@@ -141,6 +141,7 @@ static u_char bch8_vector[] = {0xf3, 0xdb, 0x14, 0x16, 0x8b, 0xd2, 0xbe, 0xcc,
0xac, 0x6b, 0xff, 0x99, 0x7b};
static u_char bch4_vector[] = {0x00, 0x6b, 0x31, 0xdd, 0x41, 0xbc, 0x10};
#endif
+static u8 bch4_polynomial[] = {0x28, 0x13, 0xcc, 0x39, 0x96, 0xac, 0x7f};
/* oob info generated runtime depending on ecc algorithm and layout selected */
static struct nand_ecclayout omap_oobinfo;
@@ -1124,45 +1125,6 @@ static void omap3_enable_hwecc_bch(struct mtd_info *mtd, int mode)
#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
* @dat: The pointer to data on which ecc is computed
@@ -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
@@ -1253,6 +1214,7 @@ 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]);
@@ -1271,6 +1233,12 @@ static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd,
/* ECC scheme specific syndrome customizations */
switch (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;
@@ -1289,6 +1257,7 @@ static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd,
return 0;
}
+#ifdef CONFIG_MTD_NAND_OMAP_BCH
/**
* omap_elm_correct_data - corrects page data area in case error reported
* @mtd: MTD device structure
@@ -1823,7 +1792,7 @@ 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 /
chip->ecc.calculate() is used for calculating and fetching of ECC syndrome by processing the data passed during Read/Write accesses. All H/W ECC schemes use GPMC controller for ECC syndrome calculation,but each ecc-scheme implements its own calback to config, process and fetch ECC syndrome. This patch merges omap3_calculate_ecc_bch4() into omap_calculate_ecc_bch() to re-use common code between BCH4_HW and BCH4_HW_DETECTION_SW +---------------------+-------------------------------------------------------+ |ecc-scheme | implementations for nand_chip->calculate() | +---------------------+-------------------------------------------------------+ |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() | +---------------------+-------------------------------------------------------+ Signed-off-by: Pekon Gupta <pekon@ti.com> --- drivers/mtd/nand/omap2.c | 51 ++++++++++-------------------------------------- 1 file changed, 10 insertions(+), 41 deletions(-)