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| author | pekon gupta <pekon@ti.com> | 2014-06-02 17:14:42 +0530 |
|---|---|---|
| committer | Tom Rini <trini@ti.com> | 2014-06-06 17:46:10 -0400 |
| commit | 46840f66caf564866d191886d2bd86742f982010 (patch) | |
| tree | aa719a57b1c9745b9cd00e9e44f283046f79c7a2 /include/linux/mtd | |
| parent | 8d13a730dea1b5b4d32b31b5584cb8fdea27a248 (diff) | |
| download | u-boot-imx-46840f66caf564866d191886d2bd86742f982010.zip u-boot-imx-46840f66caf564866d191886d2bd86742f982010.tar.gz u-boot-imx-46840f66caf564866d191886d2bd86742f982010.tar.bz2 | |
mtd: nand: omap: add support for BCH16_ECC - NAND driver updates
This patch add support for BCH16_ECC to omap_gpmc driver.
*need to BCH16 ECC scheme*
With newer SLC Flash technologies and MLC NAND, and large densities, pagesizes
Flash devices have become more suspectible to bit-flips. Thus stronger
ECC schemes are required for protecting the data.
But stronger ECC schemes have come with larger-sized ECC syndromes which require
more space in OOB/Spare. This puts constrains like;
(a) BCH16_ECC can correct 16 bit-flips per 512Bytes of data.
(b) BCH16_ECC generates 26-bytes of ECC syndrome / 512B.
Due to (b) this scheme can only be used with NAND devices which have enough
OOB to satisfy following equation:
OOBsize per page >= 26 * (page-size / 512)
Signed-off-by: Pekon Gupta <pekon@ti.com>
Diffstat (limited to 'include/linux/mtd')
| -rw-r--r-- | include/linux/mtd/omap_gpmc.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/mtd/omap_gpmc.h b/include/linux/mtd/omap_gpmc.h index d55fe32..9a86582 100644 --- a/include/linux/mtd/omap_gpmc.h +++ b/include/linux/mtd/omap_gpmc.h @@ -27,6 +27,8 @@ enum omap_ecc { OMAP_ECC_BCH8_CODE_HW_DETECTION_SW, /* 8-bit ECC calculation by GPMC, Error detection by ELM */ OMAP_ECC_BCH8_CODE_HW, + /* 16-bit ECC calculation by GPMC, Error detection by ELM */ + OMAP_ECC_BCH16_CODE_HW, }; struct gpmc_cs { @@ -47,6 +49,10 @@ struct bch_res_0_3 { u32 bch_result_x[4]; }; +struct bch_res_4_6 { + u32 bch_result_x[3]; +}; + struct gpmc { u8 res1[0x10]; u32 sysconfig; /* 0x10 */ @@ -77,6 +83,8 @@ struct gpmc { u32 testmomde_ctrl; /* 0x230 */ u8 res8[12]; /* 0x234 */ struct bch_res_0_3 bch_result_0_3[GPMC_MAX_SECTORS]; /* 0x240,0x250, */ + u8 res9[16 * 4]; /* 0x2C0 - 0x2FF */ + struct bch_res_4_6 bch_result_4_6[GPMC_MAX_SECTORS]; /* 0x300,0x310, */ }; /* Used for board specific gpmc initialization */ |