/dev/inputからキー入力を取得する(python evdev)

# はじめに

キー変換器を作るための準備としてUSBやbluetoothでRaspberry Pi Zero Wに接続されたキーボードからの入力を取得する

# 利用したもの

 - Raspberry Pi Zero W
 - Thinkpad Tracpoint Keyboard USB
 - USB micro-B OTGケーブル

# /dev/input

/proc/bus/input/devicesで接続されている入力デバイスがわかる
Thinkpad Tracpoint Keyboardをつなげた場合はhandlerに"sysrq kbd leds"があるものが相当する

```
pi@raspberrypi:~ $ cat /proc/bus/input/devices 
I: Bus=0003 Vendor=17ef Product=6047 Version=0100
N: Name="Lenovo ThinkPad Compact USB Keyboard with TrackPoint"
P: Phys=usb-20980000.usb-1/input0
S: Sysfs=/devices/platform/soc/20980000.usb/usb1/1-1/1-1:1.0/0003:17EF:6047.0005/input/input14
U: Uniq=
H: Handlers=sysrq kbd leds event0 
B: PROP=0
B: EV=120013
B: KEY=10000 7 ff800000 7ff febeffdf ffefffff ffffffff fffffffe
B: MSC=10
B: LED=1f
```

hexdumpで値を表示するだけは可能（なんだかわからないけど）

```
pi@raspberrypi:~ $ hexdump /dev/input/event0
0000000 a065 5eae 5f51 0009 0004 0004 0009 0007
0000010 a065 5eae 5f51 0009 0001 0021 0001 0000
```

## 値の意味

``` /usr/include/input.hより抜粋
/*
 * The event structure itself
 * Note that __USE_TIME_BITS64 is defined by libc based on
 * application's request to use 64 bit time_t.
 */

struct input_event {
#if (__BITS_PER_LONG != 32 || !defined(__USE_TIME_BITS64)) && !defined(__KERNEL)
	struct timeval time;
#define input_event_sec time.tv_sec
#define input_event_usec time.tv_usec
#else
	__kernel_ulong_t __sec;
	__kernel_ulong_t __usec;
#define input_event_sec  __sec
#define input_event_usec __usec
#endif
	__u16 type;
	__u16 code;
	__s32 value;
};
```
## Pythonを使って読み取ってみる

### 準備

```
$ pip install evdev
```

### キー入力をモニター

```
$ python
>>> from evdev import InputDevice, categorize, ecodes
>>> dev = InputDevice('/dev/input/event0')
>>> print(dev)
device /dev/input/event0, name "Lenovo ThinkPad Compact USB Keyboard with TrackPoint", phys "usb-20980000.usb-1/input0"
>>> dev.capabilities(verbose=True)
{('EV_LED', 17L): [('LED_NUML', 0L), ('LED_CAPSL', 1L), ('LED_SCROLLL', 2L), ('LED_COMPOSE', 3L), ('LED_KANA', 4L)], ('EV_MSC', 4L): [('MSC_SCAN', 4L)], ('EV_KEY', 1L): [('KEY_ESC', 1L), ('KEY_1', 2L), ('KEY_2', 3L), ('KEY_3', 4L), ('KEY_4', 5L), ('KEY_5', 6L), ('KEY_6', 7L), ('KEY_7', 8L), ('KEY_8', 9L), ('KEY_9', 10L), ('KEY_0', 11L), ('KEY_MINUS', 12L), ('KEY_EQUAL', 13L), ('KEY_BACKSPACE', 14L), ('KEY_TAB', 15L), ('KEY_Q', 16L), ('KEY_W', 17L), ('KEY_E', 18L), ('KEY_R', 19L), ('KEY_T', 20L), ('KEY_Y', 21L), ('KEY_U', 22L), ('KEY_I', 23L), ('KEY_O', 24L), ('KEY_P', 25L), ('KEY_LEFTBRACE', 26L), ('KEY_RIGHTBRACE', 27L), ('KEY_ENTER', 28L), ('KEY_LEFTCTRL', 29L), ('KEY_A', 30L), ('KEY_S', 31L), ('KEY_D', 32L), ('KEY_F', 33L), ('KEY_G', 34L), ('KEY_H', 35L), ('KEY_J', 36L), ('KEY_K', 37L), ('KEY_L', 38L), ('KEY_SEMICOLON', 39L), ('KEY_APOSTROPHE', 40L), ('KEY_GRAVE', 41L), ('KEY_LEFTSHIFT', 42L), ('KEY_BACKSLASH', 43L), ('KEY_Z', 44L), ('KEY_X', 45L), ('KEY_C', 46L), ('KEY_V', 47L), ('KEY_B', 48L), ('KEY_N', 49L), ('KEY_M', 50L), ('KEY_COMMA', 51L), ('KEY_DOT', 52L), ('KEY_SLASH', 53L), ('KEY_RIGHTSHIFT', 54L), ('KEY_KPASTERISK', 55L), ('KEY_LEFTALT', 56L), ('KEY_SPACE', 57L), ('KEY_CAPSLOCK', 58L), ('KEY_F1', 59L), ('KEY_F2', 60L), ('KEY_F3', 61L), ('KEY_F4', 62L), ('KEY_F5', 63L), ('KEY_F6', 64L), ('KEY_F7', 65L), ('KEY_F8', 66L), ('KEY_F9', 67L), ('KEY_F10', 68L), ('KEY_NUMLOCK', 69L), ('KEY_SCROLLLOCK', 70L), ('KEY_KP7', 71L), ('KEY_KP8', 72L), ('KEY_KP9', 73L), ('KEY_KPMINUS', 74L), ('KEY_KP4', 75L), ('KEY_KP5', 76L), ('KEY_KP6', 77L), ('KEY_KPPLUS', 78L), ('KEY_KP1', 79L), ('KEY_KP2', 80L), ('KEY_KP3', 81L), ('KEY_KP0', 82L), ('KEY_KPDOT', 83L), ('KEY_ZENKAKUHANKAKU', 85L), ('KEY_102ND', 86L), ('KEY_F11', 87L), ('KEY_F12', 88L), ('KEY_RO', 89L), ('KEY_KATAKANA', 90L), ('KEY_HIRAGANA', 91L), ('KEY_HENKAN', 92L), ('KEY_KATAKANAHIRAGANA', 93L), ('KEY_MUHENKAN', 94L), ('KEY_KPJPCOMMA', 95L), ('KEY_KPENTER', 96L), ('KEY_RIGHTCTRL', 97L), ('KEY_KPSLASH', 98L), ('KEY_SYSRQ', 99L), ('KEY_RIGHTALT', 100L), ('KEY_HOME', 102L), ('KEY_UP', 103L), ('KEY_PAGEUP', 104L), ('KEY_LEFT', 105L), ('KEY_RIGHT', 106L), ('KEY_END', 107L), ('KEY_DOWN', 108L), ('KEY_PAGEDOWN', 109L), ('KEY_INSERT', 110L), ('KEY_DELETE', 111L), (['KEY_MIN_INTERESTING', 'KEY_MUTE'], 113L), ('KEY_VOLUMEDOWN', 114L), ('KEY_VOLUMEUP', 115L), ('KEY_POWER', 116L), ('KEY_KPEQUAL', 117L), ('KEY_PAUSE', 119L), ('KEY_KPCOMMA', 121L), (['KEY_HANGEUL', 'KEY_HANGUEL'], 122L), ('KEY_HANJA', 123L), ('KEY_YEN', 124L), ('KEY_LEFTMETA', 125L), ('KEY_RIGHTMETA', 126L), ('KEY_COMPOSE', 127L), ('KEY_STOP', 128L), ('KEY_AGAIN', 129L), ('KEY_PROPS', 130L), ('KEY_UNDO', 131L), ('KEY_FRONT', 132L), ('KEY_COPY', 133L), ('KEY_OPEN', 134L), ('KEY_PASTE', 135L), ('KEY_FIND', 136L), ('KEY_CUT', 137L), ('KEY_HELP', 138L), ('KEY_F13', 183L), ('KEY_F14', 184L), ('KEY_F15', 185L), ('KEY_F16', 186L), ('KEY_F17', 187L), ('KEY_F18', 188L), ('KEY_F19', 189L), ('KEY_F20', 190L), ('KEY_F21', 191L), ('KEY_F22', 192L), ('KEY_F23', 193L), ('KEY_F24', 194L), ('KEY_UNKNOWN', 240L)], ('EV_SYN', 0L): [('SYN_REPORT', 0L), ('SYN_CONFIG', 1L), ('?', 4L), ('?', 17L), ('?', 20L)]}
>>> for event in dev.read_loop():
...     if event.type == ecodes.EV_KEY:
...             print(categorize(event))
... 
(キーを押してみる）
key event at 1588676502.615220, 30 (KEY_A), down
key event at 1588676502.743221, 30 (KEY_A), up
key event at 1588676507.023183, 57 (KEY_SPACE), down
key event at 1588676507.167180, 57 (KEY_SPACE), up
key event at 1588676511.455180, 94 (KEY_MUHENKAN), down
key event at 1588676511.551190, 94 (KEY_MUHENKAN), up
key event at 1588676519.855091, 28 (KEY_ENTER), down
key event at 1588676519.951096, 28 (KEY_ENTER), up

>>> for event in dev.read_loop():
...     if event.type == ecodes.EV_KEY:
...             print(event)
... 
event at 1588676839.036923, code 30, type 01, val 01
event at 1588676839.156917, code 30, type 01, val 00
event at 1588676850.044849, code 57, type 01, val 01
event at 1588676850.140902, code 57, type 01, val 00
event at 1588676872.860695, code 30, type 01, val 01
event at 1588676873.114706, code 30, type 01, val 02
event at 1588676873.164685, code 30, type 01, val 02
(val: 00 up, 01 down, 02 hold になっている)
```

### マウスボタンをモニター

```
>>> from evdev import InputDevice, categorize, ecodes
>>> dev = InputDevice('/dev/input/event1')
>>> print(dev)
device /dev/input/event1, name "Lenovo ThinkPad Compact USB Keyboard with TrackPoint Mouse", phys "usb-20980000.usb-1/input1"
>>> dev.capabilities(verbose=True)
{('EV_MSC', 4L): [('MSC_SCAN', 4L)], ('EV_KEY', 1L): [(['BTN_LEFT', 'BTN_MOUSE'], 272L), ('BTN_RIGHT', 273L), ('BTN_MIDDLE', 274L), ('BTN_SIDE', 275L), ('BTN_EXTRA', 276L)], ('EV_REL', 2L): [('REL_X', 0L), ('REL_Y', 1L), ('REL_HWHEEL', 6L), ('REL_WHEEL', 8L)], ('EV_SYN', 0L): [('SYN_REPORT', 0L), ('SYN_CONFIG', 1L), ('SYN_MT_REPORT', 2L), ('?', 4L)]}
>>> for event in dev.read_loop():
...     if event.type == ecodes.EV_KEY:
...             print(categorize(event))
... 
key event at 1588677297.069200, 272 (['BTN_LEFT', 'BTN_MOUSE']), down
key event at 1588677297.181200, 272 (['BTN_LEFT', 'BTN_MOUSE']), up
key event at 1588677304.573205, 273 (BTN_RIGHT), down
key event at 1588677304.717200, 273 (BTN_RIGHT), up
key event at 1588677307.053195, 274 (BTN_MIDDLE), down
key event at 1588677307.325200, 274 (BTN_MIDDLE), up
key event at 1588677313.549196, 274 (BTN_MIDDLE), down
key event at 1588677313.757202, 274 (BTN_MIDDLE), up
key event at 1588677317.453202, 274 (BTN_MIDDLE), down
key event at 1588677317.949163, 274 (BTN_MIDDLE), up
...     if event.type == ecodes.EV_KEY:
...             print(event)
... 
event at 1588677538.444881, code 272, type 01, val 01
event at 1588677538.540875, code 272, type 01, val 00
event at 1588677542.492876, code 273, type 01, val 01
event at 1588677542.684843, code 273, type 01, val 00
event at 1588677545.580863, code 274, type 01, val 01
event at 1588677545.676858, code 274, type 01, val 00
```

### Tracpointをモニター

``` mouse.py
from evdev import InputDevice, categorize, ecodes

dev = InputDevice('/dev/input/event1')
for event in dev.read_loop():
	if event.type == ecodes.EV_REL:
		if event.code == ecodes.REL_X:
			print('REL_X:{}'. format(event.value))
		elif event.code == ecodes.REL_Y:
			print('REL_Y:{}'.format(event.value))
		if event.code == ecodes.REL_WHEEL:
			print('REL_WHEEL:{}'.format(event.value))
```

```
$ python mouse.py 
REL_X:1
REL_X:1
REL_Y:-1
REL_Y:-1
REL_Y:-3
REL_X:-1
REL_Y:-4
REL_X:-1
REL_WHEEL:-1
REL_WHEEL:-1
```

c.f.
[Linux の入力デバイスをカスタマイズ](https://qiita.com/propella/items/a73fc333c95d14d06835)
[python tutorial](https://python-evdev.readthedocs.io/en/latest/tutorial.html)

 - Tranpointをモニターする

``` mouse2.py
from evdev import InputDevice, categorize, ecodes

dev = InputDevice('/dev/input/event1')
for event in dev.read_loop():
	if event.type == ecodes.EV_REL:
		if event.code == ecodes.REL_X:
			print('REL_X:{}'. format(event.value))
		elif event.code == ecodes.REL_Y:
			print('REL_Y:{}'.format(event.value))
		if event.code == ecodes.REL_WHEEL:
			print('REL_WHEEL:{}'.format(event.value))
	elif event.type == ecodes.EV_KEY:
		if event.code == ecodes.BTN_LEFT:
			print('BTN_LEFT:{}'.format(event.value))
		elif event.code == ecodes.BTN_RIGHT:
			print('BTN_RIGHT:{}'.format(event.value))
		if event.code == ecodes.BTN_MIDDLE:
			print('BTN_MIDDLE:{}'.format(event.value))
```

# udevを使ってキーボード接続時にプログラムを動作させる

## USB

デバイス情報の取得

```
pi@raspberrypi:~/hid_test $ udevadm info -a --path=$(udevadm info -q path -n /dev/input/event0)

Udevadm info starts with the device specified by the devpath and then
walks up the chain of parent devices. It prints for every device
found, all possible attributes in the udev rules key format.
A rule to match, can be composed by the attributes of the device
and the attributes from one single parent device.

  looking at device '//devices/platform/soc/20980000.usb/usb1/1-1/1-1:1.0/0003:17EF:6047.0001/input/input0/event0':
    KERNEL=="event0"
    SUBSYSTEM=="input"
    DRIVER==""

  looking at parent device '//devices/platform/soc/20980000.usb/usb1/1-1/1-1:1.0/0003:17EF:6047.0001/input/input0':
    KERNELS=="input0"
    SUBSYSTEMS=="input"
    DRIVERS==""
    ATTRS{properties}=="0"
    ATTRS{uniq}==""
    ATTRS{name}=="Lenovo ThinkPad Compact USB Keyboard with TrackPoint"
    ATTRS{phys}=="usb-20980000.usb-1/input0"

  looking at parent device '//devices/platform/soc/20980000.usb/usb1/1-1/1-1:1.0/0003:17EF:6047.0001':
    KERNELS=="0003:17EF:6047.0001"
    SUBSYSTEMS=="hid"
    DRIVERS=="hid-generic"
    ATTRS{country}=="00"

  looking at parent device '//devices/platform/soc/20980000.usb/usb1/1-1/1-1:1.0':
    KERNELS=="1-1:1.0"
    SUBSYSTEMS=="usb"
    DRIVERS=="usbhid"
    ATTRS{bNumEndpoints}=="01"
    ATTRS{bInterfaceProtocol}=="01"
    ATTRS{bAlternateSetting}==" 0"
    ATTRS{bInterfaceSubClass}=="01"
    ATTRS{bInterfaceClass}=="03"
    ATTRS{bInterfaceNumber}=="00"
    ATTRS{supports_autosuspend}=="1"
    ATTRS{authorized}=="1"

  looking at parent device '//devices/platform/soc/20980000.usb/usb1/1-1':
    KERNELS=="1-1"
    SUBSYSTEMS=="usb"
    DRIVERS=="usb"
    ATTRS{bNumConfigurations}=="1"
    ATTRS{manufacturer}=="Lenovo"
    ATTRS{avoid_reset_quirk}=="0"
    ATTRS{speed}=="12"
    ATTRS{tx_lanes}=="1"
    ATTRS{busnum}=="1"
    ATTRS{devpath}=="1"
    ATTRS{bmAttributes}=="a0"
    ATTRS{bConfigurationValue}=="1"
    ATTRS{version}==" 2.00"
    ATTRS{removable}=="unknown"
    ATTRS{quirks}=="0x0"
    ATTRS{bDeviceProtocol}=="00"
    ATTRS{bDeviceSubClass}=="00"
    ATTRS{devnum}=="2"
    ATTRS{product}=="ThinkPad Compact USB Keyboard with TrackPoint"
    ATTRS{maxchild}=="0"
    ATTRS{bcdDevice}=="0330"
    ATTRS{devspec}=="  (null)"
    ATTRS{ltm_capable}=="no"
    ATTRS{rx_lanes}=="1"
    ATTRS{urbnum}=="19"
    ATTRS{idVendor}=="17ef"
    ATTRS{bDeviceClass}=="00"
    ATTRS{bMaxPower}=="100mA"
    ATTRS{idProduct}=="6047"
    ATTRS{authorized}=="1"
    ATTRS{configuration}==""
    ATTRS{bNumInterfaces}==" 2"
    ATTRS{bMaxPacketSize0}=="8"

  looking at parent device '//devices/platform/soc/20980000.usb/usb1':
    KERNELS=="usb1"
    SUBSYSTEMS=="usb"
    DRIVERS=="usb"
    ATTRS{bMaxPower}=="0mA"
    ATTRS{bConfigurationValue}=="1"
    ATTRS{bMaxPacketSize0}=="64"
    ATTRS{idVendor}=="1d6b"
    ATTRS{maxchild}=="1"
    ATTRS{urbnum}=="27"
    ATTRS{bDeviceProtocol}=="01"
    ATTRS{bNumInterfaces}==" 1"
    ATTRS{bmAttributes}=="e0"
    ATTRS{removable}=="unknown"
    ATTRS{ltm_capable}=="no"
    ATTRS{bDeviceSubClass}=="00"
    ATTRS{bNumConfigurations}=="1"
    ATTRS{configuration}==""
    ATTRS{version}==" 2.00"
    ATTRS{devpath}=="0"
    ATTRS{bDeviceClass}=="09"
    ATTRS{authorized}=="1"
    ATTRS{manufacturer}=="Linux 4.19.97+ dwc2_hsotg"
    ATTRS{idProduct}=="0002"
    ATTRS{authorized_default}=="1"
    ATTRS{rx_lanes}=="1"
    ATTRS{devnum}=="1"
    ATTRS{tx_lanes}=="1"
    ATTRS{serial}=="20980000.usb"
    ATTRS{avoid_reset_quirk}=="0"
    ATTRS{busnum}=="1"
    ATTRS{product}=="DWC OTG Controller"
    ATTRS{bcdDevice}=="0419"
    ATTRS{speed}=="480"
    ATTRS{interface_authorized_default}=="1"
    ATTRS{quirks}=="0x0"

  looking at parent device '//devices/platform/soc/20980000.usb':
    KERNELS=="20980000.usb"
    SUBSYSTEMS=="platform"
    DRIVERS=="dwc2"
    ATTRS{driver_override}=="(null)"

  looking at parent device '//devices/platform/soc':
    KERNELS=="soc"
    SUBSYSTEMS=="platform"
    DRIVERS==""
    ATTRS{driver_override}=="(null)"

  looking at parent device '//devices/platform':
    KERNELS=="platform"
    SUBSYSTEMS==""
    DRIVERS==""
```

ATTRのidVendor = 17ef, idProduct = 6047 を使う

``` /etc/udev/rules.d/99-tracpoint-keyboard.rules 
ACTION=="add" ATTRS{idVendor}=="17ef", ATTRS{idProduct}=="6047", RUN+="/home/pi/hid_test/logger.sh"
```
``` logger.sh
logger "test message"
```

ルールのテスト

```
pi@raspberrypi:/etc/udev/rules.d $ udevadm test --action=add /devices/platform/soc/20980000.usb/usb1/1-1/1-1:1.0/0003:17EF:6047.0001/input/input0/event0
This program is for debugging only, it does not run any program
specified by a RUN key. It may show incorrect results, because
some values may be different, or not available at a simulation run.

Load module index
Skipping empty file: /etc/systemd/network/99-default.link
Created link configuration context.
Reading rules file: /lib/udev/rules.d/10-local-rpi.rules
（中略）
Reading rules file: /etc/udev/rules.d/99-tracpoint-keyboard.rules
Rules contain 393216 bytes tokens (32768 * 12 bytes), 26214 bytes strings
20241 strings (160784 bytes), 17669 de-duplicated (137143 bytes), 2573 trie nodes used
Invalid inotify descriptor.
Starting 'libinput-device-group /sys/devices/platform/soc/20980000.usb/usb1/1-1/1-1:1.0/0003:17EF:6047.0001/input/input0/event0'
'libinput-device-group /sys/devices/platform/soc/20980000.usb/usb1/1-1/1-1:1.0/0003:17EF:6047.0001/input/input0/event0'(out) '3/17ef/6047:usb-20980000.usb-1'
Process 'libinput-device-group /sys/devices/platform/soc/20980000.usb/usb1/1-1/1-1:1.0/0003:17EF:6047.0001/input/input0/event0' succeeded.
DEVPATH=/devices/platform/soc/20980000.usb/usb1/1-1/1-1:1.0/0003:17EF:6047.0001/input/input0/event0
DEVNAME=/dev/input/event0
MAJOR=13
MINOR=64
ACTION=add
SUBSYSTEM=input
ID_INPUT=1
ID_INPUT_KEY=1
ID_INPUT_KEYBOARD=1
ID_VENDOR=Lenovo
ID_VENDOR_ENC=Lenovo
ID_VENDOR_ID=17ef
ID_MODEL=ThinkPad_Compact_USB_Keyboard_with_TrackPoint
ID_MODEL_ENC=ThinkPad\x20Compact\x20USB\x20Keyboard\x20with\x20TrackPoint
ID_MODEL_ID=6047
ID_REVISION=0330
ID_SERIAL=Lenovo_ThinkPad_Compact_USB_Keyboard_with_TrackPoint
ID_TYPE=hid
ID_BUS=usb
ID_USB_INTERFACES=:030101:030102:
ID_USB_INTERFACE_NUM=00
ID_USB_DRIVER=usbhid
.INPUT_CLASS=kbd
DEVLINKS=/dev/input/by-id/usb-Lenovo_ThinkPad_Compact_USB_Keyboard_with_TrackPoint-event-kbd /dev/input/by-path/platform-20980000.usb-usb-0:1:1.0-event-kbd
ID_PATH=platform-20980000.usb-usb-0:1:1.0
ID_PATH_TAG=platform-20980000_usb-usb-0_1_1_0
XKBMODEL=pc105
XKBLAYOUT=jp
BACKSPACE=guess
TAGS=:power-switch:
LIBINPUT_DEVICE_GROUP=3/17ef/6047:usb-20980000.usb-1
USEC_INITIALIZED=693923915
run: '/usr/sbin/th-cmd --socket /var/run/thd.socket --passfd --udev'
run: '/home/pi/hid_test/logger.sh'
Unload module index
Unloaded link configuration context.
```

スクリプトの動作確認

```
pi@raspberrypi:/etc/udev/rules.d $ tail -n5  /var/log/messages
May  6 21:43:09 raspberrypi mtp-probe: checking bus 1, device 2: "/sys/devices/platform/soc/20980000.usb/usb1/1-1"
May  6 21:43:09 raspberrypi mtp-probe: bus: 1, device: 2 was not an MTP device
May  6 21:43:10 raspberrypi mtp-probe: checking bus 1, device 2: "/sys/devices/platform/soc/20980000.usb/usb1/1-1"
May  6 21:43:10 raspberrypi mtp-probe: bus: 1, device: 2 was not an MTP device
May  6 21:55:32 raspberrypi pi: test message
```

 - 参考
[http://yukirinmk2.hatenablog.com/entry/2013/10/23/210559](http://yukirinmk2.hatenablog.com/entry/2013/10/23/210559)

## Bluetooth

### キーボードの接続

参考：[https://qiita.com/da1fujimoto/items/c0d652049e8455894fd9](https://qiita.com/da1fujimoto/items/c0d652049e8455894fd9)

```
pi@raspberrypi:~ $ sudo hciconfig hci0 down
pi@raspberrypi:~ $ sudo hciconfig hci0 up
pi@raspberrypi:~ $ bluetoothctl 
Agent registered
[bluetooth]# scan on
Discovery started
...
[NEW] Device 90:7F:61:55:CA:1A 90-7F-61-55-CA-1A # 電源を入れた
[CHG] Device 90:7F:61:55:CA:1A LegacyPairing: no
[CHG] Device 90:7F:61:55:CA:1A Name: ThinkPad Compact Bluetooth Keyboard with TrackPoint
[CHG] Device 90:7F:61:55:CA:1A Alias: ThinkPad Compact Bluetooth Keyboard with TrackPoint
...
[bluetooth]# scan off
 ...
[CHG] Device 90:7F:61:xx:xx:xx RSSI is nil
...
Discovery stopped
[bluetooth]# pair 90:7f:61:xx:xx:xx:
Attempting to pair with 90:7F:61:xx:xx:xx
[CHG] Device 90:7F:61:55:CA:1A Connected: yes
[agent] Passkey: 762917 # キーボードでこの数字を入力してEnter
[CHG] Device 90:7F:61:xx:xx:xx Modalias: usb:v17EFp6048d0312
[CHG] Device 90:7F:61:xx:xx:xx UUIDs: 00001000-0000-1000-8000-00805f9b34fb
[CHG] Device 90:7F:61:xx:xx:xx UUIDs: 00001124-0000-1000-8000-00805f9b34fb
[CHG] Device 90:7F:61:xx:xx:xx UUIDs: 00001200-0000-1000-8000-00805f9b34fb
[CHG] Device 90:7F:61:xx:xx:xx ServicesResolved: yes
[CHG] Device 90:7F:61:xx:xx:xx Paired: yes
Pairing successful
[CHG] Device 90:7F:61:xx:xx:xx ServicesResolved: no
[CHG] Device 90:7F:61:xx:xx:xx Connected: no
[bluetooth]# connect 90:7f:61:xx:xx:xx
Attempting to connect to 90:7f:61:xx:xx:xx
[CHG] Device 90:7F:61:xx:xx:xx Connected: yes
Connection successful
[CHG] Device 90:7F:61:xx:xx:xx ServicesResolved: yes
[ThinkPad Compact Bluetooth Keyboard with TrackPoint]# trust 90:7f:61:55:ca:1a
[CHG] Device 90:7F:61:55:CA:1A Trusted: yes
Changing 90:7F:61:55:CA:1A trust succeeded
[ThinkPad Compact Bluetooth Keyboard with TrackPoint]# quit
```
これでペアリングできる

デバイス情報の確認

```
pi@raspberrypi:~ $ udevadm info -a --path=$(udevadm info -q path -n /dev/input/event0)

Udevadm info starts with the device specified by the devpath and then
walks up the chain of parent devices. It prints for every device
found, all possible attributes in the udev rules key format.
A rule to match, can be composed by the attributes of the device
and the attributes from one single parent device.

  looking at device '//devices/platform/soc/20201000.serial/tty/ttyAMA0/hci0/hci0:12/0005:17EF:6048.0001/input/input0/event0':
    KERNEL=="event0"
    SUBSYSTEM=="input"
    DRIVER==""

  looking at parent device '//devices/platform/soc/20201000.serial/tty/ttyAMA0/hci0/hci0:12/0005:17EF:6048.0001/input/input0':
    KERNELS=="input0"
    SUBSYSTEMS=="input"
    DRIVERS==""
    ATTRS{uniq}=="90:7f:61:55:ca:1a"
    ATTRS{name}=="ThinkPad Compact Bluetooth Keyboard with TrackPoint Keyboard"
    ATTRS{phys}=="b8:27:eb:ba:4f:00"
    ATTRS{properties}=="0"

  looking at parent device '//devices/platform/soc/20201000.serial/tty/ttyAMA0/hci0/hci0:12/0005:17EF:6048.0001':
    KERNELS=="0005:17EF:6048.0001"
    SUBSYSTEMS=="hid"
    DRIVERS=="hid-generic"
    ATTRS{country}=="21"

  looking at parent device '//devices/platform/soc/20201000.serial/tty/ttyAMA0/hci0/hci0:12':
    KERNELS=="hci0:12"
    SUBSYSTEMS=="bluetooth"
    DRIVERS==""

  looking at parent device '//devices/platform/soc/20201000.serial/tty/ttyAMA0/hci0':
    KERNELS=="hci0"
    SUBSYSTEMS=="bluetooth"
    DRIVERS==""

  looking at parent device '//devices/platform/soc/20201000.serial/tty/ttyAMA0':
    KERNELS=="ttyAMA0"
    SUBSYSTEMS=="tty"
    DRIVERS==""

  looking at parent device '//devices/platform/soc/20201000.serial':
    KERNELS=="20201000.serial"
    SUBSYSTEMS=="amba"
    DRIVERS=="uart-pl011"
    ATTRS{id}=="00241011"
    ATTRS{irq0}=="81"
    ATTRS{driver_override}=="(null)"

  looking at parent device '//devices/platform/soc':
    KERNELS=="soc"
    SUBSYSTEMS=="platform"
    DRIVERS==""
    ATTRS{driver_override}=="(null)"

  looking at parent device '//devices/platform':
    KERNELS=="platform"
    SUBSYSTEMS==""
    DRIVERS==""
```

udevのruleを更新

```/etc/udev/rules.d/99-tracpoint-keyboard.rules 
ACTION=="add" ATTRS{idVendor}=="17ef", ATTRS{idProduct}=="6047", RUN+="/home/pi/hid_test/logger.sh", SYMLINK+="input/ThinkPaaTracPointKeyboard"
ACTION=="add" ATTRS{name}=="ThinkPad Compact Bluetooth Keyboard with TrackPoint Keyboard", RUN+="/home/pi/hid_test/keyboardFoundMessage.sh", SYMLINK+="input/ThinkPadTracPointKeyboard"
ACTION=="add" ATTRS{name}=="ThinkPad Compact Bluetooth Keyboard with TrackPoint Mouse", RUN+="/home/pi/hid_test/mouseFoundMessage.sh", SYMLINK+="input/ThinkPadTracPointKeyboardMouse"
```

これでinputのデバイスは区別できる


## 入力デバイスのハンドラーの取得

デバイスが決まっているならば、eventの何番かは、by-idを使ったほうがいいかと思ったが、
udevのruleでSYMLINKで指定すればいい。

```
pi@raspberrypi:/etc/udev/rules.d $ ls -la /dev/input/by-id
合計 0
drwxr-xr-x 2 root root 120  5月  6 21:43 .
drwxr-xr-x 4 root root 240  5月  6 21:43 ..
lrwxrwxrwx 1 root root   9  5月  6 21:43 usb-Lenovo_ThinkPad_Compact_USB_Keyboard_with_TrackPoint-event-if01 -> ../event3
lrwxrwxrwx 1 root root   9  5月  6 22:11 usb-Lenovo_ThinkPad_Compact_USB_Keyboard_with_TrackPoint-event-kbd -> ../event0
lrwxrwxrwx 1 root root   9  5月  6 21:43 usb-Lenovo_ThinkPad_Compact_USB_Keyboard_with_TrackPoint-if01-event-mouse -> ../event1
lrwxrwxrwx 1 root root   9  5月  6 21:43 usb-Lenovo_ThinkPad_Compact_USB_Keyboard_with_TrackPoint-if01-mouse -> ../mouse0
```