New Serial Manager API:

SerialManager: provides access to serial ports
SerialPort: for reading and writing data to and from serial ports

IO with both array based and direct ByteBuffers is supported.

Accessing serial ports requires android.permission.SERIAL_PORT permission

Each platform must configure list of supported serial ports in the
config_serialPorts resource overlay
(this is needed to prevent apps from accidentally accessing the bluetooth
or other system UARTs).

In addition, the platform uevent.rc file must set the owner to the
/dev/tty* files to "system" so the framework can access the port.

Signed-off-by: Mike Lockwood <lockwood@android.com>

services/java/com/android/server/SerialService.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2011 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 an
+ * limitations under the License.
+ */
+
+package com.android.server;
+
+import android.content.Context;
+import android.hardware.ISerialManager;
+import android.os.ParcelFileDescriptor;
+
+import java.io.File;
+import java.util.ArrayList;
+
+public class SerialService extends ISerialManager.Stub {
+
+    private final Context mContext;
+    private final String[] mSerialPorts;
+
+    public SerialService(Context context) {
+        mContext = context;
+        mSerialPorts = context.getResources().getStringArray(
+                com.android.internal.R.array.config_serialPorts);
+    }
+
+    public String[] getSerialPorts() {
+        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.SERIAL_PORT, null);
+
+        ArrayList<String> ports = new ArrayList<String>();
+        for (int i = 0; i < mSerialPorts.length; i++) {
+            String path = mSerialPorts[i];
+            if (new File(path).exists()) {
+                ports.add(path);
+            }
+        }
+        String[] result = new String[ports.size()];
+        ports.toArray(result);
+        return result;
+    }
+
+    public ParcelFileDescriptor openSerialPort(String path) {
+        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.SERIAL_PORT, null);
+        return native_open(path);
+    }
+
+    private native ParcelFileDescriptor native_open(String path);
+}