/*
   *  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
   *

   *      Rohit Hagargundgi <h.rohit at samsung.com>,
   *      Amul Kumar Saha <amul.saha@samsung.com>:
   *      Flex-OneNAND support
   *      Copyright (C) Samsung Electronics, 2009
   *

   * 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 <common.h>

  #include <linux/compat.h>

  #include <linux/mtd/mtd.h>
  #include <linux/mtd/onenand.h>
  
  #include <asm/io.h>
  #include <asm/errno.h>

  #include <malloc.h>

  /* It should access 16-bit instead of 8-bit */

  static void *memcpy_16(void *dst, const void *src, unsigned int len)

  {
  	void *ret = dst;
  	short *d = dst;
  	const short *s = src;
  
  	len >>= 1;
  	while (len-- > 0)
  		*d++ = *s++;
  	return ret;
  }

  /**

   *  onenand_oob_128 - oob info for Flex-Onenand with 4KB page
   *  For now, we expose only 64 out of 80 ecc bytes
   */
  static struct nand_ecclayout onenand_oob_128 = {
  	.eccbytes	= 64,
  	.eccpos		= {
  		6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
  		22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
  		38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
  		54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
  		70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
  		86, 87, 88, 89, 90, 91, 92, 93, 94, 95,
  		102, 103, 104, 105
  		},
  	.oobfree	= {
  		{2, 4}, {18, 4}, {34, 4}, {50, 4},
  		{66, 4}, {82, 4}, {98, 4}, {114, 4}
  	}
  };
  
  /**

   * 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 */

  	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,	/* 80 */
  	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,	/* 96 */
  	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,	/* 112 */
  	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,	/* 128 */

  };
  
  /**
   * 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 device	the device id
   * @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 device	the device id
   * @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);
  }
  
  /**

   * flexonenand_block - Return block number for flash address
   * @param this		- OneNAND device structure
   * @param addr		- Address for which block number is needed
   */
  static unsigned int flexonenand_block(struct onenand_chip *this, loff_t addr)
  {
  	unsigned int boundary, blk, die = 0;
  
  	if (ONENAND_IS_DDP(this) && addr >= this->diesize[0]) {
  		die = 1;
  		addr -= this->diesize[0];
  	}
  
  	boundary = this->boundary[die];
  
  	blk = addr >> (this->erase_shift - 1);
  	if (blk > boundary)
  		blk = (blk + boundary + 1) >> 1;
  
  	blk += die ? this->density_mask : 0;
  	return blk;
  }
  
  unsigned int onenand_block(struct onenand_chip *this, loff_t addr)
  {
  	if (!FLEXONENAND(this))
  		return addr >> this->erase_shift;
  	return flexonenand_block(this, addr);
  }
  
  /**
   * flexonenand_addr - Return address of the block
   * @this:		OneNAND device structure
   * @block:		Block number on Flex-OneNAND
   *
   * Return address of the block
   */
  static loff_t flexonenand_addr(struct onenand_chip *this, int block)
  {
  	loff_t ofs = 0;
  	int die = 0, boundary;
  
  	if (ONENAND_IS_DDP(this) && block >= this->density_mask) {
  		block -= this->density_mask;
  		die = 1;
  		ofs = this->diesize[0];
  	}
  
  	boundary = this->boundary[die];
  	ofs += (loff_t) block << (this->erase_shift - 1);
  	if (block > (boundary + 1))
  		ofs += (loff_t) (block - boundary - 1)
  			<< (this->erase_shift - 1);
  	return ofs;
  }
  
  loff_t onenand_addr(struct onenand_chip *this, int block)
  {
  	if (!FLEXONENAND(this))
  		return (loff_t) block << this->erase_shift;
  	return flexonenand_addr(this, block);
  }
  
  /**
   * flexonenand_region - [Flex-OneNAND] Return erase region of addr
   * @param mtd		MTD device structure
   * @param addr		address whose erase region needs to be identified
   */
  int flexonenand_region(struct mtd_info *mtd, loff_t addr)
  {
  	int i;
  
  	for (i = 0; i < mtd->numeraseregions; i++)
  		if (addr < mtd->eraseregions[i].offset)
  			break;
  	return i - 1;
  }
  
  /**

   * onenand_get_density - [DEFAULT] Get OneNAND density
   * @param dev_id        OneNAND device ID
   *
   * Get OneNAND density from device ID
   */
  static inline int onenand_get_density(int dev_id)
  {
  	int density = dev_id >> ONENAND_DEVICE_DENSITY_SHIFT;
  	return (density & ONENAND_DEVICE_DENSITY_MASK);
  }
  
  /**

   * 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;

  	int block, page;

  	/* Now we use page size operation */

  	int sectors = 0, count = 0;

  
  	/* 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 FLEXONENAND_CMD_PI_ACCESS:
  		/* addr contains die index */
  		block = addr * this->density_mask;
  		page = -1;
  		break;

  	case ONENAND_CMD_ERASE:
  	case ONENAND_CMD_BUFFERRAM:

  		block = onenand_block(this, addr);

  		page = -1;
  		break;

  	case FLEXONENAND_CMD_READ_PI:
  		cmd = ONENAND_CMD_READ;
  		block = addr * this->density_mask;
  		page = 0;
  		break;

  	default:

  		block = onenand_block(this, addr);
  		page = (int) (addr
  			- onenand_addr(this, block)) >> this->page_shift;

  		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_4KB_PAGE(this))

  			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);

  		/* Select DataRAM for DDP */

  		value = onenand_bufferram_address(this, block);
  		this->write_word(value,
  				 this->base + ONENAND_REG_START_ADDRESS2);

  	}
  
  	if (page != -1) {
  		int dataram;
  
  		switch (cmd) {

  		case FLEXONENAND_CMD_RECOVER_LSB:

  		case ONENAND_CMD_READ:
  		case ONENAND_CMD_READOOB:

  			if (ONENAND_IS_4KB_PAGE(this))

  				dataram = ONENAND_SET_BUFFERRAM0(this);
  			else
  				dataram = ONENAND_SET_NEXT_BUFFERRAM(this);

  			break;
  
  		default:
  			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);

  	}
  
  	/* 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_read_ecc - return ecc status
   * @param this		onenand chip structure
   */
  static int onenand_read_ecc(struct onenand_chip *this)
  {
  	int ecc, i;
  
  	if (!FLEXONENAND(this))
  		return this->read_word(this->base + ONENAND_REG_ECC_STATUS);
  
  	for (i = 0; i < 4; i++) {
  		ecc = this->read_word(this->base
  				+ ((ONENAND_REG_ECC_STATUS + i) << 1));
  		if (likely(!ecc))
  			continue;
  		if (ecc & FLEXONENAND_UNCORRECTABLE_ERROR)
  			return ONENAND_ECC_2BIT_ALL;
  	}
  
  	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 int flags = ONENAND_INT_MASTER;
  	unsigned int interrupt = 0;

  	unsigned int ctrl;

  
  	while (1) {
  		interrupt = this->read_word(this->base + ONENAND_REG_INTERRUPT);
  		if (interrupt & flags)
  			break;
  	}
  
  	ctrl = this->read_word(this->base + ONENAND_REG_CTRL_STATUS);

  	if (interrupt & ONENAND_INT_READ) {
  		int ecc = onenand_read_ecc(this);
  		if (ecc & ONENAND_ECC_2BIT_ALL) {
  			printk("onenand_wait: ECC error = 0x%04x
  ", ecc);
  			return -EBADMSG;
  		}
  	}

  	if (ctrl & ONENAND_CTRL_ERROR) {

  		printk("onenand_wait: controller error = 0x%04x
  ", ctrl);
  		if (ctrl & ONENAND_CTRL_LOCK)
  			printk("onenand_wait: it's locked error = 0x%04x
  ",
  				ctrl);

  		return -EIO;
  	}

  
  	return 0;
  }
  
  /**
   * 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)) {
  		if (area == ONENAND_DATARAM)

  			return mtd->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, loff_t addr, 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);

  	memcpy_16(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, loff_t addr, 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);

  	memcpy_16(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, loff_t addr, 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);

  	memcpy_16(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 = onenand_block(this, addr);

  		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 int 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;

  
  	return 0;
  }
  
  /**

   * 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 void onenand_get_device(struct mtd_info *mtd, int new_state)
  {
  	/* Do nothing */
  }
  
  /**
   * 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)
  {
  	/* Do nothing */
  }
  
  /**

   * onenand_transfer_auto_oob - [INTERN] 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, 0, 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_recover_lsb - [Flex-OneNAND] Recover LSB page data
   * @param mtd		MTD device structure
   * @param addr		address to recover
   * @param status	return value from onenand_wait
   *
   * MLC NAND Flash cell has paired pages - LSB page and MSB page. LSB page has
   * lower page address and MSB page has higher page address in paired pages.
   * If power off occurs during MSB page program, the paired LSB page data can
   * become corrupt. LSB page recovery read is a way to read LSB page though page
   * data are corrupted. When uncorrectable error occurs as a result of LSB page
   * read after power up, issue LSB page recovery read.
   */
  static int onenand_recover_lsb(struct mtd_info *mtd, loff_t addr, int status)
  {
  	struct onenand_chip *this = mtd->priv;
  	int i;
  
  	/* Recovery is only for Flex-OneNAND */
  	if (!FLEXONENAND(this))
  		return status;
  
  	/* check if we failed due to uncorrectable error */

  	if (!mtd_is_eccerr(status) && status != ONENAND_BBT_READ_ECC_ERROR)

  		return status;
  
  	/* check if address lies in MLC region */
  	i = flexonenand_region(mtd, addr);
  	if (mtd->eraseregions[i].erasesize < (1 << this->erase_shift))
  		return status;
  
  	printk("onenand_recover_lsb:"
  		"Attempting to recover from uncorrectable read
  ");
  
  	/* Issue the LSB page recovery command */
  	this->command(mtd, FLEXONENAND_CMD_RECOVER_LSB, addr, this->writesize);
  	return this->wait(mtd, FL_READING);
  }
  
  /**

   * 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;

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

  	if (ops->mode == MTD_OPS_AUTO_OOB)

  		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
  ");
  		ops->retlen = 0;
  		ops->oobretlen = 0;

  		return -EINVAL;
  	}

  	stats = mtd->ecc_stats;

  	/* Read-while-load method */

  	/* Note: We can't use this feature in MLC */

  	/* Do first load to bufferRAM */
  	if (read < len) {

  		if (!onenand_check_bufferram(mtd, from)) {

  			this->main_buf = buf;

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

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

  			if (unlikely(ret))
  				ret = onenand_recover_lsb(mtd, from, ret);

  			onenand_update_bufferram(mtd, from, !ret);
  			if (ret == -EBADMSG)
  				ret = 0;

  		}

  	}

  	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 (!ONENAND_IS_4KB_PAGE(this) && read + thislen < len) {

  			this->main_buf = buf + thislen;

  			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, from - thislen, 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_OPS_AUTO_OOB)

  				onenand_transfer_auto_oob(mtd, oobbuf, oobcolumn, thisooblen);
  			else

  				this->read_bufferram(mtd, 0, ONENAND_SPARERAM, oobbuf, oobcolumn, thisooblen);

  			oobread += thisooblen;
  			oobbuf += thisooblen;
  			oobcolumn = 0;

  		}

  		if (ONENAND_IS_4KB_PAGE(this) && (read + thislen < len)) {

  			this->command(mtd, ONENAND_CMD_READ, from, writesize);
  			ret = this->wait(mtd, FL_READING);
  			if (unlikely(ret))
  				ret = onenand_recover_lsb(mtd, from, ret);
  			onenand_update_bufferram(mtd, from, !ret);

  			if (mtd_is_eccerr(ret))

  				ret = 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);

  		if (!ONENAND_IS_4KB_PAGE(this))

  			ONENAND_SET_NEXT_BUFFERRAM(this);

  		buf += thislen;

  		thislen = min_t(int, writesize, len - read);
  		column = 0;

  		if (!ONENAND_IS_4KB_PAGE(this)) {

  			/* Now wait for load */
  			ret = this->wait(mtd, FL_READING);
  			onenand_update_bufferram(mtd, from, !ret);

  			if (mtd_is_eccerr(ret))

  				ret = 0;
  		}

  	}

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

  	/* return max bitflips per ecc step; ONENANDs correct 1 bit only */
  	return mtd->ecc_stats.corrected != stats.corrected ? 1 : 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;
  	struct mtd_ecc_stats stats;
  	int read = 0, thislen, column, oobsize;
  	size_t len = ops->ooblen;

  	unsigned int mode = ops->mode;

  	u_char *buf = ops->oobbuf;

  	int ret = 0, readcmd;

  
  	from += ops->ooboffs;

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

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

  	if (mode == MTD_OPS_AUTO_OOB)

  		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
  ");
  		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
  ");
  		return -EINVAL;
  	}
  
  	stats = mtd->ecc_stats;

  	readcmd = ONENAND_IS_4KB_PAGE(this) ?
  		ONENAND_CMD_READ : ONENAND_CMD_READOOB;

  	while (read < len) {
  		thislen = oobsize - column;
  		thislen = min_t(int, thislen, len);

  		this->spare_buf = buf;

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

  
  		onenand_update_bufferram(mtd, from, 0);
  
  		ret = this->wait(mtd, FL_READING);

  		if (unlikely(ret))
  			ret = onenand_recover_lsb(mtd, from, ret);

  		if (ret && ret != -EBADMSG) {
  			printk(KERN_ERR "onenand_read_oob_nolock: read failed = 0x%x
  ", ret);
  			break;
  		}

  		if (mode == MTD_OPS_AUTO_OOB)

  			onenand_transfer_auto_oob(mtd, buf, column, thislen);
  		else

  			this->read_bufferram(mtd, 0, ONENAND_SPARERAM, buf, column, thislen);

  
  		read += thislen;
  
  		if (read == len)
  			break;
  
  		buf += thislen;
  
  		/* Read more? */
  		if (read < len) {
  			/* Page size */
  			from += mtd->writesize;
  			column = 0;
  		}
  	}
  
  	ops->oobretlen = read;
  
  	if (ret)
  		return ret;
  
  	if (mtd->ecc_stats.failed - stats.failed)
  		return -EBADMSG;
  
  	return 0;

  }
  
  /**
   * onenand_read - [MTD Interface] MTD compability function for onenand_read_ecc
   * @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
   *
   * This function simply calls onenand_read_ecc with oob buffer and oobsel = NULL
  */
  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] OneNAND read out-of-band
   * @param mtd		MTD device structure
   * @param from		offset to read from

   * @param ops		oob operations description structure

   *

   * OneNAND main and/or out-of-band

   */

  int onenand_read_oob(struct mtd_info *mtd, loff_t from,
  			struct mtd_oob_ops *ops)
  {
  	int ret;
  
  	switch (ops->mode) {

  	case MTD_OPS_PLACE_OOB:
  	case MTD_OPS_AUTO_OOB:

  		break;

  	case MTD_OPS_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 int flags = ONENAND_INT_MASTER;
  	unsigned int interrupt;
  	unsigned int ctrl;
  
  	while (1) {
  		interrupt = this->read_word(this->base + ONENAND_REG_INTERRUPT);
  		if (interrupt & flags)
  			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 (interrupt & ONENAND_INT_READ) {

  		int ecc = onenand_read_ecc(this);
  		if (ecc & ONENAND_ECC_2BIT_ALL) {
  			printk(KERN_INFO "onenand_bbt_wait: ecc error = 0x%04x"
  				", controller = 0x%04x
  ", ecc, ctrl);

  			return ONENAND_BBT_READ_ERROR;

  		}

  	} else {
  		printk(KERN_ERR "onenand_bbt_wait: read timeout!"
  				"ctrl=0x%04x intr=0x%04x
  ", ctrl, interrupt);
  		return ONENAND_BBT_READ_FATAL_ERROR;
  	}

  	/* Initial bad block case: 0x2400 or 0x0400 */
  	if (ctrl & ONENAND_CTRL_ERROR) {
  		printk(KERN_DEBUG "onenand_bbt_wait: controller error = 0x%04x
  ", ctrl);
  		return ONENAND_BBT_READ_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, readcmd;

  	size_t len = ops->ooblen;
  	u_char *buf = ops->oobbuf;

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

  	readcmd = ONENAND_IS_4KB_PAGE(this) ?
  		ONENAND_CMD_READ : ONENAND_CMD_READOOB;

  	/* 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
  ");
  		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) {

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

  		this->spare_buf = buf;

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

  
  		onenand_update_bufferram(mtd, from, 0);

  		ret = this->bbt_wait(mtd, FL_READING);

  		if (unlikely(ret))
  			ret = onenand_recover_lsb(mtd, from, ret);

  		if (ret)
  			break;

  		this->read_bufferram(mtd, 0, 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;

  	u_char *oob_buf = this->oob_buf;

  	int status, i, readcmd;

  	readcmd = ONENAND_IS_4KB_PAGE(this) ?
  		ONENAND_CMD_READ : ONENAND_CMD_READOOB;

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

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

  	this->read_bufferram(mtd, 0, ONENAND_SPARERAM, oob_buf, 0, mtd->oobsize);

  	for (i = 0; i < mtd->oobsize; i++)
  		if (buf[i] != 0xFF && buf[i] != oob_buf[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 - [INTERN] 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;

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

  
  	/* Initialize retlen, in case of early exit */

  	ops->retlen = 0;
  	ops->oobretlen = 0;

  	/* Reject writes, which are not page aligned */

  	if (unlikely(NOTALIGNED(to) || NOTALIGNED(len))) {
  		printk(KERN_ERR "onenand_write_ops_nolock: Attempt to write not page aligned data
  ");

  		return -EINVAL;
  	}

  	if (ops->mode == MTD_OPS_AUTO_OOB)

  		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);

  		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, to, 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_OPS_AUTO_OOB)

  				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, 0, 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
  ", ret);

  			break;
  		}

  		/* Only check verify write turn on */

  		ret = onenand_verify(mtd, buf, to, thislen);

  		if (ret) {

  			printk(KERN_ERR "onenand_write_ops_nolock: verify failed %d
  ", ret);

  			break;
  		}

  		written += thislen;

  		if (written == len)
  			break;

  		column = 0;

  		to += thislen;
  		buf += thislen;
  	}

  	ops->retlen = written;

  
  	return ret;
  }
  
  /**

   * onenand_write_oob_nolock - [INTERN] 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, oobcmd;

  	u_char *oobbuf;
  	size_t len = ops->ooblen;
  	const u_char *buf = ops->oobbuf;

  	unsigned int mode = ops->mode;

  	to += ops->ooboffs;

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

  
  	/* Initialize retlen, in case of early exit */

  	ops->oobretlen = 0;

  	if (mode == MTD_OPS_AUTO_OOB)

  		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
  ");

  		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
  ");
  		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
  ");
  		return -EINVAL;
  	}
  
  	oobbuf = this->oob_buf;

  	oobcmd = ONENAND_IS_4KB_PAGE(this) ?
  		ONENAND_CMD_PROG : ONENAND_CMD_PROGOOB;

  	/* Loop until all data write */
  	while (written < len) {

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

  
  		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_OPS_AUTO_OOB)

  			onenand_fill_auto_oob(mtd, oobbuf, buf, column, thislen);
  		else
  			memcpy(oobbuf + column, buf, thislen);

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

  		if (ONENAND_IS_4KB_PAGE(this)) {

  			/* Set main area of DataRAM to 0xff*/
  			memset(this->page_buf, 0xff, mtd->writesize);
  			this->write_bufferram(mtd, 0, ONENAND_DATARAM,
  				this->page_buf,	0, mtd->writesize);
  		}
  
  		this->command(mtd, oobcmd, 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
  ", ret);

  			break;

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

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

  		to += mtd->writesize;

  		buf += thislen;

  		column = 0;

  	}

  	ops->oobretlen = written;
  
  	return ret;
  }
  
  /**
   * onenand_write - [MTD Interface] compability function for onenand_write_ecc
   * @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
   */
  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] OneNAND write out-of-band
   * @param mtd		MTD device structure
   * @param to		offset to write to
   * @param ops		oob operation description structure
   *
   * OneNAND write main and/or out-of-band
   */
  int onenand_write_oob(struct mtd_info *mtd, loff_t to,
  			struct mtd_oob_ops *ops)
  {
  	int ret;
  
  	switch (ops->mode) {

  	case MTD_OPS_PLACE_OOB:
  	case MTD_OPS_AUTO_OOB:

  		break;

  	case MTD_OPS_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
   */
  int onenand_erase(struct mtd_info *mtd, struct erase_info *instr)
  {
  	struct onenand_chip *this = mtd->priv;
  	unsigned int block_size;

  	loff_t addr = instr->addr;
  	unsigned int len = instr->len;
  	int ret = 0, i;
  	struct mtd_erase_region_info *region = NULL;
  	unsigned int region_end = 0;

  	MTDDEBUG(MTD_DEBUG_LEVEL3, "onenand_erase: start = 0x%08x, len = %i
  ",
  			(unsigned int) addr, len);

  	if (FLEXONENAND(this)) {
  		/* Find the eraseregion of this address */
  		i = flexonenand_region(mtd, addr);
  		region = &mtd->eraseregions[i];
  
  		block_size = region->erasesize;
  		region_end = region->offset
  			+ region->erasesize * region->numblocks;
  
  		/* Start address within region must align on block boundary.
  		 * Erase region's start offset is always block start address.
  		 */
  		if (unlikely((addr - region->offset) & (block_size - 1))) {
  			MTDDEBUG(MTD_DEBUG_LEVEL0, "onenand_erase:"
  				" Unaligned address
  ");
  			return -EINVAL;
  		}
  	} else {
  		block_size = 1 << this->erase_shift;
  
  		/* Start address must align on block boundary */
  		if (unlikely(addr & (block_size - 1))) {
  			MTDDEBUG(MTD_DEBUG_LEVEL0, "onenand_erase:"
  						"Unaligned address
  ");
  			return -EINVAL;
  		}

  	}

  	/* Length must align on block boundary */
  	if (unlikely(len & (block_size - 1))) {

  		MTDDEBUG (MTD_DEBUG_LEVEL0,

  			 "onenand_erase: Length not block aligned
  ");

  		return -EINVAL;
  	}

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

  	instr->state = MTD_ERASING;
  
  	while (len) {

  		/* Check if we have a bad block, we do not erase bad blocks */
  		if (instr->priv == 0 && onenand_block_isbad_nolock(mtd, addr, 0)) {
  			printk(KERN_WARNING "onenand_erase: attempt to erase"
  				" a bad block at addr 0x%08x
  ",
  				(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) {
  			if (ret == -EPERM)

  				MTDDEBUG (MTD_DEBUG_LEVEL0, "onenand_erase: "

  					  "Device is write protected!!!
  ");

  			else

  				MTDDEBUG (MTD_DEBUG_LEVEL0, "onenand_erase: "

  					  "Failed erase, block %d
  ",

  					onenand_block(this, addr));

  			instr->state = MTD_ERASE_FAILED;
  			instr->fail_addr = addr;

  			goto erase_exit;
  		}
  
  		len -= block_size;
  		addr += block_size;

  
  		if (addr == region_end) {
  			if (!len)
  				break;
  			region++;
  
  			block_size = region->erasesize;
  			region_end = region->offset
  				+ region->erasesize * region->numblocks;
  
  			if (len & (block_size - 1)) {
  				/* This has been checked at MTD
  				 * partitioning level. */
  				printk("onenand_erase: Unaligned address
  ");
  				goto erase_exit;
  			}
  		}

  	}
  
  	instr->state = MTD_ERASE_DONE;

  erase_exit:

  
  	ret = instr->state == MTD_ERASE_DONE ? 0 : -EIO;
  	/* Do call back function */
  	if (!ret)
  		mtd_erase_callback(instr);
  
  	/* Deselect and wake up anyone waiting on the device */
  	onenand_release_device(mtd);
  
  	return ret;
  }
  
  /**
   * onenand_sync - [MTD Interface] sync
   * @param mtd		MTD device structure
   *
   * Sync is actually a wait for chip ready function
   */
  void onenand_sync(struct mtd_info *mtd)
  {

  	MTDDEBUG (MTD_DEBUG_LEVEL3, "onenand_sync: called
  ");

  
  	/* 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

   */
  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_OPS_PLACE_OOB,

  		.ooblen = 2,
  		.oobbuf = buf,
  		.ooboffs = 0,
  	};
  	int block;
  
  	/* Get block number */

  	block = onenand_block(this, ofs);

  	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

   */
  int onenand_block_markbad(struct mtd_info *mtd, loff_t ofs)
  {

  	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;
  	}

  	ret = mtd_block_markbad(mtd, ofs);

  	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;

  	start = onenand_block(this, ofs);
  	end = onenand_block(this, ofs + len);

  
  	/* 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(end - 1,
  				 this->base + ONENAND_REG_END_BLOCK_ADDRESS);
  		/* Write unlock command */

  		this->command(mtd, cmd, 0, 0);

  
  		/* There's no return value */
  		this->wait(mtd, FL_UNLOCKING);
  
  		/* 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 & ONENAND_WP_US))
  			printk(KERN_ERR "wp status = 0x%x
  ", status);
  
  		return 0;
  	}
  
  	/* Block lock scheme */

  	for (block = start; 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);
  		/* Write unlock command */
  		this->command(mtd, ONENAND_CMD_UNLOCK, 0, 0);
  
  		/* There's no return value */
  		this->wait(mtd, FL_UNLOCKING);
  
  		/* 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 & ONENAND_WP_US))
  			printk(KERN_ERR "block = %d, wp status = 0x%x
  ",
  			       block, status);
  	}
  
  	return 0;
  }

  #ifdef ONENAND_LINUX

  /**

   * 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;
  }

  #endif

  
  /**
   * onenand_check_lock_status - [OneNAND Interface] Check lock status
   * @param this          onenand chip data structure
   *
   * Check lock status
   */
  static int 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
  ", block, status);
  			return 0;
  		}
  	}
  
  	return 1;
  }
  
  /**
   * onenand_unlock_all - [OneNAND Interface] unlock all blocks
   * @param mtd           MTD device structure
   *
   * Unlock all blocks
   */
  static void onenand_unlock_all(struct mtd_info *mtd)
  {
  	struct onenand_chip *this = mtd->priv;
  	loff_t ofs = 0;

  	size_t len = mtd->size;

  
  	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;

  		/* Check lock status */
  		if (onenand_check_lock_status(this))
  			return;
  
  		/* Workaround for all block unlock in DDP */

  		if (ONENAND_IS_DDP(this) && !FLEXONENAND(this)) {

  			/* All blocks on another chip */
  			ofs = this->chipsize >> 1;
  			len = this->chipsize >> 1;
  		}
  	}
  
  	onenand_do_lock_cmd(mtd, ofs, len, ONENAND_CMD_UNLOCK);
  }
  
  
  /**
   * 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 = onenand_get_density(this->device_id);
  	process = this->version_id >> ONENAND_VERSION_PROCESS_SHIFT;
  
  	/* Lock scheme */
  	switch (density) {
  	case ONENAND_DEVICE_DENSITY_4Gb:

  		if (ONENAND_IS_DDP(this))
  			this->options |= ONENAND_HAS_2PLANE;
  		else
  			this->options |= ONENAND_HAS_4KB_PAGE;

  
  	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 (ONENAND_IS_MLC(this))

  		this->options |= ONENAND_HAS_4KB_PAGE;
  
  	if (ONENAND_IS_4KB_PAGE(this))

  		this->options &= ~ONENAND_HAS_2PLANE;
  
  	if (FLEXONENAND(this)) {
  		this->options &= ~ONENAND_HAS_CONT_LOCK;
  		this->options |= ONENAND_HAS_UNLOCK_ALL;
  	}

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

  	if (this->options & ONENAND_HAS_4KB_PAGE)
  		printk(KERN_DEBUG "Chip has 4KiB pagesize
  ");

  }
  
  /**

   * onenand_print_device_info - Print device ID
   * @param device        device ID
   *
   * Print device ID
   */

  char *onenand_print_device_info(int device, int version)

  {

  	int vcc, demuxed, ddp, density, flexonenand;

  	char *dev_info = malloc(80);

  	char *p = dev_info;

  
  	vcc = device & ONENAND_DEVICE_VCC_MASK;
  	demuxed = device & ONENAND_DEVICE_IS_DEMUX;
  	ddp = device & ONENAND_DEVICE_IS_DDP;

  	density = onenand_get_density(device);
  	flexonenand = device & DEVICE_IS_FLEXONENAND;
  	p += sprintf(dev_info, "%s%sOneNAND%s %dMB %sV 16-bit (0x%02x)",

  	       demuxed ? "" : "Muxed ",

  	       flexonenand ? "Flex-" : "",

  	       ddp ? "(DDP)" : "",
  	       (16 << density), vcc ? "2.65/3.3" : "1.8", device);

  	sprintf(p, "
  OneNAND version = 0x%04x", version);
  	printk("%s
  ", dev_info);

  	return dev_info;

  }
  
  static const struct onenand_manufacturers onenand_manuf_ids[] = {

  	{ONENAND_MFR_NUMONYX, "Numonyx"},

  	{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);

  	int i;

  #ifdef ONENAND_DEBUG
  	char *name;
  #endif

  	for (i = 0; i < size; i++)

  		if (manuf == onenand_manuf_ids[i].id)
  			break;

  #ifdef ONENAND_DEBUG

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

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

  #endif

  	return i == size;

  }
  
  /**

  * flexonenand_get_boundary	- Reads the SLC boundary
  * @param onenand_info		- onenand info structure
  *
  * Fill up boundary[] field in onenand_chip
  **/
  static int flexonenand_get_boundary(struct mtd_info *mtd)
  {
  	struct onenand_chip *this = mtd->priv;
  	unsigned int die, bdry;

  	int syscfg, locked;

  
  	/* Disable ECC */
  	syscfg = this->read_word(this->base + ONENAND_REG_SYS_CFG1);
  	this->write_word((syscfg | 0x0100), this->base + ONENAND_REG_SYS_CFG1);
  
  	for (die = 0; die < this->dies; die++) {
  		this->command(mtd, FLEXONENAND_CMD_PI_ACCESS, die, 0);
  		this->wait(mtd, FL_SYNCING);
  
  		this->command(mtd, FLEXONENAND_CMD_READ_PI, die, 0);

  		this->wait(mtd, FL_READING);

  
  		bdry = this->read_word(this->base + ONENAND_DATARAM);
  		if ((bdry >> FLEXONENAND_PI_UNLOCK_SHIFT) == 3)
  			locked = 0;
  		else
  			locked = 1;
  		this->boundary[die] = bdry & FLEXONENAND_PI_MASK;
  
  		this->command(mtd, ONENAND_CMD_RESET, 0, 0);

  		this->wait(mtd, FL_RESETING);

  
  		printk(KERN_INFO "Die %d boundary: %d%s
  ", die,
  		       this->boundary[die], locked ? "(Locked)" : "(Unlocked)");
  	}
  
  	/* Enable ECC */
  	this->write_word(syscfg, this->base + ONENAND_REG_SYS_CFG1);
  	return 0;
  }
  
  /**
   * flexonenand_get_size - Fill up fields in onenand_chip and mtd_info
   * 			  boundary[], diesize[], mtd->size, mtd->erasesize,
   * 			  mtd->eraseregions
   * @param mtd		- MTD device structure
   */
  static void flexonenand_get_size(struct mtd_info *mtd)
  {
  	struct onenand_chip *this = mtd->priv;
  	int die, i, eraseshift, density;
  	int blksperdie, maxbdry;
  	loff_t ofs;
  
  	density = onenand_get_density(this->device_id);
  	blksperdie = ((loff_t)(16 << density) << 20) >> (this->erase_shift);
  	blksperdie >>= ONENAND_IS_DDP(this) ? 1 : 0;
  	maxbdry = blksperdie - 1;
  	eraseshift = this->erase_shift - 1;
  
  	mtd->numeraseregions = this->dies << 1;
  
  	/* This fills up the device boundary */
  	flexonenand_get_boundary(mtd);
  	die = 0;
  	ofs = 0;
  	i = -1;
  	for (; die < this->dies; die++) {
  		if (!die || this->boundary[die-1] != maxbdry) {
  			i++;
  			mtd->eraseregions[i].offset = ofs;
  			mtd->eraseregions[i].erasesize = 1 << eraseshift;
  			mtd->eraseregions[i].numblocks =
  							this->boundary[die] + 1;
  			ofs += mtd->eraseregions[i].numblocks << eraseshift;
  			eraseshift++;
  		} else {
  			mtd->numeraseregions -= 1;
  			mtd->eraseregions[i].numblocks +=
  							this->boundary[die] + 1;
  			ofs += (this->boundary[die] + 1) << (eraseshift - 1);
  		}
  		if (this->boundary[die] != maxbdry) {
  			i++;
  			mtd->eraseregions[i].offset = ofs;
  			mtd->eraseregions[i].erasesize = 1 << eraseshift;
  			mtd->eraseregions[i].numblocks = maxbdry ^
  							 this->boundary[die];
  			ofs += mtd->eraseregions[i].numblocks << eraseshift;
  			eraseshift--;
  		} else
  			mtd->numeraseregions -= 1;
  	}
  
  	/* Expose MLC erase size except when all blocks are SLC */
  	mtd->erasesize = 1 << this->erase_shift;
  	if (mtd->numeraseregions == 1)
  		mtd->erasesize >>= 1;
  
  	printk(KERN_INFO "Device has %d eraseregions
  ", mtd->numeraseregions);
  	for (i = 0; i < mtd->numeraseregions; i++)
  		printk(KERN_INFO "[offset: 0x%08llx, erasesize: 0x%05x,"
  			" numblocks: %04u]
  ", mtd->eraseregions[i].offset,
  			mtd->eraseregions[i].erasesize,
  			mtd->eraseregions[i].numblocks);
  
  	for (die = 0, mtd->size = 0; die < this->dies; die++) {
  		this->diesize[die] = (loff_t) (blksperdie << this->erase_shift);
  		this->diesize[die] -= (loff_t) (this->boundary[die] + 1)
  						 << (this->erase_shift - 1);
  		mtd->size += this->diesize[die];
  	}
  }
  
  /**
   * flexonenand_check_blocks_erased - Check if blocks are erased
   * @param mtd_info	- mtd info structure
   * @param start		- first erase block to check
   * @param end		- last erase block to check
   *
   * Converting an unerased block from MLC to SLC
   * causes byte values to change. Since both data and its ECC
   * have changed, reads on the block give uncorrectable error.
   * This might lead to the block being detected as bad.
   *
   * Avoid this by ensuring that the block to be converted is
   * erased.
   */
  static int flexonenand_check_blocks_erased(struct mtd_info *mtd,
  					int start, int end)
  {
  	struct onenand_chip *this = mtd->priv;
  	int i, ret;
  	int block;
  	struct mtd_oob_ops ops = {

  		.mode = MTD_OPS_PLACE_OOB,

  		.ooboffs = 0,
  		.ooblen	= mtd->oobsize,
  		.datbuf	= NULL,
  		.oobbuf	= this->oob_buf,
  	};
  	loff_t addr;
  
  	printk(KERN_DEBUG "Check blocks from %d to %d
  ", start, end);
  
  	for (block = start; block <= end; block++) {
  		addr = flexonenand_addr(this, block);
  		if (onenand_block_isbad_nolock(mtd, addr, 0))
  			continue;
  
  		/*
  		 * Since main area write results in ECC write to spare,
  		 * it is sufficient to check only ECC bytes for change.
  		 */
  		ret = onenand_read_oob_nolock(mtd, addr, &ops);
  		if (ret)
  			return ret;
  
  		for (i = 0; i < mtd->oobsize; i++)
  			if (this->oob_buf[i] != 0xff)
  				break;
  
  		if (i != mtd->oobsize) {
  			printk(KERN_WARNING "Block %d not erased.
  ", block);
  			return 1;
  		}
  	}
  
  	return 0;
  }
  
  /**
   * flexonenand_set_boundary	- Writes the SLC boundary
   * @param mtd			- mtd info structure
   */
  int flexonenand_set_boundary(struct mtd_info *mtd, int die,
  				    int boundary, int lock)
  {
  	struct onenand_chip *this = mtd->priv;
  	int ret, density, blksperdie, old, new, thisboundary;
  	loff_t addr;
  
  	if (die >= this->dies)
  		return -EINVAL;
  
  	if (boundary == this->boundary[die])
  		return 0;
  
  	density = onenand_get_density(this->device_id);
  	blksperdie = ((16 << density) << 20) >> this->erase_shift;
  	blksperdie >>= ONENAND_IS_DDP(this) ? 1 : 0;
  
  	if (boundary >= blksperdie) {
  		printk("flexonenand_set_boundary:"
  			"Invalid boundary value. "
  			"Boundary not changed.
  ");
  		return -EINVAL;
  	}
  
  	/* Check if converting blocks are erased */
  	old = this->boundary[die] + (die * this->density_mask);
  	new = boundary + (die * this->density_mask);
  	ret = flexonenand_check_blocks_erased(mtd, min(old, new)
  						+ 1, max(old, new));
  	if (ret) {
  		printk(KERN_ERR "flexonenand_set_boundary: Please erase blocks before boundary change
  ");
  		return ret;
  	}
  
  	this->command(mtd, FLEXONENAND_CMD_PI_ACCESS, die, 0);
  	this->wait(mtd, FL_SYNCING);
  
  	/* Check is boundary is locked */
  	this->command(mtd, FLEXONENAND_CMD_READ_PI, die, 0);
  	ret = this->wait(mtd, FL_READING);
  
  	thisboundary = this->read_word(this->base + ONENAND_DATARAM);
  	if ((thisboundary >> FLEXONENAND_PI_UNLOCK_SHIFT) != 3) {
  		printk(KERN_ERR "flexonenand_set_boundary: boundary locked
  ");
  		goto out;
  	}
  
  	printk(KERN_INFO "flexonenand_set_boundary: Changing die %d boundary: %d%s
  ",
  			die, boundary, lock ? "(Locked)" : "(Unlocked)");
  
  	boundary &= FLEXONENAND_PI_MASK;
  	boundary |= lock ? 0 : (3 << FLEXONENAND_PI_UNLOCK_SHIFT);
  
  	addr = die ? this->diesize[0] : 0;
  	this->command(mtd, ONENAND_CMD_ERASE, addr, 0);
  	ret = this->wait(mtd, FL_ERASING);
  	if (ret) {
  		printk("flexonenand_set_boundary:"
  			"Failed PI erase for Die %d
  ", die);
  		goto out;
  	}
  
  	this->write_word(boundary, this->base + ONENAND_DATARAM);
  	this->command(mtd, ONENAND_CMD_PROG, addr, 0);
  	ret = this->wait(mtd, FL_WRITING);
  	if (ret) {
  		printk("flexonenand_set_boundary:"
  			"Failed PI write for Die %d
  ", die);
  		goto out;
  	}
  
  	this->command(mtd, FLEXONENAND_CMD_PI_UPDATE, die, 0);
  	ret = this->wait(mtd, FL_WRITING);
  out:
  	this->write_word(ONENAND_CMD_RESET, this->base + ONENAND_REG_COMMAND);
  	this->wait(mtd, FL_RESETING);
  	if (!ret)
  		/* Recalculate device size on boundary change*/
  		flexonenand_get_size(mtd);
  
  	return ret;
  }
  
  /**

   * onenand_chip_probe - [OneNAND Interface] Probe the OneNAND chip

   * @param mtd		MTD device structure
   *
   * OneNAND detection method:
   *   Compare the the values from command with ones from register
   */

  static int onenand_chip_probe(struct mtd_info *mtd)

  {
  	struct onenand_chip *this = mtd->priv;

  	int bram_maf_id, bram_dev_id, maf_id, dev_id;

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

  	return 0;
  }
  
  /**
   * onenand_probe - [OneNAND Interface] Probe the OneNAND device
   * @param mtd		MTD device structure
   *
   * OneNAND detection method:
   *   Compare the the values from command with ones from register
   */
  int onenand_probe(struct mtd_info *mtd)
  {
  	struct onenand_chip *this = mtd->priv;

  	int dev_id, ver_id;

  	int density;
  	int ret;
  
  	ret = this->chip_probe(mtd);
  	if (ret)
  		return ret;

  	/* Read device IDs from Register */

  	dev_id = this->read_word(this->base + ONENAND_REG_DEVICE_ID);
  	ver_id = this->read_word(this->base + ONENAND_REG_VERSION_ID);
  	this->technology = this->read_word(this->base + ONENAND_REG_TECHNOLOGY);

  	/* Flash device information */

  	mtd->name = onenand_print_device_info(dev_id, ver_id);

  	this->device_id = dev_id;

  	this->version_id = ver_id;

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

  	density = onenand_get_density(dev_id);

  	if (FLEXONENAND(this)) {
  		this->dies = ONENAND_IS_DDP(this) ? 2 : 1;
  		/* Maximum possible erase regions */
  		mtd->numeraseregions = this->dies << 1;
  		mtd->eraseregions = malloc(sizeof(struct mtd_erase_region_info)
  					* (this->dies << 1));
  		if (!mtd->eraseregions)
  			return -ENOMEM;
  	}
  
  	/*
  	 * For Flex-OneNAND, chipsize represents maximum possible device size.
  	 * mtd->size represents the actual device size.
  	 */

  	this->chipsize = (16 << density) << 20;
  
  	/* 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);

  	/* We use the full BufferRAM */

  	if (ONENAND_IS_4KB_PAGE(this))

  		mtd->writesize <<= 1;

  	mtd->oobsize = mtd->writesize >> 5;

  	/* Pagers per block is always 64 in OneNAND */

  	mtd->erasesize = mtd->writesize << 6;

  	/*
  	 * Flex-OneNAND SLC area has 64 pages per block.
  	 * Flex-OneNAND MLC area has 128 pages per block.
  	 * Expose MLC erase size to find erase_shift and page_mask.
  	 */
  	if (FLEXONENAND(this))
  		mtd->erasesize <<= 1;

  
  	this->erase_shift = ffs(mtd->erasesize) - 1;

  	this->page_shift = ffs(mtd->writesize) - 1;

  	this->ppb_shift = (this->erase_shift - this->page_shift);

  	this->page_mask = (mtd->erasesize / mtd->writesize) - 1;

  	/* Set density mask. it is used for DDP */
  	if (ONENAND_IS_DDP(this))
  		this->density_mask = this->chipsize >> (this->erase_shift + 1);

  	/* It's real page size */
  	this->writesize = mtd->writesize;

  
  	/* REVIST: Multichip handling */

  	if (FLEXONENAND(this))
  		flexonenand_get_size(mtd);
  	else
  		mtd->size = this->chipsize;

  	mtd->flags = MTD_CAP_NANDFLASH;

  	mtd->_erase = onenand_erase;
  	mtd->_read = onenand_read;
  	mtd->_write = onenand_write;
  	mtd->_read_oob = onenand_read_oob;
  	mtd->_write_oob = onenand_write_oob;
  	mtd->_sync = onenand_sync;
  	mtd->_block_isbad = onenand_block_isbad;
  	mtd->_block_markbad = onenand_block_markbad;

  	return 0;
  }
  
  /**
   * 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)
  		this->wait = onenand_wait;

  	if (!this->bbt_wait)
  		this->bbt_wait = onenand_bbt_wait;

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

  	if (!this->chip_probe)
  		this->chip_probe = onenand_chip_probe;

  	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
  ");
  		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
  ");
  			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
  ");
  			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;
  
  	/*
  	 * Allow subpage writes up to oobsize.
  	 */
  	switch (mtd->oobsize) {

  	case 128:
  		this->ecclayout = &onenand_oob_128;
  		mtd->subpage_sft = 0;
  		break;

  	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
  ",
  			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;

  	/* 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)
  {
  }