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Commit	Line	Data
	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
	14	typedef struct crc {
	15	uint32_t state;
	16	int order;
	17	uint32_t polynom;
	18	uint32_t initial_value;
	19	uint32_t final_xor;
	20	uint32_t mask;
	21	} crc_t;
	22
	23	/* Initialize a crc structure. order is the order of the polynom, e.g. 32 for a CRC-32
	24	* polynom is the CRC polynom. initial_value is the initial value of a clean state.
	25	* final_xor is XORed onto the state before returning it from crc_result(). */
	26	extern void crc_init(crc_t *crc, int order, uint32_t polynom, uint32_t initial_value, uint32_t final_xor);
	27
	28	/* Update the crc state. data is the data of length data_width bits (only the the
	29	* data_width lower-most bits are used).
	30	*/
	31	extern void crc_update(crc_t *crc, uint32_t data, int data_width);
	32
	33	/* Clean the crc state, e.g. reset it to initial_value */
	34	extern void crc_clear(crc_t *crc);
	35
	36	/* Get the result of the crc calculation */
	37	extern uint32_t crc_finish(crc_t *crc);
	38
	39	/* Static initialization of a crc structure */
	40	#define CRC_INITIALIZER(_order, _polynom, _initial_value, _final_xor) { \
	41	.state = ((_initial_value) & ((1L<<(_order))-1)), \
	42	.order = (_order), \
	43	.polynom = (_polynom), \
	44	.initial_value = (_initial_value), \
	45	.final_xor = (_final_xor), \
	46	.mask = ((1L<<(_order))-1) }
	47
	48	#endif /* __CRC_H */