Patchwork mtd: Add DiskOnChip G3 support

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Submitter Robert Jarzmik
Date May 22, 2011, 2:34 p.m.
Message ID <1306074869-5533-1-git-send-email-robert.jarzmik@free.fr>
Download mbox | patch
Permalink /patch/96753/
State New
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Comments

Robert Jarzmik - May 22, 2011, 2:34 p.m.
From: Robert Jarzmik <robert.jarzmik@atosorigin.com>

Add support for DiskOnChip G3 chips. The support is quite
limited yet :
 - no flash writes/erases are implemented
 - ECC fixes are not implemented
 - powerdown is not implemented
 - IPL handling is not yet done

On the brighter side, the chip reading does work.

Signed-off-by: Robert Jarzmik <robert.jarzmik@atosorigin.com>
---
 drivers/mtd/devices/Kconfig  |   10 +
 drivers/mtd/devices/Makefile |    1 +
 drivers/mtd/devices/docg3.c  | 1051 ++++++++++++++++++++++++++++++++++++++++++
 drivers/mtd/devices/docg3.h  |  196 ++++++++
 4 files changed, 1258 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mtd/devices/docg3.c
 create mode 100644 drivers/mtd/devices/docg3.h
Artem Bityutskiy - May 24, 2011, 7:22 a.m.
On Sun, 2011-05-22 at 16:34 +0200, Robert Jarzmik wrote:
> From: Robert Jarzmik <robert.jarzmik@atosorigin.com>
> 
> Add support for DiskOnChip G3 chips. The support is quite
> limited yet :
>  - no flash writes/erases are implemented
>  - ECC fixes are not implemented
>  - powerdown is not implemented
>  - IPL handling is not yet done
> 
> On the brighter side, the chip reading does work.
> 
> Signed-off-by: Robert Jarzmik <robert.jarzmik@atosorigin.com>

Hi,

the driver looks neat from the first glance, but I did not review it. We
have just changed mtd partitions API, today. You'll need to amend the
driver and re-send.

The partitions API changes have not reached the mtd tree, though, they
are sitting in my l2-mtd-2.6.git tree:

http://git.infradead.org/users/dedekind/l2-mtd-2.6.git
Robert Jarzmik - May 24, 2011, 1:40 p.m.
On 05/24/2011 09:22 AM, Artem Bityutskiy wrote:
> On Sun, 2011-05-22 at 16:34 +0200, Robert Jarzmik wrote:
>> From: Robert Jarzmik<robert.jarzmik@atosorigin.com>
>>
>> Add support for DiskOnChip G3 chips. The support is quite
>> limited yet :
>>   - no flash writes/erases are implemented
>>   - ECC fixes are not implemented
>>   - powerdown is not implemented
>>   - IPL handling is not yet done
>>
>> On the brighter side, the chip reading does work.
>>
>> Signed-off-by: Robert Jarzmik<robert.jarzmik@atosorigin.com>
> Hi,
>
> the driver looks neat from the first glance, but I did not review it. We
> have just changed mtd partitions API, today. You'll need to amend the
> driver and re-send.
Yes, I have seen them. I'll amend it, no big deal.

I'll wait 1 or 2 weeks for a review, and if nobody steps up, I'll resend 
the amended version for mtd_register stuff, and push for an inclusion 
into -next.

Cheers.

--
Robert

Patch

diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig
index 35081ce..6d91a1f 100644
--- a/drivers/mtd/devices/Kconfig
+++ b/drivers/mtd/devices/Kconfig
@@ -249,6 +249,16 @@  config MTD_DOC2001PLUS
 	  under "NAND Flash Device Drivers" (currently that driver does not
 	  support all Millennium Plus devices).
 
+config MTD_DOCG3
+	tristate "M-Systems Disk-On-Chip G3"
+	---help---
+	  This provides an MTD device driver for the M-Systems DiskOnChip
+	  G3 devices.
+
+	  The driver provides access to G3 DiskOnChip, distributed by
+	  M-Systems and now Sandisk. The support is very experimental,
+	  and doesn't give access to any write operations.
+
 config MTD_DOCPROBE
 	tristate
 	select MTD_DOCECC
diff --git a/drivers/mtd/devices/Makefile b/drivers/mtd/devices/Makefile
index f3226b1..e71991f 100644
--- a/drivers/mtd/devices/Makefile
+++ b/drivers/mtd/devices/Makefile
@@ -5,6 +5,7 @@ 
 obj-$(CONFIG_MTD_DOC2000)	+= doc2000.o
 obj-$(CONFIG_MTD_DOC2001)	+= doc2001.o
 obj-$(CONFIG_MTD_DOC2001PLUS)	+= doc2001plus.o
+obj-$(CONFIG_MTD_DOCG3)		+= docg3.o
 obj-$(CONFIG_MTD_DOCPROBE)	+= docprobe.o
 obj-$(CONFIG_MTD_DOCECC)	+= docecc.o
 obj-$(CONFIG_MTD_SLRAM)		+= slram.o
diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
new file mode 100644
index 0000000..0eb0c50
--- /dev/null
+++ b/drivers/mtd/devices/docg3.c
@@ -0,0 +1,1051 @@ 
+/*
+ * Handles the M-Systems DiskOnChip G3 chip
+ *
+ * Copyright (C) 2011 Robert Jarzmik
+ *
+ * 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 <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+
+#include "docg3.h"
+
+/*
+ * This driver handles the DiskOnChip G3 flash memory.
+ *
+ * As no specification is available from M-Systems/Sandisk, this drivers lacks
+ * several functions available on the chip, as :
+ *  - block erase
+ *  - page write
+ *  - IPL write
+ *  - ECC fixing (lack of BCH algorith understanding)
+ *  - powerdown / powerup
+ *
+ * The bus data width (8bits versus 16bits) is not handled (if_cfg flag), and
+ * the driver assumes a 16bits data bus.
+ *
+ * DocG3 relies on 2 ECC algorithms, which are handled in hardware :
+ *  - a 1 byte Hamming code stored in the OOB for each page
+ *  - a 7 bytes BCH code stored in the OOB for each page
+ * The BCH part is only used for check purpose, no correction is available as
+ * some information is missing. What is known is that :
+ *  - BCH is in GF(2^14)
+ *  - BCH is over data of 520 bytes (512 page + 7 page_info bytes
+ *                                   + 1 hamming byte)
+ *  - BCH can correct up to 4 bits (t = 4)
+ *  - BCH syndroms are calculated in hardware, and checked in hardware as well
+ *
+ */
+
+#define doc_readb(reg)	\
+	__raw_readb(docg3->base + (reg));
+#define doc_writeb(value, reg)						\
+do {									\
+	doc_vdbg("Write %02x to register %04x\n", (value), (reg));	\
+	__raw_writeb((value), docg3->base + (reg));			\
+} while (0)
+#define doc_readw(reg)	\
+	__raw_readw(docg3->base + (reg));
+#define doc_writew(value, reg)						\
+do {									\
+	doc_vdbg("Write %04x to register %04x\n", (value), (reg));	\
+	__raw_writew((value), docg3->base + (reg));			\
+} while (0)
+
+#define doc_flashCommand(cmd)						\
+do {									\
+	doc_dbg("doc_flashCommand:  %02x " #cmd "\n", DoC_Cmd_##cmd);	\
+	doc_writeb(DoC_Cmd_##cmd, DoC_FlashCommand);			\
+} while (0)
+
+#define doc_flashSequence(seq)						\
+do {									\
+	doc_dbg("doc_flashSequence: %02x " #seq "\n", DoC_Seq_##seq);	\
+	doc_writeb(DoC_Seq_##seq, DoC_FlashSequence);			\
+} while (0)
+
+#define doc_flashAddress(addr)						\
+do {									\
+	doc_dbg("doc_flashAddress:  %02x\n", (addr));			\
+	doc_writeb((addr), DoC_FlashAddress);				\
+} while (0)
+
+static const char const *part_probes[] = { "cmdlinepart", "saftlpart", NULL };
+
+static int doc_register_readb(struct docg3 *docg3, int reg)
+{
+	u8 val;
+
+	doc_writew(reg, DoC_ReadAddress);
+	val = doc_readb(reg);
+	doc_vdbg("Read register %04x : %02x\n", reg, val);
+	return val;
+}
+
+static int doc_register_readw(struct docg3 *docg3, int reg)
+{
+	u16 val;
+
+	doc_writew(reg, DoC_ReadAddress);
+	val = doc_readw(reg);
+	doc_vdbg("Read register %04x : %04x\n", reg, val);
+	return val;
+}
+
+static void doc_delay(struct docg3 *docg3, int nbNOPs)
+{
+	int i;
+
+	doc_dbg("NOP x %d\n", nbNOPs);
+	for (i = 0; i < nbNOPs; i++)
+		doc_writeb(0, DoC_NOP);
+}
+
+static int is_prot_seq_error(struct docg3 *docg3)
+{
+	int ctrl;
+
+	ctrl = doc_register_readb(docg3, DoC_FlashControl);
+	return ctrl & (Doc_Ctrl_PROTECTION_ERROR | Doc_Ctrl_SEQUENCE_ERROR);
+}
+
+static int doc_is_ready(struct docg3 *docg3)
+{
+	int ctrl;
+
+	ctrl = doc_register_readb(docg3, DoC_FlashControl);
+	return ctrl & Doc_Ctrl_FLASHREADY;
+}
+
+static int doc_wait_ready(struct docg3 *docg3)
+{
+	int maxWaitCycles = 100;
+
+	do {
+		doc_delay(docg3, 4);
+	} while (!doc_is_ready(docg3) && maxWaitCycles--);
+	doc_delay(docg3, 2);
+	if (maxWaitCycles > 0)
+		return 0;
+	else
+		return -EIO;
+}
+
+static int doc_reset_seq(struct docg3 *docg3)
+{
+	int ret;
+
+	doc_writeb(0x10, DoC_FlashControl);
+	doc_flashSequence(RESET);
+	doc_flashCommand(RESET);
+	doc_delay(docg3, 2);
+	ret = doc_wait_ready(docg3);
+
+	doc_dbg("doc_reset_seq() -> isReady=%s\n", ret ? "false" : "true");
+	return ret;
+}
+
+/**
+ * doc_read_data_area - Read data from data area
+ * @docg3: the device
+ * @buf: the buffer to fill in
+ * @len: the lenght to read
+ * @first: first time read, DoC_ReadAddress should be set
+ *
+ * Reads bytes from flash data. Handles the single byte / even bytes reads.
+ */
+static void doc_read_data_area(struct docg3 *docg3, void *buf, int len,
+			       int first)
+{
+	int i, cdr, len4;
+	u16 data16, *dst16;
+	u8 data8, *dst8;
+
+	doc_dbg("doc_read_data_area(buf=%p, len=%d)\n", buf, len);
+	cdr = len & 0x3;
+	len4 = len - cdr;
+
+	if (first)
+		doc_writew(DOC_IOSPACE_DATA, DoC_ReadAddress);
+	dst16 = buf;
+	for (i = 0; i < len4; i += 2) {
+		data16 = doc_readw(DOC_IOSPACE_DATA);
+		*dst16 = data16;
+		dst16++;
+	}
+
+	if (cdr) {
+		doc_writew(DOC_IOSPACE_DATA | Doc_ReadAddr_ONE_BYTE,
+			   DoC_ReadAddress);
+		doc_delay(docg3, 1);
+		dst8 = (u8 *)dst16;
+		for (i = 0; i < cdr; i++) {
+			data8 = doc_readb(DOC_IOSPACE_DATA);
+			*dst8 = data8;
+			dst8++;
+		}
+	}
+}
+
+/**
+ * doc_set_data_mode - Sets the flash to reliable data mode
+ * @docg3: the device
+ *
+ * The reliable data mode is a bit slower than the fast mode, but less errors
+ * occur.  Entering the reliable mode cannot be done without entering the fast
+ * mode first.
+ */
+static void doc_set_reliable_mode(struct docg3 *docg3)
+{
+	doc_dbg("doc_set_reliable_mode()\n");
+	doc_flashSequence(SET_MODE);
+	doc_flashCommand(FAST_MODE);
+	doc_flashCommand(RELIABLE_MODE);
+	doc_delay(docg3, 2);
+}
+
+/**
+ * doc_set_asic_mode - Set the ASIC mode
+ * @docg3: the device
+ * @mode: the mode
+ *
+ * The ASIC can work in 3 modes :
+ *  - RESET: all registers are zeroed
+ *  - NORMAL: receives and handles commands
+ *  - POWERDOWN: minimal poweruse, flash parts shut off
+ */
+static void doc_set_asic_mode(struct docg3 *docg3, u8 mode)
+{
+	int i;
+
+	for (i = 0; i < 12; i++)
+		doc_readb(DOC_IOSPACE_IPL);
+
+	mode |= Doc_AsicMode_MDWREN;
+	doc_dbg("doc_set_asic_mode(%02x)\n", mode);
+	doc_writeb(mode, DoC_AsicMode);
+	doc_writeb(~mode, DoC_AsicModeConfirm);
+	doc_delay(docg3, 1);
+}
+
+/**
+ * doc_set_device_id - Sets the devices id for cascaded G3 chips
+ * @docg3: the device
+ * @id: the chip to select (amongst 0, 1, 2, 3)
+ *
+ * There can be 4 cascaded G3 chips. This function selects the one which will
+ * should be the active one.
+ */
+static void doc_set_device_id(struct docg3 *docg3, int id)
+{
+	u8 ctrl;
+
+	doc_dbg("doc_set_device_id(%d)\n", id);
+	doc_writeb(id, DoC_DeviceSelect);
+	ctrl = doc_register_readb(docg3, DoC_FlashControl);
+
+	ctrl &= ~Doc_Ctrl_Violation;
+	ctrl |= Doc_Ctrl_CE;
+	doc_writeb(ctrl, DoC_FlashControl);
+}
+
+/**
+ * doc_set_extra_page_mode - Change flash page layout
+ * @docg3: the device
+ *
+ * Normally, the flash page is split into the data (512 bytes) and the out of
+ * band data (16 bytes). For each, 4 more bytes can be accessed, where the wear
+ * leveling counters are stored.  To access this last area of 4 bytes, a special
+ * mode must be input to the flash ASIC.
+ *
+ * Returns 0 if no error occured, -EIO else.
+ */
+static int doc_set_extra_page_mode(struct docg3 *docg3)
+{
+	int fctrl;
+
+	doc_dbg("doc_set_extra_page_mode()\n");
+	doc_flashSequence(PAGE_SIZE_532);
+	doc_flashCommand(PAGE_SIZE_532);
+	doc_delay(docg3, 2);
+
+	fctrl = doc_register_readb(docg3, DoC_FlashControl);
+	if (fctrl & (Doc_Ctrl_PROTECTION_ERROR | Doc_Ctrl_SEQUENCE_ERROR))
+		return -EIO;
+	else
+		return 0;
+}
+
+/**
+ * doc_seek - Set both flash planes to the specified block, page for reading
+ * @docg3: the device
+ * @block: the block index
+ * @page: the page index within the block
+ * @wear: if true, read will occur on the 4 extra bytes of the wear area
+ * @ofs: offset in page to read
+ *
+ * Programs the flash even and odd planes to the specific block and page.
+ * Alternatively, programs the flash to the wear area of the specified page.
+ */
+static int doc_read_seek(struct docg3 *docg3, int block, int page, int wear,
+	int ofs)
+{
+	int sector, ret = 0;
+
+	sector = (block << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
+	doc_dbg("doc_seek(block=%d, page=%d, wear=%d) => sector=%d\n",
+		block, page, wear, sector);
+
+	if (!wear && (ofs < 2 * DOC_LAYOUT_PAGE_SIZE)) {
+		doc_flashSequence(SET_PLANE1);
+		doc_flashCommand(READ_PLANE1);
+		doc_delay(docg3, 2);
+	} else {
+		doc_flashSequence(SET_PLANE2);
+		doc_flashCommand(READ_PLANE2);
+		doc_delay(docg3, 2);
+	}
+
+	doc_set_reliable_mode(docg3);
+	if (wear)
+		ret = doc_set_extra_page_mode(docg3);
+	if (ret)
+		goto out;
+
+	doc_flashSequence(READ);
+	doc_flashCommand(PROG_BLOCK_ADDR);
+	doc_delay(docg3, 1);
+	doc_flashAddress(sector & 0xff);
+	doc_flashAddress((sector >> 8) & 0xff);
+	doc_flashAddress((sector >> 16) & 0xff);
+	doc_delay(docg3, 1);
+
+	sector |= DOC_ADDR_PLANE_MASK;
+	doc_flashCommand(PROG_BLOCK_ADDR);
+	doc_delay(docg3, 1);
+	doc_flashAddress(sector & 0xff);
+	doc_flashAddress((sector >> 8) & 0xff);
+	doc_flashAddress((sector >> 16) & 0xff);
+	doc_delay(docg3, 2);
+
+out:
+	return ret;
+}
+
+/**
+ * doc_read_page_ecc_init - Initialize hardware ECC engine
+ * @docg3: the device
+ * @len: the number of bytes covered by the ECC (BCH covered)
+ *
+ * The function does initialize the hardware ECC engine to compute the Hamming
+ * ECC (on 1 byte) and the BCH Syndroms (on 7 bytes).
+ *
+ * Return 0 if succeeded, -EIO on error
+ */
+static int doc_read_page_ecc_init(struct docg3 *docg3, int len)
+{
+	doc_writew(Doc_ECCConf0_READ_MODE
+		   | Doc_ECCConf0_BCH_ENABLE | Doc_ECCConf0_HAMMING_ENABLE
+		   | (len & Doc_ECCConf0_DATA_BYTES_MASK),
+		   DoC_EccConf0);
+	doc_delay(docg3, 4);
+	doc_register_readb(docg3, DoC_FlashControl);
+	return doc_wait_ready(docg3);
+}
+
+/**
+ * doc_read_page_prepare - Prepares reading data from a flash page
+ * @docg3: the device
+ * @block: the block index on flash memory
+ * @page: the page index in the block
+ * @offset: the offset in the page (must be a multiple of 4)
+ *
+ * Prepares the page to be read in the flash memory :
+ *   - tell ASIC to map the flash pages
+ *   - tell ASIC to be in read mode
+ *
+ * After a call to this method, a call to doc_read_page_finish is mandatory,
+ * to end the read cycle of the flash.
+ *
+ * Read data from a flash page. The length to be read must be between 0 and
+ * (page_size + oob_size + wear_size), ie. 532, and a multiple of 4 (because
+ * the extra bytes reading is not implemented).
+ *
+ * As pages are grouped by 2 (in 2 planes), reading from odd pages requires to
+ * input the preceeding even page number, and an offset of 512+16 to shift to
+ * the next page.
+ *
+ * Returns 0 if successful, -EIO if a read error occured.
+ */
+static int doc_read_page_prepare(struct docg3 *docg3, int block, int page,
+				 int offset)
+{
+	int wear_area = 0, ret = 0;
+
+	doc_dbg("doc_read_page_prepare(block=%d, page=%d, offsetInPage=%d)\n",
+		block, page, offset);
+	if (offset >= DOC_LAYOUT_WEAR_OFFSET)
+		wear_area = 1;
+	if (!wear_area && offset > DOC_LAYOUT_PAGE_OOB_SIZE)
+		return -EINVAL;
+
+	if (page & 0x01) {
+		page--;
+		offset += DOC_LAYOUT_PAGE_OOB_SIZE;
+	}
+
+	doc_set_device_id(docg3, docg3->device_id);
+	ret = doc_reset_seq(docg3);
+	if (ret)
+		goto err;
+
+	/* Program the flash address block and page */
+	ret = doc_read_seek(docg3, block, page, wear_area, offset);
+	if (ret)
+		goto err;
+
+	doc_flashCommand(READ_ALL_PLANES);
+	doc_delay(docg3, 2);
+	doc_wait_ready(docg3);
+
+	doc_flashCommand(SET_ADDR_READ);
+	doc_delay(docg3, 1);
+	if (offset >= DOC_LAYOUT_PAGE_SIZE * 2)
+		offset -= 2 * DOC_LAYOUT_PAGE_SIZE;
+	doc_flashAddress(offset >> 2);
+	doc_delay(docg3, 1);
+	doc_wait_ready(docg3);
+
+	doc_flashCommand(READ_FLASH);
+
+	return 0;
+err:
+	doc_writeb(0, DoC_DataEnd);
+	doc_delay(docg3, 2);
+	return -EIO;
+}
+
+/**
+ * doc_read_page_getbytes - Reads bytes from a prepared page
+ * @docg3: the device
+ * @len: the number of bytes to be read (must be a multiple of 4)
+ * @buf: the buffer to be filled in
+ * @first: 1 if first time read, DoC_ReadAddress should be set
+ *
+ */
+static int doc_read_page_getbytes(struct docg3 *docg3, int len, u_char *buf,
+				  int first)
+{
+	doc_read_data_area(docg3, buf, len, first);
+	doc_delay(docg3, 2);
+	return len;
+}
+
+/**
+ * doc_get_hw_bch_syndroms - Get hardware calculated BCH syndroms
+ * @docg3: the device
+ * @syns:  the array of 7 integers where the syndroms will be stored
+ */
+static void doc_get_hw_bch_syndroms(struct docg3 *docg3, int *syns)
+{
+	int i;
+
+	for (i = 0; i < DOC_ECC_BCH_SIZE; i++)
+		syns[i] = doc_register_readb(docg3, DoC_BCH_Syndrom(i));
+}
+
+/**
+ * doc_read_page_finish - Ends reading of a flash page
+ * @docg3: the device
+ */
+static void doc_read_page_finish(struct docg3 *docg3)
+{
+	doc_writeb(0, DoC_DataEnd);
+	doc_delay(docg3, 2);
+}
+
+/**
+ * doc_read - Read bytes from flash
+ * @mtd: the device
+ * @from: the offset from first block and first page, in bytes, aligned on page
+ *        size
+ * @len: the number of bytes to read (must be a multiple of 4)
+ * @retlen: the number of bytes actually read
+ * @buf: the filled in buffer
+ *
+ * Reads flash memory pages. This function does not read the OOB chunk, but only
+ * the page data.
+ *
+ * Returns 0 if read successfull, of -EIO, -EINVAL if an error occured
+ */
+int doc_read(struct mtd_info *mtd, loff_t from, size_t len,
+	     size_t *retlen, u_char *buf)
+{
+	struct docg3 *docg3 = mtd->priv;
+	int block, page, sector, readlen, ret;
+	int syn[DOC_ECC_BCH_SIZE], eccconf1;
+	u8 oob[DOC_LAYOUT_OOB_SIZE];
+
+	ret = -EINVAL;
+	doc_dbg("doc_read(from=%lld, len=%u, buf=%p)\n", from, len, buf);
+	if (from % DOC_LAYOUT_PAGE_SIZE)
+		goto err;
+	if (len % 4)
+		goto err;
+	sector = from / DOC_LAYOUT_PAGE_SIZE;
+	block = sector / DOC_LAYOUT_PAGES_PER_BLOCK;
+	page = sector & DOC_ADDR_PAGE_MASK;
+	if (block > docg3->max_block)
+		goto err;
+
+	*retlen = 0;
+	ret = 0;
+	readlen = min(len, (size_t)DOC_LAYOUT_PAGE_SIZE);
+	while (!ret && len > 0) {
+		readlen = min(len, (size_t)DOC_LAYOUT_PAGE_SIZE);
+		ret = doc_read_page_prepare(docg3, block, page, 0);
+		if (ret < 0)
+			goto err;
+		ret = doc_read_page_ecc_init(docg3, DOC_ECC_BCH_COVERED_BYTES);
+		if (ret < 0)
+			goto err_in_read;
+		ret = doc_read_page_getbytes(docg3, readlen, buf, 1);
+		if (ret < readlen)
+			goto err_in_read;
+		ret = doc_read_page_getbytes(docg3, DOC_LAYOUT_OOB_SIZE,
+					     oob, 0);
+		if (ret < DOC_LAYOUT_OOB_SIZE)
+			goto err_in_read;
+
+		*retlen += readlen;
+		buf += readlen;
+		len -= readlen;
+		page++;
+		if (page > DOC_ADDR_PAGE_MASK) {
+			page = 0;
+			block++;
+		}
+
+		/*
+		 * There should be a BCH bitstream fixing algorithm here ...
+		 * By now, a page read failure is triggered by BCH error
+		 */
+		doc_get_hw_bch_syndroms(docg3, syn);
+		eccconf1 = doc_register_readb(docg3, DoC_EccConf1);
+
+		doc_dbg("OOB - INFO: %02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
+			 oob[0], oob[1], oob[2], oob[3], oob[4],
+			 oob[5], oob[6]);
+		doc_dbg("OOB - HAMMING: %02x\n", oob[7]);
+		doc_dbg("OOB - BCH_ECC: %02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
+			 oob[8], oob[9], oob[10], oob[11], oob[12],
+			 oob[13], oob[14]);
+		doc_dbg("OOB - UNUSED: %02x\n", oob[15]);
+		doc_dbg("ECC checks: ECCConf1=%x\n", eccconf1);
+		doc_dbg("ECC BCH syndrom: %02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
+			syn[0], syn[1], syn[2], syn[3], syn[4], syn[5], syn[6]);
+
+		ret = -EBADMSG;
+		if (block >= DOC_LAYOUT_BLOCK_FIRST_DATA) {
+			if (eccconf1 & Doc_ECCConf1_BCH_SYNDROM_ERR)
+				goto err_in_read;
+			if (is_prot_seq_error(docg3))
+				goto err_in_read;
+		}
+		doc_read_page_finish(docg3);
+	}
+
+	return 0;
+err_in_read:
+	doc_read_page_finish(docg3);
+err:
+	return ret;
+}
+
+/**
+ * doc_read_oob - Read out of band bytes from flash
+ * @mtd: the device
+ * @from: the offset from first block and first page, in bytes, aligned on page
+ *        size
+ * @ops: the mtd oob structure
+ *
+ * Reads flash memory OOB area of pages.
+ *
+ * Returns 0 if read successfull, of -EIO, -EINVAL if an error occured
+ */
+int doc_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
+{
+	struct docg3 *docg3 = mtd->priv;
+	int block, page, sector, ret;
+	u8 *buf = ops->oobbuf;
+	size_t len = ops->ooblen;
+
+	doc_dbg("doc_read_oob(from=%lld, buf=%p, len=%d)\n", from, buf, len);
+	if (len != DOC_LAYOUT_OOB_SIZE)
+		return -EINVAL;
+
+	switch (ops->mode) {
+	case MTD_OOB_PLACE:
+		buf += ops->ooboffs;
+		break;
+	default:
+		break;
+	}
+
+	sector = from / DOC_LAYOUT_PAGE_SIZE;
+	block = sector / DOC_LAYOUT_PAGES_PER_BLOCK;
+	page = sector & DOC_ADDR_PAGE_MASK;
+	if (block > docg3->max_block)
+		return -EINVAL;
+
+	ret = doc_read_page_prepare(docg3, block, page, DOC_LAYOUT_PAGE_SIZE);
+	if (!ret)
+		ret = doc_read_page_ecc_init(docg3, DOC_LAYOUT_OOB_SIZE);
+	if (!ret)
+		ret = doc_read_page_getbytes(docg3, DOC_LAYOUT_OOB_SIZE,
+					     buf, 1);
+	doc_read_page_finish(docg3);
+
+	if (ret > 0)
+		ops->oobretlen = ret;
+	else
+		ops->oobretlen = 0;
+	return (ret > 0) ? 0 : ret;
+}
+
+static int doc_reload_bbt(struct docg3 *docg3)
+{
+	int block = DOC_LAYOUT_BLOCK_BBT;
+	int ret = 0, nbpages, page;
+	u_char *buf = docg3->bbt;
+
+	nbpages = (docg3->max_block + 1) / (8 * DOC_LAYOUT_PAGE_SIZE);
+	for (page = 0; !ret && (page < nbpages); page++) {
+		ret = doc_read_page_prepare(docg3, block,
+					    page + DOC_LAYOUT_PAGE_BBT, 0);
+		if (!ret)
+			ret = doc_read_page_ecc_init(docg3,
+						     DOC_LAYOUT_PAGE_SIZE);
+		if (!ret)
+			doc_read_page_getbytes(docg3, DOC_LAYOUT_PAGE_SIZE,
+					       buf, 1);
+		buf += DOC_LAYOUT_PAGE_SIZE;
+	}
+	doc_read_page_finish(docg3);
+	return ret;
+}
+
+/**
+ * doc_block_isbad - Checks whether a block is good or not
+ * @mtd: the device
+ * @ofs: the offset to find the correct block
+ *
+ * Returns 1 if block is bad, 0 if block is good
+ */
+int doc_block_isbad(struct mtd_info *mtd, loff_t ofs)
+{
+	struct docg3 *docg3 = mtd->priv;
+	int block, sector, is_good;
+
+	doc_dbg("doc_block_isbad(from=%lld)\n", ofs);
+
+	sector = ofs / DOC_LAYOUT_PAGE_SIZE;
+	block = sector / DOC_LAYOUT_PAGES_PER_BLOCK;
+	if (block < DOC_LAYOUT_BLOCK_FIRST_DATA)
+		return 0;
+	if (block > docg3->max_block)
+		return -EINVAL;
+
+	is_good = docg3->bbt[block >> 3] & (1 << (block & 0x7));
+	return !is_good;
+}
+
+/**
+ * doc_get_erase_count - Get block erase count
+ * @docg3: the device
+ * @from: the offset in which the block is.
+ *
+ * Get the number of times a block was erased. The number is the maximum of
+ * erase times between first and second plane (which should be equal normally).
+ *
+ * Returns The number of erases, or -EINVAL or -EIO on error.
+ */
+int doc_get_erase_count(struct docg3 *docg3, loff_t from)
+{
+	u8 buf[DOC_LAYOUT_WEAR_SIZE];
+	int ret, plane1_erase_count, plane2_erase_count;
+	int block, page, sector;
+
+	doc_dbg("doc_get_erase_count(from=%lld, buf=%p)\n", from, buf);
+	if (from % DOC_LAYOUT_PAGE_SIZE)
+		return -EINVAL;
+	sector = from / DOC_LAYOUT_PAGE_SIZE;
+	block = sector / DOC_LAYOUT_PAGES_PER_BLOCK;
+	page = sector & DOC_ADDR_PAGE_MASK;
+	if (block > docg3->max_block)
+		return -EINVAL;
+
+	ret = doc_reset_seq(docg3);
+	if (!ret)
+		ret = doc_read_page_prepare(docg3, block, page,
+					    DOC_LAYOUT_WEAR_OFFSET);
+	if (!ret)
+		ret = doc_read_page_getbytes(docg3, DOC_LAYOUT_WEAR_SIZE,
+					     buf, 1);
+	doc_read_page_finish(docg3);
+
+	if (ret || (buf[0] != DOC_ERASE_MARK) || (buf[2] != DOC_ERASE_MARK))
+		return -EIO;
+	plane1_erase_count = (u8)(~buf[1]) | ((u8)(~buf[4]) << 8)
+		| ((u8)(~buf[5]) << 16);
+	plane2_erase_count = (u8)(~buf[3]) | ((u8)(~buf[6]) << 8)
+		| ((u8)(~buf[7]) << 16);
+
+	return max(plane1_erase_count, plane2_erase_count);
+}
+
+/*
+ * Debug sysfs entries
+ */
+#ifdef DEBUG
+static ssize_t dbg_flashctrl_read(struct device *dev,
+				      struct device_attribute *attr,
+				      char *buf)
+{
+	struct mtd_info *mtd = dev_get_drvdata(dev);
+	struct docg3 *docg3 = mtd->priv;
+
+	int pos = 0;
+	u8 fctrl = doc_register_readb(docg3, DoC_FlashControl);
+
+	pos += scnprintf(buf + pos, PAGE_SIZE - pos,
+		 "FlashControl : 0x%02x (%s,CE# %s,%s,%s,flash %s)\n",
+		 fctrl,
+		 fctrl & Doc_Ctrl_Violation ? "protocol violation" : "-",
+		 fctrl & Doc_Ctrl_CE ? "active" : "inactive",
+		 fctrl & Doc_Ctrl_PROTECTION_ERROR ? "protection error" : "-",
+		 fctrl & Doc_Ctrl_SEQUENCE_ERROR ? "sequence error" : "-",
+		 fctrl & Doc_Ctrl_FLASHREADY ? "ready" : "not ready");
+	return pos;
+}
+static ssize_t dbg_flashctrl_write(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf, size_t count)
+{
+	struct mtd_info *mtd = dev_get_drvdata(dev);
+	struct docg3 *docg3 = mtd->priv;
+	int i, val;
+
+	i = sscanf(buf, "0x%x", &val);
+	if (i == 0)
+		i = sscanf(buf, "%x", &val);
+	if (i == 0)
+		return -EINVAL;
+	doc_writeb(val, DoC_FlashControl);
+	return count;
+}
+DEVICE_ATTR(flashcontrol, S_IRWXU, dbg_flashctrl_read, dbg_flashctrl_write);
+
+static ssize_t dbg_reset(struct device *dev,
+			     struct device_attribute *attr,
+			     const char *buf, size_t count)
+{
+	struct mtd_info *mtd = dev_get_drvdata(dev);
+	struct docg3 *docg3 = mtd->priv;
+
+	doc_reset_seq(docg3);
+	return count;
+}
+DEVICE_ATTR(reset, S_IWUSR, NULL, dbg_reset);
+
+static ssize_t dbg_asicmode_read(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	struct mtd_info *mtd = dev_get_drvdata(dev);
+	struct docg3 *docg3 = mtd->priv;
+
+	int pos = 0;
+	int pctrl = doc_register_readb(docg3, DoC_AsicMode);
+	int mode = pctrl & 0x03;
+
+	pos += scnprintf(buf + pos, PAGE_SIZE - pos,
+			 "%04x : RAM_WE=%d,RSTIN_RESET=%d,BDETCT_RESET=%d,WRITE_ENABLE=%d,POWERDOWN=%d,MODE=%d%d (",
+			 pctrl,
+			 pctrl & Doc_AsicMode_RAM_WE ? 1 : 0,
+			 pctrl & Doc_AsicMode_RSTIN_RESET ? 1 : 0,
+			 pctrl & Doc_AsicMode_BDETCT_RESET ? 1 : 0,
+			 pctrl & Doc_AsicMode_MDWREN ? 1 : 0,
+			 pctrl & Doc_AsicMode_POWERDOWN ? 1 : 0,
+			 mode >> 1, mode & 0x1);
+
+	switch (mode) {
+	case Doc_AsicMode_RESET:
+		pos += scnprintf(buf + pos, PAGE_SIZE - pos, "reset");
+		break;
+	case Doc_AsicMode_NORMAL:
+		pos += scnprintf(buf + pos, PAGE_SIZE - pos, "normal");
+		break;
+	case Doc_AsicMode_POWERDOWN:
+		pos += scnprintf(buf + pos, PAGE_SIZE - pos, "powerdown");
+		break;
+	}
+	pos += scnprintf(buf + pos, PAGE_SIZE - pos, ")\n");
+	return pos;
+}
+static ssize_t dbg_asicmode_write(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct mtd_info *mtd = dev_get_drvdata(dev);
+	struct docg3 *docg3 = mtd->priv;
+	int i, val;
+
+	i = sscanf(buf, "0x%x", &val);
+	if (i == 1)
+		doc_set_asic_mode(docg3, val);
+	i = sscanf(buf, "%x", &val);
+	if (i == 1)
+		doc_set_asic_mode(docg3, val);
+
+	return count;
+}
+DEVICE_ATTR(asic_mode, S_IRWXU, dbg_asicmode_read, dbg_asicmode_write);
+
+static ssize_t dbg_deviceid_read(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	struct mtd_info *mtd = dev_get_drvdata(dev);
+	struct docg3 *docg3 = mtd->priv;
+	int pos = 0;
+	int id = doc_register_readb(docg3, DoC_DeviceSelect);
+
+	pos += scnprintf(buf + pos, PAGE_SIZE - pos, "DeviceId = %d\n", id);
+	return pos;
+}
+DEVICE_ATTR(device_id, S_IRUGO, dbg_deviceid_read, NULL);
+
+int doc_dbg_register(struct device *dev)
+{
+	int ret = 0;
+
+	ret = device_create_file(dev, &dev_attr_flashcontrol);
+	if (!ret)
+		ret = device_create_file(dev, &dev_attr_reset);
+	if (!ret)
+		ret = device_create_file(dev, &dev_attr_asic_mode);
+	if (!ret)
+		ret = device_create_file(dev, &dev_attr_device_id);
+	return ret;
+}
+
+void doc_dbg_unregister(struct device *dev)
+{
+	device_remove_file(dev, &dev_attr_device_id);
+	device_remove_file(dev, &dev_attr_asic_mode);
+	device_remove_file(dev, &dev_attr_reset);
+	device_remove_file(dev, &dev_attr_flashcontrol);
+}
+#endif
+
+/**
+ * doc_set_driver_info - Fill the mtd_info structure and docg3 structure
+ * @chip_id: The chip ID of the supported chip
+ * @mtd: The structure to fill
+ */
+static void __init doc_set_driver_info(int chip_id, struct mtd_info *mtd)
+{
+	struct docg3 *docg3 = mtd->priv;
+	int cfg;
+
+	cfg = doc_register_readb(docg3, DoC_Configuration);
+	docg3->if_cfg = (cfg & Doc_Conf_IF_CFG ? 1 : 0);
+
+	switch (chip_id) {
+	case DOC_CHIPID_G3:
+		mtd->name = "DiskOnChip G3";
+		docg3->max_block = 8191;
+		break;
+	}
+	mtd->type = MTD_NANDFLASH;
+	/*
+	 * Once write methods are added, the correct flags will be set.
+	 * mtd->flags = MTD_CAP_NANDFLASH;
+	 */
+	mtd->flags = MTD_CAP_ROM;
+	mtd->size = (docg3->max_block + 1) * DOC_LAYOUT_BLOCK_SIZE;
+	mtd->erasesize = DOC_LAYOUT_BLOCK_SIZE;
+	mtd->writesize = DOC_LAYOUT_PAGE_SIZE;
+	mtd->oobsize = DOC_LAYOUT_OOB_SIZE;
+	mtd->owner = THIS_MODULE;
+	mtd->erase = NULL;
+	mtd->point = NULL;
+	mtd->unpoint = NULL;
+	mtd->read = doc_read;
+	mtd->write = NULL;
+	mtd->read_oob = doc_read_oob;
+	mtd->write_oob = NULL;
+	mtd->sync = NULL;
+	mtd->block_isbad = doc_block_isbad;
+}
+
+/**
+ * doc_probe - Probe the IO space for a DiskOnChip G3 chip
+ * @pdev: platform device
+ *
+ * Probes for a G3 chip at the specified IO space in the platform data
+ * ressources.
+ *
+ * Returns 0 on success, -ENOMEM, -ENXIO on error
+ */
+static int __init docg3_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct docg3 *docg3;
+	struct mtd_info *mtd;
+	struct resource *ress;
+	struct mtd_partition *parts = NULL;
+	int ret, bbt_nbpages;
+	u16 chip_id, chip_id_inv;
+
+	ret = -ENOMEM;
+	docg3 = kzalloc(sizeof(struct docg3), GFP_KERNEL);
+	if (!docg3)
+		goto nomem1;
+	mtd = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);
+	if (!mtd)
+		goto nomem2;
+	mtd->priv = docg3;
+
+	ret = -ENXIO;
+	ress = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!ress) {
+		dev_err(dev, "No I/O memory resource defined\n");
+		goto noress;
+	}
+	docg3->base = ioremap(ress->start, DOC_IOSPACE_SIZE);
+
+	docg3->dev = &pdev->dev;
+	docg3->device_id = 0;
+	doc_set_device_id(docg3, docg3->device_id);
+	doc_set_asic_mode(docg3, Doc_AsicMode_RESET);
+	doc_set_asic_mode(docg3, Doc_AsicMode_NORMAL);
+
+	chip_id = doc_register_readw(docg3, DoC_ChipID);
+	chip_id_inv = doc_register_readw(docg3, DoC_ChipID_Inv);
+
+	ret = -ENODEV;
+	if (chip_id != (u16)(~chip_id_inv)) {
+		doc_info("No device found at IO addr %x\n", ress->start);
+		goto nochipfound;
+	}
+
+	switch (chip_id) {
+	case DOC_CHIPID_G3:
+		doc_info("Found a G3 DiskOnChip at addr %x\n", ress->start);
+		break;
+	default:
+		doc_err("Chip id %04x is not a DiskOnChip G3 chip\n", chip_id);
+		goto nochipfound;
+	}
+
+	doc_set_driver_info(chip_id, mtd);
+	platform_set_drvdata(pdev, mtd);
+
+	bbt_nbpages = (docg3->max_block + 1) / (8 * DOC_LAYOUT_PAGE_SIZE);
+	docg3->bbt = kzalloc(bbt_nbpages * DOC_LAYOUT_PAGE_SIZE, GFP_KERNEL);
+	if (!docg3->bbt)
+		goto nochipfound;
+	doc_reload_bbt(docg3);
+
+	ret = add_mtd_device(mtd);
+	if (!ret && mtd_has_partitions())
+		ret = parse_mtd_partitions(mtd, part_probes, &parts, 0);
+	if (ret > 0)
+		ret = add_mtd_partitions(mtd, parts, ret);
+
+#ifdef DEBUG
+	doc_dbg_register(docg3->dev);
+#endif
+	return 0;
+
+nochipfound:
+	iounmap(docg3->base);
+noress:
+	kfree(mtd);
+nomem2:
+	kfree(docg3);
+nomem1:
+	return ret;
+}
+
+/**
+ * docg3_release - Release the driver
+ * @pdev: the platform device
+ *
+ * Returns 0
+ */
+static int __exit docg3_release(struct platform_device *pdev)
+{
+	struct mtd_info *mtd = platform_get_drvdata(pdev);
+	struct docg3 *docg3 = mtd->priv;
+#ifdef DEBUG
+	doc_dbg_unregister(docg3->dev);
+#endif
+	if (mtd_has_partitions())
+		del_mtd_partitions(mtd);
+	iounmap(docg3->base);
+	kfree(docg3->bbt);
+	kfree(docg3);
+	del_mtd_device(mtd);
+	kfree(mtd);
+	return 0;
+}
+
+static struct platform_driver g3_driver = {
+	.driver		= {
+		.name	= "docg3",
+		.owner	= THIS_MODULE,
+	},
+	.remove		= __exit_p(docg3_release),
+};
+
+static int __init docg3_init(void)
+{
+	return platform_driver_probe(&g3_driver, docg3_probe);
+}
+module_init(docg3_init);
+
+
+static void __exit docg3_exit(void)
+{
+	platform_driver_unregister(&g3_driver);
+}
+module_exit(docg3_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
+MODULE_DESCRIPTION("MTD driver for DiskOnChip G3");
diff --git a/drivers/mtd/devices/docg3.h b/drivers/mtd/devices/docg3.h
new file mode 100644
index 0000000..0a35e17
--- /dev/null
+++ b/drivers/mtd/devices/docg3.h
@@ -0,0 +1,196 @@ 
+#include <linux/mtd/nand_bch.h>
+
+/*
+ * Flash memory areas :
+ *   - 0x0000 .. 0x07ff : IPL
+ *   - 0x0800 .. 0x0fff : Data area
+ *   - 0x1000 .. 0x17ff : Registers
+ *   - 0x1800 .. 0x1fff : Unknown
+ */
+#define DOC_IOSPACE_IPL			0x0000
+#define DOC_IOSPACE_DATA		0x0800
+#define DOC_IOSPACE_SIZE		0x2000
+
+/*
+ * DOC G3 layout and adressing scheme
+ *   A page address for the block "b", plane "P" and page "p":
+ *   address = [bbbb bPpp pppp]
+ */
+
+#define DOC_ADDR_PAGE_MASK		0x3f
+#define DOC_ADDR_PLANE_MASK		0x40
+#define DOC_ADDR_BLOCK_SHIFT		7
+#define DOC_LAYOUT_PAGES_PER_BLOCK	DOC_ADDR_PLANE_MASK
+#define DOC_LAYOUT_PAGE_SIZE		512
+#define DOC_LAYOUT_OOB_SIZE		16
+#define DOC_LAYOUT_WEAR_SIZE		8
+#define DOC_LAYOUT_PAGE_OOB_SIZE				\
+	(DOC_LAYOUT_PAGE_SIZE + DOC_LAYOUT_OOB_SIZE)
+#define DOC_LAYOUT_WEAR_OFFSET		(DOC_LAYOUT_PAGE_OOB_SIZE * 2)
+#define DOC_LAYOUT_BLOCK_SIZE					\
+	(DOC_LAYOUT_PAGES_PER_BLOCK * DOC_LAYOUT_PAGE_SIZE)
+#define DOC_ECC_BCH_SIZE		7
+#define DOC_ECC_BCH_COVERED_BYTES				\
+	(DOC_LAYOUT_PAGE_SIZE + DOC_LAYOUT_OOB_PAGEINFO_SZ +	\
+	 DOC_LAYOUT_OOB_HAMMING_SZ + DOC_LAYOUT_OOB_BCH_SZ)
+
+/*
+ * Blocks distribution
+ */
+#define DOC_LAYOUT_BLOCK_BBT		0
+#define DOC_LAYOUT_BLOCK_OTP		0
+#define DOC_LAYOUT_BLOCK_FIRST_DATA	6
+
+#define DOC_LAYOUT_PAGE_BBT		4
+
+/*
+ * Extra page OOB (16 bytes wide) layout
+ */
+#define DOC_LAYOUT_OOB_PAGEINFO_OFS	0
+#define DOC_LAYOUT_OOB_HAMMING_OFS	7
+#define DOC_LAYOUT_OOB_BCH_OFS		8
+#define DOC_LAYOUT_OOB_UNUSED_OFS	15
+#define DOC_LAYOUT_OOB_PAGEINFO_SZ	7
+#define DOC_LAYOUT_OOB_HAMMING_SZ	1
+#define DOC_LAYOUT_OOB_BCH_SZ		7
+#define DOC_LAYOUT_OOB_UNUSED_SZ	1
+
+
+#define DOC_CHIPID_G3			0x200
+#define DOC_ERASE_MARK			0xaa
+/*
+ * Flash registers
+ */
+#define DoC_ChipID			0x1000
+#define DoC_Test			0x1004
+#define DoC_BusLock			0x1006
+#define DoC_EndianControl		0x1008
+#define DoC_DeviceSelect		0x100a
+#define DoC_AsicMode			0x100c
+#define DoC_Configuration		0x100e
+#define DoC_InterruptControl		0x1010
+#define DoC_ReadAddress			0x101a
+#define DoC_DataEnd			0x101e
+#define DoC_InterruptStatus		0x1020
+
+#define DoC_FlashSequence		0x1032
+#define DoC_FlashCommand		0x1034
+#define DoC_FlashAddress		0x1036
+#define DoC_FlashControl		0x1038
+#define DoC_NOP				0x103e
+
+#define DoC_EccConf0			0x1040
+#define DoC_EccConf1			0x1042
+#define DoC_EccPreset			0x1044
+#define DoC_HammingParity		0x1046
+#define DoC_BCH_Syndrom(idx)		(0x1048 + (idx << 1))
+
+#define DoC_AsicModeConfirm		0x1072
+#define DoC_ChipID_Inv			0x1074
+
+/*
+ * Flash sequences
+ * A sequence is preset before one or more commands are input to the chip.
+ */
+#define DoC_Seq_RESET			0x00
+#define DoC_Seq_PAGE_SIZE_532		0x03
+#define DoC_Seq_SET_MODE		0x09
+#define DoC_Seq_READ			0x12
+#define DoC_Seq_SET_PLANE1		0x0e
+#define DoC_Seq_SET_PLANE2		0x10
+#define DoC_Seq_PAGE_SETUP		0x1d
+
+/*
+ * Flash commands
+ */
+#define DoC_Cmd_READ_PLANE1		0x00
+#define DoC_Cmd_SET_ADDR_READ		0x05
+#define DoC_Cmd_READ_ALL_PLANES		0x30
+#define DoC_Cmd_READ_PLANE2		0x50
+#define DoC_Cmd_READ_FLASH		0xe0
+#define DoC_Cmd_PAGE_SIZE_532		0x3c
+
+#define DoC_Cmd_PROG_BLOCK_ADDR		0x60
+#define DoC_Cmd_PROG_CYCLE1		0x80
+#define DoC_Cmd_PROG_CYCLE2		0x10
+#define DoC_Cmd_ERASECYCLE2		0xd0
+
+#define DoC_Cmd_RELIABLE_MODE		0x22
+#define DoC_Cmd_FAST_MODE		0xa2
+
+#define DoC_Cmd_RESET			0xff
+
+/*
+ * Flash register : DoC_FlashControl
+ */
+#define Doc_Ctrl_Violation		0x20
+#define Doc_Ctrl_CE			0x10
+#define Doc_Ctrl_UNKNOWN_BITS		0x08
+#define Doc_Ctrl_PROTECTION_ERROR	0x04
+#define Doc_Ctrl_SEQUENCE_ERROR		0x02
+#define Doc_Ctrl_FLASHREADY		0x01
+
+/*
+ * Flash register : DoC_AsicMode
+ */
+#define Doc_AsicMode_RESET		0x00
+#define Doc_AsicMode_NORMAL		0x01
+#define Doc_AsicMode_POWERDOWN		0x02
+#define Doc_AsicMode_MDWREN		0x04
+#define Doc_AsicMode_BDETCT_RESET	0x08
+#define Doc_AsicMode_RSTIN_RESET	0x10
+#define Doc_AsicMode_RAM_WE		0x20
+
+/*
+ * Flash register : DoC_EccConf0
+ */
+#define Doc_ECCConf0_READ_MODE		0x8000
+#define Doc_ECCConf0_AUTO_ECC_ENABLE	0x4000
+#define Doc_ECCConf0_HAMMING_ENABLE	0x1000
+#define Doc_ECCConf0_BCH_ENABLE		0x0800
+#define Doc_ECCConf0_DATA_BYTES_MASK	0x07ff
+
+/*
+ * Flash register : DoC_EccConf1
+ */
+#define Doc_ECCConf1_BCH_SYNDROM_ERR	0x80
+#define Doc_ECCConf1_UNKOWN1		0x40
+#define Doc_ECCConf1_UNKOWN2		0x20
+#define Doc_ECCConf1_UNKOWN3		0x10
+#define Doc_ECCConf1_HAMMING_BITS_MASK	0x0f
+
+/*
+ * Flash register : DoC_Configuration
+ */
+#define Doc_Conf_IF_CFG			0x80
+#define Doc_Conf_MAX_ID_MASK		0x30
+#define Doc_Conf_VCCQ_3V		0x01
+
+/*
+ * Flash register : DoC_ReadAddress
+ */
+#define Doc_ReadAddr_INC		0x8000
+#define Doc_ReadAddr_ONE_BYTE		0x4000
+#define Doc_ReadAddr_ADDR_MASK		0x1fff
+
+/**
+ * struct docg3 - DiskOnChip driver private data
+ * @dev: the device currently under control
+ * @base: mapped IO space
+ * @device_id: number of the cascaded DoCG3 device (0, 1, 2 or 3)
+ * @if_cfg: if true, reads are on 16bits, else reads are on 8bits
+ * @bbt: bad block table cache
+ */
+struct docg3 {
+	struct device *dev;
+	void __iomem *base;
+	int device_id:4;
+	int if_cfg:1;
+	int max_block;
+	u8 *bbt;
+};
+
+#define doc_err(fmt, arg...) dev_err(docg3->dev, (fmt), ## arg)
+#define doc_info(fmt, arg...) dev_info(docg3->dev, (fmt), ## arg)
+#define doc_dbg(fmt, arg...) dev_dbg(docg3->dev, (fmt), ## arg)
+#define doc_vdbg(fmt, arg...) dev_vdbg(docg3->dev, (fmt), ## arg)