mtd: nand: Add a devicetree binding for ECC strength and ECC step size

Some flashes can only be properly accessed when the ECC mode is
specified, so a way to describe such mode is required.

Together, the ECC strength and step size define the correction capability,
so that we say we will correct "{strength} bit errors per {size} bytes".

The interpretation of these parameters is implementation-defined, but they
often have ramifications on the formation, interpretation, and placement of
correction metadata on the flash. Not all implementations must support all
possible combinations. Implementations are encouraged to further define the
value(s) they support.

Acked-by: Boris BREZILLON <b.brezillon.dev@gmail.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
This commit is contained in:
Ezequiel Garcia 2014-02-24 19:24:49 -03:00 committed by Brian Norris
parent 6d9434ebb7
commit 8dd49165ef

View File

@ -5,3 +5,17 @@
"soft_bch".
- nand-bus-width : 8 or 16 bus width if not present 8
- nand-on-flash-bbt: boolean to enable on flash bbt option if not present false
- nand-ecc-strength: integer representing the number of bits to correct
per ECC step.
- nand-ecc-step-size: integer representing the number of data bytes
that are covered by a single ECC step.
The ECC strength and ECC step size properties define the correction capability
of a controller. Together, they say a controller can correct "{strength} bit
errors per {size} bytes".
The interpretation of these parameters is implementation-defined, so not all
implementations must support all possible combinations. However, implementations
are encouraged to further specify the value(s) they support.