diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mtd/nand/atmel_nand.c | 75 | ||||
| -rw-r--r-- | drivers/mtd/nand/atmel_nand_ecc.h | 4 |
2 files changed, 78 insertions, 1 deletions
diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c index 3b6093a..620b6e8 100644 --- a/drivers/mtd/nand/atmel_nand.c +++ b/drivers/mtd/nand/atmel_nand.c @@ -763,6 +763,62 @@ static int pmecc_choose_ecc(struct atmel_nand_host *host, } #endif +#if defined(NO_GALOIS_TABLE_IN_ROM) +static uint16_t *pmecc_galois_table; +static inline int deg(unsigned int poly) +{ + /* polynomial degree is the most-significant bit index */ + return fls(poly) - 1; +} + +static int build_gf_tables(int mm, unsigned int poly, + int16_t *index_of, int16_t *alpha_to) +{ + unsigned int i, x = 1; + const unsigned int k = 1 << deg(poly); + unsigned int nn = (1 << mm) - 1; + + /* primitive polynomial must be of degree m */ + if (k != (1u << mm)) + return -EINVAL; + + for (i = 0; i < nn; i++) { + alpha_to[i] = x; + index_of[x] = i; + if (i && (x == 1)) + /* polynomial is not primitive (a^i=1 with 0<i<2^m-1) */ + return -EINVAL; + x <<= 1; + if (x & k) + x ^= poly; + } + + alpha_to[nn] = 1; + index_of[0] = 0; + + return 0; +} + +static uint16_t *create_lookup_table(int sector_size) +{ + int degree = (sector_size == 512) ? + PMECC_GF_DIMENSION_13 : + PMECC_GF_DIMENSION_14; + unsigned int poly = (sector_size == 512) ? + PMECC_GF_13_PRIMITIVE_POLY : + PMECC_GF_14_PRIMITIVE_POLY; + int table_size = (sector_size == 512) ? + PMECC_INDEX_TABLE_SIZE_512 : + PMECC_INDEX_TABLE_SIZE_1024; + + int16_t *addr = kzalloc(2 * table_size * sizeof(uint16_t), GFP_KERNEL); + if (addr && build_gf_tables(degree, poly, addr, addr + table_size)) + return NULL; + + return (uint16_t *)addr; +} +#endif + static int atmel_pmecc_nand_init_params(struct nand_chip *nand, struct mtd_info *mtd) { @@ -810,11 +866,18 @@ static int atmel_pmecc_nand_init_params(struct nand_chip *nand, sector_size = host->pmecc_sector_size; /* TODO: need check whether cap & sector_size is validate */ - +#if defined(NO_GALOIS_TABLE_IN_ROM) + /* + * As pmecc_rom_base is the begin of the gallois field table, So the + * index offset just set as 0. + */ + host->pmecc_index_table_offset = 0; +#else if (host->pmecc_sector_size == 512) host->pmecc_index_table_offset = ATMEL_PMECC_INDEX_OFFSET_512; else host->pmecc_index_table_offset = ATMEL_PMECC_INDEX_OFFSET_1024; +#endif MTDDEBUG(MTD_DEBUG_LEVEL1, "Initialize PMECC params, cap: %d, sector: %d\n", @@ -823,7 +886,17 @@ static int atmel_pmecc_nand_init_params(struct nand_chip *nand, host->pmecc = (struct pmecc_regs __iomem *) ATMEL_BASE_PMECC; host->pmerrloc = (struct pmecc_errloc_regs __iomem *) ATMEL_BASE_PMERRLOC; +#if defined(NO_GALOIS_TABLE_IN_ROM) + pmecc_galois_table = create_lookup_table(host->pmecc_sector_size); + if (!pmecc_galois_table) { + dev_err(host->dev, "out of memory\n"); + return -ENOMEM; + } + + host->pmecc_rom_base = (void __iomem *)pmecc_galois_table; +#else host->pmecc_rom_base = (void __iomem *) ATMEL_BASE_ROM; +#endif /* ECC is calculated for the whole page (1 step) */ nand->ecc.size = mtd->writesize; diff --git a/drivers/mtd/nand/atmel_nand_ecc.h b/drivers/mtd/nand/atmel_nand_ecc.h index 92d4ec5..eac860d 100644 --- a/drivers/mtd/nand/atmel_nand_ecc.h +++ b/drivers/mtd/nand/atmel_nand_ecc.h @@ -141,6 +141,10 @@ struct pmecc_errloc_regs { #define PMECC_GF_DIMENSION_13 13 #define PMECC_GF_DIMENSION_14 14 +/* Primitive Polynomial used by PMECC */ +#define PMECC_GF_13_PRIMITIVE_POLY 0x201b +#define PMECC_GF_14_PRIMITIVE_POLY 0x4443 + #define PMECC_INDEX_TABLE_SIZE_512 0x2000 #define PMECC_INDEX_TABLE_SIZE_1024 0x4000 |