xref: /btstack/src/classic/hsp_hs.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_hs.c"
39 
40 // *****************************************************************************
41 //
42 // HSP Headset
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_hs.h"
66 #include "l2cap.h"
67 
68 #define HSP_AG_OK "OK"
69 #define HSP_AG_ERROR "ERROR"
70 #define HSP_AG_RING "RING"
71 #define HSP_MICROPHONE_GAIN "+VGM="
72 #define HSP_SPEAKER_GAIN "+VGS="
73 
74 #define HSP_HS_AT_CKPD "AT+CKPD=200\r\n"
75 #define HSP_HS_MICROPHONE_GAIN "AT+VGM"
76 #define HSP_HS_SPEAKER_GAIN "AT+VGS"
77 
78 static const char hsp_hs_default_service_name[] = "Headset";
79 
80 typedef enum {
81     HSP_IDLE,
82     HSP_W2_SEND_SDP_QUERY,
83     HSP_W4_SDP_QUERY_COMPLETE,
84     HSP_W4_RFCOMM_CONNECTED,
85 
86     HSP_RFCOMM_CONNECTION_ESTABLISHED,
87 
88     HSP_W2_CONNECT_SCO,
89     HSP_W4_SCO_CONNECTED,
90 
91     HSP_AUDIO_CONNECTION_ESTABLISHED,
92 
93     HSP_W2_DISCONNECT_SCO,
94     HSP_W4_SCO_DISCONNECTED,
95 
96     HSP_W2_DISCONNECT_RFCOMM,
97     HSP_W4_RFCOMM_DISCONNECTED,
98     HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN
99 } hsp_state_t;
100 
101 // higher-layer callbacks
102 static btstack_packet_handler_t hsp_hs_callback;
103 
104 static bd_addr_t hsp_hs_remote;
105 static uint8_t   hsp_hs_rfcomm_channel_nr;
106 static uint16_t  hsp_hs_rfcomm_cid;
107 static uint16_t  hsp_hs_rfcomm_mtu;
108 
109 static hci_con_handle_t hsp_hs_sco_handle;
110 static hci_con_handle_t hsp_hs_rfcomm_handle;
111 
112 static hsp_state_t hsp_state;
113 
114 static int hsp_hs_microphone_gain;
115 static int hsp_hs_speaker_gain;
116 
117 static uint8_t hsp_hs_send_button_press_triggered;
118 static uint8_t hsp_hs_wait_ok;
119 static uint8_t hsp_hs_accept_sco_connection;
120 
121 static uint8_t hsp_hs_support_custom_indications;
122 static uint8_t hsp_hs_establish_audio_connection_triggered;
123 static uint8_t hsp_hs_release_audio_connection_triggered;
124 
125 static uint16_t hsp_hs_sco_packet_types;
126 
127 static btstack_packet_callback_registration_t  hsp_hs_hci_event_callback_registration;
128 static btstack_context_callback_registration_t hsp_hs_handle_sdp_client_query_request;
129 
130 
131 static void hsp_run(void);
132 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
133 static void handle_query_rfcomm_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
134 
135 static void dummy_notify(uint8_t packet_type, uint16_t channel, uint8_t * event, uint16_t size){
136     // ok: no code
137     UNUSED(packet_type);
138     UNUSED(channel);
139     UNUSED(event);
140     UNUSED(size);
141 }
142 
143 void hsp_hs_register_packet_handler(btstack_packet_handler_t callback){
144     if (callback == NULL){
145         callback = &dummy_notify;
146     }
147     hsp_hs_callback = callback;
148 }
149 
150 static void emit_event(uint8_t event_subtype, uint8_t value){
151     if (!hsp_hs_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_hs_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
158 }
159 
160 static void emit_ring_event(void){
161     if (!hsp_hs_callback) return;
162     uint8_t event[3];
163     event[0] = HCI_EVENT_HSP_META;
164     event[1] = sizeof(event) - 2;
165     event[2] = HSP_SUBEVENT_RING;
166     (*hsp_hs_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
167 }
168 
169 static void emit_event_audio_connected(uint8_t status, uint16_t handle){
170     if (!hsp_hs_callback) return;
171     uint8_t event[6];
172     event[0] = HCI_EVENT_HSP_META;
173     event[1] = sizeof(event) - 2;
174     event[2] = HSP_SUBEVENT_AUDIO_CONNECTION_COMPLETE;
175     event[3] = status;
176     little_endian_store_16(event, 4, handle);
177     (*hsp_hs_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
178 }
179 
180 // remote audio volume control
181 // AG +VGM=13 [0..15] ; HS AT+VGM=6 | AG OK
182 
183 static int hsp_hs_send_str_over_rfcomm(uint16_t cid, const char * command){
184     if (!rfcomm_can_send_packet_now(hsp_hs_rfcomm_cid)) return 1;
185     int err = rfcomm_send(cid, (uint8_t*) command, strlen(command));
186     if (err){
187         log_info("rfcomm_send_internal -> error 0X%02x", err);
188     }
189     return err;
190 }
191 
192 void hsp_hs_enable_custom_indications(int enable){
193     hsp_hs_support_custom_indications = enable;
194 }
195 
196 int hsp_hs_send_result(const char * result){
197     if (!hsp_hs_support_custom_indications) return 1;
198     return hsp_hs_send_str_over_rfcomm(hsp_hs_rfcomm_cid, result);
199 }
200 
201 
202 void hsp_hs_create_sdp_record(uint8_t * service,  uint32_t service_record_handle, int rfcomm_channel_nr, const char * name, uint8_t have_remote_audio_control){
203     uint8_t* attribute;
204     de_create_sequence(service);
205 
206     // 0x0000 "Service Record Handle"
207     de_add_number(service, DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_RECORD_HANDLE);
208     de_add_number(service, DE_UINT, DE_SIZE_32, service_record_handle);
209 
210     // 0x0001 "Service Class ID List"
211     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST);
212     attribute = de_push_sequence(service);
213     {
214         //  see Bluetooth Erratum #3507
215         de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_HEADSET);       // 0x1108
216         de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_HEADSET_HS);    // 0x1131
217         de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_GENERIC_AUDIO); // 0x1203
218     }
219     de_pop_sequence(service, attribute);
220 
221     // 0x0004 "Protocol Descriptor List"
222     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST);
223     attribute = de_push_sequence(service);
224     {
225         uint8_t* l2cpProtocol = de_push_sequence(attribute);
226         {
227             de_add_number(l2cpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_L2CAP);
228         }
229         de_pop_sequence(attribute, l2cpProtocol);
230 
231         uint8_t* rfcomm = de_push_sequence(attribute);
232         {
233             de_add_number(rfcomm,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_RFCOMM);  // rfcomm_service
234             de_add_number(rfcomm,  DE_UINT, DE_SIZE_8,  rfcomm_channel_nr);  // rfcomm channel
235         }
236         de_pop_sequence(attribute, rfcomm);
237     }
238     de_pop_sequence(service, attribute);
239 
240     // 0x0005 "Public Browse Group"
241     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BROWSE_GROUP_LIST); // public browse group
242     attribute = de_push_sequence(service);
243     {
244         de_add_number(attribute,  DE_UUID, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PUBLIC_BROWSE_ROOT);
245     }
246     de_pop_sequence(service, attribute);
247 
248     // 0x0009 "Bluetooth Profile Descriptor List"
249     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BLUETOOTH_PROFILE_DESCRIPTOR_LIST);
250     attribute = de_push_sequence(service);
251     {
252         uint8_t *hsp_profile = de_push_sequence(attribute);
253         {
254             de_add_number(hsp_profile,  DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_HEADSET);
255             de_add_number(hsp_profile,  DE_UINT, DE_SIZE_16, 0x0102); // Verision 1.2
256         }
257         de_pop_sequence(attribute, hsp_profile);
258     }
259     de_pop_sequence(service, attribute);
260 
261     // 0x0100 "Service Name"
262     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0100);
263     if (name){
264         de_add_data(service,  DE_STRING, strlen(name), (uint8_t *) name);
265     } else {
266         de_add_data(service, DE_STRING, strlen(hsp_hs_default_service_name), (uint8_t *) hsp_hs_default_service_name);
267     }
268 
269     // Remote audio volume control
270     de_add_number(service, DE_UINT, DE_SIZE_16, 0x030C);
271     de_add_number(service, DE_BOOL, DE_SIZE_8, have_remote_audio_control);
272 }
273 
274 static void hsp_hs_reset_state(void){
275     hsp_state = HSP_IDLE;
276     hsp_hs_microphone_gain = -1;
277     hsp_hs_speaker_gain = -1;
278     hsp_hs_rfcomm_cid = 0;
279     hsp_hs_rfcomm_channel_nr = 0;
280     hsp_hs_rfcomm_handle = HCI_CON_HANDLE_INVALID;
281     hsp_hs_sco_handle    = HCI_CON_HANDLE_INVALID;
282 
283     hsp_hs_send_button_press_triggered = 0;
284     hsp_hs_wait_ok = 0;
285     hsp_hs_support_custom_indications = 0;
286 
287     hsp_hs_accept_sco_connection = 0;
288     hsp_hs_establish_audio_connection_triggered = 0;
289     hsp_hs_release_audio_connection_triggered = 0;
290 }
291 
292 void hsp_hs_init(uint8_t rfcomm_channel_nr){
293     // register for HCI events
294     hsp_hs_hci_event_callback_registration.callback = &packet_handler;
295     hci_add_event_handler(&hsp_hs_hci_event_callback_registration);
296 
297     rfcomm_register_service(packet_handler, rfcomm_channel_nr, 0xffff);  // reserved channel, mtu limited by l2cap
298 
299     hsp_hs_sco_packet_types = SCO_PACKET_TYPES_ALL;
300     hsp_hs_reset_state();
301 }
302 
303 void hsp_hs_deinit(void){
304     hsp_hs_reset_state();
305     hsp_hs_callback = NULL;
306     (void)memset(hsp_hs_remote, 0, 6);
307     (void)memset(&hsp_hs_hci_event_callback_registration, 0, sizeof(btstack_packet_callback_registration_t));
308     (void)memset(&hsp_hs_handle_sdp_client_query_request, 0, sizeof(btstack_context_callback_registration_t));
309 }
310 
311 static void hsp_hs_handle_start_sdp_client_query(void * context){
312     UNUSED(context);
313     if (hsp_state != HSP_W2_SEND_SDP_QUERY) return;
314 
315     hsp_state = HSP_W4_SDP_QUERY_COMPLETE;
316     log_info("Start SDP query %s, 0x%02x", bd_addr_to_str(hsp_hs_remote), BLUETOOTH_SERVICE_CLASS_HEADSET_AUDIO_GATEWAY_AG);
317     sdp_client_query_rfcomm_channel_and_name_for_service_class_uuid(&handle_query_rfcomm_event, hsp_hs_remote, BLUETOOTH_SERVICE_CLASS_HEADSET_AUDIO_GATEWAY_AG);
318 }
319 
320 void hsp_hs_connect(bd_addr_t bd_addr){
321     if (hsp_state != HSP_IDLE) return;
322 
323     (void)memcpy(hsp_hs_remote, bd_addr, 6);
324     hsp_state = HSP_W2_SEND_SDP_QUERY;
325     hsp_hs_handle_sdp_client_query_request.callback = &hsp_hs_handle_start_sdp_client_query;
326     // ignore ERROR_CODE_COMMAND_DISALLOWED because in that case, we already have requested an SDP callback
327     (void) sdp_client_register_query_callback(&hsp_hs_handle_sdp_client_query_request);
328 }
329 
330 void hsp_hs_disconnect(void){
331     hsp_hs_release_audio_connection();
332 
333     if (hsp_state < HSP_W4_RFCOMM_CONNECTED){
334         hsp_state = HSP_IDLE;
335         return;
336     }
337 
338     if (hsp_state == HSP_W4_RFCOMM_CONNECTED){
339         hsp_state = HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN;
340         return;
341     }
342 
343     hsp_hs_establish_audio_connection_triggered = 0;
344     rfcomm_disconnect(hsp_hs_rfcomm_cid);
345 }
346 
347 
348 void hsp_hs_establish_audio_connection(void){
349     switch (hsp_state){
350         case HSP_RFCOMM_CONNECTION_ESTABLISHED:
351             hsp_hs_establish_audio_connection_triggered = 1;
352             hsp_state = HSP_W4_SCO_CONNECTED;
353             break;
354         case HSP_W4_RFCOMM_CONNECTED:
355             hsp_state = HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN;
356             break;
357         default:
358             break;
359     }
360     hsp_run();
361 }
362 
363 void hsp_hs_release_audio_connection(void){
364     if (hsp_state >= HSP_W2_DISCONNECT_SCO) return;
365     if (hsp_state < HSP_AUDIO_CONNECTION_ESTABLISHED) return;
366     hsp_hs_release_audio_connection_triggered = 1;
367     hsp_run();
368 }
369 
370 void hsp_hs_set_microphone_gain(uint8_t gain){
371     if (gain >15) {
372         log_info("Gain must be in interval [0..15], it is given %d", gain);
373         return;
374     }
375     hsp_hs_microphone_gain = gain;
376     hsp_run();
377 }
378 
379 // AG +VGS=5  [0..15] ; HS AT+VGM=6 | AG OK
380 void hsp_hs_set_speaker_gain(uint8_t gain){
381     if (gain >15) {
382         log_info("Gain must be in interval [0..15], it is given %d", gain);
383         return;
384     }
385     hsp_hs_speaker_gain = gain;
386     hsp_run();
387 }
388 
389 static void hsp_run_handle_state(void){
390     switch (hsp_state){
391         case HSP_AUDIO_CONNECTION_ESTABLISHED:
392         case HSP_RFCOMM_CONNECTION_ESTABLISHED:
393 
394             if (hsp_hs_microphone_gain >= 0){
395                 if (!rfcomm_can_send_packet_now(hsp_hs_rfcomm_cid)) {
396                     rfcomm_request_can_send_now_event(hsp_hs_rfcomm_cid);
397                     return;
398                 }
399                 char buffer[20];
400                 snprintf(buffer, sizeof(buffer), "%s=%d\r",
401                          HSP_HS_MICROPHONE_GAIN, hsp_hs_microphone_gain);
402                 buffer[sizeof(buffer) - 1] = 0;
403                 hsp_hs_send_str_over_rfcomm(hsp_hs_rfcomm_cid, buffer);
404                 hsp_hs_microphone_gain = -1;
405                 break;
406             }
407 
408             if (hsp_hs_speaker_gain >= 0){
409                 if (!rfcomm_can_send_packet_now(hsp_hs_rfcomm_cid)) {
410                     rfcomm_request_can_send_now_event(hsp_hs_rfcomm_cid);
411                     return;
412                 }
413                 char buffer[20];
414                 snprintf(buffer, sizeof(buffer), "%s=%d\r",
415                          HSP_HS_SPEAKER_GAIN, hsp_hs_speaker_gain);
416                 buffer[sizeof(buffer) - 1] = 0;
417                 hsp_hs_send_str_over_rfcomm(hsp_hs_rfcomm_cid, buffer);
418                 hsp_hs_speaker_gain = -1;
419                 break;
420             }
421             break;
422         case HSP_W4_RFCOMM_DISCONNECTED:
423             rfcomm_disconnect(hsp_hs_rfcomm_cid);
424             break;
425         default:
426             break;
427     }
428 }
429 
430 static void hsp_run(void){
431 
432     if (hsp_hs_wait_ok) return;
433 
434     if (hsp_hs_accept_sco_connection && hci_can_send_command_packet_now()){
435 
436         bool eSCO = hsp_hs_accept_sco_connection == 2;
437         hsp_hs_accept_sco_connection = 0;
438 
439         log_info("HSP: sending hci_accept_connection_request.");
440 
441         // pick packet types based on SCO link type (SCO vs. eSCO)
442         uint16_t packet_types;
443         if (eSCO && hci_extended_sco_link_supported() && hci_remote_esco_supported(hsp_hs_rfcomm_handle)){
444             packet_types = 0x3F8;
445         } else {
446             packet_types = 0x0007;
447         }
448 
449         // packet type override
450         packet_types &= hsp_hs_sco_packet_types;
451 
452         // bits 6-9 are 'don't use'
453         packet_types ^= 0x03c0;
454 
455         uint16_t sco_voice_setting = hci_get_sco_voice_setting();
456 
457         log_info("HFP: sending hci_accept_connection_request, sco_voice_setting %02x", sco_voice_setting);
458         hci_send_cmd(&hci_accept_synchronous_connection, hsp_hs_remote, 8000, 8000, 0xffff, sco_voice_setting, 0xff, packet_types);
459         return;
460     }
461 
462     if (hsp_hs_release_audio_connection_triggered){
463         if (!rfcomm_can_send_packet_now(hsp_hs_rfcomm_cid)) {
464             rfcomm_request_can_send_now_event(hsp_hs_rfcomm_cid);
465             return;
466         }
467         hsp_hs_release_audio_connection_triggered = 0;
468         hsp_hs_wait_ok = 1;
469         hsp_hs_send_str_over_rfcomm(hsp_hs_rfcomm_cid, HSP_HS_AT_CKPD);
470         return;
471     }
472 
473     if (hsp_hs_establish_audio_connection_triggered){
474         if (!rfcomm_can_send_packet_now(hsp_hs_rfcomm_cid)) {
475             rfcomm_request_can_send_now_event(hsp_hs_rfcomm_cid);
476             return;
477         }
478         hsp_hs_establish_audio_connection_triggered = 0;
479         hsp_hs_wait_ok = 1;
480         hsp_hs_send_str_over_rfcomm(hsp_hs_rfcomm_cid, HSP_HS_AT_CKPD);
481         return;
482     }
483 
484     if (hsp_hs_send_button_press_triggered){
485         if (!rfcomm_can_send_packet_now(hsp_hs_rfcomm_cid)) {
486             rfcomm_request_can_send_now_event(hsp_hs_rfcomm_cid);
487             return;
488         }
489         hsp_hs_send_button_press_triggered = 0;
490         hsp_hs_wait_ok = 1;
491         hsp_hs_send_str_over_rfcomm(hsp_hs_rfcomm_cid, HSP_HS_AT_CKPD);
492         return;
493     }
494 
495     hsp_run_handle_state();
496 }
497 
498 
499 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
500     UNUSED(channel);    // ok: no channel for HCI_EVENT_PACKET and only single active RFCOMM channel
501     if (packet_type == RFCOMM_DATA_PACKET){
502         // skip over leading newline
503         while ((size > 0) && ((packet[0] == '\n') || (packet[0] == '\r'))){
504             size--;
505             packet++;
506         }
507         if (strncmp((char *)packet, HSP_AG_RING, strlen(HSP_AG_RING)) == 0){
508             emit_ring_event();
509         } else if (strncmp((char *)packet, HSP_AG_OK, strlen(HSP_AG_OK)) == 0){
510             hsp_hs_wait_ok = 0;
511         } else if (strncmp((char *)packet, HSP_MICROPHONE_GAIN, strlen(HSP_MICROPHONE_GAIN)) == 0){
512             uint8_t gain = (uint8_t)btstack_atoi((char*)&packet[strlen(HSP_MICROPHONE_GAIN)]);
513             emit_event(HSP_SUBEVENT_MICROPHONE_GAIN_CHANGED, gain);
514 
515         } else if (strncmp((char *)packet, HSP_SPEAKER_GAIN, strlen(HSP_SPEAKER_GAIN)) == 0){
516             uint8_t gain = (uint8_t)btstack_atoi((char*)&packet[strlen(HSP_SPEAKER_GAIN)]);
517             emit_event(HSP_SUBEVENT_SPEAKER_GAIN_CHANGED, gain);
518         } else {
519             if (!hsp_hs_callback) return;
520             // strip trailing newline
521             while ((size > 0) && ((packet[size-1] == '\n') || (packet[size-1] == '\r'))){
522                 size--;
523             }
524             // add trailing \0
525             packet[size] = 0;
526             // re-use incoming buffer to avoid reserving large buffers - ugly but efficient
527             uint8_t * event = packet - 4;
528             event[0] = HCI_EVENT_HSP_META;
529             event[1] = size + 2;
530             event[2] = HSP_SUBEVENT_AG_INDICATION;
531             event[3] = size;
532             (*hsp_hs_callback)(HCI_EVENT_PACKET, 0, event, size+4);
533         }
534         hsp_run();
535         return;
536     }
537 
538     if (packet_type != HCI_EVENT_PACKET) return;
539 
540     uint8_t event = hci_event_packet_get_type(packet);
541     bd_addr_t event_addr;
542     uint16_t handle;
543     switch (event) {
544         case HCI_EVENT_CONNECTION_REQUEST:
545             switch(hci_event_connection_request_get_link_type(packet)){
546                 case 0: //  SCO
547                 case 2: // eSCO
548                     hci_event_connection_request_get_bd_addr(packet, event_addr);
549                     if (bd_addr_cmp(event_addr, hsp_hs_remote) == 0){
550                         if (hci_event_connection_request_get_link_type(packet) == 2){
551                             hsp_hs_accept_sco_connection = 2;
552                         } else {
553                             hsp_hs_accept_sco_connection = 1;
554                         }
555                         log_info("hs_accept_sco_connection %u", hsp_hs_accept_sco_connection);
556                     }
557                     break;
558                 default:
559                     break;
560             }
561             break;
562 
563         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:{
564             if (hsp_state < HSP_RFCOMM_CONNECTION_ESTABLISHED) return;
565             hci_event_synchronous_connection_complete_get_bd_addr(packet, event_addr);
566             uint8_t status                   = hci_event_synchronous_connection_complete_get_status(packet);
567             hsp_hs_sco_handle                       = hci_event_synchronous_connection_complete_get_handle(packet);
568             uint8_t  link_type               = hci_event_synchronous_connection_complete_get_link_type(packet);
569             uint8_t  transmission_interval   = hci_event_synchronous_connection_complete_get_transmission_interval(packet);   // measured in slots
570             uint8_t  retransmission_interval = hci_event_synchronous_connection_complete_get_retransmission_interval(packet); // measured in slots
571             uint16_t rx_packet_length        = hci_event_synchronous_connection_complete_get_rx_packet_length(packet);        // measured in bytes
572             uint16_t tx_packet_length        = hci_event_synchronous_connection_complete_get_tx_packet_length(packet);        // measured in bytes
573 
574             if (status != 0){
575                 log_error("(e)SCO Connection failed, status %u", status);
576                 emit_event_audio_connected(status, hsp_hs_sco_handle);
577                 hsp_state = HSP_RFCOMM_CONNECTION_ESTABLISHED ;
578                 break;
579             }
580 
581             switch (link_type){
582                 case 0x00:
583                     log_info("SCO Connection established.");
584                     if (transmission_interval != 0) log_error("SCO Connection: transmission_interval not zero: %d.", transmission_interval);
585                     if (retransmission_interval != 0) log_error("SCO Connection: retransmission_interval not zero: %d.", retransmission_interval);
586                     if (rx_packet_length != 0) log_error("SCO Connection: rx_packet_length not zero: %d.", rx_packet_length);
587                     if (tx_packet_length != 0) log_error("SCO Connection: tx_packet_length not zero: %d.", tx_packet_length);
588                     break;
589                 case 0x02:
590                     log_info("eSCO Connection established.");
591                     break;
592                 default:
593                     log_error("(e)SCO reserved link_type 0x%2x", link_type);
594                     break;
595             }
596             log_info("sco_handle 0x%2x, address %s, transmission_interval %u slots, retransmission_interval %u slots, "
597                  " rx_packet_length %u bytes, tx_packet_length %u bytes, air_mode 0x%2x (0x02 == CVSD)", hsp_hs_sco_handle,
598                      bd_addr_to_str(event_addr), transmission_interval, retransmission_interval, rx_packet_length, tx_packet_length,
599                      hci_event_synchronous_connection_complete_get_air_mode(packet));
600 
601             hsp_state = HSP_AUDIO_CONNECTION_ESTABLISHED;
602             emit_event_audio_connected(status, hsp_hs_sco_handle);
603             break;
604         }
605 
606         case RFCOMM_EVENT_INCOMING_CONNECTION:
607             if (hsp_state != HSP_IDLE) return;
608             rfcomm_event_incoming_connection_get_bd_addr(packet, event_addr);
609             hsp_hs_rfcomm_cid = rfcomm_event_incoming_connection_get_rfcomm_cid(packet);
610             log_info("RFCOMM channel %u requested for %s", rfcomm_event_incoming_connection_get_server_channel(packet), bd_addr_to_str(event_addr));
611             hsp_state = HSP_W4_RFCOMM_CONNECTED;
612             rfcomm_accept_connection(hsp_hs_rfcomm_cid);
613             break;
614 
615         case RFCOMM_EVENT_CHANNEL_OPENED:
616             if (hsp_state != HSP_W4_RFCOMM_CONNECTED) return;
617             if (rfcomm_event_channel_opened_get_status(packet)) {
618                 log_info("RFCOMM channel open failed, status %u", rfcomm_event_channel_opened_get_status(packet));
619                 hsp_state = HSP_IDLE;
620                 hsp_hs_reset_state();
621             } else {
622                 rfcomm_event_channel_opened_get_bd_addr(packet, hsp_hs_remote);
623                 hsp_hs_rfcomm_handle = rfcomm_event_channel_opened_get_con_handle(packet);
624                 hsp_hs_rfcomm_cid    = rfcomm_event_channel_opened_get_rfcomm_cid(packet);
625                 hsp_hs_rfcomm_mtu           = rfcomm_event_channel_opened_get_max_frame_size(packet);
626                 log_info("RFCOMM channel open succeeded. New RFCOMM Channel ID %u, max frame size %u, handle %02x", hsp_hs_rfcomm_cid, hsp_hs_rfcomm_mtu, hsp_hs_rfcomm_handle);
627                 hsp_state = HSP_RFCOMM_CONNECTION_ESTABLISHED;
628             }
629             emit_event(HSP_SUBEVENT_RFCOMM_CONNECTION_COMPLETE, rfcomm_event_channel_opened_get_status(packet));
630             break;
631 
632         case RFCOMM_EVENT_CAN_SEND_NOW:
633             hsp_run();
634             break;
635 
636         case HCI_EVENT_DISCONNECTION_COMPLETE:
637             handle = hci_event_disconnection_complete_get_connection_handle(packet);
638             if (handle == hsp_hs_sco_handle){
639                 hsp_hs_sco_handle = 0;
640                 hsp_state = HSP_RFCOMM_CONNECTION_ESTABLISHED;
641                 emit_event(HSP_SUBEVENT_AUDIO_DISCONNECTION_COMPLETE,0);
642                 break;
643             }
644             break;
645 
646         case RFCOMM_EVENT_CHANNEL_CLOSED:
647             hsp_state = HSP_IDLE;
648             hsp_hs_reset_state();
649             emit_event(HSP_SUBEVENT_RFCOMM_DISCONNECTION_COMPLETE,0);
650             break;
651 
652         default:
653             break;
654     }
655 
656     hsp_run();
657 }
658 
659 static void handle_query_rfcomm_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
660     UNUSED(packet_type);    // ok: handling own sdp events
661     UNUSED(channel);        // ok: no channel
662     UNUSED(size);           // ok: handling own sdp events
663 
664     switch (hci_event_packet_get_type(packet)){
665         case SDP_EVENT_QUERY_RFCOMM_SERVICE:
666             hsp_hs_rfcomm_channel_nr = sdp_event_query_rfcomm_service_get_rfcomm_channel(packet);
667             log_info("** Service name: '%s', RFCOMM port %u", sdp_event_query_rfcomm_service_get_name(packet), hsp_hs_rfcomm_channel_nr);
668             break;
669         case SDP_EVENT_QUERY_COMPLETE:
670             if (hsp_hs_rfcomm_channel_nr > 0){
671                 hsp_state = HSP_W4_RFCOMM_CONNECTED;
672                 log_info("HSP: SDP_QUERY_COMPLETE. RFCOMM create channel, addr %s, rfcomm channel nr %d", bd_addr_to_str(hsp_hs_remote), hsp_hs_rfcomm_channel_nr);
673                 rfcomm_create_channel(packet_handler, hsp_hs_remote, hsp_hs_rfcomm_channel_nr, NULL);
674                 break;
675             }
676             hsp_hs_reset_state();
677             log_info("Service not found, status %u.", sdp_event_query_complete_get_status(packet));
678             if (sdp_event_query_complete_get_status(packet)){
679                 emit_event(HSP_SUBEVENT_AUDIO_CONNECTION_COMPLETE, sdp_event_query_complete_get_status(packet));
680             } else {
681                 emit_event(HSP_SUBEVENT_AUDIO_CONNECTION_COMPLETE, SDP_SERVICE_NOT_FOUND);
682             }
683             break;
684         default:
685             break;
686     }
687 }
688 
689 void hsp_hs_send_button_press(void){
690     if ((hsp_state < HSP_RFCOMM_CONNECTION_ESTABLISHED) || (hsp_state >= HSP_W4_RFCOMM_DISCONNECTED)) return;
691     hsp_hs_send_button_press_triggered = 1;
692     hsp_run();
693 }
694 
695 void hsp_hs_set_sco_packet_types(uint16_t packet_types){
696     hsp_hs_sco_packet_types = packet_types;
697 }
698