Android-蓝牙AVRCP功能的实现.docx

Android 蓝牙AVRCP功能的实现
作者:Macro Liu

AVRCP的按键定义:

key 200 MEDIA_PLAY_PAUSE WAKE
key 201 MEDIA_PLAY_PAUSE WAKE
key 166 MEDIA_STOP WAKE
key 163 MEDIA_NEXT WAKE
key 165 MEDIA_PREVIOUS WAKE
key 168 MEDIA_REWIND WAKE
key 208 MEDIA_FAST_FORWARD WAKE

BCM(broadcom)宏定义需要翻开:
BOARD_HAVE_BLUETOOTH_BCM := true

BT音频控制的代码

(1) 按键的MAP
static struct {
const char *name;
uint8_t avrcp;
uint16_t uinput;
} key_map[] = {
{ "PLAY", PLAY_OP, KEY_PLAYCD },
{ "STOP", STOP_OP, KEY_STOPCD },
{ "PAUSE", PAUSE_OP, KEY_PAUSECD },
{ "FORWARD", FORWARD_OP, KEY_NEXTSONG },
{ "BACKWARD", BACKWARD_OP, KEY_PREVIOUSSONG },
{ "REWIND", REWIND_OP, KEY_REWIND },
{ "FAST FORWARD", FAST_FORWARD_OP, KEY_FASTFORWARD },
{ NULL }
};
(2) 按键处理
static void handle_panel_passthrough(struct control *control,
{
…
for (i = 0; key_map[i].name != NULL; i++) {
uint8_t key_quirks;

if ((operands[0] & 0x7F) != key_map[i].avrcp)
continue;

DBG("AVRCP: %s %s", key_map[i].name, status);

key_quirks = control->key_quirks[key_map[i].avrcp];

if (key_quirks & QUIRK_NO_RELEASE) {
if (!pressed) {
DBG("AVRCP: Ignoring release");
break;
}

DBG("AVRCP: treating key press as press + release");
send_key(control->uinput, key_map[i].uinput, 1);
send_key(control->uinput, key_map[i].uinput, 0);
break;
}

send_key(control->uinput, key_map[i].uinput, pressed);
break;
}
…
}
HCIDUMP数据分析
以Sony耳机DRC-BT15为例
#adb shell
#hcidump –X

左键:
> ACL data: handle 12 flags 0x02 dlen 12
    L2CAP(d): cid 0x0042 len 8 [psm 0]
      0000: 30 11 0e 00 48 7c 4c 00                           0...H|L.
< HCI Command: Exit Sniff Mode (0x02|0x0004) plen 2
  0000: 0c 00                                             ..
< ACL data: handle 12 flags 0x00 dlen 12
    0000: 08 00 4b 00 32 11 0e 09  48 7c 4c 00              ..K.2...H|L.
> HCI Event: Max Slots Change (0x1b) plen 3
  0000: 0c 00 05                                          ...
> HCI Event: Mode Change (0x14) plen 6
  0000: 00 0c 00 00 00 00                                 ......
> HCI Event: Command Status (0x0f) plen 4
  0000: 0c 01 04 08                                       ....
> ACL data: handle 12 flags 0x02 dlen 12
    L2CAP(d): cid 0x0042 len 8 [psm 0]
      0000: 40 11 0e 00 48 7c cc 00                           @...H|?
< ACL data: handle 12 flags 0x00 dlen 12
    0000: 08 00 4b 00 42 11 0e 09  48 7c cc 00              ..K.B...H|?
> HCI Event: Number of Completed Packets (0x13) plen 5
  0000: 01 0c 00 02 00                                    .....

播放/暂停:
> ACL data: handle 12 flags 0x02 dlen 12
    L2CAP(d): cid 0x0042 len 8 [psm 0]
      0000: 50 11 0e 00 48 7c 4b 00                           P...H|K.
< ACL data: handle 12 flags 0x00 dlen 12
    0000: 08 00 4b 00 52 11 0e 09  48 7c 4b 00              ..K.R...H|K.
> ACL data: handle 12 flags 0x02 dlen 12
    L2CAPd): cid 0x0042 len 8 [psm 0]
      0000: 60 11 0e 00 48 7c cb 00                           `...H|?
< ACL data: handle 12 flags 0x00 dlen 12
    0000: 08 00 4b 00 62 11 0e 09  48 7c cb 00              ..K.b...H|?
> HCI Event: Number of Completed Packets (0x13) plen 5
  0000: 01 0c 00 02 00                                    .....

右键:
> ACL data: handle 12 flags 0x02 dlen 12
    L2CAP(d): cid 0x0042 len 8 [psm 0]
      0000: 70 11 0e 00 48 7c 46 00                           p...H|F.
< ACL data: handle 12 flags 0x00 dlen 12
    0000: 08 00 4b 00 72 11 0e 09  48 7c 46 00              ..K.r...H|F.
> ACL data: handle 12 flags 0x02 dlen 12
    L2CAP(d): cid 0x0042 len 8 [psm 0]
      0000: 80 11 0e 00 48 7c c6 00                           ....H|?
< ACL data: handle 12 flags 0x00 dlen 12
    0000: 08 00 4b 00 82 11 0e 09  48 7c c6 00              ..K.....H|?
> HCI Event: Number of Completed Packets (0x13) plen 5
  0000: 01 0c 00 02 00                                    .....
> HCI Event: Max Slots Change (0x1b) plen 3
  0000: 0c 00 01                                          ...
> HCI Event: Mode Change (0x14) plen 6
  0000: 00 0c 00 02 c8 00                                 ....?

然后将control.c的日志打印出来:
按一次〞“播放/暂停键〞:

D/ACRVP ( 237): --- handle_panel_passthrough ----
D/ACRVP ( 237): operands[0] = 46 对应PAUSE_OP
D/ACRVP ( 237): key_quirks = 0, pressed = 1按键按下
D/ACRVP ( 237): control->uinput = fffffffe,send_key = 201对应MEDIA_PLAY_PAUSE
D/ACRVP ( 237): --- handle_panel_passthrough ----
D/ACRVP ( 237): operands[0] = c6 (= 0x46 ｜ 0x80 表示按键释放了)
D/ACRVP ( 237): key_quirks = 0, pressed = 0按键释放
D/ACRVP ( 237): control->uinput = fffffffe,send_key = 201 对应MEDIA_PLAY_PAUSE

再按一次〞“播放/暂停键〞:

D/ACRVP ( 237): --- handle_panel_passthrough ----
D/ACRVP ( 237): operands[0] = 44 对应PLAY_OP
D/ACRVP ( 237): key_quirks = 0, pressed = 1 按键按下
D/ACRVP ( 237): control->uinput = fffffffe,send_key = 200 对应MEDIA_PLAY_PAUSE
D/ACRVP ( 237): --- handle_panel_passthrough ----
D/ACRVP ( 237): operands[0] = c4
D/ACRVP ( 237): key_quirks = 0, pressed = 0 按键释放
D/ACRVP ( 237): control->uinput = fffffffe,send_key = 200 对应MEDIA_PLAY_PAUSE

next key:
D/ACRVP ( 237): --- handle_panel_passthrough ----
D/ACRVP ( 237): operands[0] = 4b对应FORWARD_OP
D/ACRVP ( 237): key_quirks = 0, pressed = 1
D/ACRVP ( 237): control->uinput = fffffffe,send_key = 163 对应MEDIA_NEXT
D/ACRVP ( 237): --- handle_panel_passthrough ----
D/ACRVP ( 237): operands[0] = cb
D/ACRVP ( 237): key_quirks = 0, pressed = 0
D/ACRVP ( 237): control->uinput = fffffffe,send_key = 163

prev key:
D/ACRVP ( 237): - handle_panel_passthrough ----
D/ACRVP ( 237): operands[0] = 4c 对应BACKWARD_OP
D/ACRVP ( 237): key_quirks = 0, pressed = 1
D/ACRVP ( 237): control->uinput = fffffffe,send_key = 165 对应
D/ACRVP ( 237): --- handle_panel_passthrough ----
D/ACRVP ( 237): operands[0] = cc
D/ACRVP ( 237): key_quirks = 0, pressed = 0
D/ACRVP ( 237): control->uinput = fffffffe,send_key = 165 MEDIA_PREVIOUS
从上面可以看到bluetooth的协议栈blueZ是没有问题的

将 的LOG翻开，只能看到了control.c的日志，EventHub的getEvent完全不响应
观察所有log日志发现，openDevice里也没有装载

初步判断event有问题

event分析：
$ adb shell
# cd /proc/bus/input
# cat devices
cat devices
# cat devices
cat devices
I: Bus=0019 Vendor=0001 Product=0001 Version=0001 参考s3c
N: Name="s3c-keypad" input_dev->name = DEVICE_NAME;
P: Phys=s3c-keypad/input0 input_dev->phys = "s3c-keypad/input0";
S: Sysfs=/devices/virtual/input/input0 virtual的?
U: Uniq=

H: Handlers=event0
B: EV=3
B: KEY=4000400 0

I: Bus=0019 Vendor=0001 Product=0001 Version=0100参考
N: Name="s3c-eintkey" input->name = pdev->name, gpio_keys_device_driver.name = "s3c-eintkey",
P: Phys=gpio-keys/input0 input->phys = "gpio-keys/input0"
S: Sysfs=/devices/platform/s3c-eintkey/input/input1 为什么这里是platform目录?
U: Uniq=
H: Handlers=event1
B: EV=3
B: KEY=100000 0 0 0

I: Bus=0018 Vendor=0000 Product=0000 Version=0000 参考
N: Name="amri_ts" amri_ts_driver.name = "amri_ts"
P: Phys= 没有定义
S: Sysfs=/devices/platform/s3c2440-i2c.0/i2c-0/0-0033/input/input2 为什么这里是platform目录?
U: Uniq=
H: Handlers=event2
B: EV=b
B: KEY=400 0 0 0 0 0 40000800 40 0 0 10000
B: ABS=2650000 0

I: Bus=0000 Vendor=0000 Product=0000 Version=0000
N: Name="ecompass_data"
P: Phys=
S: Sysfs=/devices/virtual/input/input3
U: Uniq=
H: Handlers=event3
B: EV9
B: ABS=307bf

从上面可以看到，完全没有AVRCP的event。

解决方法:

Kernel
$ make menuconfig

CONFIG_INPUT_UINPUT

解决后的状况:

$ adb shell
# cd /proc/bus/input
# cat devices
显示增加了一个event

I: Bus=0005 Vendor=0000 Product=0000 Version=0000
N: Name="AVRCP"
P: Phys=
S: Sysfs=/devices/virtual/input/input4
U: Uniq=
H: Handlers=event4
B: EV=100007
B: KEY=10300 168 0 0 0 0 0
B: REL=0

看openDevice的信息:
D/EventHub( 84): EventHub::readNotify nfd: 87
D/EventHub( 84): Opening device: /dev/input/event4
D/EventHub( 84): Getting keys...
D/EventHub( 84): Getting absolute controllers...
D/EventHub( 84): keylayoutFilename = /system/usr/keylayout/AVRCP.kl
I/EventHub( 84): New keyboard: device->id=0x10003 devname='AVRCP' propName='hw.keyboards.65539.devname' keylayout='/system/usr/keylayout/AVRCP.kl'
I/EventHub( 84): New device: path=/dev/input/event4 name=AVRCP id=0x10003 of 0x4) index=4 fd=196 classes=0x1
D/EventHub( 84): Adding device /dev/input/event4 0x361800 at 4, id = 3, classes = 0x1
D/EventHub( 84): Reporting device opened: id=0x10003, name=/dev/input/event4

按键时也可以看到EventHub的信息了:
Log如下:

D/ACRVP ( 236): --- handle_panel_passthrough ----
D/ACRVP ( 236): operands[0] = 46
D/ACRVP ( 236): key_quirks = 0, pressed = 1
D/ACRVP ( 236): control->uinput = 14,send_key = 201 ，按键按下了
D/EventHub( 84): /dev/input/event4 got: t0=937, t1=582930, type=1, code=201, v=1 表示从event4得到201号键 MEDIA_PLAY_PAUSE
D/EventHub( 84): iev.code=201 keyCode=85 flags=0x00000001 err=0
D/EventHub( 84): /dev/input/event4 got: t0=937, t1=600241, type=0, code=0, v=0
D/AudioHardware( 61): AudioStreamOutALSA::setParameters() routing=0
D/ACRVP ( 236): --- handle_panel_passthrough ----
D/ACRVP ( 236): operands[0] = c6
D/ACRVP ( 236): keyquirks = 0, pressed = 0
D/ACRVP ( 236): control->uinput = 14,send_key = c9
D/EventHub( 84): /dev/input/event4 got: t0=937, t1=664391, type=1, code=201, v=0 control.c发出201号键，按键释放了
D/EventHub( 84): iev.code=201 keyCode=85 flags=0x00000001 err=0
D/EventHub( 84): /dev/input/event4 got: t0=937, t1=664406, type=0, code=0, v=0
D/A2DP ( 61): a2dp_stop
D/A2DP ( 61): bluetooth_stop
E/BluetoothEventLoop.cpp( 84): event_filter: Received signal org.bluez.AudioSink:Stopped from /org/bluez/236/hci0/dev_00_1D_BA_A5_D8_1C
E/BluetoothEventLoop.cpp( 84): event_filter: Received signal org.bluez.AudioSink:PropertyChanged from /org/bluez/236/hci0/dev_00_1D_BA_A5_D8_1C
E/BluetoothEventLoop.cpp( 84): event_filter: Received signal org.bluez.AudioSink:PropertyChanged from /org/bluez/236/hci0/dev_00_1D_BA_A5_D8_1C

D/CachedBluetoothDevice( 244): onProfileStateChanged: profile A2DP newProfileState 2
D/BluetoothA2dpService( 84): A2DP state : device: 00:1D:BA:A5:D8:1C State:4->2
D/A2DP ( 61): Received BT_RESPONSE - BT_STOP_STREAM
D/dalvikvm( 285): GC_EXPLICIT freed 87K, 56% free 2640K/5895K, external 1625K/2137K, paused 75ms

Macro Liu
2011-08-01