diff options
author | Evgeniy Polyakov <johnpol@2ka.mipt.ru> | 2005-08-17 07:17:26 -0400 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@suse.de> | 2005-09-08 17:41:27 -0400 |
commit | 7657ec1fcb69e266ab876af56332d0c484ca6d00 (patch) | |
tree | 6118ceffa2f83f43c3086941d96011dc1abeb459 /include/linux/crc16.h | |
parent | a3d65f254274567daa89d8b99ab3d481d60fcaef (diff) |
[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/crc16.h')
-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 @@ | |||
1 | /* | ||
2 | * crc16.h - CRC-16 routine | ||
3 | * | ||
4 | * Implements the standard CRC-16, as used with 1-wire devices: | ||
5 | * Width 16 | ||
6 | * Poly 0x8005 (x^16 + x^15 + x^2 + 1) | ||
7 | * Init 0 | ||
8 | * | ||
9 | * For 1-wire devices, the CRC is stored inverted, LSB-first | ||
10 | * | ||
11 | * Example buffer with the CRC attached: | ||
12 | * 31 32 33 34 35 36 37 38 39 C2 44 | ||
13 | * | ||
14 | * The CRC over a buffer with the CRC attached is 0xB001. | ||
15 | * So, if (crc16(0, buf, size) == 0xB001) then the buffer is valid. | ||
16 | * | ||
17 | * Refer to "Application Note 937: Book of iButton Standards" for details. | ||
18 | * http://www.maxim-ic.com/appnotes.cfm/appnote_number/937 | ||
19 | * | ||
20 | * Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com> | ||
21 | * | ||
22 | * This source code is licensed under the GNU General Public License, | ||
23 | * Version 2. See the file COPYING for more details. | ||
24 | */ | ||
25 | |||
26 | #ifndef __CRC16_H | ||
27 | #define __CRC16_H | ||
28 | |||
29 | #include <linux/types.h> | ||
30 | |||
31 | #define CRC16_INIT 0 | ||
32 | #define CRC16_VALID 0xb001 | ||
33 | |||
34 | extern u16 const crc16_table[256]; | ||
35 | |||
36 | extern u16 crc16(u16 crc, const u8 *buffer, size_t len); | ||
37 | |||
38 | static inline u16 crc16_byte(u16 crc, const u8 data) | ||
39 | { | ||
40 | return (crc >> 8) ^ crc16_table[(crc ^ data) & 0xff]; | ||
41 | } | ||
42 | |||
43 | #endif /* __CRC16_H */ | ||
44 | |||