From: Peng Fan Date: Wed, 15 Apr 2015 07:27:21 +0000 (+0200) Subject: mtd:mxs:nand calculate ecc strength dynamically X-Git-Tag: KARO-TX6-2015-09-18~1951 X-Git-Url: https://git.kernelconcepts.de/?p=karo-tx-uboot.git;a=commitdiff_plain;h=7d0b7fe8c2ff9b0a8fc374e26e87a7de2efc9076 mtd:mxs:nand calculate ecc strength dynamically Calculate ecc strength according oobsize, but not hardcoded which is not aligned with kernel driver Signed-off-by: Peng Fan Signed-off-by: Ye.Li Reviewed-by: Marek Vasut Signed-off-by: Jörg Krause --- diff --git a/drivers/mtd/nand/mxs_nand.c b/drivers/mtd/nand/mxs_nand.c index 19b4f4ec04..0688dd2e27 100644 --- a/drivers/mtd/nand/mxs_nand.c +++ b/drivers/mtd/nand/mxs_nand.c @@ -275,26 +275,20 @@ static int mxs_nand_gpmi_init(void) static inline uint32_t mxs_nand_get_ecc_strength(uint32_t page_data_size, uint32_t page_oob_size) { - if (page_data_size == 2048) { - if (page_oob_size == 64) - return 8; + int ecc_strength; - if (page_oob_size == 112) - return 14; - } - - if (page_data_size == 4096) { - if (page_oob_size == 128) - return 8; - - if (page_oob_size == 218) - return 16; - - if (page_oob_size == 224) - return 16; - } + /* + * Determine the ECC layout with the formula: + * ECC bits per chunk = (total page spare data bits) / + * (bits per ECC level) / (chunks per page) + * where: + * total page spare data bits = + * (page oob size - meta data size) * (bits per byte) + */ + ecc_strength = ((page_oob_size - MXS_NAND_METADATA_SIZE) * 8) + / (13 * mxs_nand_ecc_chunk_cnt(page_data_size)); - return 0; + return round_down(ecc_strength, 2); } static inline uint32_t mxs_nand_get_mark_offset(uint32_t page_data_size,