cafe_nand.c

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/*
 * 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 <[email protected]>
 */

#define DEBUG

#include <linux/device.h>
#undef DEBUG
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.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;
    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 mtd_info *mtd)
{
    struct cafe_priv *cafe = mtd->priv;
    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 mtd_info *mtd, const uint8_t *buf, int len)
{
    struct cafe_priv *cafe = mtd->priv;

    if (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 mtd_info *mtd, uint8_t *buf, int len)
{
    struct cafe_priv *cafe = mtd->priv;

    if (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 mtd_info *mtd)
{
    struct cafe_priv *cafe = mtd->priv;
    uint8_t d;

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

    return d;
}

static void cafe_nand_cmdfunc(struct mtd_info *mtd, unsigned command,
                  int column, int page_addr)
{
    struct cafe_priv *cafe = mtd->priv;
    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 (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_DEPLETE1:
    case NAND_CMD_RNDOUT:
    case NAND_CMD_STATUS_ERROR:
    case NAND_CMD_STATUS_ERROR0:
    case NAND_CMD_STATUS_ERROR1:
    case NAND_CMD_STATUS_ERROR2:
    case NAND_CMD_STATUS_ERROR3:
        cafe_writel(cafe, cafe->ctl2, NAND_CTRL2);
        return;
    }
    nand_wait_ready(mtd);
    cafe_writel(cafe, cafe->ctl2, NAND_CTRL2);
}

static void cafe_select_chip(struct mtd_info *mtd, int chipnr)
{
    struct cafe_priv *cafe = mtd->priv;

    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 cafe_priv *cafe = mtd->priv;
    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 void cafe_nand_bug(struct mtd_info *mtd)
{
    BUG();
}

static int cafe_nand_write_oob(struct mtd_info *mtd,
                   struct nand_chip *chip, int page)
{
    int status = 0;

    chip->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize, page);
    chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
    chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
    status = chip->waitfunc(mtd, chip);

    return status & NAND_STATUS_FAIL ? -EIO : 0;
}

/* Don't use -- use nand_read_oob_std for now */
static int cafe_nand_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
                  int page)
{
    chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
    chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
    return 0;
}
static int cafe_nand_read_page(struct mtd_info *mtd, struct nand_chip *chip,
                   uint8_t *buf, int oob_required, int page)
{
    struct cafe_priv *cafe = mtd->priv;
    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));

    chip->read_buf(mtd, buf, mtd->writesize);
    chip->read_buf(mtd, 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->index_of[tmp & 0xfff];
            syn[i+1] = cafe->rs->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 struct nand_ecclayout cafe_oobinfo_2048 = {
    .eccbytes = 14,
    .eccpos = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13},
    .oobfree = {{14, 50}}
};

/* 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_ecclayout cafe_oobinfo_512 = {
    .eccbytes = 14,
    .eccpos = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13},
    .oobfree = {{14, 2}}
};

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 mtd_info *mtd,
                      struct nand_chip *chip,
                      const uint8_t *buf, int oob_required)
{
    struct cafe_priv *cafe = mtd->priv;

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

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

    return 0;
}

static int cafe_nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
                const uint8_t *buf, int oob_required, int page,
                int cached, int raw)
{
    int status;

    chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);

    if (unlikely(raw))
        status = chip->ecc.write_page_raw(mtd, chip, buf, oob_required);
    else
        status = chip->ecc.write_page(mtd, chip, buf, oob_required);

    if (status < 0)
        return status;

    /*
     * Cached progamming disabled for now, Not sure if its worth the
     * trouble. The speed gain is not very impressive. (2.3->2.6Mib/s)
     */
    cached = 0;

    if (!cached || !(chip->options & NAND_CACHEPRG)) {

        chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
        status = chip->waitfunc(mtd, chip);
        /*
         * See if operation failed and additional status checks are
         * available
         */
        if ((status & NAND_STATUS_FAIL) && (chip->errstat))
            status = chip->errstat(mtd, chip, FL_WRITING, status,
                           page);

        if (status & NAND_STATUS_FAIL)
            return -EIO;
    } else {
        chip->cmdfunc(mtd, NAND_CMD_CACHEDPROG, -1, -1);
        status = chip->waitfunc(mtd, chip);
    }

    return 0;
}

static int cafe_nand_block_bad(struct mtd_info *mtd, loff_t ofs, int getchip)
{
    return 0;
}

/* F_2[X]/(X**6+X+1)  */
static unsigned short __devinit 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 __devinit 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 __devinit cafe_mul(int x)
{
    if (x == 0)
        return 1;
    return gf4096_mul(x, 0xe01);
}

static int __devinit 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);

    mtd = kzalloc(sizeof(*mtd) + sizeof(struct cafe_priv), GFP_KERNEL);
    if (!mtd) {
        dev_warn(&pdev->dev, "failed to alloc mtd_info\n");
        return  -ENOMEM;
    }
    cafe = (void *)(&mtd[1]);

    mtd->dev.parent = &pdev->dev;
    mtd->priv = cafe;
    mtd->owner = THIS_MODULE;

    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->dmabuf = dma_alloc_coherent(&cafe->pdev->dev, 2112 + sizeof(struct nand_buffers),
                      &cafe->dmaaddr, GFP_KERNEL);
    if (!cafe->dmabuf) {
        err = -ENOMEM;
        goto out_ior;
    }
    cafe->nand.buffers = (void *)cafe->dmabuf + 2112;

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

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

    cafe->nand.chip_delay = 0;

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

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

    /* 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);

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

    /* 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));

    /* Scan to find existence of the device */
    if (nand_scan_ident(mtd, 2, NULL)) {
        err = -ENXIO;
        goto out_irq;
    }

    cafe->ctl2 = 1<<27; /* Reed-Solomon ECC */
    if (mtd->writesize == 2048)
        cafe->ctl2 |= 1<<29; /* 2KiB page size */

    /* Set up ECC according to the type of chip we found */
    if (mtd->writesize == 2048) {
        cafe->nand.ecc.layout = &cafe_oobinfo_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.ecc.layout = &cafe_oobinfo_512;
        cafe->nand.bbt_td = &cafe_bbt_main_descr_512;
        cafe->nand.bbt_md = &cafe_bbt_mirror_descr_512;
    } else {
        printk(KERN_WARNING "Unexpected NAND flash writesize %d. Aborting\n",
               mtd->writesize);
        goto out_irq;
    }
    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.hwctl  = (void *)cafe_nand_bug;
    cafe->nand.ecc.calculate = (void *)cafe_nand_bug;
    cafe->nand.ecc.correct  = (void *)cafe_nand_bug;
    cafe->nand.write_page = cafe_nand_write_page;
    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;

    err = nand_scan_tail(mtd);
    if (err)
        goto out_irq;

    pci_set_drvdata(pdev, mtd);

    mtd->name = "cafe_nand";
    mtd_device_parse_register(mtd, part_probes, NULL, NULL, 0);

    goto out;

 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_free_dma:
    dma_free_coherent(&cafe->pdev->dev, 2112, cafe->dmabuf, cafe->dmaaddr);
 out_ior:
    pci_iounmap(pdev, cafe->mmio);
 out_free_mtd:
    kfree(mtd);
 out:
    return err;
}

static void __devexit cafe_nand_remove(struct pci_dev *pdev)
{
    struct mtd_info *mtd = pci_get_drvdata(pdev);
    struct cafe_priv *cafe = mtd->priv;

    /* 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(mtd);
    free_rs(cafe->rs);
    pci_iounmap(pdev, cafe->mmio);
    dma_free_coherent(&cafe->pdev->dev, 2112, cafe->dmabuf, cafe->dmaaddr);
    kfree(mtd);
}

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 cafe_priv *cafe = mtd->priv;

       /* 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 = __devexit_p(cafe_nand_remove),
    .resume = cafe_nand_resume,
};

module_pci_driver(cafe_nand_pci_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <[email protected]>");
MODULE_DESCRIPTION("NAND flash driver for OLPC CAFÉ chip");