1 files changed, 182 insertions, 0 deletions
diff --git a/android/WALT/app/src/main/java/org/chromium/latency/walt/WaltUsbConnection.java b/android/WALT/app/src/main/java/org/chromium/latency/walt/WaltUsbConnection.java
new file mode 100644
index 0000000..f118ae2
--- /dev/null
+++ b/android/WALT/app/src/main/java/org/chromium/latency/walt/WaltUsbConnection.java
@@ -0,0 +1,182 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.chromium.latency.walt;
+
+import android.content.Context;
+import android.hardware.usb.UsbDevice;
+import android.hardware.usb.UsbEndpoint;
+import android.hardware.usb.UsbInterface;
+import android.util.Log;
+
+import java.io.IOException;
+
+/**
+ * A singleton used as an interface for the physical WALT device.
+ */
+public class WaltUsbConnection extends BaseUsbConnection implements WaltConnection {
+
+    private static final int TEENSY_VID = 0x16c0;
+    // TODO: refactor to demystify PID. See BaseUsbConnection.isCompatibleUsbDevice()
+    private static final int TEENSY_PID = 0;
+    private static final int HALFKAY_PID = 0x0478;
+    private static final int USB_READ_TIMEOUT_MS = 200;
+    private static final String TAG = "WaltUsbConnection";
+
+    private UsbEndpoint endpointIn = null;
+    private UsbEndpoint endpointOut = null;
+
+    private RemoteClockInfo remoteClock = new RemoteClockInfo();
+
+    private static final Object LOCK = new Object();
+
+    private static WaltUsbConnection instance;
+
+    private WaltUsbConnection(Context context) {
+        super(context);
+    }
+
+    public static WaltUsbConnection getInstance(Context context) {
+        synchronized (LOCK) {
+            if (instance == null) {
+                instance = new WaltUsbConnection(context.getApplicationContext());
+            }
+            return instance;
+        }
+    }
+
+    @Override
+    public int getPid() {
+        return TEENSY_PID;
+    }
+
+    @Override
+    public int getVid() {
+        return TEENSY_VID;
+    }
+
+    @Override
+    protected boolean isCompatibleUsbDevice(UsbDevice usbDevice) {
+        // Allow any Teensy, but not in HalfKay bootloader mode
+        // Teensy PID depends on mode (e.g: Serail + MIDI) and also changed in TeensyDuino 1.31
+        return ((usbDevice.getProductId() != HALFKAY_PID) &&
+                (usbDevice.getVendorId() == TEENSY_VID));
+    }
+
+
+    // Called when WALT is physically unplugged from USB
+    @Override
+    public void onDisconnect() {
+        endpointIn = null;
+        endpointOut = null;
+        super.onDisconnect();
+    }
+
+
+    // Called when WALT is physically plugged into USB
+    @Override
+    public void onConnect() {
+        // Serial mode only
+        // TODO: find the interface and endpoint indexes no matter what mode it is
+        int ifIdx = 1;
+        int epInIdx = 1;
+        int epOutIdx = 0;
+
+        UsbInterface iface = usbDevice.getInterface(ifIdx);
+
+        if (usbConnection.claimInterface(iface, true)) {
+            logger.log("Interface claimed successfully\n");
+        } else {
+            logger.log("ERROR - can't claim interface\n");
+            return;
+        }
+
+        endpointIn = iface.getEndpoint(epInIdx);
+        endpointOut = iface.getEndpoint(epOutIdx);
+
+        super.onConnect();
+    }
+
+    @Override
+    public boolean isConnected() {
+        return super.isConnected() && (endpointIn != null) && (endpointOut != null);
+    }
+
+
+    @Override
+    public void sendByte(char c) throws IOException {
+        if (!isConnected()) {
+            throw new IOException("Not connected to WALT");
+        }
+        // logger.log("Sending char " + c);
+        usbConnection.bulkTransfer(endpointOut, Utils.char2byte(c), 1, 100);
+    }
+
+    @Override
+    public int blockingRead(byte[] buffer) {
+        return usbConnection.bulkTransfer(endpointIn, buffer, buffer.length, USB_READ_TIMEOUT_MS);
+    }
+
+
+    @Override
+    public RemoteClockInfo syncClock() throws IOException {
+        if (!isConnected()) {
+            throw new IOException("Not connected to WALT");
+        }
+
+        try {
+            int fd = usbConnection.getFileDescriptor();
+            int ep_out = endpointOut.getAddress();
+            int ep_in = endpointIn.getAddress();
+
+            remoteClock.baseTime = syncClock(fd, ep_out, ep_in);
+            remoteClock.minLag = 0;
+            remoteClock.maxLag = getMaxE();
+        } catch (Exception e) {
+            logger.log("Exception while syncing clocks: " + e.getStackTrace());
+        }
+        logger.log("Synced clocks, maxE=" + remoteClock.maxLag + "us");
+        Log.i(TAG, remoteClock.toString());
+        return remoteClock;
+    }
+
+    @Override
+    public void updateLag() {
+        if (! isConnected()) {
+            logger.log("ERROR: Not connected, aborting checkDrift()");
+            return;
+        }
+        updateBounds();
+        remoteClock.minLag = getMinE();
+        remoteClock.maxLag = getMaxE();
+    }
+
+
+
+    // NDK / JNI stuff
+    // TODO: add guards to avoid calls to updateBounds and getter when listener is running.
+    private native long syncClock(int fd, int endpoint_out, int endpoint_in);
+
+    private native void updateBounds();
+
+    private native int getMinE();
+
+    private native int getMaxE();
+
+    static {
+        System.loadLibrary("sync_clock_jni");
+    }
+}