1 /*
2  * Copyright 2018 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #pragma once
18 
19 #include <mutex>
20 #include <unordered_map>
21 
22 #include <android/hardware/bluetooth/audio/2.0/IBluetoothAudioPort.h>
23 #include <fmq/MessageQueue.h>
24 #include <hardware/audio.h>
25 #include <hidl/MQDescriptor.h>
26 
27 namespace android {
28 namespace bluetooth {
29 namespace audio {
30 
31 using ::android::sp;
32 using ::android::hardware::kSynchronizedReadWrite;
33 using ::android::hardware::MessageQueue;
34 using ::android::hardware::bluetooth::audio::V2_0::AudioConfiguration;
35 using ::android::hardware::bluetooth::audio::V2_0::BitsPerSample;
36 using ::android::hardware::bluetooth::audio::V2_0::ChannelMode;
37 using ::android::hardware::bluetooth::audio::V2_0::CodecConfiguration;
38 using ::android::hardware::bluetooth::audio::V2_0::IBluetoothAudioPort;
39 using ::android::hardware::bluetooth::audio::V2_0::PcmParameters;
40 using ::android::hardware::bluetooth::audio::V2_0::SampleRate;
41 using ::android::hardware::bluetooth::audio::V2_0::SessionType;
42 
43 using BluetoothAudioStatus =
44     ::android::hardware::bluetooth::audio::V2_0::Status;
45 
46 using DataMQ = MessageQueue<uint8_t, kSynchronizedReadWrite>;
47 
48 static constexpr uint16_t kObserversCookieSize = 0x0010;  // 0x0000 ~ 0x000f
49 constexpr uint16_t kObserversCookieUndefined =
50     (static_cast<uint16_t>(SessionType::UNKNOWN) << 8 & 0xff00);
ObserversCookieGetSessionType(uint16_t cookie)51 inline SessionType ObserversCookieGetSessionType(uint16_t cookie) {
52   return static_cast<SessionType>(cookie >> 8 & 0x00ff);
53 }
ObserversCookieGetInitValue(SessionType session_type)54 inline uint16_t ObserversCookieGetInitValue(SessionType session_type) {
55   return (static_cast<uint16_t>(session_type) << 8 & 0xff00);
56 }
ObserversCookieGetUpperBound(SessionType session_type)57 inline uint16_t ObserversCookieGetUpperBound(SessionType session_type) {
58   return (static_cast<uint16_t>(session_type) << 8 & 0xff00) +
59          kObserversCookieSize;
60 }
61 
62 // This presents the callbacks of started / suspended and session changed,
63 // and the bluetooth_audio module uses to receive the status notification
64 struct PortStatusCallbacks {
65   // control_result_cb_ - when the Bluetooth stack reports results of
66   // streamStarted or streamSuspended, the BluetoothAudioProvider will invoke
67   // this callback to report to the bluetooth_audio module.
68   // @param: cookie - indicates which bluetooth_audio output should handle
69   // @param: start_resp - this report is for startStream or not
70   // @param: status - the result of startStream
71   std::function<void(uint16_t cookie, bool start_resp,
72                      const BluetoothAudioStatus& status)>
73       control_result_cb_;
74   // session_changed_cb_ - when the Bluetooth stack start / end session, the
75   // BluetoothAudioProvider will invoke this callback to notify to the
76   // bluetooth_audio module.
77   // @param: cookie - indicates which bluetooth_audio output should handle
78   std::function<void(uint16_t cookie)> session_changed_cb_;
79 };
80 
81 class BluetoothAudioSession {
82   friend class BluetoothAudioSession_2_1;
83   friend class BluetoothAudioSession_2_2;
84 
85  private:
86   // using recursive_mutex to allow hwbinder to re-enter agian.
87   std::recursive_mutex mutex_;
88   SessionType session_type_;
89 
90   // audio control path to use for both software and offloading
91   sp<IBluetoothAudioPort> stack_iface_;
92   // audio data path (FMQ) for software encoding
93   std::unique_ptr<DataMQ> mDataMQ;
94   // audio data configuration for both software and offloading
95   AudioConfiguration audio_config_;
96 
97   static AudioConfiguration invalidSoftwareAudioConfiguration;
98   static AudioConfiguration invalidOffloadAudioConfiguration;
99 
100   // saving those registered bluetooth_audio's callbacks
101   std::unordered_map<uint16_t, std::shared_ptr<struct PortStatusCallbacks>>
102       observers_;
103 
104   bool UpdateDataPath(const DataMQ::Descriptor* dataMQ);
105   bool UpdateAudioConfig(const AudioConfiguration& audio_config);
106   // invoking the registered session_changed_cb_
107   void ReportSessionStatus();
108 
109  public:
110   BluetoothAudioSession(const SessionType& session_type);
111 
112   // The function helps to check if this session is ready or not
113   // @return: true if the Bluetooth stack has started the specified session
114   bool IsSessionReady();
115 
116   // The report function is used to report that the Bluetooth stack has started
117   // this session without any failure, and will invoke session_changed_cb_ to
118   // notify those registered bluetooth_audio outputs
119   void OnSessionStarted(const sp<IBluetoothAudioPort> stack_iface,
120                         const DataMQ::Descriptor* dataMQ,
121                         const AudioConfiguration& audio_config);
122 
123   // The report function is used to report that the Bluetooth stack has ended
124   // the session, and will invoke session_changed_cb_ to notify registered
125   // bluetooth_audio outputs
126   void OnSessionEnded();
127 
128   // The report function is used to report that the Bluetooth stack has notified
129   // the result of startStream or suspendStream, and will invoke
130   // control_result_cb_ to notify registered bluetooth_audio outputs
131   void ReportControlStatus(bool start_resp, const BluetoothAudioStatus& status);
132 
133   // The control function helps the bluetooth_audio module to register
134   // PortStatusCallbacks
135   // @return: cookie - the assigned number to this bluetooth_audio output
136   uint16_t RegisterStatusCback(const PortStatusCallbacks& cbacks);
137 
138   // The control function helps the bluetooth_audio module to unregister
139   // PortStatusCallbacks
140   // @param: cookie - indicates which bluetooth_audio output is
141   void UnregisterStatusCback(uint16_t cookie);
142 
143   // The control function is for the bluetooth_audio module to get the current
144   // AudioConfiguration
145   const AudioConfiguration& GetAudioConfig();
146 
147   // Those control functions are for the bluetooth_audio module to start,
148   // suspend, stop stream, to check position, and to update metadata.
149   bool StartStream();
150   bool SuspendStream();
151   void StopStream();
152   bool GetPresentationPosition(uint64_t* remote_delay_report_ns,
153                                uint64_t* total_bytes_readed,
154                                timespec* data_position);
155   void UpdateTracksMetadata(const struct source_metadata* source_metadata);
156 
157   // The control function writes stream to FMQ
158   size_t OutWritePcmData(const void* buffer, size_t bytes);
159   // The control function read stream from FMQ
160   size_t InReadPcmData(void* buffer, size_t bytes);
161 
162   static constexpr PcmParameters kInvalidPcmParameters = {
163       .sampleRate = SampleRate::RATE_UNKNOWN,
164       .channelMode = ChannelMode::UNKNOWN,
165       .bitsPerSample = BitsPerSample::BITS_UNKNOWN,
166   };
167   // can't be constexpr because of non-literal type
168   static const CodecConfiguration kInvalidCodecConfiguration;
169 
170   static constexpr AudioConfiguration& kInvalidSoftwareAudioConfiguration =
171       invalidSoftwareAudioConfiguration;
172   static constexpr AudioConfiguration& kInvalidOffloadAudioConfiguration =
173       invalidOffloadAudioConfiguration;
174 };
175 
176 class BluetoothAudioSessionInstance {
177  public:
178   // The API is to fetch the specified session of A2DP / Hearing Aid
179   static std::shared_ptr<BluetoothAudioSession> GetSessionInstance(
180       const SessionType& session_type);
181 
182  private:
183   static std::unique_ptr<BluetoothAudioSessionInstance> instance_ptr;
184   std::mutex mutex_;
185   std::unordered_map<SessionType, std::shared_ptr<BluetoothAudioSession>>
186       sessions_map_;
187 };
188 
189 }  // namespace audio
190 }  // namespace bluetooth
191 }  // namespace android
192