/*
 *  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 <log.h>
#include <watchdog.h>
#include <dm/devres.h>
#include <linux/bitops.h>
#include <linux/compat.h>
#include <linux/mtd/mtd.h>
#include "linux/mtd/flashchip.h"
#include <linux/mtd/onenand.h>

#include <asm/io.h>
#include <linux/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} }
};

/*
 * Warning! This array is used with the memcpy_16() function, thus
 * it must be aligned to 2 bytes. GCC can make this array unaligned
 * as the array is made of unsigned char, which memcpy16() doesn't
 * like and will cause unaligned access.
 */
static const unsigned char __aligned(2) 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 interrupt = 0;
        unsigned int ctrl;

        /* Wait at most 20ms ... */
        u32 timeo = (CONFIG_SYS_HZ * 20) / 1000;
        u32 time_start = get_timer(0);
        do {
                WATCHDOG_RESET();
                if (get_timer(time_start) > timeo)
                        return -EIO;
                interrupt = this->read_word(this->base + ONENAND_REG_INTERRUPT);
        } while ((interrupt & ONENAND_INT_MASTER) == 0);

        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\n", ecc);
                        return -EBADMSG;
                }
        }

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

        /* 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;

        pr_debug("onenand_read_ops_nolock: from = 0x%08x, len = %i\n",
                 (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\n");
                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;

        pr_debug("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_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\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;
        }

        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\n", 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 interrupt;
        unsigned int ctrl;

        /* Wait at most 20ms ... */
        u32 timeo = (CONFIG_SYS_HZ * 20) / 1000;
        u32 time_start = get_timer(0);
        do {
                WATCHDOG_RESET();
                if (get_timer(time_start) > timeo)
                        return ONENAND_BBT_READ_FATAL_ERROR;
                interrupt = this->read_word(this->base + ONENAND_REG_INTERRUPT);
        } while ((interrupt & ONENAND_INT_MASTER) == 0);

        /* 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\n", ecc, ctrl);
                        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;
        }

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

        pr_debug("onenand_bbt_read_oob: from = 0x%08x, len = %zi\n",
                 (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\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) {

                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_LARGE && 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_LARGE && 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;

        pr_debug("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;

        /* 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\n");
                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\n", 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\n", 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;

        pr_debug("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_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\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;

        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\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] 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;

        pr_debug("onenand_erase: start = 0x%08x, len = %i\n",
                        (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))) {
                        pr_debug("onenand_erase:" " Unaligned address\n");
                        return -EINVAL;
                }
        } else {
                block_size = 1 << this->erase_shift;

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

        /* Length must align on block boundary */
        if (unlikely(len & (block_size - 1))) {
                pr_debug("onenand_erase: Length not block aligned\n");
                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\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) {
                        if (ret == -EPERM)
                                pr_debug("onenand_erase: "
                                         "Device is write protected!!!\n");
                        else
                                pr_debug("onenand_erase: "
                                         "Failed erase, block %d\n",
                                         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\n");
                                goto erase_exit;
                        }
                }
        }

        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);

        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)
{
        pr_debug("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
 */
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)
{
        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;

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

}

/**
 * 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, "\nOneNAND version = 0x%04x", version);
        printk("%s\n", 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)\n", 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\n", 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\n", mtd->numeraseregions);
        for (i = 0; i < mtd->numeraseregions; i++)
                printk(KERN_INFO "[offset: 0x%08llx, erasesize: 0x%05x,"
                        " numblocks: %04u]\n", 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\n", 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.\n", 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.\n");
                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\n");
                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\n");
                goto out;
        }

        printk(KERN_INFO "flexonenand_set_boundary: Changing die %d boundary: %d%s\n",
                        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\n", 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\n", 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 */
        if (this->wait(mtd, FL_RESETING))
                return -ENXIO;

        /* 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->type = ONENAND_IS_MLC(this) ? MTD_MLCNANDFLASH : MTD_NANDFLASH;
        mtd->flags = MTD_CAP_NANDFLASH;
        mtd->_erase = onenand_erase;
        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;
        mtd->writebufsize = mtd->writesize;

        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\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;

        /*
         * 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\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_LARGE &&
            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)
{
}