diff options
Diffstat (limited to 'drivers/mtd/nand/core.c')
| -rw-r--r-- | drivers/mtd/nand/core.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/drivers/mtd/nand/core.c b/drivers/mtd/nand/core.c index b6de955ac8bf..5e13a03d2b32 100644 --- a/drivers/mtd/nand/core.c +++ b/drivers/mtd/nand/core.c @@ -208,6 +208,130 @@ int nanddev_mtd_max_bad_blocks(struct mtd_info *mtd, loff_t offs, size_t len) EXPORT_SYMBOL_GPL(nanddev_mtd_max_bad_blocks); /** + * nanddev_get_ecc_engine() - Find and get a suitable ECC engine + * @nand: NAND device + */ +static int nanddev_get_ecc_engine(struct nand_device *nand) +{ + int engine_type; + + /* Read the user desires in terms of ECC engine/configuration */ + of_get_nand_ecc_user_config(nand); + + engine_type = nand->ecc.user_conf.engine_type; + if (engine_type == NAND_ECC_ENGINE_TYPE_INVALID) + engine_type = nand->ecc.defaults.engine_type; + + switch (engine_type) { + case NAND_ECC_ENGINE_TYPE_NONE: + return 0; + case NAND_ECC_ENGINE_TYPE_SOFT: + nand->ecc.engine = nand_ecc_get_sw_engine(nand); + break; + case NAND_ECC_ENGINE_TYPE_ON_DIE: + nand->ecc.engine = nand_ecc_get_on_die_hw_engine(nand); + break; + case NAND_ECC_ENGINE_TYPE_ON_HOST: + pr_err("On-host hardware ECC engines not supported yet\n"); + break; + default: + pr_err("Missing ECC engine type\n"); + } + + if (!nand->ecc.engine) + return -EINVAL; + + return 0; +} + +/** + * nanddev_put_ecc_engine() - Dettach and put the in-use ECC engine + * @nand: NAND device + */ +static int nanddev_put_ecc_engine(struct nand_device *nand) +{ + switch (nand->ecc.ctx.conf.engine_type) { + case NAND_ECC_ENGINE_TYPE_ON_HOST: + pr_err("On-host hardware ECC engines not supported yet\n"); + break; + case NAND_ECC_ENGINE_TYPE_NONE: + case NAND_ECC_ENGINE_TYPE_SOFT: + case NAND_ECC_ENGINE_TYPE_ON_DIE: + default: + break; + } + + return 0; +} + +/** + * nanddev_find_ecc_configuration() - Find a suitable ECC configuration + * @nand: NAND device + */ +static int nanddev_find_ecc_configuration(struct nand_device *nand) +{ + int ret; + + if (!nand->ecc.engine) + return -ENOTSUPP; + + ret = nand_ecc_init_ctx(nand); + if (ret) + return ret; + + if (!nand_ecc_is_strong_enough(nand)) + pr_warn("WARNING: %s: the ECC used on your system is too weak compared to the one required by the NAND chip\n", + nand->mtd.name); + + return 0; +} + +/** + * nanddev_ecc_engine_init() - Initialize an ECC engine for the chip + * @nand: NAND device + */ +int nanddev_ecc_engine_init(struct nand_device *nand) +{ + int ret; + + /* Look for the ECC engine to use */ + ret = nanddev_get_ecc_engine(nand); + if (ret) { + pr_err("No ECC engine found\n"); + return ret; + } + + /* No ECC engine requested */ + if (!nand->ecc.engine) + return 0; + + /* Configure the engine: balance user input and chip requirements */ + ret = nanddev_find_ecc_configuration(nand); + if (ret) { + pr_err("No suitable ECC configuration\n"); + nanddev_put_ecc_engine(nand); + + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(nanddev_ecc_engine_init); + +/** + * nanddev_ecc_engine_cleanup() - Cleanup ECC engine initializations + * @nand: NAND device + */ +void nanddev_ecc_engine_cleanup(struct nand_device *nand) +{ + if (nand->ecc.engine) + nand_ecc_cleanup_ctx(nand); + + nanddev_put_ecc_engine(nand); +} +EXPORT_SYMBOL_GPL(nanddev_ecc_engine_cleanup); + +/** * nanddev_init() - Initialize a NAND device * @nand: NAND device * @ops: NAND device operations |