Add ArcInitiationActionFromAvr

Test: make;
Change-Id: I560a97b0c409ac8a23db46038a24c537317747f7
(cherry picked from commit b69de1dc12e0860eaeb59074e62bd9216014dde6)

services/core/java/com/android/server/hdmi/ArcInitiationActionFromAvr.java

@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2018 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.server.hdmi;
+
+import android.hardware.tv.cec.V1_0.SendMessageResult;
+
+/**
+ * Feature action that handles Audio Return Channel initiated by AVR devices.
+ */
+public class ArcInitiationActionFromAvr extends HdmiCecFeatureAction {
+    // TODO(shubang): add tests
+
+    // State in which waits for ARC response.
+    private static final int STATE_WAITING_FOR_INITIATE_ARC_RESPONSE = 1;
+    private static final int STATE_ARC_INITIATED = 2;
+
+    // the required maximum response time specified in CEC 9.2
+    private static final int TIMEOUT_MS = 1000;
+
+    ArcInitiationActionFromAvr(HdmiCecLocalDevice source) {
+        super(source);
+    }
+
+    @Override
+    boolean start() {
+        audioSystem().setArcStatus(true);
+        mState = STATE_WAITING_FOR_INITIATE_ARC_RESPONSE;
+        addTimer(mState, TIMEOUT_MS);
+        sendInitiateArc();
+        return true;
+    }
+
+    @Override
+    boolean processCommand(HdmiCecMessage cmd) {
+        if (mState != STATE_WAITING_FOR_INITIATE_ARC_RESPONSE) {
+            return false;
+        }
+        switch (cmd.getOpcode()) {
+            case Constants.MESSAGE_FEATURE_ABORT:
+            case Constants.MESSAGE_REPORT_ARC_TERMINATED:
+                audioSystem().setArcStatus(false);
+                finish();
+                return true;
+            case Constants.MESSAGE_REPORT_ARC_INITIATED:
+                mState = STATE_ARC_INITIATED;
+                finish();
+                return true;
+        }
+        return false;
+    }
+
+    @Override
+    void handleTimerEvent(int state) {
+        if (mState != state) {
+            return;
+        }
+
+        switch (mState) {
+            case STATE_WAITING_FOR_INITIATE_ARC_RESPONSE:
+                handleInitiateArcTimeout();
+                break;
+        }
+    }
+
+    protected void sendInitiateArc() {
+        sendCommand(HdmiCecMessageBuilder.buildInitiateArc(getSourceAddress(), Constants.ADDR_TV),
+                result -> {
+                    if (result != SendMessageResult.SUCCESS) {
+                        audioSystem().setArcStatus(false);
+                        finish();
+                    }
+                });
+    }
+
+    private void handleInitiateArcTimeout() {
+        HdmiLogger.debug("handleInitiateArcTimeout");
+        audioSystem().setArcStatus(false);
+        finish();
+    }
+
+}

services/core/java/com/android/server/hdmi/HdmiCecLocalDeviceAudioSystem.java

@@ -21,6 +21,7 @@ import static com.android.server.hdmi.Constants.USE_LAST_STATE_SYSTEM_AUDIO_CONT
 
 import android.hardware.hdmi.HdmiDeviceInfo;
 import android.media.AudioManager;
+import android.media.AudioSystem;
 import android.os.SystemProperties;
 import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
@@ -45,6 +46,11 @@ public class HdmiCecLocalDeviceAudioSystem extends HdmiCecLocalDevice {
 
     private boolean mTvSystemAudioModeSupport;
 
+    // Whether ARC is available or not. "true" means that ARC is established between TV and
+    // AVR as audio receiver.
+    @ServiceThreadOnly
+    private boolean mArcEstablished = false;
+
     protected HdmiCecLocalDeviceAudioSystem(HdmiControlService service) {
         super(service, HdmiDeviceInfo.DEVICE_AUDIO_SYSTEM);
         mSystemAudioControlFeatureEnabled = true;
@@ -256,6 +262,39 @@ public class HdmiCecLocalDeviceAudioSystem extends HdmiCecLocalDevice {
         return true;
     }
 
+    @ServiceThreadOnly
+    void setArcStatus(boolean enabled) {
+        // TODO(shubang): add tests
+        assertRunOnServiceThread();
+
+        HdmiLogger.debug("Set Arc Status[old:%b new:%b]", mArcEstablished, enabled);
+        // 1. Enable/disable ARC circuit.
+        enableAudioReturnChannel(enabled);
+        // 2. Notify arc status to audio service.
+        notifyArcStatusToAudioService(enabled);
+        // 3. Update arc status;
+        mArcEstablished = enabled;
+    }
+
+    /**
+     * Switch hardware ARC circuit in the system.
+     */
+    @ServiceThreadOnly
+    private void enableAudioReturnChannel(boolean enabled) {
+        assertRunOnServiceThread();
+        mService.enableAudioReturnChannel(
+                SystemProperties.getInt(
+                        Constants.PROPERTY_SYSTEM_AUDIO_DEVICE_ARC_PORT, 0),
+                enabled);
+    }
+
+    private void notifyArcStatusToAudioService(boolean enabled) {
+        // Note that we don't set any name to ARC.
+        mService.getAudioManager().setWiredDeviceConnectionState(
+                AudioSystem.DEVICE_IN_HDMI,
+                enabled ? 1 : 0, "", "");
+    }
+
     private void reportAudioStatus(HdmiCecMessage message) {
         assertRunOnServiceThread();