Re: [PATCH - v1] mtd: nand: davinci: add support for 4K page size nand devices.

[Murali Karicheri <m-karicheri2@ti.com>]

On 06/10/2015 05:02 AM, Murali Karicheri wrote:
> K2L EVM uses NAND with 4K page size. This patch add support for
> ECC layout requires to enable Micron MT29F16G08ADBCAH4 NAND available
> on this EVM.
>
> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
> Signed-off-by: Hao Zhang <hzhang@ti.com>
> ---
>   - v1 - Remove the comment as well from the code as now 4K page
>     is supported
>   drivers/mtd/nand/davinci_nand.c | 42 +++++++++++++++++++++++++++++------------
>   1 file changed, 30 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/mtd/nand/davinci_nand.c b/drivers/mtd/nand/davinci_nand.c
> index feb6d18..90b177b 100644
> --- a/drivers/mtd/nand/davinci_nand.c
> +++ b/drivers/mtd/nand/davinci_nand.c
> @@ -520,6 +520,31 @@ static struct nand_ecclayout hwecc4_2048 = {
>   	},
>   };
>
> +/* An ECC layout for using 4-bit ECC with large-page (4096bytes) flash,
> + * storing ten ECC bytes plus the manufacturer's bad block marker byte,
> + * and not overlapping the default BBT markers.
> + */
> +static struct nand_ecclayout hwecc4_4096 = {
> +	.eccbytes = 80,
> +	.eccpos = {
> +		/* at the end of spare sector */
> +		48, 49, 50, 51, 52, 53, 54, 55, 56, 57,
> +		58, 59, 60, 61, 62, 63, 64, 65, 66, 67,
> +		68, 69, 70, 71, 72, 73, 74, 75, 76, 77,
> +		78, 79, 80, 81, 82, 83, 84, 85, 86, 87,
> +		88, 89, 90, 91, 92, 93, 94, 95, 96, 97,
> +		98, 99, 100, 101, 102, 103, 104, 105, 106, 107,
> +		108, 109, 110, 111, 112, 113, 114, 115, 116, 117,
> +		118, 119, 120, 121, 122, 123, 124, 125, 126, 127,
> +		},
> +	.oobfree = {
> +		/* 2 bytes at offset 0 hold manufacturer badblock markers */
> +		{.offset = 2, .length = 46, },
> +		/* 5 bytes at offset 8 hold BBT markers */
> +		/* 8 bytes at offset 16 hold JFFS2 clean markers */
> +	},
> +};
> +
>   #if defined(CONFIG_OF)
>   static const struct of_device_id davinci_nand_of_match[] = {
>   	{.compatible = "ti,davinci-nand", },
> @@ -796,18 +821,11 @@ static int nand_davinci_probe(struct platform_device *pdev)
>   			info->chip.ecc.mode = NAND_ECC_HW_OOB_FIRST;
>   			goto syndrome_done;
>   		}
> -
> -		/* 4KiB page chips are not yet supported. The eccpos from
> -		 * nand_ecclayout cannot hold 80 bytes and change to eccpos[]
> -		 * breaks userspace ioctl interface with mtd-utils. Once we
> -		 * resolve this issue, NAND_ECC_HW_OOB_FIRST mode can be used
> -		 * for the 4KiB page chips.
> -		 *
> -		 * TODO: Note that nand_ecclayout has now been expanded and can
> -		 *  hold plenty of OOB entries.
> -		 */
> -		dev_warn(&pdev->dev, "no 4-bit ECC support yet "
> -				"for 4KiB-page NAND\n");
> +		if (chunks == 8) {
> +			info->ecclayout = hwecc4_4096;
> +			info->chip.ecc.mode = NAND_ECC_HW_OOB_FIRST;
> +			goto syndrome_done;
> +		}
>   		ret = -EIO;
>   		goto err;
>
>
MTD Maintainers,

Can you please review and queue this to next?

Thanks
-- 
Murali Karicheri
Linux Kernel, Keystone