Here we automatically select the strongest ECC scheme compatible with the size of the OOB.
Signed-off-by: Lee Jones <[email protected]> --- drivers/mtd/nand/stm_nand_bch.c | 43 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) diff --git a/drivers/mtd/nand/stm_nand_bch.c b/drivers/mtd/nand/stm_nand_bch.c index 8302273..31864e5 100644 --- a/drivers/mtd/nand/stm_nand_bch.c +++ b/drivers/mtd/nand/stm_nand_bch.c @@ -32,6 +32,13 @@ /* NANDi BCH Controller properties */ #define NANDI_BCH_SECTOR_SIZE 1024 +/* BCH ECC sizes */ +static int bch_ecc_sizes[] = { + [BCH_18BIT_ECC] = 32, + [BCH_30BIT_ECC] = 54, + [BCH_NO_ECC] = 0, +}; + /* Bad Block Table (BBT) */ struct nandi_bbt_info { uint32_t bbt_size; /* Size of bad-block table */ @@ -302,6 +309,25 @@ static void nandi_disable_interrupts(struct nandi_controller *nandi, writel(val, nandi->base + NANDBCH_INT_EN); } +/* Select strongest ECC scheme compatible with OOB size */ +static int bch_set_ecc_auto(struct nandi_controller *nandi, + struct mtd_info *mtd) +{ + int oob_bytes_per_sector = mtd->oobsize / nandi->sectors_per_page; + int try_ecc_modes[] = { BCH_30BIT_ECC, BCH_18BIT_ECC, -1 }; + int m, ecc_mode; + + for (m = 0; try_ecc_modes[m] >= 0; m++) { + ecc_mode = try_ecc_modes[m]; + if (oob_bytes_per_sector >= bch_ecc_sizes[ecc_mode]) { + nandi->bch_ecc_mode = ecc_mode; + return 0; + } + } + + return -EINVAL; +} + static void nandi_set_mtd_defaults(struct nandi_controller *nandi, struct mtd_info *mtd, struct nand_chip *chip) { @@ -939,6 +965,23 @@ static int stm_nand_bch_probe(struct platform_device *pdev) 0x10000) ? true : false; mtd->writebufsize = mtd->writesize; + /* Set ECC mode */ + if (pdata->bch_ecc_cfg == BCH_ECC_AUTO) { + err = bch_set_ecc_auto(nandi, mtd); + if (err) { + dev_err(nandi->dev, "insufficient OOB for BCH ECC\n"); + return err; + } + } else { + nandi->bch_ecc_mode = pdata->bch_ecc_cfg; + } + + chip->ecc.size = NANDI_BCH_SECTOR_SIZE; + chip->ecc.bytes = mtd->oobsize; + + info->ecclayout.eccbytes = + nandi->sectors_per_page * bch_ecc_sizes[nandi->bch_ecc_mode]; + return 0; } -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
