This patch enables support for Toshiba BENAND. The current implementation does not support vondor specific command TOSHIBA_NAND_CMD_ECC_STATUS. I would like to add the command, when the exec_op() [1] infrastructure is implemented.
[1] https://github.com/bbrezillon/linux/commits/nand/exec_op1 Changelog[v2]: Rewrite to adapt the mtd "separate vendor specific code from core" cleanup process that based on comments from the following discussion. http://patchwork.ozlabs.org/patch/767191/ Signed-off-by: KOBAYASHI Yoshitake <yoshitake.kobaya...@toshiba.co.jp> --- drivers/mtd/nand/nand_toshiba.c | 100 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 100 insertions(+) diff --git a/drivers/mtd/nand/nand_toshiba.c b/drivers/mtd/nand/nand_toshiba.c index 57df857..7a99bbe 100644 --- a/drivers/mtd/nand/nand_toshiba.c +++ b/drivers/mtd/nand/nand_toshiba.c @@ -17,6 +17,72 @@ #include <linux/mtd/rawnand.h> +/* ECC Status Read Command for BENAND */ +#define TOSHIBA_NAND_CMD_ECC_STATUS 0x7A + +/* Recommended to rewrite for BENAND */ +#define TOSHIBA_NAND_STATUS_REWRITE_RECOMMENDED BIT(3) + +static int toshiba_nand_benand_status_chk(struct mtd_info *mtd, + struct nand_chip *chip) +{ + unsigned int max_bitflips = 0; + u8 status; + + /* Check Read Status */ + chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1); + status = chip->read_byte(mtd); + + /* + * TOSHIBA_NAND_CMD_ECC_STATUS is vendor specific command. + * We will rewrite this code, after the ->exec_op() infrastructure + * is implemented + * Now, we set max_bitflips mtd->bitflip_threshold. + */ + if (status & NAND_STATUS_FAIL) { + /* uncorrectable */ + mtd->ecc_stats.failed++; + } else if (status & TOSHIBA_NAND_STATUS_REWRITE_RECOMMENDED) { + /* correctable */ + max_bitflips = mtd->bitflip_threshold; + mtd->ecc_stats.corrected += max_bitflips; + } + + return max_bitflips; +} + +static int +toshiba_nand_read_page_benand(struct mtd_info *mtd, + struct nand_chip *chip, uint8_t *buf, + int oob_required, int page) +{ + unsigned int max_bitflips = 0; + + chip->ecc.read_page_raw(mtd, chip, buf, oob_required, page); + max_bitflips = toshiba_nand_benand_status_chk(mtd, chip); + + return max_bitflips; +} + +static int +toshiba_nand_read_subpage_benand(struct mtd_info *mtd, + struct nand_chip *chip, uint32_t data_offs, + uint32_t readlen, uint8_t *bufpoi, int page) +{ + uint8_t *p; + unsigned int max_bitflips = 0; + + if (data_offs != 0) + chip->cmdfunc(mtd, NAND_CMD_RNDOUT, data_offs, -1); + + p = bufpoi + data_offs; + chip->read_buf(mtd, p, readlen); + + max_bitflips = toshiba_nand_benand_status_chk(mtd, chip); + + return max_bitflips; +} + static void toshiba_nand_decode_id(struct nand_chip *chip) { struct mtd_info *mtd = nand_to_mtd(chip); @@ -39,9 +105,43 @@ static void toshiba_nand_decode_id(struct nand_chip *chip) static int toshiba_nand_init(struct nand_chip *chip) { + struct mtd_info *mtd = nand_to_mtd(chip); + if (nand_is_slc(chip)) chip->bbt_options |= NAND_BBT_SCAN2NDPAGE; + if (nand_is_slc(chip) && (chip->id.data[4] & 0x80)) { + /* BENAND */ + + /* + * We can't disable the internal ECC engine, the user + * has to use on-die ECC, there is no alternative. + */ + if (chip->ecc.mode != NAND_ECC_ON_DIE) { + pr_err("On-die ECC should be selected.\n"); + return -EINVAL; + } + + /* + * On BENAND, all OOB reginon can be used by user (driver). + * The calculated ECC bytes are stored into other isolated + * area which is ubable to access from user. + * This is why chip->ecc.bytes = 0. + */ + chip->ecc.bytes = 0; + chip->ecc.size = 512; + chip->ecc.strength = 8; + chip->ecc.read_page = toshiba_nand_read_page_benand; + chip->ecc.read_subpage = toshiba_nand_read_subpage_benand; + chip->ecc.write_page = nand_write_page_raw; + chip->ecc.read_page_raw = nand_read_page_raw; + chip->ecc.write_page_raw = nand_write_page_raw; + + chip->options |= NAND_SUBPAGE_READ; + + mtd_set_ooblayout(mtd, &nand_ooblayout_lp_ops); + } + return 0; } -- 2.7.4
