xref: /src/sys/dev/nand/hamming.h

/*	$NetBSD: hamming.h,v 1.1.8.2 2011/06/06 09:08:07 jruoho Exp $	*/

/*
 * Copyright (c) 2008, Atmel Corporation
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the disclaimer below.
 *
 * Atmel's name may not be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
 * DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef HAMMING_H
#define HAMMING_H

#include "nand.h"

/*-
 * These are the possible errors when trying to verify a block of data encoded
 * using a Hamming code:
 *
 *  - HAMMING_ERROR_SINGLEBIT
 *  - HAMMING_ERROR_ECC
 *  - HAMMING_ERROR_MULTIPLEBITS
 */

/* A single bit was incorrect but has been recovered. */
#define HAMMING_ERROR_SINGLEBIT		NAND_ECC_CORRECTED

/* The original code has been corrupted. */
#define HAMMING_ERROR_ECC		NAND_ECC_INVALID

/* Multiple bits are incorrect in the data and they cannot be corrected. */
#define HAMMING_ERROR_MULTIPLEBITS	NAND_ECC_TWOBIT

uint8_t hamming_correct_256(uint8_t *, const uint8_t *, const uint8_t *);
void hamming_compute_256(const uint8_t *data, uint8_t *code);

#endif /* HAMMING_H */