Patchwork [U-Boot,1/3] mtd/NAND: Add FSMC driver support

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Submitter Amit Virdi
Date Feb. 27, 2012, 9:38 a.m.
Message ID <1330335504-32226-2-git-send-email-amit.virdi@st.com>
Download mbox | patch
Permalink /patch/143167/
State Superseded
Headers show

Comments

Amit Virdi - Feb. 27, 2012, 9:38 a.m.
From: Vipin KUMAR <vipin.kumar@st.com>

Flexible static memory controller is a peripheral provided by ST,
which controls the access to NAND chips along with many other
memory device chips eg NOR, SRAM.

This patch adds the driver support for FSMC controller interfacing
with NAND memory.

Signed-off-by: Vipin Kumar <vipin.kumar@st.com>
Signed-off-by: Amit Virdi <amit.virdi@st.com>
---
 drivers/mtd/nand/Makefile     |    1 +
 drivers/mtd/nand/fsmc_nand.c  |  441 +++++++++++++++++++++++++++++++++++++++++
 include/linux/mtd/fsmc_nand.h |  110 ++++++++++
 3 files changed, 552 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mtd/nand/fsmc_nand.c
 create mode 100644 include/linux/mtd/fsmc_nand.h
Scott Wood - March 1, 2012, 9:27 p.m.
On 02/27/2012 03:38 AM, Amit Virdi wrote:
> +		/*
> +		 * This is a temporary erase check. A newly erased page read
> +		 * would result in an ecc error because the oob data is also
> +		 * erased to FF and the calculated ecc for an FF data is not
> +		 * FF..FF.
> +		 * This is a workaround to skip performing correction in case
> +		 * data is FF..FF
> +		 */
> +		for (k = 0; k < eccsize; k++) {
> +			if (*(p + k) != 0xff)
> +				break;
> +		}

Shouldn't this apply over the whole page (including the ECC bytes
themselves), not just the ECC chunk?  The data could legitimately be all
0xff except for one bit, and that bit could have flipped...

Will a freshly erased page show up as having correctable errors, or
uncorrectable?  If the latter, just hold off on declaring the page as an
ECC fail until you've read the whole thing, and then if you're about to
mark it failed, check wheter it's freshly erased.

> +	nand->options = 0;
> +#if defined(CONFIG_SYS_FSMC_NAND_16BIT)
> +	nand->options |= NAND_BUSWIDTH_16;
> +#endif

No on-flash BBT?

> +	/* Detect NAND chips */
> +	if (nand_scan_ident(mtd, 1, NULL))
> +		return -ENXIO;

You should #define CONFIG_SYS_NAND_SELF_INIT if you want to call this
yourself (see the documentation for what else you need to do).

> +/*
> + * There are 13 bytes of ecc for every 512 byte block and it has to be read
> + * consecutively and immediately after the 512 byte data block for hardware to
> + * generate the error bit offsets
> + * Managing the ecc bytes in the following way is easier. This way is similar to
> + * oobfree structure maintained already in u-boot nand driver
> + */
> +#define MAX_ECCPLACE_ENTRIES	32

No FSMC namespace... is/will this file included by anything but the FSMC
 driver?

-Scott
Amit Virdi - March 2, 2012, 11:16 a.m.
Hello Scott,

On 3/2/2012 2:57 AM, Scott Wood wrote:
> On 02/27/2012 03:38 AM, Amit Virdi wrote:
>> +		/*
>> +		 * This is a temporary erase check. A newly erased page read
>> +		 * would result in an ecc error because the oob data is also
>> +		 * erased to FF and the calculated ecc for an FF data is not
>> +		 * FF..FF.
>> +		 * This is a workaround to skip performing correction in case
>> +		 * data is FF..FF
>> +		 */
>> +		for (k = 0; k<  eccsize; k++) {
>> +			if (*(p + k) != 0xff)
>> +				break;
>> +		}
>
> Shouldn't this apply over the whole page (including the ECC bytes
> themselves), not just the ECC chunk?  The data could legitimately be all
> 0xff except for one bit, and that bit could have flipped...

So you're saying that such a page is wrongly interpreted as "erased 
page" and ecc check is skipped! Yes, you are very right. This check 
should be applied to the whole page and not only the chunk.

>
> Will a freshly erased page show up as having correctable errors, or

A newly erased page contains 0xff in data as well as spare area. So most 
likely, it shows up as having uncorrectable errors.

> uncorrectable?  If the latter, just hold off on declaring the page as an
> ECC fail until you've read the whole thing, and then if you're about to
> mark it failed, check wheter it's freshly erased.

So do you mean to say:

			stat = chip->ecc.correct(mtd, p, &ecc_code[i],
					&ecc_calc[i]);
			if (stat < 0) {
			  if (data as well as the oob is 0xff)
				do nothing;
                           else
				mtd->ecc_stats.failed++;
			} else
				mtd->ecc_stats.corrected += stat;


Can we have a scenario like this:
A page has been erased - so it contains 0xff in data area as well as 
spare area. Somehow, a bit in either or say both areas are flipped, then 
the SW will not be able to distinguish if it's and erased page or a page 
with data and uncorrectable errors. How do we take care of such scenarios?

>
>> +	nand->options = 0;
>> +#if defined(CONFIG_SYS_FSMC_NAND_16BIT)
>> +	nand->options |= NAND_BUSWIDTH_16;
>> +#endif
>
> No on-flash BBT?
>

No, not implemented yet.

>> +	/* Detect NAND chips */
>> +	if (nand_scan_ident(mtd, 1, NULL))
>> +		return -ENXIO;
>
> You should #define CONFIG_SYS_NAND_SELF_INIT if you want to call this
> yourself (see the documentation for what else you need to do).
>

Ok. I see this is the new philosophy that is encouraged even for the 
existing drivers.

>> +/*
>> + * There are 13 bytes of ecc for every 512 byte block and it has to be read
>> + * consecutively and immediately after the 512 byte data block for hardware to
>> + * generate the error bit offsets
>> + * Managing the ecc bytes in the following way is easier. This way is similar to
>> + * oobfree structure maintained already in u-boot nand driver
>> + */
>> +#define MAX_ECCPLACE_ENTRIES	32
>
> No FSMC namespace... is/will this file included by anything but the FSMC
>   driver?
>

Sorry, it didn't get you here. This file (fsmc_nand.h) shall be included 
by board files.

Thanks
Amit Virdi
Scott Wood - March 5, 2012, 11:39 p.m.
On 03/02/2012 05:16 AM, Amit Virdi wrote:
> Hello Scott,
> 
> On 3/2/2012 2:57 AM, Scott Wood wrote:
>> On 02/27/2012 03:38 AM, Amit Virdi wrote:
>>> +        /*
>>> +         * This is a temporary erase check. A newly erased page read
>>> +         * would result in an ecc error because the oob data is also
>>> +         * erased to FF and the calculated ecc for an FF data is not
>>> +         * FF..FF.
>>> +         * This is a workaround to skip performing correction in case
>>> +         * data is FF..FF
>>> +         */
>>> +        for (k = 0; k<  eccsize; k++) {
>>> +            if (*(p + k) != 0xff)
>>> +                break;
>>> +        }
>>
>> Shouldn't this apply over the whole page (including the ECC bytes
>> themselves), not just the ECC chunk?  The data could legitimately be all
>> 0xff except for one bit, and that bit could have flipped...
> 
> So you're saying that such a page is wrongly interpreted as "erased
> page" and ecc check is skipped! Yes, you are very right. This check
> should be applied to the whole page and not only the chunk.
> 
>>
>> Will a freshly erased page show up as having correctable errors, or
> 
> A newly erased page contains 0xff in data as well as spare area. So most
> likely, it shows up as having uncorrectable errors.

This is what I saw as well on FSL IFC with 4-bit ECC (see is_blank() and
related code in drivers/mtd/nand/fsl_ifc_nand.c for another driver doing
this sort of check).

>> uncorrectable?  If the latter, just hold off on declaring the page as an
>> ECC fail until you've read the whole thing, and then if you're about to
>> mark it failed, check wheter it's freshly erased.
> 
> So do you mean to say:
> 
>             stat = chip->ecc.correct(mtd, p, &ecc_code[i],
>                     &ecc_calc[i]);
>             if (stat < 0) {
>               if (data as well as the oob is 0xff)
>                 do nothing;
>                           else
>                 mtd->ecc_stats.failed++;
>             } else
>                 mtd->ecc_stats.corrected += stat;

Yes, provided you check the entire page and not just the ecc subpage
after seeing an error.

> Can we have a scenario like this:
> A page has been erased - so it contains 0xff in data area as well as
> spare area. Somehow, a bit in either or say both areas are flipped, then
> the SW will not be able to distinguish if it's and erased page or a page
> with data and uncorrectable errors. How do we take care of such scenarios?

It will show up as an uncorrectable error (which is no big loss, since
the page has no data, but may result in a block being marked bad before
its time).

If you really want, you could keep a count and allow a certain number of
bits to be flipped (up to the ECC threshold) and still consider it blank
(and report the number of corrections as usual).

>>> +    /* Detect NAND chips */
>>> +    if (nand_scan_ident(mtd, 1, NULL))
>>> +        return -ENXIO;
>>
>> You should #define CONFIG_SYS_NAND_SELF_INIT if you want to call this
>> yourself (see the documentation for what else you need to do).
>>
> 
> Ok. I see this is the new philosophy that is encouraged even for the
> existing drivers.

Yes, it would be nice if the old way could go away at some point.

>>> +/*
>>> + * There are 13 bytes of ecc for every 512 byte block and it has to
>>> be read
>>> + * consecutively and immediately after the 512 byte data block for
>>> hardware to
>>> + * generate the error bit offsets
>>> + * Managing the ecc bytes in the following way is easier. This way
>>> is similar to
>>> + * oobfree structure maintained already in u-boot nand driver
>>> + */
>>> +#define MAX_ECCPLACE_ENTRIES    32
>>
>> No FSMC namespace... is/will this file included by anything but the FSMC
>>   driver?
>>
> 
> Sorry, it didn't get you here. This file (fsmc_nand.h) shall be included
> by board files.

I'd either namespace it or (preferably) keep this in the driver file
itself, but as long as nothing outside FSMC-specific code includes this
(directly or indirectly -- e.g. the board config file must not include
it) I won't complain too loudly.

-Scott

Patch

diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 998fc73..517e5c1 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -49,6 +49,7 @@  COBJS-$(CONFIG_NAND_DAVINCI) += davinci_nand.o
 COBJS-$(CONFIG_NAND_FSL_ELBC) += fsl_elbc_nand.o
 COBJS-$(CONFIG_NAND_FSL_IFC) += fsl_ifc_nand.o
 COBJS-$(CONFIG_NAND_FSL_UPM) += fsl_upm.o
+COBJS-$(CONFIG_NAND_FSMC) += fsmc_nand.o
 COBJS-$(CONFIG_NAND_JZ4740) += jz4740_nand.o
 COBJS-$(CONFIG_NAND_KB9202) += kb9202_nand.o
 COBJS-$(CONFIG_NAND_KIRKWOOD) += kirkwood_nand.o
diff --git a/drivers/mtd/nand/fsmc_nand.c b/drivers/mtd/nand/fsmc_nand.c
new file mode 100644
index 0000000..a97dc0d
--- /dev/null
+++ b/drivers/mtd/nand/fsmc_nand.c
@@ -0,0 +1,441 @@ 
+/*
+ * (C) Copyright 2010
+ * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <nand.h>
+#include <asm/io.h>
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/mtd/nand_ecc.h>
+#include <linux/mtd/fsmc_nand.h>
+#include <asm/arch/hardware.h>
+
+static u32 fsmc_version;
+static struct fsmc_regs *const fsmc_regs_p = (struct fsmc_regs *)
+	CONFIG_SYS_FSMC_BASE;
+
+/*
+ * ECC4 and ECC1 have 13 bytes and 3 bytes of ecc respectively for 512 bytes of
+ * data. ECC4 can correct up to 8 bits in 512 bytes of data while ECC1 can
+ * correct 1 bit in 512 bytes
+ */
+
+static struct nand_ecclayout fsmc_ecc4_lp_layout = {
+	.eccbytes = 104,
+	.eccpos = {  2,   3,   4,   5,   6,   7,   8,
+		9,  10,  11,  12,  13,  14,
+		18,  19,  20,  21,  22,  23,  24,
+		25,  26,  27,  28,  29,  30,
+		34,  35,  36,  37,  38,  39,  40,
+		41,  42,  43,  44,  45,  46,
+		50,  51,  52,  53,  54,  55,  56,
+		57,  58,  59,  60,  61,  62,
+		66,  67,  68,  69,  70,  71,  72,
+		73,  74,  75,  76,  77,  78,
+		82,  83,  84,  85,  86,  87,  88,
+		89,  90,  91,  92,  93,  94,
+		98,  99, 100, 101, 102, 103, 104,
+		105, 106, 107, 108, 109, 110,
+		114, 115, 116, 117, 118, 119, 120,
+		121, 122, 123, 124, 125, 126
+	},
+	.oobfree = {
+		{.offset = 15, .length = 3},
+		{.offset = 31, .length = 3},
+		{.offset = 47, .length = 3},
+		{.offset = 63, .length = 3},
+		{.offset = 79, .length = 3},
+		{.offset = 95, .length = 3},
+		{.offset = 111, .length = 3},
+		{.offset = 127, .length = 1}
+	}
+};
+
+/*
+ * ECC4 layout for NAND of pagesize 4096 bytes & OOBsize 224 bytes. 13*8 bytes
+ * of OOB size is reserved for ECC, Byte no. 0 & 1 reserved for bad block & 118
+ * bytes are free for use.
+ */
+static struct nand_ecclayout fsmc_ecc4_224_layout = {
+	.eccbytes = 104,
+	.eccpos = {  2,   3,   4,   5,   6,   7,   8,
+		9,  10,  11,  12,  13,  14,
+		18,  19,  20,  21,  22,  23,  24,
+		25,  26,  27,  28,  29,  30,
+		34,  35,  36,  37,  38,  39,  40,
+		41,  42,  43,  44,  45,  46,
+		50,  51,  52,  53,  54,  55,  56,
+		57,  58,  59,  60,  61,  62,
+		66,  67,  68,  69,  70,  71,  72,
+		73,  74,  75,  76,  77,  78,
+		82,  83,  84,  85,  86,  87,  88,
+		89,  90,  91,  92,  93,  94,
+		98,  99, 100, 101, 102, 103, 104,
+		105, 106, 107, 108, 109, 110,
+		114, 115, 116, 117, 118, 119, 120,
+		121, 122, 123, 124, 125, 126
+	},
+	.oobfree = {
+		{.offset = 15, .length = 3},
+		{.offset = 31, .length = 3},
+		{.offset = 47, .length = 3},
+		{.offset = 63, .length = 3},
+		{.offset = 79, .length = 3},
+		{.offset = 95, .length = 3},
+		{.offset = 111, .length = 3},
+		{.offset = 127, .length = 97}
+	}
+};
+
+/*
+ * ECC placement definitions in oobfree type format
+ * There are 13 bytes of ecc for every 512 byte block and it has to be read
+ * consecutively and immediately after the 512 byte data block for hardware to
+ * generate the error bit offsets in 512 byte data
+ * Managing the ecc bytes in the following way makes it easier for software to
+ * read ecc bytes consecutive to data bytes. This way is similar to
+ * oobfree structure maintained already in u-boot nand driver
+ */
+static struct fsmc_eccplace fsmc_eccpl_lp = {
+	.eccplace = {
+		{.offset = 2, .length = 13},
+		{.offset = 18, .length = 13},
+		{.offset = 34, .length = 13},
+		{.offset = 50, .length = 13},
+		{.offset = 66, .length = 13},
+		{.offset = 82, .length = 13},
+		{.offset = 98, .length = 13},
+		{.offset = 114, .length = 13}
+	}
+};
+
+static struct nand_ecclayout fsmc_ecc4_sp_layout = {
+	.eccbytes = 13,
+	.eccpos = { 0,  1,  2,  3,  6,  7, 8,
+		9, 10, 11, 12, 13, 14
+	},
+	.oobfree = {
+		{.offset = 15, .length = 1},
+	}
+};
+
+static struct fsmc_eccplace fsmc_eccpl_sp = {
+	.eccplace = {
+		{.offset = 0, .length = 4},
+		{.offset = 6, .length = 9}
+	}
+};
+
+static struct nand_ecclayout fsmc_ecc1_layout = {
+	.eccbytes = 24,
+	.eccpos = {2, 3, 4, 18, 19, 20, 34, 35, 36, 50, 51, 52,
+		66, 67, 68, 82, 83, 84, 98, 99, 100, 114, 115, 116},
+	.oobfree = {
+		{.offset = 8, .length = 8},
+		{.offset = 24, .length = 8},
+		{.offset = 40, .length = 8},
+		{.offset = 56, .length = 8},
+		{.offset = 72, .length = 8},
+		{.offset = 88, .length = 8},
+		{.offset = 104, .length = 8},
+		{.offset = 120, .length = 8}
+	}
+};
+
+static void fsmc_nand_hwcontrol(struct mtd_info *mtd, int cmd, uint ctrl)
+{
+	struct nand_chip *this = mtd->priv;
+	ulong IO_ADDR_W;
+
+	if (ctrl & NAND_CTRL_CHANGE) {
+		IO_ADDR_W = (ulong)this->IO_ADDR_W;
+
+		IO_ADDR_W &= ~(CONFIG_SYS_NAND_CLE | CONFIG_SYS_NAND_ALE);
+		if (ctrl & NAND_CLE)
+			IO_ADDR_W |= CONFIG_SYS_NAND_CLE;
+		if (ctrl & NAND_ALE)
+			IO_ADDR_W |= CONFIG_SYS_NAND_ALE;
+
+		if (ctrl & NAND_NCE) {
+			writel(readl(&fsmc_regs_p->pc) |
+					FSMC_ENABLE, &fsmc_regs_p->pc);
+		} else {
+			writel(readl(&fsmc_regs_p->pc) &
+					~FSMC_ENABLE, &fsmc_regs_p->pc);
+		}
+		this->IO_ADDR_W = (void *)IO_ADDR_W;
+	}
+
+	if (cmd != NAND_CMD_NONE)
+		writeb(cmd, this->IO_ADDR_W);
+}
+
+static int fsmc_bch8_correct_data(struct mtd_info *mtd, u_char *dat,
+		u_char *read_ecc, u_char *calc_ecc)
+{
+	/* The calculated ecc is actually the correction index in data */
+	u32 err_idx[8];
+	u64 ecc_data[2];
+	u32 num_err, i;
+
+	memcpy(ecc_data, calc_ecc, 13);
+
+	for (i = 0; i < 8; i++) {
+		if (i == 4) {
+			err_idx[4] = ((ecc_data[1] & 0x1) << 12) | ecc_data[0];
+			ecc_data[1] >>= 1;
+			continue;
+		}
+		err_idx[i] = (ecc_data[i/4] & 0x1FFF);
+		ecc_data[i/4] >>= 13;
+	}
+
+	num_err = (readl(&fsmc_regs_p->sts) >> 10) & 0xF;
+
+	if (num_err > 8)
+		return -EBADMSG;
+
+	i = 0;
+	while (num_err--) {
+		change_bit(0, &err_idx[i]);
+		change_bit(1, &err_idx[i]);
+
+		if (err_idx[i] <= 512 * 8) {
+			change_bit(err_idx[i], dat);
+			i++;
+		}
+	}
+	return i;
+}
+
+static int fsmc_read_hwecc(struct mtd_info *mtd,
+			const u_char *data, u_char *ecc)
+{
+	u_int ecc_tmp;
+
+	switch (fsmc_version) {
+	case FSMC_VER8:
+		/* Busy waiting for ecc computation to finish for 512 bytes */
+		while (!(readl(&fsmc_regs_p->sts) & FSMC_CODE_RDY))
+			;
+
+		ecc_tmp = readl(&fsmc_regs_p->ecc1);
+		ecc[0] = (u_char) (ecc_tmp >> 0);
+		ecc[1] = (u_char) (ecc_tmp >> 8);
+		ecc[2] = (u_char) (ecc_tmp >> 16);
+		ecc[3] = (u_char) (ecc_tmp >> 24);
+
+		ecc_tmp = readl(&fsmc_regs_p->ecc2);
+		ecc[4] = (u_char) (ecc_tmp >> 0);
+		ecc[5] = (u_char) (ecc_tmp >> 8);
+		ecc[6] = (u_char) (ecc_tmp >> 16);
+		ecc[7] = (u_char) (ecc_tmp >> 24);
+
+		ecc_tmp = readl(&fsmc_regs_p->ecc3);
+		ecc[8] = (u_char) (ecc_tmp >> 0);
+		ecc[9] = (u_char) (ecc_tmp >> 8);
+		ecc[10] = (u_char) (ecc_tmp >> 16);
+		ecc[11] = (u_char) (ecc_tmp >> 24);
+
+		ecc_tmp = readl(&fsmc_regs_p->sts);
+		ecc[12] = (u_char) (ecc_tmp >> 16);
+		break;
+
+	default:
+		ecc_tmp = readl(&fsmc_regs_p->ecc1);
+		ecc[0] = (u_char) (ecc_tmp >> 0);
+		ecc[1] = (u_char) (ecc_tmp >> 8);
+		ecc[2] = (u_char) (ecc_tmp >> 16);
+		break;
+	}
+
+	return 0;
+}
+
+void fsmc_enable_hwecc(struct mtd_info *mtd, int mode)
+{
+	writel(readl(&fsmc_regs_p->pc) & ~FSMC_ECCPLEN_256,
+			&fsmc_regs_p->pc);
+	writel(readl(&fsmc_regs_p->pc) & ~FSMC_ECCEN,
+			&fsmc_regs_p->pc);
+	writel(readl(&fsmc_regs_p->pc) | FSMC_ECCEN,
+			&fsmc_regs_p->pc);
+}
+
+/*
+ * fsmc_read_page_hwecc
+ * @mtd:	mtd info structure
+ * @chip:	nand chip info structure
+ * @buf:	buffer to store read data
+ * @page:	page number to read
+ *
+ * This routine is needed for fsmc verison 8 as reading from NAND chip has to be
+ * performed in a strict sequence as follows:
+ * data(512 byte) -> ecc(13 byte)
+ * After this read, fsmc hardware generates and reports error data bits(upto a
+ * max of 8 bits)
+ */
+static int fsmc_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
+				 uint8_t *buf, int page)
+{
+	struct fsmc_eccplace *fsmc_eccpl;
+	int i, j, k, s, stat, eccsize = chip->ecc.size;
+	int eccbytes = chip->ecc.bytes;
+	int eccsteps = chip->ecc.steps;
+	uint8_t *p = buf;
+	uint8_t *ecc_calc = chip->buffers->ecccalc;
+	uint8_t *ecc_code = chip->buffers->ecccode;
+	int off, len, group = 0;
+	/*
+	 * ecc_oob is intentionally taken as u16. In 16bit devices, we end up
+	 * reading 14 bytes (7 words) from oob. The local array is to maintain
+	 * word alignment
+	 */
+	uint16_t ecc_oob[7];
+	uint8_t *oob = (uint8_t *)&ecc_oob[0];
+
+	/* Differentiate between small and large page ecc place definitions */
+	if (mtd->writesize == 512)
+		fsmc_eccpl = &fsmc_eccpl_sp;
+	else
+		fsmc_eccpl = &fsmc_eccpl_lp;
+
+	for (i = 0, s = 0; s < eccsteps; s++, i += eccbytes, p += eccsize) {
+
+		chip->cmdfunc(mtd, NAND_CMD_READ0, s * eccsize, page);
+		chip->ecc.hwctl(mtd, NAND_ECC_READ);
+		chip->read_buf(mtd, p, eccsize);
+
+		for (j = 0; j < eccbytes;) {
+			off = fsmc_eccpl->eccplace[group].offset;
+			len = fsmc_eccpl->eccplace[group].length;
+			group++;
+
+			/*
+			 * length is intentionally kept a higher multiple of 2
+			 * to read at least 13 bytes even in case of 16 bit NAND
+			 * devices
+			 */
+			len = roundup(len, 2);
+			chip->cmdfunc(mtd, NAND_CMD_READOOB, off, page);
+			chip->read_buf(mtd, oob + j, len);
+			j += len;
+		}
+
+		memcpy(&ecc_code[i], ecc_oob, 13);
+		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
+
+		/*
+		 * This is a temporary erase check. A newly erased page read
+		 * would result in an ecc error because the oob data is also
+		 * erased to FF and the calculated ecc for an FF data is not
+		 * FF..FF.
+		 * This is a workaround to skip performing correction in case
+		 * data is FF..FF
+		 */
+		for (k = 0; k < eccsize; k++) {
+			if (*(p + k) != 0xff)
+				break;
+		}
+
+		if (k < eccsize) {
+			stat = chip->ecc.correct(mtd, p, &ecc_code[i],
+					&ecc_calc[i]);
+			if (stat < 0)
+				mtd->ecc_stats.failed++;
+			else
+				mtd->ecc_stats.corrected += stat;
+		}
+	}
+
+	return 0;
+}
+
+int fsmc_nand_init(struct nand_chip *nand)
+{
+	static int chip_nr;
+	struct mtd_info *mtd;
+	u32 peripid2 = readl(&fsmc_regs_p->peripid2);
+
+	fsmc_version = (peripid2 >> FSMC_REVISION_SHFT) &
+		FSMC_REVISION_MSK;
+
+	writel(readl(&fsmc_regs_p->ctrl) | FSMC_WP, &fsmc_regs_p->ctrl);
+
+#if defined(CONFIG_SYS_FSMC_NAND_16BIT)
+	writel(FSMC_DEVWID_16 | FSMC_DEVTYPE_NAND | FSMC_ENABLE | FSMC_WAITON,
+			&fsmc_regs_p->pc);
+#elif defined(CONFIG_SYS_FSMC_NAND_8BIT)
+	writel(FSMC_DEVWID_8 | FSMC_DEVTYPE_NAND | FSMC_ENABLE | FSMC_WAITON,
+			&fsmc_regs_p->pc);
+#else
+#error Please define CONFIG_SYS_FSMC_NAND_16BIT or CONFIG_SYS_FSMC_NAND_8BIT
+#endif
+	writel(readl(&fsmc_regs_p->pc) | FSMC_TCLR_1 | FSMC_TAR_1,
+			&fsmc_regs_p->pc);
+	writel(FSMC_THIZ_1 | FSMC_THOLD_4 | FSMC_TWAIT_6 | FSMC_TSET_0,
+			&fsmc_regs_p->comm);
+	writel(FSMC_THIZ_1 | FSMC_THOLD_4 | FSMC_TWAIT_6 | FSMC_TSET_0,
+			&fsmc_regs_p->attrib);
+
+	nand->options = 0;
+#if defined(CONFIG_SYS_FSMC_NAND_16BIT)
+	nand->options |= NAND_BUSWIDTH_16;
+#endif
+	nand->ecc.mode = NAND_ECC_HW;
+	nand->ecc.size = 512;
+	nand->ecc.calculate = fsmc_read_hwecc;
+	nand->ecc.hwctl = fsmc_enable_hwecc;
+	nand->cmd_ctrl = fsmc_nand_hwcontrol;
+
+	mtd = &nand_info[chip_nr++];
+	mtd->priv = nand;
+
+	/* Detect NAND chips */
+	if (nand_scan_ident(mtd, 1, NULL))
+		return -ENXIO;
+
+	switch (fsmc_version) {
+	case FSMC_VER8:
+		nand->ecc.bytes = 13;
+		nand->ecc.correct = fsmc_bch8_correct_data;
+		nand->ecc.read_page = fsmc_read_page_hwecc;
+		if (mtd->writesize == 512)
+			nand->ecc.layout = &fsmc_ecc4_sp_layout;
+		else {
+			if (mtd->oobsize == 224)
+				nand->ecc.layout = &fsmc_ecc4_224_layout;
+			else
+				nand->ecc.layout = &fsmc_ecc4_lp_layout;
+		}
+
+		break;
+	default:
+		nand->ecc.bytes = 3;
+		nand->ecc.layout = &fsmc_ecc1_layout;
+		nand->ecc.correct = nand_correct_data;
+		break;
+	}
+
+	return 0;
+}
diff --git a/include/linux/mtd/fsmc_nand.h b/include/linux/mtd/fsmc_nand.h
new file mode 100644
index 0000000..2609973
--- /dev/null
+++ b/include/linux/mtd/fsmc_nand.h
@@ -0,0 +1,110 @@ 
+/*
+ * (C) Copyright 2010
+ * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#ifndef __FSMC_NAND_H__
+#define __FSMC_NAND_H__
+
+#include <linux/mtd/nand.h>
+
+struct fsmc_regs {
+	u32 ctrl;			/* 0x00 */
+	u8 reserved_1[0x40 - 0x04];
+	u32 pc;				/* 0x40 */
+	u32 sts;			/* 0x44 */
+	u32 comm;			/* 0x48 */
+	u32 attrib;			/* 0x4c */
+	u32 ioata;			/* 0x50 */
+	u32 ecc1;			/* 0x54 */
+	u32 ecc2;			/* 0x58 */
+	u32 ecc3;			/* 0x5c */
+	u8 reserved_2[0xfe0 - 0x60];
+	u32 peripid0;			/* 0xfe0 */
+	u32 peripid1;			/* 0xfe4 */
+	u32 peripid2;			/* 0xfe8 */
+	u32 peripid3;			/* 0xfec */
+	u32 pcellid0;			/* 0xff0 */
+	u32 pcellid1;			/* 0xff4 */
+	u32 pcellid2;			/* 0xff8 */
+	u32 pcellid3;			/* 0xffc */
+};
+
+/* ctrl register definitions */
+#define FSMC_WP			(1 << 7)
+
+/* pc register definitions */
+#define FSMC_RESET		(1 << 0)
+#define FSMC_WAITON		(1 << 1)
+#define FSMC_ENABLE		(1 << 2)
+#define FSMC_DEVTYPE_NAND	(1 << 3)
+#define FSMC_DEVWID_8		(0 << 4)
+#define FSMC_DEVWID_16		(1 << 4)
+#define FSMC_ECCEN		(1 << 6)
+#define FSMC_ECCPLEN_512	(0 << 7)
+#define FSMC_ECCPLEN_256	(1 << 7)
+#define FSMC_TCLR_1		(1 << 9)
+#define FSMC_TAR_1		(1 << 13)
+
+/* sts register definitions */
+#define FSMC_CODE_RDY		(1 << 15)
+
+/* comm register definitions */
+#define FSMC_TSET_0		(0 << 0)
+#define FSMC_TWAIT_6		(6 << 8)
+#define FSMC_THOLD_4		(4 << 16)
+#define FSMC_THIZ_1		(1 << 24)
+
+/* peripid2 register definitions */
+#define FSMC_REVISION_MSK	(0xf)
+#define FSMC_REVISION_SHFT	(0x4)
+
+enum {
+	FSMC_VER1 = 1,
+	FSMC_VER2,
+	FSMC_VER3,
+	FSMC_VER4,
+	FSMC_VER5,
+	FSMC_VER6,
+	FSMC_VER7,
+	FSMC_VER8,
+};
+
+/*
+ * There are 13 bytes of ecc for every 512 byte block and it has to be read
+ * consecutively and immediately after the 512 byte data block for hardware to
+ * generate the error bit offsets
+ * Managing the ecc bytes in the following way is easier. This way is similar to
+ * oobfree structure maintained already in u-boot nand driver
+ */
+#define MAX_ECCPLACE_ENTRIES	32
+
+struct fsmc_nand_eccplace {
+	u32 offset;
+	u32 length;
+};
+
+struct fsmc_eccplace {
+	struct fsmc_nand_eccplace eccplace[MAX_ECCPLACE_ENTRIES];
+};
+
+extern int fsmc_nand_init(struct nand_chip *nand);
+#endif