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| author | Evgeniy Polyakov <johnpol@2ka.mipt.ru> | 2005-08-17 15:17:26 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2005-09-08 14:41:27 -0700 |
| commit | 7657ec1fcb69e266ab876af56332d0c484ca6d00 (patch) | |
| tree | 6118ceffa2f83f43c3086941d96011dc1abeb459 /include/linux | |
| parent | a3d65f254274567daa89d8b99ab3d481d60fcaef (diff) | |
| download | linux-3.10-7657ec1fcb69e266ab876af56332d0c484ca6d00.tar.gz linux-3.10-7657ec1fcb69e266ab876af56332d0c484ca6d00.tar.bz2 linux-3.10-7657ec1fcb69e266ab876af56332d0c484ca6d00.zip | |
[PATCH] lib/crc16: added crc16 algorithm.
Add the crc16 routines, as used by w1 devices.
Signed-off-by: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/crc16.h | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/include/linux/crc16.h b/include/linux/crc16.h new file mode 100644 index 00000000000..bdedf825b04 --- /dev/null +++ b/include/linux/crc16.h @@ -0,0 +1,44 @@ +/* + * 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 */ + |