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NAND: davinci: choose correct 1-bit h/w ECC reg

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In nand_davinci_readecc(), select the correct NANDF<n>ECC register based
on CONFIG_SYS_NAND_CS rather than hardcoding the choice of NANDF1ECC.
This allows 1-bit hardware ECC to work with chip select other than CS2.

Note this now matches the usage in nand_davinci_enable_hwecc(), which
already had the correct handling, and allows refactoring to a single
function encapsulating the register read.

Without this fix, writing NAND pages to a chip not wired to CS2 would
result in in the ECC calculation always returning FFFFFF for each
512-byte segment, and reading back a correctly written page (one with
ECC intact) would always fail. With this fix, the ECC is written and
verified correctly.

Signed-off-by: Laurence Withers <lwithers@guralp.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
This commit is contained in:
Laurence Withers 2011-09-26 16:02:30 +00:00 committed by Scott Wood
parent 0841ca90f2
commit 6016194371
1 changed files with 13 additions and 13 deletions
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26
drivers/mtd/nand/davinci_nand.c
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@ -176,12 +176,22 @@ static void nand_davinci_hwcontrol(struct mtd_info *mtd, int cmd,
#ifdef CONFIG_SYS_NAND_HW_ECC
static u_int32_t nand_davinci_readecc(struct mtd_info *mtd)
{
u_int32_t ecc = 0;
ecc = __raw_readl(&(davinci_emif_regs->nandfecc[
CONFIG_SYS_NAND_CS - 2]));
return ecc;
}
static void nand_davinci_enable_hwecc(struct mtd_info *mtd, int mode)
{
u_int32_t val;
(void)__raw_readl(&(davinci_emif_regs->nandfecc[
CONFIG_SYS_NAND_CS - 2]));
/* reading the ECC result register resets the ECC calculation */
nand_davinci_readecc(mtd);
val = __raw_readl(&davinci_emif_regs->nandfcr);
val |= DAVINCI_NANDFCR_NAND_ENABLE(CONFIG_SYS_NAND_CS);
@ -189,22 +199,12 @@ static void nand_davinci_enable_hwecc(struct mtd_info *mtd, int mode)
__raw_writel(val, &davinci_emif_regs->nandfcr);
}
static u_int32_t nand_davinci_readecc(struct mtd_info *mtd, u_int32_t region)
{
u_int32_t ecc = 0;
ecc = __raw_readl(&(davinci_emif_regs->nandfecc[region - 1]));
return ecc;
}
static int nand_davinci_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
u_char *ecc_code)
{
u_int32_t tmp;
const int region = 1;
tmp = nand_davinci_readecc(mtd, region);
tmp = nand_davinci_readecc(mtd);
/* Squeeze 4 bytes ECC into 3 bytes by removing RESERVED bits
* and shifting. RESERVED bits are 31 to 28 and 15 to 12. */