/* * Generic binary BCH encoding/decoding library * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published by * the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., 51 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Copyright © 2011 Parrot S.A. * * Author: Ivan Djelic <ivan.djelic@parrot.com> * * Description: * * This library provides runtime configurable encoding/decoding of binary * Bose-Chaudhuri-Hocquenghem (BCH) codes.*/#ifndef _BCH_H#define _BCH_H #include <linux/types.h> /** * struct bch_control - BCH control structure * @m:          Galois field order * @n:          maximum codeword size in bits (= 2^m-1) * @t:          error correction capability in bits * @ecc_bits:   ecc exact size in bits, i.e. generator polynomial degree (<=m*t) * @ecc_bytes:  ecc max size (m*t bits) in bytes * @a_pow_tab:  Galois field GF(2^m) exponentiation lookup table * @a_log_tab:  Galois field GF(2^m) log lookup table * @mod8_tab:   remainder generator polynomial lookup tables * @ecc_buf:    ecc parity words buffer * @ecc_buf2:   ecc parity words buffer * @xi_tab:     GF(2^m) base for solving degree 2 polynomial roots * @syn:        syndrome buffer * @cache:      log-based polynomial representation buffer * @elp:        error locator polynomial * @poly_2t:    temporary polynomials of degree 2t */struct bch_control {	unsigned int    m;	unsigned int    n;	unsigned int    t;	unsigned int    ecc_bits;	unsigned int    ecc_bytes;/* private: */	uint16_t       *a_pow_tab;	uint16_t       *a_log_tab;	uint32_t       *mod8_tab;	uint32_t       *ecc_buf;	uint32_t       *ecc_buf2;	unsigned int   *xi_tab;	unsigned int   *syn;	int            *cache;	struct gf_poly *elp;	struct gf_poly *poly_2t[4];}; struct bch_control *init_bch(int m, int t, unsigned int prim_poly); void free_bch(struct bch_control *bch); void encode_bch(struct bch_control *bch, const uint8_t *data,		unsigned int len, uint8_t *ecc); int decode_bch(struct bch_control *bch, const uint8_t *data, unsigned int len,	       const uint8_t *recv_ecc, const uint8_t *calc_ecc,	       const unsigned int *syn, unsigned int *errloc); #endif /* _BCH_H */