xref: /btstack/src/classic/hfp.c (revision a64cbea79fa5fb9daa58e135a19c6cce10f3e642)
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 BLUEKITCHEN
24  * GMBH 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.c"
39 
40 
41 #include "btstack_config.h"
42 
43 #include <stdint.h>
44 #include <stdio.h>
45 #include <string.h>
46 #include <inttypes.h>
47 
48 #include "bluetooth_sdp.h"
49 #include "btstack_debug.h"
50 #include "btstack_event.h"
51 #include "btstack_memory.h"
52 #include "btstack_run_loop.h"
53 #include "classic/sdp_client_rfcomm.h"
54 #include "classic/sdp_server.h"
55 #include "classic/sdp_util.h"
56 #include "classic/sdp_client.h"
57 #include "hci.h"
58 #include "hci_cmd.h"
59 #include "hci_dump.h"
60 
61 #if defined(ENABLE_CC256X_ASSISTED_HFP) && !defined(ENABLE_SCO_OVER_PCM)
62 #error "Assisted HFP is only possible over PCM/I2S. Please add define: ENABLE_SCO_OVER_PCM"
63 #endif
64 
65 #if defined(ENABLE_BCM_PCM_WBS) && !defined(ENABLE_SCO_OVER_PCM)
66 #error "WBS for PCM is only possible over PCM/I2S. Please add define: ENABLE_SCO_OVER_PCM"
67 #endif
68 
69 #define HFP_HF_FEATURES_SIZE 10
70 #define HFP_AG_FEATURES_SIZE 12
71 
72 typedef struct {
73     hfp_role_t local_role;
74     bd_addr_t  remote_address;
75 } hfp_sdp_query_context_t;
76 
77 // globals
78 
79 static btstack_linked_list_t hfp_connections ;
80 
81 static btstack_packet_handler_t hfp_hf_callback;
82 static btstack_packet_handler_t hfp_ag_callback;
83 
84 static btstack_packet_handler_t hfp_hf_rfcomm_packet_handler;
85 static btstack_packet_handler_t hfp_ag_rfcomm_packet_handler;
86 
87 static uint16_t hfp_allowed_sco_packet_types;
88 static hfp_connection_t * hfp_sco_establishment_active;
89 
90 static hfp_sdp_query_context_t                 hfp_sdp_query_context;
91 static btstack_context_callback_registration_t hfp_sdp_query_request;
92 
93 
94 
95 
96 
97 
98 // prototypes
99 static hfp_link_settings_t hfp_next_link_setting_for_connection(hfp_link_settings_t current_setting, hfp_connection_t * hfp_connection, uint8_t eSCO_S4_supported);
100 static void parse_sequence(hfp_connection_t * context);
101 
102 static const char * hfp_hf_features[] = {
103         "EC and/or NR function",
104         "Three-way calling",
105         "CLI presentation capability",
106         "Voice recognition activation",
107         "Remote volume control",
108 
109         "Enhanced call status",
110         "Enhanced call control",
111 
112         "Codec negotiation",
113 
114         "HF Indicators",
115         "eSCO S4 (and T2) Settings Supported",
116         "Reserved for future definition"
117 };
118 
119 static const char * hfp_ag_features[] = {
120         "Three-way calling",
121         "EC and/or NR function",
122         "Voice recognition function",
123         "In-band ring tone capability",
124         "Attach a number to a voice tag",
125         "Ability to reject a call",
126         "Enhanced call status",
127         "Enhanced call control",
128         "Extended Error Result Codes",
129         "Codec negotiation",
130         "HF Indicators",
131         "eSCO S4 (and T2) Settings Supported",
132         "Reserved for future definition"
133 };
134 
135 static const char * hfp_enhanced_call_dir[] = {
136         "outgoing",
137         "incoming"
138 };
139 
140 static const char * hfp_enhanced_call_status[] = {
141         "active",
142         "held",
143         "outgoing dialing",
144         "outgoing alerting",
145         "incoming",
146         "incoming waiting",
147         "call held by response and hold"
148 };
149 
150 static const char * hfp_enhanced_call_mode[] = {
151         "voice",
152         "data",
153         "fax"
154 };
155 
156 static const char * hfp_enhanced_call_mpty[] = {
157         "not a conference call",
158         "conference call"
159 };
160 
161 const char * hfp_enhanced_call_dir2str(uint16_t index){
162     if (index <= HFP_ENHANCED_CALL_DIR_INCOMING) return hfp_enhanced_call_dir[index];
163     return "not defined";
164 }
165 
166 const char * hfp_enhanced_call_status2str(uint16_t index){
167     if (index <= HFP_ENHANCED_CALL_STATUS_CALL_HELD_BY_RESPONSE_AND_HOLD) return hfp_enhanced_call_status[index];
168     return "not defined";
169 }
170 
171 const char * hfp_enhanced_call_mode2str(uint16_t index){
172     if (index <= HFP_ENHANCED_CALL_MODE_FAX) return hfp_enhanced_call_mode[index];
173     return "not defined";
174 }
175 
176 const char * hfp_enhanced_call_mpty2str(uint16_t index){
177     if (index <= HFP_ENHANCED_CALL_MPTY_CONFERENCE_CALL) return hfp_enhanced_call_mpty[index];
178     return "not defined";
179 }
180 
181 static uint16_t hfp_parse_indicator_index(hfp_connection_t * hfp_connection){
182     uint16_t index = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
183 
184     if (index > HFP_MAX_NUM_INDICATORS){
185         log_info("ignoring invalid indicator index bigger then HFP_MAX_NUM_INDICATORS");
186         return HFP_MAX_NUM_INDICATORS - 1;
187     }
188 
189     // indicator index enumeration starts with 1, we substract 1 to store in array with starting index 0
190     if (index > 0){
191         index -= 1;
192     } else {
193         log_info("ignoring invalid indicator index 0");
194         return 0;
195     }
196     return index;
197 }
198 
199 static void hfp_next_indicators_index(hfp_connection_t * hfp_connection){
200     if (hfp_connection->parser_item_index < HFP_MAX_NUM_INDICATORS - 1){
201         hfp_connection->parser_item_index++;
202     } else {
203         log_info("Ignoring additional indicator");
204     }
205 }
206 
207 static void hfp_next_codec_index(hfp_connection_t * hfp_connection){
208     if (hfp_connection->parser_item_index < HFP_MAX_NUM_CODECS - 1){
209         hfp_connection->parser_item_index++;
210     } else {
211         log_info("Ignoring additional codec index");
212     }
213 }
214 
215 static void hfp_next_remote_call_services_index(hfp_connection_t * hfp_connection){
216     if (hfp_connection->remote_call_services_index < HFP_MAX_NUM_CALL_SERVICES - 1){
217         hfp_connection->remote_call_services_index++;
218     } else {
219         log_info("Ignoring additional remote_call_services");
220     }
221 }
222 
223 const char * hfp_hf_feature(int index){
224     if (index > HFP_HF_FEATURES_SIZE){
225         return hfp_hf_features[HFP_HF_FEATURES_SIZE];
226     }
227     return hfp_hf_features[index];
228 }
229 
230 const char * hfp_ag_feature(int index){
231     if (index > HFP_AG_FEATURES_SIZE){
232         return hfp_ag_features[HFP_AG_FEATURES_SIZE];
233     }
234     return hfp_ag_features[index];
235 }
236 
237 int send_str_over_rfcomm(uint16_t cid, char * command){
238     if (!rfcomm_can_send_packet_now(cid)) return 1;
239     log_info("HFP_TX %s", command);
240     int err = rfcomm_send(cid, (uint8_t*) command, strlen(command));
241     if (err){
242         log_error("rfcomm_send -> error 0x%02x \n", err);
243     }
244 #ifdef ENABLE_HFP_AT_MESSAGES
245     hfp_connection_t * hfp_connection = get_hfp_connection_context_for_rfcomm_cid(cid);
246     hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_AT_MESSAGE_SENT, command);
247 #endif
248     return 1;
249 }
250 
251 int hfp_supports_codec(uint8_t codec, int codecs_nr, uint8_t * codecs){
252 
253     // mSBC requires support for eSCO connections
254     if ((codec == HFP_CODEC_MSBC) && !hci_extended_sco_link_supported()) return 0;
255 
256     int i;
257     for (i = 0; i < codecs_nr; i++){
258         if (codecs[i] != codec) continue;
259         return 1;
260     }
261     return 0;
262 }
263 
264 void hfp_hf_drop_mSBC_if_eSCO_not_supported(uint8_t * codecs, uint8_t * codecs_nr){
265     if (hci_extended_sco_link_supported()) return;
266     uint8_t tmp_codecs[HFP_MAX_NUM_CODECS];
267     int i;
268     int tmp_codec_nr = 0;
269     for (i=0; i < *codecs_nr; i++){
270         if (codecs[i] == HFP_CODEC_MSBC) continue;
271         tmp_codecs[tmp_codec_nr++] = codecs[i];
272     }
273     *codecs_nr = tmp_codec_nr;
274     (void)memcpy(codecs, tmp_codecs, tmp_codec_nr);
275 }
276 
277 // UTILS
278 int get_bit(uint16_t bitmap, int position){
279     return (bitmap >> position) & 1;
280 }
281 
282 int store_bit(uint32_t bitmap, int position, uint8_t value){
283     if (value){
284         bitmap |= 1 << position;
285     } else {
286         bitmap &= ~ (1 << position);
287     }
288     return bitmap;
289 }
290 
291 int join(char * buffer, int buffer_size, uint8_t * values, int values_nr){
292     if (buffer_size < (values_nr * 3)) return 0;
293     int i;
294     int offset = 0;
295     for (i = 0; i < (values_nr-1); i++) {
296       offset += snprintf(buffer+offset, buffer_size-offset, "%d,", values[i]); // puts string into buffer
297     }
298     if (i<values_nr){
299         offset += snprintf(buffer+offset, buffer_size-offset, "%d", values[i]);
300     }
301     return offset;
302 }
303 
304 int join_bitmap(char * buffer, int buffer_size, uint32_t values, int values_nr){
305     if (buffer_size < (values_nr * 3)) return 0;
306 
307     int i;
308     int offset = 0;
309     for (i = 0; i < (values_nr-1); i++) {
310       offset += snprintf(buffer+offset, buffer_size-offset, "%d,", get_bit(values,i)); // puts string into buffer
311     }
312 
313     if (i<values_nr){
314         offset += snprintf(buffer+offset, buffer_size-offset, "%d", get_bit(values,i));
315     }
316     return offset;
317 }
318 static void hfp_emit_event_for_role(hfp_role_t local_role, uint8_t * packet, uint16_t size){
319     switch (local_role){
320         case HFP_ROLE_HF:
321             (*hfp_hf_callback)(HCI_EVENT_PACKET, 0, packet, size);
322             break;
323         case HFP_ROLE_AG:
324             (*hfp_ag_callback)(HCI_EVENT_PACKET, 0, packet, size);
325             break;
326         default:
327             btstack_unreachable();
328             break;
329     }
330 }
331 
332 static void hfp_emit_event_for_context(hfp_connection_t * hfp_connection, uint8_t * packet, uint16_t size){
333     if (!hfp_connection) return;
334     hfp_emit_event_for_role(hfp_connection->local_role, packet, size);
335 }
336 
337 void hfp_emit_simple_event(hfp_connection_t * hfp_connection, uint8_t event_subtype){
338     hci_con_handle_t acl_handle = (hfp_connection != NULL) ? hfp_connection->acl_handle : HCI_CON_HANDLE_INVALID;
339     uint8_t event[5];
340     event[0] = HCI_EVENT_HFP_META;
341     event[1] = sizeof(event) - 2;
342     event[2] = event_subtype;
343     little_endian_store_16(event, 3, acl_handle);
344     hfp_emit_event_for_context(hfp_connection, event, sizeof(event));
345 }
346 
347 void hfp_emit_event(hfp_connection_t * hfp_connection, uint8_t event_subtype, uint8_t value){
348     hci_con_handle_t acl_handle = (hfp_connection != NULL) ? hfp_connection->acl_handle : HCI_CON_HANDLE_INVALID;
349     uint8_t event[6];
350     event[0] = HCI_EVENT_HFP_META;
351     event[1] = sizeof(event) - 2;
352     event[2] = event_subtype;
353     little_endian_store_16(event, 3, acl_handle);
354     event[5] = value; // status 0 == OK
355     hfp_emit_event_for_context(hfp_connection, event, sizeof(event));
356 }
357 
358 void hfp_emit_voice_recognition_enabled(hfp_connection_t * hfp_connection, uint8_t status){
359     btstack_assert(hfp_connection != NULL);
360 
361     uint8_t event[7];
362     event[0] = HCI_EVENT_HFP_META;
363     event[1] = sizeof(event) - 2;
364     event[2] = HFP_SUBEVENT_VOICE_RECOGNITION_ACTIVATED;
365 
366     little_endian_store_16(event, 3, hfp_connection->acl_handle);
367     event[5] = status; // 0:success
368     event[6] = hfp_connection->enhanced_voice_recognition_enabled ? 1 : 0;
369     hfp_emit_event_for_context(hfp_connection, event, sizeof(event));
370 }
371 
372 void hfp_emit_voice_recognition_disabled(hfp_connection_t * hfp_connection, uint8_t status){
373     btstack_assert(hfp_connection != NULL);
374 
375     uint8_t event[6];
376     event[0] = HCI_EVENT_HFP_META;
377     event[1] = sizeof(event) - 2;
378     event[2] = HFP_SUBEVENT_VOICE_RECOGNITION_DEACTIVATED;
379 
380     little_endian_store_16(event, 3, hfp_connection->acl_handle);
381     event[5] = status; // 0:success
382     hfp_emit_event_for_context(hfp_connection, event, sizeof(event));
383 }
384 
385 void hfp_emit_enhanced_voice_recognition_hf_ready_for_audio_event(hfp_connection_t * hfp_connection, uint8_t status){
386     hci_con_handle_t acl_handle = (hfp_connection != NULL) ? hfp_connection->acl_handle : HCI_CON_HANDLE_INVALID;
387 
388     uint8_t event[6];
389     event[0] = HCI_EVENT_HFP_META;
390     event[1] = sizeof(event) - 2;
391     event[2] = HFP_SUBEVENT_ENHANCED_VOICE_RECOGNITION_HF_READY_FOR_AUDIO;
392     little_endian_store_16(event, 3, acl_handle);
393     event[5] = status;
394     hfp_emit_event_for_context(hfp_connection, event, sizeof(event));
395 }
396 
397 void hfp_emit_enhanced_voice_recognition_state_event(hfp_connection_t * hfp_connection, uint8_t status){
398     hci_con_handle_t acl_handle = (hfp_connection != NULL) ? hfp_connection->acl_handle : HCI_CON_HANDLE_INVALID;
399 
400     uint8_t event[6];
401     event[0] = HCI_EVENT_HFP_META;
402     event[1] = sizeof(event) - 2;
403     switch (hfp_connection->ag_vra_state){
404         case HFP_VOICE_RECOGNITION_STATE_AG_READY_TO_ACCEPT_AUDIO_INPUT:
405             event[2] = HFP_SUBEVENT_ENHANCED_VOICE_RECOGNITION_AG_READY_TO_ACCEPT_AUDIO_INPUT;
406             break;
407         case HFP_VOICE_RECOGNITION_STATE_AG_IS_STARTING_SOUND:
408             event[2] = HFP_SUBEVENT_ENHANCED_VOICE_RECOGNITION_AG_IS_STARTING_SOUND;
409             break;
410         case HFP_VOICE_RECOGNITION_STATE_AG_IS_PROCESSING_AUDIO_INPUT:
411             event[2] = HFP_SUBEVENT_ENHANCED_VOICE_RECOGNITION_AG_IS_PROCESSING_AUDIO_INPUT;
412             break;
413         default:
414             btstack_unreachable();
415             break;
416     }
417 
418     little_endian_store_16(event, 3, acl_handle);
419     event[5] = status;
420     hfp_emit_event_for_context(hfp_connection, event, sizeof(event));
421 }
422 
423 void hfp_emit_slc_connection_event(hfp_role_t local_role, uint8_t status, hci_con_handle_t con_handle, bd_addr_t addr){
424     uint8_t event[12];
425     int pos = 0;
426     event[pos++] = HCI_EVENT_HFP_META;
427     event[pos++] = sizeof(event) - 2;
428     event[pos++] = HFP_SUBEVENT_SERVICE_LEVEL_CONNECTION_ESTABLISHED;
429     little_endian_store_16(event, pos, con_handle);
430     pos += 2;
431     event[pos++] = status; // status 0 == OK
432     reverse_bd_addr(addr,&event[pos]);
433     pos += 6;
434     hfp_emit_event_for_role(local_role, event, sizeof(event));
435 }
436 
437 static void hfp_emit_audio_connection_released(hfp_connection_t * hfp_connection, hci_con_handle_t sco_handle){
438     btstack_assert(hfp_connection != NULL);
439     uint8_t event[7];
440     int pos = 0;
441     event[pos++] = HCI_EVENT_HFP_META;
442     event[pos++] = sizeof(event) - 2;
443     event[pos++] = HFP_SUBEVENT_AUDIO_CONNECTION_RELEASED;
444     little_endian_store_16(event, pos, hfp_connection->acl_handle);
445     pos += 2;
446     little_endian_store_16(event, pos, sco_handle);
447     pos += 2;
448     hfp_emit_event_for_context(hfp_connection, event, sizeof(event));
449 }
450 
451 void hfp_emit_sco_event(hfp_connection_t * hfp_connection, uint8_t status, hci_con_handle_t sco_handle, bd_addr_t addr, uint8_t  negotiated_codec){
452     btstack_assert(hfp_connection != NULL);
453     uint8_t event[15];
454     int pos = 0;
455     event[pos++] = HCI_EVENT_HFP_META;
456     event[pos++] = sizeof(event) - 2;
457     event[pos++] = HFP_SUBEVENT_AUDIO_CONNECTION_ESTABLISHED;
458     little_endian_store_16(event, pos, hfp_connection->acl_handle);
459     pos += 2;
460     event[pos++] = status; // status 0 == OK
461     little_endian_store_16(event, pos, sco_handle);
462     pos += 2;
463     reverse_bd_addr(addr,&event[pos]);
464     pos += 6;
465     event[pos++] = negotiated_codec;
466     hfp_emit_event_for_context(hfp_connection, event, sizeof(event));
467 }
468 
469 void hfp_emit_string_event(hfp_connection_t * hfp_connection, uint8_t event_subtype, const char * value){
470     btstack_assert(hfp_connection != NULL);
471 #ifdef ENABLE_HFP_AT_MESSAGES
472     uint8_t event[256];
473 #else
474     uint8_t event[40];
475 #endif
476     uint16_t string_len = btstack_min(strlen(value), sizeof(event) - 6);
477     event[0] = HCI_EVENT_HFP_META;
478     event[1] = 4 + string_len;
479     event[2] = event_subtype;
480     little_endian_store_16(event, 3, hfp_connection->acl_handle);
481     memcpy((char*)&event[5], value, string_len);
482     event[5 + string_len] = 0;
483     hfp_emit_event_for_context(hfp_connection, event, 6 + string_len);
484 }
485 
486 btstack_linked_list_t * hfp_get_connections(void){
487     return (btstack_linked_list_t *) &hfp_connections;
488 }
489 
490 hfp_connection_t * get_hfp_connection_context_for_rfcomm_cid(uint16_t cid){
491     btstack_linked_list_iterator_t it;
492     btstack_linked_list_iterator_init(&it, hfp_get_connections());
493     while (btstack_linked_list_iterator_has_next(&it)){
494         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
495         if (hfp_connection->rfcomm_cid == cid){
496             return hfp_connection;
497         }
498     }
499     return NULL;
500 }
501 
502 hfp_connection_t * get_hfp_connection_context_for_bd_addr(bd_addr_t bd_addr, hfp_role_t hfp_role){
503     btstack_linked_list_iterator_t it;
504     btstack_linked_list_iterator_init(&it, hfp_get_connections());
505     while (btstack_linked_list_iterator_has_next(&it)){
506         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
507         if ((memcmp(hfp_connection->remote_addr, bd_addr, 6) == 0) && (hfp_connection->local_role == hfp_role)) {
508             return hfp_connection;
509         }
510     }
511     return NULL;
512 }
513 
514 hfp_connection_t * get_hfp_connection_context_for_sco_handle(uint16_t handle, hfp_role_t hfp_role){
515     btstack_linked_list_iterator_t it;
516     btstack_linked_list_iterator_init(&it, hfp_get_connections());
517     while (btstack_linked_list_iterator_has_next(&it)){
518         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
519         if ((hfp_connection->sco_handle == handle) && (hfp_connection->local_role == hfp_role)){
520             return hfp_connection;
521         }
522     }
523     return NULL;
524 }
525 
526 hfp_connection_t * get_hfp_connection_context_for_acl_handle(uint16_t handle, hfp_role_t hfp_role){
527     btstack_linked_list_iterator_t it;
528     btstack_linked_list_iterator_init(&it, hfp_get_connections());
529     while (btstack_linked_list_iterator_has_next(&it)){
530         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
531         if ((hfp_connection->acl_handle == handle) && (hfp_connection->local_role == hfp_role)){
532             return hfp_connection;
533         }
534     }
535     return NULL;
536 }
537 
538 
539 static void hfp_reset_voice_recognition(hfp_connection_t * hfp_connection){
540     btstack_assert(hfp_connection != NULL);
541     hfp_voice_recognition_activation_status_t current_vra_state = hfp_connection->vra_state;
542     hfp_connection->vra_state = HFP_VRA_VOICE_RECOGNITION_OFF;
543 
544     if (current_vra_state != HFP_VRA_VOICE_RECOGNITION_OFF){
545         hfp_emit_voice_recognition_disabled(hfp_connection, ERROR_CODE_SUCCESS);
546     } else if (hfp_connection->vra_state_requested != HFP_VRA_VOICE_RECOGNITION_OFF){
547         hfp_emit_voice_recognition_disabled(hfp_connection, ERROR_CODE_SUCCESS);
548     }
549 
550     hfp_connection->vra_state_requested = HFP_VRA_VOICE_RECOGNITION_OFF;
551     hfp_connection->activate_voice_recognition = false;
552     hfp_connection->deactivate_voice_recognition = false;
553     hfp_connection->enhanced_voice_recognition_enabled = false;
554     hfp_connection->ag_vra_status = 0;
555     hfp_connection->ag_vra_state = HFP_VOICE_RECOGNITION_STATE_AG_READY;
556 }
557 
558 void hfp_reset_context_flags(hfp_connection_t * hfp_connection){
559     if (!hfp_connection) return;
560     hfp_connection->ok_pending = 0;
561     hfp_connection->send_error = 0;
562 
563     hfp_connection->found_equal_sign = false;
564 
565     hfp_connection->change_status_update_for_individual_ag_indicators = 0;
566     hfp_connection->operator_name_changed = 0;
567 
568     hfp_connection->enable_extended_audio_gateway_error_report = 0;
569     hfp_connection->extended_audio_gateway_error = 0;
570 
571     // establish codecs hfp_connection
572     hfp_connection->suggested_codec = 0;
573     hfp_connection->negotiated_codec = 0;
574     hfp_connection->codec_confirmed = 0;
575 
576     hfp_connection->establish_audio_connection = 0;
577     hfp_connection->call_waiting_notification_enabled = 0;
578     hfp_connection->command = HFP_CMD_NONE;
579     hfp_connection->enable_status_update_for_ag_indicators = 0xFF;
580     hfp_connection->clip_have_alpha = false;
581     hfp_reset_voice_recognition(hfp_connection);
582 }
583 
584 static hfp_connection_t * create_hfp_connection_context(void){
585     hfp_connection_t * hfp_connection = btstack_memory_hfp_connection_get();
586     if (!hfp_connection) return NULL;
587 
588     hfp_connection->state = HFP_IDLE;
589     hfp_connection->call_state = HFP_CALL_IDLE;
590     hfp_connection->codecs_state = HFP_CODECS_IDLE;
591 
592     hfp_connection->parser_state = HFP_PARSER_CMD_HEADER;
593 
594     hfp_connection->acl_handle = HCI_CON_HANDLE_INVALID;
595     hfp_connection->sco_handle = HCI_CON_HANDLE_INVALID;
596 
597     hfp_reset_context_flags(hfp_connection);
598 
599     btstack_linked_list_add(&hfp_connections, (btstack_linked_item_t*)hfp_connection);
600     return hfp_connection;
601 }
602 
603 void hfp_finalize_connection_context(hfp_connection_t * hfp_connection){
604     btstack_linked_list_remove(&hfp_connections, (btstack_linked_item_t*) hfp_connection);
605     btstack_memory_hfp_connection_free(hfp_connection);
606 }
607 
608 static hfp_connection_t * hfp_create_connection(bd_addr_t bd_addr, hfp_role_t local_role){
609     hfp_connection_t * hfp_connection = get_hfp_connection_context_for_bd_addr(bd_addr, local_role);
610     if (hfp_connection) return  hfp_connection;
611     hfp_connection = create_hfp_connection_context();
612     (void)memcpy(hfp_connection->remote_addr, bd_addr, 6);
613     hfp_connection->local_role = local_role;
614     log_info("Create HFP context %p: role %u, addr %s", hfp_connection, local_role, bd_addr_to_str(bd_addr));
615 
616     return hfp_connection;
617 }
618 
619 /* @param network.
620  * 0 == no ability to reject a call.
621  * 1 == ability to reject a call.
622  */
623 
624 /* @param suported_features
625  * HF bit 0: EC and/or NR function (yes/no, 1 = yes, 0 = no)
626  * HF bit 1: Call waiting or three-way calling(yes/no, 1 = yes, 0 = no)
627  * HF bit 2: CLI presentation capability (yes/no, 1 = yes, 0 = no)
628  * HF bit 3: Voice recognition activation (yes/no, 1= yes, 0 = no)
629  * HF bit 4: Remote volume control (yes/no, 1 = yes, 0 = no)
630  * HF bit 5: Wide band speech (yes/no, 1 = yes, 0 = no)
631  */
632  /* Bit position:
633  * AG bit 0: Three-way calling (yes/no, 1 = yes, 0 = no)
634  * AG bit 1: EC and/or NR function (yes/no, 1 = yes, 0 = no)
635  * AG bit 2: Voice recognition function (yes/no, 1 = yes, 0 = no)
636  * AG bit 3: In-band ring tone capability (yes/no, 1 = yes, 0 = no)
637  * AG bit 4: Attach a phone number to a voice tag (yes/no, 1 = yes, 0 = no)
638  * AG bit 5: Wide band speech (yes/no, 1 = yes, 0 = no)
639  */
640 
641 void hfp_create_sdp_record(uint8_t * service, uint32_t service_record_handle, uint16_t service_uuid, int rfcomm_channel_nr, const char * name){
642     uint8_t* attribute;
643     de_create_sequence(service);
644 
645     // 0x0000 "Service Record Handle"
646     de_add_number(service, DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_RECORD_HANDLE);
647     de_add_number(service, DE_UINT, DE_SIZE_32, service_record_handle);
648 
649     // 0x0001 "Service Class ID List"
650     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST);
651     attribute = de_push_sequence(service);
652     {
653         //  "UUID for Service"
654         de_add_number(attribute, DE_UUID, DE_SIZE_16, service_uuid);
655         de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_GENERIC_AUDIO);
656     }
657     de_pop_sequence(service, attribute);
658 
659     // 0x0004 "Protocol Descriptor List"
660     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST);
661     attribute = de_push_sequence(service);
662     {
663         uint8_t* l2cpProtocol = de_push_sequence(attribute);
664         {
665             de_add_number(l2cpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_L2CAP);
666         }
667         de_pop_sequence(attribute, l2cpProtocol);
668 
669         uint8_t* rfcomm = de_push_sequence(attribute);
670         {
671             de_add_number(rfcomm,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_RFCOMM);  // rfcomm_service
672             de_add_number(rfcomm,  DE_UINT, DE_SIZE_8,  rfcomm_channel_nr);  // rfcomm channel
673         }
674         de_pop_sequence(attribute, rfcomm);
675     }
676     de_pop_sequence(service, attribute);
677 
678 
679     // 0x0005 "Public Browse Group"
680     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BROWSE_GROUP_LIST); // public browse group
681     attribute = de_push_sequence(service);
682     {
683         de_add_number(attribute,  DE_UUID, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PUBLIC_BROWSE_ROOT);
684     }
685     de_pop_sequence(service, attribute);
686 
687     // 0x0009 "Bluetooth Profile Descriptor List"
688     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BLUETOOTH_PROFILE_DESCRIPTOR_LIST);
689     attribute = de_push_sequence(service);
690     {
691         uint8_t *sppProfile = de_push_sequence(attribute);
692         {
693             de_add_number(sppProfile,  DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_HANDSFREE);
694             de_add_number(sppProfile,  DE_UINT, DE_SIZE_16, 0x0108); // Verision 1.8
695         }
696         de_pop_sequence(attribute, sppProfile);
697     }
698     de_pop_sequence(service, attribute);
699 
700     // 0x0100 "Service Name"
701     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0100);
702     de_add_data(service,  DE_STRING, strlen(name), (uint8_t *) name);
703 }
704 
705 static void hfp_handle_slc_setup_error(hfp_connection_t * hfp_connection, uint8_t status){
706     // cache fields for event
707     hfp_role_t local_role = hfp_connection->local_role;
708     bd_addr_t remote_addr;
709     (void)memcpy(remote_addr, hfp_connection->remote_addr, 6);
710     // finalize connection struct
711     hfp_finalize_connection_context(hfp_connection);
712     // emit event
713     hfp_emit_slc_connection_event(local_role, status, HCI_CON_HANDLE_INVALID, remote_addr);
714 }
715 
716 static void handle_query_rfcomm_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
717     UNUSED(packet_type);    // ok: handling own sdp events
718     UNUSED(channel);        // ok: no channel
719     UNUSED(size);           // ok: handling own sdp events
720 
721     hfp_connection_t * hfp_connection = get_hfp_connection_context_for_bd_addr(hfp_sdp_query_context.remote_address, hfp_sdp_query_context.local_role);
722     if (hfp_connection == NULL) {
723         log_info("connection with %s and local role %d not found", hfp_sdp_query_context.remote_address, hfp_sdp_query_context.local_role);
724         return;
725     }
726 
727     switch (hci_event_packet_get_type(packet)){
728         case SDP_EVENT_QUERY_RFCOMM_SERVICE:
729             hfp_connection->rfcomm_channel_nr = sdp_event_query_rfcomm_service_get_rfcomm_channel(packet);
730             break;
731         case SDP_EVENT_QUERY_COMPLETE:
732             if (hfp_connection->rfcomm_channel_nr > 0){
733                 hfp_connection->state = HFP_W4_RFCOMM_CONNECTED;
734                 btstack_packet_handler_t packet_handler;
735                 switch (hfp_connection->local_role){
736                     case HFP_ROLE_AG:
737                         packet_handler = hfp_ag_rfcomm_packet_handler;
738                         break;
739                     case HFP_ROLE_HF:
740                         packet_handler = hfp_hf_rfcomm_packet_handler;
741                         break;
742                     default:
743                         btstack_assert(false);
744                         return;
745                 }
746 
747                 rfcomm_create_channel(packet_handler, hfp_connection->remote_addr, hfp_connection->rfcomm_channel_nr, NULL);
748 
749             } else {
750                 uint8_t status = sdp_event_query_complete_get_status(packet);
751                 if (status == ERROR_CODE_SUCCESS){
752                     // report service not found
753                     status = SDP_SERVICE_NOT_FOUND;
754                 }
755                 hfp_handle_slc_setup_error(hfp_connection, status);
756                 log_info("rfcomm service not found, status 0x%02x", status);
757             }
758 
759             // register the SDP Query request to check if there is another connection waiting for the query
760             // ignore ERROR_CODE_COMMAND_DISALLOWED because in that case, we already have requested an SDP callback
761             (void) sdp_client_register_query_callback(&hfp_sdp_query_request);
762             break;
763         default:
764             break;
765     }
766 }
767 
768 // returns 0 if unexpected error or no other link options remained, otherwise 1
769 static int hfp_handle_failed_sco_connection(uint8_t status){
770 
771     if (!hfp_sco_establishment_active){
772         log_info("(e)SCO Connection failed but not started by us");
773         return 0;
774     }
775 
776     log_info("(e)SCO Connection failed 0x%02x", status);
777     switch (status){
778         case ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE:
779         case ERROR_CODE_UNSPECIFIED_ERROR:
780         case ERROR_CODE_CONNECTION_REJECTED_DUE_TO_LIMITED_RESOURCES:
781             break;
782         default:
783             return 0;
784     }
785 
786     // note: eSCO_S4 supported flag not available, but it's only relevant for highest CVSD link setting (and the current failed)
787     hfp_link_settings_t next_setting = hfp_next_link_setting_for_connection(hfp_sco_establishment_active->link_setting, hfp_sco_establishment_active, false);
788 
789     // handle no valid setting found
790     if (next_setting == HFP_LINK_SETTINGS_NONE) {
791         if (hfp_sco_establishment_active->negotiated_codec == HFP_CODEC_MSBC){
792             log_info("T2/T1 failed, fallback to CVSD - D1");
793             hfp_sco_establishment_active->negotiated_codec = HFP_CODEC_CVSD;
794             hfp_sco_establishment_active->sco_for_msbc_failed = 1;
795             hfp_sco_establishment_active->ag_send_common_codec = true;
796             hfp_sco_establishment_active->link_setting = HFP_LINK_SETTINGS_D1;
797         } else {
798             // no other options
799             return 0;
800         }
801     }
802 
803     log_info("e)SCO Connection: try new link_setting %d", next_setting);
804     hfp_sco_establishment_active->establish_audio_connection = 1;
805     hfp_sco_establishment_active->link_setting = next_setting;
806     hfp_sco_establishment_active = NULL;
807     return 1;
808 }
809 
810 void hfp_handle_hci_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size, hfp_role_t local_role){
811     UNUSED(packet_type);
812     UNUSED(channel);    // ok: no channel
813     UNUSED(size);
814 
815     bd_addr_t event_addr;
816     hci_con_handle_t handle;
817     hfp_connection_t * hfp_connection = NULL;
818     uint8_t status;
819 
820     log_debug("HFP HCI event handler type %u, event type %x, size %u", packet_type, hci_event_packet_get_type(packet), size);
821 
822     switch (hci_event_packet_get_type(packet)) {
823 
824         case HCI_EVENT_CONNECTION_REQUEST:
825             switch(hci_event_connection_request_get_link_type(packet)){
826                 case 0: //  SCO
827                 case 2: // eSCO
828                     hci_event_connection_request_get_bd_addr(packet, event_addr);
829                     hfp_connection = get_hfp_connection_context_for_bd_addr(event_addr, local_role);
830                     if (!hfp_connection) break;
831                     if (hci_event_connection_request_get_link_type(packet) == 2){
832                         hfp_connection->accept_sco = 2;
833                     } else {
834                         hfp_connection->accept_sco = 1;
835                     }
836 #ifdef ENABLE_CC256X_ASSISTED_HFP
837                     hfp_cc256x_prepare_for_sco(hfp_connection);
838 #endif
839 #ifdef ENABLE_BCM_PCM_WBS
840                     hfp_bcm_prepare_for_sco(hfp_connection);
841 #endif
842 #ifdef ENABLE_RTK_PCM_WBS
843                     hfp_connection->rtk_send_sco_config = true;
844 #endif
845                     log_info("accept sco %u\n", hfp_connection->accept_sco);
846                     hfp_sco_establishment_active = hfp_connection;
847                     break;
848                 default:
849                     break;
850             }
851             break;
852 
853         case HCI_EVENT_COMMAND_STATUS:
854             if (hci_event_command_status_get_command_opcode(packet) == hci_setup_synchronous_connection.opcode) {
855                 if (hfp_sco_establishment_active == NULL) break;
856                 status = hci_event_command_status_get_status(packet);
857                 if (status == ERROR_CODE_SUCCESS) break;
858 
859                 hfp_connection = hfp_sco_establishment_active;
860                 if (hfp_handle_failed_sco_connection(status)) break;
861                 hfp_connection->establish_audio_connection = 0;
862                 hfp_connection->state = HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED;
863                 hfp_emit_sco_event(hfp_connection, status, 0, hfp_connection->remote_addr, hfp_connection->negotiated_codec);
864             }
865             break;
866 
867         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:{
868             if (hfp_sco_establishment_active == NULL) break;
869             hci_event_synchronous_connection_complete_get_bd_addr(packet, event_addr);
870             hfp_connection = get_hfp_connection_context_for_bd_addr(event_addr, local_role);
871             if (!hfp_connection) {
872                 log_error("HFP: connection does not exist for remote with addr %s.", bd_addr_to_str(event_addr));
873                 return;
874             }
875 
876             status = hci_event_synchronous_connection_complete_get_status(packet);
877             if (status != ERROR_CODE_SUCCESS){
878                 hfp_connection->accept_sco = 0;
879                 if (hfp_handle_failed_sco_connection(status)) break;
880 
881                 hfp_connection->establish_audio_connection = 0;
882                 hfp_connection->state = HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED;
883                 hfp_emit_sco_event(hfp_connection, status, 0, event_addr, hfp_connection->negotiated_codec);
884                 break;
885             }
886 
887             uint16_t sco_handle = hci_event_synchronous_connection_complete_get_handle(packet);
888             uint8_t  link_type = hci_event_synchronous_connection_complete_get_link_type(packet);
889             uint8_t  transmission_interval = hci_event_synchronous_connection_complete_get_transmission_interval(packet);  // measured in slots
890             uint8_t  retransmission_interval = hci_event_synchronous_connection_complete_get_retransmission_interval(packet);// measured in slots
891             uint16_t rx_packet_length = hci_event_synchronous_connection_complete_get_rx_packet_length(packet); // measured in bytes
892             uint16_t tx_packet_length = hci_event_synchronous_connection_complete_get_tx_packet_length(packet); // measured in bytes
893 
894             switch (link_type){
895                 case 0x00:
896                     log_info("SCO Connection established.");
897                     if (transmission_interval != 0) log_error("SCO Connection: transmission_interval not zero: %d.", transmission_interval);
898                     if (retransmission_interval != 0) log_error("SCO Connection: retransmission_interval not zero: %d.", retransmission_interval);
899                     if (rx_packet_length != 0) log_error("SCO Connection: rx_packet_length not zero: %d.", rx_packet_length);
900                     if (tx_packet_length != 0) log_error("SCO Connection: tx_packet_length not zero: %d.", tx_packet_length);
901                     break;
902                 case 0x02:
903                     log_info("eSCO Connection established. \n");
904                     break;
905                 default:
906                     log_error("(e)SCO reserved link_type 0x%2x", link_type);
907                     break;
908             }
909 
910             log_info("sco_handle 0x%2x, address %s, transmission_interval %u slots, retransmission_interval %u slots, "
911                  " rx_packet_length %u bytes, tx_packet_length %u bytes, air_mode 0x%2x (0x02 == CVSD)\n", sco_handle,
912                  bd_addr_to_str(event_addr), transmission_interval, retransmission_interval, rx_packet_length, tx_packet_length,
913                  hci_event_synchronous_connection_complete_get_air_mode(packet));
914 
915             if (hfp_connection->state == HFP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN){
916                 log_info("SCO about to disconnect: HFP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN");
917                 hfp_connection->state = HFP_W2_DISCONNECT_SCO;
918                 break;
919             }
920             hfp_connection->sco_handle = sco_handle;
921             hfp_connection->establish_audio_connection = 0;
922 
923             hfp_connection->state = HFP_AUDIO_CONNECTION_ESTABLISHED;
924 
925             switch (hfp_connection->vra_state){
926                 case HFP_VRA_VOICE_RECOGNITION_ACTIVATED:
927                     hfp_connection->ag_audio_connection_opened_before_vra = false;
928                     break;
929                 default:
930                     hfp_connection->ag_audio_connection_opened_before_vra = true;
931                     break;
932             }
933             hfp_emit_sco_event(hfp_connection, status, sco_handle, event_addr, hfp_connection->negotiated_codec);
934             break;
935         }
936 
937         case HCI_EVENT_DISCONNECTION_COMPLETE:
938             handle = little_endian_read_16(packet,3);
939             hfp_connection = get_hfp_connection_context_for_sco_handle(handle, local_role);
940 
941             if (!hfp_connection) break;
942 
943 #ifdef ENABLE_CC256X_ASSISTED_HFP
944             hfp_connection->cc256x_send_wbs_disassociate = true;
945 #endif
946 #ifdef ENABLE_BCM_PCM_WBS
947             hfp_connection->bcm_send_disable_wbs = true;
948 #endif
949             if (hfp_connection->sco_handle == handle){
950                 hfp_connection->sco_handle = HCI_CON_HANDLE_INVALID;
951                 hfp_connection->release_audio_connection = 0;
952                 hfp_connection->state = HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED;
953                 hfp_emit_audio_connection_released(hfp_connection, handle);
954 
955                 hfp_connection->ag_audio_connection_opened_before_vra = false;
956 
957                 if (hfp_connection->acl_handle == HCI_CON_HANDLE_INVALID){
958                     hfp_reset_voice_recognition(hfp_connection);
959                     hfp_emit_event(hfp_connection, HFP_SUBEVENT_SERVICE_LEVEL_CONNECTION_RELEASED, 0);
960                     hfp_finalize_connection_context(hfp_connection);
961                     break;
962                 } else if (hfp_connection->release_slc_connection == 1){
963                     hfp_connection->release_slc_connection = 0;
964                     hfp_connection->state = HFP_W2_DISCONNECT_RFCOMM;
965                     rfcomm_disconnect(hfp_connection->acl_handle);
966                 }
967             }
968 
969             if (hfp_connection->state == HFP_W4_SCO_DISCONNECTED_TO_SHUTDOWN){
970                 // RFCOMM already closed -> remote power off
971 #if defined(ENABLE_CC256X_ASSISTED_HFP) || defined (ENABLE_BCM_PCM_WBS)
972                 hfp_connection->state = HFP_W4_WBS_SHUTDOWN;
973 #else
974                 hfp_finalize_connection_context(hfp_connection);
975 #endif
976                 break;
977             }
978             break;
979 
980         default:
981             break;
982     }
983 }
984 
985 
986 void hfp_handle_rfcomm_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size, hfp_role_t local_role){
987     UNUSED(packet_type);
988     UNUSED(channel);    // ok: no channel
989     UNUSED(size);
990 
991     bd_addr_t event_addr;
992     uint16_t rfcomm_cid;
993     hfp_connection_t * hfp_connection = NULL;
994     uint8_t status;
995 
996     log_debug("HFP packet_handler type %u, event type %x, size %u", packet_type, hci_event_packet_get_type(packet), size);
997 
998     switch (hci_event_packet_get_type(packet)) {
999 
1000         case RFCOMM_EVENT_INCOMING_CONNECTION:
1001             // data: event (8), len(8), address(48), channel (8), rfcomm_cid (16)
1002             rfcomm_event_incoming_connection_get_bd_addr(packet, event_addr);
1003             hfp_connection = hfp_create_connection(event_addr, local_role);
1004             if (!hfp_connection){
1005                 log_info("hfp: no memory to accept incoming connection - decline");
1006                 rfcomm_decline_connection(rfcomm_event_incoming_connection_get_rfcomm_cid(packet));
1007                 return;
1008             }
1009             if (hfp_connection->state != HFP_IDLE) {
1010                 log_error("hfp: incoming connection but not idle, reject");
1011                 rfcomm_decline_connection(rfcomm_event_incoming_connection_get_rfcomm_cid(packet));
1012                 return;
1013             }
1014 
1015             hfp_connection->rfcomm_cid = rfcomm_event_incoming_connection_get_rfcomm_cid(packet);
1016             hfp_connection->state = HFP_W4_RFCOMM_CONNECTED;
1017             rfcomm_accept_connection(hfp_connection->rfcomm_cid);
1018             break;
1019 
1020         case RFCOMM_EVENT_CHANNEL_OPENED:
1021             rfcomm_event_channel_opened_get_bd_addr(packet, event_addr);
1022 
1023             hfp_connection = get_hfp_connection_context_for_bd_addr(event_addr, local_role);
1024             btstack_assert(hfp_connection != NULL);
1025 
1026             if (hfp_connection->state != HFP_W4_RFCOMM_CONNECTED){
1027                 break;
1028             }
1029 
1030             status = rfcomm_event_channel_opened_get_status(packet);
1031             if (status != ERROR_CODE_SUCCESS) {
1032                 hfp_handle_slc_setup_error(hfp_connection, status);
1033                 break;
1034             }
1035 
1036             hfp_connection->acl_handle = rfcomm_event_channel_opened_get_con_handle(packet);
1037             hfp_connection->rfcomm_cid = rfcomm_event_channel_opened_get_rfcomm_cid(packet);
1038             hfp_connection->rfcomm_mtu = rfcomm_event_channel_opened_get_max_frame_size(packet);
1039             bd_addr_copy(hfp_connection->remote_addr, event_addr);
1040             hfp_connection->state = HFP_EXCHANGE_SUPPORTED_FEATURES;
1041 
1042             rfcomm_request_can_send_now_event(hfp_connection->rfcomm_cid);
1043             break;
1044 
1045         case RFCOMM_EVENT_CHANNEL_CLOSED:
1046             rfcomm_cid = little_endian_read_16(packet,2);
1047             hfp_connection = get_hfp_connection_context_for_rfcomm_cid(rfcomm_cid);
1048             if (!hfp_connection) break;
1049             switch (hfp_connection->state){
1050                 case HFP_W4_RFCOMM_DISCONNECTED_AND_RESTART:
1051                     hfp_connection->acl_handle = HCI_CON_HANDLE_INVALID;
1052                     hfp_connection->state = HFP_IDLE;
1053                     hfp_establish_service_level_connection(hfp_connection->remote_addr, hfp_connection->service_uuid, local_role);
1054                     break;
1055 
1056                 case HFP_AUDIO_CONNECTION_ESTABLISHED:
1057                     // service connection was released, this implicitly releases audio connection as well
1058                     hfp_connection->release_audio_connection = 0;
1059                     hfp_connection->acl_handle = HCI_CON_HANDLE_INVALID;
1060                     hfp_connection->state = HFP_W4_SCO_DISCONNECTED_TO_SHUTDOWN;
1061                     gap_disconnect(hfp_connection->sco_handle);
1062                     break;
1063 
1064                 default:
1065                     // regular case
1066                     hfp_reset_voice_recognition(hfp_connection);
1067                     hfp_emit_event(hfp_connection, HFP_SUBEVENT_SERVICE_LEVEL_CONNECTION_RELEASED, 0);
1068                     hfp_finalize_connection_context(hfp_connection);
1069                     break;
1070             }
1071             break;
1072 
1073         default:
1074             break;
1075     }
1076 }
1077 // translates command string into hfp_command_t CMD
1078 
1079 typedef struct {
1080     const char * command;
1081     hfp_command_t command_id;
1082 } hfp_command_entry_t;
1083 
1084 static hfp_command_entry_t hfp_ag_commmand_table[] = {
1085     { "AT+BAC=",   HFP_CMD_AVAILABLE_CODECS },
1086     { "AT+BCC",    HFP_CMD_TRIGGER_CODEC_CONNECTION_SETUP },
1087     { "AT+BCS=",   HFP_CMD_HF_CONFIRMED_CODEC },
1088     { "AT+BIA=",   HFP_CMD_ENABLE_INDIVIDUAL_AG_INDICATOR_STATUS_UPDATE, }, // +BIA:<enabled>,,<enabled>,,,<enabled>
1089     { "AT+BIEV=",  HFP_CMD_HF_INDICATOR_STATUS },
1090     { "AT+BIND=",  HFP_CMD_LIST_GENERIC_STATUS_INDICATORS },
1091     { "AT+BIND=?", HFP_CMD_RETRIEVE_GENERIC_STATUS_INDICATORS },
1092     { "AT+BIND?",  HFP_CMD_RETRIEVE_GENERIC_STATUS_INDICATORS_STATE },
1093     { "AT+BINP=",  HFP_CMD_HF_REQUEST_PHONE_NUMBER },
1094     { "AT+BLDN",   HFP_CMD_REDIAL_LAST_NUMBER },
1095     { "AT+BRSF=",  HFP_CMD_SUPPORTED_FEATURES },
1096     { "AT+BTRH=",  HFP_CMD_RESPONSE_AND_HOLD_COMMAND },
1097     { "AT+BTRH?",  HFP_CMD_RESPONSE_AND_HOLD_QUERY },
1098     { "AT+BVRA=",  HFP_CMD_HF_ACTIVATE_VOICE_RECOGNITION },
1099     { "AT+CCWA=",  HFP_CMD_ENABLE_CALL_WAITING_NOTIFICATION},
1100     { "AT+CHLD=",  HFP_CMD_CALL_HOLD },
1101     { "AT+CHLD=?", HFP_CMD_SUPPORT_CALL_HOLD_AND_MULTIPARTY_SERVICES },
1102     { "AT+CHUP",   HFP_CMD_HANG_UP_CALL },
1103     { "AT+CIND=?", HFP_CMD_RETRIEVE_AG_INDICATORS },
1104     { "AT+CIND?",  HFP_CMD_RETRIEVE_AG_INDICATORS_STATUS },
1105     { "AT+CLCC",   HFP_CMD_LIST_CURRENT_CALLS },
1106     { "AT+CLIP=",  HFP_CMD_ENABLE_CLIP},
1107     { "AT+CMEE=",  HFP_CMD_ENABLE_EXTENDED_AUDIO_GATEWAY_ERROR},
1108     { "AT+CMER=",  HFP_CMD_ENABLE_INDICATOR_STATUS_UPDATE },
1109     { "AT+CNUM",   HFP_CMD_GET_SUBSCRIBER_NUMBER_INFORMATION },
1110     { "AT+COPS=",  HFP_CMD_QUERY_OPERATOR_SELECTION_NAME_FORMAT },
1111     { "AT+COPS?",  HFP_CMD_QUERY_OPERATOR_SELECTION_NAME },
1112     { "AT+NREC=",  HFP_CMD_TURN_OFF_EC_AND_NR, },
1113     { "AT+VGM=",   HFP_CMD_SET_MICROPHONE_GAIN },
1114     { "AT+VGS=",   HFP_CMD_SET_SPEAKER_GAIN },
1115     { "AT+VTS=",   HFP_CMD_TRANSMIT_DTMF_CODES },
1116     { "ATA",       HFP_CMD_CALL_ANSWERED },
1117 };
1118 
1119 static hfp_command_entry_t hfp_hf_commmand_table[] = {
1120     { "+BCS:",  HFP_CMD_AG_SUGGESTED_CODEC },
1121     { "+BIND:", HFP_CMD_SET_GENERIC_STATUS_INDICATOR_STATUS },
1122     { "+BINP",  HFP_CMD_AG_SENT_PHONE_NUMBER },
1123     { "+BRSF:", HFP_CMD_SUPPORTED_FEATURES },
1124     { "+BSIR:", HFP_CMD_CHANGE_IN_BAND_RING_TONE_SETTING },
1125     { "+BTRH:", HFP_CMD_RESPONSE_AND_HOLD_STATUS },
1126     { "+BVRA:", HFP_CMD_AG_ACTIVATE_VOICE_RECOGNITION },
1127     { "+CCWA:", HFP_CMD_AG_SENT_CALL_WAITING_NOTIFICATION_UPDATE, },
1128     { "+CHLD:", HFP_CMD_SUPPORT_CALL_HOLD_AND_MULTIPARTY_SERVICES },
1129     { "+CIEV:", HFP_CMD_TRANSFER_AG_INDICATOR_STATUS},
1130     { "+CIND:", HFP_CMD_RETRIEVE_AG_INDICATORS_GENERIC },
1131     { "+CLCC:", HFP_CMD_LIST_CURRENT_CALLS },
1132     { "+CLIP:", HFP_CMD_AG_SENT_CLIP_INFORMATION },
1133     { "+CME ERROR:", HFP_CMD_EXTENDED_AUDIO_GATEWAY_ERROR },
1134     { "+CNUM:", HFP_CMD_GET_SUBSCRIBER_NUMBER_INFORMATION},
1135     { "+COPS:", HFP_CMD_QUERY_OPERATOR_SELECTION_NAME },
1136     { "+VGM:",  HFP_CMD_SET_MICROPHONE_GAIN },
1137     { "+VGM=",  HFP_CMD_SET_MICROPHONE_GAIN },
1138     { "+VGS:",  HFP_CMD_SET_SPEAKER_GAIN},
1139     { "+VGS=",  HFP_CMD_SET_SPEAKER_GAIN},
1140     { "ERROR",  HFP_CMD_ERROR},
1141     { "NOP",    HFP_CMD_NONE}, // dummy command used by unit tests
1142     { "OK",     HFP_CMD_OK },
1143     { "RING",   HFP_CMD_RING },
1144 };
1145 
1146 static hfp_command_t parse_command(const char * line_buffer, int isHandsFree){
1147 
1148     // table lookup based on role
1149     uint16_t num_entries;
1150     hfp_command_entry_t * table;
1151     if (isHandsFree == 0){
1152         table = hfp_ag_commmand_table;
1153         num_entries = sizeof(hfp_ag_commmand_table) / sizeof(hfp_command_entry_t);
1154     } else {
1155         table = hfp_hf_commmand_table;
1156         num_entries = sizeof(hfp_hf_commmand_table) / sizeof(hfp_command_entry_t);
1157     }
1158     // binary search
1159     uint16_t left = 0;
1160     uint16_t right = num_entries - 1;
1161     while (left <= right){
1162         uint16_t middle = left + (right - left) / 2;
1163         hfp_command_entry_t *entry = &table[middle];
1164         int match = strcmp(line_buffer, entry->command);
1165         if (match < 0){
1166             // search term is lower than middle element
1167             if (right == 0) break;
1168             right = middle - 1;
1169         } else if (match == 0){
1170             return entry->command_id;
1171         } else {
1172             // search term is higher than middle element
1173             left = middle + 1;
1174         }
1175     }
1176 
1177     // note: if parser in CMD_HEADER state would treats digits and maybe '+' as separator, match on "ATD" would work.
1178     // note: phone number is currently expected in line_buffer[3..]
1179     // prefix match on 'ATD', AG only
1180     if ((isHandsFree == 0) && (strncmp(line_buffer, HFP_CALL_PHONE_NUMBER, strlen(HFP_CALL_PHONE_NUMBER)) == 0)){
1181         return HFP_CMD_CALL_PHONE_NUMBER;
1182     }
1183 
1184     // Valid looking, but unknown commands/responses
1185     if ((isHandsFree == 0) && (strncmp(line_buffer, "AT+", 3) == 0)){
1186         return HFP_CMD_UNKNOWN;
1187     }
1188 
1189     if ((isHandsFree != 0) && (strncmp(line_buffer, "+", 1) == 0)){
1190         return HFP_CMD_UNKNOWN;
1191     }
1192 
1193     return HFP_CMD_NONE;
1194 }
1195 
1196 static void hfp_parser_store_byte(hfp_connection_t * hfp_connection, uint8_t byte){
1197     if ((hfp_connection->line_size + 1) >= HFP_MAX_VR_TEXT_SIZE) return;
1198     hfp_connection->line_buffer[hfp_connection->line_size++] = byte;
1199     hfp_connection->line_buffer[hfp_connection->line_size] = 0;
1200 }
1201 static int hfp_parser_is_buffer_empty(hfp_connection_t * hfp_connection){
1202     return hfp_connection->line_size == 0;
1203 }
1204 
1205 static int hfp_parser_is_end_of_line(uint8_t byte){
1206     return (byte == '\n') || (byte == '\r');
1207 }
1208 
1209 static void hfp_parser_reset_line_buffer(hfp_connection_t *hfp_connection) {
1210     hfp_connection->line_size = 0;
1211     // we don't set the first byte to '\0' to allow access to last argument e.g. in hfp_hf_handle_rfcommand
1212 }
1213 
1214 static void hfp_parser_store_if_token(hfp_connection_t * hfp_connection, uint8_t byte){
1215     switch (byte){
1216         case ',':
1217 		case '-':
1218         case ';':
1219         case '(':
1220         case ')':
1221         case '\n':
1222         case '\r':
1223             break;
1224         default:
1225             hfp_parser_store_byte(hfp_connection, byte);
1226             break;
1227     }
1228 }
1229 
1230 static bool hfp_parser_is_separator( uint8_t byte){
1231     switch (byte){
1232         case ',':
1233 		case '-':
1234         case ';':
1235         case '\n':
1236         case '\r':
1237             return true;
1238         default:
1239             return false;
1240     }
1241 }
1242 
1243 static bool hfp_parse_byte(hfp_connection_t * hfp_connection, uint8_t byte, int isHandsFree){
1244 
1245     // handle doubles quotes
1246     if (byte == '"'){
1247         hfp_connection->parser_quoted = !hfp_connection->parser_quoted;
1248         return true;
1249     }
1250     if (hfp_connection->parser_quoted) {
1251         hfp_parser_store_byte(hfp_connection, byte);
1252         return true;
1253     }
1254 
1255     // ignore spaces outside command or double quotes (required e.g. for '+CME ERROR:..") command
1256     if ((byte == ' ') && (hfp_connection->parser_state != HFP_PARSER_CMD_HEADER)) return true;
1257 
1258     bool processed = true;
1259 
1260     switch (hfp_connection->parser_state) {
1261         case HFP_PARSER_CMD_HEADER:
1262             switch (byte) {
1263                 case '\n':
1264                 case '\r':
1265                 case ';':
1266                     // ignore separator
1267                     break;
1268                 case ':':
1269                 case '?':
1270                     // store separator
1271                     hfp_parser_store_byte(hfp_connection, byte);
1272                     break;
1273                 case '=':
1274                     // equal sign: remember and wait for next char to decided between '=?' and '=\?'
1275                     hfp_connection->found_equal_sign = true;
1276                     hfp_parser_store_byte(hfp_connection, byte);
1277                     return true;
1278                 default:
1279                     // store if not lookahead
1280                     if (!hfp_connection->found_equal_sign) {
1281                         hfp_parser_store_byte(hfp_connection, byte);
1282                         return true;
1283                     }
1284                     // mark as lookahead
1285                     processed = false;
1286                     break;
1287             }
1288 
1289             // ignore empty tokens
1290             if (hfp_parser_is_buffer_empty(hfp_connection)) return true;
1291 
1292             // parse
1293             hfp_connection->command = parse_command((char *)hfp_connection->line_buffer, isHandsFree);
1294 
1295             // pick +CIND version based on connection state: descriptions during SLC vs. states later
1296             if (hfp_connection->command == HFP_CMD_RETRIEVE_AG_INDICATORS_GENERIC){
1297                 switch(hfp_connection->state){
1298                     case HFP_W4_RETRIEVE_INDICATORS_STATUS:
1299                         hfp_connection->command = HFP_CMD_RETRIEVE_AG_INDICATORS_STATUS;
1300                         break;
1301                     case HFP_W4_RETRIEVE_INDICATORS:
1302                         hfp_connection->command = HFP_CMD_RETRIEVE_AG_INDICATORS;
1303                         break;
1304                     default:
1305                         hfp_connection->command = HFP_CMD_UNKNOWN;
1306                         break;
1307                 }
1308             }
1309 
1310             log_info("command string '%s', handsfree %u -> cmd id %u", (char *)hfp_connection->line_buffer, isHandsFree, hfp_connection->command);
1311 
1312             // next state
1313             hfp_connection->found_equal_sign = false;
1314             hfp_parser_reset_line_buffer(hfp_connection);
1315             hfp_connection->parser_state = HFP_PARSER_CMD_SEQUENCE;
1316 
1317             return processed;
1318 
1319         case HFP_PARSER_CMD_SEQUENCE:
1320             // handle empty fields
1321             if ((byte == ',' ) && (hfp_connection->line_size == 0)){
1322                 hfp_connection->line_buffer[0] = 0;
1323                 hfp_connection->ignore_value = 1;
1324                 parse_sequence(hfp_connection);
1325                 return true;
1326             }
1327 
1328             hfp_parser_store_if_token(hfp_connection, byte);
1329             if (!hfp_parser_is_separator(byte)) return true;
1330 
1331             // ignore empty tokens
1332             switch (hfp_connection->command){
1333                 case HFP_CMD_AG_ACTIVATE_VOICE_RECOGNITION:
1334                     // don't ignore empty string
1335                     break;
1336                 default:
1337                     if (hfp_parser_is_buffer_empty(hfp_connection) && (hfp_connection->ignore_value == 0)) {
1338                         return true;
1339                     }
1340                     break;
1341             }
1342 
1343             parse_sequence(hfp_connection);
1344 
1345             hfp_parser_reset_line_buffer(hfp_connection);
1346 
1347             switch (hfp_connection->command){
1348                 case HFP_CMD_AG_SENT_PHONE_NUMBER:
1349                 case HFP_CMD_AG_SENT_CALL_WAITING_NOTIFICATION_UPDATE:
1350                 case HFP_CMD_AG_SENT_CLIP_INFORMATION:
1351                 case HFP_CMD_TRANSFER_AG_INDICATOR_STATUS:
1352                 case HFP_CMD_QUERY_OPERATOR_SELECTION_NAME:
1353                 case HFP_CMD_QUERY_OPERATOR_SELECTION_NAME_FORMAT:
1354                 case HFP_CMD_RETRIEVE_AG_INDICATORS:
1355                 case HFP_CMD_RETRIEVE_GENERIC_STATUS_INDICATORS_STATE:
1356                 case HFP_CMD_HF_INDICATOR_STATUS:
1357                     hfp_connection->parser_state = HFP_PARSER_SECOND_ITEM;
1358                     break;
1359                 default:
1360                     break;
1361             }
1362             return true;
1363 
1364         case HFP_PARSER_SECOND_ITEM:
1365 
1366             hfp_parser_store_if_token(hfp_connection, byte);
1367             if (!hfp_parser_is_separator(byte)) return true;
1368 
1369             switch (hfp_connection->command){
1370                 case HFP_CMD_QUERY_OPERATOR_SELECTION_NAME:
1371                     log_info("format %s, ", hfp_connection->line_buffer);
1372                     hfp_connection->network_operator.format =  btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1373                     break;
1374                 case HFP_CMD_QUERY_OPERATOR_SELECTION_NAME_FORMAT:
1375                     log_info("format %s \n", hfp_connection->line_buffer);
1376                     hfp_connection->network_operator.format =  btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1377                     break;
1378                 case HFP_CMD_LIST_GENERIC_STATUS_INDICATORS:
1379                 case HFP_CMD_RETRIEVE_GENERIC_STATUS_INDICATORS:
1380                 case HFP_CMD_RETRIEVE_GENERIC_STATUS_INDICATORS_STATE:
1381                     hfp_connection->generic_status_indicators[hfp_connection->parser_item_index].state = (uint8_t)btstack_atoi((char*)hfp_connection->line_buffer);
1382                     break;
1383                 case HFP_CMD_TRANSFER_AG_INDICATOR_STATUS:
1384                     hfp_connection->ag_indicators[hfp_connection->parser_item_index].status = (uint8_t)btstack_atoi((char*)hfp_connection->line_buffer);
1385                     log_info("%d \n", hfp_connection->ag_indicators[hfp_connection->parser_item_index].status);
1386                     hfp_connection->ag_indicators[hfp_connection->parser_item_index].status_changed = 1;
1387                     break;
1388                 case HFP_CMD_RETRIEVE_AG_INDICATORS:
1389                     hfp_connection->ag_indicators[hfp_connection->parser_item_index].min_range = btstack_atoi((char *)hfp_connection->line_buffer);
1390                     log_info("%s, ", hfp_connection->line_buffer);
1391                     break;
1392                 case HFP_CMD_AG_SENT_PHONE_NUMBER:
1393                 case HFP_CMD_AG_SENT_CALL_WAITING_NOTIFICATION_UPDATE:
1394                 case HFP_CMD_AG_SENT_CLIP_INFORMATION:
1395                     hfp_connection->bnip_type = (uint8_t)btstack_atoi((char*)hfp_connection->line_buffer);
1396                     break;
1397                 case HFP_CMD_HF_INDICATOR_STATUS:
1398                     hfp_connection->parser_indicator_value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1399                     break;
1400                 default:
1401                     break;
1402             }
1403 
1404             hfp_parser_reset_line_buffer(hfp_connection);
1405 
1406             hfp_connection->parser_state = HFP_PARSER_THIRD_ITEM;
1407 
1408             return true;
1409 
1410         case HFP_PARSER_THIRD_ITEM:
1411 
1412             hfp_parser_store_if_token(hfp_connection, byte);
1413             if (!hfp_parser_is_separator(byte)) return true;
1414 
1415             switch (hfp_connection->command){
1416                 case HFP_CMD_QUERY_OPERATOR_SELECTION_NAME:
1417                     btstack_strcpy(hfp_connection->network_operator.name, HFP_MAX_NETWORK_OPERATOR_NAME_SIZE,  (char *)hfp_connection->line_buffer);
1418                     break;
1419                 case HFP_CMD_RETRIEVE_AG_INDICATORS:
1420                     hfp_connection->ag_indicators[hfp_connection->parser_item_index].max_range = btstack_atoi((char *)hfp_connection->line_buffer);
1421                     hfp_next_indicators_index(hfp_connection);
1422                     hfp_connection->ag_indicators_nr = hfp_connection->parser_item_index;
1423                     break;
1424                 case HFP_CMD_AG_SENT_CLIP_INFORMATION:
1425                     // track if last argument exists
1426                     hfp_connection->clip_have_alpha = hfp_connection->line_size != 0;
1427                     break;
1428                 default:
1429                     break;
1430             }
1431 
1432             hfp_parser_reset_line_buffer(hfp_connection);
1433 
1434             if (hfp_connection->command == HFP_CMD_RETRIEVE_AG_INDICATORS){
1435                 hfp_connection->parser_state = HFP_PARSER_CMD_SEQUENCE;
1436             }
1437             return true;
1438 
1439         default:
1440             btstack_assert(false);
1441             return true;
1442     }
1443 }
1444 
1445 void hfp_parse(hfp_connection_t * hfp_connection, uint8_t byte, int isHandsFree){
1446     bool processed = false;
1447     while (!processed){
1448         processed = hfp_parse_byte(hfp_connection, byte, isHandsFree);
1449     }
1450     // reset parser state on end-of-line
1451     if (hfp_parser_is_end_of_line(byte)){
1452         hfp_connection->parser_item_index = 0;
1453         hfp_connection->parser_state = HFP_PARSER_CMD_HEADER;
1454     }
1455 }
1456 
1457 static void parse_sequence(hfp_connection_t * hfp_connection){
1458     int value;
1459     switch (hfp_connection->command){
1460         case HFP_CMD_SET_GENERIC_STATUS_INDICATOR_STATUS:
1461             value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1462             int i;
1463             switch (hfp_connection->parser_item_index){
1464                 case 0:
1465                     for (i=0;i<hfp_connection->generic_status_indicators_nr;i++){
1466                         if (hfp_connection->generic_status_indicators[i].uuid == value){
1467                             hfp_connection->parser_indicator_index = i;
1468                             break;
1469                         }
1470                     }
1471                     break;
1472                 case 1:
1473                     if (hfp_connection->parser_indicator_index <0) break;
1474                     hfp_connection->generic_status_indicators[hfp_connection->parser_indicator_index].state = value;
1475                     log_info("HFP_CMD_SET_GENERIC_STATUS_INDICATOR_STATUS set indicator at index %u, to %u\n",
1476                      hfp_connection->parser_item_index, value);
1477                     break;
1478                 default:
1479                     break;
1480             }
1481             hfp_next_indicators_index(hfp_connection);
1482             break;
1483 
1484         case HFP_CMD_GET_SUBSCRIBER_NUMBER_INFORMATION:
1485             switch(hfp_connection->parser_item_index){
1486                 case 0:
1487                     // <alpha>: This optional field is not supported, and shall be left blank.
1488                     break;
1489                 case 1:
1490                     // <number>: Quoted string containing the phone number in the format specified by <type>.
1491                     btstack_strcpy(hfp_connection->bnip_number, sizeof(hfp_connection->bnip_number), (char *)hfp_connection->line_buffer);
1492                     break;
1493                 case 2:
1494                     /*
1495                       <type> field specifies the format of the phone number provided, and can be one of the following values:
1496                       - values 128-143: The phone number format may be a national or international format, and may contain prefix and/or escape digits. No changes on the number presentation are required.
1497                      - values 144-159: The phone number format is an international number, including the country code prefix. If the plus sign ("+") is not included as part of the number and shall be added by the AG as needed.
1498                      - values 160-175: National number. No prefix nor escape digits included.
1499                      */
1500                     value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1501                     hfp_connection->bnip_type = value;
1502                     break;
1503                 case 3:
1504                     // <speed>: This optional field is not supported, and shall be left blank.
1505                     break;
1506                 case 4:
1507                     // <service>: Indicates which service this phone number relates to. Shall be either 4 (voice) or 5 (fax).
1508                 default:
1509                     break;
1510             }
1511             // index > 2 are ignored in switch above
1512             hfp_connection->parser_item_index++;
1513             break;
1514         case HFP_CMD_LIST_CURRENT_CALLS:
1515             switch(hfp_connection->parser_item_index){
1516                 case 0:
1517                     value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1518                     hfp_connection->clcc_idx = value;
1519                     break;
1520                 case 1:
1521                     value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1522                     hfp_connection->clcc_dir = value;
1523                     break;
1524                 case 2:
1525                     value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1526                     hfp_connection->clcc_status = value;
1527                     break;
1528                 case 3:
1529                     value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1530                     hfp_connection->clcc_mode = value;
1531                     break;
1532                 case 4:
1533                     value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1534                     hfp_connection->clcc_mpty = value;
1535                     break;
1536                 case 5:
1537                     btstack_strcpy(hfp_connection->bnip_number, sizeof(hfp_connection->bnip_number), (char *)hfp_connection->line_buffer);
1538                     break;
1539                 case 6:
1540                     value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1541                     hfp_connection->bnip_type = value;
1542                     break;
1543                 default:
1544                     break;
1545             }
1546             // index > 6 are ignored in switch above
1547             hfp_connection->parser_item_index++;
1548             break;
1549         case HFP_CMD_SET_MICROPHONE_GAIN:
1550             value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1551             hfp_connection->microphone_gain = value;
1552             log_info("hfp parse HFP_CMD_SET_MICROPHONE_GAIN %d\n", value);
1553             break;
1554         case HFP_CMD_SET_SPEAKER_GAIN:
1555             value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1556             hfp_connection->speaker_gain = value;
1557             log_info("hfp parse HFP_CMD_SET_SPEAKER_GAIN %d\n", value);
1558             break;
1559         case HFP_CMD_TURN_OFF_EC_AND_NR:
1560             value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1561             hfp_connection->ag_echo_and_noise_reduction = value;
1562             log_info("hfp parse HFP_CMD_TURN_OFF_EC_AND_NR %d\n", value);
1563             break;
1564         case HFP_CMD_CHANGE_IN_BAND_RING_TONE_SETTING:
1565             value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1566             hfp_connection->remote_supported_features = store_bit(hfp_connection->remote_supported_features, HFP_AGSF_IN_BAND_RING_TONE, value);
1567             log_info("hfp parse HFP_CHANGE_IN_BAND_RING_TONE_SETTING %d\n", value);
1568             break;
1569         case HFP_CMD_HF_CONFIRMED_CODEC:
1570             hfp_connection->codec_confirmed = btstack_atoi((char*)hfp_connection->line_buffer);
1571             log_info("hfp parse HFP_CMD_HF_CONFIRMED_CODEC %d\n", hfp_connection->codec_confirmed);
1572             break;
1573         case HFP_CMD_AG_SUGGESTED_CODEC:
1574             hfp_connection->suggested_codec = btstack_atoi((char*)hfp_connection->line_buffer);
1575             log_info("hfp parse HFP_CMD_AG_SUGGESTED_CODEC %d\n", hfp_connection->suggested_codec);
1576             break;
1577         case HFP_CMD_SUPPORTED_FEATURES:
1578             hfp_connection->remote_supported_features = btstack_atoi((char*)hfp_connection->line_buffer);
1579             log_info("Parsed supported feature %d\n", (int) hfp_connection->remote_supported_features);
1580             break;
1581         case HFP_CMD_AVAILABLE_CODECS:
1582             log_info("Parsed codec %s\n", hfp_connection->line_buffer);
1583             hfp_connection->remote_codecs[hfp_connection->parser_item_index] = (uint16_t)btstack_atoi((char*)hfp_connection->line_buffer);
1584             hfp_next_codec_index(hfp_connection);
1585             hfp_connection->remote_codecs_nr = hfp_connection->parser_item_index;
1586             break;
1587         case HFP_CMD_RETRIEVE_AG_INDICATORS:
1588             btstack_strcpy((char *)hfp_connection->ag_indicators[hfp_connection->parser_item_index].name, HFP_MAX_INDICATOR_DESC_SIZE, (char *)hfp_connection->line_buffer);
1589             hfp_connection->ag_indicators[hfp_connection->parser_item_index].index = hfp_connection->parser_item_index+1;
1590             log_info("Indicator %d: %s (", hfp_connection->ag_indicators_nr+1, hfp_connection->line_buffer);
1591             break;
1592         case HFP_CMD_RETRIEVE_AG_INDICATORS_STATUS:
1593             log_info("Parsed Indicator %d with status: %s\n", hfp_connection->parser_item_index+1, hfp_connection->line_buffer);
1594             hfp_connection->ag_indicators[hfp_connection->parser_item_index].status = btstack_atoi((char *) hfp_connection->line_buffer);
1595             hfp_next_indicators_index(hfp_connection);
1596             break;
1597         case HFP_CMD_ENABLE_INDICATOR_STATUS_UPDATE:
1598             hfp_next_indicators_index(hfp_connection);
1599             if (hfp_connection->parser_item_index != 4) break;
1600             log_info("Parsed Enable indicators: %s\n", hfp_connection->line_buffer);
1601             value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1602             hfp_connection->enable_status_update_for_ag_indicators = (uint8_t) value;
1603             break;
1604         case HFP_CMD_SUPPORT_CALL_HOLD_AND_MULTIPARTY_SERVICES:
1605             log_info("Parsed Support call hold: %s\n", hfp_connection->line_buffer);
1606             if (hfp_connection->line_size > 2 ) break;
1607             memcpy((char *)hfp_connection->remote_call_services[hfp_connection->remote_call_services_index].name, (char *)hfp_connection->line_buffer, HFP_CALL_SERVICE_SIZE-1);
1608             hfp_connection->remote_call_services[hfp_connection->remote_call_services_index].name[HFP_CALL_SERVICE_SIZE - 1] = 0;
1609             hfp_next_remote_call_services_index(hfp_connection);
1610             break;
1611         case HFP_CMD_LIST_GENERIC_STATUS_INDICATORS:
1612         case HFP_CMD_RETRIEVE_GENERIC_STATUS_INDICATORS:
1613             log_info("Parsed Generic status indicator: %s\n", hfp_connection->line_buffer);
1614             hfp_connection->generic_status_indicators[hfp_connection->parser_item_index].uuid = (uint16_t)btstack_atoi((char*)hfp_connection->line_buffer);
1615             hfp_next_indicators_index(hfp_connection);
1616             hfp_connection->generic_status_indicators_nr = hfp_connection->parser_item_index;
1617             break;
1618         case HFP_CMD_RETRIEVE_GENERIC_STATUS_INDICATORS_STATE:
1619             // HF parses inital AG gen. ind. state
1620             log_info("Parsed List generic status indicator %s state: ", hfp_connection->line_buffer);
1621             hfp_connection->parser_item_index = hfp_parse_indicator_index(hfp_connection);
1622             break;
1623         case HFP_CMD_HF_INDICATOR_STATUS:
1624             hfp_connection->parser_indicator_index = hfp_parse_indicator_index(hfp_connection);
1625             log_info("Parsed HF indicator index %u", hfp_connection->parser_indicator_index);
1626             break;
1627         case HFP_CMD_ENABLE_INDIVIDUAL_AG_INDICATOR_STATUS_UPDATE:
1628             // AG parses new gen. ind. state
1629             if (hfp_connection->ignore_value){
1630                 hfp_connection->ignore_value = 0;
1631                 log_info("Parsed Enable AG indicator pos %u('%s') - unchanged (stays %u)\n", hfp_connection->parser_item_index,
1632                     hfp_connection->ag_indicators[hfp_connection->parser_item_index].name, hfp_connection->ag_indicators[hfp_connection->parser_item_index].enabled);
1633             }
1634             else if (hfp_connection->ag_indicators[hfp_connection->parser_item_index].mandatory){
1635                 log_info("Parsed Enable AG indicator pos %u('%s') - ignore (mandatory)\n",
1636                     hfp_connection->parser_item_index, hfp_connection->ag_indicators[hfp_connection->parser_item_index].name);
1637             } else {
1638                 value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1639                 hfp_connection->ag_indicators[hfp_connection->parser_item_index].enabled = value;
1640                 log_info("Parsed Enable AG indicator pos %u('%s'): %u\n", hfp_connection->parser_item_index,
1641                     hfp_connection->ag_indicators[hfp_connection->parser_item_index].name, value);
1642             }
1643             hfp_next_indicators_index(hfp_connection);
1644             break;
1645         case HFP_CMD_TRANSFER_AG_INDICATOR_STATUS:
1646             // indicators are indexed starting with 1
1647             hfp_connection->parser_item_index = hfp_parse_indicator_index(hfp_connection);
1648             log_info("Parsed status of the AG indicator %d, status ", hfp_connection->parser_item_index);
1649             break;
1650         case HFP_CMD_QUERY_OPERATOR_SELECTION_NAME:
1651             hfp_connection->network_operator.mode = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1652             log_info("Parsed network operator mode: %d, ", hfp_connection->network_operator.mode);
1653             break;
1654         case HFP_CMD_QUERY_OPERATOR_SELECTION_NAME_FORMAT:
1655             if (hfp_connection->line_buffer[0] == '3'){
1656                 log_info("Parsed Set network operator format : %s, ", hfp_connection->line_buffer);
1657                 break;
1658             }
1659             // TODO emit ERROR, wrong format
1660             log_info("ERROR Set network operator format: index %s not supported\n", hfp_connection->line_buffer);
1661             break;
1662         case HFP_CMD_ERROR:
1663             break;
1664         case HFP_CMD_EXTENDED_AUDIO_GATEWAY_ERROR:
1665             hfp_connection->extended_audio_gateway_error = 1;
1666             hfp_connection->extended_audio_gateway_error_value = (uint8_t)btstack_atoi((char*)hfp_connection->line_buffer);
1667             break;
1668         case HFP_CMD_ENABLE_EXTENDED_AUDIO_GATEWAY_ERROR:
1669             hfp_connection->enable_extended_audio_gateway_error_report = (uint8_t)btstack_atoi((char*)hfp_connection->line_buffer);
1670             hfp_connection->ok_pending = 1;
1671             hfp_connection->extended_audio_gateway_error = 0;
1672             break;
1673         case HFP_CMD_AG_SENT_PHONE_NUMBER:
1674         case HFP_CMD_AG_SENT_CALL_WAITING_NOTIFICATION_UPDATE:
1675         case HFP_CMD_AG_SENT_CLIP_INFORMATION:
1676             btstack_strcpy((char *)hfp_connection->bnip_number, sizeof(hfp_connection->bnip_number), (char *)hfp_connection->line_buffer);
1677             break;
1678         case HFP_CMD_CALL_HOLD:
1679             hfp_connection->ag_call_hold_action = hfp_connection->line_buffer[0] - '0';
1680             if (hfp_connection->line_buffer[1] != '\0'){
1681                 hfp_connection->call_index = btstack_atoi((char *)&hfp_connection->line_buffer[1]);
1682             }
1683             break;
1684         case HFP_CMD_RESPONSE_AND_HOLD_COMMAND:
1685             hfp_connection->ag_response_and_hold_action = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1686             break;
1687         case HFP_CMD_TRANSMIT_DTMF_CODES:
1688             hfp_connection->ag_dtmf_code = hfp_connection->line_buffer[0];
1689             break;
1690         case HFP_CMD_ENABLE_CLIP:
1691             hfp_connection->clip_enabled = hfp_connection->line_buffer[0] != '0';
1692             break;
1693         case HFP_CMD_ENABLE_CALL_WAITING_NOTIFICATION:
1694             hfp_connection->call_waiting_notification_enabled = hfp_connection->line_buffer[0] != '0';
1695             break;
1696         case HFP_CMD_HF_ACTIVATE_VOICE_RECOGNITION:
1697             value = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1698             hfp_connection->ag_activate_voice_recognition_value = value;
1699             break;
1700         case HFP_CMD_AG_ACTIVATE_VOICE_RECOGNITION:
1701             switch(hfp_connection->parser_item_index){
1702                 case 0:
1703                     hfp_connection->ag_vra_status = btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1704                     break;
1705                 case 1:
1706                     hfp_connection->ag_vra_state = (hfp_voice_recognition_state_t) btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1707                     break;
1708                 case 2:
1709                     hfp_connection->ag_msg.text_id = 0;
1710                     for (i = 0 ; i < 4; i++){
1711                         hfp_connection->ag_msg.text_id = (hfp_connection->ag_msg.text_id << 4) | nibble_for_char(hfp_connection->line_buffer[i]);
1712                     }
1713                     break;
1714                 case 3:
1715                     hfp_connection->ag_msg.text_type = (hfp_text_type_t) btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1716                     break;
1717                 case 4:
1718                     hfp_connection->ag_msg.text_operation = (hfp_text_operation_t) btstack_atoi((char *)&hfp_connection->line_buffer[0]);
1719                     break;
1720                 case 5:
1721                     hfp_connection->line_buffer[hfp_connection->line_size] = 0;
1722                     hfp_connection->ag_vra_msg_length = hfp_connection->line_size + 1;
1723                     break;
1724                 default:
1725                     break;
1726             }
1727             hfp_connection->parser_item_index++;
1728             break;
1729         default:
1730             break;
1731     }
1732 }
1733 
1734 static void hfp_handle_start_sdp_client_query(void * context){
1735     UNUSED(context);
1736 
1737     btstack_linked_list_iterator_t it;
1738     btstack_linked_list_iterator_init(&it, &hfp_connections);
1739     while (btstack_linked_list_iterator_has_next(&it)){
1740         hfp_connection_t * connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1741 
1742         if (connection->state != HFP_W2_SEND_SDP_QUERY) continue;
1743 
1744         connection->state = HFP_W4_SDP_QUERY_COMPLETE;
1745         hfp_sdp_query_context.local_role = connection->local_role;
1746         (void)memcpy(hfp_sdp_query_context.remote_address, connection->remote_addr, 6);
1747         sdp_client_query_rfcomm_channel_and_name_for_service_class_uuid(&handle_query_rfcomm_event, connection->remote_addr, connection->service_uuid);
1748         return;
1749     }
1750 }
1751 
1752 uint8_t hfp_establish_service_level_connection(bd_addr_t bd_addr, uint16_t service_uuid, hfp_role_t local_role){
1753     hfp_connection_t * connection = get_hfp_connection_context_for_bd_addr(bd_addr, local_role);
1754     if (connection){
1755         return ERROR_CODE_COMMAND_DISALLOWED;
1756     }
1757 
1758     connection = hfp_create_connection(bd_addr, local_role);
1759     if (!connection){
1760         return BTSTACK_MEMORY_ALLOC_FAILED;
1761     }
1762 
1763     connection->state = HFP_W2_SEND_SDP_QUERY;
1764 
1765     bd_addr_copy(connection->remote_addr, bd_addr);
1766     connection->service_uuid = service_uuid;
1767 
1768     hfp_sdp_query_request.callback = &hfp_handle_start_sdp_client_query;
1769     // ignore ERROR_CODE_COMMAND_DISALLOWED because in that case, we already have requested an SDP callback
1770     (void) sdp_client_register_query_callback(&hfp_sdp_query_request);
1771     return ERROR_CODE_SUCCESS;
1772 }
1773 
1774 void hfp_trigger_release_service_level_connection(hfp_connection_t * hfp_connection){
1775     // called internally, NULL check already performed
1776     btstack_assert(hfp_connection != NULL);
1777 
1778     hfp_trigger_release_audio_connection(hfp_connection);
1779     if (hfp_connection->state < HFP_W4_RFCOMM_CONNECTED){
1780         hfp_connection->state = HFP_IDLE;
1781         return;
1782     }
1783 
1784     if (hfp_connection->state == HFP_W4_RFCOMM_CONNECTED){
1785         hfp_connection->state = HFP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN;
1786         return;
1787     }
1788     hfp_connection->release_slc_connection = 1;
1789     if (hfp_connection->state < HFP_W4_SCO_CONNECTED){
1790         hfp_connection->state = HFP_W2_DISCONNECT_RFCOMM;
1791         return;
1792     }
1793 
1794     if (hfp_connection->state < HFP_W4_SCO_DISCONNECTED){
1795         hfp_connection->state = HFP_W2_DISCONNECT_SCO;
1796         hfp_connection->release_audio_connection = 1;
1797         return;
1798     }
1799 }
1800 
1801 uint8_t hfp_trigger_release_audio_connection(hfp_connection_t * hfp_connection){
1802     // called internally, NULL check already performed
1803     btstack_assert(hfp_connection != NULL);
1804     if (hfp_connection->state <= HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED){
1805         return ERROR_CODE_COMMAND_DISALLOWED;
1806     }
1807     switch (hfp_connection->state) {
1808         case HFP_W2_CONNECT_SCO:
1809             hfp_connection->state = HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED;
1810             break;
1811         case HFP_W4_SCO_CONNECTED:
1812         case HFP_AUDIO_CONNECTION_ESTABLISHED:
1813             hfp_connection->release_audio_connection = 1;
1814             break;
1815         default:
1816             return ERROR_CODE_COMMAND_DISALLOWED;
1817     }
1818     return ERROR_CODE_SUCCESS;
1819 }
1820 
1821 static const struct link_settings {
1822     const uint16_t max_latency;
1823     const uint8_t  retransmission_effort;
1824     const uint16_t packet_types;
1825     const bool     eSCO;
1826     const uint8_t  codec;
1827 } hfp_link_settings [] = {
1828     { 0xffff, 0xff, SCO_PACKET_TYPES_HV1,  false, HFP_CODEC_CVSD }, // HFP_LINK_SETTINGS_D0
1829     { 0xffff, 0xff, SCO_PACKET_TYPES_HV3,  false, HFP_CODEC_CVSD }, // HFP_LINK_SETTINGS_D1
1830     { 0x0007, 0x01, SCO_PACKET_TYPES_EV3,  true,  HFP_CODEC_CVSD }, // HFP_LINK_SETTINGS_S1
1831     { 0x0007, 0x01, SCO_PACKET_TYPES_2EV3, true,  HFP_CODEC_CVSD }, // HFP_LINK_SETTINGS_S2
1832     { 0x000a, 0x01, SCO_PACKET_TYPES_2EV3, true,  HFP_CODEC_CVSD }, // HFP_LINK_SETTINGS_S3
1833     { 0x000c, 0x02, SCO_PACKET_TYPES_2EV3, true,  HFP_CODEC_CVSD }, // HFP_LINK_SETTINGS_S4
1834     { 0x0008, 0x02, SCO_PACKET_TYPES_EV3,  true,  HFP_CODEC_MSBC }, // HFP_LINK_SETTINGS_T1
1835     { 0x000d, 0x02, SCO_PACKET_TYPES_2EV3, true,  HFP_CODEC_MSBC }  // HFP_LINK_SETTINGS_T2
1836 };
1837 
1838 void hfp_setup_synchronous_connection(hfp_connection_t * hfp_connection){
1839     // all packet types, fixed bandwidth
1840     int setting = hfp_connection->link_setting;
1841     log_info("hfp_setup_synchronous_connection using setting nr %u", setting);
1842     hfp_sco_establishment_active = hfp_connection;
1843     uint16_t sco_voice_setting = hci_get_sco_voice_setting();
1844     if (hfp_connection->negotiated_codec == HFP_CODEC_MSBC){
1845 #ifdef ENABLE_BCM_PCM_WBS
1846         sco_voice_setting = 0x0063; // Transparent data, 16-bit for BCM controllers
1847 #else
1848         sco_voice_setting = 0x0043; // Transparent data, 8-bit otherwise
1849 #endif
1850     }
1851     // get packet types - bits 6-9 are 'don't allow'
1852     uint16_t packet_types = hfp_link_settings[setting].packet_types ^ 0x03c0;
1853     hci_send_cmd(&hci_setup_synchronous_connection, hfp_connection->acl_handle, 8000, 8000, hfp_link_settings[setting].max_latency,
1854         sco_voice_setting, hfp_link_settings[setting].retransmission_effort, packet_types);
1855 }
1856 
1857 void hfp_accept_synchronous_connection(hfp_connection_t * hfp_connection, bool incoming_eSCO){
1858 
1859     // remote supported feature eSCO is set if link type is eSCO
1860     // eSCO: S4 - max latency == transmission interval = 0x000c == 12 ms,
1861     uint16_t max_latency;
1862     uint8_t  retransmission_effort;
1863     uint16_t packet_types;
1864 
1865     if (incoming_eSCO && hci_extended_sco_link_supported() && hci_remote_esco_supported(hfp_connection->acl_handle)){
1866         max_latency = 0x000c;
1867         retransmission_effort = 0x02;
1868         // eSCO: EV3 and 2-EV3
1869         packet_types = 0x0048;
1870     } else {
1871         max_latency = 0xffff;
1872         retransmission_effort = 0xff;
1873         // sco: HV1 and HV3
1874         packet_types = 0x005;
1875     }
1876 
1877     // mSBC only allows for transparent data
1878     uint16_t sco_voice_setting = hci_get_sco_voice_setting();
1879     if (hfp_connection->negotiated_codec == HFP_CODEC_MSBC){
1880 #ifdef ENABLE_BCM_PCM_WBS
1881         sco_voice_setting = 0x0063; // Transparent data, 16-bit for BCM controllers
1882 #else
1883         sco_voice_setting = 0x0043; // Transparent data, 8-bit otherwise
1884 #endif
1885     }
1886 
1887     // filter packet types
1888     packet_types &= hfp_get_sco_packet_types();
1889 
1890     // bits 6-9 are 'don't allow'
1891     packet_types ^= 0x3c0;
1892 
1893     log_info("HFP: sending hci_accept_connection_request, packet types 0x%04x, sco_voice_setting 0x%02x", packet_types, sco_voice_setting);
1894     hci_send_cmd(&hci_accept_synchronous_connection, hfp_connection->remote_addr, 8000, 8000, max_latency,
1895                  sco_voice_setting, retransmission_effort, packet_types);
1896 }
1897 
1898 #ifdef ENABLE_CC256X_ASSISTED_HFP
1899 void hfp_cc256x_prepare_for_sco(hfp_connection_t * hfp_connection){
1900     hfp_connection->cc256x_send_write_codec_config = true;
1901     if (hfp_connection->negotiated_codec == HFP_CODEC_MSBC){
1902         hfp_connection->cc256x_send_wbs_associate = true;
1903     }
1904 }
1905 
1906 void hfp_cc256x_write_codec_config(hfp_connection_t * hfp_connection){
1907     uint32_t sample_rate_hz;
1908     uint16_t clock_rate_khz;
1909     if (hfp_connection->negotiated_codec == HFP_CODEC_MSBC){
1910         clock_rate_khz = 512;
1911         sample_rate_hz = 16000;
1912     } else {
1913         clock_rate_khz = 256;
1914         sample_rate_hz = 8000;
1915     }
1916     uint8_t clock_direction = 0;        // master
1917     uint16_t frame_sync_duty_cycle = 0; // i2s with 50%
1918     uint8_t  frame_sync_edge = 1;       // rising edge
1919     uint8_t  frame_sync_polarity = 0;   // active high
1920     uint8_t  reserved = 0;
1921     uint16_t size = 16;
1922     uint16_t chan_1_offset = 1;
1923     uint16_t chan_2_offset = chan_1_offset + size;
1924     uint8_t  out_edge = 1;              // rising
1925     uint8_t  in_edge = 0;               // falling
1926     hci_send_cmd(&hci_ti_write_codec_config, clock_rate_khz, clock_direction, sample_rate_hz, frame_sync_duty_cycle,
1927                  frame_sync_edge, frame_sync_polarity, reserved,
1928                  size, chan_1_offset, out_edge, size, chan_1_offset, in_edge, reserved,
1929                  size, chan_2_offset, out_edge, size, chan_2_offset, in_edge, reserved);
1930 }
1931 #endif
1932 
1933 #ifdef ENABLE_BCM_PCM_WBS
1934 void hfp_bcm_prepare_for_sco(hfp_connection_t * hfp_connection){
1935     hfp_connection->bcm_send_write_i2spcm_interface_param = true;
1936     if (hfp_connection->negotiated_codec == HFP_CODEC_MSBC){
1937         hfp_connection->bcm_send_enable_wbs = true;
1938     }
1939 }
1940 void hfp_bcm_write_i2spcm_interface_param(hfp_connection_t * hfp_connection){
1941     uint8_t sample_rate = (hfp_connection->negotiated_codec == HFP_CODEC_MSBC) ? 1 : 0;
1942     // i2s enable, master, 8/16 kHz, 512 kHz
1943     hci_send_cmd(&hci_bcm_write_i2spcm_interface_paramhci_bcm_write_i2spcm_interface_param, 1, 1, sample_rate, 2);
1944 }
1945 #endif
1946 
1947 void hfp_set_hf_callback(btstack_packet_handler_t callback){
1948     hfp_hf_callback = callback;
1949 }
1950 
1951 void hfp_set_ag_callback(btstack_packet_handler_t callback){
1952     hfp_ag_callback = callback;
1953 }
1954 
1955 void hfp_set_ag_rfcomm_packet_handler(btstack_packet_handler_t handler){
1956     hfp_ag_rfcomm_packet_handler = handler;
1957 }
1958 
1959 void hfp_set_hf_rfcomm_packet_handler(btstack_packet_handler_t handler){
1960     hfp_hf_rfcomm_packet_handler = handler;
1961 }
1962 
1963 void hfp_init(void){
1964     hfp_allowed_sco_packet_types = SCO_PACKET_TYPES_ALL;
1965 }
1966 
1967 void hfp_deinit(void){
1968     hfp_allowed_sco_packet_types = 0;
1969     hfp_connections = NULL;
1970     hfp_hf_callback = NULL;
1971     hfp_ag_callback = NULL;
1972     hfp_hf_rfcomm_packet_handler = NULL;
1973     hfp_ag_rfcomm_packet_handler = NULL;
1974     hfp_sco_establishment_active = NULL;
1975     (void) memset(&hfp_sdp_query_context, 0, sizeof(hfp_sdp_query_context_t));
1976     (void) memset(&hfp_sdp_query_request, 0, sizeof(btstack_context_callback_registration_t));
1977 }
1978 
1979 void hfp_set_sco_packet_types(uint16_t packet_types){
1980     hfp_allowed_sco_packet_types = packet_types;
1981 }
1982 
1983 uint16_t hfp_get_sco_packet_types(void){
1984     return hfp_allowed_sco_packet_types;
1985 }
1986 
1987 hfp_link_settings_t hfp_next_link_setting(hfp_link_settings_t current_setting, bool local_eSCO_supported, bool remote_eSCO_supported, bool eSCO_S4_supported, uint8_t negotiated_codec){
1988     int8_t setting = (int8_t) current_setting;
1989     bool can_use_eSCO = local_eSCO_supported && remote_eSCO_supported;
1990     while (setting > 0){
1991         setting--;
1992         // skip if eSCO required but not available
1993         if (hfp_link_settings[setting].eSCO && !can_use_eSCO) continue;
1994         // skip if S4 but not supported
1995         if ((setting == (int8_t) HFP_LINK_SETTINGS_S4) && !eSCO_S4_supported) continue;
1996         // skip wrong codec
1997         if ( hfp_link_settings[setting].codec != negotiated_codec) continue;
1998         // skip disabled packet types
1999         uint16_t required_packet_types = hfp_link_settings[setting].packet_types;
2000         uint16_t allowed_packet_types  = hfp_allowed_sco_packet_types;
2001         if ((required_packet_types & allowed_packet_types) == 0) continue;
2002 
2003         // found matching setting
2004         return (hfp_link_settings_t) setting;
2005     }
2006     return HFP_LINK_SETTINGS_NONE;
2007 }
2008 
2009 static hfp_link_settings_t hfp_next_link_setting_for_connection(hfp_link_settings_t current_setting, hfp_connection_t * hfp_connection, uint8_t eSCO_S4_supported){
2010     bool local_eSCO_supported  = hci_extended_sco_link_supported();
2011     bool remote_eSCO_supported = hci_remote_esco_supported(hfp_connection->acl_handle);
2012     uint8_t negotiated_codec   = hfp_connection->negotiated_codec;
2013     return  hfp_next_link_setting(current_setting, local_eSCO_supported, remote_eSCO_supported, eSCO_S4_supported, negotiated_codec);
2014 }
2015 
2016 void hfp_init_link_settings(hfp_connection_t * hfp_connection, uint8_t eSCO_S4_supported){
2017     // get highest possible link setting
2018     hfp_connection->link_setting = hfp_next_link_setting_for_connection(HFP_LINK_SETTINGS_NONE, hfp_connection, eSCO_S4_supported);
2019     log_info("hfp_init_link_settings: %u", hfp_connection->link_setting);
2020 }
2021 
2022 #define HFP_HF_RX_DEBUG_PRINT_LINE 80
2023 
2024 void hfp_log_rfcomm_message(const char * tag, uint8_t * packet, uint16_t size){
2025 #ifdef ENABLE_LOG_INFO
2026     // encode \n\r
2027     char printable[HFP_HF_RX_DEBUG_PRINT_LINE+2];
2028     int i = 0;
2029     int pos;
2030     for (pos=0 ; (pos < size) && (i < (HFP_HF_RX_DEBUG_PRINT_LINE - 3)) ; pos++){
2031         switch (packet[pos]){
2032             case '\n':
2033                 printable[i++] = '\\';
2034                 printable[i++] = 'n';
2035                 break;
2036             case '\r':
2037                 printable[i++] = '\\';
2038                 printable[i++] = 'r';
2039                 break;
2040             default:
2041                 printable[i++] = packet[pos];
2042                 break;
2043         }
2044     }
2045     printable[i] = 0;
2046     log_info("%s: '%s'", tag, printable);
2047 #endif
2048 }
2049