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onenand_base.c

/*
 *  linux/drivers/mtd/onenand/onenand_base.c
 *
 *  Copyright (C) 2005-2007 Samsung Electronics
 *  Kyungmin Park <kyungmin.park@samsung.com>
 *
 *  Credits:
 *    Adrian Hunter <ext-adrian.hunter@nokia.com>:
 *    auto-placement support, read-while load support, various fixes
 *    Copyright (C) Nokia Corporation, 2007
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/onenand.h>
#include <linux/mtd/partitions.h>

#include <asm/io.h>

/**
 * onenand_oob_64 - oob info for large (2KB) page
 */
static struct nand_ecclayout onenand_oob_64 = {
      .eccbytes   = 20,
      .eccpos           = {
            8, 9, 10, 11, 12,
            24, 25, 26, 27, 28,
            40, 41, 42, 43, 44,
            56, 57, 58, 59, 60,
            },
      .oobfree    = {
            {2, 3}, {14, 2}, {18, 3}, {30, 2},
            {34, 3}, {46, 2}, {50, 3}, {62, 2}
      }
};

/**
 * onenand_oob_32 - oob info for middle (1KB) page
 */
static struct nand_ecclayout onenand_oob_32 = {
      .eccbytes   = 10,
      .eccpos           = {
            8, 9, 10, 11, 12,
            24, 25, 26, 27, 28,
            },
      .oobfree    = { {2, 3}, {14, 2}, {18, 3}, {30, 2} }
};

static const unsigned char ffchars[] = {
      0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
      0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 16 */
      0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
      0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 32 */
      0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
      0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 48 */
      0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
      0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 64 */
};

/**
 * onenand_readw - [OneNAND Interface] Read OneNAND register
 * @param addr          address to read
 *
 * Read OneNAND register
 */
static unsigned short onenand_readw(void __iomem *addr)
{
      return readw(addr);
}

/**
 * onenand_writew - [OneNAND Interface] Write OneNAND register with value
 * @param value         value to write
 * @param addr          address to write
 *
 * Write OneNAND register with value
 */
static void onenand_writew(unsigned short value, void __iomem *addr)
{
      writew(value, addr);
}

/**
 * onenand_block_address - [DEFAULT] Get block address
 * @param this          onenand chip data structure
 * @param block         the block
 * @return        translated block address if DDP, otherwise same
 *
 * Setup Start Address 1 Register (F100h)
 */
static int onenand_block_address(struct onenand_chip *this, int block)
{
      /* Device Flash Core select, NAND Flash Block Address */
      if (block & this->density_mask)
            return ONENAND_DDP_CHIP1 | (block ^ this->density_mask);

      return block;
}

/**
 * onenand_bufferram_address - [DEFAULT] Get bufferram address
 * @param this          onenand chip data structure
 * @param block         the block
 * @return        set DBS value if DDP, otherwise 0
 *
 * Setup Start Address 2 Register (F101h) for DDP
 */
static int onenand_bufferram_address(struct onenand_chip *this, int block)
{
      /* Device BufferRAM Select */
      if (block & this->density_mask)
            return ONENAND_DDP_CHIP1;

      return ONENAND_DDP_CHIP0;
}

/**
 * onenand_page_address - [DEFAULT] Get page address
 * @param page          the page address
 * @param sector  the sector address
 * @return        combined page and sector address
 *
 * Setup Start Address 8 Register (F107h)
 */
static int onenand_page_address(int page, int sector)
{
      /* Flash Page Address, Flash Sector Address */
      int fpa, fsa;

      fpa = page & ONENAND_FPA_MASK;
      fsa = sector & ONENAND_FSA_MASK;

      return ((fpa << ONENAND_FPA_SHIFT) | fsa);
}

/**
 * onenand_buffer_address - [DEFAULT] Get buffer address
 * @param dataram1      DataRAM index
 * @param sectors the sector address
 * @param count         the number of sectors
 * @return        the start buffer value
 *
 * Setup Start Buffer Register (F200h)
 */
static int onenand_buffer_address(int dataram1, int sectors, int count)
{
      int bsa, bsc;

      /* BufferRAM Sector Address */
      bsa = sectors & ONENAND_BSA_MASK;

      if (dataram1)
            bsa |= ONENAND_BSA_DATARAM1;  /* DataRAM1 */
      else
            bsa |= ONENAND_BSA_DATARAM0;  /* DataRAM0 */

      /* BufferRAM Sector Count */
      bsc = count & ONENAND_BSC_MASK;

      return ((bsa << ONENAND_BSA_SHIFT) | bsc);
}

/**
 * onenand_command - [DEFAULT] Send command to OneNAND device
 * @param mtd           MTD device structure
 * @param cmd           the command to be sent
 * @param addr          offset to read from or write to
 * @param len           number of bytes to read or write
 *
 * Send command to OneNAND device. This function is used for middle/large page
 * devices (1KB/2KB Bytes per page)
 */
static int onenand_command(struct mtd_info *mtd, int cmd, loff_t addr, size_t len)
{
      struct onenand_chip *this = mtd->priv;
      int value, readcmd = 0, block_cmd = 0;
      int block, page;

      /* Address translation */
      switch (cmd) {
      case ONENAND_CMD_UNLOCK:
      case ONENAND_CMD_LOCK:
      case ONENAND_CMD_LOCK_TIGHT:
      case ONENAND_CMD_UNLOCK_ALL:
            block = -1;
            page = -1;
            break;

      case ONENAND_CMD_ERASE:
      case ONENAND_CMD_BUFFERRAM:
      case ONENAND_CMD_OTP_ACCESS:
            block_cmd = 1;
            block = (int) (addr >> this->erase_shift);
            page = -1;
            break;

      default:
            block = (int) (addr >> this->erase_shift);
            page = (int) (addr >> this->page_shift);

            if (ONENAND_IS_2PLANE(this)) {
                  /* Make the even block number */
                  block &= ~1;
                  /* Is it the odd plane? */
                  if (addr & this->writesize)
                        block++;
                  page >>= 1;
            }
            page &= this->page_mask;
            break;
      }

      /* NOTE: The setting order of the registers is very important! */
      if (cmd == ONENAND_CMD_BUFFERRAM) {
            /* Select DataRAM for DDP */
            value = onenand_bufferram_address(this, block);
            this->write_word(value, this->base + ONENAND_REG_START_ADDRESS2);

            if (ONENAND_IS_2PLANE(this))
                  /* It is always BufferRAM0 */
                  ONENAND_SET_BUFFERRAM0(this);
            else
                  /* Switch to the next data buffer */
                  ONENAND_SET_NEXT_BUFFERRAM(this);

            return 0;
      }

      if (block != -1) {
            /* Write 'DFS, FBA' of Flash */
            value = onenand_block_address(this, block);
            this->write_word(value, this->base + ONENAND_REG_START_ADDRESS1);

            if (block_cmd) {
                  /* Select DataRAM for DDP */
                  value = onenand_bufferram_address(this, block);
                  this->write_word(value, this->base + ONENAND_REG_START_ADDRESS2);
            }
      }

      if (page != -1) {
            /* Now we use page size operation */
            int sectors = 4, count = 4;
            int dataram;

            switch (cmd) {
            case ONENAND_CMD_READ:
            case ONENAND_CMD_READOOB:
                  dataram = ONENAND_SET_NEXT_BUFFERRAM(this);
                  readcmd = 1;
                  break;

            default:
                  if (ONENAND_IS_2PLANE(this) && cmd == ONENAND_CMD_PROG)
                        cmd = ONENAND_CMD_2X_PROG;
                  dataram = ONENAND_CURRENT_BUFFERRAM(this);
                  break;
            }

            /* Write 'FPA, FSA' of Flash */
            value = onenand_page_address(page, sectors);
            this->write_word(value, this->base + ONENAND_REG_START_ADDRESS8);

            /* Write 'BSA, BSC' of DataRAM */
            value = onenand_buffer_address(dataram, sectors, count);
            this->write_word(value, this->base + ONENAND_REG_START_BUFFER);

            if (readcmd) {
                  /* Select DataRAM for DDP */
                  value = onenand_bufferram_address(this, block);
                  this->write_word(value, this->base + ONENAND_REG_START_ADDRESS2);
            }
      }

      /* Interrupt clear */
      this->write_word(ONENAND_INT_CLEAR, this->base + ONENAND_REG_INTERRUPT);

      /* Write command */
      this->write_word(cmd, this->base + ONENAND_REG_COMMAND);

      return 0;
}

/**
 * onenand_wait - [DEFAULT] wait until the command is done
 * @param mtd           MTD device structure
 * @param state         state to select the max. timeout value
 *
 * Wait for command done. This applies to all OneNAND command
 * Read can take up to 30us, erase up to 2ms and program up to 350us
 * according to general OneNAND specs
 */
static int onenand_wait(struct mtd_info *mtd, int state)
{
      struct onenand_chip * this = mtd->priv;
      unsigned long timeout;
      unsigned int flags = ONENAND_INT_MASTER;
      unsigned int interrupt = 0;
      unsigned int ctrl;

      /* The 20 msec is enough */
      timeout = jiffies + msecs_to_jiffies(20);
      while (time_before(jiffies, timeout)) {
            interrupt = this->read_word(this->base + ONENAND_REG_INTERRUPT);

            if (interrupt & flags)
                  break;

            if (state != FL_READING)
                  cond_resched();
      }
      /* To get correct interrupt status in timeout case */
      interrupt = this->read_word(this->base + ONENAND_REG_INTERRUPT);

      ctrl = this->read_word(this->base + ONENAND_REG_CTRL_STATUS);

      if (ctrl & ONENAND_CTRL_ERROR) {
            printk(KERN_ERR "onenand_wait: controller error = 0x%04x\n", ctrl);
            if (ctrl & ONENAND_CTRL_LOCK)
                  printk(KERN_ERR "onenand_wait: it's locked error.\n");
            return -EIO;
      }

      if (interrupt & ONENAND_INT_READ) {
            int ecc = this->read_word(this->base + ONENAND_REG_ECC_STATUS);
            if (ecc) {
                  if (ecc & ONENAND_ECC_2BIT_ALL) {
                        printk(KERN_ERR "onenand_wait: ECC error = 0x%04x\n", ecc);
                        mtd->ecc_stats.failed++;
                        return -EBADMSG;
                  } else if (ecc & ONENAND_ECC_1BIT_ALL) {
                        printk(KERN_INFO "onenand_wait: correctable ECC error = 0x%04x\n", ecc);
                        mtd->ecc_stats.corrected++;
                  }
            }
      } else if (state == FL_READING) {
            printk(KERN_ERR "onenand_wait: read timeout! ctrl=0x%04x intr=0x%04x\n", ctrl, interrupt);
            return -EIO;
      }

      return 0;
}

/*
 * onenand_interrupt - [DEFAULT] onenand interrupt handler
 * @param irq           onenand interrupt number
 * @param dev_id  interrupt data
 *
 * complete the work
 */
static irqreturn_t onenand_interrupt(int irq, void *data)
{
      struct onenand_chip *this = data;

      /* To handle shared interrupt */
      if (!this->complete.done)
            complete(&this->complete);

      return IRQ_HANDLED;
}

/*
 * onenand_interrupt_wait - [DEFAULT] wait until the command is done
 * @param mtd           MTD device structure
 * @param state         state to select the max. timeout value
 *
 * Wait for command done.
 */
static int onenand_interrupt_wait(struct mtd_info *mtd, int state)
{
      struct onenand_chip *this = mtd->priv;

      wait_for_completion(&this->complete);

      return onenand_wait(mtd, state);
}

/*
 * onenand_try_interrupt_wait - [DEFAULT] try interrupt wait
 * @param mtd           MTD device structure
 * @param state         state to select the max. timeout value
 *
 * Try interrupt based wait (It is used one-time)
 */
static int onenand_try_interrupt_wait(struct mtd_info *mtd, int state)
{
      struct onenand_chip *this = mtd->priv;
      unsigned long remain, timeout;

      /* We use interrupt wait first */
      this->wait = onenand_interrupt_wait;

      timeout = msecs_to_jiffies(100);
      remain = wait_for_completion_timeout(&this->complete, timeout);
      if (!remain) {
            printk(KERN_INFO "OneNAND: There's no interrupt. "
                        "We use the normal wait\n");

            /* Release the irq */
            free_irq(this->irq, this);

            this->wait = onenand_wait;
      }

      return onenand_wait(mtd, state);
}

/*
 * onenand_setup_wait - [OneNAND Interface] setup onenand wait method
 * @param mtd           MTD device structure
 *
 * There's two method to wait onenand work
 * 1. polling - read interrupt status register
 * 2. interrupt - use the kernel interrupt method
 */
static void onenand_setup_wait(struct mtd_info *mtd)
{
      struct onenand_chip *this = mtd->priv;
      int syscfg;

      init_completion(&this->complete);

      if (this->irq <= 0) {
            this->wait = onenand_wait;
            return;
      }

      if (request_irq(this->irq, &onenand_interrupt,
                        IRQF_SHARED, "onenand", this)) {
            /* If we can't get irq, use the normal wait */
            this->wait = onenand_wait;
            return;
      }

      /* Enable interrupt */
      syscfg = this->read_word(this->base + ONENAND_REG_SYS_CFG1);
      syscfg |= ONENAND_SYS_CFG1_IOBE;
      this->write_word(syscfg, this->base + ONENAND_REG_SYS_CFG1);

      this->wait = onenand_try_interrupt_wait;
}

/**
 * onenand_bufferram_offset - [DEFAULT] BufferRAM offset
 * @param mtd           MTD data structure
 * @param area          BufferRAM area
 * @return        offset given area
 *
 * Return BufferRAM offset given area
 */
static inline int onenand_bufferram_offset(struct mtd_info *mtd, int area)
{
      struct onenand_chip *this = mtd->priv;

      if (ONENAND_CURRENT_BUFFERRAM(this)) {
            /* Note: the 'this->writesize' is a real page size */
            if (area == ONENAND_DATARAM)
                  return this->writesize;
            if (area == ONENAND_SPARERAM)
                  return mtd->oobsize;
      }

      return 0;
}

/**
 * onenand_read_bufferram - [OneNAND Interface] Read the bufferram area
 * @param mtd           MTD data structure
 * @param area          BufferRAM area
 * @param buffer  the databuffer to put/get data
 * @param offset  offset to read from or write to
 * @param count         number of bytes to read/write
 *
 * Read the BufferRAM area
 */
static int onenand_read_bufferram(struct mtd_info *mtd, int area,
            unsigned char *buffer, int offset, size_t count)
{
      struct onenand_chip *this = mtd->priv;
      void __iomem *bufferram;

      bufferram = this->base + area;

      bufferram += onenand_bufferram_offset(mtd, area);

      if (ONENAND_CHECK_BYTE_ACCESS(count)) {
            unsigned short word;

            /* Align with word(16-bit) size */
            count--;

            /* Read word and save byte */
            word = this->read_word(bufferram + offset + count);
            buffer[count] = (word & 0xff);
      }

      memcpy(buffer, bufferram + offset, count);

      return 0;
}

/**
 * onenand_sync_read_bufferram - [OneNAND Interface] Read the bufferram area with Sync. Burst mode
 * @param mtd           MTD data structure
 * @param area          BufferRAM area
 * @param buffer  the databuffer to put/get data
 * @param offset  offset to read from or write to
 * @param count         number of bytes to read/write
 *
 * Read the BufferRAM area with Sync. Burst Mode
 */
static int onenand_sync_read_bufferram(struct mtd_info *mtd, int area,
            unsigned char *buffer, int offset, size_t count)
{
      struct onenand_chip *this = mtd->priv;
      void __iomem *bufferram;

      bufferram = this->base + area;

      bufferram += onenand_bufferram_offset(mtd, area);

      this->mmcontrol(mtd, ONENAND_SYS_CFG1_SYNC_READ);

      if (ONENAND_CHECK_BYTE_ACCESS(count)) {
            unsigned short word;

            /* Align with word(16-bit) size */
            count--;

            /* Read word and save byte */
            word = this->read_word(bufferram + offset + count);
            buffer[count] = (word & 0xff);
      }

      memcpy(buffer, bufferram + offset, count);

      this->mmcontrol(mtd, 0);

      return 0;
}

/**
 * onenand_write_bufferram - [OneNAND Interface] Write the bufferram area
 * @param mtd           MTD data structure
 * @param area          BufferRAM area
 * @param buffer  the databuffer to put/get data
 * @param offset  offset to read from or write to
 * @param count         number of bytes to read/write
 *
 * Write the BufferRAM area
 */
static int onenand_write_bufferram(struct mtd_info *mtd, int area,
            const unsigned char *buffer, int offset, size_t count)
{
      struct onenand_chip *this = mtd->priv;
      void __iomem *bufferram;

      bufferram = this->base + area;

      bufferram += onenand_bufferram_offset(mtd, area);

      if (ONENAND_CHECK_BYTE_ACCESS(count)) {
            unsigned short word;
            int byte_offset;

            /* Align with word(16-bit) size */
            count--;

            /* Calculate byte access offset */
            byte_offset = offset + count;

            /* Read word and save byte */
            word = this->read_word(bufferram + byte_offset);
            word = (word & ~0xff) | buffer[count];
            this->write_word(word, bufferram + byte_offset);
      }

      memcpy(bufferram + offset, buffer, count);

      return 0;
}

/**
 * onenand_get_2x_blockpage - [GENERIC] Get blockpage at 2x program mode
 * @param mtd           MTD data structure
 * @param addr          address to check
 * @return        blockpage address
 *
 * Get blockpage address at 2x program mode
 */
static int onenand_get_2x_blockpage(struct mtd_info *mtd, loff_t addr)
{
      struct onenand_chip *this = mtd->priv;
      int blockpage, block, page;

      /* Calculate the even block number */
      block = (int) (addr >> this->erase_shift) & ~1;
      /* Is it the odd plane? */
      if (addr & this->writesize)
            block++;
      page = (int) (addr >> (this->page_shift + 1)) & this->page_mask;
      blockpage = (block << 7) | page;

      return blockpage;
}

/**
 * onenand_check_bufferram - [GENERIC] Check BufferRAM information
 * @param mtd           MTD data structure
 * @param addr          address to check
 * @return        1 if there are valid data, otherwise 0
 *
 * Check bufferram if there is data we required
 */
static int onenand_check_bufferram(struct mtd_info *mtd, loff_t addr)
{
      struct onenand_chip *this = mtd->priv;
      int blockpage, found = 0;
      unsigned int i;

      if (ONENAND_IS_2PLANE(this))
            blockpage = onenand_get_2x_blockpage(mtd, addr);
      else
            blockpage = (int) (addr >> this->page_shift);

      /* Is there valid data? */
      i = ONENAND_CURRENT_BUFFERRAM(this);
      if (this->bufferram[i].blockpage == blockpage)
            found = 1;
      else {
            /* Check another BufferRAM */
            i = ONENAND_NEXT_BUFFERRAM(this);
            if (this->bufferram[i].blockpage == blockpage) {
                  ONENAND_SET_NEXT_BUFFERRAM(this);
                  found = 1;
            }
      }

      if (found && ONENAND_IS_DDP(this)) {
            /* Select DataRAM for DDP */
            int block = (int) (addr >> this->erase_shift);
            int value = onenand_bufferram_address(this, block);
            this->write_word(value, this->base + ONENAND_REG_START_ADDRESS2);
      }

      return found;
}

/**
 * onenand_update_bufferram - [GENERIC] Update BufferRAM information
 * @param mtd           MTD data structure
 * @param addr          address to update
 * @param valid         valid flag
 *
 * Update BufferRAM information
 */
static void onenand_update_bufferram(struct mtd_info *mtd, loff_t addr,
            int valid)
{
      struct onenand_chip *this = mtd->priv;
      int blockpage;
      unsigned int i;

      if (ONENAND_IS_2PLANE(this))
            blockpage = onenand_get_2x_blockpage(mtd, addr);
      else
            blockpage = (int) (addr >> this->page_shift);

      /* Invalidate another BufferRAM */
      i = ONENAND_NEXT_BUFFERRAM(this);
      if (this->bufferram[i].blockpage == blockpage)
            this->bufferram[i].blockpage = -1;

      /* Update BufferRAM */
      i = ONENAND_CURRENT_BUFFERRAM(this);
      if (valid)
            this->bufferram[i].blockpage = blockpage;
      else
            this->bufferram[i].blockpage = -1;
}

/**
 * onenand_invalidate_bufferram - [GENERIC] Invalidate BufferRAM information
 * @param mtd           MTD data structure
 * @param addr          start address to invalidate
 * @param len           length to invalidate
 *
 * Invalidate BufferRAM information
 */
static void onenand_invalidate_bufferram(struct mtd_info *mtd, loff_t addr,
            unsigned int len)
{
      struct onenand_chip *this = mtd->priv;
      int i;
      loff_t end_addr = addr + len;

      /* Invalidate BufferRAM */
      for (i = 0; i < MAX_BUFFERRAM; i++) {
            loff_t buf_addr = this->bufferram[i].blockpage << this->page_shift;
            if (buf_addr >= addr && buf_addr < end_addr)
                  this->bufferram[i].blockpage = -1;
      }
}

/**
 * onenand_get_device - [GENERIC] Get chip for selected access
 * @param mtd           MTD device structure
 * @param new_state     the state which is requested
 *
 * Get the device and lock it for exclusive access
 */
static int onenand_get_device(struct mtd_info *mtd, int new_state)
{
      struct onenand_chip *this = mtd->priv;
      DECLARE_WAITQUEUE(wait, current);

      /*
       * Grab the lock and see if the device is available
       */
      while (1) {
            spin_lock(&this->chip_lock);
            if (this->state == FL_READY) {
                  this->state = new_state;
                  spin_unlock(&this->chip_lock);
                  break;
            }
            if (new_state == FL_PM_SUSPENDED) {
                  spin_unlock(&this->chip_lock);
                  return (this->state == FL_PM_SUSPENDED) ? 0 : -EAGAIN;
            }
            set_current_state(TASK_UNINTERRUPTIBLE);
            add_wait_queue(&this->wq, &wait);
            spin_unlock(&this->chip_lock);
            schedule();
            remove_wait_queue(&this->wq, &wait);
      }

      return 0;
}

/**
 * onenand_release_device - [GENERIC] release chip
 * @param mtd           MTD device structure
 *
 * Deselect, release chip lock and wake up anyone waiting on the device
 */
static void onenand_release_device(struct mtd_info *mtd)
{
      struct onenand_chip *this = mtd->priv;

      /* Release the chip */
      spin_lock(&this->chip_lock);
      this->state = FL_READY;
      wake_up(&this->wq);
      spin_unlock(&this->chip_lock);
}

/**
 * onenand_transfer_auto_oob - [Internal] oob auto-placement transfer
 * @param mtd           MTD device structure
 * @param buf           destination address
 * @param column  oob offset to read from
 * @param thislen oob length to read
 */
static int onenand_transfer_auto_oob(struct mtd_info *mtd, uint8_t *buf, int column,
                        int thislen)
{
      struct onenand_chip *this = mtd->priv;
      struct nand_oobfree *free;
      int readcol = column;
      int readend = column + thislen;
      int lastgap = 0;
      unsigned int i;
      uint8_t *oob_buf = this->oob_buf;

      free = this->ecclayout->oobfree;
      for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES && free->length; i++, free++) {
            if (readcol >= lastgap)
                  readcol += free->offset - lastgap;
            if (readend >= lastgap)
                  readend += free->offset - lastgap;
            lastgap = free->offset + free->length;
      }
      this->read_bufferram(mtd, ONENAND_SPARERAM, oob_buf, 0, mtd->oobsize);
      free = this->ecclayout->oobfree;
      for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES && free->length; i++, free++) {
            int free_end = free->offset + free->length;
            if (free->offset < readend && free_end > readcol) {
                  int st = max_t(int,free->offset,readcol);
                  int ed = min_t(int,free_end,readend);
                  int n = ed - st;
                  memcpy(buf, oob_buf + st, n);
                  buf += n;
            } else if (column == 0)
                  break;
      }
      return 0;
}

/**
 * onenand_read_ops_nolock - [OneNAND Interface] OneNAND read main and/or out-of-band
 * @param mtd           MTD device structure
 * @param from          offset to read from
 * @param ops:          oob operation description structure
 *
 * OneNAND read main and/or out-of-band data
 */
static int onenand_read_ops_nolock(struct mtd_info *mtd, loff_t from,
                        struct mtd_oob_ops *ops)
{
      struct onenand_chip *this = mtd->priv;
      struct mtd_ecc_stats stats;
      size_t len = ops->len;
      size_t ooblen = ops->ooblen;
      u_char *buf = ops->datbuf;
      u_char *oobbuf = ops->oobbuf;
      int read = 0, column, thislen;
      int oobread = 0, oobcolumn, thisooblen, oobsize;
      int ret = 0, boundary = 0;
      int writesize = this->writesize;

      DEBUG(MTD_DEBUG_LEVEL3, "onenand_read_ops_nolock: from = 0x%08x, len = %i\n", (unsigned int) from, (int) len);

      if (ops->mode == MTD_OOB_AUTO)
            oobsize = this->ecclayout->oobavail;
      else
            oobsize = mtd->oobsize;

      oobcolumn = from & (mtd->oobsize - 1);

      /* Do not allow reads past end of device */
      if ((from + len) > mtd->size) {
            printk(KERN_ERR "onenand_read_ops_nolock: Attempt read beyond end of device\n");
            ops->retlen = 0;
            ops->oobretlen = 0;
            return -EINVAL;
      }

      stats = mtd->ecc_stats;

      /* Read-while-load method */

      /* Do first load to bufferRAM */
      if (read < len) {
            if (!onenand_check_bufferram(mtd, from)) {
                  this->command(mtd, ONENAND_CMD_READ, from, writesize);
                  ret = this->wait(mtd, FL_READING);
                  onenand_update_bufferram(mtd, from, !ret);
            }
      }

      thislen = min_t(int, writesize, len - read);
      column = from & (writesize - 1);
      if (column + thislen > writesize)
            thislen = writesize - column;

      while (!ret) {
            /* If there is more to load then start next load */
            from += thislen;
            if (read + thislen < len) {
                  this->command(mtd, ONENAND_CMD_READ, from, writesize);
                  /*
                   * Chip boundary handling in DDP
                   * Now we issued chip 1 read and pointed chip 1
                   * bufferam so we have to point chip 0 bufferam.
                   */
                  if (ONENAND_IS_DDP(this) &&
                      unlikely(from == (this->chipsize >> 1))) {
                        this->write_word(ONENAND_DDP_CHIP0, this->base + ONENAND_REG_START_ADDRESS2);
                        boundary = 1;
                  } else
                        boundary = 0;
                  ONENAND_SET_PREV_BUFFERRAM(this);
            }
            /* While load is going, read from last bufferRAM */
            this->read_bufferram(mtd, ONENAND_DATARAM, buf, column, thislen);

            /* Read oob area if needed */
            if (oobbuf) {
                  thisooblen = oobsize - oobcolumn;
                  thisooblen = min_t(int, thisooblen, ooblen - oobread);

                  if (ops->mode == MTD_OOB_AUTO)
                        onenand_transfer_auto_oob(mtd, oobbuf, oobcolumn, thisooblen);
                  else
                        this->read_bufferram(mtd, ONENAND_SPARERAM, oobbuf, oobcolumn, thisooblen);
                  oobread += thisooblen;
                  oobbuf += thisooblen;
                  oobcolumn = 0;
            }

            /* See if we are done */
            read += thislen;
            if (read == len)
                  break;
            /* Set up for next read from bufferRAM */
            if (unlikely(boundary))
                  this->write_word(ONENAND_DDP_CHIP1, this->base + ONENAND_REG_START_ADDRESS2);
            ONENAND_SET_NEXT_BUFFERRAM(this);
            buf += thislen;
            thislen = min_t(int, writesize, len - read);
            column = 0;
            cond_resched();
            /* Now wait for load */
            ret = this->wait(mtd, FL_READING);
            onenand_update_bufferram(mtd, from, !ret);
      }

      /*
       * Return success, if no ECC failures, else -EBADMSG
       * fs driver will take care of that, because
       * retlen == desired len and result == -EBADMSG
       */
      ops->retlen = read;
      ops->oobretlen = oobread;

      if (mtd->ecc_stats.failed - stats.failed)
            return -EBADMSG;

      if (ret)
            return ret;

      return mtd->ecc_stats.corrected - stats.corrected ? -EUCLEAN : 0;
}

/**
 * onenand_read_oob_nolock - [MTD Interface] OneNAND read out-of-band
 * @param mtd           MTD device structure
 * @param from          offset to read from
 * @param ops:          oob operation description structure
 *
 * OneNAND read out-of-band data from the spare area
 */
static int onenand_read_oob_nolock(struct mtd_info *mtd, loff_t from,
                  struct mtd_oob_ops *ops)
{
      struct onenand_chip *this = mtd->priv;
      int read = 0, thislen, column, oobsize;
      size_t len = ops->ooblen;
      mtd_oob_mode_t mode = ops->mode;
      u_char *buf = ops->oobbuf;
      int ret = 0;

      from += ops->ooboffs;

      DEBUG(MTD_DEBUG_LEVEL3, "onenand_read_oob_nolock: from = 0x%08x, len = %i\n", (unsigned int) from, (int) len);

      /* Initialize return length value */
      ops->oobretlen = 0;

      if (mode == MTD_OOB_AUTO)
            oobsize = this->ecclayout->oobavail;
      else
            oobsize = mtd->oobsize;

      column = from & (mtd->oobsize - 1);

      if (unlikely(column >= oobsize)) {
            printk(KERN_ERR "onenand_read_oob_nolock: Attempted to start read outside oob\n");
            return -EINVAL;
      }

      /* Do not allow reads past end of device */
      if (unlikely(from >= mtd->size ||
                 column + len > ((mtd->size >> this->page_shift) -
                             (from >> this->page_shift)) * oobsize)) {
            printk(KERN_ERR "onenand_read_oob_nolock: Attempted to read beyond end of device\n");
            return -EINVAL;
      }

      while (read < len) {
            cond_resched();

            thislen = oobsize - column;
            thislen = min_t(int, thislen, len);

            this->command(mtd, ONENAND_CMD_READOOB, from, mtd->oobsize);

            onenand_update_bufferram(mtd, from, 0);

            ret = this->wait(mtd, FL_READING);
            /* First copy data and check return value for ECC handling */

            if (mode == MTD_OOB_AUTO)
                  onenand_transfer_auto_oob(mtd, buf, column, thislen);
            else
                  this->read_bufferram(mtd, ONENAND_SPARERAM, buf, column, thislen);

            if (ret) {
                  printk(KERN_ERR "onenand_read_oob_nolock: read failed = 0x%x\n", ret);
                  break;
            }

            read += thislen;

            if (read == len)
                  break;

            buf += thislen;

            /* Read more? */
            if (read < len) {
                  /* Page size */
                  from += mtd->writesize;
                  column = 0;
            }
      }

      ops->oobretlen = read;
      return ret;
}

/**
 * onenand_read - [MTD Interface] Read data from flash
 * @param mtd           MTD device structure
 * @param from          offset to read from
 * @param len           number of bytes to read
 * @param retlen  pointer to variable to store the number of read bytes
 * @param buf           the databuffer to put data
 *
 * Read with ecc
*/
static int onenand_read(struct mtd_info *mtd, loff_t from, size_t len,
      size_t *retlen, u_char *buf)
{
      struct mtd_oob_ops ops = {
            .len  = len,
            .ooblen     = 0,
            .datbuf     = buf,
            .oobbuf     = NULL,
      };
      int ret;

      onenand_get_device(mtd, FL_READING);
      ret = onenand_read_ops_nolock(mtd, from, &ops);
      onenand_release_device(mtd);

      *retlen = ops.retlen;
      return ret;
}

/**
 * onenand_read_oob - [MTD Interface] Read main and/or out-of-band
 * @param mtd:          MTD device structure
 * @param from:         offset to read from
 * @param ops:          oob operation description structure

 * Read main and/or out-of-band
 */
static int onenand_read_oob(struct mtd_info *mtd, loff_t from,
                      struct mtd_oob_ops *ops)
{
      int ret;

      switch (ops->mode) {
      case MTD_OOB_PLACE:
      case MTD_OOB_AUTO:
            break;
      case MTD_OOB_RAW:
            /* Not implemented yet */
      default:
            return -EINVAL;
      }

      onenand_get_device(mtd, FL_READING);
      if (ops->datbuf)
            ret = onenand_read_ops_nolock(mtd, from, ops);
      else
            ret = onenand_read_oob_nolock(mtd, from, ops);
      onenand_release_device(mtd);

      return ret;
}

/**
 * onenand_bbt_wait - [DEFAULT] wait until the command is done
 * @param mtd           MTD device structure
 * @param state         state to select the max. timeout value
 *
 * Wait for command done.
 */
static int onenand_bbt_wait(struct mtd_info *mtd, int state)
{
      struct onenand_chip *this = mtd->priv;
      unsigned long timeout;
      unsigned int interrupt;
      unsigned int ctrl;

      /* The 20 msec is enough */
      timeout = jiffies + msecs_to_jiffies(20);
      while (time_before(jiffies, timeout)) {
            interrupt = this->read_word(this->base + ONENAND_REG_INTERRUPT);
            if (interrupt & ONENAND_INT_MASTER)
                  break;
      }
      /* To get correct interrupt status in timeout case */
      interrupt = this->read_word(this->base + ONENAND_REG_INTERRUPT);
      ctrl = this->read_word(this->base + ONENAND_REG_CTRL_STATUS);

      if (ctrl & ONENAND_CTRL_ERROR) {
            printk(KERN_DEBUG "onenand_bbt_wait: controller error = 0x%04x\n", ctrl);
            /* Initial bad block case */
            if (ctrl & ONENAND_CTRL_LOAD)
                  return ONENAND_BBT_READ_ERROR;
            return ONENAND_BBT_READ_FATAL_ERROR;
      }

      if (interrupt & ONENAND_INT_READ) {
            int ecc = this->read_word(this->base + ONENAND_REG_ECC_STATUS);
            if (ecc & ONENAND_ECC_2BIT_ALL)
                  return ONENAND_BBT_READ_ERROR;
      } else {
            printk(KERN_ERR "onenand_bbt_wait: read timeout!"
                  "ctrl=0x%04x intr=0x%04x\n", ctrl, interrupt);
            return ONENAND_BBT_READ_FATAL_ERROR;
      }

      return 0;
}

/**
 * onenand_bbt_read_oob - [MTD Interface] OneNAND read out-of-band for bbt scan
 * @param mtd           MTD device structure
 * @param from          offset to read from
 * @param ops           oob operation description structure
 *
 * OneNAND read out-of-band data from the spare area for bbt scan
 */
int onenand_bbt_read_oob(struct mtd_info *mtd, loff_t from, 
                      struct mtd_oob_ops *ops)
{
      struct onenand_chip *this = mtd->priv;
      int read = 0, thislen, column;
      int ret = 0;
      size_t len = ops->ooblen;
      u_char *buf = ops->oobbuf;

      DEBUG(MTD_DEBUG_LEVEL3, "onenand_bbt_read_oob: from = 0x%08x, len = %zi\n", (unsigned int) from, len);

      /* Initialize return value */
      ops->oobretlen = 0;

      /* Do not allow reads past end of device */
      if (unlikely((from + len) > mtd->size)) {
            printk(KERN_ERR "onenand_bbt_read_oob: Attempt read beyond end of device\n");
            return ONENAND_BBT_READ_FATAL_ERROR;
      }

      /* Grab the lock and see if the device is available */
      onenand_get_device(mtd, FL_READING);

      column = from & (mtd->oobsize - 1);

      while (read < len) {
            cond_resched();

            thislen = mtd->oobsize - column;
            thislen = min_t(int, thislen, len);

            this->command(mtd, ONENAND_CMD_READOOB, from, mtd->oobsize);

            onenand_update_bufferram(mtd, from, 0);

            ret = onenand_bbt_wait(mtd, FL_READING);
            if (ret)
                  break;

            this->read_bufferram(mtd, ONENAND_SPARERAM, buf, column, thislen);
            read += thislen;
            if (read == len)
                  break;

            buf += thislen;

            /* Read more? */
            if (read < len) {
                  /* Update Page size */
                  from += this->writesize;
                  column = 0;
            }
      }

      /* Deselect and wake up anyone waiting on the device */
      onenand_release_device(mtd);

      ops->oobretlen = read;
      return ret;
}

#ifdef CONFIG_MTD_ONENAND_VERIFY_WRITE
/**
 * onenand_verify_oob - [GENERIC] verify the oob contents after a write
 * @param mtd           MTD device structure
 * @param buf           the databuffer to verify
 * @param to            offset to read from
 */
static int onenand_verify_oob(struct mtd_info *mtd, const u_char *buf, loff_t to)
{
      struct onenand_chip *this = mtd->priv;
      char oobbuf[64];
      int status, i;

      this->command(mtd, ONENAND_CMD_READOOB, to, mtd->oobsize);
      onenand_update_bufferram(mtd, to, 0);
      status = this->wait(mtd, FL_READING);
      if (status)
            return status;

      this->read_bufferram(mtd, ONENAND_SPARERAM, oobbuf, 0, mtd->oobsize);
      for (i = 0; i < mtd->oobsize; i++)
            if (buf[i] != 0xFF && buf[i] != oobbuf[i])
                  return -EBADMSG;

      return 0;
}

/**
 * onenand_verify - [GENERIC] verify the chip contents after a write
 * @param mtd          MTD device structure
 * @param buf          the databuffer to verify
 * @param addr         offset to read from
 * @param len          number of bytes to read and compare
 */
static int onenand_verify(struct mtd_info *mtd, const u_char *buf, loff_t addr, size_t len)
{
      struct onenand_chip *this = mtd->priv;
      void __iomem *dataram;
      int ret = 0;
      int thislen, column;

      while (len != 0) {
            thislen = min_t(int, this->writesize, len);
            column = addr & (this->writesize - 1);
            if (column + thislen > this->writesize)
                  thislen = this->writesize - column;

            this->command(mtd, ONENAND_CMD_READ, addr, this->writesize);

            onenand_update_bufferram(mtd, addr, 0);

            ret = this->wait(mtd, FL_READING);
            if (ret)
                  return ret;

            onenand_update_bufferram(mtd, addr, 1);

            dataram = this->base + ONENAND_DATARAM;
            dataram += onenand_bufferram_offset(mtd, ONENAND_DATARAM);

            if (memcmp(buf, dataram + column, thislen))
                  return -EBADMSG;

            len -= thislen;
            buf += thislen;
            addr += thislen;
      }

      return 0;
}
#else
#define onenand_verify(...)         (0)
#define onenand_verify_oob(...)           (0)
#endif

#define NOTALIGNED(x)   ((x & (this->subpagesize - 1)) != 0)

/**
 * onenand_fill_auto_oob - [Internal] oob auto-placement transfer
 * @param mtd           MTD device structure
 * @param oob_buf oob buffer
 * @param buf           source address
 * @param column  oob offset to write to
 * @param thislen oob length to write
 */
static int onenand_fill_auto_oob(struct mtd_info *mtd, u_char *oob_buf,
                          const u_char *buf, int column, int thislen)
{
      struct onenand_chip *this = mtd->priv;
      struct nand_oobfree *free;
      int writecol = column;
      int writeend = column + thislen;
      int lastgap = 0;
      unsigned int i;

      free = this->ecclayout->oobfree;
      for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES && free->length; i++, free++) {
            if (writecol >= lastgap)
                  writecol += free->offset - lastgap;
            if (writeend >= lastgap)
                  writeend += free->offset - lastgap;
            lastgap = free->offset + free->length;
      }
      free = this->ecclayout->oobfree;
      for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES && free->length; i++, free++) {
            int free_end = free->offset + free->length;
            if (free->offset < writeend && free_end > writecol) {
                  int st = max_t(int,free->offset,writecol);
                  int ed = min_t(int,free_end,writeend);
                  int n = ed - st;
                  memcpy(oob_buf + st, buf, n);
                  buf += n;
            } else if (column == 0)
                  break;
      }
      return 0;
}

/**
 * onenand_write_ops_nolock - [OneNAND Interface] write main and/or out-of-band
 * @param mtd           MTD device structure
 * @param to            offset to write to
 * @param ops           oob operation description structure
 *
 * Write main and/or oob with ECC
 */
static int onenand_write_ops_nolock(struct mtd_info *mtd, loff_t to,
                        struct mtd_oob_ops *ops)
{
      struct onenand_chip *this = mtd->priv;
      int written = 0, column, thislen, subpage;
      int oobwritten = 0, oobcolumn, thisooblen, oobsize;
      size_t len = ops->len;
      size_t ooblen = ops->ooblen;
      const u_char *buf = ops->datbuf;
      const u_char *oob = ops->oobbuf;
      u_char *oobbuf;
      int ret = 0;

      DEBUG(MTD_DEBUG_LEVEL3, "onenand_write_ops_nolock: to = 0x%08x, len = %i\n", (unsigned int) to, (int) len);

      /* Initialize retlen, in case of early exit */
      ops->retlen = 0;
      ops->oobretlen = 0;

      /* Do not allow writes past end of device */
      if (unlikely((to + len) > mtd->size)) {
            printk(KERN_ERR "onenand_write_ops_nolock: Attempt write to past end of device\n");
            return -EINVAL;
      }

      /* Reject writes, which are not page aligned */
        if (unlikely(NOTALIGNED(to)) || unlikely(NOTALIGNED(len))) {
                printk(KERN_ERR "onenand_write_ops_nolock: Attempt to write not page aligned data\n");
                return -EINVAL;
        }

      if (ops->mode == MTD_OOB_AUTO)
            oobsize = this->ecclayout->oobavail;
      else
            oobsize = mtd->oobsize;

      oobcolumn = to & (mtd->oobsize - 1);

      column = to & (mtd->writesize - 1);

      /* Loop until all data write */
      while (written < len) {
            u_char *wbuf = (u_char *) buf;

            thislen = min_t(int, mtd->writesize - column, len - written);
            thisooblen = min_t(int, oobsize - oobcolumn, ooblen - oobwritten);

            cond_resched();

            this->command(mtd, ONENAND_CMD_BUFFERRAM, to, thislen);

            /* Partial page write */
            subpage = thislen < mtd->writesize;
            if (subpage) {
                  memset(this->page_buf, 0xff, mtd->writesize);
                  memcpy(this->page_buf + column, buf, thislen);
                  wbuf = this->page_buf;
            }

            this->write_bufferram(mtd, ONENAND_DATARAM, wbuf, 0, mtd->writesize);

            if (oob) {
                  oobbuf = this->oob_buf;

                  /* We send data to spare ram with oobsize
                   * to prevent byte access */
                  memset(oobbuf, 0xff, mtd->oobsize);
                  if (ops->mode == MTD_OOB_AUTO)
                        onenand_fill_auto_oob(mtd, oobbuf, oob, oobcolumn, thisooblen);
                  else
                        memcpy(oobbuf + oobcolumn, oob, thisooblen);

                  oobwritten += thisooblen;
                  oob += thisooblen;
                  oobcolumn = 0;
            } else
                  oobbuf = (u_char *) ffchars;

            this->write_bufferram(mtd, ONENAND_SPARERAM, oobbuf, 0, mtd->oobsize);

            this->command(mtd, ONENAND_CMD_PROG, to, mtd->writesize);

            ret = this->wait(mtd, FL_WRITING);

            /* In partial page write we don't update bufferram */
            onenand_update_bufferram(mtd, to, !ret && !subpage);
            if (ONENAND_IS_2PLANE(this)) {
                  ONENAND_SET_BUFFERRAM1(this);
                  onenand_update_bufferram(mtd, to + this->writesize, !ret && !subpage);
            }

            if (ret) {
                  printk(KERN_ERR "onenand_write_ops_nolock: write filaed %d\n", ret);
                  break;
            }

            /* Only check verify write turn on */
            ret = onenand_verify(mtd, (u_char *) wbuf, to, thislen);
            if (ret) {
                  printk(KERN_ERR "onenand_write_ops_nolock: verify failed %d\n", ret);
                  break;
            }

            written += thislen;

            if (written == len)
                  break;

            column = 0;
            to += thislen;
            buf += thislen;
      }

      /* Deselect and wake up anyone waiting on the device */
      onenand_release_device(mtd);

      ops->retlen = written;

      return ret;
}


/**
 * onenand_write_oob_nolock - [Internal] OneNAND write out-of-band
 * @param mtd           MTD device structure
 * @param to            offset to write to
 * @param len           number of bytes to write
 * @param retlen  pointer to variable to store the number of written bytes
 * @param buf           the data to write
 * @param mode          operation mode
 *
 * OneNAND write out-of-band
 */
static int onenand_write_oob_nolock(struct mtd_info *mtd, loff_t to,
                            struct mtd_oob_ops *ops)
{
      struct onenand_chip *this = mtd->priv;
      int column, ret = 0, oobsize;
      int written = 0;
      u_char *oobbuf;
      size_t len = ops->ooblen;
      const u_char *buf = ops->oobbuf;
      mtd_oob_mode_t mode = ops->mode;

      to += ops->ooboffs;

      DEBUG(MTD_DEBUG_LEVEL3, "onenand_write_oob_nolock: to = 0x%08x, len = %i\n", (unsigned int) to, (int) len);

      /* Initialize retlen, in case of early exit */
      ops->oobretlen = 0;

      if (mode == MTD_OOB_AUTO)
            oobsize = this->ecclayout->oobavail;
      else
            oobsize = mtd->oobsize;

      column = to & (mtd->oobsize - 1);

      if (unlikely(column >= oobsize)) {
            printk(KERN_ERR "onenand_write_oob_nolock: Attempted to start write outside oob\n");
            return -EINVAL;
      }

      /* For compatibility with NAND: Do not allow write past end of page */
      if (unlikely(column + len > oobsize)) {
            printk(KERN_ERR "onenand_write_oob_nolock: "
                  "Attempt to write past end of page\n");
            return -EINVAL;
      }

      /* Do not allow reads past end of device */
      if (unlikely(to >= mtd->size ||
                 column + len > ((mtd->size >> this->page_shift) -
                             (to >> this->page_shift)) * oobsize)) {
            printk(KERN_ERR "onenand_write_oob_nolock: Attempted to write past end of device\n");
            return -EINVAL;
      }

      oobbuf = this->oob_buf;

      /* Loop until all data write */
      while (written < len) {
            int thislen = min_t(int, oobsize, len - written);

            cond_resched();

            this->command(mtd, ONENAND_CMD_BUFFERRAM, to, mtd->oobsize);

            /* We send data to spare ram with oobsize
             * to prevent byte access */
            memset(oobbuf, 0xff, mtd->oobsize);
            if (mode == MTD_OOB_AUTO)
                  onenand_fill_auto_oob(mtd, oobbuf, buf, column, thislen);
            else
                  memcpy(oobbuf + column, buf, thislen);
            this->write_bufferram(mtd, ONENAND_SPARERAM, oobbuf, 0, mtd->oobsize);

            this->command(mtd, ONENAND_CMD_PROGOOB, to, mtd->oobsize);

            onenand_update_bufferram(mtd, to, 0);
            if (ONENAND_IS_2PLANE(this)) {
                  ONENAND_SET_BUFFERRAM1(this);
                  onenand_update_bufferram(mtd, to + this->writesize, 0);
            }

            ret = this->wait(mtd, FL_WRITING);
            if (ret) {
                  printk(KERN_ERR "onenand_write_oob_nolock: write failed %d\n", ret);
                  break;
            }

            ret = onenand_verify_oob(mtd, oobbuf, to);
            if (ret) {
                  printk(KERN_ERR "onenand_write_oob_nolock: verify failed %d\n", ret);
                  break;
            }

            written += thislen;
            if (written == len)
                  break;

            to += mtd->writesize;
            buf += thislen;
            column = 0;
      }

      ops->oobretlen = written;

      return ret;
}

/**
 * onenand_write - [MTD Interface] write buffer to FLASH
 * @param mtd           MTD device structure
 * @param to            offset to write to
 * @param len           number of bytes to write
 * @param retlen  pointer to variable to store the number of written bytes
 * @param buf           the data to write
 *
 * Write with ECC
 */
static int onenand_write(struct mtd_info *mtd, loff_t to, size_t len,
      size_t *retlen, const u_char *buf)
{
      struct mtd_oob_ops ops = {
            .len  = len,
            .ooblen     = 0,
            .datbuf     = (u_char *) buf,
            .oobbuf     = NULL,
      };
      int ret;

      onenand_get_device(mtd, FL_WRITING);
      ret = onenand_write_ops_nolock(mtd, to, &ops);
      onenand_release_device(mtd);

      *retlen = ops.retlen;
      return ret;
}

/**
 * onenand_write_oob - [MTD Interface] NAND write data and/or out-of-band
 * @param mtd:          MTD device structure
 * @param to:           offset to write
 * @param ops:          oob operation description structure
 */
static int onenand_write_oob(struct mtd_info *mtd, loff_t to,
                       struct mtd_oob_ops *ops)
{
      int ret;

      switch (ops->mode) {
      case MTD_OOB_PLACE:
      case MTD_OOB_AUTO:
            break;
      case MTD_OOB_RAW:
            /* Not implemented yet */
      default:
            return -EINVAL;
      }

      onenand_get_device(mtd, FL_WRITING);
      if (ops->datbuf)
            ret = onenand_write_ops_nolock(mtd, to, ops);
      else
            ret = onenand_write_oob_nolock(mtd, to, ops);
      onenand_release_device(mtd);

      return ret;
}

/**
 * onenand_block_isbad_nolock - [GENERIC] Check if a block is marked bad
 * @param mtd           MTD device structure
 * @param ofs           offset from device start
 * @param allowbbt      1, if its allowed to access the bbt area
 *
 * Check, if the block is bad. Either by reading the bad block table or
 * calling of the scan function.
 */
static int onenand_block_isbad_nolock(struct mtd_info *mtd, loff_t ofs, int allowbbt)
{
      struct onenand_chip *this = mtd->priv;
      struct bbm_info *bbm = this->bbm;

      /* Return info from the table */
      return bbm->isbad_bbt(mtd, ofs, allowbbt);
}

/**
 * onenand_erase - [MTD Interface] erase block(s)
 * @param mtd           MTD device structure
 * @param instr         erase instruction
 *
 * Erase one ore more blocks
 */
static int onenand_erase(struct mtd_info *mtd, struct erase_info *instr)
{
      struct onenand_chip *this = mtd->priv;
      unsigned int block_size;
      loff_t addr;
      int len;
      int ret = 0;

      DEBUG(MTD_DEBUG_LEVEL3, "onenand_erase: start = 0x%08x, len = %i\n", (unsigned int) instr->addr, (unsigned int) instr->len);

      block_size = (1 << this->erase_shift);

      /* Start address must align on block boundary */
      if (unlikely(instr->addr & (block_size - 1))) {
            printk(KERN_ERR "onenand_erase: Unaligned address\n");
            return -EINVAL;
      }

      /* Length must align on block boundary */
      if (unlikely(instr->len & (block_size - 1))) {
            printk(KERN_ERR "onenand_erase: Length not block aligned\n");
            return -EINVAL;
      }

      /* Do not allow erase past end of device */
      if (unlikely((instr->len + instr->addr) > mtd->size)) {
            printk(KERN_ERR "onenand_erase: Erase past end of device\n");
            return -EINVAL;
      }

      instr->fail_addr = 0xffffffff;

      /* Grab the lock and see if the device is available */
      onenand_get_device(mtd, FL_ERASING);

      /* Loop throught the pages */
      len = instr->len;
      addr = instr->addr;

      instr->state = MTD_ERASING;

      while (len) {
            cond_resched();

            /* Check if we have a bad block, we do not erase bad blocks */
            if (onenand_block_isbad_nolock(mtd, addr, 0)) {
                  printk (KERN_WARNING "onenand_erase: attempt to erase a bad block at addr 0x%08x\n", (unsigned int) addr);
                  instr->state = MTD_ERASE_FAILED;
                  goto erase_exit;
            }

            this->command(mtd, ONENAND_CMD_ERASE, addr, block_size);

            onenand_invalidate_bufferram(mtd, addr, block_size);

            ret = this->wait(mtd, FL_ERASING);
            /* Check, if it is write protected */
            if (ret) {
                  printk(KERN_ERR "onenand_erase: Failed erase, block %d\n", (unsigned) (addr >> this->erase_shift));
                  instr->state = MTD_ERASE_FAILED;
                  instr->fail_addr = addr;
                  goto erase_exit;
            }

            len -= block_size;
            addr += block_size;
      }

      instr->state = MTD_ERASE_DONE;

erase_exit:

      ret = instr->state == MTD_ERASE_DONE ? 0 : -EIO;

      /* Deselect and wake up anyone waiting on the device */
      onenand_release_device(mtd);

      /* Do call back function */
      if (!ret)
            mtd_erase_callback(instr);

      return ret;
}

/**
 * onenand_sync - [MTD Interface] sync
 * @param mtd           MTD device structure
 *
 * Sync is actually a wait for chip ready function
 */
static void onenand_sync(struct mtd_info *mtd)
{
      DEBUG(MTD_DEBUG_LEVEL3, "onenand_sync: called\n");

      /* Grab the lock and see if the device is available */
      onenand_get_device(mtd, FL_SYNCING);

      /* Release it and go back */
      onenand_release_device(mtd);
}

/**
 * onenand_block_isbad - [MTD Interface] Check whether the block at the given offset is bad
 * @param mtd           MTD device structure
 * @param ofs           offset relative to mtd start
 *
 * Check whether the block is bad
 */
static int onenand_block_isbad(struct mtd_info *mtd, loff_t ofs)
{
      int ret;

      /* Check for invalid offset */
      if (ofs > mtd->size)
            return -EINVAL;

      onenand_get_device(mtd, FL_READING);
      ret = onenand_block_isbad_nolock(mtd, ofs, 0);
      onenand_release_device(mtd);
      return ret;
}

/**
 * onenand_default_block_markbad - [DEFAULT] mark a block bad
 * @param mtd           MTD device structure
 * @param ofs           offset from device start
 *
 * This is the default implementation, which can be overridden by
 * a hardware specific driver.
 */
static int onenand_default_block_markbad(struct mtd_info *mtd, loff_t ofs)
{
      struct onenand_chip *this = mtd->priv;
      struct bbm_info *bbm = this->bbm;
      u_char buf[2] = {0, 0};
      struct mtd_oob_ops ops = {
            .mode = MTD_OOB_PLACE,
            .ooblen = 2,
            .oobbuf = buf,
            .ooboffs = 0,
      };
      int block;

      /* Get block number */
      block = ((int) ofs) >> bbm->bbt_erase_shift;
        if (bbm->bbt)
                bbm->bbt[block >> 2] |= 0x01 << ((block & 0x03) << 1);

        /* We write two bytes, so we dont have to mess with 16 bit access */
        ofs += mtd->oobsize + (bbm->badblockpos & ~0x01);
        return onenand_write_oob_nolock(mtd, ofs, &ops);
}

/**
 * onenand_block_markbad - [MTD Interface] Mark the block at the given offset as bad
 * @param mtd           MTD device structure
 * @param ofs           offset relative to mtd start
 *
 * Mark the block as bad
 */
static int onenand_block_markbad(struct mtd_info *mtd, loff_t ofs)
{
      struct onenand_chip *this = mtd->priv;
      int ret;

      ret = onenand_block_isbad(mtd, ofs);
      if (ret) {
            /* If it was bad already, return success and do nothing */
            if (ret > 0)
                  return 0;
            return ret;
      }

      onenand_get_device(mtd, FL_WRITING);
      ret = this->block_markbad(mtd, ofs);
      onenand_release_device(mtd);
      return ret;
}

/**
 * onenand_do_lock_cmd - [OneNAND Interface] Lock or unlock block(s)
 * @param mtd           MTD device structure
 * @param ofs           offset relative to mtd start
 * @param len           number of bytes to lock or unlock
 * @param cmd           lock or unlock command
 *
 * Lock or unlock one or more blocks
 */
static int onenand_do_lock_cmd(struct mtd_info *mtd, loff_t ofs, size_t len, int cmd)
{
      struct onenand_chip *this = mtd->priv;
      int start, end, block, value, status;
      int wp_status_mask;

      start = ofs >> this->erase_shift;
      end = len >> this->erase_shift;

      if (cmd == ONENAND_CMD_LOCK)
            wp_status_mask = ONENAND_WP_LS;
      else
            wp_status_mask = ONENAND_WP_US;

      /* Continuous lock scheme */
      if (this->options & ONENAND_HAS_CONT_LOCK) {
            /* Set start block address */
            this->write_word(start, this->base + ONENAND_REG_START_BLOCK_ADDRESS);
            /* Set end block address */
            this->write_word(start + end - 1, this->base + ONENAND_REG_END_BLOCK_ADDRESS);
            /* Write lock command */
            this->command(mtd, cmd, 0, 0);

            /* There's no return value */
            this->wait(mtd, FL_LOCKING);

            /* Sanity check */
            while (this->read_word(this->base + ONENAND_REG_CTRL_STATUS)
                & ONENAND_CTRL_ONGO)
                  continue;

            /* Check lock status */
            status = this->read_word(this->base + ONENAND_REG_WP_STATUS);
            if (!(status & wp_status_mask))
                  printk(KERN_ERR "wp status = 0x%x\n", status);

            return 0;
      }

      /* Block lock scheme */
      for (block = start; block < start + end; block++) {
            /* Set block address */
            value = onenand_block_address(this, block);
            this->write_word(value, this->base + ONENAND_REG_START_ADDRESS1);
            /* Select DataRAM for DDP */
            value = onenand_bufferram_address(this, block);
            this->write_word(value, this->base + ONENAND_REG_START_ADDRESS2);
            /* Set start block address */
            this->write_word(block, this->base + ONENAND_REG_START_BLOCK_ADDRESS);
            /* Write lock command */
            this->command(mtd, cmd, 0, 0);

            /* There's no return value */
            this->wait(mtd, FL_LOCKING);

            /* Sanity check */
            while (this->read_word(this->base + ONENAND_REG_CTRL_STATUS)
                & ONENAND_CTRL_ONGO)
                  continue;

            /* Check lock status */
            status = this->read_word(this->base + ONENAND_REG_WP_STATUS);
            if (!(status & wp_status_mask))
                  printk(KERN_ERR "block = %d, wp status = 0x%x\n", block, status);
      }

      return 0;
}

/**
 * onenand_lock - [MTD Interface] Lock block(s)
 * @param mtd           MTD device structure
 * @param ofs           offset relative to mtd start
 * @param len           number of bytes to unlock
 *
 * Lock one or more blocks
 */
static int onenand_lock(struct mtd_info *mtd, loff_t ofs, size_t len)
{
      int ret;

      onenand_get_device(mtd, FL_LOCKING);
      ret = onenand_do_lock_cmd(mtd, ofs, len, ONENAND_CMD_LOCK);
      onenand_release_device(mtd);
      return ret;
}

/**
 * onenand_unlock - [MTD Interface] Unlock block(s)
 * @param mtd           MTD device structure
 * @param ofs           offset relative to mtd start
 * @param len           number of bytes to unlock
 *
 * Unlock one or more blocks
 */
static int onenand_unlock(struct mtd_info *mtd, loff_t ofs, size_t len)
{
      int ret;

      onenand_get_device(mtd, FL_LOCKING);
      ret = onenand_do_lock_cmd(mtd, ofs, len, ONENAND_CMD_UNLOCK);
      onenand_release_device(mtd);
      return ret;
}

/**
 * onenand_check_lock_status - [OneNAND Interface] Check lock status
 * @param this          onenand chip data structure
 *
 * Check lock status
 */
static void onenand_check_lock_status(struct onenand_chip *this)
{
      unsigned int value, block, status;
      unsigned int end;

      end = this->chipsize >> this->erase_shift;
      for (block = 0; block < end; block++) {
            /* Set block address */
            value = onenand_block_address(this, block);
            this->write_word(value, this->base + ONENAND_REG_START_ADDRESS1);
            /* Select DataRAM for DDP */
            value = onenand_bufferram_address(this, block);
            this->write_word(value, this->base + ONENAND_REG_START_ADDRESS2);
            /* Set start block address */
            this->write_word(block, this->base + ONENAND_REG_START_BLOCK_ADDRESS);

            /* Check lock status */
            status = this->read_word(this->base + ONENAND_REG_WP_STATUS);
            if (!(status & ONENAND_WP_US))
                  printk(KERN_ERR "block = %d, wp status = 0x%x\n", block, status);
      }
}

/**
 * onenand_unlock_all - [OneNAND Interface] unlock all blocks
 * @param mtd           MTD device structure
 *
 * Unlock all blocks
 */
static int onenand_unlock_all(struct mtd_info *mtd)
{
      struct onenand_chip *this = mtd->priv;

      if (this->options & ONENAND_HAS_UNLOCK_ALL) {
            /* Set start block address */
            this->write_word(0, this->base + ONENAND_REG_START_BLOCK_ADDRESS);
            /* Write unlock command */
            this->command(mtd, ONENAND_CMD_UNLOCK_ALL, 0, 0);

            /* There's no return value */
            this->wait(mtd, FL_LOCKING);

            /* Sanity check */
            while (this->read_word(this->base + ONENAND_REG_CTRL_STATUS)
                & ONENAND_CTRL_ONGO)
                  continue;

            /* Workaround for all block unlock in DDP */
            if (ONENAND_IS_DDP(this)) {
                  /* 1st block on another chip */
                  loff_t ofs = this->chipsize >> 1;
                  size_t len = mtd->erasesize;

                  onenand_do_lock_cmd(mtd, ofs, len, ONENAND_CMD_UNLOCK);
            }

            onenand_check_lock_status(this);

            return 0;
      }

      onenand_do_lock_cmd(mtd, 0x0, this->chipsize, ONENAND_CMD_UNLOCK);

      return 0;
}

#ifdef CONFIG_MTD_ONENAND_OTP

/* Interal OTP operation */
typedef int (*otp_op_t)(struct mtd_info *mtd, loff_t form, size_t len,
            size_t *retlen, u_char *buf);

/**
 * do_otp_read - [DEFAULT] Read OTP block area
 * @param mtd           MTD device structure
 * @param from          The offset to read
 * @param len           number of bytes to read
 * @param retlen  pointer to variable to store the number of readbytes
 * @param buf           the databuffer to put/get data
 *
 * Read OTP block area.
 */
static int do_otp_read(struct mtd_info *mtd, loff_t from, size_t len,
            size_t *retlen, u_char *buf)
{
      struct onenand_chip *this = mtd->priv;
      struct mtd_oob_ops ops = {
            .len  = len,
            .ooblen     = 0,
            .datbuf     = buf,
            .oobbuf     = NULL,
      };
      int ret;

      /* Enter OTP access mode */
      this->command(mtd, ONENAND_CMD_OTP_ACCESS, 0, 0);
      this->wait(mtd, FL_OTPING);

      ret = onenand_read_ops_nolock(mtd, from, &ops);

      /* Exit OTP access mode */
      this->command(mtd, ONENAND_CMD_RESET, 0, 0);
      this->wait(mtd, FL_RESETING);

      return ret;
}

/**
 * do_otp_write - [DEFAULT] Write OTP block area
 * @param mtd           MTD device structure
 * @param to            The offset to write
 * @param len           number of bytes to write
 * @param retlen  pointer to variable to store the number of write bytes
 * @param buf           the databuffer to put/get data
 *
 * Write OTP block area.
 */
static int do_otp_write(struct mtd_info *mtd, loff_t to, size_t len,
            size_t *retlen, u_char *buf)
{
      struct onenand_chip *this = mtd->priv;
      unsigned char *pbuf = buf;
      int ret;
      struct mtd_oob_ops ops;

      /* Force buffer page aligned */
      if (len < mtd->writesize) {
            memcpy(this->page_buf, buf, len);
            memset(this->page_buf + len, 0xff, mtd->writesize - len);
            pbuf = this->page_buf;
            len = mtd->writesize;
      }

      /* Enter OTP access mode */
      this->command(mtd, ONENAND_CMD_OTP_ACCESS, 0, 0);
      this->wait(mtd, FL_OTPING);

      ops.len = len;
      ops.ooblen = 0;
      ops.datbuf = pbuf;
      ops.oobbuf = NULL;
      ret = onenand_write_ops_nolock(mtd, to, &ops);
      *retlen = ops.retlen;

      /* Exit OTP access mode */
      this->command(mtd, ONENAND_CMD_RESET, 0, 0);
      this->wait(mtd, FL_RESETING);

      return ret;
}

/**
 * do_otp_lock - [DEFAULT] Lock OTP block area
 * @param mtd           MTD device structure
 * @param from          The offset to lock
 * @param len           number of bytes to lock
 * @param retlen  pointer to variable to store the number of lock bytes
 * @param buf           the databuffer to put/get data
 *
 * Lock OTP block area.
 */
static int do_otp_lock(struct mtd_info *mtd, loff_t from, size_t len,
            size_t *retlen, u_char *buf)
{
      struct onenand_chip *this = mtd->priv;
      struct mtd_oob_ops ops = {
            .mode = MTD_OOB_PLACE,
            .ooblen = len,
            .oobbuf = buf,
            .ooboffs = 0,
      };
      int ret;

      /* Enter OTP access mode */
      this->command(mtd, ONENAND_CMD_OTP_ACCESS, 0, 0);
      this->wait(mtd, FL_OTPING);

      ret = onenand_write_oob_nolock(mtd, from, &ops);

      *retlen = ops.oobretlen;

      /* Exit OTP access mode */
      this->command(mtd, ONENAND_CMD_RESET, 0, 0);
      this->wait(mtd, FL_RESETING);

      return ret;
}

/**
 * onenand_otp_walk - [DEFAULT] Handle OTP operation
 * @param mtd           MTD device structure
 * @param from          The offset to read/write
 * @param len           number of bytes to read/write
 * @param retlen  pointer to variable to store the number of read bytes
 * @param buf           the databuffer to put/get data
 * @param action  do given action
 * @param mode          specify user and factory
 *
 * Handle OTP operation.
 */
static int onenand_otp_walk(struct mtd_info *mtd, loff_t from, size_t len,
                  size_t *retlen, u_char *buf,
                  otp_op_t action, int mode)
{
      struct onenand_chip *this = mtd->priv;
      int otp_pages;
      int density;
      int ret = 0;

      *retlen = 0;

      density = this->device_id >> ONENAND_DEVICE_DENSITY_SHIFT;
      if (density < ONENAND_DEVICE_DENSITY_512Mb)
            otp_pages = 20;
      else
            otp_pages = 10;

      if (mode == MTD_OTP_FACTORY) {
            from += mtd->writesize * otp_pages;
            otp_pages = 64 - otp_pages;
      }

      /* Check User/Factory boundary */
      if (((mtd->writesize * otp_pages) - (from + len)) < 0)
            return 0;

      onenand_get_device(mtd, FL_OTPING);
      while (len > 0 && otp_pages > 0) {
            if (!action) {    /* OTP Info functions */
                  struct otp_info *otpinfo;

                  len -= sizeof(struct otp_info);
                  if (len <= 0) {
                        ret = -ENOSPC;
                        break;
                  }

                  otpinfo = (struct otp_info *) buf;
                  otpinfo->start = from;
                  otpinfo->length = mtd->writesize;
                  otpinfo->locked = 0;

                  from += mtd->writesize;
                  buf += sizeof(struct otp_info);
                  *retlen += sizeof(struct otp_info);
            } else {
                  size_t tmp_retlen;
                  int size = len;

                  ret = action(mtd, from, len, &tmp_retlen, buf);

                  buf += size;
                  len -= size;
                  *retlen += size;

                  if (ret)
                        break;
            }
            otp_pages--;
      }
      onenand_release_device(mtd);

      return ret;
}

/**
 * onenand_get_fact_prot_info - [MTD Interface] Read factory OTP info
 * @param mtd           MTD device structure
 * @param buf           the databuffer to put/get data
 * @param len           number of bytes to read
 *
 * Read factory OTP info.
 */
static int onenand_get_fact_prot_info(struct mtd_info *mtd,
                  struct otp_info *buf, size_t len)
{
      size_t retlen;
      int ret;

      ret = onenand_otp_walk(mtd, 0, len, &retlen, (u_char *) buf, NULL, MTD_OTP_FACTORY);

      return ret ? : retlen;
}

/**
 * onenand_read_fact_prot_reg - [MTD Interface] Read factory OTP area
 * @param mtd           MTD device structure
 * @param from          The offset to read
 * @param len           number of bytes to read
 * @param retlen  pointer to variable to store the number of read bytes
 * @param buf           the databuffer to put/get data
 *
 * Read factory OTP area.
 */
static int onenand_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
                  size_t len, size_t *retlen, u_char *buf)
{
      return onenand_otp_walk(mtd, from, len, retlen, buf, do_otp_read, MTD_OTP_FACTORY);
}

/**
 * onenand_get_user_prot_info - [MTD Interface] Read user OTP info
 * @param mtd           MTD device structure
 * @param buf           the databuffer to put/get data
 * @param len           number of bytes to read
 *
 * Read user OTP info.
 */
static int onenand_get_user_prot_info(struct mtd_info *mtd,
                  struct otp_info *buf, size_t len)
{
      size_t retlen;
      int ret;

      ret = onenand_otp_walk(mtd, 0, len, &retlen, (u_char *) buf, NULL, MTD_OTP_USER);

      return ret ? : retlen;
}

/**
 * onenand_read_user_prot_reg - [MTD Interface] Read user OTP area
 * @param mtd           MTD device structure
 * @param from          The offset to read
 * @param len           number of bytes to read
 * @param retlen  pointer to variable to store the number of read bytes
 * @param buf           the databuffer to put/get data
 *
 * Read user OTP area.
 */
static int onenand_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
                  size_t len, size_t *retlen, u_char *buf)
{
      return onenand_otp_walk(mtd, from, len, retlen, buf, do_otp_read, MTD_OTP_USER);
}

/**
 * onenand_write_user_prot_reg - [MTD Interface] Write user OTP area
 * @param mtd           MTD device structure
 * @param from          The offset to write
 * @param len           number of bytes to write
 * @param retlen  pointer to variable to store the number of write bytes
 * @param buf           the databuffer to put/get data
 *
 * Write user OTP area.
 */
static int onenand_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
                  size_t len, size_t *retlen, u_char *buf)
{
      return onenand_otp_walk(mtd, from, len, retlen, buf, do_otp_write, MTD_OTP_USER);
}

/**
 * onenand_lock_user_prot_reg - [MTD Interface] Lock user OTP area
 * @param mtd           MTD device structure
 * @param from          The offset to lock
 * @param len           number of bytes to unlock
 *
 * Write lock mark on spare area in page 0 in OTP block
 */
static int onenand_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
                  size_t len)
{
      unsigned char oob_buf[64];
      size_t retlen;
      int ret;

      memset(oob_buf, 0xff, mtd->oobsize);
      /*
       * Note: OTP lock operation
       *       OTP block : 0xXXFC
       *       1st block : 0xXXF3 (If chip support)
       *       Both      : 0xXXF0 (If chip support)
       */
      oob_buf[ONENAND_OTP_LOCK_OFFSET] = 0xFC;

      /*
       * Write lock mark to 8th word of sector0 of page0 of the spare0.
       * We write 16 bytes spare area instead of 2 bytes.
       */
      from = 0;
      len = 16;

      ret = onenand_otp_walk(mtd, from, len, &retlen, oob_buf, do_otp_lock, MTD_OTP_USER);

      return ret ? : retlen;
}
#endif      /* CONFIG_MTD_ONENAND_OTP */

/**
 * onenand_check_features - Check and set OneNAND features
 * @param mtd           MTD data structure
 *
 * Check and set OneNAND features
 * - lock scheme
 * - two plane
 */
static void onenand_check_features(struct mtd_info *mtd)
{
      struct onenand_chip *this = mtd->priv;
      unsigned int density, process;

      /* Lock scheme depends on density and process */
      density = this->device_id >> ONENAND_DEVICE_DENSITY_SHIFT;
      process = this->version_id >> ONENAND_VERSION_PROCESS_SHIFT;

      /* Lock scheme */
      switch (density) {
      case ONENAND_DEVICE_DENSITY_4Gb:
            this->options |= ONENAND_HAS_2PLANE;

      case ONENAND_DEVICE_DENSITY_2Gb:
            /* 2Gb DDP don't have 2 plane */
            if (!ONENAND_IS_DDP(this))
                  this->options |= ONENAND_HAS_2PLANE;
            this->options |= ONENAND_HAS_UNLOCK_ALL;

      case ONENAND_DEVICE_DENSITY_1Gb:
            /* A-Die has all block unlock */
            if (process)
                  this->options |= ONENAND_HAS_UNLOCK_ALL;
            break;

      default:
            /* Some OneNAND has continuous lock scheme */
            if (!process)
                  this->options |= ONENAND_HAS_CONT_LOCK;
            break;
      }

      if (this->options & ONENAND_HAS_CONT_LOCK)
            printk(KERN_DEBUG "Lock scheme is Continuous Lock\n");
      if (this->options & ONENAND_HAS_UNLOCK_ALL)
            printk(KERN_DEBUG "Chip support all block unlock\n");
      if (this->options & ONENAND_HAS_2PLANE)
            printk(KERN_DEBUG "Chip has 2 plane\n");
}

/**
 * onenand_print_device_info - Print device & version ID
 * @param device        device ID
 * @param version version ID
 *
 * Print device & version ID
 */
static void onenand_print_device_info(int device, int version)
{
        int vcc, demuxed, ddp, density;

        vcc = device & ONENAND_DEVICE_VCC_MASK;
        demuxed = device & ONENAND_DEVICE_IS_DEMUX;
        ddp = device & ONENAND_DEVICE_IS_DDP;
        density = device >> ONENAND_DEVICE_DENSITY_SHIFT;
        printk(KERN_INFO "%sOneNAND%s %dMB %sV 16-bit (0x%02x)\n",
                demuxed ? "" : "Muxed ",
                ddp ? "(DDP)" : "",
                (16 << density),
                vcc ? "2.65/3.3" : "1.8",
                device);
      printk(KERN_INFO "OneNAND version = 0x%04x\n", version);
}

static const struct onenand_manufacturers onenand_manuf_ids[] = {
        {ONENAND_MFR_SAMSUNG, "Samsung"},
};

/**
 * onenand_check_maf - Check manufacturer ID
 * @param manuf         manufacturer ID
 *
 * Check manufacturer ID
 */
static int onenand_check_maf(int manuf)
{
      int size = ARRAY_SIZE(onenand_manuf_ids);
      char *name;
        int i;

      for (i = 0; i < size; i++)
                if (manuf == onenand_manuf_ids[i].id)
                        break;

      if (i < size)
            name = onenand_manuf_ids[i].name;
      else
            name = "Unknown";

      printk(KERN_DEBUG "OneNAND Manufacturer: %s (0x%0x)\n", name, manuf);

      return (i == size);
}

/**
 * onenand_probe - [OneNAND Interface] Probe the OneNAND device
 * @param mtd           MTD device structure
 *
 * OneNAND detection method:
 *   Compare the values from command with ones from register
 */
static int onenand_probe(struct mtd_info *mtd)
{
      struct onenand_chip *this = mtd->priv;
      int bram_maf_id, bram_dev_id, maf_id, dev_id, ver_id;
      int density;
      int syscfg;

      /* Save system configuration 1 */
      syscfg = this->read_word(this->base + ONENAND_REG_SYS_CFG1);
      /* Clear Sync. Burst Read mode to read BootRAM */
      this->write_word((syscfg & ~ONENAND_SYS_CFG1_SYNC_READ), this->base + ONENAND_REG_SYS_CFG1);

      /* Send the command for reading device ID from BootRAM */
      this->write_word(ONENAND_CMD_READID, this->base + ONENAND_BOOTRAM);

      /* Read manufacturer and device IDs from BootRAM */
      bram_maf_id = this->read_word(this->base + ONENAND_BOOTRAM + 0x0);
      bram_dev_id = this->read_word(this->base + ONENAND_BOOTRAM + 0x2);

      /* Reset OneNAND to read default register values */
      this->write_word(ONENAND_CMD_RESET, this->base + ONENAND_BOOTRAM);
      /* Wait reset */
      this->wait(mtd, FL_RESETING);

      /* Restore system configuration 1 */
      this->write_word(syscfg, this->base + ONENAND_REG_SYS_CFG1);

      /* Check manufacturer ID */
      if (onenand_check_maf(bram_maf_id))
            return -ENXIO;

      /* Read manufacturer and device IDs from Register */
      maf_id = this->read_word(this->base + ONENAND_REG_MANUFACTURER_ID);
      dev_id = this->read_word(this->base + ONENAND_REG_DEVICE_ID);
      ver_id = this->read_word(this->base + ONENAND_REG_VERSION_ID);

      /* Check OneNAND device */
      if (maf_id != bram_maf_id || dev_id != bram_dev_id)
            return -ENXIO;

      /* Flash device information */
      onenand_print_device_info(dev_id, ver_id);
      this->device_id = dev_id;
      this->version_id = ver_id;

      density = dev_id >> ONENAND_DEVICE_DENSITY_SHIFT;
      this->chipsize = (16 << density) << 20;
      /* Set density mask. it is used for DDP */
      if (ONENAND_IS_DDP(this))
            this->density_mask = (1 << (density + 6));
      else
            this->density_mask = 0;

      /* OneNAND page size & block size */
      /* The data buffer size is equal to page size */
      mtd->writesize = this->read_word(this->base + ONENAND_REG_DATA_BUFFER_SIZE);
      mtd->oobsize = mtd->writesize >> 5;
      /* Pages per a block are always 64 in OneNAND */
      mtd->erasesize = mtd->writesize << 6;

      this->erase_shift = ffs(mtd->erasesize) - 1;
      this->page_shift = ffs(mtd->writesize) - 1;
      this->page_mask = (1 << (this->erase_shift - this->page_shift)) - 1;
      /* It's real page size */
      this->writesize = mtd->writesize;

      /* REVIST: Multichip handling */

      mtd->size = this->chipsize;

      /* Check OneNAND features */
      onenand_check_features(mtd);

      /*
       * We emulate the 4KiB page and 256KiB erase block size
       * But oobsize is still 64 bytes.
       * It is only valid if you turn on 2X program support,
       * Otherwise it will be ignored by compiler.
       */
      if (ONENAND_IS_2PLANE(this)) {
            mtd->writesize <<= 1;
            mtd->erasesize <<= 1;
      }

      return 0;
}

/**
 * onenand_suspend - [MTD Interface] Suspend the OneNAND flash
 * @param mtd           MTD device structure
 */
static int onenand_suspend(struct mtd_info *mtd)
{
      return onenand_get_device(mtd, FL_PM_SUSPENDED);
}

/**
 * onenand_resume - [MTD Interface] Resume the OneNAND flash
 * @param mtd           MTD device structure
 */
static void onenand_resume(struct mtd_info *mtd)
{
      struct onenand_chip *this = mtd->priv;

      if (this->state == FL_PM_SUSPENDED)
            onenand_release_device(mtd);
      else
            printk(KERN_ERR "resume() called for the chip which is not"
                        "in suspended state\n");
}

/**
 * onenand_scan - [OneNAND Interface] Scan for the OneNAND device
 * @param mtd           MTD device structure
 * @param maxchips      Number of chips to scan for
 *
 * This fills out all the not initialized function pointers
 * with the defaults.
 * The flash ID is read and the mtd/chip structures are
 * filled with the appropriate values.
 */
int onenand_scan(struct mtd_info *mtd, int maxchips)
{
      int i;
      struct onenand_chip *this = mtd->priv;

      if (!this->read_word)
            this->read_word = onenand_readw;
      if (!this->write_word)
            this->write_word = onenand_writew;

      if (!this->command)
            this->command = onenand_command;
      if (!this->wait)
            onenand_setup_wait(mtd);

      if (!this->read_bufferram)
            this->read_bufferram = onenand_read_bufferram;
      if (!this->write_bufferram)
            this->write_bufferram = onenand_write_bufferram;

      if (!this->block_markbad)
            this->block_markbad = onenand_default_block_markbad;
      if (!this->scan_bbt)
            this->scan_bbt = onenand_default_bbt;

      if (onenand_probe(mtd))
            return -ENXIO;

      /* Set Sync. Burst Read after probing */
      if (this->mmcontrol) {
            printk(KERN_INFO "OneNAND Sync. Burst Read support\n");
            this->read_bufferram = onenand_sync_read_bufferram;
      }

      /* Allocate buffers, if necessary */
      if (!this->page_buf) {
            this->page_buf = kzalloc(mtd->writesize, GFP_KERNEL);
            if (!this->page_buf) {
                  printk(KERN_ERR "onenand_scan(): Can't allocate page_buf\n");
                  return -ENOMEM;
            }
            this->options |= ONENAND_PAGEBUF_ALLOC;
      }
      if (!this->oob_buf) {
            this->oob_buf = kzalloc(mtd->oobsize, GFP_KERNEL);
            if (!this->oob_buf) {
                  printk(KERN_ERR "onenand_scan(): Can't allocate oob_buf\n");
                  if (this->options & ONENAND_PAGEBUF_ALLOC) {
                        this->options &= ~ONENAND_PAGEBUF_ALLOC;
                        kfree(this->page_buf);
                  }
                  return -ENOMEM;
            }
            this->options |= ONENAND_OOBBUF_ALLOC;
      }

      this->state = FL_READY;
      init_waitqueue_head(&this->wq);
      spin_lock_init(&this->chip_lock);

      /*
       * Allow subpage writes up to oobsize.
       */
      switch (mtd->oobsize) {
      case 64:
            this->ecclayout = &onenand_oob_64;
            mtd->subpage_sft = 2;
            break;

      case 32:
            this->ecclayout = &onenand_oob_32;
            mtd->subpage_sft = 1;
            break;

      default:
            printk(KERN_WARNING "No OOB scheme defined for oobsize %d\n",
                  mtd->oobsize);
            mtd->subpage_sft = 0;
            /* To prevent kernel oops */
            this->ecclayout = &onenand_oob_32;
            break;
      }

      this->subpagesize = mtd->writesize >> mtd->subpage_sft;

      /*
       * The number of bytes available for a client to place data into
       * the out of band area
       */
      this->ecclayout->oobavail = 0;
      for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES &&
          this->ecclayout->oobfree[i].length; i++)
            this->ecclayout->oobavail +=
                  this->ecclayout->oobfree[i].length;
      mtd->oobavail = this->ecclayout->oobavail;

      mtd->ecclayout = this->ecclayout;

      /* Fill in remaining MTD driver data */
      mtd->type = MTD_NANDFLASH;
      mtd->flags = MTD_CAP_NANDFLASH;
      mtd->erase = onenand_erase;
      mtd->point = NULL;
      mtd->unpoint = NULL;
      mtd->read = onenand_read;
      mtd->write = onenand_write;
      mtd->read_oob = onenand_read_oob;
      mtd->write_oob = onenand_write_oob;
#ifdef CONFIG_MTD_ONENAND_OTP
      mtd->get_fact_prot_info = onenand_get_fact_prot_info;
      mtd->read_fact_prot_reg = onenand_read_fact_prot_reg;
      mtd->get_user_prot_info = onenand_get_user_prot_info;
      mtd->read_user_prot_reg = onenand_read_user_prot_reg;
      mtd->write_user_prot_reg = onenand_write_user_prot_reg;
      mtd->lock_user_prot_reg = onenand_lock_user_prot_reg;
#endif
      mtd->sync = onenand_sync;
      mtd->lock = onenand_lock;
      mtd->unlock = onenand_unlock;
      mtd->suspend = onenand_suspend;
      mtd->resume = onenand_resume;
      mtd->block_isbad = onenand_block_isbad;
      mtd->block_markbad = onenand_block_markbad;
      mtd->owner = THIS_MODULE;

      /* Unlock whole block */
      onenand_unlock_all(mtd);

      return this->scan_bbt(mtd);
}

/**
 * onenand_release - [OneNAND Interface] Free resources held by the OneNAND device
 * @param mtd           MTD device structure
 */
void onenand_release(struct mtd_info *mtd)
{
      struct onenand_chip *this = mtd->priv;

#ifdef CONFIG_MTD_PARTITIONS
      /* Deregister partitions */
      del_mtd_partitions (mtd);
#endif
      /* Deregister the device */
      del_mtd_device (mtd);

      /* Free bad block table memory, if allocated */
      if (this->bbm) {
            struct bbm_info *bbm = this->bbm;
            kfree(bbm->bbt);
            kfree(this->bbm);
      }
      /* Buffers allocated by onenand_scan */
      if (this->options & ONENAND_PAGEBUF_ALLOC)
            kfree(this->page_buf);
      if (this->options & ONENAND_OOBBUF_ALLOC)
            kfree(this->oob_buf);
}

EXPORT_SYMBOL_GPL(onenand_scan);
EXPORT_SYMBOL_GPL(onenand_release);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Kyungmin Park <kyungmin.park@samsung.com>");
MODULE_DESCRIPTION("Generic OneNAND flash driver code");

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