RFC mtd: nand: add randomizer support

Hello,

This series is a proposal to add support for randomizers (either software or hardware) to NAND flash controller drivers.

The last patch is the sunxi HW randomizer implementation and is just given as an example (it won't apply on the MTD tree, because it depends on other stuff not yet posted on the MTD ML, but if you want a full overview of the NAND Flash controller driver you can take a look at this series [2]).

I can also provide a software implementation based on LFSR (Left Feedback Shift Register) algorithm, thought I haven't tested it yet, hence why it's not part of this series. Let me know if you're interested in this implementation.

This series depends on the "per-partition ECC" series [1], because I need the randomizer seed to be different depending on the partition (for the same reason I needed ECC config to be different for each partition: the bootrom config might not fit the NAND chip requirements).

I'd like to have feedback from both MTD maintainers and driver developers who might need to implement (or use) a randomizer in their system, so feel free to comment on this series.

Best Regards,

Boris

[1] https://lkml.org/lkml/2014/2/12/627
[2] https://groups.google.com/forum/#!msg/linux-sunxi/s3lBb01I0Js/z2NoCFJ83g4J

Boris BREZILLON (3):
mtd: nand: introduce a randomizer layer in the NAND framework
of: mtd: add NAND randomizer mode retrieval
mtd: nand: add sunxi randomizer support

 drivers/mtd/nand/nand_base.c  | 278 ++++++++++++++++++-----
 drivers/mtd/nand/sunxi_nand.c | 507 +++++++++++++++++++++++++++++++++++++++++-
 drivers/of/of_mtd.c           |  35 +++
 include/linux/mtd/nand.h      |  98 ++++++++
 include/linux/of_mtd.h        |   6 +
 5 files changed, 858 insertions(+), 66 deletions(-)

1.8.3.2