xref: /btstack/src/classic/avrcp_controller.c (revision 836408df59d0f67269f79708a1869c8855a7817b)
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 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){
54     avrcp_create_sdp_record(1, service, service_record_handle, browsing, supported_features, service_name, service_provider_name);
55 }
56 
57 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){
58     if (!callback) return;
59     uint8_t event[8];
60     int pos = 0;
61     event[pos++] = HCI_EVENT_AVRCP_META;
62     event[pos++] = sizeof(event) - 2;
63     event[pos++] = AVRCP_SUBEVENT_SHUFFLE_AND_REPEAT_MODE;
64     little_endian_store_16(event, pos, avrcp_cid);
65     pos += 2;
66     event[pos++] = ctype;
67     event[pos++] = repeat_mode;
68     event[pos++] = shuffle_mode;
69     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
70 }
71 
72 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){
73     if (!callback) return;
74     uint8_t event[7];
75     int pos = 0;
76     event[pos++] = HCI_EVENT_AVRCP_META;
77     event[pos++] = sizeof(event) - 2;
78     event[pos++] = subevent;
79     little_endian_store_16(event, pos, avrcp_cid);
80     pos += 2;
81     event[pos++] = ctype;
82     event[pos++] = operation_id;
83     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
84 }
85 
86 static void avrcp_press_and_hold_timeout_handler(btstack_timer_source_t * timer){
87     UNUSED(timer);
88     avrcp_connection_t * connection = btstack_run_loop_get_timer_context(timer);
89     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
90     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
91     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
92     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
93 }
94 
95 static void avrcp_press_and_hold_timer_start(avrcp_connection_t * connection){
96     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
97     btstack_run_loop_set_timer_handler(&connection->press_and_hold_cmd_timer, avrcp_press_and_hold_timeout_handler);
98     btstack_run_loop_set_timer_context(&connection->press_and_hold_cmd_timer, connection);
99     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
100     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
101 }
102 
103 static void avrcp_press_and_hold_timer_stop(avrcp_connection_t * connection){
104     connection->continuous_fast_forward_cmd = 0;
105     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
106 }
107 
108 static uint8_t request_pass_through_release_control_cmd(avrcp_connection_t * connection){
109     connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
110     if (connection->continuous_fast_forward_cmd){
111         avrcp_press_and_hold_timer_stop(connection);
112     }
113     connection->cmd_operands[0] = 0x80 | connection->cmd_operands[0];
114     connection->transaction_label++;
115     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
116     return ERROR_CODE_SUCCESS;
117 }
118 
119 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){
120     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, context);
121     if (!connection){
122         log_error("avrcp: could not find a connection.");
123         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
124     }
125     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
126     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
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     connection->cmd_operands_length = 0;
132 
133     connection->continuous_fast_forward_cmd = continuous_fast_forward_cmd;
134     connection->cmd_operands_length = 2;
135     connection->cmd_operands[0] = opid;
136     if (playback_speed > 0){
137         connection->cmd_operands[2] = playback_speed;
138         connection->cmd_operands_length++;
139     }
140     connection->cmd_operands[1] = connection->cmd_operands_length - 2;
141 
142     if (connection->continuous_fast_forward_cmd){
143         avrcp_press_and_hold_timer_start(connection);
144     }
145 
146     connection->transaction_label++;
147     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
148     return ERROR_CODE_SUCCESS;
149 }
150 
151 static uint8_t request_single_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
152     return request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, 0, &avrcp_controller_context);
153 }
154 
155 static uint8_t request_continuous_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
156     return request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, 1, &avrcp_controller_context);
157 }
158 
159 static int avrcp_send_cmd(uint16_t cid, avrcp_connection_t * connection){
160     uint8_t command[30];
161     int pos = 0;
162     // transport header
163     // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
164     command[pos++] = (connection->transaction_label << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
165     // Profile IDentifier (PID)
166     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
167     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
168 
169     // command_type
170     command[pos++] = connection->command_type;
171     // subunit_type | subunit ID
172     command[pos++] = (connection->subunit_type << 3) | connection->subunit_id;
173     // opcode
174     command[pos++] = (uint8_t)connection->command_opcode;
175     // operands
176     memcpy(command+pos, connection->cmd_operands, connection->cmd_operands_length);
177     pos += connection->cmd_operands_length;
178 
179     return l2cap_send(cid, command, pos);
180 }
181 
182 static int avrcp_register_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
183     if (connection->notifications_to_deregister & (1 << event_id)) return 0;
184     if (connection->notifications_enabled & (1 << event_id)) return 0;
185     if (connection->notifications_to_register & (1 << event_id)) return 0;
186     connection->notifications_to_register |= (1 << event_id);
187     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
188     return 1;
189 }
190 
191 static void avrcp_prepare_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
192     connection->transaction_label++;
193     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
194     connection->command_type = AVRCP_CTYPE_NOTIFY;
195     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
196     connection->subunit_id = AVRCP_SUBUNIT_ID;
197     int pos = 0;
198     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
199     pos += 3;
200     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REGISTER_NOTIFICATION;
201     connection->cmd_operands[pos++] = 0;                     // reserved(upper 6) | packet_type -> 0
202     big_endian_store_16(connection->cmd_operands, pos, 5);     // parameter length
203     pos += 2;
204     connection->cmd_operands[pos++] = event_id;
205     big_endian_store_32(connection->cmd_operands, pos, 0);
206     pos += 4;
207     connection->cmd_operands_length = pos;
208     // AVRCP_SPEC_V14.pdf 166
209     // answer page 61
210 }
211 
212 
213 static void avrcp_parser_reset(avrcp_connection_t * connection){
214     connection->list_offset = 0;
215     connection->num_attributes = 0;
216     connection->num_parsed_attributes = 0;
217     connection->parser_attribute_header_pos = 0;
218     connection->num_received_fragments = 0;
219     connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
220 }
221 
222 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){
223     uint8_t event[7];
224     int pos = 0;
225     event[pos++] = HCI_EVENT_AVRCP_META;
226     event[pos++] = sizeof(event) - 2;
227     event[pos++] = AVRCP_SUBEVENT_NOW_PLAYING_INFO_DONE;
228     little_endian_store_16(event, pos, avrcp_cid);
229     pos += 2;
230     event[pos++] = ctype;
231     event[pos++] = status;
232     // printf_hexdump(event, pos);
233     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
234 }
235 
236 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){
237     uint8_t event[HCI_EVENT_BUFFER_SIZE];
238     int pos = 0;
239     event[pos++] = HCI_EVENT_AVRCP_META;
240     // reserve one byte for subevent type and data len
241     int data_len_pos = pos;
242     pos++;
243     int subevent_type_pos = pos;
244     pos++;
245     little_endian_store_16(event, pos, avrcp_cid);
246     pos += 2;
247     event[pos++] = ctype;
248 
249     switch (attr_id){
250         case AVRCP_MEDIA_ATTR_TITLE:
251             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TITLE_INFO;
252             event[pos++] = value_len;
253             memcpy(event+pos, value, value_len);
254             break;
255         case AVRCP_MEDIA_ATTR_ARTIST:
256             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ARTIST_INFO;
257             event[pos++] = value_len;
258             memcpy(event+pos, value, value_len);
259             break;
260         case AVRCP_MEDIA_ATTR_ALBUM:
261             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ALBUM_INFO;
262             event[pos++] = value_len;
263             memcpy(event+pos, value, value_len);
264             break;
265         case AVRCP_MEDIA_ATTR_GENRE:
266             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_GENRE_INFO;
267             event[pos++] = value_len;
268             memcpy(event+pos, value, value_len);
269             break;
270         case AVRCP_MEDIA_ATTR_SONG_LENGTH_MS:
271             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_SONG_LENGTH_MS_INFO;
272             if (value){
273                 little_endian_store_32(event, pos, btstack_atoi((char *)value));
274             } else {
275                 little_endian_store_32(event, pos, 0);
276             }
277             pos += 4;
278             break;
279         case AVRCP_MEDIA_ATTR_TRACK:
280             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TRACK_INFO;
281             if (value){
282                 event[pos++] = btstack_atoi((char *)value);
283             } else {
284                 event[pos++] = 0;
285             }
286             break;
287         case AVRCP_MEDIA_ATTR_TOTAL_NUM_ITEMS:
288             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TOTAL_TRACKS_INFO;
289             if (value){
290                 event[pos++] = btstack_atoi((char *)value);
291             } else {
292                 event[pos++] = 0;
293             }
294             break;
295         default:
296             break;
297     }
298     event[data_len_pos] = pos - 2;
299     // printf("send attr len %d,  value %s\n", value_len, value);
300     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
301 }
302 
303 static void avrcp_parser_process_byte(uint8_t byte, avrcp_connection_t * connection, avrcp_command_type_t ctype){
304     uint16_t attribute_total_value_len;
305     uint32_t attribute_id;
306     switch(connection->parser_state){
307         case AVRCP_PARSER_GET_ATTRIBUTE_HEADER:
308             if (connection->parser_attribute_header_pos < AVRCP_ATTRIBUTE_HEADER_LEN) {
309                 connection->parser_attribute_header[connection->parser_attribute_header_pos++] = byte;
310                 connection->list_offset++;
311                 return;
312             }
313             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
314             connection->attribute_value_len = btstack_min(attribute_total_value_len, AVRCP_MAX_ATTRIBUTTE_SIZE);
315             if (connection->attribute_value_len == 0){
316                 // emit attribute although len == 0
317                 attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
318                 avrcp_controller_emit_now_playing_info_event(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, attribute_id, connection->attribute_value, connection->attribute_value_len);
319                 break;
320             }
321             connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_VALUE;
322             return;
323 
324         case AVRCP_PARSER_GET_ATTRIBUTE_VALUE:
325             if (connection->attribute_value_offset < connection->attribute_value_len){
326                 connection->attribute_value[connection->attribute_value_offset++] = byte;
327                 connection->list_offset++;
328                 return;
329             }
330 
331             // emit (potentially partial) attribute
332             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
333             avrcp_controller_emit_now_playing_info_event(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, attribute_id, connection->attribute_value, connection->attribute_value_len);
334 
335             // ignore rest of attribute
336             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
337             if (connection->attribute_value_offset < attribute_total_value_len){
338                 connection->parser_state = AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE;
339                 return;
340             }
341             break;
342 
343         case AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE:
344             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
345             if (connection->attribute_value_offset < attribute_total_value_len){
346                 connection->list_offset++;
347                 connection->attribute_value_offset++;
348                 return;
349             }
350             break;
351 
352         default:
353             return;
354     }
355 
356     // attribute fully read, check if more to come
357     if (connection->list_offset < connection->list_size){
358         // more to come
359         connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
360         connection->parser_attribute_header_pos = 0;
361     } else {
362         // fully done
363         avrcp_parser_reset(connection);
364         avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 0);
365     }
366 }
367 
368 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){
369     int i;
370     for (i=0;i<num_bytes_to_read;i++){
371         avrcp_parser_process_byte(packet[i], connection, ctype);
372     }
373 }
374 
375 static uint8_t avrcp_controller_request_abort_continuation(avrcp_connection_t * connection){
376     connection->state = AVCTP_W2_SEND_COMMAND;
377     connection->transaction_label++;
378     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
379     connection->command_type = AVRCP_CTYPE_CONTROL;
380     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
381     connection->subunit_id = AVRCP_SUBUNIT_ID;
382     int pos = 0;
383     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
384     pos += 3;
385     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REQUEST_ABORT_CONTINUING_RESPONSE; // PDU ID
386     connection->cmd_operands[pos++] = 0;
387     // Parameter Length
388     connection->cmd_operands_length = 8;
389     big_endian_store_16(connection->cmd_operands, pos, 1);
390     pos += 2;
391     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
392     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
393     return ERROR_CODE_SUCCESS;
394 }
395 
396 
397 static uint8_t avrcp_controller_request_continue_response(avrcp_connection_t * connection){
398     connection->state = AVCTP_W2_SEND_COMMAND;
399     connection->transaction_label++;
400     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
401     connection->command_type = AVRCP_CTYPE_CONTROL;
402     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
403     connection->subunit_id = AVRCP_SUBUNIT_ID;
404     int pos = 0;
405     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
406     pos += 3;
407     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REQUEST_CONTINUING_RESPONSE; // PDU ID
408     connection->cmd_operands[pos++] = 0;
409     // Parameter Length
410     connection->cmd_operands_length = 8;
411     big_endian_store_16(connection->cmd_operands, pos, 1);
412     pos += 2;
413     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
414     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
415     return ERROR_CODE_SUCCESS;
416 }
417 
418 static void avrcp_handle_l2cap_data_packet_for_signaling_connection(avrcp_connection_t * connection, uint8_t *packet, uint16_t size){
419     uint8_t operands[20];
420     uint8_t opcode;
421     int     pos = 3;
422     // uint8_t transport_header = packet[0];
423     // uint8_t transaction_label = transport_header >> 4;
424     // uint8_t packet_type = (transport_header & 0x0F) >> 2;
425     // uint8_t frame_type = (transport_header & 0x03) >> 1;
426     // uint8_t ipid = transport_header & 0x01;
427     // uint8_t byte_value = packet[2];
428     // uint16_t pid = (byte_value << 8) | packet[2];
429 
430     avrcp_command_type_t ctype = (avrcp_command_type_t) packet[pos++];
431     uint8_t byte_value = packet[pos++];
432     avrcp_subunit_type_t subunit_type = (avrcp_subunit_type_t) (byte_value >> 3);
433     avrcp_subunit_type_t subunit_id = (avrcp_subunit_type_t)   (byte_value & 0x07);
434     opcode = packet[pos++];
435 
436     // printf("    Transport header 0x%02x (transaction_label %d, packet_type %d, frame_type %d, ipid %d), pid 0x%4x\n",
437     //     transport_header, transaction_label, packet_type, frame_type, ipid, pid);
438     // // printf_hexdump(packet+pos, size-pos);
439 
440     uint8_t pdu_id;
441     uint16_t param_length;
442     switch (avrcp_cmd_opcode(packet,size)){
443         case AVRCP_CMD_OPCODE_SUBUNIT_INFO:{
444             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
445             connection->state = AVCTP_CONNECTION_OPENED;
446             // operands:
447             memcpy(operands, packet+pos, 5);
448             uint8_t unit_type = operands[1] >> 3;
449             uint8_t max_subunit_ID = operands[1] & 0x07;
450             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);
451             break;
452         }
453         case AVRCP_CMD_OPCODE_UNIT_INFO:{
454             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
455             connection->state = AVCTP_CONNECTION_OPENED;
456             // operands:
457             memcpy(operands, packet+pos, 5);
458             uint8_t unit_type = operands[1] >> 3;
459             uint8_t unit = operands[1] & 0x07;
460             uint32_t company_id = operands[2] << 16 | operands[3] << 8 | operands[4];
461             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,
462                 ctype, subunit_type, subunit_id, opcode, unit_type, unit, company_id);
463             break;
464         }
465         case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
466             if (size - pos < 7) {
467                 log_error("avrcp: wrong packet size");
468                 return;
469             };
470             // operands:
471             memcpy(operands, packet+pos, 7);
472             pos += 7;
473             // uint32_t company_id = operands[0] << 16 | operands[1] << 8 | operands[2];
474             pdu_id = operands[3];
475 
476             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE && pdu_id != AVRCP_PDU_ID_REGISTER_NOTIFICATION){
477                 log_info("AVRCP_CMD_OPCODE_VENDOR_DEPENDENT state %d", connection->state);
478                 return;
479             }
480             connection->state = AVCTP_CONNECTION_OPENED;
481 
482 
483             // uint8_t unit_type = operands[4] >> 3;
484             // uint8_t unit = operands[4] & 0x07;
485             param_length = big_endian_read_16(operands, 5);
486 
487             // 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",
488             //     ctype, subunit_type, subunit_id, opcode, unit_type, unit, company_id );
489 
490             // if (ctype == AVRCP_CTYPE_RESPONSE_INTERIM) return;
491             log_info("        VENDOR DEPENDENT response: pdu id 0x%02x, param_length %d, status %s", pdu_id, param_length, avrcp_ctype2str(ctype));
492             switch (pdu_id){
493                 case AVRCP_PDU_ID_GetCurrentPlayerApplicationSettingValue:{
494                     uint8_t num_attributes = packet[pos++];
495                     int i;
496                     avrcp_repeat_mode_t  repeat_mode =  AVRCP_REPEAT_MODE_INVALID;
497                     avrcp_shuffle_mode_t shuffle_mode = AVRCP_SHUFFLE_MODE_INVALID;
498                     for (i = 0; i < num_attributes; i++){
499                         uint8_t attribute_id    = packet[pos++];
500                         uint8_t value = packet[pos++];
501                         switch (attribute_id){
502                             case 0x02:
503                                 repeat_mode = (avrcp_repeat_mode_t) value;
504                                 break;
505                             case 0x03:
506                                 shuffle_mode = (avrcp_shuffle_mode_t) value;
507                                 break;
508                             default:
509                                 break;
510                         }
511                     }
512                     avrcp_emit_repeat_and_shuffle_mode(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, repeat_mode, shuffle_mode);
513                     break;
514                 }
515                 case AVRCP_PDU_ID_SetPlayerApplicationSettingValue:{
516                     uint8_t event[6];
517                     int offset = 0;
518                     event[offset++] = HCI_EVENT_AVRCP_META;
519                     event[offset++] = sizeof(event) - 2;
520                     event[offset++] = AVRCP_SUBEVENT_PLAYER_APPLICATION_VALUE_RESPONSE;
521                     little_endian_store_16(event, offset, connection->avrcp_cid);
522                     offset += 2;
523                     event[offset++] = ctype;
524                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
525                     break;
526                 }
527                 case AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME:{
528                     uint8_t event[7];
529                     int offset = 0;
530                     event[offset++] = HCI_EVENT_AVRCP_META;
531                     event[offset++] = sizeof(event) - 2;
532                     event[offset++] = AVRCP_SUBEVENT_SET_ABSOLUTE_VOLUME_RESPONSE;
533                     little_endian_store_16(event, offset, connection->avrcp_cid);
534                     offset += 2;
535                     event[offset++] = ctype;
536                     event[offset++] = packet[pos++];
537                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
538                     break;
539                 }
540                 case AVRCP_PDU_ID_GET_CAPABILITIES:{
541                     avrcp_capability_id_t capability_id = (avrcp_capability_id_t) packet[pos++];
542                     uint8_t capability_count = packet[pos++];
543                     int i;
544                     switch (capability_id){
545                         case AVRCP_CAPABILITY_ID_COMPANY:
546                             // log_info("Supported companies %d: ", capability_count);
547                             for (i = 0; i < capability_count; i++){
548                                 uint32_t company_id = big_endian_read_24(packet, pos);
549                                 pos += 3;
550                                 log_info("  0x%06" PRIx32 ", ", company_id);
551                             }
552                             break;
553                         case AVRCP_CAPABILITY_ID_EVENT:
554                             // log_info("Supported events %d: ", capability_count);
555                             for (i = 0; i < capability_count; i++){
556                                 uint8_t event_id = packet[pos++];
557                                 log_info("  0x%02x %s", event_id, avrcp_event2str(event_id));
558                             }
559                             break;
560                     }
561                     break;
562                 }
563                 case AVRCP_PDU_ID_GET_PLAY_STATUS:{
564                     uint32_t song_length = big_endian_read_32(packet, pos);
565                     pos += 4;
566                     uint32_t song_position = big_endian_read_32(packet, pos);
567                     pos += 4;
568                     uint8_t play_status = packet[pos];
569                     // log_info("        GET_PLAY_STATUS length 0x%04X, position 0x%04X, status %s", song_length, song_position, avrcp_play_status2str(play_status));
570 
571                     uint8_t event[15];
572                     int offset = 0;
573                     event[offset++] = HCI_EVENT_AVRCP_META;
574                     event[offset++] = sizeof(event) - 2;
575                     event[offset++] = AVRCP_SUBEVENT_PLAY_STATUS;
576                     little_endian_store_16(event, offset, connection->avrcp_cid);
577                     offset += 2;
578                     event[offset++] = ctype;
579                     little_endian_store_32(event, offset, song_length);
580                     offset += 4;
581                     little_endian_store_32(event, offset, song_position);
582                     offset += 4;
583                     event[offset++] = play_status;
584                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
585                     break;
586                 }
587                 case AVRCP_PDU_ID_REGISTER_NOTIFICATION:{
588                     avrcp_notification_event_id_t  event_id = (avrcp_notification_event_id_t) packet[pos++];
589                     uint16_t event_mask = (1 << event_id);
590                     uint16_t reset_event_mask = ~event_mask;
591                     switch (ctype){
592                         case AVRCP_CTYPE_RESPONSE_INTERIM:
593                             // register as enabled
594                             connection->notifications_enabled |= event_mask;
595                             // printf("INTERIM notifications_enabled 0x%2x, notifications_to_register 0x%2x\n", connection->notifications_enabled,  connection->notifications_to_register);
596                             break;
597                         case AVRCP_CTYPE_RESPONSE_CHANGED_STABLE:
598                             // received change, event is considered deregistered
599                             // we are re-enabling it automatically, if it is not
600                             // explicitly disabled
601                             connection->notifications_enabled &= reset_event_mask;
602                             if (! (connection->notifications_to_deregister & event_mask)){
603                                 avrcp_register_notification(connection, event_id);
604                                 // printf("CHANGED_STABLE notifications_enabled 0x%2x, notifications_to_register 0x%2x\n", connection->notifications_enabled,  connection->notifications_to_register);
605                             } else {
606                                 connection->notifications_to_deregister &= reset_event_mask;
607                             }
608                             break;
609                         default:
610                             connection->notifications_to_register &= reset_event_mask;
611                             connection->notifications_enabled &= reset_event_mask;
612                             connection->notifications_to_deregister &= reset_event_mask;
613                             break;
614                     }
615 
616                     switch (event_id){
617                         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED:{
618                             uint8_t event[7];
619                             int offset = 0;
620                             event[offset++] = HCI_EVENT_AVRCP_META;
621                             event[offset++] = sizeof(event) - 2;
622                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_STATUS_CHANGED;
623                             little_endian_store_16(event, offset, connection->avrcp_cid);
624                             offset += 2;
625                             event[offset++] = ctype;
626                             event[offset++] = packet[pos];
627                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
628                             break;
629                         }
630                         case AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED:{
631                             uint8_t event[6];
632                             int offset = 0;
633                             event[offset++] = HCI_EVENT_AVRCP_META;
634                             event[offset++] = sizeof(event) - 2;
635                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_TRACK_CHANGED;
636                             little_endian_store_16(event, offset, connection->avrcp_cid);
637                             offset += 2;
638                             event[offset++] = ctype;
639                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
640                             break;
641                         }
642                         case AVRCP_NOTIFICATION_EVENT_NOW_PLAYING_CONTENT_CHANGED:{
643                             uint8_t event[6];
644                             int offset = 0;
645                             event[offset++] = HCI_EVENT_AVRCP_META;
646                             event[offset++] = sizeof(event) - 2;
647                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_NOW_PLAYING_CONTENT_CHANGED;
648                             little_endian_store_16(event, offset, connection->avrcp_cid);
649                             offset += 2;
650                             event[offset++] = ctype;
651                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
652                             break;
653                         }
654                         case AVRCP_NOTIFICATION_EVENT_AVAILABLE_PLAYERS_CHANGED:{
655                             uint8_t event[6];
656                             int offset = 0;
657                             event[offset++] = HCI_EVENT_AVRCP_META;
658                             event[offset++] = sizeof(event) - 2;
659                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_AVAILABLE_PLAYERS_CHANGED;
660                             little_endian_store_16(event, offset, connection->avrcp_cid);
661                             offset += 2;
662                             event[offset++] = ctype;
663                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
664                             break;
665                         }
666                         case AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED:{
667                             uint8_t event[7];
668                             int offset = 0;
669                             event[offset++] = HCI_EVENT_AVRCP_META;
670                             event[offset++] = sizeof(event) - 2;
671                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED;
672                             little_endian_store_16(event, offset, connection->avrcp_cid);
673                             offset += 2;
674                             event[offset++] = ctype;
675                             event[offset++] = packet[pos++] & 0x7F;
676                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
677                             break;
678                         }
679                         case AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED:{
680                             uint8_t event[7];
681                             int offset = 0;
682                             event[offset++] = HCI_EVENT_AVRCP_META;
683                             event[offset++] = sizeof(event) - 2;
684                             event[offset++] = AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED;
685                             little_endian_store_16(event, offset, connection->avrcp_cid);
686                             offset += 2;
687                             event[offset++] = ctype;
688                             event[offset++] = packet[pos++] & 0x7F;
689                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
690                             break;
691                         }
692 
693                         // case AVRCP_NOTIFICATION_EVENT_PLAYER_APPLICATION_SETTING_CHANGED:{
694                         //     uint8_t num_PlayerApplicationSettingAttributes = packet[pos++];
695                         //     int i;
696                         //     for (i = 0; i < num_PlayerApplicationSettingAttributes; i++){
697                         //         uint8_t PlayerApplicationSetting_AttributeID = packet[pos++];
698                         //         uint8_t PlayerApplicationSettingValueID = packet[pos++];
699                         //     }
700                         //     break;
701                         // }
702                         // case AVRCP_NOTIFICATION_EVENT_ADDRESSED_PLAYER_CHANGED:
703                         //     uint16_t player_id = big_endian_read_16(packet, pos);
704                         //     pos += 2;
705                         //     uint16_t uid_counter = big_endian_read_16(packet, pos);
706                         //     pos += 2;
707                         //     break;
708                         // case AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED:
709                         //     uint16_t uid_counter = big_endian_read_16(packet, pos);
710                         //     pos += 2;
711                         //     break;
712                         default:
713                             log_info("avrcp: not implemented");
714                             break;
715                     }
716                     if (connection->notifications_to_register != 0){
717                         avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
718                     }
719                     break;
720                 }
721 
722                 case AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES:{
723                     avrcp_packet_type_t packet_type = operands[4] & 0x03;
724                     switch (packet_type){
725                         case AVRCP_START_PACKET:
726                         case AVRCP_SINGLE_PACKET:
727                             avrcp_parser_reset(connection);
728                             connection->list_size = param_length;
729                             connection->num_attributes = packet[pos++];
730 
731                             // 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);
732                             avrcp_source_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
733 
734                             if (packet_type == AVRCP_START_PACKET){
735                                 avrcp_controller_request_continue_response(connection);
736                             }
737                             break;
738                         case AVRCP_CONTINUE_PACKET:
739                         case AVRCP_END_PACKET:
740                             connection->num_received_fragments++;
741                             if (connection->num_received_fragments < connection->max_num_fragments){
742                                 avrcp_source_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
743                                 if (packet_type == AVRCP_CONTINUE_PACKET){
744                                     avrcp_controller_request_continue_response(connection);
745                                 }
746                             } else {
747                                 avrcp_controller_request_abort_continuation(connection);
748                                 avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 1);
749                                 avrcp_parser_reset(connection);
750                             }
751                             break;
752                     }
753                 }
754                 default:
755                     break;
756             }
757             break;
758         case AVRCP_CMD_OPCODE_PASS_THROUGH:{
759             // 0x80 | connection->cmd_operands[0]
760             uint8_t operation_id = packet[pos++];
761             switch (connection->state){
762                 case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
763                     if (connection->continuous_fast_forward_cmd){
764                         connection->state = AVCTP_W4_STOP;
765                     } else {
766                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
767                     }
768                     break;
769                 case AVCTP_W2_RECEIVE_RESPONSE:
770                     connection->state = AVCTP_CONNECTION_OPENED;
771                     break;
772                 default:
773                     // check for notifications? move state transition down
774                     // log_info("AVRCP_CMD_OPCODE_PASS_THROUGH state %d\n", connection->state);
775                     break;
776             }
777             if (connection->state == AVCTP_W4_STOP){
778                 avrcp_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_START, connection->avrcp_cid, ctype, operation_id);
779             }
780             if (connection->state == AVCTP_CONNECTION_OPENED) {
781                 // RELEASE response
782                 operation_id = operation_id & 0x7F;
783                 avrcp_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_COMPLETE, connection->avrcp_cid, ctype, operation_id);
784             }
785             if (connection->state == AVCTP_W2_SEND_RELEASE_COMMAND){
786                 // PRESS response
787                 request_pass_through_release_control_cmd(connection);
788             }
789             break;
790         }
791         default:
792             break;
793     }
794 }
795 
796 static void avrcp_controller_handle_can_send_now(avrcp_connection_t * connection){
797     int i;
798     switch (connection->state){
799         case AVCTP_W2_SEND_PRESS_COMMAND:
800             connection->state = AVCTP_W2_RECEIVE_PRESS_RESPONSE;
801             avrcp_send_cmd(connection->l2cap_signaling_cid, connection);
802             break;
803         case AVCTP_W2_SEND_COMMAND:
804         case AVCTP_W2_SEND_RELEASE_COMMAND:
805             connection->state = AVCTP_W2_RECEIVE_RESPONSE;
806             avrcp_send_cmd(connection->l2cap_signaling_cid, connection);
807             break;
808         case AVCTP_CONNECTION_OPENED:
809             if (connection->notifications_to_register != 0){
810                 for (i = 1; i <= AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED; i++){
811                     if (connection->notifications_to_register & (1<<i)){
812                         connection->notifications_to_register &= ~ (1 << i);
813                         avrcp_prepare_notification(connection, (avrcp_notification_event_id_t) i);
814                         connection->state = AVCTP_W2_RECEIVE_RESPONSE;
815                         avrcp_send_cmd(connection->l2cap_signaling_cid, connection);
816                         return;
817                     }
818                 }
819             }
820             return;
821         default:
822             return;
823     }
824 }
825 
826 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
827     avrcp_connection_t * connection;
828 
829     switch (packet_type) {
830         case L2CAP_DATA_PACKET:
831             connection = get_avrcp_connection_for_l2cap_signaling_cid(channel, &avrcp_controller_context);
832             if (!connection) break;
833             avrcp_handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
834             break;
835         case HCI_EVENT_PACKET:
836             switch (hci_event_packet_get_type(packet)){
837                 case L2CAP_EVENT_CAN_SEND_NOW:
838                     connection = get_avrcp_connection_for_l2cap_signaling_cid(channel, &avrcp_controller_context);
839                     if (!connection) break;
840                     avrcp_controller_handle_can_send_now(connection);
841                     break;
842             default:
843                 avrcp_packet_handler(packet_type, channel, packet, size, &avrcp_controller_context);
844                 break;
845         }
846         default:
847             break;
848     }
849 }
850 
851 void avrcp_controller_init(void){
852     avrcp_controller_context.role = AVRCP_CONTROLLER;
853     avrcp_controller_context.connections = NULL;
854     avrcp_controller_context.packet_handler = avrcp_controller_packet_handler;
855     l2cap_register_service(&avrcp_controller_packet_handler, BLUETOOTH_PROTOCOL_AVCTP, 0xffff, LEVEL_0);
856 }
857 
858 void avrcp_controller_register_packet_handler(btstack_packet_handler_t callback){
859     if (callback == NULL){
860         log_error("avrcp_register_packet_handler called with NULL callback");
861         return;
862     }
863     avrcp_controller_context.avrcp_callback = callback;
864 }
865 
866 uint8_t avrcp_controller_connect(bd_addr_t bd_addr, uint16_t * avrcp_cid){
867     return avrcp_connect(bd_addr, &avrcp_controller_context, avrcp_cid);
868 }
869 
870 uint8_t avrcp_controller_unit_info(uint16_t avrcp_cid){
871     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
872     if (!connection){
873         log_error("avrcp_unit_info: could not find a connection.");
874         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
875     }
876     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
877     connection->state = AVCTP_W2_SEND_COMMAND;
878 
879     connection->transaction_label++;
880     connection->command_opcode = AVRCP_CMD_OPCODE_UNIT_INFO;
881     connection->command_type = AVRCP_CTYPE_STATUS;
882     connection->subunit_type = AVRCP_SUBUNIT_TYPE_UNIT; //vendor unique
883     connection->subunit_id =   AVRCP_SUBUNIT_ID_IGNORE;
884     memset(connection->cmd_operands, 0xFF, connection->cmd_operands_length);
885     connection->cmd_operands_length = 5;
886     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
887     return ERROR_CODE_SUCCESS;
888 }
889 
890 uint8_t avrcp_controller_subunit_info(uint16_t avrcp_cid){
891     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
892     if (!connection){
893         log_error("avrcp_unit_info: could not find a connection.");
894         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
895     }
896     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
897     connection->state = AVCTP_W2_SEND_COMMAND;
898 
899     connection->transaction_label++;
900     connection->command_opcode = AVRCP_CMD_OPCODE_SUBUNIT_INFO;
901     connection->command_type = AVRCP_CTYPE_STATUS;
902     connection->subunit_type = AVRCP_SUBUNIT_TYPE_UNIT; //vendor unique
903     connection->subunit_id =   AVRCP_SUBUNIT_ID_IGNORE;
904     memset(connection->cmd_operands, 0xFF, connection->cmd_operands_length);
905     connection->cmd_operands[0] = 7; // page: 0, extention_code: 7
906     connection->cmd_operands_length = 5;
907     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
908     return ERROR_CODE_SUCCESS;
909 }
910 
911 static uint8_t avrcp_controller_get_capabilities(uint16_t avrcp_cid, uint8_t capability_id){
912     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
913     if (!connection){
914         log_error("avrcp_get_capabilities: could not find a connection.");
915         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
916     }
917     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
918     connection->state = AVCTP_W2_SEND_COMMAND;
919 
920     connection->transaction_label++;
921     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
922     connection->command_type = AVRCP_CTYPE_STATUS;
923     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
924     connection->subunit_id = AVRCP_SUBUNIT_ID;
925     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
926     connection->cmd_operands[3] = AVRCP_PDU_ID_GET_CAPABILITIES; // PDU ID
927     connection->cmd_operands[4] = 0;
928     big_endian_store_16(connection->cmd_operands, 5, 1); // parameter length
929     connection->cmd_operands[7] = capability_id;                  // capability ID
930     connection->cmd_operands_length = 8;
931     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
932     return ERROR_CODE_SUCCESS;
933 }
934 
935 uint8_t avrcp_controller_get_supported_company_ids(uint16_t avrcp_cid){
936     return avrcp_controller_get_capabilities(avrcp_cid, AVRCP_CAPABILITY_ID_COMPANY);
937 }
938 
939 uint8_t avrcp_controller_get_supported_events(uint16_t avrcp_cid){
940     return avrcp_controller_get_capabilities(avrcp_cid, AVRCP_CAPABILITY_ID_EVENT);
941 }
942 
943 
944 uint8_t avrcp_controller_play(uint16_t avrcp_cid){
945     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
946 }
947 
948 uint8_t avrcp_controller_stop(uint16_t avrcp_cid){
949     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
950 }
951 
952 uint8_t avrcp_controller_pause(uint16_t avrcp_cid){
953     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
954 }
955 
956 uint8_t avrcp_controller_forward(uint16_t avrcp_cid){
957     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
958 }
959 
960 uint8_t avrcp_controller_backward(uint16_t avrcp_cid){
961     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
962 }
963 
964 uint8_t avrcp_controller_start_rewind(uint16_t avrcp_cid){
965     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
966 }
967 
968 uint8_t avrcp_controller_volume_up(uint16_t avrcp_cid){
969     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
970 }
971 
972 uint8_t avrcp_controller_volume_down(uint16_t avrcp_cid){
973     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
974 }
975 
976 uint8_t avrcp_controller_mute(uint16_t avrcp_cid){
977     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
978 }
979 
980 uint8_t avrcp_controller_skip(uint16_t avrcp_cid){
981     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_SKIP, 0);
982 }
983 
984 uint8_t avrcp_controller_stop_rewind(uint16_t avrcp_cid){
985     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
986     if (!connection){
987         log_error("avrcp_stop_rewind: could not find a connection.");
988         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
989     }
990     if (connection->state != AVCTP_W4_STOP) return ERROR_CODE_COMMAND_DISALLOWED;
991     return request_pass_through_release_control_cmd(connection);
992 }
993 
994 uint8_t avrcp_controller_start_fast_forward(uint16_t avrcp_cid){
995     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
996 }
997 
998 uint8_t avrcp_controller_fast_forward(uint16_t avrcp_cid){
999     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1000 }
1001 
1002 uint8_t avrcp_controller_rewind(uint16_t avrcp_cid){
1003     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1004 }
1005 
1006 
1007 uint8_t avrcp_controller_stop_fast_forward(uint16_t avrcp_cid){
1008     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1009     if (!connection){
1010         log_error("avrcp_stop_fast_forward: could not find a connection.");
1011         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1012     }
1013     if (connection->state != AVCTP_W4_STOP) return ERROR_CODE_COMMAND_DISALLOWED;
1014     return request_pass_through_release_control_cmd(connection);
1015 }
1016 
1017 uint8_t avrcp_controller_get_play_status(uint16_t avrcp_cid){
1018     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1019     if (!connection){
1020         log_error("avrcp_get_play_status: could not find a connection.");
1021         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1022     }
1023     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1024     connection->state = AVCTP_W2_SEND_COMMAND;
1025     connection->transaction_label++;
1026     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1027     connection->command_type = AVRCP_CTYPE_STATUS;
1028     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1029     connection->subunit_id = AVRCP_SUBUNIT_ID;
1030     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
1031     connection->cmd_operands[3] = AVRCP_PDU_ID_GET_PLAY_STATUS;
1032     connection->cmd_operands[4] = 0;                     // reserved(upper 6) | packet_type -> 0
1033     big_endian_store_16(connection->cmd_operands, 5, 0); // parameter length
1034     connection->cmd_operands_length = 7;
1035     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1036     return ERROR_CODE_SUCCESS;
1037 }
1038 
1039 uint8_t avrcp_controller_enable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1040     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1041     if (!connection){
1042         log_error("avrcp_get_play_status: could not find a connection.");
1043         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1044     }
1045     avrcp_register_notification(connection, event_id);
1046     return ERROR_CODE_SUCCESS;
1047 }
1048 
1049 uint8_t avrcp_controller_disable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1050     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1051     if (!connection){
1052         log_error("avrcp_get_play_status: could not find a connection.");
1053         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1054     }
1055     connection->notifications_to_deregister |= (1 << event_id);
1056     return ERROR_CODE_SUCCESS;
1057 }
1058 
1059 uint8_t avrcp_controller_set_addressed_player(uint16_t avrcp_cid, uint16_t addressed_player_id){
1060     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1061     if (!connection){
1062         log_error("avrcp_get_capabilities: could not find a connection.");
1063         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1064     }
1065     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1066     connection->state = AVCTP_W2_SEND_COMMAND;
1067 
1068     connection->transaction_label++;
1069     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1070     connection->command_type = AVRCP_CTYPE_CONTROL;
1071     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1072     connection->subunit_id = AVRCP_SUBUNIT_ID;
1073     int pos = 0;
1074     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1075     pos += 3;
1076     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_ADDRESSED_PLAYER; // PDU ID
1077     connection->cmd_operands[pos++] = 0;
1078 
1079     // Parameter Length
1080     big_endian_store_16(connection->cmd_operands, pos, 2);
1081     pos += 2;
1082 
1083     big_endian_store_16(connection->cmd_operands, pos, addressed_player_id);
1084     pos += 2;
1085 
1086     connection->cmd_operands_length = pos;
1087     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1088     return ERROR_CODE_SUCCESS;
1089 }
1090 
1091 uint8_t avrcp_controller_get_now_playing_info(uint16_t avrcp_cid){
1092     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1093     if (!connection){
1094         log_error("avrcp_get_capabilities: could not find a connection.");
1095         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1096     }
1097     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1098     connection->state = AVCTP_W2_SEND_COMMAND;
1099 
1100     connection->transaction_label++;
1101     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1102     connection->command_type = AVRCP_CTYPE_STATUS;
1103     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1104     connection->subunit_id = AVRCP_SUBUNIT_ID;
1105     int pos = 0;
1106     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1107     pos += 3;
1108     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES; // PDU ID
1109     connection->cmd_operands[pos++] = 0;
1110 
1111     // Parameter Length
1112     big_endian_store_16(connection->cmd_operands, pos, 9);
1113     pos += 2;
1114 
1115     // write 8 bytes value
1116     memset(connection->cmd_operands + pos, 0, 8); // identifier: PLAYING
1117     pos += 8;
1118 
1119     connection->cmd_operands[pos++] = 0; // attribute count, if 0 get all attributes
1120     // every attribute is 4 bytes long
1121 
1122     connection->cmd_operands_length = pos;
1123     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1124     return ERROR_CODE_SUCCESS;
1125 }
1126 
1127 uint8_t avrcp_controller_set_absolute_volume(uint16_t avrcp_cid, uint8_t volume){
1128      avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1129     if (!connection){
1130         log_error("avrcp_get_capabilities: could not find a connection.");
1131         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1132     }
1133     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1134     connection->state = AVCTP_W2_SEND_COMMAND;
1135 
1136     connection->transaction_label++;
1137     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1138     connection->command_type = AVRCP_CTYPE_CONTROL;
1139     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1140     connection->subunit_id = AVRCP_SUBUNIT_ID;
1141     int pos = 0;
1142     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1143     pos += 3;
1144     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME; // PDU ID
1145     connection->cmd_operands[pos++] = 0;
1146 
1147     // Parameter Length
1148     big_endian_store_16(connection->cmd_operands, pos, 1);
1149     pos += 2;
1150     connection->cmd_operands[pos++] = volume;
1151 
1152     connection->cmd_operands_length = pos;
1153     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1154     return ERROR_CODE_SUCCESS;
1155 }
1156 
1157 uint8_t avrcp_controller_query_shuffle_and_repeat_modes(uint16_t avrcp_cid){
1158     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1159     if (!connection){
1160         log_error("avrcp_get_capabilities: could not find a connection.");
1161         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1162     }
1163     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1164     connection->state = AVCTP_W2_SEND_COMMAND;
1165 
1166     connection->transaction_label++;
1167     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1168     connection->command_type = AVRCP_CTYPE_STATUS;
1169     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1170     connection->subunit_id = AVRCP_SUBUNIT_ID;
1171     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
1172     connection->cmd_operands[3] = AVRCP_PDU_ID_GetCurrentPlayerApplicationSettingValue; // PDU ID
1173     connection->cmd_operands[4] = 0;
1174     big_endian_store_16(connection->cmd_operands, 5, 5); // parameter length
1175     connection->cmd_operands[7] = 4;                     // NumPlayerApplicationSettingAttributeID
1176     // PlayerApplicationSettingAttributeID1 AVRCP Spec, Appendix F, 133
1177     connection->cmd_operands[8]  = 0x01;    // equalizer  (1-OFF, 2-ON)
1178     connection->cmd_operands[9]  = 0x02;    // repeat     (1-off, 2-single track, 3-all tracks, 4-group repeat)
1179     connection->cmd_operands[10] = 0x03;    // shuffle    (1-off, 2-all tracks, 3-group shuffle)
1180     connection->cmd_operands[11] = 0x04;    // scan       (1-off, 2-all tracks, 3-group scan)
1181     connection->cmd_operands_length = 12;
1182     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1183     return ERROR_CODE_SUCCESS;
1184 }
1185 
1186 static uint8_t avrcp_controller_set_current_player_application_setting_value(uint16_t avrcp_cid, uint8_t attr_id, uint8_t attr_value){
1187     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1188     if (!connection){
1189         log_error("avrcp_get_capabilities: could not find a connection.");
1190         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1191     }
1192     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1193     connection->state = AVCTP_W2_SEND_COMMAND;
1194 
1195     connection->transaction_label++;
1196     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1197     connection->command_type = AVRCP_CTYPE_CONTROL;
1198     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1199     connection->subunit_id = AVRCP_SUBUNIT_ID;
1200     int pos = 0;
1201     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1202     pos += 3;
1203     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SetPlayerApplicationSettingValue; // PDU ID
1204     connection->cmd_operands[pos++] = 0;
1205     // Parameter Length
1206     big_endian_store_16(connection->cmd_operands, pos, 3);
1207     pos += 2;
1208     connection->cmd_operands[pos++] = 2;
1209     connection->cmd_operands_length = pos;
1210     connection->cmd_operands[pos++]  = attr_id;
1211     connection->cmd_operands[pos++]  = attr_value;
1212     connection->cmd_operands_length = pos;
1213     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1214     return ERROR_CODE_SUCCESS;
1215 }
1216 
1217 uint8_t avrcp_controller_set_shuffle_mode(uint16_t avrcp_cid, avrcp_shuffle_mode_t mode){
1218     if (mode < AVRCP_SHUFFLE_MODE_OFF || mode > AVRCP_SHUFFLE_MODE_GROUP) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1219     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x03, mode);
1220 }
1221 
1222 uint8_t avrcp_controller_set_repeat_mode(uint16_t avrcp_cid, avrcp_repeat_mode_t mode){
1223     if (mode < AVRCP_REPEAT_MODE_OFF || mode > AVRCP_REPEAT_MODE_GROUP) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1224     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x02, mode);
1225 }
1226 
1227 uint8_t avrcp_controller_disconnect(uint16_t avrcp_cid){
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     if (connection->browsing_connection){
1235         if (connection->browsing_connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1236         l2cap_disconnect(connection->browsing_connection->l2cap_browsing_cid, 0);
1237     }
1238     l2cap_disconnect(connection->l2cap_signaling_cid, 0);
1239     return ERROR_CODE_SUCCESS;
1240 }
1241 
1242 uint8_t avrcp_controller_play_item_for_scope(uint16_t avrcp_cid, uint8_t * uid, uint16_t uid_counter, avrcp_browsing_scope_t scope){
1243     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1244     if (!connection){
1245         log_error("Could not find a connection with cid 0%02x.", avrcp_cid);
1246         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1247     }
1248     if (connection->state != AVCTP_CONNECTION_OPENED){
1249         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1250         return ERROR_CODE_COMMAND_DISALLOWED;
1251     }
1252     connection->state = AVCTP_W2_SEND_COMMAND;
1253 
1254     connection->transaction_label++;
1255     connection->command_type = AVRCP_CTYPE_CONTROL;
1256     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1257     connection->subunit_id = AVRCP_SUBUNIT_ID;
1258     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1259     int pos = 0;
1260     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1261     pos += 3;
1262     connection->cmd_operands[pos++] = AVRCP_PDU_ID_PLAY_ITEM; // PDU ID
1263     // reserved
1264     connection->cmd_operands[pos++] = 0;
1265     // Parameter Length
1266     big_endian_store_16(connection->cmd_operands, pos, 11);
1267     pos += 2;
1268     connection->cmd_operands[pos++]  = scope;
1269     memset(&connection->cmd_operands[pos], 0, 8);
1270     if (uid){
1271         memcpy(&connection->cmd_operands[pos], uid, 8);
1272     }
1273     pos += 8;
1274     big_endian_store_16(connection->cmd_operands, pos, uid_counter);
1275     pos += 2;
1276     connection->cmd_operands_length = pos;
1277 
1278     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1279     return ERROR_CODE_SUCCESS;
1280 }
1281 
1282 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){
1283     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1284     if (!connection){
1285         log_error("Could not find a connection with cid 0%02x.", avrcp_cid);
1286         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1287     }
1288     if (connection->state != AVCTP_CONNECTION_OPENED){
1289         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1290         return ERROR_CODE_COMMAND_DISALLOWED;
1291     }
1292     connection->state = AVCTP_W2_SEND_COMMAND;
1293 
1294     connection->transaction_label++;
1295     connection->command_type = AVRCP_CTYPE_CONTROL;
1296     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1297     connection->subunit_id = AVRCP_SUBUNIT_ID;
1298     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1299     int pos = 0;
1300     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1301     pos += 3;
1302     connection->cmd_operands[pos++] = AVRCP_PDU_ADD_TO_NOW_PLAYING; // PDU ID
1303     // reserved
1304     connection->cmd_operands[pos++] = 0;
1305     // Parameter Length
1306     big_endian_store_16(connection->cmd_operands, pos, 11);
1307     pos += 2;
1308     connection->cmd_operands[pos++]  = scope;
1309     memset(&connection->cmd_operands[pos], 0, 8);
1310     if (uid){
1311         memcpy(&connection->cmd_operands[pos], uid, 8);
1312     }
1313     pos += 8;
1314     big_endian_store_16(connection->cmd_operands, pos, uid_counter);
1315     pos += 2;
1316     connection->cmd_operands_length = pos;
1317 
1318     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1319     return ERROR_CODE_SUCCESS;
1320 }
1321 
1322 uint8_t avrcp_controller_set_max_num_fragments(uint16_t avrcp_cid, uint8_t max_num_fragments){
1323     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1324     if (!connection){
1325         log_error("avrcp_controller_play_item: could not find a connection.");
1326         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1327     }
1328     connection->max_num_fragments = max_num_fragments;
1329     return ERROR_CODE_SUCCESS;
1330 }
1331