// SPDX-License-Identifier: GPL-2.0+
/* Freescale Enhanced Local Bus Controller FCM NAND driver
 *
 * Copyright (c) 2006-2008 Freescale Semiconductor
 *
 * Authors: Nick Spence <nick.spence@freescale.com>,
 *          Scott Wood <scottwood@freescale.com>
 */

#include <common.h>
#include <command.h>
#include <malloc.h>
#include <nand.h>
#include <dm/devres.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/rawnand.h>
#include <linux/mtd/nand_ecc.h>

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

#ifdef VERBOSE_DEBUG
#define DEBUG_ELBC
#define vdbg(format, arg...) printf("DEBUG: " format, ##arg)
#else
#define vdbg(format, arg...) do {} while (0)
#endif

/* Can't use plain old DEBUG because the linux mtd
 * headers define it as a macro.
 */
#ifdef DEBUG_ELBC
#define dbg(format, arg...) printf("DEBUG: " format, ##arg)
#else
#define dbg(format, arg...) do {} while (0)
#endif

#define MAX_BANKS 8
#define ERR_BYTE 0xFF /* Value returned for read bytes when read failed */

#define LTESR_NAND_MASK (LTESR_FCT | LTESR_PAR | LTESR_CC)

struct fsl_elbc_ctrl;

/* mtd information per set */

struct fsl_elbc_mtd {
        struct nand_chip chip;
        struct fsl_elbc_ctrl *ctrl;

        struct device *dev;
        int bank;               /* Chip select bank number           */
        u8 __iomem *vbase;      /* Chip select base virtual address  */
        int page_size;          /* NAND page size (0=512, 1=2048)    */
        unsigned int fmr;       /* FCM Flash Mode Register value     */
};

/* overview of the fsl elbc controller */

struct fsl_elbc_ctrl {
        struct nand_hw_control controller;
        struct fsl_elbc_mtd *chips[MAX_BANKS];

        /* device info */
        fsl_lbc_t *regs;
        u8 __iomem *addr;        /* Address of assigned FCM buffer        */
        unsigned int page;       /* Last page written to / read from      */
        unsigned int read_bytes; /* Number of bytes read during command   */
        unsigned int column;     /* Saved column from SEQIN               */
        unsigned int index;      /* Pointer to next byte to 'read'        */
        unsigned int status;     /* status read from LTESR after last op  */
        unsigned int mdr;        /* UPM/FCM Data Register value           */
        unsigned int use_mdr;    /* Non zero if the MDR is to be set      */
        unsigned int oob;        /* Non zero if operating on OOB data     */
};

/* These map to the positions used by the FCM hardware ECC generator */

/* Small Page FLASH with FMR[ECCM] = 0 */
static struct nand_ecclayout fsl_elbc_oob_sp_eccm0 = {
        .eccbytes = 3,
        .eccpos = {6, 7, 8},
        .oobfree = { {0, 5}, {9, 7} },
};

/* Small Page FLASH with FMR[ECCM] = 1 */
static struct nand_ecclayout fsl_elbc_oob_sp_eccm1 = {
        .eccbytes = 3,
        .eccpos = {8, 9, 10},
        .oobfree = { {0, 5}, {6, 2}, {11, 5} },
};

/* Large Page FLASH with FMR[ECCM] = 0 */
static struct nand_ecclayout fsl_elbc_oob_lp_eccm0 = {
        .eccbytes = 12,
        .eccpos = {6, 7, 8, 22, 23, 24, 38, 39, 40, 54, 55, 56},
        .oobfree = { {1, 5}, {9, 13}, {25, 13}, {41, 13}, {57, 7} },
};

/* Large Page FLASH with FMR[ECCM] = 1 */
static struct nand_ecclayout fsl_elbc_oob_lp_eccm1 = {
        .eccbytes = 12,
        .eccpos = {8, 9, 10, 24, 25, 26, 40, 41, 42, 56, 57, 58},
        .oobfree = { {1, 7}, {11, 13}, {27, 13}, {43, 13}, {59, 5} },
};

/*
 * fsl_elbc_oob_lp_eccm* specify that LP NAND's OOB free area starts at offset
 * 1, so we have to adjust bad block pattern. This pattern should be used for
 * x8 chips only. So far hardware does not support x16 chips anyway.
 */
static u8 scan_ff_pattern[] = { 0xff, };

static struct nand_bbt_descr largepage_memorybased = {
        .options = 0,
        .offs = 0,
        .len = 1,
        .pattern = scan_ff_pattern,
};

/*
 * ELBC may use HW ECC, so that OOB offsets, that NAND core uses for bbt,
 * interfere with ECC positions, that's why we implement our own descriptors.
 * OOB {11, 5}, works for both SP and LP chips, with ECCM = 1 and ECCM = 0.
 */
static u8 bbt_pattern[] = {'B', 'b', 't', '0' };
static u8 mirror_pattern[] = {'1', 't', 'b', 'B' };

static struct nand_bbt_descr bbt_main_descr = {
        .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
                   NAND_BBT_2BIT | NAND_BBT_VERSION,
        .offs = 11,
        .len = 4,
        .veroffs = 15,
        .maxblocks = 4,
        .pattern = bbt_pattern,
};

static struct nand_bbt_descr bbt_mirror_descr = {
        .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
                   NAND_BBT_2BIT | NAND_BBT_VERSION,
        .offs = 11,
        .len = 4,
        .veroffs = 15,
        .maxblocks = 4,
        .pattern = mirror_pattern,
};

/*=================================*/

/*
 * Set up the FCM hardware block and page address fields, and the fcm
 * structure addr field to point to the correct FCM buffer in memory
 */
static void set_addr(struct mtd_info *mtd, int column, int page_addr, int oob)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
        struct fsl_elbc_ctrl *ctrl = priv->ctrl;
        fsl_lbc_t *lbc = ctrl->regs;
        int buf_num;

        ctrl->page = page_addr;

        if (priv->page_size) {
                out_be32(&lbc->fbar, page_addr >> 6);
                out_be32(&lbc->fpar,
                         ((page_addr << FPAR_LP_PI_SHIFT) & FPAR_LP_PI) |
                         (oob ? FPAR_LP_MS : 0) | column);
                buf_num = (page_addr & 1) << 2;
        } else {
                out_be32(&lbc->fbar, page_addr >> 5);
                out_be32(&lbc->fpar,
                         ((page_addr << FPAR_SP_PI_SHIFT) & FPAR_SP_PI) |
                         (oob ? FPAR_SP_MS : 0) | column);
                buf_num = page_addr & 7;
        }

        ctrl->addr = priv->vbase + buf_num * 1024;
        ctrl->index = column;

        /* for OOB data point to the second half of the buffer */
        if (oob)
                ctrl->index += priv->page_size ? 2048 : 512;

        vdbg("set_addr: bank=%d, ctrl->addr=0x%p (0x%p), "
             "index %x, pes %d ps %d\n",
             buf_num, ctrl->addr, priv->vbase, ctrl->index,
             chip->phys_erase_shift, chip->page_shift);
}

/*
 * execute FCM command and wait for it to complete
 */
static int fsl_elbc_run_command(struct mtd_info *mtd)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
        struct fsl_elbc_ctrl *ctrl = priv->ctrl;
        fsl_lbc_t *lbc = ctrl->regs;
        u32 timeo = (CONFIG_SYS_HZ * 10) / 1000;
        u32 time_start;
        u32 ltesr;

        /* Setup the FMR[OP] to execute without write protection */
        out_be32(&lbc->fmr, priv->fmr | 3);
        if (ctrl->use_mdr)
                out_be32(&lbc->mdr, ctrl->mdr);

        vdbg("fsl_elbc_run_command: fmr=%08x fir=%08x fcr=%08x\n",
             in_be32(&lbc->fmr), in_be32(&lbc->fir), in_be32(&lbc->fcr));
        vdbg("fsl_elbc_run_command: fbar=%08x fpar=%08x "
             "fbcr=%08x bank=%d\n",
             in_be32(&lbc->fbar), in_be32(&lbc->fpar),
             in_be32(&lbc->fbcr), priv->bank);

        /* execute special operation */
        out_be32(&lbc->lsor, priv->bank);

        /* wait for FCM complete flag or timeout */
        time_start = get_timer(0);

        ltesr = 0;
        while (get_timer(time_start) < timeo) {
                ltesr = in_be32(&lbc->ltesr);
                if (ltesr & LTESR_CC)
                        break;
        }

        ctrl->status = ltesr & LTESR_NAND_MASK;
        out_be32(&lbc->ltesr, ctrl->status);
        out_be32(&lbc->lteatr, 0);

        /* store mdr value in case it was needed */
        if (ctrl->use_mdr)
                ctrl->mdr = in_be32(&lbc->mdr);

        ctrl->use_mdr = 0;

        vdbg("fsl_elbc_run_command: stat=%08x mdr=%08x fmr=%08x\n",
             ctrl->status, ctrl->mdr, in_be32(&lbc->fmr));

        /* returns 0 on success otherwise non-zero) */
        return ctrl->status == LTESR_CC ? 0 : -EIO;
}

static void fsl_elbc_do_read(struct nand_chip *chip, int oob)
{
        struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
        struct fsl_elbc_ctrl *ctrl = priv->ctrl;
        fsl_lbc_t *lbc = ctrl->regs;

        if (priv->page_size) {
                out_be32(&lbc->fir,
                         (FIR_OP_CW0 << FIR_OP0_SHIFT) |
                         (FIR_OP_CA  << FIR_OP1_SHIFT) |
                         (FIR_OP_PA  << FIR_OP2_SHIFT) |
                         (FIR_OP_CW1 << FIR_OP3_SHIFT) |
                         (FIR_OP_RBW << FIR_OP4_SHIFT));

                out_be32(&lbc->fcr, (NAND_CMD_READ0 << FCR_CMD0_SHIFT) |
                                    (NAND_CMD_READSTART << FCR_CMD1_SHIFT));
        } else {
                out_be32(&lbc->fir,
                         (FIR_OP_CW0 << FIR_OP0_SHIFT) |
                         (FIR_OP_CA  << FIR_OP1_SHIFT) |
                         (FIR_OP_PA  << FIR_OP2_SHIFT) |
                         (FIR_OP_RBW << FIR_OP3_SHIFT));

                if (oob)
                        out_be32(&lbc->fcr,
                                 NAND_CMD_READOOB << FCR_CMD0_SHIFT);
                else
                        out_be32(&lbc->fcr, NAND_CMD_READ0 << FCR_CMD0_SHIFT);
        }
}

/* cmdfunc send commands to the FCM */
static void fsl_elbc_cmdfunc(struct mtd_info *mtd, unsigned int command,
                             int column, int page_addr)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
        struct fsl_elbc_ctrl *ctrl = priv->ctrl;
        fsl_lbc_t *lbc = ctrl->regs;

        ctrl->use_mdr = 0;

        /* clear the read buffer */
        ctrl->read_bytes = 0;
        if (command != NAND_CMD_PAGEPROG)
                ctrl->index = 0;

        switch (command) {
        /* READ0 and READ1 read the entire buffer to use hardware ECC. */
        case NAND_CMD_READ1:
                column += 256;

        /* fall-through */
        case NAND_CMD_READ0:
                vdbg("fsl_elbc_cmdfunc: NAND_CMD_READ0, page_addr:"
                     " 0x%x, column: 0x%x.\n", page_addr, column);

                out_be32(&lbc->fbcr, 0); /* read entire page to enable ECC */
                set_addr(mtd, 0, page_addr, 0);

                ctrl->read_bytes = mtd->writesize + mtd->oobsize;
                ctrl->index += column;

                fsl_elbc_do_read(chip, 0);
                fsl_elbc_run_command(mtd);
                return;

        /* READOOB reads only the OOB because no ECC is performed. */
        case NAND_CMD_READOOB:
                vdbg("fsl_elbc_cmdfunc: NAND_CMD_READOOB, page_addr:"
                     " 0x%x, column: 0x%x.\n", page_addr, column);

                out_be32(&lbc->fbcr, mtd->oobsize - column);
                set_addr(mtd, column, page_addr, 1);

                ctrl->read_bytes = mtd->writesize + mtd->oobsize;

                fsl_elbc_do_read(chip, 1);
                fsl_elbc_run_command(mtd);

                return;

        /* READID must read all 5 possible bytes while CEB is active */
        case NAND_CMD_READID:
        case NAND_CMD_PARAM:
                vdbg("fsl_elbc_cmdfunc: NAND_CMD 0x%x.\n", command);

                out_be32(&lbc->fir, (FIR_OP_CW0 << FIR_OP0_SHIFT) |
                                    (FIR_OP_UA  << FIR_OP1_SHIFT) |
                                    (FIR_OP_RBW << FIR_OP2_SHIFT));
                out_be32(&lbc->fcr, command << FCR_CMD0_SHIFT);
                /*
                 * although currently it's 8 bytes for READID, we always read
                 * the maximum 256 bytes(for PARAM)
                 */
                out_be32(&lbc->fbcr, 256);
                ctrl->read_bytes = 256;
                ctrl->use_mdr = 1;
                ctrl->mdr = column;
                set_addr(mtd, 0, 0, 0);
                fsl_elbc_run_command(mtd);
                return;

        /* ERASE1 stores the block and page address */
        case NAND_CMD_ERASE1:
                vdbg("fsl_elbc_cmdfunc: NAND_CMD_ERASE1, "
                     "page_addr: 0x%x.\n", page_addr);
                set_addr(mtd, 0, page_addr, 0);
                return;

        /* ERASE2 uses the block and page address from ERASE1 */
        case NAND_CMD_ERASE2:
                vdbg("fsl_elbc_cmdfunc: NAND_CMD_ERASE2.\n");

                out_be32(&lbc->fir,
                         (FIR_OP_CW0 << FIR_OP0_SHIFT) |
                         (FIR_OP_PA  << FIR_OP1_SHIFT) |
                         (FIR_OP_CM1 << FIR_OP2_SHIFT));

                out_be32(&lbc->fcr,
                         (NAND_CMD_ERASE1 << FCR_CMD0_SHIFT) |
                         (NAND_CMD_ERASE2 << FCR_CMD1_SHIFT));

                out_be32(&lbc->fbcr, 0);
                ctrl->read_bytes = 0;

                fsl_elbc_run_command(mtd);
                return;

        /* SEQIN sets up the addr buffer and all registers except the length */
        case NAND_CMD_SEQIN: {
                u32 fcr;
                vdbg("fsl_elbc_cmdfunc: NAND_CMD_SEQIN/PAGE_PROG, "
                     "page_addr: 0x%x, column: 0x%x.\n",
                     page_addr, column);

                ctrl->column = column;
                ctrl->oob = 0;

                if (priv->page_size) {
                        fcr = (NAND_CMD_SEQIN << FCR_CMD0_SHIFT) |
                              (NAND_CMD_PAGEPROG << FCR_CMD1_SHIFT);

                        out_be32(&lbc->fir,
                                 (FIR_OP_CW0 << FIR_OP0_SHIFT) |
                                 (FIR_OP_CA  << FIR_OP1_SHIFT) |
                                 (FIR_OP_PA  << FIR_OP2_SHIFT) |
                                 (FIR_OP_WB  << FIR_OP3_SHIFT) |
                                 (FIR_OP_CW1 << FIR_OP4_SHIFT));
                } else {
                        fcr = (NAND_CMD_PAGEPROG << FCR_CMD1_SHIFT) |
                              (NAND_CMD_SEQIN << FCR_CMD2_SHIFT);

                        out_be32(&lbc->fir,
                                 (FIR_OP_CW0 << FIR_OP0_SHIFT) |
                                 (FIR_OP_CM2 << FIR_OP1_SHIFT) |
                                 (FIR_OP_CA  << FIR_OP2_SHIFT) |
                                 (FIR_OP_PA  << FIR_OP3_SHIFT) |
                                 (FIR_OP_WB  << FIR_OP4_SHIFT) |
                                 (FIR_OP_CW1 << FIR_OP5_SHIFT));

                        if (column >= mtd->writesize) {
                                /* OOB area --> READOOB */
                                column -= mtd->writesize;
                                fcr |= NAND_CMD_READOOB << FCR_CMD0_SHIFT;
                                ctrl->oob = 1;
                        } else if (column < 256) {
                                /* First 256 bytes --> READ0 */
                                fcr |= NAND_CMD_READ0 << FCR_CMD0_SHIFT;
                        } else {
                                /* Second 256 bytes --> READ1 */
                                fcr |= NAND_CMD_READ1 << FCR_CMD0_SHIFT;
                        }
                }

                out_be32(&lbc->fcr, fcr);
                set_addr(mtd, column, page_addr, ctrl->oob);
                return;
        }

        /* PAGEPROG reuses all of the setup from SEQIN and adds the length */
        case NAND_CMD_PAGEPROG: {
                vdbg("fsl_elbc_cmdfunc: NAND_CMD_PAGEPROG "
                     "writing %d bytes.\n", ctrl->index);

                /* if the write did not start at 0 or is not a full page
                 * then set the exact length, otherwise use a full page
                 * write so the HW generates the ECC.
                 */
                if (ctrl->oob || ctrl->column != 0 ||
                    ctrl->index != mtd->writesize + mtd->oobsize)
                        out_be32(&lbc->fbcr, ctrl->index);
                else
                        out_be32(&lbc->fbcr, 0);

                fsl_elbc_run_command(mtd);

                return;
        }

        /* CMD_STATUS must read the status byte while CEB is active */
        /* Note - it does not wait for the ready line */
        case NAND_CMD_STATUS:
                out_be32(&lbc->fir,
                         (FIR_OP_CM0 << FIR_OP0_SHIFT) |
                         (FIR_OP_RBW << FIR_OP1_SHIFT));
                out_be32(&lbc->fcr, NAND_CMD_STATUS << FCR_CMD0_SHIFT);
                out_be32(&lbc->fbcr, 1);
                set_addr(mtd, 0, 0, 0);
                ctrl->read_bytes = 1;

                fsl_elbc_run_command(mtd);

                /* The chip always seems to report that it is
                 * write-protected, even when it is not.
                 */
                out_8(ctrl->addr, in_8(ctrl->addr) | NAND_STATUS_WP);
                return;

        /* RESET without waiting for the ready line */
        case NAND_CMD_RESET:
                dbg("fsl_elbc_cmdfunc: NAND_CMD_RESET.\n");
                out_be32(&lbc->fir, FIR_OP_CM0 << FIR_OP0_SHIFT);
                out_be32(&lbc->fcr, NAND_CMD_RESET << FCR_CMD0_SHIFT);
                fsl_elbc_run_command(mtd);
                return;

        default:
                printf("fsl_elbc_cmdfunc: error, unsupported command 0x%x.\n",
                        command);
        }
}

static void fsl_elbc_select_chip(struct mtd_info *mtd, int chip)
{
        /* The hardware does not seem to support multiple
         * chips per bank.
         */
}

/*
 * Write buf to the FCM Controller Data Buffer
 */
static void fsl_elbc_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
        struct fsl_elbc_ctrl *ctrl = priv->ctrl;
        unsigned int bufsize = mtd->writesize + mtd->oobsize;

        if (len <= 0) {
                printf("write_buf of %d bytes", len);
                ctrl->status = 0;
                return;
        }

        if ((unsigned int)len > bufsize - ctrl->index) {
                printf("write_buf beyond end of buffer "
                       "(%d requested, %u available)\n",
                       len, bufsize - ctrl->index);
                len = bufsize - ctrl->index;
        }

        memcpy_toio(&ctrl->addr[ctrl->index], buf, len);
        /*
         * This is workaround for the weird elbc hangs during nand write,
         * Scott Wood says: "...perhaps difference in how long it takes a
         * write to make it through the localbus compared to a write to IMMR
         * is causing problems, and sync isn't helping for some reason."
         * Reading back the last byte helps though.
         */
        in_8(&ctrl->addr[ctrl->index] + len - 1);

        ctrl->index += len;
}

/*
 * read a byte from either the FCM hardware buffer if it has any data left
 * otherwise issue a command to read a single byte.
 */
static u8 fsl_elbc_read_byte(struct mtd_info *mtd)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
        struct fsl_elbc_ctrl *ctrl = priv->ctrl;

        /* If there are still bytes in the FCM, then use the next byte. */
        if (ctrl->index < ctrl->read_bytes)
                return in_8(&ctrl->addr[ctrl->index++]);

        printf("read_byte beyond end of buffer\n");
        return ERR_BYTE;
}

/*
 * Read from the FCM Controller Data Buffer
 */
static void fsl_elbc_read_buf(struct mtd_info *mtd, u8 *buf, int len)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
        struct fsl_elbc_ctrl *ctrl = priv->ctrl;
        int avail;

        if (len < 0)
                return;

        avail = min((unsigned int)len, ctrl->read_bytes - ctrl->index);
        memcpy_fromio(buf, &ctrl->addr[ctrl->index], avail);
        ctrl->index += avail;

        if (len > avail)
                printf("read_buf beyond end of buffer "
                       "(%d requested, %d available)\n",
                       len, avail);
}

/* This function is called after Program and Erase Operations to
 * check for success or failure.
 */
static int fsl_elbc_wait(struct mtd_info *mtd, struct nand_chip *chip)
{
        struct fsl_elbc_mtd *priv = nand_get_controller_data(chip);
        struct fsl_elbc_ctrl *ctrl = priv->ctrl;
        fsl_lbc_t *lbc = ctrl->regs;

        if (ctrl->status != LTESR_CC)
                return NAND_STATUS_FAIL;

        /* Use READ_STATUS command, but wait for the device to be ready */
        ctrl->use_mdr = 0;
        out_be32(&lbc->fir,
                 (FIR_OP_CW0 << FIR_OP0_SHIFT) |
                 (FIR_OP_RBW << FIR_OP1_SHIFT));
        out_be32(&lbc->fcr, NAND_CMD_STATUS << FCR_CMD0_SHIFT);
        out_be32(&lbc->fbcr, 1);
        set_addr(mtd, 0, 0, 0);
        ctrl->read_bytes = 1;

        fsl_elbc_run_command(mtd);

        if (ctrl->status != LTESR_CC)
                return NAND_STATUS_FAIL;

        /* The chip always seems to report that it is
         * write-protected, even when it is not.
         */
        out_8(ctrl->addr, in_8(ctrl->addr) | NAND_STATUS_WP);
        return fsl_elbc_read_byte(mtd);
}

static int fsl_elbc_read_page(struct mtd_info *mtd, struct nand_chip *chip,
                              uint8_t *buf, int oob_required, int page)
{
        fsl_elbc_read_buf(mtd, buf, mtd->writesize);
        fsl_elbc_read_buf(mtd, chip->oob_poi, mtd->oobsize);

        if (fsl_elbc_wait(mtd, chip) & NAND_STATUS_FAIL)
                mtd->ecc_stats.failed++;

        return 0;
}

/* ECC will be calculated automatically, and errors will be detected in
 * waitfunc.
 */
static int fsl_elbc_write_page(struct mtd_info *mtd, struct nand_chip *chip,
                                const uint8_t *buf, int oob_required,
                                int page)
{
        fsl_elbc_write_buf(mtd, buf, mtd->writesize);
        fsl_elbc_write_buf(mtd, chip->oob_poi, mtd->oobsize);

        return 0;
}

static struct fsl_elbc_ctrl *elbc_ctrl;

/* ECC will be calculated automatically, and errors will be detected in
 * waitfunc.
 */
static int fsl_elbc_write_subpage(struct mtd_info *mtd, struct nand_chip *chip,
                                uint32_t offset, uint32_t data_len,
                                const uint8_t *buf, int oob_required, int page)
{
        fsl_elbc_write_buf(mtd, buf, mtd->writesize);
        fsl_elbc_write_buf(mtd, chip->oob_poi, mtd->oobsize);

        return 0;
}

static void fsl_elbc_ctrl_init(void)
{
        elbc_ctrl = kzalloc(sizeof(*elbc_ctrl), GFP_KERNEL);
        if (!elbc_ctrl)
                return;

        elbc_ctrl->regs = LBC_BASE_ADDR;

        /* clear event registers */
        out_be32(&elbc_ctrl->regs->ltesr, LTESR_NAND_MASK);
        out_be32(&elbc_ctrl->regs->lteatr, 0);

        /* Enable interrupts for any detected events */
        out_be32(&elbc_ctrl->regs->lteir, LTESR_NAND_MASK);

        elbc_ctrl->read_bytes = 0;
        elbc_ctrl->index = 0;
        elbc_ctrl->addr = NULL;
}

static int fsl_elbc_chip_init(int devnum, u8 *addr)
{
        struct mtd_info *mtd;
        struct nand_chip *nand;
        struct fsl_elbc_mtd *priv;
        uint32_t br = 0, or = 0;
        int ret;

        if (!elbc_ctrl) {
                fsl_elbc_ctrl_init();
                if (!elbc_ctrl)
                        return -1;
        }

        priv = kzalloc(sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;

        priv->ctrl = elbc_ctrl;
        priv->vbase = addr;

        /* Find which chip select it is connected to.  It'd be nice
         * if we could pass more than one datum to the NAND driver...
         */
        for (priv->bank = 0; priv->bank < MAX_BANKS; priv->bank++) {
                phys_addr_t phys_addr = virt_to_phys(addr);

                br = in_be32(&elbc_ctrl->regs->bank[priv->bank].br);
                or = in_be32(&elbc_ctrl->regs->bank[priv->bank].or);

                if ((br & BR_V) && (br & BR_MSEL) == BR_MS_FCM &&
                    (br & or & BR_BA) == BR_PHYS_ADDR(phys_addr))
                        break;
        }

        if (priv->bank >= MAX_BANKS) {
                printf("fsl_elbc_nand: address did not match any "
                       "chip selects\n");
                kfree(priv);
                return -ENODEV;
        }

        nand = &priv->chip;
        mtd = nand_to_mtd(nand);

        elbc_ctrl->chips[priv->bank] = priv;

        /* fill in nand_chip structure */
        /* set up function call table */
        nand->read_byte = fsl_elbc_read_byte;
        nand->write_buf = fsl_elbc_write_buf;
        nand->read_buf = fsl_elbc_read_buf;
        nand->select_chip = fsl_elbc_select_chip;
        nand->cmdfunc = fsl_elbc_cmdfunc;
        nand->waitfunc = fsl_elbc_wait;

        /* set up nand options */
        nand->bbt_td = &bbt_main_descr;
        nand->bbt_md = &bbt_mirror_descr;

        /* set up nand options */
        nand->options = NAND_NO_SUBPAGE_WRITE;
        nand->bbt_options = NAND_BBT_USE_FLASH;

        nand->controller = &elbc_ctrl->controller;
        nand_set_controller_data(nand, priv);

        nand->ecc.read_page = fsl_elbc_read_page;
        nand->ecc.write_page = fsl_elbc_write_page;
        nand->ecc.write_subpage = fsl_elbc_write_subpage;

        priv->fmr = (15 << FMR_CWTO_SHIFT) | (2 << FMR_AL_SHIFT);

        /* If CS Base Register selects full hardware ECC then use it */
        if ((br & BR_DECC) == BR_DECC_CHK_GEN) {
                nand->ecc.mode = NAND_ECC_HW;

                nand->ecc.layout = (priv->fmr & FMR_ECCM) ?
                                   &fsl_elbc_oob_sp_eccm1 :
                                   &fsl_elbc_oob_sp_eccm0;

                nand->ecc.size = 512;
                nand->ecc.bytes = 3;
                nand->ecc.steps = 1;
                nand->ecc.strength = 1;
        } else {
                /* otherwise fall back to software ECC */
#if defined(CONFIG_NAND_ECC_BCH)
                nand->ecc.mode = NAND_ECC_SOFT_BCH;
#else
                nand->ecc.mode = NAND_ECC_SOFT;
#endif
        }

        ret = nand_scan_ident(mtd, 1, NULL);
        if (ret)
                return ret;

        /* Large-page-specific setup */
        if (mtd->writesize == 2048) {
                setbits_be32(&elbc_ctrl->regs->bank[priv->bank].or,
                             OR_FCM_PGS);
                in_be32(&elbc_ctrl->regs->bank[priv->bank].or);

                priv->page_size = 1;
                nand->badblock_pattern = &largepage_memorybased;

                /*
                 * Hardware expects small page has ECCM0, large page has
                 * ECCM1 when booting from NAND, and we follow that even
                 * when not booting from NAND.
                 */
                priv->fmr |= FMR_ECCM;

                /* adjust ecc setup if needed */
                if ((br & BR_DECC) == BR_DECC_CHK_GEN) {
                        nand->ecc.steps = 4;
                        nand->ecc.layout = (priv->fmr & FMR_ECCM) ?
                                           &fsl_elbc_oob_lp_eccm1 :
                                           &fsl_elbc_oob_lp_eccm0;
                }
        } else if (mtd->writesize == 512) {
                clrbits_be32(&elbc_ctrl->regs->bank[priv->bank].or,
                             OR_FCM_PGS);
                in_be32(&elbc_ctrl->regs->bank[priv->bank].or);
        } else {
                return -ENODEV;
        }

        ret = nand_scan_tail(mtd);
        if (ret)
                return ret;

        ret = nand_register(devnum, mtd);
        if (ret)
                return ret;

        return 0;
}

#ifndef CONFIG_SYS_NAND_BASE_LIST
#define CONFIG_SYS_NAND_BASE_LIST { CONFIG_SYS_NAND_BASE }
#endif

static unsigned long base_address[CONFIG_SYS_MAX_NAND_DEVICE] =
        CONFIG_SYS_NAND_BASE_LIST;

void board_nand_init(void)
{
        int i;

        for (i = 0; i < CONFIG_SYS_MAX_NAND_DEVICE; i++)
                fsl_elbc_chip_init(i, (u8 *)base_address[i]);
}