/*
   * Copyright (c) 2013 Google, Inc
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  #include "linux/crc8.h"
  
  #define POLY	(0x1070U << 3)
  
  static unsigned char _crc8(unsigned short data)
  {
  	int i;
  
  	for (i = 0; i < 8; i++) {
  		if (data & 0x8000)
  			data = data ^ POLY;
  		data = data << 1;
  	}
  
  	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;
  }