zephyr/include/crc16.h

81 lines
1.8 KiB
C

/*
* Copyright (c) 2017 Intel Corporation.
*
* SPDX-License-Identifier: Apache-2.0
*/
/** @file
* @brief CRC 16 computation function
*/
#ifndef __CRC16_H
#define __CRC16_H
#include <zephyr/types.h>
#include <stdbool.h>
#include <stddef.h>
/**
* @defgroup checksum Checksum
*/
/**
* @defgroup crc16 CRC 16
* @ingroup checksum
* @{
*/
/**
* @brief Generic function for computing CRC 16
*
* Compute CRC 16 by passing in the address of the input, the input length
* and polynomial used in addition to the initial value.
*
* @param src Input bytes for the computation
* @param len Length of the input in bytes
* @param polynomial The polynomial to use omitting the leading x^16
* coefficient
* @param initial_value Initial value for the CRC computation
* @param pad Adds padding with zeros at the end of input bytes
*
* @return The computed CRC16 value
*/
u16_t crc16(const u8_t *src, size_t len, u16_t polynomial,
u16_t initial_value, bool pad);
/**
* @brief Compute CCITT variant of CRC 16
*
* CCITT variant of CRC 16 is using 0x1021 as its polynomial with the initial
* value set to 0xffff.
*
* @param src Input bytes for the computation
* @param len Length of the input in bytes
*
* @return The computed CRC16 value
*/
static inline u16_t crc16_ccitt(const u8_t *src, size_t len)
{
return crc16(src, len, 0x1021, 0xffff, true);
}
/**
* @brief Compute ANSI variant of CRC 16
*
* ANSI variant of CRC 16 is using 0x8005 as its polynomial with the initial
* value set to 0xffff.
*
* @param src Input bytes for the computation
* @param len Length of the input in bytes
*
* @return The computed CRC16 value
*/
static inline u16_t crc16_ansi(const u8_t *src, size_t len)
{
return crc16(src, len, 0x8005, 0xffff, true);
}
/**
* @}
*/
#endif