/*
 * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
 * Copyright 2008 Sascha Hauer, kernel@pengutronix.de
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 */

#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>

#include <asm/mach/flash.h>
#include <mach/mxc_nand.h>

#define DRIVER_NAME "mxc_nand"

/* Addresses for NFC registers */
#define NFC_BUF_SIZE            0xE00
#define NFC_BUF_ADDR            0xE04
#define NFC_FLASH_ADDR          0xE06
#define NFC_FLASH_CMD           0xE08
#define NFC_CONFIG              0xE0A
#define NFC_ECC_STATUS_RESULT   0xE0C
#define NFC_RSLTMAIN_AREA       0xE0E
#define NFC_RSLTSPARE_AREA      0xE10
#define NFC_WRPROT              0xE12
#define NFC_UNLOCKSTART_BLKADDR 0xE14
#define NFC_UNLOCKEND_BLKADDR   0xE16
#define NFC_NF_WRPRST           0xE18
#define NFC_CONFIG1             0xE1A
#define NFC_CONFIG2             0xE1C

/* Addresses for NFC RAM BUFFER Main area 0 */
#define MAIN_AREA0              0x000
#define MAIN_AREA1              0x200
#define MAIN_AREA2              0x400
#define MAIN_AREA3              0x600

/* Addresses for NFC SPARE BUFFER Spare area 0 */
#define SPARE_AREA0             0x800
#define SPARE_AREA1             0x810
#define SPARE_AREA2             0x820
#define SPARE_AREA3             0x830

/* Set INT to 0, FCMD to 1, rest to 0 in NFC_CONFIG2 Register
 * for Command operation */
#define NFC_CMD            0x1

/* Set INT to 0, FADD to 1, rest to 0 in NFC_CONFIG2 Register
 * for Address operation */
#define NFC_ADDR           0x2

/* Set INT to 0, FDI to 1, rest to 0 in NFC_CONFIG2 Register
 * for Input operation */
#define NFC_INPUT          0x4

/* Set INT to 0, FDO to 001, rest to 0 in NFC_CONFIG2 Register
 * for Data Output operation */
#define NFC_OUTPUT         0x8

/* Set INT to 0, FD0 to 010, rest to 0 in NFC_CONFIG2 Register
 * for Read ID operation */
#define NFC_ID             0x10

/* Set INT to 0, FDO to 100, rest to 0 in NFC_CONFIG2 Register
 * for Read Status operation */
#define NFC_STATUS         0x20

/* Set INT to 1, rest to 0 in NFC_CONFIG2 Register for Read
 * Status operation */
#define NFC_INT            0x8000

#define NFC_SP_EN           (1 << 2)
#define NFC_ECC_EN          (1 << 3)
#define NFC_INT_MSK         (1 << 4)
#define NFC_BIG             (1 << 5)
#define NFC_RST             (1 << 6)
#define NFC_CE              (1 << 7)
#define NFC_ONE_CYCLE       (1 << 8)

struct mxc_nand_host {
        struct mtd_info         mtd;
        struct nand_chip        nand;
        struct mtd_partition    *parts;
        struct device           *dev;

        void __iomem            *regs;
        int                     spare_only;
        int                     status_request;
        int                     pagesize_2k;
        uint16_t                col_addr;
        struct clk              *clk;
        int                     clk_act;
        int                     irq;

        wait_queue_head_t       irq_waitq;
};

/* Define delays in microsec for NAND device operations */
#define TROP_US_DELAY   2000
/* Macros to get byte and bit positions of ECC */
#define COLPOS(x)  ((x) >> 3)
#define BITPOS(x) ((x) & 0xf)

/* Define single bit Error positions in Main & Spare area */
#define MAIN_SINGLEBIT_ERROR 0x4
#define SPARE_SINGLEBIT_ERROR 0x1

/* OOB placement block for use with hardware ecc generation */
static struct nand_ecclayout nand_hw_eccoob_8 = {
        .eccbytes = 5,
        .eccpos = {6, 7, 8, 9, 10},
        .oobfree = {{0, 5}, {11, 5}, }
};

static struct nand_ecclayout nand_hw_eccoob_16 = {
        .eccbytes = 5,
        .eccpos = {6, 7, 8, 9, 10},
        .oobfree = {{0, 5}, {11, 5}, }
};

static struct nand_ecclayout nand_hw_eccoob_64 = {
        .eccbytes = 20,
        .eccpos = {6, 7, 8, 9, 10, 22, 23, 24, 25, 26,
                   38, 39, 40, 41, 42, 54, 55, 56, 57, 58},
        .oobfree = {{2, 4}, {11, 10}, {27, 10}, {43, 10}, {59, 5}, }
};

#ifdef CONFIG_MTD_PARTITIONS
static const char *part_probes[] = { "RedBoot", "cmdlinepart", NULL };
#endif

static irqreturn_t mxc_nfc_irq(int irq, void *dev_id)
{
        struct mxc_nand_host *host = dev_id;

        uint16_t tmp;

        tmp = readw(host->regs + NFC_CONFIG1);
        tmp |= NFC_INT_MSK; /* Disable interrupt */
        writew(tmp, host->regs + NFC_CONFIG1);

        wake_up(&host->irq_waitq);

        return IRQ_HANDLED;
}

/* This function polls the NANDFC to wait for the basic operation to
 * complete by checking the INT bit of config2 register.
 */
static void wait_op_done(struct mxc_nand_host *host, int max_retries,
                                uint16_t param, int useirq)
{
        uint32_t tmp;

        if (useirq) {
                if ((readw(host->regs + NFC_CONFIG2) & NFC_INT) == 0) {

                        tmp = readw(host->regs + NFC_CONFIG1);
                        tmp  &= ~NFC_INT_MSK;   /* Enable interrupt */
                        writew(tmp, host->regs + NFC_CONFIG1);

                        wait_event(host->irq_waitq,
                                readw(host->regs + NFC_CONFIG2) & NFC_INT);

                        tmp = readw(host->regs + NFC_CONFIG2);
                        tmp  &= ~NFC_INT;
                        writew(tmp, host->regs + NFC_CONFIG2);
                }
        } else {
                while (max_retries-- > 0) {
                        if (readw(host->regs + NFC_CONFIG2) & NFC_INT) {
                                tmp = readw(host->regs + NFC_CONFIG2);
                                tmp  &= ~NFC_INT;
                                writew(tmp, host->regs + NFC_CONFIG2);
                                break;
                        }
                        udelay(1);
                }
                if (max_retries < 0)
                        DEBUG(MTD_DEBUG_LEVEL0, "%s(%d): INT not set\n",
                              __func__, param);
        }
}

/* This function issues the specified command to the NAND device and
 * waits for completion. */
static void send_cmd(struct mxc_nand_host *host, uint16_t cmd, int useirq)
{
        DEBUG(MTD_DEBUG_LEVEL3, "send_cmd(host, 0x%x, %d)\n", cmd, useirq);

        writew(cmd, host->regs + NFC_FLASH_CMD);
        writew(NFC_CMD, host->regs + NFC_CONFIG2);

        /* Wait for operation to complete */
        wait_op_done(host, TROP_US_DELAY, cmd, useirq);
}

/* This function sends an address (or partial address) to the
 * NAND device. The address is used to select the source/destination for
 * a NAND command. */
static void send_addr(struct mxc_nand_host *host, uint16_t addr, int islast)
{
        DEBUG(MTD_DEBUG_LEVEL3, "send_addr(host, 0x%x %d)\n", addr, islast);

        writew(addr, host->regs + NFC_FLASH_ADDR);
        writew(NFC_ADDR, host->regs + NFC_CONFIG2);

        /* Wait for operation to complete */
        wait_op_done(host, TROP_US_DELAY, addr, islast);
}

/* This function requests the NANDFC to initate the transfer
 * of data currently in the NANDFC RAM buffer to the NAND device. */
static void send_prog_page(struct mxc_nand_host *host, uint8_t buf_id,
                        int spare_only)
{
        DEBUG(MTD_DEBUG_LEVEL3, "send_prog_page (%d)\n", spare_only);

        /* NANDFC buffer 0 is used for page read/write */
        writew(buf_id, host->regs + NFC_BUF_ADDR);

        /* Configure spare or page+spare access */
        if (!host->pagesize_2k) {
                uint16_t config1 = readw(host->regs + NFC_CONFIG1);
                if (spare_only)
                        config1 |= NFC_SP_EN;
                else
                        config1 &= ~(NFC_SP_EN);
                writew(config1, host->regs + NFC_CONFIG1);
        }

        writew(NFC_INPUT, host->regs + NFC_CONFIG2);

        /* Wait for operation to complete */
        wait_op_done(host, TROP_US_DELAY, spare_only, true);
}

/* Requests NANDFC to initated the transfer of data from the
 * NAND device into in the NANDFC ram buffer. */
static void send_read_page(struct mxc_nand_host *host, uint8_t buf_id,
                int spare_only)
{
        DEBUG(MTD_DEBUG_LEVEL3, "send_read_page (%d)\n", spare_only);

        /* NANDFC buffer 0 is used for page read/write */
        writew(buf_id, host->regs + NFC_BUF_ADDR);

        /* Configure spare or page+spare access */
        if (!host->pagesize_2k) {
                uint32_t config1 = readw(host->regs + NFC_CONFIG1);
                if (spare_only)
                        config1 |= NFC_SP_EN;
                else
                        config1 &= ~NFC_SP_EN;
                writew(config1, host->regs + NFC_CONFIG1);
        }

        writew(NFC_OUTPUT, host->regs + NFC_CONFIG2);

        /* Wait for operation to complete */
        wait_op_done(host, TROP_US_DELAY, spare_only, true);
}

/* Request the NANDFC to perform a read of the NAND device ID. */
static void send_read_id(struct mxc_nand_host *host)
{
        struct nand_chip *this = &host->nand;
        uint16_t tmp;

        /* NANDFC buffer 0 is used for device ID output */
        writew(0x0, host->regs + NFC_BUF_ADDR);

        /* Read ID into main buffer */
        tmp = readw(host->regs + NFC_CONFIG1);
        tmp &= ~NFC_SP_EN;
        writew(tmp, host->regs + NFC_CONFIG1);

        writew(NFC_ID, host->regs + NFC_CONFIG2);

        /* Wait for operation to complete */
        wait_op_done(host, TROP_US_DELAY, 0, true);

        if (this->options & NAND_BUSWIDTH_16) {
                void __iomem *main_buf = host->regs + MAIN_AREA0;
                /* compress the ID info */
                writeb(readb(main_buf + 2), main_buf + 1);
                writeb(readb(main_buf + 4), main_buf + 2);
                writeb(readb(main_buf + 6), main_buf + 3);
                writeb(readb(main_buf + 8), main_buf + 4);
                writeb(readb(main_buf + 10), main_buf + 5);
        }
}

/* This function requests the NANDFC to perform a read of the
 * NAND device status and returns the current status. */
static uint16_t get_dev_status(struct mxc_nand_host *host)
{
        void __iomem *main_buf = host->regs + MAIN_AREA1;
        uint32_t store;
        uint16_t ret, tmp;
        /* Issue status request to NAND device */

        /* store the main area1 first word, later do recovery */
        store = readl(main_buf);
        /* NANDFC buffer 1 is used for device status to prevent
         * corruption of read/write buffer on status requests. */
        writew(1, host->regs + NFC_BUF_ADDR);

        /* Read status into main buffer */
        tmp = readw(host->regs + NFC_CONFIG1);
        tmp &= ~NFC_SP_EN;
        writew(tmp, host->regs + NFC_CONFIG1);

        writew(NFC_STATUS, host->regs + NFC_CONFIG2);

        /* Wait for operation to complete */
        wait_op_done(host, TROP_US_DELAY, 0, true);

        /* Status is placed in first word of main buffer */
        /* get status, then recovery area 1 data */
        ret = readw(main_buf);
        writel(store, main_buf);

        return ret;
}

/* This functions is used by upper layer to checks if device is ready */
static int mxc_nand_dev_ready(struct mtd_info *mtd)
{
        /*
         * NFC handles R/B internally. Therefore, this function
         * always returns status as ready.
         */
        return 1;
}

static void mxc_nand_enable_hwecc(struct mtd_info *mtd, int mode)
{
        /*
         * If HW ECC is enabled, we turn it on during init. There is
         * no need to enable again here.
         */
}

static int mxc_nand_correct_data(struct mtd_info *mtd, u_char *dat,
                                 u_char *read_ecc, u_char *calc_ecc)
{
        struct nand_chip *nand_chip = mtd->priv;
        struct mxc_nand_host *host = nand_chip->priv;

        /*
         * 1-Bit errors are automatically corrected in HW.  No need for
         * additional correction.  2-Bit errors cannot be corrected by
         * HW ECC, so we need to return failure
         */
        uint16_t ecc_status = readw(host->regs + NFC_ECC_STATUS_RESULT);

        if (((ecc_status & 0x3) == 2) || ((ecc_status >> 2) == 2)) {
                DEBUG(MTD_DEBUG_LEVEL0,
                      "MXC_NAND: HWECC uncorrectable 2-bit ECC error\n");
                return -1;
        }

        return 0;
}

static int mxc_nand_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
                                  u_char *ecc_code)
{
        return 0;
}

static u_char mxc_nand_read_byte(struct mtd_info *mtd)
{
        struct nand_chip *nand_chip = mtd->priv;
        struct mxc_nand_host *host = nand_chip->priv;
        uint8_t ret = 0;
        uint16_t col, rd_word;
        uint16_t __iomem *main_buf = host->regs + MAIN_AREA0;
        uint16_t __iomem *spare_buf = host->regs + SPARE_AREA0;

        /* Check for status request */
        if (host->status_request)
                return get_dev_status(host) & 0xFF;

        /* Get column for 16-bit access */
        col = host->col_addr >> 1;

        /* If we are accessing the spare region */
        if (host->spare_only)
                rd_word = readw(&spare_buf[col]);
        else
                rd_word = readw(&main_buf[col]);

        /* Pick upper/lower byte of word from RAM buffer */
        if (host->col_addr & 0x1)
                ret = (rd_word >> 8) & 0xFF;
        else
                ret = rd_word & 0xFF;

        /* Update saved column address */
        host->col_addr++;

        return ret;
}

static uint16_t mxc_nand_read_word(struct mtd_info *mtd)
{
        struct nand_chip *nand_chip = mtd->priv;
        struct mxc_nand_host *host = nand_chip->priv;
        uint16_t col, rd_word, ret;
        uint16_t __iomem *p;

        DEBUG(MTD_DEBUG_LEVEL3,
              "mxc_nand_read_word(col = %d)\n", host->col_addr);

        col = host->col_addr;
        /* Adjust saved column address */
        if (col < mtd->writesize && host->spare_only)
                col += mtd->writesize;

        if (col < mtd->writesize)
                p = (host->regs + MAIN_AREA0) + (col >> 1);
        else
                p = (host->regs + SPARE_AREA0) + ((col - mtd->writesize) >> 1);

        if (col & 1) {
                rd_word = readw(p);
                ret = (rd_word >> 8) & 0xff;
                rd_word = readw(&p[1]);
                ret |= (rd_word << 8) & 0xff00;

        } else
                ret = readw(p);

        /* Update saved column address */
        host->col_addr = col + 2;

        return ret;
}

/* Write data of length len to buffer buf. The data to be
 * written on NAND Flash is first copied to RAMbuffer. After the Data Input
 * Operation by the NFC, the data is written to NAND Flash */
static void mxc_nand_write_buf(struct mtd_info *mtd,
                                const u_char *buf, int len)
{
        struct nand_chip *nand_chip = mtd->priv;
        struct mxc_nand_host *host = nand_chip->priv;
        int n, col, i = 0;

        DEBUG(MTD_DEBUG_LEVEL3,
              "mxc_nand_write_buf(col = %d, len = %d)\n", host->col_addr,
              len);

        col = host->col_addr;

        /* Adjust saved column address */
        if (col < mtd->writesize && host->spare_only)
                col += mtd->writesize;

        n = mtd->writesize + mtd->oobsize - col;
        n = min(len, n);

        DEBUG(MTD_DEBUG_LEVEL3,
              "%s:%d: col = %d, n = %d\n", __func__, __LINE__, col, n);

        while (n) {
                void __iomem *p;

                if (col < mtd->writesize)
                        p = host->regs + MAIN_AREA0 + (col & ~3);
                else
                        p = host->regs + SPARE_AREA0 -
                                                mtd->writesize + (col & ~3);

                DEBUG(MTD_DEBUG_LEVEL3, "%s:%d: p = %p\n", __func__,
                      __LINE__, p);

                if (((col | (int)&buf[i]) & 3) || n < 16) {
                        uint32_t data = 0;

                        if (col & 3 || n < 4)
                                data = readl(p);

                        switch (col & 3) {
                        case 0:
                                if (n) {
                                        data = (data & 0xffffff00) |
                                            (buf[i++] << 0);
                                        n--;
                                        col++;
                                }
                        case 1:
                                if (n) {
                                        data = (data & 0xffff00ff) |
                                            (buf[i++] << 8);
                                        n--;
                                        col++;
                                }
                        case 2:
                                if (n) {
                                        data = (data & 0xff00ffff) |
                                            (buf[i++] << 16);
                                        n--;
                                        col++;
                                }
                        case 3:
                                if (n) {
                                        data = (data & 0x00ffffff) |
                                            (buf[i++] << 24);
                                        n--;
                                        col++;
                                }
                        }

                        writel(data, p);
                } else {
                        int m = mtd->writesize - col;

                        if (col >= mtd->writesize)
                                m += mtd->oobsize;

                        m = min(n, m) & ~3;

                        DEBUG(MTD_DEBUG_LEVEL3,
                              "%s:%d: n = %d, m = %d, i = %d, col = %d\n",
                              __func__,  __LINE__, n, m, i, col);

                        memcpy(p, &buf[i], m);
                        col += m;
                        i += m;
                        n -= m;
                }
        }
        /* Update saved column address */
        host->col_addr = col;
}

/* Read the data buffer from the NAND Flash. To read the data from NAND
 * Flash first the data output cycle is initiated by the NFC, which copies
 * the data to RAMbuffer. This data of length len is then copied to buffer buf.
 */
static void mxc_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
{
        struct nand_chip *nand_chip = mtd->priv;
        struct mxc_nand_host *host = nand_chip->priv;
        int n, col, i = 0;

        DEBUG(MTD_DEBUG_LEVEL3,
              "mxc_nand_read_buf(col = %d, len = %d)\n", host->col_addr, len);

        col = host->col_addr;

        /* Adjust saved column address */
        if (col < mtd->writesize && host->spare_only)
                col += mtd->writesize;

        n = mtd->writesize + mtd->oobsize - col;
        n = min(len, n);

        while (n) {
                void __iomem *p;

                if (col < mtd->writesize)
                        p = host->regs + MAIN_AREA0 + (col & ~3);
                else
                        p = host->regs + SPARE_AREA0 -
                                        mtd->writesize + (col & ~3);

                if (((col | (int)&buf[i]) & 3) || n < 16) {
                        uint32_t data;

                        data = readl(p);
                        switch (col & 3) {
                        case 0:
                                if (n) {
                                        buf[i++] = (uint8_t) (data);
                                        n--;
                                        col++;
                                }
                        case 1:
                                if (n) {
                                        buf[i++] = (uint8_t) (data >> 8);
                                        n--;
                                        col++;
                                }
                        case 2:
                                if (n) {
                                        buf[i++] = (uint8_t) (data >> 16);
                                        n--;
                                        col++;
                                }
                        case 3:
                                if (n) {
                                        buf[i++] = (uint8_t) (data >> 24);
                                        n--;
                                        col++;
                                }
                        }
                } else {
                        int m = mtd->writesize - col;

                        if (col >= mtd->writesize)
                                m += mtd->oobsize;

                        m = min(n, m) & ~3;
                        memcpy(&buf[i], p, m);
                        col += m;
                        i += m;
                        n -= m;
                }
        }
        /* Update saved column address */
        host->col_addr = col;

}

/* Used by the upper layer to verify the data in NAND Flash
 * with the data in the buf. */
static int mxc_nand_verify_buf(struct mtd_info *mtd,
                                const u_char *buf, int len)
{
        return -EFAULT;
}

/* This function is used by upper layer for select and
 * deselect of the NAND chip */
static void mxc_nand_select_chip(struct mtd_info *mtd, int chip)
{
        struct nand_chip *nand_chip = mtd->priv;
        struct mxc_nand_host *host = nand_chip->priv;

#ifdef CONFIG_MTD_NAND_MXC_FORCE_CE
        if (chip > 0) {
                DEBUG(MTD_DEBUG_LEVEL0,
                      "ERROR:  Illegal chip select (chip = %d)\n", chip);
                return;
        }

        if (chip == -1) {
                writew(readw(host->regs + NFC_CONFIG1) & ~NFC_CE,
                                host->regs + NFC_CONFIG1);
                return;
        }

        writew(readw(host->regs + NFC_CONFIG1) | NFC_CE,
                        host->regs + NFC_CONFIG1);
#endif

        switch (chip) {
        case -1:
                /* Disable the NFC clock */
                if (host->clk_act) {
                        clk_disable(host->clk);
                        host->clk_act = 0;
                }
                break;
        case 0:
                /* Enable the NFC clock */
                if (!host->clk_act) {
                        clk_enable(host->clk);
                        host->clk_act = 1;
                }
                break;

        default:
                break;
        }
}

/* Used by the upper layer to write command to NAND Flash for
 * different operations to be carried out on NAND Flash */
static void mxc_nand_command(struct mtd_info *mtd, unsigned command,
                                int column, int page_addr)
{
        struct nand_chip *nand_chip = mtd->priv;
        struct mxc_nand_host *host = nand_chip->priv;
        int useirq = true;

        DEBUG(MTD_DEBUG_LEVEL3,
              "mxc_nand_command (cmd = 0x%x, col = 0x%x, page = 0x%x)\n",
              command, column, page_addr);

        /* Reset command state information */
        host->status_request = false;

        /* Command pre-processing step */
        switch (command) {

        case NAND_CMD_STATUS:
                host->col_addr = 0;
                host->status_request = true;
                break;

        case NAND_CMD_READ0:
                host->col_addr = column;
                host->spare_only = false;
                useirq = false;
                break;

        case NAND_CMD_READOOB:
                host->col_addr = column;
                host->spare_only = true;
                useirq = false;
                if (host->pagesize_2k)
                        command = NAND_CMD_READ0; /* only READ0 is valid */
                break;

        case NAND_CMD_SEQIN:
                if (column >= mtd->writesize) {
                        /*
                         * FIXME: before send SEQIN command for write OOB,
                         * We must read one page out.
                         * For K9F1GXX has no READ1 command to set current HW
                         * pointer to spare area, we must write the whole page
                         * including OOB together.
                         */
                        if (host->pagesize_2k)
                                /* call ourself to read a page */
                                mxc_nand_command(mtd, NAND_CMD_READ0, 0,
                                                page_addr);

                        host->col_addr = column - mtd->writesize;
                        host->spare_only = true;

                        /* Set program pointer to spare region */
                        if (!host->pagesize_2k)
                                send_cmd(host, NAND_CMD_READOOB, false);
                } else {
                        host->spare_only = false;
                        host->col_addr = column;

                        /* Set program pointer to page start */
                        if (!host->pagesize_2k)
                                send_cmd(host, NAND_CMD_READ0, false);
                }
                useirq = false;
                break;

        case NAND_CMD_PAGEPROG:
                send_prog_page(host, 0, host->spare_only);

                if (host->pagesize_2k) {
                        /* data in 4 areas datas */
                        send_prog_page(host, 1, host->spare_only);
                        send_prog_page(host, 2, host->spare_only);
                        send_prog_page(host, 3, host->spare_only);
                }

                break;

        case NAND_CMD_ERASE1:
                useirq = false;
                break;
        }

        /* Write out the command to the device. */
        send_cmd(host, command, useirq);

        /* Write out column address, if necessary */
        if (column != -1) {
                /*
                 * MXC NANDFC can only perform full page+spare or
                 * spare-only read/write.  When the upper layers
                 * layers perform a read/write buf operation,
                 * we will used the saved column adress to index into
                 * the full page.
                 */
                send_addr(host, 0, page_addr == -1);
                if (host->pagesize_2k)
                        /* another col addr cycle for 2k page */
                        send_addr(host, 0, false);
        }

        /* Write out page address, if necessary */
        if (page_addr != -1) {
                /* paddr_0 - p_addr_7 */
                send_addr(host, (page_addr & 0xff), false);

                if (host->pagesize_2k) {
                        if (mtd->size >= 0x10000000) {
                                /* paddr_8 - paddr_15 */
                                send_addr(host, (page_addr >> 8) & 0xff, false);
                                send_addr(host, (page_addr >> 16) & 0xff, true);
                        } else
                                /* paddr_8 - paddr_15 */
                                send_addr(host, (page_addr >> 8) & 0xff, true);
                } else {
                        /* One more address cycle for higher density devices */
                        if (mtd->size >= 0x4000000) {
                                /* paddr_8 - paddr_15 */
                                send_addr(host, (page_addr >> 8) & 0xff, false);
                                send_addr(host, (page_addr >> 16) & 0xff, true);
                        } else
                                /* paddr_8 - paddr_15 */
                                send_addr(host, (page_addr >> 8) & 0xff, true);
                }
        }

        /* Command post-processing step */
        switch (command) {

        case NAND_CMD_RESET:
                break;

        case NAND_CMD_READOOB:
        case NAND_CMD_READ0:
                if (host->pagesize_2k) {
                        /* send read confirm command */
                        send_cmd(host, NAND_CMD_READSTART, true);
                        /* read for each AREA */
                        send_read_page(host, 0, host->spare_only);
                        send_read_page(host, 1, host->spare_only);
                        send_read_page(host, 2, host->spare_only);
                        send_read_page(host, 3, host->spare_only);
                } else
                        send_read_page(host, 0, host->spare_only);
                break;

        case NAND_CMD_READID:
                host->col_addr = 0;
                send_read_id(host);
                break;

        case NAND_CMD_PAGEPROG:
                break;

        case NAND_CMD_STATUS:
                break;

        case NAND_CMD_ERASE2:
                break;
        }
}

/* Define some generic bad / good block scan pattern which are used
 * while scanning a device for factory marked good / bad blocks. */
static uint8_t scan_ff_pattern[] = { 0xff, 0xff };

static struct nand_bbt_descr smallpage_memorybased = {
        .options = NAND_BBT_SCAN2NDPAGE,
        .offs = 5,
        .len = 1,
        .pattern = scan_ff_pattern
};

static int __init mxcnd_probe(struct platform_device *pdev)
{
        struct nand_chip *this;
        struct mtd_info *mtd;
        struct mxc_nand_platform_data *pdata = pdev->dev.platform_data;
        struct mxc_nand_host *host;
        struct resource *res;
        uint16_t tmp;
        int err = 0, nr_parts = 0;

        /* Allocate memory for MTD device structure and private data */
        host = kzalloc(sizeof(struct mxc_nand_host), GFP_KERNEL);
        if (!host)
                return -ENOMEM;

        host->dev = &pdev->dev;
        /* structures must be linked */
        this = &host->nand;
        mtd = &host->mtd;
        mtd->priv = this;
        mtd->owner = THIS_MODULE;
        mtd->dev.parent = &pdev->dev;
        mtd->name = "mxc_nand";

        /* 50 us command delay time */
        this->chip_delay = 5;

        this->priv = host;
        this->dev_ready = mxc_nand_dev_ready;
        this->cmdfunc = mxc_nand_command;
        this->select_chip = mxc_nand_select_chip;
        this->read_byte = mxc_nand_read_byte;
        this->read_word = mxc_nand_read_word;
        this->write_buf = mxc_nand_write_buf;
        this->read_buf = mxc_nand_read_buf;
        this->verify_buf = mxc_nand_verify_buf;

        host->clk = clk_get(&pdev->dev, "nfc");
        if (IS_ERR(host->clk)) {
                err = PTR_ERR(host->clk);
                goto eclk;
        }

        clk_enable(host->clk);
        host->clk_act = 1;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res) {
                err = -ENODEV;
                goto eres;
        }

        host->regs = ioremap(res->start, res->end - res->start + 1);
        if (!host->regs) {
                err = -ENOMEM;
                goto eres;
        }

        tmp = readw(host->regs + NFC_CONFIG1);
        tmp |= NFC_INT_MSK;
        writew(tmp, host->regs + NFC_CONFIG1);

        init_waitqueue_head(&host->irq_waitq);

        host->irq = platform_get_irq(pdev, 0);

        err = request_irq(host->irq, mxc_nfc_irq, 0, "mxc_nd", host);
        if (err)
                goto eirq;

        if (pdata->hw_ecc) {
                this->ecc.calculate = mxc_nand_calculate_ecc;
                this->ecc.hwctl = mxc_nand_enable_hwecc;
                this->ecc.correct = mxc_nand_correct_data;
                this->ecc.mode = NAND_ECC_HW;
                this->ecc.size = 512;
                this->ecc.bytes = 3;
                tmp = readw(host->regs + NFC_CONFIG1);
                tmp |= NFC_ECC_EN;
                writew(tmp, host->regs + NFC_CONFIG1);
        } else {
                this->ecc.size = 512;
                this->ecc.bytes = 3;
                this->ecc.layout = &nand_hw_eccoob_8;
                this->ecc.mode = NAND_ECC_SOFT;
                tmp = readw(host->regs + NFC_CONFIG1);
                tmp &= ~NFC_ECC_EN;
                writew(tmp, host->regs + NFC_CONFIG1);
        }

        /* Reset NAND */
        this->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);

        /* preset operation */
        /* Unlock the internal RAM Buffer */
        writew(0x2, host->regs + NFC_CONFIG);

        /* Blocks to be unlocked */
        writew(0x0, host->regs + NFC_UNLOCKSTART_BLKADDR);
        writew(0x4000, host->regs + NFC_UNLOCKEND_BLKADDR);

        /* Unlock Block Command for given address range */
        writew(0x4, host->regs + NFC_WRPROT);

        /* NAND bus width determines access funtions used by upper layer */
        if (pdata->width == 2) {
                this->options |= NAND_BUSWIDTH_16;
                this->ecc.layout = &nand_hw_eccoob_16;
        }

        /* first scan to find the device and get the page size */
        if (nand_scan_ident(mtd, 1)) {
                err = -ENXIO;
                goto escan;
        }

        if (mtd->writesize == 2048) {
                host->pagesize_2k = 1;
                this->badblock_pattern = &smallpage_memorybased;
        }

        if (this->ecc.mode == NAND_ECC_HW) {
                switch (mtd->oobsize) {
                case 8:
                        this->ecc.layout = &nand_hw_eccoob_8;
                        break;
                case 16:
                        this->ecc.layout = &nand_hw_eccoob_16;
                        break;
                case 64:

                        this->ecc.layout = &nand_hw_eccoob_64;
                        break;
                default:
                        /* page size not handled by HW ECC */
                        /* switching back to soft ECC */
                        this->ecc.size = 512;
                        this->ecc.bytes = 3;
                        this->ecc.layout = &nand_hw_eccoob_8;
                        this->ecc.mode = NAND_ECC_SOFT;
                        this->ecc.calculate = NULL;
                        this->ecc.correct = NULL;
                        this->ecc.hwctl = NULL;
                        tmp = readw(host->regs + NFC_CONFIG1);
                        tmp &= ~NFC_ECC_EN;
                        writew(tmp, host->regs + NFC_CONFIG1);
                        break;
                }
        }

        /* second phase scan */
        if (nand_scan_tail(mtd)) {
                err = -ENXIO;
                goto escan;
        }

        /* Register the partitions */
#ifdef CONFIG_MTD_PARTITIONS
        nr_parts =
            parse_mtd_partitions(mtd, part_probes, &host->parts, 0);
        if (nr_parts > 0)
                add_mtd_partitions(mtd, host->parts, nr_parts);
        else
#endif
        {
                pr_info("Registering %s as whole device\n", mtd->name);
                add_mtd_device(mtd);
        }

        platform_set_drvdata(pdev, host);

        return 0;

escan:
        free_irq(host->irq, host);
eirq:
        iounmap(host->regs);
eres:
        clk_put(host->clk);
eclk:
        kfree(host);

        return err;
}

static int __devexit mxcnd_remove(struct platform_device *pdev)
{
        struct mxc_nand_host *host = platform_get_drvdata(pdev);

        clk_put(host->clk);

        platform_set_drvdata(pdev, NULL);

        nand_release(&host->mtd);
        free_irq(host->irq, host);
        iounmap(host->regs);
        kfree(host);

        return 0;
}

#ifdef CONFIG_PM
static int mxcnd_suspend(struct platform_device *pdev, pm_message_t state)
{
        struct mtd_info *mtd = platform_get_drvdata(pdev);
        struct nand_chip *nand_chip = mtd->priv;
        struct mxc_nand_host *host = nand_chip->priv;
        int ret = 0;

        DEBUG(MTD_DEBUG_LEVEL0, "MXC_ND : NAND suspend\n");
        if (mtd) {
                ret = mtd->suspend(mtd);
                /* Disable the NFC clock */
                clk_disable(host->clk);
        }

        return ret;
}

static int mxcnd_resume(struct platform_device *pdev)
{
        struct mtd_info *mtd = platform_get_drvdata(pdev);
        struct nand_chip *nand_chip = mtd->priv;
        struct mxc_nand_host *host = nand_chip->priv;
        int ret = 0;

        DEBUG(MTD_DEBUG_LEVEL0, "MXC_ND : NAND resume\n");

        if (mtd) {
                /* Enable the NFC clock */
                clk_enable(host->clk);
                mtd->resume(mtd);
        }

        return ret;
}

#else
# define mxcnd_suspend   NULL
# define mxcnd_resume    NULL
#endif                          /* CONFIG_PM */

static struct platform_driver mxcnd_driver = {
        .driver = {
                   .name = DRIVER_NAME,
                   },
        .remove = __exit_p(mxcnd_remove),
        .suspend = mxcnd_suspend,
        .resume = mxcnd_resume,
};

static int __init mxc_nd_init(void)
{
        return platform_driver_probe(&mxcnd_driver, mxcnd_probe);
}

static void __exit mxc_nd_cleanup(void)
{
        /* Unregister the device structure */
        platform_driver_unregister(&mxcnd_driver);
}

module_init(mxc_nd_init);
module_exit(mxc_nd_cleanup);

MODULE_AUTHOR("Freescale Semiconductor, Inc.");
MODULE_DESCRIPTION("MXC NAND MTD driver");
MODULE_LICENSE("GPL");