This patch adds support for 4-bit ECC BCH4 for the SPEAr600 SoC. This can be used by boards equipped with a NAND chip that requires 4-bit ECC strength. The SPEAr600 HW ECC only supports 1-bit ECC strength.
To enable SW BCH4, you need to specify this in your config header:
#define CONFIG_NAND_ECC_BCH #define CONFIG_BCH
And use the command "nandecc bch4" to select this ECC scheme upon runtime.
Tested on SPEAr600 x600 board.
Signed-off-by: Stefan Roese sr@denx.de Cc: Scott Wood scottwood@freescale.com Acked-by: Viresh Kumar viresh.kumar@linaro.org --- v2: - Removed err = 0 initialization as suggested by Viresh - Completed the commit text - Added Viresh's Acked-by
drivers/mtd/nand/fsmc_nand.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+)
diff --git a/drivers/mtd/nand/fsmc_nand.c b/drivers/mtd/nand/fsmc_nand.c index 567eff0..0976a67 100644 --- a/drivers/mtd/nand/fsmc_nand.c +++ b/drivers/mtd/nand/fsmc_nand.c @@ -13,6 +13,7 @@ #include <asm/io.h> #include <linux/bitops.h> #include <linux/err.h> +#include <linux/mtd/nand_bch.h> #include <linux/mtd/nand_ecc.h> #include <linux/mtd/fsmc_nand.h> #include <asm/arch/hardware.h> @@ -390,6 +391,45 @@ static int fsmc_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip, return 0; }
+#ifndef CONFIG_SPL_BUILD +/* + * fsmc_nand_switch_ecc - switch the ECC operation between different engines + * + * @eccstrength - the number of bits that could be corrected + * (1 - HW, 4 - SW BCH4) + */ +int __maybe_unused fsmc_nand_switch_ecc(uint32_t eccstrength) +{ + struct nand_chip *nand; + struct mtd_info *mtd; + int err; + + mtd = &nand_info[nand_curr_device]; + nand = mtd->priv; + + /* Setup the ecc configurations again */ + if (eccstrength == 1) { + nand->ecc.mode = NAND_ECC_HW; + nand->ecc.bytes = 3; + nand->ecc.strength = 1; + nand->ecc.layout = &fsmc_ecc1_layout; + nand->ecc.correct = nand_correct_data; + } else { + nand->ecc.mode = NAND_ECC_SOFT_BCH; + nand->ecc.calculate = nand_bch_calculate_ecc; + nand->ecc.correct = nand_bch_correct_data; + nand->ecc.bytes = 7; + nand->ecc.strength = 4; + nand->ecc.layout = NULL; + } + + /* Update NAND handling after ECC mode switch */ + err = nand_scan_tail(mtd); + + return err; +} +#endif /* CONFIG_SPL_BUILD */ + int fsmc_nand_init(struct nand_chip *nand) { static int chip_nr;