[MTD] Add initial support for OneNAND flash chips

OneNAND is a new flash technology from Samsung with integrated SRAM
buffers and logic interface.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 1462 insertions, 0 deletions

diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
new file mode 100644
index 000000000000..bcce22ae3cb1
--- /dev/null
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -0,0 +1,1462 @@
+/*
+ *  linux/drivers/mtd/onenand/onenand_base.c
+ *
+ *  Copyright (C) 2005 Samsung Electronics
+ *  Kyungmin Park <kyungmin.park@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/onenand.h>
+#include <linux/mtd/partitions.h>
+
+#include <asm/io.h>
+
+/**
+ * onenand_oob_64 - oob info for large (2KB) page
+ */
+static struct nand_oobinfo onenand_oob_64 = {
+        .useecc         = MTD_NANDECC_AUTOPLACE,
+        .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},
+                {24, 3}, {46, 2}, {40, 3}, {62, 2} }
+};
+
+/**
+ * onenand_oob_32 - oob info for middle (1KB) page
+ */
+static struct nand_oobinfo onenand_oob_32 = {
+        .useecc         = MTD_NANDECC_AUTOPLACE,
+        .eccbytes       = 10,
+        .eccpos         = {
+                8, 9, 10, 11, 12,
+                24, 25, 26, 27, 28,
+                },
+        .oobfree        = { {2, 3}, {14, 2}, {18, 3}, {30, 2} }
+};
+
+static const unsigned char ffchars[] = {
+        0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+        0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 16 */
+        0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+        0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 32 */
+        0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+        0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 48 */
+        0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+        0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 64 */
+};
+
+/**
+ * onenand_readw - [OneNAND Interface] Read OneNAND register
+ * @param addr          address to read
+ *
+ * Read OneNAND register
+ */
+static unsigned short onenand_readw(void __iomem *addr)
+{
+        return readw(addr);
+}
+
+/**
+ * onenand_writew - [OneNAND Interface] Write OneNAND register with value
+ * @param value         value to write
+ * @param addr          address to write
+ *
+ * Write OneNAND register with value
+ */
+static void onenand_writew(unsigned short value, void __iomem *addr)
+{
+        writew(value, addr);
+}
+
+/**
+ * onenand_block_address - [DEFAULT] Get block address
+ * @param 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(int device, int block)
+{
+        if (device & ONENAND_DEVICE_IS_DDP) {
+                /* Device Flash Core select, NAND Flash Block Address */
+                int dfs = 0, density, mask;
+
+                density = device >> ONENAND_DEVICE_DENSITY_SHIFT;
+                mask = (1 << (density + 6));
+
+                if (block & mask)
+                        dfs = 1;
+
+                return (dfs << ONENAND_DDP_SHIFT) | (block & (mask - 1));
+        }
+
+        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(int device, int block)
+{
+        if (device & ONENAND_DEVICE_IS_DDP) {
+                /* Device BufferRAM Select */
+                int dbs = 0, density, mask;
+
+                density = device >> ONENAND_DEVICE_DENSITY_SHIFT;
+                mask = (1 << (density + 6));
+
+                if (block & mask)
+                        dbs = 1;
+
+                return (dbs << ONENAND_DDP_SHIFT);
+        }
+
+        return 0;
+}
+
+/**
+ * onenand_page_address - [DEFAULT] Get page address
+ * @param page          the page address
+ * @param sector        the sector address
+ * @return              combined page and sector address
+ *
+ * Setup Start Address 8 Register (F107h)
+ */
+static int onenand_page_address(int page, int sector)
+{
+        /* Flash Page Address, Flash Sector Address */
+        int fpa, fsa;
+
+        fpa = page & ONENAND_FPA_MASK;
+        fsa = sector & ONENAND_FSA_MASK;
+
+        return ((fpa << ONENAND_FPA_SHIFT) | fsa);
+}
+
+/**
+ * onenand_buffer_address - [DEFAULT] Get buffer address
+ * @param dataram1      DataRAM index
+ * @param sectors       the sector address
+ * @param count         the number of sectors
+ * @return              the start buffer value
+ *
+ * Setup Start Buffer Register (F200h)
+ */
+static int onenand_buffer_address(int dataram1, int sectors, int count)
+{
+        int bsa, bsc;
+
+        /* BufferRAM Sector Address */
+        bsa = sectors & ONENAND_BSA_MASK;
+
+        if (dataram1)
+                bsa |= ONENAND_BSA_DATARAM1;    /* DataRAM1 */
+        else
+                bsa |= ONENAND_BSA_DATARAM0;    /* DataRAM0 */
+
+        /* BufferRAM Sector Count */
+        bsc = count & ONENAND_BSC_MASK;
+
+        return ((bsa << ONENAND_BSA_SHIFT) | bsc);
+}
+
+/**
+ * onenand_command - [DEFAULT] Send command to OneNAND device
+ * @param mtd           MTD device structure
+ * @param cmd           the command to be sent
+ * @param addr          offset to read from or write to
+ * @param len           number of bytes to read or write
+ *
+ * Send command to OneNAND device. This function is used for middle/large page
+ * devices (1KB/2KB Bytes per page)
+ */
+static int onenand_command(struct mtd_info *mtd, int cmd, loff_t addr, size_t len)
+{
+        struct onenand_chip *this = mtd->priv;
+        int value, readcmd = 0;
+        int block, page;
+        /* Now we use page size operation */
+        int sectors = 4, count = 4;
+
+        /* Address translation */
+        switch (cmd) {
+        case ONENAND_CMD_UNLOCK:
+        case ONENAND_CMD_LOCK:
+        case ONENAND_CMD_LOCK_TIGHT:
+                block = -1;
+                page = -1;
+                break;
+
+        case ONENAND_CMD_ERASE:
+        case ONENAND_CMD_BUFFERRAM:
+                block = (int) (addr >> this->erase_shift);
+                page = -1;
+                break;
+
+        default:
+                block = (int) (addr >> this->erase_shift);
+                page = (int) (addr >> 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->device_id, block);
+                this->write_word(value, this->base + ONENAND_REG_START_ADDRESS2);
+
+                /* 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->device_id, block);
+                this->write_word(value, this->base + ONENAND_REG_START_ADDRESS1);
+        }
+
+        if (page != -1) {
+                int dataram;
+
+                switch (cmd) {
+                case ONENAND_CMD_READ:
+                case ONENAND_CMD_READOOB:
+                        dataram = ONENAND_SET_NEXT_BUFFERRAM(this);
+                        readcmd = 1;
+                        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);
+                        
+                if (readcmd) {
+                        /* Select DataRAM for DDP */
+                        value = onenand_bufferram_address(this->device_id, block);
+                        this->write_word(value, this->base + ONENAND_REG_START_ADDRESS2);
+                }
+        }
+
+        /* Interrupt clear */
+        this->write_word(ONENAND_INT_CLEAR, this->base + ONENAND_REG_INTERRUPT);
+
+        /* Write command */
+        this->write_word(cmd, this->base + ONENAND_REG_COMMAND);
+
+        return 0;
+}
+
+/**
+ * onenand_wait - [DEFAULT] wait until the command is done
+ * @param mtd           MTD device structure
+ * @param state         state to select the max. timeout value
+ *
+ * Wait for command done. This applies to all OneNAND command
+ * Read can take up to 30us, erase up to 2ms and program up to 350us
+ * according to general OneNAND specs
+ */
+static int onenand_wait(struct mtd_info *mtd, int state)
+{
+        struct onenand_chip * this = mtd->priv;
+        unsigned long timeout;
+        unsigned int flags = ONENAND_INT_MASTER;
+        unsigned int interrupt = 0;
+        unsigned int ctrl, ecc;
+
+        /* The 20 msec is enough */
+        timeout = jiffies + msecs_to_jiffies(20);
+        while (time_before(jiffies, timeout)) {
+                interrupt = this->read_word(this->base + ONENAND_REG_INTERRUPT);
+
+                if (interrupt & flags)
+                        break;
+
+                if (state != FL_READING)
+                        cond_resched();
+        }
+        /* To get correct interrupt status in timeout case */
+        interrupt = this->read_word(this->base + ONENAND_REG_INTERRUPT);
+
+        ctrl = this->read_word(this->base + ONENAND_REG_CTRL_STATUS);
+
+        if (ctrl & ONENAND_CTRL_ERROR) {
+                DEBUG(MTD_DEBUG_LEVEL0, "onenand_wait: controller error = 0x%04x", ctrl);
+                return -EIO;
+        }
+
+        if (ctrl & ONENAND_CTRL_LOCK) {
+                DEBUG(MTD_DEBUG_LEVEL0, "onenand_wait: it's locked error = 0x%04x", ctrl);
+                return -EIO;
+        }
+
+        if (interrupt & ONENAND_INT_READ) {
+                ecc = this->read_word(this->base + ONENAND_REG_ECC_STATUS);
+                if (ecc & ONENAND_ECC_2BIT_ALL) {
+                        DEBUG(MTD_DEBUG_LEVEL0, "onenand_wait: ECC error = 0x%04x", ecc);
+                        return -EBADMSG;
+                }
+        }
+
+        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->oobblock;
+                if (area == ONENAND_SPARERAM)
+                        return mtd->oobsize;
+        }
+
+        return 0;
+}
+
+/**
+ * onenand_read_bufferram - [OneNAND Interface] Read the bufferram area
+ * @param mtd           MTD data structure
+ * @param area          BufferRAM area
+ * @param buffer        the databuffer to put/get data
+ * @param offset        offset to read from or write to
+ * @param count         number of bytes to read/write
+ *
+ * Read the BufferRAM area
+ */
+static int onenand_read_bufferram(struct mtd_info *mtd, int area,
+                unsigned char *buffer, int offset, size_t count)
+{
+        struct onenand_chip *this = mtd->priv;
+        void __iomem *bufferram;
+
+        bufferram = this->base + area;
+
+        bufferram += onenand_bufferram_offset(mtd, area);
+
+        memcpy(buffer, bufferram + offset, count);
+
+        return 0;
+}
+
+/**
+ * onenand_write_bufferram - [OneNAND Interface] Write the bufferram area
+ * @param mtd           MTD data structure
+ * @param area          BufferRAM area
+ * @param buffer        the databuffer to put/get data
+ * @param offset        offset to read from or write to
+ * @param count         number of bytes to read/write
+ *
+ * Write the BufferRAM area
+ */
+static int onenand_write_bufferram(struct mtd_info *mtd, int area,
+                const unsigned char *buffer, int offset, size_t count)
+{
+        struct onenand_chip *this = mtd->priv;
+        void __iomem *bufferram;
+
+        bufferram = this->base + area;
+
+        bufferram += onenand_bufferram_offset(mtd, area);
+
+        memcpy(bufferram + offset, buffer, count);
+
+        return 0;
+}
+
+/**
+ * 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 block, page;
+        int i;
+        
+        block = (int) (addr >> this->erase_shift);
+        page = (int) (addr >> this->page_shift);
+        page &= this->page_mask;
+
+        i = ONENAND_CURRENT_BUFFERRAM(this);
+
+        /* Is there valid data? */
+        if (this->bufferram[i].block == block &&
+            this->bufferram[i].page == page &&
+            this->bufferram[i].valid)
+                return 1;
+
+        return 0;
+}
+
+/**
+ * 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 block, page;
+        int i;
+        
+        block = (int) (addr >> this->erase_shift);
+        page = (int) (addr >> this->page_shift);
+        page &= this->page_mask;
+
+        /* Invalidate BufferRAM */
+        for (i = 0; i < MAX_BUFFERRAM; i++) {
+                if (this->bufferram[i].block == block &&
+                    this->bufferram[i].page == page)
+                        this->bufferram[i].valid = 0;
+        }
+
+        /* Update BufferRAM */
+        i = ONENAND_CURRENT_BUFFERRAM(this);
+        this->bufferram[i].block = block;
+        this->bufferram[i].page = page;
+        this->bufferram[i].valid = valid;
+
+        return 0;
+}
+
+/**
+ * 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)
+{
+        struct onenand_chip *this = mtd->priv;
+        DECLARE_WAITQUEUE(wait, current);
+
+        /*
+         * Grab the lock and see if the device is available
+         */
+        while (1) {
+                spin_lock(&this->chip_lock);
+                if (this->state == FL_READY) {
+                        this->state = new_state;
+                        spin_unlock(&this->chip_lock);
+                        break;
+                }
+                set_current_state(TASK_UNINTERRUPTIBLE);
+                add_wait_queue(&this->wq, &wait);
+                spin_unlock(&this->chip_lock);
+                schedule();
+                remove_wait_queue(&this->wq, &wait);
+        }
+}
+
+/**
+ * onenand_release_device - [GENERIC] release chip
+ * @param mtd           MTD device structure
+ *
+ * Deselect, release chip lock and wake up anyone waiting on the device
+ */
+static void onenand_release_device(struct mtd_info *mtd)
+{
+        struct onenand_chip *this = mtd->priv;
+
+        /* Release the chip */
+        spin_lock(&this->chip_lock);
+        this->state = FL_READY;
+        wake_up(&this->wq);
+        spin_unlock(&this->chip_lock);
+}
+
+/**
+ * onenand_read_ecc - [MTD Interface] Read data with 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
+ * @param oob_buf       filesystem supplied oob data buffer
+ * @param oobsel        oob selection structure
+ *
+ * OneNAND read with ECC
+ */
+static int onenand_read_ecc(struct mtd_info *mtd, loff_t from, size_t len,
+        size_t *retlen, u_char *buf,
+        u_char *oob_buf, struct nand_oobinfo *oobsel)
+{
+        struct onenand_chip *this = mtd->priv;
+        int read = 0, column;
+        int thislen;
+        int ret = 0;
+
+        DEBUG(MTD_DEBUG_LEVEL3, "onenand_read_ecc: from = 0x%08x, len = %i\n", (unsigned int) from, (int) len);
+
+        /* Do not allow reads past end of device */
+        if ((from + len) > mtd->size) {
+                DEBUG(MTD_DEBUG_LEVEL0, "onenand_read_ecc: Attempt read beyond end of device\n");
+                *retlen = 0;
+                return -EINVAL;
+        }
+
+        /* Grab the lock and see if the device is available */
+        onenand_get_device(mtd, FL_READING);
+
+        /* TODO handling oob */
+
+        while (read < len) {
+                thislen = min_t(int, mtd->oobblock, len - read);
+
+                column = from & (mtd->oobblock - 1);
+                if (column + thislen > mtd->oobblock)
+                        thislen = mtd->oobblock - column;
+
+                if (!onenand_check_bufferram(mtd, from)) {
+                        this->command(mtd, ONENAND_CMD_READ, from, mtd->oobblock);
+
+                        ret = this->wait(mtd, FL_READING);
+                        /* First copy data and check return value for ECC handling */
+                        onenand_update_bufferram(mtd, from, 1);
+                }
+
+                this->read_bufferram(mtd, ONENAND_DATARAM, buf, column, thislen);
+
+                read += thislen;
+
+                if (read == len)
+                        break;
+
+                if (ret) {
+                        DEBUG(MTD_DEBUG_LEVEL0, "onenand_read_ecc: read failed = %d\n", ret);
+                        goto out;
+                }
+
+                from += thislen;
+                buf += thislen;
+        }
+
+out:
+        /* Deselect and wake up anyone waiting on the device */
+        onenand_release_device(mtd);
+
+        /*
+         * Return success, if no ECC failures, else -EBADMSG
+         * fs driver will take care of that, because
+         * retlen == desired len and result == -EBADMSG
+         */
+        *retlen = read;
+        return ret;
+}
+
+/**
+ * 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
+*/
+static int onenand_read(struct mtd_info *mtd, loff_t from, size_t len,
+        size_t *retlen, u_char *buf)
+{
+        return onenand_read_ecc(mtd, from, len, retlen, buf, NULL, NULL);
+}
+
+/**
+ * onenand_read_oob - [MTD Interface] OneNAND read out-of-band
+ * @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
+ *
+ * OneNAND read out-of-band data from the spare area
+ */
+static int onenand_read_oob(struct mtd_info *mtd, loff_t from, size_t len,
+        size_t *retlen, u_char *buf)
+{
+        struct onenand_chip *this = mtd->priv;
+        int read = 0, thislen, column;
+        int ret = 0;
+
+        DEBUG(MTD_DEBUG_LEVEL3, "onenand_read_oob: from = 0x%08x, len = %i\n", (unsigned int) from, (int) len);
+
+        /* Initialize return length value */
+        *retlen = 0;
+
+        /* Do not allow reads past end of device */
+        if (unlikely((from + len) > mtd->size)) {
+                DEBUG(MTD_DEBUG_LEVEL0, "onenand_read_oob: Attempt read beyond end of device\n");
+                return -EINVAL;
+        }
+
+        /* 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->command(mtd, ONENAND_CMD_READOOB, from, mtd->oobsize);
+
+                onenand_update_bufferram(mtd, from, 0);
+
+                ret = this->wait(mtd, FL_READING);
+                /* First copy data and check return value for ECC handling */
+
+                this->read_bufferram(mtd, ONENAND_SPARERAM, buf, column, thislen);
+
+                read += thislen;
+
+                if (read == len)
+                        break;
+
+                if (ret) {
+                        DEBUG(MTD_DEBUG_LEVEL0, "onenand_read_oob: read failed = %d\n", ret);
+                        goto out;
+                }
+
+                buf += thislen;
+
+                /* Read more? */
+                if (read < len) {
+                        /* Page size */
+                        from += mtd->oobblock;
+                        column = 0;
+                }
+        }
+
+out:
+        /* Deselect and wake up anyone waiting on the device */
+        onenand_release_device(mtd);
+
+        *retlen = read;
+        return ret;
+}
+
+#ifdef CONFIG_MTD_ONENAND_VERIFY_WRITE
+/**
+ * onenand_verify_page - [GENERIC] verify the chip contents after a write
+ * @param mtd           MTD device structure
+ * @param buf           the databuffer to verify
+ * @param block         block address
+ * @param page          page address
+ *
+ * Check DataRAM area directly
+ */
+static int onenand_verify_page(struct mtd_info *mtd, u_char *buf,
+        loff_t addr, int block, int page)
+{
+        struct onenand_chip *this = mtd->priv;
+        void __iomem *dataram0, *dataram1;
+        int ret = 0;
+
+        this->command(mtd, ONENAND_CMD_READ, addr, mtd->oobblock);
+
+        ret = this->wait(mtd, FL_READING);
+        if (ret)
+                return ret;
+
+        onenand_update_bufferram(mtd, addr, 1);
+
+        /* Check, if the two dataram areas are same */
+        dataram0 = this->base + ONENAND_DATARAM;
+        dataram1 = dataram0 + mtd->oobblock;
+
+        if (memcmp(dataram0, dataram1, mtd->oobblock))
+                return -EBADMSG;
+        
+        return 0;
+}
+#else
+#define onenand_verify_page(...)        (0)
+#endif
+
+#define NOTALIGNED(x)   ((x & (mtd->oobblock - 1)) != 0)
+
+/**
+ * onenand_write_ecc - [MTD Interface] OneNAND write with 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
+ * @param eccbuf        filesystem supplied oob data buffer
+ * @param oobsel        oob selection structure
+ *
+ * OneNAND write with ECC
+ */
+static int onenand_write_ecc(struct mtd_info *mtd, loff_t to, size_t len,
+        size_t *retlen, const u_char *buf,
+        u_char *eccbuf, struct nand_oobinfo *oobsel)
+{
+        struct onenand_chip *this = mtd->priv;
+        int written = 0;
+        int ret = 0;
+
+        DEBUG(MTD_DEBUG_LEVEL3, "onenand_write_ecc: to = 0x%08x, len = %i\n", (unsigned int) to, (int) len);
+
+        /* Initialize retlen, in case of early exit */
+        *retlen = 0;
+
+        /* Do not allow writes past end of device */
+        if (unlikely((to + len) > mtd->size)) {
+                DEBUG(MTD_DEBUG_LEVEL0, "onenand_write_ecc: Attempt write to past end of device\n");
+                return -EINVAL;
+        }
+
+        /* Reject writes, which are not page aligned */
+        if (unlikely(NOTALIGNED(to)) || unlikely(NOTALIGNED(len))) {
+                DEBUG(MTD_DEBUG_LEVEL0, "onenand_write_ecc: Attempt to write not page aligned data\n");
+                return -EINVAL;
+        }
+
+        /* Grab the lock and see if the device is available */
+        onenand_get_device(mtd, FL_WRITING);
+
+        /* Loop until all data write */
+        while (written < len) {
+                int thislen = min_t(int, mtd->oobblock, len - written);
+
+                this->command(mtd, ONENAND_CMD_BUFFERRAM, to, mtd->oobblock);
+
+                this->write_bufferram(mtd, ONENAND_DATARAM, buf, 0, thislen);
+                this->write_bufferram(mtd, ONENAND_SPARERAM, ffchars, 0, mtd->oobsize);
+
+                this->command(mtd, ONENAND_CMD_PROG, to, mtd->oobblock);
+
+                onenand_update_bufferram(mtd, to, 1);
+
+                ret = this->wait(mtd, FL_WRITING);
+                if (ret) {
+                        DEBUG(MTD_DEBUG_LEVEL0, "onenand_write_ecc: write filaed %d\n", ret);
+                        goto out;
+                }
+
+                written += thislen;
+
+                /* Only check verify write turn on */
+                ret = onenand_verify_page(mtd, (u_char *) buf, to, block, page);
+                if (ret) {
+                        DEBUG(MTD_DEBUG_LEVEL0, "onenand_write_ecc: verify failed %d\n", ret);
+                        goto out;
+                }
+
+                if (written == len)
+                        break;
+
+                to += thislen;
+                buf += thislen;
+        }
+
+out:
+        /* Deselect and wake up anyone waiting on the device */
+        onenand_release_device(mtd);
+
+        *retlen = 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
+ *
+ * This function simply calls onenand_write_ecc
+ * with oob buffer and oobsel = NULL
+ */
+static int onenand_write(struct mtd_info *mtd, loff_t to, size_t len,
+        size_t *retlen, const u_char *buf)
+{
+        return onenand_write_ecc(mtd, to, len, retlen, buf, NULL, NULL);
+}
+
+/**
+ * onenand_write_oob - [MTD Interface] 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
+ *
+ * OneNAND write out-of-band
+ */
+static int onenand_write_oob(struct mtd_info *mtd, loff_t to, size_t len,
+        size_t *retlen, const u_char *buf)
+{
+        struct onenand_chip *this = mtd->priv;
+        int column, status;
+        int written = 0;
+
+        DEBUG(MTD_DEBUG_LEVEL3, "onenand_write_oob: to = 0x%08x, len = %i\n", (unsigned int) to, (int) len);
+
+        /* Initialize retlen, in case of early exit */
+        *retlen = 0;
+
+        /* Do not allow writes past end of device */
+        if (unlikely((to + len) > mtd->size)) {
+                DEBUG(MTD_DEBUG_LEVEL0, "onenand_write_oob: Attempt write to past end of device\n");
+                return -EINVAL;
+        }
+
+        /* Grab the lock and see if the device is available */
+        onenand_get_device(mtd, FL_WRITING);
+
+        /* Loop until all data write */
+        while (written < len) {
+                int thislen = min_t(int, mtd->oobsize, len - written);
+
+                column = to & (mtd->oobsize - 1);
+
+                this->command(mtd, ONENAND_CMD_BUFFERRAM, to, mtd->oobsize);
+
+                this->write_bufferram(mtd, ONENAND_SPARERAM, ffchars, 0, mtd->oobsize);
+                this->write_bufferram(mtd, ONENAND_SPARERAM, buf, column, thislen);
+
+                this->command(mtd, ONENAND_CMD_PROGOOB, to, mtd->oobsize);
+
+                onenand_update_bufferram(mtd, to, 0);
+
+                status = this->wait(mtd, FL_WRITING);
+                if (status)
+                        goto out;
+
+                written += thislen;
+
+                if (written == len)
+                        break;
+
+                to += thislen;
+                buf += thislen;
+        }
+
+out:
+        /* Deselect and wake up anyone waiting on the device */
+        onenand_release_device(mtd);
+
+        *retlen = written;
+        
+        return 0;
+}
+
+/**
+ * onenand_writev_ecc - [MTD Interface] write with iovec with ecc
+ * @param mtd           MTD device structure
+ * @param vecs          the iovectors to write
+ * @param count         number of vectors
+ * @param to            offset to write to
+ * @param retlen        pointer to variable to store the number of written bytes
+ * @param eccbuf        filesystem supplied oob data buffer
+ * @param oobsel        oob selection structure
+ *
+ * OneNAND write with iovec with ecc
+ */
+static int onenand_writev_ecc(struct mtd_info *mtd, const struct kvec *vecs,
+        unsigned long count, loff_t to, size_t *retlen,
+        u_char *eccbuf, struct nand_oobinfo *oobsel)
+{
+        struct onenand_chip *this = mtd->priv;
+        unsigned char buffer[mtd->oobblock], *pbuf;
+        size_t total_len, len;
+        int i, written = 0;
+        int ret = 0;
+
+        /* Preset written len for early exit */
+        *retlen = 0;
+
+        /* Calculate total length of data */
+        total_len = 0;
+        for (i = 0; i < count; i++)
+                total_len += vecs[i].iov_len;
+
+        DEBUG(MTD_DEBUG_LEVEL3, "onenand_writev_ecc: to = 0x%08x, len = %i, count = %ld\n", (unsigned int) to, (unsigned int) total_len, count);
+
+        /* Do not allow write past end of the device */
+        if (unlikely((to + total_len) > mtd->size)) {
+                DEBUG(MTD_DEBUG_LEVEL0, "onenand_writev_ecc: Attempted write past end of device\n");
+                return -EINVAL;
+        }
+
+        /* Reject writes, which are not page aligned */
+        if (unlikely(NOTALIGNED(to)) || unlikely(NOTALIGNED(total_len))) {
+                DEBUG(MTD_DEBUG_LEVEL0, "onenand_writev_ecc: Attempt to write not page aligned data\n");
+                return -EINVAL;
+        }
+
+        /* Grab the lock and see if the device is available */
+        onenand_get_device(mtd, FL_WRITING);
+
+        /* TODO handling oob */
+        
+        /* Loop until all keve's data has been written */
+        len = 0;
+        while (count) {
+                pbuf = buffer;
+                /* 
+                 * If the given tuple is >= pagesize then
+                 * write it out from the iov
+                 */
+                if ((vecs->iov_len - len) >= mtd->oobblock) {
+                        pbuf = vecs->iov_base + len;
+
+                        len += mtd->oobblock;
+
+                        /* Check, if we have to switch to the next tuple */
+                        if (len >= (int) vecs->iov_len) {
+                                vecs++;
+                                len = 0;
+                                count--;
+                        }
+                } else {
+                        int cnt = 0, thislen;
+                        while (cnt < mtd->oobblock) {
+                                thislen = min_t(int, mtd->oobblock - cnt, vecs->iov_len - len);
+                                memcpy(buffer + cnt, vecs->iov_base + len, thislen);
+                                cnt += thislen;
+                                len += thislen;
+
+                                /* Check, if we have to switch to the next tuple */
+                                if (len >= (int) vecs->iov_len) {
+                                        vecs++;
+                                        len = 0;
+                                        count--;
+                                }
+                        }
+                }
+
+                this->command(mtd, ONENAND_CMD_BUFFERRAM, to, mtd->oobblock);
+
+                this->write_bufferram(mtd, ONENAND_DATARAM, pbuf, 0, mtd->oobblock);
+                this->write_bufferram(mtd, ONENAND_SPARERAM, ffchars, 0, mtd->oobsize);
+
+                this->command(mtd, ONENAND_CMD_PROG, to, mtd->oobblock);
+
+                onenand_update_bufferram(mtd, to, 1);
+
+                ret = this->wait(mtd, FL_WRITING);
+                if (ret) {
+                        DEBUG(MTD_DEBUG_LEVEL0, "onenand_writev_ecc: write failed %d\n", ret);
+                        goto out;
+                }
+
+
+                /* Only check verify write turn on */
+                ret = onenand_verify_page(mtd, (u_char *) pbuf, to, block, page);
+                if (ret) {
+                        DEBUG(MTD_DEBUG_LEVEL0, "onenand_writev_ecc: verify failed %d\n", ret);
+                        goto out;
+                }
+
+                written += mtd->oobblock;
+
+                to += mtd->oobblock;
+        }
+
+out:
+        /* Deselect and wakt up anyone waiting on the device */
+        onenand_release_device(mtd);
+
+        *retlen = written;
+
+        return 0;
+}
+
+/**
+ * onenand_writev - [MTD Interface] compabilty function for onenand_writev_ecc
+ * @param mtd           MTD device structure
+ * @param vecs          the iovectors to write
+ * @param count         number of vectors
+ * @param to            offset to write to
+ * @param retlen        pointer to variable to store the number of written bytes
+ *
+ * OneNAND write with kvec. This just calls the ecc function
+ */
+static int onenand_writev(struct mtd_info *mtd, const struct kvec *vecs,
+        unsigned long count, loff_t to, size_t *retlen)
+{
+        return onenand_writev_ecc(mtd, vecs, count, to, retlen, NULL, NULL);
+}
+
+/**
+ * onenand_erase - [MTD Interface] erase block(s)
+ * @param mtd           MTD device structure
+ * @param instr         erase instruction
+ *
+ * Erase one ore more blocks
+ */
+static int onenand_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+        struct onenand_chip *this = mtd->priv;
+        unsigned int block_size;
+        loff_t addr;
+        int len;
+        int ret = 0;
+
+        DEBUG(MTD_DEBUG_LEVEL3, "onenand_erase: start = 0x%08x, len = %i\n", (unsigned int) instr->addr, (unsigned int) instr->len);
+
+        block_size = (1 << this->erase_shift);
+
+        /* Start address must align on block boundary */
+        if (unlikely(instr->addr & (block_size - 1))) {
+                DEBUG(MTD_DEBUG_LEVEL0, "onenand_erase: Unaligned address\n");
+                return -EINVAL;
+        }
+
+        /* Length must align on block boundary */
+        if (unlikely(instr->len & (block_size - 1))) {
+                DEBUG(MTD_DEBUG_LEVEL0, "onenand_erase: Length not block aligned\n");
+                return -EINVAL;
+        }
+
+        /* Do not allow erase past end of device */
+        if (unlikely((instr->len + instr->addr) > mtd->size)) {
+                DEBUG(MTD_DEBUG_LEVEL0, "onenand_erase: Erase past end of device\n");
+                return -EINVAL;
+        }
+
+        instr->fail_addr = 0xffffffff;
+
+        /* Grab the lock and see if the device is available */
+        onenand_get_device(mtd, FL_ERASING);
+
+        /* Loop throught the pages */
+        len = instr->len;
+        addr = instr->addr;
+
+        instr->state = MTD_ERASING;
+
+        while (len) {
+
+                /* TODO Check badblock */
+
+                this->command(mtd, ONENAND_CMD_ERASE, addr, block_size);
+
+                ret = this->wait(mtd, FL_ERASING);
+                /* Check, if it is write protected */
+                if (ret) {
+                        if (ret == -EPERM)
+                                DEBUG(MTD_DEBUG_LEVEL0, "onenand_erase: Device is write protected!!!\n");
+                        else
+                                DEBUG(MTD_DEBUG_LEVEL0, "onenand_erase: Failed erase, block %d\n", (unsigned) (addr >> this->erase_shift));
+                        instr->state = MTD_ERASE_FAILED;
+                        instr->fail_addr = addr;
+                        goto erase_exit;
+                }
+
+                len -= block_size;
+                addr += block_size;
+        }
+
+        instr->state = MTD_ERASE_DONE;
+
+erase_exit:
+
+        ret = instr->state == MTD_ERASE_DONE ? 0 : -EIO;
+        /* Do call back function */
+        if (!ret)
+                mtd_erase_callback(instr);
+
+        /* Deselect and wake up anyone waiting on the device */
+        onenand_release_device(mtd);
+
+        return ret;
+}
+
+/**
+ * onenand_sync - [MTD Interface] sync
+ * @param mtd           MTD device structure
+ *
+ * Sync is actually a wait for chip ready function
+ */
+static void onenand_sync(struct mtd_info *mtd)
+{
+        DEBUG(MTD_DEBUG_LEVEL3, "onenand_sync: called\n");
+
+        /* Grab the lock and see if the device is available */
+        onenand_get_device(mtd, FL_SYNCING);
+
+        /* Release it and go back */
+        onenand_release_device(mtd);
+}
+
+/**
+ * onenand_block_isbad - [MTD Interface] Check whether the block at the given offset is bad
+ * @param mtd           MTD device structure
+ * @param ofs           offset relative to mtd start
+ */
+static int onenand_block_isbad(struct mtd_info *mtd, loff_t ofs)
+{
+        /*
+         * TODO 
+         * 1. Bad block table (BBT)
+         *   -> using NAND BBT to support JFFS2
+         * 2. Bad block management (BBM)
+         *   -> bad block replace scheme
+         *
+         * Currently we do nothing
+         */
+        return 0;
+}
+
+/**
+ * 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
+ */
+static int onenand_block_markbad(struct mtd_info *mtd, loff_t ofs)
+{
+        /* see above */
+        return 0;
+}
+
+/**
+ * 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)
+{
+        struct onenand_chip *this = mtd->priv;
+        int start, end, block, value, status;
+
+        start = ofs >> this->erase_shift;
+        end = len >> this->erase_shift;
+
+        /* Continuous lock scheme */
+        if (this->options & ONENAND_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, 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 "wp status = 0x%x\n", status);
+
+                return 0;
+        }
+
+        /* Block lock scheme */
+        for (block = start; block < end; block++) {
+                /* 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;
+
+                /* Set block address for read block status */
+                value = onenand_block_address(this->device_id, block);
+                this->write_word(value, this->base + ONENAND_REG_START_ADDRESS1);
+
+                /* 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;
+}
+
+/**
+ * onenand_print_device_info - Print device ID
+ * @param device        device ID
+ *
+ * Print device ID
+ */
+static void onenand_print_device_info(int device)
+{
+        int vcc, demuxed, ddp, density;
+
+        vcc = device & ONENAND_DEVICE_VCC_MASK;
+        demuxed = device & ONENAND_DEVICE_IS_DEMUX;
+        ddp = device & ONENAND_DEVICE_IS_DDP;
+        density = device >> ONENAND_DEVICE_DENSITY_SHIFT;
+        printk(KERN_INFO "%sOneNAND%s %dMB %sV 16-bit (0x%02x)\n",
+                demuxed ? "" : "Muxed ",
+                ddp ? "(DDP)" : "",
+                (16 << density),
+                vcc ? "2.65/3.3" : "1.8",
+                device);
+}
+
+static const struct onenand_manufacturers onenand_manuf_ids[] = {
+        {ONENAND_MFR_SAMSUNG, "Samsung"},
+        {ONENAND_MFR_UNKNOWN, "Unknown"}
+};
+
+/**
+ * onenand_check_maf - Check manufacturer ID
+ * @param manuf         manufacturer ID
+ *
+ * Check manufacturer ID
+ */
+static int onenand_check_maf(int manuf)
+{
+        int i;
+
+        for (i = 0; onenand_manuf_ids[i].id; i++) {
+                if (manuf == onenand_manuf_ids[i].id)
+                        break;
+        }
+
+        printk(KERN_DEBUG "OneNAND Manufacturer: %s\n",
+                onenand_manuf_ids[i].name);
+
+        return (i != ONENAND_MFR_UNKNOWN);
+}
+
+/**
+ * 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
+ */
+static int onenand_probe(struct mtd_info *mtd)
+{
+        struct onenand_chip *this = mtd->priv;
+        int bram_maf_id, bram_dev_id, maf_id, dev_id;
+        int version_id;
+        int density;
+
+        /* 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);
+
+        /* Check manufacturer ID */
+        if (onenand_check_maf(bram_maf_id))
+                return -ENXIO;
+
+        /* Reset OneNAND to read default register values */
+        this->write_word(ONENAND_CMD_RESET, this->base + ONENAND_BOOTRAM);
+
+        /* 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;
+
+        /* Flash device information */
+        onenand_print_device_info(dev_id);
+        this->device_id = dev_id;
+
+        density = dev_id >> ONENAND_DEVICE_DENSITY_SHIFT;
+        this->chipsize = (16 << density) << 20;
+
+        /* OneNAND page size & block size */
+        /* The data buffer size is equal to page size */
+        mtd->oobblock = this->read_word(this->base + ONENAND_REG_DATA_BUFFER_SIZE);
+        mtd->oobsize = mtd->oobblock >> 5;
+        /* Pagers per block is always 64 in OneNAND */
+        mtd->erasesize = mtd->oobblock << 6;
+
+        this->erase_shift = ffs(mtd->erasesize) - 1;
+        this->page_shift = ffs(mtd->oobblock) - 1;
+        this->ppb_shift = (this->erase_shift - this->page_shift);
+        this->page_mask = (mtd->erasesize / mtd->oobblock) - 1;
+
+        /* REVIST: Multichip handling */
+
+        mtd->size = this->chipsize;
+
+        /* Version ID */
+        version_id = this->read_word(this->base + ONENAND_REG_VERSION_ID);
+        printk(KERN_DEBUG "OneNAND version = 0x%04x\n", version_id);
+
+        /* Lock scheme */
+        if (density <= ONENAND_DEVICE_DENSITY_512Mb &&
+            !(version_id >> ONENAND_VERSION_PROCESS_SHIFT)) {
+                printk(KERN_INFO "Lock scheme is Continues Lock\n");
+                this->options |= ONENAND_CONT_LOCK;
+        }
+        
+        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)
+{
+        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->read_bufferram)
+                this->read_bufferram = onenand_read_bufferram;
+        if (!this->write_bufferram)
+                this->write_bufferram = onenand_write_bufferram;
+
+        if (onenand_probe(mtd))
+                return -ENXIO;
+
+        this->state = FL_READY;
+        init_waitqueue_head(&this->wq);
+        spin_lock_init(&this->chip_lock);
+
+        switch (mtd->oobsize) {
+        case 64:
+                this->autooob = &onenand_oob_64;
+                break;
+
+        case 32:
+                this->autooob = &onenand_oob_32;
+                break;
+
+        default:
+                printk(KERN_WARNING "No OOB scheme defined for oobsize %d\n",
+                        mtd->oobsize);
+                /* To prevent kernel oops */
+                this->autooob = &onenand_oob_32;
+                break;
+        }
+
+        memcpy(&mtd->oobinfo, this->autooob, sizeof(mtd->oobinfo));
+        
+        /* Fill in remaining MTD driver data */
+        mtd->type = MTD_NANDFLASH;
+        mtd->flags = MTD_CAP_NANDFLASH | MTD_ECC;
+        mtd->ecctype = MTD_ECC_SW;
+        mtd->erase = onenand_erase;
+        mtd->point = NULL;
+        mtd->unpoint = NULL;
+        mtd->read = onenand_read;
+        mtd->write = onenand_write;
+        mtd->read_ecc = onenand_read_ecc;
+        mtd->write_ecc = onenand_write_ecc;
+        mtd->read_oob = onenand_read_oob;
+        mtd->write_oob = onenand_write_oob;
+        mtd->readv = NULL;
+        mtd->readv_ecc = NULL;
+        mtd->writev = onenand_writev;
+        mtd->writev_ecc = onenand_writev_ecc;
+        mtd->sync = onenand_sync;
+        mtd->lock = NULL;
+        mtd->unlock = onenand_unlock;
+        mtd->suspend = NULL;
+        mtd->resume = NULL;
+        mtd->block_isbad = onenand_block_isbad;
+        mtd->block_markbad = onenand_block_markbad;
+        mtd->owner = THIS_MODULE;
+
+        /* Unlock whole block */
+        mtd->unlock(mtd, 0x0, this->chipsize);
+
+        return 0;
+}
+
+/**
+ * onenand_release - [OneNAND Interface] Free resources held by the OneNAND device
+ * @param mtd           MTD device structure
+ */
+void onenand_release(struct mtd_info *mtd)
+{
+#ifdef CONFIG_MTD_PARTITIONS
+        /* Deregister partitions */
+        del_mtd_partitions (mtd);
+#endif
+        /* Deregister the device */
+        del_mtd_device (mtd);
+}
+
+EXPORT_SYMBOL_GPL(onenand_scan);
+EXPORT_SYMBOL_GPL(onenand_release);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Kyungmin Park <kyungmin.park@samsung.com>");
+MODULE_DESCRIPTION("Generic OneNAND flash driver code");