Merge "Monitor alsa device files to notify USB devices connection." (82c57ac4) · Commits · e / os / android_frameworks_base

services/usb/java/com/android/server/usb/UsbAlsaManager.java

+111 −0

Original line number	Diff line number	Diff line
		@@ -23,7 +23,9 @@ import android.hardware.usb.UsbDevice;
		import android.media.IAudioService;
		import android.media.midi.MidiDeviceInfo;
		import android.os.Bundle;
		import android.os.FileObserver;
		import android.os.ServiceManager;
		import android.os.SystemClock;
		import android.provider.Settings;
		import android.service.usb.UsbAlsaManagerProto;
		import android.util.Slog;
		@@ -34,9 +36,11 @@ import com.android.server.usb.descriptors.UsbDescriptorParser;

		import libcore.io.IoUtils;

		import java.io.File;
		import java.util.ArrayList;
		import java.util.Arrays;
		import java.util.HashMap;
		import java.util.HashSet;
		import java.util.List;

		/**
		@@ -52,6 +56,11 @@ public final class UsbAlsaManager {

		private static final String ALSA_DIRECTORY = "/dev/snd/";

		private static final int ALSA_DEVICE_TYPE_UNKNOWN = 0;
		private static final int ALSA_DEVICE_TYPE_PLAYBACK = 1;
		private static final int ALSA_DEVICE_TYPE_CAPTURE = 2;
		private static final int ALSA_DEVICE_TYPE_MIDI = 3;

		private final Context mContext;
		private IAudioService mAudioService;
		private final boolean mHasMidiFeature;
		@@ -116,6 +125,21 @@ public final class UsbAlsaManager {
		// UsbMidiDevice for USB peripheral mode (gadget) device
		private UsbMidiDevice mPeripheralMidiDevice = null;

		private final HashSet<Integer> mAlsaCards = new HashSet<>();
		private final FileObserver mAlsaObserver = new FileObserver(new File(ALSA_DIRECTORY),
		FileObserver.CREATE \| FileObserver.DELETE) {
		public void onEvent(int event, String path) {
		switch (event) {
		case FileObserver.CREATE:
		alsaFileAdded(path);
		break;
		case FileObserver.DELETE:
		alsaFileRemoved(path);
		break;
		}
		}
		};

		/* package */ UsbAlsaManager(Context context) {
		mContext = context;
		mHasMidiFeature = context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_MIDI);
		@@ -124,6 +148,7 @@ public final class UsbAlsaManager {
		public void systemReady() {
		mAudioService = IAudioService.Stub.asInterface(
		ServiceManager.getService(Context.AUDIO_SERVICE));
		mAlsaObserver.startWatching();
		}

		/**
		@@ -224,6 +249,8 @@ public final class UsbAlsaManager {
		return;
		}

		waitForAlsaDevice(cardRec.getCardNum(), true /isAdded/);

		// Add it to the devices list
		boolean hasInput = parser.hasInput()
		&& !isDeviceDenylisted(usbDevice.getVendorId(), usbDevice.getProductId(),
		@@ -322,6 +349,7 @@ public final class UsbAlsaManager {
		UsbAlsaDevice alsaDevice = removeAlsaDeviceFromList(deviceAddress);
		Slog.i(TAG, "USB Audio Device Removed: " + alsaDevice);
		if (alsaDevice != null && alsaDevice == mSelectedDevice) {
		waitForAlsaDevice(alsaDevice.getCardNum(), false /isAdded/);
		deselectAlsaDevice();
		selectDefaultDevice(); // if there any external devices left, select one of them
		}
		@@ -361,6 +389,89 @@ public final class UsbAlsaManager {
		}
		}

		private boolean waitForAlsaDevice(int card, boolean isAdded) {
		if (DEBUG) {
		Slog.e(TAG, "waitForAlsaDevice(c:" + card + ")");
		}

		// This value was empirically determined.
		final int kWaitTimeMs = 2500;

		synchronized (mAlsaCards) {
		long timeoutMs = SystemClock.elapsedRealtime() + kWaitTimeMs;
		while ((isAdded ^ mAlsaCards.contains(card))
		&& timeoutMs > SystemClock.elapsedRealtime()) {
		long waitTimeMs = timeoutMs - SystemClock.elapsedRealtime();
		if (waitTimeMs > 0) {
		try {
		mAlsaCards.wait(waitTimeMs);
		} catch (InterruptedException e) {
		Slog.d(TAG, "usb: InterruptedException while waiting for ALSA file.");
		}
		}
		}
		final boolean cardFound = mAlsaCards.contains(card);
		if ((isAdded ^ cardFound) && timeoutMs > SystemClock.elapsedRealtime()) {
		Slog.e(TAG, "waitForAlsaDevice(" + card + ") timeout");
		} else {
		Slog.i(TAG, "waitForAlsaDevice for device card=" + card + ", isAdded=" + isAdded
		+ ", found=" + cardFound);
		}
		return cardFound;
		}
		}

		private int getCardNumberFromAlsaFilePath(String path) {
		int type = ALSA_DEVICE_TYPE_UNKNOWN;
		if (path.startsWith("pcmC")) {
		if (path.endsWith("p")) {
		type = ALSA_DEVICE_TYPE_PLAYBACK;
		} else if (path.endsWith("c")) {
		type = ALSA_DEVICE_TYPE_CAPTURE;
		}
		} else if (path.startsWith("midiC")) {
		type = ALSA_DEVICE_TYPE_MIDI;
		}

		if (type == ALSA_DEVICE_TYPE_UNKNOWN) {
		Slog.i(TAG, "Unknown type file(" + path + ") added.");
		return -1;
		}
		try {
		int c_index = path.indexOf('C');
		int d_index = path.indexOf('D');
		return Integer.parseInt(path.substring(c_index + 1, d_index));
		} catch (Exception e) {
		Slog.e(TAG, "Could not parse ALSA file name " + path, e);
		return -1;
		}
		}

		private void alsaFileAdded(String path) {
		Slog.i(TAG, "alsaFileAdded(" + path + ")");
		final int card = getCardNumberFromAlsaFilePath(path);
		if (card == -1) {
		return;
		}
		synchronized (mAlsaCards) {
		if (!mAlsaCards.contains(card)) {
		Slog.d(TAG, "Adding ALSA device card=" + card);
		mAlsaCards.add(card);
		mAlsaCards.notifyAll();
		}
		}
		}

		private void alsaFileRemoved(String path) {
		final int card = getCardNumberFromAlsaFilePath(path);
		if (card == -1) {
		return;
		}
		synchronized (mAlsaCards) {
		mAlsaCards.remove(card);
		}
		}

		//
		// Devices List
		//