include/linux/crc-itu-t.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  *      crc-itu-t.h - CRC ITU-T V.41 routine
   4  *
   5  * Implements the standard CRC ITU-T V.41:
   6  *   Width 16
   7  *   Poly  0x1021 (x^16 + x^12 + x^5 + 1)
   8  *   Init  0
   9  */
  10
  11 #ifndef CRC_ITU_T_H
  12 #define CRC_ITU_T_H
  13
  14 #include <linux/types.h>
  15
  16 extern u16 const crc_itu_t_table[256];
  17
  18 extern u16 crc_itu_t(u16 crc, const u8 *buffer, size_t len);
  19
  20 static inline u16 crc_itu_t_byte(u16 crc, const u8 data)
  21 {
  22         return (crc << 8) ^ crc_itu_t_table[((crc >> 8) ^ data) & 0xff];
  23 }
  24
  25 #endif /* CRC_ITU_T_H */
  26