2015-07-13 20:07:44

by Karicheri, Muralidharan

[permalink] [raw]
Subject: [RESEND: PATCH v1] mtd: nand: davinci: add support for 4K page size nand devices.

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 <[email protected]>
Signed-off-by: Hao Zhang <[email protected]>
---
- Resend after subscribing to linux-mtd mailing list. I assume
no one has seen this on this mailing list as I don't have any
comments. So re-sending.
- 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;

--
1.9.1


2015-07-20 16:58:13

by Brian Norris

[permalink] [raw]
Subject: Re: [RESEND: PATCH v1] mtd: nand: davinci: add support for 4K page size nand devices.

+ others

On Mon, Jul 13, 2015 at 04:07:16PM -0400, 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 <[email protected]>
> Signed-off-by: Hao Zhang <[email protected]>

I see a much earlier patch that is nearly identical, but whose
whitespace is a little cleaner:

http://patchwork.ozlabs.org/patch/381347/

I don't know why it was never ack'd or merged. I think I'll take it now.

Is there anyone who wants to step and have a MAINTAINERS entry on this?
I don't have hardware or anything, so it'd be great if someone who works
on these things can ack changes for davinci_nand.c.

Thanks,
Brian

> ---
> - Resend after subscribing to linux-mtd mailing list. I assume
> no one has seen this on this mailing list as I don't have any
> comments. So re-sending.
> - 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;
>
> --
> 1.9.1
>