Add HdmiEarcController stub

Add initial methods.
Bind to HdmiControlService.
Don´t yet bind to native.
Make the presence of the controller a condition for eARC being
available on the device.

Test: make
Bug: 240388106

Change-Id: Id57fa5ad5d567f8d8d58e23bbf4d1ea8df0ac89b

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

@@ -127,6 +127,8 @@ import java.util.stream.Collectors;
 /**
  * Provides a service for sending and processing HDMI control messages,
  * HDMI-CEC and MHL control command, and providing the information on both standard.
+ *
+ * Additionally takes care of establishing and managing an eARC connection.
  */
 public class HdmiControlService extends SystemService {
     private static final String TAG = "HdmiControlService";
@@ -386,7 +388,8 @@ public class HdmiControlService extends SystemService {
     @HdmiControlManager.HdmiCecControl
     private int mHdmiControlEnabled;
 
-    // Set to true while the eARC feature is supported by the hardware and the eARC HAL is present.
+    // Set to true while the eARC feature is supported by the hardware on at least one port
+    // and the eARC HAL is present.
     @GuardedBy("mLock")
     @VisibleForTesting
     protected boolean mEarcSupported;
@@ -428,6 +431,9 @@ public class HdmiControlService extends SystemService {
 
     private HdmiCecPowerStatusController mPowerStatusController;
 
+    @Nullable
+    private HdmiEarcController mEarcController;
+
     @Nullable
     private HdmiEarcLocalDevice mEarcLocalDevice;
 
@@ -664,7 +670,6 @@ public class HdmiControlService extends SystemService {
         }
         if (mCecController == null) {
             Slog.i(TAG, "Device does not support HDMI-CEC.");
-            return;
         }
         if (mMhlController == null) {
             mMhlController = HdmiMhlControllerStub.create(this);
@@ -672,20 +677,46 @@ public class HdmiControlService extends SystemService {
         if (!mMhlController.isReady()) {
             Slog.i(TAG, "Device does not support MHL-control.");
         }
+        if (mEarcController == null) {
+            mEarcController = HdmiEarcController.create(this);
+        }
+        if (mEarcController == null) {
+            Slog.i(TAG, "Device does not support eARC.");
+        }
+        if (mCecController == null && mEarcController == null) {
+            return;
+        }
         mHdmiCecNetwork = new HdmiCecNetwork(this, mCecController, mMhlController);
         if (isCecControlEnabled()) {
             initializeCec(INITIATED_BY_BOOT_UP);
         } else {
             mCecController.enableCec(false);
         }
+
         synchronized (mLock) {
-            if (mEarcSupported && mEarcEnabled) {
-                initializeEarc(INITIATED_BY_BOOT_UP);
-            }
+            mMhlDevices = Collections.emptyList();
         }
-        mMhlDevices = Collections.emptyList();
 
         mHdmiCecNetwork.initPortInfo();
+        List<HdmiPortInfo> ports = getPortInfo();
+        synchronized (mLock) {
+            mEarcSupported = false;
+            for (HdmiPortInfo port : ports) {
+                if (mEarcSupported && port.isEarcSupported()) {
+                    // The HDMI specification only allows 1 active eARC connection. Android does not
+                    // support devices with multiple eARC-enabled ports.
+                    Slog.e(TAG, "HDMI eARC supported on more than 1 port.");
+                    break;
+                }
+                mEarcSupported |= port.isEarcSupported();
+            }
+
+            mEarcSupported &= (mEarcController != null);
+        }
+        if (isEarcSupportedAndEnabled()) {
+            initializeEarc(INITIATED_BY_BOOT_UP);
+        }
+
         mHdmiCecConfig.registerChangeListener(HdmiControlManager.CEC_SETTING_NAME_HDMI_CEC_ENABLED,
                 new HdmiCecConfig.SettingChangeListener() {
                     @Override

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

@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2022 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.os.Handler;
+import android.os.Looper;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+final class HdmiEarcController {
+    private static final String TAG = "HdmiEarcController";
+
+    // Handler instance to process HAL calls.
+    private Handler mControlHandler;
+
+    private final HdmiControlService mService;
+
+    // Private constructor. Use HdmiEarcController.create().
+    private HdmiEarcController(HdmiControlService service) {
+        mService = service;
+    }
+
+    /**
+     * A factory method to get {@link HdmiEarcController}. If it fails to initialize
+     * inner device or has no device it will return {@code null}.
+     *
+     * <p>Declared as package-private, accessed by {@link HdmiControlService} only.
+     * @param service    {@link HdmiControlService} instance used to create internal handler
+     *                   and to pass callback for incoming message or event.
+     * @return {@link HdmiEarcController} if device is initialized successfully. Otherwise,
+     *         returns {@code null}.
+     */
+    static HdmiEarcController create(HdmiControlService service) {
+        // TODO add the native wrapper and return null if eARC HAL is not present.
+        HdmiEarcController controller = new HdmiEarcController(service);
+        controller.init();
+        return controller;
+    }
+
+    private void init() {
+        mControlHandler = new Handler(mService.getServiceLooper());
+    }
+
+    private void assertRunOnServiceThread() {
+        if (Looper.myLooper() != mControlHandler.getLooper()) {
+            throw new IllegalStateException("Should run on service thread.");
+        }
+    }
+
+    @VisibleForTesting
+    void runOnServiceThread(Runnable runnable) {
+        mControlHandler.post(new WorkSourceUidPreservingRunnable(runnable));
+    }
+
+    /**
+     * Enable eARC in the HAL
+     * @param enabled
+     */
+    @HdmiAnnotations.ServiceThreadOnly
+    void setEarcEnabled(boolean enabled) {
+        assertRunOnServiceThread();
+        // Stub.
+        // TODO: bind to native.
+        // TODO: handle error return values here, with logging.
+    }
+
+    // TODO: bind to native.
+}