| 1 | /* |
| 2 | * CRC16 (CCITT) Checksum Algorithm |
| 3 | * |
| 4 | * Copyright (c) 2021 Wind River Systems, Inc. |
| 5 | * |
| 6 | * Author: |
| 7 | * Bin Meng <bin.meng@windriver.com> |
| 8 | * |
| 9 | * From Linux kernel v5.10 include/linux/crc-ccitt.h |
| 10 | * |
| 11 | * SPDX-License-Identifier: GPL-2.0-only |
| 12 | */ |
| 13 | |
| 14 | #ifndef CRC_CCITT_H |
| 15 | #define CRC_CCITT_H |
| 16 | |
| 17 | extern uint16_t const crc_ccitt_table[256]; |
| 18 | extern uint16_t const crc_ccitt_false_table[256]; |
| 19 | |
| 20 | uint16_t crc_ccitt(uint16_t crc, const uint8_t *buffer, size_t len); |
| 21 | uint16_t crc_ccitt_false(uint16_t crc, const uint8_t *buffer, size_t len); |
| 22 | |
| 23 | static inline uint16_t crc_ccitt_byte(uint16_t crc, const uint8_t c) |
| 24 | { |
| 25 | return (crc >> 8) ^ crc_ccitt_table[(crc ^ c) & 0xff]; |
| 26 | } |
| 27 | |
| 28 | static inline uint16_t crc_ccitt_false_byte(uint16_t crc, const uint8_t c) |
| 29 | { |
| 30 | return (crc << 8) ^ crc_ccitt_false_table[(crc >> 8) ^ c]; |
| 31 | } |
| 32 | |
| 33 | #endif /* CRC_CCITT_H */ |