On Thu, 15 Oct 2015 19:17:23 +0200
Boris Brezillon <boris.brezil...@free-electrons.com> wrote:
> Add support for the randomizer engine available in Allwinner's NFC IP.
>
> Randomization is useful to support modern NAND chips which are sensible to
> repeated patterns. On such NANDs you might experience an unexpectedly high
> number of bitflips when you repeat the same pattern all over a given NAND
> block.
> Randomizing input data mitigate this problem by avoiding such repeated
> patterns.
>
> Signed-off-by: Boris Brezillon <boris.brezil...@free-electrons.com>
> ---
> drivers/mtd/nand/sunxi_nand.c | 274
> ++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 250 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
> index ef46ac6..5508ce8 100644
> --- a/drivers/mtd/nand/sunxi_nand.c
> +++ b/drivers/mtd/nand/sunxi_nand.c
> @@ -60,6 +60,7 @@
> #define NFC_REG_ECC_ERR_CNT(x) ((0x0040 + (x)) & ~0x3)
> #define NFC_REG_USER_DATA(x) (0x0050 + ((x) * 4))
> #define NFC_REG_SPARE_AREA 0x00A0
> +#define NFC_REG_PAT_ID 0x00A4
> #define NFC_RAM0_BASE 0x0400
> #define NFC_RAM1_BASE 0x0800
>
> @@ -225,6 +226,7 @@ struct sunxi_nand_hw_ecc {
> * @node: used to store NAND chips into a list
> * @nand: base NAND chip structure
> * @mtd: base MTD structure
> + * @randomize: randomize data
> * @clk_rate: clk_rate required for this NAND chip
> * @timing_cfg TIMING_CFG register value for this NAND chip
> * @selected: current active CS
> @@ -235,6 +237,7 @@ struct sunxi_nand_chip {
> struct list_head node;
> struct nand_chip nand;
> struct mtd_info mtd;
> + bool randomize;
This variable is a leftover from a previous version, I'll drop it for
the next version.
--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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