doc2001.c

Go to the documentation of this file.

/*
 * Linux driver for Disk-On-Chip Millennium
 * (c) 1999 Machine Vision Holdings, Inc.
 * (c) 1999, 2000 David Woodhouse <[email protected]>
 */

#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 *docmillist = NULL;

/* Perform the required delay cycles by reading from the NOP register */
static void DoC_Delay(void __iomem * docptr, unsigned short cycles)
{
    volatile char dummy;
    int i;

    for (i = 0; i < cycles; i++)
        dummy = ReadDOC(docptr, NOP);
}

/* DOC_WaitReady: Wait for RDY line to be asserted by the flash chip */
static int _DoC_WaitReady(void __iomem * docptr)
{
    unsigned short 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, CDSNControl) & CDSN_CTRL_FR_B) && --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;

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

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

    /* issue 2 read from NOP register after reading from CDSNControl register
       see Software Requirement 11.4 item 2. */
    DoC_Delay(docptr, 2);

    return ret;
}

/* DoC_Command: Send a flash command to the flash chip through the CDSN IO register
   with the internal pipeline. Each of 4 delay cycles (read from the NOP register) is
   required after writing to CDSN Control register, see Software Requirement 11.4 item 3. */

static void DoC_Command(void __iomem * docptr, unsigned char command,
                   unsigned char xtraflags)
{
    /* Assert the CLE (Command Latch Enable) line to the flash chip */
    WriteDOC(xtraflags | CDSN_CTRL_CLE | CDSN_CTRL_CE, docptr, CDSNControl);
    DoC_Delay(docptr, 4);

    /* Send the command */
    WriteDOC(command, docptr, Mil_CDSN_IO);
    WriteDOC(0x00, docptr, WritePipeTerm);

    /* Lower the CLE line */
    WriteDOC(xtraflags | CDSN_CTRL_CE, docptr, CDSNControl);
    DoC_Delay(docptr, 4);
}

/* DoC_Address: Set the current address for the flash chip through the CDSN IO register
   with the internal pipeline. Each of 4 delay cycles (read from the NOP register) is
   required after writing to CDSN Control register, see Software Requirement 11.4 item 3. */

static inline void DoC_Address(void __iomem * docptr, int numbytes, unsigned long ofs,
                   unsigned char xtraflags1, unsigned char xtraflags2)
{
    /* Assert the ALE (Address Latch Enable) line to the flash chip */
    WriteDOC(xtraflags1 | CDSN_CTRL_ALE | CDSN_CTRL_CE, docptr, CDSNControl);
    DoC_Delay(docptr, 4);

    /* Send the address */
    switch (numbytes)
        {
        case 1:
            /* Send single byte, bits 0-7. */
            WriteDOC(ofs & 0xff, docptr, Mil_CDSN_IO);
            WriteDOC(0x00, docptr, WritePipeTerm);
            break;
        case 2:
            /* Send bits 9-16 followed by 17-23 */
            WriteDOC((ofs >> 9)  & 0xff, docptr, Mil_CDSN_IO);
            WriteDOC((ofs >> 17) & 0xff, docptr, Mil_CDSN_IO);
            WriteDOC(0x00, docptr, WritePipeTerm);
        break;
        case 3:
            /* Send 0-7, 9-16, then 17-23 */
            WriteDOC(ofs & 0xff, docptr, Mil_CDSN_IO);
            WriteDOC((ofs >> 9)  & 0xff, docptr, Mil_CDSN_IO);
            WriteDOC((ofs >> 17) & 0xff, docptr, Mil_CDSN_IO);
            WriteDOC(0x00, docptr, WritePipeTerm);
        break;
        default:
        return;
        }

    /* Lower the ALE line */
    WriteDOC(xtraflags1 | xtraflags2 | CDSN_CTRL_CE, docptr, CDSNControl);
    DoC_Delay(docptr, 4);
}

/* DoC_SelectChip: Select a given flash chip within the current floor */
static int DoC_SelectChip(void __iomem * docptr, int chip)
{
    /* Select the individual flash chip requested */
    WriteDOC(chip, docptr, CDSNDeviceSelect);
    DoC_Delay(docptr, 4);

    /* Wait for it to be ready */
    return DoC_WaitReady(docptr);
}

/* DoC_SelectFloor: Select a given floor (bank of flash chips) */
static int DoC_SelectFloor(void __iomem * docptr, int floor)
{
    /* Select the floor (bank) of chips required */
    WriteDOC(floor, docptr, FloorSelect);

    /* Wait for the chip to be ready */
    return DoC_WaitReady(docptr);
}

/* 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;

    /* Page in the required floor/chip
       FIXME: is this supported by Millennium ?? */
    DoC_SelectFloor(doc->virtadr, floor);
    DoC_SelectChip(doc->virtadr, chip);

    /* Reset the chip, see Software Requirement 11.4 item 1. */
    DoC_Command(doc->virtadr, NAND_CMD_RESET, CDSN_CTRL_WP);
    DoC_WaitReady(doc->virtadr);

    /* Read the NAND chip ID: 1. Send ReadID command */
    DoC_Command(doc->virtadr, NAND_CMD_READID, CDSN_CTRL_WP);

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

    /* Read the manufacturer and device id codes of the flash device through
       CDSN IO register see Software Requirement 11.4 item 5.*/
    dummy = ReadDOC(doc->virtadr, ReadPipeInit);
    DoC_Delay(doc->virtadr, 2);
    mfr = ReadDOC(doc->virtadr, Mil_CDSN_IO);

    DoC_Delay(doc->virtadr, 2);
    id  = ReadDOC(doc->virtadr, Mil_CDSN_IO);
    dummy = ReadDOC(doc->virtadr, LastDataRead);

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

    /* FIXME: to deal with multi-flash on multi-Millennium case more carefully */
    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;
            break;
        }
    }

    if (nand_flash_ids[i].name == NULL)
        return 0;
    else
        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_MIL];
    int ret;

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

    /* For each floor, find the number of valid chips it contains */
    for (floor = 0,ret = 1; floor < MAX_FLOORS_MIL; floor++) {
        numchips[floor] = 0;
        for (chip = 0; chip < MAX_CHIPS_MIL && 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("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_MIL; 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 DoCMil_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 Millenium docs), but it seems to work. */
    tmp1 = ReadDOC(doc1->virtadr, AliasResolution);
    tmp2 = ReadDOC(doc2->virtadr, AliasResolution);
    if (tmp1 != tmp2)
        return 0;

    WriteDOC((tmp1+1) % 0xff, doc1->virtadr, AliasResolution);
    tmp2 = ReadDOC(doc2->virtadr, 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, AliasResolution);

    return retval;
}

/* This routine is found from the docprobe code by symbol_get(),
 * which will bump the use count of this module. */
void DoCMil_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 (docmillist)
        old = docmillist->priv;

    while (old) {
        if (DoCMil_is_alias(this, old)) {
            printk(KERN_NOTICE "Ignoring DiskOnChip Millennium 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";
    printk(KERN_NOTICE "DiskOnChip Millennium found at address 0x%lX\n",
           this->physadr);

    mtd->type = MTD_NANDFLASH;
    mtd->flags = MTD_CAP_NANDFLASH;

    /* FIXME: erase size is not always 8KiB */
    mtd->erasesize = 0x2000;
    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 = docmillist;
        docmillist = mtd;
        mtd->size  = this->totlen;
        mtd_device_register(mtd, NULL, 0);
        return;
    }
}
EXPORT_SYMBOL_GPL(DoCMil_init);

static int doc_read (struct mtd_info *mtd, loff_t from, size_t len,
             size_t *retlen, u_char *buf)
{
    int i, ret;
    volatile char dummy;
    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;

    /* 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;

    /* issue the Read0 or Read1 command depend on which half of the page
       we are accessing. Polling the Flash Ready bit after issue 3 bytes
       address in Sequence Read Mode, see Software Requirement 11.4 item 1.*/
    DoC_Command(docptr, (from >> 8) & 1, CDSN_CTRL_WP);
    DoC_Address(docptr, 3, from, CDSN_CTRL_WP, 0x00);
    DoC_WaitReady(docptr);

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

    /* Read the data via the internal pipeline through CDSN IO register,
       see Pipelined Read Operations 11.3 */
    dummy = ReadDOC(docptr, ReadPipeInit);
#ifndef USE_MEMCPY
    for (i = 0; i < len-1; i++) {
        /* N.B. you have to increase the source address in this way or the
           ECC logic will not work properly */
        buf[i] = ReadDOC(docptr, Mil_CDSN_IO + (i & 0xff));
    }
#else
    memcpy_fromio(buf, docptr + DoC_Mil_CDSN_IO, len - 1);
#endif
    buf[len - 1] = ReadDOC(docptr, LastDataRead);

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

    /* Read the ECC data from Spare Data Area,
       see Reed-Solomon EDC/ECC 11.1 */
    dummy = ReadDOC(docptr, ReadPipeInit);
#ifndef USE_MEMCPY
    for (i = 0; i < 5; i++) {
        /* N.B. you have to increase the source address in this way or the
           ECC logic will not work properly */
        eccbuf[i] = ReadDOC(docptr, Mil_CDSN_IO + i);
    }
#else
    memcpy_fromio(eccbuf, docptr + DoC_Mil_CDSN_IO, 5);
#endif
    eccbuf[5] = ReadDOC(docptr, LastDataRead);

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

    /* Check the ECC Status */
    if (ReadDOC(docptr, 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, 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 */
            ret = -EIO;
        }
    }

#ifdef PSYCHO_DEBUG
    printk("ECC DATA at %lx: %2.2X %2.2X %2.2X %2.2X %2.2X %2.2X\n",
           (long)from, eccbuf[0], eccbuf[1], eccbuf[2], eccbuf[3],
           eccbuf[4], eccbuf[5]);
#endif

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

    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,ret = 0;
    char eccbuf[6];
    volatile char dummy;
    struct DiskOnChip *this = mtd->priv;
    void __iomem *docptr = this->virtadr;
    struct Nand *mychip = &this->chips[to >> (this->chipshift)];

#if 0
    /* Don't allow a single write to cross a 512-byte block boundary */
    if (to + len > ( (to | 0x1ff) + 1))
        len = ((to | 0x1ff) + 1) - to;
#else
    /* Don't allow writes which aren't exactly one block */
    if (to & 0x1ff || len != 0x200)
        return -EINVAL;
#endif

    /* 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;

    /* Reset the chip, see Software Requirement 11.4 item 1. */
    DoC_Command(docptr, NAND_CMD_RESET, 0x00);
    DoC_WaitReady(docptr);
    /* Set device to main plane of flash */
    DoC_Command(docptr, NAND_CMD_READ0, 0x00);

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

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

    /* Write the data via the internal pipeline through CDSN IO register,
       see Pipelined Write Operations 11.2 */
#ifndef USE_MEMCPY
    for (i = 0; i < len; i++) {
        /* N.B. you have to increase the source address in this way or the
           ECC logic will not work properly */
        WriteDOC(buf[i], docptr, Mil_CDSN_IO + i);
    }
#else
    memcpy_toio(docptr + DoC_Mil_CDSN_IO, buf, len);
#endif
    WriteDOC(0x00, docptr, WritePipeTerm);

    /* Write ECC data to flash, the ECC info is generated by the DiskOnChip ECC logic
       see Reed-Solomon EDC/ECC 11.1 */
    WriteDOC(0, docptr, NOP);
    WriteDOC(0, docptr, NOP);
    WriteDOC(0, docptr, NOP);

    /* Read the ECC data through the DiskOnChip ECC logic */
    for (i = 0; i < 6; i++) {
        eccbuf[i] = ReadDOC(docptr, ECCSyndrome0 + i);
    }

    /* ignore the ECC engine */
    WriteDOC(DOC_ECC_DIS, docptr , ECCConf);

#ifndef USE_MEMCPY
    /* Write the ECC data to flash */
    for (i = 0; i < 6; i++) {
        /* N.B. you have to increase the source address in this way or the
           ECC logic will not work properly */
        WriteDOC(eccbuf[i], docptr, Mil_CDSN_IO + i);
    }
#else
    memcpy_toio(docptr + DoC_Mil_CDSN_IO, eccbuf, 6);
#endif

    /* write the block status BLOCK_USED (0x5555) at the end of ECC data
       FIXME: this is only a hack for programming the IPL area for LinuxBIOS
       and should be replace with proper codes in user space utilities */
    WriteDOC(0x55, docptr, Mil_CDSN_IO);
    WriteDOC(0x55, docptr, Mil_CDSN_IO + 1);

    WriteDOC(0x00, docptr, WritePipeTerm);

#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

    /* 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, CDSN_CTRL_WP);
    dummy = ReadDOC(docptr, ReadPipeInit);
    DoC_Delay(docptr, 2);
    if (ReadDOC(docptr, Mil_CDSN_IO) & 1) {
        printk("Error programming flash\n");
        /* Error in programming
           FIXME: implement Bad Block Replacement (in nftl.c ??) */
        ret = -EIO;
    }
    dummy = ReadDOC(docptr, LastDataRead);

    /* 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)
{
#ifndef USE_MEMCPY
    int i;
#endif
    volatile char dummy;
    struct DiskOnChip *this = mtd->priv;
    void __iomem *docptr = this->virtadr;
    struct Nand *mychip = &this->chips[ofs >> this->chipshift];
    uint8_t *buf = ops->oobbuf;
    size_t len = ops->len;

    BUG_ON(ops->mode != MTD_OPS_PLACE_OOB);

    ofs += ops->ooboffs;

    /* 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;

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

    /* issue the Read2 command to set the pointer to the Spare Data Area.
       Polling the Flash Ready bit after issue 3 bytes address in
       Sequence Read Mode, see Software Requirement 11.4 item 1.*/
    DoC_Command(docptr, NAND_CMD_READOOB, CDSN_CTRL_WP);
    DoC_Address(docptr, 3, ofs, CDSN_CTRL_WP, 0x00);
    DoC_WaitReady(docptr);

    /* Read the data out via the internal pipeline through CDSN IO register,
       see Pipelined Read Operations 11.3 */
    dummy = ReadDOC(docptr, ReadPipeInit);
#ifndef USE_MEMCPY
    for (i = 0; i < len-1; i++) {
        /* N.B. you have to increase the source address in this way or the
           ECC logic will not work properly */
        buf[i] = ReadDOC(docptr, Mil_CDSN_IO + i);
    }
#else
    memcpy_fromio(buf, docptr + DoC_Mil_CDSN_IO, len - 1);
#endif
    buf[len - 1] = ReadDOC(docptr, LastDataRead);

    ops->retlen = len;

    return 0;
}

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

    BUG_ON(ops->mode != MTD_OPS_PLACE_OOB);

    ofs += ops->ooboffs;

    /* 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;

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

    /* Reset the chip, see Software Requirement 11.4 item 1. */
    DoC_Command(docptr, NAND_CMD_RESET, CDSN_CTRL_WP);
    DoC_WaitReady(docptr);
    /* issue the Read2 command to set the pointer to the Spare Data Area. */
    DoC_Command(docptr, NAND_CMD_READOOB, CDSN_CTRL_WP);

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

    /* Write the data via the internal pipeline through CDSN IO register,
       see Pipelined Write Operations 11.2 */
#ifndef USE_MEMCPY
    for (i = 0; i < len; i++) {
        /* N.B. you have to increase the source address in this way or the
           ECC logic will not work properly */
        WriteDOC(buf[i], docptr, Mil_CDSN_IO + i);
    }
#else
    memcpy_toio(docptr + DoC_Mil_CDSN_IO, buf, len);
#endif
    WriteDOC(0x00, docptr, 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, ReadPipeInit);
    DoC_Delay(docptr, 2);
    if (ReadDOC(docptr, Mil_CDSN_IO) & 1) {
        printk("Error programming oob data\n");
        /* FIXME: implement Bad Block Replacement (in nftl.c ??) */
        ops->retlen = 0;
        ret = -EIO;
    }
    dummy = ReadDOC(docptr, LastDataRead);

    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];

    if (len != mtd->erasesize)
        printk(KERN_WARNING "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;

    /* issue the Erase Setup command */
    DoC_Command(docptr, NAND_CMD_ERASE1, 0x00);
    DoC_Address(docptr, 2, ofs, 0x00, 0x00);

    /* Commit the Erase Start command and wait for ready
       see Software Requirement 11.4 item 1.*/
    DoC_Command(docptr, NAND_CMD_ERASE2, 0x00);
    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.
       FIXME: it seems that we are not wait long enough, some blocks are not
       erased fully */
    DoC_Command(docptr, NAND_CMD_STATUS, CDSN_CTRL_WP);
    dummy = ReadDOC(docptr, ReadPipeInit);
    DoC_Delay(docptr, 2);
    if (ReadDOC(docptr, Mil_CDSN_IO) & 1) {
        printk("Error Erasing at 0x%x\n", ofs);
        /* There was an error
           FIXME: implement Bad Block Replacement (in nftl.c ??) */
        instr->state = MTD_ERASE_FAILED;
    } else
        instr->state = MTD_ERASE_DONE;
    dummy = ReadDOC(docptr, LastDataRead);

    mtd_erase_callback(instr);

    return 0;
}

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

static void __exit cleanup_doc2001(void)
{
    struct mtd_info *mtd;
    struct DiskOnChip *this;

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

        mtd_device_unregister(mtd);

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

module_exit(cleanup_doc2001);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <[email protected]> et al.");
MODULE_DESCRIPTION("Alternative driver for DiskOnChip Millennium");