From f5dc06fb71ae10c4f205a08f5ef26fd90fc122fc Mon Sep 17 00:00:00 2001 From: Pekon Gupta Date: Wed, 26 Feb 2014 15:53:12 +0530 Subject: [PATCH] mtd: nand: omap: ecc.calculate: refactor omap_calculate_ecc_bch for BCHx_HW ecc-scheme OMAP NAND driver supports multiple flavours of BCH4 and BCH8 ECC algorithms. +------+------------------------------------+---------------+---------------+ | Algo | ECC scheme |ECC calculation|Error detection| +------+------------------------------------+---------------+---------------+ | |OMAP_ECC_BCH4_CODE_HW_DETECTION_SW |H/W (GPMC) |S/W | | BCH4 |OMAP_ECC_BCH4_CODE_HW |H/W (GPMC) |H/W (ELM) | +------+------------------------------------+---------------+---------------+ | |OMAP_ECC_BCH8_CODE_HW_DETECTION_SW |H/W (GPMC) |S/W | | BCH8 |OMAP_ECC_BCH8_CODE_HW |H/W (GPMC) |H/W (ELM) | +------+------------------------------------+---------------+---------------+ This patch refactors omap_calculate_ecc_bch() so that - separate out ecc-scheme specific code so that common-code can be reused between different implementations of same ECC algorithm. - new ecc-schemes can be added with ease in future. Tested-by: Stefan Roese Signed-off-by: Pekon Gupta Signed-off-by: Brian Norris --- drivers/mtd/nand/omap2.c | 68 +++++++++++++++++++++------------------- 1 file changed, 35 insertions(+), 33 deletions(-) diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c index 4b98ee52e5e1..2ccd557bf77d 100644 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -1219,33 +1219,25 @@ static int omap3_calculate_ecc_bch8(struct mtd_info *mtd, const u_char *dat, * Support calculating of BCH4/8 ecc vectors for the page */ static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd, - const u_char *dat, u_char *ecc_code) + const u_char *dat, u_char *ecc_calc) { struct omap_nand_info *info = container_of(mtd, struct omap_nand_info, mtd); + int eccbytes = info->nand.ecc.bytes; + struct gpmc_nand_regs *gpmc_regs = &info->reg; + u8 *ecc_code; unsigned long nsectors, bch_val1, bch_val2, bch_val3, bch_val4; - int i, eccbchtsel; + int i; nsectors = ((readl(info->reg.gpmc_ecc_config) >> 4) & 0x7) + 1; - /* - * find BCH scheme used - * 0 -> BCH4 - * 1 -> BCH8 - */ - eccbchtsel = ((readl(info->reg.gpmc_ecc_config) >> 12) & 0x3); - for (i = 0; i < nsectors; i++) { - - /* Read hw-computed remainder */ - bch_val1 = readl(info->reg.gpmc_bch_result0[i]); - bch_val2 = readl(info->reg.gpmc_bch_result1[i]); - if (eccbchtsel) { - bch_val3 = readl(info->reg.gpmc_bch_result2[i]); - bch_val4 = readl(info->reg.gpmc_bch_result3[i]); - } - - if (eccbchtsel) { - /* BCH8 ecc scheme */ + ecc_code = ecc_calc; + switch (info->ecc_opt) { + case OMAP_ECC_BCH8_CODE_HW: + bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]); + bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]); + bch_val3 = readl(gpmc_regs->gpmc_bch_result2[i]); + bch_val4 = readl(gpmc_regs->gpmc_bch_result3[i]); *ecc_code++ = (bch_val4 & 0xFF); *ecc_code++ = ((bch_val3 >> 24) & 0xFF); *ecc_code++ = ((bch_val3 >> 16) & 0xFF); @@ -1259,14 +1251,10 @@ static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd, *ecc_code++ = ((bch_val1 >> 16) & 0xFF); *ecc_code++ = ((bch_val1 >> 8) & 0xFF); *ecc_code++ = (bch_val1 & 0xFF); - /* - * Setting 14th byte to zero to handle - * erased page & maintain compatibility - * with RBL - */ - *ecc_code++ = 0x0; - } else { - /* BCH4 ecc scheme */ + break; + case OMAP_ECC_BCH4_CODE_HW: + bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]); + bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]); *ecc_code++ = ((bch_val2 >> 12) & 0xFF); *ecc_code++ = ((bch_val2 >> 4) & 0xFF); *ecc_code++ = ((bch_val2 & 0xF) << 4) | @@ -1275,12 +1263,26 @@ static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd, *ecc_code++ = ((bch_val1 >> 12) & 0xFF); *ecc_code++ = ((bch_val1 >> 4) & 0xFF); *ecc_code++ = ((bch_val1 & 0xF) << 4); - /* - * Setting 8th byte to zero to handle - * erased page - */ - *ecc_code++ = 0x0; + break; + default: + return -EINVAL; } + + /* ECC scheme specific syndrome customizations */ + switch (info->ecc_opt) { + case OMAP_ECC_BCH4_CODE_HW: + /* Set 8th ECC byte as 0x0 for ROM compatibility */ + ecc_calc[eccbytes - 1] = 0x0; + break; + case OMAP_ECC_BCH8_CODE_HW: + /* Set 14th ECC byte as 0x0 for ROM compatibility */ + ecc_calc[eccbytes - 1] = 0x0; + break; + default: + return -EINVAL; + } + + ecc_calc += eccbytes; } return 0;