android usb解析（一）UsbDeviceManager(and5.1)

先来理下整个usb的架构，用户从UsbManager调用接口，会binder通信到UsbService。而UsbService又有两个实例，一个



UsbHostManager，一个UsbDeviceManager。UsbDeviceManager和



UsbHostManager是一个相对的概念，



UsbHostManager是手机作为一个host，比如键盘、鼠标通过usb连接手机。而UsbDeviceManager是手机与电脑连接。

先看下UsbDevice的代码：就看构造函数和systemReady

    public UsbService(Context context) {        mContext = context;        final PackageManager pm = mContext.getPackageManager();        if (pm.hasSystemFeature(PackageManager.FEATURE_USB_HOST)) {            mHostManager = new UsbHostManager(context);//new UsbHostManager        }        if (new File("/sys/class/android_usb").exists()) {            mDeviceManager = new UsbDeviceManager(context);//new UsbDeviceManager        }        setCurrentUser(UserHandle.USER_OWNER);        final IntentFilter userFilter = new IntentFilter();        userFilter.addAction(Intent.ACTION_USER_SWITCHED);        userFilter.addAction(Intent.ACTION_USER_STOPPED);        mContext.registerReceiver(mUserReceiver, userFilter, null, null);    }

    public void systemReady() {        if (mDeviceManager != null) {            mDeviceManager.systemReady();        }        if (mHostManager != null) {            mHostManager.systemReady();        }    }

今天主要介绍下UsbDeviceManager，先来看下构造函数：

    public UsbDeviceManager(Context context) {        Log.d(TAG,"UsbDeviceManager start , persist.sys.usb.config =" + SystemProperties.get("persist.sys.usb.config", ""));        mContext = context;        mContentResolver = context.getContentResolver();        mMassStorageEnable = SystemProperties.get("persist.mass_storage.enable", "true");//大容量属性        PackageManager pm = mContext.getPackageManager();        mHasUsbAccessory = pm.hasSystemFeature(PackageManager.FEATURE_USB_ACCESSORY);        initRndisAddress();//初始化usb共享的地址，用手机序列码作为地址，序列码是存在系统属性中的        readOemUsbOverrideConfig();//读取厂家设置        mHandler = new UsbHandler(FgThread.get().getLooper());//构造UsbHandler，后面详细看        if (nativeIsStartRequested()) {            if (DEBUG) Slog.d(TAG, "accessory attached at boot");            startAccessoryMode();        }        boolean secureAdbEnabled = SystemProperties.getBoolean("ro.adb.secure", false);        boolean dataEncrypted = "1".equals(SystemProperties.get("vold.decrypt"));        if (secureAdbEnabled && !dataEncrypted) {            mDebuggingManager = new UsbDebuggingManager(context);        }    }

接下来看UsbHandler这个内部类：

先看usbHandler构造函数的前半部分：

        public UsbHandler(Looper looper) {            super(looper);            try {                // persist.sys.usb.config should never be unset.  But if it is, set it to "adb"                // so we have a chance of debugging what happened.                Log.d(TAG,"UsbHandler , persist.sys.usb.config :" + SystemProperties.get("persist.sys.usb.config"));                if(SystemProperties.get("persist.sys.usb.config", "") == null || SystemProperties.get("persist.sys.usb.config", "") == "none"){//永久性属性里面没有就设置                   if("false".equals(mMassStorageEnable)){                        SystemProperties.set("persist.sys.usb.config", "mtp,adb");                   }else{                        SystemProperties.set("persist.sys.usb.config", "mtp,mass_storage,adb");                    }                }                if("false".equals(mMassStorageEnable)){//有的话就直接将获取的属性放在mDefaultFunctions                    mDefaultFunctions = SystemProperties.get("persist.sys.usb.config", "mtp,adb");                }else{                    mDefaultFunctions = SystemProperties.get("persist.sys.usb.config", "mtp,mass_storage,adb");                }                Log.d(TAG,"mMassStorageEnable ="+ mMassStorageEnable +", mDefaultFunctions :" + mDefaultFunctions);                // Check if USB mode needs to be overridden depending on OEM specific bootmode.                mDefaultFunctions = processOemUsbOverride(mDefaultFunctions);//厂家定制的                // sanity check the sys.usb.config system property                // this may be necessary if we crashed while switching USB configurations                String config = SystemProperties.get("sys.usb.config", "none");                if (!config.equals(mDefaultFunctions)) {//如果mDefaultFunctions与"sys.usb.config“属性不一样，就重新设置属性                    Slog.w(TAG, "resetting config to persistent property: " + mDefaultFunctions);                    SystemProperties.set("sys.usb.config", mDefaultFunctions);                }

上面理论上persist.sys.usb.config 与sys.usb.config属性一样的

因为在init.usb.rc中设置persist.sys.usb.config 属性，也会将sys.usb.config一同设置了。

# Used to set USB configuration at boot and to switch the configuration# when changing the default configurationon property:persist.sys.usb.config=*    setprop sys.usb.config $persist.sys.usb.config

继续分析usbHandler的构造函数

                mCurrentFunctions = getDefaultFunctions();                String state = FileUtils.readTextFile(new File(STATE_PATH), 0, null).trim();                Log.d(TAG,"UsbHandler updateState  state:" + state);                mAdbEnabled = containsFunction(mCurrentFunctions, UsbManager.USB_FUNCTION_ADB);//属性中如果有adb，就置位true                updateState(state);                Log.d(TAG," UsbHandler charging_value:" + SystemProperties.get("sys.usb.charging", "")                        + "  ro.debuggable:" + SystemProperties.get("ro.debuggable", ""));                if(SystemProperties.get("sys.usb.charging", "").equals("yes") && SystemProperties.get("ro.debuggable","").equals("1")){                    

下面再看看updateState函数，state从下面这个节点读取状态

private static final String STATE_PATH =            "/sys/class/android_usb/android0/state"

updateState函数如下：

        public void updateState(String state) {            Log.d(TAG, "updateState : state = " + state );            int connected, configured;            if ("DISCONNECTED".equals(state)) {                connected = 0;                configured = 0;                SystemProperties.set("sys.lc.usb.state", "0");            } else if ("CONNECTED".equals(state)) {                connected = 1;                configured = 0;            } else if ("CONFIGURED".equals(state)) {                connected = 1;                configured = 1;                SystemProperties.set("sys.lc.usb.state", "1");            } else {                Slog.e(TAG, "unknown state " + state);                return;            }            removeMessages(MSG_UPDATE_STATE);            Message msg = Message.obtain(this, MSG_UPDATE_STATE);            msg.arg1 = connected;            msg.arg2 = configured;            // debounce disconnects to avoid problems bringing up USB tethering            sendMessage(msg);//参数配置后发送消息

收到消息后处理

        public void handleMessage(Message msg) {            Log.d(TAG," handleMessage msg:" + msg + " msg.arg1:" + msg.arg1 + "  msg.arg2  "+ msg.arg2);            switch (msg.what) {                case MSG_UPDATE_STATE:                    mConnected = (msg.arg1 == 1);                    mConfigured = (msg.arg2 == 1);                    updateUsbNotification();                    updateAdbNotification();                    if (containsFunction(mCurrentFunctions,                            UsbManager.USB_FUNCTION_ACCESSORY)) {                        updateCurrentAccessory();                    } else if (!mConnected) {//usb断开连接后，属性设置成默认的                        // restore defaults when USB is disconnected                        setEnabledFunctions(getDefaultFunctions(), false);                    }                    if (mBootCompleted) {                        updateUsbState();//发送广播                        updateAudioSourceFunction();                    }                    break;

继续分析

                String value = SystemProperties.get("persist.service.adb.enable", "");                if (value.length() > 0) {                    char enable = value.charAt(0);                    if (enable == '1') {                        setAdbEnabled(true);                    } else if (enable == '0') {                        setAdbEnabled(false);                    }                    SystemProperties.set("persist.service.adb.enable", "");                }

分析setAdbEnabled函数

        private void setAdbEnabled(boolean enable) {            if (DEBUG) Slog.d(TAG, "setAdbEnabled: " + enable + " mCurrentFunctions:" + mCurrentFunctions);            if (enable != mAdbEnabled) {//当mAdbEnabled改变时                mAdbEnabled = enable;                // Due to the persist.sys.usb.config property trigger, changing adb state requires                // persisting default function                if(!mCurrentFunctions.equals(UsbManager.USB_FUNCTION_CHARGING)){                    setEnabledFunctions(mDefaultFunctions, true);//先设置永久属性                    // After persisting them use the lock-down aware function set                    setEnabledFunctions(getDefaultFunctions(), false);//再设置usb.config属性                    updateAdbNotification();                }            }            if (mDebuggingManager != null) {                mDebuggingManager.setAdbEnabled(mAdbEnabled);            }        }

再来看看setEnabledFunctions函数

        private void setEnabledFunctions(String functions, boolean makeDefault) {            if (DEBUG) Slog.d(TAG, "setEnabledFunctions " + functions                    + " makeDefault: " + makeDefault);            // Do not update persystent.sys.usb.config if the device is booted up            // with OEM specific mode.            if (functions != null && makeDefault && !needsOemUsbOverride()) {//设置永久属性                if (mAdbEnabled && !functions.equals(UsbManager.USB_FUNCTION_CHARGING)) {                    functions = addFunction(functions, UsbManager.USB_FUNCTION_ADB);//根据mAdbEnabled设置系统属性                } else {                    functions = removeFunction(functions, UsbManager.USB_FUNCTION_ADB);                }                if (!mDefaultFunctions.equals(functions)) {//当functions改变时                    if (!setUsbConfig("none")) {//设置none，直接断开usb，也就是差不多每次设置不一样属性。都要先断开usb。稍后详细看看setUsbConfig这个函数                        Slog.e(TAG, "Failed to disable USB");                        // revert to previous configuration if we fail                        setUsbConfig(mCurrentFunctions);//                        return;                    }                    // setting this property will also change the current USB state                    // via a property trigger                    SystemProperties.set("persist.sys.usb.config", functions);// 设置永久属性                    if (waitForState(functions)) {//就是设置的属性，去读取属性是否和设置的一样                        if(mCurrentFunctions.equals(UsbManager.USB_FUNCTION_CHARGING) && !mCurrentFunctions.equals(functions)){                            if (DEBUG) Slog.d(TAG, " change charging functions to new functions: " + functions);                                SystemProperties.set("sys.usb.charging", "no");                        }                        mCurrentFunctions = functions;                        mDefaultFunctions = functions;                    } else {//不成功，设置层默认的                        Slog.e(TAG, "Failed to switch persistent USB config to " + functions);                        // revert to previous configuration if we fail                        SystemProperties.set("persist.sys.usb.config", mDefaultFunctions);                    }                }            }

非永久属性的，和永久属性的差不多。只是一个是设置永久属性。一个是设置usb.config这个属性

else {                if (functions == null) {                    functions = mDefaultFunctions;                }                // Override with bootmode specific usb mode if needed                functions = processOemUsbOverride(functions);                if (mAdbEnabled && !functions.equals(UsbManager.USB_FUNCTION_CHARGING)) {                    functions = addFunction(functions, UsbManager.USB_FUNCTION_ADB);                } else {                    functions = removeFunction(functions, UsbManager.USB_FUNCTION_ADB);                }                if (!mCurrentFunctions.equals(functions)) {                    if (!setUsbConfig("none")) {//断开usb                        Slog.e(TAG, "Failed to disable USB");                        // revert to previous configuration if we fail                        setUsbConfig(mCurrentFunctions);                        return;                    }                    if (setUsbConfig(functions)) {                        if(mCurrentFunctions.equals(UsbManager.USB_FUNCTION_CHARGING) && !mCurrentFunctions.equals(functions)){                            if (DEBUG) Slog.d(TAG, " change charging functions to new functions: " + functions);                                SystemProperties.set("sys.usb.charging", "no");                        }                        mCurrentFunctions = functions;                    } else {                        Slog.e(TAG, "Failed to switch USB config to " + functions);                        // revert to previous configuration if we fail                        setUsbConfig(mCurrentFunctions);                    }                }            }

下面我们再来看看setUsbConfig这个函数

        private boolean setUsbConfig(String config) {            if (DEBUG) Slog.d(TAG, "setUsbConfig(" + config + ")");            // set the new configuration            SystemProperties.set("sys.usb.config", config);            return waitForState(config);        }

waitForState函数

        private boolean waitForState(String state) {            // wait for the transition to complete.            // give up after 1 second.            for (int i = 0; i < 40; i++) {                // State transition is done when sys.usb.state is set to the new configuration                if (state.equals(SystemProperties.get("sys.usb.state"))){//设置的属性和读取的属性相同                    Log.i(TAG,"Setting SystemProperties ,i =  "+i);                    if(state.equals("none")){                        if(SystemProperties.get("sys.lc.usb.state").equals("0")){                            return true;                        }else{                            Log.i(TAG,"sys.lc.usb.state ="+SystemProperties.get("sys.lc.usb.state"));                        }                    }else{                        return true;                    }                }                SystemClock.sleep(50);//不相同，睡50ms 也就是最多会睡2s            }            Slog.e(TAG, "waitForState(" + state + ") FAILED");            return false;        }

继续分析usbhandler

                mContentResolver.registerContentObserver(                        Settings.Global.getUriFor(Settings.Global.ADB_ENABLED),                                false, new AdbSettingsObserver());//注册一个adb的观察者，会发送消息。                // Watch for USB configuration changes                mUEventObserver.startObserving(USB_STATE_MATCH);//开启两个节点的监控。                mUEventObserver.startObserving(ACCESSORY_START_MATCH);                IntentFilter filter = new IntentFilter(Intent.ACTION_BOOT_COMPLETED);                filter.setPriority(IntentFilter.SYSTEM_HIGH_PRIORITY);                mContext.registerReceiver(mBootCompletedReceiver, filter);                mContext.registerReceiver(                        mUserSwitchedReceiver, new IntentFilter(Intent.ACTION_USER_SWITCHED));                mContext.registerReceiver(                        mBatteryChangedReceiver, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));

AdbSettingsObserver 发送消息

    private class AdbSettingsObserver extends ContentObserver {        public AdbSettingsObserver() {            super(null);        }        @Override        public void onChange(boolean selfChange) {            boolean enable = (Settings.Global.getInt(mContentResolver,                    Settings.Global.ADB_ENABLED, 0) > 0);            mHandler.sendMessage(MSG_ENABLE_ADB, enable);        }    }

消息处理，调用setAdbEnabled

                case MSG_ENABLE_ADB:                    setAdbEnabled(msg.arg1 == 1);                    break;

UEventObserver 分析

    private final UEventObserver mUEventObserver = new UEventObserver() {        @Override        public void onUEvent(UEventObserver.UEvent event) {            if (DEBUG) Slog.v(TAG, "USB UEVENT: " + event.toString());            String state = event.get("USB_STATE");            String accessory = event.get("ACCESSORY");            if (state != null) {//state对应一个节点                mHandler.updateState(state);//updateState函数前面分析过了            } else if ("START".equals(accessory)) {//accessory对应一个节点                if (DEBUG) Slog.d(TAG, "got accessory start");                startAccessoryMode();            }        }    }

startAccessoryMode函数

    private void startAccessoryMode() {        if (!mHasUsbAccessory) return;        mAccessoryStrings = nativeGetAccessoryStrings();        boolean enableAudio = (nativeGetAudioMode() == AUDIO_MODE_SOURCE);        // don't start accessory mode if our mandatory strings have not been set        boolean enableAccessory = (mAccessoryStrings != null &&                        mAccessoryStrings[UsbAccessory.MANUFACTURER_STRING] != null &&                        mAccessoryStrings[UsbAccessory.MODEL_STRING] != null);        String functions = null;        if (enableAccessory && enableAudio) {            functions = UsbManager.USB_FUNCTION_ACCESSORY + ","                    + UsbManager.USB_FUNCTION_AUDIO_SOURCE;        } else if (enableAccessory) {            functions = UsbManager.USB_FUNCTION_ACCESSORY;        } else if (enableAudio) {            functions = UsbManager.USB_FUNCTION_AUDIO_SOURCE;        }        if (functions != null) {            mAccessoryModeRequestTime = SystemClock.elapsedRealtime();            setCurrentFunctions(functions, false);//设置属性        }    }

还有就是用户调用usbmanger中的setCurrentFunction

    public void setCurrentFunction(String function, boolean makeDefault) {        try {            mService.setCurrentFunction(function, makeDefault);        } catch (RemoteException e) {            Log.e(TAG, "RemoteException in setCurrentFunction", e);        }    }

接着调用usbservice中的setCurrentFunction函数

    public void setCurrentFunction(String function, boolean makeDefault) {        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.MANAGE_USB, null);        // If attempt to change USB function while file transfer is restricted, ensure that        // the current function is set to "none", and return.        UserManager userManager = (UserManager) mContext.getSystemService(Context.USER_SERVICE);        if (userManager.hasUserRestriction(UserManager.DISALLOW_USB_FILE_TRANSFER)) {            if (mDeviceManager != null) mDeviceManager.setCurrentFunctions("none", false);            return;        }        if (mDeviceManager != null) {            mDeviceManager.setCurrentFunctions(function, makeDefault);        } else {            throw new IllegalStateException("USB device mode not supported");        }    }

最后调用usbdevicemanager中的setCurrentFunctions函数

    public void setCurrentFunctions(String functions, boolean makeDefault) {        String currentUsbConfig = SystemProperties.get("sys.usb.config", "none");// 先从属性里面读出来，主要看有没有adb        Log.i(TAG, "begin to setCurrentFunction : sys.usb.config = " + currentUsbConfig + " , mMassStorageEnable:"                            + mMassStorageEnable + " , functions =" + functions +" , makeDefault =" + makeDefault);        if(functions != null){            if(containsFunction(functions,UsbManager.USB_FUNCTION_ENABLE_SERIAL)){                functions = "serial";            }else if(containsFunction(functions,UsbManager.USB_FUNCTION_DISABLE_SERIAL)){                if("false".equals(mMassStorageEnable)){                    functions = "mtp";                }else{                    functions = "mtp,mass_storage";                }            }else if(containsFunction(functions,UsbManager.USB_FUNCTION_RNDIS)){// usb共享要看，串口有没有开，                if(containsFunction(currentUsbConfig,UsbManager.USB_FUNCTION_SERIAL)){                    functions = "rndis,serial";//开了串口才能把这两项都设置到属性中去                }            }        }        if(containsFunction(currentUsbConfig,UsbManager.USB_FUNCTION_ADB)){            if(functions != null)addFunction(functions,UsbManager.USB_FUNCTION_ADB);        }        Log.i(TAG, "setCurrentFunction  finally  function:"  + fixFunction(functions) + " makeDefault:" + makeDefault);        mHandler.sendMessage(MSG_SET_CURRENT_FUNCTIONS, fixFunction(functions), makeDefault);    }

fixFunction的话是将一些其他的属性加入，因为设置属性每次都要设置所有的

    private String fixFunction(String function) {        Log.d(TAG," fixFunction: function:" + function);        String ret = function;        if (null == function) {            return null;        }        if (containsFunction(function, UsbManager.USB_FUNCTION_MTP)){            if("false".equals(mMassStorageEnable)){                ret = "mtp";            } else {                ret = "mtp,mass_storage";            }        } else if (containsFunction(function, UsbManager.USB_FUNCTION_PTP)) {            if("false".equals(mMassStorageEnable)){                ret = "ptp";            } else {                ret = "ptp,mass_storage";            }        } else {            return ret;        }        if (containsFunction(function, UsbManager.USB_FUNCTION_ADB)) {            addFunction(ret, UsbManager.USB_FUNCTION_ADB);        }        return ret;    }

发送消息之后，消息处理。主要还是调用setEnabledFunctions设置属性。当属性中含有rndis和accessory经常导致不能及时获取的属性值一样。而waitforstate时会等待，所有这边就起了一个线程。

                case MSG_SET_CURRENT_FUNCTIONS:                    final String functions = (String)msg.obj;                    final boolean makeDefault = (msg.arg1 == 1);                    Log.d(TAG, "set current funtion to " + functions);                    if (null != functions){                        if(!functions.contains(UsbManager.USB_FUNCTION_CHARGING)){                            mConnected_InChargeOnlyMode = false;                        }else{                            mConnected_InChargeOnlyMode = true;                        }                    }                    if (null != functions && (functions.contains("rndis")||functions.contains("accessory"))) {                        new Thread() {                            public void run() {                                 Log.d(TAG, "new Thread setEnabledFunctions to " + functions);                               setEnabledFunctions(functions, makeDefault);                             }                            }.start();                       } else {                           setEnabledFunctions(functions, makeDefault);                    }                    break;

下面大致说下各个属性。

    public static final String USB_FUNCTION_ADB = "adb";    /**     * Name of the RNDIS ethernet USB function.     * Used in extras for the {@link #ACTION_USB_STATE} broadcast     *     * {@hide}     */    public static final String USB_FUNCTION_RNDIS = "rndis";//usb共享    /**     * Name of the MTP USB function.     * Used in extras for the {@link #ACTION_USB_STATE} broadcast     *     * {@hide}     */    public static final String USB_FUNCTION_MTP = "mtp";    /**     * Name of the PTP USB function.     * Used in extras for the {@link #ACTION_USB_STATE} broadcast     *     * {@hide}     */    public static final String USB_FUNCTION_PTP = "ptp";    /**     * Name of the audio source USB function.     * Used in extras for the {@link #ACTION_USB_STATE} broadcast     *     * {@hide}     */    public static final String USB_FUNCTION_AUDIO_SOURCE = "audio_source";    /**     * Name of the Accessory USB function.     * Used in extras for the {@link #ACTION_USB_STATE} broadcast     *     * {@hide}     */    public static final String USB_FUNCTION_ACCESSORY = "accessory";     /**     * Name of the charging USB function.     * Used in extras for the {@link #ACTION_USB_STATE} broadcast     *     * {@hide}     */    public static final String USB_FUNCTION_CHARGING = "charging";        /**     * Name of the serial USB function.     * Used in extras for the {@link #ACTION_USB_STATE} broadcast     *     * {@hide}     */    public static final String USB_FUNCTION_SERIAL = "serial";//开启串口的

还有整个usb.config属性设置后。会触发init.usb.rc中的一些触发器。这在init的博客中分析过了。

下面我们看下整个init.usb.rc，是各个排列组合都列出来了。最后一个是设置persist.sys.usb.config永久系统属性的时候也会设置 sys.usb.config属性。

# Used to disable USB when switching stateson property:sys.usb.config=none//设置属性none    stop adbd    write /sys/class/android_usb/android0/enable 0//写enable为0    write /sys/class/android_usb/android0/bDeviceClass 0    setprop sys.usb.state $sys.usb.config#mtp,mass_storage,adbon property:sys.usb.config=mtp,mass_storage,adb    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 181C    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/enable 1    start adbd    setprop sys.usb.state $sys.usb.config#mtp,mass_storageon property:sys.usb.config=mtp,mass_storage    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 181C    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/enable 1    setprop sys.usb.state $sys.usb.config#ptp,mass_storage,adbon property:sys.usb.config=ptp,mass_storage,adb    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 181D    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/enable 1    start adbd    setprop sys.usb.state $sys.usb.config#ptp,mass_storageon property:sys.usb.config=ptp,mass_storage    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 181D    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/enable 1    setprop sys.usb.state $sys.usb.config#rndis,adb,serialon property:sys.usb.config=rndis,adb,serial    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 181F    write /sys/class/android_usb/android0/functions rndis,serial,adb    write /sys/class/android_usb/android0/f_rndis/wceis 1    write /sys/class/android_usb/android0/f_serial/serial_port_num 4    write /sys/class/android_usb/android0/enable 1    start adbd    setprop sys.usb.state rndis,serial,adb#rndis,serial,adbon property:sys.usb.config=rndis,serial,adb    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 181F    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/f_rndis/wceis 1    write /sys/class/android_usb/android0/f_serial/serial_port_num 4    write /sys/class/android_usb/android0/enable 1    start adbd    setprop sys.usb.state $sys.usb.config#rndis,serialon property:sys.usb.config=rndis,serial    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 181F    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/f_rndis/wceis 1    write /sys/class/android_usb/android0/f_serial/serial_port_num 4    write /sys/class/android_usb/android0/enable 1    setprop sys.usb.state $sys.usb.config#rndis,adbon property:sys.usb.config=rndis,adb    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 181E    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/f_rndis/wceis 1    write /sys/class/android_usb/android0/enable 1    start adbd    setprop sys.usb.state $sys.usb.config#rndison property:sys.usb.config=rndis    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 181E    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/f_rndis/wceis 1    write /sys/class/android_usb/android0/enable 1    setprop sys.usb.state $sys.usb.config#mass_storage,serial,adbon property:sys.usb.config=mass_storage,serial,adb    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 181B    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/f_serial/serial_port_num 5    write /sys/class/android_usb/android0/enable 1    start adbd    setprop sys.usb.state $sys.usb.config#accessory,adbon property:sys.usb.config=accessory,adb    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 2D00    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/enable 1    start adbd    setprop sys.usb.state $sys.usb.config#accessoryon property:sys.usb.config=accessory    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 2D01    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/enable 1    setprop sys.usb.state $sys.usb.config#adbon property:sys.usb.config=adb    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 1819    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/enable 1    start adbd    setprop sys.usb.state $sys.usb.config#mtp,adbon property:sys.usb.config=mtp,adb    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 1818    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/enable 1    start adbd    setprop sys.usb.state $sys.usb.config#mtpon property:sys.usb.config=mtp    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 1818    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/enable 1    start adbd    setprop sys.usb.state $sys.usb.config#ptp,adbon property:sys.usb.config=ptp,adb    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 1817    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/enable 1    start adbd    setprop sys.usb.state $sys.usb.config#ptpon property:sys.usb.config=ptp    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 1817    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/enable 1    setprop sys.usb.state $sys.usb.config#serial,adbon property:sys.usb.config=serial,adb    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 1816    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/f_serial/serial_port_num 4    write /sys/class/android_usb/android0/enable 1    start adbd    setprop sys.usb.state $sys.usb.config#serialon property:sys.usb.config=serial    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 1816    write /sys/class/android_usb/android0/functions $sys.usb.config    write /sys/class/android_usb/android0/f_serial/serial_port_num 4    write /sys/class/android_usb/android0/enable 1    setprop sys.usb.state $sys.usb.config#USB Charging Only configuration#for android_usb device should not been none,so set a default function in this modeon property:sys.usb.config=charging    write /sys/class/android_usb/android0/enable 0    write /sys/class/android_usb/android0/idVendor 18D1    write /sys/class/android_usb/android0/idProduct 181C    write /sys/class/android_usb/android0/functions mtp,mass_storage,adb    write /sys/class/android_usb/android0/enable 1    setprop sys.usb.state $sys.usb.config    setprop sys.usb.charging yeson property:sys.usb.charging=yes    write /sys/devices/platform/comip-u2d/charge_mode 1on property:sys.usb.charging=no    write /sys/devices/platform/comip-u2d/charge_mode 0# Used to set USB configuration at boot and to switch the configuration# when changing the default configurationon property:persist.sys.usb.config=*    setprop sys.usb.config $persist.sys.usb.config

usbdevicemanager差不多分析完了。usb这块暂时先这样后续还会继续深入分析，比如UsbHostManager和UsbSettingsManager那块。