release/src-rt-6.x.4708/linux/linux-2.6.36/include/linux/crc-itu-t.h

   1 /*
   2  *      crc-itu-t.h - CRC ITU-T V.41 routine
   3  *
   4  * Implements the standard CRC ITU-T V.41:
   5  *   Width 16
   6  *   Poly  0x0x1021 (x^16 + x^12 + x^15 + 1)
   7  *   Init  0
   8  *
   9  * This source code is licensed under the GNU General Public License,
  10  * Version 2. See the file COPYING for more details.
  11  */
  12
  13 #ifndef CRC_ITU_T_H
  14 #define CRC_ITU_T_H
  15
  16 #include <linux/types.h>
  17
  18 extern u16 const crc_itu_t_table[256];
  19
  20 extern u16 crc_itu_t(u16 crc, const u8 *buffer, size_t len);
  21
  22 static inline u16 crc_itu_t_byte(u16 crc, const u8 data)
  23 {
  24         return (crc << 8) ^ crc_itu_t_table[((crc >> 8) ^ data) & 0xff];
  25 }
  26
  27 #endif /* CRC_ITU_T_H */