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.

V3 version of the patch resolves compilation warnings pointed to by Scott Wood. These compilation warnings occur when 4 BIT ECC support is not enabled

Signed-off-by: Sandeep Paulraj s-paulraj@ti.com --- For feature completeness this patch should be used along with [PATCH v2] ARM: DaVinci DM355: Updating the DM355 EVM config that i just sent to the mailing list drivers/mtd/nand/davinci_nand.c | 283 +++++++++++++++++++++++++++++- include/asm-arm/arch-davinci/emif_defs.h | 10 + 2 files changed, 291 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/davinci_nand.c b/drivers/mtd/nand/davinci_nand.c index 7837a8e..eabaf3e 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 +180,267 @@ 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 +}; + +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) +{ + 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; +} +#endif /* CONFIG_SYS_NAND_4BIT_HW_ECC_OOBFIRST */ + static int nand_davinci_dev_ready(struct mtd_info *mtd) { return emif_regs->NANDFSR & 0x1; @@ -215,7 +486,7 @@ 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 +498,15 @@ 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;