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/session/BluetoothAudioSession.h b/bluetooth/audio/2.0/default/session/BluetoothAudioSession.h
new file mode 100644
index 0000000..85e8742
--- /dev/null
+++ b/bluetooth/audio/2.0/default/session/BluetoothAudioSession.h
@@ -0,0 +1,185 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+#include <mutex>
+#include <unordered_map>
+
+#include <android/hardware/bluetooth/audio/2.0/IBluetoothAudioPort.h>
+#include <fmq/MessageQueue.h>
+#include <hardware/audio.h>
+#include <hidl/MQDescriptor.h>
+
+namespace android {
+namespace bluetooth {
+namespace audio {
+
+using ::android::sp;
+using ::android::hardware::kSynchronizedReadWrite;
+using ::android::hardware::MessageQueue;
+using ::android::hardware::bluetooth::audio::V2_0::AudioConfiguration;
+using ::android::hardware::bluetooth::audio::V2_0::BitsPerSample;
+using ::android::hardware::bluetooth::audio::V2_0::ChannelMode;
+using ::android::hardware::bluetooth::audio::V2_0::CodecConfiguration;
+using ::android::hardware::bluetooth::audio::V2_0::IBluetoothAudioPort;
+using ::android::hardware::bluetooth::audio::V2_0::PcmParameters;
+using ::android::hardware::bluetooth::audio::V2_0::SampleRate;
+using ::android::hardware::bluetooth::audio::V2_0::SessionType;
+
+using BluetoothAudioStatus =
+ ::android::hardware::bluetooth::audio::V2_0::Status;
+
+using DataMQ = MessageQueue<uint8_t, kSynchronizedReadWrite>;
+
+static constexpr uint16_t kObserversCookieSize = 0x0010; // 0x0000 ~ 0x000f
+constexpr uint16_t kObserversCookieUndefined =
+ (static_cast<uint16_t>(SessionType::UNKNOWN) << 8 & 0xff00);
+inline SessionType ObserversCookieGetSessionType(uint16_t cookie) {
+ return static_cast<SessionType>(cookie >> 8 & 0x00ff);
+}
+inline uint16_t ObserversCookieGetInitValue(SessionType session_type) {
+ return (static_cast<uint16_t>(session_type) << 8 & 0xff00);
+}
+inline uint16_t ObserversCookieGetUpperBound(SessionType session_type) {
+ return (static_cast<uint16_t>(session_type) << 8 & 0xff00) +
+ kObserversCookieSize;
+}
+
+// This presents the callbacks of started / suspended and session changed,
+// and the bluetooth_audio module uses to receive the status notification
+struct PortStatusCallbacks {
+ // control_result_cb_ - when the Bluetooth stack reports results of
+ // streamStarted or streamSuspended, the BluetoothAudioProvider will invoke
+ // this callback to report to the bluetooth_audio module.
+ // @param: cookie - indicates which bluetooth_audio output should handle
+ // @param: start_resp - this report is for startStream or not
+ // @param: status - the result of startStream
+ std::function<void(uint16_t cookie, bool start_resp,
+ const BluetoothAudioStatus& status)>
+ control_result_cb_;
+ // session_changed_cb_ - when the Bluetooth stack start / end session, the
+ // BluetoothAudioProvider will invoke this callback to notify to the
+ // bluetooth_audio module.
+ // @param: cookie - indicates which bluetooth_audio output should handle
+ std::function<void(uint16_t cookie)> session_changed_cb_;
+};
+
+class BluetoothAudioSession {
+ private:
+ // using recursive_mutex to allow hwbinder to re-enter agian.
+ std::recursive_mutex mutex_;
+ SessionType session_type_;
+
+ // audio control path to use for both software and offloading
+ sp<IBluetoothAudioPort> stack_iface_;
+ // audio data path (FMQ) for software encoding
+ std::unique_ptr<DataMQ> mDataMQ;
+ // audio data configuration for both software and offloading
+ AudioConfiguration audio_config_;
+
+ static AudioConfiguration invalidSoftwareAudioConfiguration;
+ static AudioConfiguration invalidOffloadAudioConfiguration;
+
+ // saving those registered bluetooth_audio's callbacks
+ std::unordered_map<uint16_t, std::shared_ptr<struct PortStatusCallbacks>>
+ observers_;
+
+ bool UpdateDataPath(const DataMQ::Descriptor* dataMQ);
+ bool UpdateAudioConfig(const AudioConfiguration& audio_config);
+ // invoking the registered session_changed_cb_
+ void ReportSessionStatus();
+
+ public:
+ BluetoothAudioSession(const SessionType& session_type);
+
+ // The function helps to check if this session is ready or not
+ // @return: true if the Bluetooth stack has started the specified session
+ bool IsSessionReady();
+
+ // The report function is used to report that the Bluetooth stack has started
+ // this session without any failure, and will invoke session_changed_cb_ to
+ // notify those registered bluetooth_audio outputs
+ void OnSessionStarted(const sp<IBluetoothAudioPort> stack_iface,
+ const DataMQ::Descriptor* dataMQ,
+ const AudioConfiguration& audio_config);
+
+ // The report function is used to report that the Bluetooth stack has ended
+ // the session, and will invoke session_changed_cb_ to notify registered
+ // bluetooth_audio outputs
+ void OnSessionEnded();
+
+ // The report function is used to report that the Bluetooth stack has notified
+ // the result of startStream or suspendStream, and will invoke
+ // control_result_cb_ to notify registered bluetooth_audio outputs
+ void ReportControlStatus(bool start_resp, const BluetoothAudioStatus& status);
+
+ // The control function helps the bluetooth_audio module to register
+ // PortStatusCallbacks
+ // @return: cookie - the assigned number to this bluetooth_audio output
+ uint16_t RegisterStatusCback(const PortStatusCallbacks& cbacks);
+
+ // The control function helps the bluetooth_audio module to unregister
+ // PortStatusCallbacks
+ // @param: cookie - indicates which bluetooth_audio output is
+ void UnregisterStatusCback(uint16_t cookie);
+
+ // The control function is for the bluetooth_audio module to get the current
+ // AudioConfiguration
+ const AudioConfiguration& GetAudioConfig();
+
+ // Those control functions are for the bluetooth_audio module to start,
+ // suspend, stop stream, to check position, and to update metadata.
+ bool StartStream();
+ bool SuspendStream();
+ void StopStream();
+ bool GetPresentationPosition(uint64_t* remote_delay_report_ns,
+ uint64_t* total_bytes_readed,
+ timespec* data_position);
+ void UpdateTracksMetadata(const struct source_metadata* source_metadata);
+
+ // The control function writes stream to FMQ
+ size_t OutWritePcmData(const void* buffer, size_t bytes);
+
+ static constexpr PcmParameters kInvalidPcmParameters = {
+ .sampleRate = SampleRate::RATE_UNKNOWN,
+ .bitsPerSample = BitsPerSample::BITS_UNKNOWN,
+ .channelMode = ChannelMode::UNKNOWN};
+ // can't be constexpr because of non-literal type
+ static const CodecConfiguration kInvalidCodecConfiguration;
+
+ static constexpr AudioConfiguration& kInvalidSoftwareAudioConfiguration =
+ invalidSoftwareAudioConfiguration;
+ static constexpr AudioConfiguration& kInvalidOffloadAudioConfiguration =
+ invalidOffloadAudioConfiguration;
+};
+
+class BluetoothAudioSessionInstance {
+ public:
+ // The API is to fetch the specified session of A2DP / Hearing Aid
+ static std::shared_ptr<BluetoothAudioSession> GetSessionInstance(
+ const SessionType& session_type);
+
+ private:
+ static std::unique_ptr<BluetoothAudioSessionInstance> instance_ptr;
+ std::mutex mutex_;
+ std::unordered_map<SessionType, std::shared_ptr<BluetoothAudioSession>>
+ sessions_map_;
+};
+
+} // namespace audio
+} // namespace bluetooth
+} // namespace android