lkml.org 
[lkml]   [2018]   [Aug]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v6] mtd: nand: toshiba: Add support for Toshiba Memory BENAND (Built-in ECC NAND)
On Sat,  4 Aug 2018 14:25:52 +0900
KOBAYASHI Yoshitake <yoshitake.kobayashi@toshiba.co.jp> wrote:

> This patch is a patch to support TOSHIBA MEMORY CORPORATION BENAND
> memory devices. Check the status of the built-in ECC with the Read
> Status command without using the vendor specific command. The Read
> Status command only knows whether there was bitflips above the
> threshold and can not get accurate bitflips. For now, I set
> max_bitflips mtd->bitflip_threshold.
>
> Signed-off-by: KOBAYASHI Yoshitake <yoshitake.kobayashi@toshiba.co.jp>

Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>

> ---
> drivers/mtd/nand/raw/nand_toshiba.c | 88 +++++++++++++++++++++++++++++++++++++
> 1 file changed, 88 insertions(+)
>
> diff --git a/drivers/mtd/nand/raw/nand_toshiba.c b/drivers/mtd/nand/raw/nand_toshiba.c
> index ab43f02..8aec3fa 100644
> --- a/drivers/mtd/nand/raw/nand_toshiba.c
> +++ b/drivers/mtd/nand/raw/nand_toshiba.c
> @@ -17,6 +17,89 @@
>
> #include <linux/mtd/rawnand.h>
>
> +/* Bit for detecting BENAND */
> +#define TOSHIBA_NAND_ID4_IS_BENAND BIT(7)
> +
> +/* Recommended to rewrite for BENAND */
> +#define TOSHIBA_NAND_STATUS_REWRITE_RECOMMENDED BIT(3)
> +
> +static int toshiba_nand_benand_eccstatus(struct mtd_info *mtd,
> + struct nand_chip *chip)
> +{
> + int ret;
> + unsigned int max_bitflips = 0;
> + u8 status;
> +
> + /* Check Status */
> + ret = nand_status_op(chip, &status);
> + if (ret)
> + return ret;
> +
> + if (status & NAND_STATUS_FAIL) {
> + /* uncorrected */
> + mtd->ecc_stats.failed++;
> + } else if (status & TOSHIBA_NAND_STATUS_REWRITE_RECOMMENDED) {
> + /* corrected */
> + 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)
> +{
> + int ret;
> +
> + ret = nand_read_page_raw(mtd, chip, buf, oob_required, page);
> + if (ret)
> + return ret;
> +
> + return toshiba_nand_benand_eccstatus(mtd, chip);
> +}
> +
> +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)
> +{
> + int ret;
> +
> + ret = nand_read_page_op(chip, page, data_offs,
> + bufpoi + data_offs, readlen);
> + if (ret)
> + return ret;
> +
> + return toshiba_nand_benand_eccstatus(mtd, chip);
> +}
> +
> +static void toshiba_nand_benand_init(struct nand_chip *chip)
> +{
> + struct mtd_info *mtd = nand_to_mtd(chip);
> +
> + /*
> + * On BENAND, the entire OOB region can be used by the MTD user.
> + * The calculated ECC bytes are stored into other isolated
> + * area which is not accessible to users.
> + * 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_notsupp;
> + chip->ecc.write_page_raw = nand_write_page_raw_notsupp;
> +
> + chip->options |= NAND_SUBPAGE_READ;
> +
> + mtd_set_ooblayout(mtd, &nand_ooblayout_lp_ops);
> +}
> +
> static void toshiba_nand_decode_id(struct nand_chip *chip)
> {
> struct mtd_info *mtd = nand_to_mtd(chip);
> @@ -68,6 +151,11 @@ static int toshiba_nand_init(struct nand_chip *chip)
> if (nand_is_slc(chip))
> chip->bbt_options |= NAND_BBT_SCAN2NDPAGE;
>
> + /* Check that chip is BENAND and ECC mode is on-die */
> + if (nand_is_slc(chip) && chip->ecc.mode == NAND_ECC_ON_DIE &&
> + chip->id.data[4] & TOSHIBA_NAND_ID4_IS_BENAND)
> + toshiba_nand_benand_init(chip);
> +
> return 0;
> }
>

\
 
 \ /
  Last update: 2018-08-04 07:47    [W:0.048 / U:0.752 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site