From 2c8f8afa7f92acb07641bf95b940d384ed1d0294 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Wed, 7 Jun 2017 20:52:10 +0900 Subject: mtd: nand: add generic helpers to check, match, maximize ECC settings Driver are responsible for setting up ECC parameters correctly. Those include: - Check if ECC parameters specified (usually by DT) are valid - Meet the chip's ECC requirement - Maximize ECC strength if NAND_ECC_MAXIMIZE flag is set The logic can be generalized by factoring out common code. This commit adds 3 helpers to the NAND framework: nand_check_ecc_caps - Check if preset step_size and strength are valid nand_match_ecc_req - Match the chip's requirement nand_maximize_ecc - Maximize the ECC strength To use the helpers above, a driver needs to provide: - Data array of supported ECC step size and strength - A hook that calculates ECC bytes from the combination of step_size and strength. By using those helpers, code duplication among drivers will be reduced. Signed-off-by: Masahiro Yamada Signed-off-by: Boris Brezillon --- include/linux/mtd/nand.h | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'include/linux') diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index 8b3607bde1b5..568f53e812cd 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -481,6 +481,30 @@ static inline void nand_hw_control_init(struct nand_hw_control *nfc) init_waitqueue_head(&nfc->wq); } +/** + * struct nand_ecc_step_info - ECC step information of ECC engine + * @stepsize: data bytes per ECC step + * @strengths: array of supported strengths + * @nstrengths: number of supported strengths + */ +struct nand_ecc_step_info { + int stepsize; + const int *strengths; + int nstrengths; +}; + +/** + * struct nand_ecc_caps - capability of ECC engine + * @stepinfos: array of ECC step information + * @nstepinfos: number of ECC step information + * @calc_ecc_bytes: driver's hook to calculate ECC bytes per step + */ +struct nand_ecc_caps { + const struct nand_ecc_step_info *stepinfos; + int nstepinfos; + int (*calc_ecc_bytes)(int step_size, int strength); +}; + /** * struct nand_ecc_ctrl - Control structure for ECC * @mode: ECC mode @@ -1246,6 +1270,15 @@ int nand_check_erased_ecc_chunk(void *data, int datalen, void *extraoob, int extraooblen, int threshold); +int nand_check_ecc_caps(struct nand_chip *chip, + const struct nand_ecc_caps *caps, int oobavail); + +int nand_match_ecc_req(struct nand_chip *chip, + const struct nand_ecc_caps *caps, int oobavail); + +int nand_maximize_ecc(struct nand_chip *chip, + const struct nand_ecc_caps *caps, int oobavail); + /* Default write_oob implementation */ int nand_write_oob_std(struct mtd_info *mtd, struct nand_chip *chip, int page); -- cgit v1.2.3-71-gd317