Implementation of Bluetooth Audio HAL interface v2

This is the default implementation of Bluetooth Audio Hal v2, and 3
providers are defined.

* BluetoothAudioProvider is the default provider, which is a stub when
  no SessionType matched.
* A2dpSoftwareAudioProvider uses to replace the old A2DP legacy module
  and uses IPC via HIDL interface between Bluetooth stack and Audio HAL.
* HearingAidAudioProvider uses to replace the Hearing Aids module which
  uses UNIX socket as IPC and now there is HIDL based interface.

There is also a shared library named "libbluetooth_audio_session.so" to
provide the linkage directly between this HIDL and its HAL module,
bluetooth_audio. With this library, we can break the library dependency
and guarantee those symbols of libraries while compiling.

Bug: 111519504
Bug: 122503379
Test: boot and manual test

Change-Id: I54d86291482b7fb041a3ac3e171b68a4ed7bfa07
diff --git a/bluetooth/audio/2.0/default/BluetoothAudioProvider.cpp b/bluetooth/audio/2.0/default/BluetoothAudioProvider.cpp
new file mode 100644
index 0000000..ab8973e
--- /dev/null
+++ b/bluetooth/audio/2.0/default/BluetoothAudioProvider.cpp
@@ -0,0 +1,143 @@
+/*
+ * Copyright 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.
+ */
+
+#define LOG_TAG "BTAudioProviderStub"
+
+#include <android-base/logging.h>
+
+#include "BluetoothAudioProvider.h"
+#include "BluetoothAudioSessionReport.h"
+#include "BluetoothAudioSupportedCodecsDB.h"
+
+namespace android {
+namespace hardware {
+namespace bluetooth {
+namespace audio {
+namespace V2_0 {
+namespace implementation {
+
+using ::android::bluetooth::audio::BluetoothAudioSessionReport;
+using ::android::hardware::kSynchronizedReadWrite;
+using ::android::hardware::MessageQueue;
+using ::android::hardware::Void;
+
+using DataMQ = MessageQueue<uint8_t, kSynchronizedReadWrite>;
+
+void BluetoothAudioDeathRecipient::serviceDied(
+    uint64_t cookie __unused,
+    const wp<::android::hidl::base::V1_0::IBase>& who __unused) {
+  LOG(ERROR) << "BluetoothAudioDeathRecipient::" << __func__
+             << " - BluetoothAudio Service died";
+  provider_->endSession();
+}
+
+BluetoothAudioProvider::BluetoothAudioProvider()
+    : death_recipient_(new BluetoothAudioDeathRecipient(this)),
+      session_type_(SessionType::UNKNOWN),
+      audio_config_({}) {}
+
+Return<void> BluetoothAudioProvider::startSession(
+    const sp<IBluetoothAudioPort>& hostIf,
+    const AudioConfiguration& audioConfig, startSession_cb _hidl_cb) {
+  if (hostIf == nullptr) {
+    _hidl_cb(BluetoothAudioStatus::FAILURE, DataMQ::Descriptor());
+    return Void();
+  }
+
+  /**
+   * Initialize the audio platform if audioConfiguration is supported.
+   * Save the the IBluetoothAudioPort interface, so that it can be used
+   * later to send stream control commands to the HAL client, based on
+   * interaction with Audio framework.
+   */
+  audio_config_ = audioConfig;
+  stack_iface_ = hostIf;
+  stack_iface_->linkToDeath(death_recipient_, 0);
+
+  LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_)
+            << ", AudioConfiguration=[" << toString(audio_config_) << "]";
+
+  onSessionReady(_hidl_cb);
+  return Void();
+}
+
+Return<void> BluetoothAudioProvider::streamStarted(
+    BluetoothAudioStatus status) {
+  LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_)
+            << ", status=" << toString(status);
+
+  /**
+   * Streaming on control path has started,
+   * HAL server should start the streaming on data path.
+   */
+  if (stack_iface_) {
+    BluetoothAudioSessionReport::ReportControlStatus(session_type_, true,
+                                                     status);
+  } else {
+    LOG(WARNING) << __func__ << " - SessionType=" << toString(session_type_)
+                 << ", status=" << toString(status) << " has NO session";
+  }
+
+  return Void();
+}
+
+Return<void> BluetoothAudioProvider::streamSuspended(
+    BluetoothAudioStatus status) {
+  LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_)
+            << ", status=" << toString(status);
+
+  /**
+   * Streaming on control path has suspend,
+   * HAL server should suspend the streaming on data path.
+   */
+  if (stack_iface_) {
+    BluetoothAudioSessionReport::ReportControlStatus(session_type_, false,
+                                                     status);
+  } else {
+    LOG(WARNING) << __func__ << " - SessionType=" << toString(session_type_)
+                 << ", status=" << toString(status) << " has NO session";
+  }
+
+  return Void();
+}
+
+Return<void> BluetoothAudioProvider::endSession() {
+  LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_);
+
+  if (stack_iface_) {
+    BluetoothAudioSessionReport::OnSessionEnded(session_type_);
+    stack_iface_->unlinkToDeath(death_recipient_);
+  } else {
+    LOG(INFO) << __func__ << " - SessionType=" << toString(session_type_)
+              << " has NO session";
+  }
+
+  /**
+   * Clean up the audio platform as remote audio device is no
+   * longer active
+   */
+  stack_iface_ = nullptr;
+  audio_config_ = {};
+
+  return Void();
+}
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace hardware
+}  // namespace android