Android Input子系统-含实例源码

1 Input子系统作用

Android很多外设都是用到输入输出设备，比如touchscreen，键盘，音量键等，输入

设备对应Android 框架是Android input子系统，像我们定制类比较多的，很多
需要用到输入子系统，比如一键打开相机，一键唤醒，实体按键等。

2 Android input子系统框架

Android Input框架讲解最好的一篇文章
https://blog.csdn.net/mmmccc000/article/details/49756059
Android input框架主要分为三个部分，一个是kernel，一个是kl文件，kl也可
以划分为框架层，Framework层主要做监听、过滤、分发的工作，Android App部
分主要是接收Input子系统发上来的键值做对应的操作。

3 kernel input框架

Kernel主要是涉及Input设备节点的生成，proc文件系统的生成

有一个文章写Kernel框架非常好的，我就不再讲了，给几个链接
https://blog.csdn.net/u013604527/article/details/53432623/
https://blog.csdn.net/jscese/article/details/42123673
https://blog.csdn.net/xubin341719/article/details/7881735

4 如何在kernel添加一个新的键值

4.1 先在头文件里面添加

找个共用的头文件添加要的key值，正常是在include下面的，我的代码是在这个位
置

diff --git a/include/uapi/linux/input-event-codes.h b/include/uapi/linux/input-event-codes.h
index 87cf351..45a33ab 100644
--- a/include/uapi/linux/input-event-codes.h
+++ b/include/uapi/linux/input-event-codes.h
@@ -335,7 +335,7 @@#define KEY_RFKILL             247     /* Key that controls all radios */#define KEY_MICMUTE            248     /* Mute / unmute the microphone */
-
+#define KEY_WEIQIFA_TEST 249 /* Code 255 is reserved for special needs of AT keyboard driver */

4.2 在kernel对应的位置注册和发送键值

注册的位置

    /*包含头文件*/#include <linux/input.h>/*声明input设备*/struct input_dev *button_dev;/*注册input 子设备*/ printk(KERN_ERR " xxxx_wake_init\n"); if (!(button_dev= input_allocate_device())) { printk(KERN_ERR "input_dev: not enough memory\n"); return -ENOMEM; } button_dev->name = "xxxx"; button_dev->phys = "xxxx/event0"; button_dev->id.bustype = BUS_HOST; button_dev->id.vendor = 0x0001; button_dev->id.product = 0x0002; button_dev->id.version = 0x0100; button_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS) | BIT(EV_SYN); set_bit(KEY_WEIQIFA_TEST,button_dev->keybit); err = input_register_device(button_dev); if (err) { printk(KERN_ERR " fail to input_register_device\n"); input_free_device(button_dev); return err; } printk(KERN_ERR "xxxx_wake_init success!!!\n"); return 0;

发送键值的位置

 input_report_key(button_dev, KEY_WEIQIFA_TEST, 1);input_sync(button_dev);input_report_key(button_dev, KEY_WEIQIFA_TEST, 0); input_sync(button_dev);

4.3 写一个对应这个kl文件

kl文件简单介绍

Kl文件主要是起到了承上启下的作用，kernel发过来的键值主要通过kl文件来映
射，我们来看看kl文件里面的内容把。左边的是对应kernel上报上来的键值，后
面是对应Android Framework上的键值。

 22 key 399   GRAVE23 key 2     1 ... 49 key 103 DPAD_UP 50 key 102 HOME 51 key 105 DPAD_LEFT 52 key 106 DPAD_RIGHT 53 key 115 VOLUME_UP

kl文件哪里来的呢

我们看项目配置下面，有很多kl文件，那么是每个input子系统对应一个kl文件，
还是所有的项目共用一个kl文件？
kl源码位置在

./frameworks/base/data/keyboards/AVRCP.kl
./frameworks/base/data/keyboards/G
./frameworks/base/data/keyboards/Vendor_0079_Product_0011.kl
./frameworks/base/data/keyboards/Vendor_045e_Product_028e.kl
...

在运行的设备里，它的位置如下

rk3399_mid:/ # busybox find / -iname *.kl
/system/usr/keylayout/Generic.kl
/system/usr/keylayout/Vendor_0079_Product_0011.kl
/system/usr/keylayout/qwerty.kl
/system/usr/keylayout/rk29-keypad.kl
/system/usr/keylayout/rtkbt_virtual_hid.kl
...
rk3399_mid:/ #

kl是跟input设备如何对应起来的呢

我们可以用这个命令来看看 cat /proc/bus/input/devices
kl文件里面的vendor和product分别对应下面的vendor和product

rk3399_mid:/ # cat /proc/bus/input/devices
I: Bus=0019 Vendor=0001 Product=0002 Version=0100 N: Name="xxxx" P: Phys=iflytek/event0 S: Sysfs=/devices/virtual/input/input0 U: Uniq= H: Handlers=event0 cpufreq B: PROP=0 B: EV=b B: KEY=100000 0 0 0 B: ABS=0

添加我们对应的kl文件
文件命名跟你申请的vendor和product对应上面的input设备对应的kl文件应该是：Vendor_0001_Product_0002.kl
里面的内容如下，当然如果你没有配置kl文件，默认会去Generic.kl找键值映
射，如果里面也没有，就会去其他kl文件继续找。

# OnLive, Inc. OnLive Wireless Controller
key 249 BUTTON_A

4.4 mtk平台的一个input 子系统驱动例子

上面写的是在rockchip平台做的例子，下面给出一个mtk平台的例子
[mkt平台的input子系统例子]
(https://blog.csdn.net/weiqifa0/article/details/50387504)

5 Framework input系统介绍

Framework 主要做的事情是监听底层的input，然后分发给上层
下面的这个说的框架非常好，可以看看，我介绍完主要说明如何添加一个新的key
到系统里面
https://blog.csdn.net/wangkaiblog/article/details/12085183
https://blog.csdn.net/mmmccc000/article/details/49756059

6 添加一个新的键值

主要涉及到几个文件位置
下面列出需要修改的文件还有修改的差异点
base/api/current.txt
base/api/system-current.txt
base/core/java/android/view/KeyEvent.java
base/core/res/res/values/attrs.xml
/Generic.kl这里也可以根据驱动添加/
base/data/keyboards/Generic.kl
base/policy/src/com/android/internal/policy/impl/PhoneFallbackEventHandler.java
native/include/android/keycodes.h
native/include/input/InputEventLabels.h

diff --git a/api/current.txt b/api/current.txt
index 63fa997..a7a4a2b 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -41599,6 +41599,7 @@ package android.view { field public static final int KEYCODE_ASSIST = 219; // 0xdb field public static final int KEYCODE_AT = 77; // 0x4d field public static final int KEYCODE_AUDIO = 314; // 0x13a + field public static final int KEYCODE_WEIQIFA = 315; // 0x13B field public static final int KEYCODE_AVR_INPUT = 182; // 0xb6 field public static final int KEYCODE_AVR_POWER = 181; // 0xb5 field public static final int KEYCODE_B = 30; // 0x1e diff --git a/api/system-current.txt b/api/system-current.txt index 19135aa..956ea3e 100644 --- a/api/system-current.txt +++ b/api/system-current.txt @@ -44781,6 +44781,7 @@ package android.view { field public static final int KEYCODE_ASSIST = 219; // 0xdb field public static final int KEYCODE_AT = 77; // 0x4d field public static final int KEYCODE_AUDIO = 314; // 0x13a + field public static final int KEYCODE_WEIQIFA = 315; // 0x13b field public static final int KEYCODE_AVR_INPUT = 182; // 0xb6 field public static final int KEYCODE_AVR_POWER = 181; // 0xb5 field public static final int KEYCODE_B = 30; // 0x1e diff --git a/core/java/android/view/KeyEvent.java b/core/java/android/view/KeyEvent.java index 056f2c9..f2d5235 100755 --- a/core/java/android/view/KeyEvent.java +++ b/core/java/android/view/KeyEvent.java @@ -832,6 +832,7 @@ public class KeyEvent extends InputEvent implements Parcelable { public static final int KEYCODE_TV_MEDIA_PAUSE = 304; public static final int KEYCODE_WLAN = 313; public static final int KEYCODE_AUDIO = 314; + public static final int KEYCODE_WEIQIFA = 315; //$_rbox_$_modify_$ end private static final int LAST_KEYCODE = KEYCODE_TV_MEDIA_PAUSE; diff --git a/core/java/com/android/internal/policy/PhoneFallbackEventHandler.java b/core/java/com/android/internal/policy/PhoneFallbackEventHandler.java index e6635a1..366790c 100755 --- a/core/java/com/android/internal/policy/PhoneFallbackEventHandler.java +++ b/core/java/com/android/internal/policy/PhoneFallbackEventHandler.java @@ -141,7 +141,12 @@ public class PhoneFallbackEventHandler implements FallbackEventHandler { } case KeyEvent.KEYCODE_AUDIO: { Log.i(TAG, "---KEYCODE_AUDIO DOWN---"); + } + case KeyEvent.KEYCODE_WEIQIFA: { + Log.i(TAG,"KEYCODE_WEIQIFA"); + } + case KeyEvent.KEYCODE_CAMERA: { if (getKeyguardManager().inKeyguardRestrictedInputMode() || dispatcher == null) { diff --git a/core/res/res/values/attrs.xml b/core/res/res/values/attrs.xml index 93743df..094e6c2 100755 --- a/core/res/res/values/attrs.xml +++ b/core/res/res/values/attrs.xml @@ -1861,6 +1861,7 @@ i <enum name="KEYCODE_MICMUTE" value="312" /> <enum name="KEYCODE_WLAN" value="313" /> <enum name="KEYCODE_AUDIO" value="314" /> + <enum name="KEYCODE_WEIQIFA" value="315" /> </attr> <!-- ***************************************************************** --> diff --git a/include/android/keycodes.h b/include/android/keycodes.h index e3586b2..b657424 100755 --- a/include/android/keycodes.h +++ b/include/android/keycodes.h @@ -777,6 +777,7 @@ enum { AKEYCODE_MICMUTE = 312, AKEYCODE_WLAN = 313, AKEYCODE_AUDIO = 314 + AKEYCODE_WEIQIFA = 315 // NOTE: If you add a new keycode here you must also add it to several other files. // Refer to frameworks/base/core/java/android/view/KeyEvent.java for the full list. diff --git a/include/input/InputEventLabels.h b/include/input/InputEventLabels.h index fabf912..1cd69a2 100755 --- a/include/input/InputEventLabels.h +++ b/include/input/InputEventLabels.h @@ -68,6 +68,7 @@ static const InputEventLabel KEYCODES[] = { DEFINE_KEYCODE(POWER), DEFINE_KEYCODE(WLAN), DEFINE_KEYCODE(AUDIO), + DEFINE_KEYCODE(WEIQIFA), DEFINE_KEYCODE(CAMERA), DEFINE_KEYCODE(CLEAR), DEFINE_KEYCODE(A),

如果出现以下编译错误

out/target/common/obj/PACKAGING/test-api.txt:41961: error 5: Added public field android.view.KeyEvent.KEYCODE_WEIQIFA******************************
You have tried to change the API from what has been previously approved. To make these errors go away, you have two choices: 1) You can add "@hide" javadoc comments to the methods, etc. listed in the errors above. 2) You can update current.txt by executing the following command: make update-api To submit the revised current.txt to the main Android repository, you will need approval. ******************************

提示你运行make update-api，但是要先回退current.txt 和system-current.txt，因为这两个文件就是make update-api生成出来的

git checkout api/current.txt 
git checkout api/system-current.txt
make update-api

关于make update-api详细看这个https://blog.csdn.net/u010229714/article/details/73840014

如果需要调试，可以打开下面的调试文件

--- a/services/core/java/com/android/server/input/InputManagerService.java
+++ b/services/core/java/com/android/server/input/InputManagerService.java
@@ -125,7 +125,7 @@ import libcore.util.Objects; public class InputManagerService extends IInputManager.Stub implements Watchdog.Monitor { static final String TAG = "InputManager"; - static final boolean DEBUG = false; + static final boolean DEBUG = true; private static final String EXCLUDED_DEVICES_PATH = "etc/excluded-input-devices.xml"; --- a/services/core/java/com/android/server/policy/PhoneWindowManager.java +++ b/services/core/java/com/android/server/policy/PhoneWindowManager.java @@ -172,7 +172,7 @@ public class PhoneWindowManager implements WindowManagerPolicy { static final String TAG = "WindowManager"; static final boolean DEBUG = false; static final boolean localLOGV = false; - static final boolean DEBUG_INPUT = false; + static final boolean DEBUG_INPUT = true; static final boolean DEBUG_KEYGUARD = false; static final boolean DEBUG_LAYOUT = false; static final boolean DEBUG_STARTING_WINDOW = false; --- a/services/inputflinger/InputDispatcher.cpp +++ b/services/inputflinger/InputDispatcher.cpp @@ -17,31 +17,31 @@ #define LOG_TAG "InputDispatcher" #define ATRACE_TAG ATRACE_TAG_INPUT -//#define LOG_NDEBUG 0 +#define LOG_NDEBUG 1 // Log detailed debug messages about each inbound event notification to the dispatcher. -#define DEBUG_INBOUND_EVENT_DETAILS 0 +#define DEBUG_INBOUND_EVENT_DETAILS 1 // Log detailed debug messages about each outbound event processed by the dispatcher. -#define DEBUG_OUTBOUND_EVENT_DETAILS 0 +#define DEBUG_OUTBOUND_EVENT_DETAILS 1 // Log debug messages about the dispatch cycle. -#define DEBUG_DISPATCH_CYCLE 0 +#define DEBUG_DISPATCH_CYCLE 1 // Log debug messages about registrations. -#define DEBUG_REGISTRATION 0 +#define DEBUG_REGISTRATION 1 // Log debug messages about input event injection. -#define DEBUG_INJECTION 0 +#define DEBUG_INJECTION 1 // Log debug messages about input focus tracking. -#define DEBUG_FOCUS 0 +#define DEBUG_FOCUS 1 // Log debug messages about the app switch latency optimization. -#define DEBUG_APP_SWITCH 0 +#define DEBUG_APP_SWITCH 1 // Log debug messages about hover events. -#define DEBUG_HOVER 0 +#define DEBUG_HOVER 1 #include "InputDispatcher.h" diff --git a/services/inputflinger/InputReader.cpp b/services/inputflinger/InputReader.cpp index c8dc454..3a622fc 100644 --- a/services/inputflinger/InputReader.cpp +++ b/services/inputflinger/InputReader.cpp @@ -16,10 +16,10 @@ #define LOG_TAG "InputReader" -//#define LOG_NDEBUG 0 +#define LOG_NDEBUG 1 // Log debug messages for each raw event received from the EventHub. -#define DEBUG_RAW_EVENTS 0 +#define DEBUG_RAW_EVENTS 1 // Log debug messages about touch screen filtering hacks. #define DEBUG_HACKS 0 diff --git a/libs/input/InputTransport.cpp b/libs/input/InputTransport.cpp index 2dff4e0..977aa22 100644 --- a/libs/input/InputTransport.cpp +++ b/libs/input/InputTransport.cpp @@ -5,19 +5,19 @@ // #define LOG_TAG "InputTransport" -//#define LOG_NDEBUG 0 +#define LOG_NDEBUG 1 // Log debug messages about channel messages (send message, receive message) -#define DEBUG_CHANNEL_MESSAGES 0 +#define DEBUG_CHANNEL_MESSAGES 1 // Log debug messages whenever InputChannel objects are created/destroyed -#define DEBUG_CHANNEL_LIFECYCLE 0 +#define DEBUG_CHANNEL_LIFECYCLE 1 // Log debug messages about transport actions -#define DEBUG_TRANSPORT_ACTIONS 0 +#define DEBUG_TRANSPORT_ACTIONS 1 // Log debug messages about touch event resampling -#define DEBUG_RESAMPLING 0 +#define DEBUG_RESAMPLING 1

7 App接收键值

主要参照这个链接来写
https://www.cnblogs.com/zhujiabin/p/5915802.html
例程Android studio源码
链接：https://pan.baidu.com/s/1hzhQ-dLSRnAbg2Q8w5qKPw 密码：944g

@Overridepublic boolean dispatchKeyEvent(KeyEvent event) {if(event.getKeyCode() == KeyEvent.KEYCODE_ENTER){ /*隐藏软键盘*/ InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE); if(inputMethodManager.isActive()){ inputMethodManager.hideSoftInputFromWindow(MainActivity.this.getCurrentFocus().getWindowToken(), 0); } edittext.setText("success"); webview.loadUrl(URL); return true; } return super.dispatchKeyEvent(event); }

8 命令调试

8.1 测试上报时间

触发Input上报的时间点

rk3399_mid:/ $ logcat -s "CAE_LOG"|grep -E CAEIvwCb
09-06 14:10:13.502 327 436 D CAE_LOG : CAEIvwCb angle = 23 ,beam = 0 CMScore = 1643

APK接收到键值的时间点

09-06 14:10:13.518 5693-5693/com.hu.audiotest D/audiotest_MainActivity: KeyEvent.KEYCODE_ENTER KeyCode0 09-06 14:10:13.522 5693-5693/com.hu.audiotest D/audiotest_MainActivity: KeyEvent.KEYCODE_ENTER KeyCode0

消耗的时间大概需要16MS，但是触发是通过HAL层触发的，如果从Kerne触发事间会更短一些

8.2 设备文件调试

我们kernel下面正常用 getevent 来调试
getevent -l
cat /proc/bus/input/devices

rk3399_mid:/ # getevent -l
add device 1: /dev/input/event2name:     "rk29-keypad" add device 2: /dev/input/event1 name: "as9102 Touchscreen" add device 3: /dev/input/event0 name: "iflytek" /dev/input/event0: EV_KEY 00f9 DOWN /dev/input/event0: EV_SYN SYN_REPORT 00000000 /dev/input/event0: EV_KEY 00f9 UP /dev/input/event0: EV_SYN SYN_REPORT 00000000

8.3 adb 上报键值调试

我们正常用adb shell input keyevent xx xx代表键值
可以用input来触发touchscreen也是可以的
有个比较好的文章
https://blog.csdn.net/jlminghui/article/details/39268419
大部分支持的键值如下

0 -->  "KEYCODE_UNKNOWN"
1 --> "KEYCODE_MENU" 2 --> "KEYCODE_SOFT_RIGHT" 3 --> "KEYCODE_HOME" 4 --> "KEYCODE_BACK" 5 --> "KEYCODE_CALL" 6 --> "KEYCODE_ENDCALL" 7 --> "KEYCODE_0" 8 --> "KEYCODE_1" 9 --> "KEYCODE_2" 10 --> "KEYCODE_3" 11 --> "KEYCODE_4" 12 --> "KEYCODE_5" 13 --> "KEYCODE_6" 14 --> "KEYCODE_7" 15 --> "KEYCODE_8" 16 --> "KEYCODE_9" 17 --> "KEYCODE_STAR" 18 --> "KEYCODE_POUND" 19 --> "KEYCODE_DPAD_UP" 20 --> "KEYCODE_DPAD_DOWN" 21 --> "KEYCODE_DPAD_LEFT" 22 --> "KEYCODE_DPAD_RIGHT" 23 --> "KEYCODE_DPAD_CENTER" 24 --> "KEYCODE_VOLUME_UP" 25 --> "KEYCODE_VOLUME_DOWN" 26 --> "KEYCODE_POWER" 27 --> "KEYCODE_CAMERA" 28 --> "KEYCODE_CLEAR" 29 --> "KEYCODE_A" 30 --> "KEYCODE_B" 31 --> "KEYCODE_C" 32 --> "KEYCODE_D" 33 --> "KEYCODE_E" 34 --> "KEYCODE_F" 35 --> "KEYCODE_G" 36 --> "KEYCODE_H" 37 --> "KEYCODE_I" 38 --> "KEYCODE_J" 39 --> "KEYCODE_K" 40 --> "KEYCODE_L" 41 --> "KEYCODE_M" 42 --> "KEYCODE_N" 43 --> "KEYCODE_O" 44 --> "KEYCODE_P" 45 --> "KEYCODE_Q" 46 --> "KEYCODE_R" 47 --> "KEYCODE_S" 48 --> "KEYCODE_T" 49 --> "KEYCODE_U" 50 --> "KEYCODE_V" 51 --> "KEYCODE_W" 52 --> "KEYCODE_X" 53 --> "KEYCODE_Y" 54 --> "KEYCODE_Z" 55 --> "KEYCODE_COMMA" 56 --> "KEYCODE_PERIOD" 57 --> "KEYCODE_ALT_LEFT" 58 --> "KEYCODE_ALT_RIGHT" 59 --> "KEYCODE_SHIFT_LEFT" 60 --> "KEYCODE_SHIFT_RIGHT" 61 --> "KEYCODE_TAB" 62 --> "KEYCODE_SPACE" 63 --> "KEYCODE_SYM" 64 --> "KEYCODE_EXPLORER" 65 --> "KEYCODE_ENVELOPE" 66 --> "KEYCODE_ENTER" 67 --> "KEYCODE_DEL" 68 --> "KEYCODE_GRAVE" 69 --> "KEYCODE_MINUS" 70 --> "KEYCODE_EQUALS" 71 --> "KEYCODE_LEFT_BRACKET" 72 --> "KEYCODE_RIGHT_BRACKET" 73 --> "KEYCODE_BACKSLASH" 74 --> "KEYCODE_SEMICOLON" 75 --> "KEYCODE_APOSTROPHE" 76 --> "KEYCODE_SLASH" 77 --> "KEYCODE_AT" 78 --> "KEYCODE_NUM" 79 --> "KEYCODE_HEADSETHOOK" 80 --> "KEYCODE_FOCUS" 81 --> "KEYCODE_PLUS"