android usb 从模式切换,android5.1-在系统设置里添加设置选项 以及 USB-OTG 模式切换...
以实现在设置中添加USB选项，切换HOST模式与OTG模式为例：
1,settings 应用一般在 目录：\packages\apps\Settings\src\com\android\settings\SettingsActivity.java 设置java文件
主要看如下方法：
private void updateTilesList(Listtarget) {
final boolean showDev = mDevelopmentPreferences.getBoolean(
DevelopmentSettings.PREF_SHOW,
android.os.Build.TYPE.equals("eng"));
final UserManager um = (UserManager) getSystemService(Context.USER_SERVICE);
final int size = target.size();
for (int i = 0; i < size; i++) {
DashboardCategory category = target.get(i);
// Ids are integers, so downcasting is ok
int id = (int) category.id;
int n = category.getTilesCount() - 1;
while (n >= 0) {
DashboardTile tile = category.getTile(n);
boolean removeTile = false;
id = (int) tile.id;
if (id == R.id.operator_settings || id == R.id.manufacturer_settings) {
if (!Utils.updateTileToSpecificActivityFromMetaDataOrRemove(this, tile)) {
removeTile = true;
}
} else if (id == R.id.wifi_settings) {
// Remove WiFi Settings if WiFi service is not available.
if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_WIFI)) {
removeTile = true;
}
} else if (id == R.id.bluetooth_settings) {
// Remove Bluetooth Settings if Bluetooth service is not available.
if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH)||(SystemProperties.get("ro.rk.bt_enable", "true").equals("false"))) {
removeTile = true;
}
} else if (id == R.id.data_usage_settings) {
// Remove data usage when kernel module not enabled
final INetworkManagementService netManager = INetworkManagementService.Stub
.asInterface(ServiceManager.getService(Context.NETWORKMANAGEMENT_SERVICE));
try {
if (!netManager.isBandwidthControlEnabled()) {
removeTile = true;
}
} catch (RemoteException e) {
// ignored
}
} else if (id == R.id.battery_settings) {
// Remove battery settings when battery is not available. (e.g. TV)
if (!mBatteryPresent) {
removeTile = true;
}
} else if (id == R.id.home_settings) {
if (!updateHomeSettingTiles(tile)) {
removeTile = true;
}
} else if (id == R.id.user_settings) {
boolean hasMultipleUsers =
((UserManager) getSystemService(Context.USER_SERVICE))
.getUserCount() > 1;
if (!UserHandle.MU_ENABLED
|| (!UserManager.supportsMultipleUsers()
&& !hasMultipleUsers)
|| Utils.isMonkeyRunning()) {
removeTile = true;
}
} else if (id == R.id.nfc_payment_settings) {
if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_NFC)) {
removeTile = true;
} else {
// Only show if NFC is on and we have the HCE feature
NfcAdapter adapter = NfcAdapter.getDefaultAdapter(this);
if (adapter == null || !adapter.isEnabled() ||
!getPackageManager().hasSystemFeature(
PackageManager.FEATURE_NFC_HOST_CARD_EMULATION)) {
removeTile = true;
}
}
} else if (id == R.id.print_settings) {
boolean hasPrintingSupport = getPackageManager().hasSystemFeature(
PackageManager.FEATURE_PRINTING);
if (!hasPrintingSupport) {
removeTile = true;
}
} else if (id == R.id.development_settings) {
if (!showDev || um.hasUserRestriction(
UserManager.DISALLOW_DEBUGGING_FEATURES)) {
removeTile = true;
}
} else if(id ==R.id.hdmi_settings){
boolean isTablet = "box".equals(SystemProperties.get("ro.target.product", "tablet"));
if (isTablet || SystemProperties.get("ro.rk.hdmi_enable", "true").equals("false")){
removeTile = true;
}
} else if(id ==R.id.screenshot_settings){
if (SystemProperties.get("ro.rk.screenshot_enable", "true").equals("false")){
removeTile = true;
}
} else if(id ==R.id.usb_settings){
//
//if (!"box".equals(SystemProperties.get("ro.target.product", "tablet"))){
if (SystemProperties.get("ro.rk.usb_settings", "true").equals("false")){
removeTile = true;
}
}
if (UserHandle.MU_ENABLED && UserHandle.myUserId() != 0
&& !ArrayUtils.contains(SETTINGS_FOR_RESTRICTED, id)) {
removeTile = true;
}
if (removeTile && n < category.getTilesCount()) {
category.removeTile(n);
}
n--;
}
}
}
其中,这个判断就是判断是否在设置中生成USB选项；
(id ==R.id.usb_settings){
//
//if (!"box".equals(SystemProperties.get("ro.target.product", "tablet"))){
if (SystemProperties.get("ro.rk.usb_settings", "true").equals("false")){
removeTile = true;
}
}
要使USB选项生成，需要在 \device\rockchip\common\device.mk 文件中 PRODUCT_PROPERTY_OVERRIDES 下添加上 ro.rk.usb_settings=true \
还有几个相关的文件：
\packages\apps\Settings\src\com\android\settings\Settings.java
\packages\apps\Settings\AndroidManifest.xml 声明文件
\packages\apps\Settings\res\xml\dashboard_categories.xml 布局文件
\packages\apps\Settings\src\com\android\settings\UsbSetting.java usb类文件
\packages\apps\Settings\res\xml\usb_switch.xml 布局文件
\packages\apps\Settings\res\xml\usb_settings.xml 布局文件
接下来分析USB-OTG
usb 分两种模式 HOST MODE 和 DEVICE MODE
HOST mode ：主板上作为主设备端，与从设备 进行通讯；例如，U盘插入，主板读取U盘数据
DEVICE mode ：主板作为从设备，与PC 进行连接，通过 OTG 线； 此时电脑上可以识别出从设备连接；
可以通过查看结果：
cat /sys/bus/platform/drivers/usb20_otg/force_usb_mode
可以通过修改 /sys/bus/platform/drivers/usb20_otg/force_usb_mode
中的值去打开otg 连接pc的功能。 1->0 or 1->2均可以 打开
反之，则 打开 U盘读取 功能，主板作为 主设备；
echo 1 > /sys/bus/platform/drivers/usb20_otg/force_usb_mode
以上做的 USB 选项，就是选择 切换模式
在 rk3288.dtsi 中可以选择 默认的模式
usb0: usb@ff580000 {
compatible = "rockchip,rk3288_usb20_otg";
reg = <0xff580000 0x40000>;
interrupts = ;
clocks = , ;
clock-names = "clk_usbphy0", "hclk_usb0";
resets = , ,
;
reset-names = "otg_ahb", "otg_phy", "otg_controller";
/*0 - Normal, 1 - Force Host, 2 - Force Device*/
//yr change code
//rockchip,usb-mode = <0>;
rockchip,usb-mode = <1>; // 修改默认USB-OTG为HOST模式，识别U盘
};
参考连接：
1、 http://www.cnblogs.com/grein/p/5892723.html
2、 http://blog.csdn.net/sunjing_/article/details/51085895
3、 http://www.07net01.com/program/2016/03/1391773.html