diff options
Diffstat (limited to 'lowpan_hdlc_adapter/hdlc_lite.h')
-rw-r--r-- | lowpan_hdlc_adapter/hdlc_lite.h | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/lowpan_hdlc_adapter/hdlc_lite.h b/lowpan_hdlc_adapter/hdlc_lite.h new file mode 100644 index 0000000..4d4d554 --- /dev/null +++ b/lowpan_hdlc_adapter/hdlc_lite.h @@ -0,0 +1,57 @@ +/* + * 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 |