xref: /btstack/src/classic/avrcp_controller.c (revision d9bfc63211d8cd9a7ca01d7d3bb1905437ba8031)
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++] = connection->pdu_id;
133     little_endian_store_16(in_place_buffer, pos, response_len);
134     pos += 2;
135     in_place_buffer[1] = pos + response_len - 2;
136 }
137 
138 static void avrcp_controller_emit_notification_complete(avrcp_connection_t * connection, uint8_t status, uint8_t event_id, bool enabled){
139     uint8_t event[8];
140     uint8_t pos = 0;
141     event[pos++] = HCI_EVENT_AVRCP_META;
142     event[pos++] = sizeof(event) - 2;
143     event[pos++] = AVRCP_SUBEVENT_NOTIFICATION_STATE;
144     little_endian_store_16(event, pos, connection->avrcp_cid);
145     pos += 2;
146     event[pos++] = status;
147     event[pos++] = enabled ? 1 : 0;
148     event[pos++] = event_id;
149     UNUSED(pos);
150     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
151 }
152 
153 static void avrcp_controller_emit_supported_events(avrcp_connection_t * connection){
154     uint8_t ctype = (uint8_t) AVRCP_CTYPE_RESPONSE_CHANGED_STABLE;
155     uint8_t event_id;
156 
157     for (event_id = (uint8_t) AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; event_id < (uint8_t) AVRCP_NOTIFICATION_EVENT_LAST_INDEX; event_id++){
158         if ((connection->notifications_supported_by_target & (1 << event_id)) == 0){
159             continue;
160         }
161         uint8_t event[8];
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;
166         little_endian_store_16(event, pos, connection->avrcp_cid);
167         pos += 2;
168         event[pos++] = ctype;
169         event[pos++] = 0;
170         event[pos++] = event_id;
171         UNUSED(pos);
172         (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
173     }
174 
175     uint8_t event[7];
176     uint8_t pos = 0;
177     event[pos++] = HCI_EVENT_AVRCP_META;
178     event[pos++] = sizeof(event) - 2;
179     event[pos++] = AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID_DONE;
180     little_endian_store_16(event, pos, connection->avrcp_cid);
181     pos += 2;
182     event[pos++] = ctype;
183     event[pos++] = 0;
184     UNUSED(pos);
185     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
186 }
187 
188 static void avrcp_controller_emit_notification_for_event_id(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id,
189                                                             avrcp_command_type_t ctype, const uint8_t *payload,
190                                                             uint16_t size) {
191     switch (event_id){
192         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_POS_CHANGED:{
193             if (size < 4) break;
194             uint32_t song_position = big_endian_read_32(payload, 0);
195             uint16_t offset = 0;
196             uint8_t event[10];
197             event[offset++] = HCI_EVENT_AVRCP_META;
198             event[offset++] = sizeof(event) - 2;
199             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_POS_CHANGED;
200             little_endian_store_16(event, offset, avrcp_cid);
201             offset += 2;
202             event[offset++] = ctype;
203             little_endian_store_32(event, offset, song_position);
204             offset += 4;
205             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
206             break;
207         }
208         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED:{
209             if (size < 1) break;
210             uint16_t offset = 0;
211             uint8_t event[7];
212             event[offset++] = HCI_EVENT_AVRCP_META;
213             event[offset++] = sizeof(event) - 2;
214             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_STATUS_CHANGED;
215             little_endian_store_16(event, offset, avrcp_cid);
216             offset += 2;
217             event[offset++] = ctype;
218             event[offset++] = payload[0];
219             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
220             break;
221         }
222         case AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED:{
223             uint16_t offset = 0;
224             uint8_t event[6];
225             event[offset++] = HCI_EVENT_AVRCP_META;
226             event[offset++] = sizeof(event) - 2;
227             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_TRACK_CHANGED;
228             little_endian_store_16(event, offset, avrcp_cid);
229             offset += 2;
230             event[offset++] = ctype;
231             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
232             break;
233         }
234         case AVRCP_NOTIFICATION_EVENT_NOW_PLAYING_CONTENT_CHANGED:{
235             uint16_t offset = 0;
236             uint8_t event[6];
237             event[offset++] = HCI_EVENT_AVRCP_META;
238             event[offset++] = sizeof(event) - 2;
239             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_NOW_PLAYING_CONTENT_CHANGED;
240             little_endian_store_16(event, offset, avrcp_cid);
241             offset += 2;
242             event[offset++] = ctype;
243             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
244             break;
245         }
246         case AVRCP_NOTIFICATION_EVENT_AVAILABLE_PLAYERS_CHANGED:{
247             uint16_t offset = 0;
248             uint8_t event[6];
249             event[offset++] = HCI_EVENT_AVRCP_META;
250             event[offset++] = sizeof(event) - 2;
251             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_AVAILABLE_PLAYERS_CHANGED;
252             little_endian_store_16(event, offset, avrcp_cid);
253             offset += 2;
254             event[offset++] = ctype;
255             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
256             break;
257         }
258         case AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED:{
259             if (size < 1) break;
260             uint16_t offset = 0;
261             uint8_t event[7];
262             event[offset++] = HCI_EVENT_AVRCP_META;
263             event[offset++] = sizeof(event) - 2;
264             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED;
265             little_endian_store_16(event, offset, avrcp_cid);
266             offset += 2;
267             event[offset++] = ctype;
268             event[offset++] = payload[0] & 0x7F;
269             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
270             break;
271         }
272         case AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED:{
273             if (size < 2) break;
274             uint8_t event[8];
275             uint16_t offset = 0;
276             uint16_t uuid = big_endian_read_16(payload, 0);
277             event[offset++] = HCI_EVENT_AVRCP_META;
278             event[offset++] = sizeof(event) - 2;
279             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_UIDS_CHANGED;
280             little_endian_store_16(event, offset, avrcp_cid);
281             offset += 2;
282             event[offset++] = ctype;
283             little_endian_store_16(event, offset, uuid);
284             offset += 2;
285             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
286             break;
287         }
288 
289         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_END:{
290             uint16_t offset = 0;
291             uint8_t event[6];
292             event[offset++] = HCI_EVENT_AVRCP_META;
293             event[offset++] = sizeof(event) - 2;
294             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_END;
295             little_endian_store_16(event, offset, avrcp_cid);
296             offset += 2;
297             event[offset++] = ctype;
298             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
299             break;
300         }
301         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_START:{
302             uint16_t offset = 0;
303             uint8_t event[6];
304             event[offset++] = HCI_EVENT_AVRCP_META;
305             event[offset++] = sizeof(event) - 2;
306             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_START;
307             little_endian_store_16(event, offset, avrcp_cid);
308             offset += 2;
309             event[offset++] = ctype;
310             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
311             break;
312         }
313         case AVRCP_NOTIFICATION_EVENT_BATT_STATUS_CHANGED:{
314             if (size < 1) break;
315             uint16_t offset = 0;
316             uint8_t event[7];
317             event[offset++] = HCI_EVENT_AVRCP_META;
318             event[offset++] = sizeof(event) - 2;
319             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_BATT_STATUS_CHANGED;
320             little_endian_store_16(event, offset, avrcp_cid);
321             offset += 2;
322             event[offset++] = ctype;
323             event[offset++] = payload[0];
324             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
325             break;
326         }
327 
328         case AVRCP_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED:{
329             if (size < 1) break;
330             uint16_t offset = 0;
331             uint8_t event[7];
332             event[offset++] = HCI_EVENT_AVRCP_META;
333             event[offset++] = sizeof(event) - 2;
334             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED;
335             little_endian_store_16(event, offset, avrcp_cid);
336             offset += 2;
337             event[offset++] = ctype;
338             event[offset++] = payload[0];
339             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
340             break;
341         }
342 
343         case AVRCP_NOTIFICATION_EVENT_PLAYER_APPLICATION_SETTING_CHANGED:
344         default:
345             log_info("avrcp: not implemented");
346             break;
347     }
348 }
349 
350 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){
351     btstack_assert(callback != NULL);
352 
353     uint8_t event[8];
354     int pos = 0;
355     event[pos++] = HCI_EVENT_AVRCP_META;
356     event[pos++] = sizeof(event) - 2;
357     event[pos++] = AVRCP_SUBEVENT_SHUFFLE_AND_REPEAT_MODE;
358     little_endian_store_16(event, pos, avrcp_cid);
359     pos += 2;
360     event[pos++] = ctype;
361     event[pos++] = repeat_mode;
362     event[pos++] = shuffle_mode;
363     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
364 }
365 
366 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){
367     uint8_t event[7];
368     int pos = 0;
369     event[pos++] = HCI_EVENT_AVRCP_META;
370     event[pos++] = sizeof(event) - 2;
371     event[pos++] = AVRCP_SUBEVENT_NOW_PLAYING_INFO_DONE;
372     little_endian_store_16(event, pos, avrcp_cid);
373     pos += 2;
374     event[pos++] = ctype;
375     event[pos++] = status;
376     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
377 }
378 
379 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){
380     uint8_t event[HCI_EVENT_BUFFER_SIZE];
381     int pos = 0;
382     event[pos++] = HCI_EVENT_AVRCP_META;
383     // reserve one byte for subevent type and data len
384     int data_len_pos = pos;
385     pos++;
386     int subevent_type_pos = pos;
387     pos++;
388     little_endian_store_16(event, pos, avrcp_cid);
389     pos += 2;
390     event[pos++] = ctype;
391 
392     switch (attr_id){
393         case AVRCP_MEDIA_ATTR_TITLE:
394             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TITLE_INFO;
395             event[pos++] = value_len;
396             (void)memcpy(event + pos, value, value_len);
397             break;
398         case AVRCP_MEDIA_ATTR_ARTIST:
399             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ARTIST_INFO;
400             event[pos++] = value_len;
401             (void)memcpy(event + pos, value, value_len);
402             break;
403         case AVRCP_MEDIA_ATTR_ALBUM:
404             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ALBUM_INFO;
405             event[pos++] = value_len;
406             (void)memcpy(event + pos, value, value_len);
407             break;
408         case AVRCP_MEDIA_ATTR_GENRE:
409             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_GENRE_INFO;
410             event[pos++] = value_len;
411             (void)memcpy(event + pos, value, value_len);
412             break;
413         case AVRCP_MEDIA_ATTR_SONG_LENGTH_MS:
414             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_SONG_LENGTH_MS_INFO;
415             if (value){
416                 little_endian_store_32(event, pos, btstack_atoi((char *)value));
417             } else {
418                 little_endian_store_32(event, pos, 0);
419             }
420             pos += 4;
421             break;
422         case AVRCP_MEDIA_ATTR_TRACK:
423             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TRACK_INFO;
424             if (value){
425                 event[pos++] = btstack_atoi((char *)value);
426             } else {
427                 event[pos++] = 0;
428             }
429             break;
430         case AVRCP_MEDIA_ATTR_TOTAL_NUM_ITEMS:
431             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TOTAL_TRACKS_INFO;
432             if (value){
433                 event[pos++] = btstack_atoi((char *)value);
434             } else {
435                 event[pos++] = 0;
436             }
437             break;
438         default:
439             break;
440     }
441     event[data_len_pos] = pos - 2;
442     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
443 }
444 
445 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){
446     btstack_assert(callback != NULL);
447 
448     uint8_t event[7];
449     int pos = 0;
450     event[pos++] = HCI_EVENT_AVRCP_META;
451     event[pos++] = sizeof(event) - 2;
452     event[pos++] = subevent;
453     little_endian_store_16(event, pos, avrcp_cid);
454     pos += 2;
455     event[pos++] = ctype;
456     event[pos++] = operation_id;
457     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
458 }
459 
460 static void avrcp_parser_reset(avrcp_connection_t * connection){
461     connection->list_offset = 0;
462     connection->parser_attribute_header_pos = 0;
463     connection->controller_num_received_fragments = 0;
464     connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
465 }
466 
467 static void avrcp_parser_process_byte(uint8_t byte, avrcp_connection_t * connection, avrcp_command_type_t ctype){
468     uint16_t attribute_total_value_len;
469     uint32_t attribute_id;
470     switch(connection->parser_state){
471         case AVRCP_PARSER_GET_ATTRIBUTE_HEADER:
472             connection->parser_attribute_header[connection->parser_attribute_header_pos++] = byte;
473             connection->list_offset++;
474 
475             if (connection->parser_attribute_header_pos < AVRCP_ATTRIBUTE_HEADER_LEN) return;
476 
477             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
478             connection->attribute_value_len = btstack_min(attribute_total_value_len, AVRCP_MAX_ATTRIBUTE_SIZE);
479             if (connection->attribute_value_len > 0){
480                 // get ready for attribute value
481                 connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_VALUE;
482                 return;
483             }
484 
485             // emit empty attribute
486             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
487             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);
488 
489             // done, see below
490             break;
491 
492         case AVRCP_PARSER_GET_ATTRIBUTE_VALUE:
493             connection->attribute_value[connection->attribute_value_offset++] = byte;
494             connection->list_offset++;
495 
496             if (connection->attribute_value_offset < connection->attribute_value_len) return;
497 
498             // emit (potentially partial) attribute
499             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
500             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);
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){
504                 // ignore rest of attribute
505                 connection->parser_state = AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE;
506                 return;
507             }
508 
509             // done, see below
510             break;
511 
512         case AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE:
513             connection->attribute_value_offset++;
514             connection->list_offset++;
515 
516             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
517             if (connection->attribute_value_offset < attribute_total_value_len) return;
518 
519             // done, see below
520             break;
521 
522         default:
523             return;
524     }
525 
526     // attribute fully read, check if more to come
527     if (connection->list_offset < connection->list_size){
528         // more to come, reset parser
529         connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
530         connection->parser_attribute_header_pos = 0;
531         connection->attribute_value_offset = 0;
532     } else {
533         // fully done
534         avrcp_parser_reset(connection);
535         avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 0);
536     }
537 }
538 
539 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){
540     int i;
541     for (i=0;i<num_bytes_to_read;i++){
542         avrcp_parser_process_byte(packet[i], connection, ctype);
543     }
544 }
545 
546 static void avrcp_send_cmd_with_avctp_fragmentation(avrcp_connection_t * connection){
547     l2cap_reserve_packet_buffer();
548     uint8_t * packet = l2cap_get_outgoing_buffer();
549 
550     uint16_t max_payload_size;
551     connection->avctp_packet_type = avctp_get_packet_type(connection, &max_payload_size);
552 
553     // non-fragmented: transport header (1) + PID (2)
554     // fragmented:     transport header (1) + num packets (1) + PID (2)
555 
556     uint16_t param_len = connection->data_len;
557     // AVCTP header
558     // transport header : transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
559     uint16_t pos = 0;
560     packet[pos++] = (connection->transaction_id << 4) | (connection->avctp_packet_type << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
561 
562     if (connection->avctp_packet_type == AVCTP_START_PACKET){
563         uint16_t max_frame_size = btstack_min(connection->l2cap_mtu, AVRCP_MAX_AV_C_MESSAGE_FRAME_SIZE);
564         // first packet: max_payload_size
565         // rest packets
566         uint16_t num_payload_bytes = param_len - max_payload_size;
567         uint16_t frame_size_for_continue_packet = max_frame_size - avctp_get_num_bytes_for_header(AVCTP_CONTINUE_PACKET);
568         uint16_t num_avctp_packets = (num_payload_bytes + frame_size_for_continue_packet - 1)/frame_size_for_continue_packet + 1;
569         packet[pos++] = num_avctp_packets;
570     }
571 
572     switch (connection->avctp_packet_type){
573         case AVCTP_SINGLE_PACKET:
574         case AVCTP_START_PACKET:
575             // Profile IDentifier (PID)
576             packet[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
577             packet[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
578 
579             // command_type
580             packet[pos++] = connection->command_type;
581             // subunit_type | subunit ID
582             packet[pos++] = (connection->subunit_type << 3) | connection->subunit_id;
583             // opcode
584             packet[pos++] = (uint8_t)connection->command_opcode;
585 
586             switch (connection->command_opcode){
587                 case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
588                     big_endian_store_24(packet, pos, connection->company_id);
589                     pos += 3;
590                     packet[pos++] = connection->pdu_id;
591                     packet[pos++] = 0;                       // reserved(upper 6) | packet_type -> 0
592                     big_endian_store_16(packet, pos, connection->data_len);     // parameter length
593                     pos += 2;
594                     break;
595                 case AVRCP_CMD_OPCODE_PASS_THROUGH:
596                     packet[pos++] = connection->operation_id;
597                     packet[pos++] = (uint8_t)connection->data_len;     // parameter length
598                     pos += 2;
599                     break;
600                 case AVRCP_CMD_OPCODE_UNIT_INFO:
601                     break;
602                 case AVRCP_CMD_OPCODE_SUBUNIT_INFO:
603                     break;
604                 default:
605                     btstack_assert(false);
606                     return;
607             }
608             break;
609         case AVCTP_CONTINUE_PACKET:
610         case AVCTP_END_PACKET:
611             break;
612         default:
613             btstack_assert(false);
614             return;
615     }
616     // compare number of bytes to store with the remaining buffer size
617     uint16_t bytes_to_copy = btstack_min(connection->data_len - connection->data_offset, max_payload_size - pos);
618 
619     (void)memcpy(packet + pos, &connection->data[connection->data_offset], bytes_to_copy);
620     pos += bytes_to_copy;
621     connection->data_offset += bytes_to_copy;
622 
623     l2cap_send_prepared(connection->l2cap_signaling_cid, pos);
624 }
625 
626 static int avrcp_send_register_notification(avrcp_connection_t * connection, uint8_t event_id){
627     uint8_t command[18];
628     uint16_t pos = 0;
629     // transport header : transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
630     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
631     command[pos++] = (connection->transaction_id << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
632 
633     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
634     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
635     command[pos++] = AVRCP_CTYPE_NOTIFY;
636     command[pos++] = (AVRCP_SUBUNIT_TYPE_PANEL << 3) | AVRCP_SUBUNIT_ID;
637     command[pos++] = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
638 
639     big_endian_store_24(command, pos, BT_SIG_COMPANY_ID);
640     pos += 3;
641     command[pos++] = AVRCP_PDU_ID_REGISTER_NOTIFICATION;
642     command[pos++] = 0;                       // reserved(upper 6) | packet_type -> 0
643     big_endian_store_16(command, pos, 5);     // parameter length
644     pos += 2;
645     command[pos++] = event_id;
646     big_endian_store_32(command, pos, 1);     // send notification on playback position every second, for other notifications it is ignored
647     pos += 4;
648     return l2cap_send(connection->l2cap_signaling_cid, command, pos);
649 }
650 
651 static void avrcp_press_and_hold_timeout_handler(btstack_timer_source_t * timer){
652     UNUSED(timer);
653     avrcp_connection_t * connection = (avrcp_connection_t*) btstack_run_loop_get_timer_context(timer);
654     btstack_run_loop_set_timer(&connection->controller_press_and_hold_cmd_timer, 2000); // 2 seconds timeout
655     btstack_run_loop_add_timer(&connection->controller_press_and_hold_cmd_timer);
656     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
657     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
658 }
659 
660 static void avrcp_press_and_hold_timer_start(avrcp_connection_t * connection){
661     btstack_run_loop_remove_timer(&connection->controller_press_and_hold_cmd_timer);
662     btstack_run_loop_set_timer_handler(&connection->controller_press_and_hold_cmd_timer, avrcp_press_and_hold_timeout_handler);
663     btstack_run_loop_set_timer_context(&connection->controller_press_and_hold_cmd_timer, connection);
664     btstack_run_loop_set_timer(&connection->controller_press_and_hold_cmd_timer, 2000); // 2 seconds timeout
665     btstack_run_loop_add_timer(&connection->controller_press_and_hold_cmd_timer);
666 }
667 
668 static void avrcp_press_and_hold_timer_stop(avrcp_connection_t * connection){
669     connection->controller_press_and_hold_cmd_active = false;
670     btstack_run_loop_remove_timer(&connection->controller_press_and_hold_cmd_timer);
671 }
672 
673 
674 static uint8_t avrcp_controller_request_pass_through_release_control_cmd(avrcp_connection_t * connection){
675     connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
676     if (connection->controller_press_and_hold_cmd_active){
677         avrcp_press_and_hold_timer_stop(connection);
678     }
679     connection->operation_id = (avrcp_operation_id_t)(0x80 | connection->operation_id);
680     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
681     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
682     return ERROR_CODE_SUCCESS;
683 }
684 
685 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){
686     log_info("Send command %d", opid);
687     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
688     if (!connection){
689         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
690     }
691 
692     if (connection->state != AVCTP_CONNECTION_OPENED){
693         log_error("Connection in wrong state %d, expected %d. avrcp cid 0x%02x", connection->state, AVCTP_CONNECTION_OPENED, avrcp_cid);
694         return ERROR_CODE_COMMAND_DISALLOWED;
695     }
696     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
697     avrcp_controller_pass_through_command_data_init(connection, opid);
698 
699     if (playback_speed > 0){
700         connection->data[0] = playback_speed;
701         connection->data_len = 1;
702     }
703 
704     connection->controller_press_and_hold_cmd_active = continuous_cmd;
705     if (connection->controller_press_and_hold_cmd_active){
706         avrcp_press_and_hold_timer_start(connection);
707     }
708 
709     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
710     return ERROR_CODE_SUCCESS;
711 }
712 
713 static uint8_t request_single_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
714     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, false);
715 }
716 
717 static uint8_t request_continuous_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
718     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, true);
719 }
720 
721 static void avrcp_controller_get_capabilities_for_connection(avrcp_connection_t * connection, uint8_t capability_id){
722     connection->state = AVCTP_W2_SEND_COMMAND;
723     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_CAPABILITIES);
724 
725     // Parameter Length
726     connection->data_len = 1;
727     connection->data[0] = capability_id;  // capability ID
728 
729     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
730 }
731 
732 static uint8_t avrcp_controller_register_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
733     if (connection->controller_notifications_supported_by_target_queried && (connection->notifications_supported_by_target & (1 << event_id)) == 0){
734         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
735     }
736     if ((connection->controller_notifications_to_deregister & (1 << event_id)) != 0){
737         return ERROR_CODE_COMMAND_DISALLOWED;
738     }
739     if ( (connection->notifications_enabled & (1 << event_id)) != 0){
740         return ERROR_CODE_SUCCESS;
741     }
742     connection->controller_notifications_to_register |= (1 << event_id);
743 
744     if (!connection->controller_notifications_supported_by_target_queried){
745         connection->controller_notifications_supported_by_target_suppress_emit_result = true;
746         avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_EVENT);
747         return ERROR_CODE_SUCCESS;
748     }
749     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
750     return ERROR_CODE_SUCCESS;
751 }
752 
753 static uint8_t avrcp_controller_request_continuation(avrcp_connection_t * connection, avrcp_pdu_id_t pdu_id){
754     connection->state = AVCTP_W2_SEND_COMMAND;
755     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, pdu_id);
756 
757     // Parameter Length
758     connection->data_len = 3;
759     big_endian_store_16(connection->data, 0, 1);
760     connection->data[2] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
761 
762     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
763     return ERROR_CODE_SUCCESS;
764 }
765 
766 static uint8_t avrcp_controller_request_abort_continuation(avrcp_connection_t * connection){
767     return avrcp_controller_request_continuation(connection, AVRCP_PDU_ID_REQUEST_ABORT_CONTINUING_RESPONSE);
768 }
769 
770 static uint8_t avrcp_controller_request_continue_response(avrcp_connection_t * connection){
771     return avrcp_controller_request_continuation(connection, AVRCP_PDU_ID_REQUEST_CONTINUING_RESPONSE);
772 }
773 
774 static void avrcp_controller_handle_notification(avrcp_connection_t *connection, avrcp_command_type_t ctype, uint8_t *payload, uint16_t size) {
775     if (size < 1) return;
776     uint16_t pos = 0;
777     avrcp_notification_event_id_t event_id = (avrcp_notification_event_id_t) payload[pos++];
778     if ( (event_id < AVRCP_NOTIFICATION_EVENT_FIRST_INDEX) || (event_id > AVRCP_NOTIFICATION_EVENT_LAST_INDEX)){
779         return;
780     }
781 
782     uint16_t event_mask = (1 << event_id);
783     uint16_t reset_event_mask = ~event_mask;
784 
785     switch (ctype){
786         case AVRCP_CTYPE_RESPONSE_REJECTED:
787             connection->controller_notifications_to_deregister &= reset_event_mask;
788             connection->controller_notifications_to_register   &= reset_event_mask;
789             connection->controller_initial_status_reported     &= reset_event_mask;
790             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE, event_id, false);
791             return;
792 
793         case AVRCP_CTYPE_RESPONSE_INTERIM:
794             // register as enabled
795             connection->notifications_enabled |= event_mask;
796 
797             // check if initial value is already sent
798             if ((connection->controller_initial_status_reported & event_mask) != 0 ){
799                 return;
800             }
801             // emit event only once, initially
802             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_SUCCESS, event_id, true);
803             connection->controller_initial_status_reported |= event_mask;
804             // emit initial value after this switch
805             break;
806 
807         case AVRCP_CTYPE_RESPONSE_CHANGED_STABLE:
808             // received change, event is considered de-registered
809             // we are re-enabling it automatically, if it is not
810             // explicitly disabled
811             connection->notifications_enabled &= reset_event_mask;
812             if ((connection->controller_notifications_to_deregister & event_mask) == 0){
813                 avrcp_controller_register_notification(connection, event_id);
814             } else {
815                 connection->controller_notifications_to_deregister &= reset_event_mask;
816                 connection->controller_notifications_to_register   &= reset_event_mask;
817                 connection->controller_initial_status_reported     &= reset_event_mask;
818                 avrcp_controller_emit_notification_complete(connection, ERROR_CODE_SUCCESS, event_id, false);
819             }
820             break;
821 
822         default:
823             return;
824     }
825 
826     avrcp_controller_emit_notification_for_event_id(connection->avrcp_cid, event_id, ctype, payload + pos, size - pos);
827 }
828 
829 #ifdef ENABLE_AVCTP_FRAGMENTATION
830 static void avctp_reassemble_message(avrcp_connection_t * connection, avctp_packet_type_t packet_type, uint8_t *packet, uint16_t size){
831     // after header (transaction label and packet type)
832     uint16_t pos;
833     uint16_t bytes_to_store;
834 
835     switch (packet_type){
836         case AVCTP_START_PACKET:
837             if (size < 2) return;
838 
839             // store header
840             pos = 0;
841             connection->avctp_reassembly_buffer[pos] = packet[pos];
842             pos++;
843             connection->avctp_reassembly_size = pos;
844 
845             // NOTE: num packets not needed for reassembly, ignoring it does not pose security risk -> no need to store it
846             pos++;
847 
848             // PID in reassembled packet is at offset 1, it will be read later after the avctp_reassemble_message with AVCTP_END_PACKET is called
849 
850             bytes_to_store = btstack_min(size - pos, sizeof(connection->avctp_reassembly_buffer) - connection->avctp_reassembly_size);
851             memcpy(&connection->avctp_reassembly_buffer[connection->avctp_reassembly_size], &packet[pos], bytes_to_store);
852             connection->avctp_reassembly_size += bytes_to_store;
853             break;
854 
855         case AVCTP_CONTINUE_PACKET:
856         case AVCTP_END_PACKET:
857             if (size < 1) return;
858 
859             // store remaining data, ignore header
860             pos = 1;
861             bytes_to_store = btstack_min(size - pos, sizeof(connection->avctp_reassembly_buffer) - connection->avctp_reassembly_size);
862             memcpy(&connection->avctp_reassembly_buffer[connection->avctp_reassembly_size], &packet[pos], bytes_to_store);
863             connection->avctp_reassembly_size += bytes_to_store;
864             break;
865 
866         default:
867             return;
868     }
869 }
870 #endif
871 
872 static void avrcp_handle_l2cap_data_packet_for_signaling_connection(avrcp_connection_t * connection, uint8_t *packet, uint16_t size){
873     if (size < 6u) return;
874     uint8_t  pdu_id;
875     avrcp_packet_type_t  vendor_dependent_packet_type;
876 
877     uint16_t pos = 0;
878     connection->controller_last_confirmed_transaction_id = packet[pos] >> 4;
879     avrcp_frame_type_t  frame_type =  (avrcp_frame_type_t)((packet[pos] >> 1) & 0x01);
880     avctp_packet_type_t packet_type = (avctp_packet_type_t)((packet[pos] >> 2) & 0x03);
881     pos++;
882 
883     if (frame_type != AVRCP_RESPONSE_FRAME) return;
884 
885     switch (packet_type){
886         case AVCTP_SINGLE_PACKET:
887             break;
888 
889 #ifdef ENABLE_AVCTP_FRAGMENTATION
890         case AVCTP_START_PACKET:
891         case AVCTP_CONTINUE_PACKET:
892             avctp_reassemble_message(connection, packet_type, packet, size);
893             return;
894 
895         case AVCTP_END_PACKET:
896             avctp_reassemble_message(connection, packet_type, packet, size);
897 
898             packet = connection->avctp_reassembly_buffer;
899             size   = connection->avctp_reassembly_size;
900             break;
901 #endif
902 
903         default:
904             return;
905     }
906 
907     pos += 2; // PID
908 
909     avrcp_command_type_t ctype = (avrcp_command_type_t) packet[pos++];
910 
911 #ifdef ENABLE_LOG_INFO
912     uint8_t byte_value = packet[pos];
913     avrcp_subunit_type_t subunit_type = (avrcp_subunit_type_t) (byte_value >> 3);
914     avrcp_subunit_type_t subunit_id   = (avrcp_subunit_type_t) (byte_value & 0x07);
915 #endif
916     pos++;
917 
918     uint8_t opcode = packet[pos++];
919     uint16_t param_length;
920 
921     switch (opcode){
922         case AVRCP_CMD_OPCODE_SUBUNIT_INFO:{
923             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
924             connection->state = AVCTP_CONNECTION_OPENED;
925 
926 #ifdef ENABLE_LOG_INFO
927             // page, extension code (1)
928             pos++;
929             uint8_t unit_type = packet[pos] >> 3;
930             uint8_t max_subunit_ID = packet[pos] & 0x07;
931             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);
932 #endif
933             break;
934         }
935         case AVRCP_CMD_OPCODE_UNIT_INFO:{
936             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
937             connection->state = AVCTP_CONNECTION_OPENED;
938 
939 #ifdef ENABLE_LOG_INFO
940             // byte value 7 (1)
941             pos++;
942             uint8_t unit_type = packet[pos] >> 3;
943             uint8_t unit = packet[pos] & 0x07;
944             pos++;
945             uint32_t company_id = big_endian_read_24(packet, pos);
946             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,
947                 ctype, subunit_type, subunit_id, opcode, unit_type, unit, company_id);
948 #endif
949             break;
950         }
951         case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
952 
953             if ((size - pos) < 7) return;
954 
955             // Company ID (3)
956             pos += 3;
957             pdu_id = packet[pos++];
958             vendor_dependent_packet_type = (avrcp_packet_type_t)(packet[pos++] & 0x03);
959             param_length = big_endian_read_16(packet, pos);
960             pos += 2;
961 
962             if ((size - pos) < param_length) return;
963 
964             // handle asynchronous notifications, without changing state
965             if (pdu_id == AVRCP_PDU_ID_REGISTER_NOTIFICATION){
966                 avrcp_controller_handle_notification(connection, ctype, packet + pos, size - pos);
967                 break;
968             }
969 
970             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE){
971                 log_info("AVRCP_CMD_OPCODE_VENDOR_DEPENDENT state %d", connection->state);
972                 return;
973             }
974             connection->state = AVCTP_CONNECTION_OPENED;
975 
976             log_info("VENDOR DEPENDENT response: pdu id 0x%02x, param_length %d, status %s", pdu_id, param_length, avrcp_ctype2str(ctype));
977             switch (pdu_id){
978                 case AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE:{
979                     uint8_t num_attributes = packet[pos++];
980                     int i;
981                     avrcp_repeat_mode_t  repeat_mode =  AVRCP_REPEAT_MODE_INVALID;
982                     avrcp_shuffle_mode_t shuffle_mode = AVRCP_SHUFFLE_MODE_INVALID;
983                     for (i = 0; i < num_attributes; i++){
984                         uint8_t attribute_id    = packet[pos++];
985                         uint8_t value = packet[pos++];
986                         switch (attribute_id){
987                             case 0x02:
988                                 repeat_mode = (avrcp_repeat_mode_t) value;
989                                 break;
990                             case 0x03:
991                                 shuffle_mode = (avrcp_shuffle_mode_t) value;
992                                 break;
993                             default:
994                                 break;
995                         }
996                     }
997                     avrcp_controller_emit_repeat_and_shuffle_mode(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, repeat_mode, shuffle_mode);
998                     break;
999                 }
1000 
1001                 case AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE:{
1002                     uint16_t offset = 0;
1003                     uint8_t event[6];
1004                     event[offset++] = HCI_EVENT_AVRCP_META;
1005                     event[offset++] = sizeof(event) - 2;
1006                     event[offset++] = AVRCP_SUBEVENT_PLAYER_APPLICATION_VALUE_RESPONSE;
1007                     little_endian_store_16(event, offset, connection->avrcp_cid);
1008                     offset += 2;
1009                     event[offset++] = ctype;
1010                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1011                     break;
1012                 }
1013 
1014                 case AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME:{
1015                     uint16_t offset = 0;
1016                     uint8_t event[7];
1017                     event[offset++] = HCI_EVENT_AVRCP_META;
1018                     event[offset++] = sizeof(event) - 2;
1019                     event[offset++] = AVRCP_SUBEVENT_SET_ABSOLUTE_VOLUME_RESPONSE;
1020                     little_endian_store_16(event, offset, connection->avrcp_cid);
1021                     offset += 2;
1022                     event[offset++] = ctype;
1023                     event[offset++] = packet[pos++];
1024                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1025                     break;
1026                 }
1027 
1028                 case AVRCP_PDU_ID_GET_CAPABILITIES:{
1029                     avrcp_capability_id_t capability_id = (avrcp_capability_id_t) packet[pos++];
1030                     uint8_t capability_count = 0;
1031                     if (param_length > 1){
1032                         capability_count = packet[pos++];
1033                     }
1034                     uint16_t i;
1035                     uint16_t offset = 0;
1036                     uint8_t event[10];
1037 
1038                     switch (capability_id){
1039 
1040                         case AVRCP_CAPABILITY_ID_COMPANY:
1041                             for (i = 0; (i < capability_count) && ((size - pos) >= 3); i++){
1042                                 uint32_t company_id = big_endian_read_24(packet, pos);
1043                                 pos += 3;
1044                                 log_info("  0x%06" PRIx32 ", ", company_id);
1045 
1046                                 offset = 0;
1047                                 event[offset++] = HCI_EVENT_AVRCP_META;
1048                                 event[offset++] = sizeof(event) - 2;
1049                                 event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID;
1050                                 little_endian_store_16(event, offset, connection->avrcp_cid);
1051                                 offset += 2;
1052                                 event[offset++] = ctype;
1053                                 event[offset++] = 0;
1054                                 little_endian_store_24(event, offset, company_id);
1055                                 offset += 3;
1056                                 (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
1057                             }
1058 
1059                             offset = 0;
1060                             event[offset++] = HCI_EVENT_AVRCP_META;
1061                             event[offset++] = sizeof(event) - 2;
1062                             event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID_DONE;
1063                             little_endian_store_16(event, offset, connection->avrcp_cid);
1064                             offset += 2;
1065                             event[offset++] = ctype;
1066                             event[offset++] = 0;
1067                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
1068                             break;
1069 
1070                         case AVRCP_CAPABILITY_ID_EVENT:
1071                             for (i = 0; (i < capability_count) && ((size - pos) >= 1); i++){
1072                                 uint8_t event_id = packet[pos++];
1073                                 connection->notifications_supported_by_target |= (1 << event_id);
1074                             }
1075 
1076                             // if the get supported events query is triggered by avrcp_controller_enable_notification call,
1077                             // avrcp_controller_emit_supported_events should be suppressed
1078                             if (connection->controller_notifications_supported_by_target_suppress_emit_result){
1079                                 connection->controller_notifications_supported_by_target_suppress_emit_result = false;
1080                                 // also, notification might not be supported
1081                                 // if so, emit AVRCP_SUBEVENT_ENABLE_NOTIFICATION_COMPLETE event to app,
1082                                 // and update controller_notifications_to_register bitmap
1083                                 for (i = (uint8_t)AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; i < (uint8_t) AVRCP_NOTIFICATION_EVENT_LAST_INDEX; i++){
1084                                     if ((connection->controller_notifications_to_register & (1 << i)) != 0){
1085                                         if ((connection->notifications_supported_by_target & (1 << i)) == 0){
1086                                             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE, i, false);
1087                                             connection->controller_notifications_to_register &= ~(1 << i);
1088                                         }
1089                                     }
1090                                 }
1091                                 break;
1092                             }
1093                             // supported events are emitted only if the get supported events query
1094                             // is triggered by avrcp_controller_get_supported_events call
1095                             avrcp_controller_emit_supported_events(connection);
1096                             break;
1097 
1098                         default:
1099                             // ignore
1100                             break;
1101                     }
1102                     break;
1103                 }
1104 
1105                 case AVRCP_PDU_ID_GET_PLAY_STATUS:{
1106                     uint32_t song_length = big_endian_read_32(packet, pos);
1107                     pos += 4;
1108                     uint32_t song_position = big_endian_read_32(packet, pos);
1109                     pos += 4;
1110                     uint8_t play_status = packet[pos];
1111 
1112                     uint8_t event[15];
1113                     int offset = 0;
1114                     event[offset++] = HCI_EVENT_AVRCP_META;
1115                     event[offset++] = sizeof(event) - 2;
1116                     event[offset++] = AVRCP_SUBEVENT_PLAY_STATUS;
1117                     little_endian_store_16(event, offset, connection->avrcp_cid);
1118                     offset += 2;
1119                     event[offset++] = ctype;
1120                     little_endian_store_32(event, offset, song_length);
1121                     offset += 4;
1122                     little_endian_store_32(event, offset, song_position);
1123                     offset += 4;
1124                     event[offset++] = play_status;
1125                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1126                     break;
1127                 }
1128 
1129                 case AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES:{
1130                     // TODO Review
1131                     switch (vendor_dependent_packet_type){
1132                         case AVRCP_START_PACKET:
1133                         case AVRCP_SINGLE_PACKET:
1134                             avrcp_parser_reset(connection);
1135                             connection->list_size = param_length;
1136                             // num_attributes
1137                             pos++;
1138 
1139                             avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
1140                             if (vendor_dependent_packet_type == AVRCP_START_PACKET){
1141                                 avrcp_controller_request_continue_response(connection);
1142                             }
1143                             break;
1144                         case AVRCP_CONTINUE_PACKET:
1145                         case AVRCP_END_PACKET:
1146                             connection->controller_num_received_fragments++;
1147 
1148                             if (connection->controller_num_received_fragments < connection->controller_max_num_fragments){
1149                                 avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
1150 
1151                                 if (vendor_dependent_packet_type == AVRCP_CONTINUE_PACKET){
1152                                     avrcp_controller_request_continue_response(connection);
1153                                 }
1154                             } else {
1155                                 avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 1);
1156                                 avrcp_parser_reset(connection);
1157                                 avrcp_controller_request_abort_continuation(connection);
1158                             }
1159                             break;
1160                         default:
1161                             // TODO check
1162                             btstack_assert(false);
1163                             break;
1164                     }
1165                 }
1166                 default:
1167                     // custom command response comes here
1168                     if (pdu_id == connection->pdu_id) {
1169                         uint8_t *in_place_buffer = packet + pos - 8;
1170                         avrcp_controller_prepare_custom_command_response(connection, param_length,
1171                                                                          in_place_buffer);
1172                         (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, in_place_buffer,
1173                                                                    param_length + 8);
1174                     }
1175                     break;
1176             }
1177             break;
1178         case AVRCP_CMD_OPCODE_PASS_THROUGH:{
1179             if ((size - pos) < 1) return;
1180             uint8_t operation_id = packet[pos++];
1181             switch (connection->state){
1182                 case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
1183                     // trigger release for simple command:
1184                     if (!connection->controller_press_and_hold_cmd_active){
1185                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
1186                         break;
1187                     }
1188                     // for press and hold, send release if it just has been requested, otherwise, wait for next repeat
1189                     if (connection->controller_press_and_hold_cmd_release){
1190                         connection->controller_press_and_hold_cmd_release = false;
1191                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
1192                     } else {
1193                         connection->state = AVCTP_W4_STOP;
1194                     }
1195                     break;
1196                 case AVCTP_W2_RECEIVE_RESPONSE:
1197                     connection->state = AVCTP_CONNECTION_OPENED;
1198                     break;
1199                 default:
1200                     break;
1201             }
1202             if (connection->state == AVCTP_W4_STOP){
1203                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_START, connection->avrcp_cid, ctype, operation_id);
1204             }
1205             if (connection->state == AVCTP_CONNECTION_OPENED) {
1206                 // RELEASE response
1207                 operation_id = operation_id & 0x7F;
1208                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_COMPLETE, connection->avrcp_cid, ctype, operation_id);
1209             }
1210             if (connection->state == AVCTP_W2_SEND_RELEASE_COMMAND){
1211                 // PRESS response
1212                 avrcp_controller_request_pass_through_release_control_cmd(connection);
1213             }
1214             break;
1215         }
1216         default:
1217             break;
1218     }
1219 
1220     // trigger pending notification reqistrations
1221     if ((connection->state == AVCTP_CONNECTION_OPENED) && connection->controller_notifications_to_register){
1222         avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1223     }
1224 }
1225 
1226 static void avrcp_controller_handle_can_send_now(avrcp_connection_t * connection){
1227     switch (connection->state){
1228         case AVCTP_W2_SEND_PRESS_COMMAND:
1229         case AVCTP_W2_SEND_COMMAND:
1230         case AVCTP_W2_SEND_RELEASE_COMMAND:
1231             avrcp_send_cmd_with_avctp_fragmentation(connection);
1232             if (connection->data_offset < connection->data_len){
1233                 // continue AVCTP fragmentation
1234                 avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1235                 return;
1236             }
1237             if (connection->state == AVCTP_W2_SEND_PRESS_COMMAND){
1238                 connection->state = AVCTP_W2_RECEIVE_PRESS_RESPONSE;
1239             } else {
1240                 connection->state = AVCTP_W2_RECEIVE_RESPONSE;
1241             }
1242             return;
1243         default:
1244             break;
1245     }
1246 
1247     // send register notification if queued
1248     if (connection->controller_notifications_to_register != 0){
1249         uint8_t event_id;
1250         for (event_id = (uint8_t)AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; event_id < (uint8_t)AVRCP_NOTIFICATION_EVENT_LAST_INDEX; event_id++){
1251             if (connection->controller_notifications_to_register & (1 << event_id)){
1252                 connection->controller_notifications_to_register &= ~ (1 << event_id);
1253                 avrcp_send_register_notification(connection, event_id);
1254                 return;
1255             }
1256         }
1257     }
1258 }
1259 
1260 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
1261     avrcp_connection_t * connection;
1262 
1263     switch (packet_type) {
1264         case L2CAP_DATA_PACKET:
1265             connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
1266             avrcp_handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
1267             break;
1268 
1269         case HCI_EVENT_PACKET:
1270             switch (hci_event_packet_get_type(packet)){
1271                 case L2CAP_EVENT_CAN_SEND_NOW:
1272                     connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
1273                     avrcp_controller_handle_can_send_now(connection);
1274                     break;
1275             default:
1276                 break;
1277         }
1278         default:
1279             break;
1280     }
1281 }
1282 
1283 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){
1284     avrcp_create_sdp_record(1, service, service_record_handle, avrcp_controller_supports_browsing(supported_features), supported_features, service_name, service_provider_name);
1285 }
1286 
1287 void avrcp_controller_init(void){
1288     avrcp_controller_context.role = AVRCP_CONTROLLER;
1289     avrcp_controller_context.packet_handler = avrcp_controller_packet_handler;
1290     avrcp_register_controller_packet_handler(&avrcp_controller_packet_handler);
1291 }
1292 
1293 void avrcp_controller_deinit(void){
1294     memset(&avrcp_controller_context, 0, sizeof(avrcp_context_t));
1295 }
1296 
1297 void avrcp_controller_register_packet_handler(btstack_packet_handler_t callback){
1298     btstack_assert(callback != NULL);
1299     avrcp_controller_context.avrcp_callback = callback;
1300 }
1301 
1302 
1303 uint8_t avrcp_controller_play(uint16_t avrcp_cid){
1304     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1305 }
1306 
1307 uint8_t avrcp_controller_stop(uint16_t avrcp_cid){
1308     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1309 }
1310 
1311 uint8_t avrcp_controller_pause(uint16_t avrcp_cid){
1312     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1313 }
1314 
1315 uint8_t avrcp_controller_forward(uint16_t avrcp_cid){
1316     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1317 }
1318 
1319 uint8_t avrcp_controller_backward(uint16_t avrcp_cid){
1320     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1321 }
1322 
1323 uint8_t avrcp_controller_volume_up(uint16_t avrcp_cid){
1324     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1325 }
1326 
1327 uint8_t avrcp_controller_volume_down(uint16_t avrcp_cid){
1328     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1329 }
1330 
1331 uint8_t avrcp_controller_mute(uint16_t avrcp_cid){
1332     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1333 }
1334 
1335 uint8_t avrcp_controller_skip(uint16_t avrcp_cid){
1336     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_SKIP, 0);
1337 }
1338 
1339 uint8_t avrcp_controller_fast_forward(uint16_t avrcp_cid){
1340     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1341 }
1342 
1343 uint8_t avrcp_controller_rewind(uint16_t avrcp_cid){
1344     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1345 }
1346 
1347 /* start continuous cmds */
1348 
1349 uint8_t avrcp_controller_start_press_and_hold_cmd(uint16_t avrcp_cid, avrcp_operation_id_t operation_id){
1350     return request_continuous_pass_through_press_control_cmd(avrcp_cid, operation_id, 0);
1351 }
1352 
1353 uint8_t avrcp_controller_press_and_hold_play(uint16_t avrcp_cid){
1354     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1355 }
1356 uint8_t avrcp_controller_press_and_hold_stop(uint16_t avrcp_cid){
1357     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1358 }
1359 uint8_t avrcp_controller_press_and_hold_pause(uint16_t avrcp_cid){
1360     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1361 }
1362 uint8_t avrcp_controller_press_and_hold_forward(uint16_t avrcp_cid){
1363     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1364 }
1365 uint8_t avrcp_controller_press_and_hold_backward(uint16_t avrcp_cid){
1366     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1367 }
1368 uint8_t avrcp_controller_press_and_hold_fast_forward(uint16_t avrcp_cid){
1369     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1370 }
1371 uint8_t avrcp_controller_press_and_hold_rewind(uint16_t avrcp_cid){
1372     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1373 }
1374 uint8_t avrcp_controller_press_and_hold_volume_up(uint16_t avrcp_cid){
1375     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1376 }
1377 uint8_t avrcp_controller_press_and_hold_volume_down(uint16_t avrcp_cid){
1378     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1379 }
1380 uint8_t avrcp_controller_press_and_hold_mute(uint16_t avrcp_cid){
1381     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1382 }
1383 
1384 /* stop continuous cmds */
1385 uint8_t avrcp_controller_release_press_and_hold_cmd(uint16_t avrcp_cid){
1386     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1387     if (!connection){
1388         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1389     }
1390 
1391     switch (connection->state){
1392         // respond when we receive response for (repeated) press command
1393         case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
1394             connection->controller_press_and_hold_cmd_release = true;
1395             break;
1396 
1397         // release already sent or on the way, nothing to do
1398         case AVCTP_W2_RECEIVE_RESPONSE:
1399         case AVCTP_W2_SEND_RELEASE_COMMAND:
1400             break;
1401 
1402         // about to send next repeated press command or wait for it -> release right away
1403         case AVCTP_W2_SEND_PRESS_COMMAND:
1404         case AVCTP_W4_STOP:
1405             return avrcp_controller_request_pass_through_release_control_cmd(connection);
1406 
1407         // otherwise reject request
1408         default:
1409             return ERROR_CODE_COMMAND_DISALLOWED;
1410     }
1411     return ERROR_CODE_SUCCESS;
1412 }
1413 
1414 uint8_t avrcp_controller_enable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1415     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1416     if (!connection){
1417         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1418     }
1419     return avrcp_controller_register_notification(connection, event_id);
1420 }
1421 
1422 uint8_t avrcp_controller_disable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1423     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1424     if (!connection){
1425         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1426     }
1427     if (!connection->controller_notifications_supported_by_target_queried){
1428         return ERROR_CODE_COMMAND_DISALLOWED;
1429     }
1430 
1431     if ((connection->notifications_supported_by_target & (1 << event_id)) == 0){
1432         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1433     }
1434 
1435     if ((connection->notifications_enabled & (1 << event_id)) == 0){
1436         return ERROR_CODE_SUCCESS;
1437     }
1438 
1439     connection->controller_notifications_to_deregister |= (1 << event_id);
1440     return ERROR_CODE_SUCCESS;
1441 }
1442 
1443 uint8_t avrcp_controller_unit_info(uint16_t avrcp_cid){
1444     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1445     if (!connection){
1446         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1447     }
1448     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1449 
1450     connection->state = AVCTP_W2_SEND_COMMAND;
1451     avrcp_controller_custom_command_data_init(connection, AVRCP_CMD_OPCODE_UNIT_INFO, AVRCP_CTYPE_STATUS,
1452                                               AVRCP_SUBUNIT_TYPE_UNIT, AVRCP_SUBUNIT_ID_IGNORE, AVRCP_PDU_ID_UNDEFINED,
1453                                               0);
1454 
1455     connection->data = connection->message_body;
1456     memset(connection->data, 0xFF, 5);
1457     connection->data_len = 5;
1458     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1459     return ERROR_CODE_SUCCESS;
1460 }
1461 
1462 uint8_t avrcp_controller_subunit_info(uint16_t avrcp_cid){
1463     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1464     if (!connection){
1465         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1466     }
1467     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1468 
1469     connection->state = AVCTP_W2_SEND_COMMAND;
1470     avrcp_controller_custom_command_data_init(connection, AVRCP_CMD_OPCODE_SUBUNIT_INFO, AVRCP_CTYPE_STATUS,
1471                                               AVRCP_SUBUNIT_TYPE_UNIT, AVRCP_SUBUNIT_ID_IGNORE, AVRCP_PDU_ID_UNDEFINED,
1472                                               0);
1473 
1474     connection->data = connection->message_body;
1475     memset(connection->data, 0xFF, 5);
1476     connection->data[0] = 7; // page: 0, extension_code: 7
1477     connection->data_len = 5;
1478     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1479     return ERROR_CODE_SUCCESS;
1480 }
1481 
1482 uint8_t avrcp_controller_get_supported_company_ids(uint16_t avrcp_cid){
1483     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1484     if (!connection){
1485         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1486     }
1487     if (connection->state != AVCTP_CONNECTION_OPENED){
1488         return ERROR_CODE_COMMAND_DISALLOWED;
1489     }
1490     avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_COMPANY);
1491     return ERROR_CODE_SUCCESS;
1492 }
1493 
1494 uint8_t avrcp_controller_get_supported_events(uint16_t avrcp_cid){
1495     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1496     if (!connection){
1497         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1498     }
1499     if (connection->state != AVCTP_CONNECTION_OPENED){
1500         return ERROR_CODE_COMMAND_DISALLOWED;
1501     }
1502 
1503     if (!connection->controller_notifications_supported_by_target_queried){
1504         connection->controller_notifications_supported_by_target_queried = true;
1505         avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_EVENT);
1506         return ERROR_CODE_SUCCESS;
1507     }
1508 
1509     avrcp_controller_emit_supported_events(connection);
1510     return ERROR_CODE_SUCCESS;
1511 }
1512 
1513 uint8_t avrcp_controller_get_play_status(uint16_t avrcp_cid){
1514     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1515     if (!connection){
1516         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1517     }
1518     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1519 
1520     connection->state = AVCTP_W2_SEND_COMMAND;
1521     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_PLAY_STATUS);
1522 
1523     connection->data_len = 0;
1524     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1525     return ERROR_CODE_SUCCESS;
1526 }
1527 
1528 uint8_t avrcp_controller_set_addressed_player(uint16_t avrcp_cid, uint16_t addressed_player_id){
1529     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1530     if (!connection){
1531         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1532     }
1533     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1534 
1535     connection->state = AVCTP_W2_SEND_COMMAND;
1536     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_ADDRESSED_PLAYER);
1537 
1538     connection->data_len = 2;
1539     big_endian_store_16(connection->data, 0, addressed_player_id);
1540 
1541     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1542     return ERROR_CODE_SUCCESS;
1543 }
1544 
1545 uint8_t avrcp_controller_get_element_attributes(uint16_t avrcp_cid, uint8_t num_attributes, avrcp_media_attribute_id_t * attributes){
1546     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1547     if (!connection){
1548         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1549     }
1550 
1551     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1552 
1553     if (num_attributes >= AVRCP_MEDIA_ATTR_RESERVED) {
1554         return ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS;
1555     }
1556 
1557     connection->state = AVCTP_W2_SEND_COMMAND;
1558     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES);
1559 
1560     uint8_t pos = 0;
1561     // write 8 bytes value
1562     memset(connection->data, pos, 8); // identifier: PLAYING
1563     pos += 8;
1564 
1565     uint8_t num_attributes_index = pos;
1566     pos++;
1567 
1568     // If num_attributes is set to zero, all attribute information shall be returned,
1569     // and the AttributeID field is omitted
1570     connection->data[num_attributes_index] = 0;
1571     uint8_t i;
1572     for (i = 0; i < num_attributes; i++){
1573         // ignore invalid attribute ID and "get all attributes"
1574         if (AVRCP_MEDIA_ATTR_ALL > attributes[i] && attributes[i] < AVRCP_MEDIA_ATTR_RESERVED){
1575             // every attribute is 4 bytes long
1576             big_endian_store_32(connection->data, pos, attributes[i]);
1577             pos += 4;
1578             connection->data[num_attributes_index]++;
1579         }
1580     }
1581 
1582     // Parameter Length
1583     connection->data_len = pos;
1584 
1585     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1586     return ERROR_CODE_SUCCESS;
1587 }
1588 
1589 uint8_t avrcp_controller_get_now_playing_info(uint16_t avrcp_cid){
1590     return avrcp_controller_get_element_attributes(avrcp_cid, 0, NULL);
1591 }
1592 
1593 uint8_t avrcp_controller_get_now_playing_info_for_media_attribute_id(uint16_t avrcp_cid, avrcp_media_attribute_id_t media_attribute_id){
1594     if (media_attribute_id == AVRCP_MEDIA_ATTR_ALL){
1595         return avrcp_controller_get_now_playing_info(avrcp_cid);
1596     }
1597     return avrcp_controller_get_element_attributes(avrcp_cid, 1, &media_attribute_id);
1598 }
1599 
1600 uint8_t avrcp_controller_set_absolute_volume(uint16_t avrcp_cid, uint8_t volume){
1601      avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1602     if (!connection){
1603         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1604     }
1605 
1606     //
1607     // allow sending of multiple set abs volume commands without waiting for response
1608     //
1609     uint8_t status = ERROR_CODE_COMMAND_DISALLOWED;
1610     switch (connection->state){
1611         case AVCTP_CONNECTION_OPENED:
1612             status = ERROR_CODE_SUCCESS;
1613             break;
1614         case AVCTP_W2_RECEIVE_RESPONSE:
1615             // - is pending response also set abs volume
1616             if (connection->command_opcode  != AVRCP_CMD_OPCODE_VENDOR_DEPENDENT) break;
1617             if (connection->command_type    != AVRCP_CTYPE_CONTROL)               break;
1618             if (connection->subunit_type    != AVRCP_SUBUNIT_TYPE_PANEL)          break;
1619             if (connection->subunit_id      != AVRCP_SUBUNIT_ID)                  break;
1620             if (connection->pdu_id          != AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME)  break;
1621             // - is next transaction id valid in window
1622             if (avrcp_controller_is_transaction_id_valid(connection, avrcp_controller_calc_next_transaction_label(connection->transaction_id_counter)) == false) break;
1623             status = ERROR_CODE_SUCCESS;
1624             break;
1625         default:
1626             break;
1627     }
1628     if (status != ERROR_CODE_SUCCESS) return status;
1629 
1630     connection->state = AVCTP_W2_SEND_COMMAND;
1631     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME);
1632 
1633     // Parameter Length
1634     connection->data_len = 1;
1635     connection->data[0] = volume;
1636 
1637     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1638     return ERROR_CODE_SUCCESS;
1639 }
1640 
1641 uint8_t avrcp_controller_query_shuffle_and_repeat_modes(uint16_t avrcp_cid){
1642     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1643     if (!connection){
1644         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1645     }
1646     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1647 
1648     connection->state = AVCTP_W2_SEND_COMMAND;
1649     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE);
1650 
1651     connection->data_len = 5;
1652     connection->data[0] = 4;                     // NumPlayerApplicationSettingAttributeID
1653     // PlayerApplicationSettingAttributeID1 AVRCP Spec, Appendix F, 133
1654     connection->data[1] = 0x01;   // equalizer  (1-OFF, 2-ON)
1655     connection->data[2] = 0x02;   // repeat     (1-off, 2-single track, 3-all tracks, 4-group repeat)
1656     connection->data[3] = 0x03;   // shuffle    (1-off, 2-all tracks, 3-group shuffle)
1657     connection->data[4] = 0x04;   // scan       (1-off, 2-all tracks, 3-group scan)
1658 
1659     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1660     return ERROR_CODE_SUCCESS;
1661 }
1662 
1663 static uint8_t avrcp_controller_set_current_player_application_setting_value(uint16_t avrcp_cid, uint8_t attr_id, uint8_t attr_value){
1664     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1665     if (!connection){
1666         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1667     }
1668     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1669 
1670     connection->state = AVCTP_W2_SEND_COMMAND;
1671     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE);
1672 
1673     // Parameter Length
1674     connection->data_len = 3;
1675     connection->data[0]  = 2;
1676     connection->data[1]  = attr_id;
1677     connection->data[2]  = attr_value;
1678 
1679     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1680     return ERROR_CODE_SUCCESS;
1681 }
1682 
1683 uint8_t avrcp_controller_set_shuffle_mode(uint16_t avrcp_cid, avrcp_shuffle_mode_t mode){
1684     if ((mode < AVRCP_SHUFFLE_MODE_OFF) || (mode > AVRCP_SHUFFLE_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1685     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x03, mode);
1686 }
1687 
1688 uint8_t avrcp_controller_set_repeat_mode(uint16_t avrcp_cid, avrcp_repeat_mode_t mode){
1689     if ((mode < AVRCP_REPEAT_MODE_OFF) || (mode > AVRCP_REPEAT_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1690     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x02, mode);
1691 }
1692 
1693 uint8_t avrcp_controller_play_item_for_scope(uint16_t avrcp_cid, uint8_t * uid, uint16_t uid_counter, avrcp_browsing_scope_t scope){
1694     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1695     if (!connection){
1696         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1697     }
1698     if (connection->state != AVCTP_CONNECTION_OPENED){
1699         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1700         return ERROR_CODE_COMMAND_DISALLOWED;
1701     }
1702     connection->state = AVCTP_W2_SEND_COMMAND;
1703     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_PLAY_ITEM);
1704 
1705     // Parameter Length
1706     connection->data_len = 11;
1707     connection->data[0]  = scope;
1708     memset(&connection->data[1], 0, 8);
1709     if (uid){
1710         (void)memcpy(&connection->data[1], uid, 8);
1711     }
1712     big_endian_store_16(connection->data, 9, uid_counter);
1713 
1714     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1715     return ERROR_CODE_SUCCESS;
1716 }
1717 
1718 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){
1719     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1720     if (!connection){
1721         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1722     }
1723     if (connection->state != AVCTP_CONNECTION_OPENED){
1724         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1725         return ERROR_CODE_COMMAND_DISALLOWED;
1726     }
1727 
1728     connection->state = AVCTP_W2_SEND_COMMAND;
1729     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_ADD_TO_NOW_PLAYING);
1730 
1731     // Parameter Length
1732     connection->data_len = 11;
1733     connection->data[0]  = scope;
1734     memset(&connection->data[1], 0, 8);
1735     if (uid){
1736         (void)memcpy(&connection->data[1], uid, 8);
1737     }
1738     big_endian_store_16(connection->data, 9, uid_counter);
1739 
1740     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1741     return ERROR_CODE_SUCCESS;
1742 }
1743 
1744 uint8_t avrcp_controller_set_max_num_fragments(uint16_t avrcp_cid, uint8_t max_num_fragments){
1745     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1746     if (!connection){
1747         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1748     }
1749     connection->controller_max_num_fragments = max_num_fragments;
1750     return ERROR_CODE_SUCCESS;
1751 }
1752 
1753 
1754 uint8_t avrcp_controller_send_custom_command(uint16_t avrcp_cid,
1755     avrcp_command_type_t command_type,
1756     avrcp_subunit_type_t subunit_type, avrcp_subunit_id_t subunit_id,
1757     avrcp_pdu_id_t pdu_id, uint32_t company_id,
1758     const uint8_t * data, uint16_t data_len){
1759 
1760     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1761     if (!connection){
1762         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1763     }
1764     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1765 
1766     connection->state = AVCTP_W2_SEND_COMMAND;
1767     avrcp_controller_custom_command_data_init(connection, AVRCP_CMD_OPCODE_VENDOR_DEPENDENT, command_type, subunit_type,
1768                                               subunit_id, pdu_id, company_id);
1769 
1770     connection->data = (uint8_t *)data;
1771     connection->data_len = data_len;
1772 
1773     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1774     return ERROR_CODE_SUCCESS;
1775 }
1776