import java.util.HashMap;
/**
- * <p>UsbService monitors for changes to USB state.
+ * UsbService monitors for changes to USB state.
+ * This includes code for both USB host support (where the android device is the host)
+ * as well as USB device support (android device is connected to a USB host).
+ * Accessory mode is a special case of USB device mode, where the android device is
+ * connected to a USB host that supports the android accessory protocol.
*/
class UsbService extends IUsbManager.Stub {
private static final String TAG = UsbService.class.getSimpleName();
private static final String USB_COMPOSITE_CLASS_PATH =
"/sys/class/usb_composite";
- private static final int MSG_UPDATE = 0;
+ private static final int MSG_UPDATE_STATE = 0;
+ private static final int MSG_FUNCTION_ENABLED = 1;
+ private static final int MSG_FUNCTION_DISABLED = 2;
// Delay for debouncing USB disconnects.
// We often get rapid connect/disconnect events when enabling USB functions,
private int mLastConfiguration = -1;
// lists of enabled and disabled USB functions (for USB device mode)
- // synchronize on mEnabledFunctions when using either of these lists
private final ArrayList<String> mEnabledFunctions = new ArrayList<String>();
private final ArrayList<String> mDisabledFunctions = new ArrayList<String>();
private final String[] mHostBlacklist;
private boolean mSystemReady;
+
private UsbAccessory mCurrentAccessory;
+ // functions to restore after exiting accessory mode
+ private final ArrayList<String> mAccessoryRestoreFunctions = new ArrayList<String>();
private final Context mContext;
-
- private final void functionEnabled(String function, boolean enabled) {
- synchronized (mEnabledFunctions) {
- if (enabled) {
- if (!mEnabledFunctions.contains(function)) {
- mEnabledFunctions.add(function);
- }
- mDisabledFunctions.remove(function);
- } else {
- if (!mDisabledFunctions.contains(function)) {
- mDisabledFunctions.add(function);
+ private final Object mLock = new Object();
+
+ /*
+ * Handles USB function enable/disable events (device mode)
+ */
+ private final void functionEnabledLocked(String function, boolean enabled) {
+ boolean enteringAccessoryMode =
+ (enabled && UsbManager.USB_FUNCTION_ACCESSORY.equals(function));
+
+ if (enteringAccessoryMode) {
+ // keep a list of functions to reenable after exiting accessory mode
+ mAccessoryRestoreFunctions.clear();
+ int count = mEnabledFunctions.size();
+ for (int i = 0; i < count; i++) {
+ String f = mEnabledFunctions.get(i);
+ // RNDIS should not be restored and adb is handled automatically
+ if (!UsbManager.USB_FUNCTION_RNDIS.equals(f) &&
+ !UsbManager.USB_FUNCTION_ADB.equals(f) &&
+ !UsbManager.USB_FUNCTION_ACCESSORY.equals(f)) {
+ mAccessoryRestoreFunctions.add(f);
}
- mEnabledFunctions.remove(function);
}
}
+ if (enabled) {
+ if (!mEnabledFunctions.contains(function)) {
+ mEnabledFunctions.add(function);
+ }
+ mDisabledFunctions.remove(function);
+ } else {
+ if (!mDisabledFunctions.contains(function)) {
+ mDisabledFunctions.add(function);
+ }
+ mEnabledFunctions.remove(function);
+ }
- if (enabled && UsbManager.USB_FUNCTION_ACCESSORY.equals(function)) {
+ if (enteringAccessoryMode) {
String[] strings = nativeGetAccessoryStrings();
if (strings != null) {
Log.d(TAG, "entering USB accessory mode");
}
}
+ /*
+ * Listens for uevent messages from the kernel to monitor the USB state (device mode)
+ */
private final UEventObserver mUEventObserver = new UEventObserver() {
@Override
public void onUEvent(UEventObserver.UEvent event) {
Slog.v(TAG, "USB UEVENT: " + event.toString());
}
- synchronized (this) {
+ synchronized (mLock) {
String name = event.get("SWITCH_NAME");
String state = event.get("SWITCH_STATE");
if (name != null && state != null) {
if (function != null && enabledStr != null) {
// Note: we do not broadcast a change when a function is enabled or disabled.
// We just record the state change for the next broadcast.
- boolean enabled = "1".equals(enabledStr);
- functionEnabled(function, enabled);
+ int what = ("1".equals(enabledStr) ?
+ MSG_FUNCTION_ENABLED : MSG_FUNCTION_DISABLED);
+ Message msg = Message.obtain(mHandler, what);
+ msg.obj = function;
+ mHandler.sendMessage(msg);
}
}
}
private final void init() {
char[] buffer = new char[1024];
+ // Read initial USB state (device mode)
mConfiguration = -1;
try {
FileReader file = new FileReader(USB_CONNECTED_PATH);
if (mConfiguration < 0)
return;
+ // Read initial list of enabled and disabled functions (device mode)
try {
- synchronized (mEnabledFunctions) {
- File[] files = new File(USB_COMPOSITE_CLASS_PATH).listFiles();
- for (int i = 0; i < files.length; i++) {
- File file = new File(files[i], "enable");
- FileReader reader = new FileReader(file);
- int len = reader.read(buffer, 0, 1024);
- reader.close();
- int value = Integer.valueOf((new String(buffer, 0, len)).trim());
- String functionName = files[i].getName();
- if (value == 1) {
- mEnabledFunctions.add(functionName);
- } else {
- mDisabledFunctions.add(functionName);
- }
+ File[] files = new File(USB_COMPOSITE_CLASS_PATH).listFiles();
+ for (int i = 0; i < files.length; i++) {
+ File file = new File(files[i], "enable");
+ FileReader reader = new FileReader(file);
+ int len = reader.read(buffer, 0, 1024);
+ reader.close();
+ int value = Integer.valueOf((new String(buffer, 0, len)).trim());
+ String functionName = files[i].getName();
+ if (value == 1) {
+ mEnabledFunctions.add(functionName);
+ } else {
+ mDisabledFunctions.add(functionName);
}
}
} catch (FileNotFoundException e) {
return false;
}
+ /* returns true if the USB device should not be accessible by applications (host mode) */
private boolean isBlackListed(int clazz, int subClass, int protocol) {
// blacklist hubs
if (clazz == UsbConstants.USB_CLASS_HUB) return true;
return false;
}
- // called from JNI in monitorUsbHostBus()
+ /* Called from JNI in monitorUsbHostBus() to report new USB devices (host mode) */
private void usbDeviceAdded(String deviceName, int vendorID, int productID,
int deviceClass, int deviceSubclass, int deviceProtocol,
/* array of quintuples containing id, class, subclass, protocol
return;
}
- synchronized (mDevices) {
+ synchronized (mLock) {
if (mDevices.get(deviceName) != null) {
Log.w(TAG, "device already on mDevices list: " + deviceName);
return;
}
}
- // called from JNI in monitorUsbHostBus()
+ /* Called from JNI in monitorUsbHostBus to report USB device removal (host mode) */
private void usbDeviceRemoved(String deviceName) {
- synchronized (mDevices) {
+ synchronized (mLock) {
UsbDevice device = mDevices.remove(deviceName);
if (device != null) {
Intent intent = new Intent(UsbManager.ACTION_USB_DEVICE_DETACHED);
}
void systemReady() {
- synchronized (this) {
+ synchronized (mLock) {
if (mContext.getResources().getBoolean(
com.android.internal.R.bool.config_hasUsbHostSupport)) {
// start monitoring for connected USB devices
}
}
+ /*
+ * Sends a message to update the USB connected and configured state (device mode).
+ * If delayed is true, then we add a small delay in sending the message to debounce
+ * the USB connection when enabling USB tethering.
+ */
private final void update(boolean delayed) {
- mHandler.removeMessages(MSG_UPDATE);
- mHandler.sendEmptyMessageDelayed(MSG_UPDATE, delayed ? UPDATE_DELAY : 0);
+ mHandler.removeMessages(MSG_UPDATE_STATE);
+ mHandler.sendEmptyMessageDelayed(MSG_UPDATE_STATE, delayed ? UPDATE_DELAY : 0);
}
- /* Returns a list of all currently attached USB devices */
+ /* Returns a list of all currently attached USB devices (host mdoe) */
public void getDeviceList(Bundle devices) {
mContext.enforceCallingOrSelfPermission(android.Manifest.permission.ACCESS_USB, null);
- synchronized (mDevices) {
+ synchronized (mLock) {
for (String name : mDevices.keySet()) {
devices.putParcelable(name, mDevices.get(name));
}
}
}
+ /* Opens the specified USB device (host mode) */
public ParcelFileDescriptor openDevice(String deviceName) {
if (isBlackListed(deviceName)) {
throw new SecurityException("USB device is on a restricted bus");
return nativeOpenDevice(deviceName);
}
+ /* returns the currently attached USB accessory (device mode) */
public UsbAccessory getCurrentAccessory() {
mContext.enforceCallingOrSelfPermission(android.Manifest.permission.ACCESS_USB, null);
return mCurrentAccessory;
}
+ /* opens the currently attached USB accessory (device mode) */
public ParcelFileDescriptor openAccessory() {
mContext.enforceCallingOrSelfPermission(android.Manifest.permission.ACCESS_USB, null);
return nativeOpenAccessory();
}
+ /*
+ * This handler is for deferred handling of events related to device mode and accessories.
+ */
private final Handler mHandler = new Handler() {
- private void addEnabledFunctions(Intent intent) {
- synchronized (mEnabledFunctions) {
+ private void addEnabledFunctionsLocked(Intent intent) {
// include state of all USB functions in our extras
- for (int i = 0; i < mEnabledFunctions.size(); i++) {
- intent.putExtra(mEnabledFunctions.get(i), UsbManager.USB_FUNCTION_ENABLED);
- }
- for (int i = 0; i < mDisabledFunctions.size(); i++) {
- intent.putExtra(mDisabledFunctions.get(i), UsbManager.USB_FUNCTION_DISABLED);
- }
+ for (int i = 0; i < mEnabledFunctions.size(); i++) {
+ intent.putExtra(mEnabledFunctions.get(i), UsbManager.USB_FUNCTION_ENABLED);
+ }
+ for (int i = 0; i < mDisabledFunctions.size(); i++) {
+ intent.putExtra(mDisabledFunctions.get(i), UsbManager.USB_FUNCTION_DISABLED);
}
}
@Override
public void handleMessage(Message msg) {
- switch (msg.what) {
- case MSG_UPDATE:
- synchronized (this) {
+ synchronized (mLock) {
+ switch (msg.what) {
+ case MSG_UPDATE_STATE:
if (mConnected != mLastConnected || mConfiguration != mLastConfiguration) {
if (mConnected == 0 && mCurrentAccessory != null) {
// turn off accessory mode when we are disconnected
UsbManager.USB_FUNCTION_ACCESSORY, false)) {
Log.d(TAG, "exited USB accessory mode");
+ // restore previously enabled functions
+ for (String function : mAccessoryRestoreFunctions) {
+ if (UsbManager.setFunctionEnabled(function, true)) {
+ Log.e(TAG, "could not reenable function " + function);
+ }
+ }
+ mAccessoryRestoreFunctions.clear();
+
Intent intent = new Intent(
UsbManager.ACTION_USB_ACCESSORY_DETACHED);
intent.putExtra(UsbManager.EXTRA_ACCESSORY, mCurrentAccessory);
intent.addFlags(Intent.FLAG_RECEIVER_REPLACE_PENDING);
intent.putExtra(UsbManager.USB_CONNECTED, mConnected != 0);
intent.putExtra(UsbManager.USB_CONFIGURATION, mConfiguration);
- addEnabledFunctions(intent);
+ addEnabledFunctionsLocked(intent);
mContext.sendStickyBroadcast(intent);
}
- }
- break;
+ break;
+ case MSG_FUNCTION_ENABLED:
+ case MSG_FUNCTION_DISABLED:
+ functionEnabledLocked((String)msg.obj, msg.what == MSG_FUNCTION_ENABLED);
+ break;
+ }
}
}
};
+ // host support
private native void monitorUsbHostBus();
private native ParcelFileDescriptor nativeOpenDevice(String deviceName);
+ // accessory support
private native String[] nativeGetAccessoryStrings();
private native ParcelFileDescriptor nativeOpenAccessory();
}
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