_connection->state = HFP_W4_RETRIEVE_CAN_HOLD_CALL;
672             } else if (has_hf_indicators_feature(hfp_connection)){
673                 hfp_connection->state = HFP_W4_LIST_GENERIC_STATUS_INDICATORS;
674             } else {
675                 hfp_ag_slc_established(hfp_connection);
676             }
677             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
678             return 1;
679 
680         case HFP_CMD_SUPPORT_CALL_HOLD_AND_MULTIPARTY_SERVICES:
681             if (hfp_connection->state != HFP_W4_RETRIEVE_CAN_HOLD_CALL) break;
682             if (has_hf_indicators_feature(hfp_connection)){
683                 hfp_connection->state = HFP_W4_LIST_GENERIC_STATUS_INDICATORS;
684             }
685             hfp_ag_send_retrieve_can_hold_call_cmd(hfp_connection->rfcomm_cid);
686             if (!has_hf_indicators_feature(hfp_connection)){
687                 hfp_ag_slc_established(hfp_connection);
688             }
689             return 1;
690 
691         case HFP_CMD_LIST_GENERIC_STATUS_INDICATORS:
692             if (hfp_connection->state != HFP_W4_LIST_GENERIC_STATUS_INDICATORS) break;
693             hfp_connection->state = HFP_W4_RETRIEVE_GENERIC_STATUS_INDICATORS;
694             hfp_ag_send_list_supported_generic_status_indicators_cmd(hfp_connection->rfcomm_cid);
695             return 1;
696 
697         case HFP_CMD_RETRIEVE_GENERIC_STATUS_INDICATORS:
698             if (hfp_connection->state != HFP_W4_RETRIEVE_GENERIC_STATUS_INDICATORS) break;
699             hfp_connection->state = HFP_W4_RETRIEVE_INITITAL_STATE_GENERIC_STATUS_INDICATORS;
700             hfp_ag_send_retrieve_supported_generic_status_indicators_cmd(hfp_connection->rfcomm_cid);
701             return 1;
702 
703         case HFP_CMD_RETRIEVE_GENERIC_STATUS_INDICATORS_STATE:
704             if (hfp_connection->state != HFP_W4_RETRIEVE_INITITAL_STATE_GENERIC_STATUS_INDICATORS) break;
705             hfp_ag_slc_established(hfp_connection);
706             hfp_ag_send_retrieve_initital_supported_generic_status_indicators_cmd(hfp_connection->rfcomm_cid);
707             return 1;
708         default:
709             break;
710     }
711 
712     switch (hfp_connection->state){
713         case HFP_RETRIEVE_INDICATORS: {
714             int next_segment = hfp_ag_send_retrieve_indicators_cmd_via_generator(hfp_connection->rfcomm_cid, hfp_connection, hfp_connection->send_ag_indicators_segment);
715             int num_segments = hfp_ag_indicators_cmd_generator_num_segments(hfp_connection);
716             log_info("HFP_CMD_RETRIEVE_AG_INDICATORS next segment %u, num_segments %u", next_segment, num_segments);
717             if (next_segment < num_segments){
718                 // prepare sending of next segment
719                 hfp_connection->send_ag_indicators_segment = next_segment;
720                 log_info("HFP_CMD_RETRIEVE_AG_INDICATORS more. command %u, next seg %u", hfp_connection->command, next_segment);
721             } else {
722                 // done, go to next state
723                 hfp_connection->send_ag_indicators_segment = 0;
724                 hfp_connection->state = HFP_W4_RETRIEVE_INDICATORS_STATUS;
725             }
726             return 1;
727         }
728         default:
729             break;
730     }
731     return 0;
732 }
733 
734 static int hfp_ag_run_for_context_service_level_connection_queries(hfp_connection_t * hfp_connection){
735     int sent = codecs_exchange_state_machine(hfp_connection);
736     if (sent) return 1;
737 
738     switch(hfp_connection->command){
739         case HFP_CMD_AG_ACTIVATE_VOICE_RECOGNITION:
740             hfp_supported_features = store_bit(hfp_supported_features, HFP_AGSF_VOICE_RECOGNITION_FUNCTION, hfp_connection->ag_activate_voice_recognition);
741             hfp_ag_send_activate_voice_recognition_cmd(hfp_connection->rfcomm_cid, hfp_connection->ag_activate_voice_recognition);
742             return 1;
743         case HFP_CMD_HF_ACTIVATE_VOICE_RECOGNITION:
744             if (get_bit(hfp_supported_features, HFP_AGSF_VOICE_RECOGNITION_FUNCTION)){
745                 hfp_supported_features = store_bit(hfp_supported_features, HFP_AGSF_VOICE_RECOGNITION_FUNCTION, hfp_connection->ag_activate_voice_recognition);
746                 hfp_ag_send_ok(hfp_connection->rfcomm_cid);
747                 hfp_ag_setup_audio_connection(hfp_connection);
748             } else {
749                 hfp_ag_send_error(hfp_connection->rfcomm_cid);
750             }
751             return 1;
752         case HFP_CMD_CHANGE_IN_BAND_RING_TONE_SETTING:
753             hfp_ag_send_change_in_band_ring_tone_setting_cmd(hfp_connection->rfcomm_cid);
754             return 1;
755         case HFP_CMD_QUERY_OPERATOR_SELECTION_NAME:
756             hfp_ag_send_report_network_operator_name_cmd(hfp_connection->rfcomm_cid, hfp_connection->network_operator);
757             return 1;
758         case HFP_CMD_QUERY_OPERATOR_SELECTION_NAME_FORMAT:
759             if (hfp_connection->network_operator.format != 0){
760                 hfp_ag_send_error(hfp_connection->rfcomm_cid);
761             } else {
762                 hfp_ag_send_ok(hfp_connection->rfcomm_cid);
763             }
764             return 1;
765         case HFP_CMD_ENABLE_INDIVIDUAL_AG_INDICATOR_STATUS_UPDATE:
766             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
767             return 1;
768         case HFP_CMD_ENABLE_EXTENDED_AUDIO_GATEWAY_ERROR:
769             if (hfp_connection->extended_audio_gateway_error){
770                 hfp_connection->extended_audio_gateway_error = 0;
771                 hfp_ag_send_report_extended_audio_gateway_error(hfp_connection->rfcomm_cid, hfp_connection->extended_audio_gateway_error_value);
772                 return 1;
773             }
774             break;
775         case HFP_CMD_ENABLE_INDICATOR_STATUS_UPDATE:
776             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
777             return 1;
778         default:
779             break;
780     }
781     return 0;
782 }
783 
784 static int hfp_ag_run_for_audio_connection(hfp_connection_t * hfp_connection){
785     if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED ||
786         hfp_connection->state > HFP_W2_DISCONNECT_SCO) return 0;
787 
788 
789     if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED && hfp_connection->release_audio_connection){
790         hfp_connection->state = HFP_W4_SCO_DISCONNECTED;
791         hfp_connection->release_audio_connection = 0;
792         gap_disconnect(hfp_connection->sco_handle);
793         return 1;
794     }
795 
796     if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED) return 0;
797 
798     // run codecs exchange
799     int sent = codecs_exchange_state_machine(hfp_connection);
800     if (sent) return 1;
801 
802     if (hfp_connection->codecs_state != HFP_CODECS_EXCHANGED) return 0;
803     if (hfp_connection->establish_audio_connection){
804         hfp_connection->state = HFP_W4_SCO_CONNECTED;
805         hfp_connection->establish_audio_connection = 0;
806         hfp_setup_synchronous_connection(hfp_connection);
807         return 1;
808     }
809     return 0;
810 }
811 
812 static hfp_connection_t * hfp_ag_context_for_timer(btstack_timer_source_t * ts){
813     btstack_linked_list_iterator_t it;
814     btstack_linked_list_iterator_init(&it, hfp_get_connections());
815 
816     while (btstack_linked_list_iterator_has_next(&it)){
817         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
818         if ( & hfp_connection->hfp_timeout == ts) {
819             return hfp_connection;
820         }
821     }
822     return NULL;
823 }
824 
825 static void hfp_timeout_handler(btstack_timer_source_t * timer){
826     hfp_connection_t * hfp_connection = hfp_ag_context_for_timer(timer);
827     if (!hfp_connection) return;
828 
829     log_info("HFP start ring timeout, con handle 0x%02x", hfp_connection->acl_handle);
830     hfp_connection->ag_ring = 1;
831     hfp_connection->ag_send_clip = hfp_gsm_clip_type() && hfp_connection->clip_enabled;
832 
833     btstack_run_loop_set_timer(& hfp_connection->hfp_timeout, 2000); // 2 seconds timeout
834     btstack_run_loop_add_timer(& hfp_connection->hfp_timeout);
835 
836     hfp_run_for_context(hfp_connection);
837 }
838 
839 static void hfp_timeout_start(hfp_connection_t * hfp_connection){
840     btstack_run_loop_remove_timer(& hfp_connection->hfp_timeout);
841     btstack_run_loop_set_timer_handler(& hfp_connection->hfp_timeout, hfp_timeout_handler);
842     btstack_run_loop_set_timer(& hfp_connection->hfp_timeout, 2000); // 2 seconds timeout
843     btstack_run_loop_add_timer(& hfp_connection->hfp_timeout);
844 }
845 
846 static void hfp_timeout_stop(hfp_connection_t * hfp_connection){
847     log_info("HFP stop ring timeout, con handle 0x%02x", hfp_connection->acl_handle);
848     btstack_run_loop_remove_timer(& hfp_connection->hfp_timeout);
849 }
850 
851 //
852 // transitition implementations for hfp_ag_call_state_machine
853 //
854 
855 static void hfp_ag_hf_start_ringing(hfp_connection_t * hfp_connection){
856     if (use_in_band_tone()){
857         hfp_connection->call_state = HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING;
858         hfp_ag_establish_audio_connection(hfp_connection->acl_handle);
859     } else {
860         hfp_timeout_start(hfp_connection);
861         hfp_connection->ag_ring = 1;
862         hfp_connection->ag_send_clip = hfp_gsm_clip_type() && hfp_connection->clip_enabled;
863         hfp_connection->call_state = HFP_CALL_RINGING;
864         hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_START_RINGINIG);
865     }
866 }
867 
868 static void hfp_ag_hf_stop_ringing(hfp_connection_t * hfp_connection){
869     hfp_connection->ag_ring = 0;
870     hfp_connection->ag_send_clip = 0;
871     hfp_timeout_stop(hfp_connection);
872     hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_STOP_RINGINIG);
873 }
874 
875 static void hfp_ag_trigger_incoming_call(void){
876     int indicator_index = get_ag_indicator_index_for_name("callsetup");
877     if (indicator_index < 0) return;
878 
879     btstack_linked_list_iterator_t it;
880     btstack_linked_list_iterator_init(&it, hfp_get_connections());
881     while (btstack_linked_list_iterator_has_next(&it)){
882         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
883         hfp_ag_establish_service_level_connection(hfp_connection->remote_addr);
884         if (hfp_connection->call_state == HFP_CALL_IDLE){
885             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
886             hfp_ag_hf_start_ringing(hfp_connection);
887         }
888         if (hfp_connection->call_state == HFP_CALL_ACTIVE){
889             hfp_connection->call_state = HFP_CALL_W2_SEND_CALL_WAITING;
890         }
891         hfp_run_for_context(hfp_connection);
892     }
893 }
894 
895 static void hfp_ag_transfer_callsetup_state(void){
896     int indicator_index = get_ag_indicator_index_for_name("callsetup");
897     if (indicator_index < 0) return;
898 
899     btstack_linked_list_iterator_t it;
900     btstack_linked_list_iterator_init(&it, hfp_get_connections());
901     while (btstack_linked_list_iterator_has_next(&it)){
902         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
903         hfp_ag_establish_service_level_connection(hfp_connection->remote_addr);
904         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
905         hfp_run_for_context(hfp_connection);
906     }
907 }
908 
909 static void hfp_ag_transfer_call_state(void){
910     int indicator_index = get_ag_indicator_index_for_name("call");
911     if (indicator_index < 0) return;
912 
913     btstack_linked_list_iterator_t it;
914     btstack_linked_list_iterator_init(&it, hfp_get_connections());
915     while (btstack_linked_list_iterator_has_next(&it)){
916         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
917         hfp_ag_establish_service_level_connection(hfp_connection->remote_addr);
918         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
919         hfp_run_for_context(hfp_connection);
920     }
921 }
922 
923 static void hfp_ag_transfer_callheld_state(void){
924     int indicator_index = get_ag_indicator_index_for_name("callheld");
925     if (indicator_index < 0) return;
926 
927     btstack_linked_list_iterator_t it;
928     btstack_linked_list_iterator_init(&it, hfp_get_connections());
929     while (btstack_linked_list_iterator_has_next(&it)){
930         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
931         hfp_ag_establish_service_level_connection(hfp_connection->remote_addr);
932         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
933         hfp_run_for_context(hfp_connection);
934     }
935 }
936 
937 static void hfp_ag_hf_accept_call(hfp_connection_t * source){
938 
939     int call_indicator_index = get_ag_indicator_index_for_name("call");
940     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
941 
942     btstack_linked_list_iterator_t it;
943     btstack_linked_list_iterator_init(&it, hfp_get_connections());
944     while (btstack_linked_list_iterator_has_next(&it)){
945         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
946         if (hfp_connection->call_state != HFP_CALL_RINGING &&
947             hfp_connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING) continue;
948 
949         hfp_ag_hf_stop_ringing(hfp_connection);
950         if (hfp_connection == source){
951             hfp_connection->ok_pending = 1;
952 
953             if (use_in_band_tone()){
954                 hfp_connection->call_state = HFP_CALL_ACTIVE;
955             } else {
956                 hfp_connection->call_state = HFP_CALL_W4_AUDIO_CONNECTION_FOR_ACTIVE;
957                 hfp_ag_establish_audio_connection(hfp_connection->acl_handle);
958             }
959 
960             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
961             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
962 
963         } else {
964             hfp_connection->call_state = HFP_CALL_IDLE;
965         }
966         hfp_run_for_context(hfp_connection);
967     }
968 }
969 
970 static void hfp_ag_ag_accept_call(void){
971 
972     int call_indicator_index = get_ag_indicator_index_for_name("call");
973     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
974 
975     btstack_linked_list_iterator_t it;
976     btstack_linked_list_iterator_init(&it, hfp_get_connections());
977     while (btstack_linked_list_iterator_has_next(&it)){
978         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
979         if (hfp_connection->call_state != HFP_CALL_RINGING) continue;
980 
981         hfp_ag_hf_stop_ringing(hfp_connection);
982         hfp_connection->call_state = HFP_CALL_TRIGGER_AUDIO_CONNECTION;
983 
984         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
985         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
986 
987         hfp_run_for_context(hfp_connection);
988         break;  // only single
989     }
990 }
991 
992 static void hfp_ag_trigger_reject_call(void){
993     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
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 * connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
998         if (connection->call_state != HFP_CALL_RINGING &&
999             connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING) continue;
1000         hfp_ag_hf_stop_ringing(connection);
1001         connection->ag_indicators_status_update_bitmap = store_bit(connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1002         connection->call_state = HFP_CALL_IDLE;
1003         hfp_run_for_context(connection);
1004     }
1005 }
1006 
1007 static void hfp_ag_emit_simple_event(uint8_t event_subtype){
1008     uint8_t event[3];
1009     event[0] = HCI_EVENT_HFP_META;
1010     event[1] = sizeof(event) - 2;
1011     event[2] = event_subtype;
1012     if (!hfp_ag_callback) return;
1013     (*hfp_ag_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1014 }
1015 
1016 static void hfp_ag_trigger_terminate_call(void){
1017     int call_indicator_index = get_ag_indicator_index_for_name("call");
1018 
1019     btstack_linked_list_iterator_t it;
1020     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1021     while (btstack_linked_list_iterator_has_next(&it)){
1022         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1023         hfp_ag_establish_service_level_connection(hfp_connection->remote_addr);
1024         if (hfp_connection->call_state == HFP_CALL_IDLE) continue;
1025         hfp_connection->call_state = HFP_CALL_IDLE;
1026         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
1027         hfp_connection->release_audio_connection = 1;
1028         hfp_run_for_context(hfp_connection);
1029     }
1030     hfp_ag_emit_simple_event(HFP_SUBEVENT_CALL_TERMINATED);
1031 }
1032 
1033 static void hfp_ag_set_callsetup_indicator(void){
1034     hfp_ag_indicator_t * indicator = get_ag_indicator_for_name("callsetup");
1035     if (!indicator){
1036         log_error("hfp_ag_set_callsetup_indicator: callsetup indicator is missing");
1037         return;
1038     };
1039     indicator->status = hfp_gsm_callsetup_status();
1040 }
1041 
1042 static void hfp_ag_set_callheld_indicator(void){
1043     hfp_ag_indicator_t * indicator = get_ag_indicator_for_name("callheld");
1044     if (!indicator){
1045         log_error("hfp_ag_set_callheld_state: callheld indicator is missing");
1046         return;
1047     };
1048     indicator->status = hfp_gsm_callheld_status();
1049 }
1050 
1051 static void hfp_ag_set_call_indicator(void){
1052     hfp_ag_indicator_t * indicator = get_ag_indicator_for_name("call");
1053     if (!indicator){
1054         log_error("hfp_ag_set_call_state: call indicator is missing");
1055         return;
1056     };
1057     indicator->status = hfp_gsm_call_status();
1058 }
1059 
1060 static void hfp_ag_stop_ringing(void){
1061     btstack_linked_list_iterator_t it;
1062     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1063     while (btstack_linked_list_iterator_has_next(&it)){
1064         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1065         if (hfp_connection->call_state != HFP_CALL_RINGING &&
1066             hfp_connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING) continue;
1067         hfp_ag_hf_stop_ringing(hfp_connection);
1068     }
1069 }
1070 
1071 static hfp_connection_t * hfp_ag_connection_for_call_state(hfp_call_state_t call_state){
1072     btstack_linked_list_iterator_t it;
1073     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1074     while (btstack_linked_list_iterator_has_next(&it)){
1075         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1076         if (hfp_connection->call_state == call_state) return hfp_connection;
1077     }
1078     return NULL;
1079 }
1080 
1081 static void hfp_ag_send_response_and_hold_state(hfp_response_and_hold_state_t state){
1082     btstack_linked_list_iterator_t it;
1083     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1084     while (btstack_linked_list_iterator_has_next(&it)){
1085         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1086         hfp_connection->send_response_and_hold_status = state + 1;
1087     }
1088 }
1089 
1090 static int call_setup_state_machine(hfp_connection_t * hfp_connection){
1091     int indicator_index;
1092     switch (hfp_connection->call_state){
1093         case HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING:
1094             if (hfp_connection->state != HFP_AUDIO_CONNECTION_ESTABLISHED) return 0;
1095             // we got event: audio hfp_connection established
1096             hfp_timeout_start(hfp_connection);
1097             hfp_connection->ag_ring = 1;
1098             hfp_connection->ag_send_clip = hfp_gsm_clip_type() && hfp_connection->clip_enabled;
1099             hfp_connection->call_state = HFP_CALL_RINGING;
1100             hfp_connection->call_state = HFP_CALL_RINGING;
1101             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_START_RINGINIG);
1102             break;
1103         case HFP_CALL_W4_AUDIO_CONNECTION_FOR_ACTIVE:
1104             if (hfp_connection->state != HFP_AUDIO_CONNECTION_ESTABLISHED) return 0;
1105             // we got event: audio hfp_connection established
1106             hfp_connection->call_state = HFP_CALL_ACTIVE;
1107             break;
1108         case HFP_CALL_W2_SEND_CALL_WAITING:
1109             hfp_connection->call_state = HFP_CALL_W4_CHLD;
1110             hfp_ag_send_call_waiting_notification(hfp_connection->rfcomm_cid);
1111             indicator_index = get_ag_indicator_index_for_name("callsetup");
1112             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
1113             break;
1114         default:
1115             break;
1116     }
1117     return 0;
1118 }
1119 // hfp_connection is used to identify originating HF
1120 static void hfp_ag_call_sm(hfp_ag_call_event_t event, hfp_connection_t * hfp_connection){
1121     int indicator_index;
1122     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
1123     int callheld_indicator_index = get_ag_indicator_index_for_name("callheld");
1124     int call_indicator_index = get_ag_indicator_index_for_name("call");
1125 
1126     //printf("hfp_ag_call_sm event %d \n", event);
1127     switch (event){
1128         case HFP_AG_INCOMING_CALL:
1129             switch (hfp_gsm_call_status()){
1130                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1131                     switch (hfp_gsm_callsetup_status()){
1132                         case HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS:
1133                             hfp_gsm_handle_event(HFP_AG_INCOMING_CALL);
1134                             hfp_ag_set_callsetup_indicator();
1135                             hfp_ag_trigger_incoming_call();
1136                             log_info("AG rings");
1137                             break;
1138                         default:
1139                             break;
1140                     }
1141                     break;
1142                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1143                     switch (hfp_gsm_callsetup_status()){
1144                         case HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS:
1145                             hfp_gsm_handle_event(HFP_AG_INCOMING_CALL);
1146                             hfp_ag_set_callsetup_indicator();
1147                             hfp_ag_trigger_incoming_call();
1148                             log_info("AG call waiting");
1149                             break;
1150                         default:
1151                             break;
1152                     }
1153                     break;
1154             }
1155             break;
1156         case HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG:
1157             switch (hfp_gsm_call_status()){
1158                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1159                     switch (hfp_gsm_callsetup_status()){
1160                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1161                             hfp_gsm_handle_event(HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG);
1162                             hfp_ag_set_call_indicator();
1163                             hfp_ag_set_callsetup_indicator();
1164                             hfp_ag_ag_accept_call();
1165                             log_info("AG answers call, accept call by GSM");
1166                             break;
1167                         default:
1168                             break;
1169                     }
1170                     break;
1171                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1172                     switch (hfp_gsm_callsetup_status()){
1173                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1174                             log_info("AG: current call is placed on hold, incoming call gets active");
1175                             hfp_gsm_handle_event(HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG);
1176                             hfp_ag_set_callsetup_indicator();
1177                             hfp_ag_set_callheld_indicator();
1178                             hfp_ag_transfer_callsetup_state();
1179                             hfp_ag_transfer_callheld_state();
1180                             break;
1181                         default:
1182                             break;
1183                     }
1184                     break;
1185             }
1186             break;
1187 
1188         case HFP_AG_HELD_CALL_JOINED_BY_AG:
1189             switch (hfp_gsm_call_status()){
1190                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1191                     switch (hfp_gsm_callheld_status()){
1192                         case HFP_CALLHELD_STATUS_CALL_ON_HOLD_OR_SWAPPED:
1193                             log_info("AG: joining held call with active call");
1194                             hfp_gsm_handle_event(HFP_AG_HELD_CALL_JOINED_BY_AG);
1195                             hfp_ag_set_callheld_indicator();
1196                             hfp_ag_transfer_callheld_state();
1197                             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CONFERENCE_CALL);
1198                             break;
1199                         default:
1200                             break;
1201                     }
1202                     break;
1203                 default:
1204                     break;
1205             }
1206             break;
1207 
1208         case HFP_AG_INCOMING_CALL_ACCEPTED_BY_HF:
1209             switch (hfp_gsm_call_status()){
1210                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1211                     switch (hfp_gsm_callsetup_status()){
1212                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1213                             hfp_gsm_handle_event(HFP_AG_INCOMING_CALL_ACCEPTED_BY_HF);
1214                             hfp_ag_set_callsetup_indicator();
1215                             hfp_ag_set_call_indicator();
1216                             hfp_ag_hf_accept_call(hfp_connection);
1217                             log_info("HF answers call, accept call by GSM");
1218                             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CALL_ANSWERED);
1219                             break;
1220                         default:
1221                             break;
1222                     }
1223                     break;
1224                 default:
1225                     break;
1226             }
1227             break;
1228 
1229         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_AG:
1230             switch (hfp_gsm_call_status()){
1231                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1232                     switch (hfp_gsm_callsetup_status()){
1233                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1234                             hfp_gsm_handle_event(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_AG);
1235                             hfp_ag_response_and_hold_active = 1;
1236                             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD;
1237                             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1238                             // as with regualr call
1239                             hfp_ag_set_call_indicator();
1240                             hfp_ag_set_callsetup_indicator();
1241                             hfp_ag_ag_accept_call();
1242                             log_info("AG response and hold - hold by AG");
1243                             break;
1244                         default:
1245                             break;
1246                     }
1247                     break;
1248                 default:
1249                     break;
1250             }
1251             break;
1252 
1253         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_HF:
1254             switch (hfp_gsm_call_status()){
1255                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1256                     switch (hfp_gsm_callsetup_status()){
1257                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1258                             hfp_gsm_handle_event(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_HF);
1259                             hfp_ag_response_and_hold_active = 1;
1260                             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD;
1261                             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1262                             // as with regualr call
1263                             hfp_ag_set_call_indicator();
1264                             hfp_ag_set_callsetup_indicator();
1265                             hfp_ag_hf_accept_call(hfp_connection);
1266                             log_info("AG response and hold - hold by HF");
1267                             break;
1268                         default:
1269                             break;
1270                     }
1271                     break;
1272                 default:
1273                     break;
1274             }
1275             break;
1276 
1277         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_AG:
1278         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_HF:
1279             if (!hfp_ag_response_and_hold_active) break;
1280             if (hfp_ag_response_and_hold_state != HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD) break;
1281             hfp_gsm_handle_event(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_AG);
1282             hfp_ag_response_and_hold_active = 0;
1283             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_HELD_INCOMING_ACCEPTED;
1284             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1285             log_info("Held Call accepted and active");
1286             break;
1287 
1288         case HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_AG:
1289         case HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_HF:
1290             if (!hfp_ag_response_and_hold_active) break;
1291             if (hfp_ag_response_and_hold_state != HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD) break;
1292             hfp_gsm_handle_event(HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_AG);
1293             hfp_ag_response_and_hold_active = 0;
1294             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_HELD_INCOMING_REJECTED;
1295             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1296             // from terminate by ag
1297             hfp_ag_set_call_indicator();
1298             hfp_ag_trigger_terminate_call();
1299             break;
1300 
1301         case HFP_AG_TERMINATE_CALL_BY_HF:
1302             switch (hfp_gsm_call_status()){
1303                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1304                     switch (hfp_gsm_callsetup_status()){
1305                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1306                             hfp_gsm_handle_event(HFP_AG_TERMINATE_CALL_BY_HF);
1307                             hfp_ag_set_callsetup_indicator();
1308                             hfp_ag_transfer_callsetup_state();
1309                             hfp_ag_trigger_reject_call();
1310                             log_info("HF Rejected Incoming call, AG terminate call");
1311                             break;
1312                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_DIALING_STATE:
1313                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_ALERTING_STATE:
1314                             hfp_gsm_handle_event(HFP_AG_TERMINATE_CALL_BY_HF);
1315                             hfp_ag_set_callsetup_indicator();
1316                             hfp_ag_transfer_callsetup_state();
1317                             log_info("AG terminate outgoing call process");
1318                             break;
1319                         default:
1320                             break;
1321                     }
1322                     break;
1323                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1324                     hfp_gsm_handle_event(HFP_AG_TERMINATE_CALL_BY_HF);
1325                     hfp_ag_set_call_indicator();
1326                     hfp_ag_transfer_call_state();
1327                     hfp_connection->call_state = HFP_CALL_IDLE;
1328                     log_info("AG terminate call");
1329                     break;
1330             }
1331             break;
1332 
1333         case HFP_AG_TERMINATE_CALL_BY_AG:
1334             switch (hfp_gsm_call_status()){
1335                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1336                     switch (hfp_gsm_callsetup_status()){
1337                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1338                             hfp_gsm_handle_event(HFP_AG_TERMINATE_CALL_BY_AG);
1339                             hfp_ag_set_callsetup_indicator();
1340                             hfp_ag_trigger_reject_call();
1341                             log_info("AG Rejected Incoming call, AG terminate call");
1342                             break;
1343                         default:
1344                             break;
1345                     }
1346                     break;
1347                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1348                     hfp_gsm_handle_event(HFP_AG_TERMINATE_CALL_BY_AG);
1349                     hfp_ag_set_callsetup_indicator();
1350                     hfp_ag_set_call_indicator();
1351                     hfp_ag_trigger_terminate_call();
1352                     log_info("AG terminate call");
1353                     break;
1354                 default:
1355                     break;
1356             }
1357             break;
1358         case HFP_AG_CALL_DROPPED:
1359             switch (hfp_gsm_call_status()){
1360                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1361                     switch (hfp_gsm_callsetup_status()){
1362                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1363                             hfp_ag_stop_ringing();
1364                             log_info("Incoming call interrupted");
1365                             break;
1366                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_DIALING_STATE:
1367                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_ALERTING_STATE:
1368                             log_info("Outgoing call interrupted\n");
1369                             log_info("AG notify call dropped\n");
1370                             break;
1371                         default:
1372                             break;
1373                     }
1374                     hfp_gsm_handle_event(HFP_AG_CALL_DROPPED);
1375                     hfp_ag_set_callsetup_indicator();
1376                     hfp_ag_transfer_callsetup_state();
1377                     break;
1378                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1379                     if (hfp_ag_response_and_hold_active) {
1380                         hfp_gsm_handle_event(HFP_AG_CALL_DROPPED);
1381                         hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_HELD_INCOMING_REJECTED;
1382                         hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1383                     }
1384                     hfp_gsm_handle_event(HFP_AG_CALL_DROPPED);
1385                     hfp_ag_set_callsetup_indicator();
1386                     hfp_ag_set_call_indicator();
1387                     hfp_ag_trigger_terminate_call();
1388                     log_info("AG notify call dropped");
1389                     break;
1390                 default:
1391                     break;
1392             }
1393             break;
1394 
1395         case HFP_AG_OUTGOING_CALL_INITIATED:
1396             // directly reject call if number of free slots is exceeded
1397             if (!hfp_gsm_call_possible()){
1398                 hfp_connection->send_error = 1;
1399                 hfp_run_for_context(hfp_connection);
1400                 break;
1401             }
1402             hfp_gsm_handle_event_with_call_number(HFP_AG_OUTGOING_CALL_INITIATED, (const char *) &hfp_connection->line_buffer[3]);
1403 
1404             hfp_connection->call_state = HFP_CALL_OUTGOING_INITIATED;
1405 
1406             hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_PLACE_CALL_WITH_NUMBER, (const char *) &hfp_connection->line_buffer[3]);
1407             break;
1408 
1409         case HFP_AG_OUTGOING_REDIAL_INITIATED:{
1410             // directly reject call if number of free slots is exceeded
1411             if (!hfp_gsm_call_possible()){
1412                 hfp_connection->send_error = 1;
1413                 hfp_run_for_context(hfp_connection);
1414                 break;
1415             }
1416 
1417             hfp_gsm_handle_event(HFP_AG_OUTGOING_REDIAL_INITIATED);
1418             hfp_connection->call_state = HFP_CALL_OUTGOING_INITIATED;
1419 
1420             log_info("Redial last number");
1421             char * last_dialed_number = hfp_gsm_last_dialed_number();
1422 
1423             if (strlen(last_dialed_number) > 0){
1424                 log_info("Last number exists: accept call");
1425                 hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_PLACE_CALL_WITH_NUMBER, last_dialed_number);
1426             } else {
1427                 log_info("log_infoLast number missing: reject call");
1428                 hfp_ag_outgoing_call_rejected();
1429             }
1430             break;
1431         }
1432         case HFP_AG_OUTGOING_CALL_REJECTED:
1433             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_INITIATED);
1434             if (!hfp_connection){
1435                 log_info("hfp_ag_call_sm: did not find outgoing hfp_connection in initiated state");
1436                 break;
1437             }
1438 
1439             hfp_gsm_handle_event(HFP_AG_OUTGOING_CALL_REJECTED);
1440             hfp_connection->call_state = HFP_CALL_IDLE;
1441             hfp_connection->send_error = 1;
1442             hfp_run_for_context(hfp_connection);
1443             break;
1444 
1445         case HFP_AG_OUTGOING_CALL_ACCEPTED:{
1446             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_INITIATED);
1447             if (!hfp_connection){
1448                 log_info("hfp_ag_call_sm: did not find outgoing hfp_connection in initiated state");
1449                 break;
1450             }
1451 
1452             hfp_connection->ok_pending = 1;
1453             hfp_connection->call_state = HFP_CALL_OUTGOING_DIALING;
1454 
1455             // trigger callsetup to be
1456             int put_call_on_hold = hfp_gsm_call_status() == HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT;
1457             hfp_gsm_handle_event(HFP_AG_OUTGOING_CALL_ACCEPTED);
1458 
1459             hfp_ag_set_callsetup_indicator();
1460             indicator_index = get_ag_indicator_index_for_name("callsetup");
1461             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
1462 
1463             // put current call on hold if active
1464             if (put_call_on_hold){
1465                 log_info("AG putting current call on hold for new outgoing calllog_info");
1466                 hfp_ag_set_callheld_indicator();
1467                 indicator_index = get_ag_indicator_index_for_name("callheld");
1468                 hfp_ag_send_transfer_ag_indicators_status_cmd(hfp_connection->rfcomm_cid, &hfp_ag_indicators[indicator_index]);
1469             }
1470 
1471             // start audio if needed
1472             hfp_ag_establish_audio_connection(hfp_connection->acl_handle);
1473             break;
1474         }
1475         case HFP_AG_OUTGOING_CALL_RINGING:
1476             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_DIALING);
1477             if (!hfp_connection){
1478                 log_info("hfp_ag_call_sm: did not find outgoing hfp_connection in dialing state");
1479                 break;
1480             }
1481 
1482             hfp_gsm_handle_event(HFP_AG_OUTGOING_CALL_RINGING);
1483             hfp_connection->call_state = HFP_CALL_OUTGOING_RINGING;
1484             hfp_ag_set_callsetup_indicator();
1485             hfp_ag_transfer_callsetup_state();
1486             break;
1487 
1488         case HFP_AG_OUTGOING_CALL_ESTABLISHED:{
1489             // get outgoing call
1490             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_RINGING);
1491             if (!hfp_connection){
1492                 hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_DIALING);
1493             }
1494             if (!hfp_connection){
1495                 log_info("hfp_ag_call_sm: did not find outgoing hfp_connection");
1496                 break;
1497             }
1498 
1499             int CALLHELD_STATUS_CALL_ON_HOLD_AND_NO_ACTIVE_CALLS = hfp_gsm_callheld_status() == HFP_CALLHELD_STATUS_CALL_ON_HOLD_AND_NO_ACTIVE_CALLS;
1500             hfp_gsm_handle_event(HFP_AG_OUTGOING_CALL_ESTABLISHED);
1501             hfp_connection->call_state = HFP_CALL_ACTIVE;
1502             hfp_ag_set_callsetup_indicator();
1503             hfp_ag_set_call_indicator();
1504             hfp_ag_transfer_call_state();
1505             hfp_ag_transfer_callsetup_state();
1506             if (CALLHELD_STATUS_CALL_ON_HOLD_AND_NO_ACTIVE_CALLS){
1507                 hfp_ag_set_callheld_indicator();
1508                 hfp_ag_transfer_callheld_state();
1509             }
1510             break;
1511         }
1512 
1513         case HFP_AG_CALL_HOLD_USER_BUSY:
1514             hfp_gsm_handle_event(HFP_AG_CALL_HOLD_USER_BUSY);
1515             hfp_ag_set_callsetup_indicator();
1516             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1517             hfp_connection->call_state = HFP_CALL_ACTIVE;
1518             log_info("AG: Call Waiting, User Busy");
1519             break;
1520 
1521         case HFP_AG_CALL_HOLD_RELEASE_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL:{
1522             int call_setup_in_progress = hfp_gsm_callsetup_status() != HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS;
1523             int call_held = hfp_gsm_callheld_status() != HFP_CALLHELD_STATUS_NO_CALLS_HELD;
1524 
1525             // Releases all active calls (if any exist) and accepts the other (held or waiting) call.
1526             if (call_held || call_setup_in_progress){
1527                 hfp_gsm_handle_event_with_call_index(HFP_AG_CALL_HOLD_RELEASE_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection->call_index);
1528 
1529             }
1530 
1531             if (call_setup_in_progress){
1532                 log_info("AG: Call Dropped, Accept new call");
1533                 hfp_ag_set_callsetup_indicator();
1534                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1535             } else {
1536                 log_info("AG: Call Dropped, Resume held call");
1537             }
1538             if (call_held){
1539                 hfp_ag_set_callheld_indicator();
1540                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
1541             }
1542 
1543             hfp_connection->call_state = HFP_CALL_ACTIVE;
1544             break;
1545         }
1546 
1547         case HFP_AG_CALL_HOLD_PARK_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL:{
1548             // Places all active calls (if any exist) on hold and accepts the other (held or waiting) call.
1549             // only update if callsetup changed
1550             int call_setup_in_progress = hfp_gsm_callsetup_status() != HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS;
1551             hfp_gsm_handle_event_with_call_index(HFP_AG_CALL_HOLD_PARK_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection->call_index);
1552 
1553             if (call_setup_in_progress){
1554                 log_info("AG: Call on Hold, Accept new call");
1555                 hfp_ag_set_callsetup_indicator();
1556                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1557             } else {
1558                 log_info("AG: Swap calls");
1559             }
1560 
1561             hfp_ag_set_callheld_indicator();
1562             // hfp_ag_set_callheld_state(HFP_CALLHELD_STATUS_CALL_ON_HOLD_OR_SWAPPED);
1563             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
1564             hfp_connection->call_state = HFP_CALL_ACTIVE;
1565             break;
1566         }
1567 
1568         case HFP_AG_CALL_HOLD_ADD_HELD_CALL:
1569             // Adds a held call to the conversation.
1570             if (hfp_gsm_callheld_status() != HFP_CALLHELD_STATUS_NO_CALLS_HELD){
1571                 log_info("AG: Join 3-way-call");
1572                 hfp_gsm_handle_event(HFP_AG_CALL_HOLD_ADD_HELD_CALL);
1573                 hfp_ag_set_callheld_indicator();
1574                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
1575                 hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CONFERENCE_CALL);
1576             }
1577             hfp_connection->call_state = HFP_CALL_ACTIVE;
1578             break;
1579         case HFP_AG_CALL_HOLD_EXIT_AND_JOIN_CALLS:
1580             // Connects the two calls and disconnects the subscriber from both calls (Explicit Call Transfer)
1581             hfp_gsm_handle_event(HFP_AG_CALL_HOLD_EXIT_AND_JOIN_CALLS);
1582             log_info("AG: Transfer call -> Connect two calls and disconnect");
1583             hfp_ag_set_call_indicator();
1584             hfp_ag_set_callheld_indicator();
1585             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
1586             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
1587             hfp_connection->call_state = HFP_CALL_IDLE;
1588             break;
1589 
1590         default:
1591             break;
1592     }
1593 
1594 
1595 }
1596 
1597 
1598 static void hfp_ag_send_call_status(hfp_connection_t * hfp_connection, int call_index){
1599     hfp_gsm_call_t * active_call = hfp_gsm_call(call_index);
1600     if (!active_call) return;
1601 
1602     int idx = active_call->index;
1603     hfp_enhanced_call_dir_t dir = active_call->direction;
1604     hfp_enhanced_call_status_t status = active_call->enhanced_status;
1605     hfp_enhanced_call_mode_t mode = active_call->mode;
1606     hfp_enhanced_call_mpty_t mpty = active_call->mpty;
1607     uint8_t type = active_call->clip_type;
1608     char * number = active_call->clip_number;
1609 
1610     char buffer[100];
1611     // TODO: check length of a buffer, to fit the MTU
1612     int offset = snprintf(buffer, sizeof(buffer), "\r\n%s: %d,%d,%d,%d,%d", HFP_LIST_CURRENT_CALLS, idx, dir, status, mode, mpty);
1613     if (number){
1614         offset += snprintf(buffer+offset, sizeof(buffer)-offset-3, ", \"%s\",%u", number, type);
1615     }
1616     snprintf(buffer+offset, sizeof(buffer)-offset, "\r\n");
1617     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,
1618        mode, mpty, type, number);
1619     send_str_over_rfcomm(hfp_connection->rfcomm_cid, buffer);
1620 }
1621 
1622 static void hfp_run_for_context(hfp_connection_t *hfp_connection){
1623     if (!hfp_connection) return;
1624     if (!hfp_connection->rfcomm_cid) return;
1625 
1626     if (hfp_connection->local_role != HFP_ROLE_AG) {
1627         log_info("HFP AG%p, wrong role %u", hfp_connection, hfp_connection->local_role);
1628         return;
1629     }
1630 
1631     if (!rfcomm_can_send_packet_now(hfp_connection->rfcomm_cid)) {
1632         log_info("hfp_run_for_context: request can send for 0x%02x", hfp_connection->rfcomm_cid);
1633         rfcomm_request_can_send_now_event(hfp_connection->rfcomm_cid);
1634         return;
1635     }
1636     if (hfp_connection->send_status_of_current_calls){
1637         hfp_connection->ok_pending = 0;
1638         if (hfp_connection->next_call_index < hfp_gsm_get_number_of_calls()){
1639             hfp_connection->next_call_index++;
1640             hfp_ag_send_call_status(hfp_connection, hfp_connection->next_call_index);
1641         } else {
1642             hfp_connection->next_call_index = 0;
1643             hfp_connection->ok_pending = 1;
1644             hfp_connection->send_status_of_current_calls = 0;
1645         }
1646         return;
1647     }
1648 
1649     if (hfp_connection->ag_notify_incoming_call_waiting){
1650         hfp_connection->ag_notify_incoming_call_waiting = 0;
1651         hfp_ag_send_call_waiting_notification(hfp_connection->rfcomm_cid);
1652         return;
1653     }
1654 
1655     if (hfp_connection->command == HFP_CMD_UNKNOWN){
1656         hfp_connection->ok_pending = 0;
1657         hfp_connection->send_error = 0;
1658         hfp_connection->command = HFP_CMD_NONE;
1659         hfp_ag_send_error(hfp_connection->rfcomm_cid);
1660         return;
1661     }
1662 
1663     if (hfp_connection->send_error){
1664         hfp_connection->send_error = 0;
1665         hfp_connection->command = HFP_CMD_NONE;
1666         hfp_ag_send_error(hfp_connection->rfcomm_cid);
1667         return;
1668     }
1669 
1670     // note: before update AG indicators and ok_pending
1671     if (hfp_connection->send_response_and_hold_status){
1672         int status = hfp_connection->send_response_and_hold_status - 1;
1673         hfp_connection->send_response_and_hold_status = 0;
1674         hfp_ag_send_set_response_and_hold(hfp_connection->rfcomm_cid, status);
1675         return;
1676     }
1677 
1678     if (hfp_connection->ok_pending){
1679         hfp_connection->ok_pending = 0;
1680         hfp_connection->command = HFP_CMD_NONE;
1681         hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1682         return;
1683     }
1684 
1685     // update AG indicators
1686     if (hfp_connection->ag_indicators_status_update_bitmap){
1687         int i;
1688         for (i=0;i<hfp_connection->ag_indicators_nr;i++){
1689             if (get_bit(hfp_connection->ag_indicators_status_update_bitmap, i)){
1690                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, i, 0);
1691                 if (!hfp_connection->enable_status_update_for_ag_indicators) {
1692                     log_info("+CMER:3,0,0,0 - not sending update for '%s'", hfp_ag_indicators[i].name);
1693                     break;
1694                 }
1695                 hfp_ag_send_transfer_ag_indicators_status_cmd(hfp_connection->rfcomm_cid, &hfp_ag_indicators[i]);
1696                 return;
1697             }
1698         }
1699     }
1700 
1701     if (hfp_connection->ag_ring){
1702         hfp_connection->ag_ring = 0;
1703         hfp_connection->command = HFP_CMD_NONE;
1704         hfp_ag_send_ring(hfp_connection->rfcomm_cid);
1705         return;
1706     }
1707 
1708     if (hfp_connection->ag_send_clip){
1709         hfp_connection->ag_send_clip = 0;
1710         hfp_connection->command = HFP_CMD_NONE;
1711         hfp_ag_send_clip(hfp_connection->rfcomm_cid);
1712         return;
1713     }
1714 
1715     if (hfp_connection->send_phone_number_for_voice_tag){
1716         hfp_connection->send_phone_number_for_voice_tag = 0;
1717         hfp_connection->command = HFP_CMD_NONE;
1718         hfp_connection->ok_pending = 1;
1719         hfp_ag_send_phone_number_for_voice_tag_cmd(hfp_connection->rfcomm_cid);
1720         return;
1721     }
1722 
1723     if (hfp_connection->send_subscriber_number){
1724         if (hfp_connection->next_subscriber_number_to_send < subscriber_numbers_count){
1725             hfp_phone_number_t phone = subscriber_numbers[hfp_connection->next_subscriber_number_to_send++];
1726             hfp_send_subscriber_number_cmd(hfp_connection->rfcomm_cid, phone.type, phone.number);
1727         } else {
1728             hfp_connection->send_subscriber_number = 0;
1729             hfp_connection->next_subscriber_number_to_send = 0;
1730             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1731         }
1732         hfp_connection->command = HFP_CMD_NONE;
1733 
1734     }
1735 
1736     if (hfp_connection->send_microphone_gain){
1737         hfp_connection->send_microphone_gain = 0;
1738         hfp_connection->command = HFP_CMD_NONE;
1739         hfp_ag_send_set_microphone_gain_cmd(hfp_connection->rfcomm_cid, hfp_connection->microphone_gain);
1740         return;
1741     }
1742 
1743     if (hfp_connection->send_speaker_gain){
1744         hfp_connection->send_speaker_gain = 0;
1745         hfp_connection->command = HFP_CMD_NONE;
1746         hfp_ag_send_set_speaker_gain_cmd(hfp_connection->rfcomm_cid, hfp_connection->speaker_gain);
1747         return;
1748     }
1749 
1750     if (hfp_connection->send_ag_status_indicators){
1751         hfp_connection->send_ag_status_indicators = 0;
1752         hfp_ag_send_retrieve_indicators_status_cmd(hfp_connection->rfcomm_cid);
1753         return;
1754     }
1755 
1756     // trigger codec exchange if requested by app
1757     if (hfp_connection->trigger_codec_exchange){
1758         log_info("trigger codec, command %u, codec state %u", hfp_connection->command, hfp_connection->codecs_state);
1759     }
1760     if (hfp_connection->trigger_codec_exchange && hfp_connection->command == HFP_CMD_NONE){
1761         switch (hfp_connection->codecs_state){
1762             case HFP_CODECS_IDLE:
1763             case HFP_CODECS_RECEIVED_LIST:
1764             case HFP_CODECS_AG_RESEND_COMMON_CODEC:
1765             case HFP_CODECS_ERROR:
1766                 hfp_connection->trigger_codec_exchange = 0;
1767                 hfp_connection->command = HFP_CMD_AG_SEND_COMMON_CODEC;
1768                 break;
1769             default:
1770                 break;
1771         }
1772     }
1773 
1774     int cmd_sent = hfp_ag_run_for_context_service_level_connection(hfp_connection);
1775     if (!cmd_sent){
1776         cmd_sent = hfp_ag_run_for_context_service_level_connection_queries(hfp_connection);
1777     }
1778 
1779     if (!cmd_sent){
1780         cmd_sent = call_setup_state_machine(hfp_connection);
1781     }
1782 
1783     if (!cmd_sent){
1784         cmd_sent = hfp_ag_run_for_audio_connection(hfp_connection);
1785     }
1786 
1787     if (hfp_connection->command == HFP_CMD_NONE && !cmd_sent){
1788         // log_info("hfp_connection->command == HFP_CMD_NONE");
1789         switch(hfp_connection->state){
1790             case HFP_W2_DISCONNECT_RFCOMM:
1791                 hfp_connection->state = HFP_W4_RFCOMM_DISCONNECTED;
1792                 rfcomm_disconnect(hfp_connection->rfcomm_cid);
1793                 break;
1794             default:
1795                 break;
1796         }
1797     }
1798 
1799     if (cmd_sent){
1800         hfp_connection->command = HFP_CMD_NONE;
1801         rfcomm_request_can_send_now_event(hfp_connection->rfcomm_cid);
1802     }
1803 }
1804 
1805 static hfp_generic_status_indicator_t *get_hf_indicator_by_number(int number){
1806     int i;
1807     for (i=0;i< hfp_generic_status_indicators_nr;i++){
1808         hfp_generic_status_indicator_t * indicator = &hfp_generic_status_indicators[i];
1809         if (indicator->uuid == number){
1810             return indicator;
1811         }
1812     }
1813     return NULL;
1814 }
1815 
1816 static void hfp_ag_handle_rfcomm_data(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
1817     UNUSED(packet_type);    // ok: only called with RFCOMM_DATA_PACKET
1818 
1819     // assertion: size >= 1 as rfcomm.c does not deliver empty packets
1820     if (size < 1) return;
1821 
1822     hfp_connection_t * hfp_connection = get_hfp_connection_context_for_rfcomm_cid(channel);
1823     if (!hfp_connection) return;
1824 
1825     // temp overwrite last byte (most likely \n for log_info)
1826     char last_char = packet[size-1];
1827     packet[size-1] = 0;
1828     log_info("HFP_RX %s", packet);
1829     packet[size-1] = last_char;
1830 
1831     // process messages byte-wise
1832     int pos;
1833     for (pos = 0; pos < size ; pos++){
1834         hfp_parse(hfp_connection, packet[pos], 0);
1835     }
1836     hfp_generic_status_indicator_t * indicator;
1837     int value;
1838     switch(hfp_connection->command){
1839         case HFP_CMD_RESPONSE_AND_HOLD_QUERY:
1840             if (hfp_ag_response_and_hold_active){
1841                 hfp_connection->send_response_and_hold_status = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD + 1;
1842             }
1843             hfp_connection->ok_pending = 1;
1844             break;
1845         case HFP_CMD_RESPONSE_AND_HOLD_COMMAND:
1846             value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1847             log_info("HF Response and Hold: %u", value);
1848             switch(value){
1849                 case HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD:
1850                     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_HF, hfp_connection);
1851                     break;
1852                 case HFP_RESPONSE_AND_HOLD_HELD_INCOMING_ACCEPTED:
1853                     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_HF, hfp_connection);
1854                     break;
1855                 case HFP_RESPONSE_AND_HOLD_HELD_INCOMING_REJECTED:
1856                     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_HF, hfp_connection);
1857                     break;
1858                 default:
1859                     break;
1860             }
1861             hfp_connection->ok_pending = 1;
1862             break;
1863         case HFP_CMD_HF_INDICATOR_STATUS:
1864             hfp_connection->command = HFP_CMD_NONE;
1865             // find indicator by assigned number
1866             indicator = get_hf_indicator_by_number(hfp_connection->parser_indicator_index);
1867             if (!indicator){
1868                 hfp_connection->send_error = 1;
1869                 break;
1870             }
1871             value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1872             switch (indicator->uuid){
1873                 case 1: // enhanced security
1874                     if (value > 1) {
1875                         hfp_connection->send_error = 1;
1876                         return;
1877                     }
1878                     log_info("HF Indicator 'enhanced security' set to %u", value);
1879                     break;
1880                 case 2: // battery level
1881                     if (value > 100){
1882                         hfp_connection->send_error = 1;
1883                         return;
1884                     }
1885                     log_info("HF Indicator 'battery' set to %u", value);
1886                     break;
1887                 default:
1888                     log_info("HF Indicator unknown set to %u", value);
1889                     break;
1890             }
1891             hfp_connection->ok_pending = 1;
1892             break;
1893         case HFP_CMD_RETRIEVE_AG_INDICATORS_STATUS:
1894             // expected by SLC state machine
1895             if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED) break;
1896             hfp_connection->send_ag_indicators_segment = 0;
1897             hfp_connection->send_ag_status_indicators = 1;
1898             break;
1899         case HFP_CMD_LIST_CURRENT_CALLS:
1900             hfp_connection->command = HFP_CMD_NONE;
1901             hfp_connection->next_call_index = 0;
1902             hfp_connection->send_status_of_current_calls = 1;
1903             break;
1904         case HFP_CMD_GET_SUBSCRIBER_NUMBER_INFORMATION:
1905             if (subscriber_numbers_count == 0){
1906                 hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1907                 break;
1908             }
1909             hfp_connection->next_subscriber_number_to_send = 0;
1910             hfp_connection->send_subscriber_number = 1;
1911             break;
1912         case HFP_CMD_TRANSMIT_DTMF_CODES:
1913             hfp_connection->command = HFP_CMD_NONE;
1914             hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_TRANSMIT_DTMF_CODES, (const char *) &hfp_connection->line_buffer[0]);
1915             break;
1916         case HFP_CMD_HF_REQUEST_PHONE_NUMBER:
1917             hfp_connection->command = HFP_CMD_NONE;
1918             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_ATTACH_NUMBER_TO_VOICE_TAG);
1919             break;
1920         case HFP_CMD_TURN_OFF_EC_AND_NR:
1921             hfp_connection->command = HFP_CMD_NONE;
1922             if (get_bit(hfp_supported_features, HFP_AGSF_EC_NR_FUNCTION)){
1923                 hfp_connection->ok_pending = 1;
1924                 hfp_supported_features = store_bit(hfp_supported_features, HFP_AGSF_EC_NR_FUNCTION, hfp_connection->ag_echo_and_noise_reduction);
1925                 log_info("AG: EC/NR = %u", hfp_connection->ag_echo_and_noise_reduction);
1926             } else {
1927                 hfp_connection->send_error = 1;
1928             }
1929             break;
1930         case HFP_CMD_CALL_ANSWERED:
1931             hfp_connection->command = HFP_CMD_NONE;
1932             log_info("HFP: ATA");
1933             hfp_ag_call_sm(HFP_AG_INCOMING_CALL_ACCEPTED_BY_HF, hfp_connection);
1934             break;
1935         case HFP_CMD_HANG_UP_CALL:
1936             hfp_connection->command = HFP_CMD_NONE;
1937             hfp_connection->ok_pending = 1;
1938             hfp_ag_call_sm(HFP_AG_TERMINATE_CALL_BY_HF, hfp_connection);
1939             break;
1940         case HFP_CMD_CALL_HOLD: {
1941             // TODO: fully implement this
1942             log_error("HFP: unhandled call hold type %c", hfp_connection->line_buffer[0]);
1943             hfp_connection->command = HFP_CMD_NONE;
1944             hfp_connection->ok_pending = 1;
1945             hfp_connection->call_index = 0;
1946 
1947             if (hfp_connection->line_buffer[1] != '\0'){
1948                 hfp_connection->call_index = btstack_atoi((char *)&hfp_connection->line_buffer[1]);
1949             }
1950 
1951             switch (hfp_connection->line_buffer[0]){
1952                 case '0':
1953                     // Releases all held calls or sets User Determined User Busy (UDUB) for a waiting call.
1954                     hfp_ag_call_sm(HFP_AG_CALL_HOLD_USER_BUSY, hfp_connection);
1955                     break;
1956                 case '1':
1957                     // Releases all active calls (if any exist) and accepts the other (held or waiting) call.
1958                     // Where both a held and a waiting call exist, the above procedures shall apply to the
1959                     // waiting call (i.e., not to the held call) in conflicting situation.
1960                     hfp_ag_call_sm(HFP_AG_CALL_HOLD_RELEASE_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection);
1961                     break;
1962                 case '2':
1963                     // Places all active calls (if any exist) on hold and accepts the other (held or waiting) call.
1964                     // Where both a held and a waiting call exist, the above procedures shall apply to the
1965                     // waiting call (i.e., not to the held call) in conflicting situation.
1966                     hfp_ag_call_sm(HFP_AG_CALL_HOLD_PARK_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection);
1967                     break;
1968                 case '3':
1969                     // Adds a held call to the conversation.
1970                     hfp_ag_call_sm(HFP_AG_CALL_HOLD_ADD_HELD_CALL, hfp_connection);
1971                     break;
1972                 case '4':
1973                     // Connects the two calls and disconnects the subscriber from both calls (Explicit Call Transfer).
1974                     hfp_ag_call_sm(HFP_AG_CALL_HOLD_EXIT_AND_JOIN_CALLS, hfp_connection);
1975                     break;
1976                 default:
1977                     break;
1978             }
1979             break;
1980         }
1981         case HFP_CMD_CALL_PHONE_NUMBER:
1982             hfp_connection->command = HFP_CMD_NONE;
1983             hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_INITIATED, hfp_connection);
1984             break;
1985         case HFP_CMD_REDIAL_LAST_NUMBER:
1986             hfp_connection->command = HFP_CMD_NONE;
1987             hfp_ag_call_sm(HFP_AG_OUTGOING_REDIAL_INITIATED, hfp_connection);
1988             break;
1989         case HFP_CMD_ENABLE_CLIP:
1990             hfp_connection->command = HFP_CMD_NONE;
1991             hfp_connection->clip_enabled = hfp_connection->line_buffer[8] != '0';
1992             log_info("hfp: clip set, now: %u", hfp_connection->clip_enabled);
1993             hfp_connection->ok_pending = 1;
1994             break;
1995         case HFP_CMD_ENABLE_CALL_WAITING_NOTIFICATION:
1996             hfp_connection->command = HFP_CMD_NONE;
1997             hfp_connection->call_waiting_notification_enabled = hfp_connection->line_buffer[8] != '0';
1998             log_info("hfp: call waiting notification set, now: %u", hfp_connection->call_waiting_notification_enabled);
1999             hfp_connection->ok_pending = 1;
2000             break;
2001         case HFP_CMD_SET_SPEAKER_GAIN:
2002             hfp_connection->command = HFP_CMD_NONE;
2003             hfp_connection->ok_pending = 1;
2004             log_info("HF speaker gain = %u", hfp_connection->speaker_gain);
2005             break;
2006         case HFP_CMD_SET_MICROPHONE_GAIN:
2007             hfp_connection->command = HFP_CMD_NONE;
2008             hfp_connection->ok_pending = 1;
2009             log_info("HF microphone gain = %u", hfp_connection->microphone_gain);
2010             break;
2011         default:
2012             break;
2013     }
2014 }
2015 
2016 static void hfp_run(void){
2017     btstack_linked_list_iterator_t it;
2018     btstack_linked_list_iterator_init(&it, hfp_get_connections());
2019     while (btstack_linked_list_iterator_has_next(&it)){
2020         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2021         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
2022         hfp_run_for_context(hfp_connection);
2023     }
2024 }
2025 
2026 static void rfcomm_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
2027     switch (packet_type){
2028         case RFCOMM_DATA_PACKET:
2029             hfp_ag_handle_rfcomm_data(packet_type, channel, packet, size);
2030             break;
2031         case HCI_EVENT_PACKET:
2032             if (packet[0] == RFCOMM_EVENT_CAN_SEND_NOW){
2033                 uint16_t rfcomm_cid = rfcomm_event_can_send_now_get_rfcomm_cid(packet);
2034                 hfp_run_for_context(get_hfp_connection_context_for_rfcomm_cid(rfcomm_cid));
2035                 return;
2036             }
2037             hfp_handle_rfcomm_event(packet_type, channel, packet, size, HFP_ROLE_AG);
2038             break;
2039         default:
2040             break;
2041     }
2042 
2043     hfp_run();
2044 }
2045 
2046 void hfp_ag_init_codecs(int codecs_nr, uint8_t * codecs){
2047     if (codecs_nr > HFP_MAX_NUM_CODECS){
2048         log_error("hfp_init: codecs_nr (%d) > HFP_MAX_NUM_CODECS (%d)", codecs_nr, HFP_MAX_NUM_CODECS);
2049         return;
2050     }
2051     int i;
2052     hfp_codecs_nr = codecs_nr;
2053     for (i=0; i < codecs_nr; i++){
2054         hfp_codecs[i] = codecs[i];
2055     }
2056 }
2057 
2058 void hfp_ag_init_supported_features(uint32_t supported_features){
2059     hfp_supported_features = supported_features;
2060 }
2061 
2062 void hfp_ag_init_ag_indicators(int ag_indicators_nr, hfp_ag_indicator_t * ag_indicators){
2063     hfp_ag_indicators_nr = ag_indicators_nr;
2064     memcpy(hfp_ag_indicators, ag_indicators, ag_indicators_nr * sizeof(hfp_ag_indicator_t));
2065 }
2066 
2067 void hfp_ag_init_hf_indicators(int hf_indicators_nr, hfp_generic_status_indicator_t * hf_indicators){
2068     if (hf_indicators_nr > HFP_MAX_NUM_HF_INDICATORS) return;
2069     hfp_generic_status_indicators_nr = hf_indicators_nr;
2070     memcpy(hfp_generic_status_indicators, hf_indicators, hf_indicators_nr * sizeof(hfp_generic_status_indicator_t));
2071 }
2072 
2073 void hfp_ag_init_call_hold_services(int call_hold_services_nr, const char * call_hold_services[]){
2074     hfp_ag_call_hold_services_nr = call_hold_services_nr;
2075     memcpy(hfp_ag_call_hold_services, call_hold_services, call_hold_services_nr * sizeof(char *));
2076 }
2077 
2078 
2079 void hfp_ag_init(uint16_t rfcomm_channel_nr){
2080 
2081     hfp_init();
2082 
2083     hci_event_callback_registration.callback = &hfp_handle_hci_event;
2084     hci_add_event_handler(&hci_event_callback_registration);
2085 
2086     rfcomm_register_service(&rfcomm_packet_handler, rfcomm_channel_nr, 0xffff);
2087 
2088     // used to set packet handler for outgoing rfcomm connections - could be handled by emitting an event to us
2089     hfp_set_ag_rfcomm_packet_handler(&rfcomm_packet_handler);
2090 
2091     hfp_ag_response_and_hold_active = 0;
2092     subscriber_numbers = NULL;
2093     subscriber_numbers_count = 0;
2094 
2095     hfp_gsm_init();
2096 }
2097 
2098 void hfp_ag_establish_service_level_connection(bd_addr_t bd_addr){
2099     hfp_establish_service_level_connection(bd_addr, BLUETOOTH_SERVICE_CLASS_HANDSFREE, HFP_ROLE_AG);
2100 }
2101 
2102 void hfp_ag_release_service_level_connection(hci_con_handle_t acl_handle){
2103     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2104     if (!hfp_connection){
2105         log_error("HFP AG: ACL connection 0x%2x is not found.", acl_handle);
2106         return;
2107     }
2108     hfp_release_service_level_connection(hfp_connection);
2109     hfp_run_for_context(hfp_connection);
2110 }
2111 
2112 void hfp_ag_report_extended_audio_gateway_error_result_code(hci_con_handle_t acl_handle, hfp_cme_error_t error){
2113     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2114     if (!hfp_connection){
2115         log_error("HFP AG: ACL connection 0x%2x is not found.", acl_handle);
2116         return;
2117     }
2118     hfp_connection->extended_audio_gateway_error = 0;
2119     if (!hfp_connection->enable_extended_audio_gateway_error_report){
2120         return;
2121     }
2122     hfp_connection->extended_audio_gateway_error = error;
2123     hfp_run_for_context(hfp_connection);
2124 }
2125 
2126 static void hfp_ag_setup_audio_connection(hfp_connection_t * hfp_connection){
2127     log_info("hfp_ag_setup_audio_connection state %u", hfp_connection->state);
2128     if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED) return;
2129     if (hfp_connection->state >= HFP_W2_DISCONNECT_SCO) return;
2130 
2131     hfp_connection->establish_audio_connection = 1;
2132     if (!has_codec_negotiation_feature(hfp_connection)){
2133         log_info("hfp_ag_establish_audio_connection - no codec negotiation feature, using CVSD");
2134         hfp_connection->negotiated_codec = HFP_CODEC_CVSD;
2135         hfp_connection->codecs_state = HFP_CODECS_EXCHANGED;
2136         // now, pick link settings
2137         hfp_init_link_settings(hfp_connection);
2138         return;
2139     }
2140 
2141     hfp_connection->trigger_codec_exchange = 1;
2142 }
2143 
2144 void hfp_ag_establish_audio_connection(hci_con_handle_t acl_handle){
2145     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2146     if (!hfp_connection){
2147         log_error("HFP AG: ACL connection 0x%2x is not found.", acl_handle);
2148         return;
2149     }
2150     hfp_connection->trigger_codec_exchange = 0;
2151     hfp_connection->establish_audio_connection = 0;
2152     hfp_ag_setup_audio_connection(hfp_connection);
2153     hfp_run_for_context(hfp_connection);
2154 }
2155 
2156 void hfp_ag_release_audio_connection(hci_con_handle_t acl_handle){
2157     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2158     if (!hfp_connection){
2159         log_error("HFP AG: ACL connection 0x%2x is not found.", acl_handle);
2160         return;
2161     }
2162     hfp_release_audio_connection(hfp_connection);
2163     hfp_run_for_context(hfp_connection);
2164 }
2165 
2166 /**
2167  * @brief Enable in-band ring tone
2168  */
2169 void hfp_ag_set_use_in_band_ring_tone(int use_in_band_ring_tone){
2170     if (get_bit(hfp_supported_features, HFP_AGSF_IN_BAND_RING_TONE) == use_in_band_ring_tone){
2171         return;
2172     }
2173     hfp_supported_features = store_bit(hfp_supported_features, HFP_AGSF_IN_BAND_RING_TONE, use_in_band_ring_tone);
2174 
2175     btstack_linked_list_iterator_t it;
2176     btstack_linked_list_iterator_init(&it, hfp_get_connections());
2177     while (btstack_linked_list_iterator_has_next(&it)){
2178         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2179         hfp_connection->command = HFP_CMD_CHANGE_IN_BAND_RING_TONE_SETTING;
2180         hfp_run_for_context(hfp_connection);
2181     }
2182 }
2183 
2184 /**
2185  * @brief Called from GSM
2186  */
2187 void hfp_ag_incoming_call(void){
2188     hfp_ag_call_sm(HFP_AG_INCOMING_CALL, NULL);
2189 }
2190 
2191 /**
2192  * @brief number is stored.
2193  */
2194 void hfp_ag_set_clip(uint8_t type, const char * number){
2195     hfp_gsm_handle_event_with_clip(HFP_AG_SET_CLIP, type, number);
2196 }
2197 
2198 void hfp_ag_call_dropped(void){
2199     hfp_ag_call_sm(HFP_AG_CALL_DROPPED, NULL);
2200 }
2201 
2202 // call from AG UI
2203 void hfp_ag_answer_incoming_call(void){
2204     hfp_ag_call_sm(HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG, NULL);
2205 }
2206 
2207 void hfp_ag_join_held_call(void){
2208     hfp_ag_call_sm(HFP_AG_HELD_CALL_JOINED_BY_AG, NULL);
2209 }
2210 
2211 void hfp_ag_terminate_call(void){
2212     hfp_ag_call_sm(HFP_AG_TERMINATE_CALL_BY_AG, NULL);
2213 }
2214 
2215 void hfp_ag_outgoing_call_ringing(void){
2216     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_RINGING, NULL);
2217 }
2218 
2219 void hfp_ag_outgoing_call_established(void){
2220     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_ESTABLISHED, NULL);
2221 }
2222 
2223 void hfp_ag_outgoing_call_rejected(void){
2224     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_REJECTED, NULL);
2225 }
2226 
2227 void hfp_ag_outgoing_call_accepted(void){
2228     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_ACCEPTED, NULL);
2229 }
2230 
2231 void hfp_ag_hold_incoming_call(void){
2232     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_AG, NULL);
2233 }
2234 
2235 void hfp_ag_accept_held_incoming_call(void) {
2236     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_AG, NULL);
2237 }
2238 
2239 void hfp_ag_reject_held_incoming_call(void){
2240     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_AG, NULL);
2241 }
2242 
2243 static void hfp_ag_set_ag_indicator(const char * name, int value){
2244     int indicator_index = get_ag_indicator_index_for_name(name);
2245     if (indicator_index < 0) return;
2246     hfp_ag_indicators[indicator_index].status = value;
2247 
2248 
2249     btstack_linked_list_iterator_t it;
2250     btstack_linked_list_iterator_init(&it, hfp_get_connections());
2251     while (btstack_linked_list_iterator_has_next(&it)){
2252         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2253         if (! hfp_connection->ag_indicators[indicator_index].enabled) {
2254             log_info("AG indicator '%s' changed to %u but not enabled", hfp_ag_indicators[indicator_index].name, value);
2255             continue;
2256         }
2257         log_info("AG indicator '%s' changed to %u, request transfer statur", hfp_ag_indicators[indicator_index].name, value);
2258         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
2259         hfp_run_for_context(hfp_connection);
2260     }
2261 }
2262 
2263 void hfp_ag_set_registration_status(int status){
2264     hfp_ag_set_ag_indicator("service", status);
2265 }
2266 
2267 void hfp_ag_set_signal_strength(int strength){
2268     hfp_ag_set_ag_indicator("signal", strength);
2269 }
2270 
2271 void hfp_ag_set_roaming_status(int status){
2272     hfp_ag_set_ag_indicator("roam", status);
2273 }
2274 
2275 void hfp_ag_set_battery_level(int level){
2276     hfp_ag_set_ag_indicator("battchg", level);
2277 }
2278 
2279 void hfp_ag_activate_voice_recognition(hci_con_handle_t acl_handle, int activate){
2280     if (!get_bit(hfp_supported_features, HFP_AGSF_VOICE_RECOGNITION_FUNCTION)) return;
2281     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2282     if (!hfp_connection){
2283         log_error("HFP AG: ACL connection 0x%2x is not found.", acl_handle);
2284         return;
2285     }
2286 
2287     if (!get_bit(hfp_connection->remote_supported_features, HFP_HFSF_VOICE_RECOGNITION_FUNCTION)) {
2288         log_info("AG cannot acivate voice recognition - not supported by HF");
2289         return;
2290     }
2291 
2292     if (activate){
2293         hfp_ag_establish_audio_connection(acl_handle);
2294     }
2295 
2296     hfp_connection->ag_activate_voice_recognition = activate;
2297     hfp_connection->command = HFP_CMD_AG_ACTIVATE_VOICE_RECOGNITION;
2298     hfp_run_for_context(hfp_connection);
2299 }
2300 
2301 void hfp_ag_set_microphone_gain(hci_con_handle_t acl_handle, int gain){
2302     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2303     if (!hfp_connection){
2304         log_error("HFP AG: ACL connection 0x%2x is not found.", acl_handle);
2305         return;
2306     }
2307     if (hfp_connection->microphone_gain != gain){
2308         hfp_connection->command = HFP_CMD_SET_MICROPHONE_GAIN;
2309         hfp_connection->microphone_gain = gain;
2310         hfp_connection->send_microphone_gain = 1;
2311     }
2312     hfp_run_for_context(hfp_connection);
2313 }
2314 
2315 void hfp_ag_set_speaker_gain(hci_con_handle_t acl_handle, int gain){
2316     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2317     if (!hfp_connection){
2318         log_error("HFP AG: ACL connection 0x%2x is not found.", acl_handle);
2319         return;
2320     }
2321     if (hfp_connection->speaker_gain != gain){
2322         hfp_connection->speaker_gain = gain;
2323         hfp_connection->send_speaker_gain = 1;
2324     }
2325     hfp_run_for_context(hfp_connection);
2326 }
2327 
2328 void hfp_ag_send_phone_number_for_voice_tag(hci_con_handle_t acl_handle, const char * number){
2329     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2330     if (!hfp_connection){
2331         log_error("HFP AG: ACL connection 0x%2x is not found.", acl_handle);
2332         return;
2333     }
2334     hfp_ag_set_clip(0, number);
2335     hfp_connection->send_phone_number_for_voice_tag = 1;
2336 }
2337 
2338 void hfp_ag_reject_phone_number_for_voice_tag(hci_con_handle_t acl_handle){
2339     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2340     if (!hfp_connection){
2341         log_error("HFP AG: ACL connection 0x%2x is not found.", acl_handle);
2342         return;
2343     }
2344     hfp_connection->send_error = 1;
2345 }
2346 
2347 void hfp_ag_send_dtmf_code_done(hci_con_handle_t acl_handle){
2348     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2349     if (!hfp_connection){
2350         log_error("HFP AG: ACL connection 0x%2x is not found.", acl_handle);
2351         return;
2352     }
2353     hfp_connection->ok_pending = 1;
2354 }
2355 
2356 void hfp_ag_set_subcriber_number_information(hfp_phone_number_t * numbers, int numbers_count){
2357     subscriber_numbers = numbers;
2358     subscriber_numbers_count = numbers_count;
2359 }
2360 
2361 void hfp_ag_clear_last_dialed_number(void){
2362     hfp_gsm_clear_last_dialed_number();
2363 }
2364 
2365 void hfp_ag_notify_incoming_call_waiting(hci_con_handle_t acl_handle){
2366     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2367     if (!hfp_connection){
2368         log_error("HFP AG: ACL connection 0x%2x is not found.", acl_handle);
2369         return;
2370     }
2371     if (!hfp_connection->call_waiting_notification_enabled) return;
2372 
2373     hfp_connection->ag_notify_incoming_call_waiting = 1;
2374     hfp_run_for_context(hfp_connection);
2375 }
2376 
2377