xref: /btstack/src/classic/hsp_ag.c (revision b28dc8004dd8d4fb9020a6dcd2bc81f05d36a008)
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__ "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 <stdio.h>
50 #include <string.h>
51 
52 #include "bluetooth_sdp.h"
53 #include "btstack_debug.h"
54 #include "btstack_event.h"
55 #include "btstack_memory.h"
56 #include "btstack_run_loop.h"
57 #include "classic/core.h"
58 #include "classic/sdp_server.h"
59 #include "classic/sdp_client_rfcomm.h"
60 #include "classic/sdp_util.h"
61 #include "classic/sdp_client.h"
62 #include "hci.h"
63 #include "hci_cmd.h"
64 #include "hci_dump.h"
65 #include "hsp_ag.h"
66 #include "l2cap.h"
67 
68 #define HSP_HS_BUTTON_PRESS "AT+CKPD=200"
69 #define HSP_HS_AT_CKPD "AT+CKPD\r\n"
70 #define HSP_AG_OK "\r\nOK\r\n"
71 #define HSP_AG_ERROR "\r\nERROR\r\n"
72 #define HSP_AG_RING "\r\nRING\r\n"
73 #define HSP_MICROPHONE_GAIN "+VGM"
74 #define HSP_SPEAKER_GAIN "+VGS"
75 
76 #define HSP_HS_MICROPHONE_GAIN "AT+VGM="
77 #define HSP_HS_SPEAKER_GAIN "AT+VGS="
78 
79 static const char hsp_ag_default_service_name[] = "Audio Gateway";
80 
81 typedef enum {
82     HSP_IDLE,
83     HSP_W2_SEND_SDP_QUERY,
84     HSP_W4_SDP_QUERY_COMPLETE,
85     HSP_W4_RFCOMM_CONNECTED,
86 
87     HSP_RFCOMM_CONNECTION_ESTABLISHED,
88 
89     HSP_W4_RING_ANSWER,
90     HSP_W4_USER_ACTION,
91     HSP_W2_CONNECT_SCO,
92     HSP_W4_SCO_CONNECTED,
93 
94     HSP_AUDIO_CONNECTION_ESTABLISHED,
95 
96     HSP_W2_DISCONNECT_SCO,
97     HSP_W4_SCO_DISCONNECTED,
98 
99     HSP_W2_DISCONNECT_RFCOMM,
100     HSP_W4_RFCOMM_DISCONNECTED,
101     HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN
102 } hsp_state_t;
103 
104 // higher-layer callbacks
105 static btstack_packet_handler_t hsp_ag_callback;
106 
107 static hsp_state_t hsp_ag_state;
108 
109 static int      hsp_ag_microphone_gain;
110 static int      hsp_ag_speaker_gain;
111 static uint8_t  hsp_ag_ring;
112 static uint8_t  hsp_ag_send_ok;
113 static uint8_t  hsp_ag_send_error;
114 static uint8_t  hsp_ag_support_custom_commands;
115 static uint8_t  hsp_ag_disconnect_rfcomm;
116 static uint8_t  hsp_ag_release_audio_connection_triggered;
117 static uint16_t hsp_ag_sco_packet_types;
118 
119 static bd_addr_t hsp_ag_remote;
120 static uint8_t   hsp_ag_channel_nr;
121 static uint16_t  hsp_ag_rfcomm_cid;
122 static uint16_t  hsp_ag_mtu;
123 
124 static hci_con_handle_t hsp_ag_sco_handle;
125 static hci_con_handle_t hsp_ag_rfcomm_handle;
126 
127 static btstack_timer_source_t hsp_ag_timeout;
128 
129 static btstack_packet_callback_registration_t hci_event_callback_registration;
130 static btstack_context_callback_registration_t hsp_ag_handle_sdp_client_query_request;
131 
132 static void hsp_run(void);
133 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
134 static void handle_query_rfcomm_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
135 
136 static void dummy_notify(uint8_t packet_type, uint16_t channel, uint8_t * event, uint16_t size){
137     UNUSED(packet_type);    // ok: no code
138     UNUSED(channel);        // ok: no code
139     UNUSED(event);          // ok: no code
140     UNUSED(size);           // ok: no code
141 }
142 
143 void hsp_ag_register_packet_handler(btstack_packet_handler_t callback){
144     if (callback == NULL){
145         callback = &dummy_notify;
146     }
147     hsp_ag_callback = callback;
148 }
149 
150 static void emit_event(uint8_t event_subtype, uint8_t value){
151     if (!hsp_ag_callback) return;
152     uint8_t event[4];
153     event[0] = HCI_EVENT_HSP_META;
154     event[1] = sizeof(event) - 2;
155     event[2] = event_subtype;
156     event[3] = value; // status 0 == OK
157     (*hsp_ag_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
158 }
159 
160 static void emit_event_audio_connected(uint8_t status, uint16_t handle){
161     if (!hsp_ag_callback) return;
162     uint8_t event[6];
163     event[0] = HCI_EVENT_HSP_META;
164     event[1] = sizeof(event) - 2;
165     event[2] = HSP_SUBEVENT_AUDIO_CONNECTION_COMPLETE;
166     event[3] = status;
167     little_endian_store_16(event, 4, handle);
168     (*hsp_ag_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
169 }
170 
171 void hsp_ag_create_sdp_record(uint8_t * service, uint32_t service_record_handle, int rfcomm_channel_nr, const char * name){
172     uint8_t* attribute;
173     de_create_sequence(service);
174 
175     // 0x0000 "Service Record Handle"
176     de_add_number(service, DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_RECORD_HANDLE);
177     de_add_number(service, DE_UINT, DE_SIZE_32, service_record_handle);
178 
179     // 0x0001 "Service Class ID List"
180     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST);
181     attribute = de_push_sequence(service);
182     {
183         //  "UUID for PAN Service"
184         de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_HEADSET_AUDIO_GATEWAY_AG);
185         de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_GENERIC_AUDIO);
186     }
187     de_pop_sequence(service, attribute);
188 
189     // 0x0004 "Protocol Descriptor List"
190     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST);
191     attribute = de_push_sequence(service);
192     {
193         uint8_t* l2cpProtocol = de_push_sequence(attribute);
194         {
195             de_add_number(l2cpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_L2CAP);
196         }
197         de_pop_sequence(attribute, l2cpProtocol);
198 
199         uint8_t* rfcomm = de_push_sequence(attribute);
200         {
201             de_add_number(rfcomm,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_RFCOMM);  // rfcomm_service
202             de_add_number(rfcomm,  DE_UINT, DE_SIZE_8,  rfcomm_channel_nr);  // rfcomm channel
203         }
204         de_pop_sequence(attribute, rfcomm);
205     }
206     de_pop_sequence(service, attribute);
207 
208     // 0x0005 "Public Browse Group"
209     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BROWSE_GROUP_LIST); // public browse group
210     attribute = de_push_sequence(service);
211     {
212         de_add_number(attribute,  DE_UUID, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PUBLIC_BROWSE_ROOT);
213     }
214     de_pop_sequence(service, attribute);
215 
216     // 0x0009 "Bluetooth Profile Descriptor List"
217     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BLUETOOTH_PROFILE_DESCRIPTOR_LIST);
218     attribute = de_push_sequence(service);
219     {
220         uint8_t *sppProfile = de_push_sequence(attribute);
221         {
222             de_add_number(sppProfile,  DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_HEADSET);
223             de_add_number(sppProfile,  DE_UINT, DE_SIZE_16, 0x0102); // Verision 1.2
224         }
225         de_pop_sequence(attribute, sppProfile);
226     }
227     de_pop_sequence(service, attribute);
228 
229     // 0x0100 "Service Name"
230     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0100);
231     if (name){
232         de_add_data(service,  DE_STRING, strlen(name), (uint8_t *) name);
233     } else {
234         de_add_data(service, DE_STRING, strlen(hsp_ag_default_service_name), (uint8_t *) hsp_ag_default_service_name);
235     }
236 }
237 
238 static int hsp_ag_send_str_over_rfcomm(const uint16_t cid, const char * command){
239     int err = rfcomm_send(cid, (uint8_t*) command, strlen(command));
240     if (err){
241         log_error("rfcomm_send_internal -> error 0X%02x", err);
242         return err;
243     }
244     return err;
245 }
246 
247 void hsp_ag_enable_custom_commands(int enable){
248     hsp_ag_support_custom_commands = enable;
249 }
250 
251 int hsp_ag_send_result(char * result){
252     if (!hsp_ag_support_custom_commands) return 1;
253     return hsp_ag_send_str_over_rfcomm(hsp_ag_rfcomm_cid, result);
254 }
255 
256 static void hsp_ag_reset_state(void){
257     hsp_ag_state = HSP_IDLE;
258 
259     hsp_ag_rfcomm_cid = 0;
260     hsp_ag_rfcomm_handle = HCI_CON_HANDLE_INVALID;
261     hsp_ag_channel_nr = 0;
262     hsp_ag_sco_handle = HCI_CON_HANDLE_INVALID;
263 
264     hsp_ag_send_ok = 0;
265     hsp_ag_send_error = 0;
266     hsp_ag_ring = 0;
267 
268     hsp_ag_support_custom_commands = 0;
269 
270     hsp_ag_microphone_gain = -1;
271     hsp_ag_speaker_gain = -1;
272 
273     hsp_ag_disconnect_rfcomm = 0;
274     hsp_ag_release_audio_connection_triggered = 0;
275 }
276 
277 void hsp_ag_init(uint8_t rfcomm_channel_nr){
278     // register for HCI events
279     hci_event_callback_registration.callback = &packet_handler;
280     hci_add_event_handler(&hci_event_callback_registration);
281 
282     rfcomm_register_service(packet_handler, rfcomm_channel_nr, 0xffff);  // reserved channel, mtu limited by l2cap
283 
284     hsp_ag_sco_packet_types = SCO_PACKET_TYPES_ALL;
285     hsp_ag_reset_state();
286 }
287 
288 void hsp_ag_deinit(void){
289     hsp_ag_reset_state();
290     hsp_ag_callback = NULL;
291     (void)memset(hsp_ag_remote, 0, 6);
292     (void)memset(&hsp_ag_timeout, 0, sizeof(btstack_timer_source_t));
293     (void)memset(&hci_event_callback_registration, 0, sizeof(btstack_packet_callback_registration_t));
294     (void)memset(&hsp_ag_handle_sdp_client_query_request, 0, sizeof(btstack_context_callback_registration_t));
295 }
296 
297 static void hsp_ag_handle_start_sdp_client_query(void * context){
298     UNUSED(context);
299     if (hsp_ag_state != HSP_W2_SEND_SDP_QUERY) return;
300 
301     hsp_ag_state = HSP_W4_SDP_QUERY_COMPLETE;
302     log_info("Start SDP query %s, 0x%02x", bd_addr_to_str(hsp_ag_remote), BLUETOOTH_SERVICE_CLASS_HEADSET);
303     sdp_client_query_rfcomm_channel_and_name_for_service_class_uuid(&handle_query_rfcomm_event, hsp_ag_remote, BLUETOOTH_SERVICE_CLASS_HEADSET);
304 }
305 
306 void hsp_ag_connect(bd_addr_t bd_addr){
307     if (hsp_ag_state != HSP_IDLE) return;
308 
309     (void)memcpy(hsp_ag_remote, bd_addr, 6);
310     hsp_ag_state = HSP_W2_SEND_SDP_QUERY;
311     hsp_ag_handle_sdp_client_query_request.callback = &hsp_ag_handle_start_sdp_client_query;
312     // ignore ERROR_CODE_COMMAND_DISALLOWED because in that case, we already have requested an SDP callback
313     (void) sdp_client_register_query_callback(&hsp_ag_handle_sdp_client_query_request);
314 }
315 
316 void hsp_ag_disconnect(void){
317     hsp_ag_release_audio_connection();
318     if (hsp_ag_state < HSP_W4_RFCOMM_CONNECTED){
319         hsp_ag_state = HSP_IDLE;
320         return;
321     }
322 
323     if (hsp_ag_state == HSP_W4_RFCOMM_CONNECTED){
324         hsp_ag_state = HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN;
325         return;
326     }
327     hsp_ag_disconnect_rfcomm = 1;
328     hsp_run();
329 }
330 
331 void hsp_ag_establish_audio_connection(void){
332     switch (hsp_ag_state){
333         case HSP_RFCOMM_CONNECTION_ESTABLISHED:
334             hsp_ag_state = HSP_W2_CONNECT_SCO;
335             break;
336         case HSP_W4_RFCOMM_CONNECTED:
337             hsp_ag_state = HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN;
338             break;
339         default:
340             break;
341     }
342     hsp_run();
343 }
344 
345 void hsp_ag_release_audio_connection(void){
346     if (hsp_ag_state >= HSP_W2_DISCONNECT_SCO) return;
347     if (hsp_ag_state < HSP_AUDIO_CONNECTION_ESTABLISHED) return;
348 
349     hsp_ag_release_audio_connection_triggered = 1;
350     hsp_run();
351 }
352 
353 
354 void hsp_ag_set_microphone_gain(uint8_t gain){
355     if (gain >15) {
356         log_error("Gain must be in interval [0..15], it is given %d", gain);
357         return;
358     }
359     hsp_ag_microphone_gain = gain;
360     hsp_run();
361 }
362 
363 // AG +VGS=5  [0..15] ; HS AT+VGM=6 | AG OK
364 void hsp_ag_set_speaker_gain(uint8_t gain){
365     if (gain >15) {
366         log_error("Gain must be in interval [0..15], it is given %d", gain);
367         return;
368     }
369     hsp_ag_speaker_gain = gain;
370     hsp_run();
371 }
372 
373 static void hsp_ringing_timeout_handler(btstack_timer_source_t * timer){
374     hsp_ag_ring = 1;
375     btstack_run_loop_set_timer(timer, 2000); // 2 seconds timeout
376     btstack_run_loop_add_timer(timer);
377     hsp_run();
378 }
379 
380 static void hsp_ringing_timer_start(void){
381     btstack_run_loop_remove_timer(&hsp_ag_timeout);
382     btstack_run_loop_set_timer_handler(&hsp_ag_timeout, hsp_ringing_timeout_handler);
383     btstack_run_loop_set_timer(&hsp_ag_timeout, 2000); // 2 seconds timeout
384     btstack_run_loop_add_timer(&hsp_ag_timeout);
385 }
386 
387 static void hsp_ringing_timer_stop(void){
388     btstack_run_loop_remove_timer(&hsp_ag_timeout);
389 }
390 
391 void hsp_ag_start_ringing(void){
392     hsp_ag_ring = 1;
393     if (hsp_ag_state == HSP_W2_CONNECT_SCO) {
394         hsp_ag_state = HSP_W4_RING_ANSWER;
395     }
396     hsp_ringing_timer_start();
397 }
398 
399 void hsp_ag_stop_ringing(void){
400     hsp_ag_ring = 0;
401     if (hsp_ag_state == HSP_W4_RING_ANSWER){
402         hsp_ag_state = HSP_W2_CONNECT_SCO;
403     }
404     hsp_ringing_timer_stop();
405 }
406 
407 static void hsp_run(void){
408     uint16_t packet_types;
409 
410     if (hsp_ag_send_ok){
411         if (!rfcomm_can_send_packet_now(hsp_ag_rfcomm_cid)) {
412             rfcomm_request_can_send_now_event(hsp_ag_rfcomm_cid);
413             return;
414         }
415         hsp_ag_send_ok = 0;
416         hsp_ag_send_str_over_rfcomm(hsp_ag_rfcomm_cid, HSP_AG_OK);
417         return;
418     }
419 
420     if (hsp_ag_send_error){
421         if (!rfcomm_can_send_packet_now(hsp_ag_rfcomm_cid)) {
422             rfcomm_request_can_send_now_event(hsp_ag_rfcomm_cid);
423             return;
424         }
425         hsp_ag_send_error = 0;
426         hsp_ag_send_str_over_rfcomm(hsp_ag_rfcomm_cid, HSP_AG_ERROR);
427         return;
428     }
429 
430     if (hsp_ag_ring){
431         if (!rfcomm_can_send_packet_now(hsp_ag_rfcomm_cid)) {
432             rfcomm_request_can_send_now_event(hsp_ag_rfcomm_cid);
433             return;
434         }
435         hsp_ag_ring = 0;
436         hsp_ag_send_str_over_rfcomm(hsp_ag_rfcomm_cid, HSP_AG_RING);
437         return;
438     }
439 
440     if (hsp_ag_release_audio_connection_triggered){
441         hsp_ag_release_audio_connection_triggered = 0;
442         gap_disconnect(hsp_ag_sco_handle);
443         return;
444     }
445 
446     if (hsp_ag_disconnect_rfcomm){
447         hsp_ag_disconnect_rfcomm = 0;
448         rfcomm_disconnect(hsp_ag_rfcomm_cid);
449         return;
450     }
451 
452     switch (hsp_ag_state){
453 
454         case HSP_W4_RING_ANSWER:
455             if (!rfcomm_can_send_packet_now(hsp_ag_rfcomm_cid)) {
456                 rfcomm_request_can_send_now_event(hsp_ag_rfcomm_cid);
457                 return;
458             }
459 
460             hsp_ag_send_ok = 0;
461             hsp_ag_state = HSP_W2_CONNECT_SCO;
462 
463             hsp_ag_send_str_over_rfcomm(hsp_ag_rfcomm_cid, HSP_AG_OK);
464             break;
465 
466         case HSP_W2_CONNECT_SCO:
467             if (!hci_can_send_command_packet_now()) return;
468             hsp_ag_state = HSP_W4_SCO_CONNECTED;
469             // bits 6-9 are 'don't use'
470             packet_types = hsp_ag_sco_packet_types ^ 0x3c0;
471             hci_send_cmd(&hci_setup_synchronous_connection, hsp_ag_rfcomm_handle, 8000, 8000, 0xFFFF, hci_get_sco_voice_setting(), 0xFF, packet_types);
472             break;
473 
474         case HSP_W2_DISCONNECT_SCO:
475             hsp_ag_state = HSP_W4_SCO_DISCONNECTED;
476             gap_disconnect(hsp_ag_sco_handle);
477             break;
478 
479         case HSP_W2_DISCONNECT_RFCOMM:
480             rfcomm_disconnect(hsp_ag_rfcomm_cid);
481             break;
482 
483         case HSP_AUDIO_CONNECTION_ESTABLISHED:
484         case HSP_RFCOMM_CONNECTION_ESTABLISHED:
485 
486             if (hsp_ag_microphone_gain >= 0){
487                 if (!rfcomm_can_send_packet_now(hsp_ag_rfcomm_cid)) {
488                     rfcomm_request_can_send_now_event(hsp_ag_rfcomm_cid);
489                     return;
490                 }
491                 int gain = hsp_ag_microphone_gain;
492                 hsp_ag_microphone_gain = -1;
493                 char buffer[12];
494                 snprintf(buffer, sizeof(buffer), "\r\n%s=%d\r\n",
495                          HSP_MICROPHONE_GAIN, gain);
496                 buffer[sizeof(buffer) - 1] = 0;
497                 hsp_ag_send_str_over_rfcomm(hsp_ag_rfcomm_cid, buffer);
498                 break;
499             }
500 
501             if (hsp_ag_speaker_gain >= 0){
502                 if (!rfcomm_can_send_packet_now(hsp_ag_rfcomm_cid)) {
503                     rfcomm_request_can_send_now_event(hsp_ag_rfcomm_cid);
504                     return;
505                 }
506                 int gain = hsp_ag_speaker_gain;
507                 hsp_ag_speaker_gain = -1;
508                 char buffer[12];
509                 snprintf(buffer, sizeof(buffer), "\r\n%s=%d\r\n",
510                          HSP_SPEAKER_GAIN, gain);
511                 buffer[sizeof(buffer) - 1] = 0;
512                 hsp_ag_send_str_over_rfcomm(hsp_ag_rfcomm_cid, buffer);
513                 break;
514             }
515             break;
516         default:
517             break;
518     }
519 }
520 
521 
522 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
523     UNUSED(channel);    // ok: no channel for HCI_EVENT_PACKET and only single active RFCOMM channel
524 
525     if (packet_type == RFCOMM_DATA_PACKET){
526         while ((size > 0) && ((packet[0] == '\n') || (packet[0] == '\r'))){
527             size--;
528             packet++;
529         }
530 
531         if (strncmp((char *)packet, HSP_HS_BUTTON_PRESS, strlen(HSP_HS_BUTTON_PRESS)) == 0){
532             log_info("Received button press %s", HSP_HS_BUTTON_PRESS);
533             hsp_ag_send_ok = 1;
534             emit_event(HSP_SUBEVENT_BUTTON_PRESSED, 0);
535         } else if (strncmp((char *)packet, HSP_HS_MICROPHONE_GAIN, strlen(HSP_HS_MICROPHONE_GAIN)) == 0){
536             uint8_t gain = (uint8_t)btstack_atoi((char*)&packet[strlen(HSP_HS_MICROPHONE_GAIN)]);
537             hsp_ag_send_ok = 1;
538             emit_event(HSP_SUBEVENT_MICROPHONE_GAIN_CHANGED, gain);
539 
540         } else if (strncmp((char *)packet, HSP_HS_SPEAKER_GAIN, strlen(HSP_HS_SPEAKER_GAIN)) == 0){
541             uint8_t gain = (uint8_t)btstack_atoi((char*)&packet[strlen(HSP_HS_SPEAKER_GAIN)]);
542             hsp_ag_send_ok = 1;
543             emit_event(HSP_SUBEVENT_SPEAKER_GAIN_CHANGED, gain);
544 
545         } else if (strncmp((char *)packet, "AT+", 3) == 0){
546             hsp_ag_send_error = 1;
547             if (!hsp_ag_callback) return;
548             // re-use incoming buffer to avoid reserving large buffers - ugly but efficient
549             uint8_t * event = packet - 4;
550             event[0] = HCI_EVENT_HSP_META;
551             event[1] = size + 2;
552             event[2] = HSP_SUBEVENT_HS_COMMAND;
553             event[3] = size;
554             (*hsp_ag_callback)(HCI_EVENT_PACKET, 0, event, size+4);
555         }
556 
557         hsp_run();
558         return;
559     }
560 
561     if (packet_type != HCI_EVENT_PACKET) return;
562     uint8_t event = hci_event_packet_get_type(packet);
563     bd_addr_t event_addr;
564     uint16_t handle;
565 
566     switch (event) {
567         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:{
568             if (hsp_ag_state != HSP_W4_SCO_CONNECTED) break;
569             uint8_t status = hci_event_synchronous_connection_complete_get_status(packet);
570             if (status != 0){
571                 hsp_ag_state = HSP_RFCOMM_CONNECTION_ESTABLISHED;
572                 log_error("(e)SCO Connection failed, status %u", status);
573                 emit_event_audio_connected(status, hsp_ag_sco_handle);
574                 break;
575             }
576 
577             hci_event_synchronous_connection_complete_get_bd_addr(packet, event_addr);
578             hsp_ag_sco_handle = hci_event_synchronous_connection_complete_get_handle(packet);
579             uint8_t  link_type = hci_event_synchronous_connection_complete_get_link_type(packet);
580             uint8_t  transmission_interval = hci_event_synchronous_connection_complete_get_transmission_interval(packet);  // measured in slots
581             uint8_t  retransmission_interval = hci_event_synchronous_connection_complete_get_retransmission_interval(packet);// measured in slots
582             uint16_t rx_packet_length = hci_event_synchronous_connection_complete_get_rx_packet_length(packet); // measured in bytes
583             uint16_t tx_packet_length = hci_event_synchronous_connection_complete_get_tx_packet_length(packet); // measured in bytes
584 
585             switch (link_type){
586                 case 0x00:
587                     log_info("SCO Connection established.");
588                     if (transmission_interval != 0) log_error("SCO Connection: transmission_interval not zero: %d.", transmission_interval);
589                     if (retransmission_interval != 0) log_error("SCO Connection: retransmission_interval not zero: %d.", retransmission_interval);
590                     if (rx_packet_length != 0) log_error("SCO Connection: rx_packet_length not zero: %d.", rx_packet_length);
591                     if (tx_packet_length != 0) log_error("SCO Connection: tx_packet_length not zero: %d.", tx_packet_length);
592                     break;
593                 case 0x02:
594                     log_info("eSCO Connection established.");
595                     break;
596                 default:
597                     log_error("(e)SCO reserved link_type 0x%2x", link_type);
598                     break;
599             }
600             log_info("sco_handle 0x%2x, address %s, transmission_interval %u slots, retransmission_interval %u slots, "
601                  " rx_packet_length %u bytes, tx_packet_length %u bytes, air_mode 0x%2x (0x02 == CVSD)", hsp_ag_sco_handle,
602                      bd_addr_to_str(event_addr), transmission_interval, retransmission_interval, rx_packet_length, tx_packet_length,
603                      hci_event_synchronous_connection_complete_get_air_mode(packet));
604 
605             if (hsp_ag_state == HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN){
606                 hsp_ag_state = HSP_W2_DISCONNECT_SCO;
607                 break;
608             }
609 
610             hsp_ag_state = HSP_AUDIO_CONNECTION_ESTABLISHED;
611             emit_event_audio_connected(status, hsp_ag_sco_handle);
612             break;
613         }
614 
615         case RFCOMM_EVENT_INCOMING_CONNECTION:
616             if (hsp_ag_state != HSP_IDLE) return;
617 
618             rfcomm_event_incoming_connection_get_bd_addr(packet, event_addr);
619             hsp_ag_rfcomm_cid = rfcomm_event_incoming_connection_get_rfcomm_cid(packet);
620             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), hsp_ag_rfcomm_cid);
621             hsp_ag_state = HSP_W4_RFCOMM_CONNECTED;
622             rfcomm_accept_connection(hsp_ag_rfcomm_cid);
623             break;
624 
625         case RFCOMM_EVENT_CHANNEL_OPENED:
626             log_info("RFCOMM_EVENT_CHANNEL_OPENED packet_handler type %u, packet[0] %x", packet_type, packet[0]);
627             if (rfcomm_event_channel_opened_get_status(packet)) {
628                 log_info("RFCOMM channel open failed, status %u§", rfcomm_event_channel_opened_get_status(packet));
629                 hsp_ag_reset_state();
630                 hsp_ag_state = HSP_IDLE;
631             } else {
632                 hsp_ag_rfcomm_handle = rfcomm_event_channel_opened_get_con_handle(packet);
633                 hsp_ag_rfcomm_cid = rfcomm_event_channel_opened_get_rfcomm_cid(packet);
634                 hsp_ag_mtu = rfcomm_event_channel_opened_get_max_frame_size(packet);
635                 log_info("RFCOMM channel open succeeded. New RFCOMM Channel ID %u, max frame size %u, state %d", hsp_ag_rfcomm_cid, hsp_ag_mtu, hsp_ag_state);
636                 hsp_ag_state = HSP_RFCOMM_CONNECTION_ESTABLISHED;
637             }
638             emit_event(HSP_SUBEVENT_RFCOMM_CONNECTION_COMPLETE, packet[2]);
639             break;
640 
641         case RFCOMM_EVENT_CHANNEL_CLOSED:
642             hsp_ag_reset_state();
643             emit_event(HSP_SUBEVENT_RFCOMM_DISCONNECTION_COMPLETE,0);
644             break;
645 
646         case RFCOMM_EVENT_CAN_SEND_NOW:
647             hsp_run();
648             break;
649 
650         case HCI_EVENT_DISCONNECTION_COMPLETE:
651             handle = little_endian_read_16(packet,3);
652             if (handle == hsp_ag_sco_handle){
653                 hsp_ag_sco_handle = HCI_CON_HANDLE_INVALID;
654                 hsp_ag_state = HSP_RFCOMM_CONNECTION_ESTABLISHED;
655                 emit_event(HSP_SUBEVENT_AUDIO_DISCONNECTION_COMPLETE,0);
656                 break;
657             }
658             break;
659 
660         default:
661             break;
662     }
663 
664     hsp_run();
665 }
666 
667 static void handle_query_rfcomm_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
668     UNUSED(packet_type);    // ok: handling own sdp events
669     UNUSED(channel);        // ok: no channel
670     UNUSED(size);           // ok: handling own sdp events
671 
672     switch (packet[0]){
673         case SDP_EVENT_QUERY_RFCOMM_SERVICE:
674             hsp_ag_channel_nr = sdp_event_query_rfcomm_service_get_rfcomm_channel(packet);
675             log_info("** Service name: '%s', RFCOMM port %u", sdp_event_query_rfcomm_service_get_name(packet), hsp_ag_channel_nr);
676             break;
677         case SDP_EVENT_QUERY_COMPLETE:
678             if (hsp_ag_channel_nr > 0){
679                 hsp_ag_state = HSP_W4_RFCOMM_CONNECTED;
680                 log_info("RFCOMM create channel. state %d", HSP_W4_RFCOMM_CONNECTED);
681                 rfcomm_create_channel(packet_handler, hsp_ag_remote, hsp_ag_channel_nr, NULL);
682                 break;
683             }
684             hsp_ag_reset_state();
685             log_info("Service not found, status %u.\n", sdp_event_query_complete_get_status(packet));
686             if (sdp_event_query_complete_get_status(packet)){
687                 emit_event(HSP_SUBEVENT_AUDIO_CONNECTION_COMPLETE, sdp_event_query_complete_get_status(packet));
688             } else {
689                 emit_event(HSP_SUBEVENT_AUDIO_CONNECTION_COMPLETE, SDP_SERVICE_NOT_FOUND);
690             }
691             break;
692         default:
693             break;
694     }
695 }
696 
697 void hsp_ag_set_sco_packet_types(uint16_t packet_types){
698     hsp_ag_sco_packet_types = packet_types;
699 }
700 
701