2013-11-10 17:26:47 +00:00
|
|
|
/*
|
|
|
|
* Copyright (c) 2013 Google, Inc
|
|
|
|
*
|
|
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
|
|
*/
|
|
|
|
|
|
|
|
#include "linux/crc8.h"
|
|
|
|
|
2016-04-08 13:56:29 +00:00
|
|
|
#define POLY (0x1070U << 3)
|
|
|
|
|
|
|
|
static unsigned char _crc8(unsigned short data)
|
2013-11-10 17:26:47 +00:00
|
|
|
{
|
2016-04-08 13:56:29 +00:00
|
|
|
int i;
|
|
|
|
|
|
|
|
for (i = 0; i < 8; i++) {
|
|
|
|
if (data & 0x8000)
|
|
|
|
data = data ^ POLY;
|
|
|
|
data = data << 1;
|
2013-11-10 17:26:47 +00:00
|
|
|
}
|
|
|
|
|
2016-04-08 13:56:29 +00:00
|
|
|
return (unsigned char)(data >> 8);
|
|
|
|
}
|
|
|
|
|
|
|
|
unsigned int crc8(unsigned int crc, const unsigned char *vptr, int len)
|
|
|
|
{
|
|
|
|
int i;
|
|
|
|
|
|
|
|
for (i = 0; i < len; i++)
|
|
|
|
crc = _crc8((crc ^ vptr[i]) << 8);
|
|
|
|
|
|
|
|
return crc;
|
2013-11-10 17:26:47 +00:00
|
|
|
}
|