text: /*
   * 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
   */
  
  #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 <linux/slab.h>
  #include <asm/io.h>
  
  #include <linux/mtd/mtd.h>
  #include <linux/mtd/nand.h>
  #include <linux/mtd/doc2000.h>
  #include <linux/mtd/partitions.h>
  #include <linux/mtd/inftl.h>
  
  /* Where to look for the devices? */
  #ifndef CONFIG_MTD_NAND_DISKONCHIP_PROBE_ADDRESS
  #define CONFIG_MTD_NAND_DISKONCHIP_PROBE_ADDRESS 0
  #endif
  
  static unsigned long __initdata doc_locations[] = {
  #if defined (__alpha__) || defined(__i386__) || defined(__x86_64__)
  #ifdef CONFIG_MTD_NAND_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 */
  #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;
  };
  
  /* 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,
  			      unsigned int bitmask);
  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);
  
  static int no_autopart = 0;
  module_param(no_autopart, int, 0);
  
  static int show_firmware_partition = 0;
  module_param(show_firmware_partition, int, 0);
  
  #ifdef CONFIG_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_NAND_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];
  
  	memset(syn, 0, sizeof(syn));
  	/* 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 syn[i] = s[i] / alpha^(v + i) */
  	for (i = 0; i < NROOTS; i++) {
  		if (s[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 ? -EBADMSG : 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_CMD_READID,
  			  NAND_CTRL_CLE | NAND_CTRL_CHANGE);
  	doc200x_hwcontrol(mtd, 0, NAND_CTRL_ALE | NAND_CTRL_CHANGE);
  	doc200x_hwcontrol(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
  
  	/* We cant' use dev_ready here, but at least we wait for the
  	 * command to complete
  	 */
  	udelay(50);
  
  	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_CMD_READID,
  				  NAND_CTRL_CLE | NAND_CTRL_CHANGE);
  		doc200x_hwcontrol(mtd, 0, NAND_CTRL_ALE | NAND_CTRL_CHANGE);
  		doc200x_hwcontrol(mtd, NAND_CMD_NONE,
  				  NAND_NCE | NAND_CTRL_CHANGE);
  
  		udelay(50);
  
  		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)
  {
  	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_CMD_NONE, 0 | NAND_CTRL_CHANGE);
  
  	WriteDOC(floor, docptr, FloorSelect);
  	WriteDOC(chip, docptr, CDSNDeviceSelect);
  
  	doc200x_hwcontrol(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
  
  	doc->curchip = chip;
  	doc->curfloor = floor;
  }
  
  #define CDSN_CTRL_MSK (CDSN_CTRL_CE | CDSN_CTRL_CLE | CDSN_CTRL_ALE)
  
  static void doc200x_hwcontrol(struct mtd_info *mtd, int cmd,
  			      unsigned int ctrl)
  {
  	struct nand_chip *this = mtd->priv;
  	struct doc_priv *doc = this->priv;
  	void __iomem *docptr = doc->virtadr;
  
  	if (ctrl & NAND_CTRL_CHANGE) {
  		doc->CDSNControl &= ~CDSN_CTRL_MSK;
  		doc->CDSNControl |= ctrl & CDSN_CTRL_MSK;
  		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);
  	}
  	if (cmd != NAND_CMD_NONE) {
  		if (DoC_is_2000(doc))
  			doc2000_write_byte(mtd, cmd);
  		else
  			doc2001_write_byte(mtd, cmd);
  	}
  }
  
  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->writesize) {
  			/* OOB area */
  			column -= mtd->writesize;
  			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 *isnull)
  {
  	int i, ret = 0;
  	struct nand_chip *this = mtd->priv;
  	struct doc_priv *doc = this->priv;
  	void __iomem *docptr = doc->virtadr;
  	uint8_t calc_ecc[6];
  	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 == -EBADMSG)) {
  		printk(KERN_ERR "suppressing ECC failure\n");
  		ret = 0;
  	}
  	return ret;
  }
  
  //u_char mydatabuf[528];
  
  /* The strange out-of-order .oobfree list below is a (possibly unneeded)
   * attempt to retain compatibility.  It used to read:
   * 	.oobfree = { {8, 8} }
   * Since that leaves two bytes unusable, it was changed.  But the following
   * scheme might affect existing jffs2 installs by moving the cleanmarker:
   * 	.oobfree = { {6, 10} }
   * jffs2 seems to handle the above gracefully, but the current scheme seems
   * safer.  The only problem with it is that any code that parses oobfree must
   * be able to handle out-of-order segments.
   */
  static struct nand_ecclayout doc200x_oobinfo = {
  	.eccbytes = 6,
  	.eccpos = {0, 1, 2, 3, 4, 5},
  	.oobfree = {{8, 8}, {6, 2}}
  };
  
  /* Find the (I)NFTL Media Header, and optionally also the mirror media header.
     On successful 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;
  	int ret;
  	size_t retlen;
  
  	for (offs = 0; offs < mtd->size; offs += mtd->erasesize) {
  		ret = mtd->read(mtd, offs, mtd->writesize, &retlen, buf);
  		if (retlen != mtd->writesize)
  			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->writesize, &retlen, buf);
  	if (retlen != mtd->writesize) {
  		/* 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;
  	int numparts = 0;
  	unsigned blocks, maxblocks;
  	int offs, numheaders;
  
  	buf = kmalloc(mtd->writesize, 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;
  
  	le16_to_cpus(&mh->NumEraseUnits);
  	le16_to_cpus(&mh->FirstPhysicalEUN);
  	le32_to_cpus(&mh->FormattedSize);
  
  	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);
  
  	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;
  
  	if (show_firmware_partition == 1) {
  		parts[0].name = " DiskOnChip Firmware / Media Header partition";
  		parts[0].offset = 0;
  		parts[0].size = offs;
  		numparts = 1;
  	}
  
  	parts[numparts].name = " DiskOnChip BDTL partition";
  	parts[numparts].offset = offs;
  	parts[numparts].size = (mh->NumEraseUnits - numheaders) << this->bbt_erase_shift;
  
  	offs += parts[numparts].size;
  	numparts++;
  
  	if (offs < mtd->size) {
  		parts[numparts].name = " DiskOnChip Remainder partition";
  		parts[numparts].offset = offs;
  		parts[numparts].size = mtd->size - offs;
  		numparts++;
  	}
  
  	ret = numparts;
   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->writesize, 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;
  
  	le32_to_cpus(&mh->NoOfBootImageBlocks);
  	le32_to_cpus(&mh->NoOfBinaryPartitions);
  	le32_to_cpus(&mh->NoOfBDTLPartitions);
  	le32_to_cpus(&mh->BlockMultiplierBits);
  	le32_to_cpus(&mh->FormatFlags);
  	le32_to_cpus(&mh->PercentUsed);
  
  	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);
  
  	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]);
  		le32_to_cpus(&ip->virtualUnits);
  		le32_to_cpus(&ip->firstUnit);
  		le32_to_cpus(&ip->lastUnit);
  		le32_to_cpus(&ip->flags);
  		le32_to_cpus(&ip->spareUnits);
  		le32_to_cpus(&ip->Reserved0);
  
  		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);
  
  		if ((show_firmware_partition == 1) &&
  		    (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->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->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->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->cmd_ctrl = NULL;
  	this->select_chip = doc2001plus_select_chip;
  	this->cmdfunc = doc2001plus_command;
  	this->ecc.hwctl = doc2001plus_enable_hwecc;
  
  	doc->chips_per_floor = 1;
  	mtd->name = "DiskOnChip Millennium Plus";
  
  	return 1;
  }
  
  static 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 = kzalloc(len, GFP_KERNEL);
  	if (!mtd) {
  		printk(KERN_ERR "DiskOnChip kmalloc (%d bytes) failed!\n", len);
  		ret = -ENOMEM;
  		goto fail;
  	}
  
  	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->cmd_ctrl		= doc200x_hwcontrol;
  	nand->dev_ready		= doc200x_dev_ready;
  	nand->waitfunc		= doc200x_wait;
  	nand->block_bad		= doc200x_block_bad;
  	nand->ecc.hwctl		= doc200x_enable_hwecc;
  	nand->ecc.calculate	= doc200x_calculate_ecc;
  	nand->ecc.correct	= doc200x_correct_data;
  
  	nand->ecc.layout	= &doc200x_oobinfo;
  	nand->ecc.mode		= NAND_ECC_HW_SYNDROME;
  	nand->ecc.size		= 512;
  	nand->ecc.bytes		= 6;
  	nand->options		= NAND_USE_FLASH_BBT;
  
  	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");
  