mirror of
https://github.com/team-infusion-developers/android_kernel_samsung_msm8976.git
synced 2024-11-01 10:33:27 +00:00
ad241528c4
Add CRC7 routines, used for example in MMC over SPI communication. Kerneldoc updates [akpm@linux-foundation.org: fix funny mix of const and non-const] Signed-off-by: Jan Nikitenko <jan.nikitenko@gmail.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: "Randy.Dunlap" <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
68 lines
2.3 KiB
C
68 lines
2.3 KiB
C
/*
|
|
* 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");
|