xref: /btstack/src/classic/avrcp_controller.c (revision 9611f44c90e9facd4799ec697fe064fa9456c38a)
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_prepare_custom_command_response(avrcp_connection_t * connection, uint8_t response_len, uint8_t * in_place_buffer){
125     uint8_t pos = 0;
126     in_place_buffer[pos++] = HCI_EVENT_AVRCP_META;
127     // skip len
128     pos++;
129     in_place_buffer[pos++] = AVRCP_SUBEVENT_CUSTOM_COMMAND_RESPONSE;
130     little_endian_store_16(in_place_buffer, pos, connection->avrcp_cid);
131     pos += 2;
132     in_place_buffer[pos++] = (uint8_t)connection->command_type;
133     in_place_buffer[pos++] = (uint8_t)connection->pdu_id;
134     little_endian_store_16(in_place_buffer, pos, response_len);
135     pos += 2;
136     in_place_buffer[1] = pos + response_len - 2;
137 }
138 
139 static void avrcp_controller_emit_notification_complete(avrcp_connection_t * connection, uint8_t status, uint8_t event_id, bool enabled){
140     uint8_t event[8];
141     uint8_t pos = 0;
142     event[pos++] = HCI_EVENT_AVRCP_META;
143     event[pos++] = sizeof(event) - 2;
144     event[pos++] = AVRCP_SUBEVENT_NOTIFICATION_STATE;
145     little_endian_store_16(event, pos, connection->avrcp_cid);
146     pos += 2;
147     event[pos++] = status;
148     event[pos++] = enabled ? 1 : 0;
149     event[pos++] = event_id;
150     UNUSED(pos);
151     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
152 }
153 
154 static void avrcp_controller_emit_supported_events(avrcp_connection_t * connection){
155     uint8_t ctype = (uint8_t) AVRCP_CTYPE_RESPONSE_CHANGED_STABLE;
156     uint8_t event_id;
157 
158     for (event_id = (uint8_t) AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; event_id < (uint8_t) AVRCP_NOTIFICATION_EVENT_LAST_INDEX; event_id++){
159         if ((connection->notifications_supported_by_target & (1 << event_id)) == 0){
160             continue;
161         }
162         uint8_t event[8];
163         uint8_t pos = 0;
164         event[pos++] = HCI_EVENT_AVRCP_META;
165         event[pos++] = sizeof(event) - 2;
166         event[pos++] = AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID;
167         little_endian_store_16(event, pos, connection->avrcp_cid);
168         pos += 2;
169         event[pos++] = ctype;
170         event[pos++] = 0;
171         event[pos++] = event_id;
172         UNUSED(pos);
173         (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
174     }
175 
176     uint8_t event[7];
177     uint8_t pos = 0;
178     event[pos++] = HCI_EVENT_AVRCP_META;
179     event[pos++] = sizeof(event) - 2;
180     event[pos++] = AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID_DONE;
181     little_endian_store_16(event, pos, connection->avrcp_cid);
182     pos += 2;
183     event[pos++] = ctype;
184     event[pos++] = 0;
185     UNUSED(pos);
186     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
187 }
188 
189 static void avrcp_controller_emit_notification_for_event_id(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id,
190                                                             avrcp_command_type_t ctype, const uint8_t *payload,
191                                                             uint16_t size) {
192     switch (event_id){
193         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_POS_CHANGED:{
194             if (size < 4) break;
195             uint32_t song_position = big_endian_read_32(payload, 0);
196             uint16_t offset = 0;
197             uint8_t event[10];
198             event[offset++] = HCI_EVENT_AVRCP_META;
199             event[offset++] = sizeof(event) - 2;
200             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_POS_CHANGED;
201             little_endian_store_16(event, offset, avrcp_cid);
202             offset += 2;
203             event[offset++] = ctype;
204             little_endian_store_32(event, offset, song_position);
205             offset += 4;
206             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
207             break;
208         }
209         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED:{
210             if (size < 1) break;
211             uint16_t offset = 0;
212             uint8_t event[7];
213             event[offset++] = HCI_EVENT_AVRCP_META;
214             event[offset++] = sizeof(event) - 2;
215             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_STATUS_CHANGED;
216             little_endian_store_16(event, offset, avrcp_cid);
217             offset += 2;
218             event[offset++] = ctype;
219             event[offset++] = payload[0];
220             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
221             break;
222         }
223         case AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED:{
224             uint16_t offset = 0;
225             uint8_t event[6];
226             event[offset++] = HCI_EVENT_AVRCP_META;
227             event[offset++] = sizeof(event) - 2;
228             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_TRACK_CHANGED;
229             little_endian_store_16(event, offset, avrcp_cid);
230             offset += 2;
231             event[offset++] = ctype;
232             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
233             break;
234         }
235         case AVRCP_NOTIFICATION_EVENT_NOW_PLAYING_CONTENT_CHANGED:{
236             uint16_t offset = 0;
237             uint8_t event[6];
238             event[offset++] = HCI_EVENT_AVRCP_META;
239             event[offset++] = sizeof(event) - 2;
240             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_NOW_PLAYING_CONTENT_CHANGED;
241             little_endian_store_16(event, offset, avrcp_cid);
242             offset += 2;
243             event[offset++] = ctype;
244             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
245             break;
246         }
247         case AVRCP_NOTIFICATION_EVENT_AVAILABLE_PLAYERS_CHANGED:{
248             uint16_t offset = 0;
249             uint8_t event[6];
250             event[offset++] = HCI_EVENT_AVRCP_META;
251             event[offset++] = sizeof(event) - 2;
252             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_AVAILABLE_PLAYERS_CHANGED;
253             little_endian_store_16(event, offset, avrcp_cid);
254             offset += 2;
255             event[offset++] = ctype;
256             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
257             break;
258         }
259         case AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED:{
260             if (size < 1) break;
261             uint16_t offset = 0;
262             uint8_t event[7];
263             event[offset++] = HCI_EVENT_AVRCP_META;
264             event[offset++] = sizeof(event) - 2;
265             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED;
266             little_endian_store_16(event, offset, avrcp_cid);
267             offset += 2;
268             event[offset++] = ctype;
269             event[offset++] = payload[0] & 0x7F;
270             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
271             break;
272         }
273         case AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED:{
274             if (size < 2) break;
275             uint8_t event[8];
276             uint16_t offset = 0;
277             uint16_t uuid = big_endian_read_16(payload, 0);
278             event[offset++] = HCI_EVENT_AVRCP_META;
279             event[offset++] = sizeof(event) - 2;
280             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_UIDS_CHANGED;
281             little_endian_store_16(event, offset, avrcp_cid);
282             offset += 2;
283             event[offset++] = ctype;
284             little_endian_store_16(event, offset, uuid);
285             offset += 2;
286             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
287             break;
288         }
289 
290         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_END:{
291             uint16_t offset = 0;
292             uint8_t event[6];
293             event[offset++] = HCI_EVENT_AVRCP_META;
294             event[offset++] = sizeof(event) - 2;
295             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_END;
296             little_endian_store_16(event, offset, avrcp_cid);
297             offset += 2;
298             event[offset++] = ctype;
299             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
300             break;
301         }
302         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_START:{
303             uint16_t offset = 0;
304             uint8_t event[6];
305             event[offset++] = HCI_EVENT_AVRCP_META;
306             event[offset++] = sizeof(event) - 2;
307             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_START;
308             little_endian_store_16(event, offset, avrcp_cid);
309             offset += 2;
310             event[offset++] = ctype;
311             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
312             break;
313         }
314         case AVRCP_NOTIFICATION_EVENT_BATT_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_BATT_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_SYSTEM_STATUS_CHANGED:{
330             if (size < 1) break;
331             uint16_t offset = 0;
332             uint8_t event[7];
333             event[offset++] = HCI_EVENT_AVRCP_META;
334             event[offset++] = sizeof(event) - 2;
335             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED;
336             little_endian_store_16(event, offset, avrcp_cid);
337             offset += 2;
338             event[offset++] = ctype;
339             event[offset++] = payload[0];
340             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
341             break;
342         }
343 
344         case AVRCP_NOTIFICATION_EVENT_PLAYER_APPLICATION_SETTING_CHANGED:
345         default:
346             log_info("avrcp: not implemented");
347             break;
348     }
349 }
350 
351 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){
352     btstack_assert(callback != NULL);
353 
354     uint8_t event[8];
355     int pos = 0;
356     event[pos++] = HCI_EVENT_AVRCP_META;
357     event[pos++] = sizeof(event) - 2;
358     event[pos++] = AVRCP_SUBEVENT_SHUFFLE_AND_REPEAT_MODE;
359     little_endian_store_16(event, pos, avrcp_cid);
360     pos += 2;
361     event[pos++] = ctype;
362     event[pos++] = repeat_mode;
363     event[pos++] = shuffle_mode;
364     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
365 }
366 
367 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){
368     uint8_t event[7];
369     int pos = 0;
370     event[pos++] = HCI_EVENT_AVRCP_META;
371     event[pos++] = sizeof(event) - 2;
372     event[pos++] = AVRCP_SUBEVENT_NOW_PLAYING_INFO_DONE;
373     little_endian_store_16(event, pos, avrcp_cid);
374     pos += 2;
375     event[pos++] = ctype;
376     event[pos++] = status;
377     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
378 }
379 
380 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){
381     uint8_t event[HCI_EVENT_BUFFER_SIZE];
382     int pos = 0;
383     event[pos++] = HCI_EVENT_AVRCP_META;
384     // reserve one byte for subevent type and data len
385     int data_len_pos = pos;
386     pos++;
387     int subevent_type_pos = pos;
388     pos++;
389     little_endian_store_16(event, pos, avrcp_cid);
390     pos += 2;
391     event[pos++] = ctype;
392 
393     switch (attr_id){
394         case AVRCP_MEDIA_ATTR_TITLE:
395             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TITLE_INFO;
396             event[pos++] = value_len;
397             (void)memcpy(event + pos, value, value_len);
398             break;
399         case AVRCP_MEDIA_ATTR_ARTIST:
400             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ARTIST_INFO;
401             event[pos++] = value_len;
402             (void)memcpy(event + pos, value, value_len);
403             break;
404         case AVRCP_MEDIA_ATTR_ALBUM:
405             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ALBUM_INFO;
406             event[pos++] = value_len;
407             (void)memcpy(event + pos, value, value_len);
408             break;
409         case AVRCP_MEDIA_ATTR_GENRE:
410             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_GENRE_INFO;
411             event[pos++] = value_len;
412             (void)memcpy(event + pos, value, value_len);
413             break;
414         case AVRCP_MEDIA_ATTR_SONG_LENGTH_MS:
415             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_SONG_LENGTH_MS_INFO;
416             if (value){
417                 little_endian_store_32(event, pos, btstack_atoi((char *)value));
418             } else {
419                 little_endian_store_32(event, pos, 0);
420             }
421             pos += 4;
422             break;
423         case AVRCP_MEDIA_ATTR_TRACK:
424             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TRACK_INFO;
425             if (value){
426                 event[pos++] = btstack_atoi((char *)value);
427             } else {
428                 event[pos++] = 0;
429             }
430             break;
431         case AVRCP_MEDIA_ATTR_TOTAL_NUM_ITEMS:
432             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TOTAL_TRACKS_INFO;
433             if (value){
434                 event[pos++] = btstack_atoi((char *)value);
435             } else {
436                 event[pos++] = 0;
437             }
438             break;
439         default:
440             break;
441     }
442     event[data_len_pos] = pos - 2;
443     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
444 }
445 
446 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){
447     btstack_assert(callback != NULL);
448 
449     uint8_t event[7];
450     int pos = 0;
451     event[pos++] = HCI_EVENT_AVRCP_META;
452     event[pos++] = sizeof(event) - 2;
453     event[pos++] = subevent;
454     little_endian_store_16(event, pos, avrcp_cid);
455     pos += 2;
456     event[pos++] = ctype;
457     event[pos++] = operation_id;
458     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
459 }
460 
461 static void avrcp_parser_reset(avrcp_connection_t * connection){
462     connection->list_offset = 0;
463     connection->parser_attribute_header_pos = 0;
464     connection->controller_num_received_fragments = 0;
465     connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
466 }
467 
468 static void avrcp_parser_process_byte(uint8_t byte, avrcp_connection_t * connection, avrcp_command_type_t ctype){
469     uint16_t attribute_total_value_len;
470     uint32_t attribute_id;
471     switch(connection->parser_state){
472         case AVRCP_PARSER_GET_ATTRIBUTE_HEADER:
473             connection->parser_attribute_header[connection->parser_attribute_header_pos++] = byte;
474             connection->list_offset++;
475 
476             if (connection->parser_attribute_header_pos < AVRCP_ATTRIBUTE_HEADER_LEN) return;
477 
478             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
479             connection->attribute_value_len = btstack_min(attribute_total_value_len, AVRCP_MAX_ATTRIBUTE_SIZE);
480             if (connection->attribute_value_len > 0){
481                 // get ready for attribute value
482                 connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_VALUE;
483                 return;
484             }
485 
486             // emit empty attribute
487             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
488             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);
489 
490             // done, see below
491             break;
492 
493         case AVRCP_PARSER_GET_ATTRIBUTE_VALUE:
494             connection->attribute_value[connection->attribute_value_offset++] = byte;
495             connection->list_offset++;
496 
497             if (connection->attribute_value_offset < connection->attribute_value_len) return;
498 
499             // emit (potentially partial) attribute
500             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
501             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);
502 
503             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
504             if (connection->attribute_value_offset < attribute_total_value_len){
505                 // ignore rest of attribute
506                 connection->parser_state = AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE;
507                 return;
508             }
509 
510             // done, see below
511             break;
512 
513         case AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE:
514             connection->attribute_value_offset++;
515             connection->list_offset++;
516 
517             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
518             if (connection->attribute_value_offset < attribute_total_value_len) return;
519 
520             // done, see below
521             break;
522 
523         default:
524             return;
525     }
526 
527     // attribute fully read, check if more to come
528     if (connection->list_offset < connection->list_size){
529         // more to come, reset parser
530         connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
531         connection->parser_attribute_header_pos = 0;
532         connection->attribute_value_offset = 0;
533     } else {
534         // fully done
535         avrcp_parser_reset(connection);
536         avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 0);
537     }
538 }
539 
540 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){
541     int i;
542     for (i=0;i<num_bytes_to_read;i++){
543         avrcp_parser_process_byte(packet[i], connection, ctype);
544     }
545 }
546 
547 static void avrcp_send_cmd_with_avctp_fragmentation(avrcp_connection_t * connection){
548     l2cap_reserve_packet_buffer();
549     uint8_t * packet = l2cap_get_outgoing_buffer();
550 
551     uint16_t max_payload_size;
552     connection->avctp_packet_type = avctp_get_packet_type(connection, &max_payload_size);
553     connection->avrcp_packet_type = avrcp_get_packet_type(connection);
554 
555     // non-fragmented: transport header (1) + PID (2)
556     // fragmented:     transport header (1) + num packets (1) + PID (2)
557 
558     uint16_t param_len = connection->data_len;
559     // AVCTP header
560     // transport header : transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
561     uint16_t pos = 0;
562     packet[pos++] = (connection->transaction_id << 4) | (connection->avctp_packet_type << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
563 
564     if (connection->avctp_packet_type == AVCTP_START_PACKET){
565         uint16_t max_frame_size = btstack_min(connection->l2cap_mtu, AVRCP_MAX_AV_C_MESSAGE_FRAME_SIZE);
566         // first packet: max_payload_size
567         // rest packets
568         uint16_t num_payload_bytes = param_len - max_payload_size;
569         uint16_t frame_size_for_continue_packet = max_frame_size - avctp_get_num_bytes_for_header(AVCTP_CONTINUE_PACKET);
570         uint16_t num_avctp_packets = (num_payload_bytes + frame_size_for_continue_packet - 1)/frame_size_for_continue_packet + 1;
571         packet[pos++] = num_avctp_packets;
572     }
573 
574     switch (connection->avctp_packet_type){
575         case AVCTP_SINGLE_PACKET:
576         case AVCTP_START_PACKET:
577             // Profile IDentifier (PID)
578             packet[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
579             packet[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
580 
581             // command_type
582             packet[pos++] = connection->command_type;
583             // subunit_type | subunit ID
584             packet[pos++] = (connection->subunit_type << 3) | connection->subunit_id;
585             // opcode
586             packet[pos++] = (uint8_t)connection->command_opcode;
587 
588             switch (connection->command_opcode){
589                 case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
590                     big_endian_store_24(packet, pos, connection->company_id);
591                     pos += 3;
592                     packet[pos++] = connection->pdu_id;
593                     packet[pos++] = connection->avrcp_packet_type;              // reserved(upper 6) | AVRCP packet_type
594                     big_endian_store_16(packet, pos, connection->data_len);     // parameter length
595                     pos += 2;
596                     break;
597                 case AVRCP_CMD_OPCODE_PASS_THROUGH:
598                     packet[pos++] = connection->operation_id;
599                     packet[pos++] = (uint8_t)connection->data_len;     // parameter length
600                     pos += 2;
601                     break;
602                 case AVRCP_CMD_OPCODE_UNIT_INFO:
603                     break;
604                 case AVRCP_CMD_OPCODE_SUBUNIT_INFO:
605                     break;
606                 default:
607                     btstack_assert(false);
608                     return;
609             }
610             break;
611         case AVCTP_CONTINUE_PACKET:
612         case AVCTP_END_PACKET:
613             break;
614         default:
615             btstack_assert(false);
616             return;
617     }
618     // compare number of bytes to store with the remaining buffer size
619     uint16_t bytes_to_copy = btstack_min(connection->data_len - connection->data_offset, max_payload_size - pos);
620 
621     (void)memcpy(packet + pos, &connection->data[connection->data_offset], bytes_to_copy);
622     pos += bytes_to_copy;
623     connection->data_offset += bytes_to_copy;
624 
625     l2cap_send_prepared(connection->l2cap_signaling_cid, pos);
626 }
627 
628 static int avrcp_send_register_notification(avrcp_connection_t * connection, uint8_t event_id){
629     uint8_t command[18];
630     uint16_t pos = 0;
631     // transport header : transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
632     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
633     command[pos++] = (connection->transaction_id << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
634 
635     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
636     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
637     command[pos++] = AVRCP_CTYPE_NOTIFY;
638     command[pos++] = (AVRCP_SUBUNIT_TYPE_PANEL << 3) | AVRCP_SUBUNIT_ID;
639     command[pos++] = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
640 
641     big_endian_store_24(command, pos, BT_SIG_COMPANY_ID);
642     pos += 3;
643     command[pos++] = AVRCP_PDU_ID_REGISTER_NOTIFICATION;
644     command[pos++] = 0;                       // reserved(upper 6) | packet_type -> 0
645     big_endian_store_16(command, pos, 5);     // parameter length
646     pos += 2;
647     command[pos++] = event_id;
648     big_endian_store_32(command, pos, 1);     // send notification on playback position every second, for other notifications it is ignored
649     pos += 4;
650     return l2cap_send(connection->l2cap_signaling_cid, command, pos);
651 }
652 
653 static void avrcp_press_and_hold_timeout_handler(btstack_timer_source_t * timer){
654     UNUSED(timer);
655     avrcp_connection_t * connection = (avrcp_connection_t*) btstack_run_loop_get_timer_context(timer);
656     btstack_run_loop_set_timer(&connection->controller_press_and_hold_cmd_timer, 2000); // 2 seconds timeout
657     btstack_run_loop_add_timer(&connection->controller_press_and_hold_cmd_timer);
658     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
659     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
660 }
661 
662 static void avrcp_press_and_hold_timer_start(avrcp_connection_t * connection){
663     btstack_run_loop_remove_timer(&connection->controller_press_and_hold_cmd_timer);
664     btstack_run_loop_set_timer_handler(&connection->controller_press_and_hold_cmd_timer, avrcp_press_and_hold_timeout_handler);
665     btstack_run_loop_set_timer_context(&connection->controller_press_and_hold_cmd_timer, connection);
666     btstack_run_loop_set_timer(&connection->controller_press_and_hold_cmd_timer, 2000); // 2 seconds timeout
667     btstack_run_loop_add_timer(&connection->controller_press_and_hold_cmd_timer);
668 }
669 
670 static void avrcp_press_and_hold_timer_stop(avrcp_connection_t * connection){
671     connection->controller_press_and_hold_cmd_active = false;
672     btstack_run_loop_remove_timer(&connection->controller_press_and_hold_cmd_timer);
673 }
674 
675 
676 static uint8_t avrcp_controller_request_pass_through_release_control_cmd(avrcp_connection_t * connection){
677     connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
678     if (connection->controller_press_and_hold_cmd_active){
679         avrcp_press_and_hold_timer_stop(connection);
680     }
681     connection->operation_id = (avrcp_operation_id_t)(0x80 | connection->operation_id);
682     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
683     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
684     return ERROR_CODE_SUCCESS;
685 }
686 
687 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){
688     log_info("Send command %d", opid);
689     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
690     if (!connection){
691         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
692     }
693 
694     if (connection->state != AVCTP_CONNECTION_OPENED){
695         log_error("Connection in wrong state %d, expected %d. avrcp cid 0x%02x", connection->state, AVCTP_CONNECTION_OPENED, avrcp_cid);
696         return ERROR_CODE_COMMAND_DISALLOWED;
697     }
698     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
699     avrcp_controller_pass_through_command_data_init(connection, opid);
700 
701     if (playback_speed > 0){
702         connection->data[0] = playback_speed;
703         connection->data_len = 1;
704     }
705 
706     connection->controller_press_and_hold_cmd_active = continuous_cmd;
707     if (connection->controller_press_and_hold_cmd_active){
708         avrcp_press_and_hold_timer_start(connection);
709     }
710 
711     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
712     return ERROR_CODE_SUCCESS;
713 }
714 
715 static uint8_t request_single_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
716     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, false);
717 }
718 
719 static uint8_t request_continuous_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
720     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, true);
721 }
722 
723 static void avrcp_controller_get_capabilities_for_connection(avrcp_connection_t * connection, uint8_t capability_id){
724     connection->state = AVCTP_W2_SEND_COMMAND;
725     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_CAPABILITIES);
726 
727     // Parameter Length
728     connection->data_len = 1;
729     connection->data[0] = capability_id;  // capability ID
730 
731     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
732 }
733 
734 static uint8_t avrcp_controller_register_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
735     if (connection->controller_notifications_supported_by_target_queried && (connection->notifications_supported_by_target & (1 << event_id)) == 0){
736         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
737     }
738     if ((connection->controller_notifications_to_deregister & (1 << event_id)) != 0){
739         return ERROR_CODE_COMMAND_DISALLOWED;
740     }
741     if ( (connection->notifications_enabled & (1 << event_id)) != 0){
742         return ERROR_CODE_SUCCESS;
743     }
744     connection->controller_notifications_to_register |= (1 << event_id);
745 
746     if (!connection->controller_notifications_supported_by_target_queried){
747         connection->controller_notifications_supported_by_target_suppress_emit_result = true;
748         avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_EVENT);
749         return ERROR_CODE_SUCCESS;
750     }
751     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
752     return ERROR_CODE_SUCCESS;
753 }
754 
755 static uint8_t avrcp_controller_request_continuation(avrcp_connection_t * connection, avrcp_pdu_id_t pdu_id){
756     connection->state = AVCTP_W2_SEND_COMMAND;
757     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, pdu_id);
758 
759     // Parameter Length
760     connection->data_len = 3;
761     big_endian_store_16(connection->data, 0, 1);
762     connection->data[2] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
763 
764     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
765     return ERROR_CODE_SUCCESS;
766 }
767 
768 static uint8_t avrcp_controller_request_abort_continuation(avrcp_connection_t * connection){
769     return avrcp_controller_request_continuation(connection, AVRCP_PDU_ID_REQUEST_ABORT_CONTINUING_RESPONSE);
770 }
771 
772 static uint8_t avrcp_controller_request_continue_response(avrcp_connection_t * connection){
773     return avrcp_controller_request_continuation(connection, AVRCP_PDU_ID_REQUEST_CONTINUING_RESPONSE);
774 }
775 
776 static void avrcp_controller_handle_notification(avrcp_connection_t *connection, avrcp_command_type_t ctype, uint8_t *payload, uint16_t size) {
777     if (size < 1) return;
778     uint16_t pos = 0;
779     avrcp_notification_event_id_t event_id = (avrcp_notification_event_id_t) payload[pos++];
780     if ( (event_id < AVRCP_NOTIFICATION_EVENT_FIRST_INDEX) || (event_id > AVRCP_NOTIFICATION_EVENT_LAST_INDEX)){
781         return;
782     }
783 
784     uint16_t event_mask = (1 << event_id);
785     uint16_t reset_event_mask = ~event_mask;
786 
787     switch (ctype){
788         case AVRCP_CTYPE_RESPONSE_REJECTED:
789             connection->controller_notifications_to_deregister &= reset_event_mask;
790             connection->controller_notifications_to_register   &= reset_event_mask;
791             connection->controller_initial_status_reported     &= reset_event_mask;
792             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE, event_id, false);
793             return;
794 
795         case AVRCP_CTYPE_RESPONSE_INTERIM:
796             // register as enabled
797             connection->notifications_enabled |= event_mask;
798 
799             // check if initial value is already sent
800             if ((connection->controller_initial_status_reported & event_mask) != 0 ){
801                 return;
802             }
803             // emit event only once, initially
804             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_SUCCESS, event_id, true);
805             connection->controller_initial_status_reported |= event_mask;
806             // emit initial value after this switch
807             break;
808 
809         case AVRCP_CTYPE_RESPONSE_CHANGED_STABLE:
810             // received change, event is considered de-registered
811             // we are re-enabling it automatically, if it is not
812             // explicitly disabled
813             connection->notifications_enabled &= reset_event_mask;
814             if ((connection->controller_notifications_to_deregister & event_mask) == 0){
815                 avrcp_controller_register_notification(connection, event_id);
816             } else {
817                 connection->controller_notifications_to_deregister &= reset_event_mask;
818                 connection->controller_notifications_to_register   &= reset_event_mask;
819                 connection->controller_initial_status_reported     &= reset_event_mask;
820                 avrcp_controller_emit_notification_complete(connection, ERROR_CODE_SUCCESS, event_id, false);
821             }
822             break;
823 
824         default:
825             return;
826     }
827 
828     avrcp_controller_emit_notification_for_event_id(connection->avrcp_cid, event_id, ctype, payload + pos, size - pos);
829 }
830 
831 #ifdef ENABLE_AVCTP_FRAGMENTATION
832 static void avctp_reassemble_message(avrcp_connection_t * connection, avctp_packet_type_t packet_type, uint8_t *packet, uint16_t size){
833     // after header (transaction label and packet type)
834     uint16_t pos;
835     uint16_t bytes_to_store;
836 
837     switch (packet_type){
838         case AVCTP_START_PACKET:
839             if (size < 2) return;
840 
841             // store header
842             pos = 0;
843             connection->avctp_reassembly_buffer[pos] = packet[pos];
844             pos++;
845             connection->avctp_reassembly_size = pos;
846 
847             // NOTE: num packets not needed for reassembly, ignoring it does not pose security risk -> no need to store it
848             pos++;
849 
850             // PID in reassembled packet is at offset 1, it will be read later after the avctp_reassemble_message with AVCTP_END_PACKET is called
851 
852             bytes_to_store = btstack_min(size - pos, sizeof(connection->avctp_reassembly_buffer) - connection->avctp_reassembly_size);
853             memcpy(&connection->avctp_reassembly_buffer[connection->avctp_reassembly_size], &packet[pos], bytes_to_store);
854             connection->avctp_reassembly_size += bytes_to_store;
855             break;
856 
857         case AVCTP_CONTINUE_PACKET:
858         case AVCTP_END_PACKET:
859             if (size < 1) return;
860 
861             // store remaining data, ignore header
862             pos = 1;
863             bytes_to_store = btstack_min(size - pos, sizeof(connection->avctp_reassembly_buffer) - connection->avctp_reassembly_size);
864             memcpy(&connection->avctp_reassembly_buffer[connection->avctp_reassembly_size], &packet[pos], bytes_to_store);
865             connection->avctp_reassembly_size += bytes_to_store;
866             break;
867 
868         default:
869             return;
870     }
871 }
872 #endif
873 
874 static void avrcp_handle_l2cap_data_packet_for_signaling_connection(avrcp_connection_t * connection, uint8_t *packet, uint16_t size){
875     if (size < 6u) return;
876     uint8_t  pdu_id;
877     avrcp_packet_type_t  vendor_dependent_avrcp_packet_type;
878 
879     uint16_t pos = 0;
880     connection->controller_last_confirmed_transaction_id = packet[pos] >> 4;
881     avrcp_frame_type_t  frame_type =  (avrcp_frame_type_t)((packet[pos] >> 1) & 0x01);
882     avctp_packet_type_t packet_type = (avctp_packet_type_t)((packet[pos] >> 2) & 0x03);
883     pos++;
884 
885     if (frame_type != AVRCP_RESPONSE_FRAME) return;
886 
887     switch (packet_type){
888         case AVCTP_SINGLE_PACKET:
889             break;
890 
891 #ifdef ENABLE_AVCTP_FRAGMENTATION
892         case AVCTP_START_PACKET:
893         case AVCTP_CONTINUE_PACKET:
894             avctp_reassemble_message(connection, packet_type, packet, size);
895             return;
896 
897         case AVCTP_END_PACKET:
898             avctp_reassemble_message(connection, packet_type, packet, size);
899 
900             packet = connection->avctp_reassembly_buffer;
901             size   = connection->avctp_reassembly_size;
902             break;
903 #endif
904 
905         default:
906             return;
907     }
908 
909     pos += 2; // PID
910 
911     avrcp_command_type_t ctype = (avrcp_command_type_t) packet[pos++];
912 
913 #ifdef ENABLE_LOG_INFO
914     uint8_t byte_value = packet[pos];
915     avrcp_subunit_type_t subunit_type = (avrcp_subunit_type_t) (byte_value >> 3);
916     avrcp_subunit_type_t subunit_id   = (avrcp_subunit_type_t) (byte_value & 0x07);
917 #endif
918     pos++;
919 
920     uint8_t opcode = packet[pos++];
921     uint16_t param_length;
922 
923     switch (opcode){
924         case AVRCP_CMD_OPCODE_SUBUNIT_INFO:{
925             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
926             connection->state = AVCTP_CONNECTION_OPENED;
927 
928 #ifdef ENABLE_LOG_INFO
929             // page, extension code (1)
930             pos++;
931             uint8_t unit_type = packet[pos] >> 3;
932             uint8_t max_subunit_ID = packet[pos] & 0x07;
933             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);
934 #endif
935             break;
936         }
937         case AVRCP_CMD_OPCODE_UNIT_INFO:{
938             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
939             connection->state = AVCTP_CONNECTION_OPENED;
940 
941 #ifdef ENABLE_LOG_INFO
942             // byte value 7 (1)
943             pos++;
944             uint8_t unit_type = packet[pos] >> 3;
945             uint8_t unit = packet[pos] & 0x07;
946             pos++;
947             uint32_t company_id = big_endian_read_24(packet, pos);
948             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,
949                 ctype, subunit_type, subunit_id, opcode, unit_type, unit, company_id);
950 #endif
951             break;
952         }
953         case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
954 
955             if ((size - pos) < 7) return;
956 
957             // Company ID (3)
958             pos += 3;
959             pdu_id = packet[pos++];
960             vendor_dependent_avrcp_packet_type = (avrcp_packet_type_t)(packet[pos++] & 0x03);
961             param_length = big_endian_read_16(packet, pos);
962             pos += 2;
963 
964             if ((size - pos) < param_length) return;
965 
966             // handle asynchronous notifications, without changing state
967             if (pdu_id == AVRCP_PDU_ID_REGISTER_NOTIFICATION){
968                 avrcp_controller_handle_notification(connection, ctype, packet + pos, size - pos);
969                 break;
970             }
971 
972             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE){
973                 log_info("AVRCP_CMD_OPCODE_VENDOR_DEPENDENT state %d", connection->state);
974                 return;
975             }
976             connection->state = AVCTP_CONNECTION_OPENED;
977 
978             log_info("VENDOR DEPENDENT response: pdu id 0x%02x, param_length %d, status %s", pdu_id, param_length, avrcp_ctype2str(ctype));
979             switch (pdu_id){
980                 case AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE:{
981                     uint8_t num_attributes = packet[pos++];
982                     int i;
983                     avrcp_repeat_mode_t  repeat_mode =  AVRCP_REPEAT_MODE_INVALID;
984                     avrcp_shuffle_mode_t shuffle_mode = AVRCP_SHUFFLE_MODE_INVALID;
985                     for (i = 0; i < num_attributes; i++){
986                         uint8_t attribute_id    = packet[pos++];
987                         uint8_t value = packet[pos++];
988                         switch (attribute_id){
989                             case 0x02:
990                                 repeat_mode = (avrcp_repeat_mode_t) value;
991                                 break;
992                             case 0x03:
993                                 shuffle_mode = (avrcp_shuffle_mode_t) value;
994                                 break;
995                             default:
996                                 break;
997                         }
998                     }
999                     avrcp_controller_emit_repeat_and_shuffle_mode(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, repeat_mode, shuffle_mode);
1000                     break;
1001                 }
1002 
1003                 case AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE:{
1004                     uint16_t offset = 0;
1005                     uint8_t event[6];
1006                     event[offset++] = HCI_EVENT_AVRCP_META;
1007                     event[offset++] = sizeof(event) - 2;
1008                     event[offset++] = AVRCP_SUBEVENT_PLAYER_APPLICATION_VALUE_RESPONSE;
1009                     little_endian_store_16(event, offset, connection->avrcp_cid);
1010                     offset += 2;
1011                     event[offset++] = ctype;
1012                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1013                     break;
1014                 }
1015 
1016                 case AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME:{
1017                     uint16_t offset = 0;
1018                     uint8_t event[7];
1019                     event[offset++] = HCI_EVENT_AVRCP_META;
1020                     event[offset++] = sizeof(event) - 2;
1021                     event[offset++] = AVRCP_SUBEVENT_SET_ABSOLUTE_VOLUME_RESPONSE;
1022                     little_endian_store_16(event, offset, connection->avrcp_cid);
1023                     offset += 2;
1024                     event[offset++] = ctype;
1025                     event[offset++] = packet[pos++];
1026                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1027                     break;
1028                 }
1029 
1030                 case AVRCP_PDU_ID_GET_CAPABILITIES:{
1031                     avrcp_capability_id_t capability_id = (avrcp_capability_id_t) packet[pos++];
1032                     uint8_t capability_count = 0;
1033                     if (param_length > 1){
1034                         capability_count = packet[pos++];
1035                     }
1036                     uint16_t i;
1037                     uint16_t offset = 0;
1038                     uint8_t event[10];
1039 
1040                     switch (capability_id){
1041 
1042                         case AVRCP_CAPABILITY_ID_COMPANY:
1043                             for (i = 0; (i < capability_count) && ((size - pos) >= 3); i++){
1044                                 uint32_t company_id = big_endian_read_24(packet, pos);
1045                                 pos += 3;
1046                                 log_info("  0x%06" PRIx32 ", ", company_id);
1047 
1048                                 offset = 0;
1049                                 event[offset++] = HCI_EVENT_AVRCP_META;
1050                                 event[offset++] = sizeof(event) - 2;
1051                                 event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID;
1052                                 little_endian_store_16(event, offset, connection->avrcp_cid);
1053                                 offset += 2;
1054                                 event[offset++] = ctype;
1055                                 event[offset++] = 0;
1056                                 little_endian_store_24(event, offset, company_id);
1057                                 offset += 3;
1058                                 (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
1059                             }
1060 
1061                             offset = 0;
1062                             event[offset++] = HCI_EVENT_AVRCP_META;
1063                             event[offset++] = sizeof(event) - 2;
1064                             event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID_DONE;
1065                             little_endian_store_16(event, offset, connection->avrcp_cid);
1066                             offset += 2;
1067                             event[offset++] = ctype;
1068                             event[offset++] = 0;
1069                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
1070                             break;
1071 
1072                         case AVRCP_CAPABILITY_ID_EVENT:
1073                             for (i = 0; (i < capability_count) && ((size - pos) >= 1); i++){
1074                                 uint8_t event_id = packet[pos++];
1075                                 connection->notifications_supported_by_target |= (1 << event_id);
1076                             }
1077 
1078                             // if the get supported events query is triggered by avrcp_controller_enable_notification call,
1079                             // avrcp_controller_emit_supported_events should be suppressed
1080                             if (connection->controller_notifications_supported_by_target_suppress_emit_result){
1081                                 connection->controller_notifications_supported_by_target_suppress_emit_result = false;
1082                                 // also, notification might not be supported
1083                                 // if so, emit AVRCP_SUBEVENT_ENABLE_NOTIFICATION_COMPLETE event to app,
1084                                 // and update controller_notifications_to_register bitmap
1085                                 for (i = (uint8_t)AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; i < (uint8_t) AVRCP_NOTIFICATION_EVENT_LAST_INDEX; i++){
1086                                     if ((connection->controller_notifications_to_register & (1 << i)) != 0){
1087                                         if ((connection->notifications_supported_by_target & (1 << i)) == 0){
1088                                             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE, i, false);
1089                                             connection->controller_notifications_to_register &= ~(1 << i);
1090                                         }
1091                                     }
1092                                 }
1093                                 break;
1094                             }
1095                             // supported events are emitted only if the get supported events query
1096                             // is triggered by avrcp_controller_get_supported_events call
1097                             avrcp_controller_emit_supported_events(connection);
1098                             break;
1099 
1100                         default:
1101                             // ignore
1102                             break;
1103                     }
1104                     break;
1105                 }
1106 
1107                 case AVRCP_PDU_ID_GET_PLAY_STATUS:{
1108                     uint32_t song_length = big_endian_read_32(packet, pos);
1109                     pos += 4;
1110                     uint32_t song_position = big_endian_read_32(packet, pos);
1111                     pos += 4;
1112                     uint8_t play_status = packet[pos];
1113 
1114                     uint8_t event[15];
1115                     int offset = 0;
1116                     event[offset++] = HCI_EVENT_AVRCP_META;
1117                     event[offset++] = sizeof(event) - 2;
1118                     event[offset++] = AVRCP_SUBEVENT_PLAY_STATUS;
1119                     little_endian_store_16(event, offset, connection->avrcp_cid);
1120                     offset += 2;
1121                     event[offset++] = ctype;
1122                     little_endian_store_32(event, offset, song_length);
1123                     offset += 4;
1124                     little_endian_store_32(event, offset, song_position);
1125                     offset += 4;
1126                     event[offset++] = play_status;
1127                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1128                     break;
1129                 }
1130 
1131                 case AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES:{
1132                     // TODO Review
1133                     switch (vendor_dependent_avrcp_packet_type){
1134                         case AVRCP_START_PACKET:
1135                         case AVRCP_SINGLE_PACKET:
1136                             avrcp_parser_reset(connection);
1137                             connection->list_size = param_length;
1138                             // num_attributes
1139                             pos++;
1140 
1141                             avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
1142                             if (vendor_dependent_avrcp_packet_type == AVRCP_START_PACKET){
1143                                 avrcp_controller_request_continue_response(connection);
1144                             }
1145                             break;
1146                         case AVRCP_CONTINUE_PACKET:
1147                         case AVRCP_END_PACKET:
1148                             connection->controller_num_received_fragments++;
1149 
1150                             if (connection->controller_num_received_fragments < connection->controller_max_num_fragments){
1151                                 avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
1152 
1153                                 if (vendor_dependent_avrcp_packet_type == AVRCP_CONTINUE_PACKET){
1154                                     avrcp_controller_request_continue_response(connection);
1155                                 }
1156                             } else {
1157                                 avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 1);
1158                                 avrcp_parser_reset(connection);
1159                                 avrcp_controller_request_abort_continuation(connection);
1160                             }
1161                             break;
1162                         default:
1163                             // TODO check
1164                             btstack_assert(false);
1165                             break;
1166                     }
1167                 }
1168                 default:
1169                     // custom command response comes here
1170                     switch (pdu_id){
1171                         case AVRCP_PDU_ID_REQUEST_ABORT_CONTINUING_RESPONSE:
1172                             avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 0);
1173                             break;
1174                         default:
1175                             if (pdu_id != connection->pdu_id) {
1176                                 break;
1177                             }
1178                             uint8_t *in_place_buffer = packet + pos - 9;
1179                             avrcp_controller_prepare_custom_command_response(connection, param_length,
1180                                                                              in_place_buffer);
1181                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, in_place_buffer,
1182                                                                        param_length + 9);
1183 
1184                             break;
1185                     }
1186                     break;
1187             }
1188             break;
1189         case AVRCP_CMD_OPCODE_PASS_THROUGH:{
1190             if ((size - pos) < 1) return;
1191             uint8_t operation_id = packet[pos++];
1192             switch (connection->state){
1193                 case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
1194                     // trigger release for simple command:
1195                     if (!connection->controller_press_and_hold_cmd_active){
1196                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
1197                         break;
1198                     }
1199                     // for press and hold, send release if it just has been requested, otherwise, wait for next repeat
1200                     if (connection->controller_press_and_hold_cmd_release){
1201                         connection->controller_press_and_hold_cmd_release = false;
1202                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
1203                     } else {
1204                         connection->state = AVCTP_W4_STOP;
1205                     }
1206                     break;
1207                 case AVCTP_W2_RECEIVE_RESPONSE:
1208                     connection->state = AVCTP_CONNECTION_OPENED;
1209                     break;
1210                 default:
1211                     break;
1212             }
1213             if (connection->state == AVCTP_W4_STOP){
1214                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_START, connection->avrcp_cid, ctype, operation_id);
1215             }
1216             if (connection->state == AVCTP_CONNECTION_OPENED) {
1217                 // RELEASE response
1218                 operation_id = operation_id & 0x7F;
1219                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_COMPLETE, connection->avrcp_cid, ctype, operation_id);
1220             }
1221             if (connection->state == AVCTP_W2_SEND_RELEASE_COMMAND){
1222                 // PRESS response
1223                 avrcp_controller_request_pass_through_release_control_cmd(connection);
1224             }
1225             break;
1226         }
1227         default:
1228             break;
1229     }
1230 
1231     // trigger pending notification reqistrations
1232     if ((connection->state == AVCTP_CONNECTION_OPENED) && connection->controller_notifications_to_register){
1233         avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1234     }
1235 }
1236 
1237 static void avrcp_controller_handle_can_send_now(avrcp_connection_t * connection){
1238     switch (connection->state){
1239         case AVCTP_W2_SEND_PRESS_COMMAND:
1240         case AVCTP_W2_SEND_COMMAND:
1241         case AVCTP_W2_SEND_RELEASE_COMMAND:
1242             avrcp_send_cmd_with_avctp_fragmentation(connection);
1243             if (connection->data_offset < connection->data_len){
1244                 // continue AVCTP fragmentation
1245                 avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1246                 return;
1247             }
1248             if (connection->state == AVCTP_W2_SEND_PRESS_COMMAND){
1249                 connection->state = AVCTP_W2_RECEIVE_PRESS_RESPONSE;
1250             } else {
1251                 connection->state = AVCTP_W2_RECEIVE_RESPONSE;
1252             }
1253             return;
1254         default:
1255             break;
1256     }
1257 
1258     // send register notification if queued
1259     if (connection->controller_notifications_to_register != 0){
1260         uint8_t event_id;
1261         for (event_id = (uint8_t)AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; event_id < (uint8_t)AVRCP_NOTIFICATION_EVENT_LAST_INDEX; event_id++){
1262             if (connection->controller_notifications_to_register & (1 << event_id)){
1263                 connection->controller_notifications_to_register &= ~ (1 << event_id);
1264                 avrcp_send_register_notification(connection, event_id);
1265                 return;
1266             }
1267         }
1268     }
1269 }
1270 
1271 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
1272     avrcp_connection_t * connection;
1273 
1274     switch (packet_type) {
1275         case L2CAP_DATA_PACKET:
1276             connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
1277             avrcp_handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
1278             break;
1279 
1280         case HCI_EVENT_PACKET:
1281             switch (hci_event_packet_get_type(packet)){
1282                 case L2CAP_EVENT_CAN_SEND_NOW:
1283                     connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
1284                     avrcp_controller_handle_can_send_now(connection);
1285                     break;
1286             default:
1287                 break;
1288         }
1289         default:
1290             break;
1291     }
1292 }
1293 
1294 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){
1295     avrcp_create_sdp_record(1, service, service_record_handle, avrcp_controller_supports_browsing(supported_features), supported_features, service_name, service_provider_name);
1296 }
1297 
1298 void avrcp_controller_init(void){
1299     avrcp_controller_context.role = AVRCP_CONTROLLER;
1300     avrcp_controller_context.packet_handler = avrcp_controller_packet_handler;
1301     avrcp_register_controller_packet_handler(&avrcp_controller_packet_handler);
1302 }
1303 
1304 void avrcp_controller_deinit(void){
1305     memset(&avrcp_controller_context, 0, sizeof(avrcp_context_t));
1306 }
1307 
1308 void avrcp_controller_register_packet_handler(btstack_packet_handler_t callback){
1309     btstack_assert(callback != NULL);
1310     avrcp_controller_context.avrcp_callback = callback;
1311 }
1312 
1313 
1314 uint8_t avrcp_controller_play(uint16_t avrcp_cid){
1315     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1316 }
1317 
1318 uint8_t avrcp_controller_stop(uint16_t avrcp_cid){
1319     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1320 }
1321 
1322 uint8_t avrcp_controller_pause(uint16_t avrcp_cid){
1323     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1324 }
1325 
1326 uint8_t avrcp_controller_forward(uint16_t avrcp_cid){
1327     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1328 }
1329 
1330 uint8_t avrcp_controller_backward(uint16_t avrcp_cid){
1331     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1332 }
1333 
1334 uint8_t avrcp_controller_volume_up(uint16_t avrcp_cid){
1335     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1336 }
1337 
1338 uint8_t avrcp_controller_volume_down(uint16_t avrcp_cid){
1339     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1340 }
1341 
1342 uint8_t avrcp_controller_mute(uint16_t avrcp_cid){
1343     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1344 }
1345 
1346 uint8_t avrcp_controller_skip(uint16_t avrcp_cid){
1347     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_SKIP, 0);
1348 }
1349 
1350 uint8_t avrcp_controller_fast_forward(uint16_t avrcp_cid){
1351     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1352 }
1353 
1354 uint8_t avrcp_controller_rewind(uint16_t avrcp_cid){
1355     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1356 }
1357 
1358 /* start continuous cmds */
1359 
1360 uint8_t avrcp_controller_start_press_and_hold_cmd(uint16_t avrcp_cid, avrcp_operation_id_t operation_id){
1361     return request_continuous_pass_through_press_control_cmd(avrcp_cid, operation_id, 0);
1362 }
1363 
1364 uint8_t avrcp_controller_press_and_hold_play(uint16_t avrcp_cid){
1365     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1366 }
1367 uint8_t avrcp_controller_press_and_hold_stop(uint16_t avrcp_cid){
1368     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1369 }
1370 uint8_t avrcp_controller_press_and_hold_pause(uint16_t avrcp_cid){
1371     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1372 }
1373 uint8_t avrcp_controller_press_and_hold_forward(uint16_t avrcp_cid){
1374     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1375 }
1376 uint8_t avrcp_controller_press_and_hold_backward(uint16_t avrcp_cid){
1377     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1378 }
1379 uint8_t avrcp_controller_press_and_hold_fast_forward(uint16_t avrcp_cid){
1380     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1381 }
1382 uint8_t avrcp_controller_press_and_hold_rewind(uint16_t avrcp_cid){
1383     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1384 }
1385 uint8_t avrcp_controller_press_and_hold_volume_up(uint16_t avrcp_cid){
1386     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1387 }
1388 uint8_t avrcp_controller_press_and_hold_volume_down(uint16_t avrcp_cid){
1389     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1390 }
1391 uint8_t avrcp_controller_press_and_hold_mute(uint16_t avrcp_cid){
1392     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1393 }
1394 
1395 /* stop continuous cmds */
1396 uint8_t avrcp_controller_release_press_and_hold_cmd(uint16_t avrcp_cid){
1397     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1398     if (!connection){
1399         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1400     }
1401 
1402     switch (connection->state){
1403         // respond when we receive response for (repeated) press command
1404         case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
1405             connection->controller_press_and_hold_cmd_release = true;
1406             break;
1407 
1408         // release already sent or on the way, nothing to do
1409         case AVCTP_W2_RECEIVE_RESPONSE:
1410         case AVCTP_W2_SEND_RELEASE_COMMAND:
1411             break;
1412 
1413         // about to send next repeated press command or wait for it -> release right away
1414         case AVCTP_W2_SEND_PRESS_COMMAND:
1415         case AVCTP_W4_STOP:
1416             return avrcp_controller_request_pass_through_release_control_cmd(connection);
1417 
1418         // otherwise reject request
1419         default:
1420             return ERROR_CODE_COMMAND_DISALLOWED;
1421     }
1422     return ERROR_CODE_SUCCESS;
1423 }
1424 
1425 uint8_t avrcp_controller_enable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1426     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1427     if (!connection){
1428         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1429     }
1430     return avrcp_controller_register_notification(connection, event_id);
1431 }
1432 
1433 uint8_t avrcp_controller_disable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1434     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1435     if (!connection){
1436         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1437     }
1438     if (!connection->controller_notifications_supported_by_target_queried){
1439         return ERROR_CODE_COMMAND_DISALLOWED;
1440     }
1441 
1442     if ((connection->notifications_supported_by_target & (1 << event_id)) == 0){
1443         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1444     }
1445 
1446     if ((connection->notifications_enabled & (1 << event_id)) == 0){
1447         return ERROR_CODE_SUCCESS;
1448     }
1449 
1450     connection->controller_notifications_to_deregister |= (1 << event_id);
1451     return ERROR_CODE_SUCCESS;
1452 }
1453 
1454 uint8_t avrcp_controller_unit_info(uint16_t avrcp_cid){
1455     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1456     if (!connection){
1457         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1458     }
1459     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1460 
1461     connection->state = AVCTP_W2_SEND_COMMAND;
1462     avrcp_controller_custom_command_data_init(connection, AVRCP_CMD_OPCODE_UNIT_INFO, AVRCP_CTYPE_STATUS,
1463                                               AVRCP_SUBUNIT_TYPE_UNIT, AVRCP_SUBUNIT_ID_IGNORE, AVRCP_PDU_ID_UNDEFINED,
1464                                               0);
1465 
1466     connection->data = connection->message_body;
1467     memset(connection->data, 0xFF, 5);
1468     connection->data_len = 5;
1469     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1470     return ERROR_CODE_SUCCESS;
1471 }
1472 
1473 uint8_t avrcp_controller_subunit_info(uint16_t avrcp_cid){
1474     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1475     if (!connection){
1476         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1477     }
1478     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1479 
1480     connection->state = AVCTP_W2_SEND_COMMAND;
1481     avrcp_controller_custom_command_data_init(connection, AVRCP_CMD_OPCODE_SUBUNIT_INFO, AVRCP_CTYPE_STATUS,
1482                                               AVRCP_SUBUNIT_TYPE_UNIT, AVRCP_SUBUNIT_ID_IGNORE, AVRCP_PDU_ID_UNDEFINED,
1483                                               0);
1484 
1485     connection->data = connection->message_body;
1486     memset(connection->data, 0xFF, 5);
1487     connection->data[0] = 7; // page: 0, extension_code: 7
1488     connection->data_len = 5;
1489     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1490     return ERROR_CODE_SUCCESS;
1491 }
1492 
1493 uint8_t avrcp_controller_get_supported_company_ids(uint16_t avrcp_cid){
1494     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1495     if (!connection){
1496         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1497     }
1498     if (connection->state != AVCTP_CONNECTION_OPENED){
1499         return ERROR_CODE_COMMAND_DISALLOWED;
1500     }
1501     avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_COMPANY);
1502     return ERROR_CODE_SUCCESS;
1503 }
1504 
1505 uint8_t avrcp_controller_get_supported_events(uint16_t avrcp_cid){
1506     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1507     if (!connection){
1508         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1509     }
1510     if (connection->state != AVCTP_CONNECTION_OPENED){
1511         return ERROR_CODE_COMMAND_DISALLOWED;
1512     }
1513 
1514     if (!connection->controller_notifications_supported_by_target_queried){
1515         connection->controller_notifications_supported_by_target_queried = true;
1516         avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_EVENT);
1517         return ERROR_CODE_SUCCESS;
1518     }
1519 
1520     avrcp_controller_emit_supported_events(connection);
1521     return ERROR_CODE_SUCCESS;
1522 }
1523 
1524 uint8_t avrcp_controller_get_play_status(uint16_t avrcp_cid){
1525     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1526     if (!connection){
1527         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1528     }
1529     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1530 
1531     connection->state = AVCTP_W2_SEND_COMMAND;
1532     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_PLAY_STATUS);
1533 
1534     connection->data_len = 0;
1535     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1536     return ERROR_CODE_SUCCESS;
1537 }
1538 
1539 uint8_t avrcp_controller_set_addressed_player(uint16_t avrcp_cid, uint16_t addressed_player_id){
1540     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1541     if (!connection){
1542         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1543     }
1544     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1545 
1546     connection->state = AVCTP_W2_SEND_COMMAND;
1547     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_ADDRESSED_PLAYER);
1548 
1549     connection->data_len = 2;
1550     big_endian_store_16(connection->data, 0, addressed_player_id);
1551 
1552     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1553     return ERROR_CODE_SUCCESS;
1554 }
1555 
1556 uint8_t avrcp_controller_get_element_attributes(uint16_t avrcp_cid, uint8_t num_attributes, avrcp_media_attribute_id_t * attributes){
1557     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1558     if (!connection){
1559         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1560     }
1561 
1562     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1563 
1564     if (num_attributes >= AVRCP_MEDIA_ATTR_RESERVED) {
1565         return ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS;
1566     }
1567 
1568     connection->state = AVCTP_W2_SEND_COMMAND;
1569     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES);
1570 
1571     uint8_t pos = 0;
1572     // write 8 bytes value
1573     memset(connection->data, pos, 8); // identifier: PLAYING
1574     pos += 8;
1575 
1576     uint8_t num_attributes_index = pos;
1577     pos++;
1578 
1579     // If num_attributes is set to zero, all attribute information shall be returned,
1580     // and the AttributeID field is omitted
1581     connection->data[num_attributes_index] = 0;
1582     uint8_t i;
1583     for (i = 0; i < num_attributes; i++){
1584         // ignore invalid attribute ID and "get all attributes"
1585         if (AVRCP_MEDIA_ATTR_ALL > attributes[i] && attributes[i] < AVRCP_MEDIA_ATTR_RESERVED){
1586             // every attribute is 4 bytes long
1587             big_endian_store_32(connection->data, pos, attributes[i]);
1588             pos += 4;
1589             connection->data[num_attributes_index]++;
1590         }
1591     }
1592 
1593     // Parameter Length
1594     connection->data_len = pos;
1595 
1596     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1597     return ERROR_CODE_SUCCESS;
1598 }
1599 
1600 uint8_t avrcp_controller_get_now_playing_info(uint16_t avrcp_cid){
1601     return avrcp_controller_get_element_attributes(avrcp_cid, 0, NULL);
1602 }
1603 
1604 uint8_t avrcp_controller_get_now_playing_info_for_media_attribute_id(uint16_t avrcp_cid, avrcp_media_attribute_id_t media_attribute_id){
1605     if (media_attribute_id == AVRCP_MEDIA_ATTR_ALL){
1606         return avrcp_controller_get_now_playing_info(avrcp_cid);
1607     }
1608     return avrcp_controller_get_element_attributes(avrcp_cid, 1, &media_attribute_id);
1609 }
1610 
1611 uint8_t avrcp_controller_set_absolute_volume(uint16_t avrcp_cid, uint8_t volume){
1612      avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1613     if (!connection){
1614         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1615     }
1616 
1617     //
1618     // allow sending of multiple set abs volume commands without waiting for response
1619     //
1620     uint8_t status = ERROR_CODE_COMMAND_DISALLOWED;
1621     switch (connection->state){
1622         case AVCTP_CONNECTION_OPENED:
1623             status = ERROR_CODE_SUCCESS;
1624             break;
1625         case AVCTP_W2_RECEIVE_RESPONSE:
1626             // - is pending response also set abs volume
1627             if (connection->command_opcode  != AVRCP_CMD_OPCODE_VENDOR_DEPENDENT) break;
1628             if (connection->command_type    != AVRCP_CTYPE_CONTROL)               break;
1629             if (connection->subunit_type    != AVRCP_SUBUNIT_TYPE_PANEL)          break;
1630             if (connection->subunit_id      != AVRCP_SUBUNIT_ID)                  break;
1631             if (connection->pdu_id          != AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME)  break;
1632             // - is next transaction id valid in window
1633             if (avrcp_controller_is_transaction_id_valid(connection, avrcp_controller_calc_next_transaction_label(connection->transaction_id_counter)) == false) break;
1634             status = ERROR_CODE_SUCCESS;
1635             break;
1636         default:
1637             break;
1638     }
1639     if (status != ERROR_CODE_SUCCESS) return status;
1640 
1641     connection->state = AVCTP_W2_SEND_COMMAND;
1642     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME);
1643 
1644     // Parameter Length
1645     connection->data_len = 1;
1646     connection->data[0] = volume;
1647 
1648     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1649     return ERROR_CODE_SUCCESS;
1650 }
1651 
1652 uint8_t avrcp_controller_query_shuffle_and_repeat_modes(uint16_t avrcp_cid){
1653     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1654     if (!connection){
1655         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1656     }
1657     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1658 
1659     connection->state = AVCTP_W2_SEND_COMMAND;
1660     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE);
1661 
1662     connection->data_len = 5;
1663     connection->data[0] = 4;                     // NumPlayerApplicationSettingAttributeID
1664     // PlayerApplicationSettingAttributeID1 AVRCP Spec, Appendix F, 133
1665     connection->data[1] = 0x01;   // equalizer  (1-OFF, 2-ON)
1666     connection->data[2] = 0x02;   // repeat     (1-off, 2-single track, 3-all tracks, 4-group repeat)
1667     connection->data[3] = 0x03;   // shuffle    (1-off, 2-all tracks, 3-group shuffle)
1668     connection->data[4] = 0x04;   // scan       (1-off, 2-all tracks, 3-group scan)
1669 
1670     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1671     return ERROR_CODE_SUCCESS;
1672 }
1673 
1674 static uint8_t avrcp_controller_set_current_player_application_setting_value(uint16_t avrcp_cid, uint8_t attr_id, uint8_t attr_value){
1675     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1676     if (!connection){
1677         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1678     }
1679     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1680 
1681     connection->state = AVCTP_W2_SEND_COMMAND;
1682     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE);
1683 
1684     // Parameter Length
1685     connection->data_len = 3;
1686     connection->data[0]  = 2;
1687     connection->data[1]  = attr_id;
1688     connection->data[2]  = attr_value;
1689 
1690     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1691     return ERROR_CODE_SUCCESS;
1692 }
1693 
1694 uint8_t avrcp_controller_set_shuffle_mode(uint16_t avrcp_cid, avrcp_shuffle_mode_t mode){
1695     if ((mode < AVRCP_SHUFFLE_MODE_OFF) || (mode > AVRCP_SHUFFLE_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1696     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x03, mode);
1697 }
1698 
1699 uint8_t avrcp_controller_set_repeat_mode(uint16_t avrcp_cid, avrcp_repeat_mode_t mode){
1700     if ((mode < AVRCP_REPEAT_MODE_OFF) || (mode > AVRCP_REPEAT_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1701     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x02, mode);
1702 }
1703 
1704 uint8_t avrcp_controller_play_item_for_scope(uint16_t avrcp_cid, uint8_t * uid, uint16_t uid_counter, avrcp_browsing_scope_t scope){
1705     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1706     if (!connection){
1707         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1708     }
1709     if (connection->state != AVCTP_CONNECTION_OPENED){
1710         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1711         return ERROR_CODE_COMMAND_DISALLOWED;
1712     }
1713     connection->state = AVCTP_W2_SEND_COMMAND;
1714     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_PLAY_ITEM);
1715 
1716     // Parameter Length
1717     connection->data_len = 11;
1718     connection->data[0]  = scope;
1719     memset(&connection->data[1], 0, 8);
1720     if (uid){
1721         (void)memcpy(&connection->data[1], uid, 8);
1722     }
1723     big_endian_store_16(connection->data, 9, uid_counter);
1724 
1725     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1726     return ERROR_CODE_SUCCESS;
1727 }
1728 
1729 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){
1730     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1731     if (!connection){
1732         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1733     }
1734     if (connection->state != AVCTP_CONNECTION_OPENED){
1735         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1736         return ERROR_CODE_COMMAND_DISALLOWED;
1737     }
1738 
1739     connection->state = AVCTP_W2_SEND_COMMAND;
1740     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_ADD_TO_NOW_PLAYING);
1741 
1742     // Parameter Length
1743     connection->data_len = 11;
1744     connection->data[0]  = scope;
1745     memset(&connection->data[1], 0, 8);
1746     if (uid){
1747         (void)memcpy(&connection->data[1], uid, 8);
1748     }
1749     big_endian_store_16(connection->data, 9, uid_counter);
1750 
1751     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1752     return ERROR_CODE_SUCCESS;
1753 }
1754 
1755 uint8_t avrcp_controller_set_max_num_fragments(uint16_t avrcp_cid, uint8_t max_num_fragments){
1756     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1757     if (!connection){
1758         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1759     }
1760     connection->controller_max_num_fragments = max_num_fragments;
1761     return ERROR_CODE_SUCCESS;
1762 }
1763 
1764 
1765 uint8_t avrcp_controller_send_custom_command(uint16_t avrcp_cid,
1766     avrcp_command_type_t command_type,
1767     avrcp_subunit_type_t subunit_type, avrcp_subunit_id_t subunit_id,
1768     avrcp_pdu_id_t pdu_id, uint32_t company_id,
1769     const uint8_t * data, uint16_t data_len){
1770 
1771     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1772     if (!connection){
1773         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1774     }
1775     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1776 
1777     connection->state = AVCTP_W2_SEND_COMMAND;
1778     avrcp_controller_custom_command_data_init(connection, AVRCP_CMD_OPCODE_VENDOR_DEPENDENT, command_type, subunit_type,
1779                                               subunit_id, pdu_id, company_id);
1780 
1781     connection->data = (uint8_t *)data;
1782     connection->data_len = data_len;
1783 
1784     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1785     return ERROR_CODE_SUCCESS;
1786 }
1787