Rewrite of NAND code based on what is in 2.6.12 Linux kernel

Patch by Ladislav Michl, 29 Jun 2005

1 files changed, 1782 insertions, 0 deletions

diff --git a/drivers/nand/diskonchip.c b/drivers/nand/diskonchip.c
new file mode 100644
index 0000000..02135c3
--- /dev/null
+++ b/drivers/nand/diskonchip.c
@@ -0,0 +1,1782 @@
+/* 
+ * drivers/mtd/nand/diskonchip.c
+ *
+ * (C) 2003 Red Hat, Inc.
+ * (C) 2004 Dan Brown <dan_brown@ieee.org>
+ * (C) 2004 Kalev Lember <kalev@smartlink.ee>
+ *
+ * Author: David Woodhouse <dwmw2@infradead.org>
+ * Additional Diskonchip 2000 and Millennium support by Dan Brown <dan_brown@ieee.org>
+ * Diskonchip Millennium Plus support by Kalev Lember <kalev@smartlink.ee>
+ * 
+ * Error correction code lifted from the old docecc code
+ * Author: Fabrice Bellard (fabrice.bellard@netgem.com) 
+ * Copyright (C) 2000 Netgem S.A.
+ * converted to the generic Reed-Solomon library by Thomas Gleixner <tglx@linutronix.de>
+ *  
+ * Interface to generic NAND code for M-Systems DiskOnChip devices
+ *
+ * $Id: diskonchip.c,v 1.45 2005/01/05 18:05:14 dwmw2 Exp $
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/rslib.h>
+#include <linux/moduleparam.h>
+#include <asm/io.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/doc2000.h>
+#include <linux/mtd/compatmac.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/inftl.h>
+
+/* Where to look for the devices? */
+#ifndef CONFIG_MTD_DISKONCHIP_PROBE_ADDRESS
+#define CONFIG_MTD_DISKONCHIP_PROBE_ADDRESS 0
+#endif
+
+static unsigned long __initdata doc_locations[] = {
+#if defined (__alpha__) || defined(__i386__) || defined(__x86_64__)
+#ifdef CONFIG_MTD_DISKONCHIP_PROBE_HIGH
+	0xfffc8000, 0xfffca000, 0xfffcc000, 0xfffce000, 
+	0xfffd0000, 0xfffd2000, 0xfffd4000, 0xfffd6000,
+	0xfffd8000, 0xfffda000, 0xfffdc000, 0xfffde000, 
+	0xfffe0000, 0xfffe2000, 0xfffe4000, 0xfffe6000, 
+	0xfffe8000, 0xfffea000, 0xfffec000, 0xfffee000,
+#else /*  CONFIG_MTD_DOCPROBE_HIGH */
+	0xc8000, 0xca000, 0xcc000, 0xce000, 
+	0xd0000, 0xd2000, 0xd4000, 0xd6000,
+	0xd8000, 0xda000, 0xdc000, 0xde000, 
+	0xe0000, 0xe2000, 0xe4000, 0xe6000, 
+	0xe8000, 0xea000, 0xec000, 0xee000,
+#endif /*  CONFIG_MTD_DOCPROBE_HIGH */
+#elif defined(__PPC__)
+	0xe4000000,
+#elif defined(CONFIG_MOMENCO_OCELOT)
+	0x2f000000,
+        0xff000000,
+#elif defined(CONFIG_MOMENCO_OCELOT_G) || defined (CONFIG_MOMENCO_OCELOT_C)
+        0xff000000,
+##else
+#warning Unknown architecture for DiskOnChip. No default probe locations defined
+#endif
+	0xffffffff };
+
+static struct mtd_info *doclist = NULL;
+
+struct doc_priv {
+	void __iomem *virtadr;
+	unsigned long physadr;
+	u_char ChipID;
+	u_char CDSNControl;
+	int chips_per_floor; /* The number of chips detected on each floor */
+	int curfloor;
+	int curchip;
+	int mh0_page;
+	int mh1_page;
+	struct mtd_info *nextdoc;
+};
+
+/* Max number of eraseblocks to scan (from start of device) for the (I)NFTL
+   MediaHeader.  The spec says to just keep going, I think, but that's just
+   silly. */
+#define MAX_MEDIAHEADER_SCAN 8
+
+/* This is the syndrome computed by the HW ecc generator upon reading an empty
+   page, one with all 0xff for data and stored ecc code. */
+static u_char empty_read_syndrome[6] = { 0x26, 0xff, 0x6d, 0x47, 0x73, 0x7a };
+/* This is the ecc value computed by the HW ecc generator upon writing an empty
+   page, one with all 0xff for data. */
+static u_char empty_write_ecc[6] = { 0x4b, 0x00, 0xe2, 0x0e, 0x93, 0xf7 };
+
+#define INFTL_BBT_RESERVED_BLOCKS 4
+
+#define DoC_is_MillenniumPlus(doc) ((doc)->ChipID == DOC_ChipID_DocMilPlus16 || (doc)->ChipID == DOC_ChipID_DocMilPlus32)
+#define DoC_is_Millennium(doc) ((doc)->ChipID == DOC_ChipID_DocMil)
+#define DoC_is_2000(doc) ((doc)->ChipID == DOC_ChipID_Doc2k)
+
+static void doc200x_hwcontrol(struct mtd_info *mtd, int cmd);
+static void doc200x_select_chip(struct mtd_info *mtd, int chip);
+
+static int debug=0;
+module_param(debug, int, 0);
+
+static int try_dword=1;
+module_param(try_dword, int, 0);
+
+static int no_ecc_failures=0;
+module_param(no_ecc_failures, int, 0);
+
+#ifdef CONFIG_MTD_PARTITIONS
+static int no_autopart=0;
+module_param(no_autopart, int, 0);
+#endif
+
+#ifdef MTD_NAND_DISKONCHIP_BBTWRITE
+static int inftl_bbt_write=1;
+#else
+static int inftl_bbt_write=0;
+#endif
+module_param(inftl_bbt_write, int, 0);
+
+static unsigned long doc_config_location = CONFIG_MTD_DISKONCHIP_PROBE_ADDRESS;
+module_param(doc_config_location, ulong, 0);
+MODULE_PARM_DESC(doc_config_location, "Physical memory address at which to probe for DiskOnChip");
+
+
+/* Sector size for HW ECC */
+#define SECTOR_SIZE 512
+/* The sector bytes are packed into NB_DATA 10 bit words */
+#define NB_DATA (((SECTOR_SIZE + 1) * 8 + 6) / 10)
+/* Number of roots */
+#define NROOTS 4
+/* First consective root */
+#define FCR 510
+/* Number of symbols */
+#define NN 1023
+
+/* the Reed Solomon control structure */
+static struct rs_control *rs_decoder;
+
+/* 
+ * The HW decoder in the DoC ASIC's provides us a error syndrome,
+ * which we must convert to a standard syndrom usable by the generic
+ * Reed-Solomon library code.
+ *
+ * Fabrice Bellard figured this out in the old docecc code. I added
+ * some comments, improved a minor bit and converted it to make use
+ * of the generic Reed-Solomon libary. tglx
+ */
+static int doc_ecc_decode (struct rs_control *rs, uint8_t *data, uint8_t *ecc)
+{
+	int i, j, nerr, errpos[8];
+	uint8_t parity;
+	uint16_t ds[4], s[5], tmp, errval[8], syn[4];
+
+	/* Convert the ecc bytes into words */
+	ds[0] = ((ecc[4] & 0xff) >> 0) | ((ecc[5] & 0x03) << 8);
+	ds[1] = ((ecc[5] & 0xfc) >> 2) | ((ecc[2] & 0x0f) << 6);
+	ds[2] = ((ecc[2] & 0xf0) >> 4) | ((ecc[3] & 0x3f) << 4);
+	ds[3] = ((ecc[3] & 0xc0) >> 6) | ((ecc[0] & 0xff) << 2);
+	parity = ecc[1];
+
+	/* Initialize the syndrom buffer */
+	for (i = 0; i < NROOTS; i++)
+		s[i] = ds[0];
+	/* 
+	 *  Evaluate 
+	 *  s[i] = ds[3]x^3 + ds[2]x^2 + ds[1]x^1 + ds[0]
+	 *  where x = alpha^(FCR + i)
+	 */
+	for(j = 1; j < NROOTS; j++) {
+		if(ds[j] == 0)
+			continue;
+		tmp = rs->index_of[ds[j]];
+		for(i = 0; i < NROOTS; i++)
+			s[i] ^= rs->alpha_to[rs_modnn(rs, tmp + (FCR + i) * j)];
+	}
+
+	/* Calc s[i] = s[i] / alpha^(v + i) */
+	for (i = 0; i < NROOTS; i++) {
+		if (syn[i])
+ 			syn[i] = rs_modnn(rs, rs->index_of[s[i]] + (NN - FCR - i));
+	}
+	/* Call the decoder library */
+	nerr = decode_rs16(rs, NULL, NULL, 1019, syn, 0, errpos, 0, errval);
+
+	/* Incorrectable errors ? */
+	if (nerr < 0)
+		return nerr;
+
+	/* 
+	 * Correct the errors. The bitpositions are a bit of magic,
+	 * but they are given by the design of the de/encoder circuit
+	 * in the DoC ASIC's.
+	 */
+	for(i = 0;i < nerr; i++) {
+		int index, bitpos, pos = 1015 - errpos[i];
+		uint8_t val;
+		if (pos >= NB_DATA && pos < 1019)
+			continue;
+		if (pos < NB_DATA) {
+			/* extract bit position (MSB first) */
+			pos = 10 * (NB_DATA - 1 - pos) - 6;
+			/* now correct the following 10 bits. At most two bytes
+			   can be modified since pos is even */
+			index = (pos >> 3) ^ 1;
+			bitpos = pos & 7;
+			if ((index >= 0 && index < SECTOR_SIZE) || 
+			    index == (SECTOR_SIZE + 1)) {
+				val = (uint8_t) (errval[i] >> (2 + bitpos));
+				parity ^= val;
+				if (index < SECTOR_SIZE)
+					data[index] ^= val;
+			}
+			index = ((pos >> 3) + 1) ^ 1;
+			bitpos = (bitpos + 10) & 7;
+			if (bitpos == 0)
+				bitpos = 8;
+			if ((index >= 0 && index < SECTOR_SIZE) || 
+			    index == (SECTOR_SIZE + 1)) {
+				val = (uint8_t)(errval[i] << (8 - bitpos));
+				parity ^= val;
+				if (index < SECTOR_SIZE)
+					data[index] ^= val;
+			}
+		}
+	}
+	/* If the parity is wrong, no rescue possible */
+	return parity ? -1 : nerr;
+}
+
+static void DoC_Delay(struct doc_priv *doc, unsigned short cycles)
+{
+	volatile char dummy;
+	int i;
+	
+	for (i = 0; i < cycles; i++) {
+		if (DoC_is_Millennium(doc))
+			dummy = ReadDOC(doc->virtadr, NOP);
+		else if (DoC_is_MillenniumPlus(doc))
+			dummy = ReadDOC(doc->virtadr, Mplus_NOP);
+		else
+			dummy = ReadDOC(doc->virtadr, DOCStatus);
+	}
+	
+}
+
+#define CDSN_CTRL_FR_B_MASK	(CDSN_CTRL_FR_B0 | CDSN_CTRL_FR_B1)
+
+/* DOC_WaitReady: Wait for RDY line to be asserted by the flash chip */
+static int _DoC_WaitReady(struct doc_priv *doc)
+{
+        void __iomem *docptr = doc->virtadr;
+	unsigned long timeo = jiffies + (HZ * 10);
+
+	if(debug) printk("_DoC_WaitReady...\n");
+	/* Out-of-line routine to wait for chip response */
+	if (DoC_is_MillenniumPlus(doc)) {
+		while ((ReadDOC(docptr, Mplus_FlashControl) & CDSN_CTRL_FR_B_MASK) != CDSN_CTRL_FR_B_MASK) {
+			if (time_after(jiffies, timeo)) {
+				printk("_DoC_WaitReady timed out.\n");
+				return -EIO;
+			}
+			udelay(1);
+			cond_resched();
+		}
+	} else {
+		while (!(ReadDOC(docptr, CDSNControl) & CDSN_CTRL_FR_B)) {
+			if (time_after(jiffies, timeo)) {
+				printk("_DoC_WaitReady timed out.\n");
+				return -EIO;
+			}
+			udelay(1);
+			cond_resched();
+		}
+	}
+
+	return 0;
+}
+
+static inline int DoC_WaitReady(struct doc_priv *doc)
+{
+        void __iomem *docptr = doc->virtadr;
+	int ret = 0;
+
+	if (DoC_is_MillenniumPlus(doc)) {
+		DoC_Delay(doc, 4);
+
+		if ((ReadDOC(docptr, Mplus_FlashControl) & CDSN_CTRL_FR_B_MASK) != CDSN_CTRL_FR_B_MASK)
+			/* Call the out-of-line routine to wait */
+			ret = _DoC_WaitReady(doc);
+	} else {
+		DoC_Delay(doc, 4);
+
+		if (!(ReadDOC(docptr, CDSNControl) & CDSN_CTRL_FR_B))
+			/* Call the out-of-line routine to wait */
+			ret = _DoC_WaitReady(doc);
+		DoC_Delay(doc, 2);
+	}
+
+	if(debug) printk("DoC_WaitReady OK\n");
+	return ret;
+}
+
+static void doc2000_write_byte(struct mtd_info *mtd, u_char datum)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+
+	if(debug)printk("write_byte %02x\n", datum);
+	WriteDOC(datum, docptr, CDSNSlowIO);
+	WriteDOC(datum, docptr, 2k_CDSN_IO);
+}
+
+static u_char doc2000_read_byte(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+	u_char ret;
+
+	ReadDOC(docptr, CDSNSlowIO);
+	DoC_Delay(doc, 2);
+	ret = ReadDOC(docptr, 2k_CDSN_IO);
+	if (debug) printk("read_byte returns %02x\n", ret);
+	return ret;
+}
+
+static void doc2000_writebuf(struct mtd_info *mtd, 
+			     const u_char *buf, int len)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+	int i;
+	if (debug)printk("writebuf of %d bytes: ", len);
+	for (i=0; i < len; i++) {
+		WriteDOC_(buf[i], docptr, DoC_2k_CDSN_IO + i);
+		if (debug && i < 16)
+			printk("%02x ", buf[i]);
+	}
+	if (debug) printk("\n");
+}
+
+static void doc2000_readbuf(struct mtd_info *mtd, 
+			    u_char *buf, int len)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+ 	int i;
+
+	if (debug)printk("readbuf of %d bytes: ", len);
+
+	for (i=0; i < len; i++) {
+		buf[i] = ReadDOC(docptr, 2k_CDSN_IO + i);
+	}
+}
+
+static void doc2000_readbuf_dword(struct mtd_info *mtd, 
+			    u_char *buf, int len)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+ 	int i;
+
+	if (debug) printk("readbuf_dword of %d bytes: ", len);
+
+	if (unlikely((((unsigned long)buf)|len) & 3)) {
+		for (i=0; i < len; i++) {
+			*(uint8_t *)(&buf[i]) = ReadDOC(docptr, 2k_CDSN_IO + i);
+		}
+	} else {
+		for (i=0; i < len; i+=4) {
+			*(uint32_t*)(&buf[i]) = readl(docptr + DoC_2k_CDSN_IO + i);
+		}
+	}
+}
+
+static int doc2000_verifybuf(struct mtd_info *mtd, 
+			      const u_char *buf, int len)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+	int i;
+
+	for (i=0; i < len; i++)
+		if (buf[i] != ReadDOC(docptr, 2k_CDSN_IO))
+			return -EFAULT;
+	return 0;
+}
+
+static uint16_t __init doc200x_ident_chip(struct mtd_info *mtd, int nr)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+	uint16_t ret;
+
+	doc200x_select_chip(mtd, nr);
+	doc200x_hwcontrol(mtd, NAND_CTL_SETCLE);
+	this->write_byte(mtd, NAND_CMD_READID);
+	doc200x_hwcontrol(mtd, NAND_CTL_CLRCLE);
+	doc200x_hwcontrol(mtd, NAND_CTL_SETALE);
+	this->write_byte(mtd, 0);
+	doc200x_hwcontrol(mtd, NAND_CTL_CLRALE);
+
+	ret = this->read_byte(mtd) << 8;
+	ret |= this->read_byte(mtd);
+
+	if (doc->ChipID == DOC_ChipID_Doc2k && try_dword && !nr) {
+		/* First chip probe. See if we get same results by 32-bit access */
+		union {
+			uint32_t dword;
+			uint8_t byte[4];
+		} ident;
+		void __iomem *docptr = doc->virtadr;
+
+		doc200x_hwcontrol(mtd, NAND_CTL_SETCLE);
+		doc2000_write_byte(mtd, NAND_CMD_READID);
+		doc200x_hwcontrol(mtd, NAND_CTL_CLRCLE);
+		doc200x_hwcontrol(mtd, NAND_CTL_SETALE);
+		doc2000_write_byte(mtd, 0);
+		doc200x_hwcontrol(mtd, NAND_CTL_CLRALE);
+
+		ident.dword = readl(docptr + DoC_2k_CDSN_IO);
+		if (((ident.byte[0] << 8) | ident.byte[1]) == ret) {
+			printk(KERN_INFO "DiskOnChip 2000 responds to DWORD access\n");
+			this->read_buf = &doc2000_readbuf_dword;
+		}
+	}
+		
+	return ret;
+}
+
+static void __init doc2000_count_chips(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+	uint16_t mfrid;
+	int i;
+
+	/* Max 4 chips per floor on DiskOnChip 2000 */
+	doc->chips_per_floor = 4;
+
+	/* Find out what the first chip is */
+	mfrid = doc200x_ident_chip(mtd, 0);
+
+	/* Find how many chips in each floor. */
+	for (i = 1; i < 4; i++) {
+		if (doc200x_ident_chip(mtd, i) != mfrid)
+			break;
+	}
+	doc->chips_per_floor = i;
+	printk(KERN_DEBUG "Detected %d chips per floor.\n", i);
+}
+
+static int doc200x_wait(struct mtd_info *mtd, struct nand_chip *this, int state)
+{
+	struct doc_priv *doc = this->priv;
+
+	int status;
+	
+	DoC_WaitReady(doc);
+	this->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
+	DoC_WaitReady(doc);
+	status = (int)this->read_byte(mtd);
+
+	return status;
+}
+
+static void doc2001_write_byte(struct mtd_info *mtd, u_char datum)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+
+	WriteDOC(datum, docptr, CDSNSlowIO);
+	WriteDOC(datum, docptr, Mil_CDSN_IO);
+	WriteDOC(datum, docptr, WritePipeTerm);
+}
+
+static u_char doc2001_read_byte(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+
+	//ReadDOC(docptr, CDSNSlowIO);
+	/* 11.4.5 -- delay twice to allow extended length cycle */
+	DoC_Delay(doc, 2);
+	ReadDOC(docptr, ReadPipeInit);
+	//return ReadDOC(docptr, Mil_CDSN_IO);
+	return ReadDOC(docptr, LastDataRead);
+}
+
+static void doc2001_writebuf(struct mtd_info *mtd, 
+			     const u_char *buf, int len)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+	int i;
+
+	for (i=0; i < len; i++)
+		WriteDOC_(buf[i], docptr, DoC_Mil_CDSN_IO + i);
+	/* Terminate write pipeline */
+	WriteDOC(0x00, docptr, WritePipeTerm);
+}
+
+static void doc2001_readbuf(struct mtd_info *mtd, 
+			    u_char *buf, int len)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+	int i;
+
+	/* Start read pipeline */
+	ReadDOC(docptr, ReadPipeInit);
+
+	for (i=0; i < len-1; i++)
+		buf[i] = ReadDOC(docptr, Mil_CDSN_IO + (i & 0xff));
+
+	/* Terminate read pipeline */
+	buf[i] = ReadDOC(docptr, LastDataRead);
+}
+
+static int doc2001_verifybuf(struct mtd_info *mtd, 
+			     const u_char *buf, int len)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+	int i;
+
+	/* Start read pipeline */
+	ReadDOC(docptr, ReadPipeInit);
+
+	for (i=0; i < len-1; i++)
+		if (buf[i] != ReadDOC(docptr, Mil_CDSN_IO)) {
+			ReadDOC(docptr, LastDataRead);
+			return i;
+		}
+	if (buf[i] != ReadDOC(docptr, LastDataRead))
+		return i;
+	return 0;
+}
+
+static u_char doc2001plus_read_byte(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+	u_char ret;
+
+        ReadDOC(docptr, Mplus_ReadPipeInit);
+        ReadDOC(docptr, Mplus_ReadPipeInit);
+        ret = ReadDOC(docptr, Mplus_LastDataRead);
+	if (debug) printk("read_byte returns %02x\n", ret);
+	return ret;
+}
+
+static void doc2001plus_writebuf(struct mtd_info *mtd, 
+			     const u_char *buf, int len)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+	int i;
+
+	if (debug)printk("writebuf of %d bytes: ", len);
+	for (i=0; i < len; i++) {
+		WriteDOC_(buf[i], docptr, DoC_Mil_CDSN_IO + i);
+		if (debug && i < 16)
+			printk("%02x ", buf[i]);
+	}
+	if (debug) printk("\n");
+}
+
+static void doc2001plus_readbuf(struct mtd_info *mtd, 
+			    u_char *buf, int len)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+	int i;
+
+	if (debug)printk("readbuf of %d bytes: ", len);
+
+	/* Start read pipeline */
+	ReadDOC(docptr, Mplus_ReadPipeInit);
+	ReadDOC(docptr, Mplus_ReadPipeInit);
+
+	for (i=0; i < len-2; i++) {
+		buf[i] = ReadDOC(docptr, Mil_CDSN_IO);
+		if (debug && i < 16)
+			printk("%02x ", buf[i]);
+	}
+
+	/* Terminate read pipeline */
+	buf[len-2] = ReadDOC(docptr, Mplus_LastDataRead);
+	if (debug && i < 16)
+		printk("%02x ", buf[len-2]);
+	buf[len-1] = ReadDOC(docptr, Mplus_LastDataRead);
+	if (debug && i < 16)
+		printk("%02x ", buf[len-1]);
+	if (debug) printk("\n");
+}
+
+static int doc2001plus_verifybuf(struct mtd_info *mtd, 
+			     const u_char *buf, int len)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+	int i;
+
+	if (debug)printk("verifybuf of %d bytes: ", len);
+
+	/* Start read pipeline */
+	ReadDOC(docptr, Mplus_ReadPipeInit);
+	ReadDOC(docptr, Mplus_ReadPipeInit);
+
+	for (i=0; i < len-2; i++)
+		if (buf[i] != ReadDOC(docptr, Mil_CDSN_IO)) {
+			ReadDOC(docptr, Mplus_LastDataRead);
+			ReadDOC(docptr, Mplus_LastDataRead);
+			return i;
+		}
+	if (buf[len-2] != ReadDOC(docptr, Mplus_LastDataRead))
+		return len-2;
+	if (buf[len-1] != ReadDOC(docptr, Mplus_LastDataRead))
+		return len-1;
+	return 0;
+}
+
+static void doc2001plus_select_chip(struct mtd_info *mtd, int chip)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+	int floor = 0;
+
+	if(debug)printk("select chip (%d)\n", chip);
+
+	if (chip == -1) {
+		/* Disable flash internally */
+		WriteDOC(0, docptr, Mplus_FlashSelect);
+		return;
+	}
+
+	floor = chip / doc->chips_per_floor;
+	chip -= (floor *  doc->chips_per_floor);
+
+	/* Assert ChipEnable and deassert WriteProtect */
+	WriteDOC((DOC_FLASH_CE), docptr, Mplus_FlashSelect);
+	this->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
+
+	doc->curchip = chip;
+	doc->curfloor = floor;
+}
+
+static void doc200x_select_chip(struct mtd_info *mtd, int chip)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+	int floor = 0;
+
+	if(debug)printk("select chip (%d)\n", chip);
+
+	if (chip == -1)
+		return;
+
+	floor = chip / doc->chips_per_floor;
+	chip -= (floor *  doc->chips_per_floor);
+
+	/* 11.4.4 -- deassert CE before changing chip */
+	doc200x_hwcontrol(mtd, NAND_CTL_CLRNCE);
+
+	WriteDOC(floor, docptr, FloorSelect);
+	WriteDOC(chip, docptr, CDSNDeviceSelect);
+
+	doc200x_hwcontrol(mtd, NAND_CTL_SETNCE);
+
+	doc->curchip = chip;
+	doc->curfloor = floor;
+}
+
+static void doc200x_hwcontrol(struct mtd_info *mtd, int cmd)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+
+	switch(cmd) {
+	case NAND_CTL_SETNCE:
+		doc->CDSNControl |= CDSN_CTRL_CE;
+		break;
+	case NAND_CTL_CLRNCE:
+		doc->CDSNControl &= ~CDSN_CTRL_CE;
+		break;
+	case NAND_CTL_SETCLE:
+		doc->CDSNControl |= CDSN_CTRL_CLE;
+		break;
+	case NAND_CTL_CLRCLE:
+		doc->CDSNControl &= ~CDSN_CTRL_CLE;
+		break;
+	case NAND_CTL_SETALE:
+		doc->CDSNControl |= CDSN_CTRL_ALE;
+		break;
+	case NAND_CTL_CLRALE:
+		doc->CDSNControl &= ~CDSN_CTRL_ALE;
+		break;
+	case NAND_CTL_SETWP:
+		doc->CDSNControl |= CDSN_CTRL_WP;
+		break;
+	case NAND_CTL_CLRWP:
+		doc->CDSNControl &= ~CDSN_CTRL_WP;
+		break;
+	}
+	if (debug)printk("hwcontrol(%d): %02x\n", cmd, doc->CDSNControl);
+	WriteDOC(doc->CDSNControl, docptr, CDSNControl);
+	/* 11.4.3 -- 4 NOPs after CSDNControl write */
+	DoC_Delay(doc, 4);
+}
+
+static void doc2001plus_command (struct mtd_info *mtd, unsigned command, int column, int page_addr)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+
+	/*
+	 * Must terminate write pipeline before sending any commands
+	 * to the device.
+	 */
+	if (command == NAND_CMD_PAGEPROG) {
+		WriteDOC(0x00, docptr, Mplus_WritePipeTerm);
+		WriteDOC(0x00, docptr, Mplus_WritePipeTerm);
+	}
+
+	/*
+	 * Write out the command to the device.
+	 */
+	if (command == NAND_CMD_SEQIN) {
+		int readcmd;
+
+		if (column >= mtd->oobblock) {
+			/* OOB area */
+			column -= mtd->oobblock;
+			readcmd = NAND_CMD_READOOB;
+		} else if (column < 256) {
+			/* First 256 bytes --> READ0 */
+			readcmd = NAND_CMD_READ0;
+		} else {
+			column -= 256;
+			readcmd = NAND_CMD_READ1;
+		}
+		WriteDOC(readcmd, docptr, Mplus_FlashCmd);
+	}
+	WriteDOC(command, docptr, Mplus_FlashCmd);
+	WriteDOC(0, docptr, Mplus_WritePipeTerm);
+	WriteDOC(0, docptr, Mplus_WritePipeTerm);
+
+	if (column != -1 || page_addr != -1) {
+		/* Serially input address */
+		if (column != -1) {
+			/* Adjust columns for 16 bit buswidth */
+			if (this->options & NAND_BUSWIDTH_16)
+				column >>= 1;
+			WriteDOC(column, docptr, Mplus_FlashAddress);
+		}
+		if (page_addr != -1) {
+			WriteDOC((unsigned char) (page_addr & 0xff), docptr, Mplus_FlashAddress);
+			WriteDOC((unsigned char) ((page_addr >> 8) & 0xff), docptr, Mplus_FlashAddress);
+			/* One more address cycle for higher density devices */
+			if (this->chipsize & 0x0c000000) {
+				WriteDOC((unsigned char) ((page_addr >> 16) & 0x0f), docptr, Mplus_FlashAddress);
+				printk("high density\n");
+			}
+		}
+		WriteDOC(0, docptr, Mplus_WritePipeTerm);
+		WriteDOC(0, docptr, Mplus_WritePipeTerm);
+		/* deassert ALE */
+		if (command == NAND_CMD_READ0 || command == NAND_CMD_READ1 || command == NAND_CMD_READOOB || command == NAND_CMD_READID)
+			WriteDOC(0, docptr, Mplus_FlashControl);
+	}
+
+	/* 
+	 * program and erase have their own busy handlers
+	 * status and sequential in needs no delay
+	*/
+	switch (command) {
+
+	case NAND_CMD_PAGEPROG:
+	case NAND_CMD_ERASE1:
+	case NAND_CMD_ERASE2:
+	case NAND_CMD_SEQIN:
+	case NAND_CMD_STATUS:
+		return;
+
+	case NAND_CMD_RESET:
+		if (this->dev_ready)
+			break;
+		udelay(this->chip_delay);
+		WriteDOC(NAND_CMD_STATUS, docptr, Mplus_FlashCmd);
+		WriteDOC(0, docptr, Mplus_WritePipeTerm);
+		WriteDOC(0, docptr, Mplus_WritePipeTerm);
+		while ( !(this->read_byte(mtd) & 0x40));
+		return;
+
+	/* This applies to read commands */
+	default:
+		/* 
+		 * If we don't have access to the busy pin, we apply the given
+		 * command delay
+		*/
+		if (!this->dev_ready) {
+			udelay (this->chip_delay);
+			return;
+		}
+	}
+
+	/* Apply this short delay always to ensure that we do wait tWB in
+	 * any case on any machine. */
+	ndelay (100);
+	/* wait until command is processed */
+	while (!this->dev_ready(mtd));
+}
+
+static int doc200x_dev_ready(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+
+	if (DoC_is_MillenniumPlus(doc)) {
+		/* 11.4.2 -- must NOP four times before checking FR/B# */
+		DoC_Delay(doc, 4);
+		if ((ReadDOC(docptr, Mplus_FlashControl) & CDSN_CTRL_FR_B_MASK) != CDSN_CTRL_FR_B_MASK) {
+			if(debug)
+				printk("not ready\n");
+			return 0;
+		}
+		if (debug)printk("was ready\n");
+		return 1;
+	} else {
+		/* 11.4.2 -- must NOP four times before checking FR/B# */
+		DoC_Delay(doc, 4);
+		if (!(ReadDOC(docptr, CDSNControl) & CDSN_CTRL_FR_B)) {
+			if(debug)
+				printk("not ready\n");
+			return 0;
+		}
+		/* 11.4.2 -- Must NOP twice if it's ready */
+		DoC_Delay(doc, 2);
+		if (debug)printk("was ready\n");
+		return 1;
+	}
+}
+
+static int doc200x_block_bad(struct mtd_info *mtd, loff_t ofs, int getchip)
+{
+	/* This is our last resort if we couldn't find or create a BBT.  Just
+	   pretend all blocks are good. */
+	return 0;
+}
+
+static void doc200x_enable_hwecc(struct mtd_info *mtd, int mode)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+
+	/* Prime the ECC engine */
+	switch(mode) {
+	case NAND_ECC_READ:
+		WriteDOC(DOC_ECC_RESET, docptr, ECCConf);
+		WriteDOC(DOC_ECC_EN, docptr, ECCConf);
+		break;
+	case NAND_ECC_WRITE:
+		WriteDOC(DOC_ECC_RESET, docptr, ECCConf);
+		WriteDOC(DOC_ECC_EN | DOC_ECC_RW, docptr, ECCConf);
+		break;
+	}
+}
+
+static void doc2001plus_enable_hwecc(struct mtd_info *mtd, int mode)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+
+	/* Prime the ECC engine */
+	switch(mode) {
+	case NAND_ECC_READ:
+		WriteDOC(DOC_ECC_RESET, docptr, Mplus_ECCConf);
+		WriteDOC(DOC_ECC_EN, docptr, Mplus_ECCConf);
+		break;
+	case NAND_ECC_WRITE:
+		WriteDOC(DOC_ECC_RESET, docptr, Mplus_ECCConf);
+		WriteDOC(DOC_ECC_EN | DOC_ECC_RW, docptr, Mplus_ECCConf);
+		break;
+	}
+}
+
+/* This code is only called on write */
+static int doc200x_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
+				 unsigned char *ecc_code)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+	int i;
+	int emptymatch = 1;
+
+	/* flush the pipeline */
+	if (DoC_is_2000(doc)) {
+		WriteDOC(doc->CDSNControl & ~CDSN_CTRL_FLASH_IO, docptr, CDSNControl);
+		WriteDOC(0, docptr, 2k_CDSN_IO);
+		WriteDOC(0, docptr, 2k_CDSN_IO);
+		WriteDOC(0, docptr, 2k_CDSN_IO);
+		WriteDOC(doc->CDSNControl, docptr, CDSNControl);
+	} else if (DoC_is_MillenniumPlus(doc)) {
+		WriteDOC(0, docptr, Mplus_NOP);
+		WriteDOC(0, docptr, Mplus_NOP);
+		WriteDOC(0, docptr, Mplus_NOP);
+	} else {
+		WriteDOC(0, docptr, NOP);
+		WriteDOC(0, docptr, NOP);
+		WriteDOC(0, docptr, NOP);
+	}
+
+	for (i = 0; i < 6; i++) {
+		if (DoC_is_MillenniumPlus(doc))
+			ecc_code[i] = ReadDOC_(docptr, DoC_Mplus_ECCSyndrome0 + i);
+		else 
+			ecc_code[i] = ReadDOC_(docptr, DoC_ECCSyndrome0 + i);
+		if (ecc_code[i] != empty_write_ecc[i])
+			emptymatch = 0;
+	}
+	if (DoC_is_MillenniumPlus(doc))
+		WriteDOC(DOC_ECC_DIS, docptr, Mplus_ECCConf);
+	else
+		WriteDOC(DOC_ECC_DIS, docptr, ECCConf);
+#if 0
+	/* If emptymatch=1, we might have an all-0xff data buffer.  Check. */
+	if (emptymatch) {
+		/* Note: this somewhat expensive test should not be triggered
+		   often.  It could be optimized away by examining the data in
+		   the writebuf routine, and remembering the result. */
+		for (i = 0; i < 512; i++) {
+			if (dat[i] == 0xff) continue;
+			emptymatch = 0;
+			break;
+		}
+	}
+	/* If emptymatch still =1, we do have an all-0xff data buffer.
+	   Return all-0xff ecc value instead of the computed one, so
+	   it'll look just like a freshly-erased page. */
+	if (emptymatch) memset(ecc_code, 0xff, 6);
+#endif
+	return 0;
+}
+
+static int doc200x_correct_data(struct mtd_info *mtd, u_char *dat, u_char *read_ecc, u_char *calc_ecc)
+{
+	int i, ret = 0;
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+        void __iomem *docptr = doc->virtadr;
+	volatile u_char dummy;
+	int emptymatch = 1;
+	
+	/* flush the pipeline */
+	if (DoC_is_2000(doc)) {
+		dummy = ReadDOC(docptr, 2k_ECCStatus);
+		dummy = ReadDOC(docptr, 2k_ECCStatus);
+		dummy = ReadDOC(docptr, 2k_ECCStatus);
+	} else if (DoC_is_MillenniumPlus(doc)) {
+		dummy = ReadDOC(docptr, Mplus_ECCConf);
+		dummy = ReadDOC(docptr, Mplus_ECCConf);
+		dummy = ReadDOC(docptr, Mplus_ECCConf);
+	} else {
+		dummy = ReadDOC(docptr, ECCConf);
+		dummy = ReadDOC(docptr, ECCConf);
+		dummy = ReadDOC(docptr, ECCConf);
+	}
+	
+	/* Error occured ? */
+	if (dummy & 0x80) {
+		for (i = 0; i < 6; i++) {
+			if (DoC_is_MillenniumPlus(doc))
+				calc_ecc[i] = ReadDOC_(docptr, DoC_Mplus_ECCSyndrome0 + i);
+			else
+				calc_ecc[i] = ReadDOC_(docptr, DoC_ECCSyndrome0 + i);
+			if (calc_ecc[i] != empty_read_syndrome[i])
+				emptymatch = 0;
+		}
+		/* If emptymatch=1, the read syndrome is consistent with an
+		   all-0xff data and stored ecc block.  Check the stored ecc. */
+		if (emptymatch) {
+			for (i = 0; i < 6; i++) {
+				if (read_ecc[i] == 0xff) continue;
+				emptymatch = 0;
+				break;
+			}
+		}
+		/* If emptymatch still =1, check the data block. */
+		if (emptymatch) {
+		/* Note: this somewhat expensive test should not be triggered
+		   often.  It could be optimized away by examining the data in
+		   the readbuf routine, and remembering the result. */
+			for (i = 0; i < 512; i++) {
+				if (dat[i] == 0xff) continue;
+				emptymatch = 0;
+				break;
+			}
+		}
+		/* If emptymatch still =1, this is almost certainly a freshly-
+		   erased block, in which case the ECC will not come out right.
+		   We'll suppress the error and tell the caller everything's
+		   OK.  Because it is. */
+		if (!emptymatch) ret = doc_ecc_decode (rs_decoder, dat, calc_ecc);
+		if (ret > 0)
+			printk(KERN_ERR "doc200x_correct_data corrected %d errors\n", ret);
+	}	
+	if (DoC_is_MillenniumPlus(doc))
+		WriteDOC(DOC_ECC_DIS, docptr, Mplus_ECCConf);
+	else
+		WriteDOC(DOC_ECC_DIS, docptr, ECCConf);
+	if (no_ecc_failures && (ret == -1)) {
+		printk(KERN_ERR "suppressing ECC failure\n");
+		ret = 0;
+	}
+	return ret;
+}
+		
+//u_char mydatabuf[528];
+
+static struct nand_oobinfo doc200x_oobinfo = {
+        .useecc = MTD_NANDECC_AUTOPLACE,
+        .eccbytes = 6,
+        .eccpos = {0, 1, 2, 3, 4, 5},
+        .oobfree = { {8, 8} }
+};
+ 
+/* Find the (I)NFTL Media Header, and optionally also the mirror media header.
+   On sucessful return, buf will contain a copy of the media header for
+   further processing.  id is the string to scan for, and will presumably be
+   either "ANAND" or "BNAND".  If findmirror=1, also look for the mirror media
+   header.  The page #s of the found media headers are placed in mh0_page and
+   mh1_page in the DOC private structure. */
+static int __init find_media_headers(struct mtd_info *mtd, u_char *buf,
+				     const char *id, int findmirror)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+	unsigned offs, end = (MAX_MEDIAHEADER_SCAN << this->phys_erase_shift);
+	int ret;
+	size_t retlen;
+
+	end = min(end, mtd->size); // paranoia
+	for (offs = 0; offs < end; offs += mtd->erasesize) {
+		ret = mtd->read(mtd, offs, mtd->oobblock, &retlen, buf);
+		if (retlen != mtd->oobblock) continue;
+		if (ret) {
+			printk(KERN_WARNING "ECC error scanning DOC at 0x%x\n",
+				offs);
+		}
+		if (memcmp(buf, id, 6)) continue;
+		printk(KERN_INFO "Found DiskOnChip %s Media Header at 0x%x\n", id, offs);
+		if (doc->mh0_page == -1) {
+			doc->mh0_page = offs >> this->page_shift;
+			if (!findmirror) return 1;
+			continue;
+		}
+		doc->mh1_page = offs >> this->page_shift;
+		return 2;
+	}
+	if (doc->mh0_page == -1) {
+		printk(KERN_WARNING "DiskOnChip %s Media Header not found.\n", id);
+		return 0;
+	}
+	/* Only one mediaheader was found.  We want buf to contain a
+	   mediaheader on return, so we'll have to re-read the one we found. */
+	offs = doc->mh0_page << this->page_shift;
+	ret = mtd->read(mtd, offs, mtd->oobblock, &retlen, buf);
+	if (retlen != mtd->oobblock) {
+		/* Insanity.  Give up. */
+		printk(KERN_ERR "Read DiskOnChip Media Header once, but can't reread it???\n");
+		return 0;
+	}
+	return 1;
+}
+
+static inline int __init nftl_partscan(struct mtd_info *mtd,
+				struct mtd_partition *parts)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+	int ret = 0;
+	u_char *buf;
+	struct NFTLMediaHeader *mh;
+	const unsigned psize = 1 << this->page_shift;
+	unsigned blocks, maxblocks;
+	int offs, numheaders;
+
+	buf = kmalloc(mtd->oobblock, GFP_KERNEL);
+	if (!buf) {
+		printk(KERN_ERR "DiskOnChip mediaheader kmalloc failed!\n");
+		return 0;
+	}
+	if (!(numheaders=find_media_headers(mtd, buf, "ANAND", 1))) goto out;
+	mh = (struct NFTLMediaHeader *) buf;
+
+//#ifdef CONFIG_MTD_DEBUG_VERBOSE
+//	if (CONFIG_MTD_DEBUG_VERBOSE >= 2)
+	printk(KERN_INFO "    DataOrgID        = %s\n"
+			 "    NumEraseUnits    = %d\n"
+			 "    FirstPhysicalEUN = %d\n"
+			 "    FormattedSize    = %d\n"
+			 "    UnitSizeFactor   = %d\n",
+		mh->DataOrgID, mh->NumEraseUnits,
+		mh->FirstPhysicalEUN, mh->FormattedSize,
+		mh->UnitSizeFactor);
+//#endif
+
+	blocks = mtd->size >> this->phys_erase_shift;
+	maxblocks = min(32768U, mtd->erasesize - psize);
+
+	if (mh->UnitSizeFactor == 0x00) {
+		/* Auto-determine UnitSizeFactor.  The constraints are:
+		   - There can be at most 32768 virtual blocks.
+		   - There can be at most (virtual block size - page size)
+		     virtual blocks (because MediaHeader+BBT must fit in 1).
+		*/
+		mh->UnitSizeFactor = 0xff;
+		while (blocks > maxblocks) {
+			blocks >>= 1;
+			maxblocks = min(32768U, (maxblocks << 1) + psize);
+			mh->UnitSizeFactor--;
+		}
+		printk(KERN_WARNING "UnitSizeFactor=0x00 detected.  Correct value is assumed to be 0x%02x.\n", mh->UnitSizeFactor);
+	}
+
+	/* NOTE: The lines below modify internal variables of the NAND and MTD
+	   layers; variables with have already been configured by nand_scan.
+	   Unfortunately, we didn't know before this point what these values
+	   should be.  Thus, this code is somewhat dependant on the exact
+	   implementation of the NAND layer.  */
+	if (mh->UnitSizeFactor != 0xff) {
+		this->bbt_erase_shift += (0xff - mh->UnitSizeFactor);
+		mtd->erasesize <<= (0xff - mh->UnitSizeFactor);
+		printk(KERN_INFO "Setting virtual erase size to %d\n", mtd->erasesize);
+		blocks = mtd->size >> this->bbt_erase_shift;
+		maxblocks = min(32768U, mtd->erasesize - psize);
+	}
+
+	if (blocks > maxblocks) {
+		printk(KERN_ERR "UnitSizeFactor of 0x%02x is inconsistent with device size.  Aborting.\n", mh->UnitSizeFactor);
+		goto out;
+	}
+
+	/* Skip past the media headers. */
+	offs = max(doc->mh0_page, doc->mh1_page);
+	offs <<= this->page_shift;
+	offs += mtd->erasesize;
+
+	//parts[0].name = " DiskOnChip Boot / Media Header partition";
+	//parts[0].offset = 0;
+	//parts[0].size = offs;
+
+	parts[0].name = " DiskOnChip BDTL partition";
+	parts[0].offset = offs;
+	parts[0].size = (mh->NumEraseUnits - numheaders) << this->bbt_erase_shift;
+
+	offs += parts[0].size;
+	if (offs < mtd->size) {
+		parts[1].name = " DiskOnChip Remainder partition";
+		parts[1].offset = offs;
+		parts[1].size = mtd->size - offs;
+		ret = 2;
+		goto out;
+	}
+	ret = 1;
+out:
+	kfree(buf);
+	return ret;
+}
+
+/* This is a stripped-down copy of the code in inftlmount.c */
+static inline int __init inftl_partscan(struct mtd_info *mtd,
+				 struct mtd_partition *parts)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+	int ret = 0;
+	u_char *buf;
+	struct INFTLMediaHeader *mh;
+	struct INFTLPartition *ip;
+	int numparts = 0;
+	int blocks;
+	int vshift, lastvunit = 0;
+	int i;
+	int end = mtd->size;
+
+	if (inftl_bbt_write)
+		end -= (INFTL_BBT_RESERVED_BLOCKS << this->phys_erase_shift);
+
+	buf = kmalloc(mtd->oobblock, GFP_KERNEL);
+	if (!buf) {
+		printk(KERN_ERR "DiskOnChip mediaheader kmalloc failed!\n");
+		return 0;
+	}
+
+	if (!find_media_headers(mtd, buf, "BNAND", 0)) goto out;
+	doc->mh1_page = doc->mh0_page + (4096 >> this->page_shift);
+	mh = (struct INFTLMediaHeader *) buf;
+
+	mh->NoOfBootImageBlocks = le32_to_cpu(mh->NoOfBootImageBlocks);
+	mh->NoOfBinaryPartitions = le32_to_cpu(mh->NoOfBinaryPartitions);
+	mh->NoOfBDTLPartitions = le32_to_cpu(mh->NoOfBDTLPartitions);
+	mh->BlockMultiplierBits = le32_to_cpu(mh->BlockMultiplierBits);
+	mh->FormatFlags = le32_to_cpu(mh->FormatFlags);
+	mh->PercentUsed = le32_to_cpu(mh->PercentUsed);
+ 
+//#ifdef CONFIG_MTD_DEBUG_VERBOSE
+//	if (CONFIG_MTD_DEBUG_VERBOSE >= 2)
+	printk(KERN_INFO "    bootRecordID          = %s\n"
+			 "    NoOfBootImageBlocks   = %d\n"
+			 "    NoOfBinaryPartitions  = %d\n"
+			 "    NoOfBDTLPartitions    = %d\n"
+			 "    BlockMultiplerBits    = %d\n"
+			 "    FormatFlgs            = %d\n"
+			 "    OsakVersion           = %d.%d.%d.%d\n"
+			 "    PercentUsed           = %d\n",
+		mh->bootRecordID, mh->NoOfBootImageBlocks,
+		mh->NoOfBinaryPartitions,
+		mh->NoOfBDTLPartitions,
+		mh->BlockMultiplierBits, mh->FormatFlags,
+		((unsigned char *) &mh->OsakVersion)[0] & 0xf,
+		((unsigned char *) &mh->OsakVersion)[1] & 0xf,
+		((unsigned char *) &mh->OsakVersion)[2] & 0xf,
+		((unsigned char *) &mh->OsakVersion)[3] & 0xf,
+		mh->PercentUsed);
+//#endif
+
+	vshift = this->phys_erase_shift + mh->BlockMultiplierBits;
+
+	blocks = mtd->size >> vshift;
+	if (blocks > 32768) {
+		printk(KERN_ERR "BlockMultiplierBits=%d is inconsistent with device size.  Aborting.\n", mh->BlockMultiplierBits);
+		goto out;
+	}
+
+	blocks = doc->chips_per_floor << (this->chip_shift - this->phys_erase_shift);
+	if (inftl_bbt_write && (blocks > mtd->erasesize)) {
+		printk(KERN_ERR "Writeable BBTs spanning more than one erase block are not yet supported.  FIX ME!\n");
+		goto out;
+	}
+
+	/* Scan the partitions */
+	for (i = 0; (i < 4); i++) {
+		ip = &(mh->Partitions[i]);
+		ip->virtualUnits = le32_to_cpu(ip->virtualUnits);
+		ip->firstUnit = le32_to_cpu(ip->firstUnit);
+		ip->lastUnit = le32_to_cpu(ip->lastUnit);
+		ip->flags = le32_to_cpu(ip->flags);
+		ip->spareUnits = le32_to_cpu(ip->spareUnits);
+		ip->Reserved0 = le32_to_cpu(ip->Reserved0);
+
+//#ifdef CONFIG_MTD_DEBUG_VERBOSE
+//		if (CONFIG_MTD_DEBUG_VERBOSE >= 2)
+		printk(KERN_INFO	"    PARTITION[%d] ->\n"
+			"        virtualUnits    = %d\n"
+			"        firstUnit       = %d\n"
+			"        lastUnit        = %d\n"
+			"        flags           = 0x%x\n"
+			"        spareUnits      = %d\n",
+			i, ip->virtualUnits, ip->firstUnit,
+			ip->lastUnit, ip->flags,
+			ip->spareUnits);
+//#endif
+
+/*
+		if ((i == 0) && (ip->firstUnit > 0)) {
+			parts[0].name = " DiskOnChip IPL / Media Header partition";
+			parts[0].offset = 0;
+			parts[0].size = mtd->erasesize * ip->firstUnit;
+			numparts = 1;
+		}
+*/
+
+		if (ip->flags & INFTL_BINARY)
+			parts[numparts].name = " DiskOnChip BDK partition";
+		else
+			parts[numparts].name = " DiskOnChip BDTL partition";
+		parts[numparts].offset = ip->firstUnit << vshift;
+		parts[numparts].size = (1 + ip->lastUnit - ip->firstUnit) << vshift;
+		numparts++;
+		if (ip->lastUnit > lastvunit) lastvunit = ip->lastUnit;
+		if (ip->flags & INFTL_LAST) break;
+	}
+	lastvunit++;
+	if ((lastvunit << vshift) < end) {
+		parts[numparts].name = " DiskOnChip Remainder partition";
+		parts[numparts].offset = lastvunit << vshift;
+		parts[numparts].size = end - parts[numparts].offset;
+		numparts++;
+	}
+	ret = numparts;
+out:
+	kfree(buf);
+	return ret;
+}
+
+static int __init nftl_scan_bbt(struct mtd_info *mtd)
+{
+	int ret, numparts;
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+	struct mtd_partition parts[2];
+
+	memset((char *) parts, 0, sizeof(parts));
+	/* On NFTL, we have to find the media headers before we can read the
+	   BBTs, since they're stored in the media header eraseblocks. */
+	numparts = nftl_partscan(mtd, parts);
+	if (!numparts) return -EIO;
+	this->bbt_td->options = NAND_BBT_ABSPAGE | NAND_BBT_8BIT |
+				NAND_BBT_SAVECONTENT | NAND_BBT_WRITE |
+				NAND_BBT_VERSION;
+	this->bbt_td->veroffs = 7;
+	this->bbt_td->pages[0] = doc->mh0_page + 1;
+	if (doc->mh1_page != -1) {
+		this->bbt_md->options = NAND_BBT_ABSPAGE | NAND_BBT_8BIT |
+					NAND_BBT_SAVECONTENT | NAND_BBT_WRITE |
+					NAND_BBT_VERSION;
+		this->bbt_md->veroffs = 7;
+		this->bbt_md->pages[0] = doc->mh1_page + 1;
+	} else {
+		this->bbt_md = NULL;
+	}
+
+	/* It's safe to set bd=NULL below because NAND_BBT_CREATE is not set.
+	   At least as nand_bbt.c is currently written. */
+	if ((ret = nand_scan_bbt(mtd, NULL)))
+		return ret;
+	add_mtd_device(mtd);
+#ifdef CONFIG_MTD_PARTITIONS
+	if (!no_autopart)
+		add_mtd_partitions(mtd, parts, numparts);
+#endif
+	return 0;
+}
+
+static int __init inftl_scan_bbt(struct mtd_info *mtd)
+{
+	int ret, numparts;
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+	struct mtd_partition parts[5];
+
+	if (this->numchips > doc->chips_per_floor) {
+		printk(KERN_ERR "Multi-floor INFTL devices not yet supported.\n");
+		return -EIO;
+	}
+
+	if (DoC_is_MillenniumPlus(doc)) {
+		this->bbt_td->options = NAND_BBT_2BIT | NAND_BBT_ABSPAGE;
+		if (inftl_bbt_write)
+			this->bbt_td->options |= NAND_BBT_WRITE;
+		this->bbt_td->pages[0] = 2;
+		this->bbt_md = NULL;
+	} else {
+		this->bbt_td->options = NAND_BBT_LASTBLOCK | NAND_BBT_8BIT |
+					NAND_BBT_VERSION;
+		if (inftl_bbt_write)
+			this->bbt_td->options |= NAND_BBT_WRITE;
+		this->bbt_td->offs = 8;
+		this->bbt_td->len = 8;
+		this->bbt_td->veroffs = 7;
+		this->bbt_td->maxblocks = INFTL_BBT_RESERVED_BLOCKS;
+		this->bbt_td->reserved_block_code = 0x01;
+		this->bbt_td->pattern = "MSYS_BBT";
+
+		this->bbt_md->options = NAND_BBT_LASTBLOCK | NAND_BBT_8BIT |
+					NAND_BBT_VERSION;
+		if (inftl_bbt_write)
+			this->bbt_md->options |= NAND_BBT_WRITE;
+		this->bbt_md->offs = 8;
+		this->bbt_md->len = 8;
+		this->bbt_md->veroffs = 7;
+		this->bbt_md->maxblocks = INFTL_BBT_RESERVED_BLOCKS;
+		this->bbt_md->reserved_block_code = 0x01;
+		this->bbt_md->pattern = "TBB_SYSM";
+	}
+
+	/* It's safe to set bd=NULL below because NAND_BBT_CREATE is not set.
+	   At least as nand_bbt.c is currently written. */
+	if ((ret = nand_scan_bbt(mtd, NULL)))
+		return ret;
+	memset((char *) parts, 0, sizeof(parts));
+	numparts = inftl_partscan(mtd, parts);
+	/* At least for now, require the INFTL Media Header.  We could probably
+	   do without it for non-INFTL use, since all it gives us is
+	   autopartitioning, but I want to give it more thought. */
+	if (!numparts) return -EIO;
+	add_mtd_device(mtd);
+#ifdef CONFIG_MTD_PARTITIONS
+	if (!no_autopart)
+		add_mtd_partitions(mtd, parts, numparts);
+#endif
+	return 0;
+}
+
+static inline int __init doc2000_init(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+
+	this->write_byte = doc2000_write_byte;
+	this->read_byte = doc2000_read_byte;
+	this->write_buf = doc2000_writebuf;
+	this->read_buf = doc2000_readbuf;
+	this->verify_buf = doc2000_verifybuf;
+	this->scan_bbt = nftl_scan_bbt;
+
+	doc->CDSNControl = CDSN_CTRL_FLASH_IO | CDSN_CTRL_ECC_IO;
+	doc2000_count_chips(mtd);
+	mtd->name = "DiskOnChip 2000 (NFTL Model)";
+	return (4 * doc->chips_per_floor);
+}
+
+static inline int __init doc2001_init(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+
+	this->write_byte = doc2001_write_byte;
+	this->read_byte = doc2001_read_byte;
+	this->write_buf = doc2001_writebuf;
+	this->read_buf = doc2001_readbuf;
+	this->verify_buf = doc2001_verifybuf;
+
+	ReadDOC(doc->virtadr, ChipID);
+	ReadDOC(doc->virtadr, ChipID);
+	ReadDOC(doc->virtadr, ChipID);
+	if (ReadDOC(doc->virtadr, ChipID) != DOC_ChipID_DocMil) {
+		/* It's not a Millennium; it's one of the newer
+		   DiskOnChip 2000 units with a similar ASIC. 
+		   Treat it like a Millennium, except that it
+		   can have multiple chips. */
+		doc2000_count_chips(mtd);
+		mtd->name = "DiskOnChip 2000 (INFTL Model)";
+		this->scan_bbt = inftl_scan_bbt;
+		return (4 * doc->chips_per_floor);
+	} else {
+		/* Bog-standard Millennium */
+		doc->chips_per_floor = 1;
+		mtd->name = "DiskOnChip Millennium";
+		this->scan_bbt = nftl_scan_bbt;
+		return 1;
+	}
+}
+
+static inline int __init doc2001plus_init(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd->priv;
+	struct doc_priv *doc = this->priv;
+
+	this->write_byte = NULL;
+	this->read_byte = doc2001plus_read_byte;
+	this->write_buf = doc2001plus_writebuf;
+	this->read_buf = doc2001plus_readbuf;
+	this->verify_buf = doc2001plus_verifybuf;
+	this->scan_bbt = inftl_scan_bbt;
+	this->hwcontrol = NULL;
+	this->select_chip = doc2001plus_select_chip;
+	this->cmdfunc = doc2001plus_command;
+	this->enable_hwecc = doc2001plus_enable_hwecc;
+
+	doc->chips_per_floor = 1;
+	mtd->name = "DiskOnChip Millennium Plus";
+
+	return 1;
+}
+
+static inline int __init doc_probe(unsigned long physadr)
+{
+	unsigned char ChipID;
+	struct mtd_info *mtd;
+	struct nand_chip *nand;
+	struct doc_priv *doc;
+	void __iomem *virtadr;
+	unsigned char save_control;
+	unsigned char tmp, tmpb, tmpc;
+	int reg, len, numchips;
+	int ret = 0;
+
+	virtadr = ioremap(physadr, DOC_IOREMAP_LEN);
+	if (!virtadr) {
+		printk(KERN_ERR "Diskonchip ioremap failed: 0x%x bytes at 0x%lx\n", DOC_IOREMAP_LEN, physadr);
+		return -EIO;
+	}
+
+	/* It's not possible to cleanly detect the DiskOnChip - the
+	 * bootup procedure will put the device into reset mode, and
+	 * it's not possible to talk to it without actually writing
+	 * to the DOCControl register. So we store the current contents
+	 * of the DOCControl register's location, in case we later decide
+	 * that it's not a DiskOnChip, and want to put it back how we
+	 * found it. 
+	 */
+	save_control = ReadDOC(virtadr, DOCControl);
+
+	/* Reset the DiskOnChip ASIC */
+	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET, 
+		 virtadr, DOCControl);
+	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET, 
+		 virtadr, DOCControl);
+
+	/* Enable the DiskOnChip ASIC */
+	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL, 
+		 virtadr, DOCControl);
+	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL, 
+		 virtadr, DOCControl);
+
+	ChipID = ReadDOC(virtadr, ChipID);
+
+	switch(ChipID) {
+	case DOC_ChipID_Doc2k:
+		reg = DoC_2k_ECCStatus;
+		break;
+	case DOC_ChipID_DocMil:
+		reg = DoC_ECCConf;
+		break;
+	case DOC_ChipID_DocMilPlus16:
+	case DOC_ChipID_DocMilPlus32:
+	case 0:
+		/* Possible Millennium Plus, need to do more checks */
+		/* Possibly release from power down mode */
+		for (tmp = 0; (tmp < 4); tmp++)
+			ReadDOC(virtadr, Mplus_Power);
+
+		/* Reset the Millennium Plus ASIC */
+		tmp = DOC_MODE_RESET | DOC_MODE_MDWREN | DOC_MODE_RST_LAT |
+			DOC_MODE_BDECT;
+		WriteDOC(tmp, virtadr, Mplus_DOCControl);
+		WriteDOC(~tmp, virtadr, Mplus_CtrlConfirm);
+
+		mdelay(1);
+		/* Enable the Millennium Plus ASIC */
+		tmp = DOC_MODE_NORMAL | DOC_MODE_MDWREN | DOC_MODE_RST_LAT |
+			DOC_MODE_BDECT;
+		WriteDOC(tmp, virtadr, Mplus_DOCControl);
+		WriteDOC(~tmp, virtadr, Mplus_CtrlConfirm);
+		mdelay(1);
+
+		ChipID = ReadDOC(virtadr, ChipID);
+
+		switch (ChipID) {
+		case DOC_ChipID_DocMilPlus16:
+			reg = DoC_Mplus_Toggle;
+			break;
+		case DOC_ChipID_DocMilPlus32:
+			printk(KERN_ERR "DiskOnChip Millennium Plus 32MB is not supported, ignoring.\n");
+		default:
+			ret = -ENODEV;
+			goto notfound;
+		}
+		break;
+
+	default:
+		ret = -ENODEV;
+		goto notfound;
+	}
+	/* Check the TOGGLE bit in the ECC register */
+	tmp  = ReadDOC_(virtadr, reg) & DOC_TOGGLE_BIT;
+	tmpb = ReadDOC_(virtadr, reg) & DOC_TOGGLE_BIT;
+	tmpc = ReadDOC_(virtadr, reg) & DOC_TOGGLE_BIT;
+	if ((tmp == tmpb) || (tmp != tmpc)) {
+		printk(KERN_WARNING "Possible DiskOnChip at 0x%lx failed TOGGLE test, dropping.\n", physadr);
+		ret = -ENODEV;
+		goto notfound;
+	}
+
+	for (mtd = doclist; mtd; mtd = doc->nextdoc) {
+		unsigned char oldval;
+		unsigned char newval;
+		nand = mtd->priv;
+		doc = nand->priv;
+		/* Use the alias resolution register to determine if this is
+		   in fact the same DOC aliased to a new address.  If writes
+		   to one chip's alias resolution register change the value on
+		   the other chip, they're the same chip. */
+		if (ChipID == DOC_ChipID_DocMilPlus16) {
+			oldval = ReadDOC(doc->virtadr, Mplus_AliasResolution);
+			newval = ReadDOC(virtadr, Mplus_AliasResolution);
+		} else {
+			oldval = ReadDOC(doc->virtadr, AliasResolution);
+			newval = ReadDOC(virtadr, AliasResolution);
+		}
+		if (oldval != newval)
+			continue;
+		if (ChipID == DOC_ChipID_DocMilPlus16) {
+			WriteDOC(~newval, virtadr, Mplus_AliasResolution);
+			oldval = ReadDOC(doc->virtadr, Mplus_AliasResolution);
+			WriteDOC(newval, virtadr, Mplus_AliasResolution); // restore it
+		} else {
+			WriteDOC(~newval, virtadr, AliasResolution);
+			oldval = ReadDOC(doc->virtadr, AliasResolution);
+			WriteDOC(newval, virtadr, AliasResolution); // restore it
+		}
+		newval = ~newval;
+		if (oldval == newval) {
+			printk(KERN_DEBUG "Found alias of DOC at 0x%lx to 0x%lx\n", doc->physadr, physadr);
+			goto notfound;
+		}
+	}
+
+	printk(KERN_NOTICE "DiskOnChip found at 0x%lx\n", physadr);
+
+	len = sizeof(struct mtd_info) +
+	      sizeof(struct nand_chip) +
+	      sizeof(struct doc_priv) +
+	      (2 * sizeof(struct nand_bbt_descr));
+	mtd =  kmalloc(len, GFP_KERNEL);
+	if (!mtd) {
+		printk(KERN_ERR "DiskOnChip kmalloc (%d bytes) failed!\n", len);
+		ret = -ENOMEM;
+		goto fail;
+	}
+	memset(mtd, 0, len);
+
+	nand			= (struct nand_chip *) (mtd + 1);
+	doc			= (struct doc_priv *) (nand + 1);
+	nand->bbt_td		= (struct nand_bbt_descr *) (doc + 1);
+	nand->bbt_md		= nand->bbt_td + 1;
+
+	mtd->priv		= nand;
+	mtd->owner		= THIS_MODULE;
+
+	nand->priv		= doc;
+	nand->select_chip	= doc200x_select_chip;
+	nand->hwcontrol		= doc200x_hwcontrol;
+	nand->dev_ready		= doc200x_dev_ready;
+	nand->waitfunc		= doc200x_wait;
+	nand->block_bad		= doc200x_block_bad;
+	nand->enable_hwecc	= doc200x_enable_hwecc;
+	nand->calculate_ecc	= doc200x_calculate_ecc;
+	nand->correct_data	= doc200x_correct_data;
+
+	nand->autooob		= &doc200x_oobinfo;
+	nand->eccmode		= NAND_ECC_HW6_512;
+	nand->options		= NAND_USE_FLASH_BBT | NAND_HWECC_SYNDROME;
+
+	doc->physadr		= physadr;
+	doc->virtadr		= virtadr;
+	doc->ChipID		= ChipID;
+	doc->curfloor		= -1;
+	doc->curchip		= -1;
+	doc->mh0_page		= -1;
+	doc->mh1_page		= -1;
+	doc->nextdoc		= doclist;
+
+	if (ChipID == DOC_ChipID_Doc2k)
+		numchips = doc2000_init(mtd);
+	else if (ChipID == DOC_ChipID_DocMilPlus16)
+		numchips = doc2001plus_init(mtd);
+	else
+		numchips = doc2001_init(mtd);
+
+	if ((ret = nand_scan(mtd, numchips))) {
+		/* DBB note: i believe nand_release is necessary here, as
+		   buffers may have been allocated in nand_base.  Check with
+		   Thomas. FIX ME! */
+		/* nand_release will call del_mtd_device, but we haven't yet
+		   added it.  This is handled without incident by
+		   del_mtd_device, as far as I can tell. */
+		nand_release(mtd);
+		kfree(mtd);
+		goto fail;
+	}
+
+	/* Success! */
+	doclist = mtd;
+	return 0;
+
+notfound:
+	/* Put back the contents of the DOCControl register, in case it's not
+	   actually a DiskOnChip.  */
+	WriteDOC(save_control, virtadr, DOCControl);
+fail:
+	iounmap(virtadr);
+	return ret;
+}
+
+static void release_nanddoc(void)
+{
+ 	struct mtd_info *mtd, *nextmtd;
+	struct nand_chip *nand;
+	struct doc_priv *doc;
+
+	for (mtd = doclist; mtd; mtd = nextmtd) {
+		nand = mtd->priv;
+		doc = nand->priv;
+
+		nextmtd = doc->nextdoc;
+		nand_release(mtd);
+		iounmap(doc->virtadr);
+		kfree(mtd);
+	}
+}
+
+static int __init init_nanddoc(void)
+{
+	int i, ret = 0;
+
+	/* We could create the decoder on demand, if memory is a concern.
+	 * This way we have it handy, if an error happens 
+	 *
+	 * Symbolsize is 10 (bits)
+	 * Primitve polynomial is x^10+x^3+1
+	 * first consecutive root is 510
+	 * primitve element to generate roots = 1
+	 * generator polinomial degree = 4
+	 */
+	rs_decoder = init_rs(10, 0x409, FCR, 1, NROOTS);
+ 	if (!rs_decoder) {
+		printk (KERN_ERR "DiskOnChip: Could not create a RS decoder\n");
+		return -ENOMEM;
+	}
+
+	if (doc_config_location) {
+		printk(KERN_INFO "Using configured DiskOnChip probe address 0x%lx\n", doc_config_location);
+		ret = doc_probe(doc_config_location);
+		if (ret < 0)
+			goto outerr;
+	} else {
+		for (i=0; (doc_locations[i] != 0xffffffff); i++) {
+			doc_probe(doc_locations[i]);
+		}
+	}
+	/* No banner message any more. Print a message if no DiskOnChip
+	   found, so the user knows we at least tried. */
+	if (!doclist) {
+		printk(KERN_INFO "No valid DiskOnChip devices found\n");
+		ret = -ENODEV;
+		goto outerr;
+	}
+	return 0;
+outerr:
+	free_rs(rs_decoder);
+	return ret;
+}
+
+static void __exit cleanup_nanddoc(void)
+{
+	/* Cleanup the nand/DoC resources */
+	release_nanddoc();
+
+	/* Free the reed solomon resources */
+	if (rs_decoder) {
+		free_rs(rs_decoder);
+	}
+}
+
+module_init(init_nanddoc);
+module_exit(cleanup_nanddoc);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
+MODULE_DESCRIPTION("M-Systems DiskOnChip 2000, Millennium and Millennium Plus device driver\n");