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/*
* crc16.h - CRC-16 routine
*
* Implements the standard CRC-16, as used with 1-wire devices:
* Width 16
* Poly 0x8005 (x^16 + x^15 + x^2 + 1)
* Init 0
*
* For 1-wire devices, the CRC is stored inverted, LSB-first
*
* Example buffer with the CRC attached:
* 31 32 33 34 35 36 37 38 39 C2 44
*
* The CRC over a buffer with the CRC attached is 0xB001.
* So, if (crc16(0, buf, size) == 0xB001) then the buffer is valid.
*
* Refer to "Application Note 937: Book of iButton Standards" for details.
* http://www.maxim-ic.com/appnotes.cfm/appnote_number/937
*
* Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#ifndef __CRC16_H
#define __CRC16_H
#include <linux/types.h>
#define CRC16_INIT 0
#define CRC16_VALID 0xb001
extern u16 const crc16_table[256];
extern u16 crc16(u16 crc, const u8 *buffer, size_t len);
static inline u16 crc16_byte(u16 crc, const u8 data)
{
return (crc >> 8) ^ crc16_table[(crc ^ data) & 0xff];
}
#endif /* __CRC16_H */
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