xref: /btstack/src/classic/hsp_ag.c (revision cd5f23a3250874824c01a2b3326a9522fea3f99f)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "hsp_ag.c"
39 
40 // *****************************************************************************
41 //
42 // HSP Audio Gateway
43 //
44 // *****************************************************************************
45 
46 #include "btstack_config.h"
47 
48 #include <stdint.h>
49 #include <string.h>
50 
51 #include "bluetooth_sdp.h"
52 #include "btstack_debug.h"
53 #include "btstack_event.h"
54 #include "btstack_memory.h"
55 #include "btstack_run_loop.h"
56 #include "classic/core.h"
57 #include "classic/sdp_server.h"
58 #include "classic/sdp_client_rfcomm.h"
59 #include "classic/sdp_util.h"
60 #include "classic/sdp_client.h"
61 #include "hci.h"
62 #include "hci_cmd.h"
63 #include "hci_dump.h"
64 #include "hsp_ag.h"
65 #include "l2cap.h"
66 
67 #define HSP_HS_BUTTON_PRESS "AT+CKPD=200"
68 #define HSP_HS_AT_CKPD "AT+CKPD\r\n"
69 #define HSP_AG_OK "\r\nOK\r\n"
70 #define HSP_AG_ERROR "\r\nERROR\r\n"
71 #define HSP_AG_RING "\r\nRING\r\n"
72 #define HSP_MICROPHONE_GAIN "+VGM"
73 #define HSP_SPEAKER_GAIN "+VGS"
74 
75 #define HSP_HS_MICROPHONE_GAIN "AT+VGM="
76 #define HSP_HS_SPEAKER_GAIN "AT+VGS="
77 
78 static const char default_hsp_ag_service_name[] = "Audio Gateway";
79 
80 static bd_addr_t remote;
81 static uint8_t channel_nr;
82 
83 static uint16_t mtu;
84 static uint16_t rfcomm_cid;
85 static hci_con_handle_t sco_handle;
86 static hci_con_handle_t rfcomm_handle;
87 static btstack_timer_source_t hs_timeout;
88 
89 static int ag_microphone_gain;
90 static int ag_speaker_gain;
91 static uint8_t ag_ring;
92 static uint8_t ag_send_ok;
93 static uint8_t ag_send_error;
94 static uint8_t ag_support_custom_commands;
95 static uint8_t hsp_disconnect_rfcomm;
96 static uint8_t hsp_release_audio_connection;
97 
98 static uint16_t hsp_ag_sco_packet_types;
99 
100 static btstack_packet_callback_registration_t hci_event_callback_registration;
101 
102 typedef enum {
103     HSP_IDLE,
104     HSP_W2_SEND_SDP_QUERY,
105     HSP_W4_SDP_QUERY_COMPLETE,
106     HSP_W4_RFCOMM_CONNECTED,
107 
108     HSP_RFCOMM_CONNECTION_ESTABLISHED,
109 
110     HSP_W4_RING_ANSWER,
111     HSP_W4_USER_ACTION,
112     HSP_W2_CONNECT_SCO,
113     HSP_W4_SCO_CONNECTED,
114 
115     HSP_AUDIO_CONNECTION_ESTABLISHED,
116 
117     HSP_W2_DISCONNECT_SCO,
118     HSP_W4_SCO_DISCONNECTED,
119 
120     HSP_W2_DISCONNECT_RFCOMM,
121     HSP_W4_RFCOMM_DISCONNECTED,
122     HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN
123 } hsp_state_t;
124 
125 static hsp_state_t hsp_state;
126 
127 static btstack_context_callback_registration_t hsp_ag_handle_sdp_client_query_request;
128 static btstack_packet_handler_t hsp_ag_callback;
129 
130 static void hsp_run(void);
131 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
132 static void handle_query_rfcomm_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
133 
134 static void dummy_notify(uint8_t packet_type, uint16_t channel, uint8_t * event, uint16_t size){
135     UNUSED(packet_type);    // ok: no code
136     UNUSED(channel);        // ok: no code
137     UNUSED(event);          // ok: no code
138     UNUSED(size);           // ok: no code
139 }
140 
141 void hsp_ag_register_packet_handler(btstack_packet_handler_t callback){
142     if (callback == NULL){
143         callback = &dummy_notify;
144     }
145     hsp_ag_callback = callback;
146 }
147 
148 static void emit_event(uint8_t event_subtype, uint8_t value){
149     if (!hsp_ag_callback) return;
150     uint8_t event[4];
151     event[0] = HCI_EVENT_HSP_META;
152     event[1] = sizeof(event) - 2;
153     event[2] = event_subtype;
154     event[3] = value; // status 0 == OK
155     (*hsp_ag_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
156 }
157 
158 static void emit_event_audio_connected(uint8_t status, uint16_t handle){
159     if (!hsp_ag_callback) return;
160     uint8_t event[6];
161     event[0] = HCI_EVENT_HSP_META;
162     event[1] = sizeof(event) - 2;
163     event[2] = HSP_SUBEVENT_AUDIO_CONNECTION_COMPLETE;
164     event[3] = status;
165     little_endian_store_16(event, 4, handle);
166     (*hsp_ag_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
167 }
168 
169 void hsp_ag_create_sdp_record(uint8_t * service, uint32_t service_record_handle, int rfcomm_channel_nr, const char * name){
170     uint8_t* attribute;
171     de_create_sequence(service);
172 
173     // 0x0000 "Service Record Handle"
174     de_add_number(service, DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_RECORD_HANDLE);
175     de_add_number(service, DE_UINT, DE_SIZE_32, service_record_handle);
176 
177     // 0x0001 "Service Class ID List"
178     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST);
179     attribute = de_push_sequence(service);
180     {
181         //  "UUID for PAN Service"
182         de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_HEADSET_AUDIO_GATEWAY_AG);
183         de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_GENERIC_AUDIO);
184     }
185     de_pop_sequence(service, attribute);
186 
187     // 0x0004 "Protocol Descriptor List"
188     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST);
189     attribute = de_push_sequence(service);
190     {
191         uint8_t* l2cpProtocol = de_push_sequence(attribute);
192         {
193             de_add_number(l2cpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_L2CAP);
194         }
195         de_pop_sequence(attribute, l2cpProtocol);
196 
197         uint8_t* rfcomm = de_push_sequence(attribute);
198         {
199             de_add_number(rfcomm,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_RFCOMM);  // rfcomm_service
200             de_add_number(rfcomm,  DE_UINT, DE_SIZE_8,  rfcomm_channel_nr);  // rfcomm channel
201         }
202         de_pop_sequence(attribute, rfcomm);
203     }
204     de_pop_sequence(service, attribute);
205 
206     // 0x0005 "Public Browse Group"
207     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BROWSE_GROUP_LIST); // public browse group
208     attribute = de_push_sequence(service);
209     {
210         de_add_number(attribute,  DE_UUID, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PUBLIC_BROWSE_ROOT);
211     }
212     de_pop_sequence(service, attribute);
213 
214     // 0x0009 "Bluetooth Profile Descriptor List"
215     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BLUETOOTH_PROFILE_DESCRIPTOR_LIST);
216     attribute = de_push_sequence(service);
217     {
218         uint8_t *sppProfile = de_push_sequence(attribute);
219         {
220             de_add_number(sppProfile,  DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_HEADSET);
221             de_add_number(sppProfile,  DE_UINT, DE_SIZE_16, 0x0102); // Verision 1.2
222         }
223         de_pop_sequence(attribute, sppProfile);
224     }
225     de_pop_sequence(service, attribute);
226 
227     // 0x0100 "Service Name"
228     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0100);
229     if (name){
230         de_add_data(service,  DE_STRING, strlen(name), (uint8_t *) name);
231     } else {
232         de_add_data(service,  DE_STRING, strlen(default_hsp_ag_service_name), (uint8_t *) default_hsp_ag_service_name);
233     }
234 }
235 
236 static int hsp_ag_send_str_over_rfcomm(const uint16_t cid, const char * command){
237     int err = rfcomm_send(cid, (uint8_t*) command, strlen(command));
238     if (err){
239         log_error("rfcomm_send_internal -> error 0X%02x", err);
240         return err;
241     }
242     return err;
243 }
244 
245 void hsp_ag_enable_custom_commands(int enable){
246     ag_support_custom_commands = enable;
247 }
248 
249 int hsp_ag_send_result(char * result){
250     if (!ag_support_custom_commands) return 1;
251     return hsp_ag_send_str_over_rfcomm(rfcomm_cid, result);
252 }
253 
254 static void hsp_ag_reset_state(void){
255     hsp_state = HSP_IDLE;
256 
257     rfcomm_cid = 0;
258     rfcomm_handle = HCI_CON_HANDLE_INVALID;
259     channel_nr = 0;
260     sco_handle = HCI_CON_HANDLE_INVALID;
261 
262     ag_send_ok = 0;
263     ag_send_error = 0;
264     ag_ring = 0;
265 
266     ag_support_custom_commands = 0;
267 
268     ag_microphone_gain = -1;
269     ag_speaker_gain = -1;
270 
271     hsp_disconnect_rfcomm = 0;
272     hsp_release_audio_connection = 0;
273 }
274 
275 void hsp_ag_init(uint8_t rfcomm_channel_nr){
276     // register for HCI events
277     hci_event_callback_registration.callback = &packet_handler;
278     hci_add_event_handler(&hci_event_callback_registration);
279 
280     rfcomm_register_service(packet_handler, rfcomm_channel_nr, 0xffff);  // reserved channel, mtu limited by l2cap
281 
282     hsp_ag_sco_packet_types = SCO_PACKET_TYPES_ALL;
283     hsp_ag_reset_state();
284 }
285 
286 void hsp_ag_deinit(void){
287     (void)memset(remote, 0, 6);
288     (void)memset(&hs_timeout, 0, sizeof(btstack_timer_source_t));
289     (void)memset(&hci_event_callback_registration, 0, sizeof(btstack_packet_callback_registration_t));
290     (void)memset(&hsp_ag_handle_sdp_client_query_request, 0, sizeof(btstack_context_callback_registration_t));
291     hsp_ag_callback = NULL;
292 }
293 
294 static void hsp_ag_handle_start_sdp_client_query(void * context){
295     UNUSED(context);
296     if (hsp_state != HSP_W2_SEND_SDP_QUERY) return;
297 
298     hsp_state = HSP_W4_SDP_QUERY_COMPLETE;
299     log_info("Start SDP query %s, 0x%02x", bd_addr_to_str(remote), BLUETOOTH_SERVICE_CLASS_HEADSET);
300     sdp_client_query_rfcomm_channel_and_name_for_service_class_uuid(&handle_query_rfcomm_event, remote, BLUETOOTH_SERVICE_CLASS_HEADSET);
301 }
302 
303 void hsp_ag_connect(bd_addr_t bd_addr){
304     if (hsp_state != HSP_IDLE) return;
305 
306     (void)memcpy(remote, bd_addr, 6);
307     hsp_state = HSP_W2_SEND_SDP_QUERY;
308     hsp_ag_handle_sdp_client_query_request.callback = &hsp_ag_handle_start_sdp_client_query;
309     // ignore ERROR_CODE_COMMAND_DISALLOWED because in that case, we already have requested an SDP callback
310     (void) sdp_client_register_query_callback(&hsp_ag_handle_sdp_client_query_request);
311 }
312 
313 void hsp_ag_disconnect(void){
314     hsp_ag_release_audio_connection();
315     if (hsp_state < HSP_W4_RFCOMM_CONNECTED){
316         hsp_state = HSP_IDLE;
317         return;
318     }
319 
320     if (hsp_state == HSP_W4_RFCOMM_CONNECTED){
321         hsp_state = HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN;
322         return;
323     }
324     hsp_disconnect_rfcomm = 1;
325     hsp_run();
326 }
327 
328 void hsp_ag_establish_audio_connection(void){
329     switch (hsp_state){
330         case HSP_RFCOMM_CONNECTION_ESTABLISHED:
331             hsp_state = HSP_W2_CONNECT_SCO;
332             break;
333         case HSP_W4_RFCOMM_CONNECTED:
334             hsp_state = HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN;
335             break;
336         default:
337             break;
338     }
339     hsp_run();
340 }
341 
342 void hsp_ag_release_audio_connection(void){
343     if (hsp_state >= HSP_W2_DISCONNECT_SCO) return;
344     if (hsp_state < HSP_AUDIO_CONNECTION_ESTABLISHED) return;
345 
346     hsp_release_audio_connection = 1;
347     hsp_run();
348 }
349 
350 
351 void hsp_ag_set_microphone_gain(uint8_t gain){
352     if (gain >15) {
353         log_error("Gain must be in interval [0..15], it is given %d", gain);
354         return;
355     }
356     ag_microphone_gain = gain;
357     hsp_run();
358 }
359 
360 // AG +VGS=5  [0..15] ; HS AT+VGM=6 | AG OK
361 void hsp_ag_set_speaker_gain(uint8_t gain){
362     if (gain >15) {
363         log_error("Gain must be in interval [0..15], it is given %d", gain);
364         return;
365     }
366     ag_speaker_gain = gain;
367     hsp_run();
368 }
369 
370 static void hsp_ringing_timeout_handler(btstack_timer_source_t * timer){
371     ag_ring = 1;
372     btstack_run_loop_set_timer(timer, 2000); // 2 seconds timeout
373     btstack_run_loop_add_timer(timer);
374     hsp_run();
375 }
376 
377 static void hsp_ringing_timer_start(void){
378     btstack_run_loop_remove_timer(&hs_timeout);
379     btstack_run_loop_set_timer_handler(&hs_timeout, hsp_ringing_timeout_handler);
380     btstack_run_loop_set_timer(&hs_timeout, 2000); // 2 seconds timeout
381     btstack_run_loop_add_timer(&hs_timeout);
382 }
383 
384 static void hsp_ringing_timer_stop(void){
385     btstack_run_loop_remove_timer(&hs_timeout);
386 }
387 
388 void hsp_ag_start_ringing(void){
389     ag_ring = 1;
390     if (hsp_state == HSP_W2_CONNECT_SCO) {
391         hsp_state = HSP_W4_RING_ANSWER;
392     }
393     hsp_ringing_timer_start();
394 }
395 
396 void hsp_ag_stop_ringing(void){
397     ag_ring = 0;
398     if (hsp_state == HSP_W4_RING_ANSWER){
399         hsp_state = HSP_W2_CONNECT_SCO;
400     }
401     hsp_ringing_timer_stop();
402 }
403 
404 static void hsp_run(void){
405     uint16_t packet_types;
406 
407     if (ag_send_ok){
408         if (!rfcomm_can_send_packet_now(rfcomm_cid)) {
409             rfcomm_request_can_send_now_event(rfcomm_cid);
410             return;
411         }
412         ag_send_ok = 0;
413         hsp_ag_send_str_over_rfcomm(rfcomm_cid, HSP_AG_OK);
414         return;
415     }
416 
417     if (ag_send_error){
418         if (!rfcomm_can_send_packet_now(rfcomm_cid)) {
419             rfcomm_request_can_send_now_event(rfcomm_cid);
420             return;
421         }
422         ag_send_error = 0;
423         hsp_ag_send_str_over_rfcomm(rfcomm_cid, HSP_AG_ERROR);
424         return;
425     }
426 
427     if (ag_ring){
428         if (!rfcomm_can_send_packet_now(rfcomm_cid)) {
429             rfcomm_request_can_send_now_event(rfcomm_cid);
430             return;
431         }
432         ag_ring = 0;
433         hsp_ag_send_str_over_rfcomm(rfcomm_cid, HSP_AG_RING);
434         return;
435     }
436 
437     if (hsp_release_audio_connection){
438         hsp_release_audio_connection = 0;
439         gap_disconnect(sco_handle);
440         return;
441     }
442 
443     if (hsp_disconnect_rfcomm){
444         hsp_disconnect_rfcomm = 0;
445         rfcomm_disconnect(rfcomm_cid);
446         return;
447     }
448 
449     switch (hsp_state){
450 
451         case HSP_W4_RING_ANSWER:
452             if (!rfcomm_can_send_packet_now(rfcomm_cid)) {
453                 rfcomm_request_can_send_now_event(rfcomm_cid);
454                 return;
455             }
456 
457             ag_send_ok = 0;
458             hsp_state = HSP_W2_CONNECT_SCO;
459 
460             hsp_ag_send_str_over_rfcomm(rfcomm_cid, HSP_AG_OK);
461             break;
462 
463         case HSP_W2_CONNECT_SCO:
464             if (!hci_can_send_command_packet_now()) return;
465             hsp_state = HSP_W4_SCO_CONNECTED;
466             // bits 6-9 are 'don't use'
467             packet_types = hsp_ag_sco_packet_types ^ 0x3c0;
468             hci_send_cmd(&hci_setup_synchronous_connection, rfcomm_handle, 8000, 8000, 0xFFFF, hci_get_sco_voice_setting(), 0xFF, packet_types);
469             break;
470 
471         case HSP_W2_DISCONNECT_SCO:
472             hsp_state = HSP_W4_SCO_DISCONNECTED;
473             gap_disconnect(sco_handle);
474             break;
475 
476         case HSP_W2_DISCONNECT_RFCOMM:
477             rfcomm_disconnect(rfcomm_cid);
478             break;
479 
480         case HSP_AUDIO_CONNECTION_ESTABLISHED:
481         case HSP_RFCOMM_CONNECTION_ESTABLISHED:
482 
483             if (ag_microphone_gain >= 0){
484                 if (!rfcomm_can_send_packet_now(rfcomm_cid)) {
485                     rfcomm_request_can_send_now_event(rfcomm_cid);
486                     return;
487                 }
488                 int gain = ag_microphone_gain;
489                 ag_microphone_gain = -1;
490                 char buffer[10];
491                 sprintf(buffer, "%s=%d\r\n", HSP_MICROPHONE_GAIN, gain);
492                 hsp_ag_send_str_over_rfcomm(rfcomm_cid, buffer);
493                 break;
494             }
495 
496             if (ag_speaker_gain >= 0){
497                 if (!rfcomm_can_send_packet_now(rfcomm_cid)) {
498                     rfcomm_request_can_send_now_event(rfcomm_cid);
499                     return;
500                 }
501                 int gain = ag_speaker_gain;
502                 ag_speaker_gain = -1;
503                 char buffer[10];
504                 sprintf(buffer, "%s=%d\r\n", HSP_SPEAKER_GAIN, gain);
505                 hsp_ag_send_str_over_rfcomm(rfcomm_cid, buffer);
506                 break;
507             }
508             break;
509         default:
510             break;
511     }
512 }
513 
514 
515 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
516     UNUSED(channel);    // ok: no channel for HCI_EVENT_PACKET and only single active RFCOMM channel
517 
518     if (packet_type == RFCOMM_DATA_PACKET){
519         while ((size > 0) && ((packet[0] == '\n') || (packet[0] == '\r'))){
520             size--;
521             packet++;
522         }
523 
524         if (strncmp((char *)packet, HSP_HS_BUTTON_PRESS, strlen(HSP_HS_BUTTON_PRESS)) == 0){
525             log_info("Received button press %s", HSP_HS_BUTTON_PRESS);
526             ag_send_ok = 1;
527             switch (hsp_state){
528                 case HSP_AUDIO_CONNECTION_ESTABLISHED:
529                     hsp_release_audio_connection = 1;
530                     break;
531                 case HSP_RFCOMM_CONNECTION_ESTABLISHED:
532                     hsp_state = HSP_W2_CONNECT_SCO;
533                     break;
534                 default:
535                     break;
536             }
537         } else if (strncmp((char *)packet, HSP_HS_MICROPHONE_GAIN, strlen(HSP_HS_MICROPHONE_GAIN)) == 0){
538             uint8_t gain = (uint8_t)btstack_atoi((char*)&packet[strlen(HSP_HS_MICROPHONE_GAIN)]);
539             ag_send_ok = 1;
540             emit_event(HSP_SUBEVENT_MICROPHONE_GAIN_CHANGED, gain);
541 
542         } else if (strncmp((char *)packet, HSP_HS_SPEAKER_GAIN, strlen(HSP_HS_SPEAKER_GAIN)) == 0){
543             uint8_t gain = (uint8_t)btstack_atoi((char*)&packet[strlen(HSP_HS_SPEAKER_GAIN)]);
544             ag_send_ok = 1;
545             emit_event(HSP_SUBEVENT_SPEAKER_GAIN_CHANGED, gain);
546 
547         } else if (strncmp((char *)packet, "AT+", 3) == 0){
548             ag_send_error = 1;
549             if (!hsp_ag_callback) return;
550             // re-use incoming buffer to avoid reserving large buffers - ugly but efficient
551             uint8_t * event = packet - 4;
552             event[0] = HCI_EVENT_HSP_META;
553             event[1] = size + 2;
554             event[2] = HSP_SUBEVENT_HS_COMMAND;
555             event[3] = size;
556             (*hsp_ag_callback)(HCI_EVENT_PACKET, 0, event, size+4);
557         }
558 
559         hsp_run();
560         return;
561     }
562 
563     if (packet_type != HCI_EVENT_PACKET) return;
564     uint8_t event = hci_event_packet_get_type(packet);
565     bd_addr_t event_addr;
566     uint16_t handle;
567 
568     switch (event) {
569         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:{
570             if (hsp_state != HSP_W4_SCO_CONNECTED) break;
571             uint8_t status = hci_event_synchronous_connection_complete_get_status(packet);
572             if (status != 0){
573                 hsp_state = HSP_RFCOMM_CONNECTION_ESTABLISHED;
574                 log_error("(e)SCO Connection failed, status %u", status);
575                 emit_event_audio_connected(status, sco_handle);
576                 break;
577             }
578 
579             hci_event_synchronous_connection_complete_get_bd_addr(packet, event_addr);
580             sco_handle = hci_event_synchronous_connection_complete_get_handle(packet);
581             uint8_t  link_type = hci_event_synchronous_connection_complete_get_link_type(packet);
582             uint8_t  transmission_interval = hci_event_synchronous_connection_complete_get_transmission_interval(packet);  // measured in slots
583             uint8_t  retransmission_interval = hci_event_synchronous_connection_complete_get_retransmission_interval(packet);// measured in slots
584             uint16_t rx_packet_length = hci_event_synchronous_connection_complete_get_rx_packet_length(packet); // measured in bytes
585             uint16_t tx_packet_length = hci_event_synchronous_connection_complete_get_tx_packet_length(packet); // measured in bytes
586 
587             switch (link_type){
588                 case 0x00:
589                     log_info("SCO Connection established.");
590                     if (transmission_interval != 0) log_error("SCO Connection: transmission_interval not zero: %d.", transmission_interval);
591                     if (retransmission_interval != 0) log_error("SCO Connection: retransmission_interval not zero: %d.", retransmission_interval);
592                     if (rx_packet_length != 0) log_error("SCO Connection: rx_packet_length not zero: %d.", rx_packet_length);
593                     if (tx_packet_length != 0) log_error("SCO Connection: tx_packet_length not zero: %d.", tx_packet_length);
594                     break;
595                 case 0x02:
596                     log_info("eSCO Connection established.");
597                     break;
598                 default:
599                     log_error("(e)SCO reserved link_type 0x%2x", link_type);
600                     break;
601             }
602             log_info("sco_handle 0x%2x, address %s, transmission_interval %u slots, retransmission_interval %u slots, "
603                  " rx_packet_length %u bytes, tx_packet_length %u bytes, air_mode 0x%2x (0x02 == CVSD)", sco_handle,
604                  bd_addr_to_str(event_addr), transmission_interval, retransmission_interval, rx_packet_length, tx_packet_length,
605                  hci_event_synchronous_connection_complete_get_air_mode(packet));
606 
607             if (hsp_state == HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN){
608                 hsp_state = HSP_W2_DISCONNECT_SCO;
609                 break;
610             }
611 
612             hsp_state = HSP_AUDIO_CONNECTION_ESTABLISHED;
613             emit_event_audio_connected(status, sco_handle);
614             break;
615         }
616 
617         case RFCOMM_EVENT_INCOMING_CONNECTION:
618             if (hsp_state != HSP_IDLE) return;
619 
620             rfcomm_event_incoming_connection_get_bd_addr(packet, event_addr);
621             rfcomm_cid = rfcomm_event_incoming_connection_get_rfcomm_cid(packet);
622             log_info("RFCOMM channel %u requested for %s with cid 0x%04x", rfcomm_event_incoming_connection_get_server_channel(packet), bd_addr_to_str(event_addr), rfcomm_cid);
623             hsp_state = HSP_W4_RFCOMM_CONNECTED;
624             rfcomm_accept_connection(rfcomm_cid);
625             break;
626 
627         case RFCOMM_EVENT_CHANNEL_OPENED:
628             log_info("RFCOMM_EVENT_CHANNEL_OPENED packet_handler type %u, packet[0] %x", packet_type, packet[0]);
629             if (rfcomm_event_channel_opened_get_status(packet)) {
630                 log_info("RFCOMM channel open failed, status %u§", rfcomm_event_channel_opened_get_status(packet));
631                 hsp_ag_reset_state();
632                 hsp_state = HSP_IDLE;
633             } else {
634                 rfcomm_handle = rfcomm_event_channel_opened_get_con_handle(packet);
635                 rfcomm_cid = rfcomm_event_channel_opened_get_rfcomm_cid(packet);
636                 mtu = rfcomm_event_channel_opened_get_max_frame_size(packet);
637                 log_info("RFCOMM channel open succeeded. New RFCOMM Channel ID %u, max frame size %u, state %d", rfcomm_cid, mtu, hsp_state);
638                 hsp_state = HSP_RFCOMM_CONNECTION_ESTABLISHED;
639             }
640             emit_event(HSP_SUBEVENT_RFCOMM_CONNECTION_COMPLETE, packet[2]);
641             break;
642 
643         case RFCOMM_EVENT_CHANNEL_CLOSED:
644             hsp_ag_reset_state();
645             emit_event(HSP_SUBEVENT_RFCOMM_DISCONNECTION_COMPLETE,0);
646             break;
647 
648         case RFCOMM_EVENT_CAN_SEND_NOW:
649             hsp_run();
650             break;
651 
652         case HCI_EVENT_DISCONNECTION_COMPLETE:
653             handle = little_endian_read_16(packet,3);
654             if (handle == sco_handle){
655                 sco_handle = HCI_CON_HANDLE_INVALID;
656                 hsp_state = HSP_RFCOMM_CONNECTION_ESTABLISHED;
657                 emit_event(HSP_SUBEVENT_AUDIO_DISCONNECTION_COMPLETE,0);
658                 break;
659             }
660             break;
661 
662         default:
663             break;
664     }
665 
666     hsp_run();
667 }
668 
669 static void handle_query_rfcomm_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
670     UNUSED(packet_type);    // ok: handling own sdp events
671     UNUSED(channel);        // ok: no channel
672     UNUSED(size);           // ok: handling own sdp events
673 
674     switch (packet[0]){
675         case SDP_EVENT_QUERY_RFCOMM_SERVICE:
676             channel_nr = sdp_event_query_rfcomm_service_get_rfcomm_channel(packet);
677             log_info("** Service name: '%s', RFCOMM port %u", sdp_event_query_rfcomm_service_get_name(packet), channel_nr);
678             break;
679         case SDP_EVENT_QUERY_COMPLETE:
680             if (channel_nr > 0){
681                 hsp_state = HSP_W4_RFCOMM_CONNECTED;
682                 log_info("RFCOMM create channel. state %d", HSP_W4_RFCOMM_CONNECTED);
683                 rfcomm_create_channel(packet_handler, remote, channel_nr, NULL);
684                 break;
685             }
686             hsp_ag_reset_state();
687             log_info("Service not found, status %u.\n", sdp_event_query_complete_get_status(packet));
688             if (sdp_event_query_complete_get_status(packet)){
689                 emit_event(HSP_SUBEVENT_AUDIO_CONNECTION_COMPLETE, sdp_event_query_complete_get_status(packet));
690             } else {
691                 emit_event(HSP_SUBEVENT_AUDIO_CONNECTION_COMPLETE, SDP_SERVICE_NOT_FOUND);
692             }
693             break;
694         default:
695             break;
696     }
697 }
698 
699 void hsp_ag_set_sco_packet_types(uint16_t packet_types){
700     hsp_ag_sco_packet_types = packet_types;
701 }
702 
703