1 /* 2 * Copyright 2022 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 <memory> 20 #include <vector> 21 22 #include "hci_internals.h" 23 #include "hci_packetizer.h" 24 25 namespace android::hardware::bluetooth::hci { 26 27 using PacketReadCallback = std::function<void(const std::vector<uint8_t>&)>; 28 using DisconnectCallback = std::function<void(void)>; 29 30 class H4Protocol { 31 public: 32 H4Protocol(int fd, PacketReadCallback cmd_cb, PacketReadCallback acl_cb, 33 PacketReadCallback sco_cb, PacketReadCallback event_cb, 34 PacketReadCallback iso_cb, DisconnectCallback disconnect_cb); 35 36 size_t Send(PacketType type, const uint8_t* data, size_t length); 37 size_t Send(PacketType type, const std::vector<uint8_t>& data); 38 39 void OnDataReady(); 40 41 protected: 42 size_t OnPacketReady(const std::vector<uint8_t>& packet); 43 void SendDataToPacketizer(uint8_t* buffer, size_t length); 44 45 private: 46 int uart_fd_; 47 bool disconnected_{false}; 48 49 PacketReadCallback cmd_cb_; 50 PacketReadCallback acl_cb_; 51 PacketReadCallback sco_cb_; 52 PacketReadCallback event_cb_; 53 PacketReadCallback iso_cb_; 54 DisconnectCallback disconnect_cb_; 55 56 PacketType hci_packet_type_{PacketType::UNKNOWN}; 57 HciPacketizer hci_packetizer_; 58 59 /** 60 * Question : Why read in single chunk rather than multiple reads? 61 * Answer: Using multiple reads does not work with some BT USB dongles. 62 * Reading in single shot gives expected response. 63 * ACL max length is 2 bytes, so using 64K as the buffer length. 64 */ 65 static constexpr size_t kMaxPacketLength = 64 * 1024; 66 }; 67 68 } // namespace android::hardware::bluetooth::hci 69