2018-05-06 21:58:06 +00:00
|
|
|
/* SPDX-License-Identifier: GPL-2.0 */
|
2011-10-12 07:31:59 +00:00
|
|
|
/*
|
|
|
|
|
* Generic binary BCH encoding/decoding library
|
|
|
|
|
*
|
|
|
|
|
* 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 */
|
