From 2c9f2365d1e1d0e318b068f683f18c99515b80f8 Mon Sep 17 00:00:00 2001 From: Pekon Gupta Date: Wed, 26 Feb 2014 15:53:13 +0530 Subject: [PATCH] mtd: nand: omap: ecc.calculate: merge omap3_calculate_ecc_bch4 in omap_calculate_ecc_bch merges omap3_calculate_ecc_bch4() into omap_calculate_ecc_bch() so that common callback can be used for both OMAP_ECC_BCH4_CODE_HW and OMAP_ECC_BCH4_CODE_HW_DETECTION_SW ecc-schemes +---------------------+-------------------------------------------------------+ |ecc-scheme | nand_chip->calculate() after this patch | +---------------------+-------------------------------------------------------+ |HAM1_ECC | omap_calculate_ecc() | +---------------------+-------------------------------------------------------+ |BCH4_HW_DETECTION_SW | omap3_calculate_ecc_bch4() -> omap_calculate_ecc_bch()| |BCH4_HW | omap_calculate_ecc_bch() | |BCH8_HW_DETECTION_SW | omap3_calculate_ecc_bch8() | |BCH8_HW | omap_calculate_ecc_bch() | +---------------------+-------------------------------------------------------+ Tested-by: Stefan Roese Signed-off-by: Pekon Gupta Signed-off-by: Brian Norris --- drivers/mtd/nand/omap2.c | 51 ++++++++-------------------------------- 1 file changed, 10 insertions(+), 41 deletions(-) diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c index 2ccd557bf77d..e536267231e2 100644 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -1121,47 +1121,9 @@ static void omap3_enable_hwecc_bch(struct mtd_info *mtd, int mode) writel(ECCCLEAR | ECC1, info->reg.gpmc_ecc_control); } #endif +static u8 bch4_polynomial[] = {0x28, 0x13, 0xcc, 0x39, 0x96, 0xac, 0x7f}; #ifdef CONFIG_MTD_NAND_ECC_BCH -/** - * omap3_calculate_ecc_bch4 - Generate 7 bytes of ECC bytes - * @mtd: MTD device structure - * @dat: The pointer to data on which ecc is computed - * @ecc_code: The ecc_code buffer - */ -static int omap3_calculate_ecc_bch4(struct mtd_info *mtd, const u_char *dat, - u_char *ecc_code) -{ - struct omap_nand_info *info = container_of(mtd, struct omap_nand_info, - mtd); - unsigned long nsectors, val1, val2; - int i; - - nsectors = ((readl(info->reg.gpmc_ecc_config) >> 4) & 0x7) + 1; - - for (i = 0; i < nsectors; i++) { - - /* Read hw-computed remainder */ - val1 = readl(info->reg.gpmc_bch_result0[i]); - val2 = readl(info->reg.gpmc_bch_result1[i]); - - /* - * Add constant polynomial to remainder, in order to get an ecc - * sequence of 0xFFs for a buffer filled with 0xFFs; and - * left-justify the resulting polynomial. - */ - *ecc_code++ = 0x28 ^ ((val2 >> 12) & 0xFF); - *ecc_code++ = 0x13 ^ ((val2 >> 4) & 0xFF); - *ecc_code++ = 0xcc ^ (((val2 & 0xF) << 4)|((val1 >> 28) & 0xF)); - *ecc_code++ = 0x39 ^ ((val1 >> 20) & 0xFF); - *ecc_code++ = 0x96 ^ ((val1 >> 12) & 0xFF); - *ecc_code++ = 0xac ^ ((val1 >> 4) & 0xFF); - *ecc_code++ = 0x7f ^ ((val1 & 0xF) << 4); - } - - return 0; -} - /** * omap3_calculate_ecc_bch8 - Generate 13 bytes of ECC bytes * @mtd: MTD device structure @@ -1209,7 +1171,6 @@ static int omap3_calculate_ecc_bch8(struct mtd_info *mtd, const u_char *dat, } #endif /* CONFIG_MTD_NAND_ECC_BCH */ -#ifdef CONFIG_MTD_NAND_OMAP_BCH /** * omap_calculate_ecc_bch - Generate bytes of ECC bytes * @mtd: MTD device structure @@ -1252,6 +1213,7 @@ static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd, *ecc_code++ = ((bch_val1 >> 8) & 0xFF); *ecc_code++ = (bch_val1 & 0xFF); break; + case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW: case OMAP_ECC_BCH4_CODE_HW: bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]); bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]); @@ -1270,6 +1232,12 @@ static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd, /* ECC scheme specific syndrome customizations */ switch (info->ecc_opt) { + case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW: + /* Add constant polynomial to remainder, so that + * ECC of blank pages results in 0x0 on reading back */ + for (i = 0; i < eccbytes; i++) + ecc_calc[i] ^= bch4_polynomial[i]; + break; case OMAP_ECC_BCH4_CODE_HW: /* Set 8th ECC byte as 0x0 for ROM compatibility */ ecc_calc[eccbytes - 1] = 0x0; @@ -1327,6 +1295,7 @@ static int erased_sector_bitflips(u_char *data, u_char *oob, return flip_bits; } +#ifdef CONFIG_MTD_NAND_OMAP_BCH /** * omap_elm_correct_data - corrects page data area in case error reported * @mtd: MTD device structure @@ -1835,7 +1804,7 @@ static int omap_nand_probe(struct platform_device *pdev) nand_chip->ecc.strength = 4; nand_chip->ecc.hwctl = omap3_enable_hwecc_bch; nand_chip->ecc.correct = nand_bch_correct_data; - nand_chip->ecc.calculate = omap3_calculate_ecc_bch4; + nand_chip->ecc.calculate = omap_calculate_ecc_bch; /* define ECC layout */ ecclayout->eccbytes = nand_chip->ecc.bytes * (mtd->writesize / -- 2.30.2