From 2ef9f3ddec55f1b77615613d4aab418f073220bb Mon Sep 17 00:00:00 2001 From: Afzal Mohammed Date: Thu, 4 Oct 2012 19:03:06 +0530 Subject: [PATCH] mtd: nand: omap: handle gpmc bch[48] gpmc-nand bch registers are now available in driver, make use of it to handle bch[48] instead of relying on gpmc exported functions. And so nand driver no longer needs gpmc header, remove it. Signed-off-by: Afzal Mohammed --- drivers/mtd/nand/omap2.c | 100 ++++++++++++++++++++++++++++++++++----- 1 file changed, 89 insertions(+), 11 deletions(-) diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c index f0a1b1d69d3..3282b151aa0 100644 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -28,7 +28,6 @@ #endif #include -#include #include #define DRIVER_NAME "omap2-nand" @@ -106,6 +105,7 @@ #define CS_MASK 0x7 #define ENABLE_PREFETCH (0x1 << 7) #define DMA_MPU_MODE_SHIFT 2 +#define ECCSIZE0_SHIFT 12 #define ECCSIZE1_SHIFT 22 #define ECC1RESULTSIZE 0x1 #define ECCCLEAR 0x100 @@ -1034,19 +1034,45 @@ static int omap_dev_ready(struct mtd_info *mtd) static void omap3_enable_hwecc_bch(struct mtd_info *mtd, int mode) { int nerrors; - unsigned int dev_width; + unsigned int dev_width, nsectors; struct omap_nand_info *info = container_of(mtd, struct omap_nand_info, mtd); struct nand_chip *chip = mtd->priv; + u32 val; nerrors = (info->nand.ecc.bytes == 13) ? 8 : 4; dev_width = (chip->options & NAND_BUSWIDTH_16) ? 1 : 0; + nsectors = 1; /* * Program GPMC to perform correction on one 512-byte sector at a time. * Using 4 sectors at a time (i.e. ecc.size = 2048) is also possible and * gives a slight (5%) performance gain (but requires additional code). */ - (void)gpmc_enable_hwecc_bch(info->gpmc_cs, mode, dev_width, 1, nerrors); + + writel(ECC1, info->reg.gpmc_ecc_control); + + /* + * When using BCH, sector size is hardcoded to 512 bytes. + * Here we are using wrapping mode 6 both for reading and writing, with: + * size0 = 0 (no additional protected byte in spare area) + * size1 = 32 (skip 32 nibbles = 16 bytes per sector in spare area) + */ + val = (32 << ECCSIZE1_SHIFT) | (0 << ECCSIZE0_SHIFT); + writel(val, info->reg.gpmc_ecc_size_config); + + /* BCH configuration */ + val = ((1 << 16) | /* enable BCH */ + (((nerrors == 8) ? 1 : 0) << 12) | /* 8 or 4 bits */ + (0x06 << 8) | /* wrap mode = 6 */ + (dev_width << 7) | /* bus width */ + (((nsectors-1) & 0x7) << 4) | /* number of sectors */ + (info->gpmc_cs << 1) | /* ECC CS */ + (0x1)); /* enable ECC */ + + writel(val, info->reg.gpmc_ecc_config); + + /* clear ecc and enable bits */ + writel(ECCCLEAR | ECC1, info->reg.gpmc_ecc_control); } /** @@ -1060,7 +1086,32 @@ static int omap3_calculate_ecc_bch4(struct mtd_info *mtd, const u_char *dat, { struct omap_nand_info *info = container_of(mtd, struct omap_nand_info, mtd); - return gpmc_calculate_ecc_bch4(info->gpmc_cs, dat, ecc_code); + 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; } /** @@ -1074,7 +1125,39 @@ static int omap3_calculate_ecc_bch8(struct mtd_info *mtd, const u_char *dat, { struct omap_nand_info *info = container_of(mtd, struct omap_nand_info, mtd); - return gpmc_calculate_ecc_bch8(info->gpmc_cs, dat, ecc_code); + unsigned long nsectors, val1, val2, val3, val4; + 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]); + val3 = readl(info->reg.gpmc_bch_result2[i]); + val4 = readl(info->reg.gpmc_bch_result3[i]); + + /* + * Add constant polynomial to remainder, in order to get an ecc + * sequence of 0xFFs for a buffer filled with 0xFFs. + */ + *ecc_code++ = 0xef ^ (val4 & 0xFF); + *ecc_code++ = 0x51 ^ ((val3 >> 24) & 0xFF); + *ecc_code++ = 0x2e ^ ((val3 >> 16) & 0xFF); + *ecc_code++ = 0x09 ^ ((val3 >> 8) & 0xFF); + *ecc_code++ = 0xed ^ (val3 & 0xFF); + *ecc_code++ = 0x93 ^ ((val2 >> 24) & 0xFF); + *ecc_code++ = 0x9a ^ ((val2 >> 16) & 0xFF); + *ecc_code++ = 0xc2 ^ ((val2 >> 8) & 0xFF); + *ecc_code++ = 0x97 ^ (val2 & 0xFF); + *ecc_code++ = 0x79 ^ ((val1 >> 24) & 0xFF); + *ecc_code++ = 0xe5 ^ ((val1 >> 16) & 0xFF); + *ecc_code++ = 0x24 ^ ((val1 >> 8) & 0xFF); + *ecc_code++ = 0xb5 ^ (val1 & 0xFF); + } + + return 0; } /** @@ -1130,7 +1213,7 @@ static void omap3_free_bch(struct mtd_info *mtd) */ static int omap3_init_bch(struct mtd_info *mtd, int ecc_opt) { - int ret, max_errors; + int max_errors; struct omap_nand_info *info = container_of(mtd, struct omap_nand_info, mtd); #ifdef CONFIG_MTD_NAND_OMAP_BCH8 @@ -1147,11 +1230,6 @@ static int omap3_init_bch(struct mtd_info *mtd, int ecc_opt) goto fail; } - /* initialize GPMC BCH engine */ - ret = gpmc_init_hwecc_bch(info->gpmc_cs, 1, max_errors); - if (ret) - goto fail; - /* software bch library is only used to detect and locate errors */ info->bch = init_bch(13, max_errors, 0x201b /* hw polynomial */); if (!info->bch) -- 2.46.0