From: Peng Fan <peng....@freescale.com>
Calculate ecc strength according oobsize, but not hardcoded
which is not aligned with kernel driver
Signed-off-by: Peng Fan <peng....@freescale.com>
Signed-off-by: Ye.Li <b37...@freescale.com>
Reviewed-by: Marek Vasut <ma...@denx.de>
Signed-off-by: Jörg Krause <joerg.krause@embedded.rocks>
---
Changes for v3:
- squashed "[U-Boot,v2,3/4] mtd: nand: mxs: Add comment for calculating
ECC strength"
https://patchwork.ozlabs.org/patch/460926/
- Coding Style cleanup
Changes for v2:
- None (original patch from Peng Fan)
---
drivers/mtd/nand/mxs_nand.c | 30 ++++++++++++------------------
1 file changed, 12 insertions(+), 18 deletions(-)
diff --git a/drivers/mtd/nand/mxs_nand.c b/drivers/mtd/nand/mxs_nand.c
index 7a064ab..a463de7 100644
--- a/drivers/mtd/nand/mxs_nand.c
+++ b/drivers/mtd/nand/mxs_nand.c
@@ -146,26 +146,20 @@ static uint32_t mxs_nand_aux_status_offset(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,
--
2.3.5
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