xref: /btstack/src/classic/hsp_hs.c (revision ab2c6ae4b737d5e801d3defe4117331eb244ebb7)
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_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 <stdlib.h>
51 #include <string.h>
52 
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 "hci.h"
62 #include "hci_cmd.h"
63 #include "hci_dump.h"
64 #include "hsp_hs.h"
65 #include "l2cap.h"
66 
67 #define HSP_AG_OK "OK"
68 #define HSP_AG_ERROR "ERROR"
69 #define HSP_AG_RING "RING"
70 #define HSP_MICROPHONE_GAIN "+VGM="
71 #define HSP_SPEAKER_GAIN "+VGS="
72 
73 #define HSP_HS_AT_CKPD "AT+CKPD=200\r\n"
74 #define HSP_HS_MICROPHONE_GAIN "AT+VGM"
75 #define HSP_HS_SPEAKER_GAIN "AT+VGS"
76 
77 static const char default_hsp_hs_service_name[] = "Headset";
78 
79 static bd_addr_t remote = {0x04, 0x0C, 0xCE, 0xE4, 0x85, 0xD3};
80 static uint8_t channel_nr = 0;
81 
82 static uint16_t mtu;
83 static uint16_t rfcomm_cid = 0;
84 static uint16_t sco_handle = 0;
85 static uint16_t rfcomm_handle = 0;
86 
87 // static uint8_t connection_state = 0;
88 
89 static int hs_microphone_gain = -1;
90 static int hs_speaker_gain = -1;
91 
92 static uint8_t hs_send_button_press = 0;
93 static uint8_t wait_ok = 0;
94 
95 static uint8_t hs_support_custom_indications = 0;
96 static btstack_packet_callback_registration_t hci_event_callback_registration;
97 static uint8_t hsp_disconnect_rfcomm = 0;
98 static uint8_t hsp_establish_audio_connection = 0;
99 static uint8_t hsp_release_audio_connection = 0;
100 
101 typedef enum {
102     HSP_IDLE,
103     HSP_SDP_QUERY_RFCOMM_CHANNEL,
104     HSP_W4_SDP_QUERY_COMPLETE,
105     HSP_W4_RFCOMM_CONNECTED,
106 
107     HSP_RFCOMM_CONNECTION_ESTABLISHED,
108 
109     HSP_W2_CONNECT_SCO,
110     HSP_W4_SCO_CONNECTED,
111 
112     HSP_AUDIO_CONNECTION_ESTABLISHED,
113 
114     HSP_W2_DISCONNECT_SCO,
115     HSP_W4_SCO_DISCONNECTED,
116 
117     HSP_W2_DISCONNECT_RFCOMM,
118     HSP_W4_RFCOMM_DISCONNECTED,
119     HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN
120 } hsp_state_t;
121 
122 static hsp_state_t hsp_state = HSP_IDLE;
123 
124 static void hsp_run(void);
125 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
126 static void handle_query_rfcomm_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
127 
128 static btstack_packet_handler_t hsp_hs_callback;
129 static void dummy_notify(uint8_t packet_type, uint16_t channel, uint8_t * event, uint16_t size){
130     UNUSED(packet_type);
131     UNUSED(channel);
132     UNUSED(event);
133     UNUSED(size);
134 }
135 
136 void hsp_hs_register_packet_handler(btstack_packet_handler_t callback){
137     if (callback == NULL){
138         callback = &dummy_notify;
139     }
140     hsp_hs_callback = callback;
141 }
142 
143 static void emit_event(uint8_t event_subtype, uint8_t value){
144     if (!hsp_hs_callback) return;
145     uint8_t event[4];
146     event[0] = HCI_EVENT_HSP_META;
147     event[1] = sizeof(event) - 2;
148     event[2] = event_subtype;
149     event[3] = value; // status 0 == OK
150     (*hsp_hs_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
151 }
152 
153 static void emit_ring_event(void){
154     if (!hsp_hs_callback) return;
155     uint8_t event[3];
156     event[0] = HCI_EVENT_HSP_META;
157     event[1] = sizeof(event) - 2;
158     event[2] = HSP_SUBEVENT_RING;
159     (*hsp_hs_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
160 }
161 
162 static void emit_event_audio_connected(uint8_t status, uint16_t handle){
163     if (!hsp_hs_callback) return;
164     uint8_t event[6];
165     event[0] = HCI_EVENT_HSP_META;
166     event[1] = sizeof(event) - 2;
167     event[2] = HSP_SUBEVENT_AUDIO_CONNECTION_COMPLETE;
168     event[3] = status;
169     little_endian_store_16(event, 4, handle);
170     (*hsp_hs_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
171 }
172 
173 // remote audio volume control
174 // AG +VGM=13 [0..15] ; HS AT+VGM=6 | AG OK
175 
176 static int hsp_hs_send_str_over_rfcomm(uint16_t cid, const char * command){
177     if (!rfcomm_can_send_packet_now(rfcomm_cid)) return 1;
178     int err = rfcomm_send(cid, (uint8_t*) command, strlen(command));
179     if (err){
180         log_info("rfcomm_send_internal -> error 0X%02x", err);
181     }
182     return err;
183 }
184 
185 void hsp_hs_enable_custom_indications(int enable){
186     hs_support_custom_indications = enable;
187 }
188 
189 int hsp_hs_send_result(const char * result){
190     if (!hs_support_custom_indications) return 1;
191     return hsp_hs_send_str_over_rfcomm(rfcomm_cid, result);
192 }
193 
194 
195 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){
196     uint8_t* attribute;
197     de_create_sequence(service);
198 
199     // 0x0000 "Service Record Handle"
200     de_add_number(service, DE_UINT, DE_SIZE_16, SDP_ServiceRecordHandle);
201     de_add_number(service, DE_UINT, DE_SIZE_32, service_record_handle);
202 
203     // 0x0001 "Service Class ID List"
204     de_add_number(service,  DE_UINT, DE_SIZE_16, SDP_ServiceClassIDList);
205     attribute = de_push_sequence(service);
206     {
207         //  see Bluetooth Erratum #3507
208         de_add_number(attribute, DE_UUID, DE_SIZE_16, SDP_HSP);          // 0x1108
209         de_add_number(attribute, DE_UUID, DE_SIZE_16, SDP_Headset_HS);   // 0x1131
210         de_add_number(attribute, DE_UUID, DE_SIZE_16, SDP_GenericAudio); // 0x1203
211     }
212     de_pop_sequence(service, attribute);
213 
214     // 0x0004 "Protocol Descriptor List"
215     de_add_number(service,  DE_UINT, DE_SIZE_16, SDP_ProtocolDescriptorList);
216     attribute = de_push_sequence(service);
217     {
218         uint8_t* l2cpProtocol = de_push_sequence(attribute);
219         {
220             de_add_number(l2cpProtocol,  DE_UUID, DE_SIZE_16, SDP_L2CAPProtocol);
221         }
222         de_pop_sequence(attribute, l2cpProtocol);
223 
224         uint8_t* rfcomm = de_push_sequence(attribute);
225         {
226             de_add_number(rfcomm,  DE_UUID, DE_SIZE_16, SDP_RFCOMMProtocol);  // rfcomm_service
227             de_add_number(rfcomm,  DE_UINT, DE_SIZE_8,  rfcomm_channel_nr);  // rfcomm channel
228         }
229         de_pop_sequence(attribute, rfcomm);
230     }
231     de_pop_sequence(service, attribute);
232 
233     // 0x0005 "Public Browse Group"
234     de_add_number(service,  DE_UINT, DE_SIZE_16, SDP_BrowseGroupList); // public browse group
235     attribute = de_push_sequence(service);
236     {
237         de_add_number(attribute,  DE_UUID, DE_SIZE_16, SDP_PublicBrowseGroup);
238     }
239     de_pop_sequence(service, attribute);
240 
241     // 0x0009 "Bluetooth Profile Descriptor List"
242     de_add_number(service,  DE_UINT, DE_SIZE_16, SDP_BluetoothProfileDescriptorList);
243     attribute = de_push_sequence(service);
244     {
245         uint8_t *hsp_profile = de_push_sequence(attribute);
246         {
247             de_add_number(hsp_profile,  DE_UUID, DE_SIZE_16, SDP_HSP);
248             de_add_number(hsp_profile,  DE_UINT, DE_SIZE_16, 0x0102); // Verision 1.2
249         }
250         de_pop_sequence(attribute, hsp_profile);
251     }
252     de_pop_sequence(service, attribute);
253 
254     // 0x0100 "Service Name"
255     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0100);
256     if (name){
257         de_add_data(service,  DE_STRING, strlen(name), (uint8_t *) name);
258     } else {
259         de_add_data(service,  DE_STRING, strlen(default_hsp_hs_service_name), (uint8_t *) default_hsp_hs_service_name);
260     }
261 
262     // Remote audio volume control
263     de_add_number(service, DE_UINT, DE_SIZE_16, 0x030C);
264     de_add_number(service, DE_BOOL, DE_SIZE_8, have_remote_audio_control);
265 }
266 
267 static void hsp_hs_reset_state(void){
268     hsp_state = HSP_IDLE;
269     hs_microphone_gain = -1;
270     hs_speaker_gain = -1;
271 
272     hs_send_button_press = 0;
273     wait_ok = 0;
274     hs_support_custom_indications = 0;
275 
276     hsp_disconnect_rfcomm = 0;
277     hsp_establish_audio_connection = 0;
278     hsp_release_audio_connection = 0;
279 }
280 
281 void hsp_hs_init(uint8_t rfcomm_channel_nr){
282     // register for HCI events
283     hci_event_callback_registration.callback = &packet_handler;
284     hci_add_event_handler(&hci_event_callback_registration);
285 
286     rfcomm_init();
287     rfcomm_register_service(packet_handler, rfcomm_channel_nr, 0xffff);  // reserved channel, mtu limited by l2cap
288 
289     hsp_hs_reset_state();
290 }
291 
292 
293 void hsp_hs_connect(bd_addr_t bd_addr){
294     if (hsp_state != HSP_IDLE) return;
295     hsp_state = HSP_SDP_QUERY_RFCOMM_CHANNEL;
296     memcpy(remote, bd_addr, 6);
297     hsp_run();
298 }
299 
300 void hsp_hs_disconnect(void){
301     hsp_hs_release_audio_connection();
302 
303     if (hsp_state < HSP_W4_RFCOMM_CONNECTED){
304         hsp_state = HSP_IDLE;
305         return;
306     }
307 
308     if (hsp_state == HSP_W4_RFCOMM_CONNECTED){
309         hsp_state = HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN;
310         return;
311     }
312 
313     if (hsp_state < HSP_W4_SCO_CONNECTED){
314         hsp_state = HSP_W2_DISCONNECT_RFCOMM;
315         return;
316     }
317 
318     hsp_disconnect_rfcomm = 1;
319     hsp_run();
320 }
321 
322 
323 void hsp_hs_establish_audio_connection(void){
324     switch (hsp_state){
325         case HSP_RFCOMM_CONNECTION_ESTABLISHED:
326             hsp_establish_audio_connection = 1;
327             hsp_state = HSP_W4_SCO_CONNECTED;
328             break;
329         case HSP_W4_RFCOMM_CONNECTED:
330             hsp_state = HSP_W4_CONNECTION_ESTABLISHED_TO_SHUTDOWN;
331             break;
332         default:
333             break;
334     }
335     hsp_run();
336 }
337 
338 void hsp_hs_release_audio_connection(void){
339     if (hsp_state >= HSP_W2_DISCONNECT_SCO) return;
340     if (hsp_state < HSP_AUDIO_CONNECTION_ESTABLISHED) return;
341     hsp_release_audio_connection = 1;
342     hsp_run();
343 }
344 
345 void hsp_hs_set_microphone_gain(uint8_t gain){
346     if (gain < 0 || gain >15) {
347         log_info("Gain must be in interval [0..15], it is given %d", gain);
348         return;
349     }
350     hs_microphone_gain = gain;
351     hsp_run();
352 }
353 
354 // AG +VGS=5  [0..15] ; HS AT+VGM=6 | AG OK
355 void hsp_hs_set_speaker_gain(uint8_t gain){
356     if (gain < 0 || gain >15) {
357         log_info("Gain must be in interval [0..15], it is given %d", gain);
358         return;
359     }
360     hs_speaker_gain = gain;
361     hsp_run();
362 }
363 
364 
365 static void hsp_run(void){
366 
367     if (wait_ok) return;
368 
369     if (hsp_release_audio_connection){
370         if (!rfcomm_can_send_packet_now(rfcomm_cid)) {
371             rfcomm_request_can_send_now_event(rfcomm_cid);
372             return;
373         }
374         hsp_release_audio_connection = 0;
375         wait_ok = 1;
376         hsp_hs_send_str_over_rfcomm(rfcomm_cid, HSP_HS_AT_CKPD);
377         return;
378     }
379 
380     if (hsp_disconnect_rfcomm){
381         hsp_disconnect_rfcomm = 0;
382         hsp_establish_audio_connection = 0;
383         rfcomm_disconnect(rfcomm_cid);
384         return;
385     }
386 
387     if (hsp_establish_audio_connection){
388         if (!rfcomm_can_send_packet_now(rfcomm_cid)) {
389             rfcomm_request_can_send_now_event(rfcomm_cid);
390             return;
391         }
392         hsp_establish_audio_connection = 0;
393         wait_ok = 1;
394         hsp_hs_send_str_over_rfcomm(rfcomm_cid, HSP_HS_AT_CKPD);
395         return;
396     }
397 
398     if (hs_send_button_press){
399         if (!rfcomm_can_send_packet_now(rfcomm_cid)) {
400             rfcomm_request_can_send_now_event(rfcomm_cid);
401             return;
402         }
403         hs_send_button_press = 0;
404         wait_ok = 1;
405         hsp_hs_send_str_over_rfcomm(rfcomm_cid, HSP_HS_AT_CKPD);
406         return;
407     }
408 
409     switch (hsp_state){
410         case HSP_SDP_QUERY_RFCOMM_CHANNEL:
411             hsp_state = HSP_W4_SDP_QUERY_COMPLETE;
412             sdp_client_query_rfcomm_channel_and_name_for_uuid(&handle_query_rfcomm_event, remote, SDP_Headset_AG);
413             break;
414 
415         case HSP_AUDIO_CONNECTION_ESTABLISHED:
416         case HSP_RFCOMM_CONNECTION_ESTABLISHED:
417 
418             if (hs_microphone_gain >= 0){
419                 if (!rfcomm_can_send_packet_now(rfcomm_cid)) {
420                     rfcomm_request_can_send_now_event(rfcomm_cid);
421                     return;
422                 }
423                 char buffer[20];
424                 sprintf(buffer, "%s=%d\r\n", HSP_HS_MICROPHONE_GAIN, hs_microphone_gain);
425                 hsp_hs_send_str_over_rfcomm(rfcomm_cid, buffer);
426                 hs_microphone_gain = -1;
427                 break;
428             }
429 
430             if (hs_speaker_gain >= 0){
431                 if (!rfcomm_can_send_packet_now(rfcomm_cid)) {
432                     rfcomm_request_can_send_now_event(rfcomm_cid);
433                     return;
434                 }
435                 char buffer[20];
436                 sprintf(buffer, "%s=%d\r\n", HSP_HS_SPEAKER_GAIN, hs_speaker_gain);
437                 hsp_hs_send_str_over_rfcomm(rfcomm_cid, buffer);
438                 hs_speaker_gain = -1;
439                 break;
440             }
441             break;
442         case HSP_W4_RFCOMM_DISCONNECTED:
443             rfcomm_disconnect(rfcomm_cid);
444             break;
445         default:
446             break;
447     }
448 }
449 
450 
451 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
452     UNUSED(channel);
453 
454     // printf("packet_handler type %u, packet[0] %x\n", packet_type, packet[0]);
455     if (packet_type == RFCOMM_DATA_PACKET){
456         // skip over leading newline
457         while (size > 0 && (packet[0] == '\n' || packet[0] == '\r')){
458             size--;
459             packet++;
460         }
461         if (strncmp((char *)packet, HSP_AG_RING, strlen(HSP_AG_RING)) == 0){
462             emit_ring_event();
463         } else if (strncmp((char *)packet, HSP_AG_OK, strlen(HSP_AG_OK)) == 0){
464            wait_ok = 0;
465         } else if (strncmp((char *)packet, HSP_MICROPHONE_GAIN, strlen(HSP_MICROPHONE_GAIN)) == 0){
466             uint8_t gain = (uint8_t)btstack_atoi((char*)&packet[strlen(HSP_MICROPHONE_GAIN)]);
467             emit_event(HSP_SUBEVENT_MICROPHONE_GAIN_CHANGED, gain);
468 
469         } else if (strncmp((char *)packet, HSP_SPEAKER_GAIN, strlen(HSP_SPEAKER_GAIN)) == 0){
470             uint8_t gain = (uint8_t)btstack_atoi((char*)&packet[strlen(HSP_SPEAKER_GAIN)]);
471             emit_event(HSP_SUBEVENT_SPEAKER_GAIN_CHANGED, gain);
472         } else {
473             if (!hsp_hs_callback) return;
474             // strip trailing newline
475             while (size > 0 && (packet[size-1] == '\n' || packet[size-1] == '\r')){
476                 size--;
477             }
478             // add trailing \0
479             packet[size] = 0;
480             // re-use incoming buffer to avoid reserving large buffers - ugly but efficient
481             uint8_t * event = packet - 4;
482             event[0] = HCI_EVENT_HSP_META;
483             event[1] = size + 2;
484             event[2] = HSP_SUBEVENT_AG_INDICATION;
485             event[3] = size;
486             (*hsp_hs_callback)(HCI_EVENT_PACKET, 0, event, size+4);
487         }
488         hsp_run();
489         return;
490     }
491 
492     if (packet_type != HCI_EVENT_PACKET) return;
493     uint8_t event = hci_event_packet_get_type(packet);
494     bd_addr_t event_addr;
495     uint16_t handle;
496 
497     switch (event) {
498         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:{
499             if (hsp_state < HSP_RFCOMM_CONNECTION_ESTABLISHED) return;
500             int index = 2;
501             uint8_t status = packet[index++];
502             sco_handle = little_endian_read_16(packet, index);
503             index+=2;
504             bd_addr_t address;
505             memcpy(address, &packet[index], 6);
506             index+=6;
507             uint8_t link_type = packet[index++];
508             uint8_t transmission_interval = packet[index++];  // measured in slots
509             uint8_t retransmission_interval = packet[index++];// measured in slots
510             uint16_t rx_packet_length = little_endian_read_16(packet, index); // measured in bytes
511             index+=2;
512             uint16_t tx_packet_length = little_endian_read_16(packet, index); // measured in bytes
513             index+=2;
514             uint8_t air_mode = packet[index];
515 
516             if (status != 0){
517                 log_error("(e)SCO Connection failed, status %u", status);
518                 emit_event_audio_connected(status, sco_handle);
519                 hsp_state = HSP_RFCOMM_CONNECTION_ESTABLISHED ;
520                 break;
521             }
522 
523             switch (link_type){
524                 case 0x00:
525                     log_info("SCO Connection established.");
526                     if (transmission_interval != 0) log_error("SCO Connection: transmission_interval not zero: %d.", transmission_interval);
527                     if (retransmission_interval != 0) log_error("SCO Connection: retransmission_interval not zero: %d.", retransmission_interval);
528                     if (rx_packet_length != 0) log_error("SCO Connection: rx_packet_length not zero: %d.", rx_packet_length);
529                     if (tx_packet_length != 0) log_error("SCO Connection: tx_packet_length not zero: %d.", tx_packet_length);
530                     break;
531                 case 0x02:
532                     log_info("eSCO Connection established.");
533                     break;
534                 default:
535                     log_error("(e)SCO reserved link_type 0x%2x", link_type);
536                     break;
537             }
538             log_info("sco_handle 0x%2x, address %s, transmission_interval %u slots, retransmission_interval %u slots, "
539                  " rx_packet_length %u bytes, tx_packet_length %u bytes, air_mode 0x%2x (0x02 == CVSD)", sco_handle,
540                  bd_addr_to_str(address), transmission_interval, retransmission_interval, rx_packet_length, tx_packet_length, air_mode);
541 
542             hsp_state = HSP_AUDIO_CONNECTION_ESTABLISHED;
543             emit_event_audio_connected(status, sco_handle);
544             break;
545         }
546 
547         case RFCOMM_EVENT_INCOMING_CONNECTION:
548             // data: event (8), len(8), address(48), channel (8), rfcomm_cid (16)
549             if (hsp_state != HSP_IDLE) return;
550 
551             reverse_bd_addr(&packet[2], event_addr);
552             rfcomm_cid = little_endian_read_16(packet, 9);
553             log_info("RFCOMM channel %u requested for %s", packet[8], bd_addr_to_str(event_addr));
554             hsp_state = HSP_W4_RFCOMM_CONNECTED;
555             rfcomm_accept_connection(rfcomm_cid);
556             break;
557 
558         case RFCOMM_EVENT_CHANNEL_OPENED:
559             // printf("RFCOMM_EVENT_CHANNEL_OPENED packet_handler type %u, packet[0] %x\n", packet_type, packet[0]);
560             // data: event(8), len(8), status (8), address (48), handle(16), server channel(8), rfcomm_cid(16), max frame size(16)
561             if (hsp_state != HSP_W4_RFCOMM_CONNECTED) return;
562             if (packet[2]) {
563                 log_info("RFCOMM channel open failed, status %u", packet[2]);
564                 hsp_state = HSP_IDLE;
565                 hsp_hs_reset_state();
566             } else {
567                 // data: event(8) , len(8), status (8), address (48), handle (16), server channel(8), rfcomm_cid(16), max frame size(16)
568                 rfcomm_handle = little_endian_read_16(packet, 9);
569                 rfcomm_cid = little_endian_read_16(packet, 12);
570                 mtu = little_endian_read_16(packet, 14);
571                 log_info("RFCOMM channel open succeeded. New RFCOMM Channel ID %u, max frame size %u, handle %02x", rfcomm_cid, mtu, rfcomm_handle);
572                 hsp_state = HSP_RFCOMM_CONNECTION_ESTABLISHED;
573             }
574             emit_event(HSP_SUBEVENT_RFCOMM_CONNECTION_COMPLETE, packet[2]);
575             break;
576 
577         case RFCOMM_EVENT_CAN_SEND_NOW:
578             hsp_run();
579             break;
580 
581         case HCI_EVENT_DISCONNECTION_COMPLETE:
582             handle = little_endian_read_16(packet,3);
583             if (handle == sco_handle){
584                 sco_handle = 0;
585                 hsp_state = HSP_RFCOMM_CONNECTION_ESTABLISHED;
586                 emit_event(HSP_SUBEVENT_AUDIO_DISCONNECTION_COMPLETE,0);
587                 break;
588             }
589             if (handle == rfcomm_handle) {
590                 rfcomm_handle = 0;
591                 hsp_state = HSP_IDLE;
592                 emit_event(HSP_SUBEVENT_RFCOMM_DISCONNECTION_COMPLETE,0);
593                 hsp_hs_reset_state();
594             }
595             break;
596 
597         case RFCOMM_EVENT_CHANNEL_CLOSED:
598             hsp_hs_reset_state();
599             hsp_hs_callback(HCI_EVENT_PACKET, 0, packet, size);
600             break;
601 
602         default:
603             break;
604     }
605 
606     hsp_run();
607 }
608 
609 static void handle_query_rfcomm_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
610     UNUSED(packet_type);
611     UNUSED(channel);
612     UNUSED(size);
613 
614     switch (hci_event_packet_get_type(packet)){
615         case SDP_EVENT_QUERY_RFCOMM_SERVICE:
616             channel_nr = sdp_event_query_rfcomm_service_get_rfcomm_channel(packet);
617             log_info("** Service name: '%s', RFCOMM port %u", sdp_event_query_rfcomm_service_get_name(packet), channel_nr);
618             break;
619         case SDP_EVENT_QUERY_COMPLETE:
620             if (channel_nr > 0){
621                 hsp_state = HSP_W4_RFCOMM_CONNECTED;
622                 log_info("HSP: SDP_QUERY_COMPLETE. RFCOMM create channel, addr %s, rfcomm channel nr %d", bd_addr_to_str(remote), channel_nr);
623                 rfcomm_create_channel(packet_handler, remote, channel_nr, NULL);
624                 break;
625             }
626             hsp_hs_reset_state();
627             log_info("Service not found, status %u.", sdp_event_query_complete_get_status(packet));
628             break;
629     }
630 }
631 
632 void hsp_hs_send_button_press(void){
633     if (hsp_state < HSP_RFCOMM_CONNECTION_ESTABLISHED || hsp_state >= HSP_W4_RFCOMM_DISCONNECTED) return;
634     hs_send_button_press = 1;
635     hsp_run();
636 }
637