1 //
2 // Copyright 2017 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 #include "hci_protocol.h"
18
19 #define LOG_TAG "android.hardware.bluetooth-hci-hci_protocol"
20 #include <android-base/logging.h>
21 #include <assert.h>
22 #include <fcntl.h>
23 #include <utils/Log.h>
24
25 namespace {
26
27 const size_t preamble_size_for_type[] = {
28 0, HCI_COMMAND_PREAMBLE_SIZE, HCI_ACL_PREAMBLE_SIZE, HCI_SCO_PREAMBLE_SIZE,
29 HCI_EVENT_PREAMBLE_SIZE};
30 const size_t packet_length_offset_for_type[] = {
31 0, HCI_LENGTH_OFFSET_CMD, HCI_LENGTH_OFFSET_ACL, HCI_LENGTH_OFFSET_SCO,
32 HCI_LENGTH_OFFSET_EVT};
33
HciGetPacketLengthForType(HciPacketType type,const uint8_t * preamble)34 size_t HciGetPacketLengthForType(HciPacketType type, const uint8_t* preamble) {
35 size_t offset = packet_length_offset_for_type[type];
36 if (type != HCI_PACKET_TYPE_ACL_DATA) return preamble[offset];
37 return (((preamble[offset + 1]) << 8) | preamble[offset]);
38 }
39
40 } // namespace
41
42 namespace android {
43 namespace hardware {
44 namespace bluetooth {
45 namespace hci {
46
WriteSafely(int fd,const uint8_t * data,size_t length)47 size_t HciProtocol::WriteSafely(int fd, const uint8_t* data, size_t length) {
48 size_t transmitted_length = 0;
49 while (length > 0) {
50 ssize_t ret =
51 TEMP_FAILURE_RETRY(write(fd, data + transmitted_length, length));
52
53 if (ret == -1) {
54 if (errno == EAGAIN) continue;
55 ALOGE("%s error writing to UART (%s)", __func__, strerror(errno));
56 break;
57
58 } else if (ret == 0) {
59 // Nothing written :(
60 ALOGE("%s zero bytes written - something went wrong...", __func__);
61 break;
62 }
63
64 transmitted_length += ret;
65 length -= ret;
66 }
67
68 return transmitted_length;
69 }
70
71 } // namespace hci
72 } // namespace bluetooth
73 } // namespace hardware
74 } // namespace android
75