xref: /btstack/src/classic/avrcp_controller.c (revision 4a23d858bef9b2509887ee67ec48b5ef4222873d)
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 #define AVRCP_MAX_AV_C_MESSAGE_FRAME_SIZE 512
54 
55 // made public in avrcp_controller.h
56 avrcp_context_t avrcp_controller_context;
57 
58 static uint8_t avrcp_controller_calc_next_transaction_label(uint8_t current_transaction_label){
59     current_transaction_label++;
60     if (current_transaction_label == 16){
61         current_transaction_label = 1;
62     }
63     return current_transaction_label;
64 }
65 
66 static uint8_t avrcp_controller_get_next_transaction_label(avrcp_connection_t * connection){
67     connection->transaction_id_counter = avrcp_controller_calc_next_transaction_label(connection->transaction_id_counter);
68     return connection->transaction_id_counter;
69 }
70 
71 static bool avrcp_controller_is_transaction_id_valid(avrcp_connection_t * connection, uint8_t transaction_id){
72     uint8_t delta = ((int8_t) transaction_id - connection->last_confirmed_transaction_id) & 0x0f;
73     return delta < 15;
74 }
75 
76 static uint16_t avrcp_get_max_payload_size_for_avctp_packet_type(avrcp_connection_t * connection, avctp_packet_type_t avctp_packet_type){
77     uint16_t max_frame_size = btstack_min(l2cap_get_remote_mtu_for_local_cid(connection->l2cap_signaling_cid), AVRCP_MAX_AV_C_MESSAGE_FRAME_SIZE);
78 
79     switch (avctp_packet_type){
80         case AVCTP_SINGLE_PACKET:
81             return max_frame_size - 3;
82         case AVCTP_START_PACKET:
83             return max_frame_size - 4;
84         case AVCTP_CONTINUE_PACKET:
85         case AVCTP_END_PACKET:
86             return max_frame_size - 1;
87         default:
88             btstack_assert(false);
89             return 0;
90     }
91 }
92 
93 
94 static void avrcp_custome_command_data_init(avrcp_connection_t * connection,
95     avrcp_command_opcode_t opcode, avrcp_command_type_t command_type,
96     avrcp_subunit_type_t subunit_type, avrcp_subunit_id_t subunit_id,
97     avrcp_pdu_id_t pdu_id, uint32_t company_id){
98 
99     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
100     connection->command_opcode = opcode;
101     connection->command_type = command_type;
102     connection->subunit_type = subunit_type;
103     connection->subunit_id = subunit_id;
104     connection->company_id = company_id << 16;
105     connection->pdu_id = pdu_id;
106     connection->data = NULL;
107     connection->data_offset = 0;
108     connection->data_len = 0;
109 }
110 
111 static void avrcp_vendor_dependent_command_data_init(avrcp_connection_t * connection, avrcp_command_type_t command_type, avrcp_pdu_id_t pdu_id){
112     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
113     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
114     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
115     connection->subunit_id = AVRCP_SUBUNIT_ID;
116     connection->company_id = BT_SIG_COMPANY_ID;
117 
118     connection->command_type = command_type;
119     connection->pdu_id = pdu_id;
120     connection->data = connection->cmd_operands;
121     connection->data_offset = 0;
122     connection->data_len = 0;
123 }
124 
125 static void avrcp_pass_through_command_data_init(avrcp_connection_t * connection, avrcp_operation_id_t opid){
126     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
127     connection->command_opcode =  AVRCP_CMD_OPCODE_PASS_THROUGH;
128     connection->command_type = AVRCP_CTYPE_CONTROL;
129     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
130     connection->subunit_id =   AVRCP_SUBUNIT_ID;
131 
132     connection->company_id = 0;
133     connection->pdu_id = 0;
134     connection->operation_id = opid;
135 
136     connection->data = connection->cmd_operands;
137     connection->data_offset = 0;
138     connection->data_len = 0;
139 }
140 static int avrcp_controller_supports_browsing(uint16_t controller_supported_features){
141     return controller_supported_features & AVRCP_FEATURE_MASK_BROWSING;
142 }
143 
144 static void avrcp_controller_emit_notification_complete(avrcp_connection_t * connection, uint8_t status, uint8_t event_id, bool enabled){
145     uint8_t event[8];
146     uint8_t pos = 0;
147     event[pos++] = HCI_EVENT_AVRCP_META;
148     event[pos++] = sizeof(event) - 2;
149     event[pos++] = AVRCP_SUBEVENT_NOTIFICATION_STATE;
150     little_endian_store_16(event, pos, connection->avrcp_cid);
151     pos += 2;
152     event[pos++] = status;
153     event[pos++] = enabled ? 1 : 0;
154     event[pos++] = event_id;
155     UNUSED(pos);
156     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
157 }
158 
159 static void avrcp_controller_emit_supported_events(avrcp_connection_t * connection){
160     uint8_t ctype = (uint8_t) AVRCP_CTYPE_RESPONSE_CHANGED_STABLE;
161     uint8_t event_id;
162 
163     for (event_id = (uint8_t) AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; event_id < (uint8_t) AVRCP_NOTIFICATION_EVENT_LAST_INDEX; event_id++){
164         if ( (connection->target_supported_notifications & (1<<event_id)) == 0){
165             continue;
166         }
167         uint8_t event[8];
168         uint8_t pos = 0;
169         event[pos++] = HCI_EVENT_AVRCP_META;
170         event[pos++] = sizeof(event) - 2;
171         event[pos++] = AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID;
172         little_endian_store_16(event, pos, connection->avrcp_cid);
173         pos += 2;
174         event[pos++] = ctype;
175         event[pos++] = 0;
176         event[pos++] = event_id;
177         UNUSED(pos);
178         (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
179     }
180 
181     uint8_t event[7];
182     uint8_t pos = 0;
183     event[pos++] = HCI_EVENT_AVRCP_META;
184     event[pos++] = sizeof(event) - 2;
185     event[pos++] = AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID_DONE;
186     little_endian_store_16(event, pos, connection->avrcp_cid);
187     pos += 2;
188     event[pos++] = ctype;
189     event[pos++] = 0;
190     UNUSED(pos);
191     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
192 }
193 
194 static void avrcp_controller_emit_notification_for_event_id(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id,
195                                                             avrcp_command_type_t ctype, const uint8_t *payload,
196                                                             uint16_t size) {
197     switch (event_id){
198         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_POS_CHANGED:{
199             if (size < 4) break;
200             uint32_t song_position = big_endian_read_32(payload, 0);
201             uint16_t offset = 0;
202             uint8_t event[10];
203             event[offset++] = HCI_EVENT_AVRCP_META;
204             event[offset++] = sizeof(event) - 2;
205             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_POS_CHANGED;
206             little_endian_store_16(event, offset, avrcp_cid);
207             offset += 2;
208             event[offset++] = ctype;
209             little_endian_store_32(event, offset, song_position);
210             offset += 4;
211             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
212             break;
213         }
214         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED:{
215             if (size < 1) break;
216             uint16_t offset = 0;
217             uint8_t event[7];
218             event[offset++] = HCI_EVENT_AVRCP_META;
219             event[offset++] = sizeof(event) - 2;
220             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_STATUS_CHANGED;
221             little_endian_store_16(event, offset, avrcp_cid);
222             offset += 2;
223             event[offset++] = ctype;
224             event[offset++] = payload[0];
225             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
226             break;
227         }
228         case AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED:{
229             uint16_t offset = 0;
230             uint8_t event[6];
231             event[offset++] = HCI_EVENT_AVRCP_META;
232             event[offset++] = sizeof(event) - 2;
233             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_TRACK_CHANGED;
234             little_endian_store_16(event, offset, avrcp_cid);
235             offset += 2;
236             event[offset++] = ctype;
237             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
238             break;
239         }
240         case AVRCP_NOTIFICATION_EVENT_NOW_PLAYING_CONTENT_CHANGED:{
241             uint16_t offset = 0;
242             uint8_t event[6];
243             event[offset++] = HCI_EVENT_AVRCP_META;
244             event[offset++] = sizeof(event) - 2;
245             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_NOW_PLAYING_CONTENT_CHANGED;
246             little_endian_store_16(event, offset, avrcp_cid);
247             offset += 2;
248             event[offset++] = ctype;
249             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
250             break;
251         }
252         case AVRCP_NOTIFICATION_EVENT_AVAILABLE_PLAYERS_CHANGED:{
253             uint16_t offset = 0;
254             uint8_t event[6];
255             event[offset++] = HCI_EVENT_AVRCP_META;
256             event[offset++] = sizeof(event) - 2;
257             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_AVAILABLE_PLAYERS_CHANGED;
258             little_endian_store_16(event, offset, avrcp_cid);
259             offset += 2;
260             event[offset++] = ctype;
261             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
262             break;
263         }
264         case AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED:{
265             if (size < 1) break;
266             uint16_t offset = 0;
267             uint8_t event[7];
268             event[offset++] = HCI_EVENT_AVRCP_META;
269             event[offset++] = sizeof(event) - 2;
270             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED;
271             little_endian_store_16(event, offset, avrcp_cid);
272             offset += 2;
273             event[offset++] = ctype;
274             event[offset++] = payload[0] & 0x7F;
275             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
276             break;
277         }
278         case AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED:{
279             if (size < 2) break;
280             uint8_t event[8];
281             uint16_t offset = 0;
282             uint16_t uuid = big_endian_read_16(payload, 0);
283             event[offset++] = HCI_EVENT_AVRCP_META;
284             event[offset++] = sizeof(event) - 2;
285             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_UIDS_CHANGED;
286             little_endian_store_16(event, offset, avrcp_cid);
287             offset += 2;
288             event[offset++] = ctype;
289             little_endian_store_16(event, offset, uuid);
290             offset += 2;
291             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
292             break;
293         }
294 
295         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_END:{
296             uint16_t offset = 0;
297             uint8_t event[6];
298             event[offset++] = HCI_EVENT_AVRCP_META;
299             event[offset++] = sizeof(event) - 2;
300             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_END;
301             little_endian_store_16(event, offset, avrcp_cid);
302             offset += 2;
303             event[offset++] = ctype;
304             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
305             break;
306         }
307         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_START:{
308             uint16_t offset = 0;
309             uint8_t event[6];
310             event[offset++] = HCI_EVENT_AVRCP_META;
311             event[offset++] = sizeof(event) - 2;
312             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_START;
313             little_endian_store_16(event, offset, avrcp_cid);
314             offset += 2;
315             event[offset++] = ctype;
316             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
317             break;
318         }
319         case AVRCP_NOTIFICATION_EVENT_BATT_STATUS_CHANGED:{
320             if (size < 1) break;
321             uint16_t offset = 0;
322             uint8_t event[7];
323             event[offset++] = HCI_EVENT_AVRCP_META;
324             event[offset++] = sizeof(event) - 2;
325             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_BATT_STATUS_CHANGED;
326             little_endian_store_16(event, offset, avrcp_cid);
327             offset += 2;
328             event[offset++] = ctype;
329             event[offset++] = payload[0];
330             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
331             break;
332         }
333 
334         case AVRCP_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED:{
335             if (size < 1) break;
336             uint16_t offset = 0;
337             uint8_t event[7];
338             event[offset++] = HCI_EVENT_AVRCP_META;
339             event[offset++] = sizeof(event) - 2;
340             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED;
341             little_endian_store_16(event, offset, avrcp_cid);
342             offset += 2;
343             event[offset++] = ctype;
344             event[offset++] = payload[0];
345             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
346             break;
347         }
348 
349         case AVRCP_NOTIFICATION_EVENT_PLAYER_APPLICATION_SETTING_CHANGED:
350         default:
351             log_info("avrcp: not implemented");
352             break;
353     }
354 }
355 
356 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){
357     btstack_assert(callback != NULL);
358 
359     uint8_t event[8];
360     int pos = 0;
361     event[pos++] = HCI_EVENT_AVRCP_META;
362     event[pos++] = sizeof(event) - 2;
363     event[pos++] = AVRCP_SUBEVENT_SHUFFLE_AND_REPEAT_MODE;
364     little_endian_store_16(event, pos, avrcp_cid);
365     pos += 2;
366     event[pos++] = ctype;
367     event[pos++] = repeat_mode;
368     event[pos++] = shuffle_mode;
369     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
370 }
371 
372 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){
373     uint8_t event[7];
374     int pos = 0;
375     event[pos++] = HCI_EVENT_AVRCP_META;
376     event[pos++] = sizeof(event) - 2;
377     event[pos++] = AVRCP_SUBEVENT_NOW_PLAYING_INFO_DONE;
378     little_endian_store_16(event, pos, avrcp_cid);
379     pos += 2;
380     event[pos++] = ctype;
381     event[pos++] = status;
382     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
383 }
384 
385 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){
386     uint8_t event[HCI_EVENT_BUFFER_SIZE];
387     int pos = 0;
388     event[pos++] = HCI_EVENT_AVRCP_META;
389     // reserve one byte for subevent type and data len
390     int data_len_pos = pos;
391     pos++;
392     int subevent_type_pos = pos;
393     pos++;
394     little_endian_store_16(event, pos, avrcp_cid);
395     pos += 2;
396     event[pos++] = ctype;
397 
398     switch (attr_id){
399         case AVRCP_MEDIA_ATTR_TITLE:
400             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TITLE_INFO;
401             event[pos++] = value_len;
402             (void)memcpy(event + pos, value, value_len);
403             break;
404         case AVRCP_MEDIA_ATTR_ARTIST:
405             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ARTIST_INFO;
406             event[pos++] = value_len;
407             (void)memcpy(event + pos, value, value_len);
408             break;
409         case AVRCP_MEDIA_ATTR_ALBUM:
410             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ALBUM_INFO;
411             event[pos++] = value_len;
412             (void)memcpy(event + pos, value, value_len);
413             break;
414         case AVRCP_MEDIA_ATTR_GENRE:
415             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_GENRE_INFO;
416             event[pos++] = value_len;
417             (void)memcpy(event + pos, value, value_len);
418             break;
419         case AVRCP_MEDIA_ATTR_SONG_LENGTH_MS:
420             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_SONG_LENGTH_MS_INFO;
421             if (value){
422                 little_endian_store_32(event, pos, btstack_atoi((char *)value));
423             } else {
424                 little_endian_store_32(event, pos, 0);
425             }
426             pos += 4;
427             break;
428         case AVRCP_MEDIA_ATTR_TRACK:
429             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TRACK_INFO;
430             if (value){
431                 event[pos++] = btstack_atoi((char *)value);
432             } else {
433                 event[pos++] = 0;
434             }
435             break;
436         case AVRCP_MEDIA_ATTR_TOTAL_NUM_ITEMS:
437             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TOTAL_TRACKS_INFO;
438             if (value){
439                 event[pos++] = btstack_atoi((char *)value);
440             } else {
441                 event[pos++] = 0;
442             }
443             break;
444         default:
445             break;
446     }
447     event[data_len_pos] = pos - 2;
448     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
449 }
450 
451 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){
452     btstack_assert(callback != NULL);
453 
454     uint8_t event[7];
455     int pos = 0;
456     event[pos++] = HCI_EVENT_AVRCP_META;
457     event[pos++] = sizeof(event) - 2;
458     event[pos++] = subevent;
459     little_endian_store_16(event, pos, avrcp_cid);
460     pos += 2;
461     event[pos++] = ctype;
462     event[pos++] = operation_id;
463     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
464 }
465 
466 static void avrcp_parser_reset(avrcp_connection_t * connection){
467     connection->list_offset = 0;
468     connection->num_attributes = 0;
469     connection->num_parsed_attributes = 0;
470     connection->parser_attribute_header_pos = 0;
471     connection->num_received_fragments = 0;
472     connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
473 }
474 
475 static void avrcp_parser_process_byte(uint8_t byte, avrcp_connection_t * connection, avrcp_command_type_t ctype){
476     uint16_t attribute_total_value_len;
477     uint32_t attribute_id;
478     switch(connection->parser_state){
479         case AVRCP_PARSER_GET_ATTRIBUTE_HEADER:
480             connection->parser_attribute_header[connection->parser_attribute_header_pos++] = byte;
481             connection->list_offset++;
482 
483             if (connection->parser_attribute_header_pos < AVRCP_ATTRIBUTE_HEADER_LEN) return;
484 
485             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
486             connection->attribute_value_len = btstack_min(attribute_total_value_len, AVRCP_MAX_ATTRIBUTTE_SIZE);
487             if (connection->attribute_value_len > 0){
488                 // get ready for attribute value
489                 connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_VALUE;
490                 return;
491             }
492 
493             // emit empty attribute
494             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
495             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);
496 
497             // done, see below
498             break;
499 
500         case AVRCP_PARSER_GET_ATTRIBUTE_VALUE:
501             connection->attribute_value[connection->attribute_value_offset++] = byte;
502             connection->list_offset++;
503 
504             if (connection->attribute_value_offset < connection->attribute_value_len) return;
505 
506             // emit (potentially partial) attribute
507             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
508             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);
509 
510             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
511             if (connection->attribute_value_offset < attribute_total_value_len){
512                 // ignore rest of attribute
513                 connection->parser_state = AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE;
514                 return;
515             }
516 
517             // done, see below
518             break;
519 
520         case AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE:
521             connection->attribute_value_offset++;
522             connection->list_offset++;
523 
524             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
525             if (connection->attribute_value_offset < attribute_total_value_len) return;
526 
527             // done, see below
528             break;
529 
530         default:
531             return;
532     }
533 
534     // attribute fully read, check if more to come
535     if (connection->list_offset < connection->list_size){
536         // more to come, reset parser
537         connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
538         connection->parser_attribute_header_pos = 0;
539         connection->attribute_value_offset = 0;
540     } else {
541         // fully done
542         avrcp_parser_reset(connection);
543         avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 0);
544     }
545 }
546 
547 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){
548     int i;
549     for (i=0;i<num_bytes_to_read;i++){
550         avrcp_parser_process_byte(packet[i], connection, ctype);
551     }
552 }
553 
554 static avctp_packet_type_t avrcp_get_avctp_packet_type(avrcp_connection_t * connection){
555     if (connection->data_offset == 0){
556         if (avrcp_get_max_payload_size_for_avctp_packet_type(connection, AVCTP_SINGLE_PACKET) >= connection->data_len){
557             return AVCTP_SINGLE_PACKET;
558         } else {
559             return AVCTP_START_PACKET;
560         }
561 
562     } else {
563         if ((connection->data_len - connection->data_offset) > avrcp_get_max_payload_size_for_avctp_packet_type(connection, AVCTP_CONTINUE_PACKET)){
564              return AVCTP_CONTINUE_PACKET;
565          } else {
566             return AVCTP_END_PACKET;
567          }
568     }
569 }
570 
571 static void avrcp_send_cmd_with_avctp_fragmentation(avrcp_connection_t * connection){
572     l2cap_reserve_packet_buffer();
573     uint8_t * command = l2cap_get_outgoing_buffer();
574 
575     uint16_t max_frame_size = btstack_min(l2cap_get_remote_mtu_for_local_cid(connection->l2cap_signaling_cid), AVRCP_MAX_AV_C_MESSAGE_FRAME_SIZE);
576 
577     avctp_packet_type_t avctp_packet_type = avrcp_get_avctp_packet_type(connection);
578 
579     // non-fragmented: transport header (1) + PID (2)
580     // fragmented:     transport header (1) + num packets (1) + PID (2)
581 
582     // AVCTP header
583     // transport header : transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
584     uint16_t pos = 0;
585     command[pos++] = (connection->transaction_id << 4) | (avctp_packet_type << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
586 
587 
588     switch (avctp_packet_type){
589         case AVCTP_SINGLE_PACKET:
590         case AVCTP_START_PACKET:
591             if (avctp_packet_type == AVCTP_START_PACKET){
592                 // num packets: (3 bytes overhead (PID, num packets) + command) / (MTU - transport header).
593                 // to get number of packets using integer division, we subtract 1 from the data e.g. len = 5, packet size 5 => need 1 packet
594                 command[pos++] = ((connection->data_len + 3 - 1) / (max_frame_size - 1)) + 1;
595             }
596             // Profile IDentifier (PID)
597             command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
598             command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
599 
600             // command_type
601             command[pos++] = connection->command_type;
602             // subunit_type | subunit ID
603             command[pos++] = (connection->subunit_type << 3) | connection->subunit_id;
604             // opcode
605             command[pos++] = (uint8_t)connection->command_opcode;
606 
607             switch (connection->command_opcode){
608                 case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
609                     big_endian_store_24(command, pos, connection->company_id);
610                     pos += 3;
611                     command[pos++] = connection->pdu_id;
612                     command[pos++] = 0;                       // reserved(upper 6) | packet_type -> 0
613                     big_endian_store_16(command, pos, connection->data_len);     // parameter length
614                     pos += 2;
615                     break;
616                 case AVRCP_CMD_OPCODE_PASS_THROUGH:
617                     command[pos++] = connection->operation_id;
618                     command[pos++] = (uint8_t)connection->data_len;     // parameter length
619                     pos += 2;
620                     break;
621                 case AVRCP_CMD_OPCODE_UNIT_INFO:
622                     break;
623                 case AVRCP_CMD_OPCODE_SUBUNIT_INFO:
624                     break;
625                 default:
626                     btstack_assert(false);
627                     return;
628             }
629             break;
630         case AVCTP_CONTINUE_PACKET:
631         case AVCTP_END_PACKET:
632             break;
633         default:
634             btstack_assert(false);
635             return;
636     }
637 
638     // compare bytes to store wth the remaining buffer size
639     uint16_t bytes_to_copy = btstack_min(connection->data_len - connection->data_offset, max_frame_size - pos);
640 
641     (void)memcpy(command + pos, &connection->data[connection->data_offset], bytes_to_copy);
642     pos += bytes_to_copy;
643     connection->data_offset += bytes_to_copy;
644 
645     l2cap_send_prepared(connection->l2cap_signaling_cid, pos);
646 }
647 
648 static int avrcp_send_register_notification(avrcp_connection_t * connection, uint8_t event_id){
649     uint8_t command[18];
650     uint16_t pos = 0;
651     // transport header : transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
652     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
653     command[pos++] = (connection->transaction_id << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
654 
655     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
656     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
657     command[pos++] = AVRCP_CTYPE_NOTIFY;
658     command[pos++] = (AVRCP_SUBUNIT_TYPE_PANEL << 3) | AVRCP_SUBUNIT_ID;
659     command[pos++] = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
660 
661     big_endian_store_24(command, pos, BT_SIG_COMPANY_ID);
662     pos += 3;
663     command[pos++] = AVRCP_PDU_ID_REGISTER_NOTIFICATION;
664     command[pos++] = 0;                       // reserved(upper 6) | packet_type -> 0
665     big_endian_store_16(command, pos, 5);     // parameter length
666     pos += 2;
667     command[pos++] = event_id;
668     big_endian_store_32(command, pos, 1);     // send notification on playback position every second, for other notifications it is ignored
669     pos += 4;
670     return l2cap_send(connection->l2cap_signaling_cid, command, pos);
671 }
672 
673 static void avrcp_press_and_hold_timeout_handler(btstack_timer_source_t * timer){
674     UNUSED(timer);
675     avrcp_connection_t * connection = (avrcp_connection_t*) btstack_run_loop_get_timer_context(timer);
676     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
677     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
678     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
679     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
680 }
681 
682 static void avrcp_press_and_hold_timer_start(avrcp_connection_t * connection){
683     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
684     btstack_run_loop_set_timer_handler(&connection->press_and_hold_cmd_timer, avrcp_press_and_hold_timeout_handler);
685     btstack_run_loop_set_timer_context(&connection->press_and_hold_cmd_timer, connection);
686     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
687     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
688 }
689 
690 static void avrcp_press_and_hold_timer_stop(avrcp_connection_t * connection){
691     connection->press_and_hold_cmd_active = false;
692     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
693 }
694 
695 
696 static uint8_t avrcp_controller_request_pass_through_release_control_cmd(avrcp_connection_t * connection){
697     connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
698     if (connection->press_and_hold_cmd_active){
699         avrcp_press_and_hold_timer_stop(connection);
700     }
701     connection->operation_id = 0x80 | connection->operation_id;
702     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
703     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
704     return ERROR_CODE_SUCCESS;
705 }
706 
707 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){
708     log_info("Send command %d", opid);
709     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
710     if (!connection){
711         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
712     }
713 
714     if (connection->state != AVCTP_CONNECTION_OPENED){
715         log_error("Connection in wrong state %d, expected %d. avrcp cid 0x%02x", connection->state, AVCTP_CONNECTION_OPENED, avrcp_cid);
716         return ERROR_CODE_COMMAND_DISALLOWED;
717     }
718     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
719     avrcp_pass_through_command_data_init(connection, opid);
720 
721     if (playback_speed > 0){
722         connection->data[0] = playback_speed;
723         connection->data_len = 1;
724     }
725 
726     connection->press_and_hold_cmd_active = continuous_cmd;
727     if (connection->press_and_hold_cmd_active){
728         avrcp_press_and_hold_timer_start(connection);
729     }
730 
731     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
732     return ERROR_CODE_SUCCESS;
733 }
734 
735 static uint8_t request_single_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
736     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, false);
737 }
738 
739 static uint8_t request_continuous_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
740     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, true);
741 }
742 
743 static void avrcp_controller_get_capabilities_for_connection(avrcp_connection_t * connection, uint8_t capability_id){
744     connection->state = AVCTP_W2_SEND_COMMAND;
745     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_CAPABILITIES);
746 
747     // Parameter Length
748     connection->data_len = 1;
749     connection->data[0] = capability_id;  // capability ID
750 
751     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
752 }
753 
754 static uint8_t avrcp_controller_register_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
755     if (connection->target_supported_notifications_queried && (connection->target_supported_notifications & (1 << event_id)) == 0){
756         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
757     }
758     if ( (connection->notifications_to_deregister & (1 << event_id)) != 0){
759         return ERROR_CODE_COMMAND_DISALLOWED;
760     }
761     if ( (connection->notifications_enabled & (1 << event_id)) != 0){
762         return ERROR_CODE_SUCCESS;
763     }
764     connection->notifications_to_register |= (1 << event_id);
765 
766     if (!connection->target_supported_notifications_queried){
767         connection->target_supported_notifications_suppress_emit_result = true;
768         avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_EVENT);
769         return ERROR_CODE_SUCCESS;
770     }
771     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
772     return ERROR_CODE_SUCCESS;
773 }
774 
775 static uint8_t avrcp_controller_request_continuation(avrcp_connection_t * connection, avrcp_pdu_id_t pdu_id){
776     connection->state = AVCTP_W2_SEND_COMMAND;
777     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, pdu_id);
778 
779     // Parameter Length
780     connection->data_len = 3;
781     big_endian_store_16(connection->data, 0, 1);
782     connection->data[2] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
783 
784     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
785     return ERROR_CODE_SUCCESS;
786 }
787 
788 static uint8_t avrcp_controller_request_abort_continuation(avrcp_connection_t * connection){
789     return avrcp_controller_request_continuation(connection, AVRCP_PDU_ID_REQUEST_ABORT_CONTINUING_RESPONSE);
790 }
791 
792 static uint8_t avrcp_controller_request_continue_response(avrcp_connection_t * connection){
793     return avrcp_controller_request_continuation(connection, AVRCP_PDU_ID_REQUEST_CONTINUING_RESPONSE);
794 }
795 
796 static void avrcp_controller_handle_notification(avrcp_connection_t *connection, avrcp_command_type_t ctype, uint8_t *payload, uint16_t size) {
797     if (size < 1) return;
798     uint16_t pos = 0;
799     avrcp_notification_event_id_t event_id = (avrcp_notification_event_id_t) payload[pos++];
800     if ( (event_id < AVRCP_NOTIFICATION_EVENT_FIRST_INDEX) || (event_id > AVRCP_NOTIFICATION_EVENT_LAST_INDEX)){
801         return;
802     }
803 
804     uint16_t event_mask = (1 << event_id);
805     uint16_t reset_event_mask = ~event_mask;
806 
807     switch (ctype){
808         case AVRCP_CTYPE_RESPONSE_REJECTED:
809             connection->notifications_to_deregister &= reset_event_mask;
810             connection->notifications_to_register   &= reset_event_mask;
811             connection->initial_status_reported     &= reset_event_mask;
812             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE, event_id, false);
813             return;
814 
815         case AVRCP_CTYPE_RESPONSE_INTERIM:
816             // register as enabled
817             connection->notifications_enabled |= event_mask;
818 
819             // check if initial value is already sent
820             if ( (connection->initial_status_reported & event_mask) != 0 ){
821                 return;
822             }
823             // emit event only once, initially
824             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_SUCCESS, event_id, true);
825             connection->initial_status_reported |= event_mask;
826             // emit initial value after this switch
827             break;
828 
829         case AVRCP_CTYPE_RESPONSE_CHANGED_STABLE:
830             // received change, event is considered de-registered
831             // we are re-enabling it automatically, if it is not
832             // explicitly disabled
833             connection->notifications_enabled &= reset_event_mask;
834             if ((connection->notifications_to_deregister & event_mask) == 0){
835                 avrcp_controller_register_notification(connection, event_id);
836             } else {
837                 connection->notifications_to_deregister &= reset_event_mask;
838                 connection->notifications_to_register   &= reset_event_mask;
839                 connection->initial_status_reported     &= reset_event_mask;
840                 avrcp_controller_emit_notification_complete(connection, ERROR_CODE_SUCCESS, event_id, false);
841             }
842             break;
843 
844         default:
845             return;
846     }
847 
848     avrcp_controller_emit_notification_for_event_id(connection->avrcp_cid, event_id, ctype, payload + pos, size - pos);
849 }
850 
851 #ifdef ENABLE_AVCTP_FRAGMENTATION
852 static void avctp_reassemble_message(avrcp_connection_t * connection, avctp_packet_type_t packet_type, uint8_t *packet, uint16_t size){
853     // after header (transaction label and packet type)
854     uint16_t pos;
855     uint16_t bytes_to_store;
856 
857     switch (packet_type){
858         case AVCTP_START_PACKET:
859             if (size < 2) return;
860 
861             // store header
862             pos = 0;
863             connection->avctp_reassembly_buffer[pos] = packet[pos];
864             pos++;
865             connection->avctp_reassembly_size = pos;
866 
867             // NOTE: num packets not needed for reassembly, ignoring it does not pose security risk -> no need to store it
868             pos++;
869 
870             // PID in reassembled packet is at offset 1, it will be read later after the avctp_reassemble_message with AVCTP_END_PACKET is called
871 
872             bytes_to_store = btstack_min(size - pos, sizeof(connection->avctp_reassembly_buffer) - connection->avctp_reassembly_size);
873             memcpy(&connection->avctp_reassembly_buffer[connection->avctp_reassembly_size], &packet[pos], bytes_to_store);
874             connection->avctp_reassembly_size += bytes_to_store;
875             break;
876 
877         case AVCTP_CONTINUE_PACKET:
878         case AVCTP_END_PACKET:
879             if (size < 1) return;
880 
881             // store remaining data, ignore header
882             pos = 1;
883             bytes_to_store = btstack_min(size - pos, sizeof(connection->avctp_reassembly_buffer) - connection->avctp_reassembly_size);
884             memcpy(&connection->avctp_reassembly_buffer[connection->avctp_reassembly_size], &packet[pos], bytes_to_store);
885             connection->avctp_reassembly_size += bytes_to_store;
886             break;
887 
888         default:
889             return;
890     }
891 }
892 #endif
893 
894 static void avrcp_handle_l2cap_data_packet_for_signaling_connection(avrcp_connection_t * connection, uint8_t *packet, uint16_t size){
895     if (size < 6u) return;
896     uint8_t  pdu_id;
897     avrcp_packet_type_t  vendor_dependent_packet_type;
898 
899     uint16_t pos = 0;
900     connection->last_confirmed_transaction_id = packet[pos] >> 4;
901     avrcp_frame_type_t  frame_type =  (avrcp_frame_type_t)((packet[pos] >> 1) & 0x01);
902     avctp_packet_type_t packet_type = (avctp_packet_type_t)((packet[pos] >> 2) & 0x03);
903     pos++;
904 
905     if (frame_type != AVRCP_RESPONSE_FRAME) return;
906 
907     switch (packet_type){
908         case AVCTP_SINGLE_PACKET:
909             break;
910 
911 #ifdef ENABLE_AVCTP_FRAGMENTATION
912         case AVCTP_START_PACKET:
913         case AVCTP_CONTINUE_PACKET:
914             avctp_reassemble_message(connection, packet_type, packet, size);
915             return;
916 
917         case AVCTP_END_PACKET:
918             avctp_reassemble_message(connection, packet_type, packet, size);
919 
920             packet = connection->avctp_reassembly_buffer;
921             size   = connection->avctp_reassembly_size;
922             break;
923 #endif
924 
925         default:
926             return;
927     }
928 
929     pos += 2; // PID
930 
931     avrcp_command_type_t ctype = (avrcp_command_type_t) packet[pos++];
932 
933 #ifdef ENABLE_LOG_INFO
934     uint8_t byte_value = packet[pos];
935     avrcp_subunit_type_t subunit_type = (avrcp_subunit_type_t) (byte_value >> 3);
936     avrcp_subunit_type_t subunit_id   = (avrcp_subunit_type_t) (byte_value & 0x07);
937 #endif
938     pos++;
939 
940     uint8_t opcode = packet[pos++];
941     uint16_t param_length;
942 
943     switch (opcode){
944         case AVRCP_CMD_OPCODE_SUBUNIT_INFO:{
945             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
946             connection->state = AVCTP_CONNECTION_OPENED;
947 
948 #ifdef ENABLE_LOG_INFO
949             // page, extension code (1)
950             pos++;
951             uint8_t unit_type = packet[pos] >> 3;
952             uint8_t max_subunit_ID = packet[pos] & 0x07;
953             log_info("SUBUNIT INFO response: ctype 0x%02x (0C), subunit_type 0x%02x (1F), subunit_id 0x%02x (07), opcode 0x%02x (30), unit_type 0x%02x, max_subunit_ID %d", ctype, subunit_type, subunit_id, opcode, unit_type, max_subunit_ID);
954 #endif
955             break;
956         }
957         case AVRCP_CMD_OPCODE_UNIT_INFO:{
958             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
959             connection->state = AVCTP_CONNECTION_OPENED;
960 
961 #ifdef ENABLE_LOG_INFO
962             // byte value 7 (1)
963             pos++;
964             uint8_t unit_type = packet[pos] >> 3;
965             uint8_t unit = packet[pos] & 0x07;
966             pos++;
967             uint32_t company_id = big_endian_read_24(packet, pos);
968             log_info("UNIT INFO response: ctype 0x%02x (0C), subunit_type 0x%02x (1F), subunit_id 0x%02x (07), opcode 0x%02x (30), unit_type 0x%02x, unit %d, company_id 0x%06" PRIx32,
969                 ctype, subunit_type, subunit_id, opcode, unit_type, unit, company_id);
970 #endif
971             break;
972         }
973         case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
974 
975             if ((size - pos) < 7) return;
976 
977             // Company ID (3)
978             pos += 3;
979             pdu_id = packet[pos++];
980             vendor_dependent_packet_type = (avrcp_packet_type_t)(packet[pos++] & 0x03);
981             param_length = big_endian_read_16(packet, pos);
982             pos += 2;
983 
984             if ((size - pos) < param_length) return;
985 
986             // handle asynchronous notifications, without changing state
987             if (pdu_id == AVRCP_PDU_ID_REGISTER_NOTIFICATION){
988                 avrcp_controller_handle_notification(connection, ctype, packet + pos, size - pos);
989                 break;
990             }
991 
992             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE){
993                 log_info("AVRCP_CMD_OPCODE_VENDOR_DEPENDENT state %d", connection->state);
994                 return;
995             }
996             connection->state = AVCTP_CONNECTION_OPENED;
997 
998             log_info("VENDOR DEPENDENT response: pdu id 0x%02x, param_length %d, status %s", pdu_id, param_length, avrcp_ctype2str(ctype));
999             switch (pdu_id){
1000                 case AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE:{
1001                     uint8_t num_attributes = packet[pos++];
1002                     int i;
1003                     avrcp_repeat_mode_t  repeat_mode =  AVRCP_REPEAT_MODE_INVALID;
1004                     avrcp_shuffle_mode_t shuffle_mode = AVRCP_SHUFFLE_MODE_INVALID;
1005                     for (i = 0; i < num_attributes; i++){
1006                         uint8_t attribute_id    = packet[pos++];
1007                         uint8_t value = packet[pos++];
1008                         switch (attribute_id){
1009                             case 0x02:
1010                                 repeat_mode = (avrcp_repeat_mode_t) value;
1011                                 break;
1012                             case 0x03:
1013                                 shuffle_mode = (avrcp_shuffle_mode_t) value;
1014                                 break;
1015                             default:
1016                                 break;
1017                         }
1018                     }
1019                     avrcp_controller_emit_repeat_and_shuffle_mode(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, repeat_mode, shuffle_mode);
1020                     break;
1021                 }
1022 
1023                 case AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE:{
1024                     uint16_t offset = 0;
1025                     uint8_t event[6];
1026                     event[offset++] = HCI_EVENT_AVRCP_META;
1027                     event[offset++] = sizeof(event) - 2;
1028                     event[offset++] = AVRCP_SUBEVENT_PLAYER_APPLICATION_VALUE_RESPONSE;
1029                     little_endian_store_16(event, offset, connection->avrcp_cid);
1030                     offset += 2;
1031                     event[offset++] = ctype;
1032                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1033                     break;
1034                 }
1035 
1036                 case AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME:{
1037                     uint16_t offset = 0;
1038                     uint8_t event[7];
1039                     event[offset++] = HCI_EVENT_AVRCP_META;
1040                     event[offset++] = sizeof(event) - 2;
1041                     event[offset++] = AVRCP_SUBEVENT_SET_ABSOLUTE_VOLUME_RESPONSE;
1042                     little_endian_store_16(event, offset, connection->avrcp_cid);
1043                     offset += 2;
1044                     event[offset++] = ctype;
1045                     event[offset++] = packet[pos++];
1046                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1047                     break;
1048                 }
1049 
1050                 case AVRCP_PDU_ID_GET_CAPABILITIES:{
1051                     avrcp_capability_id_t capability_id = (avrcp_capability_id_t) packet[pos++];
1052                     uint8_t capability_count = 0;
1053                     if (param_length > 1){
1054                         capability_count = packet[pos++];
1055                     }
1056                     uint16_t i;
1057                     uint16_t offset = 0;
1058                     uint8_t event[10];
1059 
1060                     switch (capability_id){
1061 
1062                         case AVRCP_CAPABILITY_ID_COMPANY:
1063                             for (i = 0; (i < capability_count) && ((size - pos) >= 3); i++){
1064                                 uint32_t company_id = big_endian_read_24(packet, pos);
1065                                 pos += 3;
1066                                 log_info("  0x%06" PRIx32 ", ", company_id);
1067 
1068                                 offset = 0;
1069                                 event[offset++] = HCI_EVENT_AVRCP_META;
1070                                 event[offset++] = sizeof(event) - 2;
1071                                 event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID;
1072                                 little_endian_store_16(event, offset, connection->avrcp_cid);
1073                                 offset += 2;
1074                                 event[offset++] = ctype;
1075                                 event[offset++] = 0;
1076                                 little_endian_store_24(event, offset, company_id);
1077                                 offset += 3;
1078                                 (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
1079                             }
1080 
1081                             offset = 0;
1082                             event[offset++] = HCI_EVENT_AVRCP_META;
1083                             event[offset++] = sizeof(event) - 2;
1084                             event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID_DONE;
1085                             little_endian_store_16(event, offset, connection->avrcp_cid);
1086                             offset += 2;
1087                             event[offset++] = ctype;
1088                             event[offset++] = 0;
1089                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
1090                             break;
1091 
1092                         case AVRCP_CAPABILITY_ID_EVENT:
1093                             for (i = 0; (i < capability_count) && ((size - pos) >= 1); i++){
1094                                 uint8_t event_id = packet[pos++];
1095                                 connection->target_supported_notifications |= (1 << event_id);
1096                             }
1097 
1098                             // if the get supported events query is triggered by avrcp_controller_enable_notification call,
1099                             // avrcp_controller_emit_supported_events should be suppressed
1100                             if (connection->target_supported_notifications_suppress_emit_result){
1101                                 connection->target_supported_notifications_suppress_emit_result = false;
1102                                 // also, notification might not be supported
1103                                 // if so, emit AVRCP_SUBEVENT_ENABLE_NOTIFICATION_COMPLETE event to app,
1104                                 // and update notifications_to_register bitmap
1105                                 for (i = (uint8_t)AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; i < (uint8_t) AVRCP_NOTIFICATION_EVENT_LAST_INDEX; i++){
1106                                     if ((connection->notifications_to_register & (1<<i)) != 0){
1107                                         if ((connection->target_supported_notifications & (1<<i)) == 0){
1108                                             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE, i, false);
1109                                             connection->notifications_to_register &= ~(1 << i);
1110                                         }
1111                                     }
1112                                 }
1113                                 break;
1114                             }
1115                             // supported events are emitted only if the get supported events query
1116                             // is triggered by avrcp_controller_get_supported_events call
1117                             avrcp_controller_emit_supported_events(connection);
1118                             break;
1119 
1120                         default:
1121                             // ignore
1122                             break;
1123                     }
1124                     break;
1125                 }
1126 
1127                 case AVRCP_PDU_ID_GET_PLAY_STATUS:{
1128                     uint32_t song_length = big_endian_read_32(packet, pos);
1129                     pos += 4;
1130                     uint32_t song_position = big_endian_read_32(packet, pos);
1131                     pos += 4;
1132                     uint8_t play_status = packet[pos];
1133 
1134                     uint8_t event[15];
1135                     int offset = 0;
1136                     event[offset++] = HCI_EVENT_AVRCP_META;
1137                     event[offset++] = sizeof(event) - 2;
1138                     event[offset++] = AVRCP_SUBEVENT_PLAY_STATUS;
1139                     little_endian_store_16(event, offset, connection->avrcp_cid);
1140                     offset += 2;
1141                     event[offset++] = ctype;
1142                     little_endian_store_32(event, offset, song_length);
1143                     offset += 4;
1144                     little_endian_store_32(event, offset, song_position);
1145                     offset += 4;
1146                     event[offset++] = play_status;
1147                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1148                     break;
1149                 }
1150 
1151                 case AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES:{
1152                     switch (vendor_dependent_packet_type){
1153                         case AVRCP_START_PACKET:
1154                         case AVRCP_SINGLE_PACKET:
1155                             avrcp_parser_reset(connection);
1156                             connection->list_size = param_length;
1157                             connection->num_attributes = packet[pos++];
1158 
1159                             avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
1160                             if (vendor_dependent_packet_type == AVRCP_START_PACKET){
1161                                 avrcp_controller_request_continue_response(connection);
1162                             }
1163                             break;
1164                         case AVRCP_CONTINUE_PACKET:
1165                         case AVRCP_END_PACKET:
1166                             connection->num_received_fragments++;
1167 
1168                             if (connection->num_received_fragments < connection->max_num_fragments){
1169                                 avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
1170 
1171                                 if (vendor_dependent_packet_type == AVRCP_CONTINUE_PACKET){
1172                                     avrcp_controller_request_continue_response(connection);
1173                                 }
1174                             } else {
1175                                 avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 1);
1176                                 avrcp_parser_reset(connection);
1177                                 avrcp_controller_request_abort_continuation(connection);
1178                             }
1179                             break;
1180                         default:
1181                             // TODO check
1182                             btstack_assert(false);
1183                             break;
1184                     }
1185                 }
1186                 default:
1187                     break;
1188             }
1189             break;
1190         case AVRCP_CMD_OPCODE_PASS_THROUGH:{
1191             if ((size - pos) < 1) return;
1192             uint8_t operation_id = packet[pos++];
1193             switch (connection->state){
1194                 case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
1195                     // trigger release for simple command:
1196                     if (!connection->press_and_hold_cmd_active){
1197                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
1198                         break;
1199                     }
1200                     // for press and hold, send release if it just has been requested, otherwise, wait for next repeat
1201                     if (connection->press_and_hold_cmd_release){
1202                         connection->press_and_hold_cmd_release = false;
1203                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
1204                     } else {
1205                         connection->state = AVCTP_W4_STOP;
1206                     }
1207                     break;
1208                 case AVCTP_W2_RECEIVE_RESPONSE:
1209                     connection->state = AVCTP_CONNECTION_OPENED;
1210                     break;
1211                 default:
1212                     break;
1213             }
1214             if (connection->state == AVCTP_W4_STOP){
1215                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_START, connection->avrcp_cid, ctype, operation_id);
1216             }
1217             if (connection->state == AVCTP_CONNECTION_OPENED) {
1218                 // RELEASE response
1219                 operation_id = operation_id & 0x7F;
1220                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_COMPLETE, connection->avrcp_cid, ctype, operation_id);
1221             }
1222             if (connection->state == AVCTP_W2_SEND_RELEASE_COMMAND){
1223                 // PRESS response
1224                 avrcp_controller_request_pass_through_release_control_cmd(connection);
1225             }
1226             break;
1227         }
1228         default:
1229             break;
1230     }
1231 
1232     // trigger pending notification reqistrations
1233     if ((connection->state == AVCTP_CONNECTION_OPENED) && connection->notifications_to_register){
1234         avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1235     }
1236 }
1237 
1238 static void avrcp_controller_handle_can_send_now(avrcp_connection_t * connection){
1239     switch (connection->state){
1240         case AVCTP_W2_SEND_PRESS_COMMAND:
1241         case AVCTP_W2_SEND_COMMAND:
1242         case AVCTP_W2_SEND_RELEASE_COMMAND:
1243         case AVCTP_W2_SEND_AVCTP_FRAGMENTED_MESSAGE:
1244             avrcp_send_cmd_with_avctp_fragmentation(connection);
1245 
1246             if (connection->data_offset < connection->data_len){
1247                 avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1248                 return;
1249             }
1250             if (connection->state == AVCTP_W2_SEND_PRESS_COMMAND){
1251                 connection->state = AVCTP_W2_RECEIVE_PRESS_RESPONSE;
1252             } else {
1253                 connection->state = AVCTP_W2_RECEIVE_RESPONSE;
1254             }
1255             break;
1256         default:
1257             break;
1258     }
1259 
1260     // send register notification if queued
1261     if (connection->notifications_to_register != 0){
1262         uint8_t event_id;
1263         for (event_id = (uint8_t)AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; event_id < (uint8_t)AVRCP_NOTIFICATION_EVENT_LAST_INDEX; event_id++){
1264             if (connection->notifications_to_register & (1<<event_id)){
1265                 connection->notifications_to_register &= ~ (1 << event_id);
1266                 avrcp_send_register_notification(connection, event_id);
1267                 return;
1268             }
1269         }
1270     }
1271 }
1272 
1273 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
1274     avrcp_connection_t * connection;
1275 
1276     switch (packet_type) {
1277         case L2CAP_DATA_PACKET:
1278             connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
1279             avrcp_handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
1280             break;
1281 
1282         case HCI_EVENT_PACKET:
1283             switch (hci_event_packet_get_type(packet)){
1284                 case L2CAP_EVENT_CAN_SEND_NOW:
1285                     connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
1286                     avrcp_controller_handle_can_send_now(connection);
1287                     break;
1288             default:
1289                 break;
1290         }
1291         default:
1292             break;
1293     }
1294 }
1295 
1296 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){
1297     avrcp_create_sdp_record(1, service, service_record_handle, avrcp_controller_supports_browsing(supported_features), supported_features, service_name, service_provider_name);
1298 }
1299 
1300 void avrcp_controller_init(void){
1301     avrcp_controller_context.role = AVRCP_CONTROLLER;
1302     avrcp_controller_context.packet_handler = avrcp_controller_packet_handler;
1303     avrcp_register_controller_packet_handler(&avrcp_controller_packet_handler);
1304 }
1305 
1306 void avrcp_controller_deinit(void){
1307     memset(&avrcp_controller_context, 0, sizeof(avrcp_context_t));
1308 }
1309 
1310 void avrcp_controller_register_packet_handler(btstack_packet_handler_t callback){
1311     btstack_assert(callback != NULL);
1312     avrcp_controller_context.avrcp_callback = callback;
1313 }
1314 
1315 
1316 uint8_t avrcp_controller_play(uint16_t avrcp_cid){
1317     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1318 }
1319 
1320 uint8_t avrcp_controller_stop(uint16_t avrcp_cid){
1321     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1322 }
1323 
1324 uint8_t avrcp_controller_pause(uint16_t avrcp_cid){
1325     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1326 }
1327 
1328 uint8_t avrcp_controller_forward(uint16_t avrcp_cid){
1329     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1330 }
1331 
1332 uint8_t avrcp_controller_backward(uint16_t avrcp_cid){
1333     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1334 }
1335 
1336 uint8_t avrcp_controller_volume_up(uint16_t avrcp_cid){
1337     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1338 }
1339 
1340 uint8_t avrcp_controller_volume_down(uint16_t avrcp_cid){
1341     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1342 }
1343 
1344 uint8_t avrcp_controller_mute(uint16_t avrcp_cid){
1345     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1346 }
1347 
1348 uint8_t avrcp_controller_skip(uint16_t avrcp_cid){
1349     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_SKIP, 0);
1350 }
1351 
1352 uint8_t avrcp_controller_fast_forward(uint16_t avrcp_cid){
1353     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1354 }
1355 
1356 uint8_t avrcp_controller_rewind(uint16_t avrcp_cid){
1357     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1358 }
1359 
1360 /* start continuous cmds */
1361 
1362 uint8_t avrcp_controller_start_press_and_hold_cmd(uint16_t avrcp_cid, avrcp_operation_id_t operation_id){
1363     return request_continuous_pass_through_press_control_cmd(avrcp_cid, operation_id, 0);
1364 }
1365 
1366 uint8_t avrcp_controller_press_and_hold_play(uint16_t avrcp_cid){
1367     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1368 }
1369 uint8_t avrcp_controller_press_and_hold_stop(uint16_t avrcp_cid){
1370     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1371 }
1372 uint8_t avrcp_controller_press_and_hold_pause(uint16_t avrcp_cid){
1373     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1374 }
1375 uint8_t avrcp_controller_press_and_hold_forward(uint16_t avrcp_cid){
1376     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1377 }
1378 uint8_t avrcp_controller_press_and_hold_backward(uint16_t avrcp_cid){
1379     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1380 }
1381 uint8_t avrcp_controller_press_and_hold_fast_forward(uint16_t avrcp_cid){
1382     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1383 }
1384 uint8_t avrcp_controller_press_and_hold_rewind(uint16_t avrcp_cid){
1385     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1386 }
1387 uint8_t avrcp_controller_press_and_hold_volume_up(uint16_t avrcp_cid){
1388     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1389 }
1390 uint8_t avrcp_controller_press_and_hold_volume_down(uint16_t avrcp_cid){
1391     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1392 }
1393 uint8_t avrcp_controller_press_and_hold_mute(uint16_t avrcp_cid){
1394     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1395 }
1396 
1397 /* stop continuous cmds */
1398 uint8_t avrcp_controller_release_press_and_hold_cmd(uint16_t avrcp_cid){
1399     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1400     if (!connection){
1401         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1402     }
1403 
1404     switch (connection->state){
1405         // respond when we receive response for (repeated) press command
1406         case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
1407             connection->press_and_hold_cmd_release = true;
1408             break;
1409 
1410         // release already sent or on the way, nothing to do
1411         case AVCTP_W2_RECEIVE_RESPONSE:
1412         case AVCTP_W2_SEND_RELEASE_COMMAND:
1413             break;
1414 
1415         // about to send next repeated press command or wait for it -> release right away
1416         case AVCTP_W2_SEND_PRESS_COMMAND:
1417         case AVCTP_W4_STOP:
1418             return avrcp_controller_request_pass_through_release_control_cmd(connection);
1419 
1420         // otherwise reject request
1421         default:
1422             return ERROR_CODE_COMMAND_DISALLOWED;
1423     }
1424     return ERROR_CODE_SUCCESS;
1425 }
1426 
1427 uint8_t avrcp_controller_enable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1428     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1429     if (!connection){
1430         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1431     }
1432     return avrcp_controller_register_notification(connection, event_id);
1433 }
1434 
1435 uint8_t avrcp_controller_disable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1436     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1437     if (!connection){
1438         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1439     }
1440     if (!connection->target_supported_notifications_queried){
1441         return ERROR_CODE_COMMAND_DISALLOWED;
1442     }
1443 
1444     if ((connection->target_supported_notifications & (1 << event_id)) == 0){
1445         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1446     }
1447 
1448     if ((connection->notifications_enabled & (1 << event_id)) == 0){
1449         return ERROR_CODE_SUCCESS;
1450     }
1451 
1452     connection->notifications_to_deregister |= (1 << event_id);
1453     return ERROR_CODE_SUCCESS;
1454 }
1455 
1456 uint8_t avrcp_controller_unit_info(uint16_t avrcp_cid){
1457     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1458     if (!connection){
1459         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1460     }
1461     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1462 
1463     connection->state = AVCTP_W2_SEND_COMMAND;
1464     avrcp_custome_command_data_init(connection, AVRCP_CMD_OPCODE_UNIT_INFO, AVRCP_CTYPE_STATUS, AVRCP_SUBUNIT_TYPE_UNIT, AVRCP_SUBUNIT_ID_IGNORE, 0, 0);
1465 
1466     memset(connection->data, 0xFF, 5);
1467     connection->data_len = 5;
1468     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1469     return ERROR_CODE_SUCCESS;
1470 }
1471 
1472 uint8_t avrcp_controller_subunit_info(uint16_t avrcp_cid){
1473     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1474     if (!connection){
1475         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1476     }
1477     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1478 
1479     connection->state = AVCTP_W2_SEND_COMMAND;
1480     avrcp_custome_command_data_init(connection, AVRCP_CMD_OPCODE_SUBUNIT_INFO, AVRCP_CTYPE_STATUS, AVRCP_SUBUNIT_TYPE_UNIT, AVRCP_SUBUNIT_ID_IGNORE, 0, 0);
1481 
1482     memset(connection->data, 0xFF, 5);
1483     connection->data[0] = 7; // page: 0, extention_code: 7
1484     connection->data_len = 5;
1485     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1486     return ERROR_CODE_SUCCESS;
1487 }
1488 
1489 uint8_t avrcp_controller_get_supported_company_ids(uint16_t avrcp_cid){
1490     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1491     if (!connection){
1492         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1493     }
1494     if (connection->state != AVCTP_CONNECTION_OPENED){
1495         return ERROR_CODE_COMMAND_DISALLOWED;
1496     }
1497     avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_COMPANY);
1498     return ERROR_CODE_SUCCESS;
1499 }
1500 
1501 uint8_t avrcp_controller_get_supported_events(uint16_t avrcp_cid){
1502     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1503     if (!connection){
1504         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1505     }
1506     if (connection->state != AVCTP_CONNECTION_OPENED){
1507         return ERROR_CODE_COMMAND_DISALLOWED;
1508     }
1509 
1510     if (!connection->target_supported_notifications_queried){
1511         connection->target_supported_notifications_queried = true;
1512         avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_EVENT);
1513         return ERROR_CODE_SUCCESS;
1514     }
1515 
1516     avrcp_controller_emit_supported_events(connection);
1517     return ERROR_CODE_SUCCESS;
1518 }
1519 
1520 uint8_t avrcp_controller_get_play_status(uint16_t avrcp_cid){
1521     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1522     if (!connection){
1523         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1524     }
1525     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1526 
1527     connection->state = AVCTP_W2_SEND_COMMAND;
1528     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_PLAY_STATUS);
1529 
1530     connection->data_len = 0;
1531     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1532     return ERROR_CODE_SUCCESS;
1533 }
1534 
1535 uint8_t avrcp_controller_set_addressed_player(uint16_t avrcp_cid, uint16_t addressed_player_id){
1536     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1537     if (!connection){
1538         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1539     }
1540     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1541 
1542     connection->state = AVCTP_W2_SEND_COMMAND;
1543     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_ADDRESSED_PLAYER);
1544 
1545     connection->data_len = 2;
1546     big_endian_store_16(connection->data, 0, addressed_player_id);
1547 
1548     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1549     return ERROR_CODE_SUCCESS;
1550 }
1551 
1552 uint8_t avrcp_controller_get_element_attributes(uint16_t avrcp_cid, uint8_t num_attributes, avrcp_media_attribute_id_t * attributes){
1553     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1554     if (!connection){
1555         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1556     }
1557 
1558     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1559 
1560     if (num_attributes >= AVRCP_MEDIA_ATTR_RESERVED) {
1561         return ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS;
1562     }
1563 
1564     connection->state = AVCTP_W2_SEND_COMMAND;
1565     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES);
1566 
1567     uint8_t pos = 0;
1568     // write 8 bytes value
1569     memset(connection->data, pos, 8); // identifier: PLAYING
1570     pos += 8;
1571 
1572     uint8_t num_attributes_index = pos;
1573     pos++;
1574 
1575     // If num_attributes is set to zero, all attribute information shall be returned,
1576     // and the AttributeID field is omitted
1577     connection->data[num_attributes_index] = 0;
1578     uint8_t i;
1579     for (i = 0; i < num_attributes; i++){
1580         // ignore invalid attribute ID and "get all attributes"
1581         if (AVRCP_MEDIA_ATTR_ALL > attributes[i] && attributes[i] < AVRCP_MEDIA_ATTR_RESERVED){
1582             // every attribute is 4 bytes long
1583             big_endian_store_32(connection->data, pos, attributes[i]);
1584             pos += 4;
1585             connection->data[num_attributes_index]++;
1586         }
1587     }
1588 
1589     // Parameter Length
1590     connection->data_len = pos;
1591 
1592     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1593     return ERROR_CODE_SUCCESS;
1594 }
1595 
1596 uint8_t avrcp_controller_get_now_playing_info(uint16_t avrcp_cid){
1597     return avrcp_controller_get_element_attributes(avrcp_cid, 0, NULL);
1598 }
1599 
1600 uint8_t avrcp_controller_get_now_playing_info_for_media_attribute_id(uint16_t avrcp_cid, avrcp_media_attribute_id_t media_attribute_id){
1601     if (media_attribute_id == AVRCP_MEDIA_ATTR_ALL){
1602         return avrcp_controller_get_now_playing_info(avrcp_cid);
1603     }
1604     return avrcp_controller_get_element_attributes(avrcp_cid, 1, &media_attribute_id);
1605 }
1606 
1607 uint8_t avrcp_controller_set_absolute_volume(uint16_t avrcp_cid, uint8_t volume){
1608      avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1609     if (!connection){
1610         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1611     }
1612 
1613     //
1614     // allow sending of multiple set abs volume commands without waiting for response
1615     //
1616     uint8_t status = ERROR_CODE_COMMAND_DISALLOWED;
1617     switch (connection->state){
1618         case AVCTP_CONNECTION_OPENED:
1619             status = ERROR_CODE_SUCCESS;
1620             break;
1621         case AVCTP_W2_RECEIVE_RESPONSE:
1622             // - is pending response also set abs volume
1623             if (connection->command_opcode  != AVRCP_CMD_OPCODE_VENDOR_DEPENDENT) break;
1624             if (connection->command_type    != AVRCP_CTYPE_CONTROL)               break;
1625             if (connection->subunit_type    != AVRCP_SUBUNIT_TYPE_PANEL)          break;
1626             if (connection->subunit_id      != AVRCP_SUBUNIT_ID)                  break;
1627             if (connection->pdu_id          != AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME)  break;
1628             // - is next transaction id valid in window
1629             if (avrcp_controller_is_transaction_id_valid(connection, avrcp_controller_calc_next_transaction_label(connection->transaction_id_counter)) == false) break;
1630             status = ERROR_CODE_SUCCESS;
1631             break;
1632         default:
1633             break;
1634     }
1635     if (status != ERROR_CODE_SUCCESS) return status;
1636 
1637     connection->state = AVCTP_W2_SEND_COMMAND;
1638     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME);
1639 
1640     // Parameter Length
1641     connection->data_len = 1;
1642     connection->data[0] = volume;
1643 
1644     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1645     return ERROR_CODE_SUCCESS;
1646 }
1647 
1648 uint8_t avrcp_controller_query_shuffle_and_repeat_modes(uint16_t avrcp_cid){
1649     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1650     if (!connection){
1651         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1652     }
1653     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1654 
1655     connection->state = AVCTP_W2_SEND_COMMAND;
1656     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE);
1657 
1658     connection->data_len = 5;
1659     connection->data[0] = 4;                     // NumPlayerApplicationSettingAttributeID
1660     // PlayerApplicationSettingAttributeID1 AVRCP Spec, Appendix F, 133
1661     connection->data[1] = 0x01;   // equalizer  (1-OFF, 2-ON)
1662     connection->data[2] = 0x02;   // repeat     (1-off, 2-single track, 3-all tracks, 4-group repeat)
1663     connection->data[3] = 0x03;   // shuffle    (1-off, 2-all tracks, 3-group shuffle)
1664     connection->data[4] = 0x04;   // scan       (1-off, 2-all tracks, 3-group scan)
1665 
1666     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1667     return ERROR_CODE_SUCCESS;
1668 }
1669 
1670 static uint8_t avrcp_controller_set_current_player_application_setting_value(uint16_t avrcp_cid, uint8_t attr_id, uint8_t attr_value){
1671     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1672     if (!connection){
1673         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1674     }
1675     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1676 
1677     connection->state = AVCTP_W2_SEND_COMMAND;
1678     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE);
1679 
1680     // Parameter Length
1681     connection->data_len = 3;
1682     connection->data[0]  = 2;
1683     connection->data[1]  = attr_id;
1684     connection->data[2]  = attr_value;
1685 
1686     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1687     return ERROR_CODE_SUCCESS;
1688 }
1689 
1690 uint8_t avrcp_controller_set_shuffle_mode(uint16_t avrcp_cid, avrcp_shuffle_mode_t mode){
1691     if ((mode < AVRCP_SHUFFLE_MODE_OFF) || (mode > AVRCP_SHUFFLE_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1692     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x03, mode);
1693 }
1694 
1695 uint8_t avrcp_controller_set_repeat_mode(uint16_t avrcp_cid, avrcp_repeat_mode_t mode){
1696     if ((mode < AVRCP_REPEAT_MODE_OFF) || (mode > AVRCP_REPEAT_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1697     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x02, mode);
1698 }
1699 
1700 uint8_t avrcp_controller_play_item_for_scope(uint16_t avrcp_cid, uint8_t * uid, uint16_t uid_counter, avrcp_browsing_scope_t scope){
1701     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1702     if (!connection){
1703         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1704     }
1705     if (connection->state != AVCTP_CONNECTION_OPENED){
1706         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1707         return ERROR_CODE_COMMAND_DISALLOWED;
1708     }
1709     connection->state = AVCTP_W2_SEND_COMMAND;
1710     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_PLAY_ITEM);
1711 
1712     // Parameter Length
1713     connection->data_len = 11;
1714     connection->data[0]  = scope;
1715     memset(&connection->data[1], 0, 8);
1716     if (uid){
1717         (void)memcpy(&connection->data[1], uid, 8);
1718     }
1719     big_endian_store_16(connection->data, 9, uid_counter);
1720 
1721     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1722     return ERROR_CODE_SUCCESS;
1723 }
1724 
1725 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){
1726     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1727     if (!connection){
1728         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1729     }
1730     if (connection->state != AVCTP_CONNECTION_OPENED){
1731         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1732         return ERROR_CODE_COMMAND_DISALLOWED;
1733     }
1734 
1735     connection->state = AVCTP_W2_SEND_COMMAND;
1736     avrcp_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_ADD_TO_NOW_PLAYING);
1737 
1738     // Parameter Length
1739     connection->data_len = 11;
1740     connection->data[0]  = scope;
1741     memset(&connection->data[1], 0, 8);
1742     if (uid){
1743         (void)memcpy(&connection->data[1], uid, 8);
1744     }
1745     big_endian_store_16(connection->data, 9, uid_counter);
1746 
1747     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1748     return ERROR_CODE_SUCCESS;
1749 }
1750 
1751 uint8_t avrcp_controller_set_max_num_fragments(uint16_t avrcp_cid, uint8_t max_num_fragments){
1752     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1753     if (!connection){
1754         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1755     }
1756     connection->max_num_fragments = max_num_fragments;
1757     return ERROR_CODE_SUCCESS;
1758 }
1759 
1760 
1761 uint8_t avrcp_controller_send_custom_command(uint16_t avrcp_cid,
1762     avrcp_command_type_t command_type,
1763     avrcp_subunit_type_t subunit_type, avrcp_subunit_id_t subunit_id,
1764     avrcp_pdu_id_t pdu_id, uint32_t company_id,
1765     const uint8_t * data, uint16_t data_len){
1766 
1767     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1768     if (!connection){
1769         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1770     }
1771     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1772 
1773     connection->state = AVCTP_W2_SEND_AVCTP_FRAGMENTED_MESSAGE;
1774     avrcp_custome_command_data_init(connection, AVRCP_CMD_OPCODE_VENDOR_DEPENDENT, command_type, subunit_type, subunit_id, pdu_id, company_id);
1775 
1776     connection->data = (uint8_t *)data;
1777     connection->data_len = data_len;
1778 
1779     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1780     return ERROR_CODE_SUCCESS;
1781 }
1782