From 92d0e09abeebdd3f699c9f12401a9e3998a20546 Mon Sep 17 00:00:00 2001 From: Huang Shijie Date: Tue, 29 Jan 2013 09:23:38 +0800 Subject: [PATCH] mtd: gpmi: add sanity check for the ECC We do the check based on the following two facts: [1] The mx23/mx28 can only support 20-bits ECC, while the mx6 can supports 40-bits ECC. [2] The mx23/mx28 can only support the GF13, while the mx6 can supports GF13 and GF14. Signed-off-by: Huang Shijie Signed-off-by: Artem Bityutskiy --- drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 28 ++++++++++++++++++++++++-- drivers/mtd/nand/gpmi-nand/gpmi-nand.h | 4 ++++ 2 files changed, 30 insertions(+), 2 deletions(-) diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c index 25216785f180..717881a3d1b8 100644 --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c @@ -94,6 +94,25 @@ static inline int get_ecc_strength(struct gpmi_nand_data *this) return round_down(ecc_strength, 2); } +static inline bool gpmi_check_ecc(struct gpmi_nand_data *this) +{ + struct bch_geometry *geo = &this->bch_geometry; + + /* Do the sanity check. */ + if (GPMI_IS_MX23(this) || GPMI_IS_MX28(this)) { + /* The mx23/mx28 only support the GF13. */ + if (geo->gf_len == 14) + return false; + + if (geo->ecc_strength > MXS_ECC_STRENGTH_MAX) + return false; + } else if (GPMI_IS_MX6Q(this)) { + if (geo->ecc_strength > MX6_ECC_STRENGTH_MAX) + return false; + } + return true; +} + int common_nfc_set_geometry(struct gpmi_nand_data *this) { struct bch_geometry *geo = &this->bch_geometry; @@ -123,8 +142,13 @@ int common_nfc_set_geometry(struct gpmi_nand_data *this) /* We use the same ECC strength for all chunks. */ geo->ecc_strength = get_ecc_strength(this); - if (!geo->ecc_strength) { - pr_err("wrong ECC strength.\n"); + if (!gpmi_check_ecc(this)) { + dev_err(this->dev, + "We can not support this nand chip." + " Its required ecc strength(%d) is beyond our" + " capability(%d).\n", geo->ecc_strength, + (GPMI_IS_MX6Q(this) ? MX6_ECC_STRENGTH_MAX + : MXS_ECC_STRENGTH_MAX)); return -EINVAL; } diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h index 3d93a5e39090..072947731277 100644 --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h @@ -284,6 +284,10 @@ extern int gpmi_read_page(struct gpmi_nand_data *, #define STATUS_ERASED 0xff #define STATUS_UNCORRECTABLE 0xfe +/* BCH's bit correction capability. */ +#define MXS_ECC_STRENGTH_MAX 20 /* mx23 and mx28 */ +#define MX6_ECC_STRENGTH_MAX 40 + /* Use the platform_id to distinguish different Archs. */ #define IS_MX23 0x0 #define IS_MX28 0x1 -- 2.39.5