[PATCH 3/4] ARM: OMAP2: gpmc: Add support for BCH ECC scheme

Peter Korsgaard jacmet at sunsite.dk
Mon Oct 15 14:48:30 EDT 2012


>>>>> Philip, Avinash <avinashphilip at ti.com> writes:

 > Add support for BCH ECC scheme to gpmc driver and also enabling multi
 > sector read/write. This helps in doing single shot NAND page read and
 > write.

 > ECC engine configurations
 > BCH 4 bit support
 > 1. write => ECC engine configured in wrap mode 6 and with ecc_size0 as 32.
 > 2. read  => ECC engine configured in wrap mode 1 and with ecc_size0 as
 > 13 and ecc_size1 as 1.

 > BCH 8 bit support
 > 1. write => ECC engine configured in wrap mode 6 and with ecc_size0 as 32.
 > 2. read  => ECC engine configured in wrap mode 1 and with ecc_size0 as
 > 26 and ecc_size1 as 2.

 > Note: For BCH8 ECC bytes set to 14 to make compatible with RBL.

On what device? In the am335x TRM (spruh73f.pdf) figure 26-15 (pg 4273)
the rom code is documented to not use any padding on the ECC bytes
(E.G. oob 2..53):

http://www.ti.com/litv/pdf/spruh73f

I see the driver in the u-boot-am33x tree (ti81xx_nand.c) seems to use
4x14 bytes as well though, so perhaps that's a bug in the documentation
instead?

-- 
Bye, Peter Korsgaard



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