doc2001plus.c

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/*
 * Linux driver for Disk-On-Chip Millennium Plus
 *
 * (c) 2002-2003 Greg Ungerer <[email protected]>
 * (c) 2002-2003 SnapGear Inc
 * (c) 1999 Machine Vision Holdings, Inc.
 * (c) 1999, 2000 David Woodhouse <[email protected]>
 *
 * Released under GPL
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/errno.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/bitops.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/doc2000.h>

/* #define ECC_DEBUG */

/* I have no idea why some DoC chips can not use memcop_form|to_io().
 * This may be due to the different revisions of the ASIC controller built-in or
 * simplily a QA/Bug issue. Who knows ?? If you have trouble, please uncomment
 * this:*/
#undef USE_MEMCPY

static int doc_read(struct mtd_info *mtd, loff_t from, size_t len,
        size_t *retlen, u_char *buf);
static int doc_write(struct mtd_info *mtd, loff_t to, size_t len,
        size_t *retlen, const u_char *buf);
static int doc_read_oob(struct mtd_info *mtd, loff_t ofs,
            struct mtd_oob_ops *ops);
static int doc_write_oob(struct mtd_info *mtd, loff_t ofs,
             struct mtd_oob_ops *ops);
static int doc_erase (struct mtd_info *mtd, struct erase_info *instr);

static struct mtd_info *docmilpluslist = NULL;


/* Perform the required delay cycles by writing to the NOP register */
static void DoC_Delay(void __iomem * docptr, int cycles)
{
    int i;

    for (i = 0; (i < cycles); i++)
        WriteDOC(0, docptr, Mplus_NOP);
}

#define CDSN_CTRL_FR_B_MASK (CDSN_CTRL_FR_B0 | CDSN_CTRL_FR_B1)

/* DOC_WaitReady: Wait for RDY line to be asserted by the flash chip */
static int _DoC_WaitReady(void __iomem * docptr)
{
    unsigned int c = 0xffff;

    pr_debug("_DoC_WaitReady called for out-of-line wait\n");

    /* Out-of-line routine to wait for chip response */
    while (((ReadDOC(docptr, Mplus_FlashControl) & CDSN_CTRL_FR_B_MASK) != CDSN_CTRL_FR_B_MASK) && --c)
        ;

    if (c == 0)
        pr_debug("_DoC_WaitReady timed out.\n");

    return (c == 0);
}

static inline int DoC_WaitReady(void __iomem * docptr)
{
    /* This is inline, to optimise the common case, where it's ready instantly */
    int ret = 0;

    /* read form NOP register should be issued prior to the read from CDSNControl
       see Software Requirement 11.4 item 2. */
    DoC_Delay(docptr, 4);

    if ((ReadDOC(docptr, Mplus_FlashControl) & CDSN_CTRL_FR_B_MASK) != CDSN_CTRL_FR_B_MASK)
        /* Call the out-of-line routine to wait */
        ret = _DoC_WaitReady(docptr);

    return ret;
}

/* For some reason the Millennium Plus seems to occasionally put itself
 * into reset mode. For me this happens randomly, with no pattern that I
 * can detect. M-systems suggest always check this on any block level
 * operation and setting to normal mode if in reset mode.
 */
static inline void DoC_CheckASIC(void __iomem * docptr)
{
    /* Make sure the DoC is in normal mode */
    if ((ReadDOC(docptr, Mplus_DOCControl) & DOC_MODE_NORMAL) == 0) {
        WriteDOC((DOC_MODE_NORMAL | DOC_MODE_MDWREN), docptr, Mplus_DOCControl);
        WriteDOC(~(DOC_MODE_NORMAL | DOC_MODE_MDWREN), docptr, Mplus_CtrlConfirm);
    }
}

/* DoC_Command: Send a flash command to the flash chip through the Flash
 * command register. Need 2 Write Pipeline Terminates to complete send.
 */
static void DoC_Command(void __iomem * docptr, unsigned char command,
                   unsigned char xtraflags)
{
    WriteDOC(command, docptr, Mplus_FlashCmd);
    WriteDOC(command, docptr, Mplus_WritePipeTerm);
    WriteDOC(command, docptr, Mplus_WritePipeTerm);
}

/* DoC_Address: Set the current address for the flash chip through the Flash
 * Address register. Need 2 Write Pipeline Terminates to complete send.
 */
static inline void DoC_Address(struct DiskOnChip *doc, int numbytes,
                   unsigned long ofs, unsigned char xtraflags1,
                   unsigned char xtraflags2)
{
    void __iomem * docptr = doc->virtadr;

    /* Allow for possible Mill Plus internal flash interleaving */
    ofs >>= doc->interleave;

    switch (numbytes) {
    case 1:
        /* Send single byte, bits 0-7. */
        WriteDOC(ofs & 0xff, docptr, Mplus_FlashAddress);
        break;
    case 2:
        /* Send bits 9-16 followed by 17-23 */
        WriteDOC((ofs >> 9)  & 0xff, docptr, Mplus_FlashAddress);
        WriteDOC((ofs >> 17) & 0xff, docptr, Mplus_FlashAddress);
        break;
    case 3:
        /* Send 0-7, 9-16, then 17-23 */
        WriteDOC(ofs & 0xff, docptr, Mplus_FlashAddress);
        WriteDOC((ofs >> 9)  & 0xff, docptr, Mplus_FlashAddress);
        WriteDOC((ofs >> 17) & 0xff, docptr, Mplus_FlashAddress);
        break;
    default:
        return;
    }

    WriteDOC(0x00, docptr, Mplus_WritePipeTerm);
    WriteDOC(0x00, docptr, Mplus_WritePipeTerm);
}

/* DoC_SelectChip: Select a given flash chip within the current floor */
static int DoC_SelectChip(void __iomem * docptr, int chip)
{
    /* No choice for flash chip on Millennium Plus */
    return 0;
}

/* DoC_SelectFloor: Select a given floor (bank of flash chips) */
static int DoC_SelectFloor(void __iomem * docptr, int floor)
{
    WriteDOC((floor & 0x3), docptr, Mplus_DeviceSelect);
    return 0;
}

/*
 * Translate the given offset into the appropriate command and offset.
 * This does the mapping using the 16bit interleave layout defined by
 * M-Systems, and looks like this for a sector pair:
 *  +-----------+-------+-------+-------+--------------+---------+-----------+
 *  | 0 --- 511 |512-517|518-519|520-521| 522 --- 1033 |1034-1039|1040 - 1055|
 *  +-----------+-------+-------+-------+--------------+---------+-----------+
 *  | Data 0    | ECC 0 |Flags0 |Flags1 | Data 1       |ECC 1    | OOB 1 + 2 |
 *  +-----------+-------+-------+-------+--------------+---------+-----------+
 */
/* FIXME: This lives in INFTL not here. Other users of flash devices
   may not want it */
static unsigned int DoC_GetDataOffset(struct mtd_info *mtd, loff_t *from)
{
    struct DiskOnChip *this = mtd->priv;

    if (this->interleave) {
        unsigned int ofs = *from & 0x3ff;
        unsigned int cmd;

        if (ofs < 512) {
            cmd = NAND_CMD_READ0;
            ofs &= 0x1ff;
        } else if (ofs < 1014) {
            cmd = NAND_CMD_READ1;
            ofs = (ofs & 0x1ff) + 10;
        } else {
            cmd = NAND_CMD_READOOB;
            ofs = ofs - 1014;
        }

        *from = (*from & ~0x3ff) | ofs;
        return cmd;
    } else {
        /* No interleave */
        if ((*from) & 0x100)
            return NAND_CMD_READ1;
        return NAND_CMD_READ0;
    }
}

static unsigned int DoC_GetECCOffset(struct mtd_info *mtd, loff_t *from)
{
    unsigned int ofs, cmd;

    if (*from & 0x200) {
        cmd = NAND_CMD_READOOB;
        ofs = 10 + (*from & 0xf);
    } else {
        cmd = NAND_CMD_READ1;
        ofs = (*from & 0xf);
    }

    *from = (*from & ~0x3ff) | ofs;
    return cmd;
}

static unsigned int DoC_GetFlagsOffset(struct mtd_info *mtd, loff_t *from)
{
    unsigned int ofs, cmd;

    cmd = NAND_CMD_READ1;
    ofs = (*from & 0x200) ? 8 : 6;
    *from = (*from & ~0x3ff) | ofs;
    return cmd;
}

static unsigned int DoC_GetHdrOffset(struct mtd_info *mtd, loff_t *from)
{
    unsigned int ofs, cmd;

    cmd = NAND_CMD_READOOB;
    ofs = (*from & 0x200) ? 24 : 16;
    *from = (*from & ~0x3ff) | ofs;
    return cmd;
}

static inline void MemReadDOC(void __iomem * docptr, unsigned char *buf, int len)
{
#ifndef USE_MEMCPY
    int i;
    for (i = 0; i < len; i++)
        buf[i] = ReadDOC(docptr, Mil_CDSN_IO + i);
#else
    memcpy_fromio(buf, docptr + DoC_Mil_CDSN_IO, len);
#endif
}

static inline void MemWriteDOC(void __iomem * docptr, unsigned char *buf, int len)
{
#ifndef USE_MEMCPY
    int i;
    for (i = 0; i < len; i++)
        WriteDOC(buf[i], docptr, Mil_CDSN_IO + i);
#else
    memcpy_toio(docptr + DoC_Mil_CDSN_IO, buf, len);
#endif
}

/* DoC_IdentChip: Identify a given NAND chip given {floor,chip} */
static int DoC_IdentChip(struct DiskOnChip *doc, int floor, int chip)
{
    int mfr, id, i, j;
    volatile char dummy;
    void __iomem * docptr = doc->virtadr;

    /* Page in the required floor/chip */
    DoC_SelectFloor(docptr, floor);
    DoC_SelectChip(docptr, chip);

    /* Millennium Plus bus cycle sequence as per figure 2, section 2.4 */
    WriteDOC((DOC_FLASH_CE | DOC_FLASH_WP), docptr, Mplus_FlashSelect);

    /* Reset the chip, see Software Requirement 11.4 item 1. */
    DoC_Command(docptr, NAND_CMD_RESET, 0);
    DoC_WaitReady(docptr);

    /* Read the NAND chip ID: 1. Send ReadID command */
    DoC_Command(docptr, NAND_CMD_READID, 0);

    /* Read the NAND chip ID: 2. Send address byte zero */
    DoC_Address(doc, 1, 0x00, 0, 0x00);

    WriteDOC(0, docptr, Mplus_FlashControl);
    DoC_WaitReady(docptr);

    /* Read the manufacturer and device id codes of the flash device through
       CDSN IO register see Software Requirement 11.4 item 5.*/
    dummy = ReadDOC(docptr, Mplus_ReadPipeInit);
    dummy = ReadDOC(docptr, Mplus_ReadPipeInit);

    mfr = ReadDOC(docptr, Mil_CDSN_IO);
    if (doc->interleave)
        dummy = ReadDOC(docptr, Mil_CDSN_IO); /* 2 way interleave */

    id  = ReadDOC(docptr, Mil_CDSN_IO);
    if (doc->interleave)
        dummy = ReadDOC(docptr, Mil_CDSN_IO); /* 2 way interleave */

    dummy = ReadDOC(docptr, Mplus_LastDataRead);
    dummy = ReadDOC(docptr, Mplus_LastDataRead);

    /* Disable flash internally */
    WriteDOC(0, docptr, Mplus_FlashSelect);

    /* No response - return failure */
    if (mfr == 0xff || mfr == 0)
        return 0;

    for (i = 0; nand_flash_ids[i].name != NULL; i++) {
        if (id == nand_flash_ids[i].id) {
            /* Try to identify manufacturer */
            for (j = 0; nand_manuf_ids[j].id != 0x0; j++) {
                if (nand_manuf_ids[j].id == mfr)
                    break;
            }
            printk(KERN_INFO "Flash chip found: Manufacturer ID: %2.2X, "
                   "Chip ID: %2.2X (%s:%s)\n", mfr, id,
                   nand_manuf_ids[j].name, nand_flash_ids[i].name);
            doc->mfr = mfr;
            doc->id = id;
            doc->chipshift = ffs((nand_flash_ids[i].chipsize << 20)) - 1;
            doc->erasesize = nand_flash_ids[i].erasesize << doc->interleave;
            break;
        }
    }

    if (nand_flash_ids[i].name == NULL)
        return 0;
    return 1;
}

/* DoC_ScanChips: Find all NAND chips present in a DiskOnChip, and identify them */
static void DoC_ScanChips(struct DiskOnChip *this)
{
    int floor, chip;
    int numchips[MAX_FLOORS_MPLUS];
    int ret;

    this->numchips = 0;
    this->mfr = 0;
    this->id = 0;

    /* Work out the intended interleave setting */
    this->interleave = 0;
    if (this->ChipID == DOC_ChipID_DocMilPlus32)
        this->interleave = 1;

    /* Check the ASIC agrees */
    if ( (this->interleave << 2) !=
         (ReadDOC(this->virtadr, Mplus_Configuration) & 4)) {
        u_char conf = ReadDOC(this->virtadr, Mplus_Configuration);
        printk(KERN_NOTICE "Setting DiskOnChip Millennium Plus interleave to %s\n",
               this->interleave?"on (16-bit)":"off (8-bit)");
        conf ^= 4;
        WriteDOC(conf, this->virtadr, Mplus_Configuration);
    }

    /* For each floor, find the number of valid chips it contains */
    for (floor = 0,ret = 1; floor < MAX_FLOORS_MPLUS; floor++) {
        numchips[floor] = 0;
        for (chip = 0; chip < MAX_CHIPS_MPLUS && ret != 0; chip++) {
            ret = DoC_IdentChip(this, floor, chip);
            if (ret) {
                numchips[floor]++;
                this->numchips++;
            }
        }
    }
    /* If there are none at all that we recognise, bail */
    if (!this->numchips) {
        printk("No flash chips recognised.\n");
        return;
    }

    /* Allocate an array to hold the information for each chip */
    this->chips = kmalloc(sizeof(struct Nand) * this->numchips, GFP_KERNEL);
    if (!this->chips){
        printk("MTD: No memory for allocating chip info structures\n");
        return;
    }

    /* Fill out the chip array with {floor, chipno} for each
     * detected chip in the device. */
    for (floor = 0, ret = 0; floor < MAX_FLOORS_MPLUS; floor++) {
        for (chip = 0 ; chip < numchips[floor] ; chip++) {
            this->chips[ret].floor = floor;
            this->chips[ret].chip = chip;
            this->chips[ret].curadr = 0;
            this->chips[ret].curmode = 0x50;
            ret++;
        }
    }

    /* Calculate and print the total size of the device */
    this->totlen = this->numchips * (1 << this->chipshift);
    printk(KERN_INFO "%d flash chips found. Total DiskOnChip size: %ld MiB\n",
           this->numchips ,this->totlen >> 20);
}

static int DoCMilPlus_is_alias(struct DiskOnChip *doc1, struct DiskOnChip *doc2)
{
    int tmp1, tmp2, retval;

    if (doc1->physadr == doc2->physadr)
        return 1;

    /* Use the alias resolution register which was set aside for this
     * purpose. If it's value is the same on both chips, they might
     * be the same chip, and we write to one and check for a change in
     * the other. It's unclear if this register is usuable in the
     * DoC 2000 (it's in the Millennium docs), but it seems to work. */
    tmp1 = ReadDOC(doc1->virtadr, Mplus_AliasResolution);
    tmp2 = ReadDOC(doc2->virtadr, Mplus_AliasResolution);
    if (tmp1 != tmp2)
        return 0;

    WriteDOC((tmp1+1) % 0xff, doc1->virtadr, Mplus_AliasResolution);
    tmp2 = ReadDOC(doc2->virtadr, Mplus_AliasResolution);
    if (tmp2 == (tmp1+1) % 0xff)
        retval = 1;
    else
        retval = 0;

    /* Restore register contents.  May not be necessary, but do it just to
     * be safe. */
    WriteDOC(tmp1, doc1->virtadr, Mplus_AliasResolution);

    return retval;
}

/* This routine is found from the docprobe code by symbol_get(),
 * which will bump the use count of this module. */
void DoCMilPlus_init(struct mtd_info *mtd)
{
    struct DiskOnChip *this = mtd->priv;
    struct DiskOnChip *old = NULL;

    /* We must avoid being called twice for the same device. */
    if (docmilpluslist)
        old = docmilpluslist->priv;

    while (old) {
        if (DoCMilPlus_is_alias(this, old)) {
            printk(KERN_NOTICE "Ignoring DiskOnChip Millennium "
                "Plus at 0x%lX - already configured\n",
                this->physadr);
            iounmap(this->virtadr);
            kfree(mtd);
            return;
        }
        if (old->nextdoc)
            old = old->nextdoc->priv;
        else
            old = NULL;
    }

    mtd->name = "DiskOnChip Millennium Plus";
    printk(KERN_NOTICE "DiskOnChip Millennium Plus found at "
        "address 0x%lX\n", this->physadr);

    mtd->type = MTD_NANDFLASH;
    mtd->flags = MTD_CAP_NANDFLASH;
    mtd->writebufsize = mtd->writesize = 512;
    mtd->oobsize = 16;
    mtd->ecc_strength = 2;
    mtd->owner = THIS_MODULE;
    mtd->_erase = doc_erase;
    mtd->_read = doc_read;
    mtd->_write = doc_write;
    mtd->_read_oob = doc_read_oob;
    mtd->_write_oob = doc_write_oob;
    this->curfloor = -1;
    this->curchip = -1;

    /* Ident all the chips present. */
    DoC_ScanChips(this);

    if (!this->totlen) {
        kfree(mtd);
        iounmap(this->virtadr);
    } else {
        this->nextdoc = docmilpluslist;
        docmilpluslist = mtd;
        mtd->size  = this->totlen;
        mtd->erasesize = this->erasesize;
        mtd_device_register(mtd, NULL, 0);
        return;
    }
}
EXPORT_SYMBOL_GPL(DoCMilPlus_init);

#if 0
static int doc_dumpblk(struct mtd_info *mtd, loff_t from)
{
    int i;
    loff_t fofs;
    struct DiskOnChip *this = mtd->priv;
    void __iomem * docptr = this->virtadr;
    struct Nand *mychip = &this->chips[from >> (this->chipshift)];
    unsigned char *bp, buf[1056];
    char c[32];

    from &= ~0x3ff;

    /* Don't allow read past end of device */
    if (from >= this->totlen)
        return -EINVAL;

    DoC_CheckASIC(docptr);

    /* Find the chip which is to be used and select it */
    if (this->curfloor != mychip->floor) {
        DoC_SelectFloor(docptr, mychip->floor);
        DoC_SelectChip(docptr, mychip->chip);
    } else if (this->curchip != mychip->chip) {
        DoC_SelectChip(docptr, mychip->chip);
    }
    this->curfloor = mychip->floor;
    this->curchip = mychip->chip;

    /* Millennium Plus bus cycle sequence as per figure 2, section 2.4 */
    WriteDOC((DOC_FLASH_CE | DOC_FLASH_WP), docptr, Mplus_FlashSelect);

    /* Reset the chip, see Software Requirement 11.4 item 1. */
    DoC_Command(docptr, NAND_CMD_RESET, 0);
    DoC_WaitReady(docptr);

    fofs = from;
    DoC_Command(docptr, DoC_GetDataOffset(mtd, &fofs), 0);
    DoC_Address(this, 3, fofs, 0, 0x00);
    WriteDOC(0, docptr, Mplus_FlashControl);
    DoC_WaitReady(docptr);

    /* disable the ECC engine */
    WriteDOC(DOC_ECC_RESET, docptr, Mplus_ECCConf);

    ReadDOC(docptr, Mplus_ReadPipeInit);
    ReadDOC(docptr, Mplus_ReadPipeInit);

    /* Read the data via the internal pipeline through CDSN IO
       register, see Pipelined Read Operations 11.3 */
    MemReadDOC(docptr, buf, 1054);
    buf[1054] = ReadDOC(docptr, Mplus_LastDataRead);
    buf[1055] = ReadDOC(docptr, Mplus_LastDataRead);

    memset(&c[0], 0, sizeof(c));
    printk("DUMP OFFSET=%x:\n", (int)from);

        for (i = 0, bp = &buf[0]; (i < 1056); i++) {
                if ((i % 16) == 0)
                        printk("%08x: ", i);
                printk(" %02x", *bp);
                c[(i & 0xf)] = ((*bp >= 0x20) && (*bp <= 0x7f)) ? *bp : '.';
                bp++;
                if (((i + 1) % 16) == 0)
                        printk("    %s\n", c);
        }
    printk("\n");

    /* Disable flash internally */
    WriteDOC(0, docptr, Mplus_FlashSelect);

    return 0;
}
#endif

static int doc_read(struct mtd_info *mtd, loff_t from, size_t len,
            size_t *retlen, u_char *buf)
{
    int ret, i;
    volatile char dummy;
    loff_t fofs;
    unsigned char syndrome[6], eccbuf[6];
    struct DiskOnChip *this = mtd->priv;
    void __iomem * docptr = this->virtadr;
    struct Nand *mychip = &this->chips[from >> (this->chipshift)];

    /* Don't allow a single read to cross a 512-byte block boundary */
    if (from + len > ((from | 0x1ff) + 1))
        len = ((from | 0x1ff) + 1) - from;

    DoC_CheckASIC(docptr);

    /* Find the chip which is to be used and select it */
    if (this->curfloor != mychip->floor) {
        DoC_SelectFloor(docptr, mychip->floor);
        DoC_SelectChip(docptr, mychip->chip);
    } else if (this->curchip != mychip->chip) {
        DoC_SelectChip(docptr, mychip->chip);
    }
    this->curfloor = mychip->floor;
    this->curchip = mychip->chip;

    /* Millennium Plus bus cycle sequence as per figure 2, section 2.4 */
    WriteDOC((DOC_FLASH_CE | DOC_FLASH_WP), docptr, Mplus_FlashSelect);

    /* Reset the chip, see Software Requirement 11.4 item 1. */
    DoC_Command(docptr, NAND_CMD_RESET, 0);
    DoC_WaitReady(docptr);

    fofs = from;
    DoC_Command(docptr, DoC_GetDataOffset(mtd, &fofs), 0);
    DoC_Address(this, 3, fofs, 0, 0x00);
    WriteDOC(0, docptr, Mplus_FlashControl);
    DoC_WaitReady(docptr);

    /* init the ECC engine, see Reed-Solomon EDC/ECC 11.1 .*/
    WriteDOC(DOC_ECC_RESET, docptr, Mplus_ECCConf);
    WriteDOC(DOC_ECC_EN, docptr, Mplus_ECCConf);

    /* Let the caller know we completed it */
    *retlen = len;
    ret = 0;

    ReadDOC(docptr, Mplus_ReadPipeInit);
    ReadDOC(docptr, Mplus_ReadPipeInit);

    /* Read the data via the internal pipeline through CDSN IO
       register, see Pipelined Read Operations 11.3 */
    MemReadDOC(docptr, buf, len);

    /* Read the ECC data following raw data */
    MemReadDOC(docptr, eccbuf, 4);
    eccbuf[4] = ReadDOC(docptr, Mplus_LastDataRead);
    eccbuf[5] = ReadDOC(docptr, Mplus_LastDataRead);

    /* Flush the pipeline */
    dummy = ReadDOC(docptr, Mplus_ECCConf);
    dummy = ReadDOC(docptr, Mplus_ECCConf);

    /* Check the ECC Status */
    if (ReadDOC(docptr, Mplus_ECCConf) & 0x80) {
        int nb_errors;
        /* There was an ECC error */
#ifdef ECC_DEBUG
        printk("DiskOnChip ECC Error: Read at %lx\n", (long)from);
#endif
        /* Read the ECC syndrome through the DiskOnChip ECC logic.
           These syndrome will be all ZERO when there is no error */
        for (i = 0; i < 6; i++)
            syndrome[i] = ReadDOC(docptr, Mplus_ECCSyndrome0 + i);

        nb_errors = doc_decode_ecc(buf, syndrome);
#ifdef ECC_DEBUG
        printk("ECC Errors corrected: %x\n", nb_errors);
#endif
        if (nb_errors < 0) {
            /* We return error, but have actually done the
               read. Not that this can be told to user-space, via
               sys_read(), but at least MTD-aware stuff can know
               about it by checking *retlen */
#ifdef ECC_DEBUG
            printk("%s(%d): Millennium Plus ECC error (from=0x%x:\n",
                __FILE__, __LINE__, (int)from);
            printk("        syndrome= %*phC\n", 6, syndrome);
            printk("        eccbuf= %*phC\n", 6, eccbuf);
#endif
                ret = -EIO;
        }
    }

#ifdef PSYCHO_DEBUG
    printk("ECC DATA at %lx: %*ph\n", (long)from, 6, eccbuf);
#endif
    /* disable the ECC engine */
    WriteDOC(DOC_ECC_DIS, docptr , Mplus_ECCConf);

    /* Disable flash internally */
    WriteDOC(0, docptr, Mplus_FlashSelect);

    return ret;
}

static int doc_write(struct mtd_info *mtd, loff_t to, size_t len,
             size_t *retlen, const u_char *buf)
{
    int i, before, ret = 0;
    loff_t fto;
    volatile char dummy;
    char eccbuf[6];
    struct DiskOnChip *this = mtd->priv;
    void __iomem * docptr = this->virtadr;
    struct Nand *mychip = &this->chips[to >> (this->chipshift)];

    /* Don't allow writes which aren't exactly one block (512 bytes) */
    if ((to & 0x1ff) || (len != 0x200))
        return -EINVAL;

    /* Determine position of OOB flags, before or after data */
    before = (this->interleave && (to & 0x200));

    DoC_CheckASIC(docptr);

    /* Find the chip which is to be used and select it */
    if (this->curfloor != mychip->floor) {
        DoC_SelectFloor(docptr, mychip->floor);
        DoC_SelectChip(docptr, mychip->chip);
    } else if (this->curchip != mychip->chip) {
        DoC_SelectChip(docptr, mychip->chip);
    }
    this->curfloor = mychip->floor;
    this->curchip = mychip->chip;

    /* Millennium Plus bus cycle sequence as per figure 2, section 2.4 */
    WriteDOC(DOC_FLASH_CE, docptr, Mplus_FlashSelect);

    /* Reset the chip, see Software Requirement 11.4 item 1. */
    DoC_Command(docptr, NAND_CMD_RESET, 0);
    DoC_WaitReady(docptr);

    /* Set device to appropriate plane of flash */
    fto = to;
    WriteDOC(DoC_GetDataOffset(mtd, &fto), docptr, Mplus_FlashCmd);

    /* On interleaved devices the flags for 2nd half 512 are before data */
    if (before)
        fto -= 2;

    /* issue the Serial Data In command to initial the Page Program process */
    DoC_Command(docptr, NAND_CMD_SEQIN, 0x00);
    DoC_Address(this, 3, fto, 0x00, 0x00);

    /* Disable the ECC engine */
    WriteDOC(DOC_ECC_RESET, docptr, Mplus_ECCConf);

    if (before) {
        /* Write the block status BLOCK_USED (0x5555) */
        WriteDOC(0x55, docptr, Mil_CDSN_IO);
        WriteDOC(0x55, docptr, Mil_CDSN_IO);
    }

    /* init the ECC engine, see Reed-Solomon EDC/ECC 11.1 .*/
    WriteDOC(DOC_ECC_EN | DOC_ECC_RW, docptr, Mplus_ECCConf);

    MemWriteDOC(docptr, (unsigned char *) buf, len);

    /* Write ECC data to flash, the ECC info is generated by
       the DiskOnChip ECC logic see Reed-Solomon EDC/ECC 11.1 */
    DoC_Delay(docptr, 3);

    /* Read the ECC data through the DiskOnChip ECC logic */
    for (i = 0; i < 6; i++)
        eccbuf[i] = ReadDOC(docptr, Mplus_ECCSyndrome0 + i);

    /* disable the ECC engine */
    WriteDOC(DOC_ECC_DIS, docptr, Mplus_ECCConf);

    /* Write the ECC data to flash */
    MemWriteDOC(docptr, eccbuf, 6);

    if (!before) {
        /* Write the block status BLOCK_USED (0x5555) */
        WriteDOC(0x55, docptr, Mil_CDSN_IO+6);
        WriteDOC(0x55, docptr, Mil_CDSN_IO+7);
    }

#ifdef PSYCHO_DEBUG
    printk("OOB data at %lx is %2.2X %2.2X %2.2X %2.2X %2.2X %2.2X\n",
           (long) to, eccbuf[0], eccbuf[1], eccbuf[2], eccbuf[3],
           eccbuf[4], eccbuf[5]);
#endif

    WriteDOC(0x00, docptr, Mplus_WritePipeTerm);
    WriteDOC(0x00, docptr, Mplus_WritePipeTerm);

    /* Commit the Page Program command and wait for ready
       see Software Requirement 11.4 item 1.*/
    DoC_Command(docptr, NAND_CMD_PAGEPROG, 0x00);
    DoC_WaitReady(docptr);

    /* Read the status of the flash device through CDSN IO register
       see Software Requirement 11.4 item 5.*/
    DoC_Command(docptr, NAND_CMD_STATUS, 0);
    dummy = ReadDOC(docptr, Mplus_ReadPipeInit);
    dummy = ReadDOC(docptr, Mplus_ReadPipeInit);
    DoC_Delay(docptr, 2);
    if ((dummy = ReadDOC(docptr, Mplus_LastDataRead)) & 1) {
        printk("MTD: Error 0x%x programming at 0x%x\n", dummy, (int)to);
        /* Error in programming
           FIXME: implement Bad Block Replacement (in nftl.c ??) */
        ret = -EIO;
    }
    dummy = ReadDOC(docptr, Mplus_LastDataRead);

    /* Disable flash internally */
    WriteDOC(0, docptr, Mplus_FlashSelect);

    /* Let the caller know we completed it */
    *retlen = len;

    return ret;
}

static int doc_read_oob(struct mtd_info *mtd, loff_t ofs,
            struct mtd_oob_ops *ops)
{
    loff_t fofs, base;
    struct DiskOnChip *this = mtd->priv;
    void __iomem * docptr = this->virtadr;
    struct Nand *mychip = &this->chips[ofs >> this->chipshift];
    size_t i, size, got, want;
    uint8_t *buf = ops->oobbuf;
    size_t len = ops->len;

    BUG_ON(ops->mode != MTD_OPS_PLACE_OOB);

    ofs += ops->ooboffs;

    DoC_CheckASIC(docptr);

    /* Find the chip which is to be used and select it */
    if (this->curfloor != mychip->floor) {
        DoC_SelectFloor(docptr, mychip->floor);
        DoC_SelectChip(docptr, mychip->chip);
    } else if (this->curchip != mychip->chip) {
        DoC_SelectChip(docptr, mychip->chip);
    }
    this->curfloor = mychip->floor;
    this->curchip = mychip->chip;

    /* Millennium Plus bus cycle sequence as per figure 2, section 2.4 */
    WriteDOC((DOC_FLASH_CE | DOC_FLASH_WP), docptr, Mplus_FlashSelect);

    /* disable the ECC engine */
    WriteDOC(DOC_ECC_RESET, docptr, Mplus_ECCConf);
    DoC_WaitReady(docptr);

    /* Maximum of 16 bytes in the OOB region, so limit read to that */
    if (len > 16)
        len = 16;
    got = 0;
    want = len;

    for (i = 0; ((i < 3) && (want > 0)); i++) {
        /* Figure out which region we are accessing... */
        fofs = ofs;
        base = ofs & 0xf;
        if (!this->interleave) {
            DoC_Command(docptr, NAND_CMD_READOOB, 0);
            size = 16 - base;
        } else if (base < 6) {
            DoC_Command(docptr, DoC_GetECCOffset(mtd, &fofs), 0);
            size = 6 - base;
        } else if (base < 8) {
            DoC_Command(docptr, DoC_GetFlagsOffset(mtd, &fofs), 0);
            size = 8 - base;
        } else {
            DoC_Command(docptr, DoC_GetHdrOffset(mtd, &fofs), 0);
            size = 16 - base;
        }
        if (size > want)
            size = want;

        /* Issue read command */
        DoC_Address(this, 3, fofs, 0, 0x00);
        WriteDOC(0, docptr, Mplus_FlashControl);
        DoC_WaitReady(docptr);

        ReadDOC(docptr, Mplus_ReadPipeInit);
        ReadDOC(docptr, Mplus_ReadPipeInit);
        MemReadDOC(docptr, &buf[got], size - 2);
        buf[got + size - 2] = ReadDOC(docptr, Mplus_LastDataRead);
        buf[got + size - 1] = ReadDOC(docptr, Mplus_LastDataRead);

        ofs += size;
        got += size;
        want -= size;
    }

    /* Disable flash internally */
    WriteDOC(0, docptr, Mplus_FlashSelect);

    ops->retlen = len;
    return 0;
}

static int doc_write_oob(struct mtd_info *mtd, loff_t ofs,
             struct mtd_oob_ops *ops)
{
    volatile char dummy;
    loff_t fofs, base;
    struct DiskOnChip *this = mtd->priv;
    void __iomem * docptr = this->virtadr;
    struct Nand *mychip = &this->chips[ofs >> this->chipshift];
    size_t i, size, got, want;
    int ret = 0;
    uint8_t *buf = ops->oobbuf;
    size_t len = ops->len;

    BUG_ON(ops->mode != MTD_OPS_PLACE_OOB);

    ofs += ops->ooboffs;

    DoC_CheckASIC(docptr);

    /* Find the chip which is to be used and select it */
    if (this->curfloor != mychip->floor) {
        DoC_SelectFloor(docptr, mychip->floor);
        DoC_SelectChip(docptr, mychip->chip);
    } else if (this->curchip != mychip->chip) {
        DoC_SelectChip(docptr, mychip->chip);
    }
    this->curfloor = mychip->floor;
    this->curchip = mychip->chip;

    /* Millennium Plus bus cycle sequence as per figure 2, section 2.4 */
    WriteDOC(DOC_FLASH_CE, docptr, Mplus_FlashSelect);


    /* Maximum of 16 bytes in the OOB region, so limit write to that */
    if (len > 16)
        len = 16;
    got = 0;
    want = len;

    for (i = 0; ((i < 3) && (want > 0)); i++) {
        /* Reset the chip, see Software Requirement 11.4 item 1. */
        DoC_Command(docptr, NAND_CMD_RESET, 0);
        DoC_WaitReady(docptr);

        /* Figure out which region we are accessing... */
        fofs = ofs;
        base = ofs & 0x0f;
        if (!this->interleave) {
            WriteDOC(NAND_CMD_READOOB, docptr, Mplus_FlashCmd);
            size = 16 - base;
        } else if (base < 6) {
            WriteDOC(DoC_GetECCOffset(mtd, &fofs), docptr, Mplus_FlashCmd);
            size = 6 - base;
        } else if (base < 8) {
            WriteDOC(DoC_GetFlagsOffset(mtd, &fofs), docptr, Mplus_FlashCmd);
            size = 8 - base;
        } else {
            WriteDOC(DoC_GetHdrOffset(mtd, &fofs), docptr, Mplus_FlashCmd);
            size = 16 - base;
        }
        if (size > want)
            size = want;

        /* Issue the Serial Data In command to initial the Page Program process */
        DoC_Command(docptr, NAND_CMD_SEQIN, 0x00);
        DoC_Address(this, 3, fofs, 0, 0x00);

        /* Disable the ECC engine */
        WriteDOC(DOC_ECC_RESET, docptr, Mplus_ECCConf);

        /* Write the data via the internal pipeline through CDSN IO
           register, see Pipelined Write Operations 11.2 */
        MemWriteDOC(docptr, (unsigned char *) &buf[got], size);
        WriteDOC(0x00, docptr, Mplus_WritePipeTerm);
        WriteDOC(0x00, docptr, Mplus_WritePipeTerm);

        /* Commit the Page Program command and wait for ready
           see Software Requirement 11.4 item 1.*/
        DoC_Command(docptr, NAND_CMD_PAGEPROG, 0x00);
        DoC_WaitReady(docptr);

        /* Read the status of the flash device through CDSN IO register
           see Software Requirement 11.4 item 5.*/
        DoC_Command(docptr, NAND_CMD_STATUS, 0x00);
        dummy = ReadDOC(docptr, Mplus_ReadPipeInit);
        dummy = ReadDOC(docptr, Mplus_ReadPipeInit);
        DoC_Delay(docptr, 2);
        if ((dummy = ReadDOC(docptr, Mplus_LastDataRead)) & 1) {
            printk("MTD: Error 0x%x programming oob at 0x%x\n",
                dummy, (int)ofs);
            /* FIXME: implement Bad Block Replacement */
            ops->retlen = 0;
            ret = -EIO;
        }
        dummy = ReadDOC(docptr, Mplus_LastDataRead);

        ofs += size;
        got += size;
        want -= size;
    }

    /* Disable flash internally */
    WriteDOC(0, docptr, Mplus_FlashSelect);

    ops->retlen = len;
    return ret;
}

int doc_erase(struct mtd_info *mtd, struct erase_info *instr)
{
    volatile char dummy;
    struct DiskOnChip *this = mtd->priv;
    __u32 ofs = instr->addr;
    __u32 len = instr->len;
    void __iomem * docptr = this->virtadr;
    struct Nand *mychip = &this->chips[ofs >> this->chipshift];

    DoC_CheckASIC(docptr);

    if (len != mtd->erasesize)
        printk(KERN_WARNING "MTD: Erase not right size (%x != %x)n",
               len, mtd->erasesize);

    /* Find the chip which is to be used and select it */
    if (this->curfloor != mychip->floor) {
        DoC_SelectFloor(docptr, mychip->floor);
        DoC_SelectChip(docptr, mychip->chip);
    } else if (this->curchip != mychip->chip) {
        DoC_SelectChip(docptr, mychip->chip);
    }
    this->curfloor = mychip->floor;
    this->curchip = mychip->chip;

    instr->state = MTD_ERASE_PENDING;

    /* Millennium Plus bus cycle sequence as per figure 2, section 2.4 */
    WriteDOC(DOC_FLASH_CE, docptr, Mplus_FlashSelect);

    DoC_Command(docptr, NAND_CMD_RESET, 0x00);
    DoC_WaitReady(docptr);

    DoC_Command(docptr, NAND_CMD_ERASE1, 0);
    DoC_Address(this, 2, ofs, 0, 0x00);
    DoC_Command(docptr, NAND_CMD_ERASE2, 0);
    DoC_WaitReady(docptr);
    instr->state = MTD_ERASING;

    /* Read the status of the flash device through CDSN IO register
       see Software Requirement 11.4 item 5. */
    DoC_Command(docptr, NAND_CMD_STATUS, 0);
    dummy = ReadDOC(docptr, Mplus_ReadPipeInit);
    dummy = ReadDOC(docptr, Mplus_ReadPipeInit);
    if ((dummy = ReadDOC(docptr, Mplus_LastDataRead)) & 1) {
        printk("MTD: Error 0x%x erasing at 0x%x\n", dummy, ofs);
        /* FIXME: implement Bad Block Replacement (in nftl.c ??) */
        instr->state = MTD_ERASE_FAILED;
    } else {
        instr->state = MTD_ERASE_DONE;
    }
    dummy = ReadDOC(docptr, Mplus_LastDataRead);

    /* Disable flash internally */
    WriteDOC(0, docptr, Mplus_FlashSelect);

    mtd_erase_callback(instr);

    return 0;
}

/****************************************************************************
 *
 * Module stuff
 *
 ****************************************************************************/

static void __exit cleanup_doc2001plus(void)
{
    struct mtd_info *mtd;
    struct DiskOnChip *this;

    while ((mtd=docmilpluslist)) {
        this = mtd->priv;
        docmilpluslist = this->nextdoc;

        mtd_device_unregister(mtd);

        iounmap(this->virtadr);
        kfree(this->chips);
        kfree(mtd);
    }
}

module_exit(cleanup_doc2001plus);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Greg Ungerer <[email protected]> et al.");
MODULE_DESCRIPTION("Driver for DiskOnChip Millennium Plus");