// SPDX-License-Identifier: GPL-2.0
/*
 * SuperH FLCTL nand controller
 *
 * Copyright (c) 2008 Renesas Solutions Corp.
 * Copyright (c) 2008 Atom Create Engineering Co., Ltd.
 *
 * Based on fsl_elbc_nand.c, Copyright (c) 2006-2007 Freescale Semiconductor
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/sh_dma.h>
#include <linux/slab.h>
#include <linux/string.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/rawnand.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/sh_flctl.h>

static int flctl_4secc_ooblayout_sp_ecc(struct mtd_info *mtd, int section,
                                        struct mtd_oob_region *oobregion)
{
        struct nand_chip *chip = mtd_to_nand(mtd);

        if (section)
                return -ERANGE;

        oobregion->offset = 0;
        oobregion->length = chip->ecc.bytes;

        return 0;
}

static int flctl_4secc_ooblayout_sp_free(struct mtd_info *mtd, int section,
                                         struct mtd_oob_region *oobregion)
{
        if (section)
                return -ERANGE;

        oobregion->offset = 12;
        oobregion->length = 4;

        return 0;
}

static const struct mtd_ooblayout_ops flctl_4secc_oob_smallpage_ops = {
        .ecc = flctl_4secc_ooblayout_sp_ecc,
        .free = flctl_4secc_ooblayout_sp_free,
};

static int flctl_4secc_ooblayout_lp_ecc(struct mtd_info *mtd, int section,
                                        struct mtd_oob_region *oobregion)
{
        struct nand_chip *chip = mtd_to_nand(mtd);

        if (section >= chip->ecc.steps)
                return -ERANGE;

        oobregion->offset = (section * 16) + 6;
        oobregion->length = chip->ecc.bytes;

        return 0;
}

static int flctl_4secc_ooblayout_lp_free(struct mtd_info *mtd, int section,
                                         struct mtd_oob_region *oobregion)
{
        struct nand_chip *chip = mtd_to_nand(mtd);

        if (section >= chip->ecc.steps)
                return -ERANGE;

        oobregion->offset = section * 16;
        oobregion->length = 6;

        if (!section) {
                oobregion->offset += 2;
                oobregion->length -= 2;
        }

        return 0;
}

static const struct mtd_ooblayout_ops flctl_4secc_oob_largepage_ops = {
        .ecc = flctl_4secc_ooblayout_lp_ecc,
        .free = flctl_4secc_ooblayout_lp_free,
};

static uint8_t scan_ff_pattern[] = { 0xff, 0xff };

static struct nand_bbt_descr flctl_4secc_smallpage = {
        .options = NAND_BBT_SCAN2NDPAGE,
        .offs = 11,
        .len = 1,
        .pattern = scan_ff_pattern,
};

static struct nand_bbt_descr flctl_4secc_largepage = {
        .options = NAND_BBT_SCAN2NDPAGE,
        .offs = 0,
        .len = 2,
        .pattern = scan_ff_pattern,
};

static void empty_fifo(struct sh_flctl *flctl)
{
        writel(flctl->flintdmacr_base | AC1CLR | AC0CLR, FLINTDMACR(flctl));
        writel(flctl->flintdmacr_base, FLINTDMACR(flctl));
}

static void start_translation(struct sh_flctl *flctl)
{
        writeb(TRSTRT, FLTRCR(flctl));
}

static void timeout_error(struct sh_flctl *flctl, const char *str)
{
        dev_err(&flctl->pdev->dev, "Timeout occurred in %s\n", str);
}

static void wait_completion(struct sh_flctl *flctl)
{
        uint32_t timeout = LOOP_TIMEOUT_MAX;

        while (timeout--) {
                if (readb(FLTRCR(flctl)) & TREND) {
                        writeb(0x0, FLTRCR(flctl));
                        return;
                }
                udelay(1);
        }

        timeout_error(flctl, __func__);
        writeb(0x0, FLTRCR(flctl));
}

static void flctl_dma_complete(void *param)
{
        struct sh_flctl *flctl = param;

        complete(&flctl->dma_complete);
}

static void flctl_release_dma(struct sh_flctl *flctl)
{
        if (flctl->chan_fifo0_rx) {
                dma_release_channel(flctl->chan_fifo0_rx);
                flctl->chan_fifo0_rx = NULL;
        }
        if (flctl->chan_fifo0_tx) {
                dma_release_channel(flctl->chan_fifo0_tx);
                flctl->chan_fifo0_tx = NULL;
        }
}

static void flctl_setup_dma(struct sh_flctl *flctl)
{
        dma_cap_mask_t mask;
        struct dma_slave_config cfg;
        struct platform_device *pdev = flctl->pdev;
        struct sh_flctl_platform_data *pdata = dev_get_platdata(&pdev->dev);
        int ret;

        if (!pdata)
                return;

        if (pdata->slave_id_fifo0_tx <= 0 || pdata->slave_id_fifo0_rx <= 0)
                return;

        /* We can only either use DMA for both Tx and Rx or not use it at all */
        dma_cap_zero(mask);
        dma_cap_set(DMA_SLAVE, mask);

        flctl->chan_fifo0_tx = dma_request_channel(mask, shdma_chan_filter,
                                (void *)(uintptr_t)pdata->slave_id_fifo0_tx);
        dev_dbg(&pdev->dev, "%s: TX: got channel %p\n", __func__,
                flctl->chan_fifo0_tx);

        if (!flctl->chan_fifo0_tx)
                return;

        memset(&cfg, 0, sizeof(cfg));
        cfg.direction = DMA_MEM_TO_DEV;
        cfg.dst_addr = flctl->fifo;
        cfg.src_addr = 0;
        ret = dmaengine_slave_config(flctl->chan_fifo0_tx, &cfg);
        if (ret < 0)
                goto err;

        flctl->chan_fifo0_rx = dma_request_channel(mask, shdma_chan_filter,
                                (void *)(uintptr_t)pdata->slave_id_fifo0_rx);
        dev_dbg(&pdev->dev, "%s: RX: got channel %p\n", __func__,
                flctl->chan_fifo0_rx);

        if (!flctl->chan_fifo0_rx)
                goto err;

        cfg.direction = DMA_DEV_TO_MEM;
        cfg.dst_addr = 0;
        cfg.src_addr = flctl->fifo;
        ret = dmaengine_slave_config(flctl->chan_fifo0_rx, &cfg);
        if (ret < 0)
                goto err;

        init_completion(&flctl->dma_complete);

        return;

err:
        flctl_release_dma(flctl);
}

static void set_addr(struct mtd_info *mtd, int column, int page_addr)
{
        struct sh_flctl *flctl = mtd_to_flctl(mtd);
        uint32_t addr = 0;

        if (column == -1) {
                addr = page_addr;       /* ERASE1 */
        } else if (page_addr != -1) {
                /* SEQIN, READ0, etc.. */
                if (flctl->chip.options & NAND_BUSWIDTH_16)
                        column >>= 1;
                if (flctl->page_size) {
                        addr = column & 0x0FFF;
                        addr |= (page_addr & 0xff) << 16;
                        addr |= ((page_addr >> 8) & 0xff) << 24;
                        /* big than 128MB */
                        if (flctl->rw_ADRCNT == ADRCNT2_E) {
                                uint32_t        addr2;
                                addr2 = (page_addr >> 16) & 0xff;
                                writel(addr2, FLADR2(flctl));
                        }
                } else {
                        addr = column;
                        addr |= (page_addr & 0xff) << 8;
                        addr |= ((page_addr >> 8) & 0xff) << 16;
                        addr |= ((page_addr >> 16) & 0xff) << 24;
                }
        }
        writel(addr, FLADR(flctl));
}

static void wait_rfifo_ready(struct sh_flctl *flctl)
{
        uint32_t timeout = LOOP_TIMEOUT_MAX;

        while (timeout--) {
                uint32_t val;
                /* check FIFO */
                val = readl(FLDTCNTR(flctl)) >> 16;
                if (val & 0xFF)
                        return;
                udelay(1);
        }
        timeout_error(flctl, __func__);
}

static void wait_wfifo_ready(struct sh_flctl *flctl)
{
        uint32_t len, timeout = LOOP_TIMEOUT_MAX;

        while (timeout--) {
                /* check FIFO */
                len = (readl(FLDTCNTR(flctl)) >> 16) & 0xFF;
                if (len >= 4)
                        return;
                udelay(1);
        }
        timeout_error(flctl, __func__);
}

static enum flctl_ecc_res_t wait_recfifo_ready
                (struct sh_flctl *flctl, int sector_number)
{
        uint32_t timeout = LOOP_TIMEOUT_MAX;
        void __iomem *ecc_reg[4];
        int i;
        int state = FL_SUCCESS;
        uint32_t data, size;

        /*
         * First this loops checks in FLDTCNTR if we are ready to read out the
         * oob data. This is the case if either all went fine without errors or
         * if the bottom part of the loop corrected the errors or marked them as
         * uncorrectable and the controller is given time to push the data into
         * the FIFO.
         */
        while (timeout--) {
                /* check if all is ok and we can read out the OOB */
                size = readl(FLDTCNTR(flctl)) >> 24;
                if ((size & 0xFF) == 4)
                        return state;

                /* check if a correction code has been calculated */
                if (!(readl(FL4ECCCR(flctl)) & _4ECCEND)) {
                        /*
                         * either we wait for the fifo to be filled or a
                         * correction pattern is being generated
                         */
                        udelay(1);
                        continue;
                }

                /* check for an uncorrectable error */
                if (readl(FL4ECCCR(flctl)) & _4ECCFA) {
                        /* check if we face a non-empty page */
                        for (i = 0; i < 512; i++) {
                                if (flctl->done_buff[i] != 0xff) {
                                        state = FL_ERROR; /* can't correct */
                                        break;
                                }
                        }

                        if (state == FL_SUCCESS)
                                dev_dbg(&flctl->pdev->dev,
                                "reading empty sector %d, ecc error ignored\n",
                                sector_number);

                        writel(0, FL4ECCCR(flctl));
                        continue;
                }

                /* start error correction */
                ecc_reg[0] = FL4ECCRESULT0(flctl);
                ecc_reg[1] = FL4ECCRESULT1(flctl);
                ecc_reg[2] = FL4ECCRESULT2(flctl);
                ecc_reg[3] = FL4ECCRESULT3(flctl);

                for (i = 0; i < 3; i++) {
                        uint8_t org;
                        unsigned int index;

                        data = readl(ecc_reg[i]);

                        if (flctl->page_size)
                                index = (512 * sector_number) +
                                        (data >> 16);
                        else
                                index = data >> 16;

                        org = flctl->done_buff[index];
                        flctl->done_buff[index] = org ^ (data & 0xFF);
                }
                state = FL_REPAIRABLE;
                writel(0, FL4ECCCR(flctl));
        }

        timeout_error(flctl, __func__);
        return FL_TIMEOUT;      /* timeout */
}

static void wait_wecfifo_ready(struct sh_flctl *flctl)
{
        uint32_t timeout = LOOP_TIMEOUT_MAX;
        uint32_t len;

        while (timeout--) {
                /* check FLECFIFO */
                len = (readl(FLDTCNTR(flctl)) >> 24) & 0xFF;
                if (len >= 4)
                        return;
                udelay(1);
        }
        timeout_error(flctl, __func__);
}

static int flctl_dma_fifo0_transfer(struct sh_flctl *flctl, unsigned long *buf,
                                        int len, enum dma_data_direction dir)
{
        struct dma_async_tx_descriptor *desc = NULL;
        struct dma_chan *chan;
        enum dma_transfer_direction tr_dir;
        dma_addr_t dma_addr;
        dma_cookie_t cookie;
        uint32_t reg;
        int ret;

        if (dir == DMA_FROM_DEVICE) {
                chan = flctl->chan_fifo0_rx;
                tr_dir = DMA_DEV_TO_MEM;
        } else {
                chan = flctl->chan_fifo0_tx;
                tr_dir = DMA_MEM_TO_DEV;
        }

        dma_addr = dma_map_single(chan->device->dev, buf, len, dir);

        if (!dma_mapping_error(chan->device->dev, dma_addr))
                desc = dmaengine_prep_slave_single(chan, dma_addr, len,
                        tr_dir, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);

        if (desc) {
                reg = readl(FLINTDMACR(flctl));
                reg |= DREQ0EN;
                writel(reg, FLINTDMACR(flctl));

                desc->callback = flctl_dma_complete;
                desc->callback_param = flctl;
                cookie = dmaengine_submit(desc);
                if (dma_submit_error(cookie)) {
                        ret = dma_submit_error(cookie);
                        dev_warn(&flctl->pdev->dev,
                                 "DMA submit failed, falling back to PIO\n");
                        goto out;
                }

                dma_async_issue_pending(chan);
        } else {
                /* DMA failed, fall back to PIO */
                flctl_release_dma(flctl);
                dev_warn(&flctl->pdev->dev,
                         "DMA failed, falling back to PIO\n");
                ret = -EIO;
                goto out;
        }

        ret =
        wait_for_completion_timeout(&flctl->dma_complete,
                                msecs_to_jiffies(3000));

        if (ret <= 0) {
                dmaengine_terminate_all(chan);
                dev_err(&flctl->pdev->dev, "wait_for_completion_timeout\n");
        }

out:
        reg = readl(FLINTDMACR(flctl));
        reg &= ~DREQ0EN;
        writel(reg, FLINTDMACR(flctl));

        dma_unmap_single(chan->device->dev, dma_addr, len, dir);

        /* ret > 0 is success */
        return ret;
}

static void read_datareg(struct sh_flctl *flctl, int offset)
{
        unsigned long data;
        unsigned long *buf = (unsigned long *)&flctl->done_buff[offset];

        wait_completion(flctl);

        data = readl(FLDATAR(flctl));
        *buf = le32_to_cpu(data);
}

static void read_fiforeg(struct sh_flctl *flctl, int rlen, int offset)
{
        int i, len_4align;
        unsigned long *buf = (unsigned long *)&flctl->done_buff[offset];

        len_4align = (rlen + 3) / 4;

        /* initiate DMA transfer */
        if (flctl->chan_fifo0_rx && rlen >= 32 &&
                flctl_dma_fifo0_transfer(flctl, buf, rlen, DMA_FROM_DEVICE) > 0)
                        goto convert;   /* DMA success */

        /* do polling transfer */
        for (i = 0; i < len_4align; i++) {
                wait_rfifo_ready(flctl);
                buf[i] = readl(FLDTFIFO(flctl));
        }

convert:
        for (i = 0; i < len_4align; i++)
                buf[i] = be32_to_cpu(buf[i]);
}

static enum flctl_ecc_res_t read_ecfiforeg
                (struct sh_flctl *flctl, uint8_t *buff, int sector)
{
        int i;
        enum flctl_ecc_res_t res;
        unsigned long *ecc_buf = (unsigned long *)buff;

        res = wait_recfifo_ready(flctl , sector);

        if (res != FL_ERROR) {
                for (i = 0; i < 4; i++) {
                        ecc_buf[i] = readl(FLECFIFO(flctl));
                        ecc_buf[i] = be32_to_cpu(ecc_buf[i]);
                }
        }

        return res;
}

static void write_fiforeg(struct sh_flctl *flctl, int rlen,
                                                unsigned int offset)
{
        int i, len_4align;
        unsigned long *buf = (unsigned long *)&flctl->done_buff[offset];

        len_4align = (rlen + 3) / 4;
        for (i = 0; i < len_4align; i++) {
                wait_wfifo_ready(flctl);
                writel(cpu_to_be32(buf[i]), FLDTFIFO(flctl));
        }
}

static void write_ec_fiforeg(struct sh_flctl *flctl, int rlen,
                                                unsigned int offset)
{
        int i, len_4align;
        unsigned long *buf = (unsigned long *)&flctl->done_buff[offset];

        len_4align = (rlen + 3) / 4;

        for (i = 0; i < len_4align; i++)
                buf[i] = cpu_to_be32(buf[i]);

        /* initiate DMA transfer */
        if (flctl->chan_fifo0_tx && rlen >= 32 &&
                flctl_dma_fifo0_transfer(flctl, buf, rlen, DMA_TO_DEVICE) > 0)
                        return; /* DMA success */

        /* do polling transfer */
        for (i = 0; i < len_4align; i++) {
                wait_wecfifo_ready(flctl);
                writel(buf[i], FLECFIFO(flctl));
        }
}

static void set_cmd_regs(struct mtd_info *mtd, uint32_t cmd, uint32_t flcmcdr_val)
{
        struct sh_flctl *flctl = mtd_to_flctl(mtd);
        uint32_t flcmncr_val = flctl->flcmncr_base & ~SEL_16BIT;
        uint32_t flcmdcr_val, addr_len_bytes = 0;

        /* Set SNAND bit if page size is 2048byte */
        if (flctl->page_size)
                flcmncr_val |= SNAND_E;
        else
                flcmncr_val &= ~SNAND_E;

        /* default FLCMDCR val */
        flcmdcr_val = DOCMD1_E | DOADR_E;

        /* Set for FLCMDCR */
        switch (cmd) {
        case NAND_CMD_ERASE1:
                addr_len_bytes = flctl->erase_ADRCNT;
                flcmdcr_val |= DOCMD2_E;
                break;
        case NAND_CMD_READ0:
        case NAND_CMD_READOOB:
        case NAND_CMD_RNDOUT:
                addr_len_bytes = flctl->rw_ADRCNT;
                flcmdcr_val |= CDSRC_E;
                if (flctl->chip.options & NAND_BUSWIDTH_16)
                        flcmncr_val |= SEL_16BIT;
                break;
        case NAND_CMD_SEQIN:
                /* This case is that cmd is READ0 or READ1 or READ00 */
                flcmdcr_val &= ~DOADR_E;        /* ONLY execute 1st cmd */
                break;
        case NAND_CMD_PAGEPROG:
                addr_len_bytes = flctl->rw_ADRCNT;
                flcmdcr_val |= DOCMD2_E | CDSRC_E | SELRW;
                if (flctl->chip.options & NAND_BUSWIDTH_16)
                        flcmncr_val |= SEL_16BIT;
                break;
        case NAND_CMD_READID:
                flcmncr_val &= ~SNAND_E;
                flcmdcr_val |= CDSRC_E;
                addr_len_bytes = ADRCNT_1;
                break;
        case NAND_CMD_STATUS:
        case NAND_CMD_RESET:
                flcmncr_val &= ~SNAND_E;
                flcmdcr_val &= ~(DOADR_E | DOSR_E);
                break;
        default:
                break;
        }

        /* Set address bytes parameter */
        flcmdcr_val |= addr_len_bytes;

        /* Now actually write */
        writel(flcmncr_val, FLCMNCR(flctl));
        writel(flcmdcr_val, FLCMDCR(flctl));
        writel(flcmcdr_val, FLCMCDR(flctl));
}

static int flctl_read_page_hwecc(struct nand_chip *chip, uint8_t *buf,
                                 int oob_required, int page)
{
        struct mtd_info *mtd = nand_to_mtd(chip);

        nand_read_page_op(chip, page, 0, buf, mtd->writesize);
        if (oob_required)
                chip->legacy.read_buf(chip, chip->oob_poi, mtd->oobsize);
        return 0;
}

static int flctl_write_page_hwecc(struct nand_chip *chip, const uint8_t *buf,
                                  int oob_required, int page)
{
        struct mtd_info *mtd = nand_to_mtd(chip);

        nand_prog_page_begin_op(chip, page, 0, buf, mtd->writesize);
        chip->legacy.write_buf(chip, chip->oob_poi, mtd->oobsize);
        return nand_prog_page_end_op(chip);
}

static void execmd_read_page_sector(struct mtd_info *mtd, int page_addr)
{
        struct sh_flctl *flctl = mtd_to_flctl(mtd);
        int sector, page_sectors;
        enum flctl_ecc_res_t ecc_result;

        page_sectors = flctl->page_size ? 4 : 1;

        set_cmd_regs(mtd, NAND_CMD_READ0,
                (NAND_CMD_READSTART << 8) | NAND_CMD_READ0);

        writel(readl(FLCMNCR(flctl)) | ACM_SACCES_MODE | _4ECCCORRECT,
                 FLCMNCR(flctl));
        writel(readl(FLCMDCR(flctl)) | page_sectors, FLCMDCR(flctl));
        writel(page_addr << 2, FLADR(flctl));

        empty_fifo(flctl);
        start_translation(flctl);

        for (sector = 0; sector < page_sectors; sector++) {
                read_fiforeg(flctl, 512, 512 * sector);

                ecc_result = read_ecfiforeg(flctl,
                        &flctl->done_buff[mtd->writesize + 16 * sector],
                        sector);

                switch (ecc_result) {
                case FL_REPAIRABLE:
                        dev_info(&flctl->pdev->dev,
                                "applied ecc on page 0x%x", page_addr);
                        mtd->ecc_stats.corrected++;
                        break;
                case FL_ERROR:
                        dev_warn(&flctl->pdev->dev,
                                "page 0x%x contains corrupted data\n",
                                page_addr);
                        mtd->ecc_stats.failed++;
                        break;
                default:
                        ;
                }
        }

        wait_completion(flctl);

        writel(readl(FLCMNCR(flctl)) & ~(ACM_SACCES_MODE | _4ECCCORRECT),
                        FLCMNCR(flctl));
}

static void execmd_read_oob(struct mtd_info *mtd, int page_addr)
{
        struct sh_flctl *flctl = mtd_to_flctl(mtd);
        int page_sectors = flctl->page_size ? 4 : 1;
        int i;

        set_cmd_regs(mtd, NAND_CMD_READ0,
                (NAND_CMD_READSTART << 8) | NAND_CMD_READ0);

        empty_fifo(flctl);

        for (i = 0; i < page_sectors; i++) {
                set_addr(mtd, (512 + 16) * i + 512 , page_addr);
                writel(16, FLDTCNTR(flctl));

                start_translation(flctl);
                read_fiforeg(flctl, 16, 16 * i);
                wait_completion(flctl);
        }
}

static void execmd_write_page_sector(struct mtd_info *mtd)
{
        struct sh_flctl *flctl = mtd_to_flctl(mtd);
        int page_addr = flctl->seqin_page_addr;
        int sector, page_sectors;

        page_sectors = flctl->page_size ? 4 : 1;

        set_cmd_regs(mtd, NAND_CMD_PAGEPROG,
                        (NAND_CMD_PAGEPROG << 8) | NAND_CMD_SEQIN);

        empty_fifo(flctl);
        writel(readl(FLCMNCR(flctl)) | ACM_SACCES_MODE, FLCMNCR(flctl));
        writel(readl(FLCMDCR(flctl)) | page_sectors, FLCMDCR(flctl));
        writel(page_addr << 2, FLADR(flctl));
        start_translation(flctl);

        for (sector = 0; sector < page_sectors; sector++) {
                write_fiforeg(flctl, 512, 512 * sector);
                write_ec_fiforeg(flctl, 16, mtd->writesize + 16 * sector);
        }

        wait_completion(flctl);
        writel(readl(FLCMNCR(flctl)) & ~ACM_SACCES_MODE, FLCMNCR(flctl));
}

static void execmd_write_oob(struct mtd_info *mtd)
{
        struct sh_flctl *flctl = mtd_to_flctl(mtd);
        int page_addr = flctl->seqin_page_addr;
        int sector, page_sectors;

        page_sectors = flctl->page_size ? 4 : 1;

        set_cmd_regs(mtd, NAND_CMD_PAGEPROG,
                        (NAND_CMD_PAGEPROG << 8) | NAND_CMD_SEQIN);

        for (sector = 0; sector < page_sectors; sector++) {
                empty_fifo(flctl);
                set_addr(mtd, sector * 528 + 512, page_addr);
                writel(16, FLDTCNTR(flctl));    /* set read size */

                start_translation(flctl);
                write_fiforeg(flctl, 16, 16 * sector);
                wait_completion(flctl);
        }
}

static void flctl_cmdfunc(struct nand_chip *chip, unsigned int command,
                        int column, int page_addr)
{
        struct mtd_info *mtd = nand_to_mtd(chip);
        struct sh_flctl *flctl = mtd_to_flctl(mtd);
        uint32_t read_cmd = 0;

        pm_runtime_get_sync(&flctl->pdev->dev);

        flctl->read_bytes = 0;
        if (command != NAND_CMD_PAGEPROG)
                flctl->index = 0;

        switch (command) {
        case NAND_CMD_READ1:
        case NAND_CMD_READ0:
                if (flctl->hwecc) {
                        /* read page with hwecc */
                        execmd_read_page_sector(mtd, page_addr);
                        break;
                }
                if (flctl->page_size)
                        set_cmd_regs(mtd, command, (NAND_CMD_READSTART << 8)
                                | command);
                else
                        set_cmd_regs(mtd, command, command);

                set_addr(mtd, 0, page_addr);

                flctl->read_bytes = mtd->writesize + mtd->oobsize;
                if (flctl->chip.options & NAND_BUSWIDTH_16)
                        column >>= 1;
                flctl->index += column;
                goto read_normal_exit;

        case NAND_CMD_READOOB:
                if (flctl->hwecc) {
                        /* read page with hwecc */
                        execmd_read_oob(mtd, page_addr);
                        break;
                }

                if (flctl->page_size) {
                        set_cmd_regs(mtd, command, (NAND_CMD_READSTART << 8)
                                | NAND_CMD_READ0);
                        set_addr(mtd, mtd->writesize, page_addr);
                } else {
                        set_cmd_regs(mtd, command, command);
                        set_addr(mtd, 0, page_addr);
                }
                flctl->read_bytes = mtd->oobsize;
                goto read_normal_exit;

        case NAND_CMD_RNDOUT:
                if (flctl->hwecc)
                        break;

                if (flctl->page_size)
                        set_cmd_regs(mtd, command, (NAND_CMD_RNDOUTSTART << 8)
                                | command);
                else
                        set_cmd_regs(mtd, command, command);

                set_addr(mtd, column, 0);

                flctl->read_bytes = mtd->writesize + mtd->oobsize - column;
                goto read_normal_exit;

        case NAND_CMD_READID:
                set_cmd_regs(mtd, command, command);

                /* READID is always performed using an 8-bit bus */
                if (flctl->chip.options & NAND_BUSWIDTH_16)
                        column <<= 1;
                set_addr(mtd, column, 0);

                flctl->read_bytes = 8;
                writel(flctl->read_bytes, FLDTCNTR(flctl)); /* set read size */
                empty_fifo(flctl);
                start_translation(flctl);
                read_fiforeg(flctl, flctl->read_bytes, 0);
                wait_completion(flctl);
                break;

        case NAND_CMD_ERASE1:
                flctl->erase1_page_addr = page_addr;
                break;

        case NAND_CMD_ERASE2:
                set_cmd_regs(mtd, NAND_CMD_ERASE1,
                        (command << 8) | NAND_CMD_ERASE1);
                set_addr(mtd, -1, flctl->erase1_page_addr);
                start_translation(flctl);
                wait_completion(flctl);
                break;

        case NAND_CMD_SEQIN:
                if (!flctl->page_size) {
                        /* output read command */
                        if (column >= mtd->writesize) {
                                column -= mtd->writesize;
                                read_cmd = NAND_CMD_READOOB;
                        } else if (column < 256) {
                                read_cmd = NAND_CMD_READ0;
                        } else {
                                column -= 256;
                                read_cmd = NAND_CMD_READ1;
                        }
                }
                flctl->seqin_column = column;
                flctl->seqin_page_addr = page_addr;
                flctl->seqin_read_cmd = read_cmd;
                break;

        case NAND_CMD_PAGEPROG:
                empty_fifo(flctl);
                if (!flctl->page_size) {
                        set_cmd_regs(mtd, NAND_CMD_SEQIN,
                                        flctl->seqin_read_cmd);
                        set_addr(mtd, -1, -1);
                        writel(0, FLDTCNTR(flctl));     /* set 0 size */
                        start_translation(flctl);
                        wait_completion(flctl);
                }
                if (flctl->hwecc) {
                        /* write page with hwecc */
                        if (flctl->seqin_column == mtd->writesize)
                                execmd_write_oob(mtd);
                        else if (!flctl->seqin_column)
                                execmd_write_page_sector(mtd);
                        else
                                pr_err("Invalid address !?\n");
                        break;
                }
                set_cmd_regs(mtd, command, (command << 8) | NAND_CMD_SEQIN);
                set_addr(mtd, flctl->seqin_column, flctl->seqin_page_addr);
                writel(flctl->index, FLDTCNTR(flctl));  /* set write size */
                start_translation(flctl);
                write_fiforeg(flctl, flctl->index, 0);
                wait_completion(flctl);
                break;

        case NAND_CMD_STATUS:
                set_cmd_regs(mtd, command, command);
                set_addr(mtd, -1, -1);

                flctl->read_bytes = 1;
                writel(flctl->read_bytes, FLDTCNTR(flctl)); /* set read size */
                start_translation(flctl);
                read_datareg(flctl, 0); /* read and end */
                break;

        case NAND_CMD_RESET:
                set_cmd_regs(mtd, command, command);
                set_addr(mtd, -1, -1);

                writel(0, FLDTCNTR(flctl));     /* set 0 size */
                start_translation(flctl);
                wait_completion(flctl);
                break;

        default:
                break;
        }
        goto runtime_exit;

read_normal_exit:
        writel(flctl->read_bytes, FLDTCNTR(flctl));     /* set read size */
        empty_fifo(flctl);
        start_translation(flctl);
        read_fiforeg(flctl, flctl->read_bytes, 0);
        wait_completion(flctl);
runtime_exit:
        pm_runtime_put_sync(&flctl->pdev->dev);
        return;
}

static void flctl_select_chip(struct nand_chip *chip, int chipnr)
{
        struct sh_flctl *flctl = mtd_to_flctl(nand_to_mtd(chip));
        int ret;

        switch (chipnr) {
        case -1:
                flctl->flcmncr_base &= ~CE0_ENABLE;

                pm_runtime_get_sync(&flctl->pdev->dev);
                writel(flctl->flcmncr_base, FLCMNCR(flctl));

                if (flctl->qos_request) {
                        dev_pm_qos_remove_request(&flctl->pm_qos);
                        flctl->qos_request = 0;
                }

                pm_runtime_put_sync(&flctl->pdev->dev);
                break;
        case 0:
                flctl->flcmncr_base |= CE0_ENABLE;

                if (!flctl->qos_request) {
                        ret = dev_pm_qos_add_request(&flctl->pdev->dev,
                                                        &flctl->pm_qos,
                                                        DEV_PM_QOS_RESUME_LATENCY,
                                                        100);
                        if (ret < 0)
                                dev_err(&flctl->pdev->dev,
                                        "PM QoS request failed: %d\n", ret);
                        flctl->qos_request = 1;
                }

                if (flctl->holden) {
                        pm_runtime_get_sync(&flctl->pdev->dev);
                        writel(HOLDEN, FLHOLDCR(flctl));
                        pm_runtime_put_sync(&flctl->pdev->dev);
                }
                break;
        default:
                BUG();
        }
}

static void flctl_write_buf(struct nand_chip *chip, const uint8_t *buf, int len)
{
        struct sh_flctl *flctl = mtd_to_flctl(nand_to_mtd(chip));

        memcpy(&flctl->done_buff[flctl->index], buf, len);
        flctl->index += len;
}

static uint8_t flctl_read_byte(struct nand_chip *chip)
{
        struct sh_flctl *flctl = mtd_to_flctl(nand_to_mtd(chip));
        uint8_t data;

        data = flctl->done_buff[flctl->index];
        flctl->index++;
        return data;
}

static void flctl_read_buf(struct nand_chip *chip, uint8_t *buf, int len)
{
        struct sh_flctl *flctl = mtd_to_flctl(nand_to_mtd(chip));

        memcpy(buf, &flctl->done_buff[flctl->index], len);
        flctl->index += len;
}

static int flctl_chip_attach_chip(struct nand_chip *chip)
{
        struct mtd_info *mtd = nand_to_mtd(chip);
        struct sh_flctl *flctl = mtd_to_flctl(mtd);

        /*
         * NAND_BUSWIDTH_16 may have been set by nand_scan_ident().
         * Add the SEL_16BIT flag in flctl->flcmncr_base.
         */
        if (chip->options & NAND_BUSWIDTH_16)
                flctl->flcmncr_base |= SEL_16BIT;

        if (mtd->writesize == 512) {
                flctl->page_size = 0;

                if (chip->chipsize > (32 << 20)) {
                        /* big than 32MB */
                        flctl->rw_ADRCNT = ADRCNT_4;
                        flctl->erase_ADRCNT = ADRCNT_3;
                } else if (chip->chipsize > (2 << 16)) {
                        /* big than 128KB */
                        flctl->rw_ADRCNT = ADRCNT_3;
                        flctl->erase_ADRCNT = ADRCNT_2;
                } else {
                        flctl->rw_ADRCNT = ADRCNT_2;
                        flctl->erase_ADRCNT = ADRCNT_1;
                }
        } else {
                flctl->page_size = 1;
                if (chip->chipsize > (128 << 20)) {
                        /* big than 128MB */
                        flctl->rw_ADRCNT = ADRCNT2_E;
                        flctl->erase_ADRCNT = ADRCNT_3;
                } else if (chip->chipsize > (8 << 16)) {
                        /* big than 512KB */
                        flctl->rw_ADRCNT = ADRCNT_4;
                        flctl->erase_ADRCNT = ADRCNT_2;
                } else {
                        flctl->rw_ADRCNT = ADRCNT_3;
                        flctl->erase_ADRCNT = ADRCNT_1;
                }
        }

        if (flctl->hwecc) {
                if (mtd->writesize == 512) {
                        mtd_set_ooblayout(mtd, &flctl_4secc_oob_smallpage_ops);
                        chip->badblock_pattern = &flctl_4secc_smallpage;
                } else {
                        mtd_set_ooblayout(mtd, &flctl_4secc_oob_largepage_ops);
                        chip->badblock_pattern = &flctl_4secc_largepage;
                }

                chip->ecc.size = 512;
                chip->ecc.bytes = 10;
                chip->ecc.strength = 4;
                chip->ecc.read_page = flctl_read_page_hwecc;
                chip->ecc.write_page = flctl_write_page_hwecc;
                chip->ecc.mode = NAND_ECC_HW;

                /* 4 symbols ECC enabled */
                flctl->flcmncr_base |= _4ECCEN;
        } else {
                chip->ecc.mode = NAND_ECC_SOFT;
                chip->ecc.algo = NAND_ECC_HAMMING;
        }

        return 0;
}

static const struct nand_controller_ops flctl_nand_controller_ops = {
        .attach_chip = flctl_chip_attach_chip,
};

static irqreturn_t flctl_handle_flste(int irq, void *dev_id)
{
        struct sh_flctl *flctl = dev_id;

        dev_err(&flctl->pdev->dev, "flste irq: %x\n", readl(FLINTDMACR(flctl)));
        writel(flctl->flintdmacr_base, FLINTDMACR(flctl));

        return IRQ_HANDLED;
}

struct flctl_soc_config {
        unsigned long flcmncr_val;
        unsigned has_hwecc:1;
        unsigned use_holden:1;
};

static struct flctl_soc_config flctl_sh7372_config = {
        .flcmncr_val = CLK_16B_12L_4H | TYPESEL_SET | SHBUSSEL,
        .has_hwecc = 1,
        .use_holden = 1,
};

static const struct of_device_id of_flctl_match[] = {
        { .compatible = "renesas,shmobile-flctl-sh7372",
                                .data = &flctl_sh7372_config },
        {},
};
MODULE_DEVICE_TABLE(of, of_flctl_match);

static struct sh_flctl_platform_data *flctl_parse_dt(struct device *dev)
{
        const struct flctl_soc_config *config;
        struct sh_flctl_platform_data *pdata;

        config = of_device_get_match_data(dev);
        if (!config) {
                dev_err(dev, "%s: no OF configuration attached\n", __func__);
                return NULL;
        }

        pdata = devm_kzalloc(dev, sizeof(struct sh_flctl_platform_data),
                                                                GFP_KERNEL);
        if (!pdata)
                return NULL;

        /* set SoC specific options */
        pdata->flcmncr_val = config->flcmncr_val;
        pdata->has_hwecc = config->has_hwecc;
        pdata->use_holden = config->use_holden;

        return pdata;
}

static int flctl_probe(struct platform_device *pdev)
{
        struct resource *res;
        struct sh_flctl *flctl;
        struct mtd_info *flctl_mtd;
        struct nand_chip *nand;
        struct sh_flctl_platform_data *pdata;
        int ret;
        int irq;

        flctl = devm_kzalloc(&pdev->dev, sizeof(struct sh_flctl), GFP_KERNEL);
        if (!flctl)
                return -ENOMEM;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        flctl->reg = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(flctl->reg))
                return PTR_ERR(flctl->reg);
        flctl->fifo = res->start + 0x24; /* FLDTFIFO */

        irq = platform_get_irq(pdev, 0);
        if (irq < 0) {
                dev_err(&pdev->dev, "failed to get flste irq data: %d\n", irq);
                return irq;
        }

        ret = devm_request_irq(&pdev->dev, irq, flctl_handle_flste, IRQF_SHARED,
                               "flste", flctl);
        if (ret) {
                dev_err(&pdev->dev, "request interrupt failed.\n");
                return ret;
        }

        if (pdev->dev.of_node)
                pdata = flctl_parse_dt(&pdev->dev);
        else
                pdata = dev_get_platdata(&pdev->dev);

        if (!pdata) {
                dev_err(&pdev->dev, "no setup data defined\n");
                return -EINVAL;
        }

        platform_set_drvdata(pdev, flctl);
        nand = &flctl->chip;
        flctl_mtd = nand_to_mtd(nand);
        nand_set_flash_node(nand, pdev->dev.of_node);
        flctl_mtd->dev.parent = &pdev->dev;
        flctl->pdev = pdev;
        flctl->hwecc = pdata->has_hwecc;
        flctl->holden = pdata->use_holden;
        flctl->flcmncr_base = pdata->flcmncr_val;
        flctl->flintdmacr_base = flctl->hwecc ? (STERINTE | ECERB) : STERINTE;

        /* Set address of hardware control function */
        /* 20 us command delay time */
        nand->legacy.chip_delay = 20;

        nand->legacy.read_byte = flctl_read_byte;
        nand->legacy.write_buf = flctl_write_buf;
        nand->legacy.read_buf = flctl_read_buf;
        nand->legacy.select_chip = flctl_select_chip;
        nand->legacy.cmdfunc = flctl_cmdfunc;
        nand->legacy.set_features = nand_get_set_features_notsupp;
        nand->legacy.get_features = nand_get_set_features_notsupp;

        if (pdata->flcmncr_val & SEL_16BIT)
                nand->options |= NAND_BUSWIDTH_16;

        pm_runtime_enable(&pdev->dev);
        pm_runtime_resume(&pdev->dev);

        flctl_setup_dma(flctl);

        nand->legacy.dummy_controller.ops = &flctl_nand_controller_ops;
        ret = nand_scan(nand, 1);
        if (ret)
                goto err_chip;

        ret = mtd_device_register(flctl_mtd, pdata->parts, pdata->nr_parts);
        if (ret)
                goto cleanup_nand;

        return 0;

cleanup_nand:
        nand_cleanup(nand);
err_chip:
        flctl_release_dma(flctl);
        pm_runtime_disable(&pdev->dev);
        return ret;
}

static int flctl_remove(struct platform_device *pdev)
{
        struct sh_flctl *flctl = platform_get_drvdata(pdev);

        flctl_release_dma(flctl);
        nand_release(&flctl->chip);
        pm_runtime_disable(&pdev->dev);

        return 0;
}

static struct platform_driver flctl_driver = {
        .remove         = flctl_remove,
        .driver = {
                .name   = "sh_flctl",
                .of_match_table = of_match_ptr(of_flctl_match),
        },
};

module_platform_driver_probe(flctl_driver, flctl_probe);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Yoshihiro Shimoda");
MODULE_DESCRIPTION("SuperH FLCTL driver");
MODULE_ALIAS("platform:sh_flctl");