| /* |
| * Copyright (C) 2017 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. |
| */ |
| |
| #ifndef HEADER_HDLC_LITE_H_INCLUDED |
| #define HEADER_HDLC_LITE_H_INCLUDED 1 |
| |
| #include <stdint.h> |
| #include <stdbool.h> |
| |
| #if defined(__cplusplus) |
| extern "C" { |
| #endif |
| |
| static const uint8_t kHdlcResetSignal[] = { 0x7E, 0x13, 0x11, 0x7E }; |
| static const uint16_t kHdlcCrcCheckValue = 0xf0b8; |
| static const uint16_t kHdlcCrcResetValue = 0xffff; |
| |
| #define HDLC_BYTE_FLAG 0x7E |
| #define HDLC_BYTE_ESC 0x7D |
| #define HDLC_BYTE_XON 0x11 |
| #define HDLC_BYTE_XOFF 0x13 |
| #define HDLC_BYTE_SPECIAL 0xF8 |
| #define HDLC_ESCAPE_XFORM 0x20 |
| |
| /** HDLC CRC function */ |
| extern uint16_t hdlc_crc16(uint16_t fcs, uint8_t byte); |
| |
| /** HDLC CRC Finalize function */ |
| extern uint16_t hdlc_crc16_finalize(uint16_t fcs); |
| |
| /** Returns true if the byte needs to be escaped, false otherwise */ |
| extern bool hdlc_byte_needs_escape(uint8_t byte); |
| |
| /** |
| * Writes one or two HDLC-encoded bytes to out_buffer, |
| * and returns how many bytes were written. |
| */ |
| extern int hdlc_write_byte(uint8_t* out_buffer, uint8_t byte); |
| |
| #if defined(__cplusplus) |
| } |
| #endif |
| |
| #endif // HEADER_HDLC_LITE_H_INCLUDED |