From 6121560d7714d6d8e41ce1687a1388a1a8fea4cb Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=B6rg=20Krause?= Date: Wed, 15 Apr 2015 09:27:23 +0200 Subject: tools: mxsboot: Calculate ECC strength dynamically MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Calculating the ECC strength dynamically to be aligned with the mxs NAND driver and the Linux Kernel. Signed-off-by: Jörg Krause Reviewed-by: Marek Vasut --- tools/mxsboot.c | 35 ++++++++++++++++++++++------------- 1 file changed, 22 insertions(+), 13 deletions(-) diff --git a/tools/mxsboot.c b/tools/mxsboot.c index 08219b3..185b327 100644 --- a/tools/mxsboot.c +++ b/tools/mxsboot.c @@ -14,6 +14,10 @@ #include "compiler.h" +/* Taken from */ +#define __round_mask(x, y) ((__typeof__(x))((y)-1)) +#define round_down(x, y) ((x) & ~__round_mask(x, y)) + /* * Default BCB layout. * @@ -126,6 +130,11 @@ struct mx28_sd_config_block { struct mx28_sd_drive_info drv_info[1]; }; +static inline uint32_t mx28_nand_ecc_chunk_cnt(uint32_t page_data_size) +{ + return page_data_size / MXS_NAND_CHUNK_DATA_CHUNK_SIZE; +} + static inline uint32_t mx28_nand_ecc_size_in_bits(uint32_t ecc_strength) { return ecc_strength * MXS_NAND_BITS_PER_ECC_LEVEL; @@ -134,21 +143,21 @@ static inline uint32_t mx28_nand_ecc_size_in_bits(uint32_t ecc_strength) static inline uint32_t mx28_nand_get_ecc_strength(uint32_t page_data_size, uint32_t page_oob_size) { - if (page_data_size == 2048) - return 8; - - if (page_data_size == 4096) { - if (page_oob_size == 128) - return 8; + int ecc_strength; - 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) + / (MXS_NAND_BITS_PER_ECC_LEVEL * + mx28_nand_ecc_chunk_cnt(page_data_size)); - return 0; + return round_down(ecc_strength, 2); } static inline uint32_t mx28_nand_get_mark_offset(uint32_t page_data_size, -- cgit v1.1