xref: /btstack/src/classic/avrcp_controller.c (revision 11014891506325e9907b111abb1120e484300aab)
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 MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define __BTSTACK_FILE__ "avrcp_controller.c"
39 
40 #include <stdint.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <inttypes.h>
45 
46 #include "btstack.h"
47 #include "classic/avrcp.h"
48 #include "classic/avrcp_controller.h"
49 
50 // made public in avrcp_controller.h
51 avrcp_context_t avrcp_controller_context;
52 
53 static int avrcp_controller_supports_browsing(uint16_t controller_supported_features){
54     return controller_supported_features & (1 << AVRCP_CONTROLLER_SUPPORTED_FEATURE_BROWSING);
55 }
56 
57 void avrcp_controller_create_sdp_record(uint8_t * service, uint32_t service_record_handle, uint8_t browsing, uint16_t supported_features, const char * service_name, const char * service_provider_name){
58     if (browsing){
59         supported_features |= (1 << AVRCP_CONTROLLER_SUPPORTED_FEATURE_BROWSING);
60     }
61     avrcp_create_sdp_record(1, service, service_record_handle, avrcp_controller_supports_browsing(supported_features), supported_features, service_name, service_provider_name);
62 }
63 
64 static void avrcp_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){
65     if (!callback) return;
66     uint8_t event[8];
67     int pos = 0;
68     event[pos++] = HCI_EVENT_AVRCP_META;
69     event[pos++] = sizeof(event) - 2;
70     event[pos++] = AVRCP_SUBEVENT_SHUFFLE_AND_REPEAT_MODE;
71     little_endian_store_16(event, pos, avrcp_cid);
72     pos += 2;
73     event[pos++] = ctype;
74     event[pos++] = repeat_mode;
75     event[pos++] = shuffle_mode;
76     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
77 }
78 
79 static void avrcp_emit_operation_status(btstack_packet_handler_t callback, uint8_t subevent, uint16_t avrcp_cid, uint8_t ctype, uint8_t operation_id){
80     if (!callback) return;
81     uint8_t event[7];
82     int pos = 0;
83     event[pos++] = HCI_EVENT_AVRCP_META;
84     event[pos++] = sizeof(event) - 2;
85     event[pos++] = subevent;
86     little_endian_store_16(event, pos, avrcp_cid);
87     pos += 2;
88     event[pos++] = ctype;
89     event[pos++] = operation_id;
90     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
91 }
92 
93 static void avrcp_press_and_hold_timeout_handler(btstack_timer_source_t * timer){
94     UNUSED(timer);
95     avrcp_connection_t * connection = (avrcp_connection_t*) btstack_run_loop_get_timer_context(timer);
96     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
97     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
98     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
99     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
100 }
101 
102 static void avrcp_press_and_hold_timer_start(avrcp_connection_t * connection){
103     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
104     btstack_run_loop_set_timer_handler(&connection->press_and_hold_cmd_timer, avrcp_press_and_hold_timeout_handler);
105     btstack_run_loop_set_timer_context(&connection->press_and_hold_cmd_timer, connection);
106     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
107     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
108 }
109 
110 static void avrcp_press_and_hold_timer_stop(avrcp_connection_t * connection){
111     connection->continuous_fast_forward_cmd = 0;
112     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
113 }
114 
115 static uint8_t request_pass_through_release_control_cmd(avrcp_connection_t * connection){
116     connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
117     if (connection->continuous_fast_forward_cmd){
118         avrcp_press_and_hold_timer_stop(connection);
119     }
120     connection->cmd_operands[0] = 0x80 | connection->cmd_operands[0];
121     connection->transaction_label++;
122     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
123     return ERROR_CODE_SUCCESS;
124 }
125 
126 static inline uint8_t request_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed, uint8_t continuous_fast_forward_cmd, avrcp_context_t * context){
127     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, context);
128     if (!connection){
129         log_error("avrcp: could not find a connection.");
130         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
131     }
132     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
133     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
134     connection->command_opcode =  AVRCP_CMD_OPCODE_PASS_THROUGH;
135     connection->command_type = AVRCP_CTYPE_CONTROL;
136     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
137     connection->subunit_id =   AVRCP_SUBUNIT_ID;
138     connection->cmd_operands_length = 0;
139 
140     connection->continuous_fast_forward_cmd = continuous_fast_forward_cmd;
141     connection->cmd_operands_length = 2;
142     connection->cmd_operands[0] = opid;
143     if (playback_speed > 0){
144         connection->cmd_operands[2] = playback_speed;
145         connection->cmd_operands_length++;
146     }
147     connection->cmd_operands[1] = connection->cmd_operands_length - 2;
148 
149     if (connection->continuous_fast_forward_cmd){
150         avrcp_press_and_hold_timer_start(connection);
151     }
152 
153     connection->transaction_label++;
154     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
155     return ERROR_CODE_SUCCESS;
156 }
157 
158 static uint8_t request_single_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
159     return request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, 0, &avrcp_controller_context);
160 }
161 
162 static uint8_t request_continuous_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
163     return request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, 1, &avrcp_controller_context);
164 }
165 
166 #define AVRCP_CMD_BUFFER_SIZE 30
167 static uint16_t avrcp_get_max_payload_size_for_packet_type(avrcp_packet_type_t packet_type){
168     switch (packet_type){
169         case AVRCP_SINGLE_PACKET:
170             return AVRCP_CMD_BUFFER_SIZE - 3;
171         case AVRCP_START_PACKET:
172             return AVRCP_CMD_BUFFER_SIZE - 4;
173         case AVRCP_CONTINUE_PACKET:
174         case AVRCP_END_PACKET:
175             return AVRCP_CMD_BUFFER_SIZE - 1;
176     }
177     return 0;
178 }
179 
180 static int avrcp_send_cmd(avrcp_connection_t * connection, avrcp_packet_type_t packet_type){
181     uint8_t command[AVRCP_CMD_BUFFER_SIZE];
182     int pos = 0;
183     uint16_t max_bytes = sizeof(command) - 1;
184 
185     // transport header
186     // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
187     command[pos++] = (connection->transaction_label << 4) | (packet_type << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
188 
189     if (packet_type == AVRCP_START_PACKET){
190         // num packets: (3 bytes overhead (PID, num packets) + command) / (MTU - transport header)
191         command[pos++] = ((connection->cmd_operands_fragmented_len + 3 - 1) / (AVRCP_CMD_BUFFER_SIZE - 1)) + 1;
192         max_bytes -= 3;
193     }
194 
195     if (packet_type == AVRCP_SINGLE_PACKET || packet_type == AVRCP_START_PACKET){
196         // Profile IDentifier (PID)
197         command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
198         command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
199 
200         // command_type
201         command[pos++] = connection->command_type;
202         // subunit_type | subunit ID
203         command[pos++] = (connection->subunit_type << 3) | connection->subunit_id;
204         // opcode
205         command[pos++] = (uint8_t)connection->command_opcode;
206     }
207 
208     if (packet_type == AVRCP_SINGLE_PACKET){
209         // operands
210         memcpy(command+pos, connection->cmd_operands, connection->cmd_operands_length);
211         pos += connection->cmd_operands_length;
212     } else {
213         uint16_t bytes_to_copy = btstack_min(connection->cmd_operands_fragmented_len-connection->cmd_operands_fragmented_pos, max_bytes);
214         memcpy(command+pos, &connection->cmd_operands_fragmented_buffer[connection->cmd_operands_fragmented_pos], bytes_to_copy);
215         pos += bytes_to_copy;
216         connection->cmd_operands_fragmented_pos += bytes_to_copy;
217     }
218 
219     return l2cap_send(connection->l2cap_signaling_cid, command, pos);
220 }
221 
222 static int avrcp_register_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
223     if (connection->notifications_to_deregister & (1 << event_id)) return 0;
224     if (connection->notifications_enabled & (1 << event_id)) return 0;
225     if (connection->notifications_to_register & (1 << event_id)) return 0;
226     connection->notifications_to_register |= (1 << event_id);
227     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
228     return 1;
229 }
230 
231 static void avrcp_prepare_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
232     connection->transaction_label++;
233     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
234     connection->command_type = AVRCP_CTYPE_NOTIFY;
235     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
236     connection->subunit_id = AVRCP_SUBUNIT_ID;
237     int pos = 0;
238     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
239     pos += 3;
240     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REGISTER_NOTIFICATION;
241     connection->cmd_operands[pos++] = 0;                     // reserved(upper 6) | packet_type -> 0
242     big_endian_store_16(connection->cmd_operands, pos, 5);     // parameter length
243     pos += 2;
244     connection->cmd_operands[pos++] = event_id;
245     big_endian_store_32(connection->cmd_operands, pos, 1); // send notification on playback position every second, for other notifications it is ignored
246     pos += 4;
247     connection->cmd_operands_length = pos;
248     // AVRCP_SPEC_V14.pdf 166
249     // answer page 61
250 }
251 
252 
253 static void avrcp_parser_reset(avrcp_connection_t * connection){
254     connection->list_offset = 0;
255     connection->num_attributes = 0;
256     connection->num_parsed_attributes = 0;
257     connection->parser_attribute_header_pos = 0;
258     connection->num_received_fragments = 0;
259     connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
260 }
261 
262 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){
263     uint8_t event[7];
264     int pos = 0;
265     event[pos++] = HCI_EVENT_AVRCP_META;
266     event[pos++] = sizeof(event) - 2;
267     event[pos++] = AVRCP_SUBEVENT_NOW_PLAYING_INFO_DONE;
268     little_endian_store_16(event, pos, avrcp_cid);
269     pos += 2;
270     event[pos++] = ctype;
271     event[pos++] = status;
272     // printf_hexdump(event, pos);
273     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
274 }
275 
276 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){
277     uint8_t event[HCI_EVENT_BUFFER_SIZE];
278     int pos = 0;
279     event[pos++] = HCI_EVENT_AVRCP_META;
280     // reserve one byte for subevent type and data len
281     int data_len_pos = pos;
282     pos++;
283     int subevent_type_pos = pos;
284     pos++;
285     little_endian_store_16(event, pos, avrcp_cid);
286     pos += 2;
287     event[pos++] = ctype;
288 
289     switch (attr_id){
290         case AVRCP_MEDIA_ATTR_TITLE:
291             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TITLE_INFO;
292             event[pos++] = value_len;
293             memcpy(event+pos, value, value_len);
294             break;
295         case AVRCP_MEDIA_ATTR_ARTIST:
296             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ARTIST_INFO;
297             event[pos++] = value_len;
298             memcpy(event+pos, value, value_len);
299             break;
300         case AVRCP_MEDIA_ATTR_ALBUM:
301             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ALBUM_INFO;
302             event[pos++] = value_len;
303             memcpy(event+pos, value, value_len);
304             break;
305         case AVRCP_MEDIA_ATTR_GENRE:
306             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_GENRE_INFO;
307             event[pos++] = value_len;
308             memcpy(event+pos, value, value_len);
309             break;
310         case AVRCP_MEDIA_ATTR_SONG_LENGTH_MS:
311             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_SONG_LENGTH_MS_INFO;
312             if (value){
313                 little_endian_store_32(event, pos, btstack_atoi((char *)value));
314             } else {
315                 little_endian_store_32(event, pos, 0);
316             }
317             pos += 4;
318             break;
319         case AVRCP_MEDIA_ATTR_TRACK:
320             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TRACK_INFO;
321             if (value){
322                 event[pos++] = btstack_atoi((char *)value);
323             } else {
324                 event[pos++] = 0;
325             }
326             break;
327         case AVRCP_MEDIA_ATTR_TOTAL_NUM_ITEMS:
328             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TOTAL_TRACKS_INFO;
329             if (value){
330                 event[pos++] = btstack_atoi((char *)value);
331             } else {
332                 event[pos++] = 0;
333             }
334             break;
335         default:
336             break;
337     }
338     event[data_len_pos] = pos - 2;
339     // printf("Send attribute 0x%02x, len %u\n", attr_id, value_len);
340     // printf_hexdump(value, value_len);
341     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
342 }
343 
344 static void avrcp_parser_process_byte(uint8_t byte, avrcp_connection_t * connection, avrcp_command_type_t ctype){
345     uint16_t attribute_total_value_len;
346     uint32_t attribute_id;
347     // printf("avrcp_parser_process_byte: %02x, state %02x\n", byte, connection->parser_state);
348     switch(connection->parser_state){
349         case AVRCP_PARSER_GET_ATTRIBUTE_HEADER:
350             connection->parser_attribute_header[connection->parser_attribute_header_pos++] = byte;
351             connection->list_offset++;
352 
353             if (connection->parser_attribute_header_pos < AVRCP_ATTRIBUTE_HEADER_LEN) return;
354 
355             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
356             connection->attribute_value_len = btstack_min(attribute_total_value_len, AVRCP_MAX_ATTRIBUTTE_SIZE);
357             if (connection->attribute_value_len > 0){
358                 // get ready for attribute value
359                 connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_VALUE;
360                 return;
361             }
362 
363             // emit empty attribute
364             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
365             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);
366 
367             // done, see below
368             break;
369 
370         case AVRCP_PARSER_GET_ATTRIBUTE_VALUE:
371             connection->attribute_value[connection->attribute_value_offset++] = byte;
372             connection->list_offset++;
373 
374             if (connection->attribute_value_offset < connection->attribute_value_len) return;
375 
376             // emit (potentially partial) attribute
377             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
378             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);
379 
380             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
381             if (connection->attribute_value_offset < attribute_total_value_len){
382                 // ignore rest of attribute
383                 connection->parser_state = AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE;
384                 return;
385             }
386 
387             // done, see below
388             break;
389 
390         case AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE:
391             connection->attribute_value_offset++;
392             connection->list_offset++;
393 
394             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
395             if (connection->attribute_value_offset < attribute_total_value_len) return;
396 
397             // done, see below
398             break;
399 
400         default:
401             return;
402     }
403 
404     // attribute fully read, check if more to come
405     if (connection->list_offset < connection->list_size){
406         // more to come, reset parser
407         connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
408         connection->parser_attribute_header_pos = 0;
409         connection->attribute_value_offset = 0;
410     } else {
411         // fully done
412         avrcp_parser_reset(connection);
413         avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 0);
414     }
415 }
416 
417 static void avrcp_source_parse_and_emit_element_attrs(uint8_t * packet, uint16_t num_bytes_to_read, avrcp_connection_t * connection, avrcp_command_type_t ctype){
418     int i;
419     for (i=0;i<num_bytes_to_read;i++){
420         avrcp_parser_process_byte(packet[i], connection, ctype);
421     }
422 }
423 
424 static uint8_t avrcp_controller_request_abort_continuation(avrcp_connection_t * connection){
425     connection->state = AVCTP_W2_SEND_COMMAND;
426     connection->transaction_label++;
427     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
428     connection->command_type = AVRCP_CTYPE_CONTROL;
429     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
430     connection->subunit_id = AVRCP_SUBUNIT_ID;
431     int pos = 0;
432     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
433     pos += 3;
434     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REQUEST_ABORT_CONTINUING_RESPONSE; // PDU ID
435     connection->cmd_operands[pos++] = 0;
436     // Parameter Length
437     connection->cmd_operands_length = 8;
438     big_endian_store_16(connection->cmd_operands, pos, 1);
439     pos += 2;
440     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
441     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
442     return ERROR_CODE_SUCCESS;
443 }
444 
445 
446 static uint8_t avrcp_controller_request_continue_response(avrcp_connection_t * connection){
447     connection->state = AVCTP_W2_SEND_COMMAND;
448     connection->transaction_label++;
449     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
450     connection->command_type = AVRCP_CTYPE_CONTROL;
451     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
452     connection->subunit_id = AVRCP_SUBUNIT_ID;
453     int pos = 0;
454     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
455     pos += 3;
456     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REQUEST_CONTINUING_RESPONSE; // PDU ID
457     connection->cmd_operands[pos++] = 0;
458     // Parameter Length
459     connection->cmd_operands_length = 8;
460     big_endian_store_16(connection->cmd_operands, pos, 1);
461     pos += 2;
462     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
463     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
464     return ERROR_CODE_SUCCESS;
465 }
466 
467 static void avrcp_handle_l2cap_data_packet_for_signaling_connection(avrcp_connection_t * connection, uint8_t *packet, uint16_t size){
468     uint8_t operands[20];
469     uint8_t opcode;
470     int     pos = 3;
471     // uint8_t transport_header = packet[0];
472     // uint8_t transaction_label = transport_header >> 4;
473     // uint8_t packet_type = (transport_header & 0x0F) >> 2;
474     // uint8_t frame_type = (transport_header & 0x03) >> 1;
475     // uint8_t ipid = transport_header & 0x01;
476     // uint8_t byte_value = packet[2];
477     // uint16_t pid = (byte_value << 8) | packet[2];
478 
479     avrcp_command_type_t ctype = (avrcp_command_type_t) packet[pos++];
480     uint8_t byte_value = packet[pos++];
481     avrcp_subunit_type_t subunit_type = (avrcp_subunit_type_t) (byte_value >> 3);
482     avrcp_subunit_type_t subunit_id = (avrcp_subunit_type_t)   (byte_value & 0x07);
483     opcode = packet[pos++];
484 
485     // printf("    Transport header 0x%02x (transaction_label %d, packet_type %d, frame_type %d, ipid %d), pid 0x%4x\n",
486     //     transport_header, transaction_label, packet_type, frame_type, ipid, pid);
487     // // printf_hexdump(packet+pos, size-pos);
488 
489     uint8_t pdu_id;
490     uint16_t param_length;
491     switch (avrcp_cmd_opcode(packet,size)){
492         case AVRCP_CMD_OPCODE_SUBUNIT_INFO:{
493             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
494             connection->state = AVCTP_CONNECTION_OPENED;
495             // operands:
496             memcpy(operands, packet+pos, 5);
497             uint8_t unit_type = operands[1] >> 3;
498             uint8_t max_subunit_ID = operands[1] & 0x07;
499             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);
500             break;
501         }
502         case AVRCP_CMD_OPCODE_UNIT_INFO:{
503             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
504             connection->state = AVCTP_CONNECTION_OPENED;
505             // operands:
506             memcpy(operands, packet+pos, 5);
507             uint8_t unit_type = operands[1] >> 3;
508             uint8_t unit = operands[1] & 0x07;
509             uint32_t company_id = operands[2] << 16 | operands[3] << 8 | operands[4];
510             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,
511                 ctype, subunit_type, subunit_id, opcode, unit_type, unit, company_id);
512             break;
513         }
514         case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
515             if (size - pos < 7) {
516                 log_error("avrcp: wrong packet size");
517                 return;
518             };
519             // operands:
520             memcpy(operands, packet+pos, 7);
521             pos += 7;
522             // uint32_t company_id = operands[0] << 16 | operands[1] << 8 | operands[2];
523             pdu_id = operands[3];
524 
525             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE && pdu_id != AVRCP_PDU_ID_REGISTER_NOTIFICATION){
526                 log_info("AVRCP_CMD_OPCODE_VENDOR_DEPENDENT state %d", connection->state);
527                 return;
528             }
529             connection->state = AVCTP_CONNECTION_OPENED;
530 
531 
532             // uint8_t unit_type = operands[4] >> 3;
533             // uint8_t unit = operands[4] & 0x07;
534             param_length = big_endian_read_16(operands, 5);
535 
536             // printf("    VENDOR DEPENDENT 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%06x\n",
537             //     ctype, subunit_type, subunit_id, opcode, unit_type, unit, company_id );
538 
539             // if (ctype == AVRCP_CTYPE_RESPONSE_INTERIM) return;
540             log_info("        VENDOR DEPENDENT response: pdu id 0x%02x, param_length %d, status %s", pdu_id, param_length, avrcp_ctype2str(ctype));
541             switch (pdu_id){
542                 case AVRCP_PDU_ID_GetCurrentPlayerApplicationSettingValue:{
543                     uint8_t num_attributes = packet[pos++];
544                     int i;
545                     avrcp_repeat_mode_t  repeat_mode =  AVRCP_REPEAT_MODE_INVALID;
546                     avrcp_shuffle_mode_t shuffle_mode = AVRCP_SHUFFLE_MODE_INVALID;
547                     for (i = 0; i < num_attributes; i++){
548                         uint8_t attribute_id    = packet[pos++];
549                         uint8_t value = packet[pos++];
550                         switch (attribute_id){
551                             case 0x02:
552                                 repeat_mode = (avrcp_repeat_mode_t) value;
553                                 break;
554                             case 0x03:
555                                 shuffle_mode = (avrcp_shuffle_mode_t) value;
556                                 break;
557                             default:
558                                 break;
559                         }
560                     }
561                     avrcp_emit_repeat_and_shuffle_mode(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, repeat_mode, shuffle_mode);
562                     break;
563                 }
564                 case AVRCP_PDU_ID_SetPlayerApplicationSettingValue:{
565                     uint8_t event[6];
566                     int offset = 0;
567                     event[offset++] = HCI_EVENT_AVRCP_META;
568                     event[offset++] = sizeof(event) - 2;
569                     event[offset++] = AVRCP_SUBEVENT_PLAYER_APPLICATION_VALUE_RESPONSE;
570                     little_endian_store_16(event, offset, connection->avrcp_cid);
571                     offset += 2;
572                     event[offset++] = ctype;
573                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
574                     break;
575                 }
576                 case AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME:{
577                     uint8_t event[7];
578                     int offset = 0;
579                     event[offset++] = HCI_EVENT_AVRCP_META;
580                     event[offset++] = sizeof(event) - 2;
581                     event[offset++] = AVRCP_SUBEVENT_SET_ABSOLUTE_VOLUME_RESPONSE;
582                     little_endian_store_16(event, offset, connection->avrcp_cid);
583                     offset += 2;
584                     event[offset++] = ctype;
585                     event[offset++] = packet[pos++];
586                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
587                     break;
588                 }
589                 case AVRCP_PDU_ID_GET_CAPABILITIES:{
590                     avrcp_capability_id_t capability_id = (avrcp_capability_id_t) packet[pos++];
591                     uint8_t capability_count = packet[pos++];
592                     int i;
593                     switch (capability_id){
594                         case AVRCP_CAPABILITY_ID_COMPANY:
595                             // log_info("Supported companies %d: ", capability_count);
596                             for (i = 0; i < capability_count; i++){
597                                 uint32_t company_id = big_endian_read_24(packet, pos);
598                                 pos += 3;
599                                 log_info("  0x%06" PRIx32 ", ", company_id);
600                             }
601                             break;
602                         case AVRCP_CAPABILITY_ID_EVENT:
603                             // log_info("Supported events %d: ", capability_count);
604                             for (i = 0; i < capability_count; i++){
605                                 uint8_t event_id = packet[pos++];
606                                 log_info("  0x%02x %s", event_id, avrcp_event2str(event_id));
607                             }
608                             break;
609                     }
610                     break;
611                 }
612                 case AVRCP_PDU_ID_GET_PLAY_STATUS:{
613                     uint32_t song_length = big_endian_read_32(packet, pos);
614                     pos += 4;
615                     uint32_t song_position = big_endian_read_32(packet, pos);
616                     pos += 4;
617                     uint8_t play_status = packet[pos];
618                     // log_info("        GET_PLAY_STATUS length 0x%04X, position 0x%04X, status %s", song_length, song_position, avrcp_play_status2str(play_status));
619 
620                     uint8_t event[15];
621                     int offset = 0;
622                     event[offset++] = HCI_EVENT_AVRCP_META;
623                     event[offset++] = sizeof(event) - 2;
624                     event[offset++] = AVRCP_SUBEVENT_PLAY_STATUS;
625                     little_endian_store_16(event, offset, connection->avrcp_cid);
626                     offset += 2;
627                     event[offset++] = ctype;
628                     little_endian_store_32(event, offset, song_length);
629                     offset += 4;
630                     little_endian_store_32(event, offset, song_position);
631                     offset += 4;
632                     event[offset++] = play_status;
633                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
634                     break;
635                 }
636                 case AVRCP_PDU_ID_REGISTER_NOTIFICATION:{
637                     avrcp_notification_event_id_t  event_id = (avrcp_notification_event_id_t) packet[pos++];
638                     uint16_t event_mask = (1 << event_id);
639                     uint16_t reset_event_mask = ~event_mask;
640                     switch (ctype){
641                         case AVRCP_CTYPE_RESPONSE_INTERIM:
642                             // register as enabled
643                             connection->notifications_enabled |= event_mask;
644                             // printf("INTERIM notifications_enabled 0x%2x, notifications_to_register 0x%2x\n", connection->notifications_enabled,  connection->notifications_to_register);
645                             break;
646                         case AVRCP_CTYPE_RESPONSE_CHANGED_STABLE:
647                             // received change, event is considered deregistered
648                             // we are re-enabling it automatically, if it is not
649                             // explicitly disabled
650                             connection->notifications_enabled &= reset_event_mask;
651                             if (! (connection->notifications_to_deregister & event_mask)){
652                                 avrcp_register_notification(connection, event_id);
653                                 // printf("CHANGED_STABLE notifications_enabled 0x%2x, notifications_to_register 0x%2x\n", connection->notifications_enabled,  connection->notifications_to_register);
654                             } else {
655                                 connection->notifications_to_deregister &= reset_event_mask;
656                             }
657                             break;
658                         default:
659                             connection->notifications_to_register &= reset_event_mask;
660                             connection->notifications_enabled &= reset_event_mask;
661                             connection->notifications_to_deregister &= reset_event_mask;
662                             break;
663                     }
664 
665                     switch (event_id){
666                         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_POS_CHANGED:{
667                             uint32_t song_position = big_endian_read_32(packet, pos);
668                             uint8_t event[10];
669                             int offset = 0;
670                             event[offset++] = HCI_EVENT_AVRCP_META;
671                             event[offset++] = sizeof(event) - 2;
672                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_POS_CHANGED;
673                             little_endian_store_16(event, offset, connection->avrcp_cid);
674                             offset += 2;
675                             event[offset++] = ctype;
676                             little_endian_store_32(event, offset, song_position);
677                             offset += 4;
678                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
679                             break;
680                         }
681                         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED:{
682                             uint8_t event[7];
683                             int offset = 0;
684                             event[offset++] = HCI_EVENT_AVRCP_META;
685                             event[offset++] = sizeof(event) - 2;
686                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_STATUS_CHANGED;
687                             little_endian_store_16(event, offset, connection->avrcp_cid);
688                             offset += 2;
689                             event[offset++] = ctype;
690                             event[offset++] = packet[pos];
691                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
692                             break;
693                         }
694                         case AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED:{
695                             uint8_t event[6];
696                             int offset = 0;
697                             event[offset++] = HCI_EVENT_AVRCP_META;
698                             event[offset++] = sizeof(event) - 2;
699                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_TRACK_CHANGED;
700                             little_endian_store_16(event, offset, connection->avrcp_cid);
701                             offset += 2;
702                             event[offset++] = ctype;
703                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
704                             break;
705                         }
706                         case AVRCP_NOTIFICATION_EVENT_NOW_PLAYING_CONTENT_CHANGED:{
707                             uint8_t event[6];
708                             int offset = 0;
709                             event[offset++] = HCI_EVENT_AVRCP_META;
710                             event[offset++] = sizeof(event) - 2;
711                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_NOW_PLAYING_CONTENT_CHANGED;
712                             little_endian_store_16(event, offset, connection->avrcp_cid);
713                             offset += 2;
714                             event[offset++] = ctype;
715                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
716                             break;
717                         }
718                         case AVRCP_NOTIFICATION_EVENT_AVAILABLE_PLAYERS_CHANGED:{
719                             uint8_t event[6];
720                             int offset = 0;
721                             event[offset++] = HCI_EVENT_AVRCP_META;
722                             event[offset++] = sizeof(event) - 2;
723                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_AVAILABLE_PLAYERS_CHANGED;
724                             little_endian_store_16(event, offset, connection->avrcp_cid);
725                             offset += 2;
726                             event[offset++] = ctype;
727                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
728                             break;
729                         }
730                         case AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED:{
731                             uint8_t event[7];
732                             int offset = 0;
733                             event[offset++] = HCI_EVENT_AVRCP_META;
734                             event[offset++] = sizeof(event) - 2;
735                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED;
736                             little_endian_store_16(event, offset, connection->avrcp_cid);
737                             offset += 2;
738                             event[offset++] = ctype;
739                             event[offset++] = packet[pos++] & 0x7F;
740                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
741                             break;
742                         }
743                         case AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED:{
744                             uint8_t event[7];
745                             int offset = 0;
746                             event[offset++] = HCI_EVENT_AVRCP_META;
747                             event[offset++] = sizeof(event) - 2;
748                             event[offset++] = AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED;
749                             little_endian_store_16(event, offset, connection->avrcp_cid);
750                             offset += 2;
751                             event[offset++] = ctype;
752                             event[offset++] = packet[pos++] & 0x7F;
753                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
754                             break;
755                         }
756 
757                         // case AVRCP_NOTIFICATION_EVENT_PLAYER_APPLICATION_SETTING_CHANGED:{
758                         //     uint8_t num_PlayerApplicationSettingAttributes = packet[pos++];
759                         //     int i;
760                         //     for (i = 0; i < num_PlayerApplicationSettingAttributes; i++){
761                         //         uint8_t PlayerApplicationSetting_AttributeID = packet[pos++];
762                         //         uint8_t PlayerApplicationSettingValueID = packet[pos++];
763                         //     }
764                         //     break;
765                         // }
766                         // case AVRCP_NOTIFICATION_EVENT_ADDRESSED_PLAYER_CHANGED:
767                         //     uint16_t player_id = big_endian_read_16(packet, pos);
768                         //     pos += 2;
769                         //     uint16_t uid_counter = big_endian_read_16(packet, pos);
770                         //     pos += 2;
771                         //     break;
772                         // case AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED:
773                         //     uint16_t uid_counter = big_endian_read_16(packet, pos);
774                         //     pos += 2;
775                         //     break;
776                         default:
777                             log_info("avrcp: not implemented");
778                             break;
779                     }
780                     if (connection->notifications_to_register != 0){
781                         avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
782                     }
783                     break;
784                 }
785 
786                 case AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES:{
787                     avrcp_packet_type_t packet_type = (avrcp_packet_type_t) (operands[4] & 0x03);
788                     switch (packet_type){
789                         case AVRCP_START_PACKET:
790                         case AVRCP_SINGLE_PACKET:
791                             avrcp_parser_reset(connection);
792                             connection->list_size = param_length;
793                             connection->num_attributes = packet[pos++];
794 
795                             // printf("AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES num_attributes %d, total size %d, packet type 0x%02x \n", connection->num_attributes, connection->list_size, operands[4] & 0x03);
796                             avrcp_source_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
797 
798                             if (packet_type == AVRCP_START_PACKET){
799                                 avrcp_controller_request_continue_response(connection);
800                             }
801                             break;
802                         case AVRCP_CONTINUE_PACKET:
803                         case AVRCP_END_PACKET:
804                             connection->num_received_fragments++;
805                             if (connection->num_received_fragments < connection->max_num_fragments){
806                                 avrcp_source_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
807                                 if (packet_type == AVRCP_CONTINUE_PACKET){
808                                     avrcp_controller_request_continue_response(connection);
809                                 }
810                             } else {
811                                 avrcp_controller_request_abort_continuation(connection);
812                                 avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 1);
813                                 avrcp_parser_reset(connection);
814                             }
815                             break;
816                     }
817                 }
818                 default:
819                     break;
820             }
821             break;
822         case AVRCP_CMD_OPCODE_PASS_THROUGH:{
823             // 0x80 | connection->cmd_operands[0]
824             uint8_t operation_id = packet[pos++];
825             switch (connection->state){
826                 case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
827                     if (connection->continuous_fast_forward_cmd){
828                         connection->state = AVCTP_W4_STOP;
829                     } else {
830                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
831                     }
832                     break;
833                 case AVCTP_W2_RECEIVE_RESPONSE:
834                     connection->state = AVCTP_CONNECTION_OPENED;
835                     break;
836                 default:
837                     // check for notifications? move state transition down
838                     // log_info("AVRCP_CMD_OPCODE_PASS_THROUGH state %d\n", connection->state);
839                     break;
840             }
841             if (connection->state == AVCTP_W4_STOP){
842                 avrcp_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_START, connection->avrcp_cid, ctype, operation_id);
843             }
844             if (connection->state == AVCTP_CONNECTION_OPENED) {
845                 // RELEASE response
846                 operation_id = operation_id & 0x7F;
847                 avrcp_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_COMPLETE, connection->avrcp_cid, ctype, operation_id);
848             }
849             if (connection->state == AVCTP_W2_SEND_RELEASE_COMMAND){
850                 // PRESS response
851                 request_pass_through_release_control_cmd(connection);
852             }
853             break;
854         }
855         default:
856             break;
857     }
858 
859     // trigger pending notification reqistrations
860     if (connection->state == AVCTP_CONNECTION_OPENED && connection->notifications_to_register){
861         avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
862     }
863 }
864 
865 static void avrcp_controller_handle_can_send_now(avrcp_connection_t * connection){
866     int i;
867     switch (connection->state){
868         case AVCTP_W2_SEND_PRESS_COMMAND:
869             connection->state = AVCTP_W2_RECEIVE_PRESS_RESPONSE;
870             avrcp_send_cmd(connection, AVRCP_SINGLE_PACKET);
871             break;
872         case AVCTP_W2_SEND_COMMAND:
873         case AVCTP_W2_SEND_RELEASE_COMMAND:
874             connection->state = AVCTP_W2_RECEIVE_RESPONSE;
875             avrcp_send_cmd(connection, AVRCP_SINGLE_PACKET);
876             break;
877         case AVCTP_CONNECTION_OPENED:
878             if (connection->notifications_to_register != 0){
879                 for (i = 1; i <= AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED; i++){
880                     if (connection->notifications_to_register & (1<<i)){
881                         connection->notifications_to_register &= ~ (1 << i);
882                         avrcp_prepare_notification(connection, (avrcp_notification_event_id_t) i);
883                         connection->state = AVCTP_W2_RECEIVE_RESPONSE;
884                         avrcp_send_cmd(connection, AVRCP_SINGLE_PACKET);
885                         return;
886                     }
887                 }
888             }
889             return;
890         case AVCTP_W2_SEND_FRAGMENTED_COMMAND:
891             if (connection->cmd_operands_fragmented_pos == 0){
892                  avrcp_send_cmd(connection, AVRCP_START_PACKET);
893                  avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
894             } else {
895                 if (connection->cmd_operands_fragmented_len - connection->cmd_operands_fragmented_pos > avrcp_get_max_payload_size_for_packet_type(AVRCP_CONTINUE_PACKET)){
896                      avrcp_send_cmd(connection, AVRCP_CONTINUE_PACKET);
897                      avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
898                  } else {
899                     connection->state = AVCTP_W2_RECEIVE_RESPONSE;
900                     avrcp_send_cmd(connection, AVRCP_END_PACKET);
901                  }
902             }
903         default:
904             return;
905     }
906 }
907 
908 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
909     avrcp_connection_t * connection;
910 
911     switch (packet_type) {
912         case L2CAP_DATA_PACKET:
913             connection = get_avrcp_connection_for_l2cap_signaling_cid(channel, &avrcp_controller_context);
914             if (!connection) break;
915             avrcp_handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
916             break;
917         case HCI_EVENT_PACKET:
918             switch (hci_event_packet_get_type(packet)){
919                 case L2CAP_EVENT_CAN_SEND_NOW:
920                     connection = get_avrcp_connection_for_l2cap_signaling_cid(channel, &avrcp_controller_context);
921                     if (!connection) break;
922                     avrcp_controller_handle_can_send_now(connection);
923                     break;
924             default:
925                 avrcp_packet_handler(packet_type, channel, packet, size, &avrcp_controller_context);
926                 break;
927         }
928         default:
929             break;
930     }
931 }
932 
933 void avrcp_controller_init(void){
934     avrcp_controller_context.role = AVRCP_CONTROLLER;
935     avrcp_controller_context.connections = NULL;
936     avrcp_controller_context.packet_handler = avrcp_controller_packet_handler;
937     l2cap_register_service(&avrcp_controller_packet_handler, BLUETOOTH_PROTOCOL_AVCTP, 0xffff, LEVEL_2);
938 }
939 
940 void avrcp_controller_register_packet_handler(btstack_packet_handler_t callback){
941     if (callback == NULL){
942         log_error("avrcp_register_packet_handler called with NULL callback");
943         return;
944     }
945     avrcp_controller_context.avrcp_callback = callback;
946 }
947 
948 uint8_t avrcp_controller_connect(bd_addr_t bd_addr, uint16_t * avrcp_cid){
949     return avrcp_connect(bd_addr, &avrcp_controller_context, avrcp_cid);
950 }
951 
952 uint8_t avrcp_controller_unit_info(uint16_t avrcp_cid){
953     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
954     if (!connection){
955         log_error("avrcp_unit_info: could not find a connection.");
956         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
957     }
958     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
959     connection->state = AVCTP_W2_SEND_COMMAND;
960 
961     connection->transaction_label++;
962     connection->command_opcode = AVRCP_CMD_OPCODE_UNIT_INFO;
963     connection->command_type = AVRCP_CTYPE_STATUS;
964     connection->subunit_type = AVRCP_SUBUNIT_TYPE_UNIT; //vendor unique
965     connection->subunit_id =   AVRCP_SUBUNIT_ID_IGNORE;
966     memset(connection->cmd_operands, 0xFF, connection->cmd_operands_length);
967     connection->cmd_operands_length = 5;
968     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
969     return ERROR_CODE_SUCCESS;
970 }
971 
972 uint8_t avrcp_controller_subunit_info(uint16_t avrcp_cid){
973     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
974     if (!connection){
975         log_error("avrcp_unit_info: could not find a connection.");
976         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
977     }
978     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
979     connection->state = AVCTP_W2_SEND_COMMAND;
980 
981     connection->transaction_label++;
982     connection->command_opcode = AVRCP_CMD_OPCODE_SUBUNIT_INFO;
983     connection->command_type = AVRCP_CTYPE_STATUS;
984     connection->subunit_type = AVRCP_SUBUNIT_TYPE_UNIT; //vendor unique
985     connection->subunit_id =   AVRCP_SUBUNIT_ID_IGNORE;
986     memset(connection->cmd_operands, 0xFF, connection->cmd_operands_length);
987     connection->cmd_operands[0] = 7; // page: 0, extention_code: 7
988     connection->cmd_operands_length = 5;
989     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
990     return ERROR_CODE_SUCCESS;
991 }
992 
993 static uint8_t avrcp_controller_get_capabilities(uint16_t avrcp_cid, uint8_t capability_id){
994     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
995     if (!connection){
996         log_error("avrcp_get_capabilities: could not find a connection.");
997         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
998     }
999     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1000     connection->state = AVCTP_W2_SEND_COMMAND;
1001 
1002     connection->transaction_label++;
1003     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1004     connection->command_type = AVRCP_CTYPE_STATUS;
1005     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1006     connection->subunit_id = AVRCP_SUBUNIT_ID;
1007     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
1008     connection->cmd_operands[3] = AVRCP_PDU_ID_GET_CAPABILITIES; // PDU ID
1009     connection->cmd_operands[4] = 0;
1010     big_endian_store_16(connection->cmd_operands, 5, 1); // parameter length
1011     connection->cmd_operands[7] = capability_id;                  // capability ID
1012     connection->cmd_operands_length = 8;
1013     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1014     return ERROR_CODE_SUCCESS;
1015 }
1016 
1017 uint8_t avrcp_controller_get_supported_company_ids(uint16_t avrcp_cid){
1018     return avrcp_controller_get_capabilities(avrcp_cid, AVRCP_CAPABILITY_ID_COMPANY);
1019 }
1020 
1021 uint8_t avrcp_controller_get_supported_events(uint16_t avrcp_cid){
1022     return avrcp_controller_get_capabilities(avrcp_cid, AVRCP_CAPABILITY_ID_EVENT);
1023 }
1024 
1025 
1026 uint8_t avrcp_controller_play(uint16_t avrcp_cid){
1027     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1028 }
1029 
1030 uint8_t avrcp_controller_stop(uint16_t avrcp_cid){
1031     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1032 }
1033 
1034 uint8_t avrcp_controller_pause(uint16_t avrcp_cid){
1035     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1036 }
1037 
1038 uint8_t avrcp_controller_forward(uint16_t avrcp_cid){
1039     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1040 }
1041 
1042 uint8_t avrcp_controller_backward(uint16_t avrcp_cid){
1043     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1044 }
1045 
1046 uint8_t avrcp_controller_volume_up(uint16_t avrcp_cid){
1047     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1048 }
1049 
1050 uint8_t avrcp_controller_volume_down(uint16_t avrcp_cid){
1051     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1052 }
1053 
1054 uint8_t avrcp_controller_mute(uint16_t avrcp_cid){
1055     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1056 }
1057 
1058 uint8_t avrcp_controller_skip(uint16_t avrcp_cid){
1059     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_SKIP, 0);
1060 }
1061 
1062 uint8_t avrcp_controller_fast_forward(uint16_t avrcp_cid){
1063     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1064 }
1065 
1066 uint8_t avrcp_controller_rewind(uint16_t avrcp_cid){
1067     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1068 }
1069 
1070 
1071 /* start cmds */
1072 
1073 uint8_t avrcp_controller_release_press_and_hold_cmd(uint16_t avrcp_cid){
1074     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1075     if (!connection){
1076         log_error("avrcp_stop_play: could not find a connection.");
1077         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1078     }
1079     if (connection->state != AVCTP_W4_STOP) return ERROR_CODE_COMMAND_DISALLOWED;
1080     return request_pass_through_release_control_cmd(connection);
1081 }
1082 
1083 uint8_t avrcp_controller_press_and_hold_play(uint16_t avrcp_cid){
1084     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1085 }
1086 uint8_t avrcp_controller_press_and_hold_stop(uint16_t avrcp_cid){
1087     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1088 }
1089 uint8_t avrcp_controller_press_and_hold_pause(uint16_t avrcp_cid){
1090     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1091 }
1092 uint8_t avrcp_controller_press_and_hold_forward(uint16_t avrcp_cid){
1093     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1094 }
1095 uint8_t avrcp_controller_press_and_hold_backward(uint16_t avrcp_cid){
1096     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1097 }
1098 uint8_t avrcp_controller_press_and_hold_fast_forward(uint16_t avrcp_cid){
1099     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1100 }
1101 uint8_t avrcp_controller_press_and_hold_rewind(uint16_t avrcp_cid){
1102     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1103 }
1104 uint8_t avrcp_controller_press_and_hold_volume_up(uint16_t avrcp_cid){
1105     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1106 }
1107 uint8_t avrcp_controller_press_and_hold_volume_down(uint16_t avrcp_cid){
1108     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1109 }
1110 uint8_t avrcp_controller_press_and_hold_mute(uint16_t avrcp_cid){
1111     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1112 }
1113 
1114 
1115 /* stop continuous cmds */
1116 
1117 uint8_t avrcp_controller_get_play_status(uint16_t avrcp_cid){
1118     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1119     if (!connection){
1120         log_error("avrcp_get_play_status: could not find a connection.");
1121         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1122     }
1123     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1124     connection->state = AVCTP_W2_SEND_COMMAND;
1125     connection->transaction_label++;
1126     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1127     connection->command_type = AVRCP_CTYPE_STATUS;
1128     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1129     connection->subunit_id = AVRCP_SUBUNIT_ID;
1130     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
1131     connection->cmd_operands[3] = AVRCP_PDU_ID_GET_PLAY_STATUS;
1132     connection->cmd_operands[4] = 0;                     // reserved(upper 6) | packet_type -> 0
1133     big_endian_store_16(connection->cmd_operands, 5, 0); // parameter length
1134     connection->cmd_operands_length = 7;
1135     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1136     return ERROR_CODE_SUCCESS;
1137 }
1138 
1139 uint8_t avrcp_controller_enable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1140     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1141     if (!connection){
1142         log_error("avrcp_get_play_status: could not find a connection.");
1143         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1144     }
1145     avrcp_register_notification(connection, event_id);
1146     return ERROR_CODE_SUCCESS;
1147 }
1148 
1149 uint8_t avrcp_controller_disable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1150     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1151     if (!connection){
1152         log_error("avrcp_get_play_status: could not find a connection.");
1153         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1154     }
1155     connection->notifications_to_deregister |= (1 << event_id);
1156     return ERROR_CODE_SUCCESS;
1157 }
1158 
1159 uint8_t avrcp_controller_set_addressed_player(uint16_t avrcp_cid, uint16_t addressed_player_id){
1160     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1161     if (!connection){
1162         log_error("avrcp_get_capabilities: could not find a connection.");
1163         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1164     }
1165     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1166     connection->state = AVCTP_W2_SEND_COMMAND;
1167 
1168     connection->transaction_label++;
1169     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1170     connection->command_type = AVRCP_CTYPE_CONTROL;
1171     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1172     connection->subunit_id = AVRCP_SUBUNIT_ID;
1173     int pos = 0;
1174     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1175     pos += 3;
1176     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_ADDRESSED_PLAYER; // PDU ID
1177     connection->cmd_operands[pos++] = 0;
1178 
1179     // Parameter Length
1180     big_endian_store_16(connection->cmd_operands, pos, 2);
1181     pos += 2;
1182 
1183     big_endian_store_16(connection->cmd_operands, pos, addressed_player_id);
1184     pos += 2;
1185 
1186     connection->cmd_operands_length = pos;
1187     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1188     return ERROR_CODE_SUCCESS;
1189 }
1190 
1191 uint8_t avrcp_controller_get_now_playing_info(uint16_t avrcp_cid){
1192     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1193     if (!connection){
1194         log_error("avrcp_get_capabilities: could not find a connection.");
1195         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1196     }
1197     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1198     connection->state = AVCTP_W2_SEND_COMMAND;
1199 
1200     connection->transaction_label++;
1201     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1202     connection->command_type = AVRCP_CTYPE_STATUS;
1203     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1204     connection->subunit_id = AVRCP_SUBUNIT_ID;
1205     int pos = 0;
1206     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1207     pos += 3;
1208     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES; // PDU ID
1209     connection->cmd_operands[pos++] = 0;
1210 
1211     // Parameter Length
1212     big_endian_store_16(connection->cmd_operands, pos, 9);
1213     pos += 2;
1214 
1215     // write 8 bytes value
1216     memset(connection->cmd_operands + pos, 0, 8); // identifier: PLAYING
1217     pos += 8;
1218 
1219     connection->cmd_operands[pos++] = 0; // attribute count, if 0 get all attributes
1220     // every attribute is 4 bytes long
1221 
1222     connection->cmd_operands_length = pos;
1223     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1224     return ERROR_CODE_SUCCESS;
1225 }
1226 
1227 uint8_t avrcp_controller_set_absolute_volume(uint16_t avrcp_cid, uint8_t volume){
1228      avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1229     if (!connection){
1230         log_error("avrcp_get_capabilities: could not find a connection.");
1231         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1232     }
1233     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1234     connection->state = AVCTP_W2_SEND_COMMAND;
1235 
1236     connection->transaction_label++;
1237     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1238     connection->command_type = AVRCP_CTYPE_CONTROL;
1239     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1240     connection->subunit_id = AVRCP_SUBUNIT_ID;
1241     int pos = 0;
1242     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1243     pos += 3;
1244     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME; // PDU ID
1245     connection->cmd_operands[pos++] = 0;
1246 
1247     // Parameter Length
1248     big_endian_store_16(connection->cmd_operands, pos, 1);
1249     pos += 2;
1250     connection->cmd_operands[pos++] = volume;
1251 
1252     connection->cmd_operands_length = pos;
1253     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1254     return ERROR_CODE_SUCCESS;
1255 }
1256 
1257 uint8_t avrcp_controller_query_shuffle_and_repeat_modes(uint16_t avrcp_cid){
1258     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1259     if (!connection){
1260         log_error("avrcp_get_capabilities: could not find a connection.");
1261         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1262     }
1263     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1264     connection->state = AVCTP_W2_SEND_COMMAND;
1265 
1266     connection->transaction_label++;
1267     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1268     connection->command_type = AVRCP_CTYPE_STATUS;
1269     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1270     connection->subunit_id = AVRCP_SUBUNIT_ID;
1271     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
1272     connection->cmd_operands[3] = AVRCP_PDU_ID_GetCurrentPlayerApplicationSettingValue; // PDU ID
1273     connection->cmd_operands[4] = 0;
1274     big_endian_store_16(connection->cmd_operands, 5, 5); // parameter length
1275     connection->cmd_operands[7] = 4;                     // NumPlayerApplicationSettingAttributeID
1276     // PlayerApplicationSettingAttributeID1 AVRCP Spec, Appendix F, 133
1277     connection->cmd_operands[8]  = 0x01;    // equalizer  (1-OFF, 2-ON)
1278     connection->cmd_operands[9]  = 0x02;    // repeat     (1-off, 2-single track, 3-all tracks, 4-group repeat)
1279     connection->cmd_operands[10] = 0x03;    // shuffle    (1-off, 2-all tracks, 3-group shuffle)
1280     connection->cmd_operands[11] = 0x04;    // scan       (1-off, 2-all tracks, 3-group scan)
1281     connection->cmd_operands_length = 12;
1282     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1283     return ERROR_CODE_SUCCESS;
1284 }
1285 
1286 static uint8_t avrcp_controller_set_current_player_application_setting_value(uint16_t avrcp_cid, uint8_t attr_id, uint8_t attr_value){
1287     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1288     if (!connection){
1289         log_error("avrcp_get_capabilities: could not find a connection.");
1290         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1291     }
1292     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1293     connection->state = AVCTP_W2_SEND_COMMAND;
1294 
1295     connection->transaction_label++;
1296     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1297     connection->command_type = AVRCP_CTYPE_CONTROL;
1298     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1299     connection->subunit_id = AVRCP_SUBUNIT_ID;
1300     int pos = 0;
1301     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1302     pos += 3;
1303     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SetPlayerApplicationSettingValue; // PDU ID
1304     connection->cmd_operands[pos++] = 0;
1305     // Parameter Length
1306     big_endian_store_16(connection->cmd_operands, pos, 3);
1307     pos += 2;
1308     connection->cmd_operands[pos++] = 2;
1309     connection->cmd_operands_length = pos;
1310     connection->cmd_operands[pos++]  = attr_id;
1311     connection->cmd_operands[pos++]  = attr_value;
1312     connection->cmd_operands_length = pos;
1313     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1314     return ERROR_CODE_SUCCESS;
1315 }
1316 
1317 uint8_t avrcp_controller_set_shuffle_mode(uint16_t avrcp_cid, avrcp_shuffle_mode_t mode){
1318     if (mode < AVRCP_SHUFFLE_MODE_OFF || mode > AVRCP_SHUFFLE_MODE_GROUP) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1319     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x03, mode);
1320 }
1321 
1322 uint8_t avrcp_controller_set_repeat_mode(uint16_t avrcp_cid, avrcp_repeat_mode_t mode){
1323     if (mode < AVRCP_REPEAT_MODE_OFF || mode > AVRCP_REPEAT_MODE_GROUP) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1324     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x02, mode);
1325 }
1326 
1327 uint8_t avrcp_controller_disconnect(uint16_t avrcp_cid){
1328     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1329     if (!connection){
1330         log_error("avrcp_get_capabilities: could not find a connection.");
1331         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1332     }
1333     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1334     if (connection->browsing_connection){
1335         if (connection->browsing_connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1336         l2cap_disconnect(connection->browsing_connection->l2cap_browsing_cid, 0);
1337     }
1338     l2cap_disconnect(connection->l2cap_signaling_cid, 0);
1339     return ERROR_CODE_SUCCESS;
1340 }
1341 
1342 uint8_t avrcp_controller_play_item_for_scope(uint16_t avrcp_cid, uint8_t * uid, uint16_t uid_counter, avrcp_browsing_scope_t scope){
1343     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1344     if (!connection){
1345         log_error("Could not find a connection with cid 0%02x.", avrcp_cid);
1346         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1347     }
1348     if (connection->state != AVCTP_CONNECTION_OPENED){
1349         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1350         return ERROR_CODE_COMMAND_DISALLOWED;
1351     }
1352     connection->state = AVCTP_W2_SEND_COMMAND;
1353 
1354     connection->transaction_label++;
1355     connection->command_type = AVRCP_CTYPE_CONTROL;
1356     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1357     connection->subunit_id = AVRCP_SUBUNIT_ID;
1358     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1359     int pos = 0;
1360     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1361     pos += 3;
1362     connection->cmd_operands[pos++] = AVRCP_PDU_ID_PLAY_ITEM; // PDU ID
1363     // reserved
1364     connection->cmd_operands[pos++] = 0;
1365     // Parameter Length
1366     big_endian_store_16(connection->cmd_operands, pos, 11);
1367     pos += 2;
1368     connection->cmd_operands[pos++]  = scope;
1369     memset(&connection->cmd_operands[pos], 0, 8);
1370     if (uid){
1371         memcpy(&connection->cmd_operands[pos], uid, 8);
1372     }
1373     pos += 8;
1374     big_endian_store_16(connection->cmd_operands, pos, uid_counter);
1375     pos += 2;
1376     connection->cmd_operands_length = pos;
1377 
1378     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1379     return ERROR_CODE_SUCCESS;
1380 }
1381 
1382 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){
1383     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1384     if (!connection){
1385         log_error("Could not find a connection with cid 0%02x.", avrcp_cid);
1386         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1387     }
1388     if (connection->state != AVCTP_CONNECTION_OPENED){
1389         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1390         return ERROR_CODE_COMMAND_DISALLOWED;
1391     }
1392     connection->state = AVCTP_W2_SEND_COMMAND;
1393 
1394     connection->transaction_label++;
1395     connection->command_type = AVRCP_CTYPE_CONTROL;
1396     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1397     connection->subunit_id = AVRCP_SUBUNIT_ID;
1398     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1399     int pos = 0;
1400     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1401     pos += 3;
1402     connection->cmd_operands[pos++] = AVRCP_PDU_ID_ADD_TO_NOW_PLAYING; // PDU ID
1403     // reserved
1404     connection->cmd_operands[pos++] = 0;
1405     // Parameter Length
1406     big_endian_store_16(connection->cmd_operands, pos, 11);
1407     pos += 2;
1408     connection->cmd_operands[pos++]  = scope;
1409     memset(&connection->cmd_operands[pos], 0, 8);
1410     if (uid){
1411         memcpy(&connection->cmd_operands[pos], uid, 8);
1412     }
1413     pos += 8;
1414     big_endian_store_16(connection->cmd_operands, pos, uid_counter);
1415     pos += 2;
1416     connection->cmd_operands_length = pos;
1417 
1418     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1419     return ERROR_CODE_SUCCESS;
1420 }
1421 
1422 uint8_t avrcp_controller_set_max_num_fragments(uint16_t avrcp_cid, uint8_t max_num_fragments){
1423     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1424     if (!connection){
1425         log_error("avrcp_controller_play_item: could not find a connection.");
1426         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1427     }
1428     connection->max_num_fragments = max_num_fragments;
1429     return ERROR_CODE_SUCCESS;
1430 }
1431 
1432 uint8_t avrcp_controller_send_custom_command(uint16_t avrcp_cid, avrcp_command_type_t command_type, avrcp_subunit_type_t subunit_type, avrcp_subunit_id_t subunit_id, avrcp_command_opcode_t command_opcode, const uint8_t * command_buffer, uint16_t command_len){
1433     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1434     if (!connection){
1435         log_error("avrcp_controller_play_item: could not find a connection.");
1436         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1437     }
1438 
1439     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1440     connection->state = AVCTP_W2_SEND_FRAGMENTED_COMMAND;
1441 
1442     connection->transaction_label++;
1443     connection->command_opcode = command_opcode;
1444     connection->command_type = command_type;
1445     connection->subunit_type = subunit_type;
1446     connection->subunit_id = subunit_id;
1447     connection->cmd_operands_fragmented_buffer = command_buffer;
1448     connection->cmd_operands_fragmented_pos = 0;
1449     connection->cmd_operands_fragmented_len = command_len;
1450 
1451     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1452     return ERROR_CODE_SUCCESS;
1453 }
1454