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1 | //----------------------------------------------------------------------------- | |
2 | // This code is licensed to you under the terms of the GNU GPL, version 2 or, | |
3 | // at your option, any later version. See the LICENSE.txt file for the text of | |
4 | // the license. | |
5 | //----------------------------------------------------------------------------- | |
6 | // Generic CRC calculation code. | |
7 | //----------------------------------------------------------------------------- | |
8 | ||
9 | #ifndef __CRC_H | |
10 | #define __CRC_H | |
11 | ||
12 | #include <stdint.h> | |
13 | #include <stddef.h> | |
14 | #include <stdbool.h> | |
15 | ||
16 | typedef struct crc { | |
17 | uint32_t state; | |
18 | int order; | |
19 | uint32_t polynom; | |
20 | uint32_t initial_value; | |
21 | uint32_t final_xor; | |
22 | uint32_t mask; | |
23 | } crc_t; | |
24 | ||
25 | /* Initialize a crc structure. order is the order of the polynom, e.g. 32 for a CRC-32 | |
26 | * polynom is the CRC polynom. initial_value is the initial value of a clean state. | |
27 | * final_xor is XORed onto the state before returning it from crc_result(). */ | |
28 | extern void crc_init(crc_t *crc, int order, uint32_t polynom, uint32_t initial_value, uint32_t final_xor); | |
29 | ||
30 | /* Update the crc state. data is the data of length data_width bits (only the | |
31 | * data_width lower-most bits are used). | |
32 | */ | |
33 | extern void crc_update(crc_t *crc, uint32_t data, int data_width); | |
34 | ||
35 | /* Clean the crc state, e.g. reset it to initial_value */ | |
36 | extern void crc_clear(crc_t *crc); | |
37 | ||
38 | /* Get the result of the crc calculation */ | |
39 | extern uint32_t crc_finish(crc_t *crc); | |
40 | ||
41 | // Calculate CRC-8/Maxim checksum | |
42 | uint32_t CRC8Maxim(uint8_t *buff, size_t size ); | |
43 | ||
44 | // Calculate CRC-8 Mifare MAD checksum | |
45 | uint32_t CRC8Mad(uint8_t *buff, size_t size); | |
46 | ||
47 | /* Static initialization of a crc structure */ | |
48 | #define CRC_INITIALIZER(_order, _polynom, _initial_value, _final_xor) { \ | |
49 | .state = ((_initial_value) & ((1L<<(_order))-1)), \ | |
50 | .order = (_order), \ | |
51 | .polynom = (_polynom), \ | |
52 | .initial_value = (_initial_value), \ | |
53 | .final_xor = (_final_xor), \ | |
54 | .mask = ((1L<<(_order))-1) } | |
55 | ||
56 | #endif /* __CRC_H */ |