crc8.c 492 B

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  1. /*
  2. * Copyright (c) 2013 Google, Inc
  3. *
  4. * SPDX-License-Identifier: GPL-2.0+
  5. */
  6. #include "linux/crc8.h"
  7. #define POLY (0x1070U << 3)
  8. static unsigned char _crc8(unsigned short data)
  9. {
  10. int i;
  11. for (i = 0; i < 8; i++) {
  12. if (data & 0x8000)
  13. data = data ^ POLY;
  14. data = data << 1;
  15. }
  16. return (unsigned char)(data >> 8);
  17. }
  18. unsigned int crc8(unsigned int crc, const unsigned char *vptr, int len)
  19. {
  20. int i;
  21. for (i = 0; i < len; i++)
  22. crc = _crc8((crc ^ vptr[i]) << 8);
  23. return crc;
  24. }