xref: /OK3568_Linux_fs/kernel/include/linux/crc-itu-t.h (revision 4882a59341e53eb6f0b4789bf948001014eff981) 
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0-only */
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  *	crc-itu-t.h - CRC ITU-T V.41 routine
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  * Implements the standard CRC ITU-T V.41:
6*4882a593Smuzhiyun  *   Width 16
7*4882a593Smuzhiyun  *   Poly  0x1021 (x^16 + x^12 + x^15 + 1)
8*4882a593Smuzhiyun  *   Init  0
9*4882a593Smuzhiyun  */
10*4882a593Smuzhiyun 
11*4882a593Smuzhiyun #ifndef CRC_ITU_T_H
12*4882a593Smuzhiyun #define CRC_ITU_T_H
13*4882a593Smuzhiyun 
14*4882a593Smuzhiyun #include <linux/types.h>
15*4882a593Smuzhiyun 
16*4882a593Smuzhiyun extern u16 const crc_itu_t_table[256];
17*4882a593Smuzhiyun 
18*4882a593Smuzhiyun extern u16 crc_itu_t(u16 crc, const u8 *buffer, size_t len);
19*4882a593Smuzhiyun 
crc_itu_t_byte(u16 crc,const u8 data)20*4882a593Smuzhiyun static inline u16 crc_itu_t_byte(u16 crc, const u8 data)
21*4882a593Smuzhiyun {
22*4882a593Smuzhiyun 	return (crc << 8) ^ crc_itu_t_table[((crc >> 8) ^ data) & 0xff];
23*4882a593Smuzhiyun }
24*4882a593Smuzhiyun 
25*4882a593Smuzhiyun #endif /* CRC_ITU_T_H */
26*4882a593Smuzhiyun 
27