[U-Boot] [PATCH v2] NAND: DaVinci: V2 Adding 4 BIT ECC support
s-paulraj at ti.com
s-paulraj at ti.com
Tue Aug 18 16:10:42 CEST 2009
From: Sandeep Paulraj <s-paulraj at ti.com>
This patch adds 4 BIT ECC support in the DaVinci NAND
driver. Tested on both the DM355 and DM365.
Signed-off-by: Sandeep Paulraj <s-paulraj at ti.com>
---
I had earlier sent another patch along with this patch to add 4 BIT ECC support
[PATCH] ARM: DaVinci DM355: Updating the DM355 EVM config
The above patch has not changed
drivers/mtd/nand/davinci_nand.c | 284 +++++++++++++++++++++++++++++-
include/asm-arm/arch-davinci/emif_defs.h | 10 +
2 files changed, 292 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/nand/davinci_nand.c b/drivers/mtd/nand/davinci_nand.c
index 7837a8e..37d8b73 100644
--- a/drivers/mtd/nand/davinci_nand.c
+++ b/drivers/mtd/nand/davinci_nand.c
@@ -47,6 +47,16 @@
#include <asm/arch/nand_defs.h>
#include <asm/arch/emif_defs.h>
+/* Definitions for 4-bit hardware ECC */
+#define NAND_TIMEOUT 10240
+#define NAND_ECC_BUSY 0xC
+#define NAND_4BITECC_MASK 0x03FF03FF
+#define EMIF_NANDFSR_ECC_STATE_MASK 0x00000F00
+#define ECC_STATE_NO_ERR 0x0
+#define ECC_STATE_TOO_MANY_ERRS 0x1
+#define ECC_STATE_ERR_CORR_COMP_P 0x2
+#define ECC_STATE_ERR_CORR_COMP_N 0x3
+
static emif_registers *const emif_regs = (void *) DAVINCI_ASYNC_EMIF_CNTRL_BASE;
static void nand_davinci_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
@@ -170,6 +180,268 @@ static int nand_davinci_correct_data(struct mtd_info *mtd, u_char *dat, u_char *
}
#endif /* CONFIG_SYS_NAND_HW_ECC */
+#ifdef CONFIG_SYS_NAND_4BIT_HW_ECC_OOBFIRST
+static struct nand_ecclayout nand_davinci_4bit_layout_oobfirst = {
+/*
+ * TI uses a different layout for 4K page deviecs. Since the
+ * eccpos filed can hold only a limited number of entries, adding
+ * support for 4K page will result in compilation warnings
+ * 4K Support will be added later
+ */
+#ifdef CONFIG_SYS_NAND_PAGE_2K
+ .eccbytes = 40,
+ .eccpos = {
+ 24, 25, 26, 27, 28,
+ 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
+ 39, 40, 41, 42, 43, 44, 45, 46, 47, 48,
+ 49, 50, 51, 52, 53, 54, 55, 56, 57, 58,
+ 59, 60, 61, 62, 63,
+ },
+ .oobfree = {
+ {.offset = 2, .length = 22, },
+ },
+#endif
+};
+#endif
+
+static void nand_davinci_4bit_enable_hwecc(struct mtd_info *mtd, int mode)
+{
+ u32 val;
+
+ switch (mode) {
+ case NAND_ECC_WRITE:
+ case NAND_ECC_READ:
+ /*
+ * Start a new ECC calculation for reading or writing 512 bytes
+ * of data.
+ */
+ val = (emif_regs->NANDFCR & ~(3 << 4)) | (1 << 12);
+ emif_regs->NANDFCR = val;
+ break;
+ case NAND_ECC_READSYN:
+ val = emif_regs->NAND4BITECC1;
+ break;
+ default:
+ break;
+ }
+}
+
+static u32 nand_davinci_4bit_readecc(struct mtd_info *mtd, unsigned int ecc[4])
+{
+ ecc[0] = emif_regs->NAND4BITECC1 & NAND_4BITECC_MASK;
+ ecc[1] = emif_regs->NAND4BITECC2 & NAND_4BITECC_MASK;
+ ecc[2] = emif_regs->NAND4BITECC3 & NAND_4BITECC_MASK;
+ ecc[3] = emif_regs->NAND4BITECC4 & NAND_4BITECC_MASK;
+
+ return 0;
+}
+
+static int nand_davinci_4bit_calculate_ecc(struct mtd_info *mtd,
+ const uint8_t *dat,
+ uint8_t *ecc_code)
+{
+ unsigned int hw_4ecc[4] = { 0, 0, 0, 0 };
+ unsigned int const1 = 0, const2 = 0;
+ unsigned char count1 = 0;
+
+ nand_davinci_4bit_readecc(mtd, hw_4ecc);
+
+ /*Convert 10 bit ecc value to 8 bit */
+ for (count1 = 0; count1 < 2; count1++) {
+ const2 = count1 * 5;
+ const1 = count1 * 2;
+
+ /* Take first 8 bits from val1 (count1=0) or val5 (count1=1) */
+ ecc_code[const2] = hw_4ecc[const1] & 0xFF;
+
+ /*
+ * Take 2 bits as LSB bits from val1 (count1=0) or val5
+ * (count1=1) and 6 bits from val2 (count1=0) or
+ * val5 (count1=1)
+ */
+ ecc_code[const2 + 1] =
+ ((hw_4ecc[const1] >> 8) & 0x3) | ((hw_4ecc[const1] >> 14) &
+ 0xFC);
+
+ /*
+ * Take 4 bits from val2 (count1=0) or val5 (count1=1) and
+ * 4 bits from val3 (count1=0) or val6 (count1=1)
+ */
+ ecc_code[const2 + 2] =
+ ((hw_4ecc[const1] >> 22) & 0xF) |
+ ((hw_4ecc[const1 + 1] << 4) & 0xF0);
+
+ /*
+ * Take 6 bits from val3(count1=0) or val6 (count1=1) and
+ * 2 bits from val4 (count1=0) or val7 (count1=1)
+ */
+ ecc_code[const2 + 3] =
+ ((hw_4ecc[const1 + 1] >> 4) & 0x3F) |
+ ((hw_4ecc[const1 + 1] >> 10) & 0xC0);
+
+ /* Take 8 bits from val4 (count1=0) or val7 (count1=1) */
+ ecc_code[const2 + 4] = (hw_4ecc[const1 + 1] >> 18) & 0xFF;
+ }
+ return 0;
+}
+
+
+static int nand_davinci_4bit_correct_data(struct mtd_info *mtd, uint8_t *dat,
+ uint8_t *read_ecc, uint8_t *calc_ecc)
+{
+ struct nand_chip *this = mtd->priv;
+ unsigned short ecc_10bit[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
+ int i;
+ unsigned int hw_4ecc[4] = { 0, 0, 0, 0 }, iserror = 0;
+ unsigned short *pspare = NULL, *pspare1 = NULL;
+ unsigned int numerrors, erroraddress, errorvalue;
+ u32 val;
+
+ /*
+ * Check for an ECC where all bytes are 0xFF. If this is the case, we
+ * will assume we are looking at an erased page and we should ignore
+ * the ECC.
+ */
+ for (i = 0; i < 10; i++) {
+ if (read_ecc[i] != 0xFF)
+ break;
+ }
+ if (i == 10)
+ return 0;
+
+ /* Convert 8 bit in to 10 bit */
+ pspare = (unsigned short *)&read_ecc[2];
+ pspare1 = (unsigned short *)&read_ecc[0];
+
+ /* Take 10 bits from 0th and 1st bytes */
+ ecc_10bit[0] = (*pspare1) & 0x3FF;
+
+ /* Take 6 bits from 1st byte and 4 bits from 2nd byte */
+ ecc_10bit[1] = (((*pspare1) >> 10) & 0x3F)
+ | (((pspare[0]) << 6) & 0x3C0);
+
+ /* Take 4 bits form 2nd bytes and 6 bits from 3rd bytes */
+ ecc_10bit[2] = ((pspare[0]) >> 4) & 0x3FF;
+
+ /*Take 2 bits from 3rd byte and 8 bits from 4th byte */
+ ecc_10bit[3] = (((pspare[0]) >> 14) & 0x3)
+ | ((((pspare[1])) << 2) & 0x3FC);
+
+ /* Take 8 bits from 5th byte and 2 bits from 6th byte */
+ ecc_10bit[4] = ((pspare[1]) >> 8)
+ | ((((pspare[2])) << 8) & 0x300);
+
+ /* Take 6 bits from 6th byte and 4 bits from 7th byte */
+ ecc_10bit[5] = (pspare[2] >> 2) & 0x3FF;
+
+ /* Take 4 bits from 7th byte and 6 bits from 8th byte */
+ ecc_10bit[6] = (((pspare[2]) >> 12) & 0xF)
+ | ((((pspare[3])) << 4) & 0x3F0);
+
+ /*Take 2 bits from 8th byte and 8 bits from 9th byte */
+ ecc_10bit[7] = ((pspare[3]) >> 6) & 0x3FF;
+
+ /*
+ * Write the parity values in the NAND Flash 4-bit ECC Load register.
+ * Write each parity value one at a time starting from 4bit_ecc_val8
+ * to 4bit_ecc_val1.
+ */
+ for (i = 7; i >= 0; i--)
+ emif_regs->NAND4BITECCLOAD = ecc_10bit[i];
+
+ /*
+ * Perform a dummy read to the EMIF Revision Code and Status register.
+ * This is required to ensure time for syndrome calculation after
+ * writing the ECC values in previous step.
+ */
+
+ val = emif_regs->NANDFSR;
+
+ /*
+ * Read the syndrome from the NAND Flash 4-Bit ECC 1-4 registers.
+ * A syndrome value of 0 means no bit errors. If the syndrome is
+ * non-zero then go further otherwise return.
+ */
+ nand_davinci_4bit_readecc(mtd, hw_4ecc);
+
+ if (hw_4ecc[0] == ECC_STATE_NO_ERR && hw_4ecc[1] == ECC_STATE_NO_ERR &&
+ hw_4ecc[2] == ECC_STATE_NO_ERR && hw_4ecc[3] == ECC_STATE_NO_ERR)
+ return 0;
+
+ /*
+ * Clear any previous address calculation by doing a dummy read of an
+ * error address register.
+ */
+ val = emif_regs->NANDERRADD1;
+
+ /*
+ * Set the addr_calc_st bit(bit no 13) in the NAND Flash Control
+ * register to 1.
+ */
+ emif_regs->NANDFCR |= 1 << 13;
+
+ /*
+ * Wait for the corr_state field (bits 8 to 11)in the
+ * NAND Flash Status register to be equal to 0x0, 0x1, 0x2, or 0x3.
+ */
+ i = NAND_TIMEOUT;
+ do {
+ val = emif_regs->NANDFSR;
+ val &= 0xc00;
+ i--;
+ } while ((i > 0) && val);
+
+ iserror = emif_regs->NANDFSR;
+ iserror &= EMIF_NANDFSR_ECC_STATE_MASK;
+ iserror = iserror >> 8;
+
+ /*
+ * ECC_STATE_TOO_MANY_ERRS (0x1) means errors cannot be
+ * corrected (five or more errors). The number of errors
+ * calculated (err_num field) differs from the number of errors
+ * searched. ECC_STATE_ERR_CORR_COMP_P (0x2) means error
+ * correction complete (errors on bit 8 or 9).
+ * ECC_STATE_ERR_CORR_COMP_N (0x3) means error correction
+ * complete (error exists).
+ */
+
+ if (iserror == ECC_STATE_NO_ERR) {
+ val = emif_regs->NANDERRVAL1;
+ return 0;
+ } else if (iserror == ECC_STATE_TOO_MANY_ERRS) {
+ val = emif_regs->NANDERRVAL1;
+ return -1;
+ }
+
+ numerrors = ((emif_regs->NANDFSR >> 16) & 0x3) + 1;
+
+ /* Read the error address, error value and correct */
+ for (i = 0; i < numerrors; i++) {
+ if (i > 1) {
+ erroraddress =
+ ((emif_regs->NANDERRADD2 >>
+ (16 * (i & 1))) & 0x3FF);
+ erroraddress = ((512 + 7) - erroraddress);
+ errorvalue =
+ ((emif_regs->NANDERRVAL2 >>
+ (16 * (i & 1))) & 0xFF);
+ } else {
+ erroraddress =
+ ((emif_regs->NANDERRADD1 >>
+ (16 * (i & 1))) & 0x3FF);
+ erroraddress = ((512 + 7) - erroraddress);
+ errorvalue =
+ ((emif_regs->NANDERRVAL1 >>
+ (16 * (i & 1))) & 0xFF);
+ }
+ /* xor the corrupt data with error value */
+ if (erroraddress < 512)
+ dat[erroraddress] ^= errorvalue;
+ }
+
+ return numerrors;
+}
+
static int nand_davinci_dev_ready(struct mtd_info *mtd)
{
return emif_regs->NANDFSR & 0x1;
@@ -215,7 +487,7 @@ void davinci_nand_init(struct nand_chip *nand)
{
nand->chip_delay = 0;
#ifdef CONFIG_SYS_NAND_USE_FLASH_BBT
- nand->options = NAND_USE_FLASH_BBT;
+ nand->options |= NAND_USE_FLASH_BBT;
#endif
#ifdef CONFIG_SYS_NAND_HW_ECC
nand->ecc.mode = NAND_ECC_HW;
@@ -227,7 +499,15 @@ void davinci_nand_init(struct nand_chip *nand)
#else
nand->ecc.mode = NAND_ECC_SOFT;
#endif /* CONFIG_SYS_NAND_HW_ECC */
-
+#ifdef CONFIG_SYS_NAND_4BIT_HW_ECC_OOBFIRST
+ nand->ecc.mode = NAND_ECC_HW_OOB_FIRST;
+ nand->ecc.size = 512;
+ nand->ecc.bytes = 10;
+ nand->ecc.calculate = nand_davinci_4bit_calculate_ecc;
+ nand->ecc.correct = nand_davinci_4bit_correct_data;
+ nand->ecc.hwctl = nand_davinci_4bit_enable_hwecc;
+ nand->ecc.layout = &nand_davinci_4bit_layout_oobfirst;
+#endif
/* Set address of hardware control function */
nand->cmd_ctrl = nand_davinci_hwcontrol;
diff --git a/include/asm-arm/arch-davinci/emif_defs.h b/include/asm-arm/arch-davinci/emif_defs.h
index 646fc77..c91e30c 100644
--- a/include/asm-arm/arch-davinci/emif_defs.h
+++ b/include/asm-arm/arch-davinci/emif_defs.h
@@ -55,6 +55,16 @@ typedef struct {
dv_reg NANDF2ECC;
dv_reg NANDF3ECC;
dv_reg NANDF4ECC;
+ u_int8_t RSVD2[60];
+ dv_reg NAND4BITECCLOAD;
+ dv_reg NAND4BITECC1;
+ dv_reg NAND4BITECC2;
+ dv_reg NAND4BITECC3;
+ dv_reg NAND4BITECC4;
+ dv_reg NANDERRADD1;
+ dv_reg NANDERRADD2;
+ dv_reg NANDERRVAL1;
+ dv_reg NANDERRVAL2;
} emif_registers;
typedef emif_registers *emifregs;
--
1.6.0.4
More information about the U-Boot
mailing list