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yaml
---
r: 60784
b: refs/heads/master
c: ad24152
h: refs/heads/master
v: v3
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Jan Nikitenko authored and Linus Torvalds committed Jul 17, 2007
1 parent 221bdc7 commit 83c797b
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2 changes: 1 addition & 1 deletion [refs]
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@@ -1,2 +1,2 @@
---
refs/heads/master: c06e677aed0c86480b01faa894967daa8aa3568a
refs/heads/master: ad241528c4919505afccb022acbab3eeb0db4d80
4 changes: 3 additions & 1 deletion trunk/Documentation/DocBook/kernel-api.tmpl
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Expand Up @@ -139,8 +139,10 @@ X!Ilib/string.c
!Elib/cmdline.c
</sect1>

<sect1><title>CRC Functions</title>
<sect1 id="crc"><title>CRC Functions</title>
!Elib/crc7.c
!Elib/crc16.c
!Elib/crc-itu-t.c
!Elib/crc32.c
!Elib/crc-ccitt.c
</sect1>
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14 changes: 14 additions & 0 deletions trunk/include/linux/crc7.h
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#ifndef _LINUX_CRC7_H
#define _LINUX_CRC7_H
#include <linux/types.h>

extern const u8 crc7_syndrome_table[256];

static inline u8 crc7_byte(u8 crc, u8 data)
{
return crc7_syndrome_table[(crc << 1) ^ data];
}

extern u8 crc7(u8 crc, const u8 *buffer, size_t len);

#endif
8 changes: 8 additions & 0 deletions trunk/lib/Kconfig
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Expand Up @@ -41,6 +41,14 @@ config CRC32
kernel tree does. Such modules that use library CRC32 functions
require M here.

config CRC7
tristate "CRC7 functions"
help
This option is provided for the case where no in-kernel-tree
modules require CRC7 functions, but a module built outside
the kernel tree does. Such modules that use library CRC7
functions require M here.

config LIBCRC32C
tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check"
help
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1 change: 1 addition & 0 deletions trunk/lib/Makefile
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Expand Up @@ -43,6 +43,7 @@ obj-$(CONFIG_CRC_CCITT) += crc-ccitt.o
obj-$(CONFIG_CRC16) += crc16.o
obj-$(CONFIG_CRC_ITU_T) += crc-itu-t.o
obj-$(CONFIG_CRC32) += crc32.o
obj-$(CONFIG_CRC7) += crc7.o
obj-$(CONFIG_LIBCRC32C) += libcrc32c.o
obj-$(CONFIG_GENERIC_ALLOCATOR) += genalloc.o

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68 changes: 68 additions & 0 deletions trunk/lib/crc7.c
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/*
* crc7.c
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/

#include <linux/types.h>
#include <linux/module.h>
#include <linux/crc7.h>


/* Table for CRC-7 (polynomial x^7 + x^3 + 1) */
const u8 crc7_syndrome_table[256] = {
0x00, 0x09, 0x12, 0x1b, 0x24, 0x2d, 0x36, 0x3f,
0x48, 0x41, 0x5a, 0x53, 0x6c, 0x65, 0x7e, 0x77,
0x19, 0x10, 0x0b, 0x02, 0x3d, 0x34, 0x2f, 0x26,
0x51, 0x58, 0x43, 0x4a, 0x75, 0x7c, 0x67, 0x6e,
0x32, 0x3b, 0x20, 0x29, 0x16, 0x1f, 0x04, 0x0d,
0x7a, 0x73, 0x68, 0x61, 0x5e, 0x57, 0x4c, 0x45,
0x2b, 0x22, 0x39, 0x30, 0x0f, 0x06, 0x1d, 0x14,
0x63, 0x6a, 0x71, 0x78, 0x47, 0x4e, 0x55, 0x5c,
0x64, 0x6d, 0x76, 0x7f, 0x40, 0x49, 0x52, 0x5b,
0x2c, 0x25, 0x3e, 0x37, 0x08, 0x01, 0x1a, 0x13,
0x7d, 0x74, 0x6f, 0x66, 0x59, 0x50, 0x4b, 0x42,
0x35, 0x3c, 0x27, 0x2e, 0x11, 0x18, 0x03, 0x0a,
0x56, 0x5f, 0x44, 0x4d, 0x72, 0x7b, 0x60, 0x69,
0x1e, 0x17, 0x0c, 0x05, 0x3a, 0x33, 0x28, 0x21,
0x4f, 0x46, 0x5d, 0x54, 0x6b, 0x62, 0x79, 0x70,
0x07, 0x0e, 0x15, 0x1c, 0x23, 0x2a, 0x31, 0x38,
0x41, 0x48, 0x53, 0x5a, 0x65, 0x6c, 0x77, 0x7e,
0x09, 0x00, 0x1b, 0x12, 0x2d, 0x24, 0x3f, 0x36,
0x58, 0x51, 0x4a, 0x43, 0x7c, 0x75, 0x6e, 0x67,
0x10, 0x19, 0x02, 0x0b, 0x34, 0x3d, 0x26, 0x2f,
0x73, 0x7a, 0x61, 0x68, 0x57, 0x5e, 0x45, 0x4c,
0x3b, 0x32, 0x29, 0x20, 0x1f, 0x16, 0x0d, 0x04,
0x6a, 0x63, 0x78, 0x71, 0x4e, 0x47, 0x5c, 0x55,
0x22, 0x2b, 0x30, 0x39, 0x06, 0x0f, 0x14, 0x1d,
0x25, 0x2c, 0x37, 0x3e, 0x01, 0x08, 0x13, 0x1a,
0x6d, 0x64, 0x7f, 0x76, 0x49, 0x40, 0x5b, 0x52,
0x3c, 0x35, 0x2e, 0x27, 0x18, 0x11, 0x0a, 0x03,
0x74, 0x7d, 0x66, 0x6f, 0x50, 0x59, 0x42, 0x4b,
0x17, 0x1e, 0x05, 0x0c, 0x33, 0x3a, 0x21, 0x28,
0x5f, 0x56, 0x4d, 0x44, 0x7b, 0x72, 0x69, 0x60,
0x0e, 0x07, 0x1c, 0x15, 0x2a, 0x23, 0x38, 0x31,
0x46, 0x4f, 0x54, 0x5d, 0x62, 0x6b, 0x70, 0x79
};
EXPORT_SYMBOL(crc7_syndrome_table);

/**
* crc7 - update the CRC7 for the data buffer
* @crc: previous CRC7 value
* @buffer: data pointer
* @len: number of bytes in the buffer
* Context: any
*
* Returns the updated CRC7 value.
*/
u8 crc7(u8 crc, const u8 *buffer, size_t len)
{
while (len--)
crc = crc7_byte(crc, *buffer++);
return crc;
}
EXPORT_SYMBOL(crc7);

MODULE_DESCRIPTION("CRC7 calculations");
MODULE_LICENSE("GPL");

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