[MTD] NAND: Add hardware ECC correction support to CAFÉ NAND driver

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 722 insertions, 0 deletions

diff --git a/drivers/mtd/nand/cafe.c b/drivers/mtd/nand/cafe.c
new file mode 100644
index 000000000000..1fe110836cc1
--- /dev/null
+++ b/drivers/mtd/nand/cafe.c
@@ -0,0 +1,722 @@
+/* 
+ * cafe_nand.c
+ *
+ * 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/nand.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/interrupt.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_ECC_SYN01     0x50
+#define CAFE_NAND_ECC_SYN23     0x54
+#define CAFE_NAND_ECC_SYN45     0x58
+#define CAFE_NAND_ECC_SYN67     0x5c
+#define CAFE_NAND_DMA_CTRL      0x40
+#define CAFE_NAND_DMA_ADDR0     0x44
+#define CAFE_NAND_DMA_ADDR1     0x48
+#define CAFE_NAND_READ_DATA     0x1000
+#define CAFE_NAND_WRITE_DATA    0x2000
+
+int cafe_correct_ecc(unsigned char *buf,
+                     unsigned short *chk_syndrome_list);
+
+struct cafe_priv {
+        struct nand_chip nand;
+        struct pci_dev *pdev;
+        void __iomem *mmio;
+        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 = 0;
+module_param(usedma, int, 0644);
+
+static int skipbbt = 0;
+module_param(skipbbt, int, 0644);
+
+static int debug = 0;
+module_param(debug, int, 0644);
+
+/* 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)
+
+
+static int cafe_device_ready(struct mtd_info *mtd)
+{
+        struct cafe_priv *cafe = mtd->priv;
+        int result = !!(readl(cafe->mmio + CAFE_NAND_STATUS) | 0x40000000);
+
+        uint32_t irqs = readl(cafe->mmio + CAFE_NAND_IRQ);
+        writel(irqs, cafe->mmio+CAFE_NAND_IRQ);
+        cafe_dev_dbg(&cafe->pdev->dev, "NAND device is%s ready, IRQ %x (%x) (%x,%x)\n",
+                result?"":" not", irqs, readl(cafe->mmio + CAFE_NAND_IRQ),
+                readl(cafe->mmio + 0x3008), readl(cafe->mmio + 0x300c));
+        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;
+        int i;
+
+        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 */
+                writel(cafe->ctl2 | 0x100 | command, cafe->mmio + 0x04);
+                ctl1 = cafe->ctl1;
+                cafe_dev_dbg(&cafe->pdev->dev, "Continue command, ctl1 %08x, #data %d\n",
+                          cafe->ctl1, cafe->nr_data);
+                goto do_command;
+        }
+        /* Reset ECC engine */
+        writel(0, cafe->mmio + CAFE_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) {
+                writel(column, cafe->mmio + 0x1c);
+                adrbytes = 2;
+                if (page_addr != -1)
+                        goto write_adr2;
+        } else if (page_addr != -1) {
+                writel(page_addr & 0xffff, cafe->mmio + 0x1c);
+                page_addr >>= 16;
+        write_adr2:
+                writel(page_addr, cafe->mmio+0x20);
+                adrbytes += 2;
+                if (mtd->size > mtd->writesize << 16)
+                        adrbytes++;
+        }
+
+        cafe->data_pos = cafe->datalen = 0;
+
+        /* Set command valid bit */
+        ctl1 = 0x80000000 | command;
+
+        /* 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->ctl2 = 0;
+                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)
+                writel(cafe->ctl2 | 0x100 | NAND_CMD_RNDOUTSTART, cafe->mmio + CAFE_NAND_CTRL2);
+        else if (command == NAND_CMD_READ0 && mtd->writesize > 512)
+                writel(cafe->ctl2 | 0x100 | NAND_CMD_READSTART, cafe->mmio + CAFE_NAND_CTRL2);
+
+ do_command:
+#if 0
+        // ECC on read only works if we ...
+        if (cafe->datalen == 2112)
+                cafe->datalen = 2062;
+#endif
+        cafe_dev_dbg(&cafe->pdev->dev, "dlen %x, ctl1 %x, ctl2 %x\n", 
+                cafe->datalen, ctl1, readl(cafe->mmio+CAFE_NAND_CTRL2));
+        /* NB: The datasheet lies -- we really should be subtracting 1 here */
+        writel(cafe->datalen, cafe->mmio + CAFE_NAND_DATA_LEN);
+        writel(0x90000000, cafe->mmio + CAFE_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;
+                }
+                writel(dmactl, cafe->mmio + 0x40);
+        }
+#if 0
+        printk("DMA setup is %x, status %x, ctl1 %x\n", readl(cafe->mmio + 0x40), readl(cafe->mmio + 0x0c), readl(cafe->mmio));
+        printk("DMA setup is %x, status %x, ctl1 %x\n", readl(cafe->mmio + 0x40), readl(cafe->mmio + 0x0c), readl(cafe->mmio));
+#endif
+        cafe->datalen = 0;
+
+#if 0
+        printk("About to write command %08x\n", ctl1);
+        for (i=0; i< 0x5c; i+=4)
+                printk("Register %x: %08x\n", i, readl(cafe->mmio + i));
+#endif
+        writel(ctl1, cafe->mmio + CAFE_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 = 500000;
+                uint32_t irqs;
+
+                while (c--) {
+                        irqs = readl(cafe->mmio + 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();
+                }
+                writel(doneint, cafe->mmio + CAFE_NAND_IRQ);
+                cafe_dev_dbg(&cafe->pdev->dev, "Command %x completed after %d usec, irqs %x (%x)\n", command, 50000-c, irqs, readl(cafe->mmio + CAFE_NAND_IRQ));
+        }
+
+
+        cafe->ctl2 &= ~(1<<8);
+        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:
+                writel(cafe->ctl2, cafe->mmio + CAFE_NAND_CTRL2);
+                return;
+        }
+        nand_wait_ready(mtd);
+        writel(cafe->ctl2, cafe->mmio + CAFE_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);
+}
+static int cafe_nand_interrupt(int irq, void *id, struct pt_regs *regs)
+{
+        struct mtd_info *mtd = id;
+        struct cafe_priv *cafe = mtd->priv;
+        uint32_t irqs = readl(cafe->mmio + CAFE_NAND_IRQ);
+        writel(irqs & ~0x90000000, cafe->mmio + CAFE_NAND_IRQ);
+        if (!irqs)
+                return IRQ_NONE;
+
+        cafe_dev_dbg(&cafe->pdev->dev, "irq, bits %x (%x)\n", irqs, readl(cafe->mmio + 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, int sndcmd)
+{
+        chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
+        chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
+        return 1;
+}
+/**
+ * cafe_nand_read_page_syndrome - {REPLACABLE] hardware ecc syndrom based page read
+ * @mtd:        mtd info structure
+ * @chip:       nand chip info structure
+ * @buf:        buffer to store read data
+ *
+ * The hw generator calculates the error syndrome automatically. Therefor
+ * we need a special oob layout and handling.
+ */
+static int cafe_nand_read_page(struct mtd_info *mtd, struct nand_chip *chip,
+                               uint8_t *buf)
+{
+        struct cafe_priv *cafe = mtd->priv;
+
+        dev_dbg(&cafe->pdev->dev, "ECC result %08x SYN1,2 %08x\n",
+                readl(cafe->mmio + CAFE_NAND_ECC_RESULT),
+                readl(cafe->mmio + CAFE_NAND_ECC_SYN01));
+
+        chip->read_buf(mtd, buf, mtd->writesize);
+        chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
+
+        if (readl(cafe->mmio + CAFE_NAND_ECC_RESULT) & (1<<18)) {
+                unsigned short syn[8];
+                int i;
+
+                for (i=0; i<8; i+=2) {
+                        uint32_t tmp = readl(cafe->mmio + CAFE_NAND_ECC_SYN01 + (i*2));
+                        syn[i] = tmp & 0xfff;
+                        syn[i+1] = (tmp >> 16) & 0xfff;
+                } 
+
+                if ((i = cafe_correct_ecc(buf, syn)) < 0) {
+                        dev_dbg(&cafe->pdev->dev, "Failed to correct ECC\n");
+                        mtd->ecc_stats.failed++;
+                } else {
+                        dev_dbg(&cafe->pdev->dev, "Corrected %d symbol errors\n", i);
+                        mtd->ecc_stats.corrected += i;
+                }
+        }
+
+
+        return 0;
+}
+
+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 */
+static uint8_t cafe_bbt_pattern[] = {'B', 'b', 't', '0' };
+static uint8_t cafe_mirror_pattern[] = {'1', 't', 'b', 'B' };
+
+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 | NAND_BBT_PERCHIP,
+        .offs = 14,
+        .len = 4,
+        .veroffs = 18,
+        .maxblocks = 4,
+        .pattern = cafe_bbt_pattern
+};
+
+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 | NAND_BBT_PERCHIP,
+        .offs = 14,
+        .len = 4,
+        .veroffs = 18,
+        .maxblocks = 4,
+        .pattern = cafe_mirror_pattern
+};
+
+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 void cafe_nand_write_page_lowlevel(struct mtd_info *mtd,
+                                          struct nand_chip *chip, const uint8_t *buf)
+{
+        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<<27) | (1<<30);
+        if (mtd->writesize == 2048)
+                cafe->ctl2 |= (1<<29);
+}
+
+static int cafe_nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
+                                const uint8_t *buf, int page, int cached, int raw)
+{
+        int status;
+
+        chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
+
+        if (unlikely(raw))
+                chip->ecc.write_page_raw(mtd, chip, buf);
+        else
+                chip->ecc.write_page(mtd, chip, buf);
+
+        /*
+         * 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);
+        }
+
+#ifdef CONFIG_MTD_NAND_VERIFY_WRITE
+        /* Send command to read back the data */
+        chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
+
+        if (chip->verify_buf(mtd, buf, mtd->writesize))
+                return -EIO;
+#endif
+        return 0;
+}
+
+static int cafe_nand_block_bad(struct mtd_info *mtd, loff_t ofs, int getchip)
+{
+        return 0;
+}
+
+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;
+
+        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->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->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.options = NAND_USE_FLASH_BBT | NAND_NO_AUTOINCR | NAND_OWN_BUFFERS;
+
+        if (skipbbt) {
+                cafe->nand.options |= NAND_SKIP_BBTSCAN;
+                cafe->nand.block_bad = cafe_nand_block_bad;
+        }
+        
+        /* Timings from Marvell's test code (not verified or calculated by us) */
+        writel(0xffffffff, cafe->mmio + CAFE_NAND_IRQ_MASK);
+#if 1
+        writel(0x01010a0a, cafe->mmio + CAFE_NAND_TIMING1);
+        writel(0x24121212, cafe->mmio + CAFE_NAND_TIMING2);
+        writel(0x11000000, cafe->mmio + CAFE_NAND_TIMING3);
+#else
+        writel(0xffffffff, cafe->mmio + CAFE_NAND_TIMING1);
+        writel(0xffffffff, cafe->mmio + CAFE_NAND_TIMING2);
+        writel(0xffffffff, cafe->mmio + CAFE_NAND_TIMING3);
+#endif
+        writel(0xffffffff, cafe->mmio + CAFE_NAND_IRQ_MASK);
+        err = request_irq(pdev->irq, &cafe_nand_interrupt, SA_SHIRQ, "CAFE NAND", mtd);
+        if (err) {
+                dev_warn(&pdev->dev, "Could not register IRQ %d\n", pdev->irq);
+                
+                goto out_free_dma;
+        }
+#if 1
+        /* Disable master reset, enable NAND clock */
+        ctrl = readl(cafe->mmio + 0x3004);
+        ctrl &= 0xffffeff0;
+        ctrl |= 0x00007000;
+        writel(ctrl | 0x05, cafe->mmio + 0x3004);
+        writel(ctrl | 0x0a, cafe->mmio + 0x3004);
+        writel(0, cafe->mmio + 0x40);
+
+        writel(0x7006, cafe->mmio + 0x3004);
+        writel(0x700a, cafe->mmio + 0x3004);
+
+        /* Set up DMA address */
+        writel(cafe->dmaaddr & 0xffffffff, cafe->mmio + 0x44);
+        if (sizeof(cafe->dmaaddr) > 4)
+                writel((cafe->dmaaddr >> 16) >> 16, cafe->mmio + 0x48);
+        else
+                writel(0, cafe->mmio + 0x48);
+        cafe_dev_dbg(&cafe->pdev->dev, "Set DMA address to %x (virt %p)\n",
+                readl(cafe->mmio+0x44), cafe->dmabuf);
+
+        /* Enable NAND IRQ in global IRQ mask register */
+        writel(0x80000007, cafe->mmio + 0x300c);
+        cafe_dev_dbg(&cafe->pdev->dev, "Control %x, IRQ mask %x\n",
+                readl(cafe->mmio + 0x3004), readl(cafe->mmio + 0x300c));
+#endif
+#if 1
+        mtd->writesize=2048;
+        mtd->oobsize = 0x40;
+        memset(cafe->dmabuf, 0x5a, 2112);
+        cafe->nand.cmdfunc(mtd, NAND_CMD_READID, 0, -1);
+        cafe->nand.read_byte(mtd);
+        cafe->nand.read_byte(mtd);
+        cafe->nand.read_byte(mtd);
+        cafe->nand.read_byte(mtd);
+        cafe->nand.read_byte(mtd);
+#endif
+#if 0
+        cafe->nand.cmdfunc(mtd, NAND_CMD_READ0, 0, 0);
+        //      nand_wait_ready(mtd);
+        cafe->nand.read_byte(mtd);
+        cafe->nand.read_byte(mtd);
+        cafe->nand.read_byte(mtd);
+        cafe->nand.read_byte(mtd);
+#endif
+#if 0
+        writel(0x84600070, cafe->mmio);
+        udelay(10);
+        cafe_dev_dbg(&cafe->pdev->dev, "Status %x\n", readl(cafe->mmio + 0x30));
+#endif          
+        /* Scan to find existance of the device */
+        if (nand_scan_ident(mtd, 1)) {
+                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 == 512 || mtd->writesize == 2048) {
+                cafe->nand.ecc.mode = NAND_ECC_HW_SYNDROME;
+                cafe->nand.ecc.size = mtd->writesize;
+                cafe->nand.ecc.bytes = 14;
+                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;
+                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;
+
+        } else {
+                printk(KERN_WARNING "Unexpected NAND flash writesize %d. Using software ECC\n",
+                       mtd->writesize);
+                cafe->nand.ecc.mode = NAND_ECC_NONE;
+        }
+
+        err = nand_scan_tail(mtd);
+        if (err)
+                goto out_irq;
+
+        pci_set_drvdata(pdev, mtd);
+        add_mtd_device(mtd);
+        goto out;
+
+ out_irq:
+        /* Disable NAND IRQ in global IRQ mask register */
+        writel(~1 & readl(cafe->mmio + 0x300c), cafe->mmio + 0x300c);
+        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;
+
+        del_mtd_device(mtd);
+        /* Disable NAND IRQ in global IRQ mask register */
+        writel(~1 & readl(cafe->mmio + 0x300c), cafe->mmio + 0x300c);
+        free_irq(pdev->irq, mtd);
+        nand_release(mtd);
+        pci_iounmap(pdev, cafe->mmio);
+        dma_free_coherent(&cafe->pdev->dev, 2112, cafe->dmabuf, cafe->dmaaddr);
+        kfree(mtd);
+}
+
+static struct pci_device_id cafe_nand_tbl[] = {
+        { 0x11ab, 0x4100, PCI_ANY_ID, PCI_ANY_ID, PCI_CLASS_MEMORY_FLASH << 8, 0xFFFF0 }
+};
+
+MODULE_DEVICE_TABLE(pci, cafe_nand_tbl);
+
+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),
+#ifdef CONFIG_PMx
+        .suspend = cafe_nand_suspend,
+        .resume = cafe_nand_resume,
+#endif
+};
+
+static int cafe_nand_init(void)
+{
+        return pci_register_driver(&cafe_nand_pci_driver);
+}
+
+static void cafe_nand_exit(void)
+{
+        pci_unregister_driver(&cafe_nand_pci_driver);
+}
+module_init(cafe_nand_init);
+module_exit(cafe_nand_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
+MODULE_DESCRIPTION("NAND flash driver for OLPC CAFE chip");
+
+/* Correct ECC for 2048 bytes of 0xff:
+   41 a0 71 65 54 27 f3 93 ec a9 be ed 0b a1 */
+
+/* dwmw2's B-test board, in case of completely screwing it:
+Bad eraseblock 2394 at 0x12b40000
+Bad eraseblock 2627 at 0x14860000
+Bad eraseblock 3349 at 0x1a2a0000
+*/