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 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 */ 34