diskonchip.c

基于linux-2.6.28的mtd驱动

	case NAND_ECC_READ:
		WriteDOC(DOC_ECC_RESET, docptr, Mplus_ECCConf);
		WriteDOC(DOC_ECC_EN, docptr, Mplus_ECCConf);
		break;
	case NAND_ECC_WRITE:
		WriteDOC(DOC_ECC_RESET, docptr, Mplus_ECCConf);
		WriteDOC(DOC_ECC_EN | DOC_ECC_RW, docptr, Mplus_ECCConf);
		break;
	}
}

/* This code is only called on write */
static int doc200x_calculate_ecc(struct mtd_info *mtd, const u_char *dat, unsigned char *ecc_code)
{
	struct nand_chip *this = mtd->priv;
	struct doc_priv *doc = this->priv;
	void __iomem *docptr = doc->virtadr;
	int i;
	int emptymatch = 1;

	/* flush the pipeline */
	if (DoC_is_2000(doc)) {
		WriteDOC(doc->CDSNControl & ~CDSN_CTRL_FLASH_IO, docptr, CDSNControl);
		WriteDOC(0, docptr, 2k_CDSN_IO);
		WriteDOC(0, docptr, 2k_CDSN_IO);
		WriteDOC(0, docptr, 2k_CDSN_IO);
		WriteDOC(doc->CDSNControl, docptr, CDSNControl);
	} else if (DoC_is_MillenniumPlus(doc)) {
		WriteDOC(0, docptr, Mplus_NOP);
		WriteDOC(0, docptr, Mplus_NOP);
		WriteDOC(0, docptr, Mplus_NOP);
	} else {
		WriteDOC(0, docptr, NOP);
		WriteDOC(0, docptr, NOP);
		WriteDOC(0, docptr, NOP);
	}

	for (i = 0; i < 6; i++) {
		if (DoC_is_MillenniumPlus(doc))
			ecc_code[i] = ReadDOC_(docptr, DoC_Mplus_ECCSyndrome0 + i);
		else
			ecc_code[i] = ReadDOC_(docptr, DoC_ECCSyndrome0 + i);
		if (ecc_code[i] != empty_write_ecc[i])
			emptymatch = 0;
	}
	if (DoC_is_MillenniumPlus(doc))
		WriteDOC(DOC_ECC_DIS, docptr, Mplus_ECCConf);
	else
		WriteDOC(DOC_ECC_DIS, docptr, ECCConf);
#if 0
	/* If emptymatch=1, we might have an all-0xff data buffer.  Check. */
	if (emptymatch) {
		/* Note: this somewhat expensive test should not be triggered
		   often.  It could be optimized away by examining the data in
		   the writebuf routine, and remembering the result. */
		for (i = 0; i < 512; i++) {
			if (dat[i] == 0xff)
				continue;
			emptymatch = 0;
			break;
		}
	}
	/* If emptymatch still =1, we do have an all-0xff data buffer.
	   Return all-0xff ecc value instead of the computed one, so
	   it'll look just like a freshly-erased page. */
	if (emptymatch)
		memset(ecc_code, 0xff, 6);
#endif
	return 0;
}

static int doc200x_correct_data(struct mtd_info *mtd, u_char *dat,
				u_char *read_ecc, u_char *isnull)
{
	int i, ret = 0;
	struct nand_chip *this = mtd->priv;
	struct doc_priv *doc = this->priv;
	void __iomem *docptr = doc->virtadr;
	uint8_t calc_ecc[6];
	volatile u_char dummy;
	int emptymatch = 1;

	/* flush the pipeline */
	if (DoC_is_2000(doc)) {
		dummy = ReadDOC(docptr, 2k_ECCStatus);
		dummy = ReadDOC(docptr, 2k_ECCStatus);
		dummy = ReadDOC(docptr, 2k_ECCStatus);
	} else if (DoC_is_MillenniumPlus(doc)) {
		dummy = ReadDOC(docptr, Mplus_ECCConf);
		dummy = ReadDOC(docptr, Mplus_ECCConf);
		dummy = ReadDOC(docptr, Mplus_ECCConf);
	} else {
		dummy = ReadDOC(docptr, ECCConf);
		dummy = ReadDOC(docptr, ECCConf);
		dummy = ReadDOC(docptr, ECCConf);
	}

	/* Error occured ? */
	if (dummy & 0x80) {
		for (i = 0; i < 6; i++) {
			if (DoC_is_MillenniumPlus(doc))
				calc_ecc[i] = ReadDOC_(docptr, DoC_Mplus_ECCSyndrome0 + i);
			else
				calc_ecc[i] = ReadDOC_(docptr, DoC_ECCSyndrome0 + i);
			if (calc_ecc[i] != empty_read_syndrome[i])
				emptymatch = 0;
		}
		/* If emptymatch=1, the read syndrome is consistent with an
		   all-0xff data and stored ecc block.  Check the stored ecc. */
		if (emptymatch) {
			for (i = 0; i < 6; i++) {
				if (read_ecc[i] == 0xff)
					continue;
				emptymatch = 0;
				break;
			}
		}
		/* If emptymatch still =1, check the data block. */
		if (emptymatch) {
			/* Note: this somewhat expensive test should not be triggered
			   often.  It could be optimized away by examining the data in
			   the readbuf routine, and remembering the result. */
			for (i = 0; i < 512; i++) {
				if (dat[i] == 0xff)
					continue;
				emptymatch = 0;
				break;
			}
		}
		/* If emptymatch still =1, this is almost certainly a freshly-
		   erased block, in which case the ECC will not come out right.
		   We'll suppress the error and tell the caller everything's
		   OK.  Because it is. */
		if (!emptymatch)
			ret = doc_ecc_decode(rs_decoder, dat, calc_ecc);
		if (ret > 0)
			printk(KERN_ERR "doc200x_correct_data corrected %d errors\n", ret);
	}
	if (DoC_is_MillenniumPlus(doc))
		WriteDOC(DOC_ECC_DIS, docptr, Mplus_ECCConf);
	else
		WriteDOC(DOC_ECC_DIS, docptr, ECCConf);
	if (no_ecc_failures && (ret == -EBADMSG)) {
		printk(KERN_ERR "suppressing ECC failure\n");
		ret = 0;
	}
	return ret;
}

//u_char mydatabuf[528];

/* The strange out-of-order .oobfree list below is a (possibly unneeded)
 * attempt to retain compatibility.  It used to read:
 * 	.oobfree = { {8, 8} }
 * Since that leaves two bytes unusable, it was changed.  But the following
 * scheme might affect existing jffs2 installs by moving the cleanmarker:
 * 	.oobfree = { {6, 10} }
 * jffs2 seems to handle the above gracefully, but the current scheme seems
 * safer.  The only problem with it is that any code that parses oobfree must
 * be able to handle out-of-order segments.
 */
static struct nand_ecclayout doc200x_oobinfo = {
	.eccbytes = 6,
	.eccpos = {0, 1, 2, 3, 4, 5},
	.oobfree = {{8, 8}, {6, 2}}
};

/* Find the (I)NFTL Media Header, and optionally also the mirror media header.
   On sucessful return, buf will contain a copy of the media header for
   further processing.  id is the string to scan for, and will presumably be
   either "ANAND" or "BNAND".  If findmirror=1, also look for the mirror media
   header.  The page #s of the found media headers are placed in mh0_page and
   mh1_page in the DOC private structure. */
static int __init find_media_headers(struct mtd_info *mtd, u_char *buf, const char *id, int findmirror)
{
	struct nand_chip *this = mtd->priv;
	struct doc_priv *doc = this->priv;
	unsigned offs;
	int ret;
	size_t retlen;

	for (offs = 0; offs < mtd->size; offs += mtd->erasesize) {
		ret = mtd->read(mtd, offs, mtd->writesize, &retlen, buf);
		if (retlen != mtd->writesize)
			continue;
		if (ret) {
			printk(KERN_WARNING "ECC error scanning DOC at 0x%x\n", offs);
		}
		if (memcmp(buf, id, 6))
			continue;
		printk(KERN_INFO "Found DiskOnChip %s Media Header at 0x%x\n", id, offs);
		if (doc->mh0_page == -1) {
			doc->mh0_page = offs >> this->page_shift;
			if (!findmirror)
				return 1;
			continue;
		}
		doc->mh1_page = offs >> this->page_shift;
		return 2;
	}
	if (doc->mh0_page == -1) {
		printk(KERN_WARNING "DiskOnChip %s Media Header not found.\n", id);
		return 0;
	}
	/* Only one mediaheader was found.  We want buf to contain a
	   mediaheader on return, so we'll have to re-read the one we found. */
	offs = doc->mh0_page << this->page_shift;
	ret = mtd->read(mtd, offs, mtd->writesize, &retlen, buf);
	if (retlen != mtd->writesize) {
		/* Insanity.  Give up. */
		printk(KERN_ERR "Read DiskOnChip Media Header once, but can't reread it???\n");
		return 0;
	}
	return 1;
}

static inline int __init nftl_partscan(struct mtd_info *mtd, struct mtd_partition *parts)
{
	struct nand_chip *this = mtd->priv;
	struct doc_priv *doc = this->priv;
	int ret = 0;
	u_char *buf;
	struct NFTLMediaHeader *mh;
	const unsigned psize = 1 << this->page_shift;
	int numparts = 0;
	unsigned blocks, maxblocks;
	int offs, numheaders;

	buf = kmalloc(mtd->writesize, GFP_KERNEL);
	if (!buf) {
		printk(KERN_ERR "DiskOnChip mediaheader kmalloc failed!\n");
		return 0;
	}
	if (!(numheaders = find_media_headers(mtd, buf, "ANAND", 1)))
		goto out;
	mh = (struct NFTLMediaHeader *)buf;

	le16_to_cpus(&mh->NumEraseUnits);
	le16_to_cpus(&mh->FirstPhysicalEUN);
	le32_to_cpus(&mh->FormattedSize);

	printk(KERN_INFO "    DataOrgID        = %s\n"
			 "    NumEraseUnits    = %d\n"
			 "    FirstPhysicalEUN = %d\n"
			 "    FormattedSize    = %d\n"
			 "    UnitSizeFactor   = %d\n",
		mh->DataOrgID, mh->NumEraseUnits,
		mh->FirstPhysicalEUN, mh->FormattedSize,
		mh->UnitSizeFactor);

	blocks = mtd->size >> this->phys_erase_shift;
	maxblocks = min(32768U, mtd->erasesize - psize);

	if (mh->UnitSizeFactor == 0x00) {
		/* Auto-determine UnitSizeFactor.  The constraints are:
		   - There can be at most 32768 virtual blocks.
		   - There can be at most (virtual block size - page size)
		   virtual blocks (because MediaHeader+BBT must fit in 1).
		 */
		mh->UnitSizeFactor = 0xff;
		while (blocks > maxblocks) {
			blocks >>= 1;
			maxblocks = min(32768U, (maxblocks << 1) + psize);
			mh->UnitSizeFactor--;
		}
		printk(KERN_WARNING "UnitSizeFactor=0x00 detected.  Correct value is assumed to be 0x%02x.\n", mh->UnitSizeFactor);
	}

	/* NOTE: The lines below modify internal variables of the NAND and MTD
	   layers; variables with have already been configured by nand_scan.
	   Unfortunately, we didn't know before this point what these values
	   should be.  Thus, this code is somewhat dependant on the exact
	   implementation of the NAND layer.  */
	if (mh->UnitSizeFactor != 0xff) {
		this->bbt_erase_shift += (0xff - mh->UnitSizeFactor);
		mtd->erasesize <<= (0xff - mh->UnitSizeFactor);
		printk(KERN_INFO "Setting virtual erase size to %d\n", mtd->erasesize);
		blocks = mtd->size >> this->bbt_erase_shift;
		maxblocks = min(32768U, mtd->erasesize - psize);
	}

	if (blocks > maxblocks) {
		printk(KERN_ERR "UnitSizeFactor of 0x%02x is inconsistent with device size.  Aborting.\n", mh->UnitSizeFactor);
		goto out;
	}

	/* Skip past the media headers. */
	offs = max(doc->mh0_page, doc->mh1_page);
	offs <<= this->page_shift;
	offs += mtd->erasesize;

	if (show_firmware_partition == 1) {
		parts[0].name = " DiskOnChip Firmware / Media Header partition";
		parts[0].offset = 0;
		parts[0].size = offs;
		numparts = 1;
	}

	parts[numparts].name = " DiskOnChip BDTL partition";
	parts[numparts].offset = offs;
	parts[numparts].size = (mh->NumEraseUnits - numheaders) << this->bbt_erase_shift;

	offs += parts[numparts].size;
	numparts++;

	if (offs < mtd->size) {
		parts[numparts].name = " DiskOnChip Remainder partition";
		parts[numparts].offset = offs;
		parts[numparts].size = mtd->size - offs;
		numparts++;
	}

	ret = numparts;
 out:
	kfree(buf);
	return ret;
}

/* This is a stripped-down copy of the code in inftlmount.c */
static inline int __init inftl_partscan(struct mtd_info *mtd, struct mtd_partition *parts)
{
	struct nand_chip *this = mtd->priv;
	struct doc_priv *doc = this->priv;
	int ret = 0;
	u_char *buf;
	struct INFTLMediaHeader *mh;
	struct INFTLPartition *ip;
	int numparts = 0;
	int blocks;
	int vshift, lastvunit = 0;
	int i;
	int end = mtd->size;

	if (inftl_bbt_write)
		end -= (INFTL_BBT_RESERVED_BLOCKS << this->phys_erase_shift);

	buf = kmalloc(mtd->writesize, GFP_KERNEL);
	if (!buf) {
		printk(KERN_ERR "DiskOnChip mediaheader kmalloc failed!\n");
		return 0;
	}

	if (!find_media_headers(mtd, buf, "BNAND", 0))
		goto out;
	doc->mh1_page = doc->mh0_page + (4096 >> this->page_shift);
	mh = (struct INFTLMediaHeader *)buf;

	le32_to_cpus(&mh->NoOfBootImageBlocks);
	le32_to_cpus(&mh->NoOfBinaryPartitions);
	le32_to_cpus(&mh->NoOfBDTLPartitions);
	le32_to_cpus(&mh->BlockMultiplierBits);
	le32_to_cpus(&mh->FormatFlags);
	le32_to_cpus(&mh->PercentUsed);

	printk(KERN_INFO "    bootRecordID          = %s\n"
			 "    NoOfBootImageBlocks   = %d\n"
			 "    NoOfBinaryPartitions  = %d\n"
			 "    NoOfBDTLPartitions    = %d\n"
			 "    BlockMultiplerBits    = %d\n"
			 "    FormatFlgs            = %d\n"
			 "    OsakVersion           = %d.%d.%d.%d\n"
			 "    PercentUsed           = %d\n",
		mh->bootRecordID, mh->NoOfBootImageBlocks,
		mh->NoOfBinaryPartitions,
		mh->NoOfBDTLPartitions,
		mh->BlockMultiplierBits, mh->FormatFlags,
		((unsigned char *) &mh->OsakVersion)[0] & 0xf,
		((unsigned char *) &mh->OsakVersion)[1] & 0xf,
		((unsigned char *) &mh->OsakVersion)[2] & 0xf,
		((unsigned char *) &mh->OsakVersion)[3] & 0xf,
		mh->PercentUsed);

	vshift = this->phys_erase_shift + mh->BlockMultiplierBits;

	blocks = mtd->size >> vshift;
	if (blocks > 32768) {
		printk(KERN_ERR "BlockMultiplierBits=%d is inconsistent with device size.  Aborting.\n", mh->BlockMultiplierBits);
		goto out;
	}

	blocks = doc->chips_per_floor << (this->chip_shift - this->phys_erase_shift);
	if (inftl_bbt_write && (blocks > mtd->erasesize)) {
		printk(KERN_ERR "Writeable BBTs spanning more than one erase block are not yet supported.  FIX ME!\n");
		goto out;
	}

	/* Scan the partitions */
	for (i = 0; (i < 4); i++) {
		ip = &(mh->Partitions[i]);
		le32_to_cpus(&ip->virtualUnits);
		le32_to_cpus(&ip->firstUnit);
		le32_to_cpus(&ip->lastUnit);
		le32_to_cpus(&ip->flags);
		le32_to_cpus(&ip->spareUnits);
		le32_to_cpus(&ip->Reserved0);

		printk(KERN_INFO	"    PARTITION[%d] ->\n"
			"        virtualUnits    = %d\n"
			"        firstUnit       = %d\n"
			"        lastUnit        = %d\n"
			"        flags           = 0x%x\n"
			"        spareUnits      = %d\n",
			i, ip->virtualUnits, ip->firstUnit,
			ip->lastUnit, ip->flags,
			ip->spareUnits);

		if ((show_firmware_partition == 1) &&
		    (i == 0) && (ip->firstUnit > 0)) {
			parts[0].name = " DiskOnChip IPL / Media Header partition";
			parts[0].offset = 0;
			parts[0].size = mtd->erasesize * ip->firstUnit;
			numparts = 1;
		}

		if (ip->flags & INFTL_BINARY)
			parts[numparts].name = " DiskOnChip BDK partition";
		else
			parts[numparts].name = " DiskOnChip BDTL partition";
		parts[numparts].offset = ip->firstUnit << vshift;
		parts[numparts].size = (1 + ip->lastUnit - ip->firstUnit) << vshift;
		numparts++;
		if (ip->lastUnit > lastvunit)
			lastvunit = ip->lastUnit;
		if (ip->flags & INFTL_LAST)
			break;
	}
	lastvunit++;
	if ((lastvunit << vshift) < end) {
		parts[numparts].name = " DiskOnChip Remainder partition";
		parts[numparts].offset = lastvunit << vshift;
		parts[numparts].size = end - parts[numparts].offset;
		numparts++;
	}
	ret = numparts;
 out:
	kfree(buf);
	return ret;
}

static int __init nftl_scan_bbt(struct mtd_info *mtd)
{
	int ret, numparts;
	struct nand_chip *this = mtd->priv;
	struct doc_priv *doc = this->priv;
	struct mtd_partition parts[2];