xref: /btstack/src/classic/hsp_ag.c (revision 95fd1475d5729e5bee7a5a0d070566bf890e4c7e)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 // *****************************************************************************
39 //
40 // HSP Audio Gateway
41 //
42 // *****************************************************************************
43 
44 #include "btstack_config.h"
45 
46 #include <stdint.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 
51 #include "btstack_debug.h"
52 #include "btstack_event.h"
53 #include "btstack_memory.h"
54 #include "btstack_run_loop.h"
55 #include "classic/core.h"
56 #include "classic/sdp_server.h"
57 #include "classic/sdp_client_rfcomm.h"
58 #include "classic/sdp_util.h"
59 #include "hci.h"
60 #include "hci_cmd.h"
61 #include "hci_dump.h"
62 #include "hsp_ag.h"
63 #include "l2cap.h"
64 
65 #define HSP_HS_BUTTON_PRESS "AT+CKPD=200"
66 #define HSP_HS_AT_CKPD "AT+CKPD\r\n"
67 #define HSP_AG_OK "\r\nOK\r\n"
68 #define HSP_AG_ERROR "\r\nERROR\r\n"
69 #define HSP_AG_RING "\r\nRING\r\n"
70 #define HSP_MICROPHONE_GAIN "+VGM"
71 #define HSP_SPEAKER_GAIN "+VGS"
72 
73 #define HSP_HS_MICROPHONE_GAIN "AT+VGM="
74 #define HSP_HS_SPEAKER_GAIN "AT+VGS="
75 
76 static const char default_hsp_ag_service_name[] = "Audio Gateway";
77 
78 static bd_addr_t remote;
79 static uint8_t channel_nr = 0;
80 
81 static uint16_t mtu;
82 static uint16_t rfcomm_cid = 0;
83 static uint16_t sco_handle = 0;
84 static uint16_t rfcomm_handle = 0;
85 static btstack_timer_source_t hs_timeout;
86 
87 static int ag_microphone_gain = -1;
88 static int ag_speaker_gain = -1;
89 static uint8_t ag_ring = 0;
90 static uint8_t ag_send_ok = 0;
91 static uint8_t ag_send_error = 0;
92 static uint8_t ag_num_button_press_received = 0;
93 static uint8_t ag_support_custom_commands = 0;
94 
95 static uint8_t hsp_disconnect_rfcomm = 0;
96 static uint8_t hsp_establish_audio_connection = 0;
97 static uint8_t hsp_release_audio_connection = 0;
98 
99 static btstack_packet_callback_registration_t hci_event_callback_registration;
100 
101 typedef enum {
102     HSP_IDLE,
103     HSP_SDP_QUERY_RFCOMM_CHANNEL,
104     HSP_W4_SDP_EVENT_QUERY_COMPLETE,
105     HSP_W4_RFCOMM_CONNECTED,
106 
107     HSP_RFCOMM_CONNECTION_ESTABLISHED,
108 
109     HSP_W4_RING_ANSWER,
110     HSP_W4_USER_ACTION,
111     HSP_W2_CONNECT_SCO,
112     HSP_W4_SCO_CONNECTED,
113 
114     HSP_AUDIO_CONNECTION_ESTABLISHED,
115 
116     HSP_W2_DISCONNECT_SCO,
117     HSP_W4_SCO_DISCONNECTED,
118 
119     HSP_W2_DISCONNECT_RFCOMM,
120     HSP_W4_RFCOMM_DISCONNECTED,
121     HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN
122 } hsp_state_t;
123 
124 static hsp_state_t hsp_state = HSP_IDLE;
125 
126 
127 static btstack_packet_handler_t hsp_ag_callback;
128 
129 static void hsp_run(void);
130 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
131 static void handle_query_rfcomm_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
132 
133 static void dummy_notify(uint8_t packet_type, uint16_t channel, uint8_t * event, uint16_t size){}
134 
135 void hsp_ag_register_packet_handler(btstack_packet_handler_t callback){
136     if (callback == NULL){
137         callback = &dummy_notify;
138     }
139     hsp_ag_callback = callback;
140 }
141 
142 static void emit_event(uint8_t event_subtype, uint8_t value){
143     if (!hsp_ag_callback) return;
144     uint8_t event[4];
145     event[0] = HCI_EVENT_HSP_META;
146     event[1] = sizeof(event) - 2;
147     event[2] = event_subtype;
148     event[3] = value; // status 0 == OK
149     (*hsp_ag_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
150 }
151 
152 static void emit_event_audio_connected(uint8_t status, uint16_t handle){
153     if (!hsp_ag_callback) return;
154     uint8_t event[6];
155     event[0] = HCI_EVENT_HSP_META;
156     event[1] = sizeof(event) - 2;
157     event[2] = HSP_SUBEVENT_AUDIO_CONNECTION_COMPLETE;
158     event[3] = status;
159     little_endian_store_16(event, 4, handle);
160     (*hsp_ag_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
161 }
162 
163 void hsp_ag_create_sdp_record(uint8_t * service, uint32_t service_record_handle, int rfcomm_channel_nr, const char * name){
164     uint8_t* attribute;
165     de_create_sequence(service);
166 
167     // 0x0000 "Service Record Handle"
168     de_add_number(service, DE_UINT, DE_SIZE_16, SDP_ServiceRecordHandle);
169     de_add_number(service, DE_UINT, DE_SIZE_32, service_record_handle);
170 
171     // 0x0001 "Service Class ID List"
172     de_add_number(service,  DE_UINT, DE_SIZE_16, SDP_ServiceClassIDList);
173     attribute = de_push_sequence(service);
174     {
175         //  "UUID for PAN Service"
176         de_add_number(attribute, DE_UUID, DE_SIZE_16, SDP_Headset_AG);
177         de_add_number(attribute, DE_UUID, DE_SIZE_16, SDP_GenericAudio);
178     }
179     de_pop_sequence(service, attribute);
180 
181     // 0x0004 "Protocol Descriptor List"
182     de_add_number(service,  DE_UINT, DE_SIZE_16, SDP_ProtocolDescriptorList);
183     attribute = de_push_sequence(service);
184     {
185         uint8_t* l2cpProtocol = de_push_sequence(attribute);
186         {
187             de_add_number(l2cpProtocol,  DE_UUID, DE_SIZE_16, SDP_L2CAPProtocol);
188         }
189         de_pop_sequence(attribute, l2cpProtocol);
190 
191         uint8_t* rfcomm = de_push_sequence(attribute);
192         {
193             de_add_number(rfcomm,  DE_UUID, DE_SIZE_16, SDP_RFCOMMProtocol);  // rfcomm_service
194             de_add_number(rfcomm,  DE_UINT, DE_SIZE_8,  rfcomm_channel_nr);  // rfcomm channel
195         }
196         de_pop_sequence(attribute, rfcomm);
197     }
198     de_pop_sequence(service, attribute);
199 
200     // 0x0005 "Public Browse Group"
201     de_add_number(service,  DE_UINT, DE_SIZE_16, SDP_BrowseGroupList); // public browse group
202     attribute = de_push_sequence(service);
203     {
204         de_add_number(attribute,  DE_UUID, DE_SIZE_16, SDP_PublicBrowseGroup);
205     }
206     de_pop_sequence(service, attribute);
207 
208     // 0x0009 "Bluetooth Profile Descriptor List"
209     de_add_number(service,  DE_UINT, DE_SIZE_16, SDP_BluetoothProfileDescriptorList);
210     attribute = de_push_sequence(service);
211     {
212         uint8_t *sppProfile = de_push_sequence(attribute);
213         {
214             de_add_number(sppProfile,  DE_UUID, DE_SIZE_16, SDP_HSP);
215             de_add_number(sppProfile,  DE_UINT, DE_SIZE_16, 0x0102); // Verision 1.2
216         }
217         de_pop_sequence(attribute, sppProfile);
218     }
219     de_pop_sequence(service, attribute);
220 
221     // 0x0100 "Service Name"
222     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0100);
223     if (name){
224         de_add_data(service,  DE_STRING, strlen(name), (uint8_t *) name);
225     } else {
226         de_add_data(service,  DE_STRING, strlen(default_hsp_ag_service_name), (uint8_t *) default_hsp_ag_service_name);
227     }
228 }
229 
230 static int hsp_ag_send_str_over_rfcomm(const uint16_t cid, char * command){
231     int err = rfcomm_send(cid, (uint8_t*) command, strlen(command));
232     if (err){
233         log_error("rfcomm_send_internal -> error 0X%02x", err);
234         return err;
235     }
236     return err;
237 }
238 
239 void hsp_ag_enable_custom_commands(int enable){
240     ag_support_custom_commands = enable;
241 }
242 
243 int hsp_ag_send_result(char * result){
244     if (!ag_support_custom_commands) return 1;
245     return hsp_ag_send_str_over_rfcomm(rfcomm_cid, result);
246 }
247 
248 static void hsp_ag_reset_state(void){
249     hsp_state = HSP_IDLE;
250 
251     rfcomm_cid = 0;
252     rfcomm_handle = 0;
253     sco_handle = 0;
254 
255     ag_send_ok = 0;
256     ag_send_error = 0;
257     ag_ring = 0;
258 
259     ag_num_button_press_received = 0;
260     ag_support_custom_commands = 0;
261 
262     ag_microphone_gain = -1;
263     ag_speaker_gain = -1;
264 
265     hsp_disconnect_rfcomm = 0;
266     hsp_establish_audio_connection = 0;
267     hsp_release_audio_connection = 0;
268 }
269 
270 void hsp_ag_init(uint8_t rfcomm_channel_nr){
271     // register for HCI events
272     hci_event_callback_registration.callback = &packet_handler;
273     hci_add_event_handler(&hci_event_callback_registration);
274 
275     rfcomm_register_service(packet_handler, rfcomm_channel_nr, 0xffff);  // reserved channel, mtu limited by l2cap
276 
277     hsp_ag_reset_state();
278 }
279 
280 void hsp_ag_connect(bd_addr_t bd_addr){
281     if (hsp_state != HSP_IDLE) return;
282     hsp_state = HSP_SDP_QUERY_RFCOMM_CHANNEL;
283     memcpy(remote, bd_addr, 6);
284     hsp_run();
285 }
286 
287 void hsp_ag_disconnect(void){
288     hsp_ag_release_audio_connection();
289     printf(" rfcomm diconnect %d\n", hsp_state);
290     if (hsp_state < HSP_W4_RFCOMM_CONNECTED){
291         hsp_state = HSP_IDLE;
292         return;
293     }
294 
295     if (hsp_state == HSP_W4_RFCOMM_CONNECTED){
296         hsp_state = HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN;
297         return;
298     }
299     hsp_disconnect_rfcomm = 1;
300     hsp_run();
301 }
302 
303 void hsp_ag_establish_audio_connection(void){
304     printf("hsp_ag_establish_audio_connection state %d\n", hsp_state);
305 
306     switch (hsp_state){
307         case HSP_RFCOMM_CONNECTION_ESTABLISHED:
308             hsp_establish_audio_connection = 1;
309             hsp_state = HSP_W4_SCO_CONNECTED;
310             break;
311         case HSP_W4_RFCOMM_CONNECTED:
312             hsp_state = HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN;
313             break;
314         default:
315             break;
316     }
317     hsp_run();
318 }
319 
320 void hsp_ag_release_audio_connection(void){
321     if (hsp_state >= HSP_W2_DISCONNECT_SCO) return;
322     if (hsp_state < HSP_AUDIO_CONNECTION_ESTABLISHED) return;
323 
324     hsp_release_audio_connection = 1;
325     hsp_run();
326 }
327 
328 
329 void hsp_ag_set_microphone_gain(uint8_t gain){
330     if (gain < 0 || gain >15) {
331         log_error("Gain must be in interval [0..15], it is given %d", gain);
332         return;
333     }
334     ag_microphone_gain = gain;
335     hsp_run();
336 }
337 
338 // AG +VGS=5  [0..15] ; HS AT+VGM=6 | AG OK
339 void hsp_ag_set_speaker_gain(uint8_t gain){
340     if (gain < 0 || gain >15) {
341         log_error("Gain must be in interval [0..15], it is given %d", gain);
342         return;
343     }
344     ag_speaker_gain = gain;
345     hsp_run();
346 }
347 
348 static void hsp_ringing_timeout_handler(btstack_timer_source_t * timer){
349     ag_ring = 1;
350     btstack_run_loop_set_timer(&hs_timeout, 2000); // 2 seconds timeout
351     btstack_run_loop_add_timer(&hs_timeout);
352     hsp_run();
353 }
354 
355 static void hsp_ringing_timer_start(void){
356     btstack_run_loop_remove_timer(&hs_timeout);
357     btstack_run_loop_set_timer_handler(&hs_timeout, hsp_ringing_timeout_handler);
358     btstack_run_loop_set_timer(&hs_timeout, 2000); // 2 seconds timeout
359     btstack_run_loop_add_timer(&hs_timeout);
360 }
361 
362 static void hsp_ringing_timer_stop(void){
363     btstack_run_loop_remove_timer(&hs_timeout);
364 }
365 
366 void hsp_ag_start_ringing(void){
367     ag_ring = 1;
368     if (hsp_state == HSP_W2_CONNECT_SCO) {
369         hsp_state = HSP_W4_RING_ANSWER;
370     }
371     hsp_ringing_timer_start();
372 }
373 
374 void hsp_ag_stop_ringing(void){
375     ag_ring = 0;
376     if (hsp_state == HSP_W4_RING_ANSWER){
377         hsp_state = HSP_W2_CONNECT_SCO;
378     }
379     hsp_ringing_timer_stop();
380 }
381 
382 static void hsp_run(void){
383 
384     if (ag_send_ok){
385         if (!rfcomm_can_send_packet_now(rfcomm_cid)) {
386             rfcomm_request_can_send_now_event(rfcomm_cid);
387             return;
388         }
389         ag_send_ok = 0;
390         hsp_ag_send_str_over_rfcomm(rfcomm_cid, HSP_AG_OK);
391         return;
392     }
393 
394     if (ag_send_error){
395         if (!rfcomm_can_send_packet_now(rfcomm_cid)) {
396             rfcomm_request_can_send_now_event(rfcomm_cid);
397             return;
398         }
399         ag_send_error = 0;
400         hsp_ag_send_str_over_rfcomm(rfcomm_cid, HSP_AG_ERROR);
401         return;
402     }
403 
404     if (ag_ring){
405         if (!rfcomm_can_send_packet_now(rfcomm_cid)) {
406             rfcomm_request_can_send_now_event(rfcomm_cid);
407             return;
408         }
409         ag_ring = 0;
410         hsp_ag_send_str_over_rfcomm(rfcomm_cid, HSP_AG_RING);
411         return;
412     }
413 
414     if (hsp_establish_audio_connection){
415         if (!hci_can_send_command_packet_now()) return;
416         hsp_establish_audio_connection = 0;
417         hci_send_cmd(&hci_setup_synchronous_connection, rfcomm_handle, 8000, 8000, 0xFFFF, hci_get_sco_voice_setting(), 0xFF, 0x003F);
418         return;
419     }
420 
421     if (hsp_release_audio_connection){
422         hsp_release_audio_connection = 0;
423         gap_disconnect(sco_handle);
424         return;
425     }
426 
427     if (hsp_disconnect_rfcomm){
428         hsp_disconnect_rfcomm = 0;
429         hsp_establish_audio_connection = 0;
430         rfcomm_disconnect(rfcomm_cid);
431         return;
432     }
433 
434     switch (hsp_state){
435         case HSP_SDP_QUERY_RFCOMM_CHANNEL:
436             hsp_state = HSP_W4_SDP_EVENT_QUERY_COMPLETE;
437             log_info("Start SDP query %s, 0x%02x", bd_addr_to_str(remote), SDP_HSP);
438             sdp_client_query_rfcomm_channel_and_name_for_uuid(&handle_query_rfcomm_event, remote, SDP_HSP);
439             break;
440 
441         case HSP_W4_RING_ANSWER:
442             if (!ag_num_button_press_received) break;
443 
444             if (!rfcomm_can_send_packet_now(rfcomm_cid)) {
445                 rfcomm_request_can_send_now_event(rfcomm_cid);
446                 return;
447             }
448 
449             ag_send_ok = 0;
450             ag_num_button_press_received = 0;
451             hsp_state = HSP_W2_CONNECT_SCO;
452 
453             hsp_ag_send_str_over_rfcomm(rfcomm_cid, HSP_AG_OK);
454             break;
455 
456         case HSP_W2_CONNECT_SCO:
457             if (!hci_can_send_command_packet_now()) return;
458             hsp_state = HSP_W4_SCO_CONNECTED;
459             hci_send_cmd(&hci_setup_synchronous_connection, rfcomm_handle, 8000, 8000, 0xFFFF, hci_get_sco_voice_setting(), 0xFF, 0x003F);
460             break;
461 
462         case HSP_W2_DISCONNECT_SCO:
463             ag_num_button_press_received = 0;
464 
465             hsp_state = HSP_W4_SCO_DISCONNECTED;
466             gap_disconnect(sco_handle);
467             break;
468 
469         case HSP_W2_DISCONNECT_RFCOMM:
470             rfcomm_disconnect(rfcomm_cid);
471             break;
472 
473         case HSP_AUDIO_CONNECTION_ESTABLISHED:
474         case HSP_RFCOMM_CONNECTION_ESTABLISHED:
475 
476             if (ag_microphone_gain >= 0){
477                 if (!rfcomm_can_send_packet_now(rfcomm_cid)) {
478                     rfcomm_request_can_send_now_event(rfcomm_cid);
479                     return;
480                 }
481                 int gain = ag_microphone_gain;
482                 ag_microphone_gain = -1;
483                 char buffer[10];
484                 sprintf(buffer, "%s=%d\r\n", HSP_MICROPHONE_GAIN, gain);
485                 hsp_ag_send_str_over_rfcomm(rfcomm_cid, buffer);
486                 break;
487             }
488 
489             if (ag_speaker_gain >= 0){
490                 if (!rfcomm_can_send_packet_now(rfcomm_cid)) {
491                     rfcomm_request_can_send_now_event(rfcomm_cid);
492                     return;
493                 }
494                 int gain = ag_speaker_gain;
495                 ag_speaker_gain = -1;
496                 char buffer[10];
497                 sprintf(buffer, "%s=%d\r\n", HSP_SPEAKER_GAIN, gain);
498                 hsp_ag_send_str_over_rfcomm(rfcomm_cid, buffer);
499                 break;
500             }
501             break;
502         default:
503             break;
504     }
505 }
506 
507 
508 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
509     if (packet_type == RFCOMM_DATA_PACKET){
510         while (size > 0 && (packet[0] == '\n' || packet[0] == '\r')){
511             size--;
512             packet++;
513         }
514 
515         if (strncmp((char *)packet, HSP_HS_BUTTON_PRESS, strlen(HSP_HS_BUTTON_PRESS)) == 0){
516             log_info("Received button press %s", HSP_HS_BUTTON_PRESS);
517             ag_send_ok = 1;
518             switch (hsp_state){
519                 case HSP_AUDIO_CONNECTION_ESTABLISHED:
520                     hsp_release_audio_connection = 1;
521                     break;
522                 case HSP_RFCOMM_CONNECTION_ESTABLISHED:
523                     hsp_establish_audio_connection = 1;
524                     break;
525                 default:
526                     break;
527             }
528         } else if (strncmp((char *)packet, HSP_HS_MICROPHONE_GAIN, strlen(HSP_HS_MICROPHONE_GAIN)) == 0){
529             uint8_t gain = (uint8_t)atoi((char*)&packet[strlen(HSP_HS_MICROPHONE_GAIN)]);
530             ag_send_ok = 1;
531             emit_event(HSP_SUBEVENT_MICROPHONE_GAIN_CHANGED, gain);
532 
533         } else if (strncmp((char *)packet, HSP_HS_SPEAKER_GAIN, strlen(HSP_HS_SPEAKER_GAIN)) == 0){
534             uint8_t gain = (uint8_t)atoi((char*)&packet[strlen(HSP_HS_SPEAKER_GAIN)]);
535             ag_send_ok = 1;
536             emit_event(HSP_SUBEVENT_SPEAKER_GAIN_CHANGED, gain);
537 
538         } else if (strncmp((char *)packet, "AT+", 3) == 0){
539             ag_send_error = 1;
540             if (!hsp_ag_callback) return;
541             // re-use incoming buffer to avoid reserving large buffers - ugly but efficient
542             uint8_t * event = packet - 4;
543             event[0] = HCI_EVENT_HSP_META;
544             event[1] = size + 2;
545             event[2] = HSP_SUBEVENT_HS_COMMAND;
546             event[3] = size;
547             (*hsp_ag_callback)(HCI_EVENT_PACKET, 0, event, size+4);
548         }
549 
550         hsp_run();
551         return;
552     }
553 
554     if (packet_type != HCI_EVENT_PACKET) return;
555     uint8_t event = hci_event_packet_get_type(packet);
556     bd_addr_t event_addr;
557     uint16_t handle;
558 
559     switch (event) {
560         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:{
561             int index = 2;
562             uint8_t status = packet[index++];
563             sco_handle = little_endian_read_16(packet, index);
564             index+=2;
565             bd_addr_t address;
566             memcpy(address, &packet[index], 6);
567             index+=6;
568             uint8_t link_type = packet[index++];
569             uint8_t transmission_interval = packet[index++];  // measured in slots
570             uint8_t retransmission_interval = packet[index++];// measured in slots
571             uint16_t rx_packet_length = little_endian_read_16(packet, index); // measured in bytes
572             index+=2;
573             uint16_t tx_packet_length = little_endian_read_16(packet, index); // measured in bytes
574             index+=2;
575             uint8_t air_mode = packet[index];
576 
577             if (status != 0){
578                 log_error("(e)SCO Connection failed, status %u", status);
579                 emit_event_audio_connected(status, sco_handle);
580                 break;
581             }
582             switch (link_type){
583                 case 0x00:
584                     log_info("SCO Connection established.");
585                     if (transmission_interval != 0) log_error("SCO Connection: transmission_interval not zero: %d.", transmission_interval);
586                     if (retransmission_interval != 0) log_error("SCO Connection: retransmission_interval not zero: %d.", retransmission_interval);
587                     if (rx_packet_length != 0) log_error("SCO Connection: rx_packet_length not zero: %d.", rx_packet_length);
588                     if (tx_packet_length != 0) log_error("SCO Connection: tx_packet_length not zero: %d.", tx_packet_length);
589                     break;
590                 case 0x02:
591                     log_info("eSCO Connection established.");
592                     break;
593                 default:
594                     log_error("(e)SCO reserved link_type 0x%2x", link_type);
595                     break;
596             }
597             log_info("sco_handle 0x%2x, address %s, transmission_interval %u slots, retransmission_interval %u slots, "
598                  " rx_packet_length %u bytes, tx_packet_length %u bytes, air_mode 0x%2x (0x02 == CVSD)", sco_handle,
599                  bd_addr_to_str(address), transmission_interval, retransmission_interval, rx_packet_length, tx_packet_length, air_mode);
600 
601             if (hsp_state == HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN){
602                 hsp_state = HSP_W2_DISCONNECT_SCO;
603                 break;
604             }
605 
606             hsp_state = HSP_AUDIO_CONNECTION_ESTABLISHED;
607             emit_event_audio_connected(status, sco_handle);
608             break;
609         }
610 
611         case RFCOMM_EVENT_INCOMING_CONNECTION:
612             // data: event (8), len(8), address(48), channel (8), rfcomm_cid (16)
613             if (hsp_state != HSP_IDLE) return;
614 
615             rfcomm_event_incoming_connection_get_bd_addr(packet, event_addr);
616             rfcomm_cid = rfcomm_event_incoming_connection_get_server_channel(packet);
617             log_info("RFCOMM channel %u requested for %s", packet[8], bd_addr_to_str(event_addr));
618             hsp_state = HSP_W4_RFCOMM_CONNECTED;
619             rfcomm_accept_connection(rfcomm_cid);
620             break;
621 
622         case RFCOMM_EVENT_CHANNEL_OPENED:
623             log_info("RFCOMM_EVENT_CHANNEL_OPENED packet_handler type %u, packet[0] %x", packet_type, packet[0]);
624             // data: event(8), len(8), status (8), address (48), handle(16), server channel(8), rfcomm_cid(16), max frame size(16)
625             if (rfcomm_event_channel_opened_get_status(packet)) {
626                 log_info("RFCOMM channel open failed, status %u§", rfcomm_event_channel_opened_get_status(packet));
627                 hsp_ag_reset_state();
628                 hsp_state = HSP_IDLE;
629             } else {
630                 // data: event(8) , len(8), status (8), address (48), handle (16), server channel(8), rfcomm_cid(16), max frame size(16)
631                 rfcomm_handle = rfcomm_event_channel_opened_get_con_handle(packet);
632                 rfcomm_cid = rfcomm_event_channel_opened_get_rfcomm_cid(packet);
633                 mtu = rfcomm_event_channel_opened_get_max_frame_size(packet);
634                 log_info("RFCOMM channel open succeeded. New RFCOMM Channel ID %u, max frame size %u, state %d", rfcomm_cid, mtu, hsp_state);
635                 hsp_state = HSP_RFCOMM_CONNECTION_ESTABLISHED;
636             }
637             emit_event(HSP_SUBEVENT_RFCOMM_CONNECTION_COMPLETE, packet[2]);
638             break;
639 
640         case RFCOMM_EVENT_CHANNEL_CLOSED:
641             rfcomm_handle = 0;
642             hsp_state = HSP_IDLE;
643             hsp_ag_reset_state();
644             emit_event(HSP_SUBEVENT_RFCOMM_DISCONNECTION_COMPLETE,0);
645             break;
646 
647         case RFCOMM_EVENT_CAN_SEND_NOW:
648             hsp_run();
649             break;
650 
651         case HCI_EVENT_DISCONNECTION_COMPLETE:
652             handle = little_endian_read_16(packet,3);
653             if (handle == sco_handle){
654                 sco_handle = 0;
655                 hsp_state = HSP_RFCOMM_CONNECTION_ESTABLISHED;
656                 emit_event(HSP_SUBEVENT_AUDIO_DISCONNECTION_COMPLETE,0);
657                 break;
658             }
659             if (handle == rfcomm_handle) {
660                 rfcomm_handle = 0;
661                 hsp_state = HSP_IDLE;
662                 hsp_ag_reset_state();
663                 emit_event(HSP_SUBEVENT_RFCOMM_DISCONNECTION_COMPLETE,0);
664             }
665             break;
666 
667         default:
668             break;
669     }
670 
671     hsp_run();
672 }
673 
674 static void handle_query_rfcomm_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
675     switch (packet[0]){
676         case SDP_EVENT_QUERY_RFCOMM_SERVICE:
677             channel_nr = sdp_event_query_rfcomm_service_get_rfcomm_channel(packet);
678             log_info("** Service name: '%s', RFCOMM port %u", sdp_event_query_rfcomm_service_get_name(packet), channel_nr);
679             break;
680         case SDP_EVENT_QUERY_COMPLETE:
681             if (channel_nr > 0){
682                 hsp_state = HSP_W4_RFCOMM_CONNECTED;
683                 log_info("RFCOMM create channel. state %d", HSP_W4_RFCOMM_CONNECTED);
684                 rfcomm_create_channel(packet_handler, remote, channel_nr, NULL);
685                 break;
686             }
687             hsp_ag_reset_state();
688             log_info("Service not found, status %u.\n", sdp_event_query_complete_get_status(packet));
689             if (sdp_event_query_complete_get_status(packet)){
690                 emit_event(HSP_SUBEVENT_AUDIO_CONNECTION_COMPLETE, sdp_event_query_complete_get_status(packet));
691             } else {
692                 emit_event(HSP_SUBEVENT_AUDIO_CONNECTION_COMPLETE, SDP_SERVICE_NOT_FOUND);
693             }
694             break;
695         default:
696             break;
697     }
698 }
699 
700 
701