// SPDX-License-Identifier: GPL-2.0-only
/*
 * Driver for One Laptop Per Child ‘CAFÉ’ controller, aka Marvell 88ALP01
 *
 * The data sheet for this device can be found at:
 *    http://wiki.laptop.org/go/Datasheets 
 *
 * Copyright © 2006 Red Hat, Inc.
 * Copyright © 2006 David Woodhouse <dwmw2@infradead.org>
 */

#define DEBUG

#include <linux/device.h>
#undef DEBUG
#include <linux/mtd/mtd.h>
#include <linux/mtd/rawnand.h>
#include <linux/mtd/partitions.h>
#include <linux/rslib.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <asm/io.h>

#define CAFE_NAND_CTRL1         0x00
#define CAFE_NAND_CTRL2         0x04
#define CAFE_NAND_CTRL3         0x08
#define CAFE_NAND_STATUS        0x0c
#define CAFE_NAND_IRQ           0x10
#define CAFE_NAND_IRQ_MASK      0x14
#define CAFE_NAND_DATA_LEN      0x18
#define CAFE_NAND_ADDR1         0x1c
#define CAFE_NAND_ADDR2         0x20
#define CAFE_NAND_TIMING1       0x24
#define CAFE_NAND_TIMING2       0x28
#define CAFE_NAND_TIMING3       0x2c
#define CAFE_NAND_NONMEM        0x30
#define CAFE_NAND_ECC_RESULT    0x3C
#define CAFE_NAND_DMA_CTRL      0x40
#define CAFE_NAND_DMA_ADDR0     0x44
#define CAFE_NAND_DMA_ADDR1     0x48
#define CAFE_NAND_ECC_SYN01     0x50
#define CAFE_NAND_ECC_SYN23     0x54
#define CAFE_NAND_ECC_SYN45     0x58
#define CAFE_NAND_ECC_SYN67     0x5c
#define CAFE_NAND_READ_DATA     0x1000
#define CAFE_NAND_WRITE_DATA    0x2000

#define CAFE_GLOBAL_CTRL        0x3004
#define CAFE_GLOBAL_IRQ         0x3008
#define CAFE_GLOBAL_IRQ_MASK    0x300c
#define CAFE_NAND_RESET         0x3034

/* Missing from the datasheet: bit 19 of CTRL1 sets CE0 vs. CE1 */
#define CTRL1_CHIPSELECT        (1<<19)

struct cafe_priv {
        struct nand_chip nand;
        struct pci_dev *pdev;
        void __iomem *mmio;
        struct rs_control *rs;
        uint32_t ctl1;
        uint32_t ctl2;
        int datalen;
        int nr_data;
        int data_pos;
        int page_addr;
        bool usedma;
        dma_addr_t dmaaddr;
        unsigned char *dmabuf;
};

static int usedma = 1;
module_param(usedma, int, 0644);

static int skipbbt = 0;
module_param(skipbbt, int, 0644);

static int debug = 0;
module_param(debug, int, 0644);

static int regdebug = 0;
module_param(regdebug, int, 0644);

static int checkecc = 1;
module_param(checkecc, int, 0644);

static unsigned int numtimings;
static int timing[3];
module_param_array(timing, int, &numtimings, 0644);

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

/* Hrm. Why isn't this already conditional on something in the struct device? */
#define cafe_dev_dbg(dev, args...) do { if (debug) dev_dbg(dev, ##args); } while(0)

/* Make it easier to switch to PIO if we need to */
#define cafe_readl(cafe, addr)                  readl((cafe)->mmio + CAFE_##addr)
#define cafe_writel(cafe, datum, addr)          writel(datum, (cafe)->mmio + CAFE_##addr)

static int cafe_device_ready(struct nand_chip *chip)
{
        struct cafe_priv *cafe = nand_get_controller_data(chip);
        int result = !!(cafe_readl(cafe, NAND_STATUS) & 0x40000000);
        uint32_t irqs = cafe_readl(cafe, NAND_IRQ);

        cafe_writel(cafe, irqs, NAND_IRQ);

        cafe_dev_dbg(&cafe->pdev->dev, "NAND device is%s ready, IRQ %x (%x) (%x,%x)\n",
                result?"":" not", irqs, cafe_readl(cafe, NAND_IRQ),
                cafe_readl(cafe, GLOBAL_IRQ), cafe_readl(cafe, GLOBAL_IRQ_MASK));

        return result;
}


static void cafe_write_buf(struct nand_chip *chip, const uint8_t *buf, int len)
{
        struct cafe_priv *cafe = nand_get_controller_data(chip);

        if (cafe->usedma)
                memcpy(cafe->dmabuf + cafe->datalen, buf, len);
        else
                memcpy_toio(cafe->mmio + CAFE_NAND_WRITE_DATA + cafe->datalen, buf, len);

        cafe->datalen += len;

        cafe_dev_dbg(&cafe->pdev->dev, "Copy 0x%x bytes to write buffer. datalen 0x%x\n",
                len, cafe->datalen);
}

static void cafe_read_buf(struct nand_chip *chip, uint8_t *buf, int len)
{
        struct cafe_priv *cafe = nand_get_controller_data(chip);

        if (cafe->usedma)
                memcpy(buf, cafe->dmabuf + cafe->datalen, len);
        else
                memcpy_fromio(buf, cafe->mmio + CAFE_NAND_READ_DATA + cafe->datalen, len);

        cafe_dev_dbg(&cafe->pdev->dev, "Copy 0x%x bytes from position 0x%x in read buffer.\n",
                  len, cafe->datalen);
        cafe->datalen += len;
}

static uint8_t cafe_read_byte(struct nand_chip *chip)
{
        struct cafe_priv *cafe = nand_get_controller_data(chip);
        uint8_t d;

        cafe_read_buf(chip, &d, 1);
        cafe_dev_dbg(&cafe->pdev->dev, "Read %02x\n", d);

        return d;
}

static void cafe_nand_cmdfunc(struct nand_chip *chip, unsigned command,
                              int column, int page_addr)
{
        struct mtd_info *mtd = nand_to_mtd(chip);
        struct cafe_priv *cafe = nand_get_controller_data(chip);
        int adrbytes = 0;
        uint32_t ctl1;
        uint32_t doneint = 0x80000000;

        cafe_dev_dbg(&cafe->pdev->dev, "cmdfunc %02x, 0x%x, 0x%x\n",
                command, column, page_addr);

        if (command == NAND_CMD_ERASE2 || command == NAND_CMD_PAGEPROG) {
                /* Second half of a command we already calculated */
                cafe_writel(cafe, cafe->ctl2 | 0x100 | command, NAND_CTRL2);
                ctl1 = cafe->ctl1;
                cafe->ctl2 &= ~(1<<30);
                cafe_dev_dbg(&cafe->pdev->dev, "Continue command, ctl1 %08x, #data %d\n",
                          cafe->ctl1, cafe->nr_data);
                goto do_command;
        }
        /* Reset ECC engine */
        cafe_writel(cafe, 0, NAND_CTRL2);

        /* Emulate NAND_CMD_READOOB on large-page chips */
        if (mtd->writesize > 512 &&
            command == NAND_CMD_READOOB) {
                column += mtd->writesize;
                command = NAND_CMD_READ0;
        }

        /* FIXME: Do we need to send read command before sending data
           for small-page chips, to position the buffer correctly? */

        if (column != -1) {
                cafe_writel(cafe, column, NAND_ADDR1);
                adrbytes = 2;
                if (page_addr != -1)
                        goto write_adr2;
        } else if (page_addr != -1) {
                cafe_writel(cafe, page_addr & 0xffff, NAND_ADDR1);
                page_addr >>= 16;
        write_adr2:
                cafe_writel(cafe, page_addr, NAND_ADDR2);
                adrbytes += 2;
                if (mtd->size > mtd->writesize << 16)
                        adrbytes++;
        }

        cafe->data_pos = cafe->datalen = 0;

        /* Set command valid bit, mask in the chip select bit  */
        ctl1 = 0x80000000 | command | (cafe->ctl1 & CTRL1_CHIPSELECT);

        /* Set RD or WR bits as appropriate */
        if (command == NAND_CMD_READID || command == NAND_CMD_STATUS) {
                ctl1 |= (1<<26); /* rd */
                /* Always 5 bytes, for now */
                cafe->datalen = 4;
                /* And one address cycle -- even for STATUS, since the controller doesn't work without */
                adrbytes = 1;
        } else if (command == NAND_CMD_READ0 || command == NAND_CMD_READ1 ||
                   command == NAND_CMD_READOOB || command == NAND_CMD_RNDOUT) {
                ctl1 |= 1<<26; /* rd */
                /* For now, assume just read to end of page */
                cafe->datalen = mtd->writesize + mtd->oobsize - column;
        } else if (command == NAND_CMD_SEQIN)
                ctl1 |= 1<<25; /* wr */

        /* Set number of address bytes */
        if (adrbytes)
                ctl1 |= ((adrbytes-1)|8) << 27;

        if (command == NAND_CMD_SEQIN || command == NAND_CMD_ERASE1) {
                /* Ignore the first command of a pair; the hardware
                   deals with them both at once, later */
                cafe->ctl1 = ctl1;
                cafe_dev_dbg(&cafe->pdev->dev, "Setup for delayed command, ctl1 %08x, dlen %x\n",
                          cafe->ctl1, cafe->datalen);
                return;
        }
        /* RNDOUT and READ0 commands need a following byte */
        if (command == NAND_CMD_RNDOUT)
                cafe_writel(cafe, cafe->ctl2 | 0x100 | NAND_CMD_RNDOUTSTART, NAND_CTRL2);
        else if (command == NAND_CMD_READ0 && mtd->writesize > 512)
                cafe_writel(cafe, cafe->ctl2 | 0x100 | NAND_CMD_READSTART, NAND_CTRL2);

 do_command:
        cafe_dev_dbg(&cafe->pdev->dev, "dlen %x, ctl1 %x, ctl2 %x\n",
                cafe->datalen, ctl1, cafe_readl(cafe, NAND_CTRL2));

        /* NB: The datasheet lies -- we really should be subtracting 1 here */
        cafe_writel(cafe, cafe->datalen, NAND_DATA_LEN);
        cafe_writel(cafe, 0x90000000, NAND_IRQ);
        if (cafe->usedma && (ctl1 & (3<<25))) {
                uint32_t dmactl = 0xc0000000 + cafe->datalen;
                /* If WR or RD bits set, set up DMA */
                if (ctl1 & (1<<26)) {
                        /* It's a read */
                        dmactl |= (1<<29);
                        /* ... so it's done when the DMA is done, not just
                           the command. */
                        doneint = 0x10000000;
                }
                cafe_writel(cafe, dmactl, NAND_DMA_CTRL);
        }
        cafe->datalen = 0;

        if (unlikely(regdebug)) {
                int i;
                printk("About to write command %08x to register 0\n", ctl1);
                for (i=4; i< 0x5c; i+=4)
                        printk("Register %x: %08x\n", i, readl(cafe->mmio + i));
        }

        cafe_writel(cafe, ctl1, NAND_CTRL1);
        /* Apply this short delay always to ensure that we do wait tWB in
         * any case on any machine. */
        ndelay(100);

        if (1) {
                int c;
                uint32_t irqs;

                for (c = 500000; c != 0; c--) {
                        irqs = cafe_readl(cafe, NAND_IRQ);
                        if (irqs & doneint)
                                break;
                        udelay(1);
                        if (!(c % 100000))
                                cafe_dev_dbg(&cafe->pdev->dev, "Wait for ready, IRQ %x\n", irqs);
                        cpu_relax();
                }
                cafe_writel(cafe, doneint, NAND_IRQ);
                cafe_dev_dbg(&cafe->pdev->dev, "Command %x completed after %d usec, irqs %x (%x)\n",
                             command, 500000-c, irqs, cafe_readl(cafe, NAND_IRQ));
        }

        WARN_ON(cafe->ctl2 & (1<<30));

        switch (command) {

        case NAND_CMD_CACHEDPROG:
        case NAND_CMD_PAGEPROG:
        case NAND_CMD_ERASE1:
        case NAND_CMD_ERASE2:
        case NAND_CMD_SEQIN:
        case NAND_CMD_RNDIN:
        case NAND_CMD_STATUS:
        case NAND_CMD_RNDOUT:
                cafe_writel(cafe, cafe->ctl2, NAND_CTRL2);
                return;
        }
        nand_wait_ready(chip);
        cafe_writel(cafe, cafe->ctl2, NAND_CTRL2);
}

static void cafe_select_chip(struct nand_chip *chip, int chipnr)
{
        struct cafe_priv *cafe = nand_get_controller_data(chip);

        cafe_dev_dbg(&cafe->pdev->dev, "select_chip %d\n", chipnr);

        /* Mask the appropriate bit into the stored value of ctl1
           which will be used by cafe_nand_cmdfunc() */
        if (chipnr)
                cafe->ctl1 |= CTRL1_CHIPSELECT;
        else
                cafe->ctl1 &= ~CTRL1_CHIPSELECT;
}

static irqreturn_t cafe_nand_interrupt(int irq, void *id)
{
        struct mtd_info *mtd = id;
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct cafe_priv *cafe = nand_get_controller_data(chip);
        uint32_t irqs = cafe_readl(cafe, NAND_IRQ);
        cafe_writel(cafe, irqs & ~0x90000000, NAND_IRQ);
        if (!irqs)
                return IRQ_NONE;

        cafe_dev_dbg(&cafe->pdev->dev, "irq, bits %x (%x)\n", irqs, cafe_readl(cafe, NAND_IRQ));
        return IRQ_HANDLED;
}

static int cafe_nand_write_oob(struct nand_chip *chip, int page)
{
        struct mtd_info *mtd = nand_to_mtd(chip);

        return nand_prog_page_op(chip, page, mtd->writesize, chip->oob_poi,
                                 mtd->oobsize);
}

/* Don't use -- use nand_read_oob_std for now */
static int cafe_nand_read_oob(struct nand_chip *chip, int page)
{
        struct mtd_info *mtd = nand_to_mtd(chip);

        return nand_read_oob_op(chip, page, 0, chip->oob_poi, mtd->oobsize);
}
/**
 * cafe_nand_read_page_syndrome - [REPLACEABLE] hardware ecc syndrome based page read
 * @mtd:        mtd info structure
 * @chip:       nand chip info structure
 * @buf:        buffer to store read data
 * @oob_required:       caller expects OOB data read to chip->oob_poi
 *
 * The hw generator calculates the error syndrome automatically. Therefore
 * we need a special oob layout and handling.
 */
static int cafe_nand_read_page(struct nand_chip *chip, uint8_t *buf,
                               int oob_required, int page)
{
        struct mtd_info *mtd = nand_to_mtd(chip);
        struct cafe_priv *cafe = nand_get_controller_data(chip);
        unsigned int max_bitflips = 0;

        cafe_dev_dbg(&cafe->pdev->dev, "ECC result %08x SYN1,2 %08x\n",
                     cafe_readl(cafe, NAND_ECC_RESULT),
                     cafe_readl(cafe, NAND_ECC_SYN01));

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

        if (checkecc && cafe_readl(cafe, NAND_ECC_RESULT) & (1<<18)) {
                unsigned short syn[8], pat[4];
                int pos[4];
                u8 *oob = chip->oob_poi;
                int i, n;

                for (i=0; i<8; i+=2) {
                        uint32_t tmp = cafe_readl(cafe, NAND_ECC_SYN01 + (i*2));

                        syn[i] = cafe->rs->codec->index_of[tmp & 0xfff];
                        syn[i+1] = cafe->rs->codec->index_of[(tmp >> 16) & 0xfff];
                }

                n = decode_rs16(cafe->rs, NULL, NULL, 1367, syn, 0, pos, 0,
                                pat);

                for (i = 0; i < n; i++) {
                        int p = pos[i];

                        /* The 12-bit symbols are mapped to bytes here */

                        if (p > 1374) {
                                /* out of range */
                                n = -1374;
                        } else if (p == 0) {
                                /* high four bits do not correspond to data */
                                if (pat[i] > 0xff)
                                        n = -2048;
                                else
                                        buf[0] ^= pat[i];
                        } else if (p == 1365) {
                                buf[2047] ^= pat[i] >> 4;
                                oob[0] ^= pat[i] << 4;
                        } else if (p > 1365) {
                                if ((p & 1) == 1) {
                                        oob[3*p/2 - 2048] ^= pat[i] >> 4;
                                        oob[3*p/2 - 2047] ^= pat[i] << 4;
                                } else {
                                        oob[3*p/2 - 2049] ^= pat[i] >> 8;
                                        oob[3*p/2 - 2048] ^= pat[i];
                                }
                        } else if ((p & 1) == 1) {
                                buf[3*p/2] ^= pat[i] >> 4;
                                buf[3*p/2 + 1] ^= pat[i] << 4;
                        } else {
                                buf[3*p/2 - 1] ^= pat[i] >> 8;
                                buf[3*p/2] ^= pat[i];
                        }
                }

                if (n < 0) {
                        dev_dbg(&cafe->pdev->dev, "Failed to correct ECC at %08x\n",
                                cafe_readl(cafe, NAND_ADDR2) * 2048);
                        for (i = 0; i < 0x5c; i += 4)
                                printk("Register %x: %08x\n", i, readl(cafe->mmio + i));
                        mtd->ecc_stats.failed++;
                } else {
                        dev_dbg(&cafe->pdev->dev, "Corrected %d symbol errors\n", n);
                        mtd->ecc_stats.corrected += n;
                        max_bitflips = max_t(unsigned int, max_bitflips, n);
                }
        }

        return max_bitflips;
}

static int cafe_ooblayout_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.total;

        return 0;
}

static int cafe_ooblayout_free(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 = chip->ecc.total;
        oobregion->length = mtd->oobsize - chip->ecc.total;

        return 0;
}

static const struct mtd_ooblayout_ops cafe_ooblayout_ops = {
        .ecc = cafe_ooblayout_ecc,
        .free = cafe_ooblayout_free,
};

/* Ick. The BBT code really ought to be able to work this bit out
   for itself from the above, at least for the 2KiB case */
static uint8_t cafe_bbt_pattern_2048[] = { 'B', 'b', 't', '0' };
static uint8_t cafe_mirror_pattern_2048[] = { '1', 't', 'b', 'B' };

static uint8_t cafe_bbt_pattern_512[] = { 0xBB };
static uint8_t cafe_mirror_pattern_512[] = { 0xBC };


static struct nand_bbt_descr cafe_bbt_main_descr_2048 = {
        .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
                | NAND_BBT_2BIT | NAND_BBT_VERSION,
        .offs = 14,
        .len = 4,
        .veroffs = 18,
        .maxblocks = 4,
        .pattern = cafe_bbt_pattern_2048
};

static struct nand_bbt_descr cafe_bbt_mirror_descr_2048 = {
        .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
                | NAND_BBT_2BIT | NAND_BBT_VERSION,
        .offs = 14,
        .len = 4,
        .veroffs = 18,
        .maxblocks = 4,
        .pattern = cafe_mirror_pattern_2048
};

static struct nand_bbt_descr cafe_bbt_main_descr_512 = {
        .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
                | NAND_BBT_2BIT | NAND_BBT_VERSION,
        .offs = 14,
        .len = 1,
        .veroffs = 15,
        .maxblocks = 4,
        .pattern = cafe_bbt_pattern_512
};

static struct nand_bbt_descr cafe_bbt_mirror_descr_512 = {
        .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
                | NAND_BBT_2BIT | NAND_BBT_VERSION,
        .offs = 14,
        .len = 1,
        .veroffs = 15,
        .maxblocks = 4,
        .pattern = cafe_mirror_pattern_512
};


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

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

        /* Set up ECC autogeneration */
        cafe->ctl2 |= (1<<30);

        return nand_prog_page_end_op(chip);
}

static int cafe_nand_block_bad(struct nand_chip *chip, loff_t ofs)
{
        return 0;
}

/* F_2[X]/(X**6+X+1)  */
static unsigned short gf64_mul(u8 a, u8 b)
{
        u8 c;
        unsigned int i;

        c = 0;
        for (i = 0; i < 6; i++) {
                if (a & 1)
                        c ^= b;
                a >>= 1;
                b <<= 1;
                if ((b & 0x40) != 0)
                        b ^= 0x43;
        }

        return c;
}

/* F_64[X]/(X**2+X+A**-1) with A the generator of F_64[X]  */
static u16 gf4096_mul(u16 a, u16 b)
{
        u8 ah, al, bh, bl, ch, cl;

        ah = a >> 6;
        al = a & 0x3f;
        bh = b >> 6;
        bl = b & 0x3f;

        ch = gf64_mul(ah ^ al, bh ^ bl) ^ gf64_mul(al, bl);
        cl = gf64_mul(gf64_mul(ah, bh), 0x21) ^ gf64_mul(al, bl);

        return (ch << 6) ^ cl;
}

static int cafe_mul(int x)
{
        if (x == 0)
                return 1;
        return gf4096_mul(x, 0xe01);
}

static int cafe_nand_attach_chip(struct nand_chip *chip)
{
        struct mtd_info *mtd = nand_to_mtd(chip);
        struct cafe_priv *cafe = nand_get_controller_data(chip);
        int err = 0;

        cafe->dmabuf = dma_alloc_coherent(&cafe->pdev->dev, 2112,
                                          &cafe->dmaaddr, GFP_KERNEL);
        if (!cafe->dmabuf)
                return -ENOMEM;

        /* Set up DMA address */
        cafe_writel(cafe, lower_32_bits(cafe->dmaaddr), NAND_DMA_ADDR0);
        cafe_writel(cafe, upper_32_bits(cafe->dmaaddr), NAND_DMA_ADDR1);

        cafe_dev_dbg(&cafe->pdev->dev, "Set DMA address to %x (virt %p)\n",
                     cafe_readl(cafe, NAND_DMA_ADDR0), cafe->dmabuf);

        /* Restore the DMA flag */
        cafe->usedma = usedma;

        cafe->ctl2 = BIT(27); /* Reed-Solomon ECC */
        if (mtd->writesize == 2048)
                cafe->ctl2 |= BIT(29); /* 2KiB page size */

        /* Set up ECC according to the type of chip we found */
        mtd_set_ooblayout(mtd, &cafe_ooblayout_ops);
        if (mtd->writesize == 2048) {
                cafe->nand.bbt_td = &cafe_bbt_main_descr_2048;
                cafe->nand.bbt_md = &cafe_bbt_mirror_descr_2048;
        } else if (mtd->writesize == 512) {
                cafe->nand.bbt_td = &cafe_bbt_main_descr_512;
                cafe->nand.bbt_md = &cafe_bbt_mirror_descr_512;
        } else {
                dev_warn(&cafe->pdev->dev,
                         "Unexpected NAND flash writesize %d. Aborting\n",
                         mtd->writesize);
                err = -ENOTSUPP;
                goto out_free_dma;
        }

        cafe->nand.ecc.mode = NAND_ECC_HW_SYNDROME;
        cafe->nand.ecc.size = mtd->writesize;
        cafe->nand.ecc.bytes = 14;
        cafe->nand.ecc.strength = 4;
        cafe->nand.ecc.write_page = cafe_nand_write_page_lowlevel;
        cafe->nand.ecc.write_oob = cafe_nand_write_oob;
        cafe->nand.ecc.read_page = cafe_nand_read_page;
        cafe->nand.ecc.read_oob = cafe_nand_read_oob;

        return 0;

 out_free_dma:
        dma_free_coherent(&cafe->pdev->dev, 2112, cafe->dmabuf, cafe->dmaaddr);

        return err;
}

static void cafe_nand_detach_chip(struct nand_chip *chip)
{
        struct cafe_priv *cafe = nand_get_controller_data(chip);

        dma_free_coherent(&cafe->pdev->dev, 2112, cafe->dmabuf, cafe->dmaaddr);
}

static const struct nand_controller_ops cafe_nand_controller_ops = {
        .attach_chip = cafe_nand_attach_chip,
        .detach_chip = cafe_nand_detach_chip,
};

static int cafe_nand_probe(struct pci_dev *pdev,
                                     const struct pci_device_id *ent)
{
        struct mtd_info *mtd;
        struct cafe_priv *cafe;
        uint32_t ctrl;
        int err = 0;

        /* Very old versions shared the same PCI ident for all three
           functions on the chip. Verify the class too... */
        if ((pdev->class >> 8) != PCI_CLASS_MEMORY_FLASH)
                return -ENODEV;

        err = pci_enable_device(pdev);
        if (err)
                return err;

        pci_set_master(pdev);

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

        mtd = nand_to_mtd(&cafe->nand);
        mtd->dev.parent = &pdev->dev;
        nand_set_controller_data(&cafe->nand, cafe);

        cafe->pdev = pdev;
        cafe->mmio = pci_iomap(pdev, 0, 0);
        if (!cafe->mmio) {
                dev_warn(&pdev->dev, "failed to iomap\n");
                err = -ENOMEM;
                goto out_free_mtd;
        }

        cafe->rs = init_rs_non_canonical(12, &cafe_mul, 0, 1, 8);
        if (!cafe->rs) {
                err = -ENOMEM;
                goto out_ior;
        }

        cafe->nand.legacy.cmdfunc = cafe_nand_cmdfunc;
        cafe->nand.legacy.dev_ready = cafe_device_ready;
        cafe->nand.legacy.read_byte = cafe_read_byte;
        cafe->nand.legacy.read_buf = cafe_read_buf;
        cafe->nand.legacy.write_buf = cafe_write_buf;
        cafe->nand.legacy.select_chip = cafe_select_chip;
        cafe->nand.legacy.set_features = nand_get_set_features_notsupp;
        cafe->nand.legacy.get_features = nand_get_set_features_notsupp;

        cafe->nand.legacy.chip_delay = 0;

        /* Enable the following for a flash based bad block table */
        cafe->nand.bbt_options = NAND_BBT_USE_FLASH;

        if (skipbbt) {
                cafe->nand.options |= NAND_SKIP_BBTSCAN;
                cafe->nand.legacy.block_bad = cafe_nand_block_bad;
        }

        if (numtimings && numtimings != 3) {
                dev_warn(&cafe->pdev->dev, "%d timing register values ignored; precisely three are required\n", numtimings);
        }

        if (numtimings == 3) {
                cafe_dev_dbg(&cafe->pdev->dev, "Using provided timings (%08x %08x %08x)\n",
                             timing[0], timing[1], timing[2]);
        } else {
                timing[0] = cafe_readl(cafe, NAND_TIMING1);
                timing[1] = cafe_readl(cafe, NAND_TIMING2);
                timing[2] = cafe_readl(cafe, NAND_TIMING3);

                if (timing[0] | timing[1] | timing[2]) {
                        cafe_dev_dbg(&cafe->pdev->dev, "Timing registers already set (%08x %08x %08x)\n",
                                     timing[0], timing[1], timing[2]);
                } else {
                        dev_warn(&cafe->pdev->dev, "Timing registers unset; using most conservative defaults\n");
                        timing[0] = timing[1] = timing[2] = 0xffffffff;
                }
        }

        /* Start off by resetting the NAND controller completely */
        cafe_writel(cafe, 1, NAND_RESET);
        cafe_writel(cafe, 0, NAND_RESET);

        cafe_writel(cafe, timing[0], NAND_TIMING1);
        cafe_writel(cafe, timing[1], NAND_TIMING2);
        cafe_writel(cafe, timing[2], NAND_TIMING3);

        cafe_writel(cafe, 0xffffffff, NAND_IRQ_MASK);
        err = request_irq(pdev->irq, &cafe_nand_interrupt, IRQF_SHARED,
                          "CAFE NAND", mtd);
        if (err) {
                dev_warn(&pdev->dev, "Could not register IRQ %d\n", pdev->irq);
                goto out_ior;
        }

        /* Disable master reset, enable NAND clock */
        ctrl = cafe_readl(cafe, GLOBAL_CTRL);
        ctrl &= 0xffffeff0;
        ctrl |= 0x00007000;
        cafe_writel(cafe, ctrl | 0x05, GLOBAL_CTRL);
        cafe_writel(cafe, ctrl | 0x0a, GLOBAL_CTRL);
        cafe_writel(cafe, 0, NAND_DMA_CTRL);

        cafe_writel(cafe, 0x7006, GLOBAL_CTRL);
        cafe_writel(cafe, 0x700a, GLOBAL_CTRL);

        /* Enable NAND IRQ in global IRQ mask register */
        cafe_writel(cafe, 0x80000007, GLOBAL_IRQ_MASK);
        cafe_dev_dbg(&cafe->pdev->dev, "Control %x, IRQ mask %x\n",
                cafe_readl(cafe, GLOBAL_CTRL),
                cafe_readl(cafe, GLOBAL_IRQ_MASK));

        /* Do not use the DMA during the NAND identification */
        cafe->usedma = 0;

        /* Scan to find existence of the device */
        cafe->nand.legacy.dummy_controller.ops = &cafe_nand_controller_ops;
        err = nand_scan(&cafe->nand, 2);
        if (err)
                goto out_irq;

        pci_set_drvdata(pdev, mtd);

        mtd->name = "cafe_nand";
        err = mtd_device_parse_register(mtd, part_probes, NULL, NULL, 0);
        if (err)
                goto out_cleanup_nand;

        goto out;

 out_cleanup_nand:
        nand_cleanup(&cafe->nand);
 out_irq:
        /* Disable NAND IRQ in global IRQ mask register */
        cafe_writel(cafe, ~1 & cafe_readl(cafe, GLOBAL_IRQ_MASK), GLOBAL_IRQ_MASK);
        free_irq(pdev->irq, mtd);
 out_ior:
        pci_iounmap(pdev, cafe->mmio);
 out_free_mtd:
        kfree(cafe);
 out:
        return err;
}

static void cafe_nand_remove(struct pci_dev *pdev)
{
        struct mtd_info *mtd = pci_get_drvdata(pdev);
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct cafe_priv *cafe = nand_get_controller_data(chip);

        /* Disable NAND IRQ in global IRQ mask register */
        cafe_writel(cafe, ~1 & cafe_readl(cafe, GLOBAL_IRQ_MASK), GLOBAL_IRQ_MASK);
        free_irq(pdev->irq, mtd);
        nand_release(chip);
        free_rs(cafe->rs);
        pci_iounmap(pdev, cafe->mmio);
        dma_free_coherent(&cafe->pdev->dev, 2112, cafe->dmabuf, cafe->dmaaddr);
        kfree(cafe);
}

static const struct pci_device_id cafe_nand_tbl[] = {
        { PCI_VENDOR_ID_MARVELL, PCI_DEVICE_ID_MARVELL_88ALP01_NAND,
          PCI_ANY_ID, PCI_ANY_ID },
        { }
};

MODULE_DEVICE_TABLE(pci, cafe_nand_tbl);

static int cafe_nand_resume(struct pci_dev *pdev)
{
        uint32_t ctrl;
        struct mtd_info *mtd = pci_get_drvdata(pdev);
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct cafe_priv *cafe = nand_get_controller_data(chip);

       /* Start off by resetting the NAND controller completely */
        cafe_writel(cafe, 1, NAND_RESET);
        cafe_writel(cafe, 0, NAND_RESET);
        cafe_writel(cafe, 0xffffffff, NAND_IRQ_MASK);

        /* Restore timing configuration */
        cafe_writel(cafe, timing[0], NAND_TIMING1);
        cafe_writel(cafe, timing[1], NAND_TIMING2);
        cafe_writel(cafe, timing[2], NAND_TIMING3);

        /* Disable master reset, enable NAND clock */
        ctrl = cafe_readl(cafe, GLOBAL_CTRL);
        ctrl &= 0xffffeff0;
        ctrl |= 0x00007000;
        cafe_writel(cafe, ctrl | 0x05, GLOBAL_CTRL);
        cafe_writel(cafe, ctrl | 0x0a, GLOBAL_CTRL);
        cafe_writel(cafe, 0, NAND_DMA_CTRL);
        cafe_writel(cafe, 0x7006, GLOBAL_CTRL);
        cafe_writel(cafe, 0x700a, GLOBAL_CTRL);

        /* Set up DMA address */
        cafe_writel(cafe, cafe->dmaaddr & 0xffffffff, NAND_DMA_ADDR0);
        if (sizeof(cafe->dmaaddr) > 4)
        /* Shift in two parts to shut the compiler up */
                cafe_writel(cafe, (cafe->dmaaddr >> 16) >> 16, NAND_DMA_ADDR1);
        else
                cafe_writel(cafe, 0, NAND_DMA_ADDR1);

        /* Enable NAND IRQ in global IRQ mask register */
        cafe_writel(cafe, 0x80000007, GLOBAL_IRQ_MASK);
        return 0;
}

static struct pci_driver cafe_nand_pci_driver = {
        .name = "CAFÉ NAND",
        .id_table = cafe_nand_tbl,
        .probe = cafe_nand_probe,
        .remove = cafe_nand_remove,
        .resume = cafe_nand_resume,
};

module_pci_driver(cafe_nand_pci_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("NAND flash driver for OLPC CAFÉ chip");