diff options
Diffstat (limited to 'Documentation/devicetree/bindings/mtd/mtk-nand.txt')
-rw-r--r-- | Documentation/devicetree/bindings/mtd/mtk-nand.txt | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/Documentation/devicetree/bindings/mtd/mtk-nand.txt b/Documentation/devicetree/bindings/mtd/mtk-nand.txt index c5ba6a4..4d3ec5e 100644 --- a/Documentation/devicetree/bindings/mtd/mtk-nand.txt +++ b/Documentation/devicetree/bindings/mtd/mtk-nand.txt @@ -48,14 +48,19 @@ Optional: - nand-on-flash-bbt: Store BBT on NAND Flash. - nand-ecc-mode: the NAND ecc mode (check driver for supported modes) - nand-ecc-step-size: Number of data bytes covered by a single ECC step. - valid values: 512 and 1024. + valid values: + 512 and 1024 on mt2701 and mt2712. + 512 only on mt7622. 1024 is recommended for large page NANDs. - nand-ecc-strength: Number of bits to correct per ECC step. - The valid values that the controller supports are: 4, 6, - 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36, 40, 44, - 48, 52, 56, 60. + The valid values that each controller supports: + mt2701: 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, + 32, 36, 40, 44, 48, 52, 56, 60. + mt2712: 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, + 32, 36, 40, 44, 48, 52, 56, 60, 68, 72, 80. + mt7622: 4, 6, 8, 10, 12, 14, 16. The strength should be calculated as follows: - E = (S - F) * 8 / 14 + E = (S - F) * 8 / B S = O / (P / Q) E : nand-ecc-strength. S : spare size per sector. @@ -64,6 +69,15 @@ Optional: O : oob size. P : page size. Q : nand-ecc-step-size. + B : number of parity bits needed to correct + 1 bitflip. + According to MTK NAND controller design, + this number depends on max ecc step size + that MTK NAND controller supports. + If max ecc step size supported is 1024, + then it should be always 14. And if max + ecc step size is 512, then it should be + always 13. If the result does not match any one of the listed choices above, please select the smaller valid value from the list. |