Add Usb control to svc.

We used to have control over usb via ndc but recent changes removed that.
The reverse_tether.sh script needs control (on rooted devices) to run
so added this.

bug:4208971
Change-Id: I722fc0e14540890be0d79a0b7d22f23b2d57f20c

cmds/svc/src/com/android/commands/svc/Svc.java

@@ -94,6 +94,7 @@ public class Svc {
             COMMAND_HELP,
             new PowerCommand(),
             new DataCommand(),
-            new WifiCommand()
+            new WifiCommand(),
+            new UsbCommand()
     };
 }

cmds/svc/src/com/android/commands/svc/UsbCommand.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2008 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 com.android.commands.svc;
+
+import android.content.Context;;
+import android.hardware.usb.IUsbManager;
+import android.os.RemoteException;
+import android.os.ServiceManager;
+import android.os.SystemProperties;
+
+public class UsbCommand extends Svc.Command {
+    public UsbCommand() {
+        super("usb");
+    }
+
+    public String shortHelp() {
+        return "Control Usb state";
+    }
+
+    public String longHelp() {
+        return shortHelp() + "\n"
+                + "\n"
+                + "usage: svc usb setFunction [function]\n"
+                + "         Set the current usb function.\n\n"
+                + "       svc usb getFunction\n"
+                + "          Gets the list of currently enabled functions\n";
+    }
+
+    public void run(String[] args) {
+        boolean validCommand = false;
+        if (args.length >= 2) {
+            if ("setFunction".equals(args[1])) {
+                IUsbManager usbMgr = IUsbManager.Stub.asInterface(ServiceManager.getService(
+                        Context.USB_SERVICE));
+                try {
+                    usbMgr.setCurrentFunction((args.length >=3 ? args[2] : null), false);
+                } catch (RemoteException e) {
+                    System.err.println("Error communicating with UsbManager: " + e);
+                }
+                return;
+            } else if ("getFunction".equals(args[1])) {
+                System.err.println(SystemProperties.get("sys.usb.config"));
+                return;
+            }
+        }
+        System.err.println(longHelp());
+    }
+}