From: Sandeep Paulraj s-paulraj@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@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;