xref: /btstack/src/classic/avrcp_controller.c (revision f3bb6622e45d1968c4fb9b4bf850bc7f3b9e5ad5)
1 /*
2  * Copyright (C) 2016 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__ "avrcp_controller.c"
39 
40 #include <stdint.h>
41 #include <string.h>
42 #include <inttypes.h>
43 
44 #include "classic/avrcp.h"
45 #include "classic/avrcp_controller.h"
46 
47 #include "bluetooth_sdp.h"
48 #include "btstack_debug.h"
49 #include "btstack_event.h"
50 #include "btstack_util.h"
51 #include "l2cap.h"
52 
53 // made public in avrcp_controller.h
54 avrcp_context_t avrcp_controller_context;
55 
56 static uint8_t avrcp_controller_calc_next_transaction_label(uint8_t current_transaction_label){
57     current_transaction_label++;
58     if (current_transaction_label == 16){
59         current_transaction_label = 1;
60     }
61     return current_transaction_label;
62 }
63 
64 static uint8_t avrcp_controller_get_next_transaction_label(avrcp_connection_t * connection){
65     connection->transaction_id_counter = avrcp_controller_calc_next_transaction_label(connection->transaction_id_counter);
66     return connection->transaction_id_counter;
67 }
68 
69 static bool avrcp_controller_is_transaction_id_valid(avrcp_connection_t * connection, uint8_t transaction_id){
70     uint8_t delta = ((int8_t) transaction_id - connection->controller_last_confirmed_transaction_id) & 0x0f;
71     return delta < 15;
72 }
73 
74 static void avrcp_controller_custom_command_data_init(avrcp_connection_t * connection,
75                                                       avrcp_command_opcode_t opcode, avrcp_command_type_t command_type,
76                                                       avrcp_subunit_type_t subunit_type, avrcp_subunit_id_t subunit_id,
77                                                       avrcp_pdu_id_t pdu_id, uint32_t company_id){
78 
79     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
80     connection->command_opcode = opcode;
81     connection->command_type = command_type;
82     connection->subunit_type = subunit_type;
83     connection->subunit_id = subunit_id;
84     connection->company_id = company_id;
85     connection->pdu_id = pdu_id;
86     connection->data = NULL;
87     connection->data_offset = 0;
88     connection->data_len = 0;
89 }
90 
91 static void avrcp_controller_vendor_dependent_command_data_init(avrcp_connection_t * connection, avrcp_command_type_t command_type, avrcp_pdu_id_t pdu_id){
92     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
93     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
94     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
95     connection->subunit_id = AVRCP_SUBUNIT_ID;
96     connection->company_id = BT_SIG_COMPANY_ID;
97 
98     connection->command_type = command_type;
99     connection->pdu_id = pdu_id;
100     connection->data = connection->message_body;
101     connection->data_offset = 0;
102     connection->data_len = 0;
103 }
104 
105 static void avrcp_controller_pass_through_command_data_init(avrcp_connection_t * connection, avrcp_operation_id_t opid){
106     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
107     connection->command_opcode =  AVRCP_CMD_OPCODE_PASS_THROUGH;
108     connection->command_type = AVRCP_CTYPE_CONTROL;
109     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
110     connection->subunit_id =   AVRCP_SUBUNIT_ID;
111 
112     connection->company_id = 0;
113     connection->pdu_id = AVRCP_PDU_ID_UNDEFINED;
114     connection->operation_id = opid;
115 
116     connection->data = connection->message_body;
117     connection->data_offset = 0;
118     connection->data_len = 0;
119 }
120 static int avrcp_controller_supports_browsing(uint16_t controller_supported_features){
121     return controller_supported_features & AVRCP_FEATURE_MASK_BROWSING;
122 }
123 
124 static void avrcp_controller_emit_notification_complete(avrcp_connection_t * connection, uint8_t status, uint8_t event_id, bool enabled){
125     uint8_t event[8];
126     uint8_t pos = 0;
127     event[pos++] = HCI_EVENT_AVRCP_META;
128     event[pos++] = sizeof(event) - 2;
129     event[pos++] = AVRCP_SUBEVENT_NOTIFICATION_STATE;
130     little_endian_store_16(event, pos, connection->avrcp_cid);
131     pos += 2;
132     event[pos++] = status;
133     event[pos++] = enabled ? 1 : 0;
134     event[pos++] = event_id;
135     UNUSED(pos);
136     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
137 }
138 
139 static void avrcp_controller_emit_supported_events(avrcp_connection_t * connection){
140     uint8_t ctype = (uint8_t) AVRCP_CTYPE_RESPONSE_CHANGED_STABLE;
141     uint8_t event_id;
142 
143     for (event_id = (uint8_t) AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; event_id < (uint8_t) AVRCP_NOTIFICATION_EVENT_LAST_INDEX; event_id++){
144         if ((connection->notifications_supported_by_target & (1 << event_id)) == 0){
145             continue;
146         }
147         uint8_t event[8];
148         uint8_t pos = 0;
149         event[pos++] = HCI_EVENT_AVRCP_META;
150         event[pos++] = sizeof(event) - 2;
151         event[pos++] = AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID;
152         little_endian_store_16(event, pos, connection->avrcp_cid);
153         pos += 2;
154         event[pos++] = ctype;
155         event[pos++] = 0;
156         event[pos++] = event_id;
157         UNUSED(pos);
158         (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
159     }
160 
161     uint8_t event[7];
162     uint8_t pos = 0;
163     event[pos++] = HCI_EVENT_AVRCP_META;
164     event[pos++] = sizeof(event) - 2;
165     event[pos++] = AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID_DONE;
166     little_endian_store_16(event, pos, connection->avrcp_cid);
167     pos += 2;
168     event[pos++] = ctype;
169     event[pos++] = 0;
170     UNUSED(pos);
171     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
172 }
173 
174 static void avrcp_controller_emit_notification_for_event_id(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id,
175                                                             avrcp_command_type_t ctype, const uint8_t *payload,
176                                                             uint16_t size) {
177     switch (event_id){
178         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_POS_CHANGED:{
179             if (size < 4) break;
180             uint32_t song_position = big_endian_read_32(payload, 0);
181             uint16_t offset = 0;
182             uint8_t event[10];
183             event[offset++] = HCI_EVENT_AVRCP_META;
184             event[offset++] = sizeof(event) - 2;
185             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_POS_CHANGED;
186             little_endian_store_16(event, offset, avrcp_cid);
187             offset += 2;
188             event[offset++] = ctype;
189             little_endian_store_32(event, offset, song_position);
190             offset += 4;
191             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
192             break;
193         }
194         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED:{
195             if (size < 1) break;
196             uint16_t offset = 0;
197             uint8_t event[7];
198             event[offset++] = HCI_EVENT_AVRCP_META;
199             event[offset++] = sizeof(event) - 2;
200             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_STATUS_CHANGED;
201             little_endian_store_16(event, offset, avrcp_cid);
202             offset += 2;
203             event[offset++] = ctype;
204             event[offset++] = payload[0];
205             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
206             break;
207         }
208         case AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED:{
209             uint16_t offset = 0;
210             uint8_t event[6];
211             event[offset++] = HCI_EVENT_AVRCP_META;
212             event[offset++] = sizeof(event) - 2;
213             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_TRACK_CHANGED;
214             little_endian_store_16(event, offset, avrcp_cid);
215             offset += 2;
216             event[offset++] = ctype;
217             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
218             break;
219         }
220         case AVRCP_NOTIFICATION_EVENT_NOW_PLAYING_CONTENT_CHANGED:{
221             uint16_t offset = 0;
222             uint8_t event[6];
223             event[offset++] = HCI_EVENT_AVRCP_META;
224             event[offset++] = sizeof(event) - 2;
225             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_NOW_PLAYING_CONTENT_CHANGED;
226             little_endian_store_16(event, offset, avrcp_cid);
227             offset += 2;
228             event[offset++] = ctype;
229             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
230             break;
231         }
232         case AVRCP_NOTIFICATION_EVENT_AVAILABLE_PLAYERS_CHANGED:{
233             uint16_t offset = 0;
234             uint8_t event[6];
235             event[offset++] = HCI_EVENT_AVRCP_META;
236             event[offset++] = sizeof(event) - 2;
237             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_AVAILABLE_PLAYERS_CHANGED;
238             little_endian_store_16(event, offset, avrcp_cid);
239             offset += 2;
240             event[offset++] = ctype;
241             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
242             break;
243         }
244         case AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED:{
245             if (size < 1) break;
246             uint16_t offset = 0;
247             uint8_t event[7];
248             event[offset++] = HCI_EVENT_AVRCP_META;
249             event[offset++] = sizeof(event) - 2;
250             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED;
251             little_endian_store_16(event, offset, avrcp_cid);
252             offset += 2;
253             event[offset++] = ctype;
254             event[offset++] = payload[0] & 0x7F;
255             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
256             break;
257         }
258         case AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED:{
259             if (size < 2) break;
260             uint8_t event[8];
261             uint16_t offset = 0;
262             uint16_t uuid = big_endian_read_16(payload, 0);
263             event[offset++] = HCI_EVENT_AVRCP_META;
264             event[offset++] = sizeof(event) - 2;
265             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_UIDS_CHANGED;
266             little_endian_store_16(event, offset, avrcp_cid);
267             offset += 2;
268             event[offset++] = ctype;
269             little_endian_store_16(event, offset, uuid);
270             offset += 2;
271             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
272             break;
273         }
274 
275         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_END:{
276             uint16_t offset = 0;
277             uint8_t event[6];
278             event[offset++] = HCI_EVENT_AVRCP_META;
279             event[offset++] = sizeof(event) - 2;
280             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_END;
281             little_endian_store_16(event, offset, avrcp_cid);
282             offset += 2;
283             event[offset++] = ctype;
284             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
285             break;
286         }
287         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_START:{
288             uint16_t offset = 0;
289             uint8_t event[6];
290             event[offset++] = HCI_EVENT_AVRCP_META;
291             event[offset++] = sizeof(event) - 2;
292             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_START;
293             little_endian_store_16(event, offset, avrcp_cid);
294             offset += 2;
295             event[offset++] = ctype;
296             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
297             break;
298         }
299         case AVRCP_NOTIFICATION_EVENT_BATT_STATUS_CHANGED:{
300             if (size < 1) break;
301             uint16_t offset = 0;
302             uint8_t event[7];
303             event[offset++] = HCI_EVENT_AVRCP_META;
304             event[offset++] = sizeof(event) - 2;
305             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_BATT_STATUS_CHANGED;
306             little_endian_store_16(event, offset, avrcp_cid);
307             offset += 2;
308             event[offset++] = ctype;
309             event[offset++] = payload[0];
310             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
311             break;
312         }
313 
314         case AVRCP_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED:{
315             if (size < 1) break;
316             uint16_t offset = 0;
317             uint8_t event[7];
318             event[offset++] = HCI_EVENT_AVRCP_META;
319             event[offset++] = sizeof(event) - 2;
320             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED;
321             little_endian_store_16(event, offset, avrcp_cid);
322             offset += 2;
323             event[offset++] = ctype;
324             event[offset++] = payload[0];
325             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
326             break;
327         }
328 
329         case AVRCP_NOTIFICATION_EVENT_PLAYER_APPLICATION_SETTING_CHANGED:
330         default:
331             log_info("avrcp: not implemented");
332             break;
333     }
334 }
335 
336 static void avrcp_controller_emit_repeat_and_shuffle_mode(btstack_packet_handler_t callback, uint16_t avrcp_cid, uint8_t ctype, avrcp_repeat_mode_t repeat_mode, avrcp_shuffle_mode_t shuffle_mode){
337     btstack_assert(callback != NULL);
338 
339     uint8_t event[8];
340     int pos = 0;
341     event[pos++] = HCI_EVENT_AVRCP_META;
342     event[pos++] = sizeof(event) - 2;
343     event[pos++] = AVRCP_SUBEVENT_SHUFFLE_AND_REPEAT_MODE;
344     little_endian_store_16(event, pos, avrcp_cid);
345     pos += 2;
346     event[pos++] = ctype;
347     event[pos++] = repeat_mode;
348     event[pos++] = shuffle_mode;
349     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
350 }
351 
352 static void avrcp_controller_emit_now_playing_info_event_done(btstack_packet_handler_t callback, uint16_t avrcp_cid, uint8_t ctype, uint8_t status){
353     uint8_t event[7];
354     int pos = 0;
355     event[pos++] = HCI_EVENT_AVRCP_META;
356     event[pos++] = sizeof(event) - 2;
357     event[pos++] = AVRCP_SUBEVENT_NOW_PLAYING_INFO_DONE;
358     little_endian_store_16(event, pos, avrcp_cid);
359     pos += 2;
360     event[pos++] = ctype;
361     event[pos++] = status;
362     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
363 }
364 
365 static void avrcp_controller_emit_now_playing_info_event(btstack_packet_handler_t callback, uint16_t avrcp_cid, uint8_t ctype, avrcp_media_attribute_id_t attr_id, uint8_t * value, uint16_t value_len){
366     uint8_t event[HCI_EVENT_BUFFER_SIZE];
367     int pos = 0;
368     event[pos++] = HCI_EVENT_AVRCP_META;
369     // reserve one byte for subevent type and data len
370     int data_len_pos = pos;
371     pos++;
372     int subevent_type_pos = pos;
373     pos++;
374     little_endian_store_16(event, pos, avrcp_cid);
375     pos += 2;
376     event[pos++] = ctype;
377 
378     switch (attr_id){
379         case AVRCP_MEDIA_ATTR_TITLE:
380             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TITLE_INFO;
381             event[pos++] = value_len;
382             (void)memcpy(event + pos, value, value_len);
383             break;
384         case AVRCP_MEDIA_ATTR_ARTIST:
385             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ARTIST_INFO;
386             event[pos++] = value_len;
387             (void)memcpy(event + pos, value, value_len);
388             break;
389         case AVRCP_MEDIA_ATTR_ALBUM:
390             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ALBUM_INFO;
391             event[pos++] = value_len;
392             (void)memcpy(event + pos, value, value_len);
393             break;
394         case AVRCP_MEDIA_ATTR_GENRE:
395             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_GENRE_INFO;
396             event[pos++] = value_len;
397             (void)memcpy(event + pos, value, value_len);
398             break;
399         case AVRCP_MEDIA_ATTR_SONG_LENGTH_MS:
400             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_SONG_LENGTH_MS_INFO;
401             if (value){
402                 little_endian_store_32(event, pos, btstack_atoi((char *)value));
403             } else {
404                 little_endian_store_32(event, pos, 0);
405             }
406             pos += 4;
407             break;
408         case AVRCP_MEDIA_ATTR_TRACK:
409             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TRACK_INFO;
410             if (value){
411                 event[pos++] = btstack_atoi((char *)value);
412             } else {
413                 event[pos++] = 0;
414             }
415             break;
416         case AVRCP_MEDIA_ATTR_TOTAL_NUM_ITEMS:
417             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TOTAL_TRACKS_INFO;
418             if (value){
419                 event[pos++] = btstack_atoi((char *)value);
420             } else {
421                 event[pos++] = 0;
422             }
423             break;
424         default:
425             break;
426     }
427     event[data_len_pos] = pos - 2;
428     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
429 }
430 
431 static void avrcp_controller_emit_operation_status(btstack_packet_handler_t callback, uint8_t subevent, uint16_t avrcp_cid, uint8_t ctype, uint8_t operation_id){
432     btstack_assert(callback != NULL);
433 
434     uint8_t event[7];
435     int pos = 0;
436     event[pos++] = HCI_EVENT_AVRCP_META;
437     event[pos++] = sizeof(event) - 2;
438     event[pos++] = subevent;
439     little_endian_store_16(event, pos, avrcp_cid);
440     pos += 2;
441     event[pos++] = ctype;
442     event[pos++] = operation_id;
443     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
444 }
445 
446 static void avrcp_parser_reset(avrcp_connection_t * connection){
447     connection->list_offset = 0;
448     connection->parser_attribute_header_pos = 0;
449     connection->num_received_fragments = 0;
450     connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
451 }
452 
453 static void avrcp_parser_process_byte(uint8_t byte, avrcp_connection_t * connection, avrcp_command_type_t ctype){
454     uint16_t attribute_total_value_len;
455     uint32_t attribute_id;
456     switch(connection->parser_state){
457         case AVRCP_PARSER_GET_ATTRIBUTE_HEADER:
458             connection->parser_attribute_header[connection->parser_attribute_header_pos++] = byte;
459             connection->list_offset++;
460 
461             if (connection->parser_attribute_header_pos < AVRCP_ATTRIBUTE_HEADER_LEN) return;
462 
463             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
464             connection->attribute_value_len = btstack_min(attribute_total_value_len, AVRCP_MAX_ATTRIBUTE_SIZE);
465             if (connection->attribute_value_len > 0){
466                 // get ready for attribute value
467                 connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_VALUE;
468                 return;
469             }
470 
471             // emit empty attribute
472             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
473             avrcp_controller_emit_now_playing_info_event(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, (avrcp_media_attribute_id_t) attribute_id, connection->attribute_value, connection->attribute_value_len);
474 
475             // done, see below
476             break;
477 
478         case AVRCP_PARSER_GET_ATTRIBUTE_VALUE:
479             connection->attribute_value[connection->attribute_value_offset++] = byte;
480             connection->list_offset++;
481 
482             if (connection->attribute_value_offset < connection->attribute_value_len) return;
483 
484             // emit (potentially partial) attribute
485             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
486             avrcp_controller_emit_now_playing_info_event(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, (avrcp_media_attribute_id_t) attribute_id, connection->attribute_value, connection->attribute_value_len);
487 
488             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
489             if (connection->attribute_value_offset < attribute_total_value_len){
490                 // ignore rest of attribute
491                 connection->parser_state = AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE;
492                 return;
493             }
494 
495             // done, see below
496             break;
497 
498         case AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE:
499             connection->attribute_value_offset++;
500             connection->list_offset++;
501 
502             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
503             if (connection->attribute_value_offset < attribute_total_value_len) return;
504 
505             // done, see below
506             break;
507 
508         default:
509             return;
510     }
511 
512     // attribute fully read, check if more to come
513     if (connection->list_offset < connection->list_size){
514         // more to come, reset parser
515         connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
516         connection->parser_attribute_header_pos = 0;
517         connection->attribute_value_offset = 0;
518     } else {
519         // fully done
520         avrcp_parser_reset(connection);
521         avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 0);
522     }
523 }
524 
525 static void avrcp_controller_parse_and_emit_element_attrs(uint8_t * packet, uint16_t num_bytes_to_read, avrcp_connection_t * connection, avrcp_command_type_t ctype){
526     int i;
527     for (i=0;i<num_bytes_to_read;i++){
528         avrcp_parser_process_byte(packet[i], connection, ctype);
529     }
530 }
531 
532 static void avrcp_send_cmd_with_avctp_fragmentation(avrcp_connection_t * connection){
533     l2cap_reserve_packet_buffer();
534     uint8_t * command = l2cap_get_outgoing_buffer();
535 
536     uint16_t max_payload_size;
537     avctp_packet_type_t avctp_packet_type = avctp_get_packet_type(connection, &max_payload_size);
538 
539     // non-fragmented: transport header (1) + PID (2)
540     // fragmented:     transport header (1) + num packets (1) + PID (2)
541 
542     // AVCTP header
543     // transport header : transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
544     uint16_t pos = 0;
545     command[pos++] = (connection->transaction_id << 4) | (avctp_packet_type << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
546 
547     switch (avctp_packet_type){
548         case AVCTP_SINGLE_PACKET:
549         case AVCTP_START_PACKET:
550             if (avctp_packet_type == AVCTP_START_PACKET){
551                 // num packets
552                 command[pos++] = ((connection->data_len + max_payload_size - 1) / max_payload_size);
553             }
554 
555             // Profile IDentifier (PID)
556             command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
557             command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
558 
559             // command_type
560             command[pos++] = connection->command_type;
561             // subunit_type | subunit ID
562             command[pos++] = (connection->subunit_type << 3) | connection->subunit_id;
563             // opcode
564             command[pos++] = (uint8_t)connection->command_opcode;
565 
566             switch (connection->command_opcode){
567                 case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
568                     big_endian_store_24(command, pos, connection->company_id);
569                     pos += 3;
570                     command[pos++] = connection->pdu_id;
571                     command[pos++] = 0;                       // reserved(upper 6) | packet_type -> 0
572                     big_endian_store_16(command, pos, connection->data_len);     // parameter length
573                     pos += 2;
574                     break;
575                 case AVRCP_CMD_OPCODE_PASS_THROUGH:
576                     command[pos++] = connection->operation_id;
577                     command[pos++] = (uint8_t)connection->data_len;     // parameter length
578                     pos += 2;
579                     break;
580                 case AVRCP_CMD_OPCODE_UNIT_INFO:
581                     break;
582                 case AVRCP_CMD_OPCODE_SUBUNIT_INFO:
583                     break;
584                 default:
585                     btstack_assert(false);
586                     return;
587             }
588             break;
589         case AVCTP_CONTINUE_PACKET:
590         case AVCTP_END_PACKET:
591             break;
592         default:
593             btstack_assert(false);
594             return;
595     }
596     // compare number of bytes to store with the remaining buffer size
597     uint16_t bytes_to_copy = btstack_min(connection->data_len - connection->data_offset, max_payload_size - pos);
598 
599     (void)memcpy(command + pos, &connection->data[connection->data_offset], bytes_to_copy);
600     pos += bytes_to_copy;
601     connection->data_offset += bytes_to_copy;
602 
603     l2cap_send_prepared(connection->l2cap_signaling_cid, pos);
604 }
605 
606 static int avrcp_send_register_notification(avrcp_connection_t * connection, uint8_t event_id){
607     uint8_t command[18];
608     uint16_t pos = 0;
609     // transport header : transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
610     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
611     command[pos++] = (connection->transaction_id << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
612 
613     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
614     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
615     command[pos++] = AVRCP_CTYPE_NOTIFY;
616     command[pos++] = (AVRCP_SUBUNIT_TYPE_PANEL << 3) | AVRCP_SUBUNIT_ID;
617     command[pos++] = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
618 
619     big_endian_store_24(command, pos, BT_SIG_COMPANY_ID);
620     pos += 3;
621     command[pos++] = AVRCP_PDU_ID_REGISTER_NOTIFICATION;
622     command[pos++] = 0;                       // reserved(upper 6) | packet_type -> 0
623     big_endian_store_16(command, pos, 5);     // parameter length
624     pos += 2;
625     command[pos++] = event_id;
626     big_endian_store_32(command, pos, 1);     // send notification on playback position every second, for other notifications it is ignored
627     pos += 4;
628     return l2cap_send(connection->l2cap_signaling_cid, command, pos);
629 }
630 
631 static void avrcp_press_and_hold_timeout_handler(btstack_timer_source_t * timer){
632     UNUSED(timer);
633     avrcp_connection_t * connection = (avrcp_connection_t*) btstack_run_loop_get_timer_context(timer);
634     btstack_run_loop_set_timer(&connection->controller_press_and_hold_cmd_timer, 2000); // 2 seconds timeout
635     btstack_run_loop_add_timer(&connection->controller_press_and_hold_cmd_timer);
636     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
637     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
638 }
639 
640 static void avrcp_press_and_hold_timer_start(avrcp_connection_t * connection){
641     btstack_run_loop_remove_timer(&connection->controller_press_and_hold_cmd_timer);
642     btstack_run_loop_set_timer_handler(&connection->controller_press_and_hold_cmd_timer, avrcp_press_and_hold_timeout_handler);
643     btstack_run_loop_set_timer_context(&connection->controller_press_and_hold_cmd_timer, connection);
644     btstack_run_loop_set_timer(&connection->controller_press_and_hold_cmd_timer, 2000); // 2 seconds timeout
645     btstack_run_loop_add_timer(&connection->controller_press_and_hold_cmd_timer);
646 }
647 
648 static void avrcp_press_and_hold_timer_stop(avrcp_connection_t * connection){
649     connection->controller_press_and_hold_cmd_active = false;
650     btstack_run_loop_remove_timer(&connection->controller_press_and_hold_cmd_timer);
651 }
652 
653 
654 static uint8_t avrcp_controller_request_pass_through_release_control_cmd(avrcp_connection_t * connection){
655     connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
656     if (connection->controller_press_and_hold_cmd_active){
657         avrcp_press_and_hold_timer_stop(connection);
658     }
659     connection->operation_id = (avrcp_operation_id_t)(0x80 | connection->operation_id);
660     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
661     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
662     return ERROR_CODE_SUCCESS;
663 }
664 
665 static uint8_t avrcp_controller_request_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed, bool continuous_cmd){
666     log_info("Send command %d", opid);
667     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
668     if (!connection){
669         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
670     }
671 
672     if (connection->state != AVCTP_CONNECTION_OPENED){
673         log_error("Connection in wrong state %d, expected %d. avrcp cid 0x%02x", connection->state, AVCTP_CONNECTION_OPENED, avrcp_cid);
674         return ERROR_CODE_COMMAND_DISALLOWED;
675     }
676     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
677     avrcp_controller_pass_through_command_data_init(connection, opid);
678 
679     if (playback_speed > 0){
680         connection->data[0] = playback_speed;
681         connection->data_len = 1;
682     }
683 
684     connection->controller_press_and_hold_cmd_active = continuous_cmd;
685     if (connection->controller_press_and_hold_cmd_active){
686         avrcp_press_and_hold_timer_start(connection);
687     }
688 
689     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
690     return ERROR_CODE_SUCCESS;
691 }
692 
693 static uint8_t request_single_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
694     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, false);
695 }
696 
697 static uint8_t request_continuous_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
698     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, true);
699 }
700 
701 static void avrcp_controller_get_capabilities_for_connection(avrcp_connection_t * connection, uint8_t capability_id){
702     connection->state = AVCTP_W2_SEND_COMMAND;
703     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_CAPABILITIES);
704 
705     // Parameter Length
706     connection->data_len = 1;
707     connection->data[0] = capability_id;  // capability ID
708 
709     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
710 }
711 
712 static uint8_t avrcp_controller_register_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
713     if (connection->controller_notifications_supported_by_target_queried && (connection->notifications_supported_by_target & (1 << event_id)) == 0){
714         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
715     }
716     if ((connection->controller_notifications_to_deregister & (1 << event_id)) != 0){
717         return ERROR_CODE_COMMAND_DISALLOWED;
718     }
719     if ( (connection->notifications_enabled & (1 << event_id)) != 0){
720         return ERROR_CODE_SUCCESS;
721     }
722     connection->controller_notifications_to_register |= (1 << event_id);
723 
724     if (!connection->controller_notifications_supported_by_target_queried){
725         connection->controller_notifications_supported_by_target_suppress_emit_result = true;
726         avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_EVENT);
727         return ERROR_CODE_SUCCESS;
728     }
729     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
730     return ERROR_CODE_SUCCESS;
731 }
732 
733 static uint8_t avrcp_controller_request_continuation(avrcp_connection_t * connection, avrcp_pdu_id_t pdu_id){
734     connection->state = AVCTP_W2_SEND_COMMAND;
735     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, pdu_id);
736 
737     // Parameter Length
738     connection->data_len = 3;
739     big_endian_store_16(connection->data, 0, 1);
740     connection->data[2] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
741 
742     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
743     return ERROR_CODE_SUCCESS;
744 }
745 
746 static uint8_t avrcp_controller_request_abort_continuation(avrcp_connection_t * connection){
747     return avrcp_controller_request_continuation(connection, AVRCP_PDU_ID_REQUEST_ABORT_CONTINUING_RESPONSE);
748 }
749 
750 static uint8_t avrcp_controller_request_continue_response(avrcp_connection_t * connection){
751     return avrcp_controller_request_continuation(connection, AVRCP_PDU_ID_REQUEST_CONTINUING_RESPONSE);
752 }
753 
754 static void avrcp_controller_handle_notification(avrcp_connection_t *connection, avrcp_command_type_t ctype, uint8_t *payload, uint16_t size) {
755     if (size < 1) return;
756     uint16_t pos = 0;
757     avrcp_notification_event_id_t event_id = (avrcp_notification_event_id_t) payload[pos++];
758     if ( (event_id < AVRCP_NOTIFICATION_EVENT_FIRST_INDEX) || (event_id > AVRCP_NOTIFICATION_EVENT_LAST_INDEX)){
759         return;
760     }
761 
762     uint16_t event_mask = (1 << event_id);
763     uint16_t reset_event_mask = ~event_mask;
764 
765     switch (ctype){
766         case AVRCP_CTYPE_RESPONSE_REJECTED:
767             connection->controller_notifications_to_deregister &= reset_event_mask;
768             connection->controller_notifications_to_register   &= reset_event_mask;
769             connection->controller_initial_status_reported     &= reset_event_mask;
770             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE, event_id, false);
771             return;
772 
773         case AVRCP_CTYPE_RESPONSE_INTERIM:
774             // register as enabled
775             connection->notifications_enabled |= event_mask;
776 
777             // check if initial value is already sent
778             if ((connection->controller_initial_status_reported & event_mask) != 0 ){
779                 return;
780             }
781             // emit event only once, initially
782             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_SUCCESS, event_id, true);
783             connection->controller_initial_status_reported |= event_mask;
784             // emit initial value after this switch
785             break;
786 
787         case AVRCP_CTYPE_RESPONSE_CHANGED_STABLE:
788             // received change, event is considered de-registered
789             // we are re-enabling it automatically, if it is not
790             // explicitly disabled
791             connection->notifications_enabled &= reset_event_mask;
792             if ((connection->controller_notifications_to_deregister & event_mask) == 0){
793                 avrcp_controller_register_notification(connection, event_id);
794             } else {
795                 connection->controller_notifications_to_deregister &= reset_event_mask;
796                 connection->controller_notifications_to_register   &= reset_event_mask;
797                 connection->controller_initial_status_reported     &= reset_event_mask;
798                 avrcp_controller_emit_notification_complete(connection, ERROR_CODE_SUCCESS, event_id, false);
799             }
800             break;
801 
802         default:
803             return;
804     }
805 
806     avrcp_controller_emit_notification_for_event_id(connection->avrcp_cid, event_id, ctype, payload + pos, size - pos);
807 }
808 
809 #ifdef ENABLE_AVCTP_FRAGMENTATION
810 static void avctp_reassemble_message(avrcp_connection_t * connection, avctp_packet_type_t packet_type, uint8_t *packet, uint16_t size){
811     // after header (transaction label and packet type)
812     uint16_t pos;
813     uint16_t bytes_to_store;
814 
815     switch (packet_type){
816         case AVCTP_START_PACKET:
817             if (size < 2) return;
818 
819             // store header
820             pos = 0;
821             connection->avctp_reassembly_buffer[pos] = packet[pos];
822             pos++;
823             connection->avctp_reassembly_size = pos;
824 
825             // NOTE: num packets not needed for reassembly, ignoring it does not pose security risk -> no need to store it
826             pos++;
827 
828             // PID in reassembled packet is at offset 1, it will be read later after the avctp_reassemble_message with AVCTP_END_PACKET is called
829 
830             bytes_to_store = btstack_min(size - pos, sizeof(connection->avctp_reassembly_buffer) - connection->avctp_reassembly_size);
831             memcpy(&connection->avctp_reassembly_buffer[connection->avctp_reassembly_size], &packet[pos], bytes_to_store);
832             connection->avctp_reassembly_size += bytes_to_store;
833             break;
834 
835         case AVCTP_CONTINUE_PACKET:
836         case AVCTP_END_PACKET:
837             if (size < 1) return;
838 
839             // store remaining data, ignore header
840             pos = 1;
841             bytes_to_store = btstack_min(size - pos, sizeof(connection->avctp_reassembly_buffer) - connection->avctp_reassembly_size);
842             memcpy(&connection->avctp_reassembly_buffer[connection->avctp_reassembly_size], &packet[pos], bytes_to_store);
843             connection->avctp_reassembly_size += bytes_to_store;
844             break;
845 
846         default:
847             return;
848     }
849 }
850 #endif
851 
852 static void avrcp_handle_l2cap_data_packet_for_signaling_connection(avrcp_connection_t * connection, uint8_t *packet, uint16_t size){
853     if (size < 6u) return;
854     uint8_t  pdu_id;
855     avrcp_packet_type_t  vendor_dependent_packet_type;
856 
857     uint16_t pos = 0;
858     connection->controller_last_confirmed_transaction_id = packet[pos] >> 4;
859     avrcp_frame_type_t  frame_type =  (avrcp_frame_type_t)((packet[pos] >> 1) & 0x01);
860     avctp_packet_type_t packet_type = (avctp_packet_type_t)((packet[pos] >> 2) & 0x03);
861     pos++;
862 
863     if (frame_type != AVRCP_RESPONSE_FRAME) return;
864 
865     switch (packet_type){
866         case AVCTP_SINGLE_PACKET:
867             break;
868 
869 #ifdef ENABLE_AVCTP_FRAGMENTATION
870         case AVCTP_START_PACKET:
871         case AVCTP_CONTINUE_PACKET:
872             avctp_reassemble_message(connection, packet_type, packet, size);
873             return;
874 
875         case AVCTP_END_PACKET:
876             avctp_reassemble_message(connection, packet_type, packet, size);
877 
878             packet = connection->avctp_reassembly_buffer;
879             size   = connection->avctp_reassembly_size;
880             break;
881 #endif
882 
883         default:
884             return;
885     }
886 
887     pos += 2; // PID
888 
889     avrcp_command_type_t ctype = (avrcp_command_type_t) packet[pos++];
890 
891 #ifdef ENABLE_LOG_INFO
892     uint8_t byte_value = packet[pos];
893     avrcp_subunit_type_t subunit_type = (avrcp_subunit_type_t) (byte_value >> 3);
894     avrcp_subunit_type_t subunit_id   = (avrcp_subunit_type_t) (byte_value & 0x07);
895 #endif
896     pos++;
897 
898     uint8_t opcode = packet[pos++];
899     uint16_t param_length;
900 
901     switch (opcode){
902         case AVRCP_CMD_OPCODE_SUBUNIT_INFO:{
903             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
904             connection->state = AVCTP_CONNECTION_OPENED;
905 
906 #ifdef ENABLE_LOG_INFO
907             // page, extension code (1)
908             pos++;
909             uint8_t unit_type = packet[pos] >> 3;
910             uint8_t max_subunit_ID = packet[pos] & 0x07;
911             log_info("SUBUNIT INFO response: ctype 0x%02x (0C), subunit_type 0x%02x (1F), subunit_id 0x%02x (07), opcode 0x%02x (30), target_unit_type 0x%02x, max_subunit_ID %d", ctype, subunit_type, subunit_id, opcode, unit_type, max_subunit_ID);
912 #endif
913             break;
914         }
915         case AVRCP_CMD_OPCODE_UNIT_INFO:{
916             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
917             connection->state = AVCTP_CONNECTION_OPENED;
918 
919 #ifdef ENABLE_LOG_INFO
920             // byte value 7 (1)
921             pos++;
922             uint8_t unit_type = packet[pos] >> 3;
923             uint8_t unit = packet[pos] & 0x07;
924             pos++;
925             uint32_t company_id = big_endian_read_24(packet, pos);
926             log_info("UNIT INFO response: ctype 0x%02x (0C), subunit_type 0x%02x (1F), subunit_id 0x%02x (07), opcode 0x%02x (30), target_unit_type 0x%02x, unit %d, company_id 0x%06" PRIx32,
927                 ctype, subunit_type, subunit_id, opcode, unit_type, unit, company_id);
928 #endif
929             break;
930         }
931         case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
932 
933             if ((size - pos) < 7) return;
934 
935             // Company ID (3)
936             pos += 3;
937             pdu_id = packet[pos++];
938             vendor_dependent_packet_type = (avrcp_packet_type_t)(packet[pos++] & 0x03);
939             param_length = big_endian_read_16(packet, pos);
940             pos += 2;
941 
942             if ((size - pos) < param_length) return;
943 
944             // handle asynchronous notifications, without changing state
945             if (pdu_id == AVRCP_PDU_ID_REGISTER_NOTIFICATION){
946                 avrcp_controller_handle_notification(connection, ctype, packet + pos, size - pos);
947                 break;
948             }
949 
950             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE){
951                 log_info("AVRCP_CMD_OPCODE_VENDOR_DEPENDENT state %d", connection->state);
952                 return;
953             }
954             connection->state = AVCTP_CONNECTION_OPENED;
955 
956             log_info("VENDOR DEPENDENT response: pdu id 0x%02x, param_length %d, status %s", pdu_id, param_length, avrcp_ctype2str(ctype));
957             switch (pdu_id){
958                 case AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE:{
959                     uint8_t num_attributes = packet[pos++];
960                     int i;
961                     avrcp_repeat_mode_t  repeat_mode =  AVRCP_REPEAT_MODE_INVALID;
962                     avrcp_shuffle_mode_t shuffle_mode = AVRCP_SHUFFLE_MODE_INVALID;
963                     for (i = 0; i < num_attributes; i++){
964                         uint8_t attribute_id    = packet[pos++];
965                         uint8_t value = packet[pos++];
966                         switch (attribute_id){
967                             case 0x02:
968                                 repeat_mode = (avrcp_repeat_mode_t) value;
969                                 break;
970                             case 0x03:
971                                 shuffle_mode = (avrcp_shuffle_mode_t) value;
972                                 break;
973                             default:
974                                 break;
975                         }
976                     }
977                     avrcp_controller_emit_repeat_and_shuffle_mode(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, repeat_mode, shuffle_mode);
978                     break;
979                 }
980 
981                 case AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE:{
982                     uint16_t offset = 0;
983                     uint8_t event[6];
984                     event[offset++] = HCI_EVENT_AVRCP_META;
985                     event[offset++] = sizeof(event) - 2;
986                     event[offset++] = AVRCP_SUBEVENT_PLAYER_APPLICATION_VALUE_RESPONSE;
987                     little_endian_store_16(event, offset, connection->avrcp_cid);
988                     offset += 2;
989                     event[offset++] = ctype;
990                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
991                     break;
992                 }
993 
994                 case AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME:{
995                     uint16_t offset = 0;
996                     uint8_t event[7];
997                     event[offset++] = HCI_EVENT_AVRCP_META;
998                     event[offset++] = sizeof(event) - 2;
999                     event[offset++] = AVRCP_SUBEVENT_SET_ABSOLUTE_VOLUME_RESPONSE;
1000                     little_endian_store_16(event, offset, connection->avrcp_cid);
1001                     offset += 2;
1002                     event[offset++] = ctype;
1003                     event[offset++] = packet[pos++];
1004                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1005                     break;
1006                 }
1007 
1008                 case AVRCP_PDU_ID_GET_CAPABILITIES:{
1009                     avrcp_capability_id_t capability_id = (avrcp_capability_id_t) packet[pos++];
1010                     uint8_t capability_count = 0;
1011                     if (param_length > 1){
1012                         capability_count = packet[pos++];
1013                     }
1014                     uint16_t i;
1015                     uint16_t offset = 0;
1016                     uint8_t event[10];
1017 
1018                     switch (capability_id){
1019 
1020                         case AVRCP_CAPABILITY_ID_COMPANY:
1021                             for (i = 0; (i < capability_count) && ((size - pos) >= 3); i++){
1022                                 uint32_t company_id = big_endian_read_24(packet, pos);
1023                                 pos += 3;
1024                                 log_info("  0x%06" PRIx32 ", ", company_id);
1025 
1026                                 offset = 0;
1027                                 event[offset++] = HCI_EVENT_AVRCP_META;
1028                                 event[offset++] = sizeof(event) - 2;
1029                                 event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID;
1030                                 little_endian_store_16(event, offset, connection->avrcp_cid);
1031                                 offset += 2;
1032                                 event[offset++] = ctype;
1033                                 event[offset++] = 0;
1034                                 little_endian_store_24(event, offset, company_id);
1035                                 offset += 3;
1036                                 (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
1037                             }
1038 
1039                             offset = 0;
1040                             event[offset++] = HCI_EVENT_AVRCP_META;
1041                             event[offset++] = sizeof(event) - 2;
1042                             event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID_DONE;
1043                             little_endian_store_16(event, offset, connection->avrcp_cid);
1044                             offset += 2;
1045                             event[offset++] = ctype;
1046                             event[offset++] = 0;
1047                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
1048                             break;
1049 
1050                         case AVRCP_CAPABILITY_ID_EVENT:
1051                             for (i = 0; (i < capability_count) && ((size - pos) >= 1); i++){
1052                                 uint8_t event_id = packet[pos++];
1053                                 connection->notifications_supported_by_target |= (1 << event_id);
1054                             }
1055 
1056                             // if the get supported events query is triggered by avrcp_controller_enable_notification call,
1057                             // avrcp_controller_emit_supported_events should be suppressed
1058                             if (connection->controller_notifications_supported_by_target_suppress_emit_result){
1059                                 connection->controller_notifications_supported_by_target_suppress_emit_result = false;
1060                                 // also, notification might not be supported
1061                                 // if so, emit AVRCP_SUBEVENT_ENABLE_NOTIFICATION_COMPLETE event to app,
1062                                 // and update controller_notifications_to_register bitmap
1063                                 for (i = (uint8_t)AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; i < (uint8_t) AVRCP_NOTIFICATION_EVENT_LAST_INDEX; i++){
1064                                     if ((connection->controller_notifications_to_register & (1 << i)) != 0){
1065                                         if ((connection->notifications_supported_by_target & (1 << i)) == 0){
1066                                             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE, i, false);
1067                                             connection->controller_notifications_to_register &= ~(1 << i);
1068                                         }
1069                                     }
1070                                 }
1071                                 break;
1072                             }
1073                             // supported events are emitted only if the get supported events query
1074                             // is triggered by avrcp_controller_get_supported_events call
1075                             avrcp_controller_emit_supported_events(connection);
1076                             break;
1077 
1078                         default:
1079                             // ignore
1080                             break;
1081                     }
1082                     break;
1083                 }
1084 
1085                 case AVRCP_PDU_ID_GET_PLAY_STATUS:{
1086                     uint32_t song_length = big_endian_read_32(packet, pos);
1087                     pos += 4;
1088                     uint32_t song_position = big_endian_read_32(packet, pos);
1089                     pos += 4;
1090                     uint8_t play_status = packet[pos];
1091 
1092                     uint8_t event[15];
1093                     int offset = 0;
1094                     event[offset++] = HCI_EVENT_AVRCP_META;
1095                     event[offset++] = sizeof(event) - 2;
1096                     event[offset++] = AVRCP_SUBEVENT_PLAY_STATUS;
1097                     little_endian_store_16(event, offset, connection->avrcp_cid);
1098                     offset += 2;
1099                     event[offset++] = ctype;
1100                     little_endian_store_32(event, offset, song_length);
1101                     offset += 4;
1102                     little_endian_store_32(event, offset, song_position);
1103                     offset += 4;
1104                     event[offset++] = play_status;
1105                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1106                     break;
1107                 }
1108 
1109                 case AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES:{
1110                     // TODO Review
1111                     switch (vendor_dependent_packet_type){
1112                         case AVRCP_START_PACKET:
1113                         case AVRCP_SINGLE_PACKET:
1114                             avrcp_parser_reset(connection);
1115                             connection->list_size = param_length;
1116                             // num_attributes
1117                             pos++;
1118 
1119                             avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
1120                             if (vendor_dependent_packet_type == AVRCP_START_PACKET){
1121                                 avrcp_controller_request_continue_response(connection);
1122                             }
1123                             break;
1124                         case AVRCP_CONTINUE_PACKET:
1125                         case AVRCP_END_PACKET:
1126                             connection->num_received_fragments++;
1127 
1128                             if (connection->num_received_fragments < connection->max_num_fragments){
1129                                 avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
1130 
1131                                 if (vendor_dependent_packet_type == AVRCP_CONTINUE_PACKET){
1132                                     avrcp_controller_request_continue_response(connection);
1133                                 }
1134                             } else {
1135                                 avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 1);
1136                                 avrcp_parser_reset(connection);
1137                                 avrcp_controller_request_abort_continuation(connection);
1138                             }
1139                             break;
1140                         default:
1141                             // TODO check
1142                             btstack_assert(false);
1143                             break;
1144                     }
1145                 }
1146                 default:
1147                     break;
1148             }
1149             break;
1150         case AVRCP_CMD_OPCODE_PASS_THROUGH:{
1151             if ((size - pos) < 1) return;
1152             uint8_t operation_id = packet[pos++];
1153             switch (connection->state){
1154                 case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
1155                     // trigger release for simple command:
1156                     if (!connection->controller_press_and_hold_cmd_active){
1157                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
1158                         break;
1159                     }
1160                     // for press and hold, send release if it just has been requested, otherwise, wait for next repeat
1161                     if (connection->controller_press_and_hold_cmd_release){
1162                         connection->controller_press_and_hold_cmd_release = false;
1163                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
1164                     } else {
1165                         connection->state = AVCTP_W4_STOP;
1166                     }
1167                     break;
1168                 case AVCTP_W2_RECEIVE_RESPONSE:
1169                     connection->state = AVCTP_CONNECTION_OPENED;
1170                     break;
1171                 default:
1172                     break;
1173             }
1174             if (connection->state == AVCTP_W4_STOP){
1175                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_START, connection->avrcp_cid, ctype, operation_id);
1176             }
1177             if (connection->state == AVCTP_CONNECTION_OPENED) {
1178                 // RELEASE response
1179                 operation_id = operation_id & 0x7F;
1180                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_COMPLETE, connection->avrcp_cid, ctype, operation_id);
1181             }
1182             if (connection->state == AVCTP_W2_SEND_RELEASE_COMMAND){
1183                 // PRESS response
1184                 avrcp_controller_request_pass_through_release_control_cmd(connection);
1185             }
1186             break;
1187         }
1188         default:
1189             break;
1190     }
1191 
1192     // trigger pending notification reqistrations
1193     if ((connection->state == AVCTP_CONNECTION_OPENED) && connection->controller_notifications_to_register){
1194         avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1195     }
1196 }
1197 
1198 static void avrcp_controller_handle_can_send_now(avrcp_connection_t * connection){
1199     switch (connection->state){
1200         case AVCTP_W2_SEND_PRESS_COMMAND:
1201         case AVCTP_W2_SEND_COMMAND:
1202         case AVCTP_W2_SEND_RELEASE_COMMAND:
1203         case AVCTP_W2_SEND_AVCTP_FRAGMENTED_MESSAGE:
1204             avrcp_send_cmd_with_avctp_fragmentation(connection);
1205 
1206             if (connection->data_offset < connection->data_len){
1207                 avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1208                 return;
1209             }
1210             if (connection->state == AVCTP_W2_SEND_PRESS_COMMAND){
1211                 connection->state = AVCTP_W2_RECEIVE_PRESS_RESPONSE;
1212             } else {
1213                 connection->state = AVCTP_W2_RECEIVE_RESPONSE;
1214             }
1215             break;
1216         default:
1217             break;
1218     }
1219 
1220     // send register notification if queued
1221     if (connection->controller_notifications_to_register != 0){
1222         uint8_t event_id;
1223         for (event_id = (uint8_t)AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; event_id < (uint8_t)AVRCP_NOTIFICATION_EVENT_LAST_INDEX; event_id++){
1224             if (connection->controller_notifications_to_register & (1 << event_id)){
1225                 connection->controller_notifications_to_register &= ~ (1 << event_id);
1226                 avrcp_send_register_notification(connection, event_id);
1227                 return;
1228             }
1229         }
1230     }
1231 }
1232 
1233 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
1234     avrcp_connection_t * connection;
1235 
1236     switch (packet_type) {
1237         case L2CAP_DATA_PACKET:
1238             connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
1239             avrcp_handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
1240             break;
1241 
1242         case HCI_EVENT_PACKET:
1243             switch (hci_event_packet_get_type(packet)){
1244                 case L2CAP_EVENT_CAN_SEND_NOW:
1245                     connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
1246                     avrcp_controller_handle_can_send_now(connection);
1247                     break;
1248             default:
1249                 break;
1250         }
1251         default:
1252             break;
1253     }
1254 }
1255 
1256 void avrcp_controller_create_sdp_record(uint8_t * service, uint32_t service_record_handle, uint16_t supported_features, const char * service_name, const char * service_provider_name){
1257     avrcp_create_sdp_record(1, service, service_record_handle, avrcp_controller_supports_browsing(supported_features), supported_features, service_name, service_provider_name);
1258 }
1259 
1260 void avrcp_controller_init(void){
1261     avrcp_controller_context.role = AVRCP_CONTROLLER;
1262     avrcp_controller_context.packet_handler = avrcp_controller_packet_handler;
1263     avrcp_register_controller_packet_handler(&avrcp_controller_packet_handler);
1264 }
1265 
1266 void avrcp_controller_deinit(void){
1267     memset(&avrcp_controller_context, 0, sizeof(avrcp_context_t));
1268 }
1269 
1270 void avrcp_controller_register_packet_handler(btstack_packet_handler_t callback){
1271     btstack_assert(callback != NULL);
1272     avrcp_controller_context.avrcp_callback = callback;
1273 }
1274 
1275 
1276 uint8_t avrcp_controller_play(uint16_t avrcp_cid){
1277     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1278 }
1279 
1280 uint8_t avrcp_controller_stop(uint16_t avrcp_cid){
1281     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1282 }
1283 
1284 uint8_t avrcp_controller_pause(uint16_t avrcp_cid){
1285     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1286 }
1287 
1288 uint8_t avrcp_controller_forward(uint16_t avrcp_cid){
1289     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1290 }
1291 
1292 uint8_t avrcp_controller_backward(uint16_t avrcp_cid){
1293     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1294 }
1295 
1296 uint8_t avrcp_controller_volume_up(uint16_t avrcp_cid){
1297     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1298 }
1299 
1300 uint8_t avrcp_controller_volume_down(uint16_t avrcp_cid){
1301     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1302 }
1303 
1304 uint8_t avrcp_controller_mute(uint16_t avrcp_cid){
1305     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1306 }
1307 
1308 uint8_t avrcp_controller_skip(uint16_t avrcp_cid){
1309     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_SKIP, 0);
1310 }
1311 
1312 uint8_t avrcp_controller_fast_forward(uint16_t avrcp_cid){
1313     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1314 }
1315 
1316 uint8_t avrcp_controller_rewind(uint16_t avrcp_cid){
1317     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1318 }
1319 
1320 /* start continuous cmds */
1321 
1322 uint8_t avrcp_controller_start_press_and_hold_cmd(uint16_t avrcp_cid, avrcp_operation_id_t operation_id){
1323     return request_continuous_pass_through_press_control_cmd(avrcp_cid, operation_id, 0);
1324 }
1325 
1326 uint8_t avrcp_controller_press_and_hold_play(uint16_t avrcp_cid){
1327     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1328 }
1329 uint8_t avrcp_controller_press_and_hold_stop(uint16_t avrcp_cid){
1330     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1331 }
1332 uint8_t avrcp_controller_press_and_hold_pause(uint16_t avrcp_cid){
1333     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1334 }
1335 uint8_t avrcp_controller_press_and_hold_forward(uint16_t avrcp_cid){
1336     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1337 }
1338 uint8_t avrcp_controller_press_and_hold_backward(uint16_t avrcp_cid){
1339     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1340 }
1341 uint8_t avrcp_controller_press_and_hold_fast_forward(uint16_t avrcp_cid){
1342     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1343 }
1344 uint8_t avrcp_controller_press_and_hold_rewind(uint16_t avrcp_cid){
1345     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1346 }
1347 uint8_t avrcp_controller_press_and_hold_volume_up(uint16_t avrcp_cid){
1348     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1349 }
1350 uint8_t avrcp_controller_press_and_hold_volume_down(uint16_t avrcp_cid){
1351     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1352 }
1353 uint8_t avrcp_controller_press_and_hold_mute(uint16_t avrcp_cid){
1354     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1355 }
1356 
1357 /* stop continuous cmds */
1358 uint8_t avrcp_controller_release_press_and_hold_cmd(uint16_t avrcp_cid){
1359     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1360     if (!connection){
1361         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1362     }
1363 
1364     switch (connection->state){
1365         // respond when we receive response for (repeated) press command
1366         case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
1367             connection->controller_press_and_hold_cmd_release = true;
1368             break;
1369 
1370         // release already sent or on the way, nothing to do
1371         case AVCTP_W2_RECEIVE_RESPONSE:
1372         case AVCTP_W2_SEND_RELEASE_COMMAND:
1373             break;
1374 
1375         // about to send next repeated press command or wait for it -> release right away
1376         case AVCTP_W2_SEND_PRESS_COMMAND:
1377         case AVCTP_W4_STOP:
1378             return avrcp_controller_request_pass_through_release_control_cmd(connection);
1379 
1380         // otherwise reject request
1381         default:
1382             return ERROR_CODE_COMMAND_DISALLOWED;
1383     }
1384     return ERROR_CODE_SUCCESS;
1385 }
1386 
1387 uint8_t avrcp_controller_enable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1388     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1389     if (!connection){
1390         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1391     }
1392     return avrcp_controller_register_notification(connection, event_id);
1393 }
1394 
1395 uint8_t avrcp_controller_disable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1396     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1397     if (!connection){
1398         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1399     }
1400     if (!connection->controller_notifications_supported_by_target_queried){
1401         return ERROR_CODE_COMMAND_DISALLOWED;
1402     }
1403 
1404     if ((connection->notifications_supported_by_target & (1 << event_id)) == 0){
1405         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1406     }
1407 
1408     if ((connection->notifications_enabled & (1 << event_id)) == 0){
1409         return ERROR_CODE_SUCCESS;
1410     }
1411 
1412     connection->controller_notifications_to_deregister |= (1 << event_id);
1413     return ERROR_CODE_SUCCESS;
1414 }
1415 
1416 uint8_t avrcp_controller_unit_info(uint16_t avrcp_cid){
1417     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1418     if (!connection){
1419         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1420     }
1421     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1422 
1423     connection->state = AVCTP_W2_SEND_COMMAND;
1424     avrcp_controller_custom_command_data_init(connection, AVRCP_CMD_OPCODE_UNIT_INFO, AVRCP_CTYPE_STATUS,
1425                                               AVRCP_SUBUNIT_TYPE_UNIT, AVRCP_SUBUNIT_ID_IGNORE, AVRCP_PDU_ID_UNDEFINED,
1426                                               0);
1427 
1428     connection->data = connection->message_body;
1429     memset(connection->data, 0xFF, 5);
1430     connection->data_len = 5;
1431     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1432     return ERROR_CODE_SUCCESS;
1433 }
1434 
1435 uint8_t avrcp_controller_subunit_info(uint16_t avrcp_cid){
1436     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1437     if (!connection){
1438         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1439     }
1440     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1441 
1442     connection->state = AVCTP_W2_SEND_COMMAND;
1443     avrcp_controller_custom_command_data_init(connection, AVRCP_CMD_OPCODE_SUBUNIT_INFO, AVRCP_CTYPE_STATUS,
1444                                               AVRCP_SUBUNIT_TYPE_UNIT, AVRCP_SUBUNIT_ID_IGNORE, AVRCP_PDU_ID_UNDEFINED,
1445                                               0);
1446 
1447     memset(connection->data, 0xFF, 5);
1448     connection->data = connection->message_body;
1449     connection->data[0] = 7; // page: 0, extension_code: 7
1450     connection->data_len = 5;
1451     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1452     return ERROR_CODE_SUCCESS;
1453 }
1454 
1455 uint8_t avrcp_controller_get_supported_company_ids(uint16_t avrcp_cid){
1456     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1457     if (!connection){
1458         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1459     }
1460     if (connection->state != AVCTP_CONNECTION_OPENED){
1461         return ERROR_CODE_COMMAND_DISALLOWED;
1462     }
1463     avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_COMPANY);
1464     return ERROR_CODE_SUCCESS;
1465 }
1466 
1467 uint8_t avrcp_controller_get_supported_events(uint16_t avrcp_cid){
1468     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1469     if (!connection){
1470         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1471     }
1472     if (connection->state != AVCTP_CONNECTION_OPENED){
1473         return ERROR_CODE_COMMAND_DISALLOWED;
1474     }
1475 
1476     if (!connection->controller_notifications_supported_by_target_queried){
1477         connection->controller_notifications_supported_by_target_queried = true;
1478         avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_EVENT);
1479         return ERROR_CODE_SUCCESS;
1480     }
1481 
1482     avrcp_controller_emit_supported_events(connection);
1483     return ERROR_CODE_SUCCESS;
1484 }
1485 
1486 uint8_t avrcp_controller_get_play_status(uint16_t avrcp_cid){
1487     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1488     if (!connection){
1489         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1490     }
1491     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1492 
1493     connection->state = AVCTP_W2_SEND_COMMAND;
1494     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_PLAY_STATUS);
1495 
1496     connection->data_len = 0;
1497     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1498     return ERROR_CODE_SUCCESS;
1499 }
1500 
1501 uint8_t avrcp_controller_set_addressed_player(uint16_t avrcp_cid, uint16_t addressed_player_id){
1502     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1503     if (!connection){
1504         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1505     }
1506     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1507 
1508     connection->state = AVCTP_W2_SEND_COMMAND;
1509     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_ADDRESSED_PLAYER);
1510 
1511     connection->data_len = 2;
1512     big_endian_store_16(connection->data, 0, addressed_player_id);
1513 
1514     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1515     return ERROR_CODE_SUCCESS;
1516 }
1517 
1518 uint8_t avrcp_controller_get_element_attributes(uint16_t avrcp_cid, uint8_t num_attributes, avrcp_media_attribute_id_t * attributes){
1519     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1520     if (!connection){
1521         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1522     }
1523 
1524     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1525 
1526     if (num_attributes >= AVRCP_MEDIA_ATTR_RESERVED) {
1527         return ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS;
1528     }
1529 
1530     connection->state = AVCTP_W2_SEND_COMMAND;
1531     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES);
1532 
1533     uint8_t pos = 0;
1534     // write 8 bytes value
1535     memset(connection->data, pos, 8); // identifier: PLAYING
1536     pos += 8;
1537 
1538     uint8_t num_attributes_index = pos;
1539     pos++;
1540 
1541     // If num_attributes is set to zero, all attribute information shall be returned,
1542     // and the AttributeID field is omitted
1543     connection->data[num_attributes_index] = 0;
1544     uint8_t i;
1545     for (i = 0; i < num_attributes; i++){
1546         // ignore invalid attribute ID and "get all attributes"
1547         if (AVRCP_MEDIA_ATTR_ALL > attributes[i] && attributes[i] < AVRCP_MEDIA_ATTR_RESERVED){
1548             // every attribute is 4 bytes long
1549             big_endian_store_32(connection->data, pos, attributes[i]);
1550             pos += 4;
1551             connection->data[num_attributes_index]++;
1552         }
1553     }
1554 
1555     // Parameter Length
1556     connection->data_len = pos;
1557 
1558     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1559     return ERROR_CODE_SUCCESS;
1560 }
1561 
1562 uint8_t avrcp_controller_get_now_playing_info(uint16_t avrcp_cid){
1563     return avrcp_controller_get_element_attributes(avrcp_cid, 0, NULL);
1564 }
1565 
1566 uint8_t avrcp_controller_get_now_playing_info_for_media_attribute_id(uint16_t avrcp_cid, avrcp_media_attribute_id_t media_attribute_id){
1567     if (media_attribute_id == AVRCP_MEDIA_ATTR_ALL){
1568         return avrcp_controller_get_now_playing_info(avrcp_cid);
1569     }
1570     return avrcp_controller_get_element_attributes(avrcp_cid, 1, &media_attribute_id);
1571 }
1572 
1573 uint8_t avrcp_controller_set_absolute_volume(uint16_t avrcp_cid, uint8_t volume){
1574      avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1575     if (!connection){
1576         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1577     }
1578 
1579     //
1580     // allow sending of multiple set abs volume commands without waiting for response
1581     //
1582     uint8_t status = ERROR_CODE_COMMAND_DISALLOWED;
1583     switch (connection->state){
1584         case AVCTP_CONNECTION_OPENED:
1585             status = ERROR_CODE_SUCCESS;
1586             break;
1587         case AVCTP_W2_RECEIVE_RESPONSE:
1588             // - is pending response also set abs volume
1589             if (connection->command_opcode  != AVRCP_CMD_OPCODE_VENDOR_DEPENDENT) break;
1590             if (connection->command_type    != AVRCP_CTYPE_CONTROL)               break;
1591             if (connection->subunit_type    != AVRCP_SUBUNIT_TYPE_PANEL)          break;
1592             if (connection->subunit_id      != AVRCP_SUBUNIT_ID)                  break;
1593             if (connection->pdu_id          != AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME)  break;
1594             // - is next transaction id valid in window
1595             if (avrcp_controller_is_transaction_id_valid(connection, avrcp_controller_calc_next_transaction_label(connection->transaction_id_counter)) == false) break;
1596             status = ERROR_CODE_SUCCESS;
1597             break;
1598         default:
1599             break;
1600     }
1601     if (status != ERROR_CODE_SUCCESS) return status;
1602 
1603     connection->state = AVCTP_W2_SEND_COMMAND;
1604     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME);
1605 
1606     // Parameter Length
1607     connection->data_len = 1;
1608     connection->data[0] = volume;
1609 
1610     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1611     return ERROR_CODE_SUCCESS;
1612 }
1613 
1614 uint8_t avrcp_controller_query_shuffle_and_repeat_modes(uint16_t avrcp_cid){
1615     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1616     if (!connection){
1617         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1618     }
1619     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1620 
1621     connection->state = AVCTP_W2_SEND_COMMAND;
1622     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE);
1623 
1624     connection->data_len = 5;
1625     connection->data[0] = 4;                     // NumPlayerApplicationSettingAttributeID
1626     // PlayerApplicationSettingAttributeID1 AVRCP Spec, Appendix F, 133
1627     connection->data[1] = 0x01;   // equalizer  (1-OFF, 2-ON)
1628     connection->data[2] = 0x02;   // repeat     (1-off, 2-single track, 3-all tracks, 4-group repeat)
1629     connection->data[3] = 0x03;   // shuffle    (1-off, 2-all tracks, 3-group shuffle)
1630     connection->data[4] = 0x04;   // scan       (1-off, 2-all tracks, 3-group scan)
1631 
1632     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1633     return ERROR_CODE_SUCCESS;
1634 }
1635 
1636 static uint8_t avrcp_controller_set_current_player_application_setting_value(uint16_t avrcp_cid, uint8_t attr_id, uint8_t attr_value){
1637     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1638     if (!connection){
1639         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1640     }
1641     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1642 
1643     connection->state = AVCTP_W2_SEND_COMMAND;
1644     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE);
1645 
1646     // Parameter Length
1647     connection->data_len = 3;
1648     connection->data[0]  = 2;
1649     connection->data[1]  = attr_id;
1650     connection->data[2]  = attr_value;
1651 
1652     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1653     return ERROR_CODE_SUCCESS;
1654 }
1655 
1656 uint8_t avrcp_controller_set_shuffle_mode(uint16_t avrcp_cid, avrcp_shuffle_mode_t mode){
1657     if ((mode < AVRCP_SHUFFLE_MODE_OFF) || (mode > AVRCP_SHUFFLE_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1658     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x03, mode);
1659 }
1660 
1661 uint8_t avrcp_controller_set_repeat_mode(uint16_t avrcp_cid, avrcp_repeat_mode_t mode){
1662     if ((mode < AVRCP_REPEAT_MODE_OFF) || (mode > AVRCP_REPEAT_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1663     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x02, mode);
1664 }
1665 
1666 uint8_t avrcp_controller_play_item_for_scope(uint16_t avrcp_cid, uint8_t * uid, uint16_t uid_counter, avrcp_browsing_scope_t scope){
1667     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1668     if (!connection){
1669         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1670     }
1671     if (connection->state != AVCTP_CONNECTION_OPENED){
1672         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1673         return ERROR_CODE_COMMAND_DISALLOWED;
1674     }
1675     connection->state = AVCTP_W2_SEND_COMMAND;
1676     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_PLAY_ITEM);
1677 
1678     // Parameter Length
1679     connection->data_len = 11;
1680     connection->data[0]  = scope;
1681     memset(&connection->data[1], 0, 8);
1682     if (uid){
1683         (void)memcpy(&connection->data[1], uid, 8);
1684     }
1685     big_endian_store_16(connection->data, 9, uid_counter);
1686 
1687     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1688     return ERROR_CODE_SUCCESS;
1689 }
1690 
1691 uint8_t avrcp_controller_add_item_from_scope_to_now_playing_list(uint16_t avrcp_cid, uint8_t * uid, uint16_t uid_counter, avrcp_browsing_scope_t scope){
1692     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1693     if (!connection){
1694         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1695     }
1696     if (connection->state != AVCTP_CONNECTION_OPENED){
1697         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1698         return ERROR_CODE_COMMAND_DISALLOWED;
1699     }
1700 
1701     connection->state = AVCTP_W2_SEND_COMMAND;
1702     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_ADD_TO_NOW_PLAYING);
1703 
1704     // Parameter Length
1705     connection->data_len = 11;
1706     connection->data[0]  = scope;
1707     memset(&connection->data[1], 0, 8);
1708     if (uid){
1709         (void)memcpy(&connection->data[1], uid, 8);
1710     }
1711     big_endian_store_16(connection->data, 9, uid_counter);
1712 
1713     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1714     return ERROR_CODE_SUCCESS;
1715 }
1716 
1717 uint8_t avrcp_controller_set_max_num_fragments(uint16_t avrcp_cid, uint8_t max_num_fragments){
1718     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1719     if (!connection){
1720         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1721     }
1722     connection->max_num_fragments = max_num_fragments;
1723     return ERROR_CODE_SUCCESS;
1724 }
1725 
1726 
1727 uint8_t avrcp_controller_send_custom_command(uint16_t avrcp_cid,
1728     avrcp_command_type_t command_type,
1729     avrcp_subunit_type_t subunit_type, avrcp_subunit_id_t subunit_id,
1730     avrcp_pdu_id_t pdu_id, uint32_t company_id,
1731     const uint8_t * data, uint16_t data_len){
1732 
1733     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1734     if (!connection){
1735         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1736     }
1737     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1738 
1739     connection->state = AVCTP_W2_SEND_AVCTP_FRAGMENTED_MESSAGE;
1740     avrcp_controller_custom_command_data_init(connection, AVRCP_CMD_OPCODE_VENDOR_DEPENDENT, command_type, subunit_type,
1741                                               subunit_id, pdu_id, company_id);
1742 
1743     connection->data = (uint8_t *)data;
1744     connection->data_len = data_len;
1745 
1746     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1747     return ERROR_CODE_SUCCESS;
1748 }
1749