// SPDX-License-Identifier: GPL-2.0+
/* Integrated Flash Controller NAND Machine Driver
 *
 * Copyright (c) 2012 Freescale Semiconductor, Inc
 *
 * Authors: Dipen Dudhat <Dipen.Dudhat@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>
#include <fsl_ifc.h>

#ifndef CONFIG_SYS_FSL_IFC_BANK_COUNT
#define CONFIG_SYS_FSL_IFC_BANK_COUNT   4
#endif

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

struct fsl_ifc_ctrl;

/* mtd information per set */
struct fsl_ifc_mtd {
        struct nand_chip chip;
        struct fsl_ifc_ctrl *ctrl;

        struct device *dev;
        int bank;               /* Chip select bank number                */
        unsigned int bufnum_mask; /* bufnum = page & bufnum_mask */
        u8 __iomem *vbase;      /* Chip select base virtual address       */
};

/* overview of the fsl ifc controller */
struct fsl_ifc_ctrl {
        struct nand_hw_control controller;
        struct fsl_ifc_mtd *chips[MAX_BANKS];

        /* device info */
        struct fsl_ifc regs;
        void __iomem *addr;      /* Address of assigned IFC 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 NEESR after last op  */
        unsigned int oob;        /* Non zero if operating on OOB data     */
        unsigned int eccread;    /* Non zero for a full-page ECC read     */
};

static struct fsl_ifc_ctrl *ifc_ctrl;

/* 512-byte page with 4-bit ECC, 8-bit */
static struct nand_ecclayout oob_512_8bit_ecc4 = {
        .eccbytes = 8,
        .eccpos = {8, 9, 10, 11, 12, 13, 14, 15},
        .oobfree = { {0, 5}, {6, 2} },
};

/* 512-byte page with 4-bit ECC, 16-bit */
static struct nand_ecclayout oob_512_16bit_ecc4 = {
        .eccbytes = 8,
        .eccpos = {8, 9, 10, 11, 12, 13, 14, 15},
        .oobfree = { {2, 6}, },
};

/* 2048-byte page size with 4-bit ECC */
static struct nand_ecclayout oob_2048_ecc4 = {
        .eccbytes = 32,
        .eccpos = {
                8, 9, 10, 11, 12, 13, 14, 15,
                16, 17, 18, 19, 20, 21, 22, 23,
                24, 25, 26, 27, 28, 29, 30, 31,
                32, 33, 34, 35, 36, 37, 38, 39,
        },
        .oobfree = { {2, 6}, {40, 24} },
};

/* 4096-byte page size with 4-bit ECC */
static struct nand_ecclayout oob_4096_ecc4 = {
        .eccbytes = 64,
        .eccpos = {
                8, 9, 10, 11, 12, 13, 14, 15,
                16, 17, 18, 19, 20, 21, 22, 23,
                24, 25, 26, 27, 28, 29, 30, 31,
                32, 33, 34, 35, 36, 37, 38, 39,
                40, 41, 42, 43, 44, 45, 46, 47,
                48, 49, 50, 51, 52, 53, 54, 55,
                56, 57, 58, 59, 60, 61, 62, 63,
                64, 65, 66, 67, 68, 69, 70, 71,
        },
        .oobfree = { {2, 6}, {72, 56} },
};

/* 4096-byte page size with 8-bit ECC -- requires 218-byte OOB */
static struct nand_ecclayout oob_4096_ecc8 = {
        .eccbytes = 128,
        .eccpos = {
                8, 9, 10, 11, 12, 13, 14, 15,
                16, 17, 18, 19, 20, 21, 22, 23,
                24, 25, 26, 27, 28, 29, 30, 31,
                32, 33, 34, 35, 36, 37, 38, 39,
                40, 41, 42, 43, 44, 45, 46, 47,
                48, 49, 50, 51, 52, 53, 54, 55,
                56, 57, 58, 59, 60, 61, 62, 63,
                64, 65, 66, 67, 68, 69, 70, 71,
                72, 73, 74, 75, 76, 77, 78, 79,
                80, 81, 82, 83, 84, 85, 86, 87,
                88, 89, 90, 91, 92, 93, 94, 95,
                96, 97, 98, 99, 100, 101, 102, 103,
                104, 105, 106, 107, 108, 109, 110, 111,
                112, 113, 114, 115, 116, 117, 118, 119,
                120, 121, 122, 123, 124, 125, 126, 127,
                128, 129, 130, 131, 132, 133, 134, 135,
        },
        .oobfree = { {2, 6}, {136, 82} },
};

/* 8192-byte page size with 4-bit ECC */
static struct nand_ecclayout oob_8192_ecc4 = {
        .eccbytes = 128,
        .eccpos = {
                8, 9, 10, 11, 12, 13, 14, 15,
                16, 17, 18, 19, 20, 21, 22, 23,
                24, 25, 26, 27, 28, 29, 30, 31,
                32, 33, 34, 35, 36, 37, 38, 39,
                40, 41, 42, 43, 44, 45, 46, 47,
                48, 49, 50, 51, 52, 53, 54, 55,
                56, 57, 58, 59, 60, 61, 62, 63,
                64, 65, 66, 67, 68, 69, 70, 71,
                72, 73, 74, 75, 76, 77, 78, 79,
                80, 81, 82, 83, 84, 85, 86, 87,
                88, 89, 90, 91, 92, 93, 94, 95,
                96, 97, 98, 99, 100, 101, 102, 103,
                104, 105, 106, 107, 108, 109, 110, 111,
                112, 113, 114, 115, 116, 117, 118, 119,
                120, 121, 122, 123, 124, 125, 126, 127,
                128, 129, 130, 131, 132, 133, 134, 135,
        },
        .oobfree = { {2, 6}, {136, 208} },
};

/* 8192-byte page size with 8-bit ECC -- requires 218-byte OOB */
static struct nand_ecclayout oob_8192_ecc8 = {
        .eccbytes = 256,
        .eccpos = {
                8, 9, 10, 11, 12, 13, 14, 15,
                16, 17, 18, 19, 20, 21, 22, 23,
                24, 25, 26, 27, 28, 29, 30, 31,
                32, 33, 34, 35, 36, 37, 38, 39,
                40, 41, 42, 43, 44, 45, 46, 47,
                48, 49, 50, 51, 52, 53, 54, 55,
                56, 57, 58, 59, 60, 61, 62, 63,
                64, 65, 66, 67, 68, 69, 70, 71,
                72, 73, 74, 75, 76, 77, 78, 79,
                80, 81, 82, 83, 84, 85, 86, 87,
                88, 89, 90, 91, 92, 93, 94, 95,
                96, 97, 98, 99, 100, 101, 102, 103,
                104, 105, 106, 107, 108, 109, 110, 111,
                112, 113, 114, 115, 116, 117, 118, 119,
                120, 121, 122, 123, 124, 125, 126, 127,
                128, 129, 130, 131, 132, 133, 134, 135,
                136, 137, 138, 139, 140, 141, 142, 143,
                144, 145, 146, 147, 148, 149, 150, 151,
                152, 153, 154, 155, 156, 157, 158, 159,
                160, 161, 162, 163, 164, 165, 166, 167,
                168, 169, 170, 171, 172, 173, 174, 175,
                176, 177, 178, 179, 180, 181, 182, 183,
                184, 185, 186, 187, 188, 189, 190, 191,
                192, 193, 194, 195, 196, 197, 198, 199,
                200, 201, 202, 203, 204, 205, 206, 207,
                208, 209, 210, 211, 212, 213, 214, 215,
                216, 217, 218, 219, 220, 221, 222, 223,
                224, 225, 226, 227, 228, 229, 230, 231,
                232, 233, 234, 235, 236, 237, 238, 239,
                240, 241, 242, 243, 244, 245, 246, 247,
                248, 249, 250, 251, 252, 253, 254, 255,
                256, 257, 258, 259, 260, 261, 262, 263,
        },
        .oobfree = { {2, 6}, {264, 80} },
};

/*
 * Generic flash bbt descriptors
 */
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 = 2, /* 0 on 8-bit small page */
        .len = 4,
        .veroffs = 6,
        .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 = 2, /* 0 on 8-bit small page */
        .len = 4,
        .veroffs = 6,
        .maxblocks = 4,
        .pattern = mirror_pattern,
};

/*
 * Set up the IFC hardware block and page address fields, and the ifc nand
 * structure addr field to point to the correct IFC 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_ifc_mtd *priv = nand_get_controller_data(chip);
        struct fsl_ifc_ctrl *ctrl = priv->ctrl;
        struct fsl_ifc_runtime *ifc = ctrl->regs.rregs;
        int buf_num;

        ctrl->page = page_addr;

        /* Program ROW0/COL0 */
        ifc_out32(&ifc->ifc_nand.row0, page_addr);
        ifc_out32(&ifc->ifc_nand.col0, (oob ? IFC_NAND_COL_MS : 0) | column);

        buf_num = page_addr & priv->bufnum_mask;

        ctrl->addr = priv->vbase + buf_num * (mtd->writesize * 2);
        ctrl->index = column;

        /* for OOB data point to the second half of the buffer */
        if (oob)
                ctrl->index += mtd->writesize;
}

/* returns nonzero if entire page is blank */
static int check_read_ecc(struct mtd_info *mtd, struct fsl_ifc_ctrl *ctrl,
                          u32 eccstat, unsigned int bufnum)
{
        return (eccstat >> ((3 - bufnum % 4) * 8)) & 15;
}

/*
 * execute IFC NAND command and wait for it to complete
 */
static int fsl_ifc_run_command(struct mtd_info *mtd)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct fsl_ifc_mtd *priv = nand_get_controller_data(chip);
        struct fsl_ifc_ctrl *ctrl = priv->ctrl;
        struct fsl_ifc_runtime *ifc = ctrl->regs.rregs;
        u32 timeo = (CONFIG_SYS_HZ * 10) / 1000;
        u32 time_start;
        u32 eccstat;
        int i;

        /* set the chip select for NAND Transaction */
        ifc_out32(&ifc->ifc_nand.nand_csel, priv->bank << IFC_NAND_CSEL_SHIFT);

        /* start read/write seq */
        ifc_out32(&ifc->ifc_nand.nandseq_strt,
                  IFC_NAND_SEQ_STRT_FIR_STRT);

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

        while (get_timer(time_start) < timeo) {
                ctrl->status = ifc_in32(&ifc->ifc_nand.nand_evter_stat);

                if (ctrl->status & IFC_NAND_EVTER_STAT_OPC)
                        break;
        }

        ifc_out32(&ifc->ifc_nand.nand_evter_stat, ctrl->status);

        if (ctrl->status & IFC_NAND_EVTER_STAT_FTOER)
                printf("%s: Flash Time Out Error\n", __func__);
        if (ctrl->status & IFC_NAND_EVTER_STAT_WPER)
                printf("%s: Write Protect Error\n", __func__);

        if (ctrl->eccread) {
                int errors;
                int bufnum = ctrl->page & priv->bufnum_mask;
                int sector_start = bufnum * chip->ecc.steps;
                int sector_end = sector_start + chip->ecc.steps - 1;
                u32 *eccstat_regs;

                eccstat_regs = ifc->ifc_nand.nand_eccstat;
                eccstat = ifc_in32(&eccstat_regs[sector_start / 4]);

                for (i = sector_start; i <= sector_end; i++) {
                        if ((i != sector_start) && !(i % 4))
                                eccstat = ifc_in32(&eccstat_regs[i / 4]);

                        errors = check_read_ecc(mtd, ctrl, eccstat, i);

                        if (errors == 15) {
                                /*
                                 * Uncorrectable error.
                                 * We'll check for blank pages later.
                                 *
                                 * We disable ECCER reporting due to erratum
                                 * IFC-A002770 -- so report it now if we
                                 * see an uncorrectable error in ECCSTAT.
                                 */
                                ctrl->status |= IFC_NAND_EVTER_STAT_ECCER;
                                continue;
                        }

                        mtd->ecc_stats.corrected += errors;
                }

                ctrl->eccread = 0;
        }

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

static void fsl_ifc_do_read(struct nand_chip *chip,
                            int oob,
                            struct mtd_info *mtd)
{
        struct fsl_ifc_mtd *priv = nand_get_controller_data(chip);
        struct fsl_ifc_ctrl *ctrl = priv->ctrl;
        struct fsl_ifc_runtime *ifc = ctrl->regs.rregs;

        /* Program FIR/IFC_NAND_FCR0 for Small/Large page */
        if (mtd->writesize > 512) {
                ifc_out32(&ifc->ifc_nand.nand_fir0,
                          (IFC_FIR_OP_CW0 << IFC_NAND_FIR0_OP0_SHIFT) |
                          (IFC_FIR_OP_CA0 << IFC_NAND_FIR0_OP1_SHIFT) |
                          (IFC_FIR_OP_RA0 << IFC_NAND_FIR0_OP2_SHIFT) |
                          (IFC_FIR_OP_CMD1 << IFC_NAND_FIR0_OP3_SHIFT) |
                          (IFC_FIR_OP_RBCD << IFC_NAND_FIR0_OP4_SHIFT));
                ifc_out32(&ifc->ifc_nand.nand_fir1, 0x0);

                ifc_out32(&ifc->ifc_nand.nand_fcr0,
                          (NAND_CMD_READ0 << IFC_NAND_FCR0_CMD0_SHIFT) |
                          (NAND_CMD_READSTART << IFC_NAND_FCR0_CMD1_SHIFT));
        } else {
                ifc_out32(&ifc->ifc_nand.nand_fir0,
                          (IFC_FIR_OP_CW0 << IFC_NAND_FIR0_OP0_SHIFT) |
                          (IFC_FIR_OP_CA0 << IFC_NAND_FIR0_OP1_SHIFT) |
                          (IFC_FIR_OP_RA0  << IFC_NAND_FIR0_OP2_SHIFT) |
                          (IFC_FIR_OP_RBCD << IFC_NAND_FIR0_OP3_SHIFT));

                if (oob)
                        ifc_out32(&ifc->ifc_nand.nand_fcr0,
                                  NAND_CMD_READOOB << IFC_NAND_FCR0_CMD0_SHIFT);
                else
                        ifc_out32(&ifc->ifc_nand.nand_fcr0,
                                  NAND_CMD_READ0 << IFC_NAND_FCR0_CMD0_SHIFT);
        }
}

/* cmdfunc send commands to the IFC NAND Machine */
static void fsl_ifc_cmdfunc(struct mtd_info *mtd, unsigned int command,
                             int column, int page_addr)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct fsl_ifc_mtd *priv = nand_get_controller_data(chip);
        struct fsl_ifc_ctrl *ctrl = priv->ctrl;
        struct fsl_ifc_runtime *ifc = ctrl->regs.rregs;

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

        switch (command) {
        /* READ0 read the entire buffer to use hardware ECC. */
        case NAND_CMD_READ0: {
                ifc_out32(&ifc->ifc_nand.nand_fbcr, 0);
                set_addr(mtd, 0, page_addr, 0);

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

                if (chip->ecc.mode == NAND_ECC_HW)
                        ctrl->eccread = 1;

                fsl_ifc_do_read(chip, 0, mtd);
                fsl_ifc_run_command(mtd);
                return;
        }

        /* READOOB reads only the OOB because no ECC is performed. */
        case NAND_CMD_READOOB:
                ifc_out32(&ifc->ifc_nand.nand_fbcr, mtd->oobsize - column);
                set_addr(mtd, column, page_addr, 1);

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

                fsl_ifc_do_read(chip, 1, mtd);
                fsl_ifc_run_command(mtd);

                return;

        /* READID must read all possible bytes while CEB is active */
        case NAND_CMD_READID:
        case NAND_CMD_PARAM: {
                int timing = IFC_FIR_OP_RB;
                if (command == NAND_CMD_PARAM)
                        timing = IFC_FIR_OP_RBCD;

                ifc_out32(&ifc->ifc_nand.nand_fir0,
                          (IFC_FIR_OP_CW0 << IFC_NAND_FIR0_OP0_SHIFT) |
                          (IFC_FIR_OP_UA  << IFC_NAND_FIR0_OP1_SHIFT) |
                          (timing << IFC_NAND_FIR0_OP2_SHIFT));
                ifc_out32(&ifc->ifc_nand.nand_fcr0,
                          command << IFC_NAND_FCR0_CMD0_SHIFT);
                ifc_out32(&ifc->ifc_nand.row3, column);

                /*
                 * although currently it's 8 bytes for READID, we always read
                 * the maximum 256 bytes(for PARAM)
                 */
                ifc_out32(&ifc->ifc_nand.nand_fbcr, 256);
                ctrl->read_bytes = 256;

                set_addr(mtd, 0, 0, 0);
                fsl_ifc_run_command(mtd);
                return;
        }

        /* ERASE1 stores the block and page address */
        case NAND_CMD_ERASE1:
                set_addr(mtd, 0, page_addr, 0);
                return;

        /* ERASE2 uses the block and page address from ERASE1 */
        case NAND_CMD_ERASE2:
                ifc_out32(&ifc->ifc_nand.nand_fir0,
                          (IFC_FIR_OP_CW0 << IFC_NAND_FIR0_OP0_SHIFT) |
                          (IFC_FIR_OP_RA0 << IFC_NAND_FIR0_OP1_SHIFT) |
                          (IFC_FIR_OP_CMD1 << IFC_NAND_FIR0_OP2_SHIFT));

                ifc_out32(&ifc->ifc_nand.nand_fcr0,
                          (NAND_CMD_ERASE1 << IFC_NAND_FCR0_CMD0_SHIFT) |
                          (NAND_CMD_ERASE2 << IFC_NAND_FCR0_CMD1_SHIFT));

                ifc_out32(&ifc->ifc_nand.nand_fbcr, 0);
                ctrl->read_bytes = 0;
                fsl_ifc_run_command(mtd);
                return;

        /* SEQIN sets up the addr buffer and all registers except the length */
        case NAND_CMD_SEQIN: {
                u32 nand_fcr0;
                ctrl->column = column;
                ctrl->oob = 0;

                if (mtd->writesize > 512) {
                        nand_fcr0 =
                                (NAND_CMD_SEQIN << IFC_NAND_FCR0_CMD0_SHIFT) |
                                (NAND_CMD_STATUS << IFC_NAND_FCR0_CMD1_SHIFT) |
                                (NAND_CMD_PAGEPROG << IFC_NAND_FCR0_CMD2_SHIFT);

                        ifc_out32(&ifc->ifc_nand.nand_fir0,
                                  (IFC_FIR_OP_CW0 << IFC_NAND_FIR0_OP0_SHIFT) |
                                  (IFC_FIR_OP_CA0 << IFC_NAND_FIR0_OP1_SHIFT) |
                                  (IFC_FIR_OP_RA0 << IFC_NAND_FIR0_OP2_SHIFT) |
                                  (IFC_FIR_OP_WBCD  <<
                                                IFC_NAND_FIR0_OP3_SHIFT) |
                                  (IFC_FIR_OP_CMD2 << IFC_NAND_FIR0_OP4_SHIFT));
                        ifc_out32(&ifc->ifc_nand.nand_fir1,
                                  (IFC_FIR_OP_CW1 << IFC_NAND_FIR1_OP5_SHIFT) |
                                  (IFC_FIR_OP_RDSTAT <<
                                        IFC_NAND_FIR1_OP6_SHIFT) |
                                  (IFC_FIR_OP_NOP << IFC_NAND_FIR1_OP7_SHIFT));
                } else {
                        nand_fcr0 = ((NAND_CMD_PAGEPROG <<
                                        IFC_NAND_FCR0_CMD1_SHIFT) |
                                    (NAND_CMD_SEQIN <<
                                        IFC_NAND_FCR0_CMD2_SHIFT) |
                                    (NAND_CMD_STATUS <<
                                        IFC_NAND_FCR0_CMD3_SHIFT));

                        ifc_out32(&ifc->ifc_nand.nand_fir0,
                                  (IFC_FIR_OP_CW0 << IFC_NAND_FIR0_OP0_SHIFT) |
                                  (IFC_FIR_OP_CMD2 << IFC_NAND_FIR0_OP1_SHIFT) |
                                  (IFC_FIR_OP_CA0 << IFC_NAND_FIR0_OP2_SHIFT) |
                                  (IFC_FIR_OP_RA0 << IFC_NAND_FIR0_OP3_SHIFT) |
                                  (IFC_FIR_OP_WBCD << IFC_NAND_FIR0_OP4_SHIFT));
                        ifc_out32(&ifc->ifc_nand.nand_fir1,
                                  (IFC_FIR_OP_CMD1 << IFC_NAND_FIR1_OP5_SHIFT) |
                                  (IFC_FIR_OP_CW3 << IFC_NAND_FIR1_OP6_SHIFT) |
                                  (IFC_FIR_OP_RDSTAT <<
                                        IFC_NAND_FIR1_OP7_SHIFT) |
                                  (IFC_FIR_OP_NOP << IFC_NAND_FIR1_OP8_SHIFT));

                        if (column >= mtd->writesize)
                                nand_fcr0 |=
                                NAND_CMD_READOOB << IFC_NAND_FCR0_CMD0_SHIFT;
                        else
                                nand_fcr0 |=
                                NAND_CMD_READ0 << IFC_NAND_FCR0_CMD0_SHIFT;
                }

                if (column >= mtd->writesize) {
                        /* OOB area --> READOOB */
                        column -= mtd->writesize;
                        ctrl->oob = 1;
                }
                ifc_out32(&ifc->ifc_nand.nand_fcr0, nand_fcr0);
                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:
                if (ctrl->oob)
                        ifc_out32(&ifc->ifc_nand.nand_fbcr,
                                  ctrl->index - ctrl->column);
                else
                        ifc_out32(&ifc->ifc_nand.nand_fbcr, 0);

                fsl_ifc_run_command(mtd);
                return;

        case NAND_CMD_STATUS:
                ifc_out32(&ifc->ifc_nand.nand_fir0,
                          (IFC_FIR_OP_CW0 << IFC_NAND_FIR0_OP0_SHIFT) |
                          (IFC_FIR_OP_RB << IFC_NAND_FIR0_OP1_SHIFT));
                ifc_out32(&ifc->ifc_nand.nand_fcr0,
                          NAND_CMD_STATUS << IFC_NAND_FCR0_CMD0_SHIFT);
                ifc_out32(&ifc->ifc_nand.nand_fbcr, 1);
                set_addr(mtd, 0, 0, 0);
                ctrl->read_bytes = 1;

                fsl_ifc_run_command(mtd);

                /*
                 * The chip always seems to report that it is
                 * write-protected, even when it is not.
                 */
                if (chip->options & NAND_BUSWIDTH_16)
                        ifc_out16(ctrl->addr,
                                  ifc_in16(ctrl->addr) | NAND_STATUS_WP);
                else
                        out_8(ctrl->addr, in_8(ctrl->addr) | NAND_STATUS_WP);
                return;

        case NAND_CMD_RESET:
                ifc_out32(&ifc->ifc_nand.nand_fir0,
                          IFC_FIR_OP_CW0 << IFC_NAND_FIR0_OP0_SHIFT);
                ifc_out32(&ifc->ifc_nand.nand_fcr0,
                          NAND_CMD_RESET << IFC_NAND_FCR0_CMD0_SHIFT);
                fsl_ifc_run_command(mtd);
                return;

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

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

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

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

        memcpy_toio(ctrl->addr + ctrl->index, buf, len);
        ctrl->index += len;
}

/*
 * read a byte from either the IFC hardware buffer if it has any data left
 * otherwise issue a command to read a single byte.
 */
static u8 fsl_ifc_read_byte(struct mtd_info *mtd)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct fsl_ifc_mtd *priv = nand_get_controller_data(chip);
        struct fsl_ifc_ctrl *ctrl = priv->ctrl;
        unsigned int offset;

        /*
         * If there are still bytes in the IFC buffer, then use the
         * next byte.
         */
        if (ctrl->index < ctrl->read_bytes) {
                offset = ctrl->index++;
                return in_8(ctrl->addr + offset);
        }

        printf("%s beyond end of buffer\n", __func__);
        return ERR_BYTE;
}

/*
 * Read two bytes from the IFC hardware buffer
 * read function for 16-bit buswith
 */
static uint8_t fsl_ifc_read_byte16(struct mtd_info *mtd)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct fsl_ifc_mtd *priv = nand_get_controller_data(chip);
        struct fsl_ifc_ctrl *ctrl = priv->ctrl;
        uint16_t data;

        /*
         * If there are still bytes in the IFC buffer, then use the
         * next byte.
         */
        if (ctrl->index < ctrl->read_bytes) {
                data = ifc_in16(ctrl->addr + ctrl->index);
                ctrl->index += 2;
                return (uint8_t)data;
        }

        printf("%s beyond end of buffer\n", __func__);
        return ERR_BYTE;
}

/*
 * Read from the IFC Controller Data Buffer
 */
static void fsl_ifc_read_buf(struct mtd_info *mtd, u8 *buf, int len)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct fsl_ifc_mtd *priv = nand_get_controller_data(chip);
        struct fsl_ifc_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("%s beyond end of buffer "
                       "(%d requested, %d available)\n",
                       __func__, len, avail);
}

/* This function is called after Program and Erase Operations to
 * check for success or failure.
 */
static int fsl_ifc_wait(struct mtd_info *mtd, struct nand_chip *chip)
{
        struct fsl_ifc_mtd *priv = nand_get_controller_data(chip);
        struct fsl_ifc_ctrl *ctrl = priv->ctrl;
        struct fsl_ifc_runtime *ifc = ctrl->regs.rregs;
        u32 nand_fsr;
        int status;

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

        /* Use READ_STATUS command, but wait for the device to be ready */
        ifc_out32(&ifc->ifc_nand.nand_fir0,
                  (IFC_FIR_OP_CW0 << IFC_NAND_FIR0_OP0_SHIFT) |
                  (IFC_FIR_OP_RDSTAT << IFC_NAND_FIR0_OP1_SHIFT));
        ifc_out32(&ifc->ifc_nand.nand_fcr0, NAND_CMD_STATUS <<
                  IFC_NAND_FCR0_CMD0_SHIFT);
        ifc_out32(&ifc->ifc_nand.nand_fbcr, 1);
        set_addr(mtd, 0, 0, 0);
        ctrl->read_bytes = 1;

        fsl_ifc_run_command(mtd);

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

        nand_fsr = ifc_in32(&ifc->ifc_nand.nand_fsr);
        status = nand_fsr >> 24;

        /* Chip sometimes reporting write protect even when it's not */
        return status | NAND_STATUS_WP;
}

/*
 * The controller does not check for bitflips in erased pages,
 * therefore software must check instead.
 */
static int
check_erased_page(struct nand_chip *chip, u8 *buf, struct mtd_info *mtd)
{
        u8 *ecc = chip->oob_poi;
        const int ecc_size = chip->ecc.bytes;
        const int pkt_size = chip->ecc.size;
        int i, res, bitflips;

        /* IFC starts ecc bytes at offset 8 in the spare area. */
        ecc += 8;
        bitflips = 0;
        for (i = 0; i < chip->ecc.steps; i++) {
                res = nand_check_erased_ecc_chunk(buf, pkt_size, ecc, ecc_size,
                                                  NULL, 0, chip->ecc.strength);

                if (res < 0) {
                        printf("fsl-ifc: NAND Flash ECC Uncorrectable Error\n");
                        mtd->ecc_stats.failed++;
                } else if (res > 0) {
                        mtd->ecc_stats.corrected += res;
                }
                bitflips = max(res, bitflips);
                buf += pkt_size;
                ecc += ecc_size;
        }

        return bitflips;
}

static int fsl_ifc_read_page(struct mtd_info *mtd, struct nand_chip *chip,
                             uint8_t *buf, int oob_required, int page)
{
        struct fsl_ifc_mtd *priv = nand_get_controller_data(chip);
        struct fsl_ifc_ctrl *ctrl = priv->ctrl;

        fsl_ifc_read_buf(mtd, buf, mtd->writesize);
        fsl_ifc_read_buf(mtd, chip->oob_poi, mtd->oobsize);

        if (ctrl->status & IFC_NAND_EVTER_STAT_ECCER)
                return check_erased_page(chip, buf, mtd);

        if (ctrl->status != IFC_NAND_EVTER_STAT_OPC)
                mtd->ecc_stats.failed++;

        return 0;
}

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

        return 0;
}

static void fsl_ifc_ctrl_init(void)
{
        uint32_t ver = 0;
        ifc_ctrl = kzalloc(sizeof(*ifc_ctrl), GFP_KERNEL);
        if (!ifc_ctrl)
                return;

        ifc_ctrl->regs.gregs = IFC_FCM_BASE_ADDR;

        ver = ifc_in32(&ifc_ctrl->regs.gregs->ifc_rev);
        if (ver >= FSL_IFC_V2_0_0)
                ifc_ctrl->regs.rregs =
                        (void *)CONFIG_SYS_IFC_ADDR + IFC_RREGS_64KOFFSET;
        else
                ifc_ctrl->regs.rregs =
                        (void *)CONFIG_SYS_IFC_ADDR + IFC_RREGS_4KOFFSET;

        /* clear event registers */
        ifc_out32(&ifc_ctrl->regs.rregs->ifc_nand.nand_evter_stat, ~0U);
        ifc_out32(&ifc_ctrl->regs.rregs->ifc_nand.pgrdcmpl_evt_stat, ~0U);

        /* Enable error and event for any detected errors */
        ifc_out32(&ifc_ctrl->regs.rregs->ifc_nand.nand_evter_en,
                  IFC_NAND_EVTER_EN_OPC_EN |
                  IFC_NAND_EVTER_EN_PGRDCMPL_EN |
                  IFC_NAND_EVTER_EN_FTOER_EN |
                  IFC_NAND_EVTER_EN_WPER_EN);

        ifc_out32(&ifc_ctrl->regs.rregs->ifc_nand.ncfgr, 0x0);
}

static void fsl_ifc_select_chip(struct mtd_info *mtd, int chip)
{
}

static int fsl_ifc_sram_init(struct fsl_ifc_mtd *priv, uint32_t ver)
{
        struct fsl_ifc_runtime *ifc = ifc_ctrl->regs.rregs;
        uint32_t cs = 0, csor = 0, csor_8k = 0, csor_ext = 0;
        uint32_t ncfgr = 0;
        u32 timeo = (CONFIG_SYS_HZ * 10) / 1000;
        u32 time_start;

        if (ver > FSL_IFC_V1_1_0) {
                ncfgr = ifc_in32(&ifc->ifc_nand.ncfgr);
                ifc_out32(&ifc->ifc_nand.ncfgr, ncfgr | IFC_NAND_SRAM_INIT_EN);

                /* wait for  SRAM_INIT bit to be clear or timeout */
                time_start = get_timer(0);
                while (get_timer(time_start) < timeo) {
                        ifc_ctrl->status =
                                ifc_in32(&ifc->ifc_nand.nand_evter_stat);

                        if (!(ifc_ctrl->status & IFC_NAND_SRAM_INIT_EN))
                                return 0;
                }
                printf("fsl-ifc: Failed to Initialise SRAM\n");
                return 1;
        }

        cs = priv->bank;

        /* Save CSOR and CSOR_ext */
        csor = ifc_in32(&ifc_ctrl->regs.gregs->csor_cs[cs].csor);
        csor_ext = ifc_in32(&ifc_ctrl->regs.gregs->csor_cs[cs].csor_ext);

        /* chage PageSize 8K and SpareSize 1K*/
        csor_8k = (csor & ~(CSOR_NAND_PGS_MASK)) | 0x0018C000;
        ifc_out32(&ifc_ctrl->regs.gregs->csor_cs[cs].csor, csor_8k);
        ifc_out32(&ifc_ctrl->regs.gregs->csor_cs[cs].csor_ext, 0x0000400);

        /* READID */
        ifc_out32(&ifc->ifc_nand.nand_fir0,
                  (IFC_FIR_OP_CW0 << IFC_NAND_FIR0_OP0_SHIFT) |
                  (IFC_FIR_OP_UA  << IFC_NAND_FIR0_OP1_SHIFT) |
                  (IFC_FIR_OP_RB << IFC_NAND_FIR0_OP2_SHIFT));
        ifc_out32(&ifc->ifc_nand.nand_fcr0,
                  NAND_CMD_READID << IFC_NAND_FCR0_CMD0_SHIFT);
        ifc_out32(&ifc->ifc_nand.row3, 0x0);

        ifc_out32(&ifc->ifc_nand.nand_fbcr, 0x0);

        /* Program ROW0/COL0 */
        ifc_out32(&ifc->ifc_nand.row0, 0x0);
        ifc_out32(&ifc->ifc_nand.col0, 0x0);

        /* set the chip select for NAND Transaction */
        ifc_out32(&ifc->ifc_nand.nand_csel, priv->bank << IFC_NAND_CSEL_SHIFT);

        /* start read seq */
        ifc_out32(&ifc->ifc_nand.nandseq_strt, IFC_NAND_SEQ_STRT_FIR_STRT);

        time_start = get_timer(0);

        while (get_timer(time_start) < timeo) {
                ifc_ctrl->status = ifc_in32(&ifc->ifc_nand.nand_evter_stat);

                if (ifc_ctrl->status & IFC_NAND_EVTER_STAT_OPC)
                        break;
        }

        if (ifc_ctrl->status != IFC_NAND_EVTER_STAT_OPC) {
                printf("fsl-ifc: Failed to Initialise SRAM\n");
                return 1;
        }

        ifc_out32(&ifc->ifc_nand.nand_evter_stat, ifc_ctrl->status);

        /* Restore CSOR and CSOR_ext */
        ifc_out32(&ifc_ctrl->regs.gregs->csor_cs[cs].csor, csor);
        ifc_out32(&ifc_ctrl->regs.gregs->csor_cs[cs].csor_ext, csor_ext);

        return 0;
}

static int fsl_ifc_chip_init(int devnum, u8 *addr)
{
        struct mtd_info *mtd;
        struct nand_chip *nand;
        struct fsl_ifc_mtd *priv;
        struct nand_ecclayout *layout;
        struct fsl_ifc_fcm *gregs = NULL;
        uint32_t cspr = 0, csor = 0, ver = 0;
        int ret = 0;

        if (!ifc_ctrl) {
                fsl_ifc_ctrl_init();
                if (!ifc_ctrl)
                        return -1;
        }

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

        priv->ctrl = ifc_ctrl;
        priv->vbase = addr;
        gregs = ifc_ctrl->regs.gregs;

        /* Find which chip select it is connected to.
         */
        for (priv->bank = 0; priv->bank < MAX_BANKS; priv->bank++) {
                phys_addr_t phys_addr = virt_to_phys(addr);

                cspr = ifc_in32(&gregs->cspr_cs[priv->bank].cspr);
                csor = ifc_in32(&gregs->csor_cs[priv->bank].csor);

                if ((cspr & CSPR_V) && (cspr & CSPR_MSEL) == CSPR_MSEL_NAND &&
                    (cspr & CSPR_BA) == CSPR_PHYS_ADDR(phys_addr))
                        break;
        }

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

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

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

        /* fill in nand_chip structure */
        /* set up function call table */

        nand->write_buf = fsl_ifc_write_buf;
        nand->read_buf = fsl_ifc_read_buf;
        nand->select_chip = fsl_ifc_select_chip;
        nand->cmdfunc = fsl_ifc_cmdfunc;
        nand->waitfunc = fsl_ifc_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;

        if (cspr & CSPR_PORT_SIZE_16) {
                nand->read_byte = fsl_ifc_read_byte16;
                nand->options |= NAND_BUSWIDTH_16;
        } else {
                nand->read_byte = fsl_ifc_read_byte;
        }

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

        nand->ecc.read_page = fsl_ifc_read_page;
        nand->ecc.write_page = fsl_ifc_write_page;

        /* Hardware generates ECC per 512 Bytes */
        nand->ecc.size = 512;
        nand->ecc.bytes = 8;

        switch (csor & CSOR_NAND_PGS_MASK) {
        case CSOR_NAND_PGS_512:
                if (nand->options & NAND_BUSWIDTH_16) {
                        layout = &oob_512_16bit_ecc4;
                } else {
                        layout = &oob_512_8bit_ecc4;

                        /* Avoid conflict with bad block marker */
                        bbt_main_descr.offs = 0;
                        bbt_mirror_descr.offs = 0;
                }

                nand->ecc.strength = 4;
                priv->bufnum_mask = 15;
                break;

        case CSOR_NAND_PGS_2K:
                layout = &oob_2048_ecc4;
                nand->ecc.strength = 4;
                priv->bufnum_mask = 3;
                break;

        case CSOR_NAND_PGS_4K:
                if ((csor & CSOR_NAND_ECC_MODE_MASK) ==
                    CSOR_NAND_ECC_MODE_4) {
                        layout = &oob_4096_ecc4;
                        nand->ecc.strength = 4;
                } else {
                        layout = &oob_4096_ecc8;
                        nand->ecc.strength = 8;
                        nand->ecc.bytes = 16;
                }

                priv->bufnum_mask = 1;
                break;

        case CSOR_NAND_PGS_8K:
                if ((csor & CSOR_NAND_ECC_MODE_MASK) ==
                    CSOR_NAND_ECC_MODE_4) {
                        layout = &oob_8192_ecc4;
                        nand->ecc.strength = 4;
                } else {
                        layout = &oob_8192_ecc8;
                        nand->ecc.strength = 8;
                        nand->ecc.bytes = 16;
                }

                priv->bufnum_mask = 0;
                break;


        default:
                printf("ifc nand: bad csor %#x: bad page size\n", csor);
                return -ENODEV;
        }

        /* Must also set CSOR_NAND_ECC_ENC_EN if DEC_EN set */
        if (csor & CSOR_NAND_ECC_DEC_EN) {
                nand->ecc.mode = NAND_ECC_HW;
                nand->ecc.layout = layout;
        } else {
                nand->ecc.mode = NAND_ECC_SOFT;
        }

        ver = ifc_in32(&gregs->ifc_rev);
        if (ver >= FSL_IFC_V1_1_0)
                ret = fsl_ifc_sram_init(priv, ver);
        if (ret)
                return ret;

        if (ver >= FSL_IFC_V2_0_0)
                priv->bufnum_mask = (priv->bufnum_mask * 2) + 1;

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

        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_ifc_chip_init(i, (u8 *)base_address[i]);
}