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  private:
83   // using recursive_mutex to allow hwbinder to re-enter agian.
84   std::recursive_mutex mutex_;
85   SessionType session_type_;
86 
87   // audio control path to use for both software and offloading
88   sp<IBluetoothAudioPort> stack_iface_;
89   // audio data path (FMQ) for software encoding
90   std::unique_ptr<DataMQ> mDataMQ;
91   // audio data configuration for both software and offloading
92   AudioConfiguration audio_config_;
93 
94   static AudioConfiguration invalidSoftwareAudioConfiguration;
95   static AudioConfiguration invalidOffloadAudioConfiguration;
96 
97   // saving those registered bluetooth_audio's callbacks
98   std::unordered_map<uint16_t, std::shared_ptr<struct PortStatusCallbacks>>
99       observers_;
100 
101   bool UpdateDataPath(const DataMQ::Descriptor* dataMQ);
102   bool UpdateAudioConfig(const AudioConfiguration& audio_config);
103   // invoking the registered session_changed_cb_
104   void ReportSessionStatus();
105 
106  public:
107   BluetoothAudioSession(const SessionType& session_type);
108 
109   // The function helps to check if this session is ready or not
110   // @return: true if the Bluetooth stack has started the specified session
111   bool IsSessionReady();
112 
113   // The report function is used to report that the Bluetooth stack has started
114   // this session without any failure, and will invoke session_changed_cb_ to
115   // notify those registered bluetooth_audio outputs
116   void OnSessionStarted(const sp<IBluetoothAudioPort> stack_iface,
117                         const DataMQ::Descriptor* dataMQ,
118                         const AudioConfiguration& audio_config);
119 
120   // The report function is used to report that the Bluetooth stack has ended
121   // the session, and will invoke session_changed_cb_ to notify registered
122   // bluetooth_audio outputs
123   void OnSessionEnded();
124 
125   // The report function is used to report that the Bluetooth stack has notified
126   // the result of startStream or suspendStream, and will invoke
127   // control_result_cb_ to notify registered bluetooth_audio outputs
128   void ReportControlStatus(bool start_resp, const BluetoothAudioStatus& status);
129 
130   // The control function helps the bluetooth_audio module to register
131   // PortStatusCallbacks
132   // @return: cookie - the assigned number to this bluetooth_audio output
133   uint16_t RegisterStatusCback(const PortStatusCallbacks& cbacks);
134 
135   // The control function helps the bluetooth_audio module to unregister
136   // PortStatusCallbacks
137   // @param: cookie - indicates which bluetooth_audio output is
138   void UnregisterStatusCback(uint16_t cookie);
139 
140   // The control function is for the bluetooth_audio module to get the current
141   // AudioConfiguration
142   const AudioConfiguration& GetAudioConfig();
143 
144   // Those control functions are for the bluetooth_audio module to start,
145   // suspend, stop stream, to check position, and to update metadata.
146   bool StartStream();
147   bool SuspendStream();
148   void StopStream();
149   bool GetPresentationPosition(uint64_t* remote_delay_report_ns,
150                                uint64_t* total_bytes_readed,
151                                timespec* data_position);
152   void UpdateTracksMetadata(const struct source_metadata* source_metadata);
153 
154   // The control function writes stream to FMQ
155   size_t OutWritePcmData(const void* buffer, size_t bytes);
156 
157   static constexpr PcmParameters kInvalidPcmParameters = {
158       .sampleRate = SampleRate::RATE_UNKNOWN,
159       .channelMode = ChannelMode::UNKNOWN,
160       .bitsPerSample = BitsPerSample::BITS_UNKNOWN,
161   };
162   // can't be constexpr because of non-literal type
163   static const CodecConfiguration kInvalidCodecConfiguration;
164 
165   static constexpr AudioConfiguration& kInvalidSoftwareAudioConfiguration =
166       invalidSoftwareAudioConfiguration;
167   static constexpr AudioConfiguration& kInvalidOffloadAudioConfiguration =
168       invalidOffloadAudioConfiguration;
169 };
170 
171 class BluetoothAudioSessionInstance {
172  public:
173   // The API is to fetch the specified session of A2DP / Hearing Aid
174   static std::shared_ptr<BluetoothAudioSession> GetSessionInstance(
175       const SessionType& session_type);
176 
177  private:
178   static std::unique_ptr<BluetoothAudioSessionInstance> instance_ptr;
179   std::mutex mutex_;
180   std::unordered_map<SessionType, std::shared_ptr<BluetoothAudioSession>>
181       sessions_map_;
182 };
183 
184 }  // namespace audio
185 }  // namespace bluetooth
186 }  // namespace android
187