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diskonchip.c

/*
 * 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 1.55 2005/11/07 11:14:30 gleixner 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_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 */
#elif defined(__PPC__)
      0xe4000000,
#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];

      /* 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 ? -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 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;
      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;

      mh->NumEraseUnits = le16_to_cpu(mh->NumEraseUnits);
      mh->FirstPhysicalEUN = le16_to_cpu(mh->FirstPhysicalEUN);
      mh->FormattedSize = le32_to_cpu(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;

      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);

      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]);
            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);

            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\n");

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